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Sample records for addendum modified gear

  1. Lubricant jet flow phenomena in spur and helical gears with modified center distances and/or addendums for out-of-mesh conditions

    NASA Technical Reports Server (NTRS)

    Akin, L. S.; Townsend, D. P.

    1983-01-01

    Out-of-mesh jet lubrication of gears was examined. The pinion impingement cycle was described briefly. An analysis was developed for the lubricant jet flow in the out-of-mesh condition. The analysis provides for the inclusion of modified center distances and modified addendums. Equations were generated for the limit values of variables necessary to remove the severe limitations to facilitate computer analysis. A computer program was designed using these limit formulas to prevent negative impingement (missing) on the pinion.

  2. Lubricant jet flow phenomena in spur and helical gears with modified addendums - For radially directed individual jets

    NASA Technical Reports Server (NTRS)

    Akin, L. S.; Townsend, D. P.

    1989-01-01

    This paper develops the mathematical relations for the Virtual Kinetic Model as an improvement over the vectorial model developed earlier. The model solution described provides the most energy efficient means of cooling gears, i.e., it requires the least pressure or pumping power to distribute the coolant onto the tooth surface. Further, this nozzle orientation allows impingement to the root of the tooth if needed and provides the most cooling control when compared to into-mesh and out-of-mesh cooling.

  3. Lubricant Jet Flow Phenomena in Spur and Helical Gears with Modified Addendums; for Radially Directed Individual Jets

    NASA Technical Reports Server (NTRS)

    Akin, Lee S.; Townsend, Dennis P.

    1989-01-01

    This paper develops the mathematical relations for the Virtual Kinetic Model as an improvement over the vectorial model developed earlier. The model solution described provides the most energy efficient means of cooling gears, i.e., it requires the least pressure or pumping power to distribute the coolant onto the tooth surface. Further, this nozzle orientation allows impingement to the root of the tooth if needed and provides the most cooling control when compared to into-mesh and out-of-mesh cooling.

  4. Contact Stress of Modified Curvilinear Gears

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Cheng; Gu, Ming-Lune

    2010-10-01

    The contact characteristics of a modified curvilinear gear set were investigated based on finite element analysis in this study. Firstly, the mathematical model of the modified curvilinear gears was developed based on the theory of gearing. Then a solid model of a modified curvilinear gear set was built by utilizing computer-aided design software. Finite element analysis enabled us to investigate the contact stress of a contact teeth pair. The variation and distribution of the contact stresses and bending stresses are also studied under different gear design parameters. Finally, illustrative examples were presented to demonstrate the contact characteristics of the modified curvilinear gears.

  5. Selection criteria of the addendum modification coefficients of spur gear pairs with smaller number of pinion teeth

    NASA Astrophysics Data System (ADS)

    Atanasiu, V.; Oprişan, C.; Leohchi, D.

    2016-08-01

    A design procedure for the optimum distribution of the addendum modification coefficients of spur gear pairs with smaller number of pinion teeth is presented for the case of a fixed centred distance. The geometrical, kinematics and load capacity criteria are considered in the design analysis. The geometric and kinematics criteria are used to prevent the negative phenomena of the generating and engagement processes. The relation between the contact pressure of meshing teeth and specific sliding are analysed in relation with addendum modification coefficients. A dynamic model is developed to simulate the load sharing characteristics through a mesh cycle. The specific phenomenon of contact tooth pairs alternation during mesh cycle is integrated in this dynamic load modelling. A comparative study is included, which shows the effects of the distribution factor of the addendum modification coefficients on the contact surface characteristics of the gear pairs.

  6. A study of the optimum configuration of injection molded plastic gear by modification of gear tooth

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Suep; Kwon, Young-Doo; Doc, Jin-Uk; Leed, Jun-Hyuk

    2009-07-01

    In this study, the gear system is optimized by modifying the tooth configuration of the plastic gears. Plastic gear is widely used as a machine element in industries of electric and electronic parts, automotive parts etc. Unlike the steel gear, the plastic gear has low load- transmission, durability and reliability. On the other hand, it is light-weight, low-noise, operable without a lubricant, shock absorptive, and anti-corrosive. The gear characteristics are calculated and analyzed by Hexagon and FEM (Finite Element Method) tools, and the characteristics of the standard gear and the addendum modified gear of the steel gear and the plastic gear are compared. When torque is applied to these gear systems, the system using the addendum modified gear can realize soft contact between gears. So, the noise of the addendum modified gear system was less than that of the common normal gear system. However, this is not applicable to any material, such as steel which is governed by DIN (Deuteshe Industrie Norm) recommendation. This study adopted the narrow tip tooth plastic gear, and proposed the optimum addendum modified gear with respect to stress, noise and contact ratio. To calculate and analyze the simulation of gear matching, we used commercial tools like CATIA, Auto-CAD, MARC for simulation and Hexagon for calculation.

  7. A method for static and dynamic load analysis of standard and modified spur gears

    NASA Technical Reports Server (NTRS)

    Kasuba, R.

    1983-01-01

    The mesh stiffness and dynamic load characteristics for several cases of the Normal Contract Ratio and High Contact ratio gearing. The considered contact ratios were grouped in the general range of 1.7,2.0, and 2.3. The HCR gearing is defined by contact ratios equal to or greater than 2.0. The HCR gearing is represented by a group of small pressure angle, fine pitch, and long addendum gearing.

  8. 50 CFR Figure 26 to Part 679 - Modified Nonpelagic Trawl Gear

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Modified Nonpelagic Trawl Gear 26 Figure... ALASKA Pt. 679, Fig. 26 Figure 26 to Part 679—Modified Nonpelagic Trawl Gear This figure shows the location of elevating devices in the elevated section of modified nonpelagic trawl gear, as specified...

  9. Gearing

    NASA Technical Reports Server (NTRS)

    Coy, J. J.; Townsend, D. P.; Zaretsky, E. V.

    1985-01-01

    Gearing technology in its modern form has a history of only 100 years. However, the earliest form of gearing can probably be traced back to fourth century B.C. Greece. Current gear practice and recent advances in the technology are drawn together. The history of gearing is reviewed briefly in the Introduction. Subsequent sections describe types of gearing and their geometry, processing, and manufacture. Both conventional and more recent methods of determining gear stress and deflections are considered. The subjects of life prediction and lubrication are additions to the literature. New and more complete methods of power loss predictions as well as an optimum design of spur gear meshes are described. Conventional and new types of power transmission systems are presented.

  10. 50 CFR Figure 26 to Part 679 - Modified Nonpelagic Trawl Gear

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Modified Nonpelagic Trawl Gear 26 Figure 26 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 26 Figure 26 to Part 679—Modified Nonpelagic Trawl Gear ER06OC10.050...

  11. 50 CFR Figure 26 to Part 679 - Modified Nonpelagic Trawl Gear

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Modified Nonpelagic Trawl Gear 26 Figure 26 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 26 Figure 26 to Part 679—Modified Nonpelagic Trawl Gear ER06OC10.050...

  12. 50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169...

  13. 50 CFR Figure 26 to Part 679 - Modified Nonpelagic Trawl Gear

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Modified Nonpelagic Trawl Gear 26 Figure 26 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... ALASKA Pt. 679, Fig. 26 Figure 26 to Part 679—Modified Nonpelagic Trawl Gear ER06OC10.050...

  14. 50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169...

  15. 50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC..., Table 51 Table 51 to Part 679—Modified Gear Trawl Zone Longitude Latitude 171 45.00 W 61 00.00 N 169...

  16. Modified Involute Helical Gears: Computerized Design, Simulation of Meshing, and Stress Analysis

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert (Technical Monitor); Litvin, Faydor L.; Gonzalez-Perez, Ignacio; Carnevali, Luca; Kawasaki, Kazumasa; Fuentes-Aznar, Alfonso

    2003-01-01

    The computerized design, methods for generation, simulation of meshing, and enhanced stress analysis of modified involute helical gears is presented. The approaches proposed for modification of conventional involute helical gears are based on conjugation of double-crowned pinion with a conventional helical involute gear. Double-crowning of the pinion means deviation of cross-profile from an involute one and deviation in longitudinal direction from a helicoid surface. Using the method developed, the pinion-gear tooth surfaces are in point-contact, the bearing contact is localized and oriented longitudinally, and edge contact is avoided. Also, the influence of errors of aligment on the shift of bearing contact, vibration, and noise are reduced substantially. The theory developed is illustrated with numerical examples that confirm the advantages of the gear drives of the modified geometry in comparison with conventional helical involute gears.

  17. Modified Involute Helical Gears: Computerized Design, Simulation of Meshing and Stress Analysis

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The computerized design, methods for generation, simulation of meshing, and enhanced stress analysis of modified involute helical gears is presented. The approaches proposed for modification of conventional involute helical gears are based on conjugation of double-crowned pinion with a conventional helical involute gear. Double-crowning of the pinion means deviation of cross-profile from an involute one and deviation in longitudinal direction from a helicoid surface. Using the method developed, the pinion-gear tooth surfaces are in point-contact, the bearing contact is localized and oriented longitudinally, and edge contact is avoided. Also, the influence of errors of alignment on the shift of bearing contact, vibration, and noise are reduced substantially. The theory developed is illustrated with numerical examples that confirm the advantages of the gear drives of the modified geometry in comparison with conventional helical involute gears.

  18. Computerized Design and Generation of Low-noise Helical Gears with Modified Surface Topology

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Chen, N. X.; Lu, J.; Handschuh, R. F.

    1994-01-01

    An approach for design and generation of low-noise helical gears with localized bearing contact is proposed. The approach is applied to double circular arc helical gears and modified involute helical gears. The reduction of noise and vibration is achieved by application of a predesigned parabolic function of transmission errors that is able to absorb a discontinuous linear function of transmission errors caused by misalignment. The localization of the bearing contact is achieved by the mismatch of pinion-gear tooth surfaces. Computerized simulation of meshing and contact of the designed gears demonstrated that the proposed approach will produce a pair of gears that has a parabolic transmission error function even when misalignment is present. Numerical examples for illustration of the developed approach are given.

  19. Generation and Computerized Simulation of Meshing and Contact of Modified Involute Helical Gears

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Chen, Ningxin; Lu, Jian

    1995-01-01

    The design and generation of modified involute helical gears that have a localized and stable bearing contact, and reduced noise and vibration characteristics are described. The localization of the bearing contact is achieved by the mismatch of the two generating surfaces that are used for generation of the pinion and the gear. The reduction of noise and vibration will be achieved by application of a parabolic function of transmission errors that is able to absorb the almost linear function of transmission errors caused by gear misalignment. The meshing and contact of misaligned gear drives can be analyzed by application of computer programs that have been developed. The computations confirmed the effectiveness of the proposed modification of the gear geometry. A numerical example that illustrates the developed theory is provided.

  20. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  1. Comparisons of modified Vasco X-2 and AISI 9310 gear steels

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Endurance tests were conducted with four groups of spur gears manufactured from three heats of consumable electrode vacuum melted (CVM) modified Vasco X-2. Endurance tests were also conducted with gears manufactured from CVM AISI 9310. Bench type rolling element fatigue tests were conducted with both materials. Hardness measurements were made to 811 K. There was no statistically significant life difference between the two materials. Life differences between the different heats of modified Vasco X-2 can be attributed to heat treat variation and resultant hardness. Carburization of gear flanks only can eliminate tooth fracture as a primary failure mode for modified Vasco X-2. However, a tooth surface fatigue spall can act as a nucleus of a tooth fracture failure for the modified Vasco X-2.

  2. 50 CFR Table 51 to Part 679 - Modified Gear Trawl Zone

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Modified Gear Trawl Zone 51 Table 51 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 51 Table 51 to Part...

  3. Addendum 2: Forum for Injection Technique, India

    PubMed Central

    Kalra, Sanjay; Balhara, Yatan Pal Singh; Baruah, Manash P.; Chadha, Manoj; Chandalia, Hemraj B.; Chowdhury, Subhankar; Kesavadev, Jothydev; Prasanna Kumar, K. M.; Modi, Sonal; Pitale, Shailesh; Rishi, Shukla; Sahay, Rakesh; Sundaram, Annamalai; Unnikrishnan, Ambika G.; Wangnoo, Subhash K.

    2014-01-01

    The second addendum to the Forum for Injection Techniques (FIT), India recommendations, first published in 2012 and followed by an addendum in 2013, covers various important issues. It describes how the impact of the so-called non-modifiable factors, which influence the injection technique, can be modulated; provides fresh information on timing of glucagon-like peptide 1 receptor agonist injections, methods of minimizing pain during injections, amyloidosis, and factors that impact adherence to insulin therapy. The addendum also lists semantic changes made to keep the FIT recommendations updated.

  4. Topology of modified helical gears and Tooth Contact Analysis (TCA) program

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Zhang, Jiao

    1989-01-01

    The contents of this report covers: (1) development of optimal geometries for crowned helical gears; (2) a method for their generation; (3) tooth contact analysis (TCA) computer programs for the analysis of meshing and bearing contact of the crowned helical gears; and (4) modelling and simulation of gear shaft deflection. The developed method for synthesis was used to determine the optimal geometry for a crowned helical pinion surface and was directed to localize the bearing contact and guarantee favorable shape and a low level of transmission errors. Two new methods for generation of the crowned helical pinion surface are proposed. One is based on the application of a tool with a surface of revolution that slightly deviates from a regular cone surface. The tool can be used as a grinding wheel or as a shaver. The other is based on a crowning pinion tooth surface with predesigned transmission errors. The pinion tooth surface can be generated by a computer-controlled automatic grinding machine. The TCA program simulates the meshing and bearing contact of the misaligned gears. The transmission errors are also determined. The gear shaft deformation was modelled and investigated. It was found that the deflection of gear shafts has the same effect as gear misalignment.

  5. Design, Generation and Tooth Contact Analysis (TCA) of Asymmetric Face Gear Drive With Modified Geometry

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Fuentes, Alfonso; Hawkins, J. M.; Handschuh, Robert F.

    2001-01-01

    A new type of face gear drive for application in transmissions, particularly in helicopters, has been developed. The new geometry differs from the existing geometry by application of asymmetric profiles and double-crowned pinion of the face gear mesh. The paper describes the computerized design, simulation of meshing and contact, and stress analysis by finite element method. Special purpose computer codes have been developed to conduct the analysis. The analysis of this new type of face gear is illustrated with a numerical example.

  6. Gear tooth topological modification

    NASA Technical Reports Server (NTRS)

    Kish, Jules G. (Inventor); Isabelle, Charles (Inventor)

    1994-01-01

    The topology of parallel axis gears, such as spur and helical gears is modified to produce quieter and more smoothly operating gear sets with more uniform load distribution. A finite element analysis of the gear in its operating mode is made to produce a plot of radial and tangential deflections of the pinion and gear tooth surfaces which will occur when the gears are loaded during operation. The resultant plot is then inverted to produce a plot, or set of coordinates, which will define the path of travel of the gear tooth grinding wheel, which path is a mirror image of the plot of the finite element analysis. The resulting gears, when subjected to operating loads, will thus be deflected tangentially and radially to their optimum operating, or theoretical true involute, positions so as to produce quieter, smoother, and more evenly loaded gear trains.

  7. Effects of lubrication on the performance of high speed spur gears

    NASA Technical Reports Server (NTRS)

    Mizutani, Hachiro; Isikawa, Yuuichi; Townsend, Dennis P.

    1989-01-01

    An experimental analysis was conducted to determine power loss and gear noise of high speed spur gears with long addendum under various conditions of load, speed, and oil jet pressure for into mesh lubrication. Power losses were calculated from temperature measurements of lubricating oil, gears, gear box, and oil flow rate. Furthermore, power loss was divided into windage loss, friction loss and churning loss. The results show that windage loss and churning loss were the main components of gear power loss of high gear speed. In addition, lubricating conditions had some influences on gear noise especially under low oil temperature or high viscosity.

  8. Hybrid Gear

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  9. Effect of contact ratio on spur gear dynamic load

    NASA Technical Reports Server (NTRS)

    Liou, Chuen-Huei; Lin, Hsiang Hsi; Oswald, Fred B.; Townsend, Dennis P.

    1992-01-01

    A computer simulation is presented which shows how the gear contact ratio affects the dynamic load on a spur gear transmission. The contact ratio can be affected by the tooth addendum, the pressure angle, the tooth size (diametral pitch), and the center distance. The analysis presented was performed using the NASA gear dynamics code, DANST. In the analysis, the contact ratio was varied over the range 1.20 to 2.40 by changing the length of the tooth addendum. In order to simplify the analysis, other parameters related to contact ratio were held constant. The contact ratio was found to have a significant influence on gear dynamics. Over a wide range of operating speeds, a contact ratio close to 2.0 minimized dynamic load. For low contact ratio gears (contact ratio less than 2.0), increasing the contact ratio reduced the gear dynamic load. For high contact ratio gears (contact ratio = or greater than 2.0), the selection of contact ratio should take into consideration the intended operating speeds. In general, high contact ratio gears minimized dynamic load better than low contact ratio gears.

  10. Optimum Design Of Addendum Surfaces In Sheet Metal Forming Process

    NASA Astrophysics Data System (ADS)

    Debray, K.; Sun, Z. C.; Radjai, R.; Guo, Y. Q.; Dai, L.; Gu, Y. X.

    2004-06-01

    The design of addendum surfaces in sheet forming process is very important for the product quality, but it is very time-consuming and needs tedious trial-error corrections. In this paper, we propose a methodology to automatically generate the addendum surfaces and then to optimize them using a forming modelling solver. The surfaces' parameters are taken as design variables and modified in course of optimization. The finite element mesh is created on the initial addendum surfaces and mapped onto the modified surfaces without remeshing operation. The Feasible Sequential Quadratic Programming (FSQP) is adopted as our algorithm of optimization. Two objective functions are used: the first one is the thickness function to minimize the thickness variation on the workpiece ; the second one is the appearance function aiming to avoid the scratching defects on the external surfaces of panels. The FSQP is combined with our "Inverse Approach" or "One Step Approach" which is a very fast forming solver. This leads to a very efficient optimization procedure. The present methodology is applied to a square box. The addendum surfaces are characterised by four geometrical variables. The influence of optimization criteria is studied and discussed.

  11. Differential gearing

    SciTech Connect

    Tamiya, S.

    1986-07-29

    A differential for motor vehicles is described and the like comprising, an input drive shaft, a pair of coaxially spaced drive gears simultaneously driven by the input shaft in a same direction at a same speed of rotation about a common axis of rotation, a driven gear driven peripherally by the pair of drive gears for transmission of power from the input drive shaft, two coaxial opposed bevel sun gears having an axis of rotation concentric with an axis of rotation of the driven gear, two planetary gears disposed between the sun gears for differential driving thereof during turns of the vehicle to the right and to the left of each meshing with the sun gears for driving the suns gears. Each planetary gear has a separate axis of rotation carried by the driven gear disposed therein radially and symmetrically relative to the axis of rotation of the sun gears, and each sun gear having a respective power output shaft connected thereto for rotation therewith.

  12. Performances of a balanced hydraulic motor with planetary gear train

    NASA Astrophysics Data System (ADS)

    Yu, Hongying; Luo, Changjie; Wang, Huimin

    2012-07-01

    The current research of a balanced hydraulic motor focuses on the characteristics of the motor with three planet gears. References of a balanced hydraulic motor with more than three planet gears are hardly found. In order to study the characteristics of a balanced hydraulic motor with planetary gear train that includes more than three planet gears, on the basis of analysis of the structure and working principle of a balanced hydraulic motor with planetary gear train, formulas are deduced for calculating the hydraulic motor's primary performance indexes such as displacement, unit volume displacement, flowrate fluctuation ratio, etc. Influences of the gears' tooth number on displacement and flowrate characteristics are analyzed. In order to guarantee the reliability of sealing capability, the necessary conditions that tooth number of the sun gear and the planet gears should satisfy are discussed. Selecting large unit volume displacement and small displacement fluctuation ratio as designing objectives, a balanced hydraulic motor with three planet gears and a common gear motor are designed under the conditions of same displacement, tooth addendum coefficien and clearance coefficient. By comparing the unit volume displacement and fluctuation ratio of the two motors, it can be seen that the balanced hydraulic motor with planetary gear train has the advantages of smaller fluctuation ratio and larger unit volume displacement. The results provide theoretical basis for choosing gear tooth-number of this kind of hydraulic motor.

  13. Bending strength model for internal spur gear teeth

    NASA Technical Reports Server (NTRS)

    Savage, Michael; Rubadeux, K. L.; Coe, H. H.

    1995-01-01

    Internal spur gear teeth are normally stronger than pinion teeth of the same pitch and face width since external teeth are smaller at the base. However, ring gears which are narrower have an unequal addendum or are made of a material with a lower strength than that of the meshing pinion may be loaded more critically in bending. In this study, a model for the bending strength of an internal gear tooth as a function of the applied load pressure angle is presented which is based on the inscribed Lewis constant strength parabolic beam. The bending model includes a stress concentration factor and an axial compression term which are extensions of the model for an external gear tooth. The geometry of the Lewis factor determination is presented, the iteration to determine the factor is described, and the bending strength J factor is compared to that of an external gear tooth. This strength model will assist optimal design efforts for unequal addendum gears and gears of mixed materials.

  14. A Parametric Study of Spur Gear Dynamics

    NASA Technical Reports Server (NTRS)

    Lin, Hsiang Hsi; Liou, Chuen-Huei

    1998-01-01

    A parametric study of a spur gear system was performed through a numerical analysis approach. This study used the gear dynamic program DANST, a computer simulator, to determine the dynamic behavior of a spur gear system. The analytical results have taken the deflection of shafts and bearings into consideration for static analysis, and the influence of these deflections on gear dynamics was investigated. Damping in the gear system usually is an unknown quantity, but it has an important effect in resonance vibration. Typical values as reported in the literature were used in the present analysis. The dynamic response due to different damping factors was evaluated and compared. The effect of the contact ratio on spur gear dynamic load and dynamic stress was investigated through a parameter study. The contact ratio was varied over the range of 1.26 to 2.46 by adjusting the tooth addendum. Gears with contact ratio near 2.0 were found to have the most favorable dynamic performance.

  15. Separation distance and static transmission error of involute spur gears

    NASA Technical Reports Server (NTRS)

    Tse, David K.; Lin, Hsiang H.

    1992-01-01

    The effects of separation distance and deflection of gear teeth on the static transmission error of involute spur gears are investigated. In this paper, only low-contact-ratio gears with true involute profile are studied. Gear ratio and tooth addendum are varied to examine their effects on the separation distance and static transmission error. Results obtained from the investigation shows that the contact ratio and static transmission error are affected significantly if considering the separation distance. In general, the magnitude of contact ratio has been increased and the variation of static transmission error has been smoothed. The most significant change occurs for a gear pair with a theoretical contact ratio close to 1.95.

  16. Scoring of precision spur gears

    SciTech Connect

    Budinski, K.G. )

    1994-09-01

    A group of manufacturing machines employed precision spur gears as the timing mechanism for machine operations. These machines had worked successfully for about ten years with little or no problems with gear wear or deterioration. When new machines were brought on line with recently made gears there were immediate problems with gear tooth scoring. A laboratory study was conducted to determine if metallurgical conditions were related to the gear scoring. Recent gears were made from a modification of the alloy used in early gears. The new alloy has been modified to make it more resistant to softening in coating operations. Reciprocating wear tests and galling tests were conducted to compare the tribological characteristics of the old and new gear steels. It was determined that the threshold galling stress of the gear steels was strongly dependent on the hardness. The reciprocating wear tests indicated that the wear resistance was affected by the volume fraction of hard phases in the steels. The recommended short-term solution was to alter the tempering procedure for the steel to keep Rockwell C hardness above 60; the long-term solution was to change the gear material and lubrication.

  17. Geared power transmission technology

    NASA Technical Reports Server (NTRS)

    Coy, J. J.

    1983-01-01

    The historical path of the science and art of gearing is reviewed. The present state of gearing technology is discussed along with examples of some of the NASA-sponsored contributions to gearing technology. Future requirements in gearing are summarized.

  18. Apparatus for controlling automatic gear transmission

    SciTech Connect

    Yoshimura, H.; Iida, Y.

    1989-04-25

    An apparatus is described for controlling an automatic gear transmission of a motor vehicle having an engine with an output and being subjected to a running resistance, the automatic gear transmission having a present gear position the apparatus comprising: arithmetic means, operatively connected to receive an optimum gear position, for computing a maximum output of the engine for the present gear position if the optimum gear position is the present gear position; arithmetic means, operatively connected to receive an optimum gear position, for computing an engine output corresponding to the running resistance of the motor vehicle for the present gear position; comparison means for comparing the computed maximum output of the engine and the computed engine output; and command modifying means for modifying the optimum gear position to a lower gear position and commanding a shiftdown when the computed engine output corresponding to running resistance is larger than the computed maximum engine output based on the result of comparison effected by the comparison means.

  19. 50 CFR 622.46 - Prevention of gear conflicts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... restrictions of the FMP for the Shrimp Fishery of the Gulf of Mexico, the RA may modify or establish separation zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions...

  20. 50 CFR 622.46 - Prevention of gear conflicts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... restrictions of the FMP for the Shrimp Fishery of the Gulf of Mexico, the RA may modify or establish separation zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions...

  1. 50 CFR 622.46 - Prevention of gear conflicts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... restrictions of the FMP for the Shrimp Fishery of the Gulf of Mexico, the RA may modify or establish separation zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions...

  2. Transmission gearing arrangement

    SciTech Connect

    Klemen, D.

    1987-08-04

    A gearing arrangement is described for an automotive power transmission comprising: an input shaft and an output shaft; first, second, and third simple planetary gear sets. Each has a sun gear, a ring gear, and a planet gears meshing with the sun and the ring gears and rotatably supported on a planet carrier; means rigidly interconnecting the ring gear of the third gear set and the carrier of the second gear set; means rigidly interconnecting the ring gear of the second gear set and the carrier of the first gear set; means rigidly connecting the output shaft and the carrier of the third gear set; a first intermediate shaft rigidly interconnecting the sun gears of the second and the third gear sets for unitary rotation; a second intermediate shaft rigidly connected to the carrier of the second gear set; a third intermediate shaft continuously connected to the input shaft and to the sun gear of the first gear set; first, second, and third brake means operative to selectively brake rotation of the ring gears of the first, the second, and the third gear sets, respectively; a first rotating clutch selectively operable to connect the input shaft and the first intermediate shaft for unitary rotation; a second rotating clutch selectively operable to connect the input shaft and the second intermediate shaft for unitary rotation; a fourth simple planetary gear set including a sun gear and a ring gear and planet gears meshing with the sun and the ring gears and rotatably supported on a planet carrier; means rigidly connecting the sun gear of the fourth gear set to the third intermediate shaft; means rigidly connecting the ring gear of the fourth gear set to the carrier of the first gear set; and a fourth brake means selectively operable to brake the carrier of the fourth gear set. The nine forward ratios are obtainable while preserving a single transition shifting over the entire nine forward ratios.

  3. Flex-Gears

    NASA Technical Reports Server (NTRS)

    Tsai, Lung-Wen; Peritt, Jonathan

    1993-01-01

    Flex-Gears are being developed as an alternative to brushes and slip rings to conduct electricity across a rotating joint. Flex-Gears roll in the annulus of sun and ring gears for electrical contact while maintaining their position by using a novel application of involute gears. A single Flex-Gear is predicted to transfer up to 2.8 amps, thereby allowing a six inch diameter device, holding 30 Flex-Gears, to transfer over 80 amps. Semi-rigid Flex-Gears are proposed to decrease Flex-Gear stress and insure proper gear meshing.

  4. 50 CFR 622.59 - Prevention of gear conflicts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ATLANTIC Shrimp Fishery of the Gulf of Mexico § 622.59 Prevention of gear conflicts. (a) No person may... the procedures and restrictions of the Gulf Shrimp FMP, the RA may modify or establish separation zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions...

  5. 50 CFR 622.59 - Prevention of gear conflicts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ATLANTIC Shrimp Fishery of the Gulf of Mexico § 622.59 Prevention of gear conflicts. (a) No person may... the procedures and restrictions of the Gulf Shrimp FMP, the RA may modify or establish separation zones for shrimp trawling and the use of fixed gear to prevent gear conflicts. Necessary prohibitions...

  6. Gear box assembly

    SciTech Connect

    Harrod, L.R.; Siebern, M.R.

    1989-04-25

    This patent describes a gearbox assembly for a vehicle which includes a driven axle shaft extending transversely of the vehicle having wheels secured thereto: a drive gear concentric with the axle shaft nonrotatably connected to the shaft, the drive gear having an integral hub on each of opposite sides thereof, a pinion gear shiftably mounted above the drive gear having one position engaging the drive gear and shiftable laterally to disengage from the drive gear, a shift lever mounted in a position projecting upwardly from the pinion gear actuatable to shift the pinion gear, an electric motor with output shaft mounted with the output shaft paralleling the axle shaft and having a driving gear mounted thereon, a multiple gear gear train mounted so as to establish a driving connection between the driving gear and the pinion gear, and a transmission housing enclosing the driving gar, gear train, pinion gear and drive gear, the housing including sleeve portions rotatably receiving the hubs of the drive gear and thus rotatably mounting the drive gear and the axle shaft connected to the drive gear.

  7. On Landing Gear Stresses

    NASA Technical Reports Server (NTRS)

    Gentric, A.

    1956-01-01

    Information on landing gear stresses is presented on the following: vibratory phenomena, tangential forces applied to landing gear, fore and aft oscillations of landing gears, examples of fatigue failures, vibration calculations, and improvement of existing test equipment.

  8. 76 FR 53942 - Notice of Lodging of First Addendum to Consent Decree Under the Emergency Planning and Community...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... Addendum to Consent Decree modifies deadlines for benzene waste NESHAP program enhancements at two INVISTA... two options for further benzene emission reductions and extends the time to implement the selected option. INVISTA will continue to comply with the benzene NESHAP throughout this period. The Department...

  9. Effects of a modified through-mask drinking system (MDS) on fluid intake during exercise in chemical protective gear. Report for January-May 1989

    SciTech Connect

    Szlyk, P.C.; Sils, I.V.; Tharion, W.J.; Francesconi, R.P.; Mahnke, R.B.

    1989-10-12

    This study was designed to evaluate the effects of a modified through-mask drinking system (MDS) on voluntary fluid consumption. Eighteen male volunteers walked on a treadmill (4.02 km/hr, 0 deg. grade, 50 min/hr for 6 hr) in a climatic chamber (dry bulb=32.6 deg C, wet bulb=17.5 deg C, 20.4% relative humidity, and windspeed=8.05 km/hr, producing a WBGT of 22.1 deg C). Subjects wore chemical protective gear (trousers, jacket, boots, gloves, and M17A1 protective mask) and were randomly assigned one of two through-mask and were randomly assigned one of two through-mask drinking systems: CS (n=9), the current gravity fed system or MDS (n=9), a prototype hand-pump drinking system. Because decontamination of the mask and drinking connections was performed prior to drinking, the overall use of the CS was rated significantly more difficult during both work and rest than the MDS. Failure to decontaminate connections prior to drinking was noted early in the trial in 2 soldiers using the CS suggesting an increase risk of accidental contamination associated with this system. Drinking with the MDS had no measurable adverse effect on hydration status of the test subjects: water intake rate, 0.36 L/hr (CS) and 0.42 L/hr (MDS); sweat rate, 0.63 L/hr (CS) and 0.67 L/hr (MDS); body weight loss, 0.32 %/hr (CS) and 0.31 %/hr (MDS).

  10. New Design and Improvement of Planetary Gear Trains

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert (Technical Monitor); Litvin, Faydor L.; Fuentes, Alfonso; Vecchiato, Daniele; Gonzalez-Perez, Ignacio

    2004-01-01

    The development of new types of planetary and planetary face-gear drives is proposed. The new designs are based on regulating backlash between the gears and modifying the tooth surfaces to improve the design. The goal of this work is to obtain a nearly uniform distribution of load between the planet gears. In addition, a new type of planetary face-gear drive was developed in this project.

  11. Directional gear ratio transmissions

    NASA Technical Reports Server (NTRS)

    Lafever, A. E. (Inventor)

    1984-01-01

    Epicyclic gear transmissions which transmit output at a gear ratio dependent only upon the input's direction are considered. A transmission housing envelops two epicyclic gear assemblies, and has shafts extending from it. One shaft is attached to a sun gear within the first epicyclic gear assembly. Planet gears are held symmetrically about the sun gear by a planet gear carrier and are in mesh with both the sun gear and a ring gear. Two unidirectional clutches restrict rotation of the first planet gear carrier and ring gear to one direction. A connecting shaft drives a second sun gear at the same speed and direction as the first planet gear carrier while a connecting portion drives a second planet gear carrier at the same speed and direction as the first ring gear. The transmission's output is then transmitted by the second ring gear to the second shaft. Input is transmitted at a higher gear ratio and lower speed for all inputs in the first direction than in the opposite direction.

  12. Planetary gear train

    SciTech Connect

    Hiraiwa, K.

    1988-10-04

    A planetary gear train is described comprising: an input member; an output member; a first planetary gear set including a first sun gear, a first ring gear, and a first pinion carrier rotatably supporting first planet pinions; a secondary planetary gear set including a second sun gear, and second ring gear and a second pinion carrier rotatably supporting second planet pinions; first drive means for connecting the input member with the first ring gear; second drive means for connecting the input member with the first sun gear; third drive means for constantly connecting the first sun gear with the second sun gear and establishing a force transmitting positive drive from the first sun gear to the second sun gear, whereby the first sun gear rotates at a speed different from the second sun gear; first brake means for braking the second sun gear; second brake means for braking the second pinion carrier; fourth drive means for connecting the second ring gear with the output member and providing a first speed ratio therebetween; and fifth drive means for connecting the first pinion carrier with the output member and providing a second speed ratio therebetween, the second speed ratio being different from the first speed ratio.

  13. Addendum to Fragrance material review on linalool.

    PubMed

    Lapczynski, A; Letizia, C S; Api, A M

    2008-11-01

    A Fragrance material review on linalool was published by Letizia et al. in Food and Chemical Toxicology 41 (2003) 943-964. This addendum to the earlier publication will only report studies that were conducted after the Fragrance material review was published.

  14. Large computer systems and new architectures addendum

    NASA Astrophysics Data System (ADS)

    Bloch, T.

    1982-05-01

    This addendum brings the paper referenced up-to-date as of January 1981. The new market situation in the area of super computers is reviewed and the only really new machine, the CDC CYBER 205, is described. The CRAY-1S series is briefly described and the FPS-164 is mentioned. The fact that Burroughs discontinued the BSP project is mentioned.

  15. Maximum life spur gear design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Mackulin, B. J.; Coe, H. H.; Coy, J. J.

    1991-01-01

    Optimization procedures allow one to design a spur gear reduction for maximum life and other end use criteria. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial guess values. The optimization algorithm is described, and the models for gear life and performance are presented. The algorithm is compact and has been programmed for execution on a desk top computer. Two examples are presented to illustrate the method and its application.

  16. New Gear Transmission Error Measurement System Designed

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.

    2001-01-01

    The prime source of vibration and noise in a gear system is the transmission error between the meshing gears. Transmission error is caused by manufacturing inaccuracy, mounting errors, and elastic deflections under load. Gear designers often attempt to compensate for transmission error by modifying gear teeth. This is done traditionally by a rough "rule of thumb" or more recently under the guidance of an analytical code. In order for a designer to have confidence in a code, the code must be validated through experiment. NASA Glenn Research Center contracted with the Design Unit of the University of Newcastle in England for a system to measure the transmission error of spur and helical test gears in the NASA Gear Noise Rig. The new system measures transmission error optically by means of light beams directed by lenses and prisms through gratings mounted on the gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. A photodetector circuit converts the light to an analog electrical signal. To increase accuracy and reduce "noise" due to transverse vibration, there are parallel light paths at the top and bottom of the gears. The two signals are subtracted via differential amplifiers in the electronics package. The output of the system is 40 mV/mm, giving a resolution in the time domain of better than 0.1 mm, and discrimination in the frequency domain of better than 0.01 mm. The new system will be used to validate gear analytical codes and to investigate mechanisms that produce vibration and noise in parallel axis gears.

  17. An electric control for an electrohydraulic active control aircraft landing gear

    NASA Technical Reports Server (NTRS)

    Ross, I.; Edson, R.

    1979-01-01

    An electronic controller for an electrohydraulic active control aircraft landing gear was developed. Drop tests of a modified gear from a 2722 Kg (6000 lbm) class of airplane were conducted to illustrate controller performance. The results indicate that the active gear effects a force reduction, relative to that of the passive gear, from 9 to 31 percent depending on the aircraft sink speed and the static gear pressure.

  18. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  19. Low-Noise Spiral Bevel Gears

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Handschuh, Robert F.; Coy, John J.; Henry, Zachary; Thomas, John; Litvin, Faydor L.

    1994-01-01

    Modified spiral bevel gears that generate relatively little noise and vibration designed and fabricated for use in U.S. Army OH-58D helicopter. Noise reduced by 12 to 19 dB. Similar low-noise, low-vibration spiral bevel gears used in other helicopters, with consequent benefits in comfort and health of pilots and passengers, enhancement of pilots' performance and safety through reduction of audible distraction, and reduction in cost and weight of helicopters through reduction in amount of sound-proofing material. Low-noise, low-vibration spiral bevel gears also used in drive axles of cars and trucks for smoother, quieter rides.

  20. Anti-backlash gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission. One preferred embodiment discloses and describes an anti-backlash feature to counter ''dead zones'' in the gear bearing movement.

  1. Molecular Dynamics Simulation of Carbon Nanotube Based Gears

    NASA Technical Reports Server (NTRS)

    Han, Jie; Globus, Al; Jaffe, Richard; Deardorff, Glenn; Chancellor, Marisa K. (Technical Monitor)

    1996-01-01

    We used molecular dynamics to investigate the properties and design space of molecular gears fashioned from carbon nanotubes with teeth added via a benzyne reaction known to occur with C60. A modified, parallelized version of Brenner's potential was used to model interatomic forces within each molecule. A Leonard-Jones 6-12 potential was used for forces between molecules. One gear was powered by forcing the atoms near the end of the buckytube to rotate, and a second gear was allowed.to rotate by keeping the atoms near the end of its buckytube on a cylinder. The meshing aromatic gear teeth transfer angular momentum from the powered gear to the driven gear. A number of gear and gear/shaft configurations were simulated. Cases in vacuum and with an inert atmosphere were examined. In an extension to molecular dynamics technology, some simulations used a thermostat on the atmosphere while the hydrocarbon gear's temperature was allowed to fluctuate. This models cooling the gears with an atmosphere. Results suggest that these gears can operate at up to 50-100 gigahertz in a vacuum or inert atmosphere at room temperature. The failure mode involves tooth slip, not bond breaking, so failed gears can be returned to operation by lowering temperature and/or rotation rate. Videos and atomic trajectory files in xyz format are presented.

  2. 48 CFR 1352.239-70 - Software license addendum.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Software license addendum. As prescribed in 48 CFR 1339.107, insert the following clause: Software License... 48 Federal Acquisition Regulations System 5 2011-10-01 2011-10-01 false Software license addendum. 1352.239-70 Section 1352.239-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE...

  3. 48 CFR 1352.239-70 - Software license addendum.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Software license addendum. As prescribed in 48 CFR 1339.107, insert the following clause: Software License... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Software license addendum. 1352.239-70 Section 1352.239-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE...

  4. 48 CFR 1352.239-70 - Software license addendum.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Software license addendum. As prescribed in 48 CFR 1339.107, insert the following clause: Software License... 48 Federal Acquisition Regulations System 5 2013-10-01 2013-10-01 false Software license addendum. 1352.239-70 Section 1352.239-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE...

  5. 48 CFR 1352.239-70 - Software license addendum.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Software license addendum. As prescribed in 48 CFR 1339.107, insert the following clause: Software License... 48 Federal Acquisition Regulations System 5 2012-10-01 2012-10-01 false Software license addendum. 1352.239-70 Section 1352.239-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE...

  6. 48 CFR 1352.239-70 - Software license addendum.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Software license addendum. As prescribed in 48 CFR 1339.107, insert the following clause: Software License... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Software license addendum. 1352.239-70 Section 1352.239-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE...

  7. 10 CFR 1045.41 - Use of classified addendums.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and Review of Documents Containing Restricted Data and Formerly Restricted Data § 1045.41 Use of... simplify document handling procedures, document originators should segregate RD or FRD into an addendum...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged...

  8. Offset Compound Gear Drive

    NASA Technical Reports Server (NTRS)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  9. Gear bearing drive

    NASA Technical Reports Server (NTRS)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  10. Landing gear noise attenuation

    NASA Technical Reports Server (NTRS)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  11. Modelling polymer draft gears

    NASA Astrophysics Data System (ADS)

    Wu, Qing; Yang, Xiangjian; Cole, Colin; Luo, Shihui

    2016-09-01

    This paper developed a new and simple approach to model polymer draft gears. Two types of polymer draft gears were modelled and compared with experimental data. Impact characteristics, in-train characteristics and frequency responses of these polymer draft gears were studied and compared with those of a friction draft gear. The impact simulations show that polymer draft gears can withstand higher impact speeds than the friction draft gear. Longitudinal train dynamics simulations show that polymer draft gears have significantly longer deflections than friction draft gears in normal train operations. The maximum draft gear working velocities are lower than 0.2 m/s, which are significantly lower than the impact velocities during shunting operations. Draft gears' in-train characteristics are similar to their static characteristics but are very different from their impact characteristics; this conclusion has also been reached from frequency response simulations. An analysis of gangway bridge plate failures was also conducted and it was found that they were caused by coupler angling behaviour and long draft gear deflections.

  12. Phase-Oriented Gear Systems

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    2007-01-01

    Phase-oriented gear systems are differential planetary transmissions in which each planet gear has two sets of unequal numbers of teeth indexed at prescribed relative angles (phases). The figure illustrates an application of the phase-oriented gearing concept to a relatively simple speed-reducing differential planetary transmission that includes a sun gear, an idler gear, three identical planet gears, a ground internal ring gear, and an output internal ring gear. Typically, the ground internal ring gear and output internal ring gear have different numbers of teeth, giving rise to a progressive and periodic phase shift between the corresponding pairs of teeth engaged by each successive planet gear. To accommodate this phase shift, it is necessary to introduce a compensating phase shift between the ground-gear-engaging and output-gearengaging sections of each planet gear. This is done by individually orienting each planet gear

  13. Transmission errors and bearing contact of spur, helical and spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Zhang, J.; Lee, H.-T.; Handschuh, R. F.

    1988-01-01

    An investigation of transmission errors and bearing contact of spur, helical and spiral bevel gears was performed. Modified tooth surfaces for these gears have been proposed in order to absorb linear transmission errors caused by gear misalignment and localize the bearing contact. Numerical examples for spur, helical, and spiral bevel gears are presented to illustrate the behavior of the modified gear surfaces to misalignment and errors of assembly.The numerical results indicate that the modified surfaces will perform with a low level of transmission error in nonideal operating environment.

  14. Optimal design of compact spur gear reductions

    NASA Technical Reports Server (NTRS)

    Savage, M.; Lattime, S. B.; Kimmel, J. A.; Coe, H. H.

    1992-01-01

    The optimal design of compact spur gear reductions includes the selection of bearing and shaft proportions in addition to gear mesh parameters. Designs for single mesh spur gear reductions are based on optimization of system life, system volume, and system weight including gears, support shafts, and the four bearings. The overall optimization allows component properties to interact, yielding the best composite design. A modified feasible directions search algorithm directs the optimization through a continuous design space. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for optimization. After finding the continuous optimum, the designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearings on the optimal configurations.

  15. Gearing Up for Mountain Biking.

    ERIC Educational Resources Information Center

    Jahnke, Thomas; Hamson, Mike

    1999-01-01

    Examines the gear system of a mountain bike to discover any redundancy in the many gear settings available to the cyclist. Suggests a best strategy for changing up through the gears on a typical 21-gear system and an adjustment to the available gears that would result in a smoother change. (Author/ASK)

  16. Addendum to NuMI shielding assessment

    SciTech Connect

    Vaziri, Kamran; /Fermilab

    2007-10-01

    The original safety assessment and the Safety Envelope for the NuMI beam line corresponds to 400 kW of beam power. The Main Injector is currently capable of and approved for producing 500 kW of beam power2. However, operation of the NuMI beam line at 400 kW of power brings up the possibility of an occasional excursion above 400 kW due to better than usual tuning in one of the machines upstream of the NuMI beam line. An excursion above the DOE approved Safety Envelope will constitute a safety violation. The purpose of this addendum is to evaluate the radiological issues and modifications required to operate the NuMI beam line at 500 kW. This upgrade will allow 400 kW operations with a reasonable safety margin. Configuration of the NuMI beam line, boundaries, safety system and the methodologies used for the calculations are as described in the original NuMI SAD. While most of the calculations presented in the original shielding assessment were based on Monte Carlo simulations, which were based on the design geometries, most of the results presented in this addendum are based on the measurements conducted by the AD ES&H radiation safety group.

  17. PAT-1 safety analysis report addendum.

    SciTech Connect

    Weiner, Ruth F.; Schmale, David T.; Kalan, Robert J.; Akin, Lili A.; Miller, David Russell; Knorovsky, Gerald Albert; Yoshimura, Richard Hiroyuki; Lopez, Carlos; Harding, David Cameron; Jones, Perry L.; Morrow, Charles W.

    2010-09-01

    The Plutonium Air Transportable Package, Model PAT-1, is certified under Title 10, Code of Federal Regulations Part 71 by the U.S. Nuclear Regulatory Commission (NRC) per Certificate of Compliance (CoC) USA/0361B(U)F-96 (currently Revision 9). The purpose of this SAR Addendum is to incorporate plutonium (Pu) metal as a new payload for the PAT-1 package. The Pu metal is packed in an inner container (designated the T-Ampoule) that replaces the PC-1 inner container. The documentation and results from analysis contained in this addendum demonstrate that the replacement of the PC-1 and associated packaging material with the T-Ampoule and associated packaging with the addition of the plutonium metal content are not significant with respect to the design, operating characteristics, or safe performance of the containment system and prevention of criticality when the package is subjected to the tests specified in 10 CFR 71.71, 71.73 and 71.74.

  18. An electronic control for an electrohydraulic active control landing gear for the F-4 aircraft

    NASA Technical Reports Server (NTRS)

    Ross, I.

    1982-01-01

    A controller for an electrohydraulic active control landing gear was developed for the F-4 aircraft. A controller was modified for this application. Simulation results indicate that during landing and rollout over repaired bomb craters the active gear effects a force reduction, relative to the passive gear, or approximately 70%.

  19. 12. TRANSMISSION GEARING SHOWING RELATION TO SEGMENT GEAR ON WATERWHEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. TRANSMISSION GEARING SHOWING RELATION TO SEGMENT GEAR ON WATERWHEEL william E. Barrett, photographer, 1973 (copy negative) - Thomas Shepherd's Grist Mill, High Street Vicinity, Shepherdstown, Jefferson County, WV

  20. X-38 Landing Gear Skid Test Report

    NASA Technical Reports Server (NTRS)

    Gafka, George K.; Daugherty, Robert H.

    2000-01-01

    NASA incorporates skid-equipped landing gear on its series of X-38 flight test vehicles. The X-38 test program is the proving ground for the Crew Return Vehicle (CRV) a gliding parafoil-equipped vehicle designed to land at relatively low speeds. The skid-equipped landing gear is designed to attenuate the vertical landing energy of the vehicle at touchdown using crushable materials within the struts themselves. The vehicle then slides out as the vehicle horizontal energy is dissipated through the skids. A series of tests was conducted at Edwards Airforce Base (EAFB) in an attempt to quantify the drag force produced while "dragging" various X-38 landing gear skids across lakebed regions of varying surface properties. These data were then used to calculate coefficients of friction for each condition. Coefficient of friction information is critical for landing analyses as well as for landing gear load and interface load analysis. The skid specimens included full- and sub-scale V201 (space test vehicle) nose and main gear designs, a V131/V 132 (atmospheric flight test vehicles) main gear skid (actual flight hardware), and a newly modified, full-scale V201 nose -ear skid with substantially increased edge curvature as compared to its original design. Results of the testing are discussed along with comments on the relative importance of various parameters that influence skid stability and other dynamic behavior.

  1. Liquid rocket engine turbopump gears

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Design and fabrication of gear drives for rocket engine turbopumps are described in the sequence encountered during the design process as follows: (1) selection of overall arrangement; (2) selection of gear type; (3) preliminary sizing; (4) lubrication system design; (5) detail tooth design; (6) selection of gear materials; and (7) gear fabrication and testing as it affects the design. The description is oriented towards the use of involute spur gears, although reference material for helical gears is also cited.

  2. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  3. 46 CFR Appendix IV to Part 390 - Sample Addendum to Maritime Administration Capital Construction Fund Agreement

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ___ (“Party”), a citizen of the United States of America, as an Addendum to that certain agreement, Contract... executed this addendum, in quadruplicate, effective as of the date indicated below. United States of... 46 Shipping 8 2014-10-01 2014-10-01 false Sample Addendum to Maritime Administration...

  4. 46 CFR Appendix IV to Part 390 - Sample Addendum to Maritime Administration Capital Construction Fund Agreement

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ___ (“Party”), a citizen of the United States of America, as an Addendum to that certain agreement, Contract... executed this addendum, in quadruplicate, effective as of the date indicated below. United States of... 46 Shipping 8 2013-10-01 2013-10-01 false Sample Addendum to Maritime Administration...

  5. 46 CFR Appendix IV to Part 390 - Sample Addendum to Maritime Administration Capital Construction Fund Agreement

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ___ (“Party”), a citizen of the United States of America, as an Addendum to that certain agreement, Contract... executed this addendum, in quadruplicate, effective as of the date indicated below. United States of... 46 Shipping 8 2011-10-01 2011-10-01 false Sample Addendum to Maritime Administration...

  6. Design of Gear Drives With High Gear Ratio

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Fuentes, Alfonso; Vecchiato, Daniele; Gonzalez-Perez, Ignacio

    2005-01-01

    A three part paper to describe the results of several gear drive types with a high gear ratio is presented. A single stage planetary gear train with double helical gears is described with methods to reduce transmission errors and improve load distribution by regulating backlash during assembly. A new arrangement for face gear is also described. This new mechanism can perform rotations between axes that are collinear and intersected. Finally the design and simulation of an isostatic planetary gear train is presented. Conditions that can lead to noise and vibration of the planetary gear drive are described.

  7. Addendum to the Phase 2 Sampling and Analysis Plan for the Clinch River Remedial Investigation

    SciTech Connect

    Not Available

    1994-03-01

    This document is an addendum to the Phase 2 Sampling and Analysis Plan for the Clinch River Remedial Investigation (DOE 1993). The Department of Energy--Oak Ridge Operations (DOE-ORO) is proposing this addendum to the US Envianmental Protection Agency, Region IV (EPA-IV), and the Tennessee Department of Environment and Conservation (TDEC) as a reduced sampling program on the Clinch River arm of Watts Bar Reservoir and on Poplar Creek. DOE-ORO is proposing to maximize the use of existing data and minimize the collection of new data for water, sediment, and biota during Phase 2 of the Clinch River Remedial Investigation. The existing data along with the additional data collected in Phase 2 would be used to perform a baseline risk assessment and make remedial decisions. DOE-ORO considers that the existing data, the additional data collected in Phase 2, and on-site remedial investigation data would be sufficient to understand the nature and extent of the contamination problem in the Clinch River, perform a baseline risk assessment,and make remedial decisions. This addendum is organized in three sections. The first section provides background information and describes a rationale for modifying the Phase 2 Sampling and Analysis Plan. Section 2 presents a summary of the existing data for the Clinch River arm of Watts Bar Reservoir and an evaluation of the sufficiency of this data for a baseline human health and ecological risk assessment. Section 3 describes the revised Phase 2 Sampling and Analysis Plan for surface water, sediment, and biota in the Clinch River OU and in the Poplar Creek OU.

  8. High-Ratio Gear Train

    NASA Technical Reports Server (NTRS)

    Lefever, A. E.

    1982-01-01

    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  9. Gear assembly for automobile transmission

    SciTech Connect

    Ikemoto, K.; Tera Kura, Y.; Miyake, T.

    1986-03-25

    This patent describes a gear assembly including a pair of driving and driven gears permanently in meshing engagement with each other to provide a torque transmission therebetween. The driven gear is formed at one side thereof with a boss portion, and an additional gear axially slidable and rotatable on the boss portion of the driven gear and is permanently in meshing engagement with the driving gear to rotate at a gear ratio different from that of the driving and driven gears, additional gear is also resiliently in contact with a synchronizer mechanism assembled adjaecnt to the additional gear and having a spline piece fixed to the boss portion of the driven gear. The improvement wherein a toothed portion of the driven gear is formed at one end thereof with an annual stepped portion for provision of a predetermined annular gap between the additional gear and the one end face of the toothed portion of the driven gear. The resilient means is a waveshaped ring spring arranged in surrounding relationship with the boss portion of the driven gear and is engaged at its one end face with the additional gear and at its other end face with the spline piece of the synchronizer mechanism.

  10. Aircraft landing gear systems

    NASA Technical Reports Server (NTRS)

    Tanner, John A. (Editor)

    1990-01-01

    Topics presented include the laboratory simulation of landing gear pitch-plane dynamics, a summary of recent aircraft/ground vehicle friction measurement tests, some recent aircraft tire thermal studies, and an evaluation of critical speeds in high-speed aircraft. Also presented are a review of NASA antiskid braking research, titanium matrix composite landing gear development, the current methods and perspective of aircraft flotation analysis, the flow rate and trajectory of water spray produced by an aircraft tire, and spin-up studies of the Space Shuttle Orbiter main gear tire.

  11. Epicyclic gear speed change mechanism

    SciTech Connect

    Shimizu, Y.

    1987-02-24

    This patent describes a speed change pulley drive mechanism employing an epicyclic gear train with a ring gear, multiple planet gears and a sun gear, input and output members, and a clutch operable to either directly connect the input and output rotary members or indirectly connect the input and output members through the epicyclic gear train. The improvement described here comprises means supporting the sun gear for preventing rotational movement while permitting only limited radial movement and for relatively uniformly engaging the multiple planet gears.

  12. Computing Stresses In Spur Gears

    NASA Technical Reports Server (NTRS)

    Oswald, F. B.; Lin, H. H.

    1995-01-01

    Dynamic Analysis of Spur Gear Transmissions (DANST) developed as easy-to-use program for static and dynamic analysis of spur-gear systems. Used for parametric studies to predict effects of operating speed, torque, stiffness, damping, inertia, and tooth profile on dynamic loads and tooth-bending stresses in spur gears. Performs geometric modeling and dynamic analysis for low- or high-contact-ratio spur gears. Simulates gear systems with contact ratios ranging from one to three. Written in FORTRAN 77.

  13. 50 CFR 622.188 - Required gear, authorized gear, and unauthorized gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO..., sea bass pot, and spearfishing gear. (c) Unauthorized gear. All gear types other than those specified... unauthorized gear on board may not be transferred at sea, regardless of where such transfer takes place,...

  14. 50 CFR 622.188 - Required gear, authorized gear, and unauthorized gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO..., sea bass pot, and spearfishing gear. (c) Unauthorized gear. All gear types other than those specified... unauthorized gear on board may not be transferred at sea, regardless of where such transfer takes place,...

  15. Planetary gear unit

    SciTech Connect

    Takahashi, S.

    1986-10-07

    This patent describes a planetary gear unit for the transmission of a motor vehicle, comprising: a first planetary gear unit which includes a pinion shaft, a planet pinion rotatably mounted on the pinion shaft, a sun gear engaging the planet pinion, and an arm member supporting the pinion shaft and having an extending portion extending to a point adjacent the sun gear; a thrust washer contacting the arm member, the thrust washer having radiating conduit means formed on a contacting surface thereof so as to communicate an inner circumference of the extending portion of the arm member with the pinion shaft, the pinion shaft having a conduit formed therein so as to communicate with the radiating conduit means with an inner surface of the planet pinion wherein the radiating conduit means further comprises uniform spaced bevel surfaces and grooves in communication with the bevel surfaces.

  16. Communication: Molecular gears.

    PubMed

    Burnell, E Elliott; de Lange, Cornelis A; Meerts, W Leo

    2016-09-01

    The (1)H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear. PMID:27608981

  17. Communication: Molecular gears

    NASA Astrophysics Data System (ADS)

    Burnell, E. Elliott; de Lange, Cornelis A.; Meerts, W. Leo

    2016-09-01

    The 1H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  18. Application of tire dynamics to aircraft landing gear design analysis

    NASA Technical Reports Server (NTRS)

    Black, R. J.

    1983-01-01

    The tire plays a key part in many analyses used for design of aircraft landing gear. Examples include structural design of wheels, landing gear shimmy, brake whirl, chatter and squeal, complex combination of chatter and shimmy on main landing gear (MLG) systems, anti-skid performance, gear walk, and rough terrain loads and performance. Tire parameters needed in the various analyses are discussed. Two tire models are discussed for shimmy analysis, the modified Moreland approach and the von Schlippe-Dietrich approach. It is shown that the Moreland model can be derived from the Von Schlippe-Dietrich model by certain approximations. The remaining analysis areas are discussed in general terms and the tire parameters needed for each are identified. Accurate tire data allows more accurate design analysis and the correct prediction of dynamic performance of aircraft landing gear.

  19. Presto 4.20 user's guide : addendum for shock capabilities.

    SciTech Connect

    Spencer, Benjamin Whiting

    2011-06-01

    This is an addendum to the Presto 4.20 User's Guide to document additional capabilities that are available for use in the Presto{_}ITAR code that are not available for use in the standard version of Presto. Presto{_}ITAR is an enhanced version of Presto that provides capabilities that make it regulated under the U.S. Department of State's International Traffic in Arms Regulations (ITAR) export-control rules. This code is part of the Vivace product, and is only distributed to entities that comply with ITAR regulations. The enhancements primarily focus on material models that include an energy-dependent pressure response, appropriate for very large deformations and strain rates. Since this is an addendum to the standard Presto User's Guide, please refer to that document first for general descriptions of code capability and use. This addendum documents material models and element features that support energy-dependent material models.

  20. Addendum to Environmental Monitoring Plan, Nevada Test Site and Support Facilities; Addendum 2

    SciTech Connect

    1993-11-01

    This 1993 Addendum to the ``Environmental Monitoring Plan Nevada Test Site and Support Facilities -- 1991,`` Report No. DOE/NV/10630-28 (EMP) applies to the US Department of Energy`s (DOE`s) operations on the Continental US (including Amchitka Island, Alaska) that are under the purview of the DOE Nevada Operations Office (DOE/NV). The primary purpose of these operations is the conduct of the nuclear weapons testing program for the DOE and the Department of Defense. Since 1951, these tests have been conducted principally at the Nevada Test Site (NTS), which is located approximately 100 miles northwest of Las Vegas, Nevada. In accordance with DOE Order 5400.1, this 1993 Addendum to the EMP brings together, in one document, updated information and/or new sections to the description of the environmental activities conducted at the NTS by user organizations, operations support contractors, and the US Environmental Protection Agency (EPA) originally published in the EMP. The EPA conducts both the offsite environmental monitoring program around the NTS and post-operational monitoring efforts at non-NTS test locations used between 1961 and 1973 in other parts of the continental US. All of these monitoring activities are conducted under the auspices of the DOE/NV, which has the stated policy of conducting its operations in compliance with both the letter and the spirit of applicable environmental statutes, regulations, and standards.

  1. Multi-mesh gear dynamics program evaluation and enhancements

    NASA Technical Reports Server (NTRS)

    Boyd, L. S.; Pike, J.

    1985-01-01

    A multiple mesh gear dynamics computer program was continually developed and modified during the last four years. The program can handle epicyclic gear systems as well as single mesh systems with internal, buttress, or helical tooth forms. The following modifications were added under the current funding: variable contact friction, planet cage and ring gear rim flexibility options, user friendly options, dynamic side bands, a speed survey option and the combining of the single and multiple mesh options into one general program. The modified program was evaluated by comparing calculated values to published test data and to test data taken on a Hamilton Standard turboprop reduction gear-box. In general, the correlation between the test data and the analytical data is good.

  2. LIME KILN BUILDING, KILN BOTTOM SHOWING ROTATOR GEAR. (GEAR IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LIME KILN BUILDING, KILN BOTTOM SHOWING ROTATOR GEAR. (GEAR IS POINTED DOWN FOR PROPER ORIENTATION). - Solvay Process Company, Lime Kiln Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  3. An investigation of the transient thermal analysis of spur gears

    NASA Technical Reports Server (NTRS)

    El-Bayoumy, L. E.; Akin, L. S.; Townsend, D. P.

    1985-01-01

    A finite element computer program is developed for evaluating the transient behavior of surface temperature in high performance spur gears. The time dimension is implemented using two and three point finite difference schemes. The different schemes are provided for the purpose of numerical stability and convergence studies. A detailed explanation of the gear cooling process leading to the establishment of a modified Blok model is also included. Other conventional models for approximating the heat transfer coefficients are available for comparison. Preliminary results are given showing snap shots of gear temperature contours at the initial stages of tooth engagement.

  4. Dynamic analysis of a gear drive system in aeroengine

    NASA Astrophysics Data System (ADS)

    Yuan, Xiangdong; Zhou, Chuanrong

    1993-04-01

    A new technique of structural dynamic analysis especially for analysis of a gear drive system has been developed, which combines the principle of substructure analysis with the idea of structure modification. A gear stiffness model of the degrees of the freedom of the structure node in which the gear relation exists has also been developed. It has the advantages of both the method of substructure analysis and vibration reanalysis of modified structure. The natural frequencies and modes calculated by the present program are in quite good agreement with the results calculated by FEM.

  5. An investigation of the transient thermal analysis of spur gears

    NASA Technical Reports Server (NTRS)

    El-Bayoumy, L. E.; Akin, L. S.; Townsend, D. P.

    1984-01-01

    A finite element computer program is developed for evaluating the transient behavior of surface temperature in high performance spur gears. The time dimension is implemented using two and three point finite difference schemes. The different schemes are provided for the purpose of numerical stability and convergence studies. A detailed explanation of the gear cooling process leading to the establishment of a modified Blok model is also included. Other conventional models for approximating the heat transfer coefficients are available for comparison. Preliminary results are given showing snap shots of gear temperature contours at the initial stages of tooth engagement.

  6. Gear type transmission apparatus

    SciTech Connect

    Sakamoto, K.; Shirai, E.; Moriyama, K.; Nagamatsu, H.

    1988-11-15

    This patent describes a gear type transmission apparatus comprising, a transmission case containing a gear train arrangement including gear trains and an output shaft to which an output of an engine is transmitted through the gear train arrangement and provided with an opening at an upper portion thereof, a cover member mounted on the upper portion of the transmission case to cover the opening, a holder member formed separately from the cover member and fixed on an under surface of the cover member to be positioned at the inside of a contacting face of the cover member provided for coming into contact with an upper end face of the transmission case, wherein the holder member is provided with a shift rod supporting portion disposed to be at least partially lower than the level of the contacting face of the cover member, and a shift rod supported by the shift rod supporting portion of the holder member to be movable in a direction along its axis at a position above the output shaft for causing the gear trains to be in operation to transmit the output selectively, and at least a part of one of the holder member and the shift rod is positioned to be higher than the lever of the contacting face.

  7. Gear crack propagation investigations

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Ballarini, Roberto

    1996-01-01

    Analytical and experimental studies were performed to investigate the effect of gear rim thickness on crack propagation life. The FRANC (FRacture ANalysis Code) computer program was used to simulate crack propagation. The FRANC program used principles of linear elastic fracture mechanics, finite element modeling, and a unique re-meshing scheme to determine crack tip stress distributions, estimate stress intensity factors, and model crack propagation. Various fatigue crack growth models were used to estimate crack propagation life based on the calculated stress intensity factors. Experimental tests were performed in a gear fatigue rig to validate predicted crack propagation results. Test gears were installed with special crack propagation gages in the tooth fillet region to measure bending fatigue crack growth. Good correlation between predicted and measured crack growth was achieved when the fatigue crack closure concept was introduced into the analysis. As the gear rim thickness decreased, the compressive cyclic stress in the gear tooth fillet region increased. This retarded crack growth and increased the number of crack propagation cycles to failure.

  8. Magnetic Gearing Versus Conventional Gearing in Actuators for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Puchhammer, Gregor

    2014-01-01

    Magnetic geared actuators (MGA) are designed to perform highly reliable, robust and precise motion on satellite platforms or aerospace vehicles. The design allows MGA to be used for various tasks in space applications. In contrast to conventional geared drives, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. This paper describes the fundamentals of magnetic wobbling gears (MWG) and the deduced inherent characteristics, and compares conventional and magnetic gearing.

  9. Kinematic precision of gear trains

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1983-01-01

    Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory. Previously announced in STAR as N82-32733

  10. Kinematic precision of gear trains

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1982-01-01

    Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory.

  11. A superconducting magnetic gear

    NASA Astrophysics Data System (ADS)

    Campbell, A. M.

    2016-05-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844-46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further.

  12. Education in Utah: A Call to Action. Addendum.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    Clarifications to recommendations made in the Utah Education Reform Committee report, "A Call to Action," are presented in this addendum. Earlier recommendations relating to teachers are revised and clarified and new ones relating to class size, teachers' duties, instructional materials, and the student-parent-school relationship are added.…

  13. 10 CFR 1045.41 - Use of classified addendums.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Use of classified addendums. 1045.41 Section 1045.41 Energy DEPARTMENT OF ENERGY (GENERAL PROVISIONS) NUCLEAR CLASSIFICATION AND DECLASSIFICATION Generation and Review of Documents Containing Restricted Data and Formerly Restricted Data § 1045.41 Use...

  14. Theory of gearing

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.

    1989-01-01

    Basic mathematical problems on the theory of gearing are covered in this book, such as the necessary and sufficient conditions of envelope existence, relations between principal curvatures and directions for surfaces of mating gears. Also included are singularities of surfaces accompanied by undercutting the process of generation, the phenomena of envelope of lines of contact, and the principles for generation of conjugate surfaces. Special attention is given to the algorithms for computer aided simulation of meshing and tooth contact. This edition was complemented with the results of research recently performed by the author and his doctoral students. The book contains sample problems and also problems for the reader to solve.

  15. Generation of gear tooth surfaces by application of CNC machines

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Chen, N. X.

    1994-01-01

    This study will demonstrate the importance of application of computer numerically controlled (CNC) machines in generation of gear tooth surfaces with new topology. This topology decreases gear vibration and will extend the gear capacity and service life. A preliminary investigation by a tooth contact analysis (TCA) program has shown that gear tooth surfaces in line contact (for instance, involute helical gears with parallel axes, worm gear drives with cylindrical worms, etc.) are very sensitive to angular errors of misalignment that cause edge contact and an unfavorable shape of transmission errors and vibration. The new topology of gear tooth surfaces is based on the localization of bearing contact, and the synthesis of a predesigned parabolic function of transmission errors that is able to absorb a piecewise linear function of transmission errors caused by gear misalignment. The report will describe the following topics: description of kinematics of CNC machines with six degrees of freedom that can be applied for generation of gear tooth surfaces with new topology. A new method for grinding of gear tooth surfaces by a cone surface or surface of revolution based on application of CNC machines is described. This method provides an optimal approximation of the ground surface to the given one. This method is especially beneficial when undeveloped ruled surfaces are to be ground. Execution of motions of the CNC machine is also described. The solution to this problem can be applied as well for the transfer of machine tool settings from a conventional generator to the CNC machine. The developed theory required the derivation of a modified equation of meshing based on application of the concept of space curves, space curves represented on surfaces, geodesic curvature, surface torsion, etc. Condensed information on these topics of differential geometry is provided as well.

  16. Vibro-acoustic propagation of gear dynamics in a gear-bearing-housing system

    NASA Astrophysics Data System (ADS)

    Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.; Parker, Robert G.

    2014-10-01

    This work developed a computational process to predict noise radiation from gearboxes. It developed a system-level vibro-acoustic model of an actual gearbox, including gears, bearings, shafts, and housing structure, and compared the results to experiments. The meshing action of gear teeth causes vibrations to propagate through shafts and bearings to the housing radiating noise. The vibration excitation from the gear mesh and the system response were predicted using finite element and lumped-parameter models. From these results, the radiated noise was calculated using a boundary element model of the housing. Experimental vibration and noise measurements from the gearbox confirmed the computational predictions. The developed tool was used to investigate the influence of standard rolling element and modified journal bearings on gearbox radiated noise.

  17. Design and fabrication of the NASA decoupler pylon for the F-16 aircraft, addendum 1

    NASA Technical Reports Server (NTRS)

    Clayton, J. D.; Haller, R. L.

    1985-01-01

    The results of the final analyses which were conducted using a revised structural simulation of the Decoupler Pylon are reported in this addendum. The simulation incorporates the previously published results of ground tests performed on the flight Decoupler Pylons mounted in a test fixture at General Dynamic's Fort Worth facility. The analyses show that the Decoupler Pylon will suppress wing-store flutter for the GBU-8 flight test stores configuration on an F-16 airplane. The feasibility of carrying a B-61 on the pylons is also investigated with the conclusion that the pylons would need to be modified in order to demonstrate flutter suppression. The results of a ground vibration test performed on the 1/4 scale F-16 flutter model and a wind tunnel test with this model and a model Decoupler Pylon are given.

  18. Addendum 3 to CSAR 80-027, Use of calorimeter 109B for fissile material measurement

    SciTech Connect

    Chiao, T.

    1994-12-05

    This modification to the Plutonium Finishing Plant (PFP) calorimeter system involves removing current calorimeter No. 3 from the water bath and replacing it with a calorimeter that can accommodate larger diameter items (an oversize can). The inside diameters of both the sample and the reference cells will be increased to 5.835 inches at the top opening and to 5.22 inches at the bottom, the 8 inch high measurement zone. This Addendum 3 to Criticality Safety Analysis Report 80-027 examines criticality safety during the use of the modified calorimeter (Calorimeter 109B) with enlarged cell tube diameters to assure that an adequate margin of subcriticality is maintained for all normal and contingency conditions.

  19. Evaluation of optimum profile modification curves of profile shifted spur gears based on vibration responses

    NASA Astrophysics Data System (ADS)

    Ma, Hui; Pang, Xu; Feng, Ranjiao; Wen, Bangchun

    2016-03-01

    In this paper, a mesh stiffness model is developed for profile shifted gears with addendum modifications and tooth profile modifications (TPMs). The time-varying mesh stiffness (TVMS), load sharing factor (LSF), loaded static transmission error (LSTE) and non-loaded static transmission error (NLSTE) of a profile shifted spur gear pair with TPMs are obtained by the analytical model. The optimum profile modification curve under different amounts of TPM is determined by analyzing the LSTE first. Then, considering the effect of NLSTE, finite element (FE) model of a geared rotor system is established. The system vibration responses under different TPM curves are analyzed and the optimum modification curve is further evaluated by amplitude frequency responses. The results show that the optimum modification curve is related to the amount of TPM and modification coefficients. The comparison of the optimum profile modification curves is evaluated by LSTE and vibration responses, which shows that the optimum modification curve should be determined by evaluating the vibration response of the geared rotor system in the low mesh frequency range.

  20. Bacteria turn tiny gears

    SciTech Connect

    2009-01-01

    Swarms of bacteria turn two 380-micron long gears, opening the possibility of building hybrid biological machines at the microscopic scale. Read more at Wired: http://www.wired.com/wiredscience/2009/12/bacterial-micro-machine/#more-15684 or Scientific American: http://www.scientificamerican.com/article.cfm?id=brownian-motion-bacteria

  1. Consideration of Moving Tooth Load in Gear Crack Propagation Predictions

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Handschuh, Robert F.; Spievak, Lisa E.; Wawrzynek, Paul A.; Ingraffea, Anthony R.

    2001-01-01

    Robust gear designs consider not only crack initiation, but crack propagation trajectories for a fail-safe design. In actual gear operation, the magnitude as well as the position of the force changes as the gear rotates through the mesh. A study to determine the effect of moving gear tooth load on crack propagation predictions was performed. Two-dimensional analysis of an involute spur gear and three-dimensional analysis of a spiral-bevel pinion gear using the finite element method and boundary element method were studied and compared to experiments. A modified theory for predicting gear crack propagation paths based on the criteria of Erdogan and Sih was investigated. Crack simulation based on calculated stress intensity factors and mixed mode crack angle prediction techniques using a simple static analysis in which the tooth load was located at the highest point of single tooth contact was validated. For three-dimensional analysis, however, the analysis was valid only as long as the crack did not approach the contact region on the tooth.

  2. Electronic automatic gear transmission control apparatus

    SciTech Connect

    Koshizawa, T.

    1989-04-25

    This patent describes an electronic automatic gear transmission control apparatus having a shift schedule map for commanding an optimum gear position based on a vehicle speed signal and an accelerator opening signal, the electronic automatic gear transmission control apparatus comprising: first means for comparing a gear position commanded by the shift schedule map with a present gear position; second means for effecting a gear shift to a gear position which is one gear position higher than the present gear position and for restraining a gear shift to the commanded gear position for a prescribed period of time, if the commanded gear position requires an upshift to a gear position which is two or more gear positions higher than the present gear position as a result of the comparison performed by the first means; and third means for holding the gear position which is one gear position higher than the present gear position until an accelerator pedal is depressed again, when the accelerator opening signal indicates an idling position while the gear shift up to the gear position which is one gear position higher than the present gear position, is being effected by the second means.

  3. Addendum to the post-closure permit application for the Bear Creek hydrogeologic regime at the Y-12 plant: Walk-in pits

    SciTech Connect

    1995-04-01

    In June 1987, the Resource Conservation and Recovery Act (RCRA) Closure/Post-Closure Plan for the Bear Creek Burial Grounds (BCBG) located at the Y-12 Plant on the Oak Ridge Reservation in Oak Ridge, Tennessee was submitted to the Tennessee Department of Environment and Conservation (TDEC) for review and approval.The Closure Plan has been modified and revised several times. This document is an addendum to the Post-Closure Permit Application submitted to TDEC in June, 1994. This addendum contains information on the Walk-In Pits of the BCBG which is meant to supplement the information provided in the Post-Closure Permit Application submitted for the BCBG. This document is not intended to be a stand-alone document.

  4. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  5. Computerized Design and Generation of Low-Noise Gears with Localized Bearing Contact

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Chen, Ningxin; Chen, Jui-Sheng; Lu, Jian; Handschuh, Robert F.

    1995-01-01

    The results of research projects directed at the reduction of noise caused by misalignment of the following gear drives: double-circular arc helical gears, modified involute helical gears, face-milled spiral bevel gears, and face-milled formate cut hypoid gears are presented. Misalignment in these types of gear drives causes periodic, almost linear discontinuous functions of transmission errors. The period of such functions is the cycle of meshing when one pair of teeth is changed for the next. Due to the discontinuity of such functions of transmission errors high vibration and noise are inevitable. A predesigned parabolic function of transmission errors that is able to absorb linear discontinuous functions of transmission errors and change the resulting function of transmission errors into a continuous one is proposed. The proposed idea was successfully tested using spiral bevel gears and the noise was reduced a substantial amount in comparison with the existing design. The idea of a predesigned parabolic function is applied for the reduction of noise of helical and hypoid gears. The effectiveness of the proposed approach has been investigated by developed TCA (tooth contact analysis) programs. The bearing contact for the mentioned gears is localized. Conditions that avoid edge contact for the gear drives have been determined. Manufacturing of helical gears with new topology by hobs and grinding worms has been investigated.

  6. The design of worm gear sets

    NASA Technical Reports Server (NTRS)

    Razzaghi, Andrea I.

    1987-01-01

    A method is presented for designing worm gear sets to meet torque multiplication requirements. First, the fundamentals of worm gear design are discussed, covering worm gear set nomenclature, kinematics and proportions, force analysis, and stress analysis. Then, a suggested design method is discussed, explaining how to take a worm gear set application, and specify a complete worm gear set design. The discussions are limited to cylindrical worm gear sets that have a 90 deg shaft angle between the worm and the mating gear.

  7. Generation Method Improves Spiral Bevel Gears

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Tsung, Wei-Jiung; Coy, John J.; Heine, Charles

    1989-01-01

    Conjugate tooth surfaces reduce kinematic errors. Method for generation of spiral bevel gears provides conjugated gear-tooth surfaces and improved bearing contact. Conjugated surfaces preferable because maintain constant gear ratios during tooth-contact cycles. Changing gear ratios of nonconjugated surfaces give rise to kinematical errors in transfer of motion from driving gears to driven gears. Errors major sources of noise in power transmissions. Computer program developed to simulate cutting and meshing processes for pinions and gears to minimize kinematical errors.

  8. Planetary gear train for automatic transmission

    SciTech Connect

    Hiraiwa, K.

    1987-04-28

    A planetary gear train is described for an automatic transmission, the planetary gear train having gear ratios including a first forward gear ratio and a reverse, the planetary gear train comprising: an input shaft; a basic planetary gearing including a first rotary element which is to be held stationary when the first gear ratio is established and also when the reverse is established, and a second rotary element which is to serve as an output member of the basic planetary gearing; an output planetary gear set including a ring gear, a sun gear and a pinion carrier; change speed means for establishing any desired one of the gear ratios; a clutch means for establishing a connection between the other one of the ring gear and the sun gear of the output planetary gear set and the first rotary element of the basic planetary gearing during operation with the first gear ratio and also during operation with the reverse, and a brake means for anchoring the other one of the ring gear and the sun gear of the output planetary gear set during operation with the reverse; and an output shaft connected to the pinion carrier of the output planetary gear set.

  9. 76 FR 80408 - Addendum to the Memorandum of Understanding with the Department of Energy (August 28, 1992); Oak...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

    ... Occupational Safety and Health Administration Addendum to the Memorandum of Understanding with the Department..., Occupational Safety and Health Administration (OSHA). ACTION: Addendum to Memorandum of Understanding between... Occupational Safety and Health Administration (TOSHA). SUMMARY: This document is a notice of an addendum to...

  10. 75 FR 64309 - Components for Evaluation of Direct-Reading Monitors for Gases and Vapors and Addendum

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... Monitors for Gases and Vapors and Addendum AGENCY: National Institute for Occupational Safety and Health... addendum are entitled, respectively, ``Components for Evaluation of Direct-Reading Monitors for Gases and Vapors'' and ``Addendum to Components for Evaluation of Direct-Reading Monitors for Gases and...

  11. Study of Effect of Quenching Deformation Influenced by 17CrNiMo6 Gear Shaft of Carburization

    NASA Astrophysics Data System (ADS)

    Pang, Zirui; Yu, Shenjun; Xu, Jinwu

    The 17CrNiMo6 steel is mainly used for the gear shaft of large modulus in many fields of heavy industry such as mining, transit, hoist, forging and so on[1]. The size of addendum circle and common normal line is changed a lot beyond the tolerance because of the long time of carburizing process and the out-of-step structural stress and thermal stress during the quenching process. And thus the posterior grinding efficiency and quality are influenced. In the paper comparison and analysis of the deformation affected by solid and hollow gear shafts were done and the methods of simulation and practice were both used. The results are as follows: the deformation of gear shaft was small before and after carburizing while that of gear shaft was large before and after quenching because of different cooling velocity, structure and hardness of each position. And the deformation of hollow was much smaller than that of solid. Therefore, if the hollow gear shaft is used, the waste of material will be decreased, and finishing cost will be reduced, and thus the technology of heat treatment will be optimized.

  12. Gear Performance Improved by Coating

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.

    2004-01-01

    Gears, bearings, and other mechanical elements transmit loads through contacting surfaces. Even if properly designed, manufactured, installed, and maintained, gears and bearings will eventually fail because of the fatigue of the working surfaces. Economical means for extending the fatigue lives of gears and bearings are highly desired, and coatings offer the opportunity to engineer surfaces to extend the fatigue lives of mechanical components. A tungsten-containing diamondlike-carbon coating exhibiting high hardness, low friction, and good toughness was evaluated for application to spur gears. Fatigue testing was done at the NASA Glenn Research Center on both uncoated and coated spur gears. The results showed that the coating extended the surface fatigue lives of the gears by a factor of about 5 relative to the uncoated gears. For the experiments, a lot of spur test gears made from AISI 9310 gear steel were case-carburized and ground to aerospace specifications. The geometries of the 28-tooth, 8-pitch gears were verified as meeting American Gear Manufacturing Association (AGMA) quality class 12. One-half of the gears were randomly selected for coating. The method of coating was selected to achieve desired adherence, toughness, hardness, and low-friction characteristics. First the gears to be coated were prepared by blasting (vapor honing) with Al2O3 particles and cleaning. Then, the gears were provided with a thin adhesion layer of elemental chromium followed by magnetron sputtering of the outer coating consisting of carbon (70 at.%), hydrogen (15 at.%), tungsten (12 at.%), and nickel (3 at.%) (atomic percent at the surface). In total, the coating thickness was about 2.5 to 3 microns. As compared with the steel substrate, the coated surface was harder by a factor of about 2 and had a smaller elastic modulus. All gears were tested using a 5-centistoke synthetic oil, a 10,000-rpm rotation speed, and a hertzian contact stress of at least 1.7 GPa (250 ksi). Tests were

  13. Gear Drive Testing

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Philadelphia Gear Corporation used two COSMIC computer programs; one dealing with shrink fit analysis and the other with rotor dynamics problems in computerized design and test work. The programs were used to verify existing in-house programs to insure design accuracy by checking its company-developed computer methods against procedures developed by other organizations. Its specialty is in custom units for unique applications, such as Coast Guard ice breaking ships, steel mill drives, coal crusher, sewage treatment equipment and electricity.

  14. Tool Gear Documentation

    SciTech Connect

    May, J; Gyllenhaal, J

    2002-04-03

    Tool Gear is designed to allow tool developers to insert instrumentation code into target programs using the DPCL library. This code can gather data and send it back to the Client for display or analysis. Tools can use the Tool Gear client without using the DPCL Collector. Any collector using the right protocols can send data to the Client for display and analysis. However, this document will focus on how to gather data with the DPCL Collector. There are three parts to the task of using Tool Gear to gather data through DPCL: (1) Write the instrumentation code that will be loaded and run in the target program. The code should be in the form of one or more functions, which can pass data structures back to the Client by way of DPCL. The collections of functions is compiled into a library, as described in this report. (2) Write the code that tells the DPCL Collector about the instrumentation and how to forward data back to the Client. (3) Extend the client to accept data from the Collector and display it in a useful way. The rest of this report describes how to carry out each of these steps.

  15. 46 CFR 28.885 - Cargo gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire...

  16. 46 CFR 28.885 - Cargo gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire...

  17. 46 CFR 28.885 - Cargo gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire...

  18. 46 CFR 28.885 - Cargo gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear... the load the gear is approved to lift, excluding the weight of the gear itself. (b) All wire...

  19. Pinion tooth surface generation strategy of spiral bevel gears

    NASA Astrophysics Data System (ADS)

    Liu, Guanglei; Fan, Hongwei

    2012-07-01

    Aviation spiral bevel gears are often generated by spiral generated modified (SGM) roll method. In this style, pinion tooth surface modified generation strategy has an important influence on the meshing and contact performances. For the optimal contact pattern and transmission error function, local synthesis is applied to obtain the machine-tool settings of pinion. For digitized machine, four tooth surface generation styles of pinion are proposed. For every style, tooth contact analysis (TCA) is applied to obtain contact pattern and transmission error function. For the difference between TCA transmission error function and design objective curve, the degree of symmetry and agreement are defined and the corresponding sub-objective functions are established. Linear weighted combination method is applied to get an equivalent objective function to evaluate the shape of transmission error function. The computer programs for the process above are developed to analyze the meshing performances of the four pinion tooth surface generation styles for a pair of aviation spiral bevel gears with 38/43 teeth numbers. The four analytical results are compared with each other and show that the incomplete modified roll is optimal for this gear pair. This study is an expansion to generation strategy of spiral bevel gears, and offers new alternatives to computer numerical control (CNC) manufacture of spiral bevel gears.

  20. Improved aircraft dynamic response and fatigue life during ground operations using an active control landing gear system

    NASA Technical Reports Server (NTRS)

    Mcgehee, J. R.; Carden, H. D.; Edson, R.

    1978-01-01

    A three-degree-of-freedom aircraft landing analysis incorporating a series-hydraulic active control main landing gear has been developed and verified using preliminary experimental data from drop tests of a modified main landing gear from a 2722 kg (6000 lbm) class of airplane. The verified analysis was also employed to predict the landing dynamics of a supersonic research airplane with an active control main landing gear system. The results of this investigation have shown that this type of active gear is feasible and indicate a potential for improving airplane dynamic response and reducing structural fatigue damage during ground operations by approximately 90% relative to that incurred with the passive gear.

  1. Some Thoughts on Stability in Nonlinear Periodic Focusing Systems [Addendum

    DOE R&D Accomplishments Database

    McMillan, Edwin M.

    1968-03-29

    Addendum to September 5, 1967 report with the same title and with the abstract: A brief discussion is given of the long-term stability of particle motions through periodic focusing structures containing lumped nonlinear elements. A method is presented whereby one can specify the nonlinear elements in such a way as to generate a variety of structures in which the motion has long-term stability.

  2. Improvements in spiral-bevel gears to reduce noise and increase strength

    NASA Astrophysics Data System (ADS)

    Lewicki, David G.; Handschuh, Robert F.; Henry, Zachary S.; Litvin, Faydor L.

    1994-05-01

    Advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500 hp Helicopter Transmission Test Stand. Four different gear designs were tested. The four designs tested were the current design of the OH-58D transmission, a higher-strength design the same as the current but with an increased fillet radius to reduce gear tooth bending stress, and two versions of a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved.

  3. Low-noise, high-strength, spiral-bevel gears for helicopter transmissions

    NASA Astrophysics Data System (ADS)

    Lewicki, David G.; Handschuh, Robert F.; Henry, Zachary S.; Litvin, Faydor L.

    1994-05-01

    Advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500-hp Helicopter Transmission Test Stand. Three different gear designs tested included: the current design of the OH-58D transmission; a higher-strength design the same as the current but with a full fillet radius to reduce gear tooth bending stress (and thus, weight); and a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved.

  4. Improvements in Spiral-Bevel Gears to Reduce Noise and Increase Strength

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Handschuh, Robert F.; Henry, Zachary S.; Litvin, Faydor L.

    1994-01-01

    Advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500 hp Helicopter Transmission Test Stand. Four different gear designs were tested. The four designs tested were the current design of the OH-58D transmission, a higher-strength design the same as the current but with an increased fillet radius to reduce gear tooth bending stress, and two versions of a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved.

  5. Worm Gear With Hydrostatic Engagement

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev I.

    1994-01-01

    In proposed worm-gear transmission, oil pumped at high pressure through meshes between teeth of gear and worm coil. Pressure in oil separates meshing surfaces slightly, and oil reduces friction between surfaces. Conceived for use in drive train between gas-turbine engine and rotor of helicopter. Useful in other applications in which weight critical. Test apparatus simulates and measures some loading conditions of proposed worm gear with hydrostatic engagement.

  6. Systems engineering functions and requirements for the Hanford cleanup mission: First issue. Addendum 3, Draft

    SciTech Connect

    Holmes, J.J.; Bailey, K.B.; Collings, J.L.; Hubbard, A.B.; Niepke, T.M.

    1994-05-01

    This addendum provides additional information, in the form of Functional Flow Block Diagrams (FFBD), concerning the system engineering functional analysis for the Hanford cleanup mission. Details of the mission analysis including mission statement, scope, problem statement, initial state definition, and final state definition are provided in the parent document. The results of the functional analysis as depicted in Integrated Definition language notation (IDEFO) diagrams are provided in Addendum 2 to the parent document. The FFBDs provided herein cover the total Hanford cleanup mission and depict the decomposition of functions to a reasonable level for understanding (generally level 3 or 4). Functional definitions are contained in Section 3.0 of Addendum 2 to the parent document. Specific programs such as the Tank Waste Remediation System and Environmental Restoration, whose IDEFO diagrams were presented as part of their specific baseline documentation and not included in Addendum 2, have their FFBDs included in this addendum. The information contained in this addendum will remain tied to the overall Hanford cleanup mission through the top-level (``Capstone``) functional analysis so that a complete, top-to-bottom functional documentation set always exists for all mission activities. This linkage is accomplished through the use of the Requirements Driven Design (RDD-100{reg_sign}) design tool. Through the use of RDD-100{reg_sign}, this addendum supports and is traceable to the information presented in Addendum 2 to the parent document.

  7. 77 FR 35699 - Proposed Information Collection; Request for Public Comment: Addendum to Declaration for Federal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-14

    ...: Addendum to Declaration for Federal Employment, Child Care and Indian Child Care Worker Positions AGENCY... Collection: Title: Addendum to Declaration for Federal Employment, Child Care and Indian Child Care Worker..., Child Care and Indian Child Care Worker Positions.'' Although there was a change on the form...

  8. Gears Based on Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Jaffe, Richard; Han, Jie; Globus, Al; Deardorff, Glenn

    2005-01-01

    Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular- scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely to be realizable by practical fabrication processes. The impetus for the practical development of carbon-nanotube- based gears arises, in part, from rapid recent progress in the fabrication of carbon nanotubes with prescribed diameters, lengths, chiralities, and numbers of concentric shells. The shafts of the proposed gears would be made from multiwalled carbon nanotubes. The gear teeth would be rigid molecules (typically, benzyne molecules), bonded to the nanotube shafts at atomically precise positions. For fabrication, it may be possible to position the molecular teeth by use of scanning tunneling microscopy (STM) or other related techniques. The capability to position individual organic molecules at room temperature by use of an STM tip has already been demonstrated. Routes to the chemical synthesis of carbon-nanotube-based gears are also under investigation. Chemical and physical aspects of the synthesis of molecular scale gears based on carbon nanotubes and related molecules, and dynamical properties of nanotube- based gears, have been investigated by computational simulations using established methods of quantum chemistry and molecular dynamics. Several particularly interesting and useful conclusions have been drawn from the dynamical simulations performed thus far: The forces acting on the gears would be more sensitive to local molecular motions than to gross mechanical motions of the overall gears. Although no breakage of teeth or of chemical bonds is expected at temperatures up to at least 3,000 K, the gears would not work well at temperatures above a critical range from about 600 to about 1,000 K. Gear temperature could probably be controlled by

  9. High Pressure Angle Gears: Comparison to Typical Gear Designs

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  10. Double Helical Gear Performance Results in High Speed Gear Trains

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  11. Double Helical Gear Performance Results in High Speed Gear Trains

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2009-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  12. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be.../submersibles. (b) American Samoa coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for coral reef ecosystem MUS in the management area is prohibited. (c) Existing...

  13. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may... vehicles/submersibles. (b) Mariana coral reef ecosystem MUS may not be taken by means of poisons... subpart who is established to be fishing for Mariana coral reef ecosystem MUS in the management area...

  14. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken.../submersibles. (b) Hawaii coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for Hawaii coral reef ecosystem MUS in the Hawaii management area is prohibited....

  15. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken.../submersibles. (b) Hawaii coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for Hawaii coral reef ecosystem MUS in the Hawaii management area is prohibited....

  16. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be.../submersibles. (b) American Samoa coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for coral reef ecosystem MUS in the management area is prohibited. (c) Existing...

  17. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may... vehicles/submersibles. (b) Mariana coral reef ecosystem MUS may not be taken by means of poisons... subpart who is established to be fishing for Mariana coral reef ecosystem MUS in the management area...

  18. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be.../submersibles. (b) American Samoa coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for coral reef ecosystem MUS in the management area is prohibited. (c) Existing...

  19. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken.../submersibles. (b) Hawaii coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for Hawaii coral reef ecosystem MUS in the Hawaii management area is prohibited....

  20. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may... vehicles/submersibles. (b) Mariana coral reef ecosystem MUS may not be taken by means of poisons... subpart who is established to be fishing for Mariana coral reef ecosystem MUS in the management area...

  1. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be.../submersibles. (b) American Samoa coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for coral reef ecosystem MUS in the management area is prohibited. (c) Existing...

  2. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may... vehicles/submersibles. (b) Mariana coral reef ecosystem MUS may not be taken by means of poisons... subpart who is established to be fishing for Mariana coral reef ecosystem MUS in the management area...

  3. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken.../submersibles. (b) Hawaii coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for Hawaii coral reef ecosystem MUS in the Hawaii management area is prohibited....

  4. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be...) Hand net/dip net; (5) Hoop net for Kona crab; (6) Throw net; (7) Barrier net; (8) Surround/purse net....) in the U.S. EEZ waters around Howland Island, Baker Island, Jarvis Island, Wake Island, Kingman...

  5. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be...) Hand net/dip net; (5) Hoop net for Kona crab; (6) Throw net; (7) Barrier net; (8) Surround/purse net....) in the U.S. EEZ waters around Howland Island, Baker Island, Jarvis Island, Wake Island, Kingman...

  6. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be...) Hand net/dip net; (5) Hoop net for Kona crab; (6) Throw net; (7) Barrier net; (8) Surround/purse net....) in the U.S. EEZ waters around Howland Island, Baker Island, Jarvis Island, Wake Island, Kingman...

  7. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be...) Hand net/dip net; (5) Hoop net for Kona crab; (6) Throw net; (7) Barrier net; (8) Surround/purse net....) in the U.S. EEZ waters around Howland Island, Baker Island, Jarvis Island, Wake Island, Kingman...

  8. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may be...) Hand net/dip net; (5) Hoop net for Kona crab; (6) Throw net; (7) Barrier net; (8) Surround/purse net....) in the U.S. EEZ waters around Howland Island, Baker Island, Jarvis Island, Wake Island, Kingman...

  9. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be.../submersibles. (b) American Samoa coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for coral reef ecosystem MUS in the management area is prohibited. (c) Existing...

  10. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may... vehicles/submersibles. (b) Mariana coral reef ecosystem MUS may not be taken by means of poisons... subpart who is established to be fishing for Mariana coral reef ecosystem MUS in the management area...

  11. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken.../submersibles. (b) Hawaii coral reef ecosystem MUS may not be taken by means of poisons, explosives, or... established to be fishing for Hawaii coral reef ecosystem MUS in the Hawaii management area is prohibited....

  12. Precise low cost chain gears for heliostats

    NASA Astrophysics Data System (ADS)

    Liedke, Phillip; Lewandowski, Arkadiusz; Pfahl, Andreas; Hölle, Erwin

    2016-05-01

    This work investigates the potential of chain gears as precise and low cost driving systems for rim drive heliostats. After explaining chain gear basics the polygon effect and chain lengthening are investigated. The polygon effect could be measured by a heliostat with chain rim gear and the chain lengthening with an accordant test set up. Two gear stages are scope of this work: a rim gear and an intermediate gear. Dimensioning, pretensioning and designing for both stages are explained.

  13. Planetary gear train for automatic transmission

    SciTech Connect

    Hiraiwa, K.

    1987-03-31

    A planetary gear train is described comprising: a first planetary gear set having rotary elements including a first sun gear, a first ring gear and a first pinion carrier rotatably supporting a plurality of first pinions meshing with the first sun gear and the first ring gear; a second planetary gear set having rotary elements including a second sun gear, a second ring gear and a second pinion carrier rotatably supporting a plurality of second pinions meshing with the second sun gear and the second ring gear; an input shaft drivingly-connected with the first ring gear; an output shaft; first drive connection establishing means for connecting the second ring gear with the output shaft; the first drive connection establishing means comprising: a third planetary gear set including a third sun gear constantly connected with the second ring gear, a third ring gear, and a third pinion carrier constantly connected with the output shaft. The third pinion carrier rotatably supports third pinions meshing with the third sun and ring gears.

  14. Materials for helicopter gears

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Some of the power train transmission gears in helicopter drive systems can become critical components as performance requirements are increased; accordingly, increasing attention must be paid to new alloys in order to obtain required performance reliability and survivability. Candidate advanced alloys, with improved high temperature properties, while increasing the resistance to scoring and scuffing, tend to have lower ductility and fracture toughness. An attempt is made to identify design materials, and process problems and requirements. In addition, it is recommended that the characterization of candidate steels be accelerated; preliminary investigation indicates that new alloys may provide improved capability against surface distress.

  15. Molecular Dynamics Simulation of a Multi-Walled Carbon Nanotube Based Gear

    NASA Technical Reports Server (NTRS)

    Han, Jie; Globus, Al; Srivastava, Deepak; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    We used molecular dynamics to investigate the properties of a multi-walled carbon nanotube based gear. Previous work computationally suggested that molecular gears fashioned from (14,0) single-walled carbon nanotubes operate well at 50-100 gigahertz. The gears were formed from nanotubes with teeth added via a benzyne reaction known to occur with C60. A modified, parallelized version of Brenner's potential was used to model interatomic forces within each molecule. A Leonard-Jones 6-12 potential was used for forces between molecules. The gear in this study was based on the smallest multi-walled nanotube supported by some experimental evidence. Each gear was a (52,0) nanotube surrounding a (37,10) nanotube with approximate 20.4 and 16,8 A radii respectively. These sizes were chosen to be consistent with inter-tube spacing observed by and were slightly larger than graphite inter-layer spacings. The benzyne teeth were attached via 2+4 cycloaddition to exterior of the (52,0) tube. 2+4 bonds were used rather than the 2+2 bonds observed by Hoke since 2+4 bonds are preferred by naphthalene and quantum calculations by Jaffe suggest that 2+4 bonds are preferred on carbon nanotubes of sufficient diameter. One gear was 'powered' by forcing the atoms near the end of the outside buckytube to rotate to simulate a motor. A second gear was allowed to rotate by keeping the atoms near the end of its outside buckytube on a cylinder. The ends of both gears were constrained to stay in an approximately constant position relative to each other, simulating a casing, to insure that the gear teeth meshed. The stiff meshing aromatic gear teeth transferred angular momentum from the powered gear to the driven gear. The simulation was performed in a vacuum and with a software thermostat. Preliminary results suggest that the powered gear had trouble turning the driven gear without slip. The larger radius and greater mass of these gears relative to the (14,0) gears previously studied requires a

  16. Torque-Splitting Gear Drive

    NASA Technical Reports Server (NTRS)

    Kish, J.

    1991-01-01

    Geared drive train transmits torque from input shaft in equal parts along two paths in parallel, then combines torques in single output shaft. Scheme reduces load on teeth of meshing gears while furnishing redundancy to protect against failures. Such splitting and recombination of torques common in design of turbine engines.

  17. Reliability model for planetary gear

    NASA Technical Reports Server (NTRS)

    Savage, M.; Paridon, C. A.; Coy, J. J.

    1982-01-01

    A reliability model is presented for planetary gear trains in which the ring gear is fixed, the Sun gear is the input, and the planet arm is the output. The input and output shafts are coaxial and the input and output torques are assumed to be coaxial with these shafts. Thrust and side loading are neglected. This type of gear train is commonly used in main rotor transmissions for helicopters and in other applications which require high reductions in speed. The reliability model is based on the Weibull distribution of the individual reliabilities of the transmission components. The transmission's basic dynamic capacity is defined as the input torque which may be applied for one million input rotations of the Sun gear. Load and life are related by a power law. The load life exponent and basic dynamic capacity are developed as functions of the component capacities.

  18. Thermal deformation of helical gears

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Fei, Ye-tai; Liu, Shan-lin

    2010-08-01

    The analytical equation for the thermal field of a helical gear under normal working condition in a stable thermal field is established using mathematical physics, and the thermal deformation of the gear can be computed using this equation. The variations of gear geometric parameters, such as radial dimension, tooth depth, spiral angle, pressure angle, flank clearance and etc., are investigated with respect to the temperature change. According to the analytical and computational results obtained using the equation, the thermal deformation of the gear is strongly dependent on the choice of parameters, which is also confirmed using simulation software (COMSOL Multiphysic software). This is significant for the improvement of the rotation precision and working efficiency of screw gears.

  19. Improved Gear Shapes for Face Worm Gear Drives

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Nava, Alessandro; Fan, Qi; Fuentes, Alfonso

    2005-01-01

    Shapes different from the traditional ones have been proposed for face worm gears and for conical and cylindrical worms that mesh with them. The proposed shapes are based on the concept of generating a face worm gear surface by use of a tilted head cutter instead of by the traditional use of a hob. (As used here, head cutter is also meant to signify, alternatively, a head grinding tool.) The gear-surface-generation equipment would be similar to that used for generation of spiral bevel and hypoid gears. In comparison with the corresponding traditional hob, a tilted head cutter according to the proposal would be larger, could be fabricated with greater precision, and would enable the generation of gear surfaces with greater precision and greater productivity. A face worm gear would be generated (see figure) by use of a tilted head cutter, the blades or grinding surfaces of which would have straight-line profiles. The tilt of the head cutter would prevent interference with teeth adjacent to the groove being cut or ground. A worm to mesh with the face worm gear would be generated by use of a tilted head cutter mounted on the cradle of a generating machine. The blades or grinding surfaces of the head cutter would have a parabolic profile and would deviate from the straight-line profiles of the head cutter for the face worm gear. The shortest distance between the worm and the cradle would follow a parabolic function during the cycle of meshing in the generating process to provide a parabolic function of transmission errors to the gear drive. The small mismatch between the profiles of the face-worm-gear and worm head cutters would make it possible to localize the bearing contact in the worm gear drive. The parabolic function of transmission errors could absorb discontinuous linear functions of transmission errors caused by errors of alignment; this could afford a significant benefit, in that such errors are main sources of noise and vibration in gear drives. The main

  20. Local Synthesis and Tooth Contact Analysis of Face-Milled Spiral Bevel Gears

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Zhang, Yi

    1991-01-01

    Computerized simulation of meshing and bearing contact for spiral bevel gears and hypoid gears is a significant achievement that could substantially improve the technology and the quality of the gears. An approach to the synthesis of face-milled spiral bevel gears and their tooth contact analysis is presented. The proposed approach is based on the following ideas: application of the principle of local synthesis that provides optimal conditions of meshing and contact at the mean contact point, M, and in the neighborhood of M; and application of relations between principle directions and curvatures for surfaces being in line contact or in point contact. The developed local synthesis of gears provides the following: (1) the required gear ratio at M; (2) a localized bearing contact with the desired direction of the tangent to the contact path on gear tooth surface and the desired length of the major axis of contact ellipse at M; (3) a predesigned parabolic function of a controlled level for transmission errors which enables absorption of linear functions of transmission errors caused by misalignment and reduces the level of vibrations. The proposed approach does not require either the tilt of the head-cutter for the process of generation or modified roll for the pinion generation. Improved conditions of meshing and contact of the gears can be achieved without the above mentioned parameters. A computer program for determination of basic machine-tool settings and tooth contact analysis for the designed gears is presented. The approach is illustrated with a numerical example.

  1. Generation of noncircular gears for variable motion of the crank-slider mechanism

    NASA Astrophysics Data System (ADS)

    Niculescu, M.; Andrei, L.; Cristescu, A.

    2016-08-01

    The paper proposes a modified kinematics for the crank-slider mechanism of a nails machine. The variable rotational motion of the driven gear allows to slow down the velocity of the slider in the head forming phase and increases the period for the forming forces to be applied, improving the quality of the final product. The noncircular gears are designed based on a hybrid function for the gear transmission ratio whose parameters enable multiple variations of the noncircular driven gears and crack-slider mechanism kinematics, respectively. The AutoCAD graphical and programming facilities are used (i) to analyse and optimize the slider-crank mechanism output functions, in correlation with the predefined noncircular gears transmission ratio, (ii) to generate the noncircular centrodes using the kinematics hypothesis, (iii) to generate the variable geometry of the gear teeth profiles, based on the rolling method, and (iv) to produce the gears solid virtual models. The study highlights the benefits/limits that the noncircular gears transmission ratio defining hybrid functions have on both crank-slider mechanism kinematics and gears geometry.

  2. Gear shift controller for automatic transmission

    SciTech Connect

    Nishikawa, M.; Sakai, S.; Sakurai, T.

    1987-01-20

    A gear shift controller is described for an automatic transmission having a gear shift, comprising: a hydraulic torque converter; a gear change group, having a plurality of gears, each gear providing a different transmission ratio for the transmission of power from the hydraulic torque converter to the output of the transmission, each of the gears comprising a gear train; a one-way clutch interposed in at least one of the gear trains; a plurality of clutch means operatively connected with the gear trains for actuating each of the gear trains selectively; a gear change determination circuit operatively connected with the clutch means to control the operation of each of the clutch means according to a predetermined gear shifting program for engaging a gear train selected by the program; a coasting detection circuit for detecting a car in the coasting state; a gear shift limiting circuit, operatively connected with the gear change determination circuit and with the coasting detection circuit. The circuit is for actuating only the gear train in which the one-way clutch is interposed immediately, regardless of the selected gear train and of the operation of the gear change determination circuit, when the coasting detection circuit has determined the car to be coasting; and an operation transfer control system including a brake operation detecting means and a mode selector switch means for transferring the operation of the gear shift limiting circuit. The operation transfer control system is adapted to stop, upon detection of one of the brake operation and a reset state of the mode selector switch, the operation of the gear shift limiting circuit and to place the plurality of clutch means under the control of the gear change determination circuit.

  3. 50 CFR 648.84 - Gear-marking requirements and gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear-marking requirements and gear... Management Measures for the NE Multispecies and Monkfish Fisheries § 648.84 Gear-marking requirements and gear restrictions. (a) Bottom-tending fixed gear, including, but not limited to, gillnets and...

  4. Automated Inspection And Precise Grinding Of Gears

    NASA Technical Reports Server (NTRS)

    Frint, Harold; Glasow, Warren

    1995-01-01

    Method of precise grinding of spiral bevel gears involves automated inspection of gear-tooth surfaces followed by adjustments of machine-tool settings to minimize differences between actual and nominal surfaces. Similar to method described in "Computerized Inspection of Gear-Tooth Surfaces" (LEW-15736). Yields gears of higher quality, with significant reduction in manufacturing and inspection time.

  5. Functioning of reduction gears on airplane engines

    NASA Technical Reports Server (NTRS)

    Matteucci, Raffaelli

    1926-01-01

    In undertaking to analyze the functioning conditions of a reduction gear on an aviation engine, we will consider an ordinary twelve-cylinder V-engine. The reduction gear employed consists either of a pair of spur gears, one of which is integral with the engine shaft and the other with the propeller shaft, or of a planetary system of gears.

  6. 29 CFR 1918.54 - Rigging gear.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  7. 29 CFR 1918.54 - Rigging gear.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  8. 29 CFR 1918.54 - Rigging gear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  9. 29 CFR 1918.54 - Rigging gear.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  10. 29 CFR 1918.54 - Rigging gear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  11. Computerized Inspection Of Gear-Tooth Surfaces

    NASA Technical Reports Server (NTRS)

    Handschuh, R. F.; Litvin, F. L.; Zhang, Y.; Kuan, C.

    1994-01-01

    Method of manufacturing gears with precisely shaped teeth involves computerized inspection of gear-tooth surfaces followed by adjustments of machine-tool settings to minimize deviations between real and theoretical versions of surfaces. Thus, iterated cycles of cutting gear teeth, inspection, and adjustments help increase and/or maintain precision of subsequently manufactured gears.

  12. Communication Platform Payload Definition (CPPD) study. Volume 3: Addendum

    NASA Technical Reports Server (NTRS)

    Hunter, E. M.; Driggers, T.; Jorasch, R.

    1986-01-01

    This is Volume 3 (Addendum) of the Ford Aerospace & Communications Corporation Final Report for the Communication Platform Payload Definition (CPPD) Study Program conducted for NASA Lewis Research Center under contract No. NAS3-24235. This report presents the results of the study effort leading to five potential platform payloads to service CONUS and WARC Region 2 traffic demand as projected to the year 2008. The report addresses establishing the data bases, developing service aggregation scenarios, selecting and developing 5 payload concepts, performing detailed definition of the 5 payloads, costing them, identifying critical technology, and finally comparing the payloads with each other and also with non-aggregated equivalent services.

  13. Gearing up chromatin

    PubMed Central

    Mandemaker, Imke K; Vermeulen, Wim; Marteijn, Jurgen A

    2014-01-01

    During transcription, RNA polymerase may encounter DNA lesions, which causes stalling of transcription. To overcome the RNA polymerase blocking lesions, the transcribed strand is repaired by a dedicated repair mechanism, called transcription coupled nucleotide excision repair (TC-NER). After repair is completed, it is essential that transcription restarts. So far, the regulation and exact molecular mechanism of this transcriptional restart upon genotoxic damage has remained elusive. Recently, three different chromatin remodeling factors, HIRA, FACT, and Dot1L, were identified to stimulate transcription restart after DNA damage. These factors either incorporate new histones or establish specific chromatin marks that will gear up the chromatin to subsequently promote transcription recovery. This adds a new layer to the current model of chromatin remodeling necessary for repair and indicates that this specific form of transcription, i.e., the transcriptional restart upon DNA damage, needs specific chromatin remodeling events. PMID:24809693

  14. Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Zakrajsek, James J.

    2001-01-01

    NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

  15. Bearing, gearing, and lubrication technology

    NASA Technical Reports Server (NTRS)

    Anderson, W. J.

    1978-01-01

    Results of selected NASA research programs on rolling-element and fluid-film bearings, gears, and elastohydrodynamic lubrication are reported. Advances in rolling-element bearing material technology, which have resulted in a significant improvement in fatigue life, and which make possible new applications for rolling bearings, are discussed. Research on whirl-resistant, fluid-film bearings, suitable for very high-speed applications, is discussed. An improved method for predicting gear pitting life is reported. An improved formula for calculating the thickness of elastohydrodynamic films (the existence of which help to define the operating regime of concentrated contact mechanisms such as bearings, gears, and cams) is described.

  16. Development in Geared Turbofan Aeroengine

    NASA Astrophysics Data System (ADS)

    Mohd Tobi, A. L.; Ismail, A. E.

    2016-05-01

    This paper looks into the implementation of epicyclic gear system to the aeroengine in order to increase the efficiency of the engine. The improvement made is in the direction of improving fuel consumption, reduction in pollutant gasses and perceived noise. Introduction of epicyclic gear system is capable to achieve bypass ratio of up to 15:1 with the benefits of weight and noise reduction. Radical new aircraft designs and engine installation are being studied to overcome some of the challenges associated with the future geared turbofan and open-rotor engine.

  17. Numerical Simulation Of Cutting Of Gear Teeth

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Huston, Ronald L.; Mavriplis, Dimitrios

    1994-01-01

    Shapes of gear teeth produced by gear cutters of specified shape simulated computationally, according to approach based on principles of differential geometry. Results of computer simulation displayed as computer graphics and/or used in analyses of design, manufacturing, and performance of gears. Applicable to both standard and non-standard gear-tooth forms. Accelerates and facilitates analysis of alternative designs of gears and cutters. Simulation extended to study generation of surfaces other than gears. Applied to cams, bearings, and surfaces of arbitrary rolling elements as well as to gears. Possible to develop analogous procedures for simulating manufacture of skin surfaces like automobile fenders, airfoils, and ship hulls.

  18. Parallel axes gear set optimization in two-parameter space

    NASA Astrophysics Data System (ADS)

    Theberge, Y.; Cardou, A.; Cloutier, L.

    1991-05-01

    This paper presents a method for optimal spur and helical gear transmission design that may be used in a computer aided design (CAD) approach. The design objective is generally taken as obtaining the most compact set for a given power input and gear ratio. A mixed design procedure is employed which relies both on heuristic considerations and computer capabilities. Strength and kinematic constraints are considered in order to define the domain of feasible designs. Constraints allowed include: pinion tooth bending strength, gear tooth bending strength, surface stress (resistance to pitting), scoring resistance, pinion involute interference, gear involute interference, minimum pinion tooth thickness, minimum gear tooth thickness, and profile or transverse contact ratio. A computer program was developed which allows the user to input the problem parameters, to select the calculation procedure, to see constraint curves in graphic display, to have an objective function level curve drawn through the design space, to point at a feasible design point and to have constraint values calculated at that point. The user can also modify some of the parameters during the design process.

  19. Concrete samples for organic samples, data package and 222-S validation summary report. Addendum 1A

    SciTech Connect

    Vogel, R.E.

    1994-11-01

    This document is in two parts: the first is the data package entitled ``Concrete Samples for Organic Samples`` and the second is entitled ``Concrete Samples for Organic Samples -- Addendum 1A`` which is the 222-S validation summary report.

  20. 76 FR 65512 - Record of Decision Addendum for the Department of Homeland Security Headquarters Consolidation at...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-21

    ... From the Federal Register Online via the Government Publishing Office GENERAL SERVICES ADMINISTRATION Record of Decision Addendum for the Department of Homeland Security Headquarters Consolidation at St. Elizabeths in Southeast, Washington, DC AGENCY: National Capital Region, U.S. General...

  1. Comprehension monitoring program, groundwater, technical plan, version 3.3 (addendum). Final technical report

    SciTech Connect

    1990-09-01

    This addendum details modifications proposed for the CMP groundwater monitoring program. These modifications are based on previous CMP monitoring experience and are directed toward optimizing network efficiencies and maximizing data utility.

  2. 77 FR 7131 - Addendum to Environmental Technologies Trade Advisory Committee Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    ... International Trade Administration Addendum to Environmental Technologies Trade Advisory Committee Public... Environmental Technologies Trade Advisory Committee (ETTAC) will be changed to include additional topics. DATES... administration of programs to expand U.S. exports of environmental technologies, goods, services, and...

  3. SAFETY ANALYSIS REPORT FOR PACKAGING, MODEL 9977, ADDENDUM 3, JUSTIFICATION FOR SMALL GRAM QUANTITY CONTENTS

    SciTech Connect

    Abramczyk, G.

    2011-10-31

    This Addendum establishes a new family of content envelopes consisting of small quantities of radioactive materials. These content envelopes and specific packing configurations are shown to be subcritical. However, the dose rates of some payloads must be measured and shown to comply with applicable radiation limits. Authorization for shipment of the content envelop requires acceptance of this Addendum by the DOE-HQ certifying official as a supplement to the 9977 SARP Revision 2 and DOE-HQ's subsequent revision of the CoC Revision 10 (which is based on SARP Addendum 2 and SARP Addendum 4) to authorize the additional content envelope. The Small Gram Quantity Content Envelopes and packing configurations will be incorporated in the next revision of the 9977 SARP.

  4. Facility design criteria AN/GSC-39(V) 1 Earth terminal complex fixed site configuration. Addendum 1. HEMP considerations

    NASA Astrophysics Data System (ADS)

    Clark, S. A., Jr.; Chase, R. J.; Penar, J. D.

    1981-03-01

    This addendum provides high altitude electromagnetic pulse (HEMP) hardening design criteria for the AN/GSC-39 Earth Terminal Complex fixed site facilities. In addition to other criteria, this addendum is to be used for preparing construction plans and specifications for the Earth terminal complex. These HEMP criteria are based on two reports for HEMP hardening of the AN/FSC-78 Satellite Communications Terminal. The hardening measures developed in this Addendum will enhance protection for the digital communications subsystem.

  5. Addendum to Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site

    SciTech Connect

    Bergeron, Marcel P.; Freeman, Eugene J.; Wurstner, Signe K.; Kincaid, Charles T.; Coony, Mike M.; Strenge, Dennis L.; Aaberg, Rosanne L.; Eslinger, Paul W.

    2001-09-28

    This report summarizes efforts to complete an addendum analysis to the first iteration of the Composite Analysis for Low-Level Waste Disposal in the 200 Area Plateau of the Hanford Site (Composite Analysis). This document describes the background and performance objectives of the Composite Analysis and this addendum analysis. The methods used, results, and conclusions for this Addendum analysis are summarized, and recommendations are made for work to be undertaken in anticipation of a second analysis.

  6. Gear shift control mechanism

    SciTech Connect

    Janson, D.A.

    1987-03-10

    A gear shift control mechanism is described comprising: multiple shift rods directed substantially parallel to one another, each rod carrying a shift fork for axial movement; a shift lever supported for pivotal movement about a first axis directed parallel to the axes of the shift rods and for pivotal movement about a second axis directed substantially perpendicular to the axes of the shift rods. The lever is moveable about the first axis and the second axis into engagement with a selected shift fork; interlock means located on each lateral side of the shift lever and mounted for pivotal movement about the first axis for blocking engagement with the shift forks; detent means for holding the shift lever in multiple predetermined angular positions about the second axis; and spring means located on a lateral side of the shift lever and mounted for pivotal movement about the first axis into interference contact with the shift forks for producing a force tending to resiliently bias the shift lever out of engagement with the selected shift fork.

  7. Molecular gearing systems

    DOE PAGES

    Gakh, Andrei A.; Sachleben, Richard A.; Bryan, Jeff C.

    1997-11-01

    The race to create smaller devices is fueling much of the research in electronics. The competition has intensified with the advent of microelectromechanical systems (MEMS), in which miniaturization is already reaching the dimensional limits imposed by physics of current lithographic techniques. Also, in the realm of biochemistry, evidence is accumulating that certain enzyme complexes are capable of very sophisticated modes of motion. Complex synergistic biochemical complexes driven by sophisticated biomechanical processes are quite common. Their biochemical functions are based on the interplay of mechanical and chemical processes, including allosteric effects. In addition, the complexity of this interplay far exceeds thatmore » of typical chemical reactions. Understanding the behavior of artificial molecular devices as well as complex natural molecular biomechanical systems is difficult. Fortunately, the problem can be successfully resolved by direct molecular engineering of simple molecular systems that can mimic desired mechanical or electronic devices. These molecular systems are called technomimetics (the name is derived, by analogy, from biomimetics). Several classes of molecular systems that can mimic mechanical, electronic, or other features of macroscopic devices have been successfully synthesized by conventional chemical methods during the past two decades. In this article we discuss only one class of such model devices: molecular gearing systems.« less

  8. Molecular gearing systems

    SciTech Connect

    Gakh, Andrei A.; Sachleben, Richard A.; Bryan, Jeff C.

    1997-11-01

    The race to create smaller devices is fueling much of the research in electronics. The competition has intensified with the advent of microelectromechanical systems (MEMS), in which miniaturization is already reaching the dimensional limits imposed by physics of current lithographic techniques. Also, in the realm of biochemistry, evidence is accumulating that certain enzyme complexes are capable of very sophisticated modes of motion. Complex synergistic biochemical complexes driven by sophisticated biomechanical processes are quite common. Their biochemical functions are based on the interplay of mechanical and chemical processes, including allosteric effects. In addition, the complexity of this interplay far exceeds that of typical chemical reactions. Understanding the behavior of artificial molecular devices as well as complex natural molecular biomechanical systems is difficult. Fortunately, the problem can be successfully resolved by direct molecular engineering of simple molecular systems that can mimic desired mechanical or electronic devices. These molecular systems are called technomimetics (the name is derived, by analogy, from biomimetics). Several classes of molecular systems that can mimic mechanical, electronic, or other features of macroscopic devices have been successfully synthesized by conventional chemical methods during the past two decades. In this article we discuss only one class of such model devices: molecular gearing systems.

  9. Summary of NASA landing-gear research

    NASA Technical Reports Server (NTRS)

    Fisher, B. D.; Sleeper, R. K.; Stubbs, S. M.

    1978-01-01

    This paper presents a brief summary of the airplane landing gear research underway at NASA. The technology areas include: ground handling simulator, antiskid braking systems, space shuttle nose-gear shimmy, active control landing gear, wire brush skid landing gear, air cushion landing systems, tire/surface friction characteristics, tire mechanical properties, tire-tread materials, powered wheels for taxiing, and crosswind landing gear. This paper deals mainly with the programs on tire-tread materials, powered wheel taxiing, air cushion landing systems, and crosswind landing gear research with particular emphasis on previously unreported results of recently completed flight tests. Work in the remaining areas is only mentioned.

  10. Advanced Face Gear Surface Durability Evaluations

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  11. Analysis and modification of a single-mesh gear fatigue rig for use in diagnostic studies

    NASA Astrophysics Data System (ADS)

    Zakrajsek, James J.; Townsend, Dennis P.; Oswald, Fred B.; Decker, Harry J.

    1992-05-01

    A single-mesh gear fatigue rig was analyzed and modified for use in gear mesh diagnostic research. The fatigue rig allowed unwanted vibration to mask the test-gear vibration signal, making it difficult to perform diagnostic studies. Several possible sources and factors contributing to the unwanted components of the vibration signal were investigated. Sensor mounting location was found to have a major effect on the content of the vibration signal. In the presence of unwanted vibration sources, modal amplification made unwanted components strong. A sensor location was found that provided a flatter frequency response. This resulted in a more useful vibration signal. A major network was performed on the fatigue rig to reduce the influence of the most probable sources of the noise in the vibration signal. The slave gears were machined to reduce weight and increase tooth loading. The housing and the shafts were modified to reduce imbalance, looseness, and misalignment in the rotating components. These changes resulted in an improved vibration signal, with the test-gear mesh frequency now the dominant component in the signal. Also, with the unwanted sources eliminated, the sensor mounting location giving the most robust representation of the test-gear meshing energy was found to be at a point close to the test gears in the load zone of the bearings.

  12. Analysis and modification of a single-mesh gear fatigue rig for use in diagnostic studies

    NASA Technical Reports Server (NTRS)

    Zakrajsek, James J.; Townsend, Dennis P.; Oswald, Fred B.; Decker, Harry J.

    1992-01-01

    A single-mesh gear fatigue rig was analyzed and modified for use in gear mesh diagnostic research. The fatigue rig allowed unwanted vibration to mask the test-gear vibration signal, making it difficult to perform diagnostic studies. Several possible sources and factors contributing to the unwanted components of the vibration signal were investigated. Sensor mounting location was found to have a major effect on the content of the vibration signal. In the presence of unwanted vibration sources, modal amplification made unwanted components strong. A sensor location was found that provided a flatter frequency response. This resulted in a more useful vibration signal. A major network was performed on the fatigue rig to reduce the influence of the most probable sources of the noise in the vibration signal. The slave gears were machined to reduce weight and increase tooth loading. The housing and the shafts were modified to reduce imbalance, looseness, and misalignment in the rotating components. These changes resulted in an improved vibration signal, with the test-gear mesh frequency now the dominant component in the signal. Also, with the unwanted sources eliminated, the sensor mounting location giving the most robust representation of the test-gear meshing energy was found to be at a point close to the test gears in the load zone of the bearings.

  13. 32. DETAIL VIEW OF PIVOT SPAN TURNTABLE, SHOWING MORTISE GEAR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. DETAIL VIEW OF PIVOT SPAN TURNTABLE, SHOWING MORTISE GEAR, GEAR SHAFT, DRIVE GEAR AND BULL GEAR, LOOKING SOUTHEAST - Alton Bridge, Spanning Mississippi River between IL & MO, Alton, Madison County, IL

  14. Addendum to the Closure Report for Corrective Action Unit 403: Second Gas Station, Tonopah Test Range, Nevada, Revision 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Closure Report for Corrective Action Unit 403: Second Gas Station, Tonopah Test Range, Nevada, September 1998 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 03-02-004-0360, Underground Storage Tanks. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR

  15. Addendum to the Closure Report for Corrective Action Unit 398: Area 25 Spill Sites, Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Lynn Kidman

    2008-10-01

    This document constitutes an addendum to the April 2003, Closure Report for Corrective Action Unit 398: Area 25 Spill Sites as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 25-25-17, Subsurface Hydraulic Oil Spill. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above

  16. Addendum to the Closure Report for Corrective Action Unit 214: Bunkers and Storage Areas Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Lynn Kidman

    2008-10-01

    This document constitutes an addendum to the September 2006, Closure Report for Corrective Action Unit 214: Bunkers and Storage Areas as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the URs for: • CAS 25-23-01, Contaminated Materials • CAS 25-23-19, Radioactive Material Storage These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove

  17. Investigation into nitrided spur gears

    SciTech Connect

    Yilbas, B.S.; Coban, A.; Nickel, J.; Sunar, M.; Sami, M.; Abdul Aleem, B.J.

    1996-12-01

    The cold forging method has been widely used in industry to produce machine parts. In general, gears are produced by shaping or hobbing. One of the shaping techniques is precision forging, which has several advantages over hobbing. In the present study, cold forging of spur gears from Ti-6Al-4V material is introduced. To improve the surface properties of the resulting gears, plasma nitriding was carried out. Nuclear reaction analysis was carried out to obtain the nitrogen concentration, while the micro-PIXE technique was used to determine the elemental distribution in the matrix after forging and nitriding processes. Scanning electron microscopy and x-ray powder diffraction were used to investigate the metallurgical changes and formation of nitride components in the surface region. Microhardness and friction tests were carried out to measure the hardness depth profile and friction coefficient at the surface. Finally, scoring failure tests were conducted to determine the rotational speed at which the gears failed. Three distinct regions were obtained in the nitride region, and at the initial stages of the scoring tests, failure in surface roughness was observed in the vicinity of the tip of the gear tooth. This occurred at a particular rotational speed and work input.

  18. Planetary gear train of automatic transmission

    SciTech Connect

    Hiraiwa, K.

    1987-03-31

    A planetary gear train is described for an automatic transmission having input and output shafts, comprising: a first planetary gear unit including a first sun gear, a first internal gear and a first pinion carrier; a second planetary gear unit including a second sun gear, a second internal gear and a second pinion carrier, the first internal gear and the second pinion carrier being constantly connected to the output shaft; a first brake unit capable of braking the first and second sun gears which are connected to each other to rotate together; a clutch through which the first pinion carrier is connectable to the input shaft; a second brake unit capable of braking the first pinion carrier; a third brake unit capable of braking the second internal gear; and first and second groups of one-way means which are parallelly interposed between the input shaft and the first sun gear and arranged in a mutually reversed relationship so that the power transmission from the input shaft to the first sun gear and that from the first sun gear to the input shaft are respectively carried out by the first and second groups of one-way means.

  19. Transmission with two parallel driving shafts bearing two driving gears each meshed with same driven gear on parallel driven shaft

    SciTech Connect

    Akashi, T.; Ito, H.; Yamada, S.

    1986-06-17

    A transmission mechanism for a vehicle is described for receiving input of rotational power from a power supply member which rotates in a particular rotational direction and for outputting rotational power to a power receiving member which includes: an input member connected to the power supply member and which is rotatably mounted and receives supplying of the rotational power from the power supply member; a first driving gear wheel shaft; a second driving gear wheel shaft mounted generally parallel to the first driving gear wheel shaft; a driven gear wheel shaft mounted generally parallel to the first and second driving gear wheel shafts, the driven gear wheel shaft being rotationally connected to the power receiving member; a first driven gear wheel fixedly mounted on the driven gear wheel shaft; a first driving gear wheel which is rotatably mounted on the first driving gear wheel shaft and is constant mesh with the driven gear wheel, the first driving and driven gear wheels providing a first reduction gear ratio from the first driving gear wheel shaft to the driven gear wheel shaft; a second driven gear wheel fixedly mounted on the driven gear wheel shaft; a second driving gear wheel which is rotatably mounted on the second driving gear wheel shaft and is in constant mesh with the first driven gear wheel, the second driving and the first driven gear wheels providing a second reduction gear ratio smaller than the first reduction gear ratio from the second driving gear wheel shaft to the driven gear wheel shaft; a third driving gear wheel which is rotatably mounted on the first driving gear wheel shaft and is in constant mesh with the second driven gear wheel, the third driving and the second driven gear wheels providing a third reduction gear ratio smaller than the second reduction gear ratio from the first driving gear wheel shaft to the driven gear wheel shaft.

  20. Analytical evaluation of resonant response of spiral bevel gears in the RAH-66 helicopter Fantail transmission

    NASA Astrophysics Data System (ADS)

    Drago, R. J.; Brown, F. W.

    1992-07-01

    Consideration is given to an analytical approach to the dual problems of defining the occurrence of a potentially damaging resonance and modifying the design of a gear to avoid the resonance. Resonant frequencies were determined for the RAH-66 Fantail gears. A dynamic response level was predicted on the basis of frequency response analyses. The method and criteria utilized indicate acceptable performance without incorporation of axillary damping provisions.

  1. Swimming bacteria power microscopic gears.

    SciTech Connect

    Sokolov, A.; Apodaca, M. M.; Grzybowski, B. A.; Aranson, I. S.; Materials Science Division; Princeton Univ.; Northwestern Univ.

    2010-01-19

    Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be 'rectified' under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

  2. School Counseling Programs: Comparing GEAR UP Schools with Non-GEAR UP Schools

    ERIC Educational Resources Information Center

    Thorngren, Jill M.; Nelson, Mark D.; Baker, Larry J.

    2004-01-01

    A survey was conducted using qualitative means to assess school counseling programs in Montana. Schools that were demonstration schools in a federal initiative, Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) were compared to non-GEAR UP schools. Several differences between GEAR UP and non-GEAR UP schools are noted and…

  3. Development of a gear vibration indicator and its application in gear wear monitoring

    NASA Astrophysics Data System (ADS)

    Hu, Chongqing; Smith, Wade A.; Randall, Robert B.; Peng, Zhongxiao

    2016-08-01

    Gear tooth wear is an inevitable phenomenon and has a significant influence on gear dynamic features. Although vibration analysis has been widely used to diagnose localised gear tooth faults, its techniques for gear wear monitoring have not been well-established. This paper aims at developing a vibration indicator to evaluate the effects of wear on gear performance. For this purpose, a gear state vector is extracted from time synchronous averaged gear signals to describe the gear state. This gear state vector consists of the sideband ratios obtained from a number of tooth meshing harmonics and their sidebands. Then, two averaged logarithmic ratios, ALR and mALR, are defined with fixed and moving references, respectively, to provide complementary information for gear wear monitoring. Since a fixed reference is utilised in the definition of ALR, it reflects the cumulated wear effects on the gear state. An increase in the ALR value indicates that the gear state deviates further from its reference condition. With the use of a moving reference, the indicator mALR shows changes in the gear state within short time intervals, making it suitable for wear process monitoring. The efficiency of these vibration indicators is demonstrated using experimental results from two sets of tests, in which the gears experienced different wear processes. In addition to gear wear monitoring, the proposed indicators can be used as general parameters to detect the occurrence of other faults, such as a tooth crack or shaft misalignment, because these faults would also change the gear vibrations.

  4. Sequencing device utilizing planetary gear set

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T. (Inventor)

    1979-01-01

    A planetary (epicyclic) gear set is provided with a reversible rotating input shaft and individual outputs shafts actuated, respectively, by the ring gear and planet gear carrier. Latch means is positioned to selectively and automatically stop the ring gear or carrier member while releasing the other to provide the desired sequential output operation. The output shafts are reversed in sequence and direction of rotation by reversing rotational direction of the input shaft.

  5. Computer simulation of gear tooth manufacturing processes

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  6. Air cushion landing gear applications study

    NASA Technical Reports Server (NTRS)

    Earl, T. D.

    1979-01-01

    A series of air cushion landing gear (ACLG) applications was studied and potential benefits analyzed in order to identify the most attractive of these. The selected applications are new integrated designs (not retrofits) and employ a modified design approach with improved characteristics and performance. To aid the study, a survey of potential users was made. Applications were evaluated in the light of comments received. A technology scenario is developed, with discussion of problem areas, current technology level and future needs. Feasible development timetables are suggested. It is concluded that near-term development of small-size ACLG trunks, exploration of flight effects and braking are key items. The most attractive applications are amphibious with very large cargo aircraft and small general aviation having the greatest potential.

  7. Gear teeth impacts in hydrodynamic conjunctions promoting idle gear rattle

    NASA Astrophysics Data System (ADS)

    Theodossiades, S.; Tangasawi, O.; Rahnejat, H.

    2007-06-01

    The rattle phenomenon in vehicular transmissions and its impact on the automotive industry have been widely reported in the literature. A variety of palliative measures have been suggested for attenuation of rattle such as use of backlash eliminators, clutch dampers or dual-mass flywheels. These palliative measures incur further costs and can have untoward implications in powertrain noise and vibration problems. A fundamental investigation of the dynamics of impacting gears is undoubtedly the way forward for a root cause solution. This paper introduces a new approach for understanding the interactions between the transmission gears during engine idle conditions by taking into account the effect of lubrication. Gear impacting surfaces are treated as lubricated conjunctions rather than the usually reported dry impacting solids. Depending on load and speed of entraining motion of the lubricant into the contact domains, the regime of lubrication alters. In this paper, the influence of lubricant in torsional vibration of lightly loaded idling gears is examined which promotes iso-viscous hydrodynamic conditions. It is shown that the lubricant film under these conditions behaves as a time-varying nonlinear spring-damper element. Spectral analysis of the system response is compared to the findings of the linearised system.

  8. 50 CFR 622.272 - Authorized gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.272 Authorized gear. (a) Atlantic dolphin and wahoo—(1) Authorized gear. The following are the only authorized gear types in the fisheries for dolphin and wahoo in...

  9. 50 CFR 622.272 - Authorized gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF COMMERCE FISHERIES OF THE CARIBBEAN, GULF OF MEXICO, AND SOUTH ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.272 Authorized gear. (a) Atlantic dolphin and wahoo—(1) Authorized gear. The following are the only authorized gear types in the fisheries for dolphin and wahoo in...

  10. 50 CFR 648.163 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Gear restrictions. 648.163 Section 648... Atlantic Bluefish Fishery § 648.163 Gear restrictions. Link to an amendment published at 76 FR 60640, Sept... gear restrictions are necessary to assure that the fishing mortality rate is not exceeded, or to...

  11. 50 CFR 665.605 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear restrictions. 665.605 Section 665... Fisheries § 665.605 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for PRIA bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  12. 50 CFR 665.804 - Gear identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear identification. 665.804 Section 665... Fisheries § 665.804 Gear identification. (a) Identification. The operator of each permitted vessel in the... action. Longline gear not marked in compliance with paragraph (a) of this section and found deployed...

  13. 50 CFR 660.506 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 660.506 Section 660.506 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 660.506 Gear restrictions. The only fishing gear authorized for use in the reduction fishery...

  14. 50 CFR 665.104 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 665.104 Section 665... § 665.104 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for American Samoa bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  15. 50 CFR 665.804 - Gear identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear identification. 665.804 Section 665... Fisheries § 665.804 Gear identification. (a) Identification. The operator of each permitted vessel in the... action. Longline gear not marked in compliance with paragraph (a) of this section and found deployed...

  16. 50 CFR 665.164 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear restrictions. 665.164 Section 665.164 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 665.164 Gear restrictions. Only selective gear may be used to harvest coral from any precious...

  17. 50 CFR 665.605 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 665.605 Section 665... Fisheries § 665.605 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for PRIA bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  18. 50 CFR 660.506 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear restrictions. 660.506 Section 660.506..., DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES Coastal Pelagics Fisheries § 660.506 Gear restrictions. The only fishing gear authorized for use in the reduction fishery for northern anchovy...

  19. 50 CFR 665.264 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear restrictions. 665.264 Section 665.264 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  20. 50 CFR 665.605 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 665.605 Section 665... Fisheries § 665.605 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for PRIA bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  1. 50 CFR 665.164 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 665.164 Section 665.164 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 665.164 Gear restrictions. Only selective gear may be used to harvest coral from any precious...

  2. 50 CFR 665.164 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 665.164 Section 665.164 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 665.164 Gear restrictions. Only selective gear may be used to harvest coral from any precious...

  3. 50 CFR 665.164 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear restrictions. 665.164 Section 665.164..., DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC American Samoa Fisheries § 665.164 Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  4. 50 CFR 660.506 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 660.506 Section 660.506 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 660.506 Gear restrictions. The only fishing gear authorized for use in the reduction fishery...

  5. 50 CFR 665.264 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 665.264 Section 665.264 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  6. 50 CFR 665.804 - Gear identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear identification. 665.804 Section 665... Fisheries § 665.804 Gear identification. (a) Identification. The operator of each permitted vessel in the... action. Longline gear not marked in compliance with paragraph (a) of this section and found deployed...

  7. 50 CFR 665.804 - Gear identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear identification. 665.804 Section 665... Fisheries § 665.804 Gear identification. (a) Identification. The operator of each permitted vessel in the... action. Longline gear not marked in compliance with paragraph (a) of this section and found deployed...

  8. 50 CFR 665.264 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear restrictions. 665.264 Section 665.264..., DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Hawaii Fisheries § 665.264 Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  9. 50 CFR 665.664 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear restrictions. 665.664 Section 665.664 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION... § 665.664 Gear restrictions. Only selective gear may be used to harvest coral from any precious...

  10. 50 CFR 665.264 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 665.264 Section 665.264 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  11. 50 CFR 660.506 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 660.506 Section 660.506 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 660.506 Gear restrictions. The only fishing gear authorized for use in the reduction fishery...

  12. 50 CFR 665.664 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 665.664 Section 665.664 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fisheries § 665.664 Gear restrictions. Only selective gear may be used to harvest coral from any...

  13. 50 CFR 665.104 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 665.104 Section 665... § 665.104 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for American Samoa bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  14. 50 CFR 665.804 - Gear identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear identification. 665.804 Section 665... Fisheries § 665.804 Gear identification. (a) Identification. The operator of each permitted vessel in the... action. Longline gear not marked in compliance with paragraph (a) of this section and found deployed...

  15. 50 CFR 665.605 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 665.605 Section 665... Fisheries § 665.605 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for PRIA bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  16. 50 CFR 665.605 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear restrictions. 665.605 Section 665.605... § 665.605 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for PRIA bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear. Possession of...

  17. 50 CFR 665.264 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 665.264 Section 665.264 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear restrictions. Only selective gear may be used to harvest coral from any precious coral permit area....

  18. 50 CFR 665.164 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 665.164 Section 665.164 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... § 665.164 Gear restrictions. Only selective gear may be used to harvest coral from any precious...

  19. 50 CFR 665.664 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear restrictions. 665.664 Section 665.664 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fisheries § 665.664 Gear restrictions. Only selective gear may be used to harvest coral from any...

  20. 50 CFR 665.104 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear restrictions. 665.104 Section 665... § 665.104 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for American Samoa bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  1. 50 CFR 648.163 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear restrictions. 648.163 Section 648.163... Bluefish Fishery § 648.163 Gear restrictions. If the Council determines through its annual review or framework adjustment process that gear restrictions are necessary to assure that the fishing mortality...

  2. 50 CFR 665.104 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear restrictions. 665.104 Section 665... § 665.104 Gear restrictions. (a) Bottom trawls and bottom set gillnets. Fishing for American Samoa bottomfish MUS with bottom trawls and bottom set gillnets is prohibited. (b) Possession of gear....

  3. 50 CFR 665.664 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear restrictions. 665.664 Section 665.664 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fisheries § 665.664 Gear restrictions. Only selective gear may be used to harvest coral from any...

  4. 50 CFR 665.664 - Gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear restrictions. 665.664 Section 665.664 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fisheries § 665.664 Gear restrictions. Only selective gear may be used to harvest coral from any...

  5. 50 CFR 648.203 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Atlantic Herring Fishery § 648.203 Gear restrictions. (a) Midwater trawl gear may only be used by a vessel issued a valid herring permit in the GOM/GB Exemption Area as defined in § 648.80(a)(17), and in the... a Letter of Authorization. (b) Purse seine gear may only be used by a vessel issued a valid...

  6. 50 CFR 648.203 - Gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Atlantic Herring Fishery § 648.203 Gear restrictions. (a) Midwater trawl gear may only be used by a vessel issued a valid herring permit in the GOM/GB Exemption Area as defined in § 648.80(a)(17), and in the... a Letter of Authorization. (b) Purse seine gear may only be used by a vessel issued a valid...

  7. 50 CFR 648.203 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Herring Fishery § 648.203 Gear restrictions. (a) Midwater trawl gear may only be used by a vessel issued a valid herring permit in the GOM/GB Exemption Area as defined in § 648.80(a)(17), and in the Nantucket... Authorization. (b) Purse seine gear may only be used by a vessel issued a valid herring permit in the...

  8. 50 CFR 648.203 - Gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Atlantic Herring Fishery § 648.203 Gear restrictions. (a) Midwater trawl gear may only be used by a vessel issued a valid herring permit in the GOM/GB Exemption Area as defined in § 648.80(a)(17), and in the... a Letter of Authorization. (b) Purse seine gear may only be used by a vessel issued a valid...

  9. Modification Of Gear Teeth To Reduce Vibrations

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Oswald, Fred B.; Lin, Hsiang Hsi

    1990-01-01

    Computer simulations yield data useful in designing for low noise. Effects of modifications in shape of gear teeth upon static transmission error and dynamic loading of gears now analyzed systematically. Design curves generated by conducting numerical simulations of dynamic effects at successive incremental modifications of gear systems operated at various applied loads. Modifications that result in minimum dynamic effect determined from design curves.

  10. Feasibility study of enhanced oil recovery in six oil fields of Colombia. Addendum to final report. Export trade information

    SciTech Connect

    Not Available

    1986-12-01

    The document is an addendum to the final report submitted by Scientific Software-Intercomp to Empresa Colombiana de Petrolos. The addendum replaces Table 23 in the final report with a new table, Table 23A. The data to support the new table is also enclosed.

  11. Illinois Shifting Gears Policy Evaluation

    ERIC Educational Resources Information Center

    Weitzel, Peter C.

    2009-01-01

    Illinois Shifting Gears is a multilevel initiative that has simultaneously created bridge programs in the field and altered state policy to facilitate the creation of more programs in the future. These efforts have informed each other, giving policymakers the opportunity to interact with practitioners, troubleshoot bridge programs, and make…

  12. GEAR UP Aspirations Project Evaluation

    ERIC Educational Resources Information Center

    Trimble, Brad A.

    2013-01-01

    The purpose of this study was to conduct a formative evaluation of the first two years of the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) Aspirations Project (Aspirations) using a Context, Input, Process, and Product (CIPP) model so as to gain an in-depth understanding of the project during the middle school…

  13. Recent manufacturing advances for spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Bill, Robert C.

    1991-01-01

    The U.S. Army Aviation Systems Command (AVSCOM), through the Propulsion Directorate at NASA Lewis Research Center, has recently sponsored projects to advance the manufacturing process for spiral bevel gears. This type of gear is a critical component in rotary-wing propulsion systems. Two successfully completed contracted projects are described. The first project addresses the automated inspection of spiral bevel gears through the use of coordinate measuring machines. The second project entails the computer-numerical-control (CNC) conversion of a spiral bevel gear grinding machine that is used for all aerospace spiral bevel gears. The results of these projects are described with regard to the savings effected in manufacturing time.

  14. Recent manufacturing advances for spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Bill, Robert C.

    1991-01-01

    The U.S. Army Aviation Systems Command (AVSCOM), through the Propulsion Directorate at NASA LRC, has recently sponsored projects to advance the manufacturing process for spiral bevel gears. This type of gear is a critical component in rotary-wing propulsion systems. Two successfully completed contracted projects are described. The first project addresses the automated inspection of spiral bevel gears through the use of coordinate measuring machines. The second project entails the computer-numerical-control (CNC) conversion of a spiral bevel gear grinding machine that is used for all aerospace spiral bevel gears. The results of these projects are described with regard to the savings effected in manufacturing time.

  15. Elasto-dynamic analysis of a gear pump-Part III: Experimental validation procedure and model extension to helical gears

    NASA Astrophysics Data System (ADS)

    Mucchi, E.; Dalpiaz, G.

    2015-01-01

    This work concerns external gear pumps for automotive applications, which operate at high speed and low pressure. In previous works of the authors (Part I and II, [1,2]), a non-linear lumped-parameter kineto-elastodynamic model for the prediction of the dynamic behaviour of external gear pumps was presented. It takes into account the most important phenomena involved in the operation of this kind of machine. The two main sources of noise and vibration are considered: pressure pulsation and gear meshing. The model has been used in order to foresee the influence of working conditions and design modifications on vibration generation. The model's experimental validation is a difficult task. Thus, Part III proposes a novel methodology for the validation carried out by the comparison of simulations and experimental results concerning forces and moments: it deals with the external and inertial components acting on the gears, estimated by the model, and the reactions and inertial components on the pump casing and the test plate, obtained by measurements. The validation is carried out comparing the level of the time synchronous average in the time domain and the waterfall maps in the frequency domain, with particular attention to identify system resonances. The validation results are satisfactory globally, but discrepancies are still present. Moreover, the assessed model has been properly modified for the application to a new virtual pump prototype with helical gears in order to foresee gear accelerations and dynamic forces. Part IV is focused on improvements in the modelling and analysis of the phenomena bound to the pressure evolution around the gears in order to achieve results closer to the measured values. As a matter of fact, the simulation results have shown that a variable meshing stiffness has a notable contribution on the dynamic behaviour of the pump but this is not as important as the pressure phenomena. As a consequence, the original model was modified with the

  16. Driving gear for front and rear wheels of automobile

    SciTech Connect

    Ashikawa, N.; Sakuma, S.

    1986-10-21

    A driving gear is described for front and rear wheels of an automobile, comprising an engine with a crank shaft disposed in a direction of width of a body of the automobile, a transmission supported on an engine case at one side axially of the crank shaft, and a clutch provided between the engine and the transmission. The driving gear includes a first differential gear of a planetary gear type coupled to the transmission via a reduction gear, a second differential gear of a bevel gear type transmission an output of the first differential gear to left and right front wheels of the automobile, and a third differential gear transmitting an output of the first differential gear to left and right rear wheels of the automobile. The first differential gear is disposed adjacent to the reduction gear and comprises a sun gear, a ring gear and planet gears engaging with the sun and ring gears. The planet gears are pivoted directly on and driven by the reduction gear; the first and second differential gears are provided on opposite sides of a plane perpendicular to the crankshaft and including the clutch. The first and second differential gears also lie along a common axis parallel to the crank shaft. The sun gear and the ring gear are coupled individually to the front and rear wheels respectively.

  17. Thermal influence on precise gear transmission

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Fei, Yetai; Miao, EnMing; Zhang, Xiao-rou

    2013-01-01

    Conjugate meshing of involute gears is required in precise gear transmission. However, in the working process, the heat generated in friction results in deformation of the tooth profile of the gear, radial and axial deformation of the shaft and bearing. Meanwhile, there is thermal deformation with non-similarity in the gear box that the shafts and bearings are installed on, which leads to a change of the bearing clearance, axis deflection of the shaft and the gear meshing state. As a result of all these effects, vibration and noise are generated in the transmission system, and it intensifies the possibility of damaging the parts. In this paper, mathematical physics methods and thermal elastic theory are employed to analyze the influence of tooth profiles, gear parameters (transmission ratio i, overlapping coefficients ɛ, backlash jn, etc), gear meshing, working clearance of the bearing (it relates with the initial clearance, tolerance matching, rotational speed, temperature changes, etc) and the shape of the gear box (cylindricity error, axis deflection, etc) caused by the temperature change. The result can be employed in selecting gear parameters and designing the shape of the gear tooth, bearing clearance and shell structure, and it is also helpful to the design of gear transmissions and screw transmissions.

  18. Gear-change apparatus for vehicle transmission

    SciTech Connect

    Kuratsu, H.; Yoshimura, Y.; Sekine, N.; Kima, Y.

    1988-11-22

    This patent describes a gear-change apparatus for a vehicular transmission having forward gear trains each established through an associated synchronizing mechanism, and a reverse gear train established by axial movement on a shaft of a reverse idler gear, an improvement comprising: a cam mechanism having a first cam fixed in place on a reverse shift fork for shifting the reverse idler gear from an inoperative position to an engaged reverse gear train position thereof and, a second cam fixed in place on a forward shift fork for establishing one forward gear train, the first and second cams being arranged such that when the reverse shift fork is moved in a direction which causes the first cam to engage the second cam the forward shift fork is shifted by a predetermined small stroke sufficient for the synchronizing mechanism of that one forward gear corresponding to the forward shift fork to effect only the synchronizing action thereof in response to the movement of the reverse shift fork from the inoperative position of the reverse idler gear to a position immediately before the engaged reverse gear train position of the reverse idler gear.

  19. Modeling and analysis of gear tooth crack growth under variable-amplitude loading

    NASA Astrophysics Data System (ADS)

    Yin, Juliang; Wang, Wenyi; Man, Zhihong; Khoo, Suiyang

    2013-10-01

    The purpose of this paper is to reveal the pattern of gear tooth crack growth under variable-amplitude loading. To this end, a nonlinear dynamic model is proposed to describe the gear tooth crack growth. The state variables of the model are crack length and crack opening stress. The dynamics of crack growth is modeled as a modified Paris equation based on the concept of crack closure. A nonlinear second-order autoregressive equation is developed to model the dynamic behavior of the crack opening stresses. The model parameters are estimated by means of a two-step estimation method because of relatively small sample size of crack length data for G6 gear tests. The model is also validated with the crack growth data of the G6 gear.

  20. Computerized Design of Low-noise Face-milled Spiral Bevel Gears

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Zhang, YI; Handschuh, Robert F.

    1994-01-01

    An advanced design methodology is proposed for the face-milled spiral bevel gears with modified tooth surface geometry that provides a reduced level of noise and has a stabilized bearing contact. The approach is based on the local synthesis of the gear drive that provides the 'best' machine-tool settings. The theoretical aspects of the local synthesis approach are based on the application of a predesigned parabolic function for absorption of undesirable transmission errors caused by misalignment and the direct relations between principal curvatures and directions for mating surfaces. The meshing and contact of the gear drive is synthesized and analyzed by a computer program. The generation of gears with the proposed geometry design can be accomplished by application of existing equipment. A numerical example that illustrates the proposed theory is presented.

  1. Expansion of epicyclic gear dynamic analysis program

    NASA Technical Reports Server (NTRS)

    Boyd, Linda Smith; Pike, James A.

    1987-01-01

    The multiple mesh/single stage dynamics program is a gear tooth analysis program which determines detailed geometry, dynamic loads, stresses, and surface damage factors. The program can analyze a variety of both epicyclic and single mesh systems with spur or helical gear teeth including internal, external, and buttress tooth forms. The modifications refine the options for the flexible carrier and flexible ring gear rim and adds three options: a floating Sun gear option; a natural frequency option; and a finite element compliance formulation for helical gear teeth. The option for a floating Sun incorporates two additional degrees of freedom at the Sun center. The natural frequency option evaluates the frequencies of planetary, star, or differential systems as well as the effect of additional springs at the Sun center and those due to a flexible carrier and/or ring gear rim. The helical tooth pair finite element calculated compliance is obtained from an automated element breakup of the helical teeth and then is used with the basic gear dynamic solution and stress postprocessing routines. The flexible carrier or ring gear rim option for planetary and star spur gear systems allows the output torque per carrier and ring gear rim segment to vary based on the dynamic response of the entire system, while the total output torque remains constant.

  2. Precision of spiral-bevel gears

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1982-01-01

    The kinematic errors in spiral bevel gear trains caused by the generation of nonconjugate surfaces, by axial displacements of the gears during assembly, and by eccentricity of the assembled gears were determined. One mathematical model corresponds to the motion of the contact ellipse across the tooth surface, (geometry I) and the other along the tooth surface (geometry II). The following results were obtained: (1) kinematic errors induced by errors of manufacture may be minimized by applying special machine settings, the original error may be reduced by order of magnitude, the procedure is most effective for geometry 2 gears, (2) when trying to adjust the bearing contact pattern between the gear teeth for geometry 1 gears, it is more desirable to shim the gear axially; for geometry II gears, shim the pinion axially; (3) the kinematic accuracy of spiral bevel drives are most sensitive to eccentricities of the gear and less sensitive to eccentricities of the pinion. The precision of mounting accuracy and manufacture are most crucial for the gear, and less so for the pinion.

  3. Precision of spiral-bevel gears

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1983-01-01

    The kinematic errors in spiral bevel gear trains caused by the generation of nonconjugate surfaces, by axial displacements of the gears during assembly, and by eccentricity of the assembled gears were determined. One mathematical model corresponds to the motion of the contact ellipse across the tooth surface, (geometry I) and the other along the tooth surface (geometry II). The following results were obtained: (1) kinematic errors induced by errors of manufacture may be minimized by applying special machine settings, the original error may be reduced by order of magnitude, the procedure is most effective for geometry 2 gears, (2) when trying to adjust the bearing contact pattern between the gear teeth for geometry I gears, it is more desirable to shim the gear axially; for geometry II gears, shim the pinion axially; (3) the kinematic accuracy of spiral bevel drives are most sensitive to eccentricities of the gear and less sensitive to eccentricities of the pinion. The precision of mounting accuracy and manufacture are most crucial for the gear, and less so for the pinion. Previously announced in STAR as N82-30552

  4. Human Exploration of Mars Design Reference Architecture 5.0, Addendum #2

    NASA Technical Reports Server (NTRS)

    Drake, Bret G. (Editor); Watts Kevin D. (Editor)

    2014-01-01

    This report serves as the second Addendum to NASA-SP-2009-566, "Human Exploration of Mars Design Reference Architecture 5.0." The data and descriptions contained within this Addendum capture some of the key assessments and studies produced since publication of the original document, predominately covering those conducted from 2009 through 2012. The assessments and studies described herein are for the most part independent stand-alone contributions. Effort has not been made to assimilate the findings to provide an updated integrated strategy. That is a recognized future effort. This report should not be viewed as constituting a formal plan for the human exploration of Mars.

  5. Zero torque gear head wrench

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  6. Swimming bacteria power microscopic gears

    SciTech Connect

    Sokolov, Andrey; Apodaca, Mario M.; Grzybowski, Bartosz A.; Aranson, Igor S.

    2010-01-19

    Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be “rectified” under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears’ angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.

  7. Bacteria turn a tiny gear

    SciTech Connect

    2009-01-01

    Thousands of tiny Bacillus subtillis bacteria turn a single gear, just 380 microns across. (A human hair is about 100 microns across.) The method could be used to create micro-machines. Argonne National Laboratory scientist Igor Aronson pioneered this technique. Read more at the New York Times: http://ow.ly/ODfI or at Argonne: http://ow.ly/ODfa Video courtesy Igor Aronson.

  8. Output gear of automatic transmission

    SciTech Connect

    Ideta, Y.; Miida, S.

    1986-12-16

    An automatic transmission is described for a front engine, front wheel drive vehicle, comprising: a torque converter; a main power train comprising a rotatory terminal member, the main power train being connected with the torque converter for transmitting a driving torque from the torque converter to the terminal member; housing means enclosing the main power train, the housing means having a cylindrical bore and at least one oil feed passage opening in a cylindrical surface of the bore, and an output gear rotatably supported by the housing means and connected detachably with the terminal member of the main power train for transmitting the driving torque from the main power train to front wheels of the vehicle. The main power train is placed between the torque converter and the output gear, the output gear having a hub which is splined detachably to the terminal member, and which is fitting in the bore of the housing means in such a manner that the hub can rotate in the bore. The hub has an annular groove formed on an outer cylindrical surface of the hub, the output gear being formed with lubricating means extending from the annular groove for conveying oil from the annular groove, the oil feed passage of the housing means opening into the annular groove for supplying oil into the lubricating means through the annular groove. The annular groove has sufficient depth and width within a range permitted by a strength of the hub to prevent a shortage of the oil supply through the annular groove to the lubricating means due to a centrifugal force of the oil rotating in the annular groove together with walls of the annular groove.

  9. 49 CFR 230.92 - Draw gear and draft systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Draw gear and draft systems. 230.92 Section 230.92... Tenders Draw Gear and Draft Systems § 230.92 Draw gear and draft systems. Couplers, draft gear and... condition for service. Driving Gear...

  10. 50 CFR 660.219 - Fixed gear identification and marking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Fixed gear identification and marking... West Coast Groundfish-Limited Entry Fixed Gear Fisheries § 660.219 Fixed gear identification and marking. (a) Gear identification. (1) Limited entry fixed gear (longline, trap or pot) must be marked...

  11. 50 CFR 660.219 - Fixed gear identification and marking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Fixed gear identification and marking... West Coast Groundfish-Limited Entry Fixed Gear Fisheries § 660.219 Fixed gear identification and marking. (a) Gear identification. (1) Limited entry fixed gear (longline, trap or pot) must be marked...

  12. 50 CFR 622.375 - Authorized and unauthorized gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Authorized and unauthorized gear. 622.375... unauthorized gear. (a) Authorized gear. Subject to the prohibitions on gear/methods specified in § 622.9, the following are the only fishing gears that may be used in the Gulf, Mid-Atlantic, and South Atlantic EEZ...

  13. 49 CFR 230.92 - Draw gear and draft systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Draw gear and draft systems. 230.92 Section 230.92... Tenders Draw Gear and Draft Systems § 230.92 Draw gear and draft systems. Couplers, draft gear and... condition for service. Driving Gear...

  14. 49 CFR 230.92 - Draw gear and draft systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Draw gear and draft systems. 230.92 Section 230.92... Tenders Draw Gear and Draft Systems § 230.92 Draw gear and draft systems. Couplers, draft gear and... condition for service. Driving Gear...

  15. 49 CFR 230.92 - Draw gear and draft systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Draw gear and draft systems. 230.92 Section 230.92... Tenders Draw Gear and Draft Systems § 230.92 Draw gear and draft systems. Couplers, draft gear and... condition for service. Driving Gear...

  16. 49 CFR 230.92 - Draw gear and draft systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Draw gear and draft systems. 230.92 Section 230.92... Tenders Draw Gear and Draft Systems § 230.92 Draw gear and draft systems. Couplers, draft gear and... condition for service. Driving Gear...

  17. 50 CFR 648.51 - Gear and crew restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Gear and crew restrictions. 648.51... Measures for the Atlantic Sea Scallop Fishery § 648.51 Gear and crew restrictions. (a) Trawl vessel gear... long axis of the net. (3) Chafing gear and other gear obstructions—(i) Net obstruction or...

  18. 50 CFR 660.219 - Fixed gear identification and marking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Fixed gear identification and marking... West Coast Groundfish-Limited Entry Fixed Gear Fisheries § 660.219 Fixed gear identification and marking. (a) Gear identification. (1) Limited entry fixed gear (longline, trap or pot) must be marked...

  19. 50 CFR 697.23 - Restricted gear areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed... all mobile gear is on board the vessel while inside the area. (ii) Lobster trap gear. From June 16 through September 30 of each fishing year, no fishing vessel with lobster trap gear or person on a...

  20. 50 CFR 697.23 - Restricted gear areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed... all mobile gear is on board the vessel while inside the area. (ii) Lobster trap gear. From June 16 through September 30 of each fishing year, no fishing vessel with lobster trap gear or person on a...

  1. 50 CFR 697.23 - Restricted gear areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed... all mobile gear is on board the vessel while inside the area. (ii) Lobster trap gear. From June 16 through September 30 of each fishing year, no fishing vessel with lobster trap gear or person on a...

  2. 50 CFR 697.23 - Restricted gear areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed... all mobile gear is on board the vessel while inside the area. (ii) Lobster trap gear. From June 16 through September 30 of each fishing year, no fishing vessel with lobster trap gear or person on a...

  3. 50 CFR 697.23 - Restricted gear areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed... all mobile gear is on board the vessel while inside the area. (ii) Lobster trap gear. From June 16 through September 30 of each fishing year, no fishing vessel with lobster trap gear or person on a...

  4. 29 CFR 1919.19 - Gear requiring welding.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  5. 29 CFR 1919.19 - Gear requiring welding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  6. 29 CFR 1919.19 - Gear requiring welding.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  7. 29 CFR 1919.19 - Gear requiring welding.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  8. 29 CFR 1919.19 - Gear requiring welding.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  9. Automatic transmission's Ravigneaux type planetary gear train having two ring gears

    SciTech Connect

    Hiraiwa, K.

    1989-02-07

    A planetary gear system is described comprising: a stationary member; input means for receiving a driving torque; an output shaft; a compound planetary gear train; a clutch group including a first clutch disposed between the input means and the first sun gear for connection and disconnection therebetween, a second clutch disposed between the input means and the second sun gear for connection and disconnection therebetween, and a third clutch disposed between the input means and the pinion carrier for connection and disconnection therebetween; and a holding device group including a first holding device disposed between the first sun gear and the stationary member for holding the first sun gear, a second holding device disposed between the pinion carrier and the stationary member for holding the pinion carrier, and a third holding device disposed between the second ring gear and the stationary member for holding the second ring gear.

  10. Lubrication and cooling for high speed gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1985-01-01

    The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

  11. Topological and parametric optimization of gear trains

    NASA Astrophysics Data System (ADS)

    Swantner, Albert; Campbell, Matthew I.

    2012-11-01

    A method for automating the design of gear trains comprised of simple, compound, bevel and worm is described. The search process combines topological changes, discrete variable choices and continuous variable optimization. By combing best-first search, implicit enumeration, automated optimization invocation and gradient-based optimization, a near guarantee of the optimal solution can be made. While the combination of methods is specific to gear trains, there are aspects of the work that make it amenable to other engineering design problems. In addition, the topological and discrete modifications to the candidate solutions are specific to gear trains, but the graph grammar methodology that is adopted has been tailored to other problems. This article presents details on the rules that generate feasible gear trains, the evaluation routines used in determining the objective functions and constraints, and the interaction among the three search methods. Resulting gear trains are presented for a variety of gear problems.

  12. Tool Gear: Infrastructure for Parallel Tools

    SciTech Connect

    May, J; Gyllenhaal, J

    2003-04-17

    Tool Gear is a software infrastructure for developing performance analysis and other tools. Unlike existing integrated toolkits, which focus on providing a suite of capabilities, Tool Gear is designed to help tool developers create new tools quickly. It combines dynamic instrumentation capabilities with an efficient database and a sophisticated and extensible graphical user interface. This paper describes the design of Tool Gear and presents examples of tools that have been built with it.

  13. Gear train housing of an engine

    SciTech Connect

    Sweetland, R.D.; Hager, F.M.

    1989-12-12

    This patent describes a gear train housing of a engine of the type having an internal gear space located within housing parts, which includes at least one housing body part and at least one housing cover part. The housing parts being joined together at opposed vertical oriented edge faces, with a gasket seal therebetween, by bolts passing through the housing parts and bosses of the housing body part formed at the edge face thereof so as to be situated projecting into the gear space. Wherein the gear space is defined by internal wall surfaces of the housing parts which include upwardly facing sloping wall surfaces along which some of the bosses are located.

  14. Design of spur gears for improved efficiency

    NASA Technical Reports Server (NTRS)

    Anderson, N. E.; Loewenthal, S. H.

    1981-01-01

    A method to calculate spur gear system power loss for a wide range of gear geometries and operating conditions is used to determine design requirements for an efficient gearset. The effects of spur gear size, pitch, ratio, pitch-line-velocity and load on efficiency are shown. A design example is given to illustrate how the method is to be applied. In general, peak efficiencies were found to be greater for larger diameter and fine pitched gears and tare (no-load) losses were found to be significant.

  15. Effects of gear crack propagation paths on vibration responses of the perforated gear system

    NASA Astrophysics Data System (ADS)

    Ma, Hui; Pang, Xu; Zeng, Jin; Wang, Qibin; Wen, Bangchun

    2015-10-01

    This paper investigates the dynamic behaviors of a perforated gear system considering effects of the gear crack propagation paths and this study focuses on the effects of a crack propagating through the rim on the time-varying mesh stiffness (TVMS) and vibration responses. Considering the effects of the extended tooth contact, a finite element (FE) model of a gear pair is established based on ANSYS software. TVMS of the perforated gear with crack propagating through tooth and rim are calculated by using the FE model. Furthermore, a lumped mass model is adopted to investigate the vibration responses of the perforated gear system. The results show that there exist three periods related to slots of the gear body in a rotating period of the perforated gear. Gear cracks propagating through tooth and rim both reduce the gear body stiffness and lead to reduction of TVMS besides the crack tooth contact moment, and the TVMS weakening for the former is less than that for the latter. Moreover, the results also show that the gear crack propagating through the rim (CPR) has a greater effect on vibration responses than the gear crack propagating through the tooth (CPT) under the same crack level. Vibration level increases with the increasing crack depth, especially for the gear with CPR.

  16. Optimum weight design of functionally graded material gears

    NASA Astrophysics Data System (ADS)

    Jing, Shikai; Zhang, He; Zhou, Jingtao; Song, Guohua

    2015-11-01

    Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials (FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization (GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem.

  17. Addendum to the Calcined Waste Storage at the Idaho Nuclear Technology Center

    SciTech Connect

    M. D. Staiger; Michael Swenson; T. R. Thomas

    2004-05-01

    This report is an addendum to the report Calcined Waste Storage at the Idaho Nuclear Technology and Engineering Center, INEEL/EXT-98-00455 Rev. 1, June 2003. The original report provided a summary description of the Calcined Solids Storage Facilities (CSSFs). It also contained dozens of pages of detailed data tables documenting the volume and composition (chemical content and radionuclide activity) of the calcine stored in the CSSFs and the liquid waste from which the calcine was derived. This addendum report compiles the calcine composition data from the original report. It presents the compiled data in a graphical format with units (weight percent, curies per cubic meter, and nanocuries per gram) that are commonly used in regulatory and waste acceptance criteria documents. The compiled data are easier to use and understand when comparing the composition of the calcine with potential regulatory or waste acceptance criteria. This addendum report also provides detailed explanations for the large variability in the calcine composition among the CSSFs. The calcine composition varies as a result of reprocessing different types of fuel that had different cladding materials. Different chemicals were used to dissolve the various types of fuel, extract the uranium, and calcine the resulting waste. This resulted in calcine with variable compositions. This addendum report also identifies a few trace chemicals and radionuclides for which the accuracy of the amounts estimated to be in the calcine could be improved by making adjustments to the assumptions and methods used in making the estimates.

  18. ADDENDUM TO ASSESSMENT OF STYRENE EMISSION CONTROLS FOR FRP/C AND BOAT BUILDING INDUSTRIES

    EPA Science Inventory

    This report is an addendum to a 1996 report, Assessment of Styrene Emission Controls for FRP/C and Boat Building Industries. It presents additional evaluation of the biological treatment of styrene emissions, Dow Chemical Company's Sorbathene solvent vapor recovery system, Occupa...

  19. 77 FR 52749 - 30-Day Proposed Information Collection: Addendum to Declaration for Federal Employment, Child...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ... information collection project was previously published in the Federal Register (77 FR 115) on June 14, 2012... Federal Employment, Child Care and Indian Child Care Worker Positions; Request for Public Comment AGENCY... Collection: Title: Addendum to Declaration for Federal Employment, Child Care and Indian Child Care...

  20. Addendum to the Safety Analysis Report for the Steel Waste Packaging. Revision 1

    SciTech Connect

    Crow, S R

    1996-02-15

    The Battelle Pacific Northwest National Laboratory Safety Analysis Report (SAR) for the Steel Waste Package requires additional analyses to support the shipment of remote-handled radioactive waste and special-case waste from the 324 building hot cells to PUREX for interim storage. This addendum provides the analyses required to show that this waste can be safely shipped onsite in the configuration shown.

  1. Addendum to Richard D. Altick's Chapter Six on Libraries in "The Art of Literary Research."

    ERIC Educational Resources Information Center

    Moore-Smith, Mary

    This addendum is designed to compensate for Altick's omission of materials by or about black writers in "The Art of Literary Research" and to identify some of the most outstanding public, university, and private library holdings in the United States on American blacks, as well as major Afro-American collections. Major public library holdings…

  2. Action Research: Addendum to the Encyclopedia of Distance Education Research in Iowa. Revised 2nd Edition.

    ERIC Educational Resources Information Center

    Maushak, Nancy J. Ed.; Manternach-Wigans, Lynn, Ed.

    "Action Research" and the "Encyclopedia of Distance Education Research" (1994) are designed as resources for distance education research in Iowa, including information on developing, implementing, and administering distance education systems. This addendum containing an additional seven research studies includes the following papers: "Innovations…

  3. Addendum to Effectiveness of Cognitive Tutor Algebra I at Scale. Working Paper WR-1050-DEIES

    ERIC Educational Resources Information Center

    Pane, John F.; Griffin, Beth Ann; McCaffrey, Daniel F.; Karam, Rita

    2014-01-01

    This addendum to previously published results presents alternative analyses of data from large-scale effectiveness studies of Cognitive Tutor Algebra I in middle schools and high schools. These alternative analyses produce results that are substantively the same as previously reported. We find a significant positive effect of 0.21 standard…

  4. Reference Mission Version 3.0 Addendum to the Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team. Addendum; 3.0

    NASA Technical Reports Server (NTRS)

    Drake, Bret G. (Editor)

    1998-01-01

    This Addendum to the Mars Reference Mission was developed as a companion document to the NASA Special Publication 6107, "Human Exploration of Mars: The Reference Mission of the NASA Mars Exploration Study Team." It summarizes changes and updates to the Mars Reference Missions that were developed by the Exploration Office since the final draft of SP 6107 was printed in early 1999. The Reference Mission is a tool used by the exploration community to compare and evaluate approaches to mission and system concepts that could be used for human missions to Mars. It is intended to identify and clarify system drivers, significant sources of cost, performance, risk, and schedule variation. Several alternative scenarios, employing different technical approaches to solving mission and technology challenges, are discussed in this Addendum. Comparing alternative approaches provides the basis for continual improvement to technology investment plan and a general understanding of future human missions to Mars. The Addendum represents a snapshot of work in progress in support of planning for future human exploration missions through May 1998.

  5. Local meshing plane analysis as a source of information about the gear quality

    NASA Astrophysics Data System (ADS)

    Mączak, Jędrzej

    2013-07-01

    In the paper the application of the local meshing plane concept is discussed and applied for detecting of tooth degradation due to fatigue, and for overall gear quality assessment. Knowing the kinematic properties of the machine (i.e. gear tooth numbers) it is possible to modify the diagnostic signal in such a manner that its fragments will be linked to different rotating parts. This allows for presentation of either raw or processed gearbox signal in a form of three dimensional map on the plane "pinion teeth×gear teeth", called local meshing plane. The meshing plane in Cartesian coordinates z1×z2 allows for precise location and assessment of gear faults in terms of meshing quality of consecutive tooth pairs. Although the method was applied to simulated signals generated by the gearbox model, similar results were obtained for the measurement signals recorded during the back-to-back test stand experiment. The described method could be used for assessing the manufacturing quality of gears, the assembly quality as well as for the gear failure evaluation during normal exploitation.

  6. Low-noise, high-strength, spiral-bevel gears for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; Handschuh, Robert F.; Henry, Zachary S.; Litvin, Faydor L.

    1993-01-01

    Improvements in spiral-bevel gear design were investigated to support the Army/NASA Advanced Rotorcraft Transmission program. Program objectives were to reduce weight by 25 percent, reduce noise by 10 dB, and increase life to 5000 hr mean-time-between-removal. To help meet these goals, advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500-hp Helicopter Transmission Test Stand. Three different gear designs tested included: (1) the current design of the OH-58D transmission except gear material X-53 instead of AISI 9310; (2) a higher-strength design the same as the current but with a full fillet radius to reduce gear tooth bending stress (and thus, weight); and (3) a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved.

  7. Low-noise, high-strength, spiral-bevel gears for helicopter transmissions

    SciTech Connect

    Lewicki, D.G.; Handschuh, R.F.; Henry, Z.S.; Litvin, F.L.

    1993-06-01

    Improvements in spiral-bevel gear design were investigated to support the Army/NASA Advanced Rotorcraft Transmission program. Program objectives were to reduce weight by 25 percent, reduce noise by 10 dB, and increase life to 5000 hr mean-time-between-removal. To help meet these goals, advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500-hp Helicopter Transmission Test Stand. Three different gear designs tested included: (1) the current design of the OH-58D transmission except gear material X-53 instead of AISI 9310; (2) a higher-strength design the same as the current but with a full fillet radius to reduce gear tooth bending stress (and thus, weight); and (3) a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved.

  8. Detecting gear tooth fracture in a high contact ratio face gear mesh

    NASA Technical Reports Server (NTRS)

    Zakrajsek, James J.; Handschuh, Robert F.; Lewicki, David G.; Decker, Harry J.

    1995-01-01

    This paper summarized the results of a study in which three different vibration diagnostic methods were used to detect gear tooth fracture in a high contact ratio face gear mesh. The NASA spiral bevel gear fatigue test rig was used to produce unseeded fault, natural failures of four face gear specimens. During the fatigue tests, which were run to determine load capacity and primary failure mechanisms for face gears, vibration signals were monitored and recorded for gear diagnostic purposes. Gear tooth bending fatigue and surface pitting were the primary failure modes found in the tests. The damage ranged from partial tooth fracture on a single tooth in one test to heavy wear, severe pitting, and complete tooth fracture of several teeth on another test. Three gear fault detection techniques, FM4, NA4*, and NB4, were applied to the experimental data. These methods use the signal average in both the time and frequency domain. Method NA4* was able to conclusively detect the gear tooth fractures in three out of the four fatigue tests, along with gear tooth surface pitting and heavy wear. For multiple tooth fractures, all of the methods gave a clear indication of the damage. It was also found that due to the high contact ratio of the face gear mesh, single tooth fractures did not significantly affect the vibration signal, making this type of failure difficult to detect.

  9. The transfer function method for gear system dynamics applied to conventional and minimum excitation gearing designs

    NASA Technical Reports Server (NTRS)

    Mark, W. D.

    1982-01-01

    A transfer function method for predicting the dynamic responses of gear systems with more than one gear mesh is developed and applied to the NASA Lewis four-square gear fatigue test apparatus. Methods for computing bearing-support force spectra and temporal histories of the total force transmitted by a gear mesh, the force transmitted by a single pair of teeth, and the maximum root stress in a single tooth are developed. Dynamic effects arising from other gear meshes in the system are included. A profile modification design method to minimize the vibration excitation arising from a pair of meshing gears is reviewed and extended. Families of tooth loading functions required for such designs are developed and examined for potential excitation of individual tooth vibrations. The profile modification design method is applied to a pair of test gears.

  10. Improving Efficiency of Gear Shaping of Wheels with Internal Non-involute Gears

    NASA Astrophysics Data System (ADS)

    Tarapanov, A.; Anisimov, R.; Kanatnikov, N.; Pilipenko, A.

    2016-04-01

    In the article questions of improving efficiency of gear shaping of wheels with internal non-involute profile gears. The technique of the analysis of kinematics parameters of gear shaping process is presented. Researches devoted to the influence of root profile form of processed wheel with interna. In the article questions of improving efficiency of gear shaping of wheels with internal non-involute profile gears. The technique of the analysis of kinematics parameters of gear shaping process is presented. Researches devoted to the influence of root profile form of processed wheel with internal non-involute gears on the thickness of the cutting-off metal layer, size of components of cutting forces and a roughness of the processed surface are given.

  11. 50 CFR 648.23 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Mackerel, Squid, and Butterfish Fisheries § 648.23 Gear restrictions. Link to an amendment published at 76...) Mackerel, squid, and butterfish bottom trawling restricted areas. (i) Oceanographer Canyon. No permitted mackerel, squid, or butterfish vessel may fish with bottom trawl gear in the Oceanographer Canyon or be...

  12. Computer programs for generating involute gears

    SciTech Connect

    Emery, J.D.; Wolf, M.L.

    1992-02-01

    Methods and computer programs are given for computing the shapes of involute gears. A proof is given of conditions under which uniform angular velocity is maintained for a pair of interacting cams. A program is given for the animation of gear motion. It runs on an APOLLO 4500 computer. The other programs are general and are written in FORTRAN and C.

  13. 50 CFR 622.376 - Gear identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear identification. 622.376 Section 622.376 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Migratory Pelagic Resources (Gulf of Mexico and South Atlantic) § 622.376 Gear identification. (a)...

  14. 50 CFR 665.246 - Gear identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Gear identification. 665.246 Section 665.246 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear identification. In Permit Area 1, the vessel's official number must be marked legibly on all...

  15. 50 CFR 665.246 - Gear identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 11 2011-10-01 2011-10-01 false Gear identification. 665.246 Section 665.246 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear identification. In Permit Area 1, the vessel's official number must be marked legibly on all...

  16. 50 CFR 622.376 - Gear identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Gear identification. 622.376 Section 622.376 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Migratory Pelagic Resources (Gulf of Mexico and South Atlantic) § 622.376 Gear identification. (a)...

  17. 50 CFR 665.246 - Gear identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Gear identification. 665.246 Section 665.246 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear identification. In Permit Area 1, the vessel's official number must be marked legibly on all...

  18. 50 CFR 665.246 - Gear identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Gear identification. 665.246 Section 665.246 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear identification. In Permit Area 1, the vessel's official number must be marked legibly on all...

  19. 50 CFR 622.430 - Gear identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Gear identification. 622.430 Section 622.430 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fishery of Puerto Rico and the U.S. Virgin Islands § 622.430 Gear identification. (a) Fish traps...

  20. 50 CFR 622.430 - Gear identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear identification. 622.430 Section 622.430 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Fishery of Puerto Rico and the U.S. Virgin Islands § 622.430 Gear identification. (a) Fish traps...

  1. 50 CFR 665.246 - Gear identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 13 2013-10-01 2013-10-01 false Gear identification. 665.246 Section 665.246 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC... Gear identification. In Permit Area 1, the vessel's official number must be marked legibly on all...

  2. 50 CFR 648.123 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... § 648.123 Gear restrictions. (a) Trawl vessel gear restrictions—(1) Minimum mesh size. No owner or... October 31, unless fishing with nets that have a minimum mesh size of 5.0-inch (12.7-cm) diamond mesh... extension) of fewer than 75 meshes, the entire trawl net must have a minimum mesh size of 5.0 inches...

  3. Gear Lubrication and Cooling Experiment and Analysis

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Akin, L. S.

    1983-01-01

    A gear tooth temperature analysis was performed using a finite element method combined with a calculated heat input, a calculated oil jet impingement depth, and estimated heat transfer coefficients for the different parts of the gear tooth that are oil cooled and air cooled. Experimental measurements of gear tooth average surface temperature and gear tooth instantaneous surface temperature were made with a fast response, infrared, radiometric microscope. Increasing oil pressure has a significant effect on both average surface temperature and peak surface temperature at loads above 1895 N/cm(1083 lb/in) and speeds of 10,000 and 7500 rpm. Both increasing speed (from 5000 to 10,000 rpm) at constant speed cause a significant rise in the average surface temperature and in the instantaneous peak surface temperatures on the gear teeth. The oil jet pressure required to provide the best cooling for gears is the pressure required to obtain full gear tooth impingement. Calculated results for gear tooth temperatures were close to experimental results for various oil jet impingement depths for identical operating conditions.

  4. 50 CFR 648.144 - Gear restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES Management Measures for the Black Sea Bass Fishery § 648.144 Gear restrictions. (a) Trawl gear restrictions—(1) General. (i) Otter trawlers whose owners are issued a black sea bass moratorium permit and that land or possess 500 lb (226.8 kg) or...

  5. 50 CFR 648.144 - Gear restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... restrictions—(1) General. (i) Otter trawlers whose owners are issued a black sea bass moratorium permit and... Black Sea Bass Fishery § 648.144 Gear restrictions. Link to an amendment published at 76 FR 60637, Sept. 29, 2011. (a) Trawl gear restrictions—(1) General. (i) Otter trawlers whose owners are issued a...

  6. Computer aided design of spur gear teeth

    NASA Technical Reports Server (NTRS)

    Huston, R. L.; Mavriplis, D.; Oswald, F. B.

    1989-01-01

    Procedures for computer-modeling of spur gear tooth fabrication are given. It is shown that the standard involute tooth form results from a cutter with an involute shape rolling onto a gear blank. Specifically, the envelope of an involute is an involute. Examples are given and applications are discussed.

  7. Dynamic Tooth Loads for Spur Gears

    NASA Technical Reports Server (NTRS)

    Cornell, R.; Westervelt, W.

    1986-01-01

    Computer program developed using time-history, interactive, closed-form solution for dynamic tooth loads for both low- and high-contact-ratio spur gears. Facilitates application of high-contact-ratio spur gear concepts. Program written in FORTRAN IV.

  8. Improvements to the FATOLA computer program including added actively controlled landing gear subroutines

    NASA Technical Reports Server (NTRS)

    Mall, G. H.

    1983-01-01

    Modifications to a multi-degree-of-freedom flexible aircraft take-off and landing analysis (FATOLA) computer program, including a provision for actively controlled landing gears to expand the programs simulation capabilities, are presented. Supplemental instructions for preparation of data and for use of the modified program are included.

  9. Planetary gear profile modification design based on load sharing modelling

    NASA Astrophysics Data System (ADS)

    Iglesias, Miguel; Fernández Del Rincón, Alfonso; De-Juan, Ana Magdalena; Garcia, Pablo; Diez, Alberto; Viadero, Fernando

    2015-07-01

    In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.

  10. Vibration signature analysis of multistage gear transmission

    NASA Technical Reports Server (NTRS)

    Choy, F. K.; Tu, Y. K.; Savage, M.; Townsend, D. P.

    1989-01-01

    An analysis is presented for multistage multimesh gear transmission systems. The analysis predicts the overall system dynamics and the transmissibility to the gear box or the enclosed structure. The modal synthesis approach of the analysis treats the uncoupled lateral/torsional model characteristics of each stage or component independently. The vibration signature analysis evaluates the global dynamics coupling in the system. The method synthesizes the interaction of each modal component or stage with the nonlinear gear mesh dynamics and the modal support geometry characteristics. The analysis simulates transient and steady state vibration events to determine the resulting torque variations, speeds, changes, rotor imbalances, and support gear box motion excitations. A vibration signature analysis examines the overall dynamic characteristics of the system, and the individual model component responses. The gear box vibration analysis also examines the spectral characteristics of the support system.

  11. Analysis of Landing-Gear Behavior

    NASA Technical Reports Server (NTRS)

    Milwitzky, Benjamin; Cook, Francis E

    1953-01-01

    This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection. The applicability of the analysis to actual landing gears has been investigated for the particular case of a vertical landing gear in the absence of drag loads by comparing calculated results with experimental drop-test data for impacts with and without tire bottoming. The calculated behavior of the landing gear was found to be in good agreement with the drop-test data.

  12. Smooth Teeth: Why Multipoles Are Perfect Gears

    NASA Astrophysics Data System (ADS)

    Schönke, Johannes

    2015-12-01

    A type of gear is proposed based on the interaction of individual multipoles. The underlying principle relies on previously unknown continuous degenerate ground states for pairs of interacting multipoles which are free to rotate around specific axes. These special rotation axes, in turn, form a one-parameter family of possible configurations. This allows for the construction of magnetic bevel gears with any desired inclination angle between the in- and output axes. Further, the design of gear systems with more than two multipoles is possible and facilitates tailored applications. Ultimately, an analogy between multipoles and mechanical gears is revealed. In contrast to the mechanical case, the multipole "teeth" mesh smoothly. As an illustrative application, the example of a quadrupole-dipole interaction is then used to construct a 1 ∶2 gear ratio.

  13. The Dilemma of Derelict Gear.

    PubMed

    Scheld, A M; Bilkovic, D M; Havens, K J

    2016-01-01

    Every year, millions of pots and traps are lost in crustacean fisheries around the world. Derelict fishing gear has been found to produce several harmful environmental and ecological effects, however socioeconomic consequences have been investigated less frequently. We analyze the economic effects of a substantial derelict pot removal program in the largest estuary of the United States, the Chesapeake Bay. By combining spatially resolved data on derelict pot removals with commercial blue crab (Callinectes sapidus) harvests and effort, we show that removing 34,408 derelict pots led to significant gains in gear efficiency and an additional 13,504 MT in harvest valued at US $21.3 million--a 27% increase above that which would have occurred without removals. Model results are extended to a global analysis where it is seen that US $831 million in landings could be recovered annually by removing less than 10% of the derelict pots and traps from major crustacean fisheries. An unfortunate common pool externality, the degradation of marine environments is detrimental not only to marine organisms and biota, but also to those individuals and communities whose livelihoods and culture depend on profitable and sustainable marine resource use. PMID:26790394

  14. The Dilemma of Derelict Gear

    PubMed Central

    Scheld, A. M.; Bilkovic, D. M.; Havens, K. J.

    2016-01-01

    Every year, millions of pots and traps are lost in crustacean fisheries around the world. Derelict fishing gear has been found to produce several harmful environmental and ecological effects, however socioeconomic consequences have been investigated less frequently. We analyze the economic effects of a substantial derelict pot removal program in the largest estuary of the United States, the Chesapeake Bay. By combining spatially resolved data on derelict pot removals with commercial blue crab (Callinectes sapidus) harvests and effort, we show that removing 34,408 derelict pots led to significant gains in gear efficiency and an additional 13,504 MT in harvest valued at US $21.3 million—a 27% increase above that which would have occurred without removals. Model results are extended to a global analysis where it is seen that US $831 million in landings could be recovered annually by removing less than 10% of the derelict pots and traps from major crustacean fisheries. An unfortunate common pool externality, the degradation of marine environments is detrimental not only to marine organisms and biota, but also to those individuals and communities whose livelihoods and culture depend on profitable and sustainable marine resource use. PMID:26790394

  15. Dynamics of early planetary gear trains

    NASA Technical Reports Server (NTRS)

    August, R.; Kasuba, R.; Frater, J. L.; Pintz, A.

    1984-01-01

    A method to analyze the static and dynamic loads in a planetary gear train was developed. A variable-variable mesh stiffness (VVMS) model was used to simulate the external and internal spur gear mesh behavior, and an equivalent conventional gear train concept was adapted for the dynamic studies. The analysis can be applied either involute or noninvolute spur gearing. By utilizing the equivalent gear train concept, the developed method may be extended for use for all types of epicyclic gearing. The method is incorporated into a computer program so that the static and dynamic behavior of individual components can be examined. Items considered in the analysis are: (1) static and dynamic load sharing among the planets; (2) floating or fixed Sun gear; (3) actual tooth geometry, including errors and modifications; (4) positioning errors of the planet gears; (5) torque variations due to noninvolute gear action. A mathematical model comprised of power source, load, and planetary transmission is used to determine the instantaneous loads to which the components are subjected. It considers fluctuating output torque, elastic behavior in the system, and loss of contact between gear teeth. The dynamic model has nine degrees of freedom resulting in a set of simultaneous second order differential equations with time varying coefficients, which are solved numerically. The computer program was used to determine the effect of manufacturing errors, damping and component stiffness, and transmitted load on dynamic behavior. It is indicated that this methodology offers the designer/analyst a comprehensive tool with which planetary drives may be quickly and effectively evaluated.

  16. Addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 452: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 452: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, April 1998 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the URs for CASs: • 25-25-09, Spill H940825C (from UST 25-3101-1) • 25-25-14, Spill H940314E (from UST 25-3102-3) • 25-25-15, Spill H941020E (from UST 25-3152-1) These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs

  17. Addendum to the Closure Report for Corrective Action Unit 394: Areas 12, 18, and 29 Spill/Release Sites Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Lynn Kidman

    2008-10-01

    This document constitutes an addendum to the September 2003, Closure Report for Corrective Action Unit 394: Areas 12, 18, and 29 Spill/Release Sites as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the URs for: • CAS 12-25-04, UST 12-16-2 Waste Oil Release • CAS 18-25-01, Oil Spills • CAS 18-25-02, Oil Spills • CAS 18-25-03, Oil Spill • CAS 29-44-01, Fuel Spill These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the

  18. Addendum 2 to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 454: Historical Underground Storage Tank Release Sites, Nevada Test Site, Nevada, April 1998 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the URs for CASs: • 12-25-08, Spill H950524F (from UST 12-B-1) • 12-25-10, Spill H950919A (from UST 12-COMM-1) These URs were established as part of Federal Facility Agreement and Consent Order (FFACO) corrective actions and were based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since these URs were established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, these URs were re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the URs) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove these URs because contamination is not present at these sites above the risk-based FALs. Requirements for inspecting and maintaining these URs will be

  19. Addendum to the Closure Report for Corrective Action Unit 342: Area 23 Mercury Fire Training Pit Nevada Test Site, Nevada, Revision 0

    SciTech Connect

    Lynn Kidman

    2008-10-01

    This document constitutes an addendum to the April 2000, Closure Report for Corrective Action Unit 342: Area 23 Mercury Fire Training Pit as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications. In conformance with the UR Modification document, this addendum consists of: • This cover page that refers the reader to the UR Modification document for additional information • The cover and signature pages of the UR Modification document • The NDEP approval letter • The corresponding section of the UR Modification document This addendum provides the documentation justifying the cancellation of the UR for CAS 23-56-01, Former Mercury Fire Training Pit. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996; as amended August 2006). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was re-evaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006c). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at

  20. Addendum 2 to the Closure Report for Corrective Action Unit 358: Areas 18, 19, 20 Cellars/Mud Pits, Nevada Test Site, Nevada, Revison 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Closure Report for Corrective Action Unit 358: Areas 18, 19, 20 Cellars/Mud Pits, Nevada Test Site, Nevada, January 2004 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 19-09-05, Mud Pit. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the FFACO UR such as for

  1. Addendum to the Closure Report for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada, Revision 1

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Closure Report for Corrective Action Unit 326: Areas 6 and 27 Release Sites, Nevada Test Site, Nevada (Revision 1), December 2002 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 06-25-01, CP-1 Heating Oil Release. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to

  2. Addendum to the Closure Report for Corrective Action Unit 339: Area 12 Fleet Operations Steam Cleaning Discharge Area, Nevada Test Site, Revision 0

    SciTech Connect

    Grant Evenson

    2009-05-01

    This document constitutes an addendum to the Closure Report for CAU 339: Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site, December 1997 as described in the document Supplemental Investigation Report for FFACO Use Restrictions, Nevada Test Site, Nevada (SIR) dated November 2008. The SIR document was approved by NDEP on December 5, 2008. The approval of the SIR document constituted approval of each of the recommended UR removals. In conformance with the SIR document, this addendum consists of: • This page that refers the reader to the SIR document for additional information • The cover, title, and signature pages of the SIR document • The NDEP approval letter • The corresponding section of the SIR document This addendum provides the documentation justifying the cancellation of the UR for CAS 12-19-01, A12 Fleet Ops Steam Cleaning Efflu. This UR was established as part of a Federal Facility Agreement and Consent Order (FFACO) corrective action and is based on the presence of contaminants at concentrations greater than the action levels established at the time of the initial investigation (FFACO, 1996). Since this UR was established, practices and procedures relating to the implementation of risk-based corrective actions (RBCA) have changed. Therefore, this UR was reevaluated against the current RBCA criteria as defined in the Industrial Sites Project Establishment of Final Action Levels (NNSA/NSO, 2006). This re-evaluation consisted of comparing the original data (used to define the need for the UR) to risk-based final action levels (FALs) developed using the current Industrial Sites RBCA process. The re-evaluation resulted in a recommendation to remove the UR because contamination is not present at the site above the risk-based FALs. Requirements for inspecting and maintaining this UR will be canceled, and the postings and signage at this site will be removed. Fencing and posting may be present at this site that are unrelated to the

  3. Apparatus for controlling transmission gear shift selection

    SciTech Connect

    Bailey, T.M.

    1986-07-29

    In an automotive engine having an electrical power source and an automatic or semi-automatic transmission including a manually operated transmission gear shift lever having at least two forward drive positions, an apparatus is described which consists of: (a) a speed sensing means for sensing the rotation speed of the engine and generating an output signal when the engine reaches a preselected rotational speed; and (b) a gear shifting means for changing the shift positions of the gear shift lever from a first drive position to a second drive position automatically in response to the output signal from the speed sensing means, the gear shifting means including (i) a latch actuable between open and closed positions, (ii) a normally de-energized solenoid having a plunger connected to the latch and operable to move the latch to the open position when the solenoid is energized by the electrical power source, (iii) a relay means for allowing the energizing of the solenoid by the power source in response to the output signal from the speed sensing means, and (iv) an actuating means, including a spring biased linkage mechanism operably connected to the gear shift lever and the latch, for actuating the movement of the gear shift lever from the first drive position to the second drive position in response to movement of the latch from the closed to the open position, thereby causing gear shifting to occur when the engine reaches the preselected rotational speed.

  4. Flexible universal gear box system with yokes

    SciTech Connect

    Giocastro, J.; Giocastro, S.

    1987-01-20

    This patent describes a flexible joint system associated with the front and rear portions of a motor vehicle, comprising, in combination: a generally horizontal pivot member, a pair of opposed first and second yoke means rotatably connected to the pivot member the first yoke means being secured to the front portion of the vehicle and the second yoke means being secured to the rear portion of the vehicle. The final and second yoke means are movable relative to one another, a generally horizontal shaft member rotatably connected to and transversely passing through the first yoke means and disposed approximately perpendicular to the pivot member, first bevel gear means secured to the pivot member between the first and second yoke means, second bevel gear means perpendicular and meshing with the first bevel gear means and secured to the shaft member, and the second yoke means being for rotating about the pivot member relative to the first yoke means and for rotating the second bevel gear means relative to the first bevel gear means in response to movement of the rear portion of the motor vehicle. The first yoke means is for rotating about the pivot member relative to and for rotating the first bevel gear means relative to the second bevel gear means in response to movement of the front portion of the motor vehicle.

  5. The application of elastohydrodynamic lubrication in gear tooth contacts

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1972-01-01

    An analytical method is presented for determining elastohydrodynamic film thickness in gears from theory and how the film affects gear failure and life. The practical aspects of gear lubrication are presented, including mechanical and service variables which must be considered to obtain optimum gear performance under severe operating conditions.

  6. 14 CFR 25.1515 - Landing gear speeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  7. 14 CFR 25.1515 - Landing gear speeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  8. 14 CFR 25.1515 - Landing gear speeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  9. 14 CFR 25.1515 - Landing gear speeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  10. 14 CFR 25.1515 - Landing gear speeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  11. 14 CFR 23.477 - Landing gear arrangement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  12. 14 CFR 23.477 - Landing gear arrangement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  13. 50 CFR 622.31 - Buoy gear identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Buoy gear identification. 622.31 Section... Resources of the Gulf of Mexico § 622.31 Buoy gear identification. (a) Buoy gear. In the Gulf EEZ, if buoy gear is used or possessed, each buoy must display the official number of the vessel. See § 622.2...

  14. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  15. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  16. 29 CFR 1919.31 - Proof tests-loose gear.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear...

  17. 29 CFR 1919.31 - Proof tests-loose gear.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear...

  18. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  19. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  20. 29 CFR 1919.31 - Proof tests-loose gear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear...

  1. 29 CFR 1919.31 - Proof tests-loose gear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear...

  2. 14 CFR 23.477 - Landing gear arrangement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  3. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  4. 14 CFR 23.477 - Landing gear arrangement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  5. 50 CFR 600.510 - Gear avoidance and disposal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear avoidance and disposal. 600.510... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds where fishing vessels are already fishing or have set their gear for that purpose must ascertain the...

  6. 14 CFR 23.477 - Landing gear arrangement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  7. 50 CFR 622.31 - Buoy gear identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Buoy gear identification. 622.31 Section... Resources of the Gulf of Mexico § 622.31 Buoy gear identification. (a) Buoy gear. In the Gulf EEZ, if buoy gear is used or possessed, each buoy must display the official number of the vessel. See § 622.2...

  8. 46 CFR 108.641 - Instructions for changing steering gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  9. Calculation of the efficiency of aircraft gear drives

    NASA Astrophysics Data System (ADS)

    Shatalov, B. I.

    Expressions are presented for determining the efficiency of helical, spur, and beveled gear drives. It is shown that losses in the gearing increase significantly with the decreasing number of teeth; the efficiency of external gears is less than that of internal gears. A formula for determining friction losses is included.

  10. Engagement of Metal Debris into Gear Mesh

    NASA Technical Reports Server (NTRS)

    handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  11. An Integrated Approach for Gear Health Prognostics

    NASA Technical Reports Server (NTRS)

    He, David; Bechhoefer, Eric; Dempsey, Paula; Ma, Jinghua

    2012-01-01

    In this paper, an integrated approach for gear health prognostics using particle filters is presented. The presented method effectively addresses the issues in applying particle filters to gear health prognostics by integrating several new components into a particle filter: (1) data mining based techniques to effectively define the degradation state transition and measurement functions using a one-dimensional health index obtained by whitening transform; (2) an unbiased l-step ahead RUL estimator updated with measurement errors. The feasibility of the presented prognostics method is validated using data from a spiral bevel gear case study.

  12. NASA Orbiter Extended Nose Landing Gear

    NASA Technical Reports Server (NTRS)

    King, Steven R.; Jensen, Scott A.; Hansen, Christopher P.

    1999-01-01

    This paper discusses the design, development, test, and evaluation of a prototype Extended Nose Landing Gear (ENLG) for NASA's Space Shuttle orbiters. The ENLG is a proposed orbiter modification developed in-house at NASA's Johnson Space Center (JSC) by a joint government/industry team. It increases the orbiter's nose landing gear (NLG) length, thereby changing the vehicle's angle of attack during rollout, which lowers the aerodynamic forces on the vehicle. This, in combination with a dynamic elevon change, will lower the loads on the orbiter's main landing gear (MLG). The extension is accomplished by adding a telescoping section to the current NLG strut that will be pneumatically extended during NLG deployment.

  13. Procedure for shifting a transmission composed of several gear units

    SciTech Connect

    Schwarz, R.; Stuhrmann, H.; Nobis, D.

    1989-02-07

    A process is described for shifting a transmission having: a first gear unit drivably connectible to an engine; a last gear unit having at least one synchronizer to drivingly connect the last gear unit to at least one driven component; and at least one intermediate gear unit releasably connecting the first and last gear units. The process consists of releasing at least one synchronizer and at least one intermediate gear unit; connecting at least one synchronizer; and connecting at least one intermediate gear unit.

  14. Multi-angle pinion and gear power transmission

    SciTech Connect

    Hart, F.M.

    1986-02-04

    This patent describes a worm and gear power transmission which consists of a housing, an input shaft, two axially aligned, different ratio worms formed on the input shaft in the housing. It also includes a pair of gears spaced apart in the housing such that a first gear of the pair meshes with one of the worms, and a second gear of the pair meshes with the other worm, the first and second gears positioned such that planes through the gears and the axis of the input shaft are at a right angle to one another, and output shafts extending out of the housing from the respective gears.

  15. Gear fatigue crack prognosis using embedded model, gear dynamic model and fracture mechanics

    NASA Astrophysics Data System (ADS)

    Li, C. James; Lee, Hyungdae

    2005-07-01

    This paper presents a model-based method that predicts remaining useful life of a gear with a fatigue crack. The method consists of an embedded model to identify gear meshing stiffness from measured gear torsional vibration, an inverse method to estimate crack size from the estimated meshing stiffness; a gear dynamic model to simulate gear meshing dynamics and determine the dynamic load on the cracked tooth; and a fast crack propagation model to forecast the remaining useful life based on the estimated crack size and dynamic load. The fast crack propagation model was established to avoid repeated calculations of FEM and facilitate field deployment of the proposed method. Experimental studies were conducted to validate and demonstrate the feasibility of the proposed method for prognosis of a cracked gear.

  16. High Speed Gear Sized and Configured to Reduce Windage Loss

    NASA Technical Reports Server (NTRS)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  17. Addendum 2: Logs of monitor wells drilled May 1988 through December 1992

    SciTech Connect

    Stout, J.; Qualheim, B.; McPherrin, R.; Barber, K.; Hedegaard, R.; McConihe, W.; Miller, T.

    1993-11-01

    The logs in this addendum were plotted in a new format by the same software package (LOGGER by Rockware, Denver, CO) that was used in the original publication. The scale remains the same, 1 inch = 15 foot. The header is totally automated with a subheading indexing the well-construction symbols. Geophysical curves are labeled in their respective channels, and percentage core recovery is plotted in a histogram. Lithologic symbols are plotted to scale in a channel similar to previous logs. The lithologic description also has been automated to assure consistency in terminology. Descriptions are more extensive and are referenced by leader lines to the lithologic symbol. Additional figures included for this Addendum are: a plot of all the monitoring well locations at the LLNL Main site and a plot detailing the gasoline spill area well locations in the vicinity of Building 403.

  18. Surface micromachined microengine as the driver for micromechanical gears

    SciTech Connect

    Garcia, E.J.; Sniegowski, J.J.

    1995-05-01

    The transmission of mechanical power is often accomplished through the use of gearing. The recently developed surface micromachined microengine provides us with an actuator which is suitable for driving surface micromachined geared systems. In this paper we will present aspects of the microengine as they relate to the driving of geared mechanisms, issues relating to the design of micro gear mechanisms, and details of a design of a microengine-driven geared shutter mechanism.

  19. 9. VIEW SOUTHWEST OF PRIMARY REDUCING GEARS; NOTE BRAKE WHEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW SOUTHWEST OF PRIMARY REDUCING GEARS; NOTE BRAKE WHEEL AND PADS AT RIGHT CENTER BEHIND PRIMARY GEAR; MITER GEAR AT CENTER IS PART OF MECHANISM FOR MANUAL OPERATION OF BRIDGE; FLANGE FOR COUPLING THE NORTH AND SOUTH REDUCTION GEAR TRAINS IS AT CENTER OF PHOTOGRAPH BEHIND SOUTH PRIMARY REDUCTION GEAR - East Washington Avenue Bridge, Spanning Pequonnock River at East Washington Avenue, Bridgeport, Fairfield County, CT

  20. Dynamic Forces in Spur Gears - Measurement, Prediction, and Code Validation

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.; Townsend, Dennis P.; Rebbechi, Brian; Lin, Hsiang Hsi

    1996-01-01

    Measured and computed values for dynamic loads in spur gears were compared to validate a new version of the NASA gear dynamics code DANST-PC. Strain gage data from six gear sets with different tooth profiles were processed to determine the dynamic forces acting between the gear teeth. Results demonstrate that the analysis code successfully simulates the dynamic behavior of the gears. Differences between analysis and experiment were less than 10 percent under most conditions.

  1. Straddle Design Of Spiral Bevel And Hypoid Gears

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Litvin, Faydor L.; Kuan, Chihping; Kieffer, Jonathan; Bossler, Robert

    1994-01-01

    Computer-assisted method of analysis of straddle designs for spiral bevel and hypoid gears helps prevent undercutting of gear shafts during cutting of gear teeth. Analytical method and computer program based on equations for surface traced out by motion of head cutter, equation for cylindrical surface of shaft, and equations expressing relationships among coordinate systems fixed to various components of gear-cutting machine tool and gear.

  2. Addendum to Revision 1 of the Corrective Action Investigation Plan for Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nevada (Addendum Revision No. 1)

    SciTech Connect

    U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office

    2001-06-06

    This document is submitted as an addendum to the Corrective Action Investigation Plan (CAIP) for Corrective Action Unit (CAU) 98: Frenchman Flat, Nevada Test Site (NTS), Nevada. The addendum was prepared to propose work activities in response to comments resulting from the U.S. Department of Energy's (DOE's) review of the draft Frenchman Flat CAU model of groundwater flow and contaminant transport completed in April 1999. The reviewers included an external panel of experts and the Nevada Division of Environmental Protection. As a result of the review, additional work scope, including new data-collection and modeling activities, has been identified for the Frenchman Flat CAU. The proposed work scope described in this addendum will be conducted in accordance with the revised Underground Test Area strategy contained in the December 2000 amendment to the Federal Facility Agreement and Consent Order. The Frenchman Flat CAU model is a group of interdependent models designed to predict the extent of contamination in groundwater due to the underground nuclear tests conducted within this CAU. At the time of the DOE review, the CAU model consisted of a CAU groundwater flow and transport model comprised of two major components: a groundwater flow model and a recharge model. The CAU groundwater flow model is supported by a hydrostratigraphic model and a recharge model, whereas the CAU transport model is supported by a source-term model. As part of the modeling activities proposed in this addendum, two new major components may be added to the Frenchman Flat CAU model: a total-system model and two local groundwater flow and transport models. The reviewers identified several issues relating to insufficiency of data and inadequacy of the modeling process that should be addressed to provide additional confidence in the modeling results with respect to the potential for contaminant migration to the Lower Carbonate Aquifer. The proposed additional work scope includes new data

  3. Gear visual inspection system and application in logarithmic spiral bevel gear

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Liu, Yi; Yan, Hongbo

    2011-12-01

    The system uses machine vision technology to inspect logarithmic spiral bevel gears. This is a new non-contact measurement technique with high precision and efficiency. Use two cameras in a different location to shoot two images of gear, and collect gear images into the computer. Use correspondence between feature points of two images and optical imaging geometric model to solve three-dimensional coordinates of the tooth surface points. Then, discriminate the tooth shape by comparing to ideal surface point parameters. This kind of inspection method flexibility and provides technical support for processing, detection and correction of logarithmic spiral bevel gears.

  4. Gear visual inspection system and application in logarithmic spiral bevel gear

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Liu, Yi; Yan, Hongbo

    2012-01-01

    The system uses machine vision technology to inspect logarithmic spiral bevel gears. This is a new non-contact measurement technique with high precision and efficiency. Use two cameras in a different location to shoot two images of gear, and collect gear images into the computer. Use correspondence between feature points of two images and optical imaging geometric model to solve three-dimensional coordinates of the tooth surface points. Then, discriminate the tooth shape by comparing to ideal surface point parameters. This kind of inspection method flexibility and provides technical support for processing, detection and correction of logarithmic spiral bevel gears.

  5. Mariner Mars 1971 television picture catalog: Sequence design and picture coverage, volume 2, addendum 1

    NASA Technical Reports Server (NTRS)

    Koskela, P. E.

    1973-01-01

    This addendum to the Mariner Mars 1971 Television Picture Catalog, Volume 2 (for abstract, see N73-20850) contains data for the Mariner 9 TV pictures taken after Rev 262. Some of the data presented in Volume 2 is brought up to date. The new provisional mapping pole is discussed, and tables provide the latitude and longitude with respect to the new pole, prime meridian, and rotation rate for the centerpoints of all the Mariner 9 TV pictures.

  6. Addendum 6 to CSAR 79-038 out-of-hood plutonium storage (burial box)

    SciTech Connect

    Chiao, T.

    1995-06-14

    The Addendum considered an increase in the limit of fissile material in a stacked container array to 500 grams. In other words, the sum of fissile material in an array of containers is limited to 500 grams, regardless of whether the containers are stacked or not. The results of this evaluation indicates that with the modification of the fissile limits described, the system of a container array will stay sub-critical.

  7. Health assessment for American Smelting and Refining, Tacoma, Washington, Region 10 (addendum to). Final report

    SciTech Connect

    Not Available

    1989-09-25

    The Agency for Toxic Substances and Disease Registry (ATSDR) prepared a Preliminary Health Assessment for the American Smelting and Refining Company (ASARCO) site on January 2, 1989. Since that time, the authors have received two additional reports on the site - the Endangerment Assessment (1) and the Engineering Evaluation/Cost Analysis of Removal Action Alternatives (2) The addendum will specifically address public health concerns related to the contamination of off-site soils with arsenic.

  8. Addendum to the MiniBooNE Run Plab. MinneBooNE Physics in 2006

    SciTech Connect

    Aguilar-Arevalo, A. A.

    2004-11-02

    The primary physics goal of Mini BooNE is to confirm or rule out the LSND vμ→ve oscilliation observation with high significance. In the 2003 Run Plan document presented to the PAC, we outlined the need for 1 X 1021 protons on target (POT) to achieve this goal. In this document, we present an addendum to our run plan for fiscal year 2006 (FY2006).

  9. ADDENDUM: The classification of Novikov algebras in low dimensions: invariant bilinear forms

    NASA Astrophysics Data System (ADS)

    Bai, Chengming; Meng, Daoji

    2001-10-01

    In this note, we give a complete classification of the (non-degenerate) symmetric invariant bilinear forms on Novikov algebras in dimension 2 and 3, which can be regarded as an addendum of the classification of Novikov algebras in low dimensions given in our previous work (Bai C M and Meng D J 2001 J. Phys. A: Math. Gen. 34 1581-94).

  10. Nonlinear modeling of adaptive magnetorheological landing gear dampers under impact conditions

    NASA Astrophysics Data System (ADS)

    Ahuré Powell, Louise A.; Choi, Young T.; Hu, Wei; Wereley, Norman M.

    2016-11-01

    Adaptive landing gear dampers that can continuously adjust their stroking load in response to various operating conditions have been investigated for improving the landing performance of a lightweight helicopter. In prior work, adaptive magnetorheological (MR) landing gear dampers that maintained a constant peak stroking force of 4000 lbf across sink rates ranging from 6 to 12 ft s‑1 were designed, fabricated and successfully tested. In this follow-on effort, it is desired to expand the high end of the sink rate range to hold the peak stroking load constant for sink rates ranging from 6 to 26 ft s‑1, thus extending the high end of the speed range from 12 (in the first study) to 26 ft s‑1. To achieve this increase, a spring-based relief valve MR landing gear damper was developed. In order to better understand the MR landing gear damper behavior, a modified nonlinear Bingham Plastic model was formulated, and it incorporates Darcy friction, viscous forces across the MR and relief valves to better account for the damper force behavior at higher speeds. In addition, gas pressure inside the MR damper piston is considered so the total damper force includes a gas force. The MR landing gear damper performance is characterized using drop tests, and the experiments are used to validate model predictions data at low and high nominal impact speeds up to 26 ft s‑1 (shaft velocity of 9.6 ft s‑1).

  11. Performance and Molding of Photosetting Resin Composite (PRC) Spur Gears by Stereolithography

    NASA Astrophysics Data System (ADS)

    Horiguchi, Masahiro; Suzuki, Kensuke; Takase, Kazuya; Sato, Sadao

    The performance of spur gears composed of photosetting resin composites (PRCs) containing various fillers was investigated experimentally. The materials used in the experiment were acrylic resin (PSA) and epoxy resin (PSEP), cured by irradiation with a helium-cadmium (He-Cd) ultraviolet laser (UVL) at a wavelength of 325 nm. The spur gears were molded by stereolithography using a UVL. The optimum time for the post cure in stereo lithography molding was about 20 minutes. The dedendum bending strength of spur gears made from PSA composites containing 1 wt% organic-modified montmorillonite (OMMT) increased by about 20% compared to neat PSA. The kinetics durability of the PRC spur gears was also found to increase due to the reinforcing effect of the filler. The tensile strength and flexural strength of the PSA/OMMT composite were about 1.2 times those of neat PSA. On the other hand, the flexural strength and modulus of neat PSEP were about 2 times greater than that of neat PSA itself. Moreover, the kinetics durability of neat PSEP also shows high values. From these results, it was concluded that the addition of filler has a significant influence on the characteristics and mechanical properties of spur gears made from photosetting resins.

  12. Influence of Tooth Spacing Error on Gears With and Without Profile Modifications

    NASA Technical Reports Server (NTRS)

    Padmasolala, Giri; Lin, Hsiang H.; Oswald, Fred B.

    2000-01-01

    A computer simulation was conducted to investigate the effectiveness of profile modification for reducing dynamic loads in gears with different tooth spacing errors. The simulation examined varying amplitudes of spacing error and differences in the span of teeth over which the error occurs. The modification considered included both linear and parabolic tip relief. The analysis considered spacing error that varies around most of the gear circumference (similar to a typical sinusoidal error pattern) as well as a shorter span of spacing errors that occurs on only a few teeth. The dynamic analysis was performed using a revised version of a NASA gear dynamics code, modified to add tooth spacing errors to the analysis. Results obtained from the investigation show that linear tip relief is more effective in reducing dynamic loads on gears with small spacing errors but parabolic tip relief becomes more effective as the amplitude of spacing error increases. In addition, the parabolic modification is more effective for the more severe error case where the error is spread over a longer span of teeth. The findings of this study can be used to design robust tooth profile modification for improving dynamic performance of gear sets with different tooth spacing errors.

  13. Gear noise behavior induced by their topological quality

    NASA Astrophysics Data System (ADS)

    Jolivet, S.; Mezghani, S.; El Mansori, M.; Zahouani, H.

    2014-01-01

    The upcoming fuel economy standards will result in the rapid development of electric or hybrid vehicles. Such regulatory demands will affect transmission design, which is currently driving changes in the number, type, size and quality levels of gears. Thus, gear manufacturers need to create high quality gear flanks with special topological modifications. The most important objectives are to increase the load-carrying capacity of gears and also to reduce the gear noise behavior. The teeth surface is at the heart of gear meshing mechanics and is one of the main elements in the generation of noise. The most common gear wear mechanisms are micro-pitting, pitting and spalling, which often occur on teeth surface during the early stage of failure. This study aims to identify the scale effect of pitting defects of gear teeth surface on the acoustics response of a spur gear pair. Consequently, we have developed a two-dimensional finite-element simulation model of a one-stage gear system. The transmission system was composed of two identical spur gears with one degree of freedom. Pitting defects versus topological features at different scales were modeled on the gear tooth flanks. To quantify their impact on gear noises and vibrations, we used contact stiffness as our criteria because it is directly linked to gear noise. The prevalence of the gear quality and its topological features on power density and sound issues are computed and discussed in this paper.

  14. 46 CFR 28.885 - Cargo gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... shall be marked on the heel of each cargo boom, crane, or derrick. These letters and figures are to be... proof load applied to the winches, booms, derricks, cranes and all associated gear shall be lifted...

  15. 50 CFR 300.109 - Gear disposal.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals or any manmade items retrieved in...

  16. 50 CFR 300.109 - Gear disposal.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals or any manmade items retrieved in...

  17. 50 CFR 300.109 - Gear disposal.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals or any manmade items retrieved in...

  18. 50 CFR 300.109 - Gear disposal.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals or any manmade items retrieved in...

  19. 50 CFR 300.109 - Gear disposal.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic bags, oil drums, petroleum containers, oil, toxic chemicals or any manmade items retrieved in...

  20. Empirical Prediction of Aircraft Landing Gear Noise

    NASA Technical Reports Server (NTRS)

    Golub, Robert A. (Technical Monitor); Guo, Yue-Ping

    2005-01-01

    This report documents a semi-empirical/semi-analytical method for landing gear noise prediction. The method is based on scaling laws of the theory of aerodynamic noise generation and correlation of these scaling laws with current available test data. The former gives the method a sound theoretical foundation and the latter quantitatively determines the relations between the parameters of the landing gear assembly and the far field noise, enabling practical predictions of aircraft landing gear noise, both for parametric trends and for absolute noise levels. The prediction model is validated by wind tunnel test data for an isolated Boeing 737 landing gear and by flight data for the Boeing 777 airplane. In both cases, the predictions agree well with data, both in parametric trends and in absolute noise levels.

  1. Doing Mathematics with Bicycle Gear Ratios.

    ERIC Educational Resources Information Center

    Stump, Sheryl L.

    2000-01-01

    Describes an activity in which students examine bicycle chain-rings, cogs, and gear ratios as a means of exploring algebraic relationships, data collection, scatter plots, and lines of best fit. (KHR)

  2. Tool Gear Version 2.3

    SciTech Connect

    2011-12-05

    Tool Gear Version 2 is an expanded collection of programs and software libraries that form the infrastructure on which software tools may be built. The software tools help application developers understand the performance of the programs or help them find programming errors. Tool Gear includes components for gathering data from target programs, either through direct instrumentations or by parsing the output of third-party tools, transmitting the data to a databse, organizing and storing the data, presenting it through a variety of graphical interfaces. Tool Gear is designed to be an extensible system, so users can manage a variety of data and create new ways to present it. Too Gear is sesigned to work with both sequential and parallel programs on multiple computer platforms

  3. Vibration Based Sun Gear Damage Detection

    NASA Technical Reports Server (NTRS)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  4. Tool Gear Version 2.3

    2011-12-05

    Tool Gear Version 2 is an expanded collection of programs and software libraries that form the infrastructure on which software tools may be built. The software tools help application developers understand the performance of the programs or help them find programming errors. Tool Gear includes components for gathering data from target programs, either through direct instrumentations or by parsing the output of third-party tools, transmitting the data to a databse, organizing and storing the data,more » presenting it through a variety of graphical interfaces. Tool Gear is designed to be an extensible system, so users can manage a variety of data and create new ways to present it. Too Gear is sesigned to work with both sequential and parallel programs on multiple computer platforms« less

  5. Instabilities of geared couplings: Theory and practice

    NASA Technical Reports Server (NTRS)

    Kirk, R. G.; Mondy, R. E.; Murphy, R. C.

    1982-01-01

    The use of couplings for high speed turbocompressors or pumps is essential to transmit power from the driver. Typical couplings are either of the lubricated gear or dry diaphragm type design. Gear couplings have been the standard design for many years and recent advances in power and speed requirements have pushed the standard design criteria to the limit. Recent test stand and field data on continuous lube gear type couplings have forced a closer examination of design tolerances and concepts to avoid operational instabilities. Two types of mechanical instabilities are reviewed in this paper: (1) entrapped fluid, and (2) gear mesh instability resulting in spacer throw-out onset. Test stand results of these types of instabilities and other directly related problems are presented together with criteria for proper coupling design to avoid these conditions. An additional test case discussed shows the importance of proper material selection and processing and what can happen to an otherwise good design.

  6. Gear drive automatically indexes rotary table

    NASA Technical Reports Server (NTRS)

    Johns, M. F.

    1966-01-01

    Combination indexer and drive unit drills equally spaced circular hole patterns on rotary tables. It automatically rotates the table a distance exactly equal to one hole spacing for each revolution of a special idler gear.

  7. Hazards Analysis Report Addendum Buildign 518/518A Industrial Gases & Chemtrack Receiving & Barcoding Facility

    SciTech Connect

    Hickman, R D

    2000-02-04

    This report documents the Hazards Analysis Report (HAR) Addendum for Buildings 518 and 518A. In summary, the description of the facility and the operations given in the 1995 PHA are the same as the present in this year 2000. The hazards description also remains the same. The hazards analysis in this HAR Addendum is different in that it needs to be compared to operations routinely ''performed'' by the public. The HAR Addendum characterizes the level of intrinsic potential hazards associated with a facility and provides the basis for hazard classification. The hazard classification determines the level of safety documentation required and the DOE order governing the safety analysis. The hazard classification also determines the level of review and approval required for the safety analysis. This facility does not contain any safety class systems or systems important to safety as defined in Department of Energy standard DOE-STD-3009-94. The hazards of primary concern associated with B518 and B518A are chemical in nature. The hazard classification is determined by comparing facility inventories of chemicals with threshold values for the various hazard classification levels. In this way, the hazard level of the facility can be ascertained. The most significant hazards that could affect people in the local area of B518 and B518A, elsewhere on the LLNL site, and off site, are associated with hazardous and toxic materials. These hazards are the focus of this report and are the basis for the facility hazard classification.

  8. Sierra/SolidMechanics 4.22 user's guide : addendum for shock capabilities.

    SciTech Connect

    Not Available

    2011-10-01

    This is an addendum to the Sierra/SolidMechanics 4.22 User's Guide to document additional capabilities that are available for use in the Presto{_}ITAR code that are not available for use in the standard version of Sierra/SolidMechanics (Sierra/SM). Presto{_}ITAR is an enhanced version of Sierra/SM that provides capabilities that make it regulated under the U.S. Department of State's International Traffic in Arms Regulations (ITAR) export-control rules. This code is part of the Vivace product, and is only distributed to entities that comply with ITAR regulations. The enhancements primarily focus on material models that include an energy-dependent pressure response, appropriate for very large deformations and strain rates. Since this is an addendum to the standard Sierra/SolidMechanics User's Guide, please refer to that document first for general descriptions of code capability and use. This addendum documents material models and element features that support energy-dependent material models.

  9. 32 CFR Appendix C to Part 68 - Addendum for Education Services Between [Name of Educational Institution] and the U.S. Army

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... U.S. Army C Appendix C to Part 68 National Defense Department of Defense OFFICE OF THE SECRETARY OF...—Addendum for Education Services Between and the U.S. Army 1. Purpose. This addendum is between (Name of Educational Institution), hereafter referred to as the “Institution,” and the United States Army. The...

  10. Assessment of worm gearing for helicopter transmissions

    NASA Technical Reports Server (NTRS)

    Chaiko, Lev

    1990-01-01

    A high-efficiency hydrostatic worm gear drive for helicopter transmissions is assessed. The example given is for a large cargo helicopter with three 4000-kW engines and transmission reduction ratio of 110. Also contained are: an efficiency calculation, a description of the test stand for evaluating the feasibility of worm gear hydrostatic mesh, a weight calculation, and a comparison with conventional helicopter transmissions of the same power and transmission reduction ratio.

  11. Computerized inspection of gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Yi, Zhang; Kieffer, Jonathan; Handschuh, Robert F.; Coy, John J.

    1989-01-01

    An approach is proposed that uses coordinate measurements of the real surface of spiral bevel gears to determine the actual machine tool setting applied during the gear manufacturing process. The deviations of the real surface from the theoretical one are also determined. Adjustments are then applied by machine tool corrections to minimize these surface deviations. This is accomplished by representing the real surface analytically in the same Gaussian coordinates as the theoretical surface.

  12. Systems and Methods for Implementing Bulk Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

    NASA Technical Reports Server (NTRS)

    Hofmann, Douglas C. (Inventor); Wilcox, Brian (Inventor)

    2016-01-01

    Bulk metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a strain wave gear includes: a wave generator; a flexspline that itself includes a first set of gear teeth; and a circular spline that itself includes a second set of gear teeth; where at least one of the wave generator, the flexspline, and the circular spline, includes a bulk metallic glass-based material.

  13. Bearing and gear steels for aerospace applications

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1990-01-01

    Research in metallurgy and processing for bearing and gear steels has resulted in improvements in rolling-element bearing and gear life for aerospace application by a factor of approximately 200 over that obtained in the early 1940's. The selection and specification of a bearing or gear steel is dependent on the integration of multiple metallurgical and physical variables. For most aerospace bearings, through-hardened VIM-VAR AISI M-50 steel is the material of preference. For gears, the preferential material is case-carburized VAR AISI 9310. However, the VAR processing for this material is being replaced by VIM-VAR processing. Since case-carburized VIM-VAR M-50NiL incorporates the desirable qualities of both the AISI M-50 and AISI 9310 materials, optimal life and reliability can be achieved in both bearings and gears with a single steel. Hence, this material offers the promise of a common steel for both bearings and gears for future aerospace applications.

  14. An Overview of Landing Gear Dynamics

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn I.

    1999-01-01

    One of the problems facing the aircraft community is landing gear dynamics, especially shimmy and brake-induced vibration. Although neither shimmy nor brake-induced vibrations are usually catastrophic, they can lead to accidents due to excessive wear and shortened life of gear parts and contribute to pilot and passenger discomfort. Recently, NASA has initiated an effort to increase the safety of air travel by reducing the number of accidents by a factor of five in ten years. This safety initiative has spurred an increased interest in improving landing gear design to minimize shimmy and brake-induced vibration that are still largely misunderstood phenomena. In order to increase the understanding of these problems, a literature survey was performed. The major focus of the paper is to summarize work documented from the last ten years to highlight the latest efforts in solving these vibration problems. Older publications are included to understand the longevity of the problem and the findings from earlier researchers. The literature survey revealed a variety of analyses, testing, modeling, and simulation of aircraft landing gear. Experimental validation and characterization of shimmy and brake-induced vibration of aircraft landing gear are also reported. This paper presents an overview of the problem documented in the references together with a history of landing gear dynamic problems and solutions. Based on the assessment of this survey, recommendations of the most critically needed enhancements to the state of the art are given.

  15. Gear Tooth Root Stresses of a Very Heavily Loaded Gear Pair-Case Study: Orbiter Body Flap Actuator Pinion and Ring Gear

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Handschuh, Robert F.

    2015-01-01

    The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.

  16. Application of Face-Gear Drives in Helicopter Transmissions

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  17. The Stiller-Smith Engine: Floating gear analysis

    SciTech Connect

    Craven, R.; Smith, J.E.; Butler, S.

    1987-01-01

    The Stiller-Smith Engine employs a non-standard gear train and as such requires a closer examination of the design and sizing of the gears. To accomplish this the motion of the Stiller-Smith gear train is compared to more familiar arrangements. The results of a kinematic and dynamic analysis introduce the irregular forces that the gears are subjected to. The ''floating'' or ''trammel'' gear is examined more closely, first stochastically and then with finite element analysis. This pinpoints high stress concentrations on the gear and where they occur during the engine cycle. The configuration considered is an output shaft, negligible idler gear forces, and floating gear pins that are part of the connecting rods rather than the floating gear. Various loading techniques are discussed with possible ramifications of each.

  18. Gear-driven draw works have high reliability

    SciTech Connect

    Heinrichs, P. )

    1995-02-20

    Gear-driven draw works have several advantages over conventional chain-driven draw works. Gear-driven draw works have a longer life and working availability (reliability) than chain-driven units, and these factors lead to lower operating costs because of fewer rig shut downs for repairs. The gear shift allows higher speeds and a better adaptation to the performance curve for greater operational efficiency. Additionally, more variable speed selection is possible with direct shifting from 1st to 4th speed. On failure of a gear shift, operation can be continued, with reduced performance, with the autodriller which is integrated directly into the gear shift. Additionally, the gear-driven unit makes less noise and vibration and has a compact construction for reduced weight. The oldest gear-driven draw works have been in use without any gear failure for 27 years, and other gear-driven draw works have worked for many years with no failure.

  19. Handbook on Face Gear Drives with a Spur Involute Pinion

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Egelja, A.; Tan, J.; Chen, D. Y.-D.; Heath, G.

    2000-01-01

    The use of face gears in power transmission and drive systems has a significant number of benefits. Face gears allow a variety of new transmission arrangements as well as high reduction ratio capability. This leads to drive system weight reduction and improvements in performance. In this work, basic information about the design and analysis of face gear drives is presented. The work considers face gears in mesh with spur involute pinions for both intersecting axes and offset drives. Tooth geometry, kinematics, generation of face gears with localized bearing contact by cutting and grinding, avoidance of tooth undercutting, avoidance of tooth pointing, tooth contact analysis, and algorithms for the simulation of meshing and contact arc all topics which are discussed. In addition, applications of face gear drives are presented. Included are design uses in aerospace applications such as helicopter transmissions, split-torque face gear arrangements, comparisons of face gears with bevel gears, and general design considerations.

  20. Gear shift control for an automatic transmission of a vehicle

    SciTech Connect

    Nagaoka, M.; Oda, K.

    1986-04-29

    This patent describes an automatic transmission for vehicles. The automatic transmission consists of: a torque converter having an input member and an output member, a multiple stage transmission gear mechanism connected with the output member of the torque converter and having a plurality of gear stages, gear selecting means for selecting one of the gear stages in the transmission gear mechanism, vehicle operating condition detecting means for detecting vehicle operating conditions and producing vehicle operating condition signals, gear shift control means for operating the gear selecting means in accordance with the vehicle operating condition signals to thereby make the gear selecting means select one of the gear stages, the gear shift control means including first gear shift means having memories of first vehicle operating conditions wherein the gear selecting means is to be operated, second gear shift means having memories of second vehicle operating conditions wherein the gear selecting means is to be operated, traffic jam detecting means for detecting a traffic jam, and means for operating the gear selecting means under the first gear shift means when the traffic jam is not detected but under the second gear shift means when the traffic jam is detected so that a corresponding gear shift operation is carried out at a lower vehicle speed in a traffic jam than in an operating condition wherein the traffic jam is not detected, the traffic jam detecting means including memory means having memories of a traffic jam zone defined by a relationship between average vehicle speeds and acceleration rates corresponding to the average vehicle speeds.

  1. Gear and Transmission Research at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.

    1997-01-01

    This paper is a review of some of the research work of the NASA Lewis Research Center Mechanical Components Branch. It includes a brief review of the NASA Lewis Research Center and the Mechanical Components Branch. The research topics discussed are crack propagation of gear teeth, gear noise of spiral bevel and other gears, design optimization methods, methods we have investigated for transmission diagnostics, the analytical and experimental study of gear thermal conditions, the analytical and experimental study of split torque systems, the evaluation of several new advanced gear steels and transmission lubricants and the evaluation of various aircraft transmissions. The area of research needs for gearing and transmissions is also discussed.

  2. Extending gear life in a coal pulverizer gearbox

    SciTech Connect

    Hansen, T.

    2007-08-15

    A coal-fired power plant in the Western United States experienced short gearbox life in the 13 coal pulverizers operating at the plant. Wear on the bronze bull gear faces was suspected to have been caused by high particulate loading of coal dust and dirt in the gear oil, catalytic reaction between gear oil additives and some of the particulates generated, and high levels of copper in the gear oil. By addressing particulate ingress, adding filtration and switching to a synthetic gear oil, significant benefits were made to the power plant and gear oil life was extended. 2 photos., 1 tab.

  3. Computer aided design and analysis of gear tooth geometry

    NASA Technical Reports Server (NTRS)

    Chang, S. H.; Huston, R. L.

    1987-01-01

    A simulation method for gear hobbing and shaping of straight and spiral bevel gears is presented. The method is based upon an enveloping theory for gear tooth profile generation. The procedure is applicable in the computer aided design of standard and nonstandard tooth forms. An inverse procedure for finding a conjugate gear tooth profile is presented for arbitrary cutter geometry. The kinematic relations for the tooth surfaces of straight and spiral bevel gears are proposed. The tooth surface equations for these gears are formulated in a manner suitable for their automated numerical development and solution.

  4. A Computational Investigation of Gear Windage

    NASA Technical Reports Server (NTRS)

    Hill, Matthew J.; Kunz, Robert F.

    2012-01-01

    A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear windage loss, including the physics of loss mitigation strategies, and to propose and evaluate new approaches for minimizing loss. Absolute and relative frame CFD simulation, overset gridding, multiphase flow analysis, and sub-layer resolved turbulence modeling were brought to bear in achieving these goals. Several spur gear geometries were studied for which experimental data are available. Various shrouding configurations and free-spinning (no shroud) cases were studied. Comparisons are made with experimental data from the open literature, and data recently obtained in the NASA Glenn Research Center Gear Windage Test Facility. The results show good agreement with experiment. Interrogation of the validative and exploratory CFD results have led, for the first time, to a detailed understanding of the physical mechanisms of gear windage loss, and have led to newly proposed mitigation strategies whose effectiveness is computationally explored.

  5. An Overview of Landing Gear Dynamics

    NASA Technical Reports Server (NTRS)

    Pritchard, Jocelyn I.

    1999-01-01

    One of the problems facing the aircraft community is landing gear dynamics, especially shimmy and brake-induced vibration. Shimmy and brake-induced vibrations can lead to accidents due to excessive wear and shortened life of gear parts and contribute to pilot and passenger discomfort. To increase understanding of these problems, a literature survey was performed. The major focus is on work from the last ten years. Some older publications are included to understand the longevity of the problem and the background from earlier researchers. The literature survey includes analyses, testing, modeling, and simulation of aircraft landing gear; and experimental validation and characterization of shimmy and brake-induced vibration of aircraft landing gear. The paper presents an overview of the problem, background information, and a history of landing gear dynamics problems and solutions. Based on the survey an assessment and recommendations of the most critically needed enhancements to the state of the art will be presented. The status of Langley work contributing to this activity will be given.

  6. Gear Transmission Error Measurement System Made Operational

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B.

    2002-01-01

    A system directly measuring the transmission error between the meshing spur or helical gears was installed at the NASA Glenn Research Center and made operational in August 2001. This system employs light beams directed by lenses and prisms through gratings mounted on the two gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. The device is capable of resolution better than 0.1 mm (one thousandth the thickness of a human hair). The measured transmission error can be displayed in a "map" that shows how the transmission error varies with the gear rotation or it can be converted to spectra to show the components at the meshing frequencies. Accurate transmission error data will help researchers better understand the mechanisms that cause gear noise and vibration and will lead to The Design Unit at the University of Newcastle in England specifically designed the new system for NASA. It is the only device in the United States that can measure dynamic transmission error at high rotational speeds. The new system will be used to develop new techniques to reduce dynamic transmission error along with the resulting noise and vibration of aeronautical transmissions.

  7. Modal analysis of gear housing and mounts

    NASA Technical Reports Server (NTRS)

    Lim, Teik C.; Singh, RAJ.; Zakrajsek, James J.

    1989-01-01

    Dynamic finite element analysis of a real gear housing is presented. The analysis was conducted for the housing without the rotating components (gears, shafts, and bearings). Both rigid and flexible mounting conditions for the gear housing are considered in this analysis. The flexible support simulates the realistic mounting condition on a rotorcraft, and the rigid one is analyzed for comparison purposes. The effect of gear housing stiffeners is also evaluated. The results indicate that the first six natural modes of the flexibly mounted gear housing in the 0 to 200 Hz range correspond to the translational and rotational rigid body vibration modes of the housing. Above this range, the housing plate elastic modes begin to occur. In the case of the rigid mount, only the housing plate elastic modes are observed which are verified by modal analysis experiments. Parametric studies show that the housing plate stiffeners and rigid mounts tend to increase most of the natural frequencies, the lower ones being affected the most.

  8. A computational investigation of gear windage

    NASA Astrophysics Data System (ADS)

    Hill, Matthew J.

    A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear windage loss, including the physics of loss mitigation strategies, and to propose and evaluate new approaches for minimizing loss. Absolute and relative frame CFD simulation, overset gridding, multiphase flow analysis, and sub-layer resolved turbulence modeling were brought to bear in achieving these goals. Several spur gear geometries were studied for which experimental data are available. Various shrouding configurations and free-spinning (no shroud) cases were studied. Comparisons are made with experimental data from the open literature, and data recently obtained in the NASA Glenn Research Center Gear Windage Test Facility. The results show good agreement with experiment. Interrogation of the validative and exploratory CFD results have led, for the first time, to a detailed understanding of the physical mechanisms of gear windage loss, and have led to newly proposed mitigation strategies whose effectiveness is computationally explored.

  9. Planetary gear train for automotive transmission or the like

    SciTech Connect

    Hiraiwa, K.

    1987-01-27

    This patent describes a planetary gear train transmission comprising: an input shaft operatively connected with a source of rotational energy; first and second plAnetary gear sets respectively including first and second sun gears, first and second ring gears, first and second pinions carriers and first and second sets of pinion gears operatively mounted on the first and second pinion carriers and respectively arranged to mesh with their respective sun and ring gears; a first clutch selectively providing a drive connection between the input shaft and the first sun gear; a second clutch selectively providing a drive connection between the input shaft and the first sun gear; a third clutch selectively providing a drive connection between first and second sun gears; a fourth clutch selectively providing a drive connection between the first sun gear and the second pinion carrier; a first brake selectively rendering the second sun gear stationary with respect to a housing in which the transmission is disposed; a second brake selectively rendering the second pinion carrier stationary with respect to the housing; and an output shaft in drive connection with the first pinion carrier and the second ring gear, such that the transmission produces four forward speeds using only two planetary gear sets.

  10. Time-synchronous-averaging of gear-meshing-vibration transducer responses for elimination of harmonic contributions from the mating gear and the gear pair

    NASA Astrophysics Data System (ADS)

    Mark, William D.

    2015-10-01

    The transmission-error frequency spectrum of meshing gear pairs, operating at constant speed and constant loading, is decomposed into harmonics arising from the fundamental period of the gear pair, rotational harmonics of the individual gears of the pair, and tooth-meshing harmonics. In the case of hunting-tooth gear pairs, no rotational harmonics from the individual gears, other than the tooth-meshing harmonics, are shown to occur at the same frequencies. Time-synchronous averages utilizing a number of contiguous revolutions of the gear of interest equal to an integer multiple of the number of teeth on the mating gear is shown to eliminate non-tooth-meshing transmission-error rotational-harmonic contributions from the mating gear, and those from the gear pair, in the case of hunting-tooth gear pairs, and to minimize these contributions in the case of non-hunting-tooth gear pairs. An example computation is shown to illustrate the effectiveness of the suggested time-synchronous-averaging procedure.

  11. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  12. Retrofitting gear couplings with diaphragm couplings

    SciTech Connect

    Mancuso, J.R. )

    1988-10-01

    Retrofitting a coupling should not be an afterthought when upgrading a system. Couplings are an integral part of a drive train and should be a major consideration. This article discusses guidelines that should be used when replacing gear couplings with diaphragm couplings. Reviewed are the coupling selection process: how and to what extent the desired diaphragm couplings should be matched to the gear coupling. Also discussed are the details of coupling modification that can be made to accommodate system performance. Included are how changes in materials, configuration and design can help tune a diaphragm coupling to meet the characteristics of the previous gear couplings. The article also discusses the retrofit process for a specific syngas train at International Minerals and Chemical Corp., Sterlington, La.

  13. Thermal elastohydrodynamic lubrication of spur gears

    NASA Technical Reports Server (NTRS)

    Wang, K. L.; Cheng, H. S.

    1980-01-01

    An analysis and computer program called TELSGE were developed to predict the variations of dynamic load, surface temperature, and lubricant film thickness along the contacting path during the engagement of a pair of involute spur gears. The analysis of dynamic load includes the effect of gear inertia, the effect of load sharing of adjacent teeth, and the effect of variable tooth stiffness which are obtained by a finite-element method. Results obtained from TELSGE for the dynamic load distributions along the contacting path for various speeds of a pair of test gears show patterns similar to that observed experimentally. Effects of damping ratio, contact ratio, tip relief, and tooth error on the dynamic load were examined. In addition, two dimensionless charts are included for predicting the maximum equilibrium surface temperature, which can be used to estimate directly the lubricant film thickness based on well established EHD analysis.

  14. Jerky loads on surface-hardened gears

    NASA Technical Reports Server (NTRS)

    Rettig, H.; Wirth, X.

    1978-01-01

    Damage occurs again and again in practice in the form of transmissions with surface hardened gears which break after a very long operating time (explained by seldom occurring jerky loads). Gear drives are frequently exposed to jerky stresses which are greater than their fatigue limit. These stresses are considered in gear calculations, first, by shock factors when the transmission is to be designed as high endurance with regard to overloads and, second, in the form of operating ratios when the design is to be time enduring with regard to overloads. The size of the operating ratio depends not only on torque characteristics, drive and processing machine, but also on the material and heat treatment.

  15. Enhanced automated spiral bevel gear inspection

    NASA Technical Reports Server (NTRS)

    Frint, Harold K.; Glasow, Warren

    1992-01-01

    Presented here are the results of a manufacturing and technology program to define, develop, and evaluate an enhanced inspection system for spiral bevel gears. The method uses a multi-axis coordinate measuring machine which maps the working surface of the tooth and compares it with nominal reference values stored in the machine's computer. The enhanced technique features a means for automatically calculating corrective grinding machine settings, involving both first and second order changes, to control the tooth profile to within specified tolerance limits. This enhanced method eliminates the subjective decision making involved in the tooth patterning method, still in use today, which compares contract patterns obtained when the gear is set to run under light load in a rolling test machine. It produces a higher quality gear with significant inspection time and cost savings.

  16. Two stage gear tooth dynamics program

    NASA Technical Reports Server (NTRS)

    Boyd, Linda S.

    1989-01-01

    The epicyclic gear dynamics program was expanded to add the option of evaluating the tooth pair dynamics for two epicyclic gear stages with peripheral components. This was a practical extension to the program as multiple gear stages are often used for speed reduction, space, weight, and/or auxiliary units. The option was developed for either stage to be a basic planetary, star, single external-external mesh, or single external-internal mesh. The two stage system allows for modeling of the peripherals with an input mass and shaft, an output mass and shaft, and a connecting shaft. Execution of the initial test case indicated an instability in the solution with the tooth paid loads growing to excessive magnitudes. A procedure to trace the instability is recommended as well as a method of reducing the program's computation time by reducing the number of boundary condition iterations.

  17. Practical experiences with worm gearing for spacecraft power transmission applications

    NASA Technical Reports Server (NTRS)

    Purdy, William; Mccown, William

    1989-01-01

    Experiences of several organizations using worm gearing for spacecraft are discussed. Practical aspects and subtleties of using worm gearing for design and operation is included. Knowledge gained from these applications is analyzed, and guidelines for usage are proposed.

  18. Design of aircraft turbine fan drive gear transmission system

    NASA Technical Reports Server (NTRS)

    Dent, E.; Hirsch, R. A.; Peterson, V. W.

    1970-01-01

    The following basic types of gear reduction concepts were studied as being feasible power train systems for a low-bypass-ratio, single-spool, geared turbofan engine for general aircraft use: (1) single-stage external-internal reduction, (2) gears (offset shafting), (3) multiple compound idler gear system (concentric shafting), and (4) star gear planetary system with internal ring gear final output member (concentric shafting-counterrotation). In addition, studies were made of taking the accessories drive power off both the high-speed and low-speed shafting, using either face gears or spiral bevel gears. Both antifriction and sleeve-type bearings were considered for the external-internal and star-planet reduction concepts.

  19. Profile modification to minimize spur gear dynamic loading

    NASA Technical Reports Server (NTRS)

    Lin, Hsiang Hsi; Townsend, Dennis P.; Oswald, Fred B.

    1987-01-01

    An analytical computer simulation program for dynamic modeling of low-contact-ratio spur gear systems is presented. The procedure computes the static transmission error of the gears operating under load and uses a fast Fourier transform to generate the frequency spectrum of the static transmission error at various tooth profile modifications. The dynamic loading response of an unmodified (perfect involute) gear pair was compared with that of gears with various profile modifications. Correlations were found between various profile modifications and the resulting dynamic loads. An effective error, obtained from frequency domain analysis of the static transmission error of the gears, gave a very good indication of the optimum profile modification to reduce gear dynamic loading. Design curves generated by dynamic simulation at various profile modifications are given for gear systems operated at various loads. Optimum profile modifications can be determined from these design curves for improved gear design.

  20. Profile modification to minimize spur gear dynamic loading

    NASA Technical Reports Server (NTRS)

    Lin, H. H.; Townsend, D. P.; Oswald, F. B.

    1989-01-01

    An analytical computer simulation program for dynamic modeling of low-contact-ratio spur gear systems is presented. The procedure computes the static transmission error of the gears operating under load and uses a fast Fourier transform to generate the frequency spectrum of the static transmission error at various tooth profile modifications. The dynamic loading response of an unmodified (perfect involute) gear pair was compared with that of gears with various profile modifications. Correlations were found between various profile modifications and the resulting dynamic loads. An effective error, obtained from frequency domain analysis of the static transmission error of the gears, gave a very good indication of the optimum profile modification to reduce gear dynamic loading. Design curves generated by dynamic simulation at various profile modifications are given for gear systems operated at various loads. Optimum profile modifications can be determined from these design curves for improved gear design.

  1. 13. Detail view of drum screen short shaft gears, journal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. Detail view of drum screen short shaft gears, journal bearing, rotation drive chain, upper sprocket gear, and drum screen edge in background, facing southeast (downstream) from drum screen cover. - Congdon Canal, Fish Screen, Naches River, Yakima, Yakima County, WA

  2. 4. END VIEW OF HOIST, SHOWING REDUCTION GEARS AND BED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. END VIEW OF HOIST, SHOWING REDUCTION GEARS AND BED FOR (MISSING) CLUTCH/DRIVE GEAR UNIT, LOOKING SOUTHEAST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  3. 55. VIEW TO NORTHEAST OF MOTOR AND REDUCTION GEAR NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. VIEW TO NORTHEAST OF MOTOR AND REDUCTION GEAR NO. 1: View towards the northeast of Motor and Reduction Gear No. 1, installed in 1957. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  4. 32. DETAIL OF GEARS LOOKING NORTH WITH SHEATHING REMOVED AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. DETAIL OF GEARS LOOKING NORTH WITH SHEATHING REMOVED AND SHAFT OF KING GEAR BEYOND - Caleb Crosby Threshing Barn, Noeton (moved to Norris Dam State Park, Lake City), Morristown, Hamblen County, TN

  5. 3. SIDE VIEW OF HOIST, SHOWING REDUCTION GEARS AND BED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. SIDE VIEW OF HOIST, SHOWING REDUCTION GEARS AND BED FOR (MISSING) CLUTCH/DRIVE GEAR UNIT, LOOKING SOUTH - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  6. 17. Detail view of coupling shaft connection between reduction gear ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Detail view of coupling shaft connection between reduction gear and cane mill drive gears - Hacienda Azucarera la Igualdad, Sugar Mill Ruins & Steam Engine, PR Route 332, Guanica, Guanica Municipio, PR

  7. 53. REAR OF MOTOR AND REDUCTION GEAR NO. 2: View ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. REAR OF MOTOR AND REDUCTION GEAR NO. 2: View towards northwest showing rear of Motor and Reduction Gear No. 2, installed in 1926. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  8. 58. DETAIL OF PINION AND BULL GEARS: Detail view towards ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. DETAIL OF PINION AND BULL GEARS: Detail view towards northeast of the pinion and bull gears of the winding machinery. - San Francisco Cable Railway, Washington & Mason Streets, San Francisco, San Francisco County, CA

  9. 17. View of disassembled reduction gear parts including bull and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. View of disassembled reduction gear parts including bull and intermediate gears and pedestal bearing. - Hacienda Azucarera La Esperanza, Steam Engine & Mill, 2.65 Mi. N of PR Rt. 2 Bridge over Manati River, Manati, Manati Municipio, PR

  10. 22. Steering gear box and wheel from starboard side. Mizzen ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Steering gear box and wheel from starboard side. Mizzen boom has been removed for repairs (note boom cradle just forward of steering gear box). - Schooner C.A. THAYER, Hyde Street Pier, San Francisco, San Francisco County, CA

  11. 7. VIEW OF GEAR SHAPER. Built 1935 (Conrail 00015). Fellows ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF GEAR SHAPER. Built 1935 (Conrail 00015). Fellows Gear Shaper Company, Springfield, Vermont. - Juniata Shops, Machine Shop No. 1, East of Fourth Avenue at Third Street, Altoona, Blair County, PA

  12. 50 CFR 660.372 - Fixed gear sablefish fishery management.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... limited entry permit with both a gear endorsement for longline or trap (or pot) gear and a sablefish... vessels that are not participating in the primary season under § 660.370(c). Trip and/or size limits...

  13. Data Fusion Tool for Spiral Bevel Gear Condition Indicator Data

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Antolick, Lance J.; Branning, Jeremy S.; Thomas, Josiah

    2014-01-01

    Tests were performed on two spiral bevel gear sets in the NASA Glenn Spiral Bevel Gear Fatigue Test Rig to simulate the fielded failures of spiral bevel gears installed in a helicopter. Gear sets were tested until damage initiated and progressed on two or more gear or pinion teeth. During testing, gear health monitoring data was collected with two different health monitoring systems. Operational parameters were measured with a third data acquisition system. Tooth damage progression was documented with photographs taken at inspection intervals throughout the test. A software tool was developed for fusing the operational data and the vibration based gear condition indicator (CI) data collected from the two health monitoring systems. Results of this study illustrate the benefits of combining the data from all three systems to indicate progression of damage for spiral bevel gears. The tool also enabled evaluation of the effectiveness of each CI with respect to operational conditions and fault mode.

  14. 6. VIEW OF DRIFT SHAFT, HOIST MOTOR, WORM WHEEL GEAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VIEW OF DRIFT SHAFT, HOIST MOTOR, WORM WHEEL GEAR ASSEMBLY, CROSS SHAFT, AND INTERMEDIATE GEAR HOIST ASSEMBLY FOR CONTROL GATE NO. 6, LOOKING WEST - Long Lake Hydroelectric Plant, Spillway Dam, Spanning Spokane River, Ford, Stevens County, WA

  15. Theoretical analysis on flow characteristics of melt gear pump

    NASA Astrophysics Data System (ADS)

    Zhao, R. J.; Wang, J. Q.; Kong, F. Y.

    2016-05-01

    The relationship between Geometric parameters and theoretical flow of melt gear pump is revealed, providing a theoretical basis to melt gear pump design. The paper has an analysis of meshing movement of melt gear pump on the condition of four different tooth numbers, stack movement law and flow ripple. The regulation of flow pulsation coefficient is researched by MATLAB software. The modulus formula of melt gear pump is proposed, consistent with actual situation.

  16. Surface geometry of circular cut spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Huston, R. L.; Coy, J. J.

    1981-01-01

    An analysis of the surface geometry of spiral bevel gears formed by a circular cutter is presented. The emphasis is upon determining the tooth surface principal radii of curvature of crown (flat) gears. Specific results are presented for involute, straight, and hyperbolic cutter profiles. It is shown that the geometry of circular cut spiral bevel gears is somewhat simpler than a theoretical logarithmic spiral bevel gear.

  17. Ideal spiral bevel gears: A new approach to surface geometry

    NASA Technical Reports Server (NTRS)

    Huston, R. L.; Coy, J. J.

    1980-01-01

    The fundamental geometrical characteristics of spiral bevel gear tooth surfaces are discussed. The parametric representation of an ideal spiral bevel tooth is developed based on the elements of involute geometry, differential geometry, and fundamental gearing kinematics. A foundation is provided for the study of nonideal gears and the effects of deviations from ideal geometry on the contact stresses, lubrication, wear, fatigue life, and gearing kinematics.

  18. Ideal spiral bevel gears - A new approach to surface geometry

    NASA Technical Reports Server (NTRS)

    Huston, R. L.; Coy, J. J.

    1980-01-01

    This paper discusses the fundamental geometrical characteristics of spiral bevel gear tooth surfaces. The parametric representation of an ideal spiral bevel tooth is developed. The development is based on the elements of involute geometry, differential geometry, and fundamental gearing kinematics. A foundation is provided for the study of nonideal gears and the effects of deviations from ideal geometry on the contact stresses, lubrication, wear, fatigue life, and gearing kinematics.

  19. Method for generation of spiral bevel gears with conjugate gear tooth surfaces

    NASA Technical Reports Server (NTRS)

    Litvin, F. L.; Coy, J. J.; Heine, C.; Tsung, Wei-Jiung

    1987-01-01

    A method for generation of spiral bevel gears is proposed that provides conjugate gear tooth surfaces. This method is based on a new principle for the performance of parallel motion of a straight line that slides along two mating ellipses with related dimensions and parameters of orientation. The parallel motion of the straight line, that is, the contact normal, is performed parallel to the line which passes through the foci of symmetry of the related ellipses. The manufacturing of gears can be performed with the existing Gleason's equipment.

  20. Common problems and pitfalls in gear design

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.

    1986-01-01

    There are several pitfalls and problems associated with the successful design of a new gear transmission. A new design will require the knowledge and experience of several technical areas of engineering. Most of the pitfalls and problems associated with a new design are related to an inadequate evaluation of several areas, such as, the lubrication and cooling requirements, complete static and dynamic load analysis, evaluation of materials and heat treatment and the latest manufacturing technology. Some of the common problems of the gear design process are discussed with recommendations made for avoiding these conditions.

  1. Measurement of Gear Tooth Dynamic Friction

    NASA Technical Reports Server (NTRS)

    Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

    1996-01-01

    Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

  2. Documented Safety Analysis Addendum for the Neutron Radiography Reactor Facility Core Conversion

    SciTech Connect

    Boyd D. Christensen

    2009-05-01

    The Neutron Radiography Reactor Facility (NRAD) is a Training, Research, Isotope Production, General Atomics (TRIGA) reactor which was installed in the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) at the Materials and Fuels Complex (MFC) in the mid 1970s. The facility provides researchers the capability to examine both irradiated and non-irradiated materials in support of reactor fuel and components programs through non-destructive neutron radiography examination. The facility has been used in the past as one facet of a suite of reactor fuels and component examination facilities available to researchers at the INL and throughout the DOE complex. The facility has also served various commercial research activities in addition to the DOE research and development support. The reactor was initially constructed using Fuel Lifetime Improvement Program (FLIP)- type highly enriched uranium (HEU) fuel obtained from the dismantled Puerto Rico Nuclear Center (PRNC) reactor. In accordance with international non-proliferation agreements, the NRAD core will be converted to a low enriched uranium (LEU) fuel and will continue to utilize the PRNC control rods, control rod drives, startup source, and instrument console as was previously used with the HEU core. The existing NRAD Safety Analysis Report (SAR) was created and maintained in the preferred format of the day, combining sections of both DOE-STD-3009 and Nuclear Regulatory Commission Regulatory Guide 1.70. An addendum was developed to cover the refueling and reactor operation with the LEU core. This addendum follows the existing SAR format combining required formats from both the DOE and NRC. This paper discusses the project to successfully write a compliant and approved addendum to the existing safety basis documents.

  3. 29 CFR 1919.31 - Proof tests-loose gear.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear (whether... the following table: Article of gear Proof load Chain, ring, hook, shackle or swivel 100 percent in... over 40 tons 50 percent in excess of the safe working load. Pitched chains used with...

  4. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  5. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  6. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  7. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  8. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  9. Molecular dynamics simulations of carbon nanotube-based gears

    NASA Astrophysics Data System (ADS)

    Han, Jie; Globus, Al; Jaffe, Richard; Deardorff, Glenn

    1997-09-01

    We use a molecular dynamics simulation to investigate the properties and design space of molecular gears fashioned from carbon nanotubes with teeth added via a benzyne reaction known to occur with 0957-4484/8/3/001/img1. Brenner's reactive hydrocarbon potential is used to model interatomic forces within each molecular gear. A Lennard - Jones 6 - 12 potential or the Buckingham 0957-4484/8/3/001/img2 potential plus electrostatic interaction terms are used for intermolecular interactions between gears. A number of gear and gear/shaft configurations are simulated on parallel computers. One gear is powered by forcing the atoms near the end of the nanotube to rotate, and a second gear is allowed to rotate by keeping the atoms near the end of its nanotube constrained to a cylinder. The meshing aromatic gear teeth transfer angular momentum from the powered gear to the driven gear. Results suggest that these gears can operate at up to 50 - 100 GHz in a vacuum at room temperature. The failure mode involves tooth slip, not bond breaking, so failed gears can be returned to operation by lowering the temperature and/or rotation rate.

  10. 50 CFR 622.35 - Gear restricted areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Gear restricted areas. 622.35 Section 622... Resources of the Gulf of Mexico § 622.35 Gear restricted areas. (a) Reef fish stressed area. The stressed... to the footrope, which makes it possible to fish the gear over rough bottom, that is, in...

  11. 14 CFR 29.477 - Landing gear arrangement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing gear arrangement. 29.477 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.477 Landing gear arrangement. Sections 29.235, 29.479 through 29.485, and 29.493 apply to landing gear with two wheels aft,...

  12. 50 CFR 622.72 - Prohibited gear and methods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Prohibited gear and methods. 622.72... ATLANTIC Coral and Coral Reefs of the Gulf of Mexico § 622.72 Prohibited gear and methods. Also see § 622.9 for additional prohibited gear and methods that apply more broadly to multiple fisheries or in...

  13. 46 CFR 167.65-25 - Steering gear tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means...

  14. 50 CFR 660.20 - Vessel and gear identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 13 2012-10-01 2012-10-01 false Vessel and gear identification. 660.20... Groundfish Fisheries § 660.20 Vessel and gear identification. (a) Vessel identification—(1) Display. The... its fishing gear obstructs the view of the official number from an enforcement vessel or aircraft....

  15. 47. Detail of gears for steam powered Marine Railway #1, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. Detail of gears for steam powered Marine Railway #1, and drive equipment for Railways #l and #2, Marine Railway Headhouse, ground floor, north end, drive gears in foreground, pulling gears for Railway # 1 in background. - Thames Tow Boat Company, Foot of Farnsworth Street, New London, New London County, CT

  16. 14 CFR 25.477 - Landing gear arrangement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Landing gear arrangement. 25.477 Section 25... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.477 Landing gear arrangement. Sections 25.479 through 25.485 apply to airplanes with conventional arrangements of main and nose gears,...

  17. 50 CFR 622.180 - Prohibited gear and methods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Prohibited gear and methods. 622.180... ATLANTIC Snapper-Grouper Fishery of the South Atlantic Region § 622.180 Prohibited gear and methods. Also see § 622.9 for additional prohibited gear and methods that apply more broadly to multiple...

  18. 29 CFR 1915.116 - Use of gear.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Use of gear. 1915.116 Section 1915.116 Labor Regulations...) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Gear and Equipment for Rigging and Materials Handling § 1915.116 Use of gear. (a) The provisions of this section shall apply to ship...

  19. 14 CFR 29.477 - Landing gear arrangement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Landing gear arrangement. 29.477 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.477 Landing gear arrangement. Sections 29.235, 29.479 through 29.485, and 29.493 apply to landing gear with two wheels aft,...

  20. 46 CFR 182.610 - Main steering gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all...