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Sample records for hydraulic brakes

  1. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, Rama R.; Mericle, Gerald E.

    1981-06-02

    A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  2. Combined hydraulic and regenerative braking system

    DOEpatents

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  3. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  4. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  5. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  6. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic..., except as noted. (a) Air brake system integrity. The air brake system shall demonstrate integrity...

  7. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  8. Modified hydraulic braking system limits angular deceleration to safe values

    NASA Technical Reports Server (NTRS)

    Briggs, R. S.; Council, M.; Green, P. M.

    1966-01-01

    Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

  9. Development of Hydraulic Friction Brake for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Chenvisuwat, Thum; Park, Sung-Hwan; Kitagawa, Ato

    A novel hydraulic brake pressure control (BPC) valve for the railway rolling stock was proposed in the part I of this study. As a second report, this paper is concerned with the dynamic analysis and the performance evaluation of the hydraulic brake system using the BPC valve. In order to analyze the behavior of the BPC valve, a simplified transfer function and a nonlinear model of the valve are derived respectively. By use of simple linear model, it is achieved to determine the initial values of essential parameter simply. In addition, it is also achieved to investigate overall dynamic performance of brake system and to evaluate the effect of design parameters through the numerical analysis using detailed nonlinear model. The validity of mathematical models is confirmed by experiments. Finally, the performance of the hydraulic brake system using newly manufactured BPC valve is confirmed with an actual braking device of the E2 series Shinkansen railway.

  10. COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT ...

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

    COUNTERWEIGHT, CONNECTED TO HYDRAULIC BRAKE SYSTEM, IN REAR OF VAULT MOTOR ROOM, LOOKING SOUTHWEST. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  11. Development of Hydraulic Friction Brake for Railway Rolling Stock

    NASA Astrophysics Data System (ADS)

    Chenvisuwat, Thum; Park, Sung-Hwan; Kitagawa, Ato

    In this study, a novel hydraulic brake system is proposed in order to increase the reliability of railway brake systems. The reason hydraulic brake systems have not been taken up as a practical railway brake system until now is that the brake pressure control valve inherently has internal leakage and this causes insufficient fail-safe function. Accordingly, We focus on the development of a hydraulic brake pressure control valve (BPC valve) in this study. By virtue of adopting poppet elements in the valve, the braking force is maintained without internal leakage even when the electric power supply fails. The developed BPC valve includes a built-in pressure feedback mechanism and it enables the pressure control function to be maintained when the pressure transducer is broken. The operating principle and wear compensation methods for poppet elements are also examined in this study. The experimental results verify the linearity of static behavior, the stability, and the performance of the valve in maintaining output pressure.

  12. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Hydraulic brake system. 570.55 Section 570.55 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.55...

  13. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Hydraulic brake system. 570.55 Section 570.55 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.55...

  14. Piezoelectric-hydraulic pump based band brake actuation system for automotive transmission control

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Woo; Wang, K. W.

    2007-04-01

    The actuation system of friction elements (such as band brakes) is essential for high quality operations in modern automotive automatic transmissions (in short, ATs). The current band brake actuation system consists of several hydraulic components, including the oil pump, the regulating valve and the control valves. In general, it has been recognized that the current AT band brake actuation system has many limitations. For example, the oil pump and valve body are relatively heavy and complex. Also, the oil pumps induce inherently large drag torque, which affects fuel economy. This research is to overcome these problems of the current system by exploring the utilization of a hybrid type piezo-hydraulic pump device for AT band brake control. This new actuating system integrates a piezo-hydraulic pump to the input of the band brake. Compared with the current systems, this new actuator features much simpler structure, smaller size, and lower weight. This paper describes the development, design and fabrication of the new stand-alone prototype actuator for AT band brake control. An analytical model is developed and validated using experimental data. Performance tests on the hardware and system simulations utilizing the validated model are performed to characterize the new prototype actuator. It is predicted that with increasing of accumulator pressure and driving frequency, the proposed prototype actuating system will satisfy the band brake requirement for AT shift control.

  15. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Standard No. 105; Hydraulic and electric brake systems. 571.105 Section 571.105 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle...

  16. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Standard No. 105; Hydraulic and electric brake systems. 571.105 Section 571.105 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle...

  17. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR 571.101... of brake fluid as specified in 49 CFR 571.116, e.g., “DOT 3”). The lettering shall be— (a... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 105; Hydraulic and electric...

  18. Fault diagnosis of automobile hydraulic brake system using statistical features and support vector machines

    NASA Astrophysics Data System (ADS)

    Jegadeeshwaran, R.; Sugumaran, V.

    2015-02-01

    Hydraulic brakes in automobiles are important components for the safety of passengers; therefore, the brakes are a good subject for condition monitoring. The condition of the brake components can be monitored by using the vibration characteristics. On-line condition monitoring by using machine learning approach is proposed in this paper as a possible solution to such problems. The vibration signals for both good as well as faulty conditions of brakes were acquired from a hydraulic brake test setup with the help of a piezoelectric transducer and a data acquisition system. Descriptive statistical features were extracted from the acquired vibration signals and the feature selection was carried out using the C4.5 decision tree algorithm. There is no specific method to find the right number of features required for classification for a given problem. Hence an extensive study is needed to find the optimum number of features. The effect of the number of features was also studied, by using the decision tree as well as Support Vector Machines (SVM). The selected features were classified using the C-SVM and Nu-SVM with different kernel functions. The results are discussed and the conclusion of the study is presented.

  19. The Application of Boolean Algebra in Modelling of Leakage Condition of a Car Hydraulic Braking System

    NASA Astrophysics Data System (ADS)

    Idzikowski, A.; Salamon, S.

    2013-06-01

    A general characteristics of a car hydraulic braking system (CHBS) is presented in this publication. A graphical model of properties-component objects is developed for the above-mentioned system. Moreover, four mathematical models in terms of logic, the set theory and the Boolean algebra of Boolean functions are developed. The examination is ended with a general model of the CHBS for n - Boolean variables and the construction and mathematical-technical interpretation of this model is presented.

  20. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Electric brakes. Each vehicle with electrically-actuated service brakes (brake power unit) shall comply... electrically-actuated service brakes, failure of the source of electric power to the brakes, or diminution of... word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR...

  1. Automotive Brake Systems.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  2. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR 571.101... of brake fluid as specified in 49 CFR 571.116, e.g., “DOT 3”). The lettering shall be— (a... dissipating electrical energy. Skid number means the frictional resistance of a pavement measured...

  3. Brakes Specialist. Teacher Edition. Automotive Service Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the

  4. Brakes Specialist. Teacher Edition. Automotive Service Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the…

  5. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes 393.41 Parking brake system. (a) Hydraulic-braked vehicles... 49 Transportation 5 2012-10-01 2012-10-01 false Parking brake system. 393.41 Section 393.41...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  6. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... shoe with two pads; or worn to the wear indicator if the lining is so marked, for air drum brakes. The....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes... for drum brakes); or less than 3.2 mm (1/8 inch) for disc brakes. Hydraulic or electric...

  7. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... shoe with two pads; or worn to the wear indicator if the lining is so marked, for air drum brakes. The....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes... for drum brakes); or less than 3.2 mm (1/8 inch) for disc brakes. Hydraulic or electric...

  8. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... shoe with two pads; or worn to the wear indicator if the lining is so marked, for air drum brakes. The....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes... for drum brakes); or less than 3.2 mm (1/8 inch) for disc brakes. Hydraulic or electric...

  9. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... shoe with two pads; or worn to the wear indicator if the lining is so marked, for air drum brakes. The....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes... for drum brakes); or less than 3.2 mm (1/8 inch) for disc brakes. Hydraulic or electric...

  10. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... brake, including an air-over-hydraulic brake subsystem, but does not include a system that uses compressed air or vacuum only to assist the driver in applying muscular force to hydraulic or mechanical components. Air-over-hydraulic brake subsystem means a subsystem of the air brake system that uses...

  11. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... brake, including an air-over-hydraulic brake subsystem, but does not include a system that uses compressed air or vacuum only to assist the driver in applying muscular force to hydraulic or mechanical components. Air-over-hydraulic brake subsystem means a subsystem of the air brake system that uses...

  12. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the

  13. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    ERIC Educational Resources Information Center

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  14. An Instructor's Guide for a Program in Brake Services.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The instructor's guide is designed to present an understanding of the automotive hydraulic brake system and to help individuals develop new skills for employment in this specialized field of automotive service. Applicable for secondary or adult education, this guide describes: the brake system, types of brakes, diagnosis and correction of brake

  15. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to ensure... performance of the brake system. ... applicable requirements of FMVSS No. 106 (49 CFR 571.106). (b) Brake tubing and hose installation....

  16. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  17. Gravity brake

    DOEpatents

    Lujan, Richard E. (Santa Fe, NM)

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  18. Better Brakes

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  19. Braking system

    DOEpatents

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  20. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  1. Magnetostrictive Brake

    NASA Technical Reports Server (NTRS)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  2. Hydraulics.

    ERIC Educational Resources Information Center

    Engelbrecht, Nancy; And Others

    These instructional materials provide an orientation to hydraulics for use at the postsecondary level. The first of 12 sections presents an introduction to hydraulics, including discussion of principles of liquids, definitions, liquid flow, the two types of hydraulic fluids, pressure gauges, and strainers and filters. The second section identifies…

  3. New generation of single pin caliper brakes

    SciTech Connect

    Carre, J.J.; Delp, L.E.

    1987-01-01

    The Broad acceptance of disc brakes has presented a real improvement in braking torque stability. This characteristic has led to its almost universal application on the front axle of passenger cars and light trucks, and on both axles for higher performances. On trucks, there is the same tendancy to use hydraulic or air actuated front disc brakes. The experience on this technology in production since the 1960s, has enabled the authors to continuously evolve the design to optimum performance and manufacturability.

  4. Hydraulics.

    ERIC Educational Resources Information Center

    Decker, Robert L.

    Designed for use in courses where students are expected to become proficient in the area of hydraulics, including diesel engine mechanic programs, this curriculum guide is comprised of fourteen units of instruction. Unit titles include (1) Introduction, (2) Fundamentals of Hydraulics, (3) Reservoirs, (4) Lines, Fittings, and Couplers, (5) Seals,…

  5. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R. (Wixom, MI)

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  6. Skin temperature and motorcyclists' braking performance.

    PubMed

    Parry, M

    1982-06-01

    16 male and 12 female students who had previous experience with hand-operated lever-braking systems performed braking tests with their hands at normal temperatures (mean hand temperatures 27.8 degrees C) and with their hands cooled to give finger temperatures of 6 degrees C and back of hand temperatures of 14 degrees C. Tasks required subjects, in response to a visual stimulus of a red light, to extend their digits to grip a motorcycle brake and pull it on. Reduced times were measured for (a) responding to the stimulus by grabbing the brake lever and pulling it to full braking pressure in the hydraulic system, (b) extending the digits, and (c) flexing the digits and pulling on the brake. In each case conditions produced a significant decrement in performance. This effect may occur when riding a motorcycle with cold hands, a common occurrence in Northern Europe. PMID:7110872

  7. Vehicle braking

    SciTech Connect

    Baker, A.K.

    1986-01-01

    This book deals with virtually all braking equipment in current use, so its coverage begins in the mid-1950's. Concerns are for cars, commercial vehicles, motor cycles, trailers, and tractors. The work is a practical approach but theory is not ignored. Based principally on European practice but the Far East and American practices are also considered.

  8. Compression relief engine brake

    SciTech Connect

    Meneely, V.A.

    1987-10-06

    A compression relief brake is described for four cycle internal-combustion engines, comprising: a pressurized oil supply; means for selectively pressurizing a hydraulic circuit with oil from the oil supply; a master piston and cylinder communicating with a slave piston and cylinder via the hydraulic circuit; an engine exhaust valve mechanically coupled to the engine and timed to open during the exhaust cycle of the engine the exhaust valve coupled to the slave piston. The exhaust valve is spring-based in a closed state to contact a valve seat; a sleeve frictionally and slidably disposed within a cavity defined by the slave piston which cavity communicates with the hydraulic circuit. When the hydraulic circuit is selectively pressurized and the engine is operating the sleeve entraps an incompressible volume of oil within the cavity to generate a displacement of the slave piston within the slave cylinder, whereby a first gap is maintained between the exhaust valve and its associated seat; and means for reciprocally activating the master piston for increasing the pressure within the previously pressurized hydraulic circuit during at least a portion of the expansion cycle of the engine whereby a second gap is reciprocally maintained between the exhaust valve and its associated seat.

  9. Engine brake control in automatic transmission

    SciTech Connect

    Hayasaki, K.; Sugano, K.

    1988-09-13

    This patent describes an engine braking control for a transmission for an automotive vehicle having an engine, the transmission including an input member drivingly coupled to the engine and an output member subject to load from driving wheels of the automotive vehicle, the transmission also including a first rotary member, a second rotary member, a hydraulically operated clutch selectively establishing a drive connection between the first rotary member and the second rotary member, and a one-way clutch arranged in parallel to the hydraulically operated clutch such that when the hydraulically operated clutch is released, the one-way clutch transmits forward torque from the first rotary member to the second rotary member, but interrupts transmission of revers torque to the first rotary member from the second rotary member, the engine braking control comprising: means for providing an engine braking command fluid pressure signal when demanded by a vehicle operator; a valve means for normally discharging hydraulic fluid from the hydraulically operated clutch to deactivate the hydraulically operated clutch, the valve means being fluidly connected to the hydraulically operated clutch, the engine braking command fluid pressure signal providing means and a drain port. The valve means including a valve spool having a first position where the hydraulically operated clutch is allowed to communicate with the drain port to permit discharge of hydraulic fluid therefrom and thus the hydraulically operated clutch is caused to be deactivated and a second position where the hydraulically operated clutch is disconnected from the drain port and allowed to communicate with the engine braking command fluid pressure signal.

  10. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R.

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  11. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  12. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... any condition of loading in which it is found on a public road (free of ice and snow). An agricultural... condition of loading in which it is found on a public road (free of ice and snow). (2) The parking...

  13. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... any condition of loading in which it is found on a public road (free of ice and snow). An agricultural... condition of loading in which it is found on a public road (free of ice and snow). (2) The parking...

  14. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... any condition of loading in which it is found on a public road (free of ice and snow). An agricultural... condition of loading in which it is found on a public road (free of ice and snow). (2) The parking...

  15. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... any condition of loading in which it is found on a public road (free of ice and snow). An agricultural... condition of loading in which it is found on a public road (free of ice and snow). (2) The parking...

  16. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... independent of brake air, hydraulic, and other pressure, and independent of other controls, unless the braking... safeguarded against backflow of air to the towing vehicle upon reduction of the towing vehicle air...

  17. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... independent of brake air, hydraulic, and other pressure, and independent of other controls, unless the braking... safeguarded against backflow of air to the towing vehicle upon reduction of the towing vehicle air...

  18. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... protection valve or similar device shall operate automatically when the air pressure on the towing vehicle is... independent of brake air, hydraulic, and other pressure, and independent of other controls, unless the braking... safeguarded against backflow of air to the towing vehicle upon reduction of the towing vehicle air...

  19. A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

    NASA Technical Reports Server (NTRS)

    Barthlome, D. E.

    1975-01-01

    Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

  20. 49 CFR 571.122a - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... recommended type of brake fluid as specified in 49 CFR 571.116, e.g., DOT 3.) The lettering shall be: (a... authority at 49 CFR 1.50 and 49 CFR 501.8) ... service brake system. A leakage failure in a hydraulic service brake system shall not result in a loss...

  1. 49 CFR 393.45 - Brake tubing and hoses; hose assemblies and end fittings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... applicable requirements of FMVSS No. 106 (49 CFR 571.106). (b) Brake tubing and hose installation. Brake... damage; and (3) Be installed in a manner that prevents it from contacting the vehicle's exhaust system or... connections. All connections for air, vacuum, or hydraulic braking systems shall be installed so as to...

  2. Automotive disc brake squeal

    NASA Astrophysics Data System (ADS)

    Kinkaid, N. M.; O'Reilly, O. M.; Papadopoulos, P.

    2003-10-01

    Disc brake squeal remains an elusive problem in the automotive industry. Since the early 20th century, many investigators have examined the problem with experimental, analytical, and computational techniques, but there is as yet no method to completely suppress disc brake squeal. This paper provides a comprehensive review and bibliography of works on disc brake squeal. In an effort to make this review accessible to a large audience, background sections on vibrations, contact and disc brake systems are also included.

  3. Hydraulic drive system prevents backlash

    NASA Technical Reports Server (NTRS)

    Acord, J. D.

    1965-01-01

    Hydraulic drive system uses a second drive motor operating at reduced torque. This exerts a relative braking action which eliminates the normal gear train backlash that is intolerable when driving certain heavy loads.

  4. Brake Fundamentals. Automotive Articulation Project.

    ERIC Educational Resources Information Center

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each

  5. Optimal design of an automotive magnetorheological brake considering geometric dimensions and zero-field friction heat

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.

    2010-11-01

    This paper presents an optimal design of a magnetorheological (MR) brake for a middle-sized passenger car which can replace a conventional hydraulic disc-type brake. In the optimization, the required braking torque, the temperature due to zero-field friction of MR fluid, the mass of the brake system and all significant geometric dimensions are considered. After describing the configuration, the braking torque of the proposed MR brake is derived on the basis of the field-dependent Bingham and Herschel-Bulkley rheological model of the MR fluid. The optimal design of the MR brake is then analyzed taking into account available space, mass, braking torque and steady heat generated by zero-field friction torque of the MR brake. The optimization procedure based on the finite element analysis integrated with an optimization tool is proposed to obtain optimal geometric dimensions of the MR brake. Based on the proposed procedure, optimal solutions of single and multiple disc-type MR brakes featuring different types of MR fluid are achieved. From the results, the most effective MR brake for the middle-sized passenger car is identified and some discussions on the performance improvement of the optimized MR brake are described.

  6. A New Dynamometer Brake

    NASA Technical Reports Server (NTRS)

    Segre, Marco

    1921-01-01

    The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.

  7. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption... of kinetic energy throughout the defined wear range of the brake. The energy absorption rate derived.... The accelerate-stop brake kinetic energy absorption requirement of each wheel, brake, and...

  8. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption... of kinetic energy throughout the defined wear range of the brake. The energy absorption rate derived.... The accelerate-stop brake kinetic energy absorption requirement of each wheel, brake, and...

  9. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption... of kinetic energy throughout the defined wear range of the brake. The energy absorption rate derived.... The accelerate-stop brake kinetic energy absorption requirement of each wheel, brake, and...

  10. Improved Electromagnetic Brake

    NASA Technical Reports Server (NTRS)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may still be possible to set the brake by applying an electromagnet current to aid the permanent magnetic field instead of canceling it, this action can mask an out-of-tolerance condition in the brake and it does not restore the fail-safe function of setting the brake when current is lost.

  11. 78 FR 21189 - Agency Requests for Approval of a New Information Collection: Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... as packagers of hydraulic system mineral oils. The information to be collected will be used to and/or... performance and design requirements for motor vehicle brake fluids and hydraulic system mineral oils. Section... packagers of hydraulic system mineral oils. The information on the label of a container of motor...

  12. Braking System for Wind Turbines

    NASA Technical Reports Server (NTRS)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  13. Vehicle brake testing system

    DOEpatents

    Stevens, Samuel S. (Harriman, TN); Hodgson, Jeffrey W. (Lenoir City, TN)

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  14. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... dynamic brake does not result in exceeding the allowable stopping distance; (2) The friction brake alone... speed for safe operation of the train using only the friction brake portion of the blended brake with...

  15. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... dynamic brake does not result in exceeding the allowable stopping distance; (2) The friction brake alone... speed for safe operation of the train using only the friction brake portion of the blended brake with...

  16. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... braking force is measured by a performance-based brake tester which meets the requirements of functional specifications for performance-based brake testers for commercial motor vehicles, where braking force is the sum...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle...

  17. The braking performance of a vehicle anti-lock brake system featuring an electro-rheological valve pressure modulator

    NASA Astrophysics Data System (ADS)

    Choi, Seung-Bok; Sung, Kum-Gil; Cho, Myung-Soo; Lee, Yang-Sub

    2007-08-01

    This paper presents the braking performances of a vehicle anti-lock brake system (ABS) featuring an electro-rheological (ER) valve pressure modulator. As a first step, the principal design parameters of the ER valve and hydraulic booster are appropriately determined by considering the Bingham property of the ER fluid and the braking pressure variation during the ABS operation. An ER fluid composed of chemically treated starch particles and silicone oil is used. An electrically controllable pressure modulator is then constructed and its pressure controllability is empirically evaluated. Subsequently, a quarter-car wheel slip model is established and integrated with the governing equation of the pressure modulator. A sliding mode controller for slip rate control is designed and implemented via the hardware-in-the-loop simulation (HILS). In order to demonstrate the superior braking performance of the proposed ABS, a full car model is derived and a sliding mode controller is formulated to achieve the desired yaw rate. The braking performances in terms of braking distance and step input steering are evaluated and presented in time domain through full car simulations.

  18. Comparative analysis into the tractor-trailer braking dynamics: tractor with single axle brakes, tractor with all wheel brakes

    NASA Astrophysics Data System (ADS)

    Nastasoiu, Mircea; Ispas, Nicolae

    2014-06-01

    The paper elaborates a mathematical model in order to conduct a study into the dynamics of tractor-trailer systems during braking. The braking dynamics is analyzed by considering two versions for the braking system: 1) braking applied on the rear axle and 2) braking applied on all four wheels. In both versions the trailer is braked on all wheels. The mathematical model enables us to determine and graphically illustrate the evolution of the following parameters: braking deceleration, braking speed and the distance traveled by the tractor during braking. The mathematical model elaborated is applied on a tractor-trailer system completing transportation works.

  19. Experiments with airplane brakes

    NASA Technical Reports Server (NTRS)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  20. Deployable Engine Air Brake

    NASA Technical Reports Server (NTRS)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  1. Tether Deployer And Brake

    NASA Technical Reports Server (NTRS)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

    Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

  2. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... the braking surface. (iii) Braking is to be performed using only those braking systems, including... upon other available evidence to determine whether the service brake system meets the...

  3. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  4. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  5. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  6. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  7. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake...

  8. Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

    NASA Astrophysics Data System (ADS)

    Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-08-01

    In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

  9. Chaos in brake squeal noise

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2011-02-01

    Brake squeal has become an increasing concern to the automotive industry because of warranty costs and the requirement for continued interior vehicle noise reduction. Most research has been directed to either analytical and experimental studies of brake squeal mechanisms or the prediction of brake squeal propensity using finite element methods. By comparison, there is a lack of systematic analysis of brake squeal data obtained from a noise dynamometer. It is well known that brake squeal is a nonlinear transient phenomenon and a number of studies using analytical and experimental models of brake systems (e.g., pin-on-disc) indicate that it could be treated as a chaotic phenomenon. Data obtained from a full brake system on a noise dynamometer were examined with nonlinear analysis techniques. The application of recurrence plots reveals chaotic structures even in noisy data from the squealing events. By separating the time series into different regimes, lower dimensional attractors are isolated and quantified by dynamic invariants such as correlation dimension estimates or Lyapunov exponents. Further analysis of the recurrence plot of squealing events by means of recurrence quantification analysis measures reveals different regimes of laminar and random behaviour, periodicity and chaos-forming recurrent transitions. These results help to classify brake squeal mechanisms and to enhance understanding of friction-related noise phenomena.

  10. Design of hydraulic output Stirling engine

    NASA Technical Reports Server (NTRS)

    Toscano, W. M.; Harvey, A. C.; Lee, K.

    1983-01-01

    A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

  11. Automatic transmission brake assembly including an overrunning roller brake and a friction brake

    SciTech Connect

    Premiski, V.; Hohnel, R.; Premiski, C.

    1988-10-11

    This patent describes an overrunning roller brake assembly for a planetary gear unit in an automatic transmission for automobiles, the gear unit having a ring gear, a carrier and a sun gear, the carrier having planet pinions thereon engaging the sun and ring gears; a brake for anchoring a reaction member of the gear unit, at least one other member of the gear unit being adapted to receive driving torque; the brake comprising an annular inner brake race surrounding a fixed part of the transmission, an annular outer brake race connected to the reaction member and surrounding the inner race, the outer race comprising an extrusion with an outer brake drum surface adapted to be engaged by a reaction friction brake band; overrunning brake rollers between the races, a pair of support rings between the races on either side of the rollers; the support rings having a C-shaped cross section whereby the inner and outer surfaces thereof provide a bearing support for the races; retainer rings enclosed within the support rings, the retainer rings having a radial thickness approximately equal to the radial inside dimension of the C-shaped cross section of the support rings whereby radial loads are transmitted between the races through the retainer rings and support rings.

  12. Pulsar braking: magnetodipole vs. wind

    NASA Astrophysics Data System (ADS)

    Tong, Hao

    2016-01-01

    Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done with unprecedented accuracy. More pulsars have braking indices measured. The period derivative of intermittent pulsars and magnetars can vary by a factor of several. However, during pulsar studies, the magnetic dipole braking in vacuum is still often assumed. It is shown that the fundamental assumption of magnetic dipole braking (vacuum condition) does not exist and it is not consistent with the observations. The physical torque must consider the presence of the pulsar magnetosphere. Among various efforts, the wind braking model can explain many observations of pulsars and magnetars in a unified way. It is also consistent with the up-to-date observations. It is time for a paradigm shift in pulsar studies: from magnetic dipole braking to wind braking. As one alternative to the magnetospheric model, the fallback disk model is also discussed.

  13. Position control optimization of aerodynamic brake device for high-speed trains

    NASA Astrophysics Data System (ADS)

    Zuo, Jianyong; Luo, Zhuojun; Chen, Zhongkai

    2014-03-01

    The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions—constant, linear, and quadratic—are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25.71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

  14. Regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1982-01-12

    Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

  15. Adjustable Tooling for Bending Brake

    NASA Technical Reports Server (NTRS)

    Ellis, J. M.

    1986-01-01

    Deep metal boxes and other parts easily fabricated. Adjustable tooling jig for bending brake accommodates spacing blocks and either standard male press-brake die or bar die. Holds spacer blocks, press-brake die, bar window die, or combination of three. Typical bending operations include bending of cut metal sheet into box and bending of metal strip into bracket with multiple inward 90 degree bends. By increasing free space available for bending sheet-metal parts jig makes it easier to fabricate such items as deep metal boxes or brackets with right-angle bends.

  16. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Landing Gear § 25.735 Brakes and... designed and constructed so that: (1) Excessive control force is not required for their operation. (2)...

  17. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Landing Gear § 25.735 Brakes and... designed and constructed so that: (1) Excessive control force is not required for their operation. (2)...

  18. Benefits of front brakes on heavy trucks

    SciTech Connect

    Radlinski, R.W.; Flick, M.A.

    1987-01-01

    This paper addresses the issue of front wheel braking on heavy trucks and reviews testing that has been performed over the years dating back to 1948 to evaluate the effect of front brakes on braking performance. It also describes in detail a test and demonstration program on front wheel brakes that was conducted in September 1986. The paper indicates that front wheel brakes have a strong effect on braking performance and that vehicles without front wheel brakes take longer distances to stop and are more likely to lose control in emergency situations. The paper also indicates that the use of front brake pressure limiting valves with typical, current design front brakes degrades vehicle braking performance.

  19. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Brake Systems.

    ERIC Educational Resources Information Center

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory, operation, and repair of drum brakes, disc brakes, and brake system components. The course is comprised of six units: (1) Fundamentals of Brake Systems, (2) Master Cylinder, (3) Drum Brakes, (4) Disc Brakes, (5) Power Brakes, and (6)…

  20. Wheel brakes and their application to aircraft

    NASA Technical Reports Server (NTRS)

    Dowty, G H

    1928-01-01

    The advantages to be gained from braking have not been ignored, and in the search for a suitable method many schemes have been suggested and tried. Some of the methods discussed in this paper include: 1) increasing the height of the landing gear; 2) air brakes of various forms; 3) sprags on tail skid and axle; and 4) wheel brakes. This report focuses on the design of wheel brakes and wheel brake controls.

  1. Single acting translational/rotational brake

    NASA Technical Reports Server (NTRS)

    Allred, Johnny W. (Inventor); Fleck, Jr., Vincent J. (Inventor)

    1996-01-01

    A brake system is provided that applies braking forces on surfaces in both the translational and rotational directions using a single acting self-contained actuator that travels with the translational mechanism. The brake engages a mechanical lock and creates a frictional force on the translational structure preventing translation while simultaneously creating a frictional torque that prevents rotation of the vertical support. The system may include serrations on the braking surfaces to provide increased braking forces.

  2. Brake Stops Both Rotation And Translation

    NASA Technical Reports Server (NTRS)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  3. Development of aircraft brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T.-L.; Peterson, M. B.

    1976-01-01

    A program has been carried out to study and develop high temperature aircraft brake materials. A survey of the requirements of brake materials was made to select materials to meet these requirements. Based upon their physical and thermal properties, a number of materials were selected and evaluated in sliding tests which simulated aircraft braking. The mating material is 17-22 AS steel. Additives were incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials. Optimum materials were developed which had improved wear behavior over conventional brake materials in the simulated test. The best materials were a nickel, aluminum oxide, lead tungstate composition containing graphite and a molybdenum base material containing LPA 100 (an intermetallic compound of cobalt, molybdenum and silicon).

  4. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  5. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Tenders Brake and Signal Equipment 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  6. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Tenders Brake and Signal Equipment 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  7. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Tenders Brake and Signal Equipment 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  8. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... packaged lot and tested simultaneously. Hydraulic system mineral oil means a mineral-oil-based fluid... humidified under controlled conditions; 350 ml. of SAE triethylene glycol monomethyl ether, brake fluid grade... when testing DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered...

  9. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... packaged lot and tested simultaneously. Hydraulic system mineral oil means a mineral-oil-based fluid... humidified under controlled conditions; 350 ml. of SAE triethylene glycol monomethyl ether, brake fluid grade... DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered dry air...

  10. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... packaged lot and tested simultaneously. Hydraulic system mineral oil means a mineral-oil-based fluid... humidified under controlled conditions; 350 ml. of SAE triethylene glycol monomethyl ether, brake fluid grade... when testing DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered...

  11. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... packaged lot and tested simultaneously. Hydraulic system mineral oil means a mineral-oil-based fluid... humidified under controlled conditions; 350 ml. of SAE triethylene glycol monomethyl ether, brake fluid grade... DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered dry air...

  12. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... packaged lot and tested simultaneously. Hydraulic system mineral oil means a mineral-oil-based fluid... humidified under controlled conditions; 350 ml. of SAE triethylene glycol monomethyl ether, brake fluid grade... DOT 5 fluids) followed by an acetone or ether rinse. Pass a slow stream of filtered dry air...

  13. Hydraulic control system for automatic transmission

    SciTech Connect

    Sakaguchi, Y

    1989-05-16

    A hydraulic control system is described for an automatic transmission including hydraulic servos for clutches and brakes to engage and disengage components in the transmission gear mechanism and having a forward clutch hydraulic servo and a brake hydraulic servo, and a manual valve, comprising:a modulator valve for adjusting line pressure to a predetermined modulator pressure; a control valve adapted to be shifted in response to signals based on positions of the manual valve and the vehicle running condition; a first oil path connected between the control valve and the manual valve as a line pressure oil path; the control valve including a first port connecting to the forward clutch hydraulic servo; a second oil path connected between the control valve and the brake hydraulic servo; and a shift valve situated in the second oil path, the shift valve not operating during a low speed vehicle condition, the shift valve being adapted to connect the second oil path when the shift valve shifts to a low speed position and to disconnect the oil path when the shift valve shifts to a high speed position.

  14. 49 CFR 393.44 - Front brake lines, protection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Front brake lines, protection. 393.44 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes 393.44 Front brake lines, protection. On every bus, if equipped with air brakes, the braking system shall be so constructed that in the event any brake line...

  15. 49 CFR 393.44 - Front brake lines, protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Front brake lines, protection. 393.44 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes 393.44 Front brake lines, protection. On every bus, if equipped with air brakes, the braking system shall be so constructed that in the event any brake line...

  16. Four-wheel dual braking for automobiles

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.

    1981-01-01

    Each master cylinder applies braking power to all four wheels unlike conventional systems where cylinder operates only two wheels. If one master system fails because of fluid loss, other stops car by braking all four wheels although at half force.

  17. A Demonstration of Car Braking Instabilities.

    ERIC Educational Resources Information Center

    Irwin, Jack; Swinson, Derek

    1990-01-01

    Detailed are the construction of a demonstration car, apparatus and procedures used in the demonstration, and the analysis of the effects of car braking. The cases of rear-wheel and front-wheel braking are considered. (CW)

  18. Minimal models for disk brake squeal

    NASA Astrophysics Data System (ADS)

    von Wagner, Utz; Hochlenert, Daniel; Hagedorn, Peter

    2007-05-01

    Numerous publications on the modeling of disk brake squeal can be found in the literature. Recent publications describe the onset of disk brake squeal as an instability of the trivial solution resulting from the non-conservative friction forces even for a constant friction coefficient. Therefore, a minimal model of disk brake squeal must contain at least two degrees of freedom. A literature review of minimal models shows that there is still a lack of a minimal model describing the basic behavior of disk brake squeal which can easily be associated to an automotive disk brake. Therefore, a new minimal model of a disk brake is introduced here, showing an obvious relation to the technical system. In this model, the vibration of the disk is taken into account, as it plays a dominant role in brake squeal. The model is analyzed with respect to its stability behavior, and consequences in using it in the optimization of disk brake systems are discussed.

  19. Anti-skid brake control system for automotive vehicle with feature of assuring prevention of wheel-locking at any driving condition

    SciTech Connect

    Matsuda, T.

    1989-02-14

    An anti-skid brake control system is described for an automotive vehicle, comprising: a hydraulic brake circuit including wheel cylinders for establishing braking pressure for decelerating vehicular wheels; first and second anti-skid brake control valves, each associated at least one of first and second wheel cylinders which are associated with first and second wheels for adjusting braking pressure therein, each of the anti-skid brake control valves being operable to increase braking pressure in the associated wheel cylinder in a first mode position, and to decrease the braking pressure in the associated wheel cylinder in a second mode position; first sensor for monitoring rotation speed of the first wheel for producing a first wheel speed indicative signal; second sensor for monitoring rotation speed of the second wheel for producing a second wheel speed indicative signal; first means for monitoring wheel slippage at the first and second wheels based on the first and second wheel speed indicative signals and detecting a wheel slippage at one of the first and second wheels when the wheel slippage increases across a given slippage threshold for operating the first and second anti-skid brake control valves in the second mode position; and second means for detecting the first and second wheel speed indicative signals for operating the first and second anti-skid brake control valves in the first mode position when a predetermined brake condition is satisfied while the first and second anti-skid brake control valves are in the second mode position, the second means increasing a rate of braking pressure in the first and second wheel cylinders in response to the detection so that the braking pressure in a third wheel cylinder is increased at a greater increasing rate than that in a fourth wheel cylinder.

  20. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT IX, AUTOMATIC TRANSMISSIONS--HYDRAULIC SYSTEM (PART I).

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OIL FLOW WITHIN HYDRAULIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE GENERAL DESCRIPTION, HYDRAULIC CIRCUITS, AND BRAKE HYDRAULIC CIRCUIT AND OPERATION. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL PROGRAMED TRAINING FILM "LEARNING ABOUT THE ALLISON…

  1. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... its typical load on the maximum grade it travels. (3) All braking systems installed on the equipment... those braking systems, including auxiliary retarders, which are designed to bring the equipment to a... brake system meets the performance requirement of this standard....

  2. Compact, Lightweight Servo-Controllable Brakes

    NASA Technical Reports Server (NTRS)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  3. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake gauges. 229.53 Section 229.53 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System 229.53 Brake gauges. All mechanical gauges and all devices providing indication of air pressure electronically that are used by...

  4. 49 CFR 229.53 - Brake gauges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Brake gauges. 229.53 Section 229.53 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System 229.53 Brake gauges. All mechanical gauges and all devices providing indication of air pressure electronically that are used by...

  5. Brake wear warning device: A concept

    NASA Technical Reports Server (NTRS)

    Hawkins, S. F.

    1973-01-01

    Heat-insulated wire is introduced through brake shoe and partially into brake lining. Wire is connected to positive terminal and light bulb. When brakes wear to critical point, contact between wire and wheel drum grounds circuit and turns on warning light.

  6. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  7. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  8. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  9. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  10. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from...

  11. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes. 29.735 Section 29.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking...

  12. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes. 27.735 Section 27.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking...

  13. Bidirectional drive and brake mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A. (Inventor)

    1991-01-01

    A space transport vehicle is disclosed as including a body which is arranged to be movably mounted on an elongated guide member disposed in outer space and driven therealong. A drive wheel is mounted on a drive shaft and arranged to be positioned in rolling engagement with the elongated guide carrying the vehicle. A brake member is arranged on the drive shaft for movement into and out of engagement with an adjacent surface of the drive wheel. An actuator is mounted on the body to be manually moved back and forth between spaced positions in an arc of movement. A ratchet-and-pawl mechanism is arranged to operate upon movements of the actuator in one direction between first and second positions for coupling the actuator to the drive wheel to incrementally rotate the wheel in one rotational direction and to operate upon movements of the actuator in the opposite direction for uncoupling the actuator from the wheel. The brake member is threadedly coupled to the drive shaft in order that the brake member will be operated only when the actuator is moved on beyond its first and second positions for shifting the brake member along the drive shaft and into frictional engagement with the adjacent surface on the drive wheel.

  14. Brake blending strategy for a hybrid vehicle

    DOEpatents

    Boberg, Evan S. (Hazel Park, MI)

    2000-12-05

    A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

  15. Eddy current braking experiment using brake disc from aluminium series of A16061 and A17075

    NASA Astrophysics Data System (ADS)

    Baharom, M. Z.; Nuawi, M. Z.; Priyandoko, G.; Harris, S. M.

    2012-09-01

    The electromagnetic braking using eddy current was studied, focused on two series of aluminium as the brake disc which are A16061 and A17075. This paper presents the comparison for both series in a few varied parameters related to eddy current braking such as air-gap, number of turns and brake disc thickness. Optical tachometer has been used along with PULSE analyzer to capture the speed (rpm) and time (s). The findings shows that the smaller the air-gap, the larger of electromagnet turns and the thicker disc thickness is, will generate higher braking torque to stop the rotational motion of disc brake and give great performance for eddy current braking. Thos parameters that been evaluated also addressed a potential on expanding this knowledge to develop an electromagnetic braking system to replace the conventional braking system.

  16. Hydraulic control device for automatic transmissions

    SciTech Connect

    Sakaguchi, Y.; Taga, Y.; Kashihara, Y.

    1989-06-20

    This patent describes a hydraulic control device for an automatic transmission including a control unit, a shift gear mechanism, clutches and brakes for controlling the shift gear mechanism, hydraulic servos for actuating the clutches and brakes to control the shift gear mechanism and having hydraulic servo for a forward clutch, and an electronically operated regulating value for regulating pressure according to signals from the control unit. The control device consists of: a selecting value switched by signals indicating stopping and running condition of a vehicle, the selecting valve being connected to the hydraulic servo for the forward clutch for engaging and transmitting torque during the forward running conditon, the selecting valve selectively receiving a line pressure and a control pressure from the regulating valve so that hydraulic pressure just below engaging pressure regulated by the regulating valve is applied to the hydraulic servo for the forward clutch during stopping, and a line pressure is applied to the hydraulic servo for the forward clutch during running.

  17. Electromagnetic braking for Mars spacecraft

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  18. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-tension shall be sufficient to prevent slippage. Inspection procedure. With the air system charged, open... towed vehicle. (6) The compressor drive belt shall not be badly worn or frayed and belt tension shall...

  19. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-tension shall be sufficient to prevent slippage. Inspection procedure. With the air system charged, open... towed vehicle. (6) The compressor drive belt shall not be badly worn or frayed and belt tension shall...

  20. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-tension shall be sufficient to prevent slippage. Inspection procedure. With the air system charged, open... towed vehicle. (6) The compressor drive belt shall not be badly worn or frayed and belt tension shall...

  1. What brakes the Crab pulsar?

    NASA Astrophysics Data System (ADS)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  2. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  3. Two stage brake control valve

    SciTech Connect

    Miller, J.A.; Nelson, R.J.; Vaughn, B.J.

    1988-04-19

    A two stage brake valve for communicating fluid pressure to at least one set of friction elements of a brake system is described comprising: a valve body; a stepped bore within the body having large and small diameter sections; an assembly; a first fluid chamber defined by the extending end of the piston and the larger diameter section; a second fluid chamber defined by the extending end of the pressure valve and the small diameter section, the second chamber being in fluid communication with at least one set of friction elements of the brake system; a first passageway for communicating the first chamber with the second chamber; a second passageway, at least partially defined by the assembly, for communicating the first chamber with a reservoir; a relief valve located in the assembly and positioned to bypass the second passageway, the relief valve opening in response to fluid pressure in the first and second chambers; and means to bypass at least part of the first passageway for decreasing resistance to fluid flow between the first chamber and the second chamber in response to a positive pressure differential between the first and second chambers.

  4. Braking performance of heavy U. S. vehicles

    SciTech Connect

    Radlinski, R.W.

    1987-01-01

    This paper provides a synthesis of the information available describing the braking performance of heavy (on-highway) vehicles in the U.S. and contrasts the braking performance of heavy vehicles with that of passenger cars. It discusses the unique demands that are placed on heavy vehicle brake systems and shows that it is difficult to optimize braking performance for all operating conditions without adding complexity to the system. As designed, U.S. heavy vehicles do not perform as well as cars. In addition, heavy vehicle brake performance can degrade significantly from the design-intent level if proper maintenance is not performed. The brake maintenance situation in the U.S. leaves something to be desired.

  5. Bidirectional Drive-And-Brake Mechanism

    NASA Technical Reports Server (NTRS)

    Swan, Scott A.

    1991-01-01

    Vehicle that crawls along monorail combines features of both bicycle and railroad handcar. Bidirectional drive-and-brake mechanism includes selectable-pawl-and-ratchet overrunning clutch (drive mechanism) and mating stationary and rotating conical surfaces pressing against each other (brake mechanism). Operates similarly to bicycle drive-and-brake mechanism except limits rotation of sprocket in both directions and brakes at both limits. Conceived for use by astronaut traveling along structure in outer space, concept also applied on Earth to make very small railraod handcars or crawling vehicles for use on large structures, in pipelines under construction, or underwater.

  6. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    ERIC Educational Resources Information Center

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and

  7. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    ERIC Educational Resources Information Center

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  8. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  9. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  10. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  11. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  12. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  13. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., separate. (c) Emergency brake requirements, vacuum brakes. Every truck tractor and truck when used for towing other vehicles equipped with vacuum brakes, shall have, in addition to the single control...

  14. 49 CFR 393.43 - Breakaway and emergency braking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., separate. (c) Emergency brake requirements, vacuum brakes. Every truck tractor and truck when used for towing other vehicles equipped with vacuum brakes, shall have, in addition to the single control...

  15. Braking index of isolated pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, O.; Stone, J. R.; Urbanec, M.; Urbancov, G.

    2015-03-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities ? , and their time derivatives that show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of detailed debate, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of ? . This relation leads to the power law ? ? =-K ?n where n is called the braking index. The MDR model predicts n exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of n , individually accurate to a few percent or better, in the range 1 braking index within the MDR model. Four microscopic equations of state are employed as input to two different computational codes that solve Einstein's equations numerically, either exactly or using the perturbative Hartle-Thorne method, to calculate the moment of inertia and other macroscopic properties of rotating neutron stars. The calculations are performed for fixed values of MB (as masses of isolated pulsars are not known) ranging from 1.0 - 2.2 M? , and fixed magnetic dipole moment and inclination angle between the rotational and magnetic field axes. The results are used to solve for the value of the braking index as a function of frequency, and find the effect of the choice of the EoS, MB. The density profile of a star with a given MB is calculated to determine the transition between the crust and the core and used in estimation of the effect of core superfluidity on the braking index. Our results show conclusively that, within the model used in this work, any significant deviation of the braking index away from the value n =3 occurs at frequencies higher than about ten times the frequency of the slow rotating isolated pulsars most accurately measured to date. The rate of change of n with frequency is related to the softness of the EoS and the MB of the star as this controls the degree of departure from sphericity. Change in the moment of inertia in the MDR model alone, even with the more realistic features considered here, cannot explain the observational data on the braking index and other mechanisms have to be sought.

  16. ENVIRONMENTAL HYDRAULICS

    EPA Science Inventory

    The thermal, chemical, and biological quality of water in rivers, lakes, reservoirs, and near coastal areas is inseparable from a consideration of hydraulic engineering principles: therefore, the term environmental hydraulics. In this chapter we discuss the basic principles of w...

  17. Landing and Braking of Airplanes

    NASA Technical Reports Server (NTRS)

    Breguet, Louis

    1929-01-01

    In the numerical examples, we have considered an airplane landing in calm air in a fixed direction after crossing the border (with its obstacles) at a height of 30 m. Its stopping point is at a distance D from the obstacle, comprising: a distance D(sub 1) in regular gliding flight; a distance D(sub 2) in levelling off; a distance D(sub 3) in taxying on the ground. The calculations enable us to make out the following table, which gives an idea of the improvements to be expected in the use of various possible methods of braking in the air and on the ground.

  18. Constraining the braking indices of magnetars

    NASA Astrophysics Data System (ADS)

    Gao, Z. F.; Li, X.-D.; Wang, N.; Yuan, J. P.; Wang, P.; Peng, Q. H.; Du, Y. J.

    2016-02-01

    Because of the lack of long-term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index n of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of the mean braking indices of eight magnetars with SNRs, and find that they cluster in the range of 1-42. Five magnetars have smaller mean braking indices of 1 < n < 3, and we interpret them within a combination of magneto-dipole radiation and wind-aided braking. The larger mean braking indices of n > 3 for the other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with 1 < n < 3, and the dipolar magnetic field decay rates for the magnetars with n > 3, within the updated magneto-thermal evolution models. Although the constrained range of the magnetars' braking indices is tentative, as a result of the uncertainties in the SNR ages due to distance uncertainties and the unknown conditions of the expanding shells, our method provides an effective way to constrain the magnetars' braking indices if the measurements of the SNR ages are reliable, which can be improved by future observations.

  19. Accelerometer-controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1973-01-01

    Braking system, which employs angular accelerometer to control wheel braking and results in low level of tire slip, has been developed and tested. Tests indicate that system is feasible for operations on surfaces of different slipperinesses. System restricts tire slip and is capable of adapting to rapidly-changing surface conditions.

  20. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Reversed braking. 25.507 Section 25.507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads 25.507 Reversed braking. (a) The airplane must be in a three point static...

  1. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vehicle weight lbs. Equipment speed, MPH 10 11 12 13 14 15 16 17 18 19 20 Service Brake Maximum Stopping... values include a one-second operator response time. Table M-2The Speed of a Vehicle Can be Determined by... Devices and Maintenance Requirements 56.14101 Brakes. (a) Minimum requirements. (1)...

  2. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vehicle weight lbs. Equipment speed, MPH 10 11 12 13 14 15 16 17 18 19 20 Service Brake Maximum Stopping... values include a one-second operator response time. Table M-2The Speed of a Vehicle Can be Determined by... Devices and Maintenance Requirements 56.14101 Brakes. (a) Minimum requirements. (1)...

  3. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... vehicle weight lbs. Equipment speed, MPH 10 11 12 13 14 15 16 17 18 19 20 Service Brake Maximum Stopping... values include a one-second operator response time. Table M-2The Speed of a Vehicle Can be Determined by... Devices and Maintenance Requirements 56.14101 Brakes. (a) Minimum requirements. (1)...

  4. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vehicle weight lbs. Equipment speed, MPH 10 11 12 13 14 15 16 17 18 19 20 Service Brake Maximum Stopping... values include a one-second operator response time. Table M-2The Speed of a Vehicle Can be Determined by... Devices and Maintenance Requirements 56.14101 Brakes. (a) Minimum requirements. (1)...

  5. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... each main wheel brake assembly may be derived from the following formula: KE=0.0443 WV2/N where—...

  6. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... each main wheel brake assembly may be derived from the following formula: KE=0.0443 WV2/N where—...

  7. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Brake system. 238.431 Section 238.431 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Specific Requirements for Tier II Passenger Equipment 238.431 Brake system. (a)...

  8. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the controlling power car to wheel-slide conditions on any axle of the train. ... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset...

  9. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to (1) Counteract any normal...

  10. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to (1) Counteract any normal...

  11. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to (1) Counteract any normal...

  12. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is (a) Controllable by the pilot; (b) Usable during power-off landings; and (c) Adequate to (1) Counteract any normal...

  13. Air brake-dynamometer accurately measures torque

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  14. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Reversed braking. 25.507 Section 25.507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads 25.507 Reversed braking. (a) The airplane must be in a three point static...

  15. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Reversed braking. 25.507 Section 25.507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  16. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Reversed braking. 25.507 Section 25.507 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... nominal maximum static brake torque, whichever is less. (b) For airplanes with nose wheels, the...

  17. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... less than the kinetic energy absorption requirements determined under either of the following methods: (1) The brake kinetic energy absorption requirements must be based on a conservative rational... rational analysis, the kinetic energy absorption requirements for each main wheel brake assembly may...

  18. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined under either of the following methods: (1) The brake kinetic energy absorption requirements must be... design landing weight. (2) Instead of a rational analysis, the kinetic energy absorption requirements...

  19. Some wear studies on aircraft brake systems

    NASA Technical Reports Server (NTRS)

    Ho, T. L.

    1975-01-01

    An initial investigation of worn surfaces in friction pads and steel rotors used in current aircraft brakes was carried out using electron microprobe and X-ray diffraction analysis. It consists of the topographical study and the analysis of chemical element distribution. Based upon this initial examination, two approaches, microscopic and macroscopic have been conducted to interpret and formulate the wear mechanism of the aircraft brake materials. Microscopically, the wear particles were examined. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. Macroscopically, it has been found that, for the current copper based brake material sliding against 17-22 AS steel in a caliper brake, the surface temperature raised due to frictional heat is nonlinearly proportional to the load applied and slide time with speed at 1750 rpm. The wear of brake materials is then proportional to this temperature and is also a function of the melting temperature for copper.

  20. Design of MR brake featuring tapered inner magnetic core

    NASA Astrophysics Data System (ADS)

    Sohn, Jung Woo; Oh, Jong-Soek; Choi, Seung-Bok

    2015-04-01

    In this work, a new type of MR brake featuring tapered inner magnetic core is proposed and its braking performance is numerically evaluated. In order to achieve high braking torque with restricted size and weight of MR brake system, tapered inner magnetic core is designed and expands the area that the magnetic flux is passing by MR fluid-filled gap. The mathematical braking torque model of the proposed MR brake is derived based on the field-dependent Bingham rheological model of MR fluid. Finite element analysis is carried out to identify electromagnetic characteristics of the conventional and the proposed MR brake configuration. To demonstrate the superiority of the proposed MR brake, the braking torque of the proposed MR brake is numerically evaluated and compared with that of conventional MR brake model.

  1. Method and apparatus for electromagnetically braking a motor

    NASA Technical Reports Server (NTRS)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  2. How effective are brakes on infant walkers?

    PubMed

    Ridenour, M V

    1997-06-01

    62 children, between the ages of 9 and 18 months old, were observed in an instrumented walker to measure the peak horizontal pull forces. These pull forces were later used to evaluate an infant walker with a braking system that would stop on the top step of the stairs before falling down the stairs. This brake system is activated when part of the walker crosses over the edge of the top step. Using the range of horizontal pull forces generated by the 62 children, the horizontal brake system for walkers would not always prevent the walker from falling down the stairs. Four floor surfaces were compared: carpet, vinyl, glossy wood, and unfinished wood. The walker brake system did not always stop the walkers on these floor surfaces. Using the measured weights and horizontal forces of the 21 nonwalking children between 9 and 13 months old who represent children who typically fall down the stairs in a walker, a simulation procedure was completed to represent the worse possible force condition, the peak horizontal force, for each of the 21 children. During this simulation, brakes would have failed all the time for 18 of the 21 children, and at least half the time for the remaining 3 children. These brake systems may provide false security to parents who use these walkers, since there are no published standards regarding the performance of brake systems for infant walkers as a safety device. PMID:9172223

  3. Brake wear particle emissions: a review.

    PubMed

    Grigoratos, Theodoros; Martini, Giorgio

    2015-02-01

    Traffic-related sources have been recognized as a significant contributor of particulate matter particularly within major cities. Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related PM10 emissions. Non-exhaust particles can be generated either from non-exhaust sources such as brake, tyre, clutch and road surface wear or already exist in the form of deposited material at the roadside and become resuspended due to traffic-induced turbulence. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Studies mention that in urban environments, brake wear can contribute up to 55 % by mass to total non-exhaust traffic-related PM10 emissions and up to 21 % by mass to total traffic-related PM10 emissions, while in freeways, this contribution is lower due to lower braking frequency. As exhaust emissions control become stricter, relative contributions of non-exhaust sources-and therefore brake wear-to traffic-related emissions will become more significant and will raise discussions on possible regulatory needs. The aim of the present literature review study is to present the state-of-the-art of the different aspects regarding PM resulting from brake wear and provide all the necessary information in terms of importance, physicochemical characteristics, emission factors and possible health effects. PMID:25318420

  4. Modeling regenerative braking and storage for vehicles

    SciTech Connect

    Wicks, F.; Donnelly, K.

    1997-12-31

    The fuel savings benefits of regenerative braking and storage for vehicles are often described but not quantified. For example, the federal government and automobile manufacturers are sponsoring a Program for a New Generation of Vehicles (PGNV) with a goal of obtaining a performance of 80 mpg in a family size car. It is typically suggested that such a vehicle will be a hybrid engine and electric drive with regenerative braking. The authors note that while regenerative braking has the potential of saving fuel, it may also do more harm than good as a result of additional weight, less than ideal charge/discharge efficiency on the batteries or storage flywheels and the limited portion of the entire driving cycle when regenerative braking can be utilized. The authors also noted that if regenerative braking can have a net benefit, it would be on a heavy vehicle such as a municipal bus because of the frequent stop and go requirements for both traffic light and passengers. Thus the authors initiated a study of regenerative braking on such a vehicle. The resulting analysis presented in this paper includes data following municipal buses to define the driving cycle, modeling the bus power requirements from weight, aerodynamics and rolling resistance, and then calculating the fuel saving that could result from an ideal regenerative braking system.

  5. Vehicle braking and kinetic energy recovery system

    SciTech Connect

    Lowther, F. E.

    1981-09-22

    An auxiliary kinetic energy recovery system is provided for a vehicle with a rotary sliding vane engine including a compressor, a combustion chamber and a motor in which the braking is done by connecting the rotor of the compressor to a wheel and braking rotation of the rotor by controlling the gas flow through the rotary sliding vane compressor, such as by varying the outlet to increase the pressure ratio. This eliminates the conventional friction brakes. The compressed air generated during braking is fed to a surge tank for later use in operating the vehicle engine , thus recovering a portion of the kinetic energy of the vehicle. Additional amounts of kinetic energy are recovered by means of a closed circuit compressible gas circulating system which comprises an auxiliary compressor actuated by the same shaft as that attached to the engine compressor. Expansion of the compressed gas provides torque to the rotor of a motor which drives a shaft by means of which kinetic energy can be recovered as storable electrical power or compressed air. The rotary slide vane motor can also be used as the brake by controlling the inlet thereto. The compressor and motor can be separate units or portions of one unitary rotary sliding vane device. The compressor-brake and motor-brake can be used together or separately and as integral or separate parts of a rotary sliding vane engine and also with other different types of engines.

  6. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... part to have been performed, with less than 100 percent operative brakes. (g) A Class I brake test... side of each car's brake system responds properly to application and release signals; (2) The brake...) The communicating signal system is tested and known to be operating as intended; a tested...

  7. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... part to have been performed, with less than 100 percent operative brakes. (g) A Class I brake test... side of each car's brake system responds properly to application and release signals; (2) The brake...) The communicating signal system is tested and known to be operating as intended; a tested...

  8. Brakes. Auto Mechanics Curriculum Guide. Module 6. Instructor's Guide.

    ERIC Educational Resources Information Center

    Allain, Robert

    This module is the sixth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Eight units cover: introduction to automotive brake systems; disc and drum brake system components and how they operate; properties of brake fluid and procedures for bleeding the brake system; diagnosing and determining needed repairs on

  9. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... manufacturer's maximum current rating. In progressing from zero to maximum, the ammeter indication shall...

  10. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... manufacturer's maximum current rating. In progressing from zero to maximum, the ammeter indication shall...

  11. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... manufacturer's maximum current rating. In progressing from zero to maximum, the ammeter indication shall...

  12. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... manufacturer's maximum current rating. In progressing from zero to maximum, the ammeter indication shall...

  13. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... manufacturer's maximum current rating. In progressing from zero to maximum, the ammeter indication shall...

  14. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... section shall contain the date, time, and location of the last Class I brake test. (d) Each Class I brake... 49 Transportation 4 2010-10-01 2010-10-01 false Class I brake test. 238.313 Section 238.313... Requirements for Tier I Passenger Equipment § 238.313 Class I brake test. (a) Each commuter and...

  15. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... brake test has been performed. (d) The Class IA brake test shall be performed by either a qualified... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake test. 238.315 Section 238.315... Requirements for Tier I Passenger Equipment § 238.315 Class IA brake test. (a) Except as provided in...

  16. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Class II brake test. 238.317 Section 238.317... Requirements for Tier I Passenger Equipment 238.317 Class II brake test. (a) A Class II brake test shall be.... In these circumstances, a Class II brake test shall be performed prior to the train's departure...

  17. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of... included in the exemption to the requirement for brakes on all wheels, 393.42(b); (3) Unladen converter... NECESSARY FOR SAFE OPERATION Brakes 393.48 Brakes to be operative. (a) General rule. Except as provided...

  18. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of... included in the exemption to the requirement for brakes on all wheels, 393.42(b); (3) Unladen converter... NECESSARY FOR SAFE OPERATION Brakes 393.48 Brakes to be operative. (a) General rule. Except as provided...

  19. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of... included in the exemption to the requirement for brakes on all wheels, 393.42(b); (3) Unladen converter... NECESSARY FOR SAFE OPERATION Brakes 393.48 Brakes to be operative. (a) General rule. Except as provided...

  20. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of... included in the exemption to the requirement for brakes on all wheels, 393.42(b); (3) Unladen converter... NECESSARY FOR SAFE OPERATION Brakes 393.48 Brakes to be operative. (a) General rule. Except as provided...

  1. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of... included in the exemption to the requirement for brakes on all wheels, 393.42(b); (3) Unladen converter... NECESSARY FOR SAFE OPERATION Brakes 393.48 Brakes to be operative. (a) General rule. Except as provided...

  2. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 23.493 Section 23....493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their... at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  3. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Braked roll conditions. 23.493 Section 23....493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their... at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  4. Asbestos dust exposure during brake repair.

    PubMed

    Rdelsperger, K; Jahn, H; Brckel, B; Manke, J; Paur, R; Woitowitz, H J

    1986-01-01

    About 10,000 tons of chrysotile per year are used in the Federal Republic of Germany for the production of friction materials. During brake repair an unknown number of approximately 300,000 mechanics in automobile service stations are exposed to asbestos dust. In a field study, asbestos fiber concentrations during brake repair were measured. Occupational histories and chest X-rays of brake service mechanics are being examined. Ninety dust measurements in 76 service stations were made by phase contrast microscopy and by scanning transmission electron microscopy. By electron microscopy, extremely fine chrysotile fibers with lengths less than 5 microns were identified in brake drum dust. Fibers with lengths greater than or equal to 5 microns constituted less than 1% of all chrysotile fibers counted in brake drum dust. Short-term asbestos dust exposures were measured by light microscopy in 101 personal samples during blowing out of brakes, and grinding and turning of brake linings. During blowing out of car brakes, as well as during grinding of brake linings, the product of fiber concentration with length greater than 5 microns and sampling time amounted to about 4-5 fibers/ml X min corresponding to a concentration of 10(6) fibers/m3 over 4-5 min. For trucks and buses higher amounts of 5-10 X 10(6) fibers/m3 X min were observed during these operations. From occupational histories of 210 vehicle mechanics, an average duration of employment of mean +/- s = 21 +/- 10 years and a mean cumulative fiber dose of mean +/- s = (0.54 +/- 1.1) X 10(6) fibers/m3 X years were calculated. PMID:3017102

  5. Asbestos dust exposure during brake repair

    SciTech Connect

    Roedelsperger, K.J.; Jahn, H.; Brueckel, B.M.; Manke, J.; Paur, R.; Woitowitz, H.J.

    1986-01-01

    About 10,000 tons of chrysotile per year are used in the Federal Republic of Germany for the production of friction materials. During brake repair an unknown number of approximately 300,000 mechanics in automobile service stations are exposed to asbestos dust. In a field study, asbestos fiber concentrations during brake repair were measured. Occupational histories and chest X-rays of brake service mechanics are being examined. Ninety dust measurements in 76 service stations were made by phase contrast microscopy and by scanning transmission electron microscopy. By electron microscopy, extremely fine chrysotile fibers with lengths less than 5 microns were identified in brake drum dust. Fibers with lengths greater than or equal to 5 microns constituted less than 1% of all chrysotile fibers counted in brake drum dust. Short-term asbestos dust exposures were measured by light microscopy in 101 personal samples during blowing out of brakes, and grinding and turning of brake linings. During blowing out of car brakes, as well as during grinding of brake linings, the product of fiber concentration with length greater than 5 microns and sampling time amounted to about 4-5 fibers/ml X min corresponding to a concentration of 10(6) fibers/m3 over 4-5 min. For trucks and buses higher amounts of 5-10 X 10(6) fibers/m3 X min were observed during these operations. From occupational histories of 210 vehicle mechanics, an average duration of employment of mean +/- s = 21 +/- 10 years and a mean cumulative fiber dose of mean +/- s = (0.54 +/- 1.1) X 10(6) fibers/m3 X years were calculated.

  6. Statistical analysis of brake squeal noise

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2011-06-01

    Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to understand the mechanisms, a design of experiments study, using a noise dynamometer, was performed by a brake system manufacturer to determine the influence of geometrical parameters (namely, the number and location of slots) of brake pads on brake squeal noise. The experimental results were evaluated with a noise index and ranked for warm and cold brake stops. These data are analysed here using statistical descriptors based on population distributions, and a correlation analysis, to gain greater insight into the functional dependency between the time-averaged friction coefficient as the input and the peak sound pressure level data as the output quantity. The correlation analysis between the time-averaged friction coefficient and peak sound pressure data is performed by applying a semblance analysis and a joint recurrence quantification analysis. Linear measures are compared with complexity measures (nonlinear) based on statistics from the underlying joint recurrence plots. Results show that linear measures cannot be used to rank the noise performance of the four test pad configurations. On the other hand, the ranking of the noise performance of the test pad configurations based on the noise index agrees with that based on nonlinear measures: the higher the nonlinearity between the time-averaged friction coefficient and peak sound pressure, the worse the squeal. These results highlight the nonlinear character of brake squeal and indicate the potential of using nonlinear statistical analysis tools to analyse disc brake squeal.

  7. Screw-released roller brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  8. Review of NASA antiskid braking research

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1982-01-01

    NASA antiskid braking system research programs are reviewed. These programs include experimental studies of four antiskid systems on the Langley Landing Loads Track, flights tests with a DC-9 airplane, and computer simulation studies. Results from these research efforts include identification of factors contributing to degraded antiskid performance under adverse weather conditions, tire tread temperature measurements during antiskid braking on dry runway surfaces, and an assessment of the accuracy of various brake pressure-torque computer models. This information should lead to the development of better antiskid systems in the future.

  9. Wear studies on aircraft brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T. L.

    1977-01-01

    An investigation of both worn surfaces of friction pads and steel rotors which are being applied in current aircraft brakes has been carried out by employing an X-ray diffraction technique. It consists of the analysis of chemical element distribution in the surface layers. The wear particles were also examined by using the scanning electron microscope. The initiation and growth of surface cracks and the oxidation were emphasized in this investigation. A wear model was proposed for the current aircraft brake materials. Essentially this model proposed that cracks are formed in the surface layer of the brake material due to the normal and frictional stresses. It is primarily surface temperature dependent.

  10. Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.

    1972-01-01

    An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

  11. HYDRAULIC SERVO

    DOEpatents

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  12. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., with any of the brakes cut-out, inoperative, or defective. (d) In performing a Class II brake test on a... 49 Transportation 4 2010-10-01 2010-10-01 false Class II brake test. 238.317 Section 238.317... Requirements for Tier I Passenger Equipment § 238.317 Class II brake test. (a) A Class II brake test shall...

  13. Optimal design and selection of magneto-rheological brake types based on braking torque and mass

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Lang, V. T.; Choi, S. B.

    2015-06-01

    In developing magnetorheological brakes (MRBs), it is well known that the braking torque and the mass of the MRBs are important factors that should be considered in the product’s design. This research focuses on the optimal design of different types of MRBs, from which we identify an optimal selection of MRB types, considering braking torque and mass. In the optimization, common types of MRBs such as disc-type, drum-type, hybrid-type, and T-shape types are considered. The optimization problem is to find an optimal MRB structure that can produce the required braking torque while minimizing its mass. After a brief description of the configuration of the MRBs, the MRBs’ braking torque is derived based on the Herschel-Bulkley rheological model of the magnetorheological fluid. Then, the optimal designs of the MRBs are analyzed. The optimization objective is to minimize the mass of the brake while the braking torque is constrained to be greater than a required value. In addition, the power consumption of the MRBs is also considered as a reference parameter in the optimization. A finite element analysis integrated with an optimization tool is used to obtain optimal solutions for the MRBs. Optimal solutions of MRBs with different required braking torque values are obtained based on the proposed optimization procedure. From the results, we discuss the optimal selection of MRB types, considering braking torque and mass.

  14. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  15. Method and apparatus for wind turbine braking

    DOEpatents

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  16. Characterisation of Semi-Metallic Brake Pads using Brake Dynamometer

    NASA Astrophysics Data System (ADS)

    Talib, R. J.; Othman, E.; Kasiran, R.

    2010-03-01

    Friction materials are complex mix of fibres, modifiers, additives, fillers and a binder resin which holds them together and are composed of between 5 and 20 elements in the composition. Each element has its own function and changing any element or its weight percentage will change the friction material properties. Besides, there is no rule of thumb whereupon the friction and wear performance can be predicted based on physical and mechanical properties. Therefore, each developed formulation needs to be subjected to dynamometer test for screening purpose prior to on-vehicle test to reduce development cost and. In this study, four formulations developed for passenger cars through powder metallurgy technique were subjected to dynamometer tests in accordance with Society of Automotive Engineers standard SAE 2552, dynamometer global brake effectiveness test. Test results show that sample S2 and S8 comply with the minimum requirement under all test segments and hence prototype sample could be prepared for further evaluation by performing on the road performance test.

  17. Automated visual inspection of brake shoe wear

    NASA Astrophysics Data System (ADS)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  18. Brake for counter rotating bladed members

    SciTech Connect

    Cedoz, R.W.

    1987-02-10

    This patent describes a propulsion system including a gas turbine engine having an output shaft and a gear drive having a planetary gear set with a first element connected to the engine output shaft and a second element connected to a first bladed member and a third element connected to a second bladed member whereby the first and second bladed members are rotated in opposite directions by the output shaft. A brake is described comprising, a first transfer shaft supported on a stationary housing for rotation about an axis of the latter, a second transfer shaft supported on the stationary housing for rotation about the axis, gear means between one of the counter rotating bladed members and the first transfer shaft and gear means between the other of the counter rotating bladed members and the second transfer shaft. The brake also includes a selectively operable brake actuator on the housing movable between an extended position and a retracted position, and friction means between the brake actuator and each of first and second transfer shafts operative in the extended position of the brake actuator to simultaneously frictionally retard rotation of each of the first and the second transfer shafts whereby each of the counter rotating bladed members is simultaneously braked.

  19. Consideration of Materials for Aircraft Brakes

    NASA Technical Reports Server (NTRS)

    Peterson, M. B.; Ho, T.

    1972-01-01

    An exploratory investigation was conducted concerning materials and their properties for use in aircraft brakes. Primary consideration was given to the heat dissipation and the frictional behavior of materials. Used brake pads and rotors were analyzed as part of the investigation. A simple analysis was conducted in order to determine the most significant factors which affect surface temperatures. It was found that where size and weight restrictions are necessary, the specific heat of the material, and maintaining uniform contact area are the most important factors. A criterion was suggested for optimum sizing of the brake disks. Bench friction tests were run with brake materials. It was found that there is considerable friction variation due to the formation and removal of surface oxide films. Other causes of friction variations are surface softening and melting. The friction behavior at high temperature was found to be more characteristic of the steel surface rather than the copper brake material. It is concluded that improved brake materials are feasible.

  20. Modelling and validation of magnetorheological brake responses using parametric approach

    NASA Astrophysics Data System (ADS)

    Z, Zainordin A.; A, Abdullah M.; K, Hudha

    2013-12-01

    Magnetorheological brake (MR Brake) is one x-by-wire systems which performs better than conventional brake systems. MR brake consists of a rotating disc that is immersed with Magnetorheological Fluid (MR Fluid) in an enclosure of an electromagnetic coil. The applied magnetic field will increase the yield strength of the MR fluid where this fluid was used to decrease the speed of the rotating shaft. The purpose of this paper is to develop a mathematical model to represent MR brake with a test rig. The MR brake model is developed based on actual torque characteristic which is coupled with motion of a test rig. Next, the experimental are performed using MR brake test rig and obtained three output responses known as angular velocity response, torque response and load displacement response. Furthermore, the MR brake was subjected to various current. Finally, the simulation results of MR brake model are then verified with experimental results.

  1. Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization

    NASA Astrophysics Data System (ADS)

    Lü, Hui; Yu, Dejie

    2014-12-01

    An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

  2. Braking Index of Isolated Pulsars

    NASA Astrophysics Data System (ADS)

    Hamil, Oliver; Stone, Jirina; Urbanec, Martin; Urbancova, Gabriela

    2015-04-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities ?, and their time derivatives which show unambiguously that the pulsars are slowing down. The exact mechanism of the spin-down is a question of debate in detail, but the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR). The energy loss by a rotating pulsar is proportional to a model dependent power of ?. This relation leads to the power law ?? = -K ?n where n is called the braking index, equal to the ratio (???)/ ??2 . The simple MDR model predicts the value of n = 3, but observations of isolated pulsars provide rather precise values of n, individually accurate to a few percent or better, in the range 1 < n < 2.8, which is consistently less than the predictions of the MDR model. In this work, we study the dynamical limits of the MDR model as a function of angular velocity. The effects of variation in the rest mass, the moment of inertia, and the dependence on a realistic Equation of State of the rotating star are considered. Furthermore, we introduce a simulated superfluid effect by which the angular momentum of the core is eliminated from the calculation.

  3. Electromagnetic brake/clutch device

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (inventor)

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  4. Desperately Driven and No Brakes

    PubMed Central

    Andersen, Susan L.; Teicher, Martin H.

    2009-01-01

    ANDERSEN, S.L. and TEICHER, M.H. Desperately driven and no brakes: Developmental stress exposure and subsequent risk for substance abuse. NEUROSCI BIOBEHAV REV XX(X) XXX-XXX, 2008. Adverse life events are associated with a wide range of psychopathology, including an increased risk for substance abuse. In this review, we focus on the inter-relationship between exposure to adversity and brain development, and relate this to enhanced windows of vulnerability. This review encompasses clinical and preclinical data, drawing evidence from epidemiological studies, morphometric and functional imaging studies, and molecular biology and genetics. The interaction of exposure during a sensitive period and maturational events produces a cascade that leads to the initiation of substance use at younger ages, and increases the likelihood of addiction by adolescence or early adulthood. A stress-incubation/corticolimbic dysfunction model is proposed based on the interplay of stress exposure, development stage, and neuromaturational events that may explain the seeking of specific classes of drugs later in life. Three main factors contribute to this age-based progression of increased drug use: 1) a sensitized stress response system; 2) sensitive periods of vulnerability; and 3) maturational processes during adolescence. Together, these factors may explain why exposure to early adversity increases risk to abuse substances during adolescence. PMID:18938197

  5. Recent studies of tire braking performance. [for aircraft

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.; Leland, T. J. W.

    1973-01-01

    The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

  6. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, Roy I. (Ypsilanti, MI)

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  7. Adaptive controller for regenerative and friction braking system

    DOEpatents

    Davis, R.I.

    1990-10-16

    A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

  8. 2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...

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

    2. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES, BRAKE HANDLE, AND REDUCTION GEARS, LOOKING SOUTHWEST - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  9. Thermal tribological behaviour of composite carbon metal/steel brake

    NASA Astrophysics Data System (ADS)

    Zaidi, H.; Senouci, A.

    1999-04-01

    Friction behaviour of carbon brake block/brake drum system is studied at high sliding speed ( ?=2000 tr/mn; v=13 m/s) under high applied normal load ( P=20 Kg). The mean contact temperature is measured by K-thermocouple placed in brake block and in brake drum. The real contact temperature is calculated. Friction behaviour and temperature evolution will be given and discussed versus the brake block effusivity/drum brake effusivity ratio and versus Peclet number. Carbon brake block thermal and mechanical damage is observed under high dynamic load (high applied normal load and high sliding speed). The transferred films are analysed and quantified by Scanning Electron Microscopy. The aim of this paper is to present the tribological results versus normal load and sliding speed; and the contact temperature. We will present and discuss thermo-mechanical surface damage analysis of brake block.

  10. 1. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE ...

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

    1. OBLIQUE VIEW OF HOIST, SHOWING CABLE DRUM, WOODEN BRAKE SHOES AND BRAKE HANDLE, LOOKING NORTH - Buffalo Coal Mine, Vulcan Cable Hoist, Wishbone Hill, Southeast end, near Moose Creek, Sutton, Matanuska-Susitna Borough, AK

  11. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Braked roll conditions. 27.493 Section 27.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... value based on limiting brake torque....

  12. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Braked roll conditions. 27.493 Section 27.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... value based on limiting brake torque....

  13. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Braked roll conditions. 29.493 Section 29.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... value based on limiting brake torque....

  14. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Braked roll conditions. 29.493 Section 29.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... value based on limiting brake torque....

  15. Transient thermal behavior of a cylindrical brake system

    NASA Astrophysics Data System (ADS)

    Naji, M.; Al-Nimr, M.; Masoud, S.

    A mathematical model is presented to describe the thermal behavior of a brake system which consists of shoe and drum. The model is solved analytically using Green's function method for any type of the stopping braking action. In terms of the obtained solutions, the transient temperature distribution of the brake is described. The thermal behavior is investigated for three specified braking actions which are the impulse, unit step and trigonometric stopping actions.

  16. Measuring transient temperatures in brake rotors

    SciTech Connect

    Idogaki, T.; Kawai, H.; Harada, H.; Inoune, H.

    1987-06-01

    A vehicle's kinetic energy is converted into thermal energy when its brakes are applied. If this energy is dissipated in the disc rotor, it can cause local temperature rises which induce disc distortions. Although analysis of this thermal phenomenon has been attempted by several means, a study of the transient temperature distribution has not been made due to the difficulty of measuring it by conventional means. The system to be discussed in this article makes non-contact measurement possible even in a narrow space. Temperature distribution patterns during a revolution of high speed braking can be determined for both sides of a disc rotor.

  17. Parker Hybrid Hydraulic Drivetrain Demonstration

    SciTech Connect

    Collett, Raymond; Howland, James; Venkiteswaran, Prasad

    2014-03-31

    This report examines the benefits of Parker Hannifin hydraulic hybrid brake energy recovery systems used in commercial applications for vocational purposes. A detailed background on the problem statement being addressed as well as the solution set specific for parcel delivery will be provided. Objectives of the demonstration performed in high start & stop applications included opportunities in fuel usage reduction, emissions reduction, vehicle productivity, and vehicle maintenance. Completed findings during the demonstration period and parallel investigations with NREL, CALSTART, along with a literature review will be provided herein on this research area. Lastly, results identified in the study by third parties validated the savings potential in fuel reduction of on average of 19% to 52% over the baseline in terms of mpg (Lammert, 2014, p11), Parker data for parcel delivery vehicles in the field parallels this at a range of 35% - 50%, emissions reduction of 17.4% lower CO2 per mile and 30.4% lower NOx per mile (Gallo, 2014, p15), with maintenance improvement in the areas of brake and starter replacement, while leaving room for further study in the area of productivity in terms of specific metrics that can be applied and studied.

  18. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for braking system. 1512.5... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.5 Requirements for braking system. (a) Braking system... of at least 68.1 kg (150 lb) weight in accordance with the performance test, § 1512.18(d)(2) (v)...

  19. 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...

  20. 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...

  1. 49 CFR 232.215 - Transfer train brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Transfer train brake tests. 232.215 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements 232.215 Transfer train brake tests. (a) A transfer train, as defined in 232.5, shall receive a brake test performed by...

  2. 49 CFR 232.215 - Transfer train brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Transfer train brake tests. 232.215 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES Inspection and Testing Requirements 232.215 Transfer train brake tests. (a) A transfer train, as defined in 232.5, shall receive a brake test performed by...

  3. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Dynamic brake requirements. 232.109 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements 232.109 Dynamic brake requirements. (a... operational status of the dynamic brakes on all locomotive units in the consist at the initial terminal for...

  4. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Dynamic brake requirements. 232.109 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements 232.109 Dynamic brake requirements. (a... operational status of the dynamic brakes on all locomotive units in the consist at the initial terminal for...

  5. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Dynamic brake requirements. 232.109 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements 232.109 Dynamic brake requirements. (a... operational status of the dynamic brakes on all locomotive units in the consist at the initial terminal for...

  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, 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...

  8. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  9. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Braking system. 75.1404-1 Section 75.1404-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips 75.1404-1 Braking system. A locomotive equipped with a dual braking...

  10. 30 CFR 75.1404-1 - Braking system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Braking system. 75.1404-1 Section 75.1404-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips 75.1404-1 Braking system. A locomotive equipped with a dual braking...

  11. 30 CFR 75.1400-1 - Hoists; brakes, capability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Hoists; brakes, capability. 75.1400-1 Section 75.1400-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... Hoists; brakes, capability. Brakes on hoists used to transport persons shall be capable of stopping...

  12. 30 CFR 75.1400-1 - Hoists; brakes, capability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Hoists; brakes, capability. 75.1400-1 Section 75.1400-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... Hoists; brakes, capability. Brakes on hoists used to transport persons shall be capable of stopping...

  13. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  14. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Class IA brake test. 238.315 Section 238.315... Requirements for Tier I Passenger Equipment § 238.315 Class IA brake test. (a) Except as provided in paragraph (b) of this section, either a Class I or a Class IA brake test shall be performed: (1) Prior to...

  15. 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...

  16. 49 CFR 229.47 - Emergency brake valve.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Emergency brake valve. 229.47 Section 229.47... Emergency brake valve. (a) Except for locomotives with cabs designed for occupancy by only one person, each road locomotive shall be equipped with a brake pipe valve that is accessible to a member of the...

  17. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 27.493 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions (a) The...

  18. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 29.493 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions (a) The...

  19. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Braked roll conditions. 27.493 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions (a) The...

  20. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Braked roll conditions. 29.493 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions (a) The...

  1. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Dynamic brake requirements. 232.109 Section 232... TRAINS AND EQUIPMENT; END-OF-TRAIN DEVICES General Requirements 232.109 Dynamic brake requirements. (a... operational status of the dynamic brakes on all locomotive units in the consist at the initial terminal for...

  2. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Pounds or Less 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  3. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Pounds or Less 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  4. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Pounds or Less 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  5. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Pounds or Less 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  6. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Pounds or Less 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken, improperly mounted, or audibly leaking. With residual vacuum exhausted and a constant 25 pound force on the... engine and apply service brakes several times to destroy vacuum in system. Depress brake pedal with...

  7. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Requirements for braking system. 1512.5 Section 1512.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.5 Requirements for braking system. (a) Braking...

  8. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Requirements for braking system. 1512.5 Section 1512.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.5 Requirements for braking system. (a) Braking...

  9. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Requirements for braking system. 1512.5 Section 1512.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.5 Requirements for braking system. (a) Braking...

  10. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Requirements for braking system. 1512.5 Section 1512.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.5 Requirements for braking system. (a) Braking...

  11. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Braked roll conditions. 27.493 Section 27.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads 27.493 Braked roll conditions. Under braked roll conditions...

  12. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Braked roll conditions. 29.493 Section 29.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads 29.493 Braked roll conditions. Under braked roll...

  13. Hydraulic system for a ratio change transmission

    DOEpatents

    Kalns, Ilmars

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  14. Motion capture of a pad measured with accelerometers during squeal noise in a real brake system

    NASA Astrophysics Data System (ADS)

    Renaud, Franck; Chevallier, Gaël; Dion, Jean-Luc; Taudière, Guillaume

    2012-11-01

    The operating deflection shape of a pad during squeal noise is measured on a real brake system with three-axis accelerometers. A time-frequency analysis is performed that highlights the dependency of squeal on the hydraulic pressure of the system and shows that squeal occurs simultaneously with harmonic components. The operating deflection shape of this pad before and during squeal is then visualized using interpolation, showing the predominance of bending motion. Finally, the pad motions observed are compared to the real modal basis of a detailed Finite Element model.

  15. Experimental Identification of Brake Pad Material PropertiesA Step Towards a Better Prediction of Brake Squeal

    NASA Astrophysics Data System (ADS)

    Hornig, Sylwia; Hochlenert, Daniel; von Wagner, Utz

    2010-09-01

    Automotive brake squeal is a disruptive high frequency sound radiation phenomenon generated by friction-induced self-excited vibrations of the brake system. The brake system loses its stability and starts oscillating in a limit cycle with amplitudes limited by nonlinearities, the main origin of the nonlinearities being brake lining material. In order to perform a reliable brake squeal prediction using established mathematical-mechanical models, the knowledge of the lining material properties is of great importance. The present paper deals with the experimental identification of lining material properties, expecially referring to the elastic properties. Since these strongly vary depending on the operating conditions of brake systems, it is necessary to reproduce the operating conditions during brake squeal as close as possible in experimental setups. In this context a special test rig, the test data evaluation and the experimentally determined nonlinear elastic brake lining properties are presented. Assuming these brake lining properties to be the prominent source of the nonlinearity, a nonlinear stability analysis is performed on a realistic disk brake model. The results referring to brake squeal are discussed, whereas basic phenomena known from operating experience of brake systems can be explained on the basis of this analysis.

  16. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot... Devices and Maintenance Requirements 57.14101 Brakes. (a) Minimum requirements. (1)...

  17. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot... Devices and Maintenance Requirements 57.14101 Brakes. (a) Minimum requirements. (1)...

  18. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot... Devices and Maintenance Requirements 57.14101 Brakes. (a) Minimum requirements. (1)...

  19. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot... Devices and Maintenance Requirements 57.14101 Brakes. (a) Minimum requirements. (1)...

  20. Wind-Tunnel Investigations of Diving Brakes

    NASA Technical Reports Server (NTRS)

    Fucha, D.

    1942-01-01

    Unduly high diving speeds can be effectively controlled by diving brakes but their employment involves at the same time a number of disagreeable features: namely, rotation of zero lift direction, variation of diviving moment, and, the creation of a potent dead air region.

  1. Magnetic Braking and Protostellar Disk Formation

    NASA Astrophysics Data System (ADS)

    Mellon, Richard R.; Li, Z.

    2009-01-01

    It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Non-ideal MHD effects are expected to weaken the magnetic braking, perhaps allowing the disk to reappear. I concentrate on one such effect, ambipolar diffusion, which enables the field lines to slip relative to the bulk neutral matter. I will report the results of a set of 2D (axisymmetric) simulations of the collapse of rotating, singluar isothermal cores with different degrees of magnetization and cosmic ray ionization. I demonstrate that the slippage does not sufficiently weaken the braking to allow rotationally supported disks to form for realistic levels of cloud magnetization and cosmic rayionization rate; in some cases, the magnetic braking is even enhanced. Only in dense cores with both exceptionally weak fields and unreasonably low ionization rate do such disks start to form in our simulations. I conclude that additional processes, such as Ohmic dissipation or Hall effect, are needed to enable disk formation. Alternatively, the disk may form at late times when the massive envelope that anchors the magnetic brake is dissipated, perhaps by a protostellar wind. This research was supported in part by grants from NSF and NASA.

  2. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., smooth, and free of loose material. (2) The vehicle must be in the center of a 12-foot-wide lane when the test begins and must not deviate from that lane during the test. (d) Vehicle brake performance table... a truck or bus chassis and having a manufacturer's GVWR of 10,000 pounds or less 52.8 17 25 66...

  3. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., smooth, and free of loose material. (2) The vehicle must be in the center of a 12-foot-wide lane when the test begins and must not deviate from that lane during the test. (d) Vehicle brake performance table... a truck or bus chassis and having a manufacturer's GVWR of 10,000 pounds or less 52.8 17 25 66...

  4. Fuzzy control of an automotive while braking

    NASA Astrophysics Data System (ADS)

    Yan, Shirong

    2005-12-01

    To investigate the dynamic characteristics of an automotive and develop a control method for its safe braking, a dynamic model of the car with active suspension devices during its braking was established. The dynamic model was with 4 degrees of freedom, that is, two degrees of freedom with the car body and others with forefront wheels and rear wheels. For the purpose of reliable use of the control method in most cases, a wavy road was included in the problem. Considering random road surface, braking deceleration and traveling speed of the car when braking, a fuzzy control method was used. Based on a real car made in China, computer simulation was adopted to investigate the dynamic characteristics of the car and the fuzzy control method. The results show that under the condition of an elaborately developed fuzzy control method used in the 4 active suspension devices, the displacement of the mass center and the turnover angle of the car body are greatly reduced and about only one half of their original values are remained.

  5. A High Braking Index for a Pulsar

    NASA Astrophysics Data System (ADS)

    Archibald, R. F.; Gotthelf, E. V.; Ferdman, R. D.; Kaspi, V. M.; Guillot, S.; Harrison, F. A.; Keane, E. F.; Pivovaroff, M. J.; Stern, D.; Tendulkar, S. P.; Tomsick, J. A.

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640–4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640–4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  6. Use of elastomers in regenerative braking systems

    NASA Astrophysics Data System (ADS)

    The storage of potential energy as strain energy in elastomers was investigated. The evolution of the preferred stressing scheme is described, and test results on full-size elastomeric energy storage units sized for an automotive regenerative braking system application are presented. The need for elastomeric material improvements is also discussed.

  7. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Brakes. 27.735 Section 27.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  8. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Brakes. 29.735 Section 29.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  9. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Brakes. 27.735 Section 27.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  10. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Brakes. 29.735 Section 29.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  11. Road transducer - Objective brake balance measurement without vehicle instrumentation

    SciTech Connect

    Wolanin, M.J.; Baptist, T.A.

    1987-01-01

    During braking, the ability to utilize available tire-road friction is determined by brake balance. Previous methods for objectively measuring balance require various degrees of vehicle instrumentation and modification. The Road Transducer is a new measurement technique based on instrumented sections of roadway. Individual braking forces developed by each wheel are measured without vehicle instrumentation, modification, or special set up. This facilitates assessment of many vehicles required for statistical analyses. Brake balance data for several hundred vehicles are presented and provide insight to the nominal levels and variability of braking efficiencies found in the field.

  12. The effect of aftermarket linings on braking efficiency

    SciTech Connect

    Flick, M.A.; Radlinski, R.W.; Kirkbride, R.L.

    1987-01-01

    Currently there are no adequate standards or regulations that address the performance of aftermarket replacement brake linings to insure that the use of these materials does not degrade vehicle braking performance from the original equipment (OE) design intent level. This paper discusses the results of an evaluation of a large sampling of aftermarket linings available for the rear brake of a specific model passenger car and shows that many of these linings have significantly different performance than the OE material. The paper also shows how this deviation can adversely affect vehicle braking efficiency or the ability of the brake system to utilize available tire/roadway friction without locking wheels and losing control.

  13. Pedestrian injury mitigation by autonomous braking.

    PubMed

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness. PMID:20728647

  14. Experimental investigation of an accelerometer controlled automatic braking system

    NASA Technical Reports Server (NTRS)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

  15. Modeling hydraulic regenerative hybrid vehicles using AMESim and Matlab/Simulink

    NASA Astrophysics Data System (ADS)

    Lynn, Alfred; Smid, Edzko; Eshraghi, Moji; Caldwell, Niall; Woody, Dan

    2005-05-01

    This paper presents the overview of the simulation modeling of a hydraulic system with regenerative braking used to improve vehicle emissions and fuel economy. Two simulation software packages were used together to enhance the simulation capability for fuel economy results and development of vehicle and hybrid control strategy. AMESim, a hydraulic simulation software package modeled the complex hydraulic circuit and component hardware and was interlinked with a Matlab/Simulink model of the vehicle, engine and the control strategy required to operate the vehicle and the hydraulic hybrid system through various North American and European drive cycles.

  16. Braking hazards of golf cars and low speed vehicles.

    PubMed

    Seluga, K J; Ojalvo, I U

    2006-11-01

    Research and analysis of braking issues for golf cars and other low speed vehicles (LSVs) are reported in this study. It is shown that many such vehicles only provide braking for their rear wheels, which can lead to a driver losing control during travel on typical steep downgrades. The braking performance of a golf car equipped with brakes on two or four wheels was analyzed to determine the effects of two and four wheel brake designs on braking efficiency and vehicle yaw stability. Besides reducing braking efficiency, it is demonstrated that installing brakes on only the rear wheels can lead to directional instability (fishtailing) and rollover when the rear wheels are braked until skidding occurs. The nonexistence of golf course standards and the inadequacy of golf car and LSV standards are noted and a connection between this and the comparatively high level of accidents with such vehicles is inferred. Based on these results, it is advisable to install brakes on all four wheels of golf cars and LSVs. In addition, new safety standards should be considered to reduce the occurrence of golf car accidents on steep downhill slopes. PMID:16806027

  17. Wind rotor thrust-actuated brake

    SciTech Connect

    Smith, D.R.

    1984-04-17

    A new type of overspeed control system for a rotor driven by wind or some other fluid flow. The rotor support is mounted so that it can move back some small distance along the direction of the fluid flow, the rotor axis remaining in substantially the same direction during this movement. This backward movement is in response to the thrust generated by the lift and drag forces on the rotor impellers. At a predetermined thrust force, indicating that the rotor is operating in a fluid velocity high enough to cause overspeeding, the backward movement of the rotor engages a brake to slow the rotor. Essential to the invention is the use of the backward movement of the rotor to brake the rotor.

  18. Wind turbine trailing edge aerodynamic brakes

    SciTech Connect

    Migliore, P G; Miller, L S; Quandt, G A

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  19. Debiasing overoptimistic beliefs about braking capacity.

    PubMed

    Svenson, Ola; Eriksson, Gabriella; Mertz, C K

    2013-09-01

    We investigated, using questionnaires, different strategies for removing drivers' overoptimism (Svenson et al., 2012a) about how fast their speed could be decreased when they were speeding compared with braking at the speed limit speed. Three different learning groups and a control group made collision speed judgments. The first learning group had the distance a car travels during a driver's reaction time for each problem. The second group had this information and also feedback after each judgment (correct speed). The third group judged collision speed but also braking distance and received correct facts after each problem. The control group had no information at all about reaction time and the distance traveled during that time. The results suggested the following rank order from poor to improved performance: control, group 1, group 3 and group 2 indicating that information about distance driven during a driver's reaction time improved collision speed judgments and that adding stopping distance information did not add to this improvement. PMID:23743252

  20. Plasma Braking Due to External Magnetic Perturbations

    NASA Astrophysics Data System (ADS)

    Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

    2010-11-01

    The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

  1. Well servicing methods using a hydraulic actuated workover mast

    SciTech Connect

    Maroney, P.F.; Blalock, F.C.

    1988-07-12

    A method is described of removing a stuck object from a well by operating a hydraulically operated workover rig which has a mast with a crown and a traveling block, a first winch with a brake, a first hydraulic motor, a line connected to the winch, and tubing in a well, which comprises: (a) connecting the end of the line to the tubing; (b) providing hydraulic power fluid to drive the first motor to drive the first winch to put high stress on the tubing; (c) abruptly cutting off the hydraulic power fluid to the motor to allow the tubing to contract; (d) then operating the brake to impart a shock down the tubing; (e) repeating steps (b) and (d) above as necessary until the object becomes unstuck. A method is also described of lowering objects into a well bore using a mast having a crown block, a first drum on which a line is mounted, a first hydraulic motor for driving the first drum.

  2. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    NASA Astrophysics Data System (ADS)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  3. The effect of friction on drum brakes

    SciTech Connect

    Huang, Y.M.; Shyr, J.S.

    1995-12-31

    The boundary element method (BEM) has been developed for a long period of time. Cruse and Wilson developed an isoparametric quadratic element. Rizzo, Cruse, Rizzo and Shippy, and Swedlow and cruse applied the method to various problems. It shows that the BEM can provide a very good analytical result in the linear problem and it can reduce time in preparation of numerical data. Watson and Newcomb pointed out that the pressure distribution on the contact surface of the brake drum and the lining plate do not vary significantly along the axis. The deflection can be reduced by an appropriate design of the web; therefore, two dimensional analysis with the BEM is used in this analysis. Based on the authors` knowledge, this is the first paper to analyze the drum brake by using the BEM. The assumptions are the brake drum to be a rigid body, perfect interface contact between the drum and the shoe, the constant friction coefficient of the friction material and the thermal effect to be neglected. The two dimensional equations are derived based on the Somigliana`s identity. Since there is no shape function and no need of the Jacobin for the coordinate transform, to integrate numerically is easier and to write a computer code is simpler for the constant value element than the second order element. The linear element is inappropriate to treat the comer problem. Using the linear elements or second order elements creates discontinuous phenomena along the irregular boundary. The common nodal point has different normal vector and boundary conditions. It is necessary to have an extra equation to provide a unique solution for the final linear equation. Using the constant value element can get rid of this problem. The effect of the friction on the pressure distribution at the friction interface is studied. The calculated results of the pressure distribution are compared with the available data. The mathematical model can be used as a design tool to predict the performance of drum brakes.

  4. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... 49 Transportation 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232... Train brake tests conducted using yard air. (a) When a train air brake system is tested from a yard...

  5. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... passenger equipment containing a power brake defect at the time a Class I or IA brake test is performed... route after a Class I or IA brake test was performed), a commuter or passenger train that has in its consist passenger equipment containing a power brake defect at the time that a Class I or IA brake...

  6. Squeal noise in simple numerical brake models

    NASA Astrophysics Data System (ADS)

    Oberst, S.; Lai, J. C. S.

    2015-09-01

    Since the early 1920s, automotive disc brake squeal has caused warranty issues and customer dissatisfaction. Despite a good deal of progress achieved, predicting brake squeal propensity is as difficult as ever as not all mechanisms and interactions are known owing to their highly fugitive complex nature. In recent years, research has been focused on the prediction of unstable vibration modes by the complex eigenvalue analysis (CEA) for the mode-coupling type of instability. There has been very limited consideration given to the calculation of the acoustic radiation properties due to friction contact between a pad and a rotor. Recent analyses using a forced response analysis with harmonic contact pressure excitation indicates negative dissipated energy at some pad eigenfrequencies predicted to be stable by the CEA. A transient nonlinear time domain analysis with no external excitation indicates that squeal could develop at these eigenfrequencies. Here, the acoustic radiation characteristics of those pad modes are determined by analysing the acoustic power levels and radiation efficiencies of simplified brake models in the form of a pad rubbing on a plate or on a disc using the acoustic boundary element method based on velocities extracted from the forced response analysis. Results show that unstable pad modes trigger unstable disc vibrations resulting in instantaneous mode squeal similar to those observed experimentally. Changes in the radiation efficiency with pressure variations are smaller than those with friction coefficient variations and are caused by the phase difference of the velocities out-of-plane vibration between the pad and the disc.

  7. Asbestos in brakes: exposure and risk of disease.

    PubMed

    Lemen, Richard A

    2004-03-01

    Asbestos has been incorporated into friction products since the early 1900s. Epidemiological studies have been equivocal in their analysis of the incidence of disease among mechanics servicing brakes. Decomposition of asbestos occurs during the normal usage of the brake due to thermal decomposition into forsterite, although not all asbestos is so converted. Short fibers, below 5 microm in length, are also found in brake products. Several facts are discussed including the toxicity of the remaining asbestos fibers, short asbestos fibers, and the health implications of exposure to forsterite. Control methodologies, when used appropriately, have reduced exposure to asbestos during brake servicing, but have not been able to entirely eliminate exposure to asbestos, thus bring into question the controlled use of asbestos for friction product such as brakes. Even the so called "controlled" use of asbestos containing brakes poses a health risk to workers, users, and their families. PMID:14991849

  8. Status of recent aircraft braking and cornering research

    NASA Technical Reports Server (NTRS)

    Stubbs, S. M.; Tanner, J. A.

    1976-01-01

    The sources of degraded performance which sometimes occurs under adverse runway conditions, are investigated to obtain data necessary to the development of more advanced systems, in an effort to insure safe ground handling operations under all-weather conditions. Tire-to-ground friction characteristics are determined under braking conditions which closely resemble those of airplanes under heavy braking. Braking data from single-wheel landing loads track tests are related with those available from full-scale flight tests.

  9. A proposal for dynamic calibration of brake tester

    NASA Astrophysics Data System (ADS)

    Ferreira, Paulo L. S.; Couto, Paulo R. G.; Cabral, Luiz C.; Reis, Ronaldo G.; Zillner, Marcos

    2015-10-01

    In Brazil there are about 400 security inspection lines carrier operating in Inspection Bodies accredited by Cgcre Inmetro [1]. The equipment in this proposal is a Brake Tester that measure vehicle braking forces and it is a component of an inspection line. This paper proposes a dynamic Brake Tester calibration using a reference torque transducer. This article can also be the basis for future discussions of the revised standard manufacturing of vehicle inspection line according to ABNT NBR 14040 [2].

  10. Tau as a Potential Control Variable for Visually Guided Braking

    ERIC Educational Resources Information Center

    Rock, Paul B.; Harris, Mike G.

    2006-01-01

    D. N. Lee (1976) described a braking strategy based on optical expansion in which the driver brakes so that the target's time-to-contact declines around a constant slope in the range -0.5 less than or equal to tau less than 0. The present results from a series of braking simulations confirm and extend earlier reports (E. H. Yilmaz & W. H. Warren,

  11. Aerodynamic braking of high speed ground transportation vehicles.

    NASA Technical Reports Server (NTRS)

    Marte, J. E.; Marko, W. J.

    1973-01-01

    The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

  12. Hydraulic fracturing-1

    SciTech Connect

    Not Available

    1990-01-01

    This book contains papers on hydraulic fracturing. Topics covered include: An overview of recent advances in hydraulic fracturing technology; Containment of massive hydraulic fracture; and Fracturing with a high-strength proppant.

  13. Speciation of Sb in airborne particulate matter, vehicle brake linings, and brake pad wear residues

    NASA Astrophysics Data System (ADS)

    Varrica, D.; Bardelli, F.; Dongarrà, G.; Tamburo, E.

    2013-01-01

    Insights into the speciation of Sb in samples of brake linings, brake pad wear residues, road dust, and atmospheric particulate matter PM10 and PM2.5 were obtained combining several well established and advanced characterization techniques, such as scanning electron microscopy - energy dispersive spectrometry (SEM-EDS), inductively coupled plasma mass spectrometry (ICP-MS) and synchrotron radiation X-ray absorption spectroscopy (SR-XAS). The advantage of SR-XAS is that samples do not undergo any chemical treatment prior to measurements, thus excluding possible alterations. These analyses revealed that the samples of wheel rims dust, road dust, and atmospheric particulate matter are composed by an admixture of Sb(III) and Sb(V) in different relative abundances. Brake linings turned out to be composed by Sb(III) oxide (Sb2O3) and stibnite (Sb2S3). Stibnite was also detected in some of the particulate matter samples. The obtained data suggest that Sb2S3 during the brake abrasion process is easily decomposed forming more stable compounds such as antimony mixed oxidic forms. Sb redox speciation, in particular and well studied circumstances, may enhance the potential and selectivity of this element as a tracer of motor vehicle emissions in apportioning studies.

  14. From the Kinetic Energy Recovery System to the Thermo-Hydraulic Hybrid Motor Vehicle

    NASA Astrophysics Data System (ADS)

    Cristescu, Corneliu; Drumea, Petrin; Guta, Dragos; Dumitrescu, Catalin

    2011-12-01

    The paper presents some theoretical and experimental results obtained by the Hydraulics and Pneumatics Research Institute INOE 2000-IHP with its partners, regarding the creating of one hydraulic system able to recovering the kinetic energy of the motor vehicles, in the braking phases, and use this recovered energy in the starting and accelerating phases. Also, in the article is presented a testing stand, which was especially designed for testing the hydraulic system for recovery the kinetic energy. Through mounting of the kinetic energy recovering hydraulic system, on one motor vehicle, this vehicle became a thermo-hydraulic hybrid vehicle. Therefore, the dynamic behavior was analyzed for the whole hybrid motor vehicle, which includes the energy recovery system. The theoretical and experimental results demonstrate the possible performances of the hybrid vehicle and that the kinetic energy recovery hydraulic systems are good means to increase energy efficiency of the road motor vehicles and to decrease of the fuel consumption.

  15. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements... brake system that meets the requirements of FMVSS No. 105 in effect on the date of manufacture. Motor... system that meets the applicable requirements of 393.42, 393.48, 393.49, 393.51, and 393.52 of...

  16. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements... brake system that meets the requirements of FMVSS No. 105 in effect on the date of manufacture. Motor... system that meets the applicable requirements of 393.42, 393.48, 393.49, 393.51, and 393.52 of...

  17. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... performed, or was required by this part to have been performed, with less than 100 percent operative brakes... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  18. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements... brake system that meets the requirements of FMVSS No. 105 in effect on the date of manufacture. Motor... system that meets the applicable requirements of 393.42, 393.48, 393.49, 393.51, and 393.52 of...

  19. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... performed, or was required by this part to have been performed, with less than 100 percent operative brakes... and release of the brakes on the last car in the train; and (6) The communicating signal system is tested and known to be operating as intended; a tested and operating two-way radio system meets...

  20. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements... brake system that meets the requirements of FMVSS No. 105 in effect on the date of manufacture. Motor... system that meets the applicable requirements of 393.42, 393.48, 393.49, 393.51, and 393.52 of...

  1. 49 CFR 393.40 - Required brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements... brake system that meets the requirements of FMVSS No. 105 in effect on the date of manufacture. Motor... system that meets the applicable requirements of 393.42, 393.48, 393.49, 393.51, and 393.52 of...

  2. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... task to be accomplished and can perform that task; and (2) Is knowledgeable of and has mastered the methods, procedures, tools and equipment used when performing an assigned brake service or inspection task... person to perform the assigned brake service or inspection task (including passage of Commercial...

  3. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... task to be accomplished and can perform that task; and (2) Is knowledgeable of and has mastered the methods, procedures, tools and equipment used when performing an assigned brake service or inspection task... person to perform the assigned brake service or inspection task (including passage of Commercial...

  4. Control of asbestos exposure during brake drum service

    SciTech Connect

    Sheehy, J.W.; Cooper, T.C.; O'Brien, D.M.; McGlothlin, J.D.; Froehlich, P.A.

    1989-08-01

    Earlier studies of airborne asbestos exposure to mechanics during brake maintenance operations showed overexposure to asbestos fibers during brake servicing, especially brake assembly cleaning. Because an estimated 150,000 brake mechanics and garage workers in the U.S. are potentially exposed to asbestos, a known carcinogen, and the lack of information available on the effectiveness of available controls, an evaluation of these methods was initiated. Detailed field surveys were conducted at five facilities employing five methods for controlling exposure to asbestos during brake repair. These included the use of two commercial enclosure devices with ventilation provided by HEPA filter-equipped vacuum, a HEPA filter-equipped vacuum alone, a brush with recirculating cleaning solution, and cleaning solvents in aerosol cans. These controls were evaluated while servicing brakes to automobiles, pickup trucks, vans, and vehicles with a 4-wheel rear axle. Detailed evaluations of these control measures involved a program consisting of traditional air sampling methods, incorporating phase contrast microscopy (PCM) and transmission electron microscopy (TEM), and a real-time analysis of brake dust exposure. Personal and area air samples were collected during brake repair to each vehicle.

  5. 49 CFR 232.215 - Transfer train brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... coupled between all freight cars; (2) After the brake system is charged to not less than 60 psi as indicated by an accurate gauge or end-of-train device at the rear of the train, a 15-psi service brake...

  6. 49 CFR 232.215 - Transfer train brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... coupled between all freight cars; (2) After the brake system is charged to not less than 60 psi as indicated by an accurate gauge or end-of-train device at the rear of the train, a 15-psi service brake...

  7. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Service brake system. 570.5 Section 570.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of 10,000 Pounds or Less § 570.5 Service brake...

  8. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... percent equipped with air dryers and is equipped with PS-68, 26-C, 26-L, PS-90, CS-1, RT-2, RT-5A, GRB-1, CS-2, or 26-R brake systems. (This listing of brake system types is intended to subsume all...

  9. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... percent equipped with air dryers and is equipped with PS-68, 26-C, 26-L, PS-90, CS-1, RT-2, RT-5A, GRB-1, CS-2, or 26-R brake systems. (This listing of brake system types is intended to subsume all...

  10. 49 CFR 232.215 - Transfer train brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Transfer train brake tests. 232.215 Section 232.215 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER TRAINS AND EQUIPMENT; END-OF-TRAIN...

  11. 30 CFR 57.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  12. 30 CFR 56.19006 - Automatic hoist braking devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with...

  13. 30 CFR 56.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....14102 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and Maintenance Requirements 56.14102 Brakes for rail equipment. Braking...

  14. DC torque motor actuated anti-lock brake controller

    SciTech Connect

    Agarwal, P.D.; Kade, A.

    1989-02-21

    A wheel lock control system is described for limiting the brake pressure applied to the brake of a vehicle wheel traveling over a road surface, the system comprising: an actuator for controlling the brake pressure to the brake of the wheel, the actuator including a torque motor for generating a motor torque in response to motor current to control the applied brake pressure in accordance with the value of the motor torque, the motor torque having a value proportional to the value of the motor current; means for determining the tire torque tending to accelerate the wheel during the application of brake pressure; means for storing the value of motor current corresponding to the maximum determined value of tire torque; means for detecting an incipient wheel lockup condition; and means for establishing the motor current following a detected incipient wheel lockup condition at a value having a predetermined relationship to the stored value of motor current to control the brake pressure at a predetermined braking condition.

  15. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... motor vehicle shall be equipped with brakes acting on all wheels. (b) Exception. (1) Trucks or truck... on the front wheels. However, these vehicles must meet the requirements of 393.52. (2) Motor... 49 Transportation 5 2010-10-01 2010-10-01 false Brakes required on all wheels. 393.42 Section...

  16. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a... used if it is substantiated that an effective drag force of 0.8 times the vertical reaction cannot be... maximum braking force. The airplane is considered to be at design takeoff weight with the nose and...

  17. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a... used if it is substantiated that an effective drag force of 0.8 times the vertical reaction cannot be... maximum braking force. The airplane is considered to be at design takeoff weight with the nose and...

  18. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Braked roll conditions. 25.493 Section 25.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a) An airplane with a tail wheel is...

  19. Braking system for use with an arbor of a microscope

    DOEpatents

    Norgren, Duane U. (Orinda, CA)

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  20. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... 49 Transportation 6 2013-10-01 2013-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  1. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.5 Section 570.5... Pounds or Less § 570.5 Service brake system. Unless otherwise noted, the force to be applied...

  2. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Service brake system. 570.5 Section 570.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of 10,000 Pounds or Less § 570.5 Service brake...

  3. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Service brake system. 570.5 Section 570.5 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of 10,000 Pounds or Less § 570.5 Service brake...

  4. Method and apparatus for braking a derrick winch

    SciTech Connect

    Falcon, J.F.

    1989-09-12

    This patent describes an apparatus for braking a derrick winch with a winch brake. It comprises: a control lever remotely located from the winch; a servo-control circuit connecting the lever and brake for actuating the brake in response to movement of the lever, and including: a torque motor having a shaft mechanically coupled to the control lever; a brake activating device for actuating the winch brake; a first position transducer for sensing the position of the control lever; a second position transducer for sensing the position of the winch brake; a first force transducer for measuring the force applied to the winch brake; a first comparator; a second comparator. The first comparator being connected to receive signals from the first and second position transducers and to deliver an error signal to the torque motor and to the second comparator. The second comparator being connected to receive signals from the first comparator and from the first force transducer and to deliver an error signal to the actuating device.

  5. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Braked roll conditions. 23.493 Section 23.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... the maximum value based on limiting brake torque....

  6. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Braked roll conditions. 23.493 Section 23.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Ground Loads 23.493 Braked roll conditions. Under...

  7. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Braked roll conditions. 23.493 Section 23.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... the maximum value based on limiting brake torque....

  8. Analysis of heat conduction in a disk brake system

    NASA Astrophysics Data System (ADS)

    Talati, Faramarz; Jalalifar, Salman

    2009-06-01

    In this paper, the governing heat equations for the disk and the pad are extracted in the form of transient heat equations with heat generation that is dependant to time and space. In the derivation of the heat equations, parameters such as the duration of braking, vehicle velocity, geometries and the dimensions of the brake components, materials of the disk brake rotor and the pad and contact pressure distribution have been taken into account. The problem is solved analytically using Greens function approach. It is concluded that the heat generated due to friction between the disk and the pad should be ideally dissipated to the environment to avoid decreasing the friction coefficient between the disk and the pad and to avoid the temperature rise of various brake components and brake fluid vaporization due to excessive heating.

  9. Design optimization of a magnetorheological brake in powered knee orthosis

    NASA Astrophysics Data System (ADS)

    Ma, Hao; Liao, Wei-Hsin

    2015-04-01

    Magneto-rheological (MR) fluids have been utilized in devices like orthoses and prostheses to generate controllable braking torque. In this paper, a flat shape rotary MR brake is designed for powered knee orthosis to provide adjustable resistance. Multiple disk structure with interior inner coil is adopted in the MR brake configuration. In order to increase the maximal magnetic flux, a novel internal structure design with smooth transition surface is proposed. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and, particularly, average power consumption. The optimization is then performed with Finite Element Analysis (FEA), and the optimal design is obtained among the Pareto-optimal set considering the trade-offs in design objectives.

  10. Engineering report. Part 3: NASA lightweight wheel and brake sub-system. Lightweight brake development. [for application to space shuttle

    NASA Technical Reports Server (NTRS)

    Bok, L. D.

    1973-01-01

    The development of light weight wheel and brake systems designed to meet the space shuttle type requirements was investigated. The study includes the use of carbon graphite composite and beryllium as heat sink materials and the compatibility of these heat sink materials with the other structural components of the wheel and brake.

  11. Hydraulic pump

    SciTech Connect

    Polak, P.R.; Jantzen, D.E.

    1984-05-15

    This invention relates to an improved pump jack characterized by a hollow piston rod which telescopes down over the sucker rod to which it is clamped for reciprocating motion. The cylinder, in turn, is fastened in fixed position directly to the upper exposed end of the well casing. As fluid is introduced into the lower end of the cylinder it raises the piston into engagement with a pushrod housed in the upper cylinder head that lifts switch-actuating means associated therewith into a position operative to actuate a switch located adjacent thereto thereby causing the latter to change state and actuate a multi-function solenoid valve so as to cut off fluid flow to the cylinder. As gravity lowers the sucker rod and piston exhausting the hydraulic fluid therebeneath, an adjustable stop engages the pushrod from above so as to return it together with the switch-actuating means associated therewith to their original positions thereby resetting the switch to complete the operating cycle.

  12. Composite hydraulic system

    SciTech Connect

    Williamson, W.A.

    1987-03-17

    A composite hydraulic system is described for a work vehicle having an implement hydraulic circuit and a steering hydraulic circuit comprising a first pump which supplies the implement hydraulic circuit primarily, a second pump which supplies the steering hydraulic circuit primarily, a third pump which is operable also as a motor and which transfers hydraulic fluid between the implement and the steering hydraulic circuits, an engine which operates the three pumps simultaneously, and servo system means whereby the third pump under at least one condition of operation operates as a motor to provide regeneration.

  13. EEG potentials predict upcoming emergency brakings during simulated driving.

    PubMed

    Haufe, Stefan; Treder, Matthias S; Gugler, Manfred F; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h(-1) driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed. PMID:21799241

  14. Airborne asbestos exposure during light aircraft brake replacement.

    PubMed

    Blake, Charles L; Johnson, Giffe T; Harbison, Raymond D

    2009-08-01

    Asbestos containing materials are a component of many vehicle brake systems, including those found in some light aircraft. To characterize the asbestos exposure that results from the installation and maintenance of these components, an aircraft fitted with asbestos containing brake pads had brake changes performed while both area and personal air samples were taken. The brake changing process took place in a closed, unventilated aircraft hanger and all operations were performed according to the manufacturer's recommended procedure. Personal air samples did not detect any measurable amount of asbestos fibers during the brake changing or subsequent cleanup procedures. Analysis of personal samples (n=9) using phase contrast microscopy indicated airborne fiber concentrations at or below 0.003f/ml as 8-h time weighted averages (TWAs) and less than 0.069f/ml averaged over 28-30min sampling periods. Airborne chrysotile fibers were detected by two area air samples with fiber concentrations remaining at or below 0.0013f/ml over an 8-h TWA. These results indicate that normal brake changing work practices on aircraft with asbestos containing brake pads does not produce a harmful level of asbestos exposure for aircraft mechanics. PMID:19409949

  15. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... percent of the cars in a train operating in ECP brake mode shall have effective and operative brakes prior...) A freight car equipped with an ECP brake system that is known to have arrived with ineffective...

  16. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... percent of the cars in a train operating in ECP brake mode shall have effective and operative brakes prior...) A freight car equipped with an ECP brake system that is known to have arrived with ineffective...

  17. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... percent of the cars in a train operating in ECP brake mode shall have effective and operative brakes prior...) A freight car equipped with an ECP brake system that is known to have arrived with ineffective...

  18. Optimal design of a hybrid MR brake for haptic wrist application

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Nguyen, Phuong Bac; Choi, Seung-Bok

    2011-03-01

    In this work, a new configuration of a magnetorheological (MR) brake is proposed and an optimal design of the proposed MR brake for haptic wrist application is performed considering the required braking torque, the zero-field friction torque, the size and mass of the brake. The proposed MR brake configuration is a combination of disc-type and drum-type which is referred as a hybrid configuration in this study. After the MR brake with the hybrid configuration is proposed, braking torque of the brake is analyzed based on Bingham rheological model of the MR fluid. The zero-field friction torque of the MR brake is also obtained. An optimization procedure based on finite element analysis integrated with an optimization tool is developed for the MR brake. The purpose of the optimal design is to find the optimal geometric dimensions of the MR brake structure that can produce the required braking torque and minimize the uncontrollable torque (passive torque) of the haptic wrist. Based on developed optimization procedure, optimal solution of the proposed MR brake is achieved. The proposed optimized hybrid brake is then compared with conventional types of MR brake and discussions on working performance of the proposed MR brake are described.

  19. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class III brake tests-trainline continuity... 232.211 Class III brake tests-trainline continuity inspection. (a) A Class III brake test shall be... on the remotely controlled locomotive. (d) Whenever the continuity of the brake pipe is broken...

  20. Braking formula for electrons of relativistic speed

    NASA Astrophysics Data System (ADS)

    Bethe, H.; Bartschat, Klaus

    2014-12-01

    The current translation is by Klaus Bartschat, Department of Physics and Astronomy, Drake University, Des Moines, Iowa 50311, USA. An attempt has been made to preserve Bethe's writing style as much as possible, including his use of "Volt" instead of "electron volt". Even though the term "stopping power" is quite common in present scientific English, we generally use "braking [capability]" rather than "stopping [power]", in order to emphasize the act [and ability] of slowing down the particle rather than the ultimate result of bringing it to a complete halt. Also, a few typographical errors were kept in the English translation to ensure the translation replicates the original paper. Please, see Section 3 of the annotation to Bethe's article [Fontes, C.J., Bostock, C.J. and Bartschat, K. 2014. Eur. Phys. J. H, 39: 517-536] for a list. The references were converted to EPJH style, and the footnotes are numbered consecutively.

  1. A Pulsar Eases Off the Brakes

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    In 2006, pulsar PSR 18460258 unexpectedly launched into a series of energetic X-ray outbursts. Now a study has determined that this event may have permanently changed the behavior of this pulsar, raising questions about our understanding of how pulsars evolve.Between CategoriesA pulsar a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation can be powered by one of three mechanisms:Rotation-powered pulsars transform rotational energy into radiation, gradually slowing down in a predictable way.Accretion-powered pulsars convert the gravitational energy of accreting matter into radiation.Magnetars are powered by the decay of their extremely strong magnetic fields.Astronomical classification often results in one pesky object that doesnt follow the rules. In this case, that object is PSR 18460258, a young pulsar categorized as rotation-powered. But in 2006, PSR 18460258 suddenly emitted a series of short, hard X-ray bursts and underwent a flux increase behavior that is usually only exhibited by magnetars. After this outburst, it returned to normal, rotation-powered-pulsar behavior.Since the discovery of this event, scientists have been attempting to learn more about this strange pulsar that seems to straddle the line between rotation-powered pulsars and magnetars.Unprecedented DropOne way to examine whats going on with PSR 18460258 is to evaluate whats known as its braking index, a measure of how quickly the pulsars rotation slows down. For a rotation-powered pulsar, the braking index should be roughly constant. The pulsar then slows down according to a fixed power law, where the slower it rotates, the slower it slows down.In a recent study, Robert Archibald (McGill University) and collaborators report on 7 years worth of timing observations of PSR 18460258 after its odd magnetar-like outburst. They then compare these observations to 6.5 years of data from before the outburst. The team finds that the braking index for this bizarre pulsar dropped suddenly by 14.5 after the outburst a change thats unprecedented both in how large and how long-lived its been.Why is this a problem? Many of the quoted properties of pulsars (like ages, magnetic fields, and luminosities) are determined based on models that envision pulsars as magnetic dipoles in a vacuum. But if this is the case, a pulsars braking index should be constant or, in more realistic scenarios, we might expect it to change slightly over the span of thousands of years. The fact that PSR 18460258 underwent such a drastic change during its outburst poses a significant challenge to these models of pulsar behavior and evolution.CitationR. F. Archibald et al 2015 ApJ 810 67. doi:10.1088/0004-637X/810/1/67

  2. Tribomaterial factors in space mechanism brake performance

    NASA Technical Reports Server (NTRS)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  3. Brake mechanics, asbestos, and disease risk.

    PubMed

    Huncharek, M

    1990-09-01

    Health risks posed by inhalable asbestos fibers are known to exist in a variety of industrial and nonindustrial settings. Although early studies described an increased risk of asbestosis, lung cancer, and mesothelioma in asbestos-industry workers, subsequent research revealed the existence of a potential asbestos-related health hazard in nonasbestos industries such as the textile and railroad industries. Brake mechanics and garage workers constitute a large work force with potential exposures to levels of asbestos capable of producing disease. Unfortunately, the health risk faced by these workers has received little attention. This article briefly discusses currently available information on the asbestos health risks of workers in this setting, and highlights the need for further investigations of this occupational group. PMID:2171325

  4. A Pulsar Eases Off the Brakes

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-10-01

    In 2006, pulsar PSR 18460258 unexpectedly launched into a series of energetic X-ray outbursts. Now a study has determined that this event may have permanently changed the behavior of this pulsar, raising questions about our understanding of how pulsars evolve.Between CategoriesA pulsar a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation can be powered by one of three mechanisms:Rotation-powered pulsars transform rotational energy into radiation, gradually slowing down in a predictable way.Accretion-powered pulsars convert the gravitational energy of accreting matter into radiation.Magnetars are powered by the decay of their extremely strong magnetic fields.Astronomical classification often results in one pesky object that doesnt follow the rules. In this case, that object is PSR 18460258, a young pulsar categorized as rotation-powered. But in 2006, PSR 18460258 suddenly emitted a series of short, hard X-ray bursts and underwent a flux increase behavior that is usually only exhibited by magnetars. After this outburst, it returned to normal, rotation-powered-pulsar behavior.Since the discovery of this event, scientists have been attempting to learn more about this strange pulsar that seems to straddle the line between rotation-powered pulsars and magnetars.Unprecedented DropOne way to examine whats going on with PSR 18460258 is to evaluate whats known as its braking index, a measure of how quickly the pulsars rotation slows down. For a rotation-powered pulsar, the braking index should be roughly constant. The pulsar then slows down according to a fixed power law, where the slower it rotates, the slower it slows down.In a recent study, Robert Archibald (McGill University) and collaborators report on 7 years worth of timing observations of PSR 18460258 after its odd magnetar-like outburst. They then compare these observations to 6.5 years of data from before the outburst. The team finds that the braking index for this bizarre pulsar dropped suddenly by 14.5 after the outburst a change thats unprecedented both in how large and how long-lived its been.Why is this a problem? Many of the quoted properties of pulsars (like ages, magnetic fields, and luminosities) are determined based on models that envision pulsars as magnetic dipoles in a vacuum. But if this is the case, a pulsars braking index should be constant or, in more realistic scenarios, we might expect it to change slightly over the span of thousands of years. The fact that PSR 18460258 underwent such a drastic change during its outburst poses a significant challenge to these models of pulsar behavior and evolution.CitationR. F. Archibald et al 2015 ApJ 810 67. doi:10.1088/0004-637X/810/1/67

  5. Brake lock mechanism for the two axis pointing system

    NASA Technical Reports Server (NTRS)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed.

  6. Residual stresses in a cast iron automotive brake disc rotor

    NASA Astrophysics Data System (ADS)

    Ripley, Maurice I.; Kirstein, Oliver

    2006-11-01

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed.

  7. Superfund Record of Decision (EPA Region 9): MGM Brakes site, Cloverdale, California (first remedial action), September 1988. Final report

    SciTech Connect

    Not Available

    1988-09-29

    The MGM Brakes site consists of a five-acre plot containing an automotive brakes casting plant, a paved area surrounding the plant, and an open field. It is located in the community of Cloverdale, California, in Alexander Valley, approximately 80 miles north of San Francisco. From 1965 until 1972, hydraulic fluid containing PCBs was discharged onto site property. Waste water containing ethylene glycol was disposed onsite between 1972 and 1981. The ethylene glycol acted as a co-solvent with water, facilitating the transport of PCBs in soil. Approximately 13,510 cu yds of soil within a 3-acre area were contaminated with PCBs at concentrations up to 4500 ppm. The primary contaminants of concern affecting soil, sediments, surface water, and air are PCBs. The selected remedial action for the site includes: dismantling of the MGM Brakes process building; crushing of concrete slab, and excavation of soil. The estimated capital cost for the remedial action is $5,369,300 with no annual O M costs.

  8. Behavior of aircraft antiskid braking systems on dry and wet runway surfaces: Hydromechanically controlled system

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Stubbs, S. M.; Smith, E. G.

    1981-01-01

    The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The landing-gear strut was replaced by a dynamometer. During maximum braking, average braking behavior indexes based upon brake pressure, brake torque, and drag-force friction coefficient developed by the antiskid system were generally higher on dry surfaces than on wet surfaces. The three braking behavior indexes gave similar results but should not be used interchangeably as a measure of the braking of this antiskid sytem. During the transition from a dry to a flooded surface under heavy braking, the wheel entered into a deep skid but the antiskid system reacted quickly by reducing brake pressure and performed normally during the remainder of the run on the flooded surface. The brake-pressure recovery following transition from a flooded to a dry surface was shown to be a function of the antiskid modulating orifice.

  9. Driver Behavioral Changes through Interactions with an Automatic Brake System for Collision Avoidance

    NASA Astrophysics Data System (ADS)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

    This paper discusses driver's behavioral changes as a result of driver's use of an automatic brake system for preventing a rear-end collision from occurring. Three types of automatic brake systems are investigated in this study. Type 1 brake system applies a strong automatic brake when a collision is very imminent. Type 2 brake system initiates brake operation softly when a rear-end crash may be anticipated. Types 1 and 2 are for avoidance of a collision. Type 3 brake system, on the other hand, applies a strong automatic brake to reduce the damage when a collision can not be avoided. An experiment was conducted with a driving simulator in order to analyze the driver's possible behavioral changes. The results showed that the time headway (THW) during car following phase was reduced by use of an automatic brake system of any type. The inverse of time to collision (TTC), which is an index of the driver's brake timing, increased by use of Type 1 brake system when the deceleration rate of the lead vehicle was relatively low. However, the brake timing did not change when the drivers used Type 2 or 3 brake system. As a whole, dangerous behavioral changes, such as overreliance on a brake system, were not observed for either type of brake system.

  10. 49 CFR 396.25 - Qualifications of brake inspectors.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 396.25 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE 396.25 Qualifications of brake inspectors. (a) Motor carriers and...

  11. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    PubMed

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. PMID:25311161

  12. 54. West emergency brake in the south machinery room (interior ...

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

    54. West emergency brake in the south machinery room (interior of both machinery rooms is identical). Facing west. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  13. Metals associated with stormwater-relevant brake and tire samples

    PubMed Central

    McKenzie, Erica R.; Money, Jon E.; Green, Peter G.; Young, Thomas M.

    2009-01-01

    Properly apportioning the loads of metals in highway stormwater runoff to the appropriate sources requires accurate data on source composition, especially regarding constituents that help to distinguish among sources. Representative tire and brake samples were collected from privately owned vehicles and aqueous extracts were analyzed for twenty-eight elements. Correlation principal components analysis (PCA) revealed that tires were most influenced by Zn, Pb, and Cu, while brakes were best characterized by Na and Fe followed by Ba, Cu, Mg, Mn, and K; the latter three may be due to roadside soil contributions. Notably elevated Cd contributions were found in several brake samples. A targeted Cd-plated brake rotor was sampled, producing results consistent with the elevated levels found in the larger sample population. This enriched source of Cd is of particular concern due to high toxicity of Cd in aquatic ecosystems. PMID:19709720

  14. 6. DETAIL OF THE BRAKE SHOE ON THE EAST DRUM ...

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

    6. DETAIL OF THE BRAKE SHOE ON THE EAST DRUM AT THE STEWARD MINE, LOOKING EAST. THE EAST DRUM WAS UNDER SHOT, THE WEST OVERSHOT - Butte Mineyards, Stewart Mine, Intersection of Main & Woolman Streets, Butte, Silver Bow County, MT

  15. Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm

    NASA Astrophysics Data System (ADS)

    Mittal, Ruchi; Kaur, Magandeep

    2010-11-01

    In this paper an application of Fuzzy Logic for Automatic Braking system is proposed. Anti-blocking system (ABS) brake controllers pose unique challenges to the designer: a) For optimal performance, the controller must operate at an unstable equilibrium point, b) Depending on road conditions, the maximum braking torque may vary over a wide range, c) The tire slippage measurement signal, crucial for controller performance, is both highly uncertain and noisy. A digital controller design was chosen which combines a fuzzy logic element and a decision logic network. The controller identifies the current road condition and generates a command braking pressure signal Depending upon the speed and distance of train. This paper describes design criteria, and the decision and rule structure of the control system. The simulation results present the system's performance depending upon the varying speed and distance of the train.

  16. 27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. ...

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

    27. UPPER STATION, LOWER FLOOR, BULL WHEEL, BRAKE AIR CYLINDER. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  17. 28. UPPER STATION, LOWER FLOOR, BULL WHEEL ROOM, SAFETY BRAKE ...

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

    28. UPPER STATION, LOWER FLOOR, BULL WHEEL ROOM, SAFETY BRAKE ADJUSTING MACHINERY. - Monongahela Incline Plane, Connecting North side of Grandview Avenue at Wyoming Street with West Carson Street near Smithfield Street, Pittsburgh, Allegheny County, PA

  18. 4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE ...

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

    4. FLOOR 3; GENERAL VIEW LOOKING NORTH SHOWS WALLOWER, BRAKE LEVER, CASE FOR SCREENER, TOP OF GRAIN ELEVATOR, LAYSHAFT WHICH POWERS THE SCREENER AND ELEVATOR - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  19. Experimental investigations for uncertainty quantification in brake squeal analysis

    NASA Astrophysics Data System (ADS)

    Renault, A.; Massa, F.; Lallemand, B.; Tison, T.

    2016-04-01

    The aim of this paper is to improve the correlation between the experimental and the numerical prediction of unstable frequencies for automotive brake systems considering uncertainty. First, an experimental quantification of uncertainty and a discussion analysing the contributions of uncertainty to a numerical squeal simulation are proposed. Frequency and transient simulations are performed considering nominal values of model parameters, determined experimentally. The obtained results are compared with those derived from experimental tests to highlight the limitation of deterministic simulations. The effects of the different kinds of uncertainty detected in working conditions of brake system, the pad boundary condition, the brake system material properties and the pad surface topography are discussed by defining different unstable mode classes. Finally, a correlation between experimental and numerical results considering uncertainty is successfully proposed for an industrial brake system. Results from the different comparisons reveal also a major influence of the pad topography and consequently the contact distribution.

  20. View of main hoist wire rope drum and brakes, open ...

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

    View of main hoist wire rope drum and brakes, open contact boards are in view at the far right wall - Puget Sound Naval Shipyard, Portal Gantry Crane No. 42, Pier 5, Farragut Avenue, Bremerton, Kitsap County, WA

  1. 22. General view inside air brake shop section of roundhouse. ...

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

    22. General view inside air brake shop section of roundhouse. View to west. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  2. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a.... (e) In the absence of a more rational analysis, the nose gear vertical reaction prescribed...

  3. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a.... (e) In the absence of a more rational analysis, the nose gear vertical reaction prescribed...

  4. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  5. Typical Brake Reaction Times Across the Life Span.

    PubMed

    Dickerson, Anne E; Reistetter, Timothy A; Burhans, Stacey; Apple, Katie

    2016-04-01

    This paper provides average brake reaction times for healthy community living adults from 16 to 90+ years of age, divided by gender. Using consistent directions and context, the RT-2S Simple Brake Reaction shows that average brake reactions for males is 0.50 seconds (median = 0.48, minimum = 0.25 maximum = 0.92) and for females is 0.53 seconds (median = 0.51 minimum = 0.30 maximum = 1.36). The use of a brake reaction timer to assess fitness to drive may be useful for clients recovering from orthopedic surgery, while use as a driving determinate of older adults should be done in conjunction with other tools. PMID:26376036

  6. 49 CFR 236.701 - Application, brake; full service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES...

  7. 11. STOVE NUT USED IN THE MILL WHEN THE BRAKE ...

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

    11. STOVE NUT USED IN THE MILL WHEN THE BRAKE WHEEL DROVE ONE PAIR OF MILLSTONES DIRECTLY; FOUND ON THE FIRST FLOOR OF THE WINDMILL AT WATERMILL - Windmill at Water Mill, Montauk Highway & Halsey Lane, Water Mill, Suffolk County, NY

  8. Investigation of aerodynamic braking devices for wind turbine applications

    SciTech Connect

    Griffin, D.A.

    1997-04-01

    This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

  9. Research study on antiskid braking systems for the space shuttle

    NASA Technical Reports Server (NTRS)

    Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

    1973-01-01

    A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

  10. 6. North wall and east end of air brake shop ...

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

    6. North wall and east end of air brake shop section of roundhouse at center. East end of boiler shop section of roundhouse to the right of air brake shop. East end of blacksmith shop section of roundhouse at far right. View to southeast. - Duluth & Iron Range Rail Road Company Shops, Roundhouse, Southwest of downtown Two Harbors, northwest of Agate Bay, Two Harbors, Lake County, MN

  11. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... meets the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5... indicator system that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3). (c) Air brake systems... of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)). (2) Each air braked commercial motor vehicle...

  12. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... meets the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5... indicator system that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3). (c) Air brake systems... of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)). (2) Each air braked commercial motor vehicle...

  13. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... meets the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5... indicator system that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3). (c) Air brake systems... of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)). (2) Each air braked commercial motor vehicle...

  14. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... meets the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5... indicator system that meets the requirements of FMVSS No. 105 (49 CFR 571.105, S5.3). (c) Air brake systems... of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b)). (2) Each air braked commercial motor vehicle...

  15. Braking and cornering studies on an air cushion landing system

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  16. Hall drift and the braking indices of young pulsars

    NASA Astrophysics Data System (ADS)

    Gourgouliatos, K. N.; Cumming, A.

    2015-01-01

    Braking index measurements of young radio pulsars are all smaller than the value expected for spin-down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that an ?1014 G quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall time-scale. The observed braking indices of pulsars with inferred dipole fields of ? 1013 G can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with Bd ? 1013 G, we find that the magnetic stresses in the crust exceed the maximum shear stress before the pulsar reaches its current age, likely quenching the Hall effect. This may have implications for the magnetar activity seen in the high magnetic field radio pulsar PSR J1846-0258. Observations of braking indices may therefore be a new piece of evidence that neutron stars contain subsurface toroidal fields that are significantly stronger than the dipole field, and may indicate that the Hall effect is important in a wider range of neutron stars than previously thought.

  17. Will the tachyonic universe survive the big brake?

    NASA Astrophysics Data System (ADS)

    Keresztes, Zoltn; Gergely, Lszl .; Kamenshchik, Alexander Yu.; Gorini, Vittorio; Polarski, David

    2010-12-01

    We investigate a Friedmann universe filled with a tachyon scalar field, which behaved as dustlike matter in the past, while it is able to accelerate the expansion rate of the Universe at late times. The comparison with type Ia supernovae (SNIa) data allows for evolutions driving the Universe into a Big Brake. Some of the evolutions leading to a Big Brake exhibit a large variation of the equation of state parameter at low redshifts, which is potentially observable with future data, though hardly detectable with present SNIa data. The soft Big Brake singularity occurs at finite values of the scale factor, vanishing energy density and Hubble parameter, but diverging deceleration and infinite pressure. We show that the geodesics can be continued through the Big Brake and that our model universe will recollapse eventually in a Big Crunch. Although the time to the Big Brake strongly depends on the present values of the tachyonic field and of its time derivative, the time from the Big Brake to the Big Crunch represents a kind of invariant time scale for all field parameters allowed by SNIa.

  18. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  19. Thermal measurement of brake pad lining surfaces during the braking process

    NASA Astrophysics Data System (ADS)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  20. Hydraulic dynamic analysis

    NASA Technical Reports Server (NTRS)

    Gale, R. L.; Nease, A. W.; Nelson, D. J.

    1978-01-01

    Computer program mathematically describes complete hydraulic systems to study their dynamic performance. Program employs subroutines that simulate components of hydraulic system, which are then controlled by main program. Program is useful to engineers working with detailed performance results of aircraft, spacecraft, or similar hydraulic systems.

  1. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    NASA Astrophysics Data System (ADS)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  2. Airborne asbestos concentrations associated with heavy equipment brake removal.

    PubMed

    Madl, A K; Gaffney, S H; Balzer, J L; Paustenbach, D J

    2009-11-01

    Asbestos-containing brake linings were used in heavy-duty construction equipment such as tractors, backhoes, and bulldozers prior to the 1980s. While several published studies have evaluated exposures to mechanics during brake repair work, most have focused on automobiles and light trucks, not on heavy agricultural or construction vehicles. The purpose of this study is to characterize the airborne concentration of asbestos to workers and bystanders from brake wear debris during brake removal from 12 loader/backhoes and tractors manufactured between 1960 and 1980. Asbestos content in brake lining (average 20% chrysotile by polarized light microscopy) and brake wear debris [average 0.49% chrysotile by transmission electron microscopy (TEM)] was also quantified. Breathing zone samples on the lapel of mechanics (n = 44) and area samples at bystander (n = 34), remote (n = 22), and ambient (n = 12) locations were collected during 12 brake changes and analyzed using phase contrast microscopy (PCM) [National Institute for Occupational Safety and Health (NIOSH) 7400] and TEM (NIOSH 7402). In addition, the fiber distribution by size and morphology was evaluated according to the International Organization for Standardization method for asbestos. Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results, the average airborne chrysotile concentrations (PCM equivalent) were 0.024 f/cc for the mechanic and 0.009 f/cc for persons standing 1.2-3.1 m from the activity during the period of exposure ( approximately 0.5 to 1 h). Considering the time involved in the activity, and assuming three brake jobs per shift, these results would convert to an average 8-h time-weighted average of 0.009 f/cc for a mechanic and 0.006 f/cc for a bystander. The results indicate that (i) the airborne concentrations for worker and bystander samples were significantly less than the current occupational exposure limit of 0.1 f/cc; (ii) approximately 2% of respirable fibers were >20 microm in length; and (iii) approximately 95% of chrysotile in the brake linings degraded in the friction process. The industrial hygiene data presented here should be useful for conducting retrospective and current exposure assessments of individuals, as well as hazard assessments of work activities that involve repairing and replacing asbestos-containing brakes in heavy construction equipment. PMID:19692501

  3. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  4. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of the regenerative system.

  5. The contribution of stereo vision to the control of braking.

    PubMed

    Tijtgat, Pieter; Mazyn, Liesbeth; De Laey, Christophe; Lenoir, Matthieu

    2008-03-01

    In this study the contribution of stereo vision to the control of braking in front of a stationary target vehicle was investigated. Participants with normal (StereoN) and weak (StereoW) stereo vision drove a go-cart along a linear track towards a stationary vehicle. They could start braking from a distance of 4, 7, or 10m from the vehicle. Deceleration patterns were measured by means of a laser. A lack of stereo vision was associated with an earlier onset of braking, but the duration of the braking manoeuvre was similar. During the deceleration, the time of peak deceleration occurred earlier in drivers with weak stereo vision. Stopping distance was greater in those lacking in stereo vision. A lack of stereo vision was associated with a more prudent brake behaviour, in which the driver took into account a larger safety margin. This compensation might be caused either by an unconscious adaptation of the human perceptuo-motor system, or by a systematic underestimation of distance remaining due to the lack of stereo vision. In general, a lack of stereo vision did not seem to increase the risk of rear-end collisions. PMID:18329426

  6. Thermophysical Properties of Automotive Metallic Brake Disk Materials

    NASA Astrophysics Data System (ADS)

    Kim, S. W.; Park, K.; Lee, S. H.; Kang, K. H.; Lim, K. T.

    2008-12-01

    The temperature distribution, the thermal deformation, and the thermal stress of automotive brake disks have quite close relations with car safety; therefore, much research in this field has been performed. However, successful and satisfactory results have not been obtained because the temperature-dependent thermophysical properties of brake disk materials are not sufficiently known. In this study, the thermophysical properties (thermal diffusivity, the specific heat, and the coefficient of thermal expansion) of three kinds of iron alloy series brake disk materials, FC250, FC170, and FCD50, and two kinds of aluminum alloy series brake disk materials, Al MMC and A356, were measured in the temperature range from room temperature to 500 °C, and the thermal conductivity was calculated using the measured thermal diffusivity, specific heat capacity, and density. As expected, the results show that the two series have significant differences in respect of the thermophysical properties, and to reduce the thermal deformation of the brake disk, the aluminum alloys with a high thermal conductivity and the iron alloys with low thermal expansion are recommended.

  7. Prosthetic leg powered by MR brake and SMA wires

    NASA Astrophysics Data System (ADS)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  8. An analysis of the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    SciTech Connect

    Greenfield, M.A.; Sargent, T.J.

    1995-11-01

    The Environmental Evaluation Group (EEG) previously analyzed the probability of a catastrophic accident in the waste hoist of the Waste Isolation Pilot Plant (WIPP) and published the results in Greenfield (1990; EEG-44) and Greenfield and Sargent (1993; EEG-53). The most significant safety element in the waste hoist is the hydraulic brake system, whose possible failure was identified in these studies as the most important contributor in accident scenarios. Westinghouse Electric Corporation, Waste Isolation Division has calculated the probability of an accident involving the brake system based on studies utilizing extensive fault tree analyses. This analysis conducted for the U.S. Department of Energy (DOE) used point estimates to describe the probability of failure and includes failure rates for the various components comprising the brake system. An additional controlling factor in the DOE calculations is the mode of operation of the brake system. This factor enters for the following reason. The basic failure rate per annum of any individual element is called the Event Probability (EP), and is expressed as the probability of failure per annum. The EP in turn is the product of two factors. One is the {open_quotes}reported{close_quotes} failure rate, usually expressed as the probability of failure per hour and the other is the expected number of hours that the element is in use, called the {open_quotes}mission time{close_quotes}. In many instances the {open_quotes}mission time{close_quotes} will be the number of operating hours of the brake system per annum. However since the operation of the waste hoist system includes regular {open_quotes}reoperational check{close_quotes} tests, the {open_quotes}mission time{close_quotes} for standby components is reduced in accordance with the specifics of the operational time table.

  9. The application of hydraulics in the 2,000 kW wind turbine generator

    NASA Technical Reports Server (NTRS)

    Onufreiczuk, S.

    1978-01-01

    A 2000 kW turbine generator using hydraulic power in two of its control systems is being built under the management of NASA Lewis Research Center. The hydraulic systems providing the control torques and forces for the yaw and blade pitch control systems are discussed. The yaw-drive-system hydraulic supply provides the power for positioning the nacelle so that the rotary axis is kept in line with the direction of the prevailing wind, as well as pressure to the yaw and high speed shaft brakes. The pitch-change-mechanism hydraulic system provides the actuation to the pitch change mechanism and permits feathering of the blades during an emergency situation. It operates in conjunction with the overall windmill computer system, with the feather control permitting slewing control flow to pass from the servo valve to the actuators without restriction.

  10. Optimal design of a magneto-rheological brake absorber for torsional vibration control

    NASA Astrophysics Data System (ADS)

    Nguyen, Q. H.; Choi, S. B.

    2012-02-01

    This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given.

  11. Surrogate models for efficient stability analysis of brake systems

    NASA Astrophysics Data System (ADS)

    Nechak, Lyes; Gillot, Frédéric; Besset, Sébastien; Sinou, Jean-Jacques

    2015-07-01

    This study assesses capacities of the global sensitivity analysis combined together with the kriging formalism to be useful in the robust stability analysis of brake systems, which is too costly when performed with the classical complex eigenvalues analysis (CEA) based on finite element models (FEMs). By considering a simplified brake system, the global sensitivity analysis is first shown very helpful for understanding the effects of design parameters on the brake system's stability. This is allowed by the so-called Sobol indices which discriminate design parameters with respect to their influence on the stability. Consequently, only uncertainty of influent parameters is taken into account in the following step, namely, the surrogate modelling based on kriging. The latter is then demonstrated to be an interesting alternative to FEMs since it allowed, with a lower cost, an accurate estimation of the system's proportions of instability corresponding to the influent parameters.

  12. Double pulsed holography used to investigate noisy brakes

    NASA Astrophysics Data System (ADS)

    Fieldhouse, J. D.; Newcomb, T. P.

    1996-12-01

    The vibrational characteristics of a noisy passenger car disc brake have been studied using the double pulsed holographic technique which has been developed to allow three orthogonal visual images of a vibrating brake system to be recorded simultaneously. These images show the disc to be vibrating in a bending mode whereas the pad is seen to be excited in a variety of modes such as bending, torsion, and often a combination of both. The development of the technique includes alternative ways of triggering the laser and typical results from the application of these differing methods are also included along with mechanical signals which confirm the visual interpretations. Final results, using a laser trigger delay technique, show that the disc mode waveform rotates about the disc at a rate equivalent to the frequency of vibration divided by the diametral mode order. Early work on a passenger car drum brake is also introduced, this complementing commercial 'noise fix' solutions and a proposed theoretical model.

  13. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    NASA Astrophysics Data System (ADS)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

    Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyze the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor. The analysis also gives us, the heat flux distribution for the two discs.

  14. Regenerative braking device with rotationally mounted energy storage means

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1982-03-16

    A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

  15. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect

    Wilson, DF

    2002-10-22

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  16. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-01-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  17. Hydraulic fracture design optimization

    SciTech Connect

    Lee, Tae-Soo; Advani, S.H.

    1992-06-01

    This research and development investigation, sponsored by US DOE and the oil and gas industry, extends previously developed hydraulic fracture geometry models and applied energy related characteristic time concepts towards the optimal design and control of hydraulic fracture geometries. The primary objective of this program is to develop rational criteria, by examining the associated energy rate components during the hydraulic fracture evolution, for the formulation of stimulation treatment design along with real-time fracture configuration interpretation and control.

  18. Industrial research on the quality of brake shoes meant for rolling stock

    NASA Astrophysics Data System (ADS)

    Popa, E.; Pascu, L.; Socalici, A.; Lascufoni, A.

    2016-02-01

    Brake shoes wear appears as a normal exploitation process and depends both on the braking force and on the material the shoe is made of. Brake shoes are made of molded sulfurous cast iron. The industrial research and experiments aim at determining the specific characteristics of the phosphorous cast iron (chemical and structural homogeneity, hardness) and their optimization in view of improving the quality of the brake shoes meant for the rolling stock

  19. Transient analysis of thermoelastic contact problem of disk brakes

    NASA Astrophysics Data System (ADS)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-06-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used with coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  20. Thermal-mechanical coupled analysis of a brake disk rotor

    NASA Astrophysics Data System (ADS)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  1. Aluminum runway surface as possible aid to aircraft braking

    NASA Technical Reports Server (NTRS)

    Miller, C. D.; Pinkel, I. I.

    1973-01-01

    Several concepts are described for use singly or in combination to improve aircraft braking. All involve a thin layer of aluminum covering all or part of the runway. Advantage would derive from faster heat conduction from the tire-runway interface. Heating of tread surface with consequent softening and loss of friction coefficient should be reduced. Equations are developed indicating that at least 99 percent of friction heat should flow into the aluminum. Preliminary test results indicate a coefficient of sliding friction of 1.4, with predictably slight heating of tread. Elimination of conventional brakes is at least a remote possibility.

  2. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the recommended type of brake fluid as specified in accordance with 49 CFR 571.116, e.g., “DOT 3... CFR 571.101). S5.2Durability. S5.2.1Compensation for wear. Wear of the brakes shall be compensated for... rider in order to supply and regulate the energy required for braking the motorcycle. Driver mass...

  3. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (ECP) Braking Systems § 232.609 Handling of defective equipment with ECP brake systems. (a) Ninety-five... systems. 232.609 Section 232.609 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR...

  4. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... develop unique or complicated braking systems to comply with these requirements. \\9\\ See 74 FR 37152-53.... 121, Air Brake Systems, to require improved stopping distance performance for heavy truck tractors.\\1... distance requirements on in-service braking performance set by the Federal Motor Carrier...

  5. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... performance that is seen from higher initial braking speeds. The agency is also increasing the stopping... that a tractor that would not have as good of braking performance as the tractor tested, such that it... anticipate that tractors with improved braking performance will be designed to have a...

  6. Auto Mechanics I. Learning Activity Packets (LAPs). Section E--Brakes.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) that outline the study activities for the "brakes" instructional area for an Auto Mechanics I course. The two LAPs cover the following topics: brake systems and power disc brakes. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the

  7. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    PubMed Central

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  8. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    ERIC Educational Resources Information Center

    Hockicko, Peter; Trpiov, Beta; Ondru, Jn

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in

  9. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  10. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  11. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  12. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  13. 49 CFR 214.529 - In-service failure of primary braking system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  14. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ..., Motorcycle Brake Systems, Notice of Proposed Rulemaking, 73 FR 54020 (Sept. 17, 2008) (hereinafter ``FMVSS No... passenger cars.\\7\\ \\6\\ Response to Petitions for Reconsideration, Motorcycle Brake Systems, 37 FR 11973 (June 16, 1972). \\7\\ See Brake Systems on Motorcycles Proposed Motor Vehicle Safety Standard, 36 FR...

  15. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  16. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    ERIC Educational Resources Information Center

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  17. Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

    NASA Astrophysics Data System (ADS)

    Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

    2016-02-01

    The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

  18. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... April 11, 2000 (65 FR 19477-78). FOR FURTHER INFORMATION CONTACT: For non-legal issues: Mr. Samuel... Brake Fluid, and SAE J1704, Borate Ether Based Brake Fluid. a. Definition of ``Brake Fluid'' To apply... (Federalism) NHTSA has examined today's NPRM pursuant to Executive Order 13132 (64 FR 43255, August 10,...

  19. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    PubMed

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  20. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  1. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  2. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... diameter brake cylinders, piston travel shall be within 6 to 9 inches. If piston travel is found to be less... equipped with 81/2-inch or 10-inch diameter brake cylinders, piston travel shall be within the piston travel stenciled or marked on the car or badge plate. Minimum brake cylinder piston travel of...

  3. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy of the incorporated document from...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... General requirements for all train brake systems. (a) The primary brake system of a train shall be...

  4. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy of the incorporated document from...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... General requirements for all train brake systems. (a) The primary brake system of a train shall be...

  5. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy of the incorporated document from...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... General requirements for all train brake systems. (a) The primary brake system of a train shall be...

  6. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy of the incorporated document from...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... General requirements for all train brake systems. (a) The primary brake system of a train shall be...

  7. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain a copy of the incorporated document from...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... General requirements for all train brake systems. (a) The primary brake system of a train shall be...

  8. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Modification of the single car air brake test... Requirements 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  9. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Modification of the single car air brake test... Requirements 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  10. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  11. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake...

  12. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the necessary repairs can be made. (4) Long-distance intercity and long-distance Tier II passenger trains developing 75-99 operative power brakes. (i) 75-84 percent operative brakes. Long-distance intercity and long-distance Tier II passenger trains which develop inoperative power brake...

  13. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... service demonstration of the new brake system technology in accordance with the approved plan,...

  14. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... service demonstration of the new brake system technology in accordance with the approved plan,...

  15. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... service demonstration of the new brake system technology in accordance with the approved plan,...

  16. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... service demonstration of the new brake system technology in accordance with the approved plan,...

  17. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... service demonstration of the new brake system technology in accordance with the approved plan,...

  18. Thermally Actuated Hydraulic Pumps

    NASA Technical Reports Server (NTRS)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research vessels. Heretofore, electrically actuated hydraulic pumps have been used for this purpose. By eliminating the demand for electrical energy for pumping, the use of the thermally actuated hydraulic pumps could prolong the intervals between battery charges, thus making it possible to greatly increase the durations of undersea exploratory missions.

  19. Analyzing hydraulic transients

    SciTech Connect

    Logan, T.H.

    1992-03-01

    The operational mode of a hydroturbine determines hydraulic pressures and flows. The more starts and stops the turbine makes, the more pressure changes will occur. The faster the flow changes, the greater their magnitude. Analyses of hydraulic transients-known as waterhammer-should be part of preliminary engineering studies of any proposed hydro project that will operate as a peaking plant.

  20. Downhole hydraulic seismic generator

    DOEpatents

    Gregory, Danny L.; Hardee, Harry C.; Smallwood, David O.

    1992-01-01

    A downhole hydraulic seismic generator system for transmitting energy wave vibrations into earth strata surrounding a borehole. The system contains an elongated, unitary housing operably connected to a well head aboveground by support and electrical cabling, and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a hydraulic oscillator containing a double-actuating piston whose movement is controlled by an electro-servovalve regulating a high pressure hydraulic fluid flow into and out of upper and lower chambers surrounding the piston. The spent hydraulic fluid from the hydraulic oscillator is stored and pumped back into the system to provide high pressure fluid for conducting another run at the same, or a different location within the borehole.

  1. Neural-network hybrid control for antilock braking systems.

    PubMed

    Lin, Chih-Min; Hsu, C F

    2003-01-01

    The antilock braking systems are designed to maximize wheel traction by preventing the wheels from locking during braking, while also maintaining adequate vehicle steerability; however, the performance is often degraded under harsh road conditions. In this paper, a hybrid control system with a recurrent neural network (RNN) observer is developed for antilock braking systems. This hybrid control system is comprised of an ideal controller and a compensation controller. The ideal controller, containing an RNN uncertainty observer, is the principal controller; and the compensation controller is a compensator for the difference between the system uncertainty and the estimated uncertainty. Since for dynamic response the RNN has capabilities superior to the feedforward NN, it is utilized for the uncertainty observer. The Taylor linearization technique is employed to increase the learning ability of the RNN. In addition, the on-line parameter adaptation laws are derived based on a Lyapunov function, so the stability of the system can be guaranteed. Simulations are performed to demonstrate the effectiveness of the proposed NN hybrid control system for antilock braking control under various road conditions. PMID:18238018

  2. 27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. ...

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

    27. Historic drawing, Marine Railway. Detail of Emergency Brake, 1917. Photographic copy of original. Boston National Historical Park Archives, Charlestown Navy Yard. BOSTS 13439, #551-16 - Charlestown Navy Yard, Marine Railway, Between Piers 2 & 3, on Charlestown Waterfront at west end of Navy Yard, Boston, Suffolk County, MA

  3. Brakes Specialist. Teacher Edition. Automotive Service Series. Second Edition.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide for automatic brakes service is one in a series of automotive service speciality publications that is based on the National Institute of Automotive Service Excellence task lists. The curriculum is composed of four units. Each unit of instruction may contain some or all of the following components: objective sheet, suggested

  4. Electromagnetic brake for a camshaft phase change device

    SciTech Connect

    Muir, D.J.; Brune, J.E.; Van Deusen, B.K.; Day, J.K.

    1991-07-16

    This patent describes a phase change device. It comprises a first shaft; an input member supported for rotation on the first shaft; an output member fixed to the first shaft; advancing means interconnecting the input and output members, the advancing means being operative upon axial movement to effect limited relative rotation between the input and output members; drum means supported for rotation on the first shaft and engaged with the advancing means to effect the axial movement of the advancing means when a retarding force is applied to the drum means; and actuating means operable to apply the retarding force; the improvement wherein the actuating means comprises an electromagnetic brake assembly, the electromagnetic brake assembly comprising an annular housing defining pole pieces of the electromagnet, a magnetic coil received in the housing, a nonmagnetic plate member enclosing the housing, friction material adhered to the plate member, a brake disc surface formed on the drum, and means for mounting the housing on the first shaft in juxtaposition with the brake disc surface in a substantially fixed angular position while permitting limited axial movement relative to the disc surface.

  5. Magnetic Braking Revisited: An Activity for "How Science Works"

    ERIC Educational Resources Information Center

    Ireson, Gren; Twidle, John

    2008-01-01

    The National Curriculum for 14-16 year old students in England contains a mandatory element called "How science works". Included in this material is interpretation of data, collecting data from primary sources, using ICT tools, and developing an argument and drawing conclusions. What follows is an activity, based on magnetic braking, which allows

  6. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Section 57.19017 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel... with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  7. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Section 56.19017 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel... with a manually-operable switch that will initiate emergency braking action to bring the conveyance...

  8. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Service brake system. 570.59 Section 570.59 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.59 Service...

  9. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Service brake system. 570.59 Section 570.59 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.59 Service...

  10. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Service brake system. 570.59 Section 570.59 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.59 Service...

  11. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.59 Section 570.59 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.59 Service...

  12. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... changed to facilitate the movement of a passenger train from one track to another within a terminal..., DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment 238.319 Running brake test. (a) As soon as conditions...

  13. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... changed to facilitate the movement of a passenger train from one track to another within a terminal..., DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment 238.319 Running brake test. (a) As soon as conditions...

  14. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Class IA brake test. 238.315 Section 238.315 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment...

  15. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Class II brake test. 238.317 Section 238.317 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment...

  16. 49 CFR 238.319 - Running brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Running brake test. 238.319 Section 238.319 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment...

  17. 30 CFR 57.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Emergency braking for electric hoists. 57.19017 Section 57.19017 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Personnel Hoisting Hoists 57.19017...

  18. 30 CFR 56.19017 - Emergency braking for electric hoists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Emergency braking for electric hoists. 56.19017 Section 56.19017 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Personnel Hoisting Hoists 56.19017...

  19. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Brakes for rail equipment. 57.14102 Section 57.14102 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and...

  20. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Brakes for rail equipment. 57.14102 Section 57.14102 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and...

  1. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakes for rail equipment. 57.14102 Section 57.14102 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety Devices and...

  2. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rigging or the system mounted on the car for the transmission of the braking force operates as intended... occurs first, that the train remains in continuous passenger service. (c) Each passenger car and each... performed on the car within the previous calendar day and the car has not been disconnected from a source...

  3. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... rigging or the system mounted on the car for the transmission of the braking force operates as intended... occurs first, that the train remains in continuous passenger service. (c) Each passenger car and each... performed on the car within the previous calendar day and the car has not been disconnected from a source...

  4. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... grids on the system; and (2) Display in real-time in the cab of the controlling (lead) locomotive the... received at the grids on the system; and (2) Display either the train deceleration rate or in real-time in... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER...

  5. 5. FLOOR 3; SHOWS BRAKE LEVER, BLOCK FORMERLY USED TO ...

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

    5. FLOOR 3; SHOWS BRAKE LEVER, BLOCK FORMERLY USED TO RAISE IT AND HOOK WHICH KEPT IT IN THE 'OFF' POSITION; ALSO SEEN ARE THE LARGE BLOCKS SUSPENDED FROM THE CAP FRAME WHICH HOLD THE TRUCK WHEELS TO CENTER THE CAP - Hayground Windmill, Windmill Lane, East Hampton, Suffolk County, NY

  6. Magnetic Braking and Protostellar Disk Formation: Ambipolar Diffusion

    NASA Astrophysics Data System (ADS)

    Mellon, Richard R.; Li, Zhi-Yun

    2009-06-01

    It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Nonideal MHD effects are expected to weaken the magnetic braking, perhaps allowing the disk to reappear. We concentrate on one such effect, ambipolar diffusion, which enables the field lines to slip relative to the bulk neutral matter. We find that the slippage does not sufficiently weaken the braking to allow rotationally supported disks to form for realistic levels of cloud magnetization and cosmic ray ionization rate; in some cases, the magnetic braking is even enhanced. Only in dense cores with both exceptionally weak fields and unreasonably low ionization rate do such disks start to form in our simulations. We conclude that additional processes, such as Ohmic dissipation or Hall effect, are needed to enable disk formation. Alternatively, the disk may form at late times when the massive envelope that anchors the magnetic brake is dissipated, perhaps by a protostellar wind.

  7. An improved automotive brake lining using fibrous potassium titanate

    NASA Technical Reports Server (NTRS)

    Mansfield, J. A.; Halberstadt, M. L.; Riccitiello, S. R.; Rhee, S. K.

    1976-01-01

    Simultaneous fade reduction and wear improvement of a commercial automotive brake lining were achieved by adding fibrous potassium titanate. The dependence of friction and wear characteristics on quantitative variations in potassium titanate, asbestos, phenolic binder, and organic and inorganic modifiers was evaluated.

  8. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    SciTech Connect

    Qu, Jun; Blau, Peter Julian; Jolly, Brian C

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 ?C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  9. A Laboratory Activity on the Eddy Current Brake

    ERIC Educational Resources Information Center

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  10. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Class II brake test. 238.317 Section 238.317 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Inspection, Testing, and Maintenance Requirements for Tier I Passenger Equipment...

  11. 49 CFR 393.49 - Control valves for brakes.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Control valves for brakes. 393.49 Section 393.49 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND...

  12. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Service brake system. 570.59 Section 570.59 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.59 Service...

  13. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... motor vehicle shall be equipped with brakes acting on all wheels. This requirement also applies to certain motor vehicles being towed in a driveaway-towaway operation, as follows: (1) Any motor vehicle.... However, these vehicles must meet the requirements of 393.52. (2) Motor vehicles being towed in...

  14. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... motor vehicle shall be equipped with brakes acting on all wheels. This requirement also applies to certain motor vehicles being towed in a driveaway-towaway operation, as follows: (1) Any motor vehicle.... However, these vehicles must meet the requirements of 393.52. (2) Motor vehicles being towed in...

  15. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... motor vehicle shall be equipped with brakes acting on all wheels. This requirement also applies to certain motor vehicles being towed in a driveaway-towaway operation, as follows: (1) Any motor vehicle.... However, these vehicles must meet the requirements of 393.52. (2) Motor vehicles being towed in...

  16. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... must meet the requirements of 393.52. (2) Motor vehicles being towed in a driveaway-towaway operation...) Every commercial motor vehicle shall be equipped with brakes acting on all wheels. This requirement also applies to certain motor vehicles being towed in a driveaway-towaway operation, as follows: (1) Any...

  17. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 77.1401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  18. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 77.1401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  19. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 77.1401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...

  20. 30 CFR 77.1401 - Automatic controls and brakes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 77.1401 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the...