Science.gov

Sample records for hydraulic brakes

  1. Combined hydraulic and regenerative braking system

    SciTech Connect

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

    1981-06-02

    A combined hydraulic and regenerative braking system and method is disclosed for an electric vehicle. 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, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

    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.

  3. 49 CFR 570.55 - Hydraulic brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  4. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Air brake system and air-over-hydraulic brake subsystem. 570.57 Section...57 Air brake system and air-over-hydraulic brake subsystem. The following requirements...vehicles with air brake and air-over-hydraulic brake systems. Trailer(s)...

  5. 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...

  6. 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...

  7. 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... 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...

  8. 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... 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...

  9. 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...

  10. 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...

  11. Aalborg Universitet Disturbance Control of the Hydraulic Brake in a Wind Turbine

    E-print Network

    Yang, Zhenyu

    Aalborg Universitet Disturbance Control of the Hydraulic Brake in a Wind Turbine Jepsen, Frank Brake in a Wind Turbine. In Energy Conference and Exhibition (EnergyCon), 2010 IEEE International . (pp from vbn.aau.dk on: juli 07, 2015 #12;Disturbance Control of the Hydraulic Brake in a Wind Turbine

  12. 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...

  13. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 2013-10-01 2013-10-01 false Standard No. 105; Hydraulic and electric...

  14. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...trailers, and motorcycles, and to hydraulic, air, and vacuum brake hose, brake...metal tubing. S5. Requirements—hydraulic brake hose, brake hose assemblies... S5.1 Construction. (a) Each hydraulic brake hose assembly shall have...

  15. 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…

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Variable proportioning brake system means a system that automatically adjusts the...vehicle static axle loading and/or dynamic weight transfer between axles...Requirements. S5.1Service brake systems. Each vehicle must be...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Variable proportioning brake system means a system that automatically adjusts the...vehicle static axle loading and/or dynamic weight transfer between axles...Requirements. S5.1Service brake systems. Each vehicle must be...

  18. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Variable proportioning brake system means a system that automatically adjusts the...vehicle static axle loading and/or dynamic weight transfer between axles...Requirements. S5.1Service brake systems. Each vehicle must be...

  19. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Variable proportioning brake system means a system that automatically adjusts the...vehicle static axle loading and/or dynamic weight transfer between axles...Requirements. S5.1Service brake systems. Each vehicle must be...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Variable proportioning brake system means a system that automatically adjusts the...vehicle static axle loading and/or dynamic weight transfer between axles...Requirements. S5.1Service brake systems. Each vehicle must be...

  1. 76 FR 7623 - Parts and Accessories Necessary for Safe Operation; Brakes; Application for Exemption From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-10

    ...self-contained, permanently closed hydraulic brake system'' [Emphasis added...FMCSRs to allow the use of automatic hydraulic inertia brake systems (surge brakes...self-contained, permanently closed hydraulic brake system for trailers that...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... dynamic weight transfer between axles during deceleration. Wheel lockup means 100 percent wheel slip. S5... 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—...

  3. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (1) If any electrical, pneumatic, hydraulic, or mechanical...of each wheel, brake, and tire assembly must be determined...testing that the wheel, brake and tire assembly is capable of absorbing...of each wheel, brake, and tire assembly must be...

  4. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... (1) If any electrical, pneumatic, hydraulic, or mechanical...of each wheel, brake, and tire assembly must be determined...testing that the wheel, brake and tire assembly is capable of absorbing...of each wheel, brake, and tire assembly must be...

  5. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (1) If any electrical, pneumatic, hydraulic, or mechanical...of each wheel, brake, and tire assembly must be determined...testing that the wheel, brake and tire assembly is capable of absorbing...of each wheel, brake, and tire assembly must be...

  6. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (1) If any electrical, pneumatic, hydraulic, or mechanical...of each wheel, brake, and tire assembly must be determined...testing that the wheel, brake and tire assembly is capable of absorbing...of each wheel, brake, and tire assembly must be...

  7. 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…

  8. 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)…

  9. 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…

  10. 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…

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 compressed...-type failure, in any other brake system, of a part designed to contain compressed air or brake...

  12. 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

    ...brake fluids as well as packagers of hydraulic system mineral oils. The information...requirements for motor vehicle brake fluids and hydraulic system mineral oils. Section 5.2...brake fluids as well as packagers of hydraulic system mineral oils. The...

  13. 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,…

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

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

    DOEpatents

    Cikanek, Susan R. (Wixom, MI)

    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.

  3. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

  4. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

  5. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

  6. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

  7. 49 CFR 393.41 - Parking brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...found on a public road (free of ice and snow). Hydraulic-braked vehicles which...found on a public road (free of ice and snow). An agricultural commodity trailer...found on a public road (free of ice and snow). (2) The parking brake...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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.

  13. Optimal design of a disc-type MR brake for middle-sized motorcycle

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc-Hung; Jeon, Juncheol; Choi, Seung-Bok

    2011-03-01

    This research work focuses on optimal design of a disc-type magneto-rheological (MR) brake that can replace a conventional hydraulic brake (CHB) of middle-sized motorcycles. Firstly, a MR brake configuration is proposed considering the available space and the simplicity to replace a CHB by the proposed MR brake. An optimal design of the proposed MR brake is then performed considering the required braking torque, operating temperature, mass and size of the brake. In order to perform the optimization of the brake, the braking torque of the brake is analyzed based on Herschel-Bulkley rheological model of MR fluid. The constrain on operating temperature of the MR brake is determined by considering the steady temperature of the brake when the motorcycle is cruising and the temperature increase during a braking process. An optimization procedure based on finite element analysis integrated with an optimization tool is employed to obtain optimal geometric dimensions of the MR brake. Optimal solution of the MR brake is then presented and simulated performance of the optimized brake is shown with remarkable discussions.

  14. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...design landing stop brake kinetic energy absorption requirement of each wheel, brake...wear range of the brake. The energy absorption rate derived from the airplane manufacturer's...accelerate-stop brake kinetic energy absorption requirement of each wheel,...

  15. 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.

  16. TGV disc brake squeal

    NASA Astrophysics Data System (ADS)

    Lorang, X.; Foy-Margiocchi, F.; Nguyen, Q. S.; Gautier, P. E.

    2006-06-01

    The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes of the brake system under the contact and Coulomb friction.

  17. Roller Locking Brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  18. Commercial Motor Vehicle Brake Assessment Tools

    E-print Network

    ability #12;Performance-Based Brake Tester · Assessment of brake efficiency ­ BE = ­ Equivalent performance Total Braking Force Total Vehicle Weight Total Braking Force Total Vehicle Weight #12;Related

  19. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption requirement of each wheel, brake, and tire assembly must be determined. It must be substantiated...

  20. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption requirement of each wheel, brake, and tire assembly must be determined. It must be substantiated...

  1. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption requirement of each wheel, brake, and tire assembly must be determined. It must be substantiated...

  2. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... operational landing stop at maximum landing weight. The design landing stop brake kinetic energy absorption requirement of each wheel, brake, and tire assembly must be determined. It must be substantiated...

  3. 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…

  4. Aircraft hydraulic systems. Third edition

    SciTech Connect

    Neese, W.A.

    1991-12-31

    The first nine chapters concern hydraulic components including: tubing, hoses, fittings, seals, pumps, valves, cylinders, and motors. General hydraulic system considerations are included in chapters five and nine, while pneumatic systems are covered in chapter ten. Chapters eleven through fifteen are devoted to aircraft-specific systems such as: landing gear, flight controls, brakes, etc. The material is rounded out with excerpts from the Canadair Challenger 601 training guide to illustrate the use of hydraulic systems in a specific aircraft application.

  5. WIND BRAKING OF MAGNETARS

    SciTech Connect

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-05-10

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L{sub x}<- E-dot{sub rot} may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  6. 14 CFR 25.735 - Brakes and braking systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes and braking systems. 25.735 Section 25.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Landing Gear § 25.735 Brakes and braking systems. (a) Approval....

  7. 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.

  8. 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.

  9. From Brake to Syzygy

    E-print Network

    Moeckel, Richard; Venturelli, Andrea

    2011-01-01

    In the planar three-body problem, we study solutions with zero initial velocity (brake orbits). Following such a solution until the three masses become collinear (syzygy), we obtain a continuous, flow-induced Poincar\\'e map. We study the image of the map in the set of collinear configurations and define a continuous extension to the Lagrange triple collision orbit. In addition we provide a variational characterization of some of the resulting brake-to-syzygy orbits and find simple examples of periodic brake orbits.

  10. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...49 CFR 571.105, S5.5). (b) ABS malfunction indicators for hydraulic braked...of this section shall be equipped with an ABS malfunction indicator system that meets...converter dollies and full trailers). (d) ABS malfunction circuits and signals for...

  11. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...49 CFR 571.105, S5.5). (b) ABS malfunction indicators for hydraulic braked...of this section shall be equipped with an ABS malfunction indicator system that meets...converter dollies and full trailers). (d) ABS malfunction circuits and signals for...

  12. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...49 CFR 571.105, S5.5). (b) ABS malfunction indicators for hydraulic braked...of this section shall be equipped with an ABS malfunction indicator system that meets...converter dollies and full trailers). (d) ABS malfunction circuits and signals for...

  13. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...49 CFR 571.105, S5.5). (b) ABS malfunction indicators for hydraulic braked...of this section shall be equipped with an ABS malfunction indicator system that meets...converter dollies and full trailers). (d) ABS malfunction circuits and signals for...

  14. 49 CFR 393.55 - Antilock brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...49 CFR 571.105, S5.5). (b) ABS malfunction indicators for hydraulic braked...of this section shall be equipped with an ABS malfunction indicator system that meets...converter dollies and full trailers). (d) ABS malfunction circuits and signals for...

  15. Unidirectional high gain brake stop

    NASA Technical Reports Server (NTRS)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  16. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Brakes must be provided. The landing brake kinetic energy capacity rating of each main wheel brake assembly must not be less than the kinetic energy absorption requirements determined...following methods: (1) The brake kinetic energy absorption requirements...

  17. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Brakes must be provided. The landing brake kinetic energy capacity rating of each main wheel brake assembly must not be less than the kinetic energy absorption requirements determined...following methods: (1) The brake kinetic energy absorption requirements...

  18. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Brakes must be provided. The landing brake kinetic energy capacity rating of each main wheel brake assembly must not be less than the kinetic energy absorption requirements determined...following methods: (1) The brake kinetic energy absorption requirements...

  19. 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...

  20. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  1. 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...

  2. 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.

  3. 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.

  4. Evaluation of aircraft brake materials

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1977-01-01

    A test program was carried out to evaluate several new high-temperature friction materials for use in aircraft disk brakes. A specially built test apparatus utilizing a disk brake and wheel half from a small jet aircraft was used. The apparatus enabled control of brake pressure, velocity and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The materials evaluation showed that two newly developed friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary, however, since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  5. 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.

  6. 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.

  7. 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).

  8. 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.

  9. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...until it is known that the air brake system is properly charged. (i) Passenger...1) The blending of friction and dynamic brake to obtain the correct retarding... (k) For new designs of braking systems, the design process shall...

  10. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...until it is known that the air brake system is properly charged. (i) Passenger...1) The blending of friction and dynamic brake to obtain the correct retarding... (k) For new designs of braking systems, the design process shall...

  11. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...until it is known that the air brake system is properly charged. (i) Passenger...1) The blending of friction and dynamic brake to obtain the correct retarding... (k) For new designs of braking systems, the design process shall...

  12. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...until it is known that the air brake system is properly charged. (i) Passenger...1) The blending of friction and dynamic brake to obtain the correct retarding... (k) For new designs of braking systems, the design process shall...

  13. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...until it is known that the air brake system is properly charged. (i) Passenger...1) The blending of friction and dynamic brake to obtain the correct retarding... (k) For new designs of braking systems, the design process shall...

  14. Commercial Motor Vehicle Brake-Related Research

    E-print Network

    Commercial Motor Vehicle Brake-Related Research Commercial Motor Vehicle Roadside Technology Corridor Safety Technology Showcase October 14, 2010 Commercial Motor Vehicle Roadside Technology Corridor CMVRTC Brake Research · Evaluation of Smart Infrared Inspection System · Real-Time Dynamic Brake

  15. 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.

  16. 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.

  17. 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…

  18. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that... be designed so that: (1) The blending of friction and dynamic brake to obtain the correct retarding force is automatic; (2) Loss of power or failure of the dynamic brake does not result in exceeding...

  19. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that... be designed so that: (1) The blending of friction and dynamic brake to obtain the correct retarding force is automatic; (2) Loss of power or failure of the dynamic brake does not result in exceeding...

  20. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that... be designed so that: (1) The blending of friction and dynamic brake to obtain the correct retarding force is automatic; (2) Loss of power or failure of the dynamic brake does not result in exceeding...

  1. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that... be designed so that: (1) The blending of friction and dynamic brake to obtain the correct retarding force is automatic; (2) Loss of power or failure of the dynamic brake does not result in exceeding...

  2. 49 CFR 238.231 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that... be designed so that: (1) The blending of friction and dynamic brake to obtain the correct retarding force is automatic; (2) Loss of power or failure of the dynamic brake does not result in exceeding...

  3. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

  4. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

  5. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

  6. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

  7. 49 CFR 238.431 - Brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...unit. (d) The brake system shall be designed to prevent...apply to blended braking systems: (1) Loss of power or failure of the dynamic brake does not result in...electric portion of the brake system shall be displayed for...

  8. 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)…

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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).

  15. 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...

  16. 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...

  17. 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...

  18. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 6 2013-10-01 2013-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  19. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 6 2012-10-01 2012-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  20. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 6 2011-10-01 2011-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  1. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 6 2014-10-01 2014-10-01 false Vacuum brake assist unit and vacuum brake system. 570.56 Section 570.56 ...GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system....

  2. 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...

  3. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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...

  4. 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...

  5. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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...

  6. 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...

  7. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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...

  8. 14 CFR 27.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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...

  9. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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...

  10. 14 CFR 29.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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...

  11. 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...

  12. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mobile equipment shall be equipped with a service brake system capable of stopping and holding the... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment...

  13. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mobile equipment shall be equipped with a service brake system capable of stopping and holding the... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment...

  14. 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.

  15. Magnetic braking in convective stars

    E-print Network

    Hussain, G A J

    2012-01-01

    Magnetic braking causes the spin-down of single stars as they evolve on the main sequence. Models of magnetic braking can also explain the evolution of close binary systems, including cataclysmic variables. The well-known period gap in the orbital period distribution of cataclysmic variable systems indicates that magnetic braking must be significantly disrupted in secondaries that are fully convective. However, activity studies show that fully convective stars are some of the most active stars observed in young open clusters. There is therefore conflicting evidence about what happens to magnetic activity in fully convective stars. Results from spectro-polarimetric studies of cool stars have found that the field morphologies and field strengths are dependent on spectral type and rotation rate. While rapidly rotating stars with radiative cores show strong, complex magnetic fields, they have relatively weak dipole components. Fully convective stars that are rapidly rotating also possess strong magnetic fields, b...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the drain cocks in the service and supply reservoir on the truck or truck-tractor. Note the pressure.... Close the drain cocks, and, with the trailer(s) uncoupled, check air pressure buildup at the... sufficient to prevent slippage. Inspection procedure. With the air system charged, open the drain cocks...

  1. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the drain cocks in the service and supply reservoir on the truck or truck-tractor. Note the pressure.... Close the drain cocks, and, with the trailer(s) uncoupled, check air pressure buildup at the... sufficient to prevent slippage. Inspection procedure. With the air system charged, open the drain cocks...

  2. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the drain cocks in the service and supply reservoir on the truck or truck-tractor. Note the pressure.... Close the drain cocks, and, with the trailer(s) uncoupled, check air pressure buildup at the... sufficient to prevent slippage. Inspection procedure. With the air system charged, open the drain cocks...

  3. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the drain cocks in the service and supply reservoir on the truck or truck-tractor. Note the pressure.... Close the drain cocks, and, with the trailer(s) uncoupled, check air pressure buildup at the... sufficient to prevent slippage. Inspection procedure. With the air system charged, open the drain cocks...

  4. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Trailer(s) must be coupled to a truck or truck-tractor...3) The warning device (visual or audible...or audible warning device connected to...to fast idle and charge the system to its...or audible warning device connected to the...to fast idle and charge the system to...

  5. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Trailer(s) must be coupled to a truck or truck-tractor...3) The warning device (visual or audible...or audible warning device connected to...to fast idle and charge the system to its...or audible warning device connected to the...to fast idle and charge the system to...

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Trailer(s) must be coupled to a truck or truck-tractor...3) The warning device (visual or audible...or audible warning device connected to...to fast idle and charge the system to its...or audible warning device connected to the...to fast idle and charge the system to...

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Trailer(s) must be coupled to a truck or truck-tractor...3) The warning device (visual or audible...or audible warning device connected to...to fast idle and charge the system to its...or audible warning device connected to the...to fast idle and charge the system to...

  8. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear.... Brake shoes must be properly applied and kept approximately in line with the tread of the wheel....

  9. 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.... Brake shoes must be properly applied and kept approximately in line with the tread of the wheel....

  10. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear.... Brake shoes must be properly applied and kept approximately in line with the tread of the wheel....

  11. 49 CFR 230.77 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear.... Brake shoes must be properly applied and kept approximately in line with the tread of the wheel....

  12. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...integrity test of the dynamic brake to determine...at the grids on the system; and (2) Display...train with a brake system that includes dynamic brakes shall adopt...train with a brake system that includes dynamic brakes shall...

  13. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...integrity test of the dynamic brake to determine...at the grids on the system; and (2) Display...train with a brake system that includes dynamic brakes shall adopt...train with a brake system that includes dynamic brakes shall...

  14. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...integrity test of the dynamic brake to determine...at the grids on the system; and (2) Display...train with a brake system that includes dynamic brakes shall adopt...train with a brake system that includes dynamic brakes shall...

  15. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...integrity test of the dynamic brake to determine...at the grids on the system; and (2) Display...train with a brake system that includes dynamic brakes shall adopt...train with a brake system that includes dynamic brakes shall...

  16. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...integrity test of the dynamic brake to determine...at the grids on the system; and (2) Display...train with a brake system that includes dynamic brakes shall adopt...train with a brake system that includes dynamic brakes shall...

  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. Space shuttle wheels and brakes

    NASA Technical Reports Server (NTRS)

    Carsley, R. B.

    1985-01-01

    The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

  19. 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…

  20. 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.

  1. 49 CFR 236.701 - Application, brake; full service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a split reduction in brake pipe pressure at a service rate until maximum brake cylinder pressure is... other than emergency which develops the maximum brake cylinder pressure, as determined by the design...

  2. 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.

  3. 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 STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.507 Reversed braking. (a) The airplane must be in a three point static...

  4. 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 STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.507 Reversed braking. (a) The airplane must be in a three point static...

  5. 14 CFR 25.507 - Reversed braking.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 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...

  6. 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...

  7. 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...

  8. TMV Technology Capabilities Brake Stroke Monitor

    E-print Network

    TMV Technology Capabilities Brake Stroke Monitor Brake monitoring systems are proactive maintenance This technology allows for CMV operators to have knowledge of their steer, drive, and tandem axle group weights setup is required. Current Safety/Enforcement Technologies EOBR (electronic on-board recorder) On

  9. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... percentage of its gross weight specified in the table in paragraph (d) of this section; (2) Decelerating to a... of the braking force at each wheel of the vehicle or vehicle combination as a percentage of gross vehicle or combination weight. (b) Upon application of its emergency brake system and with no other...

  10. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Brakes. 23.735 Section 23.735 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Landing Gear § 23.735 Brakes. Link to an amendment...

  11. 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...

  12. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 5 2012-10-01 2012-10-01 false Brake performance. 393.52 Section 393.52 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.52...

  13. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Brake performance. 393.52 Section 393.52 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.52...

  14. Orbital-Transfer Vehicle With Aerodynamic Braking

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Nagy, K.; Roberts, B. B.; Ried, R. C.; Kroll, K.; Gamble, J.

    1986-01-01

    Vehicle includes airbrake for deceleration into lower orbit. Report describes vehicle for carrying payloads between low and high orbits around Earth. Vehicle uses thin, upper atmosphere for braking when returning to low orbit. Since less propellant needed than required for full retrorocket braking, vehicle carries larger payload and therefore reduces cost of space transportation.

  15. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-system application and braking distance in feet” (column 4) is a definite measure of the overall... section; and (3) Stopping from 20 miles per hour in a distance, measured from the point at which movement of the service brake pedal or control begins, that is not greater than the distance specified in...

  16. 49 CFR 393.52 - Brake performance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-system application and braking distance in feet” (column 4) is a definite measure of the overall... section; and (3) Stopping from 20 miles per hour in a distance, measured from the point at which movement of the service brake pedal or control begins, that is not greater than the distance specified in...

  17. 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.

  18. 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.

  19. What brakes the Crab pulsar?

    E-print Network

    ?adež, A; Barbieri, C; Calvani, M; Naletto, G; Barbieri, M; Ponikvar, D

    2015-01-01

    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. 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. 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. From our analysis, we demonstrate that the power law index undergoes "inst...

  20. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...of the set and release of the brakes shall be completed by walking the train to directly observe the set and release of each brake...that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the...

  1. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...of the set and release of the brakes shall be completed by walking the train to directly observe the set and release of each brake...that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the...

  2. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...of the set and release of the brakes shall be completed by walking the train to directly observe the set and release of each brake...that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the...

  3. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...of the set and release of the brakes shall be completed by walking the train to directly observe the set and release of each brake...that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the...

  4. 49 CFR 238.315 - Class IA brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...of the set and release of the brakes shall be completed by walking the train to directly observe the set and release of each brake...that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the...

  5. 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…

  6. 49 CFR 238.317 - Class II brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 be.... In these circumstances, a Class II brake test shall be performed prior to the train's departure...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  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. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Hydraulic system for a ratio change transmission

    DOEpatents

    Kalns, Ilmars (Northville, MI)

    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.

  1. An engine air-brake integration study

    E-print Network

    Mulchandani, Hiten

    2011-01-01

    The feasibility of operating an engine air-brake (EAB) integrated with a pylon duct bifurcation in a realistic aircraft engine environment has been analyzed. The EAB uses variable exit guide vanes downstream of a high ...

  2. Power-Factor Controller With Regenerative Braking

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1982-01-01

    Modified power-factor motor-control circuit operates motor as a phase-controlled generator when load attempts to turn at higher than synchronous speed. An induction motor is required to act at times as a brake. Circuit modification allows power-factor controller to save energy in motoring mode and convert automatically to an induction-generator controller in generating, or braking, mode.

  3. Method and apparatus for wind turbine braking

    DOEpatents

    Barbu, Corneliu (Laguna Hills, CA); Teichmann, Ralph (Nishkayuna, NY); Avagliano, Aaron (Houston, TX); Kammer, Leonardo Cesar (Niskayuna, NY); Pierce, Kirk Gee (Simpsonville, SC); Pesetsky, David Samuel (Greenville, SC); Gauchel, Peter (Muenster, DE)

    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.

  4. 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.

  5. Constraining the Braking Indices of Magnetars

    E-print Network

    Gao, Z F; Wang, N; Yuan, J P; Peng, Q H; Du, Y J

    2015-01-01

    Due to 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 $n$ of nine magnetars with SNRs, and find that they cluster in a range of $1\\sim$41. Six magnetars have smaller braking indices of $13$ for 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 $13$ within the updated magneto-thermal evolution models. We point out that there could be some connections between the magnetar's anti-glitch event and its braking index, and the magnitude of $n$ should be taken into account when explaining the event. Although the constrained range of the magnetars' braking indices is tentative, our method provides an effective way to constrain the magnetars' braking indices if th...

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle

    SciTech Connect

    Michel, R.

    1985-06-04

    Hydropneumatic energy reservoir for accumulating the braking energy recovered on a vehicle by means of a hydrostatic energy recovery-restoration device, combined or not with the vehicle transmission and working between a high-pressure accumulator and a low-pressure accumulator, characterized in that it comprises several oblong cylindrical hydropneumatic accumulators connected hydraulically in parallel and placed side by side inside a single casing of small height, the space included between the said casing and the said accumulators forming the low-pressure accumulator.

  18. 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

  19. 49 CFR 570.58 - Electric brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Electric brake system. 570.58 ...DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.58 Electric brake system. (a)...

  20. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  1. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  2. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  3. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit vertical load must be based on a load factor of at least—...

  4. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety...14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional...

  5. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety...14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional...

  6. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety...14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional...

  7. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety...14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional...

  8. 30 CFR 57.14102 - Brakes for rail equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety...14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional...

  9. A pressure control scheme for air brakes in commercial vehicles 

    E-print Network

    Bowlin, Christopher Leland

    2007-04-25

    This research is focused on developing a control scheme for regulating the pressure in the brake chamber of an air brake system found in most commercial vehicles like trucks, tractor-trailers and buses. Such a control ...

  10. 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...

  11. 49 CFR 232.109 - Dynamic brake requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 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...

  12. 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...

  13. 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...

  14. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Foundation brake gear. 229.57 Section 229.57... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  15. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Foundation brake gear. 229.57 Section 229.57... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  16. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Foundation brake gear. 229.57 Section 229.57... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  17. 49 CFR 229.57 - 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. 229.57 Section 229.57... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  18. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Foundation brake gear. 229.57 Section 229.57... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  19. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of...-wheel braking effort) if that device meets the applicable requirements of paragraphs (b)(1) and (2)...

  20. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of...-wheel braking effort) if that device meets the applicable requirements of paragraphs (b)(1) and (2)...

  1. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case of...-wheel braking effort) if that device meets the applicable requirements of paragraphs (b)(1) and (2)...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Brake Wear and Performance Test Final December 2009

    E-print Network

    Brake Wear and Performance Test Final Report December 2009 #12;FOREWORD This study focuses on using and quantifying associated brake component wear as a function of mileage. Additionally, ORNL was tasked. Report Date December 2009 4. Title and Subtitle Brake Wear and Performance Test Final Report 6

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Brake power unit. 570.6 Section 570.6... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken... power assist system. This test is not applicable to vehicles equipped with full power brake system...

  13. 49 CFR 570.6 - Brake power unit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Brake power unit. 570.6 Section 570.6... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken... power assist system. This test is not applicable to vehicles equipped with full power brake system...

  14. The design of aircraft brake systems, employing cooling to increase brake life

    NASA Technical Reports Server (NTRS)

    Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

    1975-01-01

    A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

  15. 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.

  16. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...=Kinetic energy per wheel (ft.-lb.); W=Design landing weight (lb.); V=Airplane speed in knots. V must be... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... design landing weight. (2) Instead of a rational analysis, the kinetic energy absorption requirements...

  17. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...=Kinetic energy per wheel (ft.-lb.); W=Design landing weight (lb.); V=Airplane speed in knots. V must be... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... design landing weight. (2) Instead of a rational analysis, the kinetic energy absorption requirements...

  18. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...=Kinetic energy per wheel (ft.-lb.); W=Design landing weight (lb.); V=Airplane speed in knots. V must be... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... design landing weight. (2) Instead of a rational analysis, the kinetic energy absorption requirements...

  19. 14 CFR 23.735 - Brakes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...=Kinetic energy per wheel (ft.-lb.); W=Design landing weight (lb.); V=Airplane speed in knots. V must be... main wheel brake assembly must not be less than the kinetic energy absorption requirements determined... design landing weight. (2) Instead of a rational analysis, the kinetic energy absorption requirements...

  20. 30 CFR 56.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Brakes. 56.14101 Section 56.14101 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 §...

  1. 30 CFR 57.14101 - Brakes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Brakes. 57.14101 Section 57.14101 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 Maintenance Requirements §...

  2. 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.

  3. 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.

  4. Braking the Gas in the ? Pictoris Disk

    NASA Astrophysics Data System (ADS)

    Fernández, Rodrigo; Brandeker, Alexis; Wu, Yanqin

    2006-05-01

    The star ? Pictoris hosts the best studied circumstellar disk to date. Nonetheless, a long-standing puzzle has been around since the detection of metallic gas in the disk: radiation pressure from the star should blow the gas away, yet the observed motion is consistent with Keplerian rotation. In this work we search for braking mechanisms that can resolve this discrepancy. We find that all species affected by radiation force are largely ionized and dynamically coupled into a single fluid by Coulomb collisions, reducing the radiation force on species feeling the strongest acceleration. For a gas of solar composition, the effective radiation force still exceeds gravity, while a gas of enhanced carbon abundance could be self-braking. We also explore two other braking agents: collisions with dust grains and neutral gas. Grains surrounding ? Pic are photoelectrically charged to a positive electrostatic potential. If a significant fraction of the grains are carbonaceous (10% in the midplane and larger at higher altitudes), ions can be slowed down to satisfy the observed velocity constraints. For neutral gas to brake the ion fluid, we find a minimum required mass ~0.03 M?, consistent with observed upper limits on the hydrogen column density and substantially reduced relative to previous estimates. Our results favor a scenario in which metallic gas is generated by grain evaporation in the disk, perhaps during grain-grain collisions. We exclude a primordial origin for the gas but cannot rule out its production by falling evaporating bodies near the star.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. 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).

  10. Hibernation Revived by Weak Magnetic Braking

    E-print Network

    Rebecca G. Martin; Christopher A. Tout

    2006-09-07

    Cataclysmic variables undergo periodic nova explosions during which a finite mass of material is expelled on a short timescale. The system widens and, as a result, the mass-transfer rate drops. This state of hibernation may account for the variety of cataclysmic variable types observed in systems of similar mass and period. In the light of recent changes to the theory of nova ignition and magnetic braking we investigate whether hibernation remains a viable mechanism for creating cataclysmic variable diversity. We model the ratio of time spent as dwarf novae (DNe) to nova-like systems (NLs). Above a critical mass-transfer rate the system is NL and below it a DN. The dominant loss of angular momentum is by magnetic braking but the rate is uncertain. It is also uncertain what fraction of the mass accreted is expelled during the novae. We compare the models of the ratios against the period of the system for different magnetic braking rates and different ejected masses with the ratio of the number of observed NLs to DNe. We deduce that a rate of angular momentum loss a factor of ten smaller than that traditionally assumed is necessary if hibernation is to account for the observed ratios.

  11. Hibernation Revived by Weak Magnetic Braking

    E-print Network

    Martin, R G; Martin, Rebecca G.; Tout, Christopher A.

    2005-01-01

    Cataclysmic variables undergo periodic nova explosions during which a finite mass of material is expelled on a short timescale. The system widens and, as a result, the mass-transfer rate drops. This state of hibernation may account for the variety of cataclysmic variable types observed in systems of similar mass and period. In the light of recent changes to the theory of nova ignition and magnetic braking we investigate whether hibernation remains a viable mechanism for creating cataclysmic variable diversity. We model the ratio of time spent as dwarf novae (DNe) to nova-like systems (NLs). Above a critical mass-transfer rate the system is NL and below it a DN. The dominant loss of angular momentum is by magnetic braking but the rate is uncertain. It is also uncertain what fraction of the mass accreted is expelled during the novae. We compare the models of the ratios against the period of the system for different magnetic braking rates and different ejected masses with the ratio of the number of observed NLs ...

  12. 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

  13. 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].

  14. Evaluation of materials and design modifications for aircraft brakes

    NASA Technical Reports Server (NTRS)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  15. Optimal design of a novel configuration of MR brake with coils placed on the side housings

    NASA Astrophysics Data System (ADS)

    Nguyen, Quoc Hung; Nguyen, Ngoc Diep; Choi, Seung-Bok

    2014-03-01

    It is well known that in design of traditional magneto-rheological brake (MRB), coils are placed on the cylindrical housing of the brake. In this study, a new configuration of MR brake with coils placed on the side housings of the brake is proposed and analyzed. After briefly explaining the operating principle of the proposed configuration, the braking torque of the MR brake is analyze based on Bingham-plastic rheological model of MR fluid. The optimization of the proposed and conventional MR brakes is then performed considering maximum braking torque and mass of the brake. Based on the optimal results, a comparison between the proposed MR brakes and the conventional ones is undertaken. In addition, experimental test of the MR brakes is conducted and the results are presented in order to validate the performance characteristics of the proposed MR brake.

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

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  18. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  19. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  20. 49 CFR 232.503 - Process to introduce new brake system technology.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Process to introduce new brake system technology. 232.503 Section 232.503... Introduction of New Brake System Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the...

  1. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236.554 Transportation...pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure reduction during an automatic...

  2. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236.554 Transportation...pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure reduction during an automatic...

  3. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Rate of pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236... Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure...

  4. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Rate of pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236... Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure...

  5. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Rate of pressure reduction; equalizing reservoir or brake pipe. 236.554 Section 236... Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure...

  6. Measurement and control of brake pedal feel quality in automobile manufacturing

    E-print Network

    Cerilles, Jeffrey T. (Jeffrey Thomas)

    2005-01-01

    Customer perception of brake pedal feel quality, as related to the perception of the brake pedal feeling soft or mushy, depends on both the customer's subjective judgment of quality and the actual build quality of the brake ...

  7. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...load changes and/or dynamic weight transfer, or...S5.1. Service brake system. Each vehicle shall...variable brake proportioning system, this determination...variable brake proportioning system, dynamic tests are run...

  8. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...load changes and/or dynamic weight transfer, or...S5.1. Service brake system. Each vehicle shall...variable brake proportioning system, this determination...variable brake proportioning system, dynamic tests are run...

  9. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...load changes and/or dynamic weight transfer, or...S5.1. Service brake system. Each vehicle shall...variable brake proportioning system, this determination...variable brake proportioning system, dynamic tests are run...

  10. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...load changes and/or dynamic weight transfer, or...S5.1. Service brake system. Each vehicle shall...variable brake proportioning system, this determination...variable brake proportioning system, dynamic tests are run...

  11. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...load changes and/or dynamic weight transfer, or...S5.1. Service brake system. Each vehicle shall...variable brake proportioning system, this determination...variable brake proportioning system, dynamic tests are run...

  12. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...If the vehicle has a low-vacuum indicator, the indicator activation level shall not be less than 8 inches of mercury. (1...the brake application and check for low-vacuum indicator activation. (ii) For a combination vehicle equipped with...

  13. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent of its cross-sectional area, cracked, broken, or missing. All pins shall be secured in place with...

  14. 49 CFR 229.57 - Foundation brake gear.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...System § 229.57 Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent of its cross-sectional area, cracked, broken, or missing. All pins shall be secured in place with...

  15. Why Brake-By-Wire (BBW) ? Advantages of BBW

    E-print Network

    Yao, Bin

    at wheel] #12;Sectional Drawing of the Electromechanically Actuated Disk Brake From ITT Brake Pads Caliper Central Bearing Planetary Gear Bearing Planetary Gear Stator Rotor Bearing Motor Revolver Revolver Bearing Force Sensor Cap Nut (Carrier) Spindle Planetary Rollers Internal Gear Sun Gear Pressure Pin Holder

  16. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  17. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  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. Multidisciplinary design optimization of an automotive magnetorheological brake design

    E-print Network

    Park, Edward

    such as the MR fluid selection, magnetic circuit design, torque requirements, weight constraints, dimensions on each wheel and the brake pedal with electrical components. There are many advantages of using a pure, we propose a MR actuator design for the brake in each wheel. The actuator consists of a rotating disk

  20. A diagnostic system for air brakes in commercial vehicles 

    E-print Network

    Coimbatore Subramanian, Shankar Ram

    2007-09-17

    to maintenance and hence they require frequent inspections. Current inspection techniques require an inspector to go underneath a vehicle to check the brake system for possible faults, such as leaks, worn brake pads, out-of-adjustment of push rods, etc...

  1. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  2. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...apply and remain applied on each car in the train until a release of...brakes has been initiated on each car in response to train line electric, pneumatic, or other signals...verification that each side of each car's brake system responds...

  3. 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.

  4. 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...

  5. 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...-second of an inch over the rivet heads, or the brake shoe on bonded linings or pads. Brake linings and... attached to shoe plates. (1) Inspection procedure. Examine visually for conditions indicated, and...

  6. 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.

  7. 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.

  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 Green’s 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. 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.

  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. Protobinary Evolution Driven By Magnetic Braking

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Zhi-Yun

    2013-07-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  12. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Li, Z.; Kratter, K. M.

    2014-01-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  13. 76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... Federal Railroad Administration Petition for Modification of Single Car Air Brake Test Procedures In... air brake test procedures as prescribed in 49 CFR 232.305(a). FRA assigned the request Docket Number... straight air brake employed on PATH cars. The single car air brake test described in Association...

  14. 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... brake fluid. S5.3Measurement of dynamic performance. There are two ways in which brake...

  15. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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... brake fluid. S5.3Measurement of dynamic performance. There are two ways in which brake...

  16. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...the time that a Class I or IA brake test...the railroad's air brake or power...en route after a Class I or IA brake test... (C) Piston travel that is in excess of the Class I brake test limits...the train at the first location...

  17. 49 CFR 232.103 - General requirements for all train brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...shall have its air brakes in effective...609. The air brakes on a...if the piston travel exceeds: ...for the car at Class I brake tests...different from Class I brake test...service for the first time on or...either the piston travel, an accurate...less than the air compressor...

  18. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...the time that a Class I or IA brake test...the railroad's air brake or power...en route after a Class I or IA brake test... (C) Piston travel that is in excess of the Class I brake test limits...the train at the first location...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. Airbus A320 Braking as Predicate-Action Peter B. Ladkin

    E-print Network

    Ladkin, Peter B.

    to interest us and others in the design of the A320 braking system [FI.93a, FI.93b, FI.93c]. This paper]. The Braking System Design of the A320. The braking system design of the A320 is described in the A320 Flight). The brakes and anti-skid system are described in [FCOM, 1.32.30: Landing Gear: Brakes and Anti

  10. 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.

  11. Geomechanics of hydraulic fracturing microseismicity

    E-print Network

    Ze'ev, Reches

    Geomechanics of hydraulic fracturing microseismicity: Part 1. Shear, hybrid, and tensile events of hydraulic- fracturing-induced microseismicity. Microseismic events are commonly used to discern stimulation patterns and hydraulic fracture evolution; however, techniques beyond fracture mapping are required

  12. Geomechanics of hydraulic fracturing microseismicity

    E-print Network

    Ze'ev, Reches

    Geomechanics of hydraulic fracturing microseismicity: Part 2. Stress state determination Seth Busetti and Ze'ev Reches ABSTRACT We investigate the hydraulic fracturing process by analysis, stress shadowing adjacent to large parent hydraulic fractures, and crack tip stress perturbations. Data

  13. Regenerative braking on bicycles to power LED safety flashers

    E-print Network

    Collier, Ian M

    2005-01-01

    This work develops a method for capturing some of the kinetic energy ordinarily lost during braking on bicycles to power LED safety flashers. The system is designed to eliminate: (a) battery changing in popular LED flashers, ...

  14. 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

  15. 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

  16. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction...wheel with brakes, except that the drag reaction need not exceed the...

  17. 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

  18. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...removed, repaired, or replaced: (i) Brake reservoir; (ii) Control valve mounting gasket; (iii) Pipe bracket stud; (iv) Service portion; (v) Emergency portion; or (vi) Pipe bracket. (5) A car is found with one or more...

  19. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...removed, repaired, or replaced: (i) Brake reservoir; (ii) Control valve mounting gasket; (iii) Pipe bracket stud; (iv) Service portion; (v) Emergency portion; or (vi) Pipe bracket. (5) A car is found with one or more...

  20. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...removed, repaired, or replaced: (i) Brake reservoir; (ii) Control valve mounting gasket; (iii) Pipe bracket stud; (iv) Service portion; (v) Emergency portion; or (vi) Pipe bracket. (5) A car is found with one or more...

  1. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...removed, repaired, or replaced: (i) Brake reservoir; (ii) Control valve mounting gasket; (iii) Pipe bracket stud; (iv) Service portion; (v) Emergency portion; or (vi) Pipe bracket. (5) A car is found with one or more...

  2. 49 CFR 232.305 - Single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...removed, repaired, or replaced: (i) Brake reservoir; (ii) Control valve mounting gasket; (iii) Pipe bracket stud; (iv) Service portion; (v) Emergency portion; or (vi) Pipe bracket. (5) A car is found with one or more...

  3. 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

  4. 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

  5. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...the surface at the thinnest point on the lining or pad. (d) Structural and mechanical parts. Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing,...

  6. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...the surface at the thinnest point on the lining or pad. (d) Structural and mechanical parts. Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing,...

  7. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...the surface at the thinnest point on the lining or pad. (d) Structural and mechanical parts. Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing,...

  8. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the surface at the thinnest point on the lining or pad. (d) Structural and mechanical parts. Backing plates, brake spiders and caliper assemblies shall not be deformed or cracked. System parts shall not be broken, misaligned, missing,...

  9. 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...

  10. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Friction materials. On each brake, the thickness of the lining or pad shall not be less than one thirty... cracks that do not impair attachment. The wire in wire-backed lining shall not be visible on the...

  11. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Friction materials. On each brake, the thickness of the lining or pad shall not be less than one thirty... cracks that do not impair attachment. The wire in wire-backed lining shall not be visible on the...

  12. 49 CFR 570.59 - Service brake system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Friction materials. On each brake, the thickness of the lining or pad shall not be less than one thirty... cracks that do not impair attachment. The wire in wire-backed lining shall not be visible on the...

  13. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types...) Friction materials. On each brake the thickness of the lining or pad shall not be less than one...

  14. Stability analysis and \\mu-synthesis control of brake systems

    E-print Network

    Lignon, Sylvain; Jezequel, Louis

    2008-01-01

    The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the instability regions in relation to possible system parameter combinations, robust stability via \\mu-synthesis is applied. By comparing the unstable regions between the initial and controlled brake system, some general indications emerge and it appears that robust stability via \\mu-synthesis has some effect on the instability of the brake system.

  15. 49 CFR 393.48 - Brakes to be operative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...reduce or remove front-wheel braking effort may only be used on buses, trucks, and truck tractors manufactured before March 1...house moving dollies, specialized trailers and dollies used to transport industrial furnaces, reactors, and similar motor...

  16. 49 CFR 238.313 - Class I brake test.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the train properly apply; (13) Each brake disc is free of any crack in accordance with the manufacturer's specifications or, if no specifications exist, free of any crack to the extent that the design permits; (14) If the...

  17. 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

  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. Downhole hydraulic seismic generator

    DOEpatents

    Gregory, Danny L. (Corrales, NM); Hardee, Harry C. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM)

    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.

  20. 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

  1. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Bicycles shall be equipped with front- and rear-wheel brakes or rear-wheel brakes only. (b) Handbrakes...)(2), and shall be rocked back and forth with the weight of a 68.1 kg (150 lb) rider on the seat with... of at least 68.1 kg (150 lb) weight in accordance with the performance test, § 1512.18(d)(2) (v)...

  2. 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.

  3. Will the tachyonic universe survive the big brake?

    NASA Astrophysics Data System (ADS)

    Keresztes, Zoltán; Gergely, László Á.; 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.

  4. 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.

  5. Infrared characterization of thermal gradients on disc brakes

    NASA Astrophysics Data System (ADS)

    Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

    2003-04-01

    The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

  6. 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.

  7. 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).

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    Pi?tkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Ma?achowski, Jerzy; Mazurkiewicz, ?ukasz

    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.

  10. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... compensate for vehicle static axle loading and/or dynamic weight transfer between axles during deceleration... accordance with American Society for Testing and Materials (ASTM) Method E-274-70 (as revised July, 1974) at... word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR...

  11. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... compensate for vehicle static axle loading and/or dynamic weight transfer between axles during deceleration... accordance with American Society for Testing and Materials (ASTM) Method E-274-70 (as revised July, 1974) at... word, words or abbreviation, in accordance with the requirements of Standard No. 101 (49 CFR...

  12. 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.

  13. Hydraulic Fracturing Sand

    USGS Multimedia Gallery

    Fine-grained silica sand is mixed with chemicals and water before being pumped into rock formations to prevent the newly created artificial fractures from closing after hydraulic fracturing is completed....

  14. Hydraulic hoisting and backfilling

    NASA Astrophysics Data System (ADS)

    Sauermann, H. B.

    In a country such as South Africa, with its large deep level mining industry, improvements in mining and hoisting techniques could result in substantial savings. Hoisting techniques, for example, may be improved by the introduction of hydraulic hoisting. The following are some of the advantages of hydraulic hoisting as against conventional skip hoisting: (1) smaller shafts are required because the pipes to hoist the same quantity of ore hydraulically require less space in the shaft than does skip hoisting equipment; (2) the hoisting capacity of a mine can easily be increased without the necessity of sinking new shafts. Large savings in capital costs can thus be made; (3) fully automatic control is possible with hydraulic hoisting and therefore less manpower is required; and (4) health and safety conditions will be improved.

  15. Portable Hydraulic Powerpack

    NASA Technical Reports Server (NTRS)

    Anderson, L. A.; Henry, R. L.; Fedor, O. H.; Owens, L. J.

    1986-01-01

    Rechargeable hydraulic powerpack functions as lightweight, compact source of mechanical energy. Self-contained hydraulic powerpack derives energy from solid chemical charge. Combustion of charge initiated by small hammer, and revolving feeder replaces charges expended. Combustion gases cool during expansion in turbine and not too hot for release to atmosphere. Unit has applications driving wheelchairs and operating drills, winches, and other equipment in remote areas. Also replaces electric motors and internal-combustion engines as source of power in explosive atmospheres.

  16. 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.

  17. 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.

  18. Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris vittata L.)

    E-print Network

    Ma, Lena

    Arsenic species and leachability in the fronds of the hyperaccumulator Chinese brake (Pteris June 2002; accepted 9 December 2002 ``Capsule'': Arsenic was predominantly present as inorganic arsenite in the fronds of the hyperaccumulator Chinese brake. Abstract Arsenic speciation is important

  19. Brake Defect Causa on and Abatement Study (BDCAS) The Federal Motor Carrier Safety

    E-print Network

    whose brake force is less than 43.5 percent of its gross vehicle weight is not allowed to return to its capability of a vehicle through measurement of the brake force developed as a function of weight. Any vehicle

  20. 77 FR 46633 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ...for Safe Operation: Brakes; Adjustment Limits AGENCY: Federal Motor Carrier Safety...requirements regarding brake readjustment limits in the Federal Motor Carrier Safety Regulations...This rule amends the readjustment limits, clarifies their application, and...

  1. 76 FR 54721 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ...for Safe Operation: Brakes; Adjustment Limits AGENCY: Federal Motor Carrier Safety...rotochamber brake actuator readjustment limits in the Federal Motor Carrier Safety Regulations...NPRM) is to amend the readjustment limits, clarify their application, and...

  2. 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.

  3. 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.

  4. 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.

  5. Periodic brake orbits in the planar isosceles three-body problem

    NASA Astrophysics Data System (ADS)

    Chen, Nai-Chia

    2013-10-01

    A brake orbit is an orbit that starts with zero initial velocity. The purpose of this paper is to find periodic brake orbits in the isosceles three-body problem. We use various shooting arguments; we follow a curve of brake initial conditions under the flow until it reaches a suitable surface, and show that the image curve includes a point that corresponds to a periodic orbit. As a result, we prove the existence of six types of periodic brake orbits.

  6. 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.

  7. 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... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  8. 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... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  9. 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... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  10. 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

  11. 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... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  12. 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…

  13. The Chinese brake fern (Pteris vittata L.), native to China, is widely naturalized in

    E-print Network

    Ma, Lena

    The Chinese brake fern (Pteris vittata L.), native to China, is widely naturalized in many areas and anatomical aspects of Chinese brake fern (Pteris vittata; Pteridaceae) Bhaskar Bondada1, Cong Tu, and Lena Ma-0290, U.S.A.; e-mail: lqma@ifas.ufl.edu). Sur- face structure and anatomical aspects of Chinese brake fern

  14. Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern)

    E-print Network

    Ma, Lena

    Thiol synthesis and arsenic hyperaccumulation in Pteris vittata (Chinese brake fern) Weihua Zhanga in arsenic detoxification. Abstract Pteris vittata (Chinese brake fern) has potential for phytoremediation to be a supplement. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Pteris vittata; Chinese brake fern; Thiols

  15. 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…

  16. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ...report's title is: The Effectiveness of ABS [Antilock Braking Systems] in Heavy Truck...121) mandates antilock braking systems (ABS) on all new air-braked vehicles with a GVWR of 10,000 pounds or greater. ABS is required on tractors manufactured...

  17. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...compensated for by means of a system of automatic or manual... S5.3Measurement of dynamic performance. There are two ways in which brake system performance is measured...surface is used for all dynamic brake tests excluding...1.4Parking brake system tests. The...

  18. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...compensated for by means of a system of automatic or manual... S5.3Measurement of dynamic performance. There are two ways in which brake system performance is measured...surface is used for all dynamic brake tests excluding...1.4Parking brake system tests. The...

  19. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...compensated for by means of a system of automatic or manual... S5.3Measurement of dynamic performance. There are two ways in which brake system performance is measured...surface is used for all dynamic brake tests excluding...1.4Parking brake system tests. The...

  20. 77 FR 39561 - Advanced Braking Technologies That Rely on Forward-Looking Sensors; Request for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-03

    ...NHTSA-2012-0057] Advanced Braking Technologies That Rely on Forward-Looking...studying advanced braking technologies that rely on forward-looking...will activate brake assist technologies in some vehicles and not...camera, LIDAR, and/or infrared sensors to assess the...

  1. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  2. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  3. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  4. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  5. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Equipment and devices used to perform single car air brake tests. 232.309 Section...Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for...

  6. 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

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of the rated strokes listed in SAE J1817—Long Stroke Air Brake Actuator Marking, July 2001 (See § 393... percent of the rated stroke marked on the brake chamber by the chamber manufacturer, or the readjustment... long stroke clamp type brake actuators must be less than 51 mm (2 inches) or 80 percent of the...

  8. 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... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a...

  9. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...that the lining thickness of drum brake shoes may be visually inspected...removing the drums, and so that disc brake friction lining thickness may...the most heavily loaded shoe or disc pad, one per brake, as shown in Figure 1....

  10. 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...

  11. 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...

  12. 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...

  13. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... discernible without magnification; (c) The water-wet brake fluid at the end of the test shall show no jelling... walls or the surface of the metal strips; (e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume; (f) The pH value of water-wet brake fluid,...

  14. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... discernible without magnification; (c) The water-wet brake fluid at the end of the test shall show no jelling... walls or the surface of the metal strips; (e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume; (f) The pH value of water-wet brake fluid,...

  15. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... discernible without magnification; (c) The water-wet brake fluid at the end of the test shall show no jelling... walls or the surface of the metal strips; (e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume; (f) The pH value of water-wet brake fluid,...

  16. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... discernible without magnification; (c) The water-wet brake fluid at the end of the test shall show no jelling... walls or the surface of the metal strips; (e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume; (f) The pH value of water-wet brake fluid,...

  17. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... discernible without magnification; (c) The water-wet brake fluid at the end of the test shall show no jelling... walls or the surface of the metal strips; (e) At the end of the test, sedimentation of the water-wet brake fluid shall not exceed 0.10 percent by volume; (f) The pH value of water-wet brake fluid,...

  18. 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.

  19. 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.

  20. Disc brake squeal characterization through simplified test rigs

    NASA Astrophysics Data System (ADS)

    Akay, A.; Giannini, O.; Massi, F.; Sestieri, A.

    2009-11-01

    This paper presents a review of recent investigations on brake squeal noise carried out on simplified experimental rigs. The common theme of these works is that of approaching the study of squeal noise on experimental set-ups that are much simpler than commercial disc brakes, providing the possibility of repeatable measurements of squeal occurrence. As a consequence, it is possible to build consistent and robust models of the experimental apparatus to simulate the squeal events and to understand the physics behind squeal instabilities.

  1. Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads and tracer data

    E-print Network

    Cirpka, Olaf Arie

    Geostatistical inference of hydraulic conductivity and dispersivities from hydraulic heads; accepted 25 April 2006; published 10 August 2006. [1] In groundwater, hydraulic heads and solute arrival times depend primarily on the hydraulic conductivity field and hydraulic boundary conditions. The spread

  2. Failure analysis of energy storage spring in automobile composite brake chamber

    NASA Astrophysics Data System (ADS)

    Luo, Zai; Wei, Qing; Hu, Xiaofeng

    2015-02-01

    This paper set energy storage spring of parking brake cavity, part of automobile composite brake chamber, as the research object. And constructed the fault tree model of energy storage spring which caused parking brake failure based on the fault tree analysis method. Next, the parking brake failure model of energy storage spring was established by analyzing the working principle of composite brake chamber. Finally, the data of working load and the push rod stroke measured by comprehensive test-bed valve was used to validate the failure model above. The experimental result shows that the failure model can distinguish whether the energy storage spring is faulted.

  3. Project Startup: Evaluating the Performance of Hydraulic Hybrid Refuse Vehicles

    SciTech Connect

    2015-09-01

    The Fleet Test and Evaluation Team at the National Renewable Energy Laboratory (NREL) is evaluating the in-service performance of 10 next-generation hydraulic hybrid refuse vehicles (HHVs), 8 previous-generation HHVs, and 8 comparable conventional diesel vehicles operated by Miami-Dade County's Public Works and Waste Management Department in southern Florida. The HHVs under study - Autocar E3 refuse trucks equipped with Parker Hannifin's RunWise Advanced Series Hybrid Drive systems - can recover as much as 70 percent of the energy typically lost during braking and reuse it to power the vehicle. NREL's evaluation will assess the performance of this technology in commercial operation and help Miami-Dade County determine the ideal routes for maximizing the fuel-saving potential of its HHVs.

  4. 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

  5. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...a)(2); and (b) The structure must be designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2) The...

  6. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...a)(2); and (b) The structure must be designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2) The...

  7. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2); and (b) The structure must be designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2)...

  8. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2); and (b) The structure must be designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8; and (2)...

  9. DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL ...

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

    DISC BRAKE SYSTEM (CENTER), INCLUDING BELT DRIVE TO SECONDARY GENERAL MOTORS ENGINE (LEFT)AND FERREL REDUCTION GEAR CONNECTION TO ALLIS-CHALMERS DIESEL ENGINE (RIGHT), LOOKING NORTH. NOTE TORQUE CONVERTER (TOP) AND THROTTLE (BELOW) LINES CONNECTING TO PRIMARY ENGINE. - Mad River Glen, Single Chair Ski Lift, 62 Mad River Glen Resort Road, Fayston, Washington County, VT

  10. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a gross weight of 1,361 kg (3,000 pounds) or less which is subject to this part is not required to be equipped with brakes if the axle weight of the towed vehicle does not exceed 40 percent of the sum of the axle weights of the towing vehicle. (4) Any full trailer or four-wheel pole trailer (laden...

  11. Sudden Radiative Braking in Colliding Hot-Star Winds

    NASA Astrophysics Data System (ADS)

    Gayley, K. G.; Owocki, S. P.; Cranmer, S. R.

    1997-02-01

    Hot, massive stars have strong stellar winds, and in hot-star binaries these winds can undergo violent collision. Because such winds are thought to be radiatively driven, radiative forces may also play an important role in moderating the wind collision. However, previous studies have been limited to considering how such forces may inhibit the initial acceleration of the companion stellar wind. In this paper we analyze the role of an even stronger radiative braking effect, whereby the primary wind is rather suddenly decelerated by the radiative momentum flux it encounters as it approaches a bright companion. We further show that the braking location and velocity law along the line of centers between the stars can be approximated analytically using a simple one-dimensional analysis. The results of this analysis agree well with a detailed two-dimensional hydrodynamical simulation of the wind collision in the WR + O binary V444 Cygni and demonstrate that radiative braking can significantly alter the bow-shock geometry and reduce the strength of the wind collision. We then apply the derived analytic theory to a set of 14 hot-star binary systems, and conclude that radiative braking is likely to be of widespread importance for wind-wind collisions in WR + O binaries with close to medium separation, D <~ 100 R?. It may also be important in other types of hot-star binaries that exhibit a large imbalance between the component wind strengths.

  12. Sudden Radiative Braking in Colliding Hot-Star Winds

    NASA Astrophysics Data System (ADS)

    Gayley, K.; Owocki, S.; Cranmer, S.

    1996-05-01

    Hot, massive stars have strong stellar winds, and in hot-star binaries these winds can undergo violent collision. Because such winds are thought to be radiatively driven, radiative forces may also play an important role in moderating the wind collision. However, previous studies have been limited to considering how such forces may inhibit the initial acceleration of the companion stellar wind. In this poster we describe the role of an even stronger radiative braking effect, whereby the primary wind is rather suddenly decelerated by the radiative momentum flux it encounters as it approaches a bright companion. We show that the braking location and velocity law along the line of centers between the stars can be approximated analytically using a simple one-dimensional analysis. The results of this analysis agree well with a detailed two-dimensional hydrodynamical simulation of the wind collision in the WR+O binary V444 Cygni, and demonstrate that radiative braking can significantly alter the bow-shock geometry and reduce the strength of the wind collision. We also apply the derived analytic theory to a set of 14 hot-star binary systems, and conclude that radiative braking is likely to be of widespread importance for wind-wind collisions in WR+O binaries with close to medium separation, D <= 100 Rsun. It may also be important in other types of hot-star binaries that exhibit a large imbalance between the component wind strengths.

  13. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

  14. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

  15. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

  16. 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.

  17. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction...

  18. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  19. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  20. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  1. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  2. 14 CFR 23.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be applied at the ground contact point of each wheel with brakes, except that the drag reaction need not...

  3. Dr.-Ing. Norbert Frhleke PIBRAC -Piezoelectrical Brake Actuator

    E-print Network

    Noé, Reinhold

    -mass ultrasonic Power supply and control development Dr.-Ing. Norbert Fröhleke, Department of Power Electronics Böcker, Dr.-Ing. Norbert Fröhleke Current Aircraft Brake Actuator #12;Power Electronics and Electrical" aircraft: · Reduction in volume and weight · Increase in reliability and operating safety · Reduction costs

  4. 14 CFR 27.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...479(a)(2); and (b) The structure must be designed to withstand at the ground contact point of each wheel with brakes, a drag load at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of 0.8;...

  5. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...with the load on the main wheels, in accordance with...design ramp weight. A drag reaction equal to the...an airplane with a nose wheel the limit vertical load...design ramp weight. A drag reaction equal to the...contact point of each wheel with brakes. The...

  6. 14 CFR 29.493 - Braked roll conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...479(a)(2); and (b) The structure must be designed to withstand, at the ground contact point of each wheel with brakes, a drag load of at least the lesser of— (1) The vertical load multiplied by a coefficient of friction of...

  7. Wear and related characteristics of an aircraft tire during braking

    NASA Technical Reports Server (NTRS)

    Mccarty, J. L.

    1972-01-01

    Wear and related characteristics of friction and temperature developed during braking of size 22 x 5.5, type aircraft tires are studied. The testing technique involved gearing the tire to a driving wheel of a ground vehicle to provide operations at constant slip ratios on asphalt, concrete, and slurry-seal surfaces. Data were obtained over the range of slip ratios generally attributed to an aircraft braking system during dry runway operations. The results show that the cumulative tire wear varies linearly with distance traveled and the wear rate increases with increasing slip ratio and is influenced by the runway-surface character. Differences in the wear rates associated with the various surfaces suggest that runways can be rated on the basis of tire wear. The results also show that the friction coefficients developed during fixed-slip-ratio operations are in good agreement with those obtained by other investigators during cyclic braking, in that the dry friction is insensitive to the tire tread temperature is shown to increase with increasing slip ratio and, at the higher ratios, to be greater during braking on asphalt and slurry seal than on concrete.

  8. 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...

  9. 14 CFR 25.493 - Braked roll conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...application of maximum braking force as described in paragraphs (b) and (c) of this section. (e) In the absence of a more rational analysis, the nose gear vertical reaction prescribed in paragraph (d) of this section must be calculated according to...

  10. 6. OBLIQUE VIEW OF HOIST, SHOWING WOODEN BRAKE SHOES, REDUCTION ...

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

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

  11. 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…

  12. 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…

  13. 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.

  14. Disk brake squeal prediction using the ABLE algorithm

    NASA Astrophysics Data System (ADS)

    Lou, G.; Wu, T. W.; Bai, Z.

    2004-05-01

    Disk brake squeal noise is mainly due to unstable friction-induced vibration. A typical disk brake system includes two pads, a rotor, a caliper and a piston. In order to predict if a disk brake system will generate squeal, the finite element method (FEM) is used to simulate the system. At the contact interfaces between the pads and the rotor, the normal displacement is continuous and Coulomb's friction law is applied. Thus, the resulting FEM matrices of the dynamic system become unsymmetric, which will yield complex eigenvalues. Any complex eigenvalue with a positive real part indicates an unstable mode, which may result in squeal. In real-world applications, the FEM model of a disk brake system usually contains tens of thousands of degrees of freedom (d.o.f.s). Therefore any direct eigenvalue solver based on the dense matrix data structure cannot efficiently perform the analysis, mainly due to its huge memory requirement and long computation time. It is well known that the FEM matrices are generally sparse and hence only the non-zeros of the matrices need to be stored for eigenvalue analysis. A recently developed iterative method named ABLE is used in this paper to search for any unstable modes within a certain user-specified frequency range. The complex eigenvalue solver ABLE is based on an adaptive block Lanczos method for sparse unsymmetric matrices. Numerical examples are presented to demonstrate the formulation and the eigenvalues are compared to the results from the component modal synthesis (CMS).

  15. 49 CFR 570.5 - Service brake system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... pedal travel. Depress the brake pedal, and with the force applied measure the distance (B) from the... per hour and the vehicle shall be brought to a stop as specified. Measure the distance required...

  16. 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... pedal travel. Depress the brake pedal, and with the force applied measure the distance (B) from the... per hour and the vehicle shall be brought to a stop as specified. Measure the distance required...

  17. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... as determined by the equivalent ground speed specified in § 1512.18(d)(2)(vi). (2) Hand lever access. Hand lever mechanisms shall be located on the handlebars in a position that is readily accessible to... dimension between the brake hand lever and the handlebars in the plane containing the centerlines of...

  18. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... as determined by the equivalent ground speed specified in § 1512.18(d)(2)(vi). (2) Hand lever access. Hand lever mechanisms shall be located on the handlebars in a position that is readily accessible to... dimension between the brake hand lever and the handlebars in the plane containing the centerlines of...

  19. 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

  20. 16 CFR 1512.5 - Requirements for braking system.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... as determined by the equivalent ground speed specified in § 1512.18(d)(2)(vi). (2) Hand lever access. Hand lever mechanisms shall be located on the handlebars in a position that is readily accessible to... dimension between the brake hand lever and the handlebars in the plane containing the centerlines of...

  1. 44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE ...

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

    44. SOUTHWEST TO CIRCA 1900 SHEET METAL BRAKE, THE MACHINE USED TO BEND SHEET METAL TO EXACT ANGLES AS IN STEEL WATER TANK MANUFACTURE. IN THE BACKGROUND IS THE INTERIOR WEST WALL OF THE FACTORY, ITS SHELVES BEARING WATER PUMPS, PARTS FOR PUMPS AND WATER SUPPLY EQUIPMENT, AND NEW OLD STOCK MERCHANDISE. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  2. Cradle modification for hydraulic ram

    SciTech Connect

    Koons, B.M.

    1995-03-02

    The analysis of the cradle hydraulic system considers stress, weld strength, and hydraulic forces required to lift and support the cradle/pump assembly. The stress and weld strength of the cradle modifications is evaluated to ensure that they meet the requirements of the American Institute for Steel Construction (AISC 1989). The hydraulic forces are evaluated to ensure that the hydraulic system is capable of rotating the cradle and pump assembly to the vertical position (between 70{degrees} and 90{degrees}).

  3. Analytica Chimica Acta 504 (2004) 199207 Arsenic speciation in Chinese brake fern by ion-pair high-performance

    E-print Network

    Ma, Lena

    2004-01-01

    Analytica Chimica Acta 504 (2004) 199­207 Arsenic speciation in Chinese brake fern by ion-pair high) and arsenate [As(V)] in Chinese brake fern (Pteris vittata L.). The separation was performed on a reverse in the Chinese brake fern, indicating that Chinese brake fern can convert MMA to DMA by methylation. © 2003

  4. Integration in Hydraulics.

    ERIC Educational Resources Information Center

    Sworder, Steven C.

    This paper presents an application of integration to the field of hydraulics. An integral relation for the time required to drop the fluid contained in a cylindrical tank from one level to another using a hole in the tank wall is derived. Procedures for constructing the experimental equipment and procedures for determining the coefficient of…

  5. Water Treatment Technology - Hydraulics.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  6. Hydraulic Shutdown Monitor

    NASA Technical Reports Server (NTRS)

    Fleming, S. T.; Harrington, D. B.

    1986-01-01

    Adding switch allows inappropriate control actions to be overridden. Four-pole, double-throw switch added to front panel of controller to disable tracking-error and endpoint-error circuitry yet still retain overload-detection capability. Previously, it was necessary to use adjustable-voltage-level detection equipment connected with cables to hydraulic "dump" or shutdown circuitry in controller.

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

    NASA Astrophysics Data System (ADS)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-12-01

    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 obtaining their estimates of these quantities before and after watching a video recording of a car braking from various initial speeds to a complete stop and subsequent application of mathematical statistics to the obtained sets of students' answers. The results revealed that the difference between the value of the car braking distance estimated before watching the video and the real value of this distance was not caused by a random error but by a systematic error which was due to the incorrect students' conceptions about the car braking process. Watching the video significantly improved the students' estimates of the car braking distance, and we show that in this case, the difference between the estimated value and the real value of the car braking distance was due only to a random error, i.e. the students' conceptions about the car braking process were corrected. Some of the students subsequently performed video analysis of the braking processes of cars of various brands and under various conditions by means of Tracker that gave them exact knowledge of the physical quantities, which characterize a motor vehicle braking. Interviewing some of these students brought very positive reactions to this novel method of learning.

  8. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    NASA Astrophysics Data System (ADS)

    Sarkar, C.; Hirani, H.

    2013-11-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel-Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0-2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear.

  9. Aalborg Universitet Hydraulic Yaw System

    E-print Network

    Pedersen, Henrik C.

    Aalborg Universitet Hydraulic Yaw System Stubkier, Søren; Pedersen, Henrik Clemmensen; Mørkholt, M, M. (2012). Hydraulic Yaw System. Poster session presented at AWEA Windpower 2012, Georgia, Atlanta of the art-hydraulic yaw systems for wind turbines. 2011. [10] S. Stubkier and H. C. Pedersen. Design

  10. Viscous Hydraulic Jumps Submitted by

    E-print Network

    Bush, John W.M.

    Viscous Hydraulic Jumps Submitted by Jeffrey M. Aristoff, Jeffrey D. Leblanc, Annette E. Hosoi, and John W. M. Bush, Massachusetts Institute of Technology We examine the form of the viscous hydraulic of height 2­10 mm. Elegaard et al.1 first demonstrated that the axial symme- try of the viscous hydraulic

  11. Guidelines for numerical vibration and acoustic analysis of disc brake squeal using simple models of brake systems

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    Brake squeal has become of increasing concern to the automotive industry but guidelines on how to confidently predict squeal propensity are yet to be established. While it is standard practice to use the complex eigenvalue analysis to predict unstable vibration modes, there have been few attempts to calculate their acoustic radiation. Here guidelines are developed for numerical vibration and acoustic analysis of brake squeal using models of simplified brake systems with friction contact by considering (1) the selection of appropriate elements, contact and mesh; (2) the extraction of surface velocities via forced response; and (3) the calculation of the acoustic response itself. Results indicate that quadratic tetrahedral elements offer the best option for meshing more realistic geometry. A mesh has to be sufficiently fine especially in the contact region to predict mesh-independent unstable vibration modes. Regarding the vibration response, only the direct, steady-state method with a pressurised pad and finite sliding formulation (allowing contact separation) should be used. Comparison of different numerical methods suggest that a obroadband fast multi-pole boundary element method with the Burton-Miller formulation would efficiently solve the acoustic radiation of a full brake system. Results also suggest that a pad lift-off can amplify the acoustic radiation similar to a horn effect. A horn effect is also observed for chamfered pads which are used in practice to reduce the number and strength of unstable vibration modes. These results highlight the importance of optimising the pad shape to reduce acoustic radiation of unstable vibration modes.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  13. Hydraulic manipulator research at ORNL

    SciTech Connect

    Kress, R.L.; Jansen, J.F.; Love, L.J.

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  14. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    SciTech Connect

    Lascurain, Mary Beth; Capps, Gary J; Franzese, Oscar

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data revealed a linear relationship between brake application pressure and was used to develop an algorithm to normalize stopping data for weight and initial speed.

  15. Remotely Adjustable Hydraulic Pump

    NASA Technical Reports Server (NTRS)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  16. Independent Orbiter Assessment (IOA): Analysis of the hydraulics/water spray boiler subsystem

    NASA Technical Reports Server (NTRS)

    Duval, J. D.; Davidson, W. R.; Parkman, William E.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. This report documents the independent analysis results for the Orbiter Hydraulics/Water Spray Boiler Subsystem. The hydraulic system provides hydraulic power to gimbal the main engines, actuate the main engine propellant control valves, move the aerodynamic flight control surfaces, lower the landing gear, apply wheel brakes, steer the nosewheel, and dampen the external tank (ET) separation. Each hydraulic system has an associated water spray boiler which is used to cool the hydraulic fluid and APU lubricating oil. The IOA analysis process utilized available HYD/WSB hardware drawings, schematics and documents for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 430 failure modes analyzed, 166 were determined to be PCIs.

  17. Anharmonic oscillatory flow braking in the Earth's magnetotail

    NASA Astrophysics Data System (ADS)

    Panov, E. V.; Wolf, R. A.; Kubyshkina, M. V.; Nakamura, R.; Baumjohann, W.

    2015-05-01

    Plasma sheet bursty bulk flows often oscillate around their equilibrium position at about 10 RE downtail. The radial magnetic field, pressure, and flux tube volume profiles usually behave differently earthward and tailward of this position. Using data from five Time History of Events and Macroscale Interactions during Substorms (THEMIS) probes, we reconstruct these profiles with the help of an empirical model and apply thin filament theory to show that the oscillatory flow braking can occur in an asymmetric potential. Thus, the thin filament oscillations appear to be anharmonic, with a power spectrum exhibiting peaks at both the fundamental frequency and the first harmonic. Such anharmonic oscillatory braking can explain the presence of the first harmonic in Pi2 pulsations (frequency doubling), which are simultaneously observed by magnetometers on the ground near the conjugate THEMIS footprints.

  18. Plasma Jet Braking: Energy Dissipation and Nonadiabatic Electrons

    SciTech Connect

    Khotyaintsev, Yu. V.; Cully, C. M.; Vaivads, A.; Andre, M.; Owen, C. J.

    2011-04-22

    We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the electron temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of electrons and isotropization of the electron distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the electron dynamics and thus play an important role in the energy conversion chain during plasma jet braking.

  19. Plasma jet braking: energy dissipation and nonadiabatic electrons.

    PubMed

    Khotyaintsev, Yu V; Cully, C M; Vaivads, A; André, M; Owen, C J

    2011-04-22

    We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the electron temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of electrons and isotropization of the electron distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the electron dynamics and thus play an important role in the energy conversion chain during plasma jet braking. PMID:21599373

  20. Bohmian quantization of the big-brake singularity

    NASA Astrophysics Data System (ADS)

    Pinto-Neto, Nelson; Pantoja, Diego Moraes

    2014-04-01

    The aim of this paper is to study the quantum aspects of the big-brake singularity. This is a singularity where the expansion of the universe stops abruptly, with infinity deceleration, caused by the divergence of the pressure of the fluid which describes the matter content of the model. In order to obtain our results, we interpret the quantum solutions of the Wheeler-DeWitt equation obtained from the canonical quantization of the classical model using the de Broglie-Bohm (dBB) quantum theory. Analyzing the Bohmian trajectories, we show that when one approaches the big-brake singularity, the universe still stops expanding, but now with finite deceleration, and initiates a smooth contracting phase. The pressure and the curvature never diverge.

  1. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    E-print Network

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  2. Heat generation in aircraft tires under braked rolling conditions

    NASA Technical Reports Server (NTRS)

    Clark, S. K.; Dodge, R. N.

    1984-01-01

    An analytical model was developed to approximate the internal temperature distribution in an aircraft tire operating under conditions of unyawed braked rolling. The model employs an array of elements to represent the tire cross section and considers the heat generated within the tire to be caused by the change in strain energy associated with cyclic tire deflection. The additional heating due to tire slip and stresses induced by braking are superimposed on the previously developed free rolling model. An extensive experimental program was conducted to verify temperatures predicted from the analytical model. Data from these tests were compared with calculations over a range of operating conditions. The model results were in reasonably good agreement with measured values.

  3. Thermal design of AOTV heatshields for a conical drag brake

    NASA Technical Reports Server (NTRS)

    Pitts, W. C.; Murbach, M. S.

    1985-01-01

    Results are presented from an on-going study of the thermal performance of thermal protection systems for a conical drag brake type AOTV. Three types of heatshield are considered: rigid ceramic insulation, flexible ceramic blankets, and ceramic cloths. The results for the rigid insulation apply to other types of AOTV as well. Charts are presented in parametric form so that they may be applied to a variety of missions and vehicle configurations. The parameters considered include: braking maneuver heat flux and total heat load, heatshield material and thickness, heatshield thermal mass and conductivity, absorptivity and emissivity of surfaces, thermal mass of support structure, and radiation transmission through thin heatshields. Results of temperature calculations presented show trends with and sensitivities to these parameters. The emphasis is on providing information that will be useful in estimating the minimum required mass of these heatshield materials.

  4. Analytical Investigation on Squeal Phenomena Generated in Bicycle Disc Brakes

    NASA Astrophysics Data System (ADS)

    Nakae, Takashi; Sueoka, Atsuo; Ryu, Takahiro

    The squeal phenomenon is often generated in bicycle disc brakes. This paper deals analytically with the generation mechanism and the criterion of whether or not the squeal occurs. According to the experimental studies, it has been made clear that the squeal is mainly in-plane vibration in the direction of disc surface with the frequency about 1kHz caused by frictional characteristics with negative slope with respect to the relative velocity. An analytical model of the bicycle disc brake system has been devised to confirm the experimental results, in which a coupled in-plane and out-of-plane vibrating system is composed of the disc, hub, caliper and spokes. The resulting frequency of squeal and the unstable vibration modes of the disc and spokes from the analytical model agreed well with the experimental results.

  5. Stellar dynamo driven wind braking versus disc coupling

    NASA Astrophysics Data System (ADS)

    von Rekowski, B.; Brandenburg, A.

    2006-01-01

    Star-disc coupling is considered in numerical models where the stellar field is not an imposed perfect dipole, but instead a more irregular self-adjusting dynamo-generated field. Using axisymmetric simulations of the hydromagnetic mean-field equations, it is shown that the resulting stellar field configuration is more complex, but significantly better suited for driving a stellar wind. In agreement with recent findings by a number of people, star-disc coupling is less efficient in braking the star than previously thought. Moreover, stellar wind braking becomes equally important. In contrast to a perfect stellar dipole field, dynamo-generated stellar fields favor field-aligned accretion with considerably higher velocity at low latitudes, where the field is weaker and originating in the disc. Accretion is no longer nearly periodic (as it is in the case of a stellar dipole), but it is more irregular and episodic.

  6. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    PubMed

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level. PMID:18665198

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

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

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

  8. Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems

    SciTech Connect

    Peter J. Blau

    2000-04-26

    This document was prepared to support the primary goals of the Department of Energy, Office of Heavy Vehicle Technologies. These were recently stated as follows: ''Develop by 2004 the enabling technologies for a class 7-8 truck with a fuel efficiency of 10 mpg (at 65 mph) which will meet prevailing emission standards. For Class 3-6 trucks operating on an urban driving cycle, develop by 2004 commercially viable vehicles that achieve at least double the fuel economy of comparable current vehicles (1999), and as a research goal, reduce criteria pollutants to 30% below EPA standards. Develop by 2004 the diesel engine enabling technologies to support large-scale industry dieselization of Class 1 and 2 trucks, achieving a 35 % fuel efficiency improvement over comparable gasoline-fueled trucks, while meeting applicable emissions standards.'' The enabling technologies for improving the fuel efficiency of trucks, include not only engine technologies but also technologies involved with lowering the rolling resistance of tires, reducing vehicle aerodynamic drag, improving thermal management, and reducing parasitic frictional losses in drive train components. Opportunities also exist for making better use of the energy that might ordinarily be dissipated during vehicle braking. Braking systems must be included in this evaluation since safety in truck operations is vital, and braking requirements are greater for vehicles having lowered resistance to rolling. The Office of Heavy Vehicle Technologies has initiated a program to improve the aerodynamics of heavy vehicles through wind tunnel testing, computational modeling, and on-road evaluations. That activity is described in a separate multi-year plan; therefore, emphasis in this document will be on tires, drive trains, and braking systems. Recent, dramatic fluctuations in diesel fuel prices have emphasized the importance of effecting savings in truck fuel economy by implementing new component designs and materials.

  9. Evaluation of asbestos exposure during brake repair and replacement.

    PubMed

    Kakooei, Hossein; Hormozy, Maryam; Marioryad, Hossein

    2011-01-01

    Occupational exposure to asbestos fiber of brake repair job (auto mechanics) has seldom been evaluated in Iran. Accordingly, we evaluated asbestos fiber concentrations in the breathing zone of auto mechanics between July 2008 and December 2008. The asbestos fiber concentrations of 60 personal air samples collected from 30 cars and trucks brake replacement and they were analyzed by phase-contrast optical microscopy (PCM) and scanning electron microscopy (SEM) by energy-dispersive X-ray analysis. The geometric means of the personal monitoring fiber concentrations were 0.92 PCM f/ml and 0.46 PCM f/ml respectively in car and passenger heavy truck auto shops. There was a significant differences in the asbestos fiber concentrations between the car and truck auto shops (p=0.006). Based on these findings, auto mechanics who worked with asbestos containing brake may have been exposed to asbestos concentrations approximately 7 times higher than the current occupational safety and health agency (OSHA) permissible exposure limit (PEL) of 0.1 f/ml. Fiber morphology and energy dispersive X-ray analysis by SEM revealed that amphibole fibers such as tremolite and actinolite existed in the brakes dust and that the vast majority (>30%) of the airborne chrysotile fibers were greater than 1 ?m in diameter. It can be concluded that the imported chrysotile asbestos contains trace amounts of tremolite and actinolite fibers and they are responsible for the high airborne asbestos levels and occupational exposure to amphibole asbestos in auto mechanics job in Iran. Thus, it is to be expected that the auto mechanics will suffer negative health effects due to exposure to the serpentine and amphibole asbestos fibers. PMID:21372435

  10. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or four-wheel pole trailer (laden or unladen) with a gross weight of 1,361 kg (3,000 pounds) or less... semitrailer or pole trailer (laden or unladen) with a gross weight of 1,361 kg (3,000 pounds) or less which is subject to this part is not required to be equipped with brakes if the axle weight of the towed...

  11. Nonlinear transient and chaotic interactions in disc brake squeal

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    In automotive disc-brake squeal, most numerical studies have been focussed on the prediction of unstable vibration modes in the frequency domain using the complex eigenvalue analysis. However, the magnitude of the positive real part of a complex eigenvalue is an unreliable indicator of squeal occurrence. Although nonlinearities have been shown to play a significant role in brake squeal, transient nonlinear time domain analyses have rarely been applied owing to high computational costs. Here the complex eigenvalue analysis, the direct steady-state analysis and the transient nonlinear time domain analysis are applied to an isotropic pad-on-disc finite element model representing a simple model of a brake system. While in this investigation, in-plane pad-mode instabilities are not detected by the complex eigenvalue analysis, the dissipated energy obtained by the direct steady-state analysis of the model subjected to harmonic contact pressure excitation is negative at frequencies of pad modes, indicating a potential for instabilities. Transient nonlinear time domain analysis of the pad and disc dynamics reveal that in-plane pad vibrations excite a dominant out-of-plane disc mode. For intermittently chaotic pad motion, the disc dynamics is quasi-periodic; and for chaotic motion of the pad, a toroidal attractor is found for the disc's out-of-plane motion. Nonlinear interactions between the pad and the disc highlight that different parts in a brake system display different dynamic behaviour and need to be analysed separately. The type II intermittency route to chaos could be the cause for the experimentally observed instantaneous mode squeal.

  12. Simulation study of the plasma-brake effect

    NASA Astrophysics Data System (ADS)

    Janhunen, P.

    2014-10-01

    Plasma brake is a thin, negatively biased tether that has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma-brake tether by a high-performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic-field orientation and plasma-ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar (i.e. smooth and not turbulent) when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case in which the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also correct an error in an earlier reference. According to the simulations, the predicted thrust of the plasma brake is large enough to make the method promising for low-Earth-orbit (LEO) satellite deorbiting. As a numerical example, we estimate that a 5 km long plasma-brake tether weighing 0.055 kg could produce 0.43 mN breaking force, which is enough to reduce the orbital altitude of a 260 kg object mass by 100 km over 1 year.

  13. Carbon nanotube torsional springs for regenerative braking systems

    NASA Astrophysics Data System (ADS)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9?kJ?kg-1??±??1.2?kJ?kg-1 and 3.4?kJ?kg-1??±??0.4?kJ?kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3?kJ?kg-1 and 0.67?kW?kg-1, respectively, with maximum measured values of up to 4.7?kJ?kg-1 and 1.2?kW?kg-1, respectively. A slightly lower energy density of up to 1.2?kJ?kg-1 and a 0.29?kW?kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  14. Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit

    NASA Astrophysics Data System (ADS)

    Mellon, Richard R.; Li, Zhi-Yun

    2008-07-01

    Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (?<~1). We show that, in disk formation, the requirement is far less stringent. This conclusion is drawn from a set of 2D (axisymmetric) simulations of the collapse of rotating, singular isothermal cores magnetized to different degrees. We find that a weak field corresponding to ?~100 can begin to disrupt the rotationally supported disk through magnetic braking, by creating regions of rapid, supersonic collapse in the disk. These regions are separated by one or more centrifugal barriers, where the rapid infall is temporarily halted. The number of centrifugal barriers increases with the mass-to-flux ratio ?. When ?>~100, they merge together to form a more or less contiguous, rotationally supported disk. Even though the magnetic field in such a case is extremely weak on the scale of dense cores, it is amplified by collapse and differential rotation, to the extent that its pressure dominates the thermal pressure in both the disk and its surrounding region. For relatively strongly magnetized cores with ?<~10, the disk formation is suppressed completely, as found previously. A new feature is that the mass accretion is highly episodic, due to reconnection of the magnetic field lines accumulated near the center. For rotationally supported disks to appear during the protostellar mass accretion phase of star formation in dense cores with realistic field strengths, the powerful magnetic brake must be weakened, perhaps through nonideal MHD effects. Another possibility is to remove, through protostellar winds, the material that acts to brake the disk rotation. We discuss the possibility of observing a generic product of the magnetic braking, an extended circumstellar region that is supported by a combination of toroidal magnetic field and rotation-a ``magnetogyrosphere''-interferometrically.

  15. The method of feed-in energy on disc brake squeal

    NASA Astrophysics Data System (ADS)

    Guan, Dihua; Huang, Jinchun

    2003-03-01

    Brake squeal is studied in this paper by feed-in energy analysis. Based on the brake closed-loop coupling model, a calculation method of feed-in energy for squeal mode is derived. Result of the feed-in energy indicates squeal tendency of the brake system, while formula for calculating it discloses the relation among brake squeal phenomenon and structural parameters, such as frictional coefficient, geometric shape of brake pads, elastic modulus of frictional material, substructure modal shape, etc. The method also helps to analyze the effectiveness of various structural modification schemes attempted to eliminate the squeal noise. Finally, this method is illustrated by application to a typical squealing disc brake.

  16. Computational Fluid Dynamics (CFD) investigation onto passenger car disk brake design

    NASA Astrophysics Data System (ADS)

    Munisamy, Kannan M.; Kanasan Moorthy, Shangkari K.

    2013-06-01

    The aim of this study is to investigate the flow and heat transfer in ventilated disc brakes using Computational Fluid Dynamics (CFD). NACA Series blade is designed for ventilated disc brake and the cooling characteristic is compared to the baseline design. The ventilated disc brakes are simulated using commercial CFD software FLUENTTM using simulation configuration that was obtained from experiment data. The NACA Series blade design shows improvements in Nusselt number compared to baseline design.

  17. Emission Factor for Antimony in Brake Abrasion Dusts as One of the

    E-print Network

    Short, Daniel

    / braking/car for PM2.5. These essential data will contribute to the modeling of atmospheric Sb and weighed. From the experimental data, dust emission could be regressed as a function of the initial kinetic) were calculated as 5.8 mg/braking/car for PM10 and 3.9 mg/braking/car for PM2.5. The elemental

  18. Fluid Power/Basic Hydraulics. Instructor's Guide.

    ERIC Educational Resources Information Center

    Stanbery, Richard

    This guide is designed to assist industrial vocational instructors in teaching a course on fluid power and basic hydraulics. Covered in the unit on the basics of fluid power and hydraulics are the following topics: the fundamentals of fluid power and hydraulics, basic hydraulic circuits, and servicing a hydraulic jack. The second unit, consisting…

  19. Hydraulic mining method

    DOEpatents

    Huffman, Lester H. (Kent, WA); Knoke, Gerald S. (Kent, WA)

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  20. Driving/Braking Force Distribution of Four Wheel Vehicle by Quadratic Programming with Constraints

    NASA Astrophysics Data System (ADS)

    Ikeda, Yuichi; Suzuki, Ryo; Chida, Yuichi

    This paper proposes a yaw rate tracking control method that distributes the driving/ braking force exerted on vehicles at the time of negotiating sharp turns and driving at high speeds. The proposed method employs quadratic programming to distribute the driving/braking force in order to equalize the tire load factor on all wheels and consider the limits of the driving/braking force. The yaw rate tracking performance can be improved even while driving at high speeds and negotiating sharp turns by setting limits for the driving/braking force, differential moment, etc. The effectiveness of our proposed method is proven by a numerical simulation.