|this article treats the construction unit for speed decrease. For the insect of the same name, see brakes.|
Brakes serve for the decrease and/or. Delimitation of the speed of moved machine parts or vehicles. They mostly function by the transformation of the supplied kinetic energy over friction in heat energy. Brakes are related as mechanical component closely to clutches, which are brake a special clutch, with which a side is certain. To that extent many brake types can be derived from clutches.
By far the kinds of brake most frequently used in vehicles are thoseKlotzbremse, disc brake and the drum brake. Usually a brake is used for the decrease of the rotational speed by rotary parts. But many of the aforementioned principles one can use linear movements also for the reduction, even if the building methods differ somewhat.
Partiallyalso the kind of the manipulation of the brake is used for categorization. However for example the designation compressed air brake or hydraulic brake states nothing over the design, but indicates only kind of the power transmission to the mechanical placing elements.
Table of contents
- the block brake is a mechanical brake, with some turning cylinder from the outside throughpressed in slightly brake linings one brakes. A very simple execution is the Klotzbremse. With their only one brake wedge is used. It presses partly directly on the bearing surface of the Rades which can be braked.
- The hindrance represents a primitve form of the Klotzbremse.
- Those Drum brake has a cylindric circulating housing (drum), to which when braking interior or external, being certain brake shoes are pressed. The manipulation of the brake shoes is made usually by means of hydraulic cylinders within the drum or by turning Exzenterbolzen from the outside. Depending upon constructionfurther designs differentiated between
- the disc brake exhibits a brake disk running along on the wave , to which brake linings are pressed reciprocally on the disk.
Brake test stand. Before one in-drives into the roles, one convinces oneself whether the tires the prescribedAnd in which condition they have air pressure to be. Since also the profile enters also brake measurement, all wheels should have the same profile. One drives with the front wheels into the test stand roles in such a way inside that the vehicle: 1. perpendicularlyto the pairs of roles stands. 2. in the center of the test stand roles stands. If the vehicle is located exactly perpendicularly to the test stand in the roles and the toe-in positively or zero are, the vehicle may not constantly oscillate hin-und, it must without contactthe steering wheel straight run out. If it does not do that, then the trace is not correctly adjusted. Next one examines Höhen-und of lateral run outs of the wheels. With Höhen-und lateral run outs over 2mm, the vehicle visibly moves in the rhythm of the wheel number of revolutions up andoff, or forwards and back. Then one operates the brake pedal, until the first pointer of the two indicators indicates 1000N braking force. One holds the pedal in this position and examines: 1. whether the pointers during the wheel circulation vary. 2. whetherat the other pointer the announcement is equivalent high. If the announcement varies over plus minus 100N (thus around 200N altogether) or more, then the brake disks have impact, or the brake drums are out of round. With the service brake the announcement between right may deviate and left according to regulation by 25% from the maximum value. With the parking brake the deviation may amount to 50%. The proportional deceleration is legally prescribed and must amount to with the passenger car for the service brake at least 50%. For the parking brake at least 16%. The decelerationone computes: Hums all braking force in N, multiplied with 100%, divide by the vehicle weight in N.
- Band brake is likewise a mechanicalBrake, with which however contrary to the block brake a volume is bolted around a drum.
- With magnet slipper brakes a brake wedge is pressed by magnetic field strength on the rail, on which the vehicle drives.
- Fliehkraftbremsen do not serve usually directly a strongDecrease of the number of revolutions, but the delimitation the same. They function according to the same principle as centrifugal clutches. A usual application is the delimitation of the back rotating speed with dial telephones, the dial in such a way specified.
- Gleisbremsen are for example inserted on marshalling yards in the track body.
- the eddy current brake use the eddy current - effect. With their an electrically conductive material (usually a metal disk) is moved by a magnetic field. In the material electrical eddy currents are induced. These produce for their part a magnetic field, for the producingField works against. The disk is braked thereby.
- With a brake by electric motors the driving motor is used with the deceleration as generator.
- With Widerstandsbremsen the river over electrical of resistances produced by the generator is converted into warmth. With modern generator brakes of this design energy becomesback into electricity mains (rail-mounted vehicles), and/or. an energy storage (electric road vehicle) fed. This procedure is called also recuperation.
- The multiple-plate brake is a wear-free disk brake. It consists of several disks (at least 2, a turning and a being certain) one behind the other on an axlelie and drehfest with the firm and/or. are connected for the rotary part. (CAD model of a multiple-plate brake:)
- of a liquid (oil) uses hydrodynamic brakes, fluid brakes a Retarder, in order to slow the rotating motion down of a wave. The Retarder workswear-free and therefore often as continuous brake in LKWs or penalties one uses. With the latters also, because it can be regulated in its delay achievement almost gradate-free, thus without jerking.
- With high-speed vehicles, in particular air and space travel, brake screens and airs brake are usedin order to increase air resistance and reduce the speed. With the new Mercedes Benz SLR McLaren with a strong delay of the tail spoilers around 65 degrees employed over by an eddy an cw-increase in value and so a better delay and a higherTail contact pressure to reach (see also airbrake).
the exhaust brake marks the use of the internal resistance of the running along drive engine and the drive strand. Particularly with truck and motorbuses there is additionally the system engine rope brake.
with certain course vehicles (for example steam engines with Riggenbach counter-pressure brake), airplanes and ships is switched or returned for braking the drive into the opposite direction. With airplanes this is called thrust reversing.
brakes after application
- over-run brakes
- To brake (railway)
- brake (motor vehicle)
- continuous brake
- bicycle brake
- parking brake
- stop brake
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|Wiktionary: Brake - word origin, synonyms and translations|