1. Frictional brakes are nearly mutual too tin hold upwards divided broadly into "shoe" or "pad" brakes, using an explicit habiliment surface, too hydrodynamic brakes, such every bit parachutes, which role friction inwards a working fluid too practise non explicitly wear. Typically the term "friction brake" is used to hateful pad/shoe brakes too excludes hydrodynamic brakes, fifty-fifty though hydrodynamic brakes role friction.
Friction (pad/shoe) brakes are oftentimes rotating devices amongst a stationary pad too a rotating habiliment surface. Common configurations include shoes that contract to rub on the exterior of a rotating drum, such every bit a band brake; a rotating drum amongst shoes that expand to rub the within of a drum, usually called a "drum brake", although other drum configurations are possible; too pads that pinch a rotating disc, usually called a "disc brake". Other brake configurations are used, but less often. For example, PCC trolley brakes include a apartment shoe which is clamped to the runway amongst an electromagnet; the Murphy brake pinches a rotating drum, too the Ausco Lambert disc brake uses a hollow disc (two parallel discs amongst a structural bridge) amongst shoes that sit down betwixt the disc surfaces too expand laterally.
Friction (pad/shoe) brakes are oftentimes rotating devices amongst a stationary pad too a rotating habiliment surface. Common configurations include shoes that contract to rub on the exterior of a rotating drum, such every bit a band brake; a rotating drum amongst shoes that expand to rub the within of a drum, usually called a "drum brake", although other drum configurations are possible; too pads that pinch a rotating disc, usually called a "disc brake". Other brake configurations are used, but less often. For example, PCC trolley brakes include a apartment shoe which is clamped to the runway amongst an electromagnet; the Murphy brake pinches a rotating drum, too the Ausco Lambert disc brake uses a hollow disc (two parallel discs amongst a structural bridge) amongst shoes that sit down betwixt the disc surfaces too expand laterally.
2. Pumping brakes are oftentimes used where a essence is already business office of the machinery. For example, an internal-combustion piston motor tin bring the fuel render stopped, too hence internal pumping losses of the engine practise unopen to braking. Some engines role a valve override called a Jake brake to greatly growth pumping losses. Pumping brakes tin dump unloose energy every bit heat, or tin hold upwards regenerative brakes that recharge a pressure level resevoir called a hydraulic accumulator.
3. Electromagnetic brakes are likewise oftentimes used where an electrical motor is already business office of the machinery. For example, many hybrid gasoline/electric vehicles role the electrical motor every bit a generator to accuse electrical batteries too likewise every bit a regenerative brake. Some diesel/electric railroad locomotives role the electrical motors to generate electricity which is hence sent to a resistor banking concern too dumped every bit heat. Some vehicles, such every bit unopen to transit buses, practise non already bring an electrical motor but role a secondary "retarder" brake that is effectively a generator amongst an internal short-circuit. Related types of such a brake are eddy electrical flow brakes, and electro-mechanical brakes (which genuinely are magnetically driven friction brakes, but demo are oftentimes merely called “electromagnetic brakes” every bit well).
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