WHAT IS A BRAKE OR BRAKING SYSTEM? Brake is an equipment used in automobiles (ormachines) to slow down the vehicle by changing thekinetic energy into heat energy. Brakes generally applyfriction to change the kinetic energy into heat energy. FUNCTIONS OF THE BRAKES: To stop or slow down a vehicle in the shortest possible distance in case of emergencies. To control the vehicle to be retained when descending a hill.
TYPES OF BRAKESA. WITH RESPECT TO THE BRAKE GEAR: (1) Mechanical Brakes (2) Power BrakesB. WITH RESPECT TO NATURE OF POWER EMPLOYED: (1) Vacuum Brakes (2) Pneumatic Brakes (3) Hydraulic Brakes (4) Hydrostatic Brakes (5) Electric Brakes
Based on the arrangement, MechanicalBrakes are divided into several types: (1) Band Brakes (2) Disc Brakes (3) Drum Brakes (4) Cone Brakes
DISK BRAKES• Caliper squeezes pads to create force on the surfaces of the rotor.• Used in most automotive applications.• Benefits: – Simple design – Self adjusting – Rotor venting allows faster heat dissipation
DRUM BRAKES• Expanding shoes create force on the inner surface of the drum.• Used on the rear of some trucks and SUV’s.• Self-energizing design requires less activation force.• Require periodic adjustment.
HYDRAULIC BRAKES The hydraulics brakes are applied by the liquid pressure.The Pedal force is transmitted to the brake shoe by means ofconfined liquid through a system of force transmission. The systemis based upon Pascal’s Principle.PARTS OF A HYDRAULIC BRAKE SYSTEM BRAKE PEDAL PUSH ROD MASTER CYLINDER WHEEL CYLINDER
PNEUMATIC (OR) AIR BRAKES An air brake is a conveyance braking system actuatedby compressed air. The system uses air pressure to charge air reservoirs(tanks) on the fitted on the system. Full air pressure signals torelease the brakes. A reduction or loss of air pressure signals toapply its brakes, using the compressed air in its reservoir. Generally heavy vehicles like trucks, buses, trailers usesAir Brake system. Modern Railway engines also uses Pneumaticor Air Brake System.
MAIN PARTS OF A PNEUMATIC BRAKING SYSTEM(1) COMPRESSOR: It draws air from the atmosphere and compresses it foruse.(2) MAIN RESERVOIR: Storage tank for compressed air and other pneumaticcomponents.(3) TRIPLE VALVE: (a) Recharges the auxiliary cylinder. (b) closes the brake cylinder exhaust and allows theauxiliary reservoir air to feed into the brake cylinder. (c) Maintain the air pressure inside the system at any leveldesired by the driver.(4) DRIVERS BRAKE VALVE: The means by which the driver controls thebrake.(5) FEED VALVE: To ensure the brake pressure remains at required level, aFeed Valve is connected between the reservoir and Brake Pipe. This valve isset to a operational pressure.
BLOCK LAYOUT OF A PNEUMATIC BREAK SYSTEM UNLOADER VALVEAIR-COMPRESSOR AIR TANK PRESSURE HOSE GAUGE BRAKE VALVE HAND CONTROL VALVE SLACK ADJUSTER BRAKE CHAMBER
SERVO BRAKE A brake in which the motion of the vehicle is used to increasethe pressure on one of the shoes. (OR) A brake in which the force applied by the operator isincreased by a power-driven mechanism.USES: For a heavy vehicle the force to be applied on the brake padby the operator is very high. Thus with the use of the powergenerated by the engine this force is increased and transmitted tothe wheels.