A brake is a mechanical device used to slow down or stop a moving vehicle or machine system. The brake prevents motion by applying friction. The brake absorbs energy from the moving system causing gradual halt of the system.
There are different types of brakes. Though different braking methods are used, they work on the common principle of friction. The force that prevents free motion of solid surfaces, fluids or other materials against each other is defined as friction. In friction, one form of energy is converted to another form of energy. Braking system converts kinetic energy to other forms of energy like electric energy, heat, potential energy etc. Breaks or combination of brakes are used in automobiles, trains, airplanes, mechanical systems, electrical equipment and machines.
Brakes use friction, electromagnetic or pumping or combination of these three to cause halt. Braking system that converts kinetic energy to electrical energy is known as regenerative braking. In eddy breaking system magnetic fields are applied to convert kinetic energy to electrical energy. In pumping brakes, fluid is used to create friction.
The most common brake is friction brake and there are two major types for this category, shoe or pad and drum. In the brake shoe, brake lining is pasted to the shoe. On applying brake, shoe moves and presses the lining against the drum. The friction cased between lining and drum slows down movement and resultant energy is dissipated as heat. Brakes overheat and wear out faster. In drum brake shoes press on the inner surface of the drum. The brakes used in bicycles are of this category. If the shoes press on the outside of the drum, it is termed clasp brake. This braking system was used in old models of trucks and cars.
Pumping brakes are useful when pumps are part of machinery. In this type, pressing the brake pedal will push hydraulic fluid to each wheel to create friction. Similarly, electromagnetic brakes are applied when electric motor is a part of machinery. They are magnetically driven friction brakes. By application of magnets, friction is created. This type of brakes slows down a moving system through electromagnetic induction to create resistance. The kinetic energy is converted to heat energy or electrical energy.
Based on the purposes too brakes are classified. The brakes which are used to bring moving vehicle to halt is commonly mentioned as service brake. Emergency or parking brakes comes under secondary braking systems. These brakes are used to have added security while remaining parked, to keep a vehicle stationery while parked. Anti-Lock brake system (ABS) is a computer controlled safety measure. It is used in modern vehicles. This mechanism prevents locking up of wheels and skidding. What is an Automatic Braking System?