There are several additional components that are involved to ensure car brakes operate smooth on different road conditions and circumstances. Car accidents often happen due to poor braking systems. The more you know about these crucial systems, the better.
The brake is one of the most important controlling components of ANY vehicle. We have heard about drum brake and disk brakes (which you can read more about here LINK)). Drum brakes are widely used in the automobile industry; the brakes are required to stop the vehicle within the smallest possible distance or to slow down the vehicle when needed.
Without the brakes we cannot control the vehicle speed so it is the most important system in automobiles. All brakes work on the same principle of converting the kinetic energy of the vehicle into the heat energy, which is dissipated into the automobile.
There are many types of brakes available in the automobile industry. These are primary brakes, secondary brakes, vacuum brake, air brake, disk brake, drum brake etc. The classification of brakes is as follows:
This brake is used when the vehicle is running, to stop or slow down the vehicle. This is the main braking system, which is situated in both rear and front wheels of the vehicle.
Secondary brakes, which is also known as parking brake or emergency brake (read more about that here) , are used to keep the vehicle stationary. It is generally operated by hand, so also known as a hand brake. The main function of this brake is to keep the vehicle stationary when it is parked.
In this type of brakes a drum is attached to the axle hub whereas on the axle casing is mounted a back plate. The back plate is made of pressed steal sheet. It provides support for the expander, anchor and brake shoes. It also protects the drum and shoe assembly from mud and dust. It also known as the torque plate because it absorbed the complete torque reaction of the shoe. Two brake shoes are mounted on back plate with friction linings. On or two retractor spring are used to separate the brake shoe from drum when the brakes are not applied. The brake shoes are anchored at one end, whereas on the other ends force is applied by means of some brake actuating mechanism which forces the brake shoe against the revolving drum, so the friction force is generated between drum and the shoe and brake applied.
An adjuster is also provided to compensate for wear of friction lining with use. These brakes are widely used in motorcycle and the cars.
Disk brakes consist of a cast iron disc bolted to the wheel hub and a stationary housing called a calliper. The calliper is connected to some stationary part of the vehicle and it cast in two parts, each part containing a piston. In between each piston and the disc there is a friction pad held in position by retaining pins, springs plates etc. There are arrangements in the calliper for the fluid to enter or leave each housing. There passages are also connected to another one for bleeding. Each cylinder contains a rubber sealing ring between the cylinder and the piston.
When the brakes are applied, the hydraulically activated piston moves the friction pads into contact with the disc, applying equal and opposite forces on the later. On releasing the brakes, the rubber sealing rings act as return springs and retract the pistons and the friction pads away from the disc.
In these brakes, the brake force is applied mechanically used where we needed small force to braking. This brakes are used in the small vehicle such as in scooters, bikes etc., where only a small braking force is needed.
In the hydraulic brakes, brake force is applied by the hydraulic oil. It is one of the most useful and reliable braking system. These brakes are used in most passenger vehicles.
In this braking system, magnetic effect of electricity is used to apply the braking force. The braking piston and the disc are connected to the electricity. When we want to apply brakes, we start the electricity, which creates magnetic effect between brake pad and the disk; hence, the brake is applied.
In the air brakes, air pressure is used to generate the braking force. This braking system is used in heavy load vehicle i.e. trucks, bus etc.
These brakes used vacuum to apply the force on brake pads. This is the one of the most powerful braking systems available. This brake is used in exceptionally heavy duty vehicles, i.e. train, heavy ships etc.
Source credit: http://www.mech4study.com/2015/09/automobile-brakes-principle-and-types.html