Braking Systems

Definition This is a device which is used to slow something down or bring to a standstill, achieved by contact friction. Brakes are commonly associated with motor vehicles. With a motor vehicle, this is usually achieved by applying pressure to a pedal. The force is then transferred to a set of pads and disks or shoes and drums. The power transfer usually takes place via a hydraulic process using a slave cylinder, a master cylinder and a series of pipeline through which the active medium brake fluid (likened to a type of hydraulic oil) Brakes can also be activated by using a cable type system, but the hydraulic method is the most common and reliable method.

Automobile Pad and Disk Braking System This system comprises of a set of 2 pads which operate around a disk. As the pressure is applied to the brake pedal inside the car, the master cylinder gets pressurised & sends the brake fluid through system of pipework to the slave cylinder, which in turn activates the motion through to the brake callipers and the brake pads, which clamp around the brake disk. All of this will either slow the vehicle down or to a complete sudden stop. The material that the brake pads are made from have be an abrasion and heat resistant material (semi metallic, organic or ceramic)

Pad and Disk Brake System Action The following animation will show how a simple Pad and Disk braking system actually works. https://www.youtube.com/watch?v=F4fAPpj3p48

Automobile Shoe and Drum Braking System This system works identically to the pad and disk braking system but employs a pair of shoes which fit inside a mechanism called a drum. The same action takes place where the pressure is applied to the brake pedal inside the car, the master cylinder gets pressurised & sends the brake fluid through system of pipework to the slave cylinder, which in turn activates the motion through to the brake shoe assembly inside the drum (the shoes open outward when the brake pedal is applied) Brake shoe material, much like a brake pad is made from an abrasion and heat resistant material.

Shoe and Drum Brake System Action The following animation will show how a simple Shoe and Drum braking system actually works. https://www.youtube.com/watch?v=bnc3VnQ8kUY

Electromagnetic Brake This video clip shows you how this works by lifting the chuck guard. Once the guard is lifted, the brake is electrically energised to safely bring the chuck to a halt. http://www.youtube.com/watch?v=o-wjv82appY These are also used to bring a train or an electric motor to a halt.

Electromagnetic Brake

Bicycle Braking System On a bicycle, this simplest form of braking is used, known as rim brakes. This employs brake levers and shoes on a calliper, the action is transferred via the use of a cable. This method has been used on bicycles for many years. http://www.youtube.com/watch?v=swfTwtFcHpg

Air Brake Rather than hydraulic oil / brake fluid or electricity, air is used to power a braking system. Listen out for the compressed air vented once the vehicle has stopped. http://www.youtube.com/watch?v=Pl1UMfxa_r4 The air brake system in lorries has moved from drum to disk

Brake Type Analysis Disk Brakes These brakes are more effective in providing a stopping action, are easier to work on when changing the worn brake pads and this system can be used across a multitude of vehicles. The disks can suffer from excessive corrosion or warping. Drum Brakes These have the advantages of being self contained and inexpensive when compared with other types of brakes used on an automobile. Disadvantages include can be prone to an unsmooth action called grabbing when the drum is corroded and the complexity of the system within the drum, this can pose problems when carrying out maintenance / changing brake shoes.

Brake Type Analysis Rim / Bicycle Brakes These type are simple, inexpensive, easy to maintain. The drawback with these they become less efficient when becoming wet and can become clogged with debris from road surfaces. Hydraulic Braking System With this system, it uses an incompressible fluid which is able to be more efficient & consistent with work or power output. Any leaks from the system are easy to detect. Brake fluid itself is susceptible to contamination which will reduce the efficiency, as would any air within the fluid which would manifest itself in giving a spongy sensation when applying the brake pedal.