File Name: different types of brakes and their applications .zip
An air brake or, more formally, a compressed air brake system , is a type of friction brake for vehicles in which compressed air pressing on a piston is used to apply the pressure to the brake pad needed to stop the vehicle.
Air brakes are used in large heavy vehicles, particularly those having multiple trailers which must be linked into the brake system, such as trucks , buses , trailers , and semi-trailers , in addition to their use in railroad trains. George Westinghouse first developed air brakes for use in railway service. In the early 20th century, after its advantages were proven in railway use, it was adopted by manufacturers of trucks and heavy road vehicles.
Air brakes are typically used on heavy trucks and buses. The system consists of service brakes, parking brakes, a control pedal, and an air storage tank. For the parking brake, there is a disc or drum arrangement which is designed to be held in the 'applied' position by spring pressure. Air pressure must be produced to release these "spring brake" parking brakes.
Most types of truck air brakes are drum brakes, though there is an increasing trend towards the use of disc brakes. Most heavy vehicles have a gauge within the driver's view, indicating the availability of air pressure for safe vehicle operation, often including warning tones or lights.
A mechanical " wig wag " that automatically drops down into the driver's field of vision when the pressure drops below a certain point is also common. A sudden loss of air pressure would result in full spring brake pressure immediately.
A compressed air brake system is divided into a supply system and a control system. The supply system compresses, stores and supplies high-pressure air to the control system as well as to additional air operated auxiliary truck systems gearbox shift control, clutch pedal air assistance servo , etc. The air compressor is driven by the engine either by crankshaft pulley via a belt or directly from the engine timing gears.
It is lubricated and cooled by the engine lubrication and cooling systems. Compressed air is first routed through a cooling coil and into an air dryer which removes moisture and oil impurities and also may include a pressure regulator , safety valve and smaller purge reservoir. As an alternative to the air dryer, the supply system can be equipped with an anti-freeze device and oil separator. The system also includes various check , pressure limiting , drain and safety valves.
Air brake systems may include a wig wag device which deploys to warn the driver if the system air pressure drops too low. This device drops a mechanical arm into view when the pressure in the system drops below the threshold of sufficient pressure to reliably deploy the brakes. An automatic wig wag will rise out of view when the pressure in the system rises above the threshold. The manual-reset type must be placed in the out-of-view position manually.
Neither will stay in place unless the pressure in the system is above the threshold. The photo to the left shows a manual wig wag which the operator swings to the right out of view when the air pressure is above the threshold where it will remain as long as the pressure is sufficient.
Most U. The control system is further divided into two service brake circuits, the parking brake circuit, and the trailer brake circuit. The dual service brake circuits are further split into front and rear wheel circuits which receive compressed air from their individual reservoirs for added safety in case of an air leak.
The service brakes are applied by means of a brake pedal air valve which regulates both circuits. The parking brake is the air operated spring brake type where its applied by spring force in the spring brake cylinder and released by compressed air via a hand control valve. The trailer brake consists of a direct two line system: the supply line marked red and the separate control or service line marked blue.
The supply line receives air from the prime mover park brake air tank via a park brake relay valve and the control line is regulated via the trailer brake relay valve. The operating signals for the relay are provided by the prime mover brake pedal air valve, trailer service brake hand control subject to local heavy vehicle legislation and the prime mover park brake hand control.
Air brakes are used as an alternative to hydraulic brakes which are used on lighter vehicles such as automobiles. Hydraulic brakes use a liquid hydraulic fluid to transfer pressure from the brake pedal to the brake shoe to stop the vehicle.
Air brakes are used in heavy commercial vehicles due to their reliability. They have several advantages for large multi-trailer vehicles: . From Wikipedia, the free encyclopedia. Not to be confused with Air brake aeronautics. This article includes a list of general references , but it remains largely unverified because it lacks sufficient corresponding inline citations. Please help to improve this article by introducing more precise citations. February Learn how and when to remove this template message.
Retrieved December 4, Heavy Duty Truck Systems, 5th Ed. USA: Cengage Learning. Railway brakes. Brake van Diesel brake tender Diesel electric locomotive dynamic braking Electronically controlled pneumatic brakes Electro-pneumatic brake system on British railway trains Emergency brake train Retarder Dowty retarders.
Categories : Vehicle braking technologies. Hidden categories: All articles with dead external links Articles with dead external links from March Articles lacking in-text citations from February All articles lacking in-text citations. Namespaces Article Talk. Views Read Edit View history. Help Learn to edit Community portal Recent changes Upload file. Download as PDF Printable version. Wikimedia Commons.
They are not only used to stop a moving system but also to prevent motion of any part of a particular system. Human applies force F via pedals but is not enough to produce the braking torque. More the lever distance, less the human effort! This is important while designing ergonomics of the vehicle! Another version of these brakes contain 2 shoes on the opposite side to increase the braking torque. Such types are called Pivoted type double shoe brake. They are widely used in trains even now.
A hydraulic brake is an arrangement of braking mechanism which uses brake fluid , typically containing glycol ethers or diethylene glycol , to transfer pressure from the controlling mechanism to the braking mechanism. In , Ernest Walter Weight of Bristol, England devised and fitted a four-wheel hydraulic oil braking system to a motor car. The company, which had a factory at Luckwell Lane, Bristol, installed a four-wheel hydraulic braking system on a Metallurgique chassis, fitted with a Hill and Boll body, which was exhibited at the November London Motor Show. Although more cars had the brake system installed and the company advertised heavily, it disappeared without achieving the success it deserved.
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.
Most brakes use friction on the two sides of the wheel, the collective press on the wheel converts the kinetic energy of the moving object into heat. For example, regenerative braking turns much of the energy to electrical energy, which may be stored for later use. Eddy current brakes use magnetic fields to turn kinetic energy into electrical current in the brake disc, blade, or rail, which is converted into heat. The following are the most common types of braking systems in modern cars. This system runs on brake fluid, cylinders, and friction.
Your email address will not be published. Required fields are marked *