Transmission is the mechanism which is used to transfer the power developed by engine to the wheels of an automobile. The transmission system of an automobile includes clutch, gear box, propeller shaft axle and wheels, etc.
The term ‘Transmission’ is used for a device which is located between clutch and propeller shaft. It may be a gear box, an over drive or a torque converter, etc.
- Clutch is used to engage or disengage the engine to the transmission or gear box.
- When the clutch is in engaged position, the engine power or rotary motion of engine crankshaft is transmitted to gear box and then to wheels.
- When clutch is disengaged, the engine power does not reach to gear box (and to wheels) although engine is running.
- Clutch is also used to allow shifting or changing of gears when vehicle is running.
- For shifting gears, clutch is first disengaged then gear is shifted and then clutch is engaged.
- Clutch has to be disengaged to stop the vehicle and also at the time of idling.
Principle of the clutch:
It operates on the principle of friction.
- When two surfaces are brought in contact and are held against each other due to friction between them, they can be used to transmit power.
- If one is rotated, then other also rotates.
- One surface is connected to engine and other to the transmission system of automobile
- Thus, clutch is nothing but a combination of two friction surfaces.