Introduction to Clutch and Clutch Plate

Clutch

Clutch:

• A clutch is a mechanical device that engages and disengages the power transmission, especially from driving shaft to driven shaft.
• When the clutch is in engaged position, the rotary motion of engine crankshaft is transmitted to gear box and then wheels.
• When clutch is disengaged, the engine power does not reach to gear box although engine is running.
• Clutches are used whenever the transmission of power or motion must be controlled either in amount or over time (e.g., electric screwdrivers limit how much torque is transmitted through use of a clutch; clutches control whether automobiles transmit engine power to the wheels).

Principle of 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.

Main Parts of Clutch:

1. A Driving Member
2. A Driven Member
3. An Operating Member

Types of Clutch:

1. Friction Clutch: (i) Single Plate Clutch, (ii) Multi Plate Clutch, (iii) Cone Clutch
2. Centrifugal Clutch
3. Semi-centrifugal Clutch
4. Hydraulic Clutch
5. Positive Clutch
6. Vacuum Clutch
7. Electromagnetic Clutch

Functions of Clutch:

• Clutch does engaging and disengaging of engine from gearbox.
• To reduce the shocks and vibration of engine during transmission of engine power to rear axle by universal joint.
• To change the gear during motion of engine by disengagement of gearbox from engine.

Clutch Plate:

      (i) Single Plate Clutch: A single plate is commonly used in cars and light vehicles.  It has only one clutch plate which is mounted on the splines of the clutch shaft. A flywheel is mounted on the crankshaft of the engine. When clutch is in engaged position, the clutch plate remains gripped between flywheel and pressure plate. When the clutch plate is to be disengaged, the clutch pedal is pressed. Because of this pressure plate moves back and clutch plate is disengaged from flywheel.

     (ii) Multi Plate Clutch: Multi-plate clutch consists of more than one clutch plates contrary to single plate clutch which consists of only one plate. Due to increased number of friction surfaces, a multi-plate clutch can transmit large torque. Therefore, it is used in racing cars and heavy motor vehicles witch have high engine power. When the clutch pedal is pressed, the pressure plate moves back against the force of coil spring, then the clutch plates are disengaged and engine flywheel and gear box are decoupled.

However, when clutch pedal is not pressed the clutch remain in engaged position and the power can be transmitted from engine flywheel to the gear box.