CLUTCH

What is Clutch?

In automobile, a gear box is required to change the speed and torque of the vehicle. If we change a gear, when the engine is engaged with gear box or when the gears are in running position then it can cause of wear and tear of gears.

To overcome this problem a device is used between gear box and engine, known as clutch. Clutch is the first element of power train. The main function of clutch is to engage and disengage the engine to transmission, when the driver need or during shifting of gear. When the clutch is in engage position, the power flows from the engine to the wheel and when it is in disengage position, the power is not transmitted.

Principle of clutch:

The clutch is based on the friction. When two friction surfaces are brought into contact and pressed, then they are united due to friction force between them. This is the basic principle of clutch. The friction between these two surfaces depends on the area of surface, pressure applied upon them and the friction material between them.

The driving member of a clutch is the flywheel mounted on the engine crankshaft and the driven member is pressure plate mounted on the transmission shaft. Some friction plates, sometimes known as clutch plates are kept between these two members. This whole assembly is known as the clutch.

Function of clutch:

An automobile clutch has following function:

1. It can be disengaged. This allows engine cranking and permits the engine to run without delivering power to the transmission.

2. While disengaging it permits the driver to shift the transmission into various gear according to operating condition.

3. While engaging, the clutch slips momentarily. this provides smooth engagement and lessens the shock on gears, shaft and other parts of automobile.

4. While engaging, the clutch transmits the power to the wheel without slipping, in idea condition. 

Main parts of clutch:

In a clutch three parts are required to fulfill its function. These are known as the principle parts of the clutch. These are:

1. Driving member:

It is the member which is directly connected to the crankshaft. The driving member consists of a cover which carries the pressure plate (driving disc), the pressure springs and the releasing lever. This entire assembly is bolted on the flywheel and rotates with engine all the time. The flywheel and the pressure plate grip the driven member between them under the action of the pressure spring.

2. Driven member:

The driven member consists of a plate which is free to slide lengthwise on the splines of the clutch shaft but which drives the shaft through those splines. This plate is known as friction plate. The clutch housing also includes in the driven member.

3. Operating member:

The operating member connects the driver to this whole assembly. It consist the foot pedal, the linkage, the release lever and springs necessary to ensure proper operation of the clutch.