Clutches (Diaphragm, multi-spring, Twin Plate, Release bearings.....)

Basic Vehicle Clutch Operation

A vehicles main clutch is fitted between the engine and the transmission. It is operated by the clutch pedal and is disengaged by the driver applying the pedal.

The clutch serves 3 main purposes:

1.To provide a temporary break in transmission.

2. To provide a smooth take up of drive.

3. To assist in changing gears.

The ability of a clutch to transmit torque depends on a several factors which include:

  • Mean (average) radius of the friction lining.
  • Coefficient of friction of lining material.
  • Quantity of friction services
  • Force clamping both members together.
Diaphragm clutch and friction plate

Clutch Release/Throwout Bearing

The clutch release bearing (throwout bearing) can be a thrust type angular contact ball bearing, supported on a carrier. It slides on a hub or sleeve extending from the front of the gearbox and is operated by the release fork, pushing the bearings thrust face into contact with the clutch spring fingers or toggle levers.

This allows the release bearing to rotate with the clutch while disengaging it.

diaphragm clutch and release bearing

How a twin plate clutch works

The twin plate clutch is similar in operation to a single plate clutch with the addition of another friction plate and an intermediate plate.

Where more torque is required to be transmitted through a clutch but it would not be practical to have a larger diameter flywheel/clutch, multiple clutch plates can be used to share the torque.

Borg and Beck Twin Plate Cleatch