Clutch

The clutch is located between the engine and the transmission. It is used to disengage and engage the flywheel mounted on the engine crankshaft and the transmission input shaft.

The clutch consists of the driven (friction) disc, the clutch cover with the pressure plate and diaphragm spring, and the clutch release mechanism. The friction disc consists of two annular friction linings, which are riveted to the hub through the cushion springs.

The diaphragm spring mechanism applies a force that holds the flywheel, pressure plate and driven disc together so that they rotate as one. In this condition the clutch is engaged and transmits torque from the engine to the transmission. The clutch is operated by the clutch pedal.

The clutch is disengaged as follows. When the clutch pedal is depressed, the piston in the master cylinder moves and compresses the fluid. The fluid pressure is transmitted through the hose to the clutch slave cylinder, whose piston acts on the clutch release fork. The release fork moves the clutch release bearing, which presses on the center of the diaphragm spring. This releases the clamping force at the periphery of the spring and moves the pressure plate back. The driven disc is then released, and the engine shaft and the transmission input shaft can rotate independently of each other.

Friction linings are attached to both sides of the driven disc. The driving part of the disc is connected to the hub through the torsional damper components, which provide a flexible connection between them. The torsional damper reduces the dynamic loads that cause the driveline shafts to twist and untwist. These loads occur when vehicle speed changes abruptly, when the vehicle runs over road irregularities, when the clutch is engaged abruptly, and due to unevenness of engine torque. Elastic vibrations of driveline components cause noise in the mechanisms and assemblies, as well as vibration, which may result in damage to the parts if the amplitude of the elastic vibrations becomes large. The damper absorbs the energy of the elastic torsional vibrations.