The car clutch is located in the flywheel housing between the engine and the gearbox. The clutch assembly is screwed to the rear plane of the flywheel. The output shaft of the clutch is the input shaft of the gearbox. During the driving of the vehicle, the driver can step on or release the clutch pedal as needed to temporarily separate and gradually engage the engine and the transmission to cut off or transmit the power input by the engine to the transmission.

The friction between the active part and the driven part of the clutch by the contact surface, either using liquid as the transmission medium (hydraulic coupling) or magnetic transmission (electromagnetic clutch) to transmit the torque The two can be temporarily separated and gradually joined, and the two parts are allowed to rotate each other during the transmission process.

At present, a spring-loaded friction clutch (referred to as a friction clutch) is widely used in automobiles. The torque from the engine is transmitted to the driven plate by the friction between the flywheel and the pressure plate and the contact surface of the driven plate. When the driver steps on the clutch pedal, the transmission of the mechanism causes the large end of the diaphragm spring to drive the pressure plate to move backward, and the driven portion is separated from the active portion.