The active part and the driven part of the clutch are gradually engaged by the friction between the contact surfaces, or by using the liquid as the transmission medium (hydraulic coupling), or by using the magnetic drive (electromagnetic clutch), so that the two parts can be stated to each other during transmission.
At present, the friction clutch with spring compression is widely used in automobiles (referred to as the friction clutch). The torque emitted by the engine is transmitted to the driven disc through friction between the flywheel and the contact surface of the pressure disc and the driven disc. When the driver depresses the clutch pedal, the large end of the diaphragm spring drives the pressure disc backwards through the component's transmission. The driven part is separated from the active part.
