The clutch pressure plate is installed on the flywheel of the engine and rotates with the engine; The driven disc (that is, the friction plate) is combined with the spline of the input shaft of the gearbox through the spline groove. When the friction plate rotates, the input shaft of the gearbox rotates accordingly. When the pressure plate under the action of the spring, the pressure on the driven plate, the transmission power; When the pressure plate is under the clutch pedal, the pressure plate is back, and the driven plate has no force, that is, the separation state; If you step on the clutch lightly, the spring of the pressure plate does not fully function, this is the semi-clutch, also called the semi-linkage.