Working principle of clutch

The clutch generally consists of four parts: the active part, the driven part, the clamping mechanism, and the control mechanism, as shown in the figure.
The active part includes the flywheel, clutch cover, and pressure plate. The flywheel is a large metal disk located at the rear end of the engine crankshaft, which can store the engine's moment of inertia and ensure smooth operation. The clutch cover is a metal housing fixed to the flywheel with bolts, and is equipped with compression springs and release levers inside. The pressure plate is a metal disc with a protrusion at the rear end that extends into the window of the clutch cover and can move axially along the window. When the engine rotates, the active part also rotates and transmits pressure to the driven part through the compression spring.
The driven part includes a driven plate and a driven shaft. The driven disk is a metal disk with friction lining on both sides, which can come into contact with the flywheel and pressure plate. The driven plate is mounted on the driven shaft through a spline hub, which is the input shaft of the transmission. Its front end is supported in the center hole of the flywheel through bearings, and its rear end is supported on the transmission housing. When the driven plate comes into contact with the flywheel and pressure plate, the driven part can receive the torque transmitted from the active part and input it into the gearbox.
The clamping mechanism consists of several uniformly arranged clamping springs along the circumference, which are installed between the pressure plate and the clutch cover to press the pressure plate and driven plate towards the flywheel, making the three in close contact. Compression springs can be in different forms such as coil springs, central springs, or diaphragm springs.
The control mechanism consists of a clutch pedal, a release lever, an adjustment fork, a release fork, a release sleeve, a release bearing, a return spring, etc. They control the engagement and disengagement of the clutch through lever and hydraulic principles.
Working principle of clutch
When we do not press the clutch pedal, the clutch is in the engaged state. At this point, the compression spring compresses the flywheel, driven plate, and pressure plate together. The torque of the engine is transmitted to the driven plate through the friction between the two friction surfaces of the flywheel and pressure plate, and then input into the gearbox through the driven shaft. In this way, the car can run normally.
When we press the clutch pedal, the clutch is in a disengaged state. At this point, the separation sleeve and separation bearing are pushed by the separation fork to eliminate the gap between the separation bearing and the inner end of the separation lever. Then, the inner end of the separation lever is pushed forward, causing the outer end of the separation lever to drive the pressure plate to overcome the force of the compression spring and move backward. The friction effect disappears, and the main and driven parts of the clutch are separated, interrupting power transmission. In this way, the car can stop or shift gears.