Based on whether there is a relative rotational speed difference between the clutch's driving and driven components, the clutch can be categorized into three operating states:
Disengaged State: When the driver depresses the clutch pedal, the control mechanism pushes the release bearing, causing it to engage the pressure plate's clamping mechanism. This causes the pressure plate to retract, creating clearance between it and the flywheel. At this point, the driven plate is completely separated from both the flywheel and the pressure plate, eliminating friction. No power is transmitted between the clutch's driving and driven components, and no rotational speed difference exists. In this state, the engine can idle, the transmission can shift gears, and the vehicle can come to a stop.
Engaged State: When the driver releases the clutch pedal, the control mechanism returns to its original position. The release bearing disengages from the pressure mechanism. Under the force of the pressure springs, the pressure plate is pushed forward, eliminating the gap between it and the flywheel. At this point, the driven plate is in tight contact with both the flywheel and the pressure plate, generating sufficient friction. Power is transmitted between the clutch's driving and driven components, and there is no difference in rotational speed. In this state, engine power is fully transmitted to the transmission, enabling normal vehicle operation.
Semi-Engaged State: When the driver slowly depresses or releases the clutch pedal, the operating mechanism applies a certain force between the release bearing and the pressure plate assembly, creating a slight gap between the pressure plate and the flywheel. At this point, the driven plate maintains some friction with the flywheel and pressure plate, though insufficient to fully transmit engine power. A rotational speed difference persists between the clutch's driving and driven components. In this state, partial engine power is transmitted to the transmission, enabling the vehicle to start smoothly or travel at low speeds.
