The clutch can be understood as a switch in daily life. Generally, the clutch of a car is basically the structure shown in the figure below. The pedal on the left most of the driver's position right is the clutch pedal. After stepping on the pedal, the pressure plate will be released, so that the input shaft of the gearbox is disconnected from the flywheel, thus interrupting the transmission of power.

In addition, the clutch also has the function of preventing automobile overload. When the clutch is designed, the pressure of the pressure plate will be set within a certain range according to the design load, so that the friction force will be within a certain range when the relative sliding between the friction plate and the flywheel will not occur. When the load from the wheel exceeds the limit value, the clutch will slip, thus protecting the engine and changing The function of speed box.