Electric start overrunning clutch (also known as unidirectional clutch), also known as' forcer ', is a device that transmits the power of the automobile engine to the axle in the form of switch. The engine of a gasoline powered vehicle runs continuously while it is running. However, in order to meet the requirements of vehicle driving, the vehicle must have actions such as stopping and shifting. Therefore, a group of mechanisms must be added at the external connection of the engine to interrupt the transmission of power according to the demand, so as to achieve the action of keeping the vehicle stationary or shifting under the condition of continuous operation of the engine. This group of mechanisms is the power connection device. The clutch mechanism is installed between the engine and the manual gearbox, which is responsible for transmitting the power of the engine to the manual gearbox. When the clutch pedal is released, the pressing plate in the flywheel tightly presses the friction plate with the force of the spring, so that there is no sliding linkage between the two, so as to achieve the purpose of connection, and the power of the engine can be transmitted to the gearbox through this mechanism to complete the power transmission. When the pedal is pressed, the mechanism will pressurize the spring, so that the periphery of the spring is tilted, and the pressure skin will be separated from the friction plate. At this time, the friction plate and flywheel cannot be connected. Even if the engine continues to run, the power will not be transmitted to the gearbox and wheels. At this time, the driver can shift gears and stop without stalling the engine.