Experimental and Control Study of Slipping Decay Time of a Wedge Clutch in an Automatic Transmission

A wedge clutch with a wedge ramp transfers the tangential force into an axial force. It has unique features of self-reinforcement, and can be packaged into tight spaces. This wedge clutch is developed to apply to an automatic transmission as an implementation example.The slipping decay time is found to be critical for the shifting quality. This paper focuses on the experimental study and control of slipping decay time of the wedge clutch through the influencing factors. The mechanical system of the wedge clutch applied in an automatic transmission is described and the sensors for measuring signals are installed. A transmission dynamometer is set up for experiments.The torque magnitude and direction of the motor motion are considered as actuation factors; the driveline input speed, load torque, and oil temperatures are considered as the driveline factors. The results show how influencing factors affect the slipping decay time during gear shifting.© 2012 ASME