Overrunning clutch is a basic part which appears with the development of mechatronic integration products. It is an important part of power transmission and separation function between prime mover and working machine or machine internal drive shaft and driven shaft. It is a device with self-clutch function by using the speed change or rotation direction change of the main and driven parts.

There are three 4 types of the overrunning clutch from TIANNIU, freewheel one way clutch, one way cam clutch, one way wedge type clutch with more torque, and BR series overrunning cam clutch.