Abstract:Because of the high transmission ratio, smooth, low noise, compact structure and a unique self-locking performance of the worm drive, it is widely used in all kinds of one way transmission mechanism in the research and development and design of electromechanical device. But the electromechanical device unable resetting was made by its self-locking performance through manual reverse operation in de-energized state at the same time, which result the temporary “paralysis” of the machine. The efficiency of the machine was greatly reduced in the use of the equipment. Therefore, aiming at the irreversibility of the self-locking performance on the basis of the worm drive, relative research has been carried out to develop a friction drive device which can be operated by manual return trace in de-energized state.