Abstract: A new type piezoelectric rotary actuator is designed and developed to reduces the cost, improve the carrying capacity and adjust resolving capacity. The actuator adopts single piezoelectric stack as the prime driver. With two displacement amplifications, the deformation of piezoelectric stack is amplified, then converted into ratchet rotor rotation with the movement transformer. A prototype of the piezoelectric rotary actuator is developed and the experimental test on the actuator is performed. Experimental results show that the actuator is excellent in controllability of output rotation angle.Three stable single step output rotation angles are obtained when the voltage is 200 V, 350 V and 650 V. The resolving capacity of it is 0.034 9 rad and the maximum carrying capacity is 0.392 N•m. The maximum rotation velocity is 2.094 4 rad/s, when the frequency is 20 Hz. The actuator offers a number of advantages, including low cost, adjustable resolving capacity and carrying capacity. It has application potential in the fields of precision driving and large rotation angle driving.

Key words: displacement amplification, piezoelectric stack, resolving capacity, rotary actuator