A long range piezoelectric rotary motor with continuous output: Design, analysis and experimental performance

This study proposes a novel piezoelectric rotary motor which can output long range continuous motion. With the help of two piezo-stacks which are located at a 90° included angle, the motor can achieve circular motion trajectory of a cylindrical driving surface and the rotor can be driven by the cylindrical surface to deliver long range continuous rotary motion without pause. The structure and operational principle are introduced in detail. The stiffness of the flexure hinge system is theoretically calculated and the result is verified by finite element analysis. A prototype of the proposed motor is manufactured and a set of experimental system is established to investigate the performance of the prototype. The experimental results confirm that the motor prototype can output long range continuous rotary motion stably. With the driving frequency increasing, the angular velocity of the prototype increases gradually while the angular acceleration decreases gradually. The angular velocity can reach 221,321 μrad/s when the driving frequency is 512 Hz. The maximum loading capacity is about 2.65 N and the maximum output torque is about 4.94 Nmm when the driving voltage and frequency are 150 V and 1 Hz. The return error of the prototype is about 608 μrad during the forward stroke of 28,970 μrad and the error percentage is about 2.1%. We can obtain a satisfactory angular velocity by choosing a proper frequency for the motor.