Design and mechanical analysis of a mesh- type rotary harmonic piezoelectric motor

Abstract

To obtain a large output torque and a long lifetime, a mesh-type harmonic piezoelectric motor is proposed in this paper. In addition, the operating principle of the motor is illustrated, and the displacements and forces of amplification mechanism are provided. Moreover, the equations of forces on the transmission system and output torque for the motor are deduced. By utilizing these equations, the output torque of the motor was analyzed and the influence of the system parameters on the output torque was investigated. Furthermore, the experiments of the displacements for the amplification mechanism and the output torque for the motor were studied. The results showed that the largest test output torque is 0.383 Nm when the driving voltage is 150 V. The following parameters should be selected to increase the output torque of the motor: large offset $a$ , length $l_1$ and $l_5$ , strain constant $d_{33}$ , elastic modulus of piezoelectric actuator $c_{33}$ , sectional width $A_p$ , small parameter $b$ , lengths $l_3$ and $l_8$ and ceramic thickness $l_p$ . The results are useful for improving the performance of the motor.