A longitudinal-bending hybrid sandwich type ultrasonic actuator based on Lissajous curve driven trajectory: Design and performance evaluation

Abstract

Inspired by the Lissajous curve, a longitudinal-bending hybrid sandwich type ultrasonic actuator is proposed in this paper. Different from the traditional elliptical and linear driven trajectory, an “8” shaped Lissajous curve is used as a driven trajectory through the composition of longitudinal and bending vibration modes. The excitation signal of the ultrasonic actuator is formed by the superposition of two sinusoidal signals; thus, only a single channel driver is needed. The frequency ratio and the phase difference of the two sinusoidal signals are 2:1 and 0°, respectively. And, piezoelectric elements are sandwiched between the metal parts to excite the longitudinal and bending vibration modes. The working principle and design process of the proposed sandwich type ultrasonic actuator are presented. The desired longitudinal and bending vibration modes of the ultrasonic actuator are obtained by the finite element method. Then, the prototype is manufactured. The output performance is evaluated by experiments. The output velocity of the actuator can reach 59.70 rpm under an excitation voltage of 300 VP-P. This work provides a new sandwich type ultrasonic actuator based on the “8” shaped Lissajous driven trajectory by utilizing only one channel driver.