Curved Longitudinal-Bending Actuator for Rotary Ultrasonic Motor

摘要

Piezoelectric ultrasonic actuators using first longitudinal (L_1) and second bending vibration mode (B_2) are commonly used in the design of ultrasonic motors. Although they are mainly used to design linear motors, they show great potential in order to build compact multi-degrees of freedom rotary actuators. We propose a new type of L_1B_2 actuator using two orthogonal modes of a curved PZT beam. The motivation behind this new shape is an adaptation to the shape of the rotor providing more efficient coupling. Modal and frequency analyses are presented in addition to impedance measurement of an actuator prototype. Finally, the preliminary performance of a single degree of freedom motor using this actuator is reported.