A Cylinder-Type Multimodal Traveling Wave Piezoelectric Actuator

Abstract

Numerical and experimental investigations of a multimodal piezoelectric traveling wave actuator are presented. The actuator consists of a cylindrical stator with a conical hole and piezoceramic rings that are located at the node of the first longitudinal and second bending vibration modes; one piezoceramic ring is also placed at the bottom of the actuator. The actuator is clamped at the bottom using a special supporting cylinder and a ball bearing. Traveling-wave-type vibrations are excited at the top surface of the cylinder by employing a superposition of the first longitudinal and second bending vibration modes of the stator. The conical hole of the stator is used to amplify the vibration amplitudes of the contact surface. Four electric signals with phase difference of π/2 are used to drive the actuator. Numerical and experimental investigations showed that the proposed actuator is able to generate up to 115 RPM rotation speed at constant preload force.