Investigation of flat rotary type piezoelectric actuator

Abstract

A numerical and experimental investigation of a new small size piezoelectric actuator is presented. The actuator was developed to integrate it into a printed circuit board and use it for the small size positioning devices. The actuator consists of three piezoelectric bimorph plates located under the angle of 120 degrees. The actuator is clamped using a special T-shaped beam structure. A double-sided hemispherical rotor is placed in the center of the actuator and is preloaded by the spring. The operation principle of the actuator is based on the excitation of the first in-plane bending vibration mode of bimorph plates using three harmonic or sawtooth waveform electric signals with phase difference by 2/3π. Design optimization of the stator including clamping structure was performed to maximize the amplitude of the contact point motion. Finally, the self-heating problem of the motor was analyzed. A prototype of the piezoelectric actuator was made, and the maximum rotation speed of 380.8 rpm was obtained when the voltage of 175 Vp-p was applied.