Resonant Modes of Piezoelectric Disc Structure and their Application in Micro Ultrasonic Motors

Abstract

This article describes out-of-plane resonant modes of a piezoelectric disc structure. A new type of micro ultrasonic motor using the resonant mode B11 (Bmn, where m is the number of nodal circles, n is the number of nodal diameters) has been studied. The motor is a wobble-type motor. The stator of the motor uses this structure, consisting of a hollow metal cylinder and a piezoelectric ceramic disc bonded with a metal one, which is excited in the vibration mode by two electrical signals. The stator exhibits wobble displacement and transfers rotation to a rod rotor by the cylinder. The behavior of the stator has been simulated by the finite element analysis. The simulation results have been checked with laser scanning by a laser scanning vibrometer. The article closes with the introduction of the new micro ultrasonic motors based on this vibration mode with high rotation speed.