Vibration analysis of the stator in ultrasonic motor by FEM

A three-dimensional finite element method is proposed for the static and dynamic vibration of the stator in a piezoelectric motor which is comprised of an elastic body with slots bonded with piezoelectric ceramic elements. The validity of the computational technique is confirmed by comparison with experimental results measured by laser vibrometer. It is shown that the amplitude of the effective circumferential direction is dependent on the height of teeth cut out on the surface of the elastic body. If height of teeth is selected appropriately, the piezoelectric motor can be operated without slipping. These facts are useful for designing the shape of stator with high efficiency. The displacement in axial direction remains almost constant.