CHARACTERISTICS OF THE ULTRASONIC LINEAR MOTOR USING RADIAL AND NONAXISYMMETRIC VIBRATION MODES OF AN ANNULAR PLATE

This paper deals with an ultrasonic linear motor using nonaxisymmetric ((1, 1)) vibration and radial(R, 1) vibration modes of a piezoelectri c ceramic annular plate. A new method of making these modes degenerate is proposed. By applying this method to a vibrator, the neutral axis of vibration for ((1, 1))-mode is fixed on the prescribed position, an d the difference between the two resonance frequencies is adjusted to the optimum state for a stator vibrator. The construction and some ope rational characteristics of the linear motor are presented, The maximu m efficiency of the prototype motor was about 48%.