Piezoelectric linear motor

Abstract

A piezoelectric motor with improved efficiency and improved specific power is disclosed. The piezoelectric motor has two frictionally engaged components mounted in such a way that they can move relative to each other. One component is a piezoelectric element in the form of a rectangular plate with metal coatings on its main planar surfaces. This component defines electrodes, where either some or all of the electrodes have leads for connection to a source of alternating voltage. The piezoelectric element is pressed by either its peripheral surfaces or by some parts of its peripheral surfaces at least by one of its sides or a section of one of its side against a cylindrical or planar surface of the other frictionally engaged component. The shape of the piezoelectric element, the arrangement and the number of the electrodes are configured to satisfy the condition of resonant excitation in the piezoelement of the first order mode of bending vibration along the length in the plane of the piezoelement during operation of the motor in one direction, and resonant excitation of the first order mode of longitudinal vibrations along the length during operation of the motor in the opposite direction.