Piezoelectric motor

Abstract

A rotary motor uses a plurality of radially acting piezoelectric actuators to impart rotation to a motor shaft having surface undulations. Electrical charge distributed to the actuators causes radial actuator motion resulting in contact between the actuators and the sloped sides of the shaft undulations. The slope of each undulation transforms the radial force into tangential force that rotates the shaft. The slope of the shaft undulations provides a mechanical advantage that transforms the slow radial speed of the actuators into greater shaft rotational speed. The shaft undulations can be made in any desired or easily fabricated shape. The electrical actuation control signals can be modified electrically to produce appropriate radial actuator motion to match the undulations of the shaft. Electric charge can be shared among actuators by using switches or other circuitry. Efficiency can be increased further by using acoustic excitation and by using rollers for contact between the actuators and the shaft.

Dependencies are inferred from the claim text.