Patent ID: 7196453
Filing Date: 2007-03-27
Classification: H02N

Abstract:
1. A radial piezoelectric motor for producing mechanical energy efficiently, said piezoelectric motor comprising: a housing; a motor shaft rotatably mounted in said housing; a plurality of piezoelectric actuators positioned inside said housing, said actuators being radially disposed about the axis of said shaft; charge pumps equal in number to the number of said actuators, each of said pumps being coupled to a respective actuator to apply voltage to said actuator and cause said actuator to expand repeatedly and in succession, each said pump comprising a capacitor, a means for supplying current from said capacitor to said respective actuator when the voltage of said actuator is less than a pre-determined reference voltage, so as to make the voltage of said respective actuator closely follow said reference voltage; a plurality of drive levers, each of said driver levers being pivotally mounted in said housing adjacent to a respective actuator and responsive to the expansion of said respective actuator to pivot away from said respective actuator; a bearing, said bearing being slightly offset about said motor shaft; a plurality of flexure couplings, each of said flexure couplings being connected to said bearing and a respective drive lever and responding to said pivoting of said respective drive lever to transmit a pulling force to said bearing, said bearing responding to said pulling forces and, in turn, transmitting a torque about the axis of said motor shaft; and a crank on which said offset bearing is mounted, said crank being connected to said motor shaft and responding to said torque to turn said motor shaft.