DESIGN AND PERFORMANCE OF A ROTARY MOTOR DRIVEN BY PIEZOELECTRIC STACK ACTUATORS

The development of a rotary inchworm-motor using piezoelectric actuato rs is presented. The motor design has the advantage of a macro and mic ro stepper motor with high torque and speed. The design is capable of fast angular positioning with micro level accuracy. The rotary motor, as designed, can also be used as a clutch/brake mechanism. A construct ed prototype motor along with its characteristics are presented. The m otor consists of a torsional section that provides angular displacemen t and torque, and two alternating clamping sections which provide the holding force. The motor relies on the principal piezoelectric couplin g coefficient (d(33)) without torsional piezoelectric elements. This d esign eliminates bending moment and shear applied to the actuator elem ents and thus increases its torque capability. An innovative flexure d esign is introduced and consideration is given to contact elements whi ch affect the performance of the motor. Experimental results demonstra ting the prototype's performance based on the aforementioned design co nsiderations are presented.