Metal-PZT Composite Piezoelectric Transducers and Ultrasonic Motors

Abstract

Rotary and linear ultrasonic motors were developed in the present paper using metal-PZT composite piezoelectric stator transducer configuration. The transducer consists of a concentric PZT tube and a metal tube, which structurally improve the reliability of the stator transducer. The developed transducer can provide a free vibration velocity of 0.9 m/s under 100 Vp-p at the resonant state. The rotary motor and linear motor use the developed transducer as the driving component, which produces the rotational motion to drive the motor. The rotary motor is able to achieve about 700 rpm no-load speed, above 2 mNm torque, maximum 70 mW output power and 50% efficiency under driving voltage of 80 Vp-p. The linear motor produces rotational motion and linear motion simultaneously. The linear speed of 5 mm/s can be achieved under the driving voltage of 50 Vp-p under no-load state. Under the loaded state, maximum 8 N load has been observed to be moved by the motor at a speed of 0.6 m/s. The maximum output power and efficiency of the linear motor are 9 mW and 11%, respectively.