A position-gripped ultrasonic transducer (PGUT) for linear inchworm motor

This paper reports a new piezoelectric Position-Gripped Ultrasonic Transducer (PGUT) with ring-shaped three-pile piece construction to implement an ultrasonic clamp for linear inchworm motors. It's principle is the use of surface effect of ultrasonic vibration which can cause the changes of friction force and perform the action of the position-gripped or position-lessening. It gives the resonance frequency, effective electeromechanical coupling coefficients. The experiment shows that the PGUT can perform gripping-loosening action rapidly and smoothly, and its work voltage is low (Vrms: 30-50V). The PGUT has been applied to inchworm motor effectively.