A High Power Linear Ultrasonic Motor Using a Bending Bolt-Clamped Transducer

Based on the concept of forming elliptical movements on the two leading ends of a beam by the superimposing of two orthogonal first-order bending modes, a high power linear ultrasonic motor using a bending bolt-clamped transducer is proposed in this study. Two groups of bending PZT located at the wave loop of the bending vibration are excited by alternating voltages with the transducer's bending resonance frequency to accomplish the generations of the two orthogonal bending vibrations. The symmetrical setting of the PZT elements makes the two driving feet have the same elliptical movement trajectory. Elastic supporting is accomplished by thin beams machined on the two sides of each horn. The electromechanical coupling factors of the motor are calculated; the movement trajectories of the diving feet are simulated. After the fabrication of a prototype, its vibration characteristics and mechanical ability are tested. The proposed motor achieves a maximum speed of 1309mm/s and a maximum thrust force of 45N.