Design and fabrication of a new traveling wave-type ultrasonic linear motor

This paper describes the development of a new traveling wave-type ultrasonic linear motor. The motor consists of a metallic stator and two piezoelectric ceramic plates bonded to the stator, thereby eliminating the need for external vibrators. The two piezoceramic plates excite two ultrasonic standing waves with a certain phase difference, which convert to a traveling wave when combined together. The operation principle of the motor is presented along with the theoretical equations. and the feasibility is verified using the finite element method. Based on the finite element analyses, detailed dimensions and boundary conditions are determined for the proper generation of a traveling wave. Experimental fabrication and characterization of a sample motor is performed to confirm the numerical results and prove the practical applicability of the new structure, The new linear motor presented in this work offers a relatively simple structure compared to traditional traveling wave-types while maintaining all the characteristic features of an ultrasonic motor. (C) 2001 Elsevier Science B.V. All rights reserved.