A bidirectional standing wave ultrasonic linear motor based on Langevin bending transducer

A bidirectional ultrasonic linear motor has been developed by using Langevin type bending transducer to excite bending wave. The vibration theory was used to analyze the operating principle: the bidirectional motion could be realized by exciting two different bending waves if fix the driving teeth at overlapping zone of two adjacent node and antinode areas. The finite element method was adopted to determine the structure dimensions and to verify that teeth tips trajectory were diagonal lines. A prototype was fabricated and its mechanical output was measured, and the following performances were achieved: maximum thrust force 14N, maximum speed 180 mm/s.