Design and experimental evaluation of a linear piezoelectric ultrasonic motor using longitudinal transducers

Abstract

A U-shaped linear piezoelectric ultrasonic motor (PUM) was proposed, designed and tested in this work, in which three longitudinal transducers were used together to achieve the linear driving by two feet synchronously. Longitudinal vibrations of the transducers were generated with certain temporal shift to form the desired elliptical movements on the two driving feet. Finite element method (FEM) was used to accomplish the design process, in which the resonance frequencies of the transducers were tuned to be very close, and the movement trajectories of the driving feet were gained to show the feasibility initially. Then, a prototype was fabricated and tested to verify the proposed design further. The resonance frequencies of the two vibration modes of the prototype were tested to be about 30.184 kHz and 30.227 kHz by using the Scanning Laser Doppler Vibrometer (SLDV). The optimal working frequency of the prototype was tested to be about 29.35 kHz. The maximum output speed and maximum thrust force were tested to be about 321.6 mm/s and 12 N, respectively.