Non-Resonance Type Linear Ultrasonic Motor Using Multilayer Piezoelectric Actuators with Parallel Beams

Abstract

A linear ultrasonic motor (LUSM) with two parallel beams and two multilayer piezoelectric actuators (MPAs) has been developed. The MPAs are aligned across the beams, and the force and displacement generated by the MPAs result in the deformation of the beams in the orthogonal direction. The LUSM has two types of operation modes: dynamic and static. In dynamic operation, the MPAs are driven by alternating voltages with a phase difference, and elliptical displacement motions are generated on the surfaces of the beams. Objects touching the surfaces of the beams can be moved in the same direction by friction. In addition, micro positioning is available over a wide range by combining dynamic and static operations. The characteristics of the LUSM include a maximum speed of 41 mm/s and a maximum thrust of 3.4 N at an operating voltage of 20 V_p-p. A movement range of approximately 8 μm has been confirmed during static operation.