Vibration actuator which effectively transmits micro-amplitude vibrations

摘要

An ultrasonic vibration motor having an elastic body and piezo- electric elements which are joined to the elastic body to harmonically produce a longitudinal oscillation mode and a bending oscillation mode on the elastic body, and to produce elliptical movement of a specified part of elastic body. A rotational member contacts a specified part of the elastic body and is driven to rotate by the elliptical movement of the specified part of the elastic body. A relative movement member is driven by the rotational member. The relative movement member may be driven, even if it has a soft surface, by effectively transmitting oscillations of a micro-amplitude produced on the specified part of the elastic body.