Patent ID: 8446067
Filing Date: 2013-05-21
Classification: H01L,H02N

Abstract:
1. An ultrasonic motor comprising: an oscillator whose cross section vertical to a central axis has a rectangular shape and which generates elliptic oscillation when longitudinal oscillation that expands or contracts in the central axis direction and torsional oscillation using the central axis as a torsional axis are simultaneously excited, a length ratio of a narrow side and a wide side constituting the rectangular shape being set to a value that conforms a resonant frequency of the longitudinal oscillation exited in the oscillator to a resonant frequency of the torsional oscillation; a driven body that comes into contact with an elliptic oscillation generation surface of the oscillator in which the elliptic oscillation is generated and is driven to rotate by the elliptic oscillation around the central axis; and a pressing mechanism unit that presses the oscillator against the driven body and welds the elliptic oscillation generation surface of the oscillator to the driven body by pressing, wherein the oscillator has: a first polarization unit that is formed in a region associated with a node portion of the longitudinal oscillation and configured to excite the longitudinal oscillation in the oscillator; and a second polarization unit that is formed in a region associated with a ventral portion of the torsional oscillation and configured to excite the torsional oscillation in the oscillator.