| 摘要 |
PROBLEM TO BE SOLVED: To provide a long-life, compact, lightweight, and low-cost ultrasonic motor for efficiently extracting rotary force to a rotor by standing wave drive. SOLUTION: In an ultrasonic motor, a retainer 4 where a window part is provided at every other position in a region which is surrounded by a node and an antinode, when the standing wave of thickness flex vibration is generated is fixed to a vibrator 3a, where a piezoelectric element 2 or an electrostrictive element is jointed to a circular-plate shaped or a regular-polygon plate shaped elastic body 1. At the window part of the retainer 4, a needle 6, a ball, or a circular plate that has the same height is freely rotatably arranged, and a rotor 7 is brought into press contact with the needle 6, the ball, or the circular plate. |
