To make compact an ultrasonic motor which can deliver driving force of a plurality of axes.
An elastic body 2 which constitutes a stator is provided with an inner annular section 4 and an outer annular section 5, which are separated from each other in the radial direction by a circumferential groove 2b and serve for a plurality of resonators. A piezoelectric element 6 is pasted on the bottom faces of the annular sections 4, 5. Each of the annular sections is formed with a plurality of radial slits. It is also provided with an inner comb-like tooth section 4a or an outer comb-like tooth section 5a, which forms a comb-like tooth in the circumferential direction. Then, the high-frequency voltage of an AC power supply 11 is applied to the piezoelectric element to resonance the ring-shaped sections. A plurality of annular sections are disposed concentrically on one and are flush with each other, and therefore there is no need for largely changing the axial length of a motor equipment, and in the case of an ultrasonic motor, there is not need of increasing the diameter of a rotor since large torque can be obtained, resulting in a compact and thin-type motor. Such a motor can be easily and suitably used, even in equipment, which requires a plurality of motors and is restricted by installation space.
KASAI SHU
KOBAYASHI KOJI
Next Patent: ULTRASONIC MOTOR EQUIPMENT