| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic motor capable of preventing a deterioration of a rotation performance and inhibiting the occurrence of an usual noise. SOLUTION: The ultrasonic motor comprises a stator 1 and a rotor 2. The stator 1 comprises a first and second metal block bodies 3, 4, a first and second piezoelectric elements 5, 6 and a first and second electrode plates 7, 8. The second metal block body 4 is made from a conductive metallic aluminum alloy, and a horn section 4c, which has a thin thickness getting thinner towards the diameter direction than that of a lower-edge face side, is formed at an upper- edge face side 4a of the second metal block body 4. An orbiting groove 50 is grooved at the external peripheral surface 4e of the horn section 4c. The orbiting groove 50 is formed into a triangle shape at its cross section with a predetermined depth in the neighborhood of the upper-edge face 4a. |
