| 摘要 |
PROBLEM TO BE SOLVED: To vibrate an oscillating element in a stable state by preventing foreign matter from entering the element, in addition to efficiently drive a driven member by efficiently displacing an object to be displaced. SOLUTION: An oscillator 43, that oscillates according to a given AC electrical signal, a vibrator 44 that is excited by the oscillator 43 to generate progressive waves in the circumferential direction on its bottom end surface, and an object 45 displaced, to which the bottom end surface of the vibrator 44 is pushed, are each contained inside a casing 41 of an ultrasonic motor 40. The object 45 is supported by the casing 41 in such a way as to be rotatable about the axis and connected to a shaft part 34g of a spool 34, in such a way as to be incapable of rotating relative to the shaft part 45 which extends in the axial direction. A sealing member 49 of an elastic material such as rubber formed in a ring shape is inserted between the middle, outside circumferential surface of the vibrator 44, and the inside circumferential surface of the casing 41 is installed in between, liquid-tight with respect to each surface. |
