| 摘要 |
PURPOSE:To suppress rotational fluctuation and noise by arranging such that a resilient member, in which a traveling wave is formed, contacts with a pressure contact member not on the entire surface but at plural points. CONSTITUTION:Piezoelectric elements comprising phase A and phase B piezoelectric elements are bonded onto the bottom face of the annular resilient body 1 of an oscillation wave motor. Protrusion groups, each comprising a plurality (five) protrusions 1b, are arranged with pitches (P1, P2, P3) at plural points (three) along the circumferential direction on the surface side(contact face side with a friction member 2a) of the resilient body 1. If some degree of flatness is maintained for the protrusions 1b constituting the protrusion group, the friction member 2a can be positively brought into contact with the resilient member 1 even if the flatness of the resilient body 1 or the friction member 2a is low. |
