| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic motor wherein vibration in a coned disc spring can be reduced and produced fluttering sound can be reduced. SOLUTION: The ultrasonic motor 1 is provided with a stator 10 which is vibrated by a piezoelectric element 12 and a rotor 16 which receives vibration of the stator 10 and is rotated. A rotating shaft 6 which is integrally rotated is fixed in the rotor 16, and a plate 19 is installed on the rotating shaft 6 so that the plate 19 is prevented from moving upward from a specified position. The cone disc spring 18 which applies pressure to the rotor 16 toward the stator 10 and has substantially V-shaped cross sections throughout the periphery thereof is abutted against the plate 19. A plurality of projections 26 which protrude downward and are positioned on the same circle are formed at the radial outer portion of the lower face 19a of the disc portion of the plate 19. The projections 26 are formed with unequal pitches so that the lengths thereof in the circumferential direction are not uniform and one projection is present at least every 120 deg. on the circumference of the plate 19. The lower face of each of the projections 26 is a contact face 27 in contact with the coned disc spring 18 and each of the contact faces 27 are formed on the same plane. |
