| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultrasonic motor in which fluctuation in the force of a rotor pressing against a stator can be suppressed surely, regardless of abrasion of a frictional member interposed between the stator and the rotor. SOLUTION: A coned disc spring 19a is set while being deformed resiliently and the resilient force is utilized for pressing a rotor 15 against a stator 9. The coned disc spring 19a has a desired resilient force and and it is set while being deformed resiliently such that the overall length is confined in a safety region where fluctuation in the resilient force is suppressed over the entire length. |
