| 摘要 |
PROBLEM TO BE SOLVED: To provide a vibrator for a vibration type drive device that has small change in spring rigidity even when a contact part is worn by lap processing and motor drive, and that can perform stable drive, and that can improve power efficiency.SOLUTION: Provided is a vibrator for a vibration type drive device having an electromechanical energy conversion element, and an elastic body fixed to the electromechanical energy conversion element and provided with a hollow-structured projection part. An elliptic motion is excited to the projection part by application of an AC voltage to the electromechanical energy conversion element to relatively move a driven body in contact with the projection part. The projection part has: a contact part having a contact surface with the driven body; a wall part protruded to an opposite side to the electromechanical energy conversion element; and a coupling part coupling the wall part and the contact part and having a spring property. The contact part has a part where a cross sectional area of the contact part in a plane parallel to a contact surface of the contact part becomes larger as it goes away from the contact surface side. |
