| 摘要 |
PURPOSE:To raise the drive efficiency of an apparatus by constituting a vibrator from stainless steel other than austenitic stainless steel. CONSTITUTION:An ultrasonic motor is composed of a piezoelectric element 1, a vibrator 2, a rotating mover 3, a base stand 9, a fixing shaft 10 and others. In this case, said vibrator 2 is made of stainless steel other than austenitic stainless steel, the thermal expansion coefficient of said vibrator 2 is made almost equal to that of said piezoelectric element 1, and its mechanical factor of merit is made larger. Thus, even if tempera ture changes, the contact state of the vibrator 2 and mover 3 is good and the drive efficiency thereof is always high. Also, their mechanical efficiency is improved because of the large mechanical factor of merit. Further, a martensitic stainless steel, to which, for example, 0.26-1.20% composition carbon and 12-18% chromium are added, is suitable as the material for said motor. |
