A single piezoelectric is excited at a first frequency to cause two vibration modes in a resonator producing a first elliptical motion in a first direction at a selected contacting portion of the resonator that is placed in frictional engagement with a driven element to move the driven element in a first...http://www.google.es/patents/US6690101?utm_source=gb-gplus-sharePatente US6690101 - Vibratory motors and methods of making and using same
Vibratory motors and methods of making and using same
