Stepping ultrasonic motors for precision positioning

Piezoceramic plate vibration is converted to mechanical motion for motor applications. The bimodal motors presented here operate simultaneously with a longitudinal and a shear mode. The elliptical motion of the resonating plate contact tip, resulting from the superposition of these modes, is used to drive the rotor or linear positioning stage. Reversible linear and rotary motion motors have been developed. Stepping motion has been realised by impulse feeding. The motors with step resolution from 0.01 micron to continuous motion with 120 mm/s speed have been developed