Linear ultrasonic motor with wheel-shaped stator

A novel linear ultrasonic motor with a wheel-shaped stator using two orthogonal fourth bending modes has been developed. The stator of the motor is a notched piezoelectric composite beam. Eight piezoelectric ceramic rings are clamped orthogonally to excite two orthogonal fourth bending modes of the beam. Each piezoelectric ceramic ring is coated with two segment electrodes and under which the ceramic segments are polarized in two reverse directions. Thus, the elliptical motion of the particles on the driving feet can be obtained and the slider pressed on it can be driven alternately. A prototype has been fabricated and the performance characteristics measured are: driven by an AC signal with the frequency of 49.52 kHz, the no-load speed of the prototype is 374 mm/s, the maximum thrust is 13N, the efficiency is 18% and the thrust-weight ratio is 43:1.