Study on surface acoustic wave rotary motor

One hundred and twenty eight degrees rotated Y-cut x-propagation LiNbO₃ was used for the Rayleigh wave propagation. On the surface of the substrate, two pairs of interdigital transducers (IDTs) operating at 30 MHz were parallelly arranged in the propagation direction as a stator. When high frequency voltage was input to two IDTs, two Rayleigh wave beams were generated and propagating in opposite directions with each other on the substrate, thcn local relative motion between the stator and the rotor was produced, so two inverse frictional forces form a moment to drive the rotor. Some experimental results of the motor are given: driven by a voltage about 120 V_p-p, the motor is accelerated to rotate at a speed of 270 rpm after 400 ms; meanwhile, theoretical analysis and calculation of operation mechanism of the motor are proceeded.