This study demonstrates a new approach for constructing a rotary piezoelectric motor that utilizes an asymmetric stator driven by a single-phase signal. An asymmetric stator with four driving feet is proposed on the basis of the idea of generating asymmetric action on the rotor. This new motor consists of one piezoelectric transducer with two anchors and four driving feet placed in a parallelogram and internally connected to a circular rotor. The four feet vibrate asymmetrically to push the rotor into motion in one direction when a preload is applied. The proposed motor is designed, analyzed, and tested by using a finite element method (FEM). The vibration and impedance characteristics of the stator are measured after fabricating a prototype, and the test results are consistent with the FEM analysis results. The typical output of the prototype is a no-load speed of 176.5 rpm and a maximum torque of 29.4 N mm at an excitation voltage of 274 Vp-p.

A resonant-type piezoelectric screw motor for one degree of freedom (1-DOF) positioning platform is proposed, fabricated, and investigated in this article. The motor comprises a driver and a screw rod. The driver is composed of four transducers, a nut seat, and a flange nut. The flange nut is bolted connected on the nut seat, and the four piezoelectric transducers are connected with the nut seat by right-angle flexible hinges. Each piezoelectric transducer comprises two piezoelectric stacks and one displacement amplifier. Driven by the four piezoelectric transducers, elliptical vibration is generated by the driver, which is used to actuate the screw rod to realize the linear movement. The driver is analyzed using the finite element analysis software ANSYS. The proposed motor and positioning platform prototype are manufactured, assembled, and tested. The performance of the developed piezoelectric screw motor shows its applicability and effectiveness for the 1-DOF positioning platform with a large force. Experiments demonstrate that the maximum velocity of this motor is 10.53 mm/s without mechanical load and the maximum output force of the platform can reach 17.19 N when the excitation voltage is 230 V p-p at 365 Hz.

No abstract