Design and finite element analysis of a new stack ultrasonic motor based on in-plane mode

Abstract

This paper presents a novel piezoelectric ultrasonic motor which is able to exert the strong actuating power of piezoelectric stacks. It is a linear standing wave motor with simple structure and high positioning speed. Elliptical motion at the driving point is achieved by simultaneously matching the natural frequencies of two operating modes of the device. The matched resonance is taken to be the operating frequency at which both modes can be excited. A prototype motor is developed and numerically analyzed. Vibration characteristics of the motor, such as mode shapes, natural frequencies, output displacement in frequency and time domains, electrical impedance of the stacks and trajectories of the driving point, are obtained from finite element analysis. The results confirm that the motor has high electromechanical efficiency with good mechanical output characteristics.

Performance Enhancement of a Stack Ultrasonic Motor Using PZNPT Material

“…The motor contains three piezoelectric stacks and one aluminum central block, as shown in Figure 1. In the prototype, a common piezo material, PZT C-6 from Fuji Ceramics, is employed [5]. The upper and lower PZT stacks are symmetrical in geometric and material characteristics.…”

“…The intrinsic piezoelectric characteristics make such motors most suitable for fast and fine positioning over a very short stroke. Recently, a new standing-wave ultrasonic motor made of stacks was proposed by the authors [5]. It is a general purpose ultrasonic motor featured with fast response.…”

“…It is therefore of great importance to enhance the motor performance by means of using more powerful functional materials and/or optimizing the geometric structures. This paper examines the performance enhancement of the new stack motor in [5] by using new functional material PZNPT.…”

Comparison of Two New T-Shape Standing-Wave Ultrasonic Motors

“…As ultrasonic motors have a short history, new or novel ultrasonic motor designs are desirable for various potential applications. Recently, two new standing-wave ultrasonic motors were proposed by the authors [3][4]. Both are general purpose ultrasonic motors featured with T-shape structure.…”