RESUMO
In this study, an oblate-type ultrasonic micro-motor with multilayer piezoelectric ceramic and chamfered driving tips was proposed and experimentally researched. The micro-motor works based on the standing-wave principle and has a higher rotary speed than the traditional standing-wave one in principle, reaching a rotary speed of 2100 r/min in this study at the voltage of 20 Vp-p. When the micro-motor rotates, single phase alternating current is required, namely, V=Asinωt, and exchanging the signal wire and ground wire will not change the rotary direction of the motor, which reinforces the safety and the compaction of this motor. The ratio of the maximum displacement value of the speed feeding direction and the preload direction is approximately 4, showing a characteristic of high speed and low ability to load.
RESUMO
This paper presents a novel linear piezoelectric motor which is suitable for rapid ultra-precision positioning. The finite element analysis (FEA) was applied for optimal design and further analysis, then experiments were conducted to investigate its performance. By changing the input signal, the proposed motor was found capable of working in the fast driving mode as well as in the precision positioning mode. When working in the fast driving mode, the motor acts as an ultrasonic motor with maximum no-load speed up to 181.2mm/s and maximum thrust of 1.7N at 200Vp-p. Also, when working in precision positioning mode, the motor can be regarded as a flexible hinge piezoelectric actuator with arbitrary motion in the range of 8µm. The measurable minimum output displacement was found to be 0.08µm, but theoretically, can be even smaller. More importantly, the motor can be quickly and accurately positioned in a large stroke.
