为了在保持电机精度的同时获得较大作动行程, 提出了一种以叠层压电陶瓷作为激励振动源的压电直线电机。分析了电机的工作原理, 推导了电机驱动足在工作时的运动轨迹。设计安装了电机样机, 并对其定子进行了测试。最后, 在两种激发条件下实验研究了电机的整机性能。结果表明: 单组叠层压电陶瓷激励时, 该样机定子驱动头在接触面法向和切向同时具有振动分量, 并能够在阶跃和连续两种不同激励方式下实现单向大行程直线运动。以锯齿波激励时可实现步进运动, 激励频率为20 Hz时步距为0.1 μm; 以两路相位差π/2的正弦波激励时, 可在1.5 kHz到5.8 kHz的激励频率区间输出稳定连续的直线运动, 其运动速度随激励频率的升高而增大, 在峰-峰值110 V(50 V偏置)的正弦电压激励下其推力可达4.8 N。该电机具有高位置分辨率和宽频率响应, 可以在两种工作模式下分别稳定地实现直线步进和大行程连续运行。

A linear piezoelectric motor was proposed by using the stacked piezoelectric ceramics as a excited vibration source to enlarge its stroke and to maintain a higher precision. The working principle of the linear motor was analyzed, and the moving trajectory equation of the driving tip in the linear motor was deduced at a working state. The construction of the linear motor was designed, and a prototype of the motor was fabricated, assembled and tested. Finally, the motion performance of the motor was measured under two different exciting conditions. Experimental results indicate that the driving tip of the stator in the motor vibrates both normally and tangentially and the motor is capable of two operation modes, including the stepping mode excited by single channel saw-tooth wave voltage signal and the continuous mode excited by dual channel sinusoidal voltage signals with a phase difference of π/2. In the former mode, the resolution of step reaches 0.1 μm under driving frequency 20 Hz; while in the later mode, the motor moves stably during frequency band from 1.5 kHz to 5.8 kHz and its speed increases with the frequency. When the two sinusoidal exciting voltages are to be peak to peak of 100V,the offset of 50 V and a frequency of 5.8 kHz, the thrust of the prototype reaches 4.8 N. In conclusion, the proposed piezoelectric motor is capable of realizing both high resolution and long travel at dual operation modes.