低温环境下超声电机定子特性

Stator Characteristics of Ultrasonic Motors Under Low Temperature Condition

超声电机是一种新型的驱动器,由于其具有大力矩/重量比,控制性能好等优点,适合在航天器上使用,因此,在低温环境下对超声电机性能的变化进行研究就非常必要。分析了在低温环境下,超声电机定子弹性体和压电陶瓷元件性能变化,改进了不同环境下超声电机用压电陶瓷的压电方程,并通过该方程推出了压电陶瓷元件的d33随着温度的下降而降低。结合超声电机定子振动,归纳出低温环境下,超声电机定子对超声电机性能下降的影响。通过超声电机在低温环境下的性能测试,验证了低温环境下超声电机定子性能变化的理论分析。得到结论:压电陶瓷在低温环境下的性能下降是影响超声电机定子性能变化的主要原因。

Traveling wave type rotary ultrasonic motor（TRUM） is a new kind of driver suitable for space engineering because the motor has some advantages of superior torque/mass ratio, good control performance and so on. The space temperature environment is necessary under low temperature condition. In this paper, the stator and piezoelectric material （PZT） of ultrasonic motor, characteristics about PZT and the stator are analyzed under the low temperature condition according to the vibration of the stator. The effects of PZT and stators on the characteristics of the ultrasonic motor are studied under low temperature condition. An improved constitutive model for the temperature-dependent piezoelectric properties is presented. Using the model, the result shows that d33 of PZT decreases with the temperature decreasing. So, the characteristics of the ultrasonic motor decrease with the temperature decreasing. An ultrasonic motor is tested under the low temperature condition. Testing results show that characteristics of the ultrasonic motor decreases under the low temperature. Thus, the testing result is in agreement with the analysis result.