预紧对蠕动式被动箝位压电驱动器性能的影响

Influences of preloads on performance of inverse piezoelectric inchworm motor

为研究不同预紧力条件下被动箝位直线压电驱动器性能的变化规律,对前期研制的箝位体具有三角放大结构的被动箝位直线压电驱动器进行研究,采用测量箝位保持力的方法间接评价预紧力的大小,测试4种预紧状态下驱动器的箝位保持力、空载特性和负载特性.实验结果表明,随着预紧力的增加,驱动力呈现先增后降的变化趋势.预紧力较小时,驱动器运行速度较快,最大运行速度为1.43 mm/s,但驱动力较小;预紧力较大时,驱动器性能较低;合适的预紧状态可以使驱动器驱动力达到最大值2.1 N.测试驱动体振幅随驱动频率的变化规律,利用振动悬浮现象揭示驱动器速度随着驱动频率的增加呈现先增后降的变化规律.

To analyze the performance of inverse inchworm motor under different preloads,experiments are carried out based on an inverse piezoelectric inchworm motor researched and manufactured before. In the experiments,the clamping force is used to describe the preload indirectly. The clamping forces,no-load characteristics and load characteristics of the inverse piezoelectric inchworm motor are tested under four different preloads. The results show that the driving force increases first and then decreases with the increasing of preload. When the preload is low,the high velocity of motor is 1. 43 mm / s,but the driving force is low.When the preload is high,the performance of inchworm motor becomes worse. The best performance can be reached under proper preload and the maximum driving force is 2.1 N. The amplitudes of vibration of driving part have been tested with different driving frequency. When the frequency is high,the amplitude of vibration decreases,and the velocity of motor first increases and then decreases with the increasing of frequency.