基于滚珠丝杠副可靠性试验台研究了滚珠丝杠副预紧力的变化与测得的振动信号的关系.首先,介绍了滚珠丝杠副可靠性试验台的预紧力加载装置;接着,对预紧力加载装置进行动力学建模,搭建振动信号测试平台,采集不同预紧力水平下的振动信号;最后,通过振动信号的频域分析和预紧力加载装置的动力学分析,发现预紧力的变化可以通过两个参数进行监测:振动信号峰值频率的偏移和峰值频率振动幅值的变化.实验结果和动力学分析的结论十分吻合:随着滚珠丝杠副预紧力的增大,峰值频率不断增大,峰值频率的振动幅值也不断增大.研究结论发现,可以通过监测振动信号峰值频率的偏移和峰值频率的振动幅值来监测预紧力的变化,这为检测滚珠丝杠副的健康水平提供了一种新的研究方法,这对于促进滚珠丝杠副进给驱动系统的发展具有重大意义.%Aiming at examining the relationship between the ball screw preload variation and detected vibration signals.A preload-adjustable ball screw feed drive system based on a servo motor is constructed.Meanwhile,a lumped dynamic model to study the preload variation of the system is proposed.A MEMS accelerometer based sensing system is implemented for obtaining experimental data from the constructed feed drive system.Signals at the ball nuts are acquired and analyzed.Through spectrum analysis of the processed signals and the results of mathematical dynamic modeling,the preload variation can be diagnosed in two indexes: peak frequency shift and the magnitude variation of its peak frequency.The experimental results,agreeing with the trend of mathematical modeling,show peak frequencies display increasing values as the preload steps up and the peak power levels exhibit rising trends as the adjusted preload level of the ball screw increases.This study provides an approach to monitor the health status of the used ball screw,which can be significant for better performance of the feed drive system.
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