基于应变模态的数控机床滚动轴承可靠性检测方法

为了解决传统方法对物理参数的改变不敏感,只能对整个滚动轴承可靠性进行检测,无法针对不同测点获取可靠性检测结果,检测准确性低的弊端,通过应变模态研究数控机床滚动轴承可靠性检测问题。对各点的应变响应进行测量,得到应变振型。数控机床滚动轴承出现损伤后,应变模态一定会出现变化,同时损伤程度越大,这种变化越显著,滚动轴承可靠性越低。在对滚动轴承损伤进行识别的过程中,将应变模态差向量中元素最大绝对值作为依据,获取可靠性很低的位置。将应变模态改变率作为检测数控机床滚动轴承可靠性的敏感指标,对数控机床滚动轴承进行可靠性检测,对滚动轴承损伤前后前三阶应变模态进行提取,获取应变模态改变率,绘制曲线图,将突变部分当成损伤部分,完成对滚动轴承的可靠性检测。实验结果表明:所提方法可有效检测滚动轴承某一位置的可靠性;对数控机床滚动轴承可靠性检测结果最准确。可见所提方法能够获取不同测点的检测结果,检测准确性高。

Reliability Detection Method for Rolling Bearing of NC Machine Tool Based on Strain Modal

In order to solve the problem that traditional methods are insensitive to the change of physical parameters, only the reliability of rolling bearings can be tested, and the reliability test results can not be obtained according to different test points. The reliability test of rolling bearings of NC machine tools is studied by strain mode. The strain response of each point is measured and the strain mode is obtained. The strain mode will change when the rolling bearing of NC machine tool is damaged. At the same time, the greater the damage degree is, the more significant the change is, and the lower the reliability of rolling bearing is. In the process of identifying the damage of rolling bearing, the maximum absolute value of elements in the strain mode difference vector is taken as the basis to obtain the position with low reliability. The strain mode change rate is used as a sensitive index to detect the reliability of rolling bearings of NC machine tools. The reliability of rolling bearings of NC machine tools is tested. The first and third order strain modes before and after the damage of rolling bearings are extracted, the strain mode change rate is obtained, the curve is drawn, and the abrupt change part is regarded as the damage part to complete the reliability detection of rolling bearings. The experimental results show that the proposed method can effectively detect the reliability of a certain position of rolling bearings, and the reliability test results of rolling bearings of NC machine tools are the most accurate. It can be seen that the proposed method can obtain the results of different detection points, and the detection accuracy is high.