高速电主轴系统的极小子样试验评估方法研究

针对数控机床这类高可靠性产品的寿命实验数据极少的情况,为了提高数控机床高速电主轴系统的可靠性寿命评估精度,基于性能退化可靠性评估的理论对高速电主轴系统进行了机械应力仿真加载试验.对高速电主轴的退化数据,借助MATLAB软件利用最小二乘法对样本的退化模型参数进行估计,得出一次伪失效寿命.应用虚拟增广法和半经验评估法相结合的可靠性评估方法对高速电主轴系统进行了可靠性评估,得出了高速电主轴系统的平均无故障寿命均值的置信区间.与单纯地采用以往的半经验评估法进行可靠性评估的结果对比,进一步提高了高速电主轴系统在试验样本极小的情况下的试验寿命评估精度,为高速电主轴系统的可靠性研究提供了更加合理有效的评估方法.

The study on the extreme small-scale sample test evaluation method of high-speed motorized spindle system

Aiming at the very few data in life test of high reliability product on numerical control machine tools and in order to increase the reliability life assessment accuracy on the high-speed motorized spindle system of numerical control machine tools,the mechanical stress simulation loading test of the high-speed motorized spindle system based on the theory of performance degradation reliability evaluation was conducted.For the high-speed electric spindle degradation data,the sample of degradation parameters model was estimated by using least square method with the MATLAB software,and false failure life data were obtained.The reliability assessment method combined with the virtual augmented method and the semi-empirical evaluation method were applied for reliability assessment on the high-speed motorized spindle system,and the average trouble-free life mean confidence interval of the high speed electric spindle system was obtained.Compared the semi-empirical evaluation method,this evaluation method increases the accuracy of the test life assessment of the high-speed motorized spindle system in extreme small-scale sample size,providing a more reasonable and effective assessment method for the reliability research on high-speed motorized spindle system.