数控机床主轴磨损失效的MTBF预测及实验研究

Experimental Research and Prediction to MTBF of CNC Machine Tool Spindle Based on Wearing Failure

目前数控机床的MTBF主要通过统计得到,这就带来跟踪统计时间长、数据量大等弊端。用数控机床加工零件时,由磨损引起的主轴振动的振幅会随着时间的增加而增大,当磨损量达到极限值时,振幅激增,加工零件质量不达标,此时认为主轴失效;由此可以通过振幅、磨损与时间之间的关系推算出数控机床主轴的MTBF。针对主轴的磨损失效,提出一种通过数控机床的振动试验来预计主轴MTBF的方法,并结合具体机床进行实验分析和验证。

Presently, the MTBF of CNC machine tools is obtained mainly through statistics, which needs a long time to get a large amount of tracking data and also has other problems. While CNC machine machining products, the spindle vibration amplitude caused by wear and tear is increased with time increasing. When the wear limit is reached, the amplitude is surging, the products are incompetent, and spindle breaks down. Thereout, the MTBF of the spindle can be calculated by the relationship of wear, amplitude and time. For wear failure of the spindle, an approach was presented to expect MTBF by vibration testing of the machine tool. Experi- mental analysis and verification were given on the practical machine tool.