高速列车轴箱轴承典型故障特征的数值仿真分析

Numerical analysis for typical fault characteristics of high speed train axle box bearing

基于Adams建立考虑摩擦打滑和保持架效应的高速列车轴箱轴承完全动力学模型,分析高速列车轴箱轴承4种典型缺陷下滚子与保持架的故障动力学响应;通过EMD-包络谱抓取4种典型缺陷下的微弱故障信号特征频率,分析现有故障理论特征频率评估方法的局限性,并将EMD-包络谱方法抓取的特征频率与理论计算故障特征频率结果进行对比。研究结果表明:无论轴承是否存在缺陷,滚子的打滑率均在非承载区有所增大;外圈缺陷会导致保持架角速度比率呈正弦半波周期性变化;内圈缺陷会导致滚子角速度波动较大,保持架角速度偏高于理论角速度,保持架角速度比率呈非周期性激励波动变化,且波动频率较高;滚子缺陷仅对该缺陷的滚子的动力学特性影响较大;保持架缺陷对滚子与保持架的动力学特性的影响较小;理论特征频率计算公式需要充分考虑滚子-滚道摩擦打滑与滚子-保持架兜孔碰撞效应的影响。

A complete dynamics model of high-speed train axle-box bearings was established based on Adams software considering factors including friction, slippage and cage effects. The dynamic response was analyzed in relation to the rollers and cages of double-row tapered roller bearings with four typical defects. In addition, the characteristic frequencies were captured for the weak fault signals with four typical defects by EMD-envelope spectrum while the limitations that belong to existing theoretical characteristic frequency evaluation methods were analyzed. The characteristic frequency captured by EMD-envelope spectrum method was compared with the theoretical fault characteristic frequency. The results show that regardless of whether the defect occurs, the roller slip rate increases in the unload area. The outer ring defect leads to a sinusoidal half-wave periodic change in the cage angular velocity ratio. The inner raceway defect leads to a large fluctuation of roller angular velocity, the cage angular velocity is slightly higher than the theoretical angular velocity, and the cage angular velocity ratio changes with fluctuational aperiodic high frequency excitation. However, the roller defect only has great influence on the dynamic characteristics of the roller with defects. The cage defect has little effect on the dynamic characteristics of roller and cage. The influence of friction and slip between roller and raceway and the impact between roller and cage pocket should be fully considered in the theoretical characteristic frequency formula.