【摘要】 滚动轴承的故障所导致的内部接触状态的变化是滚动轴承振动特性发生改变的重要原因。根据故障与滚动体可能出现的接触形式,考虑故障演化过程中的不同故障大小,建立了圆柱滚子轴承存在不同程度故障时的多体接触动力学有限元模型,并通过滚动轴承外圈故障实验验证了模型的有效性。基于显式动力学法对滚动体与各组件间的动态接触力及故障区域的接触应变进行分析,揭示了不同故障程度对轴承内部接触动态特性的影响规律及故障情况下接触变形的变化规律。研究结果表明:滚动体在越障期间与各组件的接触力减小,随着故障程度的加剧,轴承内部接触力波动越发剧烈,但接触应变的波动频率和幅值降低;故障轴承滚动体在承载区与保持架兜孔两侧均会接触,使接触力出现负值;故障趋向于沿着滚动体滚动方向扩展。研究结论可为滚动轴承故障诊断及残余寿命预测提供理论依据。更多还原

【Abstract】 The change in the internal contact state caused by the failure of the rolling bearing is an important factor that causes the change in its vibration characteristics. According to the contact form of the fault and the rolling element,this paper considered the different sizes of the fault evolution process,and established the dynamic finite element model of the multi-body contact of the cylindrical roller bearing with different degrees of failure. The effectiveness of the model was verified by the experiment on the outer ring fault of the rolling bearing. Based on the explicit dynamics method,the dynamic contact force between the rolling element and each component and the contact strain of the fault area was analyzed,then the influence law of different fault degrees on the internal dynamic characteristics of the bearing and the change law of the contact deformation under the fault condition were revealed. The results show that the contact force of the rolling elements with the components is reduced when the defects are crossed. As the degree of failure increases,the fluctuation of the internal contact force of the bearing becomes more and more intense,but the fluctuation frequency and amplitude of the contact strain decrease. In the loading area,the rolling elements of faulty bearing are in contact with both sides of the cage pocket,which causing a negative contact force. The fault tends to expand along the rolling direction of the rolling element. The research conclusion can provide a theoretical basis for fault diagnosis and residual life prediction of rolling bearings.更多还原