基于耦合模型的地铁牵引电机轴承复合缺陷振动特性分析

Analysis of Vibration Characteristics of Metro Traction Motor Bearings with Combined Defects Based on a Coupling Model

为探究车辆运行工况下牵引电机轴承缺陷状态的振动特性,基于轨道-车辆耦合动力学及轴承动力学理论,提出一种包含齿轮传动系统和牵引电机的轨道-车辆-轴承耦合动力学模型。模型中综合考虑轨道不平顺、时变啮合刚度、轴承表面单一和复合缺陷等复杂激励。基于该动力学模型研究在轨道不平顺激励下牵引电机轴承在单一缺陷和复合缺陷状态下的振动特性。计算结果表明:相对于单一缺陷状态,牵引电机轴承在复合缺陷状态下所受到的缺陷冲击更加强烈和复杂;受轨道不平顺激励以及自身缺陷冲击的综合影响,电机轴承振动加剧;缺陷轴承的振动加速度会随着车辆运行速度的提高和缺陷宽度的增大而增大。计算结果可为牵引电机轴承的故障诊断和状态监测提供理论依据。

In order to detect the vibration characteristics of traction motor bearings with combined defects under vehicle running condition,a rail-vehicle-bearing coupling dynamic model including gear transmission system and traction motor was proposed based on the theory of vehicle-track coupling dynamics and bearing dynamics.Complex excitations,such as track irregularity,time-varying meshing stiffness,and single and combined defects,on the bearing surface are comprehensively considered in this model.Based on this dynamic model,the vibration characteristics of the traction motor bearing with single defect and compound defects excited by track irregularity are investigated.The calculation results show that compared with the single defect state,the defect impact of the traction motor bearing in the combined defect state is more intense and complex.Under the comprehensive influence of track irregularity excitation and its own defect impact,the vibration of motor bearing is aggravated.The vibration acceleration of the defective bearing will increase with the increase of the vehicle running speed and the defect width.The calculation results have provided a theoretical basis for fault diagnosis and condition monitoring of traction motor bearings.