高速列车齿轮箱箱体动应力影响规律

通过线路测试研究了列车运行速度、线路条件与车轮镟修对齿轮箱箱体动应力的影响规律, 结合轴箱振动加速度分析了箱体动应力的变化规律。研究结果表明: 齿轮箱箱体动应力与轴箱垂向加速度的幅值谱基本一致, 主频均为570 Hz, 反映了箱体动应力水平与轮轨相互作用产生的高频激励密切相关; 列车运行速度由200 km·h-1增大到300 km·h-1时, 齿轮箱箱体的应力幅值呈现增大趋势, 尤其在箱体开裂的齿面检查孔位置, 其等效应力由5.56 MPa增大至16.67 MPa, 增大约2倍; 轨道磨耗造成的不平顺对列车轴箱和齿轮箱箱体的振动具有较大的影响, 列车由磨耗线路运营至打磨线路时, 轴箱高频阶段振动幅值水平明显降低, 箱体关键点的等效应力由16.26 MPa减小到10.16 MPa, 减小38%;车轮高阶多边形在列车高速运行时(300 km·h-1) 产生的高频(550~650 Hz) 激扰造成箱体高频振动和动应力、等效应力大幅提升, 箱体关键点的等效应力在镟轮前后由17.45 MPa减小到8.56 MPa, 减小51%。可见, 轨道打磨与车轮镟修均改善了齿轮箱箱体的受力状态, 因此, 选择合理的轨道打磨和轮对镟修周期可有效延长齿轮箱箱体的疲劳寿命。 

Influence rule of dynamic stress of high-speed train gearbox housing

The influence rules of running speed, line condition and wheel profiling on the dynamic stress of gearbox housing were studied based on the line test, and the change rule of dynamic stress of gearbox housing was analyzed combined with the vibration acceleration of axle box. Analysis result shows that the amplitude spectrums of dynamic stress of gearbox housing and the vertical acceleration of axle box are the same, and the main frequency is 570 Hz, which reflects that the dynamic stress level of the housing is closely related to the high frequency excitation caused by wheel-rail interaction. When the train running speed increases from 200 km·h-1 to 300 km·h-1, the stress amplitude of gearbox housing shows an increasing trend, especially in the tooth surface inspection hole of cracking housing. The equivalent stress increases from 5.56 MPa to 16.67 MPa, which is about 2 times larger. The irregularity caused by the rail wear has a great influence on the vibration of axle box and gearbox housing. When the train is running from worn line to grinding line, the vibration amplitude level of axle box in high frequency stage obviously reduces, and the equivalent stress of key point of the housing reduces from 16.26 MPa to 10.16 MPa, which decreases by 38%. The high frequency (550-650 Hz) excitation caused by the high-order polygon of the wheel at high speed (300 km·h-1) causes the high frequency vibration, the dynamic stress and equivalent stress of the housing increase substantially, and the equivalent stress of key point of the housing decreases from 17.45 MPa to 8.56 MPa before and after wheel profiling, which decreases by 51%. So rail grinding and wheel profiling can improve the stress state of gearbox housing. Therefore, reasonable rail grinding and wheel profiling cycle can effectively prolong the fatigue life of gearbox housing.