地铁列车减速器直齿轮弯曲疲劳有限元分析与试验

为研究地铁列车减速器小齿轮齿根部受力情况及弯曲疲劳裂纹萌生的机理,通过建立齿轮副有限元模型,对齿轮啮合过程进行瞬态动力学分析,得到了齿轮啮合过程中齿根处的应力-时间历程进而对齿根弯曲疲劳行为进行了试验研究。瞬态动力学分析表明,小齿轮齿根处在啮合过程中受到脉动循环载荷的作用,最大拉应力出现在齿轮啮合至分度圆时;且齿根处最大主应力的方向为沿齿根切线方向。齿根弯曲疲劳试验结果表明,裂纹在齿根弧线的中间位置萌生,方向为齿根切线的垂直方向。结合有限元分析结果可发现,齿根处裂纹在最大拉应力幅值位置萌生,其扩展行为受最大拉应力的主导。为进一步优化齿轮的设计、制造工艺及材料的选择提供了依据。

Subway Train Speed Reducer Gear Finite Element Analysis and Fatigue Test

For the study of the subway train speed reducer small gear tooth root stress distribution and the mechanism of fatigue crack initiation, by establishing a finite element model of gears, the gear meshing process transient dynamics analysis, obtained in the process of gear engagement and stress of tooth root of the tooth root bending fatigue behavior were studied. Transient dynamics analysis shows that the pinion gear tooth in meshing process by pulsating cyclic load, the largest tensile stress in the gear mesh to standard pitch circle, and the direction of maximum principal stress of the tooth root of along the tooth root of tangent direction. Tooth root bending fatigue test results show that the crack in the intermediate position of the dedendum arc initiation, direction of tooth root the tangent of the vertical direction, combined with finite element analysis results can be found that the root of crack initiation in the maximum tensile stress amplitude position, its expansion behavior dominated by maximum tensile stress. This in order to further optimize the design of the gear, manufacturing process and provides evidence for the selection of materials.