Abstract: In order to solve the problem of bending fatigue fracture of the main reduction gear of a hybrid transmission in bench endurance test, the failure cause was determined and three measures were implemented through CAE and test comparison and fracture analysis. The simulation model based on MASTA software has been updated through carefully taking stiffness of abnormal gear shaft into account. Effect of stiffness change along circumferential direction on the gear fatigue strength has been studied, and simulated gear contact pattern matched test result now. A test standard which is suitable for this hybrid transmission is build. Taking stiffness of abnormal gear shaft as noise, design for six sigma method is used to design a high robust gear pair. The way to consider abnormal shaft, the method to build new dyna test standard and the procedure to design gear in this paper can be meaningful to engineering application of gear design.

Key words: Gear strength; Endurance test; Hybrid transmission; Gear fatigue fracture; Design for six sigma

摘要： 为解决某款混合动力变速箱的主减速齿轮在台架耐久测试中发生弯曲疲劳断裂的问题， 通过 CAE 与试验对比、断口分析，确定失效原因并实施三项措施。通过考虑安装齿轮的异形 轴刚度，改进变速箱 MASTA 仿真模型，得到与试验一致的齿轮接触斑点，并确认异形轴圆 周方向刚度的变化会对相应位置的齿轮强度造成影响。按照疲劳损伤积累原理，推导并制定 更贴合实际的齿轮耐久考核工况。以异形轴刚度为噪声因子，利用六西格玛设计方法设计一 组稳健性较高的齿轮参数，保证该变速箱通过了试验。这些研究内容可以为齿轮设计工作提 供有效参考。

关键词: 齿轮强度；耐久试验；混合动力变速箱；齿轮疲劳断裂；六西格玛设计