差速器齿轮失效分析

皮卡在进行整车传动系统冲击试验时，后桥差速器齿轮失效。通过对齿轮进行成分分析、金相分析和断口分析，排除材料组织缺陷和母材质量问题。通过建立用实测数据进行校准的有限元模型，模拟齿轮在失效工况下的受力情况，确认齿轮失效的根本原因。结果表明:轮齿强度不足是齿轮失效的根本原因。在优化设计后，采用CAE对优化方案辅助分析并获得通过，再用台架试验进行验证并进行整车验证，解决该问题。同时提出提高齿轮强度的建议，该研究为预防同类故障的发生提供参考。

Failure Analysis of Gear of Differential Mechanism

The rear axle differential mechanism gear of a Pickup failed in the impact test of the whole vehicle transmission system. By chemical composition analysis, metallographic examination and fracture analysis of the gear, it is found that the failure of the gear has nothing to do with the defects in the material and the quality problem of the base metal. A finite element model calibrated with measured data was established to simulate the stress of the gear under the failure condition, and the fundamental cause of the gear failure was determined. The results show that the insufficient strength of the gear tooth is the fundamental cause of the gear failure. After design optimization, CAE was used to analyze the optimized scheme and the scheme was passed. Then bench experiment was used to verify this new scheme and whole vehicle verification was also carried out to solve the problem. At the same time, suggestions were put forward to improve the gear strength. The present work can provide reference for preventing the occurrence of similar faults.