重型汽车后桥主动锥齿轮的失效分析

采用扫描电镜、光学显微镜、火花放电原子发射光谱仪、定氢仪以及布氏硬度计对重型汽车后桥主动齿轮失效原因进行了分析。结果表明:失效齿轮的各项性能指标均满足标准要求,氢含量较低,失效原因主要是由于预紧力过大致使在齿轮轴尾部螺纹空刀槽与花键连接处应力集中导致的延迟断裂失效。

Failure analysis of driving bevel gear of heavy truck rear axle

Failure reasons of a failed gear of heavy truck rear axle were analyzed by using scanning electron microscope,optical microscope,spark discharge atomic emission spectrometer,hydrogen determination instrument and Brinell hardness tester.The results show that all the performance indexes of the failure gear meet the requirements of the standard,and the hydrogen content is relatively low.The main reason for the failure is the delayed fracture failure caused by the stress concentration at the connection between the hollow groove of the screw thread and the spline at the end of the gear shaft.