变速箱齿轮断裂分析

Failure analysis of the transmission gear

某公司重型卡车变速箱齿轮在使用较短的时间后发生断齿事故。对断口进行宏观及微观分析,采用化学成分分析、硬度检测、显微镜观察及扫描电镜观察等手段对断齿齿轮进行了失效分析。结果表明:齿轮断裂形式为弯曲疲劳断裂,主要原因为齿轮次表层存在大尺寸的非金属夹杂导致了严重的应力集中。

A company’s gear for heavy truck transmission occurs fracture.Failure analysis was carried out on the gear by chemical composition analysis,hardness testing,metallographic observation and scanning electron microscopy(SEM).The result showed that the gear fracture mode is bend fatigue fracture,the main reason for the fracture is serious stress concentration caused by large size nonmetallic inclusions in subsurface layer of the gear..