某型矿车电动轮上的双联行星轮在运行过程中发生断裂。采用宏观观察、扫描电镜分析、金相检验、硬度测试等方法分析了该行星轮断裂的原因。结果表明:行星轮断齿处呈典型的疲劳断裂特征;裂纹源位于距离齿根次表面约2 mm位置,裂纹源处存在平行于齿宽方向的大尺寸纺锤形氧化铝夹杂物,裂纹从该处萌生并扩展,最终导致行星轮发生断裂。

The double planetary gear on the electric wheel of a certain type of mining car broke during operation. The reason for the fracture of the planetary gear was analyzed using methods such as macroscopic observation, scanning electron microscopy analysis, metallographic examination, and hardness testing. The results show that the typical fatigue fracture characteristics were observed at the broken teeth of the planetary gear. The crack source was located approximately 2 mm from the subsurface of the tooth root. There was a large-sized spindle shaped alumina inclusion parallel to the tooth width direction at the crack source, where the crack initiated and expanded, ultimately led to gear fracture.