某飞机中心传动装置从动锥齿轮使用95.85 h后,在高空发生断裂;对该从动锥齿轮断口进行了宏观分析和金相检验,并对从动锥齿轮的组织、硬度和化学成分进行了检验,分析了断裂原因。结果表明: 中心传动装置从动锥齿轮的断裂是由于铆钉失效或粘接剂老化,造成衬套滑出与从动锥齿轮大圆端面摩擦烧伤,致使裂纹形成,最终裂纹扩展造成疲劳断裂。

The driven bevel gear of an aircraft center transmission device fractured after use of 95.85 h at the high altitudes. Macro analysis and metallographic examination were done to the fracture of the driven bevel gear, and microstructure, hardness and chemical composition were done to the fractured driven bevel gear. The results show that it was because the failure of rivet or aging of bonding agent that result in the sliding, friction and burning between the bush and the driven bevel gear great circle, and then cracks nucleated at the great circle of the driven bevel gear, expanded and finally fatigue fractured.