电梯减速箱输出轴断裂失效分析

Failure Analysis of Fracture of the Output Shaft of the Elevator Gearbox

针对一起电梯减速箱输出轴断裂失效案例,通过宏观检查、成分分析、金相组织分析、硬度测试、断口显微分析等检测手段,对断轴进行分析。结果表明:减速箱输出轴由于内部存在疏松、氧化物夹杂、孔洞等缺陷,这些缺陷的存在产生局部应力集中,在电梯升降过程中,在承受的交变载荷作用下,加速该处疲劳裂纹源的形成。裂纹在此处萌生并由此向四周扩展,最后发生疲劳断裂。

According to the failure of the output shaft of the elevator gearbox,by means of macro-examination,component analysis,metallographic structure analysis,hardness test and fracture micro-analysis,the fracture of the output shaft was analyzed.The results show that there were some defects in the output shaft of gearbox,such as looseness and oxide inclusions and holes,which resulted in local stress concentration.During the elevator lifting process,under the action of alternating load,the formation of fatigue crack source was accelerated.The crack initiated here and then spread around,and finally fatigue fracture occured.