减速器齿轮轴断裂失效分析

Fracture Analysis of the Gear Shaft of the Reducer

运输带转向减速器在运行过程中,其齿轮轴发生断裂,通过成分分析、力学性能检测、宏观及微观金相观察、扫描电镜分析等手段,分析了该减速器齿轮轴断裂失效的原因。结果表明:齿轮轴断裂形式为旋转疲劳断裂,齿轮轴与电机链接的R角位置存在应力集中,运行时引起了疲劳裂纹的萌生及扩展,最终造成齿轮轴的断裂。提出了改进建议:运用超声冲击表面强化技术,对齿轮轴R角部位进行超声冲击,形成预制压应力场,减缓疲劳裂纹萌生,延长使用寿命。

During the operation of the transport belt steering reducer,its gear shaft might break.The reasons of the fracture were analyzed through composition analysis,mechanical performance testing with the aid of macroscopic and microscopic metallographic observation and scanning electron microscopy analysis.The results show that the fracture mode of the gear shaft was rotational fatigue fracture,and there was stress concentration at the R-angle position of the connection,between the moving shaft and the motor.During operation,it might cause the initiation and expansion of fatigue cracks,ultimately leading to the fracture of the gear shaft.It is proposed that ultrasonic peening strengthening technology can be used to perform ultrasonic peening on the R corner of the gear shaft to form a prefabricated compressive stress field and slow down the initiation of fatigue cracks,and thus the service life can be extended.