带定位板球轴承失效分析

Failure Analysis of Ball Bearing with Retaining Plate

通过对带定位板轴承失效的外观形貌检查分析确定外圈为首先失效件,同时对失效轴承各零件的尺寸、化学成分、材料及其热处理进行符合性检验,均未发现异常。分析外圈断口确定裂纹的起源位于外圈与定位板连接处的根部,并向外圈和钢球承载方向扩展,直至完全断裂。建立了轴承外圈应力分析有限元模型,借助Masta软件计算轴承所受载荷并加载到有限元模型中,得出定位板与外圈之间的拉应力过大是导致轴承外圈断裂的根本原因;通过减小定位板与壳体之间的间隙降低定位板与轴承外圈之间的应力,使轴承顺利通过变速箱耐久试验。

Through examination and analysis of appearance morphology of failure bearing with retaining plate,it is determined that the outer ring is the first failure part.At the same time,the compliance tests for size,chemical composition,material and heat treatment of each part of failure bearing are carried out,and no abnormality is found.By analyzing the outer ring fracture,it is determined that the crack originated at the root of connection between outer ring and retaining plate,and extended toward load direction of outer ring and steel ball until the crack is completely broken.The finite element model for stress analysis of outer ring of the bearing is established,and the load of the bearing is calculated and applied into finite element model with the help of Masta software.It is concluded that the excessive tensile stress between retaining plate and outer ring is the root cause of fracture of outer ring.By reducing the clearance between retaining plate and housing,the stress between retaining plate and outer ring of the bearing is reduced,so that the bearing passes the durability test of gearbox smoothly.