杆端关节轴承失效分析

Failure Analysis of Rod End Joint Bearing

针对直升机杆端关节轴承杆端体多次出现断裂故障进行失效分析,通过断口宏微观观察、材质检测、能谱分析、裂纹源周围特征观察以及疲劳试验件断口分析等,结合对未装机国产件和进口件杆端体内壁加工表面观察对比,分析出故障件的断裂性质为疲劳断裂,断裂起源于杆端体内壁与轴承外圈的微动磨损处,故障件发生微动磨损的原因与杆端内壁表面加工方式不合理有关。为深入查找原因,对改进工艺后的同一型号国产件通过不同装配方式进行疲劳试验性能分析和疲劳断裂件失效分析,得出采用温差装配改进后的轴承可最大程度的降低发生疲劳断裂的风险。

Fracture occurred to the rod end bodies of the rod end joint bearings in helicopters for several times.In order to find out the failure cause,macro and micro observation,hardness testing,energy spectrum analysis,and fracture analysis of the fatigue test parts were carried out.In addition,the inner wall characteristics of new domestic and imported rod end bodies were observed and compared.The results show that the fracture mode of the rod end bodies is fatigue fracture.The fatigue cracks initiated from the fretting wear position of the rod end baby inner wall.The fretting wear of the rod end body inner wall was mainly related to unreasonable processing.Furthermore,domestic parts by improved processing were assembled by different means and then their fatigue performances and characteristics were analyzed.It was found that the assembly means of temperature difference can reduce the fatigue fracture to the greatest extent.