某型燃气轮机圆柱滚子轴承失效原因分析

Failure Cause Analysis of Cylindrical Roller Bearing of a Gas Turbine

某型燃气轮机圆柱滚子轴承在加速寿命试验时发生了外圈滚道承载区域疲劳剥落现象。为查明失效原因,针对轴承试验件开展了尺寸精度、径向游隙、滚动表面轮廓、材料化学成分、显微组织等9项检测工作,并复查了试验系统和设备的工装尺寸和加载头设计原理。经综合分析,判断轴承试验件的失效原因为:加载套内径尺寸偏小,且选用材料硬度偏低,在使用紧固螺栓拉紧固定时,加载套导致自身及试验轴承的椭圆变形,进而引起轴承外圈的提前疲劳剥落。上述分析工作准确地定位了轴承失效原因,改进试验系统,有力地保证了某型燃气轮机圆柱滚子轴承加速寿命试验的顺利开展。

Fatigue spalling occurred in the bearing area of outer raceway of a gas turbine cylindrical roller bearing during the accelerated life test.In order to find out the cause of failure,9 tests including dimension and accuracy inspection,radial clearance inspection,rolling surface profile inspection,chemical composition of materials inspection,and microstructure detection were carried out.In addition,the test system and equipment tooling size and loading head design principle were also reviewed.After comprehensive analysis,the causes of failure are judged as follow:inside diameter of loading sleeve is too small,hardness of loading sleeve and external sleeve of bearing are too low.When fastening bolts were used to pull and tighten,the elliptic deformation of loading sleeve and test bearing were caused,and then the fatigue spalling of bearing outer ring in advance were caused.The analysis work of this paper effectively guides the improvement design of the test system,which effectively ensures the smooth progress of the accelerated life test of cylindrical roller bearing of the gas turbine.