汽轮机给水泵机组双联泵失效分析

Failure Analysis of Double⁃pump of Feed⁃water Pump Unit Turbine

为研究某汽轮机给水泵机组双联泵的失效原因,对双联泵进行解体检查,发现其轴断裂,轴承及轴上连接部件等也有不同程度的损坏。对双联泵主要受损部件进行宏观检查,对断轴的化学成分、金相组织、力学性能、断口形貌进行系统的分析,并对轴、键、轴承等部件进行了失效分析及计算。结果表明:双联泵轴承轴向预紧力过大,降低了轴承工作寿命,导致接触疲劳失效,引起轴倾斜,使得轴上转子卡住,最后轴因负载过大被扭断。研究结果为分析类似轴断裂原因提供参考。

In order to study the failure reason of the double⁃pump of a feed⁃water pump unit turbine,the double pump was disas⁃sembled and inspected.It was found that the shaft was broken,and the bearing and the connecting parts of the shaft were also damaged in different degrees.The main damaged parts of the double⁃pump were macroscopically inspected,the chemical composition,metallo⁃graphic structure,mechanical properties and fracture morphology of the broken shaft were systematically analyzed,and the failure anal⁃ysis and calculation of the shaft,key,bearing and other parts were carried out.The results show that the axial preload of the double⁃pump bearing is too large,which reduces the working life of the bearing,causes contact fatigue failure and the shaft tilt,makes the ro⁃tor on the shaft stuck,and finally the shaft is twisted off due to excessive load.The research results can provide reference for analyzing the similar shaft fracture cause.