Pump shaft sheared

[Lilly_29]

Hello Everybody,

A multistage centrifugal pump between bearing type, (160 M3/hr, 450 KW) undergone a failure with its shaft broken. Location point of sheared area is DE side of pump and just underneath inner of cylindrical roller bearing. clear signs of overheating found with bearing and shaft became blackish. Vibration trends before 15 days of failure event detected normal operation without any abnormal signature. Pl have a look at cross section of the broken shaft and mention your comments what type of failure mechanism indicated by these patterns. how much time it takes to develop such failure in case of lack of lubrication in a continuous operation.

 

[TugboatEng]

I don't know what you expect to learn here. Your bearing got so hot it caused the shaft to fail likely by a reducing in strength. There is nothing to read from the failure surface because it rubbed on itself and ground away any indications. We can tell the failure initiated in the bearing because there are indentations from the rollers.