Bearing Material Calculation

Your problem might or might not be with the bearing specifications or quality. Some other, probably more likely, issues may be in play:

Poor shaft alignment between motor and driven device.

Excessive overhung load (belt pulleys too small or located too far out on the shaft).

Lubrication not frequent enough.

Environmental, such as unsealed bearings in wet or dusty surroundings.

Please look also into those factors.

To the exact solution to the bearing failure, we must see what kind of failure is it undergoing. There are many types a bearing can fail. may be its by dry friction (no lubrication), or mis alignment, over load or higher speed or low rating. So in a nutshell, to come to proper conclusion, you need to see the trend of the failures. I think a failed sample of the bearing can pinpoint the cause.

One need more info re the failure to comment positively, however a good start will perhaps be that the bearings were exposed to ingress of liquids, washing out lubricant, lack/loss of lubricant, wrong lubricant. Which bearing failed? The rear bearing will most likely be misalignment and the front one ma be due to wrong bearing type, and since you mention a speed of 1500 to 3000, maybe cavitation as well. A type C3 or P6 bearing may serve you well. However make sure that your flowrate suits the pump speed.

Also make sure the installation is done correctly, ie pump size and power, and workload/duty

Are you using a VFD? VFDs can cause rotor shaft eddy currents that can damage bearings.

Dear Friend,

I want to supplement to the post No.5 that the VFD application - Motor bearing should be either INSULATED BEARING or conventional bearing to be provided with INSULATION.

Further, selection of the bearing for the specific application to be examined. Wrong selection means never ending trouble.

THANKS,

RAJESWARI