In one of our HT motor we found inner race defect with side bands of 1XRPM in the spectrum and yesterday we inspected the bearing and found inner race was cracked.But the history of the equipment says it has already two breakdowns with inner race problem.During the first time inner race was having dent and during second time inner race got seized.
NDE bearing:NU 228
DE bearing:NU 234 + 6234
What could be the cause of repetitive inner race damage ???
Thanks in advance.