I have a problem with a bearing failure, the case is so complicated and I hope my English help me to explain it clearly :)
we have at our company a motor pump train that deal with kerosene with 40 hp, 2935 rpm, 3 phases, 380 volts. the history of the motor says that it undergoes repeated failures after about 1 year of continuous serviec. The motor burned out which concluded after investigation that the root cause was the DE damaged bearing (NDE bearing was Not damaged). For this motor according to the manufacturer data sheet the bearing is ball bearing with grease lubrication but for different reasons ( I think with water or somthing like that) in the past they have changed it to be shielded ball bearing from both sides and C3 internal clearance. the bearing manufacturer is KOYO and we suspect that the installed bearing was not C3 !! since the number typed on the damaged bearing is not including C3 which means that when the motor overhauled the installed bearing was not C3 if we can say so
my inquiries are:
- Did koyo write the type of internal clearance (C3) on their bearings ( not in the box, I mean on the baring itself)?
- Is the change that happened for the bearing internal clearance from C3 to CN for example cause the damage of the bearing? is it possible or will not be an issue?
- another thought that the bearing might need to be redesigned to increase its capacity, if so how can I find the reactions on the bearing if the rotor coupled with pump and there is a cooling fan at the other end of the rotor ?
Thanks a lot for any valuable help you offer and appreciate your patience to complete reading until here :)