Hello Everyone,

I am new to posting on this board, so up front thanks to anyone for any insight they can provide on this failure.

Attached is a picture of the inner bearing race from a double spherical roller bearing out of an overhung process blower. It was mounted in a pillow-block housing at the coupling end of the blower shaft. My question is, what caused this damage to the inner race? We are pretty sure it is the result of EDM from welding but wondering if there is any other way this damage could be caused. Thanks!

http://www.fag.de/NASApp/Access/index.jsp?lang=1 Here is a link to FAG web page. Rolling bearing diagnosis would be choice to view different failure modes of bearings. It appears that only one half of the bearing was loaded, this maybe due to bearing alignment, installation technique, worn housing, bent shaft and the list goes on.

If you think the damage was done by welding, then why only one race damaged and not both? Roller are touching in both races when at rest. Lack of lubrication is present due to the "blue" color present on bearing race. Looks like normal fatigue spalling in the other images. Do you have any other history to share? How old is the bearing, hours/day of operation, fan size, shaft speed, shaft size, bearing mounting etc..?