Bearing Failure
Bearing Failure
(OP)
Dear All
The attached pictures ilustrates a wind generator N.D.E bearing failure.
I am interested in to know the possible causes for this damage.
Thanks and regards
Carlos
The attached pictures ilustrates a wind generator N.D.E bearing failure.
I am interested in to know the possible causes for this damage.
Thanks and regards
Carlos





RE: Bearing Failure
Bill
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"Why not the best?"
Jimmy Carter
RE: Bearing Failure
Basically I see heavy damage on inner race. Light damage on 1 or 2 balls. Some fretting on outside of outer race that doesn't seem unusual.
Can't see much of the outer race. What does the ball wear path look like on the outer race? Is it offset as if the bearing has been carrying thrust load? Is it tilted as if there was misalignment? Is it heavy as if there was excessive interference/lack of internal clearance ?
How do the shaft and housing fits compare to specification?
Looking at the inner race damage, it spans an arc of maybe 90 degrees. But the weird thing is that it goes almost all the way accross the width of the inner race. That seems unusual to me, usually spalls stay more toward the center where the balls run. Was there a lot of looseness present in the bearing before you removed it?
I see a few stripes in the inner ring pattern. Is it possible those are spaced at exactly ball spacing? (that would likely indicate damage that initially occurred while stationary, such as false brinnelling or pressing the bearing onto the shaft by pressing on the outer (vs inner) ring).
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(2B)+(2B)' ?
RE: Bearing Failure
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(2B)+(2B)' ?
RE: Bearing Failure
The lubricant is grease, the grease was very dark but we found loose fits in the bearing housings(shields), I think thats was the problem , attached you will find more pictures
Thanks again
Carlos
RE: Bearing Failure
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(2B)+(2B)' ?
RE: Bearing Failure
Just an idea.
rasevskii
RE: Bearing Failure
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(2B)+(2B)' ?
RE: Bearing Failure
http:/
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(2B)+(2B)' ?
RE: Bearing Failure
1 – the space heaters are are above the lower bearing, so may not be as effective for moisture coming past the shaft to bottom of the lower bearing.
2 – perhaps space heaters were secured for some period.
I think I will at some point combine it with our vibration data to produce a little whitepaper for another thread (don't want to side-track yours).
I'm wondering how this affects this particular failure.
The bearing does not appear to have been spinning in the housing (would have given distinct circumferential marks), so shouldn't generate heat from that interface.
I've heard fretting can cause crack that reduces fatigue strenght of ring leading to ring crack, but that did not occur.
Are you thinking that the debris from the fretting got into the bearing?
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(2B)+(2B)' ?
RE: Bearing Failure
Thanks
Bill
Bill
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"Why not the best?"
Jimmy Carter
RE: Bearing Failure
Any possibility of welding machine ground return finding its way thru the bearing?
Also outer race fit tolerance appears to have been excessive with consequent rotation in bearing landing.
RE: Bearing Failure
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If we learn from our mistakes I'm getting a great education!
RE: Bearing Failure
Scotty - that's a good one. I have a collection. I found most on google here:
Here is one from SKF:
http
One from Barden:
http
One from Koyo:
http:/
One from NSK:
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One from Fan OEM:
/url?sa=t&source=web&cd=1&ved=0CBgQFjAA&url=http%3A%2F%2Fw
One from Timken:
http:
Catalogue from NTN that includes section on bearing failures:
http://www.ntnamerica.com/pdf/Other/3017cat.pdf
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(2B)+(2B)' ?
RE: Bearing Failure
www.le
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(2B)+(2B)' ?
RE: Bearing Failure
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If we learn from our mistakes I'm getting a great education!