Attached are some pictures I received via email. Wondering if any of you guys can tell, from the pictures, what might have happened to these bearings. Do not a picture of the other half of the two bearings.

Here is another picture.

Another Picture.

Ralph,

What type of equipment is it?

Regards,

it is a 10327 RPM air blower. Do not know the brand of the blower.

Got model and maker:

Roots-Dresser Model HN194

This message has been edited. Last edited by: Ralph Stewart,

Oil loss or contamination?

Walt

Looks like it oveheated, either due to lack of lube or perhaps over load...

If overload, it looks dynamic, maybe a very very high vibration level..

Where did the water come from? Lots of rust spots and water drops, or was it just raining when they pulled the bearings?

Water in the oil might cause this....

quote:

Where did the water come from? Lots of rust spots and water drops, or was it just raining when they pulled the bearings?

Water is from old bearings laying on the pedestal for a few days in the weather. Failed about a week ago.

Blower was down for about 6 weeks during a major outage. Was running good before outage. No one seems to know what was worked on during the outage. If bearings were not opened, maybe condensate or rain might have gotten in them. Both failed. Seems like loss of oil would be the problem. Just thought may someone would know why the "side" pads failed and the center one did not. Sort of like it was squeezed from the sides, but then again, both inboard and outboard? Seems strange.

ANY VIEWS REGARDING BEARING FLUTING OR EDM? FIRST AND THIRD PADS IN FIRST PHOTOGRAPH SHOW SIGNS OF FLUTING PATTERN. FAILURE OF BOTH INBOARD AND OUTBOARD BEARINGS SUPPORTS THIS THEORY.MAY BE OUTBOARD BEARING INSULATION FROM SHAFT MIGHT HAVE NOT BEEN PUT BACK DURING OVERHAUL PROVIDING PATH FOR EDDY CURRENT FLOW.
REGARDS
IRSHAD AKHTAR

what characteristics are you looking at that suggest fluting to you? I don't see it.

quote:

Originally posted by electricpete:
what characteristics are you looking at that suggest fluting to you? I don't see it.

Pete,
Pl. see the matter on CSI website. http://www.compsys.com/drknow/aplpapr.nsf/06b6f5a4de2ea...062f412?OpenDocument

AKHTAR,

I think everyone on here knows what Elect. Fluting is. It has been beat for many an hour. However, what EPETE is saying I think, and what I will re-iterate, is where in those pictures do you see any fluting?

Those striations on the side bearings are going in the wrong direction for one, and they certainly look to me to be from a wiped (either no oil or very little oil) bearing. There may have been contaminants in what little oil was left on the bearing, or they (the striations) may be from the bearing material itself scoring the base metal.
I'm sorry, I just don't see fluting.

Dave

quote:

Steve Schultheis Posted Aug 15, 2008 12:48 PM
Looks like it oveheated, either due to lack of lube or perhaps over load...

If overload, it looks dynamic, maybe a very very high vibration level..

Question on overload and startup.

Is there a suggested or recommended procedure for starting this high of an rpm blower up loaded vs unloaded? Should the suction valve be closed or at least partially closed on startup?

Seems as no one is sure of the startup procedure.

Any ideas? This is not the first time a bearing has been lost. Second time in several years (10). No repeative problem of bearing failure but First time both have failed at the same time.

It looks like some impurities have crept into the bearing along with the oil;OR less bearing clearance.....
Was the shaft journal repaired with any kind of coating??

Sudin,

No shaft repair required.

Bearings were replaced, now running.

Problem not really found.

Down for maintenance:
No tagging or records - oil drained - not replenished? Or flushed and not replenished? Enough left in for six weeks or ?????

A rub is evident I think. NO on-line system or no vibration commissioning data or monitoring of any kind?

I would create the problem and recommend records keeping to avoid future similarities; or, I could be wrong.

quote:

Originally posted by Ralph Stewart:
Just thought may someone would know why the "side" pads failed and the center one did not.

Could it be the rub start from one side of the pad, bring the big chunk to the bottom center pad to be squezed by the shaft and bounce to hit the other side of the pad?
it will be nice if we can know the shaft center position during operation...and its movement during startup or load changing.