RCA of bearings 2

[Muhammad Mazher]

Hi everyone! I am seeking advice from experts regarding the root cause analysis for an incident at our petrochemical plant. Specifically, one of the critical blower fan's bearings on the coupling side seized, despite satisfactory oil level and condition. While one bearing remained operational, the incident has raised concerns about our maintenance practices. I am keen to understand potential issues with oil distribution and the effectiveness of lubrication within the bearing housing. Any insights or recommendations from experienced professionals would be greatly appreciated. I am attaching pictures for clear observation.

 

[3DDave]

What company made the bearing?

 

[geesaman.d]

One more thing to note that it was a locating side bearing while the other one was non locating side.

So with this bearing being a locating bearing, was the set of rollers that failed the rollers that supported thrust, or the roller set that did not take thrust?

I see locknut threads - is this a "K" taper sleeve mount, such that you have adjustment in the final radial endplay?

Less related - Based on comparing the cage bars between the failed cage and a new cage, how much wear was present in the cage bars?

 

[Muhammad Mazher]

@geesaman.d
Yes these rollers were thrust supported.

 

[geesaman.d]

Each bearing has two sets of rollers. Was the failure in the set of rollers that bore the thrust load, or the other set of rollers?

Also is the bearing mounted on a tapered sleeve?

 

[3DDave]

I do have this inspiration - that the oil looks great because the oil pump wasn't working to circulate it or the oil passages were plugged.

 

[electricpete]

I have seen a few loss of oil events. Rolling elements, cage and races ended up mostly black and adjacent area on the ring stained brown. To my thinking that appearance is the result of a slow global overheating event which occurs after loss of oil and is global affecting all those things uniformly. In contrast what we see in the OP photo are signs of rapid localized overheating (indeed enough to melt things) but not sustained heating of the whole bearing (other than as noted the shaft which may have had inner ring spinning on it at some point in time).

That's not really scientific, just the way I see it. Maybe there are different appearances for different bearings at different speeds and loading with different oil types or different rates of loss of oil (sudden or rapid oil loss). But fwiw this just doesn't feel like loss of oil to me...

Then again, I appreciate Tmoose's linked photo. That sums up my ability to nail down what happened with any degree of confidence. Which is not to say it's not worth proposing ideas and asking more questions. But I'm backing out, I have no more input about what happened.

To op - thanks for providing the requested info, but now that we've seen it, I don't know what to do with it.

Actually I will revisit one theme. Regardless of exact circumstance of this failure, it is somewhat expected that you will have occasional things like this happening if you have a critical rolling bearing machine without any condition monitoring. Among other things, rolling bearings can and do experience fatigue spalling. It generally starts on a small scale and is easily detected in early stages with vibration monitoring, but if undetected and unaddressed, the damage will continue spreading until the machine grabs your attention (by stopping if that's what it takes). Monitoring by experienced operators who pay close attention (whether by sound or feel or screwdriver) can also be a pretty good screening system. But if you have none of those then imo type of thing is an eventual inevitability.