ball / roller bearings wearing shafts

[Tmoose]

Does anyone have pictures of shaft wear resulting from races spinning/creeping when interference is inadequate, or locking mechanism fails?

thanks,

Dan Timberlake

 

[Skogsgurra]

This is a bad example. It is taken from a test rig that was built a little too quickly.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[TheRocketScientist]

Sure, how's this:

http://s19.photobucket.com/albums/b172/Rocket_Science_442/?action=view&current=7297_SHAFTS12.jpg

These were 1" shafts to start with

Tries set screws at 60 and 120 degrees, Loctite on the set screws and the shaft, PEER brand piching collars [fail], eccentric rings, etc.

all methods have some fails, some just take longer and some fail more rapidly and in greater number.

 

[Tmoose]

Thanks !

 

[unclesyd]

I have found over the years that a change in lubricants will mitigate a lot of these type problems or a least get you to where the baring and or shaft are not basket cases when you are asked for assistance.

For the pillow bearing in the referenced photo I would use a water resistant high EP bearing grease. On very similar situations on boats and at work I use Lubrication Engineer's 1275 or 3752 products.
I have gotten a lot of my farming buddies to switch to this type lubricant which has resulted in much improved farming equipment on stream time due eliminating these type failures.

http://www.le-inc.com/productPages.jsp?productID=198

 

[Tmoose]

Hi Unclesyd - you advocate lubing the shaft and bearing ID?

Dan T

 

[unclesyd]

Not really, it's the ball or rollers.
Over the years I probably receive as many dead or dying bearings and shafts as most anyone in industry, except the bearing industry, Early one I found that ascertaining the cause or mode of failure of a dead bearing was near impossible even with access to a complete metallurgical laboratory. My approach was install a like bearing and improve the lubrication to where I could get some data before failure, This was long before any practical analytical instruments for bearings. During the evolution of this investigative technique I found that over 60% of the bearing failures other than miss applications, poor installation, and over lubrication could be resolved by a change in lubricants.
Even with advent of better analytical instruments and a dedicated vibration group I was able to prevent impending failures by just changing the lube while the bearing was on line. The first time I accomplished this was while using one of the first analytical instruments for checking bearings, the Anderson Spike Energy Meter. This was my meter as the company couldn't see any advantage of having one.
As in the posted cases if you keep the bearing on line long enough you could checkout the shaft and other components.

 

[Tmoose]

I've seen plenty of HVAC "bearing" failures consisting of a ball bearing in good condition creeping around a shaft. Most commonly the bearing is an eccentric lock type, and situated adjacent to the drive sheave/pulley. A few thousandths Undersized shafting (typical commercial shafting) makes it much harder to keep a bearing inner ring locked to the shaft. The new bearing on the now-even-smaller and tapered shaft is doomed.