Ball bearing repair 1

[Nashanas]

Hello everyone,

We have to overhaul an old machine, its a marine loading arm manufactured in 1980. On top of column there is mounted a big bearing with 3 ball races. The ball races show flase brinneling marks. The bearing is manufactured in such a way that there are 3 semicicular tracks machined in the steel body, and then in each of the track there is mounted a ball race. This ball race can be removed and replaced, but since the bearing is from 1980 the manufacturer is out of business and its a bit difficult to find the replacement.

In these conditions, our foreman is proposing cold pressing of ball race to remove the false brinneling marks. He is proposing to press a ball against the ball race mounted in the track, and to rotate the ball a few times.

But to me this does not seem like a proper solution, I am thinking to anneal the ball races first and then check further steps to be done. I am trying to find some literature regarding this.

I dont know which appraoch is right, or maybe both approaches are wrong. Any help will be much appreciated.

Thanks.

 

[Jboggs]

Has the same bearing arrangement been there since the 80's? Outside? If so, you had a very well engineered piece of equipment. I would guess that your foreman's suggestion might appear to work, for a little while. But definitely not for another 30-40 years! You need a professional approach, designed and built by someone who knows what they're doing.

I assume this is some kind of thrust bearing arrangement. When I think thrust bearings, I think of two names: Timken and Torrington. Both very old school names, but highly respected. Of course they are manufacturers of commercial bearings, but someone in their application engineering staff (somebody with white hair) might know of a source for custom-engineered bearings. That's really what you're looking for - a designer and builder of large scale custom bearings. Think about it, somebody makes train turntables!

 

[Artisi]

A photo, sketch, dimensions might help your enquiry, it's quite difficult to imagine what it all looks like.

Added, just a thought, is the false brinneling a problem in operation?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[TugboatEng]

There are companies that repair bearings. I am not vouching for this one, it's the first that came up on Google.

https://www.amroll.com/bearing-repair-and-reconditioning.html

 

[dhengr]

Nashanas:
It is really important to be able to see photos, engineering drawings or well proportioned sketches with dimensions, etc., so as to understand how the system works, what that bearing really does, along with the arm capacity, dimensions, and the like. I suspect that the best solution will be replacement with a new bearing, but an knowledgeable engineer or good mechanic has to look at and understand how the new bearing will work and fit with the existing, what its loads are, range of motion, its attachment, etc. Sometimes, on equipment like this, the bearing only wears over a 90° or 180° arc, by the nature of the way the equipment operates, and maybe the bearing can be rotated 180° for new life from the unused, unloaded side. That is, the bearing is not really a fully rotating bearing, being loading over the full rotation at many rpm. Most company shops can not fix bearing races and the like, the tolerances, finishes and heat treating just get all mucked up when they try.