How to fix a loose bearing in a very big gearbox!

There is a very big gearbox (2000 x 3000 x 2000 mm) and one bearing at its mouth is loose, how can we fix it?
We used to weld the loose part and fit the bearing but this causes deformation of the gearbox shell. What do you think?

Behrouz Amanipour wrote:
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I think you haven't given us nearly enough information to even begin to guess at a good solution.

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I agree. I.e. is the bearing itself worn or just loose in housing? How much looseness etc?

Here's more information:
The bearing diameter is about 600 mm you can surely estimate how much power is exerted upon this big bearing. The bearing is loose enough that it will turn around togther with the shaft- there is about 1mm gap between the bearing and the gearbox's shell. It is only worn in the housing.

Here's more information:
The bearing diameter is about 600 mm you can surely estimate how much power is exerted upon this big bearing. The bearing is loose enough that it will turn around togther with the shaft- there is about 1mm gap between the bearing and the gearbox's shell.

Here's more information:
The bearing diameter is about 600 mm you can surely estimate how much power is exerted upon this big bearing. The bearing is loose enough that it will turn around togther with the shaft- there is about 1mm gap between the bearing and the gearbox's shell.
It is loose only in the housing.

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If the gear box case was steel I would weld it up and site machine it to the correct size, but I guess it is cast iron. If the bearing housing is very thick then it is probably possible to machine it out by 5 mm a side and fit a steel sleeve. A filled epoxy would probably do for a while if you can get the bearing aligned correctly, but metal spray would probably be the better option.

Thanks! But could you elaborate more on how to metal spray.

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I would hire a specialist contractor for this work. There are several metal spray processes, flame spray is the cheaper end, (may be all you will need), HVOF (good for more difficult problems) and plasma spray the high integrity end.
Surface preparation is very important. You may need a bond coat and separate top coat (seek advice from your contractor) or you could use a one step powder. You probably do not need a very hard coating for your application this will make it easier to finish machine. If corrosion is likely you should seal your coating (seek advice).
http://www.sulzermetco.com/eprise/Sulzermetco/Sites/Products/AboutThermalSpray/tsprocesses.html
Metal spraying needs practical experience

Flexible epoxy 3M DP190
ca
Behrouz Amanipour wrote:
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