Loose bearing in gearbox
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Posted by: Behrouz ® 04/06/2004, 14:03:47 Author Profile Mail author Edit

There is a big gearbox (3000 x 2000 x 2000 mm) with a loose bearing on the mouth, do you know how we can fix it? We used to weld the mouth and fit the bearing but this may deform the gearbox, what do you think? Modified by Behrouz at Tue, Apr 06, 2004, 14:06:16

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Re: Loose bearing in gearbox
Re: Loose bearing in gearbox -- Behrouz	Post Reply	Top of thread	Forum

Posted by: RandyKimball ® 04/06/2004, 18:29:32 Author Profile Mail author Edit

How loose, please? ...and how large is the bearing, in length and diameter? .. there are several ways.. The worst suggestion of you lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

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Re: Loose bearing in gearbox
Re: Re: Loose bearing in gearbox -- RandyKimball	Post Reply	Top of thread	Forum

Posted by: Behrouz ® 04/07/2004, 10:34:12 Author Profile Mail author Edit

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 (shell).

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Re: Loose bearing in gearbox
Re: Re: Loose bearing in gearbox -- Behrouz	Post Reply	Top of thread	Forum

Posted by: RandyKimball ® 04/07/2004, 19:02:01 Author Profile Mail author Edit

Ouch, and this has happened to the same housing before? This makes me concerned about the alignment of the housing currently. Is there a out of balanced weight somewhere on the shaft? I suspect that the out of roundness of the bore is not concentric with the center line of the shaft anymore. You really need to get the housing rebored to center line on a jig bore, horizontal mill, or machining center by a good machine shop. Be sure they have some large equipment and are used to doing large work, this can't be faked on a small machine, the results would not be true/round, and would put you back in the same place in the future. Then have them make a sleeve to go into the bore. The sleeve needs to be press fitted and then re bored on the inside to fit the new bearing correctly. If there is a bent or off centered weight it may need to be attended to. Otherwise, I would (without seeing the actual problem) attribute the first cause to a loose fit. Most times a loose fit will allow a bearing and shaft to "hammer" the slack and slowly increase the gap, as the gap grows the rate of increase accelerates. -randy- The worst suggestion of you lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them.

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