Take-up bearing alignment

This topic has 11 replies, 6 voices, and was last updated 18 December 2015 at 22:28 by Michael Gilligan.

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18 December 2015 at 19:31 #24278
David Cambridge
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@davidcambridge45658
Take-up bearing alignment
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18 December 2015 at 19:31 #216898
David Cambridge
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@davidcambridge45658
Hello All

For my (wifes!) printing press project I’ve bought some take-up bearings. I’ve noticed that the bearings aren’t mounted in the housing particular well. Point A is raised slightly above the surface of the housing, and point B is slightly below the surface of the housing. The net result of this is that the shaft doesn’t run 90 degrees with the direction of travel of the bearing housing. I’ve bought two bearings and they are both the same.

Does anyone know the best way I can sort this out, and indeed are they meant to be like this ? or should I have not bought cheap and cheerful from eBay ?

Thanks

David

Edited By David Cambridge on 18/12/2015 19:32:00
18 December 2015 at 19:51 #216902
Emgee
Participant
@emgee
Hi David

Sounds as if the bearing bores are not at 90 degrees to the other shaft coming in from the left side of pic, is there another bearing on the underside as in the picture ? If so I guess the high and low points are reversed, this would confirm my opening sentence.

Emgee
18 December 2015 at 19:56 #216905
Michael Gilligan
Participant
@michaelgilligan61133
No, David … They shouldn't look like that.
- Warm the housing with a fan heater [or hot-air gun] and tap the bearing out with a soft hammer or drift.
- Then check the bore in the housing [it may have burrs, raised by the original poor fitting] and correct any defects.
- Re-heat the housing and fit the bearing properly. [Use either a press, or a nut & bolt with suitable washers/spacers]
They were probably 'fitted' with a big hammer, and more enthusiasm than skill.

MichaelG.
18 December 2015 at 20:01 #216906
Keith Long
Participant
@keithlong89920
David, before you do anything rash, check the bearing insert number to see if it's a self aligning type. The RHP catalogue that I'm using specifies self aligning in all the housings of that family.
18 December 2015 at 20:04 #216909
JasonB
Moderator
@jasonb
Looks like you are comparing the edge of the bearing to an "as cast" surface so unlikely to be even all the way round.

J

Edited By JasonB on 18/12/2015 20:04:35
18 December 2015 at 20:05 #216911
Michael Gilligan
Participant
@michaelgilligan61133
Posted by Keith Long on 18/12/2015 20:01:08:

David, before you do anything rash, check the bearing insert number to see if it's a self aligning type. The RHP catalogue that I'm using specifies self aligning in all the housings of that family.

.

Yes indeed, Keith

If the outer race of the bearing is 'spherical' then it may just be slightly revolved.

MichaelG.
18 December 2015 at 21:13 #216932
David Cambridge
Participant
@davidcambridge45658
The bearing is sold on ebay as a ‘UCT204-12 3/4 Imperial Cast Iron Take Up Unit Self Lube Housed Bearings UCT’ with a manufactures stamp of MSB. I can’t find anything to indicate that it’s self-aligning. Here is a photo of the bearing mounted on a shaft.

My bearing came from ebay, but WychBearings (who I did not get the bearing from) say on their web site:

‘Housed Bearings – also know as Self Lube units – are used extensively in fabricated machinery as they are easy to fit, maintain and replace. They will cope with initial misalignment , are sealed and pre-greased, have integral shaft locking and simply bolt in to place.’

David

Edited By David Cambridge on 18/12/2015 21:20:13
18 December 2015 at 21:25 #216934
Keith Long
Participant
@keithlong89920
Well using your bearing description as in input to a google search suggests a bearing supplier named after a town in Lancashire and their tech data on the bearing shows a spherical outer race on the insert. In which case just twist the housing to line up with the shaft as you need. It won't just flop into place you'll have to put a bit of effort into it but it should move ok without causing any damage to the bearing insert – that's what they're made to do.

Looking at the photo you posted that is too far out of line just to be a fitting or machining fault it would need to be made at that angle specially and it's not likely to have been.
18 December 2015 at 21:49 #216936
duncan webster 1
Participant
@duncanwebster1
I'd be surprised if it isn't self aligning, just apply a modicum of force and see if it moves. It might be a bit stiff at first.
18 December 2015 at 22:26 #216943
David Cambridge
Participant
@davidcambridge45658
Brilliant – thanks everybody. Hitting the housing with the palm of my hand was all that was needed to get it to move and show the spherical outer surface.

Model engineering to the rescue again!

David
18 December 2015 at 22:28 #216944
Michael Gilligan
Participant
@michaelgilligan61133
Posted by Keith Long on 18/12/2015 21:25:31:

Looking at the photo you posted that is too far out of line just to be a fitting or machining fault

.

Agreed … Second photo surely indicates that it has a spherical outer.

[David] Please ignore my first post on the matter !!

MichaelG.

.

Edit: Water under the bridge

Edited By Michael Gilligan on 18/12/2015 22:29:22
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