Take-up bearing alignment

[David CambridgeParticipant @davidcambridge45658]

Take-up bearing alignment

[David CambridgeParticipant @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

[EmgeeParticipant @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

[Michael GilliganParticipant @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.

[Keith LongParticipant @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.

[JasonBModerator @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

[Michael GilliganParticipant @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.

[David CambridgeParticipant @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

[Keith LongParticipant @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.

[duncan webster 1Participant @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.

[David CambridgeParticipant @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

[Michael GilliganParticipant @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

[Author]

Posts