adhesives for loose bearings

Hi

I have made an error on boreing a bearing housing of 18 th". I rebored and was successful in getting the new position correct.Now I want to glue them in position but it will require an adhesive to take up the 18th" or another solution.

Frank

You need a small bottle of loctite bearing retainer, yellow guey stuff but made exactly for your application.

Is Bricky talking about needing 1/8 of an inch clearance takeup? If so I don't think a Loctite product would fill that gap and carry any load. Maybe .010" but not .125". Hope he clears up what he's after. If it's truly a 1/8" gap I would suggest a turned metal sleeve to fill the gap and Loctite brg ret on both surfs of the sleeve maybe.

I interpreted 18 th" as 18 thou, still too much for ordinary loctite AFAIK. They do a "Quickmetal" goop for worn components, but it's expensive. I've never used it.

I think I'd bore bigger and fit a sleeve if possible, as suggested above

+0.018" is how I read it.

Edited By websnail on 06/12/2017 21:54:02

Knurling is an old bodge to make things bigger. Make up a boring bar with one wheel on the end.

Have a look at tolerance rings, these are made to fit bearings in damaged housings after remachining.

Mike

Best bodge - do as Mike says or bore the hole out well oversized like 1/8 over then machine up an insert ring that matches the oversize bore and has its bore well undersized, loctite and a light press fit into oversize housing then bore that out to match the bearing .

desperate bodge - use some 0.008 thou feeler gauge strip or some shim material to make an infill ring that sits in the oversize hole then using ample bearing retainer on all surfaces push the bearing into the infill ring / housing assembly , you have to use 0.008 thou as you dont want a press fit as it will drag the shim in with the bearing if you try to press it in - i prefer the first option as it is more reliable and yields a neater repair .

@XD

0.008 inch, eg.8 thou?

Martin

Some clarification from Frank [bricky] would be helpful, but ... if we're talking 0.018" on the diameter, then Loctite 641 should do the job easily ... As fizzy mentioned.

**LINK**

http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802627649537&msdsLanguage=EN_GB&selectedTab=document

Technical DataSheet here: **LINK**

http://tds.henkel.com/tds5/Studio/ShowPDF/641-EN?pid=641&format=MTR&subformat=REAC&language=EN&plant=WERCS

MichaelG.

You could also buy some of those rings with pressed in dimples to fit the gap but you would then have to machine the hole again to the size to fit one. I dont know what they are called but have seen them on motor bearings.

Hi Martin,

Yes my post was originally meant to read 0.008 in (8 thou ) appologies for rhe typo !

I'm afraid that I am with Clive on this one. Maximum gap fill on diameter for LOCTITE 641 is quoted as 0,2mm   or  0.008" . I don't think you would achieve a satisfactory bond at 0.018" oversize on diameter.

LOCTITE 660 is an alternative, but expensive.

Personally I would be looking to sleeve and rebore if possible.

Have a look at the link to the brochure, see what you think.

**LINK**

Edited By Neil A on 07/12/2017 12:07:09

Edited By Neil A on 07/12/2017 12:07:55

You are right Michael I have not been clear enough.I was 18/1000" low on the correct position I milled the bearing housing to this amount leaving a gap of 18/1000" below thw fitted bearing.I hope this makes it clearer.

Frank

So are you saying you have the original hole and a new one bored 0.018" higher in which case you will not need to fill the top but will have a max gap of 0.018" at the bottom.

In which case I think your best option is to bore alarger hole in the correct position so that all trace of the old hole is removed and then sleeve it or find a bearing with larger OD

Edited By JasonB on 07/12/2017 13:26:45

Bricky, the one recommended by Loctite is 660, it is a paste in a tube, and it's good to .020" on dia/.010" gap. Its also good for warn splines and things like that.

Ian S C

Thanks to all for your suggestions I will have a ponder on what to do next.Jason has drawn exactly what I have ended up with.

Frank

A few years ago I worked for a company that built up very special gearboxes with ratios from 1000 to 1 up to 1 TO 200. These gearboxes were very expensive but several of the sections had designed oversize bearing bores and were assembled with a special Loctite adhesive. Several 100's of £ a bottle as I remember.

This kept all the shafts etc. in alignment and we never had a gearbox returned with any shaft problems.

Alistair.

Similar problem on here recently with over sized bore. The concensus then was to rebore the hole, plug and rebore in its correct place. If the bearing is used as a loaded support then it requires a tolerance bore/shaft as per catalogue to achieve the correct fit for the loads being applied. Applying glue of any kind in an oversize hole cannot give positional accuracy or bearing fit if the hole is not a fit in the first place. But if the bearing is non critical, just there as a support of a free shaft, then you would be ok.