Mixing of imperial taper cup and cones

[Hippo41]

A debate currently rages in my office, and I need some help to resolve the issue.

I have always been told that mixing cups and cones from different manufacturers is not recommended practice. But, there is a group of my engineers who seem to have been told that old imperial tapers can be mixed, but not metric cups and cones.

Dimensionally imperial taper cups and cones will be the same, so at a superficial level there should be no problem, but surely there are small design differences that make this a bad practice? Or am I out of date???

Would appreciate any comment please. Thanks!

Lester Milton
NBC Group Ltd, Telford, Shropshire, UK

 

[EnglishMuffin]

Since no one seems to have replied to this post yet, I'll just make the obvious comment that it would be easy to check with SKF and/or FAG and find out if their inch bearing components were interchangeable with Timken - after all, a lot of them have numbers based on the Timken numbers if you look. At least you could disprove it that way. Timken bearings have always been made so that you can mix and match various cups and cones, as I'm sure you know, so it looks to me like it actually could very well be true, and it is certainly feasible, if they had the dimensional data from Timken to go by. The metric bearings made by SKF and FAG are made to a standard ISO outside envelope and don't use the mix and match concept so it doesn't seem likely that you could do that with metric bearings, as your guys are saying. And then there are non-ISO metric bearings which are made by Timken - I'm not sure about those - they could be interchangeable too. Of course, if you call Timken and ask whether their bearings are interchangeable with SKF or FAG they are likely to say no, whether they are or not! There is also an incentive for SKF and FAG to say no, because they want to sell as many components as possible. I have a feeling that nobody else uses the case hardening process that Timken use for taper roller races - although that is probably not a critical issue, and I could be wrong anyway.

 

[diamondjim]

Les,
It would not be that difficult to check
the taper angle of the cups from several
suppliers of the same part number. If
they are the same, then they are compatable.
Of course you would have no warrantee from
either company. I think it would be more
of a liability factor than a practical
factor. When I worked at Timken, companies
in China would reverse engineer our parts
and put them on the market. Obviously the
quality was not the same and got about one
third the life. I would be surprised if they
were not interchangeable.

 

[macbradley]

There are alot of bearings components out there that can be mixed and still work well. As it was noted earlier, most of them have cross references or common numbering schemes.
What you loose in doing so is fatigue life improvments from roller profiles and advanced metallurgy. If you are in an enviroment where contaimination or lack of lubrication is what causes the end of service life to be reached, then there is no problem with mixing these parts and this is probably the cheapest design solution. But if the enviroment is controlled and the bearings are failing due to fatigue, it would be very advantageous to go to matched components PROVIDED your supplier will give you fatigue life improvers such as modern roller profiles and metallurgy changes at the same time. IF the supplier just gives you matched parts with industry std profiles you're really just wasting your money.