Oil / grease bearing

[Jonny-Jimbo]

This is not related to Triumphs, but it seemed like a good place to start.

One of our projects at uni is to design a differential for use in one of the uni racing cars. It has to be bike (chain, not shaft) driven using an Audi Torsen internal. Other than that we're pretty much free.

I want to use roller bearings on each output shaft, but I have a lack of knowledge here - will roller bearings work fine with GL5 oil, or do roller bearings need to be greased? If so, should I spec sealed bearings as the oil and grease could contaminate each other.

Any ideas?

[CharlieB]

Don't forget roller bearings only take radial load, you'll need something to take the axial load.
Bearings will work fine with GL5 unless they're made of brass!

[Gt6s]

Jonny_Jimbo wrote:

This is not related to Triumphs, but it seemed like a good place to start.

One of our projects at uni is to design a differential for use in one of the uni racing cars. It has to be bike (chain, not shaft) driven using an Audi Torsen internal. Other than that we're pretty much free.

I want to use roller bearings on each output shaft, but I have a lack of knowledge here - will roller bearings work fine with GL5 oil, or do roller bearings need to be greased? If so, should I spec sealed bearings as the oil and grease could contaminate each other.

Any ideas?

I would use sealed bearings as they are maintainance free, otherwise use greased bearings

[StagNL]

My Stag gearbox has roller thrust bearings as standard on the layshaft which is immersed in a bath of GL5 gear oil.   If it works for decades out of the factory, it should work for you.

[Jonny-Jimbo]

Thanks all, that's good enough, and thanks Charlie for reminding me about the loads imposed on bearings, I'll have to put a few paragraphs in about that.

[Jonny-Jimbo]

PS: Charlie, in terms of axial loads I was thinking of some form of thrust washer and have a small amount of end-float design into the diff and casing.

[Gt6s]

What axial loads?
You will be using a chain drive.
In a enclosed diff axial loads are created by the pinion pushing against the crown wheel, you do'nt have that.

As for running in a bath of GL5. Get a grip !

KISS   Keep it simple stupid.

[Jonny-Jimbo]

Diff has to run in a bath of GL5, or rather the outer casing has to be oil tight as we have to use the internals from an Audi Torsen diff, which must be submerged up to 2/3rds in GL5 oil.

Would I not have axial loads from the two output shafts on the bearings at the outside of the diff?

Also, I know I can't use brass in GL5 oil, but will bronze have the same problem with GL5, or will it be okay as it's an alloy of copper and tin rather than copper and zinc?

I'm thinking in terms of phosphor bronze thrust washers.

[CharlieB]

I'm not saying there will be large axial loads (like there are in Triumph) but the shaft has to be located axially which a roller brg can't do. Why not use deep groove ball bearings then no thrust washers required?