Needle roller shaft

Is plain silver steel - unhardened but needing turn/grind to profile - adequate hardness for a needle roller shaft? I don't want to have an inner sleeve as it makes the shaft thin. Hardening would risk distortion.

A bit more messy would be plain steel, case harden the journal part then finnish turn the rest using the bearing itself as part of the support for the process.

suggestions?

Depends on the application. Power. RPM. Load. Temperature. And how long you want it to last. Without hardening it wont last long under any serious loading. Usually the shaft is hardened and ground.

You might do better with Oilite bushes on a plain shaft.

Edited By Hopper on 12/07/2020 13:04:08

case hardening best no doubt, but a pain to do right

plunge in vertically?

GL

I restored a gearbox shaft with a sleeve and INA needle roller bearing, the wall thickness of the sleeve was under 1mm. Everything depends on your shaft diameter. Case hardened steel would have to be ground to finished size before using.

Case harden or induction harden, HRc 58-64, ground finish 1.6Ra max, ISO h5 tolerance. What you can get away with depends on use, time, temperature, lubrication. A soft shaft with no lubrication under reasonable load may well fret, too loose a fit may destroy both the bearing and shaft in quick time. A slow rotating speed on a loose soft shaft with grease lubrication may last a lifetime. Suck and see if there is nothing disastrous going to occur. Its a learning curve.

Or try the bearing suppliers for "Linier Shafting" (spelling ?) this is case hardened and centerless ground rod.

Speedy Sleeves are very thin stainless stel sleeves intended to slip over a shaft to replace the area worn by a lip seal.

I can see no reason why one could not be used as the inner race for a needle roller.

The important thing, if the load is fluctuating, that there is not an integer ratio between the shaft diameter and that of each of the rollers. Otherwise the load will be applied to the shaft in the same place by each roller,causing brinelling. It shortens shaft life quite rapidly!

Howard

Thanks for the suggestions. It seems sleeves are four times the cost of the bearing itself and 2mm thick if available at all in the required size.

Might try low profile ball bearings though only found metric so need a sleeve on teh outside instead but that is low tech.

Almost all ball and roller bearings are metric these days

Imperials are "specials" and priced accordingly.

Imperial bearings are just as readily available as metric bearings. I have no trouble getting them and I am sure the Americans haven't yet switched to metric?

I think you'll find metric has been industry standard for some years and imperial sizes declining even in the US.

I wish I could find 1/4" x 1/4" big end rollers for my Big Port AJS. Cutting down Harley rollers one by one can be a pain.