SKF 21306CC crankshaft double row spherical roller bearing

seattle##gs · Nov 28, 2022

Anybody have experience with this? E&V Engineering recommends this. About $105 apiece. Claims they are better than the usual superblend and will flex with the crankshaft. He's installed them on race Nortons. He will also balance crankshafts.

kommando · Nov 29, 2022

Never heard of an SKF E roller failing, so how can you better that.

cash · Nov 29, 2022

kommando said:
Never heard of an SKF E roller failing, so how can you better that.

They will give thrust control. But perhaps to quote an old saying, "don't fix it if it isn't broke" Mind if the bearing can stand the thrust and the crank spinning one on the timing side might be an advantage and, of course being a tight old bugger they appear to be cheaper so fit them on both sides.

concours · Nov 29, 2022

I have set up new SKF spherical roller bearings and replaced failed ones. On an 8" diameter shaft. Adjusted the clearances via the tapered I.D. on the inner race using a hydraulic nut.
OP, Any links or pics of the hummingbird sized ones for Commandos?

Edit: https://www.grainger.com/product/36...VNTizAB2tbwC_EAAYAyAAEgIGi_D_BwE&gclsrc=aw.ds

robs ss · Nov 29, 2022

cash said:
They will give thrust control. But perhaps to quote an old saying, "don't fix it if it isn't broke" Mind if the bearing can stand the thrust and the crank spinning one on the timing side might be an advantage and, of course being a tight old bugger they appear to be cheaper so fit them on both sides.

I believe the biggest thrust force is from the worm-driven oil pump.
Side thrust, as far as I know, was never an issue with main bearing failure.
The spherical may be better - but is it needed?
I don't think so.

SteveA · Nov 29, 2022

seattle##gs said:
Anybody have experience with this? E&V Engineering recommends this. About $105 apiece. Claims they are better than the usual superblend and will flex with the crankshaft. He's installed them on race Nortons. He will also balance crankshafts.

I have looked at Concours' link, but I still have no idea what a spherical roller is! That image looks like a double roller bearing with the rollers set at an angle to the shaft!

And how is it installed? If it is a specialist procedure, there is extra cost for people like me who install their own.

DevonNorton · Nov 29, 2022

SteveA said:
I have looked at Concours' link, but I still have no idea what a spherical roller is! That image looks like a double roller bearing with the rollers set at an angle to the shaft!

And how is it installed? If it is a specialist procedure, there is extra cost for people like me who install their own.

This is a link to FAGs info on this type of bearing. My personal view is they are not required but ymmv.
https://www.schaeffler.co.uk/en/pro...and_plain_bearings/spherical_roller_bearings/

seattle##gs · Nov 29, 2022

I mentioned them as a curiosity. The bearing is recommended by E&V Engineering who seems to know what they're talking about. New to me. I have never had a stock superblend fail or give problems. This is a one piece bearing so E&V hones the inner race so it will slip on and off the crank. But he recommends them. And races them. Will email JC for his opinion.

Matchless · Nov 29, 2022

I used to make & build lines for the paper industry in a previous life. This type of bearing was fitted to large paper rollers as they will tolerate a lot of misalignment. I have often wondered if they would be suitable for a crankshaft, or if they would cause more vibration.

Martyn.

Thomasa · Nov 29, 2022

FWIW, Eaton supplied spherical tapered rollers on truck axles through about 1972. They are no longer listed in that size, only straight tapered bearings. I have only replaced either type on axles with hundreds of thousands of miles service. Apparently Eaton found that there wasn't enough flex in the truck axle housings or hubs to warrant the expense of spherical bearings. They failed after seal failure allowed dirt into the bearing or sometimes one could see acid etching on a used bearing. I replaced those. Not a problem with Commando engines with filters and reasonably frequent oil changes.

cash · Nov 30, 2022

Matchless said:
I used to make & build lines for the paper industry in a previous life. This type of bearing was fitted to large paper rollers as they will tolerate a lot of misalignment. I have often wondered if they would be suitable for a crankshaft, or if they would cause more vibration.

Martyn.

And a lot of big industrial fans too.

ggryder · Nov 30, 2022

SteveA said:
I have looked at Concours' link, but I still have no idea what a spherical roller is!

I think "spherical" refers to the complete bearing rather than the rollers. Spherical bearings or self-aligning bearings as used in rod-ends.

concours · Nov 30, 2022

ggryder said:
I think "spherical" refers to the complete bearing rather than the rollers. Spherical bearings or self-aligning bearings as used in rod-ends.

This is inaccurate.
From my snowblower:

This is a spherical roller bearing:

SKF 21306CC crankshaft double row spherical roller bearing

The former is cheap as chips.
The latter, not cheap.

jseng1 · Nov 30, 2022

seattle##gs said:
I mentioned them as a curiosity. The bearing is recommended by E&V Engineering who seems to know what they're talking about. New to me. I have never had a stock superblend fail or give problems. This is a one piece bearing so E&V hones the inner race so it will slip on and off the crank. But he recommends them. And races them. Will email JC for his opinion.

So it must be machined to fit the crank? Slip on and off? Is it machined for a press fit? That's some extra trouble to go through.

Thomasa · Nov 30, 2022

concours said:
This is inaccurate.
From my snowblower:

View attachment 101651 View attachment 101652

This is a spherical roller bearing:
View attachment 101653

The former is cheap as chips.
The latter, not cheap.

Bad time of year to have your snow blower apart. We got 12" last night and I spent the first hour of my day shoveling so my wife could get her car out of the garage. The plow guy often makes more work for me than if I did it myself. I'm lobbying for a small tractor with a front-end PTO. Next time she shovels.

concours · Nov 30, 2022

Thomasa said:
Bad time of year to have your snow blower apart. We got 12" last night and I spent the first hour of my day shoveling so my wife could get her car out of the garage. The plow guy often makes more work for me than if I did it myself. I'm lobbying for a small tractor with a front-end PTO. Next time she shovels.

I have multiple WMD for snow

Put off the snowblower rehab to fix & ride the H2

seattle##gs · Dec 1, 2022

jseng1 said:
So it must be machined to fit the crank? Slip on and off? Is it machined for a press fit? That's some extra trouble to go through.

Yes, the inner race would need a minute hone to make it slip on and off. I think a better way would be to drive the bearing onto the crank as is, then heat the case and set it on the bearing. Repeat for the other side. It would take a couple of holding fixtures made of wood, no big deal. Would it be worth the trouble? Only if you were up in the max RPMs for a while, such as Bonneville. JC says the stock superblends will give no problems in any service and certainly easier to install. If you want more info contact E&V engineering. He builds Norton race motors using these bearings.

concours · Dec 1, 2022

seattle##gs said:
Yes, the inner race would need a minute hone to make it slip on and off. I think a better way would be to drive the bearing onto the crank as is, then heat the case and set it on the bearing. Repeat for the other side. It would take a couple of holding fixtures made of wood, no big deal. Would it be worth the trouble? Only if you were up in the max RPMs for a while, such as Bonneville. JC says the stock superblends will give no problems in any service and certainly easier to install. If you want more info contact E&V engineering. He builds Norton race motors using these bearings.

He is using the loose slip fit on the crank to allow end float, this style bearing does not give that feature like the shouldered roller bearing does.
If you fit it tight, there is no end float.

cash · Dec 3, 2022

jseng1 said:
So it must be machined to fit the crank? Slip on and off? Is it machined for a press fit? That's some extra trouble to go through.

They have to slip off and on to allow assembly/disassembly once the bearings are fitted into the cases, and of course provide some end float.

B+Bogus · Dec 3, 2022

Matchless said:
I used to make & build lines for the paper industry in a previous life. This type of bearing was fitted to large paper rollers as they will tolerate a lot of misalignment. I have often wondered if they would be suitable for a crankshaft, or if they would cause more vibration.

Martyn.

Goss's by any chance? Back when we made stuff???

As I understand it, the biggest concern with Norton cranks is the cast iron flywheel grenading at high revs, but always interesting to see potential improvements elsewhere.