Combination Bearing 30/47/27

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JRConck
Posts: 156
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Combination Bearing 30/47/27

Postby JRConck » Fri Jan 12, 2018 7:26 pm

I am working on my YZR 500s and have run into a sourcing problem for the bearing on the transmission output shaft.
THe bearing is a combination roller (radial) and ball (axial) bearing. I have located very similar bearings but not the correct size.
I need : Bore 30mm (shaft OD), OD 47 mm, width 27 mm with internal sleeve (sleeve is 30mm ID, 35mm OD, 24/x mm wide). So far I have only found 30/47/23. THe inner bearing sleeve is in two pieces with the ball bearing contacting the joint of the two pieces. Part of the problem is to match both the outer housing width (27) and the width of the inner sleeve (s) (total length of two halves ~ 48) .It seems all the YZR engines have the same setup 87 through my 95 Harris YZR.

trev45
Posts: 167
Joined: Mon Jan 11, 2016 10:18 pm

Re: Combination Bearing 30/47/27

Postby trev45 » Fri Jan 12, 2018 11:29 pm

Photo of what you want will help please
I have a good source of odd size bearings in Japan
that might be of help

Cheers Trev

JRConck
Posts: 156
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Re: Combination Bearing 30/47/27

Postby JRConck » Sat Jan 13, 2018 1:31 am

Image

This is the transmission out of the YZR. Out put shaft has a bearing inner sleeve on it (note the round out area for the ball bearing portion). THe roller part makes contact with the installed inner sleeve. The Ball part contacts the two part groove. There is a bearing keeper on the inside of the cases and a retaining ring in a groove. Space between retaining ring and the keeper is 27 mm. Bearing OD is 47 mm the portion of the inner ring that is installed is 23 mm.
Problem is the closest I have been able to get is a combination bearing width of 23 mm vs 27 needed. I can make spacers for all of it but that is not ideal.

Gerrit
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Location: Kingdom of the Netherlands

Re: Combination Bearing 30/47/27

Postby Gerrit » Sat Jan 13, 2018 6:31 pm

I'll check the INA and SKF catalogues to see whether they have a needle-ball bearing with the required dimensions.

Bud977
Posts: 118
Joined: Sat Sep 12, 2015 9:04 pm

Re: Combination Bearing 30/47/27

Postby Bud977 » Sat Jan 13, 2018 7:13 pm

That's an interesting looking bearing. I've never seen one of those before so I thought I'd have a look to understand what you've even got.

So it looks like you've got something like this:
http://www.skf.com/group/products/beari ... metricUnit

And it looks like they've used a second wide inner ring in place of the usual narrow inner ring.

The NKIB 5906 has a 23mm wide outer race. Is that the problem dimension?

JRConck
Posts: 156
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Re: Combination Bearing 30/47/27

Postby JRConck » Sat Jan 13, 2018 8:31 pm

The main problem is that it is a combination bearing where the inner ring is in two parts. If I get a 4 mm shim made for the OD ( the 23mm wide part) I also would have to get a 4 mm shim made for the inner ring so that the groove for the ball bearing is in the correct position. THis doesn't sound too bad but it is not ideal. The slack in the inner rings is taken up by the bolt that holds the sprocket on. I have looked at about 20 suppliers and not found the exact size. I have actually ordered some from IKO which are the same as those from SKF and would require the shims (spacers). THese bearings are not inexpensive. THere are bearings on the cranks which are similarly going to be challenge to source. One set (outboard left side) have a built-in captured seal and the housing has IKO but no other identification. :roll: :roll:

Bud977
Posts: 118
Joined: Sat Sep 12, 2015 9:04 pm

Re: Combination Bearing 30/47/27

Postby Bud977 » Sat Jan 13, 2018 9:57 pm

Would a 47 x 30 x 4 washer space a NKIB 5906 bearing out from the gear sufficiently?

The SKF data doesn't give the width of the inner race. Depending on how it all goes together, you may need another spacer on the sprocket side, or make up the inner washer even thicker if you need to make up the shortage of inner race length.

Gerrit
Posts: 358
Joined: Wed Oct 07, 2015 11:02 pm
Location: Kingdom of the Netherlands

Re: Combination Bearing 30/47/27

Postby Gerrit » Mon Jan 15, 2018 10:28 am

Doesn't the centre main bearing of a V-twin TZ250 have a built-in seal? If so this might be a suitable replacement. Just a thought.

JRConck
Posts: 156
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Re: Combination Bearing 30/47/27

Postby JRConck » Tue Jan 16, 2018 8:57 pm

Anyone have thespecs on the forementioned bearing ?

JRConck
Posts: 156
Joined: Mon Oct 12, 2015 1:44 pm
Location: Virginia, USA

Re: Combination Bearing 30/47/27

Postby JRConck » Tue Jan 16, 2018 9:02 pm

The specs on the outer crank bearings are: Shaft OD (bore of bearing) 25 mm, Housing OD 47 mm, Width 22 mm.
The housing has a groove for a retainer, an o-ring groove and an oil hole.


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