Thread: Any bearing experts?

Replacing this bearing and a bit mystified as to how the the tiny hole in the bearing is meant to stay lined up with the grease hole in the housing?
IMG_0006a.jpg

I can install the bearing so it does align and take grease, but there seems nothing to stop the bearing rotating out of place, and then not take grease.

In other housings I've seen an internal groove cut that would account for this, but no such feature in this one...

That's the outer race, right? Shouldn't it be a press fit in the housing then? Not much point in having rolling elements if the whole bearing can spin...

Or am I missing something?

The upper bit is the outer ring (it's the old, failed bearing with no guts) the outer surface is spherical to allow the bearing to self-align. The housing below is spherical on the inside, and gets pressed into place in the machine. There's clearance slots in the housing to allow the bearing to be inserted and rotated into place, but there's plenty of tales from the bearing shop of people who didn't realise this and have tried heating the housing and pressing the bearing into place

Originally Posted by RustyArc

The housing below is spherical on the inside, and gets pressed into place in the machine.

That's my point though, if the housing is a press fit to the bearing, it shouldn't slip out of place

Originally Posted by elanjacobs

That's my point though, if the housing is a press fit to the bearing, it shouldn't slip out of place

Yes. Friction of fit > friction of rolling elements. No problem.

Originally Posted by elanjacobs

That's my point though, if the housing is a press fit to the bearing, it shouldn't slip out of place

The housing is a press fit into the machine (has straight, parallel sides), but the bearing is *not* a press fit into the housing, as its outside surface is spherical.

This video shows a flange version of the housing, but the bearing, and the method for installing it, is the same. Note that with the housing in the video, once the bearing is removed, there's a grease groove. The housing I'm dealing with doesn't have that.
https://www.youtube.com/watch?v=1jG5...l=SKFPartsInfo

Ohhh right, now I get it

That bearing looks like the tiny ball retainers is missing. they may not be grease holes as you think.

https://partners.conbear.com.au/Product/info/C209ECO

Definitely not an expert but I'm familiar with the 'P' and 'F' style housings that use the same spherical self-aligning bearings (pillow block and flange mount; no idea what 'C' would be short for), the grease hole doesn't have to be in any particular location as there's clearance in the housing for the grease to get from the nipple to the bearing. The locating ball on the bearing is located in one of the slots in the housing and the bearing is rotated into place- the grease hole ends up wherever it ends up.
Without the grease groove, is there some less obvious form of clearance between the housing and the bearing, like a variation in the inside radius?

The other end of the shaft has a flange bearing housing, and it has a groove for the grease as per the SKF video.

Without that tiny grease hole lined up with the corresponding hole in the housing, you cannot get grease into it - I tried very hard with a couple of different grease guns. Now that I've dismantled the machine, removed the bearing, lined up the holes and reassembled it, it takes grease just fine, but that was many hours work.