Angular contact bearings 7201-2RS

It's not completely clear but I think it means the same as what I found on angular contact bearings before i.e. the printed side is where the inner race is thinner and outer race is thicker.

A related question on Angular bearings: While replacing the damaged nylon gear wheels within the headstock of my Amadeal CJ18A lathe (similar to C3), I decided to change the spindle bearings for Angular ones - 7206 B 2RS from Arceurotrade. The discussion above and the excellent Arceurotrade visual guide to installing these angular bearings helped a lot - except in my enthusiasm I forgot to put the plastic bearing cover at the Mandrel end before putting the Angular bearing on. If I had known what was to happen next - I might have cut the plastic cove in half and then glued it back together around the spindle. Using normal gear removal tools that fits to the outer ring of the bearing caused the inner ring to remain on the spindle shaft while the rest of it came away - easy to see why as that is how they are probably put together (and also how I pressed the bearing back together - although I won't use it and have bought another one). As the bearing is installed hard up against the mandrel shoulder - there is no easy way to get access to, and purchase on, the inner ring of the bearing.

So the question is - how would more experienced engineers than me go about removing these angular bearings, in this situation, without breaking them. - in case I need to do it again.

Hi Colin,

Use this type of puller

Nick.

Hi Nick,

Thanks for the reply - but the photo doesn't really show me how this would work. To explain further I've attached part of a diagram from the Arceurotrade guide to replacing angular bearings on their C3 lathe. It shows the Mandrel end of the headstock with the angular bearing in place on the spindle. Imagine the headstock casing removed and you have my problem. Using a normal gear puller on the outer race ring of the bearing causes the outer ring and ball race to become separated from the inner race tight on the spindle. This happens because of the way that angular bearing are made and the recommended facing of the bearing on the spindle. I suspect if the bearing was the other way round - pulling on the outer race would work. As you can see, with the bearing hard up against the Mandrel shoulder - there is no gap to get anything of significant leverage onto the inner race to effect removal.

Hi Colin,

This video shows how they work.

Edited By Nick Hughes on 07/09/2017 15:01:32

Hi Nick,

Yes - the question was how to remove one of these angular bearings without breaking it. I have just bought one of those gear puller kits as shown in the Video - it was also what Neil Wyatt suggested (in a private email) - but it didn't arrive until after I'd used a Draper 2-legged puller to try to get it off. Once the outer ring and ball race is removed - it's quite easy to get the inner race off. I do note that the 2 clamps supplied with the kit have a chamfered front edge which fits around the bearing. It might be possible, by reversing the clamps so that the indented side faces the mandrel shoulder rather than facing the bearing, to tighten the clamps so that the horizontal tightening produces sufficient upward movement of the bearing to then reverse the clamps to their normal operation and use in the normal way - the clamp shoulder will then sit on the inner ring rather than the outer ring. I don't particularly want to try this as I don't want to break another bearing - although Arceurotrade would appreciate another bearing sale - but it might be worth a try if I really need to get the bearing off in the future.

Realistically, for anything other than the most non critical applications, you are best off considering any bearing needing to be removed by significant force as scrap. Firm push within hand force levels, even if a tool is needed to get at things, is about my safe limit. If its in an alloy casing, minor heating to boiling water temperature or so to help release it is fine. When I was playing around with old British motorcycles I used to set the casing up open end down and warm things up until the bearing dropped out of its own accord.

Sometimes no option but to re-use for now whilst a new one is sourced. But bearings are inevitably rather deep inside so, unless its something as simple as an electric motor, temporary re-use wastes a lot of time buttoning up and unbuttoning again.

Its rare to find anything using angular contact bearings with provision for safe extraction. I have run into something with taper roller bearings that had holes drilled in the back of the outer race mount so it could be extracted. Big bearing, 4 or 5 inches diameter as I recall and very not cheap. The race was lunched so I got very careful with a pin punch. Probably proper puller for professionals with push pins aligning with the holes and something in the middle to ensure a straight pull.

Clive.

Thanks Clive,

Probably what I needed to know. With little experience of bearings and how to remove them, I just needed to know if there was a method out there that I was unaware of. Your post more or less tells me there isn't and also importantly to regard any removed bearing as possibly scrap unless the removal force is located close to the binding junction - in my case between the spindle and the inner ring of the bearing.