How do they make rose bearings?

Jun 28, 2007 20 Replies

On the end of hydraulic cylinders there is usually a spherical rose bearing welded on to the ram to take out missalignment as it operates. Consists of a ring with a female double truncated spherically turned surface, and a male double truncated sphere (a bit like the world sliced off at the tropics of Cancer and Capricorn) axially bored (through the poles to continue the analogy) to take the mounting pin.



How the heck do they get the male part inside the female part ???? (no crude comments please!)



AWEM


KY jelly??

Regards, Tony

With a big press. the outer is 'formed' over the inner. it starts as a cylinder, which the inner slides into, then the cupped edges are formed by pressing the end of the cylinder in.this is why you should only use them for loads in the radial direction not axial (might have that backwards) as the ball can pop out. sometimes the outer is fitted by injecting polymer into the gap and then flanging over thinner 'shields'

Dave

Basically then - if in doubt, hit it with a big hammer!

world

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Turns out that on these particular rose bearings that I'm dealing with (a 1986 Thwaites dumper truck steering ram) the inner bearing element (the 'double truncated globe with a boring through the poles') is available as a separate part, and the female enclosing bearing element has two slots milled so the item can be popped in and out by rotating the truncations to line up with the slots. That's the good news. The bad news is Thwaites want £39 plus vat each !!! So the hunt is on for the OEM

AWEM

Andrew, you surprise me, is that not what lathes and ball turning tools were made for?

I have a couple of ex aircraft "inners" somewhere in a box but I think that they would be about 1.25" diameter, possibly 5/16" thick for a 3/8" bolt, so fear they will be too small for you. If not let me know and I will try and find them and measure properly.

Regards

Keith

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Andrew, you surprise me, is that not what lathes and ball turning tools were made for?

I have a couple of ex aircraft "inners" somewhere in a box but I think that they would be about 1.25" diameter, possibly 5/16" thick for a 3/8" bolt, so fear they will be too small for you. If not let me know and I will try and find them and measure properly.

Regards

Keith

Kind Keith, yes I had considered that, and at the time of writing the lathe is still in comission, but most of the workshoop is now palletised ! The bore for the pin on these is about 25mm and I'm waiting for the rain to stop to pull 'em out and measure them properly.

AWEM

Only just read this, and it sounds very similar to the lower arms on tractor

3 point linkages that use changeable balls for Cat1 / 2 linkages. Cat 1 pin diamter is 1", and if you want the outside diameter, I can go find a ball and measure it. Not had to buy any new balls for a while, but they should be under a tenner each.

moray

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Moray, You may be on to something here ! I've just got one out and measured it. The pin hole is 1", the sphere is 1.75" and across the truncation flats it is 1.25". Nice round Imperial measurements Now to hunt tractor factors !!

AWEM

The standard MF ones are far bigger than 1.75", as the hole size for cat 2 is 1.25" IIRC.

Have a look on the Sparex website for an idea of what's available. It's

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select England/Wales/Scotland -> Linkages (under Tractor Parts) -> Linkage Balls -> Lower Link Balls. A basic Cat.1 ball may be a good basis if the outside diameter is right, as it would only need the flats machined in.

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Ho-ho, yes they do one that is 1.75 diameter with a 7/8 bore, so a bit of boring on the lathe will sort that !

Many thanks,

AWEM

They are not hardened or plated or anything?

Probably, but isn't that what carbide is for! Hypothetical anyway as Sparex are refusing to deal with me as an individual, the swine.

AWEM

Don't Launderettes use Rose joints then?

Mark Rand RTFM

Odering Tractor parts for a Launderette is pushing the envelope rather !

AWEM

In article , Andrew Mawson writes

I suspect their procedures simply require a company to be the buyer, I would be very surprised if they are interested in what business the company runs. Let me know off-list if that doesn't work, my friend has a company with a more "relevant" name and may be able to help you out.

David

Chances are your local tractor dealers will deal with them, if not give me a shout, and I'll see what I can find.

Andrew, there is a farm machinery dealer right near me

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If you can let me know the spec of the part you need from Sparex, I'll have a chat with them and see if they can get it in/get it priced.

Peter

Peter,

That would be very kind of you - not many tractor dealers in urban Bromley !

The Sparex part number is S1366 and it is a 1.75" sphere, with a 7/8" bore and 1.375" across the flats, which is almost what I want - and when bored out to 1" should do nicely thankee !

If you could get them to price two off it would be much appreciated.

AWEM

Not really, last century a local fellmongery came to me with some ball ended links that were the used to suspend Broadbent (UK) "spindriers". The driers were about 8' in diameter and used a peculiar 15hp motor to wind up to rather spectacular rpms. The ball ends sat in hemispherical cups to allow for the bowl to move. Used to dewater wool before passing through the final drying process. Memories of tractors past, lead me to using Sparex category 3 balls and created a nice little earner making new shafts and cups to suit, when compared with replacements from the agents.

Tom

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