I’m looking for ball bearings which have a bore diameter of 180mm but I can’t seem to find anything suitable. The outside diameter is not really important as long as it’s less than 220mm, the bearings are also not going to be under any real stress so they don’t need to be big, the smaller the better really as long as the internal bore is at least 180mm and the external diameter is less than 220mm.

I’ve had a look on simply bearings but they don’t have anything suitable (the smallest outside diamter for a 180mm bore is 225mm).

Can anyone recommend other websites which might stock suitable size bearings?

Cheers

Does it have to be ball? Have you checked out roller bearings?

Something like this? http://www.bearingboys.co.uk/GB18050DX_Split_Bearing_Bush-17242-p

or a polymer bearing or oilite etc

what’s the application? I think you’ll struggle to get something uner 220mm of a conventional type as they will be designed for the loads you would expect a 180mm shaft to take. Can you not machine out the housing?

Had a look at Igus but nothing that big from what I could see. (polymer bearings)

VXB list some big sizes, but the prices are also quite big !

What’s the application? As andyl says, any 180mm bearing is likely to be big in every way. There are a few big diameter, small ball, bearings like a lazy susan bearing that you might be able to modify. eg this style: http://www.bearing-king.co.uk/bearing/lazy-susan-turntable-bearing-square-4-inch/6089. Will a mchined ring of bearing grade plasic do the job?

Tucker, roller bearings would work as well but I’m struggling to find any in the size I’m looking for

andyl, I’m designing a holographic plate holder for a university project, it’s got to able to hold a 4×5 inch glass plate which will then have a laser shone at it. The glass plate also needs to be able to rotate as well. The idea essentially is to mount the glass plate on a rotating frame and then suspend this frame on the bearings.

That bearing bush you linked me to, am I right in thinking that would be all I’d need? i.e I would recess half the length of it in the rotating frame and then the other half of the length in some sort of housing and I’d be good to go?

As for the size the internal diameter needs to be big enough so that the 4×5 inch plate can sit inside it, the outside diameter of the rotating frame I’ve designed at the moment is 220mm (so the outside diameter of the bearing needs to be smaller than this) and I’m reluctant to change it as then I’d need to change more aspects of the design.

tony, I’m not really bothered about how much it costs as the uni will be paying for it not me 😀 I’ve been told that as long as I can justify the cost then it will be considered.

mainline bearings in Leeds.

could you not get the engineering dept to make you a bored hole of 220mm then mount 3 or more ball-races on the plate carrier, so that they engage on the bored hole?

Go to SKFs website (www.skf.com, oddly enough), register and log in, then you’ll have all the bearing info you could ever want.

Smallest standard size with a 180 bore is 225 O/D and 22 wide. SKF ref. no is 61836. Just google industrial bearing suppliers in your area, or try BSL Brammer (again, google it). Prices will be VERY expensive for ball units at that size and even more very expensive for any type of roller bearing.

If you need any design work doing, let me know.

bit of a silly error designing before you checked the bearing sizes 😉

tbh I’ve never used those types of bearings. They should work fine if you use a decent grease/oil and it doesnt get on the glass etc.

A better solution for something that big might have been a circular frame with you glass in with 3 or 4 rollers on the frame around sitting in grooves on the glass frame or rollers with flanges sitting round the edge of the glass frame. You use eccentric bolts on one or more (if using 4) the rollers so you can fine adjust them for alignment and to get rid of play.

Or V rollers and a profiled edge to the frame like this:

Meh.

Float the glass in a pool of liquid mercury and have ladies rotate it when you ask.

Get a bit James Bond Villan for goodness sake!

Igus do them, called Slew rings.

I think you can get them from RS.

Try Cockenzie power station, they may have some spares.