Oilites..?

Another beginners question:

Will oilite,s be ok for axle bearings on a small electric 5 inch loco..?

Ron

Edited By Ron Laden on 16/05/2018 10:38:53

I don't see why not . Do not get it to hot when machining as the oil will seep out.

Rik

I assume you mean as an axle bearing not a complete block. Oilite bearings need to be soaked in oil to replenish not fed from an oil point, also they like to work in a clean environment. They may be ok but I think you would be better off with something like a Glacier bearing or solid phosphor bronze. Glacier bearings or whatever they are called these days are steel shells with a bearing material on the bore. They are available with a bronze type bore with dimples for holding lubricant. Having said that with the right design any bearing could be used.

Thanks guys, Howard I was looking at Glacier type steel/bronze bearings yesterday and wondered if they would be a better option than oilites.

I dont have the space for ballraces so it is plain type bearings I will be using.

Ron

Would needle roller bearings be an option?

Thanks "not done it yet"

Needle roller bearings would be an option actually, they would fit the axle boxes. Having just done a search you can get them with one closed end which stops the ingress of dirt and helps retain the lubricant. Needle, Oilite and Glacier are all cheap and all available in the size I need.......Hmmm.......decisions..decisions.

Ron

Personally I think a plain bronze bearing with an oiling system would be better. The ability to run oil through will get rid of most of the dust that will be around when working. Needle roller bearings would need a hard and ground shaft with seals both sides. I am not saying you would need Ra 0.4 or 68Rc but it would need a good finish and fit to ensure that the needles rotated correctly. Sealed needle bearings have a more substantial outer ring than a simple drawn cup type which would need separate seals. Also you have to take into account out of alignment both static and when moving. Plain bearing would allow the easiest way of modifying the clearance between the shaft and bearing bore to correct the running clearance.

Greetings Ron,

I have tried needlerollers, and replaced them with cast iron.

water and ash gets into them, and they breakup.

I used the hardened steel bush they ran on and made cast iron sleeves the same size as the needle rollers, to replace them. make them 2 thou oversize, easy to oil, and they will last for ever.

Plain bronze bearings are also fine.

Regards

Brian

Thanks Howard/Brian

Well thats needle rollers out of the window. I dont want to build in potential problems, I will stick with plain bearings for the reasons you suggest.

Ron

Less of an issue with an electric loco, but I used plain CI on my electric loco.

Oil each time on the track.

I would suggest that cast iron would be a good way to go. On an electric loco needle rollers should be ok, there is no ash, there might be water off the track, but that will effect any bearing.

Ian S C

I would not use these for axle boxes, they are made from sintered material, a honeycomb, and do not deal as well with shock loads and heavy loads, just the sort you will get running on rail tracks.

I feel you will be better off with solid bearings and good lubrication.

Chris Gunn

At least 2 locos (steam) in our club use oilite, and have run for years and years. Don't plan on machining them, certainly not the bore as it closes up the pores and makes the self oiling ineffective. The hole you press them in to should be slightly undersize, then the bore closes down to the right size. Plenty of info on fitting on the interweb. Press them in, not hammer!

I have decided to go with the oilites for the axles. I was speaking to a guy yesterday who used them on a twin bogie/4 axle electric loco. The loco is 5 years old and the oilites are still good today.

I had an idea, knowing that oilite bearings like to be bathed in oil I thought of a simple way of achieving it.

The rough sketch shows the 9mm hole for the suspension spring which sits centrally above the oilite. I thought if I drilled say a 3mm hole down through into the bearing location (before I fit the bearing) it would provide a well to feed the bearing. I,m guessing but say 3 or 4 drops of oil just to sit in the bottom would probably be enough and it could be topped up as required.

Whether it is worth doing I dont know but it certainly cant do any arm and is very simple to do.

Ron

Edited By Ron Laden on 18/05/2018 09:59:58

this is probably nit picking, but don't take the oil hole right through the bush. The highest pressure is at the top. A long time ago some railway engineer arranged a test rig of an axle and axle box. He had a felt pad at the bottom, and a feed hole in the top. When the axle was rotating it pumped oil off the pad and out through the feed hole. If you want to feed oil to the bearing/axle interface, move the feed hole so that it is tangential to the joint line, preferably at the back in the normal direction of running

Thanks Duncan, no I will be drilling the feed hole prior to pressing in the bush. I am maybe misunderstanding this but what do you mean by the joint line..?

Ron

joint between axle and bush, hole is tangential to axle would have been a better way of putting it

Ah I see what you mean Duncan, sorry, me being a bit slow.