Big End Lubrication

[Alan Worland 1Participant @alanworland1]

I have virtually completed my horizontal engine having fitted drip type oilers to the main bearings and crosshead for lubrication.

The big end has a lubrication hole into which I apply oil which finds its way to the bearing by a small capillary hole. Not totally happy about this so I have found myself a suitably sized oiler with a screw cap which would be capable of retaining a more generous amount of oil.

Would it be better filled with grease and given a part turn every so often?

Big end is 5/8 dia by about 5/8 long, steel pin and gunmetal rod.

Alan

[Alan Worland 1Participant @alanworland1]

[Donhe7Participant @donhe7]

Posted by Alan Worland on 25/06/2012 22:10:37: a suitably sized oiler with a screw cap which would be capable of retaining a more generous amount of oil.

Would it be better filled with grease and given a part turn every so often?

This method was used in a full-sized stationary engine which was built by IHC in the 1920s, which used a deep "grease cup" on the end of the crankshaft, from whence the grease was forced through a passageway to the big end , a periodic "pat" on the end of the grease cup would keep things lubricated.

The grease cup could be removed while the engine was running as required, by quickly spinning it between the hands faster than the slow-running engine was rotating, and replaced VERY carefully, after refilling.

donhe7

[AndyfParticipant @andyf]

Would wick oilers, which use a sort of capillary siphon, be satisfactory? I have just made some tiny ones for the spindle of an old Perris lathe, and they seem to work well – see bottom of this page LINK

Andy

[Alan Worland 1Participant @alanworland1]

Thanks for that. I think what I have is a grease cup (it did have grease in it)

I have fitted it to the con rod journal which has a very small feed hole into the bearing, I shall fill it with oil and run it on compressed air to see the quantity of oil used, I could fit it with a wick to slow feed rate down if it all flows through too quickly.

I like the idea of the cup on the crank end, this could be used for all crank bearings I guess.

In hindsight I think oil might be more suitable than grease?

I think a lot of small steam engines seem to have lubricators for main bearings etc but the big end gets forgotten about!

Alan

[Ian S CParticipant @iansc]

Alan, its not only models that have lub problems with the big end, I have a bit to do with a Ruston Hornsby 6HR single cylinder, horizontal oil engine, 28 hp/ 6ft flywheel. As its only used intermitantly for demonstration runs the oiling is unreliable. There is an oil cup on top of the big end with a wick, this is filled for starting, there is an oil slinger on the side of the crank, fed by the oil pump. The big end is white metal, and due to poor lub this has been redone twice in the last twenty years, fingers crossed, and hope I'v got everyone educated now. Ian S C

[Donhe7Participant @donhe7]

Posted by Alan Worland on 26/06/2012 21:04:14:

Thanks for that. I think what I have is a grease cup (it did have grease in it)

I have fitted it to the con rod journal which has a very small feed hole into the bearing, I shall fill it with oil and run it on compressed air to see the quantity of oil used, I could fit it with a wick to slow feed rate down if it all flows through too quickly.

I like the idea of the cup on the crank end, this could be used for all crank bearings I guess.

In hindsight I think oil might be more suitable than grease?

I think a lot of small steam engines seem to have lubricators for main bearings etc but the big end gets forgotten about!

Alan

The IHC engine to which I referred, used a grease cup on each crankshaft bearing, and one on the "half-time shaft", besides the one on the crankshaft end, and used a drip-feed oiler to lubricate the cylinder (about 6-10 drops per minute), hopper-cooled, and was called a "kerosene engine", which we found would in fact, run very well on deiselene!!

donhe7

[JasonBModerator @jasonb]

I've made miniature greasers for my model IHC screen cooled to lub the crank bearings, The big end is enclosed in an oil bath with a slinger. This shows one on a the full size version

For a steam engine I'd be more inclined to use an oil cup with a lid and fit a wick if needed, something like this

Edited By JasonB on 27/06/2012 16:42:02

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