Poooooo. Bearing's died - again.

[guydewdney]

the huge bearing on the outside of my waterwheel has just died - again.

Its a 125mm (5" in old money) self aligning bearing, in a big cast iron housing - and its making (all of a sudden) horrible clunking screeching noises. 

poo. Or some words like that.

bearing cost £1,500 

[Heinz]

How much ??! 
Photo? or part number?

H

[Bodidly]

That must be one hell of a bearing is it stainless steel?

Sorry to read of your loss
Beau

[RobNute]

Thats bad news Guy, hope it works out cheaper than expected. Rob

[Bodidly]

I have just had a random thought could you use lignum vitae as a bearing I have just checked on wiki and it used to be used on ships stern tube bearings . I would have thought you could buy quite a lot for £1500.

Beau

[Justme]

Is it still in warranty?

[guydewdney]

the problem that I have is the end of the shaft is 'bent; or 'whirling' - a bit like if you point a finger and transcribe a circle with the tip, thats what the shaft is doing - by about 3 degrees.  I'm 99% certain that the seal has failed, and allowed water / ick / grit in and trashed it.

Im looking at solid bearings - like rose joints - in ptfe / bronze / carbon next. Anyone know about this sort of thing?

[Heinz]

Can the end of the shaft not be machined true in place? with a jury rigged grinder? Support the shaft with a temporary wooden V block bearing and rotate the wheel by hand? while the grinder grinds. Grinder could be a simple bench grinder on a slide able mount, angle iron? Crude and slow but things like this can produce quite accurate results.

H

[knighty]

guy, I know an awesome bearing guy... it's all he does and he does it well!

if you can send me a couple of photos/measurements/weights etc.. I'll drop into his unit and see him

I'm past a couple of times a week so it's no problem :-)


the first time I went in I told him what he needed.... and he recognised the machine, he sold my dad a gearbox 30 years ago for the machine next to it.. I picked up 2 different bearings, a couple of sprockets and a length of chain... he knew all the part numbers off the top of his head and knew the differences between different models/makes etc... it was pretty refreshing !

[guydewdney]

well - its 125mm diameter, with a 140mm shoulder, it supports about 4 tons and does 5rpm, and is about 3 or 4 degrees out of line.

pics

old bearing

http://www.navitron.org.uk/forum/index.php?action=dlattach;topic=3113.0;attach=1638;image

new shaft end

http://www.navitron.org.uk/forum/index.php?action=dlattach;topic=3113.0;attach=2547;image

http://www.navitron.org.uk/forum/index.php?action=dlattach;topic=3113.0;attach=2548;image


I think you can see the bent-ness here

http://www.navitron.org.uk/forum/index.php?action=dlattach;topic=3113.0;attach=3926;image



sorry - edit - its 150mm bore - the bearing itself is a 23130K

[camillitech]

Wrong bearing for the job I'd say Guy, go back to the original, if you do choose the 'modern way' then I'd go for a 'Cooper bearing' on each end.



And what's more when I get back to work I'll measure the ones on the ferry's prop shafts, we certainly have at least one good housing spare and there may be other good bearings in the fleet.

Good luck, Paul

[biff]

paul is right guy,
              it will run more reliably with the old brass bushin,especially loaded with grease which will keep the grit out,it will certainly not fail suddenly.you will probely have to rebuild the shaft in situ or take it down a few thou,
   i remember gathering bags of 8 of these big brass bushins for my dad,each mill he bought had at least 6 of these and sometimes more.brings back memories seeing one again.
                               biff

[renewablejohn]

I have just had a random thought could you use lignum vitae as a bearing I have just checked on wiki and it used to be used on ships stern tube bearings . I would have thought you could buy quite a lot for £1500.

Beau

I did suggest this to Guy at the time he bought the last bearing as my father was a ship wright and regularly replaced brass bearings with lignum as the lignum was harder than brass but still not as hard as the steel prop shaft. Lubrication was by water which is ideal in Guys mill application. My father would have easily been able to construct a bearing unfortunately the fine sawdust made by the Lignum led to his premature death at the age of 50.

[spaces]

The shaft will need sorting if a bearing is going to last, as I'm sure you're aware... should be straightened rather than machined otherwise loadings may be uneven as the wheel rotates. Personally I would go for solid bearings, but they require regular greasing. Automatic greasing could be activated by wheel's rotation.  

[clockmanFR]

What was wrong with the old set up, all it wanted was some new shells and possibly new clamps?

Brass/bronze, but check Naval Brass out and you will have to see what the thickest bit of block you can get.

I did some bell (in churches) bearings many years ago, big bells many tons.

Brass/Bronze Bolted to a face plate, bored and reamed out then outer diameter machined all in one operation. Then i split the bearing in half and this give a slight gap for constant lubrication to get in and be stored. The top outer clamp was not left tight as after a few months ringing the bells, the brass bearing had bedded into the old shaft, and the clamp was just tightened up when necessary.

Modern sintered bronze stuff may not take the loading.

But you will have to get that shaft straightened out a bit and take the high spot off first. Any chance of very slowly rotating the shaft in a fixed temp cradle ? Then you can set up a rigid locked in place Grinder disc and carefully grind off that high spot then polish the grinding out. Brass/bronze bushes will take a fair bit of movement and wear in accordingly but just don't get them to tight.

If you end up with a slight taper on your shaft, then just enlarge the slot on one side of your new shells bearing and it will take up the taper.