Regreasing a Jones and Shipman 540 "heavy duty" 4-bearing spindle

[mottrhed]

Posted same time again lol.

DT may exist, but DG (universal) is what most places would stock and is "better". Its not the same as the DT cant go in any other orientation than tandem, and its because they didn't hit the tolerance on one or both of the bearings race face to make it the same as the others and therefore universal.

You're somewhat backwards on the pressures. You do not want to push on the outer races to push the assembly out, (springs could collapse and separate the rear bearings) you want to push on the shaft with the bearings staying under tension by the springs. The risk there is the fit of the front bearings to the housing. Thats why we say its risky, there is no way to take this apart and mitigate all risk.

 

[ballen]

mottrhed,

trying to make sure that I have understood you correctly. A point that I am not clear on: are the two wheel-side bearings inside the front spacer or does the front spacer merely butt up against them?

Assuming the latter, would this a reasonable procedure if I am trying to save the bearings? or is there be a better approach? There are a couple of questions embedded.

(1) Remove pulley nut
(2) Remove pulley with wheel puller
(3) Remove rear (pulley side) cover plate with gasket
(4) Crack loose the rear ring nut but then snug up
(5) Remove grinding wheel hub retaining nut
(6) Remove wheel hub with wheel puller
(7) Remove front (wheel side) cover plate with gasket
(8) Remove SHCS (2 or 3?) which retain spacers
(9) Push spindle cartridge out from the rear.
Push on outer spacer? On spindle shaft? On both?
Reasonable force OK, no shocks
Heat spindle and casing to 80C to encourage motion?
(10) Mark positions of wheelside bearing outer races with
respect to forward spacer and wheel housing.
(11) Mark positions of pulley side bearing inner races with respect to
spindle shaft
(12) Remove rear ring nut from spindle shaft
(13) Mark positions of front and rear spacer relative to one another
(14) Secure rear (pulley side) outer spacer in circular clamp near
front of spacer (to avoid deforming bearing end)
(15) Press on pulley side of spindle shaft to force it out of the
two rear bearings which are trapped in the rear spacer
Reasonable force OK, no shocks
Heat rear spacer and rear bearings to 80C to encourage motion?

At this point the spindle shaft is free with both wheel side bearings
still attached and reachable from either side. So those bearings can
be washed and regreased.

The two pulley side bearings are trapped in the outside spacer but can
be washed and regreased in place, if grease can be fed into the inner
bearing.

I have not thought through reassembly yet. Not sure what challenges that poses in terms of bearing force directions.

Cheers,
Bruce


PS: off topic, from when I regreased my 1964 Deckel FP2 horizontal spindle. This was during initial stages of cleaning and inspection and deburring. Before final assembly every part was first cleaned and bagged. Spindle has worked very well since that.



Here is the runout at the nose and 300mm out:

 

[mottrhed]

trying to make sure that I have understood you correctly. A point that I am not clear on: are the two wheel-side bearings inside the front spacer or does the front spacer merely butt up against them? Butts, same od as spacers

Assuming the latter, would this a reasonable procedure if I am trying to save the bearings? or is there be a better approach? There are a couple of questions embedded.

(1) Remove pulley nut
(2) Remove pulley with wheel puller
(3) Remove rear (pulley side) cover plate with gasket
(4) Crack loose the rear ring nut but then snug up - not necessary but fine
(5) Remove grinding wheel hub retaining nut
(6) Remove wheel hub with wheel puller
(7) Remove front (wheel side) cover plate with gasket
(8) Remove SHCS (2 or 3?) which retain spacers - 2
(9) Push spindle cartridge out from the rear.
Push on outer spacer? On spindle shaft? On both? pick your poison, neither accomplish what you are looking for-no risk of damage. Id push on the shaft and rely on the spring pack to keep them loaded. You could get lucky and the unit just slides out.
Reasonable force OK, no shocks
Heat spindle and casing to 80C to encourage motion? wont hurt
(10) Mark positions of wheelside bearing outer races with
respect to forward spacer and wheel housing. not needed but fine
(11) Mark positions of pulley side bearing inner races with respect to
spindle shaft not needed but fine
(12) Remove rear ring nut from spindle shaft
(13) Mark positions of front and rear spacer relative to one another
(14) Secure rear (pulley side) outer spacer in circular clamp near
front of spacer (to avoid deforming bearing end)
(15) Press on pulley side of spindle shaft to force it out of the
two rear bearings which are trapped in the rear spacer
Reasonable force OK, no shocks
Heat rear spacer and rear bearings to 80C to encourage motion? hard to get heat to the inner race where you need it, but you can try

At this point the spindle shaft is free with both wheel side bearings
still attached and reachable from either side. So those bearings can
be washed and regreased.

---------------------------------------------------------------------------------------------------
At this point you could potentially clean and re-grease. In order to reassemble you will need the correct size bearing pusher for the 205.

 

[ballen]

Thanks for your help, this is very useful to me, and probably to others who might go through this in the future.

(8) Remove SHCS (2 or 3?) which retain spacers - 2

In the picture that you show in post #39, in the front bearing spacer one can see the "landing pads" for 2 screw tips which lock it in place. These are the two screws, right?

In the middle of the rear bearing spacer, I can see a "slot" which goes all the way around the circumference. I was assuming that this slot was for a third locater screw, which function as a "pin in the slot" and allows say 0.2mm = 0.008" of lateral motion, so that the rear bearing spacer can move back and forth as the spindle shaft or housing expand and contract. Is that incorrect?

If so, are the outer shells of the rear tandem bearing pair retained by the cover plate with labyrinth seal that goes under the pulley? So the springs push the rear spacer, the rear spacer pushes the rear bearing outer shells, and those rear outer shells bear against the rear cover plate?

Bottom line: I'm not sure what is retaining the rear spacer and the 7205 bearings inside it.

(9) Push on outer spacer? On spindle shaft? On both?
pick your poison, neither accomplish what you are looking for-no risk of damage. I'd push on the shaft and rely on the spring pack to keep them loaded. You could get lucky and the unit just slides out.

I see. If I push on the spindle shaft, that applies the "right" force to the rear bearings, and the "wrong" force to the front bearings, because it tends to separate them. Whereas if I push on the spacers, that applies the "wrong" force to the rear bearings, tending to separate them, but the "right" force to the front bearings. So six of one and half a dozen of the other.

I could turn a rear pusher which is sized to bear equally on the spacers and on the spindle shaft, so that in principle I'm not putting any load on the rear bearings. But then when the spacer springs shorten up, it's applying the "wrong" force to the front bearings.

Did I get this right?

(10) Mark positions of wheelside bearing outer races with
respect to forward spacer and wheel housing. not needed but fine
(11) Mark positions of pulley side bearing inner races with respect to
spindle shaft not needed but fine

I have read that precision bearings are marked with a high spot on both shells, and thought that during assembly the bores and shafts are also marked with the high points, and then the bearings are clocked with the bore and shaft to try and reduce those errors. So I was going to try and preserve this orientation. Is that misguided or have I misunderstood the process?

In order to reassemble you will need the correct size bearing pusher for the 205.

I see. If the 7205 bearings are still in the rear spacer, then for reassembly I need to put those bearings plus the rear spacer back over the pulley side of the spindle shaft. To do that, I need a clean steel tube with a (say) 25.2mm ID and an OD slightly smaller than the OD of the inner bearing shell on the face side. It needs to be long enough to push the bearings over the pulley taper and to seat them on the rear shoulder of the spindle shaft. Did I get that right? Fortunately I'm not working on my lathe's bearings, so easy enough to turn pushers or other disassembly/assembly tools as needed. (Do you make pushers from steel or brass or aluminium? Note that I understand the importance of proper chamfers and deburring.)

Cheers,
Bruce

 

[michiganbuck]

The acentric marks lined up make the whole shaft go the same 6 millionths or whatever off, not one bearing and the other in a duplex pair fighting 12 millionths difference. Being the same I call lope de lope.

One end of the shaft off 6 millionths (or what) and the other end of the shaft going 6 millionths off the opposite way I call wobble /wobble.

 

[ballen]

The acentric marks lined up make the whole shaft go the same 6 millionths or whatever off, not one bearing and the other in a duplex pair fighting 12 millionths difference. Being the same I call lope de lope.
One end of the shaft off 6 millionths (or what) and the other end of the shaft going 6 millionths off the opposite way I call wobble /wobble.

Thanks Buck, I think I get it.

You line up the high points of all four outer bearing shells (in the housing) and you line up the high points of all four inner bearing shells (on the shaft). If the shaft has been ground correctly its roundness errors are a lot smaller than the bearing errors, so it can go in any orientation inside the bearing shells, provided that all four inner shells are lined up correctly and all four outer ones are lined up correctly. This minimises the lope do lope and the wobble/wobble.

Is that right?

 

[john.k]

Dont pack high speed bearings like you would wheel bearings ........also ,if you hear a clicking noise when first run,there is too much grease in the bearing.

 

[michiganbuck]

Most bearing literature and bearing guys suggest 1/4 to 1/3 full..and spread that evenly, then hand turning it to see that no balls are not dry.. (X) I have seen hack guys' solvent wash a bearing and then air hose spin it to exclude to solvent -> "that is' a never do"...
In the assembly, I like to hand turn and jog start a few times

 

[mottrhed]

Thanks for your help, this is very useful to me, and probably to others who might go through this in the future.

Thats why Im here, hopefully to bring value to someone lol.

In the picture that you show in post #39, in the front bearing spacer one can see the "landing pads" for 2 screw tips which lock it in place. These are the two screws, right?

Yes

In the middle of the rear bearing spacer, I can see a "slot" which goes all the way around the circumference. I was assuming that this slot was for a third locater screw, which function as a "pin in the slot" and allows say 0.2mm = 0.008" of lateral motion, so that the rear bearing spacer can move back and forth as the spindle shaft or housing expand and contract. Is that incorrect?

No third screw, this spacer isnt pinned

If so, are the outer shells of the rear tandem bearing pair retained by the cover plate with labyrinth seal that goes under the pulley? So the springs push the rear spacer, the rear spacer pushes the rear bearing outer shells, and those rear outer shells bear against the rear cover plate?

No, they wont touch the rear cover, if they did there would be no preload and expansion would unload them further

Bottom line: I'm not sure what is retaining the rear spacer and the 7205 bearings inside it.

Im not real sure what you mean, but I think what you are missing is the rear shaft nut. That nut is holding the inner races, which push on the balls, which hit the outer races, which are shouldered in the spacer, which has spring pressure backwards.

I see. If I push on the spindle shaft, that applies the "right" force to the rear bearings, and the "wrong" force to the front bearings, because it tends to separate them. Whereas if I push on the spacers, that applies the "wrong" force to the rear bearings, tending to separate them, but the "right" force to the front bearings. So six of one and half a dozen of the other.

Bingo

I could turn a rear pusher which is sized to bear equally on the spacers and on the spindle shaft, so that in principle I'm not putting any load on the rear bearings. But then when the spacer springs shorten up, it's applying the "wrong" force to the front bearings.

precisely

Did I get this right?

yep

I have read that precision bearings are marked with a high spot on both shells, and thought that during assembly the bores and shafts are also marked with the high points, and then the bearings are clocked with the bore and shaft to try and reduce those errors. So I was going to try and preserve this orientation. Is that misguided or have I misunderstood the process?

its not a bad idea, but I highly doubt a spindle of this caliber was done that way. you have nothing to lose so go for it.

I see. If the 7205 bearings are still in the rear spacer, then for reassembly I need to put those bearings plus the rear spacer back over the pulley side of the spindle shaft. To do that, I need a clean steel tube with a (say) 25.2mm ID and an OD slightly smaller than the OD of the inner bearing shell on the face side. It needs to be long enough to push the bearings over the pulley taper and to seat them on the rear shoulder of the spindle shaft. Did I get that right? Fortunately I'm not working on my lathe's bearings, so easy enough to turn pushers or other disassembly/assembly tools as needed. (Do you make pushers from steel or brass or aluminium? Note that I understand the importance of proper chamfers and deburring.)

Yes, right. We use steel pushers that we custom make, take care that the ends are ground flat and perpendicular with the bore/od.

Cheers,
Bruce

 

[Mark Rand]

Bruce:- It's a bit late, but I finally sortof got a picture of the 1400 head in the parts list. It's a crappy picture, but it shows the layout:-

 

[Mark Rand]

Most bearing literature and bearing guys suggest 1/4 to 1/3 full..and spread that evenly, then hand turning it to see that no balls are not dry.. (X) I have seen hack guys' solvent wash a bearing and then air hose spin it to exclude to solvent -> "that is' a never do"...
In the assembly, I like to hand turn and jog start a few times

We had a backup generator for our computer rooms at work, constantly running alternator with a super-synchronous flywheel, Diesel engine with heated block in standby with a magnetically operated clutch. In the case of power loss, the flywheel kept the alternator running while the Diesel started. If the Diesel didn't start in four seconds, it just dropped the clutch and the flywheel bump started it!
Anyhow- During a major service, the contracted mechanics replaced the flywheel bearings and I spotted them completely filling them with grease. I questioned this, but they said that this was the required practice . Two weeks later it failed to start the diesel, because the clutch slipped. One month later it shut down due to excessive vibration.The ball bearings had overheated, emptied the excess grease out, seized and wrecked the shaft. £25,000 replacement bill. We had to pay due to the unit not being in warranty any more. Management wouldn't back me up when I claimed that it was the incompetence of the service fitters which had caused the damage. They also wouldn't accept my suggestion that the late John Stevenson (known on this site), 40 miles away, would be able to do a weld repair and re-machine of the damaged shaft for about £2,000 (that's what he did for a living!).

 

[ballen]

Dont pack high speed bearings like you would wheel bearings ........also ,if you hear a clicking noise when first run,there is too much grease in the bearing.

Thanks, I know, I use the Kluber formulae for NBU 15 fill factors, based on the bearing rotation speed and bearing diameter.

 

[ballen]

I'm not real sure what you mean, but I think what you are missing is the rear shaft nut. That nut is holding the inner races, which push on the balls, which hit the outer races, which are shouldered in the spacer, which has spring pressure backwards.

Duh.

OK, I got it, it's obvious and I don't see why I didn't understand it before.

The bearing (pair) outer shells are being forced apart/preloaded by the spacers which are bearing on or holding on the outer shells and being pushed apart by springs. The spindle shaft is trapped between the inner shells, by the outer shoulder on the wheel side and by the ring nut on the pulley side. Then, the front spacer is locked in place by the two setscrews. So the rear spacer and bearings are free to move back and forth within the head casting bore to take up thermal expansion/contraction, whereas the front bearing of the spindle is fixed against the front spacer by preload and the front spacer is registered in the spindle bore.

Here is the bit that I don't understand. On my J&S 540 heavy-duty spindle, if I push axially hard on the pulley, the pulley moves slightly inwards, and when I release the pressure, the pulley moves back out. I always thought that this was OK, it was just demonstrating the preloading of the
bearings by the internal springs, and showing how expansion/contraction could be taken up. But now I don't understand how such motion is possible. Presumably I am forcing the spindle shaft forwards by moving the rear spacer and the bearings inside. Does that mean that (1) the front bearings are sliding forward in the bore, away from the front spacer (2) the front bearings are separating (3) the spindle shaft is moving inside the front bearing inner shells? Or something else?

(One further possibility: I am getting senile and don't remember how the shaft behaves when pushed from behind. Will test this again at the next opportunity, about 24h from now.)

its not a bad idea, but I highly doubt a spindle of this caliber was done that way. you have nothing to lose so go for it.

In their 1980s brochure, J&S show a picture of their spindle assembly shop. It is thermally and vibration insulated from the rest of the factory, and has its own filtered purified air supply. Other people posting here have said that the bearings are individually marked with id/od to 1/10 micron and have eccentric high marks on both shells. So it appears that they did go to this level.

Yes, right. We use steel pushers that we custom make, take care that the ends are ground flat and perpendicular with the bore/od.

I can certainly grind the ends flat and perpendicular to the bore. But I thought that the bore shouldn't be a snug fit for a pusher, that it was better to allow 0.2mm = 0.008" of diametral slop so that the pusher ends will lie flat on the bearing shell, not contacting the shaft. In which case there is no need to be more than close to perpendicular. Is that wrong?

 

[ballen]

Bruce:- It's a bit late, but I finally got a picture of the 1400 head in the parts list. It's a crappy picture, but it shows the layout

Thank you very much, Mark, it's a very clear drawing!

I think this shows that the J&S 1400 spindle is NOT the same as the J&S 540 "heavy duty" spindle, even though they use the same bearings. Compare the 1400 rear spacer in your post #50 to the 540 "heavy duty" rear spacer visible in mottrhed's post #39. The 1400 rear spacer has a rear outer shoulder. The 540 heavy duty spindle rear spacer has no rear shoulder. Also the 1400 spindle rear spacer has an oval slot for a third retention screw that prevents rotation. That is absent on the 540 heavy duty spindle rear spacer.

Or am I reading the drawing wrong?

 

[mottrhed]

Duh.

OK, I got it, it's obvious and I don't see why I didn't understand it before.

The bearing (pair) outer shells are being forced apart/preloaded by the spacers which are bearing on or holding on the outer shells and being pushed apart by springs. The spindle shaft is trapped between the inner shells, by the outer shoulder on the wheel side and by the ring nut on the pulley side. Then, the front spacer is locked in place by the two setscrews. So the rear spacer and bearings are free to move back and forth within the head casting bore to take up thermal expansion/contraction, whereas the front bearing of the spindle is fixed against the front spacer by preload and the front spacer is registered in the spindle bore.

correct

Here is the bit that I don't understand. On my J&S 540 heavy-duty spindle, if I push axially hard on the pulley, the pulley moves slightly inwards, and when I release the pressure, the pulley moves back out. I always thought that this was OK, it was just demonstrating the preloading of the
bearings by the internal springs, and showing how expansion/contraction could be taken up. But now I don't understand how such motion is possible. Presumably I am forcing the spindle shaft forwards by moving the rear spacer and the bearings inside. Does that mean that (1) the front bearings are sliding forward in the bore, away from the front spacer (2) the front bearings are separating (3) the spindle shaft is moving inside the front bearing inner shells? Or something else?

1, no, outer races are captured by the front cover and cant move forward. - you can see it in the print posted
2, almost certainly
3, while physically possible it would take force to do this and with the bearings very willing (zero force) to separate, that (#2) would happen first

(One further possibility: I am getting senile and don't remember how the shaft behaves when pushed from behind. Will test this again at the next opportunity, about 24h from now.)

understanding that you are separating the front bearings, only push til preload is lost, if you go too far you will damage the front bearings by reverse loading.

In their 1980s brochure, J&S show a picture of their spindle assembly shop. It is thermally and vibration insulated from the rest of the factory, and has its own filtered purified air supply. Other people posting here have said that the bearings are individually marked with id/od to 1/10 micron and have eccentric high marks on both shells. So it appears that they did go to this level.

like I said no harm in doing what you plan to, it certainly wont make things worse.

I can certainly grind the ends flat and perpendicular to the bore. But I thought that the bore shouldn't be a snug fit for a pusher, that it was better to allow 0.2mm = 0.008" of diametral slop so that the pusher ends will lie flat on the bearing shell, not contacting the shaft. In which case there is no need to be more than close to perpendicular. Is that wrong?

you are correct, you dont need to be perfectly perpendicular as you will have some slop, but you do want to be flat inner to outer, and i just meant dont be un(non?)perpendicular by 15deg or something crazy

 

[ballen]

Mottrhed,

correct

Thanks for your patience in walking me through this and helping me to understand how it works -- I am better prepared to take this on. It won't be until later this summer or early Fall, so I'll pick up the thread then

You commented on "damaging the bearings by reverse loading". As you've made clear, there is no way to avoid this in spindle disassembly, at least for one of the two pairs. How much reverse loading is needed to do damage? Presumably just removing the preload is not enough. But is any additional force going to do damage? Or are tens/hundreds/thousands of Newtons required to do damage?

Is it right that you are in New Hampshire USA? If you were in the EU I'd be tempted to just send you the spindle.

Cheers,
Bruce

 

[mottrhed]

Happy to help, but ya other side of the pond from you.

Reverse loading, sorry I have no good answer about the force required to do permanent damage. Every bearing size and manufacturer will be different, and as far as I know they do not publish such a spec. If we have to take a spindle apart that has good bearings, its about a 50/50 that the bearings survive, with the scale getting much worse the more expensive the bearing or the higher DmN of the spindle due to the fits.

 

[Mark Rand]

To be fair, angular contact ball bearings will survive reverse pressure disassembly quit happily if the shells aren't overly constrained radially. It is how they're put together, after all.

 

[mottrhed]

O id love to see some legitimate data on that.

And what do you mean they are assembled that way?

 

[Mark Rand]

With a one-piece phenolic or brass cage, the only way to get the balls into the bearing is by pressing the balls and shells together...

There is probably more chance of damage if the outer shell is being constrained by a tichtly fitting housing.