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J Tiers
10-20-2013, 08:51 PM
You never know what you will find under all the old grease that a P.O. may have pumped into (and all over) machinery parts.

I decided today was a decent day to clean up the countershaft for a project machine, since I had some time. I pulled the shaft and bearings out of the countershaft frame, and found these.... Actually, the pictures were taken AFTER some of the grease and swarf were removed.

http://img.photobucket.com/albums/0803/jstanley/Rivett%20608/RCshaft_zps10321436.jpg (http://smg.photobucket.com/user/jstanley/media/Rivett%20608/RCshaft_zps10321436.jpg.html)

http://img.photobucket.com/albums/0803/jstanley/Rivett%20608/RCshaft2_zps42376c82.jpg (http://smg.photobucket.com/user/jstanley/media/Rivett%20608/RCshaft2_zps42376c82.jpg.html)

After some scraping, washing in strong purple cleaner, and soaking in WD-40, followed by scraping/cleaning, washing out with thin oil, and pumping quite a lot of new grease through the zerks, until clean grease came out everywhere, I found these.... A pair of Fafnir spherical mount shielded ball bearings.

They seem to be OK, which is good, because they look expensive, and I am not at all sure they are even still made. I have not looked, I figured to work these over and see if they could be rejuvenated regardless.

We bought some similar but somewhat larger ones (Japanese origin) at work, and those were well over two hundred bucks each. They were no special class, just "ordinary", too. I wasn't happy about that idea, but after the "treatment", all seems well for now.

http://img.photobucket.com/albums/0803/jstanley/Rivett%20608/RCshaft3_zps7f56f525.jpg (http://smg.photobucket.com/user/jstanley/media/Rivett%20608/RCshaft3_zps7f56f525.jpg.html)

Doozer
10-20-2013, 08:54 PM
Interesting, I have never quite seen bearings like that.

Cool.


--Doozer

JCHannum
10-20-2013, 09:12 PM
Those are cartridge insert bearings. The bearing is separate from the cast iron cartridge and is replaceable with a common pillow block insert bearing for a reasonable cost. The complete unit is expensive, the bearing inserts are much more economical.

I don't know who is making what anymore, but it is a standard lock ring bearing, similar to these;

http://catalog.amibearings.com/category/set-screw-locking-7

J Tiers
10-20-2013, 10:03 PM
Asahi is the Japanese company whose parts we bought. Only VERY poor information was available from Asahi.

The parts shown in the link are the whole part, but only one of them was "somewhat" similar. Diameter was right, but the holders might need modification to accept them. I didn't look at prices.

I would think the inserts would not be in any way standard... except for a particular manufacturer. Could be wrong. These are shielded, most I saw in catalogs are not. They would have to be.

Thanks for the info..... Could be handy if these turn out not to be as OK as they seem. I have no idea if compatible ones a reavailable from whoever bought Fafnir. I did see them, or something like them, in a Fafnir catalog, which put the spherical OD at 52mm.

The units I have are marked with a patent date of 1925..... Clearly not a new development....

Leadfootin
10-20-2013, 10:21 PM
These are run of the mill inserts, available at almost any bearing shop. Check ID as both 1.000" and 25MM are very common, both fitting into the same holder. Try SKF YET 205 (25mm) or YET 205-100 (1.000") or check website. The eccentric lock collar is the key and if used should be turned snugly in the direction of shaft rotation before tightening set screws. Don't use eccentric lock collars if shaft reverses as they will definitely come loose.

Peter

J Tiers
10-20-2013, 10:24 PM
This countershaft MOST DEFINITELY reverses..... it has a motor reversing switch.

Presumably there is a type which is similar, but is shielded, and does NOT come loose if reversed.

Leadfootin
10-20-2013, 10:47 PM
Should have qualified "if used with lock collars". These bearings are available in at least 20 different configurations of locks, load ratings, lubrication, seals, fits - maybe I missed a few. Older snowmobiles -70's used them on the clutch jackshaft and drive.

J Tiers
10-20-2013, 11:37 PM
It definitely uses the eccentric lock collars, I have verified that.

it definitely reverses, the motor has a reversing switch. Or rather, it did, the switch failed, but I will fix or replace it, and it will still be reversed.

So it is made in a way that cannot be reversed, but it is going to BE reversed, so evidently it will have to just deal with that situation.

presumably there are versions that do not rely on the crazy eccentric collars.

JCHannum
10-21-2013, 08:12 AM
The bearing inserts are common as far as I know, the cartridges will vary somewhat in dimensions between manufacturers. I would suspect the bearings have another century or so of life in them by their appearance as long as they are lubricated. The application is light duty for them.

I would not be concerned about shaft rotation having an effect on the eccentric lock collars. Did they show any sign of looseness when you dismantled the assembly?

J Tiers
10-21-2013, 08:24 AM
I would not be concerned about shaft rotation having an effect on the eccentric lock collars. Did they show any sign of looseness when you dismantled the assembly?

You saw the pictures, right? How would I have known? :D

They were so gummed up with gook that I didn't even know there were separate collars until later when they had been cleaned!

The issue isn't really lifetime, but noise. The machine has a cabinet base, and if the bearings are noisy, the base will be a huge sounding board.

So it's good to know that the inserts can probably be found.

I don't really know what effect there would be if I didn't even put ON the collars.... likely none, except that I need something to prevent end-wise motion. The collars would lock the inner race to the shaft, but so would other means.

John Stevenson
10-21-2013, 12:54 PM
Don't know about your side of the pond but we can get these inserts with two grub screws at 90 degrees to one another.
Should be available over there as bearing are pretty much universal.

J Tiers
10-21-2013, 07:44 PM
At's wha a fig'rd...

Gotta see if these are still noisy before I worry about it.

Thanks. Had no idea these things were that common.

wierdscience
10-21-2013, 09:35 PM
A handy chart-

http://www.albearings.com/eCatalog.php?c=elcib

J Tiers
10-22-2013, 08:51 AM
Thank you.

So, What's the deal with the crazy off-center lock ring ?

What on earth is the reason for THAT?

wierdscience
10-22-2013, 09:15 AM
When installed and done right they hold really well.I've had some that were locked in so tight they had to be sliced off with a grinder and a zip wheel.

JCHannum
10-22-2013, 09:38 AM
Thank you.

So, What's the deal with the crazy off-center lock ring ?

What on earth is the reason for THAT?

They have been around for 90 years. Like weirdscience, I have never had a problem with them loosening when properly installed. They are widely used in many applications, most commonly in pillowblock and flanged mounter bearings. Your cartridges are a less commonly encountered variation of this style of bearing.

http://www.timken.com/EN-US/PRODUCTS/BEARINGS/PRODUCTLIST/HOUSEDUNITS/BALLBEARING/ECCENTRIC/Pages/VSeries.aspx

DR
10-22-2013, 10:19 AM
Cartridge bearings I've seen many times and also thought they were universally interchangeable. The method of lubrication is different between brands in how the grease gets into the bearing from the zerk fitting on the bearing housing.

I have never encountered any like these with the zerk on the bearing itself. When you think about the extra effort in manufacturing that required no wonder it's not commonly done anymore.

becksmachine
10-22-2013, 10:25 AM
Thank you.

So, What's the deal with the crazy off-center lock ring ?

What on earth is the reason for THAT?

Think about it this way.

With the option of "2 grub screws" as mentioned above by Sir John, the grub/set screws force the shaft sideways in the bore of the bearing race. This pushes the inner race away from contact with the shaft due to stretching of the inner race, as well as pushing any clearance between the shaft and inner race all to one side.

So assuming a constant direction of load, this load is supported by the full area of half the internal diameter of the bearing inner race for 1/2 of a revolution of the race. For the other half of the revolution, the shaft is supported only by the two set/grub screws, due to the scenario mentioned above. This is a less than ideal situation for load capacity, as the area of the two screws in contact with the shaft is significantly less than 1/2 the inner diameter of the bearing race. It is also less than ideal from a concentricity standpoint.

The eccentric locking collar overcomes some of these limitations as it essentially guarantees that the shaft will be supported by approximately 1/2 the area of the inner race bore no matter what the load direction is. The downside is that the eccentric locking collar style is only effective if the relative rotation is constantly in one direction. For reversing motion, it could allow 1/4-1/2 revolution of slip before locking up in the other direction, per reversal, which would lead to more or less rapid failure depending on load and frequency of reversal.

This is a generalization, as the load bearing qualities are different at 1/8, 1/4, 3/8 etc of a revolution, but I think you get the idea.

Dave

becksmachine
10-22-2013, 10:33 AM
Cartridge bearings I've seen many times and also thought they were universally interchangeable. The method of lubrication is different between brands in how the grease gets into the bearing from the zerk fitting on the bearing housing.

I have never encountered any like these with the zerk on the bearing itself. When you think about the extra effort in manufacturing that required no wonder it's not commonly done anymore.

These are really no different than the standard two bolt pillow block, or 2/4 bolt flange mount pillow block from a lubrication standpoint. The zerk isn't in the bearing/cartridge, it is still in the HOUSING for the cartridge, and the cartridge is allowed to twist within the housing.

Dave

DR
10-22-2013, 10:38 AM
These are really no different than the standard two bolt pillow block, or 2/4 bolt flange mount pillow block from a lubrication standpoint. The zerk isn't in the bearing/cartridge, it is still in the HOUSING for the cartridge, and the cartridge is allowed to twist within the housing.

Dave

You're right, I didn't look close enough that does appear to be the housing and not the bearing's outer race itself.

J Tiers
10-22-2013, 07:58 PM
but I think you get the idea.

Dave

Not really......

It sounds like the idea is that the bearing goes where wanted, and is jammed in place by the 'permanently" mounted collar. Then so long as the rotation doesn't reverse it's in for keeps.

But, as these are on the inner race, and the outer race is fixed, there isn't any torque to speak of that would "seat" them. Do you take a couple stillson wrenches and "preload" the jamming?

mebbe it works, but it looks like it would "work" loose....

These have one grub screw, in the collar, but whatever.....

Me, I'd put a grub screw in the extended inner race, there's plenty room, and I'd know it was going no place. This sort of crude bearing won't be hurt much by that.

looks like a "blivet" to me.

becksmachine
10-23-2013, 07:42 AM
But, as these are on the inner race, and the outer race is fixed, there isn't any torque to speak of that would "seat" them. Do you take a couple stillson wrenches and "preload" the jamming?

mebbe it works, but it looks like it would "work" loose....

These have one grub screw, in the collar, but whatever.....



Well ok, ask yourself this, is there any torque at all?

If there is, does this torque tend to loosen or tighten the eccentric?

Or, how would any of the forces that would tend to make it "work loose" act only in the direction to do so?

I suspect that in operation it is a combination of this relatively small torque in conjunction with vibration of the system, and thermal effects, that allows even this small amount of torque to twist the shaft in the inner race, thus tightening the eccentric. Just like a nut on a vibrating bolt, except in this case, the torque that would otherwise tend to loosen the connection actually works to tighten the assembly.

Dave

J Tiers
10-23-2013, 08:28 AM
presumably...... since the system was patented in 1925, and is still in use, it must work OK.

Puzzling that the use of this "faster" method would be wanted, when you already must extract the shaft from the bearing, (or the bearing from the shaft), turn the insert until it can come out via the "loading groove" in the housing, and then reverse the process to put in the new. They saved (maybe) the use of a single grub screw in the whole fuff-diddle.