Brown and Sharpe End-Mill Oil and Seals, or Grease?

Brown and Sharpe Taper Holding Attachment: Oil and Seals, or Grease?

I have a "Taper Holding Attachment" (see image below) for the Brown and Sharpe #13 Universal and Tool Grinder that was locked up from sitting over years, probably decades. I need some help identifying the sealing and/or lubrication mechanism.



The lubricant, whether oil or grease, had thickened to the color and consistency of molasses, with the rest of the casting and bearings coasted in a shellac that prevented the bearings from rotating. All of this was easily removed with gasoline and a toothbrush. Now the bearings rotate smoothly. But what type of lubricant should I use? Oil seeps out, and these are not sealed bearings, so is grease sufficient?

Given that this is for sharpening end mills and should rotate smoothly, I would expect oil, not grease, but there are no obvious oil ports, and no obvious sealing mechanism. There was a thick, waxy substance ... almost intentionally ring-shaped in the groove shown below, but I can't see how it would seal except at its face against the bearing outer race washer, not at the inside perimiter of the casting or at the shaft where seals ought to be. So this could just be sedimentary grease that hardened in the face groove and the face groove is what coincidentally imparted a seal-like shape.


[Picture of ring with groove containing either a wax seal, or simply sediment from hardened lubricant - not sure.]

I am posting to the group to see if anyone has direct knowledge of the sealing/lubrication mechanism of this attachment - was the unit filled with an oil and sealed with some sort of wax seal? Or was it more likely lubricated with grease? Will angular ball bearings retain grease without being enclosed?

Hopefully someone here has taken theirs apart and has a better idea of the lubrication / sealing mechanism (if a seal exists.)

For now, I'm going to disassemble and pack each bearing 1/4 full with grease until I receive better advise.

Update: I took apart the end-mill sharpening attachment and this one has a thin paper gasket (if you can even call it that... it might just be shellac) but no seals around the shaft - a cap is engraved "Oil Weekly", and sure enough, oil just leaks out when it's in any position other than horizontal. The 1940's must have been a very oily, greasy time. So... more or less the same problem.

Torin...

Has labyrinth seals.
I like petroleum jelly for things like this.
Will never dry out like grease.

-Doozer

Thanks Doozer,

So grease then. I'm not worried about it drying out. By the time the moly I have on my shelf dries out, I will be long dead. I guess I'll find out if grease stays in the bearings when I inspect them in a year or so. Grease and regular inspection is tons better than having oil leaking out all over the place.


Torin...

Grease holds abrasive particles. Most machine tools use total loss oil setups in order to keep dirt, grit and chips flushed out of bearings and ways. What you are describing sounds like old oxidized way oil. Packing things with grease that are designed to be lubricated with way oil is the equivalent of not changing the oil in your vehicle. Often the oil drooled out of a bearing is designed to run onto some other part, as well. I have taken apart machines that had grease fittings substituted for oilers and usually had to clean out the oiling grooves with a hammer and chisel.

Mike,

Now it makes complete sense. What I need then is a thicker way-type oil inside these two rotating attachments. I was using spindle oil and it leaked out overnight.

BTW, I never did pack these with grease, nor will I ever knowing now what you've told me. I'll just use the oil sparingly (rather than filling to the brim) and be prepared to capture the spent oil over time. Much of this must have been assumed common knowledge at the time these machines were in operation.

Excellent advice (again) Mike, thank you.


Torin...

And sure enough, right after this I found a section in a later edition of the Operation, Maintenance and Repair Parts manual that shows "Spindle Oil Seals, Small & Large" related to a similar rotating tool holder with identical bearing-adjacent components suggesting that the waxy substance I removed earlier was indeed some kind of oil seal. Now I have a mission to look up compatible seals starting with McMasterCarr.

I don't know what brand of seals McMaster sells but I see that Chicago Rawhide ,the brand of seals that I am familiar with is now part of S.K.F.
SKF Seals
https://www.skf.com/binaries/pub12/...1_CRSeals_Handbook_Jan_2019_tcm_12-318140.pdf
SKF | Online Catalog | Interchange (457012) | Parts Lookup
Perhaps a local industrial supply house local to you that sells SKF bearings might be able to help you out.
I often take parts in to my local supplier and they can measure and cross reference with other makers to find something to help me out when I get something unusual to replace .
You may need to get make a sleeve or spacer washer to match up with a current model of seal.
Having something in your hand to try can sometimes be helpful.
Regards,
Jim

Jim,

Thank you. I had similar thoughts - disassemble the unit, take it with me (and some calipers), and see what fits. First I need to review the mechanism and determine it it's just a face seal against a spacer up against the bearing's outer race, or if the seal ought to be against the ID of the casting and the OD of the shaft. As a last resort, I have this amazing black gasket material in a tube that I can put in place of the old gasket. It cures rather quickly.

I'll check out the SKF catalog first though. If bearings had standard sizes back then, then seals probably did too. Shouldn't be too difficult to find one that fits.

Motion Industries or McMaster Carr will almost certainly have those seals. Search by dimension... ID x OD x thickness/height. A lot of the really old tools required filling with oil every day. The reservoirs were literally total loss and dribbled dry overnight. The majority of the low speed bearings on my 1918 L&S lathe are made that way. You oil it all over everytime you use it. Must be 30 oiling points.