Plillow block bearing assemblies for layshaft

Hello,

I understand that grease is a no no for the pillow block bearings when used with a lathe, so my question is firstly how to you feed oil into the bearings, secondly what oil and how much needs adding, replenishing when in use.

The bearings I have are these ones from simply bearings.

**LINK**

I have read that filling them can create them to run hot as the oil "churns" inside. I need to adapt the layshaft mounting holes to fit them but wanted to know what to use.

Sorry for the daft question but the technical data i've read has just lead to confusion, with adding sight glasses and drains ect, which I don't feel are necessary

I dont know where you got that information, but it is wrong.

Those are roller bearings that are filled with grease for all but super specialised high-speed use, which does not include lathe countershafts. That is why they have a grease nipple on top.

You should add an occasional squirt of grease to the nipple to keep the bearing lubricated. Like on installation then once or twice year thenceforth.

Don't pump ad pump and pump the bearing full of grease solid until it squirts out the seals etc. That can cause "churning" and overheat the bearing in some cases.

They should run for many years with minimal grease added.

Most certainly you do not need to run them on oil. Absolutely not. Maybe you are getting that confused with Myford headstock spindle bearings and other lathe carriage oiling points that Myford bizarrely fitted with grease nipples but provided an oil gun to hook up to them?

+1 for Hopper's comments.

Those bearings are sealed and already lubricated, you don't really need to do anything to them.

Thank you both that puts my mind at ease and I can just continue on installing them. I cant recollect where I read that, maybe I am confusing it with the spindle bearings and things written about that.

Jon

Hi Jon. I concur 100% with Hopper on the use of grease for those bearings.

regards

Probably best not to grease them as any grease you put in may be a different spec to the original grease,and mixing grease is not really a good idea,so best left alone, with the average hobby lathe they will not be used all day every day so they should last for many years,and if they do eventually fail they are cheap enough to replace.Oil nipples were quite common on machine tools,the classic one was on the feed handwheel on a Jones and Shipman 540 grinder,works well with oil,use grease and the feed mechanism ratchet ceased to function,very common error according to J & S service engineers.

Hi, this type of bearing is used in industrial plants a lot, we used to give them a shot or two on a maintenance day, but they would normally be running continuous 24/7 and were in a somewhat hostile environment, but some of them in cleaner parts of the plant, hardily got any attention and would lasts for many years. It's not likely they will need much topping up in a hobby workshop, once every 3 to 6 months depending on frequency of use.

Regards Nick.

Grease will be compatible with any modern run of the mill grease for bearings. So dont sweat that.

I've got some similar to these. I think the nipple only lubricates the swivel that copes with shaft misalignment, the actual bearings I suspect are pre-greased and sealed.

Edit, on the other hand if you google the serial number for the insert there does appear to be a feature that could be a hole into the race for lubrication....another new thing learned.

Edited By Adrian R2 on 07/05/2020 11:50:48

There are bearings with the grease hole through the outer race but you don't buy that kind of bearing for the price listed. at least on the western side of the Atlantic. I would expect to have to pay 5 to 10 times that amount for that feature in the bearing as it would be made for a much more demanding application.

Hi Adrian R2, not exactly, this type of bearing needs to be used as a pair or with another fixed bearing. The swivelling is so the platform/s they are mounted on, do not have to be exactly parallel or exactly on the same plain with each other, saves a lot of machining costs, as a fabrication can be made and these just fitted. If you have wobble of the bearing in the housing due to shaft misalignment or anything else, it will soon wear the housing and the bearing will become sloppy. There is no reason for further lubrication between the bearing outer race and the housing, in fact you need a bit of friction between the two to stop the outer race turning in the housing when in use. All of these types of bearing inserts that I've ever seen, have a small groove around the peripheral of the outer race with one or more small hole into the inside of the bearing and the groove lines up with the position of the grease nipple location. The drawing in the technical data in the link, shows a small hole but not a groove, but these grooves are only shallow.

Regards Nick.

Edited By Nicholas Farr on 07/05/2020 14:46:27

Yep, I have a pair on the layshaft of my lathe for that reason so I know how they work and why for fitting purposes but I had seen the dust seals and as they spun nicely taken them as sealed for life and not thought any further about lubrication. Fortunately as noted for occasional hobby use this doesn't matter.