Not familiar with this type of bearing

[metalmagpie]

I have an old drill press. It has a horizontal top shaft at one end of which is a pinion gear which engages with a bevel gear commonly called a crown gear. Like all such shafts, it has a bearing at each end. Instead of poured babbitt bearings with bearing caps you can unbolt, however, this one has ball bearings in some kind of bearing housing I'm not familiar with.

The manufacturer describes them as "high-grade precision ball bearing pillow blocks". Here are 2 pix:

rear shaft bearing (back of the machine looking up)

front shaft bearing (just behind the crown gear)

Sorry about the dirt, haven't cleaned up there yet. The truth is I'm a little paranoid about monkeying with the top shaft and the main spindle because the backlash on the crown gear pair looks critical to me and I'm not sure how to take it apart and put it back with the same clearances.

Anyway, these don't look like any pillow bearings I've ever seen. Do I just unbolt them and pull them straight off the shaft? How do I know if the bearings are good and can be reused?

Any suggestions would be most welcome, thanks!

metalmagpie

 

[dundeeshopnut]

I'd just unbolt them from the drill press and lift the shaft off as a unit. If the bearings are quiet and tight, don't f@#$ with them. It's not a high speed shaft with hundreds of HP behind it anyroad.

 

[dalmatiangirl61]

I'd be willing to bet the bearings press out of the housings, if you need to replace them. For setting backlash on those gears, put them together with a sheet of printer paper between the gear teeth, that will give .004" clearance between them, grease will take care of the rest.

 

[john.k]

Not pillow blocks ,but parts of the machine ......Id be careful about removing bearings from housings ,as they may be unobtainable .......Gears must be refitted with the same meshing as before ......if bevels are crowded in to reduce backlash,the tooth contact will change ,and you may get point breakage of teeth.

 

[JST]

Are they separate "ball bearings" at all? I have a small drill press with ball bearings, sort of.

Not separate bearings you can take out and look at, what they are is loose bearing balls, with races cut in the spindle housing and in a sort of collar. That's not the only machine with that sort of "bearing" that I have.

Are the "bearings" you have like that? They might have one race in the cast housing, and the other in a collar.

 

[john.k]

Bicycle type cup and cone bearings were once quite common......even used in light cars.........these can generally be 'fixed ' and new balls fitted ......the risky ones are the caged ball or roller bearings in obsolete sizes ......bust the cages ,and youre got problems.............ive got a 1920s Jones and Shipman drill with these kinds of bearings.......the bearings are branded QGR*.......the drill came from the Banyo carriage and wagon shop.........I was going to scrap it ,but noticed the name ,so its worth saving...(.* Queensland Government Railways.)

 

[projectnut]

That does look like a typical pillow block bearing housing. In many cases the insert(s) can be removed and replaced rather than having to replace the entire unit. There are several online videos showing what the housings using replaceable inserts look like and how to replace the inserts.