Among the engineering group at work, none of us knows (or maybe we just can't remember?) the term for the part of a shaft onto which a bearing is pressed. We're not thinking of the shoulder, against which the race goes, but the part of the shaft OD that fits tightly to the ID of the inner race.

Has that got a name?

Journal or bearing journal. A later adaptation from when plain journal bearings were more commonplace.

Interefance bearings are pressed on a shaft.

Taper bearings rest on a spindle (inner) and the cone rides in a race.

A journal is a machined surface that uses fluid as the actual bearing (hydraulic wedge). Some are clearance using Babbitt or Babbited bearing shells.

We (machinists) still call that part the journal, even if a race or the ID of a bearing is pressed onto it. It's common vernacular in machine shops. As I said, it's likely a carry-over from the days of journal bearings.

Years ago, as an electro-mech guy at Michelin, it had 2 distinct names.

Before the bearing is pressed on, it's a press fit shaft. When you label the shaft to be machined on a detail drawing, it's labeled as such, along with the tolerance and finish (RA/surface finish) data. May also indicate whether it's an clearance, transition, or interference fit...

After the bearing is pressed on, it's a bearing journal/shaft assembly. On the assembly drawing it may or may not be labeled but could be labeled as such, or noted as a press fit bearing.

quote:

Originally posted by vinnybass:
We (machinists) still call that part the journal, even if a race or the ID of a bearing is pressed onto it. It's common vernacular in machine shops. As I said, it's likely a carry-over from the days of journal bearings.

Same here, some journals have shoulder surface, bearing surface and pulley surface on the stuff we do.
Some are just straight shaft the whole length.

"Journal" was the term tossed about in the shop today... we just couldn't seem to convince ourselves that was right.

Still a journal in my world too.

In my world, "Journal" or "seat" is often used interchangeably. See pic on this website...

https://www.bearing-manufactur...and-shaft-tolerance/

I have usually called it a spindle or shaft.

quote:

Originally posted by sigmonkey:
Interference bearings are first heated, then pressed onto a shaft.

If heated to 150-180 deg. they can often be slid onto the shaft but must be positioned quickly before they begin to cool.
A bearing heater works better than a rosebud here.

quote:

Originally posted by Sig Vicious:

quote:

Originally posted by sigmonkey:
Interference bearings are first heated, then pressed onto a shaft.

If heated to 150-180 deg. they can often be slid onto the shaft but must be positioned quickly before they begin to cool.
A bearing heater works better than a rosebud here.

I have done all manner of bearing, bushing and other interference fit parts on aircraft and automotive, and used everything from room temp, press, to various heating methods and cryo (liquid nitrogen, dry ice, etc).

I was only trying to answer the question, which is "shaft", even though most shops call the "final resting place" the journal. Had the OP asked for specific best practices, I would have answered.

I realize a lot of times (after the fact) the question that is asked is not the question the person actually had in mind.

But, I am quite literal and it takes me some effort to "transpose" into figurative. And why I often make puns, word plays and such, as the whole "transpose" (test fitting all things possible in meaning) very quickly almost everything I hear or read, that the "funny" thing often is just too good to pass up, so I post it.

And such postings often are "out of place".

It's an autism thing. But in the end, I'm really trying to, simply, "pass the salt", not salt anyone's food.

If I may add a bearing question: what are those bearings called that have multiple long rollers that ride against a shaft? Also, if the rollers come out when you take the wheel off of your mower then that bearing is shot, right?

quote:

Originally posted by sigmonkey:
I realize a lot of times (after the fact) the question that is asked is not the question the person actually had in mind.

But, I am quite literal and it takes me some effort to "transpose" into figurative.

It's true... often a discussion turns a bit somewhat from its original intent. But by interpreting my original question literally, I believe you were doing the right thing.

As it goes, most of our press-fit bearings are installed at room temperature. We do have a project coming that's rumored to require "freezing" the inner part and heating the outer part, pressing them together, and letting the temperature recovery finish off the fit. I'm both looking forward to and wanting to avoid that process.

quote:

Originally posted by mark123:
If I may add a bearing question: what are those bearings called that have multiple long rollers that ride against a shaft? Also, if the rollers come out when you take the wheel off of your mower then that bearing is shot, right?

Mark, I believe you're thinking of taper bearings -- the good Dr. Monkey may certainly correct me if I'm wrong.

quote:

Originally posted by vthoky:

quote:

Originally posted by sigmonkey:
I realize a lot of times (after the fact) the question that is asked is not the question the person actually had in mind.

But, I am quite literal and it takes me some effort to "transpose" into figurative.

It's true... often a discussion turns a bit somewhat from its original intent. But by interpreting my original question literally, I believe you were doing the right thing.

As it goes, most of our press-fit bearings are installed at room temperature. We do have a project coming that's rumored to require "freezing" the inner part and heating the outer part, pressing them together, and letting the temperature recovery finish off the fit. I'm both looking forward to and wanting to avoid that process.

quote:

Originally posted by mark123:
If I may add a bearing question: what are those bearings called that have multiple long rollers that ride against a shaft? Also, if the rollers come out when you take the wheel off of your mower then that bearing is shot, right?

Mark, I believe you're thinking of taper bearings -- the good Dr. Monkey may certainly correct me if I'm wrong.

there’s no taper. I’ll take a picture. I have one but need another size.

Needle bearings.

quote:

Originally posted by sigmonkey:
Needle bearings.

that’s it. Danke.

I couldn’t find my spare but you got it.

Here is what they look like: https://www.completetractor.co...3-for-toro-112-7066/

See! Told ya I'd be wrong and the monkey would fix it!

"Get some damn grease..."

I ran a grinding area in a bearing plant for over a year. By the end I had ball bearing ring grinding, spherical tapered roller bearing ring grinding, roller grinding, and the metrology lab.

You would not believe the number of different ways things can not be round, and the number of different ways you have to measure them for not being round.