How to get bearings off shaft?

clevinski

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Apr 26, 2012
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Hi, All,

I rarely work with bearings, other than car bearings when I was much, Much, MUCH younger. I have a pair of bearings (about 1 inch OD) on a shaft (about 5/16" OD). The bearings are in contact with each other, and there is only about a .032" gap between the first bearing and the gear at the end of the shaft. The gear is slightly larger than the bearing OD, so I can't support the bearings so I can press the shaft out. (See photo.) One or both of the bearings are bad. (This is part of the carriage transport on a Real Bull Mini-Lathe.)

My problem is that I can't figure out how to get the bearings off the shaft. At the suggestion of a friend, I tried making up a couple of 30° wedges and used my one-ton arbor press to try forcing them between the bearings. This didn't work at all, plus the wedges weren't hard and got dinged up pretty thoroughly. Since the bearings ARE bad, I'm now thinking of using a Dremel to cut off the outer races, and then scoring the inner races in the hopes of relieving the tension and somehow working them off. My concern is that it's almost like brain surgery to avoid nicking the gear shaft, which I will have to reuse.

I know many/most of you have a lot of experience with this sort of issue, and was hoping to get some advice. Any thoughts? Thanks for any input!

Bearings.jpg

Bearings.jpg
 
The cut off tool will be the quickest way to go, in my opinion. cut the inner race at a long angle, this will allow you to get closer to the back side of the gear.

cut bearing.png
Red denotes the cut line.

cut bearing.png
 
Cutting will work but when you get close to the shaft, it will be difficult to not damage the shaft. I would try drilling or grinding some deep divots in the outer races then clamp it in a vise using the divots as a holding point point then, put it a press and force the shaft out. The divots could be of several forms such as a slot to make a lip so you can butt-up some tall (and hard) flat metal against it on both sides. Don't use your machinist parallels because the bearing race is of comparable hardness and you'll damage the parallels. You'll want such divots on both sides of the race or it will get cocked.

EDIT: BTW, don't bang on the shaft with a hammer or you'll peen the end like a mushroom.

Ray
 
Good morning .

I have a craftex mini lathe with the same apron. I would use a mapp gas torch. heat 1 bearing at a time.
I used vise grips around the bearing and worked it off . try not to over heat it.
 
Cutting will work but when you get close to the shaft, it will be difficult to not damage the shaft. I would try drilling or grinding some deep divots in the outer races then clamp it in a vise using the divots as a holding point point then, put it a press and force the shaft out. The divots could be of several forms such as a slot to make a lip so you can butt-up some tall (and hard) flat metal against it on both sides. Don't use your machinist parallels because the bearing race is of comparable hardness and you'll damage the parallels. You'll want such divots on both sides of the race or it will get cocked.

EDIT: BTW, don't bang on the shaft with a hammer or you'll peen the end like a mushroom.

Ray

Well, shoot... that's one of those ideas that, when you hear it, you say, "Why didn't *I* think of that?". I can cut out part of the outer race on either side to get a grip, then maybe use a small gear puller. That wasn't possible before because there was no opening large enough for the jaws. I'm going to try that this morning; thanks, Ray!
 
06SnowSpecToolsE_img_15.jpg

The tool on the right will get under the edge and a press will be all it takes to push the shaft out.
schemer
 
Cool... When you cut/grind those divots, do right and do it once. Make them deep or you'll make a messy situation.


Ray

Well, shoot... that's one of those ideas that, when you hear it, you say, "Why didn't *I* think of that?". I can cut out part of the outer race on either side to get a grip, then maybe use a small gear puller. That wasn't possible before because there was no opening large enough for the jaws. I'm going to try that this morning; thanks, Ray!
 
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