Electric Motors- replacing bearings

Hi,
Is there any online info 'splainin how to replace ball bearings in
electric motors? The last professional craftsman who did it for me put
the armature in a vise and whacked the bearing off with a big hammer,
ruined the motor, etc.
Thanks in advance to everyone.
Reply to
Rooster
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I have a webpage where I show how I did it.
You should use a bearing puller and be careful removing rear end bell (for single phase motors).
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i
Reply to
Ignoramus8644
Don't know if it will not come out of the housing, but as far as removing from the armature you could and prob should press them on and off to prevent damage to the bearings from stricking them.
Reply to
DJ
There's a good article on replacing motor bearings in the latest ed. of Home Shop Machinist. It tells about making a sleeve for a replacement bearing that was too small.
Bob Swinney
Reply to
Robert Swinney
I'm not an expert, but I rent my store front out to guy who does motor rewinding. I've seen him many times heat the bearing to remove and replace it on the armature. You also want to check how the bearing seats in the housing. I've seen some motors that the seat was out of round and loose, and the bearing was good.
Randy H
Reply to
Randy H.
On the submarine (at sea) we did not have access to fancy hydraulic presses, so we carefully cut off the old bearing with a die grinder and heated up the new bearing in the galley oven. I understand that they later got induction heaters, but I'll bet they still use the die grinder.
Vaughn
Reply to
Vaughn
Die grinder? I can hear the sonar watch levitating and fighting the urge to scream "high speed screws in the water"
Reply to
bamboo
I don't understand what all the fuss is about on this thread. I've been rebuilding small electric motors all my life and have never had any instructions whatever. Take them apart, replace the bearings, clean them out a little, make sure all's a'tanto, put them back together the same way they were.
On really little motors I've sometimes had trouble
1) getting the centrifugal switch mechanism off correctly 2) getting the bells centered since they're built too lightly
To deal with the centrifugal switch, I try to gently remove the bell on the far end from the shaft first, and see what I can see. Lots of times the armature will slide out.
I have never had big trouble removing bearings from any motor up to 7.5hp and I've never worked on anything bigger.
To deal with the bell centering issue (on reassembly) I mark the bells before disassembly so I can replace them exactly as they were. Then I assemble the motor lightly, and run it on the bench and tap the bells with a soft hammer until they run as quietly as possible, then tighten them. I've gotten a couple of small cheap motors to quiet down quite a bit this way.
Motor stators like being blown out with compressed air.
The only motors that I hate are the ones that when you run them they're noisy, then when you cut the power for an instant, while they're still virtually at full speed, they run silently, then when you restore the power, the noise returns. Those I've never been able to fix, so I have always replaced them and let the noisy ones go.
GWE
Reply to
Grant Erwin
I am curious where can I buy a very deep bearing puller. (for taking bearings off shafts that protrude about 6-7 inches beyond the bearing.
i
Reply to
Ignoramus27122
Jeez, silly me, I never even thought of buying one, I just took mine apart and made some longer straps for it ..
GWE
Ignoramus27122 wrote:
Reply to
Grant Erwin
good idea...
io
Reply to
Ignoramus27122
Go to
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and click on Technical Support. Then click on "On-line Catalogue / Interchange ", then "Engineering Information" at the top. Finally, under Engineering Documents click on "Proper Practice for the Cleaning, Mounting, and Removal of Bearings ". Should find a lot of good info there. Please note that when it discusses oil immersion heating to only do that with open bearings. You can flush the grease out of sealed or shielded bearings with that method. Good luck - take care.
Tom..........
Reply to
Tom
Good link Tom. There's an interesting item in their FAQ
What does the term "electric motor quality" mean? The term "electric motor quality" is freely used in describing bearings that meet a perceived "higher" level of quality than the standard ABEC1 bearing. Contact NTN marketing for an Electric Motor Quality brochure.
I'd not heard the term before.
Roger
Tom wrote:
Reply to
rlincolnh

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