Bearings extraction from BLDC motor

[alelobet]

Hello everyone!
which tool would you use to extract this bearings? they are 6x19x6mm (brand NMB type 626s)
They are in a bldc motor from a vacuum cleaner which is soldered and there is no way to open the motor without breaking it.
As you can see there is no gap to attach claws from outside so it have to be removed from the inside between the small balls

i can't find such a small extractor anywhere please can you help me?

thank you

 

[desertfox]

Hi

It’s designed I think just to throw the motor away when it no longer works.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Artisi]

A clever older fitter turner,(like myself) could make a bearing puller to fit into the ball raceway to remove the bearing, but would it be financial viable - probably not but a nice challenge.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[BrianPetersen]

Yep, designed as a throwaway.

If the motor has exposed shaft at both ends, and you can see through the openings that the next step has a hope of not doing damage (you may have to pick and choose which end you attack first), press the rotor from the opposite end and use the rotor itself to push the bearing out. (The shaft probably, hopefully, has a step that rests against the bearing. It has to be located end-to-end somehow, this is usually how it's done.)

If it's closed on the other end, drill a small hole centered where the shaft is, tap a thread into it, and use a bolt threaded into that hole to push on the end of the shaft inside. (The risk is that this damages or breaks the housing.) Failing that, insert a suitable rod into the hole that you just drilled, and whack that rod with a hammer to push the rotor out the other side, taking the bearing with it.

If that's not viable or doesn't work, obtain a few self-tapping screws of a suitable size, and drive a few of them into the ball cage between the balls, then by suitable means, attempt to pull the bearing out that way (I'd first try it with a claw hammer). Probably this will break the ball cage as opposed to pulling the bearing out, but now that the cage is out of the way, you then have a space through between the balls to the back of the bearing.

A little heat from a propane torch on the housing around the bearing will encourage the housing to expand, to facilitate relieving the press-fit.

 

[John2025]

Based on the picture, what's the chance of that shaft being in good enough shape to reuse anyway?

 

[BrianE22]

Use a Dremel type tool to grind away the outer race near the balls so that you can remove the balls. Then heat the housing and tap the motor with a hammer to hopefully get the outer race to fall out (you may have to grind it to weaken the race). Grind away at the inner race to weaken it - if it is press fit on the shaft it should break on its own if you weaken it enough.

 

[BrianE22]

...and you'll have to grind out the ball separator.

Was the motor squealing badly? Possibly the inner races of the bearings are loose on the shaft. If that's the case then heat up the case and pound on the unit with a hammer. The bearing might just fall out. You have to heat up the case quickly and then hammer quickly to keep the outer race from expanding too much. You then have a bit of a problem if the shaft bearing seat is worn away. I'd try some Loctite bearing mount between the shaft and the bearing.

 

[GregLocock]

See those 4 squarish dunch marks (technical term)? I bet that's where the casing was deformed to hold the bearing. So with a trusty cold chisel whack the dunches away from the bearing. Maybe it'll release the bearing. Or, put the whole thing into a lathe, turn away the casing near the bearing, and then turn a new bearing holder to fit in the hole you've just made.

I'm glad I haven't got a workshop any more to tempt me with silly stuff like this.


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[chicopee]

If you don't care about replacing the bearing I would carefully drill it out and replace it with a new bearing.

 

[GregLocock]

Bearings are very hard. EDM might be the way to go.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[3DDave]

I agree with Greg - start with the staking.

 

[DAVIDSTECKER]

Try the computer dust off spray to freeze the OD.
The ID should be a sliding fit on the shaft.