Removing pulley from motor / motor bearings

[Gregb23]

So terrible happenstance on Monday.
Managed to drop my fobco 7/8 whilst wheeling it into the garage. Thankfully no castings have cracked or broken. I thought I'd got away with it until I spotted some needle bearings on the floor.

Turns out of managed to drop it onto the motor... Gah was / is a lovely running three phase monster.

I've an idea of the basics of motors but what are the chances I'd get away with just a bearing change? Rotating the motor you can feel serious resistance as if the shafts is no longer inline. I'm hoping just a bearing change but the bottom motor casing has taking a fair hit.

Second problem is the pulley has been on there since the beginning of time. I've got the grub screw out and the key fell out when I dropped it but I can't get it to shift at all.

I've not put much pressure on the puller I have, the last thing I want to do is crack the pulley. I've got a bit of pressure on at the moment and a fair bit of heat in and no joy. I'm hoping if I leave it it might free itself off.

I guess if the motor is wrecked I could drill/turn/bore the shaft out on the lathe?

Any ideas?

Still can't believe I dropped it, one of those things I suppose.

 

[Barking Mat]

Get a blowtorch on the pulley, slowly warm it with pressure on the pullers.

I assume you've given it a squirt with penetrating oil ?

I assume that's a three arm puller ?

 

[Gregb23]

Yeah plenty of penetrating oil around the shaft. Swimming in it in the hope that it'll hopefully work its way down.
I'll give it another warming up in the next few days and see if we have any success. Thanks.

 

[roofman]

be very careful that does not snap a pulley edge (don't ask)...plenty of heat at the center especially if your swapping the bearings

 

[brightspark]

i presume when u have heated it and put tension on the puller u have given it a whack with a hammer to jolt it

 

[mike 109444]

Check there is not a second grub screw !
Use a cordless screw driver with a socket adapter (1/4 hex to 1/4 or 3/8 to suite socket that fits end of puller) and use the "rattling" action of the driver to try and work it free (not a duga duga gun!)

 

[brightspark]

Check there is not a second grub screw !
Use a cordless screw driver with a socket adapter (1/4 hex to 1/4 or 3/8 to suite socket that fits end of puller) and use the "rattling" action of the driver to try and work it free (not a duga duga gun!)

i was going to mention a second grubscrew. i had one that i took out and there was another on top of it

 

[Seadog]

i had one that i took out and there was another on top of it

Thats some trick, if you can pull it off

 

[brightspark]

Thats some trick, if you can pull it off

dont change your daytime job

 

[wristpin]

Definitely proceed with utmost caution pulling on the pulley flanges. If it won’t budge with moderate heat and force, consider fabricating a puller that reaches under the pulley, tight against the shaft.
Two slotted overlapping heat shields to slide in from either side under the pulley to protect the top of the motor will allow the use of more heat than might otherwise be advisable.

 

[Turbo]

I've worked with electric motors for many years & I've yet to see one fitted with needle bearings! It usually std roller bearings or solid bushings with a felt reservoir to hold oil. Are you sure the bearings are from the motor?

As for removing the pulley, the way you are doing it will likely result in breaking the edge of the pulley. You really need to use a large bearing separator placed below the pulley so that its acting on the pulley body. This ad shows what I mean.
https://www.ebay.co.uk/itm/184465881800?hash=item2af305fac8:g:txsAAOSwU~9fcbAb

I bought this hydraulic set & it has been used many times for jobs similar to yours.
https://www.ebay.co.uk/itm/154406553444?hash=item23f3590764:g:SqMAAOSweHpgbaP2

If you want to continue with your method do you know that the correct way to use that type of puller is to tension it up then strike the end of the hexagon bit with a large hammer?

For heating that you need a strong heat source like oxy acetylene or mapp gas. You need to heat the pulley up quickly to expand it before the heat travels to the motor shaft & expands it too!

 

[winchman]

Use the bearing splitter in the sets Turbo shows above, whilst they are not Sykes sets they should do the job, if you where a bit nearer you could borrow mine
Sykes Picavant are a very high quality Puller maker but not cheap

 

[piman]

Hello Brightspark,

That is done on things like Bridgeport millers, effectively the same as a lock nut.

Alec

 

[Agroshield]

As everyone else has said, check for a second grubscrew.

Also go round the full perimeter of all the pulley grooves within the length of the shaft to confirm there is not a second set of grubscrew(s) at 90 or 180 degrees to that you have found.

You may be able to drill and tap the top of the pulley near the shaft for two bolts. Then you can use a plate with three holes in it to jack the pulley off.

Unless it fell on the pulley itself, it is unlikely you have bent the motor shaft

 

[Gareth J]

If the shaft is bent, are you hoping to try to straighten it? Not saying that you can or can't but if you you will definitely change the motor if it is bent, maybe make absolutely sure it's still straight before risking damage to the pulley. If you're ready to write the motor off now, you can just chop the shaft below the pulley and push it out.

 

[Gregb23]

Thanks for the advice all!

My mistake believe they are roller bearings. Needle and roller are the same in my mind, clearly not in reality. Will have a look at it again and see if I can get the motor apart with the pulley still attached. If I can replace the bearings/assess the damage I'll know if I need to cut the shaft or not.

Well aware it's the wrong puller and the risks of using it. Will check for further grub screws including below the one I've pulled out. Did not think about that.

 

[julianf]

I had a motor a while back that had been covered in veg oil for years.

I made a puller impersonator out of some box section and a couple of G clamps.

I think i had to get the end close to glowing before the pulley would move. Motor was fine after.

 

[DAPPH]

On a difficult job in my plant hire workshop I had to cut two identical 1/4 inch thick x 3 inch wide flat bars so there was a U slot in the middle . Drilled the ends for a 1/2 inch bolt and made a top bar in 1/2 in steel with a 16 mm nut welded on the under side . Welded two nuts on to some 16 mm studding to make the extractor bolt , slipped the two halves of the U bit under the pulley so they surrounded the shaft , put the top bar on and bolted them up evenly then dropped a 1/4 thick ness of 20 mm round of brass bar over the end of the quill shaft , inserted the extractors top bolt , once there was a bit of pressure on the extracting bolt , gave it a wallop with a dead blow hammer and kept gently tightening the extractor bolt ..it slowly but surely came off with out damaging the pulley


Did you check to see if there is an Allen key screw & flat washer in the top end of the quill shaft under a felt oiler ?

 

[Gregb23]

So to update/close this thread, it's sorted. Not the most dramatic or exciting of updates.

I stripped the motor down with the pulley still attached. Nothing wrong with either bearings, ball bearings with suitable grease in. Seemed like plenty of life still within, just full or crud and all sorts of shapnel and swarf.

What appeared to have happened was some crud, swarf, bits of metal had fallen into and got caught between stator and rotor.

There were a few raised bits, I filed them down . Reassembly had the shaft spinning smoother than ever. Got it all wired back up and she's running a dream.

Just hope it stays running as that pulley is well on there.

Thanks again for all the helpful advice and tips. Will surely come in handy if I do have to replace the motor in the future.