threaded bearing

[Richard07]

Long story short, the bearing on my table saw has colapsed. Ive just got it back from me dads, so ive not had much time to look at it but after a quick inspection i can see that the shaft on the back end of the motor (not the blade side) has the tell tail signs that theres a thread on it. Obviously i dont know what type of thread it is till i remove it. My main question is, wheres the best place to get a threaded bearing or if i get a standard bearing how likely is it that i can put a thread in there? Cheers.

 

[Richard07]

Im rubbish at explaining things so hope this helps.

 

[Paul.]

Its a standard race just pressed on not threaded, try prising it with a couple of levers or borrow a bearing puller, a bit of heat on the bearing inner will help but be careful not to cook the armature

 

[Wallace]

What part of England are you in Richard? I have a selection of bearing pullers if you are anywhere near Staines. If you're good with a grinder you can gently grind through the inner race to release it, take the remains of the cage out so all the bearings slip to one side and the outer ring will come off.

 

[Richard07]

Im in sheffield mate but i appreciate the offer. Im going to borrow a puller from work tomorrow but i think it might be abit too big for the job, other than that try the grinder on it and try to be carefull i dont mess it up. Cheers.

 

[MattF]

Try a wedge behind the bearing to push it off, similar to the method bearing splitters use. Old plane blade etc. Other method, if there's enough clearance, is to put a thin strip of metal angle either side of the rear of the bearing, so that the assembly is literally suspended from the two pieces of angle rested on some solid surface, then tap the shaft out the bearing.

 

[brightspark]

if u have a black and decker workmate open it up and slip a couple of pieces of thin plate behind the bearing and lay on top tap it off with a punch

Try a wedge behind the bearing to push it off, similar to the method bearing splitters use. Old plane blade etc. Other method, if there's enough clearance, is to put a thin strip of metal angle either side of the rear of the bearing, so that the assembly is literally suspended from the two pieces of angle rested on some solid surface, then tap the shaft out the bearing.

as on a workmate i was thinkin that would work a treat ive done that before

 

[Wallace]

Shame you're so far away, I have a set of pullers that slip inside the races for bearings that are flush and you cannot get behind. If you do grind it off use plenty of gaffer tape to protect the armature etc. and when you get nearly through, the thin section that's left usually starts going gold & blue with the heat and most times it cracks before you're through to the shaft. Worse case is you have to grind both sides off. Don't forget to replace the front bearing too!

 

[pedrobedro]

If you use a puller on it you might pull the outer race off and release the bearings then you will be able to cut the inner race or clamp it and knock the shaft through.

 

[Pete.]

I would get a fat washer, weld a heavy nut in the middle of it then weld the outside to the OD of the bearing. Screw in a bolt to press it off. I wouldn't attempt pulling it off with wedges from behind. Whatever you do don't weld to the inner race.

 

[Richard07]

Cheers lads, ill have a crack at it tomorrow night. I think my best option is grinding it off as theres not much space to get a puller/wedge behinde and limmited space to clamp it. It came to me in bed last night, i thought it was threded, how can you tighten a threded bearing? Common sense realy that it cant be!

 

[Pete.]

It'd be easy to remove with a 5" grinder and 1mm cutting disc. I've removed many motorcycle headstock bottom bearing inner races from the steering stem that way. Just make sure you mask off the commutator and windings to keep conductive dust from causing a short.

 

[MattF]

Come on chaps. Grinders are not bearing removal tools. Even as a last resort they're the last resort.

 

[MattF]

if u have a black and decker workmate open it up and slip a couple of pieces of thin plate behind the bearing and lay on top tap it off with a punch
as on a workmate i was thinkin that would work a treat ive done that before

I'd not thought of a Workmate for that purpose before. One would be damn handy for the task, now you mention it.

 

[DanielW]

As Brighty said trap the race in a vice like grip and tap it out,I would trap the race in a normal vice and heat the race up with a fine blowtorch flame and then you should just be able to pull the commutator out or with the slightest tapping of the shaft.

 

[AndyStobbs]

I like Pete's idea best, but to be fair in the time we've spent discussing it, the job could have been done 10 times over.

 

[Richard07]

Which one, welded washer and bolt or grinder? Im gonna try washer and bolt welded on and a puller tonight and if that doesnt work ill try grinding. Couldnt do it yesterday as i was at college doing my C+G.

 

[AndyStobbs]

Yep welded washer and nut and bolt. Just protect the commutator and gubbins from spatter!

 

[Pete.]

You can remove a bearing race without damaging the shaft if you cut it like this. Leave the thinnest bit of material behind and it'll still spring open enough to pull off easily. You could acutally smsh out the cage, remove the balls and outer race, put your cut on the inner race then re-assemble the bearing with the balls spaced out and use the outer to pull it off.

 

[wyn]

Over the years i've found you can spend days trying to remove things carefully and still end up having to use a grinder.

I now go straight for the grinder and save time and grief.