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macona
07-21-2009, 07:14 PM
Got a motor out of our aic condition that has a bad bearing. The replcement one is at least $328 not including shipping. Its an odd ball so the universal ones are not a food fit.

So... the fan side bearing went dry and got eaten up. Now there is enough slop where the rotor and stator touch. The shaft should be salvageable. It lost about .002 to .003 on dia and should clean up. The bearing is whats holding me back though. It is a Babbitt lined steel bearing. 5/8" id 3/4" OD, 1/2" long.

Think I can replace it with a bronze bushing?

If all else fails I could jerry-rig a support to hold a ball bearing in the end bell.

-Jerry

GKman
07-21-2009, 07:30 PM
My local motor repair shop had one for mine but I didn't get the shaft cleaned up enough and it failed. He said sometimes they work and sometimes not. Since then I have seen on this site that some shafts are just pressed into the armature and can be replaced with stock shafting.

wierdscience
07-21-2009, 08:20 PM
Could you bore the old bearing back round and loctite a thin sleeve on the shaft for the larger diameter?

wmgeorge
07-21-2009, 08:22 PM
Got a motor out of our aic condition that has a bad bearing. The replcement one is at least $328 not including shipping. Its an odd ball so the universal ones are not a food fit.

So... the fan side bearing went dry and got eaten up. Now there is enough slop where the rotor and stator touch. The shaft should be salvageable. It lost about .002 to .003 on dia and should clean up. The bearing is whats holding me back though. It is a Babbitt lined steel bearing. 5/8" id 3/4" OD, 1/2" long.

Think I can replace it with a bronze bushing?

If all else fails I could jerry-rig a support to hold a ball bearing in the end bell.

-Jerry

Yes, just put in an oillite bronze bushing. I am sure a bearing supply house or ENCO will have. They usually need finish or inline reaming to fit right, your shaft may be worn enough it won't matter. Look for a new motor in the meantime.

macona
07-22-2009, 09:00 PM
Went down to the hardware store and picked up a oilite bushing. Milled a square hole like in the original for the felt wick. Pressed it in. It was a little tight but it loosened up to a nice fit. I went ahead and left the bushing a full 1" vs the 1/2" long the old one was. This ought to let it ride somewhat on fresh shaft. Even if it still not fully supported it ought to be better than nothing.

Its been running for a couple hours now and so far so good. No funny noises.. yet!

wmgeorge
07-22-2009, 09:31 PM
Just a little 20W non-detergent oil once a year and who knows how long it will last. It must have been a special RPM or frame? What brand of AC or furnance was it in? Some of the new ECM variable speed motors are ball bearing and have three phase windings running on a special circuit board. They cost $500 - $800...

macona
07-22-2009, 10:24 PM
Nothing too terrible. Its a 48 frame motor, 3 speed, 208-240 single phase, but the kicker is a 5/8" shaft.

wmgeorge
07-23-2009, 01:03 PM
Nothing too terrible. Its a 48 frame motor, 3 speed, 208-240 single phase, but the kicker is a 5/8" shaft.

You did not say what HP or RPM, indoor blower or outside condenser fan? But the one I have is 1/2" shaft anyway and just 1/4 HP. Look at Graingers, (online) which use to be WW Graingers... need to have an account to purchase. A business of course gets the wholesale price, and the more you buy per year the better the discount.

macona
07-24-2009, 12:07 AM
1/2hp 1075 RPM. Rooftop evap fan.

Grainger didnt have one motor with a 5/8" Shaft and I really dont like bushing them.

never had an issue buying with grainger without an account. Just tell them cash sale and they are more than happy to take your money.

wmgeorge
07-25-2009, 09:45 AM
1/2hp 1075 RPM. Rooftop evap fan.

Grainger didnt have one motor with a 5/8" Shaft and I really dont like bushing them.

never had an issue buying with grainger without an account. Just tell them cash sale and they are more than happy to take your money.

I am assuming you mean condensing unit, the part with the compressor? Or the compressor is inside and the condenser is on the roof, either way I am also assuming propeller fan? Sometimes we would replace the prop fan and the motor just because we could not get the right motor. They make universal fit prop fans, you need to know the diameter and the pitch of the blade. The hubs can be had in 1/2" or 5/8" and attach with screws to the blade assy. On a 1/2 HP motor very unusual to find a 5/8 shaft, as you are finding out. I would never put a 1/2 to 5/8 reducer on a fan of any kind.