"Ignoramus6689" wrote in message
.. .
For $12.00, I bought a 5 HP, SINGLE PHASE Baldor compressor motor that
has a problem. When I spin it up by hand, it turns, but a little
roughly and then spins by itself, but not for very long. It stops too
soon. It is not, by any means, seized, but there is too much friction
compared to what it should be. I did not run it under power yet

It is ball bearing based, which I concluded after seeing grease
fittings on it.

My hope is that it should be an easy fix. Either the grease caked, or
perhaps the bearings need replacement. Any thoughts on how to proceed?

I did the same just a few months ago. I was bequeathed two complete(ly
broken) and water-damaged 5HP compressors. Both had Baldor motors. One
motor was well and thoroughly burnt out. The other was "grumbling" like
yours.

It's a little of a trick to get the motor apart and get the bearings out,
but no big deal. The hardest part will be to get the shaft end bearing off
the shaft, since it usually corrodes in place. Lots of oil and fine grit
paper are the trick to getting the shaft back to its original o.d. without
damage. You'll need a small gear puller to start the bearing moving on the
shaft. Then it should slide off easily.

The bearings are stock NGK items in my local bearing shop -- about $14.00
each.

Take care pressing them back into their seats -- they aren't tight fits, but
you should avoid any pressure on the inner race. Make a tool, if you aren't
lucky enough to have a bearing pressing mandrel that fits. A large wrench
socket that is no more than, say, 0.050" smaller than the o.d. of the outer
race will work well as a tool.

LLoyd

i

"Lloyd E. Sponenburgh" wrote in message
...
snip------

Take care pressing them back into their seats -- they aren't tight fits,
but
you should avoid any pressure on the inner race. Make a tool, if you
aren't
lucky enough to have a bearing pressing mandrel that fits. A large wrench
socket that is no more than, say, 0.050" smaller than the o.d. of the
outer
race will work well as a tool.

LLoyd


That bit of instruction can be confusing for some. Bearings should be
pressed by the race that is being pressed, so no pressure is transmitted
through the balls or rollers, brinelling them in the process. If the
bearing is pressed on the shaft, it should be pressed by the inner race, not
the outer race.

Harold

"Ignoramus6689" wrote in message
.. .
For $12.00, I bought a 5 HP, SINGLE PHASE Baldor compressor motor that
has a problem. When I spin it up by hand, it turns, but a little
roughly and then spins by itself, but not for very long. It stops too
soon. It is not, by any means, seized, but there is too much friction
compared to what it should be. I did not run it under power yet

It is ball bearing based, which I concluded after seeing grease
fittings on it.

My hope is that it should be an easy fix. Either the grease caked, or
perhaps the bearings need replacement. Any thoughts on how to proceed?


Baldor usually lists the bearing # on the motor dataplate.....

Suggest should install sealed bearings instead, theses will have the same ##
but with additional "ZZ" suffix....

Upon reassembly, be sure and plug the old grease holes.

--

SVL

"Ignoramus6689" wrote in message
.. .
For $12.00, I bought a 5 HP, SINGLE PHASE Baldor compressor motor that
has a problem. When I spin it up by hand, it turns, but a little
roughly and then spins by itself, but not for very long. It stops too
soon. It is not, by any means, seized, but there is too much friction
compared to what it should be. I did not run it under power yet

It is ball bearing based, which I concluded after seeing grease
fittings on it.

My hope is that it should be an easy fix. Either the grease caked, or
perhaps the bearings need replacement. Any thoughts on how to proceed?

thanks

i


It could be just bad bearings, but I often see where the bearing has spin in
the end housing of the motor and wore it over size. So if you get to the
point of tearing it apart, be sure to check the fit of the bearings in the
motor end housings. If the housing is ruined you can buy replacements at a
good motor shop. They will have to order them.
As far as replacing the bearings you will need a puller to get them of. To
install the new bearings best thing is to press them onto the shaft, but if
you are careful you can drive them onto the shaft with a hammer and punch,
or a piece of pipe. Be sure to drive on the inner race only!! If you put any
force on the outer race you will ruin the bearing!
Greg

On Tue, 9 Aug 2005 18:20:16 -0500, "Greg O"
wrote:

. If the housing is ruined you can buy replacements at a
good motor shop. They will have to order them.

Or if you are cheap like me...bore out the housings and put in
bushings.

Gunner

If you are going to use that phrase then you should use
the full phrase of "**** Off and Die and Rot In A Ditch
and Get Eaten By Maggots and ****ed On and **** On By
a Dysenteric Elephant (but not necessarily in that order)."

Crash Street Kidd

"Ignoramus6689" wrote in message
.. .
I just learned that both motors work fine. Both almost jump when
powered.

How can I know that a motor is made for driving a belt (and is able
to
take side loads)?

i

Baldor might have the belt load data (as a function of the distance
from the bearing). If not, you can look up the dynamic load rating for
the bearings, measure the distance between them and where the load
will be applied, then calculate the bearing load for an approximation
.. Remember the bearing load is 2X the belt tension...

All that's assuming the shaft will not bend....

"Rick" wrote in message
nk.net...

"Ignoramus6689" wrote in message
.. .
I just learned that both motors work fine. Both almost jump when
powered.

How can I know that a motor is made for driving a belt (and is
able
to
take side loads)?

i

Baldor might have the belt load data (as a function of the distance
from the bearing). If not, you can look up the dynamic load rating
for
the bearings, measure the distance between them and where the load
will be applied, then calculate the bearing load for an
approximation

With appropriate safety factor : )


Remember the bearing load is 2X the belt tension...

All that's assuming the shaft will not bend....