New Power Station Motor Or Fix It

[BuckeyeDennis]

AutomationDirect has a large selection and very competitive prices on inducton motors.

https://www.automationdirect.com/adc/sh ... log/motors

Voltage (120 V), frequency (60 Hz), horsepower (3/4), RPM (3600 synchronous /3450 full-load), and number of phases (1) are easy to match. Unfortunately, Emerson doesn't show a frame number for the motor, so you might have to do some measuring and spec-checking to make sure that the mounting holes and shaft dimensions are compatible. Frame 56 is probably the most common for general-purpose 3/4 hp motors, so you might want to check that out first.

[BuckeyeDennis]

Hmmm … the exact same motor model number again. How do you suppose you are supposed to re-oil that one? Or dioes it have ball bearings, along with an incorrect label?

Now I see that the brand on the label is US Motors. Go figure.

[dusty]

I just noticed that the end caps have been manufactured with a location where oil cups could have been. I also noticed that if oil cups had been installed they would be offset from one another by 90 degrees. This forced be to check the power stations. They too are offset. I must assume that this characteristic is universal.

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No Oil Port
NOTE: I have been tinkering with the photos (to get them properly oriented). These are not the same images posted earlier.

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[jsburger]

Since SS says no lubrication required, could it be that the manufacturer used (universal) end caps that have "oil holes" that are not used in this application? It makes no sense that they are 90° off set if they are intended to be used. Also oil holes have a spring loaded caps over them to keep out dirt.

What are the bearings exactly. The outer race of a ball bearing would block the "oil hole" in the end cap. From the pictures they don't look like a bushing that would require oil.

[dusty]

Since SS says no lubrication required, could it be that the manufacturer used (universal) end caps that have "oil holes" that are not used in this application? It makes no sense that they are 90° off set if they are intended to be used. Also oil holes have a spring loaded caps over them to keep out dirt.

What are the bearings exactly. The outer race of a ball bearing would block the "oil hole" in the end cap. From the pictures they don't look like a bushing that would require oil.

I felt that way myself but then does it really make a difference. Motors are not always installed in the same orientation. On top in one could on the bottom in another.

[DLB]

Since SS says no lubrication required, could it be that the manufacturer used (universal) end caps that have "oil holes" that are not used in this application? It makes no sense that they are 90° off set if they are intended to be used. Also oil holes have a spring loaded caps over them to keep out dirt.

What are the bearings exactly. The outer race of a ball bearing would block the "oil hole" in the end cap. From the pictures they don't look like a bushing that would require oil.

In an earlier post, BuckeyeDennis said he disassembled his and determined that they were "sleeve bearings, not ball bearings." I would use the term 'bushing' but I'm sure his terminology is more correct. The OP's disassembly pictures also suggest that they have some form of wadding (possibly also not the right term). But these are all consistent with lubrication required. I think it is pretty old-school, I have one and only one tool with a similar setup and it is way older than my Greenie. (Oil ports are on top.) Scanning some discussions on line, these show up mostly in much older systems than a PS.

I don't really see a way to service these without removing the motor from the PS. Maybe lay the machine down to lubricate the shaft end? Could that be the intent of the horizontal oil port? All of that without any instruction in the manual suggests quite an oversight. Any or all of that, when they could have simply specified the more common sealed ball bearings, is beyond me.

- David

[jsburger]

I agree that motors are not installed in the same orientation. Today we have sealed bearings that don't matter. In the past when we had motor bearings that needed to be lubricated. They were designed for the specific application (orientation direction) with the oil cups up so they could be lubricated. Again it makes no sense that the holes are 90° off. I can see both being 90° off or 180° off. I think those holes have nothing to do with oil. Your motor's end caps look very similar to the OP's but without the holes. The holes may have had an orginal design purpose that never materialized. A set screw perhaps?

[BuckeyeDennis]

The oil ports on my motor have these yellow plastic plugs to seal them when not being used.

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As for the bearing type, lubrication, and oil port orientations, see this old thread from 2013 for more color. JPG's motor was just like mine.

Unfortunately, I didn't take any photos of the sleeve bearing when I had my motor apart, and I'm not eager to tear it down again. But if memory serves, it looked just like glarson's photos in the very first post of this thread. No ball bearings, just a sleeve bearing. I believe that the stamped sheet-metal caps on each side form an oil reservoir, and that either the wadding or possibly something on the motor shaft wicks or otherwise moves the oil into the sleeve bearing. I took all the "wadding" out of mine, believing it to be packed-in sawdust, and my motor is still in good shape 10 years later.

[glarson]

Called around, no longer any local places to repair or by the motor. Some places an hour away but none open on weekends. Would need to take off work to go...a little frustrating. Been searching internet for potential instructions of replacing the bushings with bearings, so far not much for the type I have. Grainger seems to be the closest match for replacement motor. Narrowed down to two for the price wanting to pay, but neither seem to match exactly (amps off a little, service factor, location of wiring box, etc.). Same distance problem ;closest grainger is 90 miles away and also not open weekends. <sigh>
Keeping all options on the table still. Fortunately, the shopsmith itself is still working well...famous last words.

Thanks for the continued suggestions.

[JPG]

At this point, I would be considering refurbishing the motor shaft and the bushing bearings...