What's sticking out of my motor?

[Bob Rankin]

I've inherited an electric motor but what's this gear on the non arbor end? I know the fan cap was removed but what's on the end?
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[Steve Peterson]

That doesn't look like any motor I have ever seen. Somebody probably jammed a piece of plastic over the exposed sharp edges. I would be more worried about getting my finger slammed by the spinning fan blades.

Steve

[Jerry Bruette]

Looks like a hub for a brake assembly to me.

[John Lanciani]

More importantly, without the shroud to direct the airflow down the length of the motor the fan is pretty much useless. If that motor is run with much load on it it is going to overheat fairly quickly.

[Dan Hintz]

More importantly, without the shroud to direct the airflow down the length of the motor the fan is pretty much useless. If that motor is run with much load on it it is going to overheat fairly quickly.


Looks like a fully-enclosed motor... that "fan" on the end isn't for cooling.

[Lee Schierer]

It looks like one half of a flexible coupling mounted on the motor shaft.

[Keith Weber]

Looks like a fully-enclosed motor... that "fan" on the end isn't for cooling.

Actually, it looks like a TEFC (Totally Enclosed Fan Cooled) motor that's missing the shroud. That fan on the back draws air from holes in the back of the shroud. The air is moved centrifugally outward inside the shroud, where it directed forward along the outside of the motor. The forward part of the shroud is slightly bigger than the motor housing, giving the air a place to go. The air moving over the enclosed motor housing wicks some of the heat off of it.

Without the shroud to direct the air (as John mentioned), the fan on the back will not do anything useful, and the motor could overheat. You can even see that the motor was painted blue with the shroud in place, so the back of the motor did not get any paint. You can see 2 of the 3 bolts used to mount the shroud in the grey area.

I'd bet that that black thing was put on there by somebody and does not belong on the motor.

I always buy TEFC motors for the wood shop because on ODP (Open Drip Proof) motors, the fan sucks wood dust in the air through the motor windings and they get all gummed up with the wood dust, which decreases its ability to cool and probably even creates a fire hazard.

[John Lanciani]

Looks like a fully-enclosed motor... that "fan" on the end isn't for cooling.

Care to share what you think it might be for then? Because it looks exactly like a totally enclosed fan cooled motor that is missing the shroud to me but I could be wrong since I only have 28 years in the electrical industry. :rolleyes:

[Mike Heidrick]

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I too think it may be a flexible shaft coupling. Shroud may have been removed to attach it to get it to spin in the right direction. Here is a pic of a Shopsmith one.

[Malcolm McLeod]

It looks like one half of a flexible coupling mounted on the motor shaft.

+1 on the TEFC motor w/ shroud removed. The black 'hub' doesn't look like any flex coupling I've seen.

If the motor is C-faced (no drive-end shaft exposed), I would speculate that in motor's previous life the user needed a means to manually rotate the motor (when not powered) - - so shade tree mechanic stripped shroud and installed a hand-grip...?

[glenn bradley]

Looks like a simplified variation on these; they come in so many form factors based on purpose. But, does it matter?

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This didn't happen to come off a hydraulic or hydrostatic drive maybe? At any rate you don't need it. If the black piece and the fan-looking doo-whopper come off and leave you a shaft you can use (and the motor specs are appropriate), rock on.

[Dan Hintz]

Care to share what you think it might be for then? Because it looks exactly like a totally enclosed fan cooled motor that is missing the shroud to me but I could be wrong since I only have 28 years in the electrical industry. :rolleyes:

My mistake... I saw no cooling fins along the body and assumed incorrectly.

I have 40+ years in the industry of life and occasionally make a mistake :rolleyes:

[Bob Rankin]

I don't know what you normally see when you take off the cap but there's about an inch shaft when I took the knob and fan blade off. It is TEFC, does the fan really cool anything down? Anyway, the fan slid on the knob's shaft and the knob (and fan) went on the motor shaft (not the regular 5/8" shaft). So not without the knob the fan won't go on (hole too large). If I were to put a spare cap back on, do I go find another fan? Leave it off or get an adapter to size it down?

[Allan Speers]

My mistake... I saw no cooling fins along the body and assumed incorrectly.

I have 40+ years in the industry of life and occasionally make a mistake :rolleyes:


External cooling fins are usually only found on inverter-grade TEFC motors.

[Keith Weber]

It is TEFC, does the fan really cool anything down? Anyway, the fan slid on the knob's shaft and the knob (and fan) went on the motor shaft (not the regular 5/8" shaft). So not without the knob the fan won't go on (hole too large). If I were to put a spare cap back on, do I go find another fan? Leave it off or get an adapter to size it down?

Bob,

Without the shroud, your fan will do next to nothing for cooling the motor. The shroud is absolutely required to direct the airflow over the motor. You can see how the air moves in the following diagram:

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That is so weird how that thing was cobbled together. Judging by the clues, that is not the original fan. The knob was probably put there in lieu of a bushing to make the existing fan fit the smaller shaft. The paint tells the story. The motor was painted with the shroud and the fan in place. You can see the outline of the fan on the back of the motor. But, there is no paint on the fan, so the fan isn't the original fan. I suspect that whoever added the fan probably didn't have a shroud and original fan, and figured wrongly that his makeshift fan would help keep the motor cool.

The best thing to do is find a replacement fan/shroud combo, which might prove difficult. Second to that, would be just to leave the fan off because it will act as a better knuckle-buster than it would as a cooling fan. You'll risk overheating the motor without a fan/shroud, but that all depends on your usage/environment. Infrequent or intermittent use in a cool area, and you might not even have to worry about overheating. You could always keep it cool with a little house fan blowing on the motor.

[Jerry Bruette]

As I suspected that's a Leeson motor. Nothing has been cobbled together and no that's not a flexible drive coupling.

If you were to Google "Stearns motor brake" you'll see what's missing from your motor.

That hub is used to drive the brake discs in a Stearns motor brake. We used to use them at work on machining centers that would drive a tapping head. The motor would drive in a CW rotation to cut the threads and then the brake would engage to stop the machining before the motor was reversed to remove the tap.

You're missing alot more than just the fan cover, but if you could find the proper cover it could be installed without the brake and your fan should cool the motor.

For safety's sake I don't think I'd run the motor with the fan on but without the fan cover. YMMV

Jerry

[Bob Rankin]

Thanks Jerry. But if that were part of the brakes does that mean it didn't have the fan shrowd or it ran with it off?

[Michael Dye]

Keith, I'm with you on this one. All the evidence points to that fan having the wrong bore. However, it is a Leeson motor, not some Chi-Com piece of junk. A call to Leeson might prove fruitful, or check with a local motor rewinding shop. Unlike the disposable chinese motors, Leesons are more commonly rebuilt and a shop might be able to come up with a cover and fan blade.

[Bill Orbine]

Thanks Jerry. But if that were part of the brakes does that mean it didn't have the fan shrowd or it ran with it off?

The motor brake assembly also doubled as the fan shroud.

[Jeff Keith]

As Jerry suggested:

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[Bob Rankin]

I think we have a winner.



As Jerry suggested:

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[Don Sundberg]

You should be able to go to a motor repair place and get a fan and shroud that will fit. The fan for my idler motor for my phase converter had spent too many years outside on top of a grain leg and blew up when I fired it up the first time. A visit to my local motor rebuilder netted me a new fan.

[Bob Rankin]

I'll try that. Out of curious it's what do you remember paying for a new fan? I wonder what a replacement shroud would be (used is fine).

[Don Sundberg]

It was a few years ago. I'm going to guess less than $20 for the fan. I would think any Leeson motor of that frame size should take the same shroud.