Author Topic: Electric motor on end  (Read 356 times)

Offline Shiroth

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Electric motor on end
« on: January 20, 2020, 03:15:33 AM »
I have been having some troubles with a new motor for the mill, the first one I got ran fine on its end (shaft downward) for a few days and would overheat often. Then it made some terrible noises and was off balanced. Replaced it with another (larger) one, started off fine, not overheating at all. but it started making noise also and became off balanced. took it off the mill and ran it on its side, made noise for a few seconds and went back to normal.

I am assuming that they aren't built to be run on end like this.

mount it on its side with 1 to 1 gearbox maybe?

any suggestions or information would be greatly appreciated.

Offline Alyn Foundry

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Re: Electric motor on end
« Reply #1 on: January 20, 2020, 02:12:52 PM »
Hi there.

Is the motor an AC version ?

Single phase or Three phase ?

Cheers Graham.

Offline Shiroth

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Re: Electric motor on end
« Reply #2 on: January 20, 2020, 02:32:32 PM »
Hi there.

Is the motor an AC version ?

Single phase or Three phase ?

Cheers Graham.

It is an AC 230 volt 3hp single phase

Offline Trevorc

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Re: Electric motor on end
« Reply #3 on: January 20, 2020, 03:25:50 PM »
I am surprised at what you are experiencing. Motors on both my mill and drill are mounted with shaft vertical with pulley at the top and have not had any problem. I thought this was the standard way to mount motor.
No doubt somebody on forum will offer good advice.
Trevorc

Offline Don1966

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Re: Electric motor on end
« Reply #4 on: January 20, 2020, 03:32:47 PM »
Not all motors are designed to run with shaft downwards . Meaning the bearings are not built to take the downward pressure of the armature or load not the mention the beari
ng retainers if it has any.  C flange  motors are made to mount different directions. I suggest you check with the vender or manufacture to see if the motor bearings can withstand the way you are mounting your motor.


Regards Don
« Last Edit: January 20, 2020, 03:35:58 PM by Don1966 »

Offline Ramon

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Re: Electric motor on end
« Reply #5 on: January 20, 2020, 04:41:11 PM »
Hello Shiroth.

Don't know if this will help but...

When I first bought my old Linley machine it had a three phase motor on it. The electrician on the rig I worked at the time passed on a redundant but working, very substantial, single phase 3/4 HP motor. Fitted vertically I experienced exactly the same symptom as you now have. I machined a steel support 'cap' - it looked like a top hat in profile,  the inside containing a small diameter thrust race sitting on a pad support. The top of the hat was tapped to take a 2BA screw which was tapered on it's end to locate in a centre in the thrust race support. Filled with a little oil this little unit was bolted to the end of the motor casing over the protruding shaft. Once inverted on the mill the screw was turned to lift the shaft into it's 'happy runnning' spot.  It ran like this without failure until I finally replaced it with a VFD unit some thirty years later.

That may help it and it may not but I hope you solve your issue as well as this one did for me :ThumbsUp:

Regards - Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Shiroth

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Re: Electric motor on end
« Reply #6 on: January 20, 2020, 05:29:51 PM »
Thanks for the replies, seems that single phase is the main issue in this orientation.

I can always return this motor and get my money back for a 3 phase, altering the motor at this point does not seem like the best solution for me.
We did however find a gearbox to use with the motor on its side, but it might be that much more modification required to get it going.

Best option I think for me is to look into the 3 phase and buy the inverter.
re winding the original motor will cost a fair amount.

Offline GWRdriver

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Re: Electric motor on end
« Reply #7 on: January 20, 2020, 05:35:13 PM »
With regard to Don's message below, . . In the distant past I've seen a few references to "Drill press" motors, which I assumed meant motors intended primarily for vertical shaft service, but I never read an explanation of what exactly the different was between a "D.P." motor and any other motor, if any.  I assumed any difference would be in the bearings, angular vs. radial perhaps, but I've never known for certain.
My drill press (Rockwell, ca.1968) is now over 50 years old and has its original (factory) motor and I've never heard whimper out of the bearings.
Cheers,
Harry

Offline Jo

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Re: Electric motor on end
« Reply #8 on: January 20, 2020, 05:57:01 PM »
Most electrical motors are intended to be run horizontally, like Don says best check with the manufacturer to find out if the motor is designed to be run on end.

Mechanically horizontal motors need to be fitted with bearings that can cope with radial loads, the weight of the motor represents a radial load to the bearing so they can get away with simple roller bearings.  Motors that are designed to be used vertically need to have bearings that are capable of taking the vertical weight of the motor and radial/Axial loads from driving the load, consequently they are fitted with thrust or taper roller bearings.

The orientation of the motor will also impact the bearing Lubrication and the different type of bearings fitted to the two types of motor are designed to cope with the different challenges 

You will often find that the Stator (shaft with the windings round it) on motors designed to be mounted vertically has a step on it onto which the bearing mounts, this step supports the vertical weight of the Stator  :)

Jo
Enjoyment is more important than achievement.

Offline Shiroth

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Re: Electric motor on end
« Reply #9 on: January 20, 2020, 06:02:36 PM »
After pondering about it for a few minutes. I might have to try a "fix" that doesn't involve altering the motor, but rather bottom out the motor shaft in the mill so that it cant drop or move out of its "happy spot" worth a shot at this point.

Offline Ramon

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Re: Electric motor on end
« Reply #10 on: January 20, 2020, 08:33:03 PM »
Well yes that's what I'm saying - the bearings are designed for most motors to run in a horizontal plane. By supporting the weight of the shaft in a vertical mounting this eliminates the armature bearing against surfaces which it is not meant to run against - no doubt causing the heat increase you experienced

My little tweak supported the weight of the armature and placed it in it's sweet spot. I agree I did have to 'modify' the motor in as much as drilling and tapping three small holes in the end cover to hold it there but there is of course another way to get over that assuming that the motor has the pulleys or drive top mounted - use a thrust race on the top of the motor beneath the pulley the armature supported by a spacer of correct length between thrust race and pulley to lift the armature in it's right place.

When you say 'in the mill' however leads me to think this may be a flange mounted motor on top of the mill so maybe making a thrust pad that can fix beneath the shaft to do the same as above may be possible.

If there is insufficient room to enable any of these simple tweaks then fitting the correct manufacturers motor which should have bearings capable of taking the weight of a vertical mounted motor seems to me may be the only option.

Tug

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Shiroth

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Re: Electric motor on end
« Reply #11 on: January 20, 2020, 09:29:18 PM »
Well yes that's what I'm saying - the bearings are designed for most motors to run in a horizontal plane. By supporting the weight of the shaft in a vertical mounting this eliminates the armature bearing against surfaces which it is not meant to run against - no doubt causing the heat increase you experienced

My little tweak supported the weight of the armature and placed it in it's sweet spot. I agree I did have to 'modify' the motor in as much as drilling and tapping three small holes in the end cover to hold it there but there is of course another way to get over that assuming that the motor has the pulleys or drive top mounted - use a thrust race on the top of the motor beneath the pulley the armature supported by a spacer of correct length between thrust race and pulley to lift the armature in it's right place.

When you say 'in the mill' however leads me to think this may be a flange mounted motor on top of the mill so maybe making a thrust pad that can fix beneath the shaft to do the same as above may be possible.

If there is insufficient room to enable any of these simple tweaks then fitting the correct manufacturers motor which should have bearings capable of taking the weight of a vertical mounted motor seems to me may be the only option.

Tug


my technical speaking is very limited =) but I do have a rough idea of what you were speaking of which is ultimately what lead me to the bottoming out idea to support the shaft.
the mill has been modified as the original motor was a long shaft with the pulley on it, ended up making 2 plates with a shaft to support that pulley and the new motor mounts downward on top of the new shaft.

I appreciate everyone's input and help with this