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Location of key on motor shaft

Posted: Wed Sep 17, 2025 2:10 am
by jo3
Is the key in this picture in the correct location? It is an Emerson motor circa 1986.

I removed the set screw, but have been unable to remove the fan sheave with only mild persuasion. Since the motor is running smoothly and quietly, I don't feel the need to force the issue farther. However, I don't know if the key was installed correctly during its alleged rebuild or if I might have inadvertently moved it during the process of trying to pull the sheave. I can see that the key goes deeper than the set screw hole.
PXL_20250917_040747570.RAW-01.COVER.jpg
PXL_20250917_040747570.RAW-01.COVER.jpg (196.46 KiB) Viewed 75860 times
Thanks again for your help and expertise!

-Joe

P.S. Does a mechanical manual with this kind of information exist?

Re: Location of key on motor shaft

Posted: Wed Sep 17, 2025 10:03 am
by JPG
Normal position. The floating sheave does not extend past the end of the key. The set screw provides clamping to the shaft.

No manual that I know of.

Re: Location of key on motor shaft

Posted: Wed Sep 17, 2025 11:21 am
by dusty
Does the other end of the key not have a slight hook that rests in a hole in the shaft beneath the sheave?? If it does then that hook positions the key in the groove.

Re: Location of key on motor shaft

Posted: Wed Sep 17, 2025 1:44 pm
by jo3
Dusty,

I haven't seen the other end of the key since I haven't been able to budge the fan sheave (tried some penetrating oil and prying with a large screw driver around the base). I don't see any problems that really require me to remove that sheave so I didn't want to force the issue. The pictures and drawings I've seen of the key don't show any hook -- maybe you are thing of the idler shaft key, or a different motor variant?

-Joe

Re: Location of key on motor shaft

Posted: Wed Sep 17, 2025 5:07 pm
by dusty
jo3 wrote: Wed Sep 17, 2025 1:44 pm Dusty,

I haven't seen the other end of the key since I haven't been able to budge the fan sheave (tried some penetrating oil and prying with a large screw driver around the base). I don't see any problems that really require me to remove that sheave so I didn't want to force the issue. The pictures and drawings I've seen of the key don't show any hook -- maybe you are thing of the idler shaft key, or a different motor variant?

-Joe
Yes, I may be thinking wrong. I've been thinking wrong an awful lot lately. I need to spend ,ore time in the shop.

Re: Location of key on motor shaft

Posted: Wed Sep 17, 2025 10:54 pm
by jo3
> I need to spend ,ore time in the shop.

Always a good plan.

Re: Location of key on motor shaft

Posted: Thu Sep 18, 2025 9:39 am
by JPG
dusty wrote: Wed Sep 17, 2025 11:21 am Does the other end of the key not have a slight hook that rests in a hole in the shaft beneath the sheave?? If it does then that hook positions the key in the groove.
There is NO hook on the end of the motor shaft key.

Re: Location of key on motor shaft

Posted: Thu Sep 18, 2025 11:59 am
by chapmanruss
Joe,

You asked,
P.S. Does a mechanical manual with this kind of information exist?
I have never seen a separate mechanical manual, just the parts diagrams in Owner's Manuals or in separate parts diagrams and lists.

As you said there is not a problem with the motor so as the old saying goes "If it ain't broke don't fix it." Prying at it with a screwdriver is probably not the best idea for getting it off. If the need arises in the future think Bearing Separator and Puller.

Do remember to put the set screw back in the fixed Fan Sheave.

Re: Location of key on motor shaft

Posted: Thu Sep 18, 2025 4:34 pm
by JPG
chapmanruss wrote: Thu Sep 18, 2025 11:59 am Joe,

You asked,
P.S. Does a mechanical manual with this kind of information exist?
I have never seen a separate mechanical manual, just the parts diagrams in Owner's Manuals or in separate parts diagrams and lists.

As you said there is not a problem with the motor so as the old saying goes "If it ain't broke don't fix it." Prying at it with a screwdriver is probably not the best idea for getting it off. If the need arises in the future think Bearing Separator and Puller.

Do remember to put the set screw back in the fixed Fan Sheave.

And act like a gorilla. Really torque it.

Re: Location of key on motor shaft

Posted: Fri Sep 19, 2025 11:26 am
by chapmanruss
Just to be clear JPG is referring to the set screw.