Extending 11mm diameter electric motor shaft 3

[Max1525]

I need to extend the shaft on a 0.18KW single phase 4 pole flange mounted electric motor, the diameter of the shaft is 11mm and the key is 4mm (63F Frame). The shaft on the motor is currently 23mm long and I need to extend this by 500mm however most readily available shaft couplings have a diameter of 8,10,12,14mm etc.

I'm just wondering what the best option would be, would it be to design a bespoke part to fit or are there alternative solutions? Also as I'm new to working on this aspect of motors I'm just wondering why they sell motors with 9 or 11mm shafts when the most common couplings available are 8, 10 or 12mm couplings?

Thanks in advance, Max

 

[jraef]

I know next to nothing about standard shaft sizes on metric motors. But I do know that it’s a common “trick of the trade” for machinery OEMs to have motors made with non-standard shafts so as to force users to buy spares from them at inflated prices instead of on the open market.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

 

[waross]

Buy a 10 MM coupling and an 11 mm reamer.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[petronila]

Max

Because you need to extend the shaft, my suggestion is make a new 12 mm shaft and use a standard (trade available) coupling. Just note, even the shaft extension is short, a 12 mm shaft will be strongest that a 11 mm shaft. So you will have a better shaft that would fit standard couplings.

Thanks

Petronila

 

[electricpete]

People have addressed the diameter considerations (buying a 10mm and reaming to 11mm would work for most coupling hubs).

I wanted to touch base on the length part.

need to extend this by 500mm

Are you planning for an intermediate shaft with bearing and coupling on each end ? (unsolicited opionion: it sounds like an ambitious project)
What is the reason the motor and load cannot be moved closer to each other?
What is this motor driving?


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(2B)+(2B)' ?

 

[ScottyUK]

A shaft extension of 500mm? That's about 20" to our North American readers.

Just don't do it - a 20" shaft of 11mm or 12mm diameter is too slender to operate at normal motor speeds without at least one additional bearing to support it. I found plenty 11mm couplings, but they're mainly resilient types designed to connect a motor to a driven shaft supported by its own bearings.

 

[Strong]

What is mounted onto the extended shaft, or what is the shaft connected to? Shaft straightness (runout) could be a big issue for unbalance vibrations or shaft misalignment vibrations. Why would you want to attach a "rigid" shaft extension that is probably longer that the entire motor rotor??

Walt