Metric standard for 2 keyways in a shaft (180 degrees apart)

[Mannes Karsten]

Hello,


Does anyone know if there's a metric standard for a shaft that has 2 keyways, spaced 180 degrees apart, but both in the same axial place on the shaft. I'm looking for general tolerances and stuff (if there's any).


Thank you.

 

[handleman]

I'm not aware of different standards for multiple keyways vs. a single keyway.

I don't think this is a particularly good idea. Why would you want two keyways?

 

[Mannes Karsten]

I'm reverse engineering an impeller, and the shaft has 2 keyways in it. Which, I agree, isn't a good idea and is troublesome to get precisely correct.

 

[robyengIT]

If I have to use two keys because of reverse rotation I would place at 90° each other (unless the speed is very high so you have problem with balancing)
ISO 3117 and ISO 3912

 

[Senthil J Prakash]

Hi
Do you mean Tangential keys? Or is it really 2 standard parallel keys?

Check this out regarding Tangential keys

keys-keyways - Tangential keys


I have never seen them in use becasue they are designed for heavy alternating laods. There is DIN standard for the tangential keys.

Senthil J Prakash CEng MIET
Senior Mechanical Design Engineer

http://www.engineeringproductdesign.com

 

[Artisi]

Why 2 keyways, does the impeller have to rotate in 2 directions, or is it poor design or a fix up that has been introduced.
What style of key /keyway is being used.
Two "standard" keyways will never share the load equally, however, using tapered keys which are very carefully hand fitted by an experience person could be OK - would think fitters with these skills is now a dying art.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)