shaft keyway repair in open type compressor

[coldkeeper1]

Dear fellows:

I have a 30 HP open type compressor which needs to be repaired: it looks like the installed pulley´s bore was a little bit larger than necessary, so that there was some extra play between the pulley and the compresor shaft. Because of this, both keyways and the key were damaged during a start-up. Would it be necessary to tear down the entire compressor in order to remove the crankshaft and remake the keyway or could this job be done without dismantling the compressor ?

[NH3LVR]

Depending on the length of the shaft and other factors, you might be able to have someone come in with a portable key mill and make a oversize keyway and key.

[Grizzly]

Coldkeeper
The damage you describe sounds quite bad to me.
So I would assume that unless there is sufficient room to carry out what NH3LVR suggests.
Then a complete strip-down and crankshaft removal would seem the only option.
I have known of situations were this type of problem has been got around by using a "Fenner" Type drive.
Not sure what they are called in your "neck of the woods".
Basically they are like a morse taper fitting.
The fitting has 2 parts which taper lock together with use of 2 Allen grub screws.
The 2 cones being drawn together clamp the inner drive onto the crankshaft.

Realistically though unless you can guarantee a perfectly mated and balanced drive coupling.
Then it's not worth the risk of further damage.
Grizzly

[chemi-cool]

Another point of view,

There is a special material which is made from metal and epoxy mixture, used in plastic molds making.

you can fill the keyway, press the key in and let it set.


the installed pulley´s bore was a little bit larger than necessary

That is worrying me much more, you must replace it or the problem will repeat itself.

[NH3LVR]

In the US we call the method Grizzly referred to of securing a hub to a shaft a "taper-lock. That has become a generic term, but everyone knows what it means.
One alternative is to machine a new keyway to fit the taper-lock hub and abandon the old one. Then you bore the old driven pulley to fit the outside diameter of the taperlock hub.
Not having seen the damage it is difficult to say whether or not this will work. Some things which worked well on the old slow speed twin cylinder machines do not work well on the 1200RPM machines.

[Grizzly]

In the US we call the method Grizzly referred to of securing a hub to a shaft a "taper-lock. That has become a generic term, but everyone knows what it means.
One alternative is to machine a new keyway to fit the taper-lock hub and abandon the old one. Then you bore the old driven pulley to fit the outside diameter of the taperlock hub.
Not having seen the damage it is difficult to say whether or not this will work. Some things which worked well on the old slow speed twin cylinder machines do not work well on the 1200RPM machines.

yep you are correct NH3LVR that's what they are called over here as well!
Fenner is a trade name over here similar to Hoover instead of Vacuum cleaner!
I suppose what we are all trying to say in our own terms is the shaft may be repairable.
But none of us know the extent of the damage?
Grizzly

[coldkeeper1]

Dear friends:

Thank you very much for your kind advice. I think I feel more comnfortable while looking at this problem, now that I know there are a few different ways to attack it. In another forum someone mentioned something about a portable keyway cutting machine as well. Tomorrow morning as soon as the machine shops open I`ll go there to check with the machinists all of your ideas. Thank you again.