Love Joy coupling

[Geochurchi]

Hi All, we need to thread a Love Joy coupling internally, to thread onto the end of an alternator shaft, can this be drilled with a key way cut into the coupling, we have the correct drill and tap,

[GlennW]

The chance of drilling it with a keyway in it and staying concentric and round are slim.

It would need to be bored.

Boring and then single point threading it on a lathe would be the best chance for concentricity if set up properly in the lathe chuck and indicated in. Possibly soft jaws.

[pete]

I'd very much agree with Glenn. That keyway is going to allow the drill to bias to that side for sure. Even without a keyway I'd still bore and single point it on a lathe just for the concentricity.

[Geochurchi]

Thanks for confirming what we suspected.
Geo

[Bob D.]

I doubt there will be joy supporting and driving a heavy Joy coupling via the short bit of threads that were for the pulley nut.
I wouldn't expect tremendous alternator output with your direct drive setup. Will be turning awfully slow. Generally they are double or more crankspeed. Why not stay belt drive and keep the engine rpms low and alt. fast? More forgiving in alignment too.

[STRR]

First, let me say: I agree with the previous posts. BUT, if you have no other choice, you might be able to tack weld a high-quality steel key into the keyway (tack weld in the outer ends). Drill and tap as needed, then face off or grind off the tack welds. NOT the best way, but it might work in a pinch. You would have to go slow and easy and use a lot of cooling/cutting oil. I would not count on the accuracy of the finished product.

[John Evans]

Normal automotive alternators are driven 4-6 times crank speed . Even if you are running that engine a 3600 RPM that would be like a car engine at idle or just above 500-800 RPM range. Not a viable idea in my opinion.

[Bill Shields]

To ask the obvious question:

Why are you threading the ID of a coupling that has a key?

Key or not...I would never recommend threading the bore of a coupling...while it is possible to do...the question is why?

[Geochurchi]

This is not my design but something we are stuck with, mounting this way is the only option, no room for pulleys, it came set up this way, the alternator failed, we removed it thinking it would be an easy replacement, the shaft on the alternator was turned down to match the coupling and a key way was cut into the shaft and locked into place with a set screw, there a lot of end play in the shaft so we thought that was part of the problem.
It appears that there should have been a spacer installed.

[Bill Shields]

Picture of the alternator shaft with the coupling out of the way? Do you have a set of micrometers and are you capable of making an accurate drawing of the end of the shaft?

It is no wonder you are having trouble..

There is a much better, non mickey mouse solution to your problem involving a sleeve over the end of the shaft to fit the bored and a properly keyed coupling.

[Rich_Carlstedt]

Just a word of caution.
is the Lovejoy coupling Aluminum or Powdered Metal ?
If it's powdered metal...good luck in doing anything that needs to come out right.
Rich

[Bob D.]

Why not swap the armatures between the old and new alternators? Then all the machine work is done for you.