It appears to me your possibly advocating a continuous weldment "spreading out the torque or the contact pressure point (power transmission over 360 degrees) between the shaft and the gear? just trying to read between the lines here.
The machine is running again in a nice 20 mph breeze. It was a two hour job to swap out the PTO shaft and get the tower jerked back up.
Yes, welding the sprocket distributes the load evenly around the whole thing to the shaft. Because the sprocket is so small on a 1" shaft, this one split thru the keyway where the cross section of the sprocket is very thin.
The bottom sprocket (drive) sits up against the rear mainshaft bearing inner race and it is not adjustable forward and aft because you can't get to it after assembly without pulling the PTO shaft out. So my idea was to use a keyed sprocket on the PTO and adjust that one for proper alignment of the sprocket set. Well, that was a bad idea.
On my older gearcases that were side loaded, it was no problem because you could get to the drive sprocket to move it back and forth for proper alignment before tightening it up. On the first one I welded the sprocket to the PTO like I always did in my 12G turbines. It is required to drill and tap the forward nose of the shaft and provide a positive thrust stop up against the bearing lock ring, because the lock rings won't hold it long term. They're not designed to handle axial load component, and they can work loose with vibration. So everything on both shafts has to be locked in place with positive thrust stops to prevent that.
Well, with a one piece PTO weldment, shimming is required on the thrust stops to properly align the gearset. I said, well, that's a bunch of s&*t. So I used the keyed sprocket and that seemed simple. Except it don't hold up
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Chris