Mr Reese thanks very much for the Link , it certainly cleared up the issues I was thinking of and top information added to my education.
The idler pulley arrangement is part of a clutching system driven by a 15 Hp 4 cycle engine , I would expect top RPM to be 1,725 but most of the time it operates 2/3 to 3/4 speed in outdoor environment open field and the only practical method of lubrication is threw a grease zerk an oil;pot would collect much contaminants tho I do like the idea , mounting may curate some issues ?.
The drill rod I mentioned earlier comes from the supplier oil quenched and ground no spec as to the BHN or RH, I would only be machining to length and cutting key way slots, I am a little concerned about the as supplied ground finish that the Torrington needle bearings will be running on and should I polish the contact area. ?.
I do have a length of 3/4 ground shafting that is ment for sintered bronze bearings application, maybe I should try it?