That would be interesting for sure.
Now when the holidays are over I found time to start working on the gearbox, I fitted the gas producer to the frame to free up some space on the work bench and it looks like it has found a good home.
Taking the power turbine section apart to get to the gearbox.
Here you can see the output shaft gear...
...and here is the input shaft housing, now you have seen the two spots in the gearbox that is a bit tricky to lubricate properly.
I spent over an hour staring at the parts trying to figure out a way to do this, I have had discussions with John and the way we decided then was to direct a jet of lube on each input bearing and one directly into the gear mesh but looking at it now that won´t be easy to do.
I would either have to bleed oil from the main pump and connect the gearbox and oil tank somehow or fit yet another oil pump to the bike and run a closed loop inside the gearbox, but since I already have four pumps running from the battery I´d rather not do that.
I came up with a bit of a special solution for now, I will run a wet sump that will keep the <5000rpm output shaft and bearings lubricated and route bleed air through an oil mist lubricator (used for lubricating pneumatic tools) and into the input shaft tunnel between the bearings. The hybrid bearings don´t need much oil and the bleed air will cool them and provide an air flow that will keep the exhaust gasses from entering the shaft tunnel.
All I need to do is trim the oil flow and keep a close watch on the oil level in the oil mist lubricator so it won´t run dry but that will only be another point on the pre run check list. I´ll inspect the gear mesh and bearings after the first couple of runs to check for signs of oil starvation and wear, if it shows any signs of damage I will simply have to rethink. This is the easiest way of doing it and I like easy.
Cheers!
/Anders