In as much as I can tell, the inner diameter of the wheel does not rotate.
The inner diameter of the wheel appears to be like the inner race of a bearing, probably like right and left bearing halves with a spur gear in the center which would be in mesh with both the drive gear and a gear on the inner face of the outer race.
The tire would then mount to the outer race portion of the wheel.
Ehhhh, that's how I would do it if money were no object.
Bearings that diameter will be ridiculously expensive about 6-8,000 each.
I replaced a couple of 8" F A G bearings on a hopper main drum last week at $760 each.
05 BRG Elise - 9:1 built motor- rev 400 66mm pulley
04 Yamaha R6
02 Volvo S80
92 Toyota Previa