The hub is fixed so the stroke position is controlled by moving the journal which goes through the fixed hub. It would be adjusted hydraulically. Stroke position can go from one direction to 0 (no stroke=neutral) to the other direction wich would be regenerate or reverse. The video shows it running on compressed air but it is designed to work as a hydraulic drive, which could be located in the wheel, or inboard if you wanted to use a half shaft.
Va Tech's calculations showed 35 HP and 385 pounds feet of torque from 0 speed, per wheel. That is with a piston diameter of 1 inch. Increase the piston diameter and the power goes up in direct proportion to the increased surface area of the piston. 4 of the Tech configuration drives would provide plenty of power for a Mercedes Sprinter size and capacity vehicle.
The air powered demonstration illustrated one absolute necessity, it has to be balanced to function as an in wheel drive, even if inboard it still has to be balanced, and the video shows it is absolutely vibration free. It is sitting on a frame machine with only my hand holding it in postion, running at an estimated 2k RPM on shop air supply, with absolutely no vibration whatsoever. That would equal about 160 MPH in a vehicle depending on tire diameter.
The drive needs no clutch, since you begin to stroke it in the highest ratio and continue to the lower ratio depending on power demand, it provides it's own clutching action.
In the process of researching the patent, I found this design, dating back to the late 1800s, by Arthur Rigg, who was once the President of the Royal Society of Engineers in England. I did not know about the Rigg Water Engine when I first filed the patent application. In that time frame in England manufacturing plants used pressurized water for power and paid for the water per unit of volume. Riggs Engine reduced the displacement for lower power levels, just like mine, but the era of water powered factories was soon replaced with electric power.
Water Engines: Page 3
When I first contacted Mr. Jaeger, I offered to come to his location and show him my design and galdly discuss it with any who was interested. The offer still stands. Since I am retired and live in Williamsburg the trip is 2-3 hours for me.
There are literally thousands of applications for this design, outside the transportation application. Tech calculated the efficiency at 93%. I have a 82 page report from their Engineering school where a group of 8 senior engineering students looked at the design and did a number of calculations concerning stresses and other factors that would affect the practicality of implementation.
regards
Mech