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Oklahoma | Not quite. The IVT is a completely different concept. It essentially utilizes a planetary gear train where the ring, sun, and planets are all allowed to rotate. However, instead of turning freely, the ring's rotational speed is controlled by a hydrostat, while the sun's speed is controlled by the engine RPMs (either directly or possibly after a gear reduction, but getting a sun to handle high input torque is where you get into trouble since it is usually the most confined in size). The planets produce the output.
Think of a regular planetary gear as you spin the sun. The ring is held, so the planets rotate. Now spin the ring opposite to the sun's rotation, and though each individual planet begins rotating faster, they do not move the carrier arm holding them together. Seeing one of these work is absolutely amazing, as you can watch the ring spin one direction and the sun the other, but nothing happens. As was mentioned, the big issue is controlling the thing. The one we had built, when the controller was supposed to be holding it in neutral or "powered park", would actually cause the machine to slightly move back and forth as the controller continually adjusted for the engine speed and hydrostat speed. Since we didn't quite get everything set right, once the hydraulic oil heated up, the only way to stop it was to disengage the manual tranny behind the setup (the low gear ratio of a slow creeping IVT means brakes don't do a thing).
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IVT fuel consumption -- Nebraska tractor tests
