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South Texas | Dear Cynic,
You stated "They didn't invent the IVT, maybe it's not so good?" I can clarify one detail.
Various low-power (a few HP) continuously variable transmissions have been around for quite some decades. Eventually the hydrostatic transmission got better and continues to be useful for a a huge variety of applications. None can quite match the efficiency of a gear which loses only a percent or so of full power at each matching gear-set.
While I don't know the Fendt system well, and it did precede the JD IVT, I can assure you JD engineers did invent their own configuration. As mentioned in this forum a few days ago, it uses multiple planetary gears. As I understand it, the design is similar to the quad shifting transmissions, but adds an additional planetary, pump and motor within the same gearcase housing. Getting the ratios right was devilishly tricky, to say nothing of getting it all to fit into the same cubic inches, but it got done. I know this since I used to sleep with the guy that did it. He's my brother, Werner, and has his name on the patent. He's been retired for a couple of years now. We're both Ag Engineers, but he's the smart one.
(I fully acknowledge that inventing something does not guarantee it's good. That issue is well discussed in other postings here.)
Take care. Stetts | |
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IVT fuel consumption -- Nebraska tractor tests
