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Aus Inventor's beltless, clutchless Infinitely Variable Transmission

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  • Aus Inventor's beltless, clutchless Infinitely Variable Transmission

    I haven't seen this mentioned before and I thought it might be something others would be interested in.

    An aussie tinkerer and inventor has come up with a new all-gear design for an IVT (which, if you aren't familiar with, basically is a continuously variable transmission with powered neutral and reverse). Everything on the market today (that I'm aware of) use either clutches or belts or other friction material to transfer power, which obviously limits the power that can be put through the transmission. That's one reason why high performance vehicles (like some of the Audis) have only recently began using CVTs/IVTs.

    Anyway, interesting read:

  • #2
    Joe, that is interesting. With the jury still ''out'' on the control power requirements , I'm a little skeptical on how well it will work.
    I will keep an eye out for more detailed info, or we could let Evan mock one up and test it for us.



    • #3
      If I understand the description correctly, it utilizes an auxiliary variable speed electric (or other) motor to change the relative rpm of one of the planetary gearset components. If the power consumption for the auxiliary control motor is low, then this looks to be quite a concept.


      • #4
        no free lunch

        Input control power could be zero if the control shaft is fixed in which case you don't need the control input. At any input control shaft speed other than fixed it's a loss. That loss is probably of similar magnitude to power transmitted. For any significant ratio range I think you'll be less than 50% efficient. Have to do the math for numbers.

        Might just as well use your control motor to provide the power directly and save all the hardware.


        • #5
          If for every force applied there is an opposite does that mean that if you put 10 Hp in you have to supply 10HP to the control axles to compensate ?

          Surely if you only supply a fraction of this to the control rods it will overcome the rods ?

          The example is only driven by small motors and all the forces are probably matched, if the input is far larger in power I wonder what will happen ?

          Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.


          • #6
            It's just a planetary CVT. Variations have been in use for nearly a century. The John Deer CVT, for example:


            Or the Prius CVT:

            "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."


            • #7
              Hmmmm... imagine a simple planetary stage, sun wheel, planet wheels and an outer annular gear.

              Power input is on the sun wheel, power output on the planet wheels. In a conventional use of the planetary gear drive is engaged by braking the annular gear.

              Now imagine that the annular gear has outer teeth to engage with a worm. A control motor would drive the worm faster or slower to vary the ratio from dead stop to full ahead.



              • #8
                If for every force applied there is an opposite does that mean that if you put 10 Hp in you have to supply 10HP to the control axles to compensate ?
                No, I do not think so. Consider a screw jack, sure you have to put effort in to raise the load but lowering does not require you to re-absorb effort.


                • #9
                  Oh well

                  That's a bummer AB.

                  I was going to leave my car in "forward" and let it run back-wards down a hill and let (hope?) it would fill the petrol (here - "gas" in the US) up.

                  The gear-box/drive in the OP operates on a system of belts and braces and is far too unsophisticated for consideration by the illustrious members here.

                  My guess is that the general consensus of opinion here - should they deign to even consider it worth considering - will be that if can't be any bloody good as it wasn't thought of or made in the USA.

                  Perhaps it was made on Chinese machines with Chinese tools!!!!

                  It might have been made from melted-down scrap "Starrett" tools and BP mills.


                  • #10
                    I watched the whole thing, then watched again, trying to see where in the "complex" explanation they actually explained how it worked. I really wanted a good look at what was going on in the back, but that side rated no more than a glance. That glance reveals all, however, the thing is a differential gearbox, nothing more. There is no variable ratio, he's controlling the speed of one of the differential inputs. A differential simply sums the two input speeds and directions. He could have done the same thing with a simpler spider gear type. This would work in a vehicle, actually. You just need two engines, and vary their speeds, that's exactly what he's doing in the clip. I suspect that he falls into one of the classic categories for these things: 1) the honest guy that gets an idea and is so immersed in it that he's convinced it's a revolutionary idea, but is without the sort of peer review (for whatever reason) that keeps others from chasing wild geese, or 2) a scammer. I vote for 1, but who knows. The best use for this gadget is to control the output speed of your perpetual motion machine.



                    • #11
                      I believe this poor fellow ( the inventor) has spent the last 20 years learning the basics of how a planetary gearset works. It has always been known that you can control the motion of any two of the three elements of the gearset to affect the motion of the third element.


                      • #12
                        It is a simple differential gear with two motor driven inputs. The output shaft speed and direction are determined by the relative speeds and directions of the drive motors. This can be done with the rear drive of any automobile.

                        By using additional gears the relative sizes of the motors can vary. He's invented the Norden bomb sight. Again.


                        • #13
                          Let's throw the Gleason Torsen into the mix and see what can be done with that. You can have a case where you're going from lockup of the gearing to allow basically a direct in-out shaft speed relationship, or you can turn a secondary shaft at any speed and the output shaft receives less speed by the same amount. It's basically power splitting- regardless of what rpm either shaft turns at or how much torque each receives, the input energy is divided accordingly. The control shaft in this case has to either dissipate the energy or be driven at a chosen speed by a secondary power source that can handle the torque split.

                          Units have been built in the past that allow the secondary shaft to turn to effect the speed of the main shaft, but in order to do so they have to have a mechanism to extract the energy produced by that shaft. This has been done using a generator powered by the shaft. If you want that shaft to turn slowly you put a large load on the generator and you try to add that power produced into the drive system. If you don't load the generator at all, that shaft is free to spin at any speed that will let the output shaft stop while the input shaft continues to turn.

                          Some careful and considerable design would allow such a system to work with a reasonable efficiency, but where usable power levels are needed, the losses are also considerable. It's possible in this day and age of strong permanent magnets and motor/generator design, coupled with modern high power electronics that this basic design could be made with a higher level of efficiency, but at what cost and degree of mechanical and electronic complexity- cost per mile over a reasonable lifetime is probably still better with a gas engine and conventional transmission.
                          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-


                          • #14
                            I just had a recollection that one of the hybrid cars, Prius, perhaps, uses a similar differential relationship to couple the electric motor and the gasoline motor in such a way as to create maximum efficiency, and to even use the electric side of things to recharge the batteries.

                            In a differential drive it is possible for the load to exceed the power of one of the drives causing it to reverse direction, hence becoming a generator. In any event it seems a bit bogus to suggest this is an infinite ratio drive given the possibility that a variable speed motor is critical to the variability. Why not just use a simpler variable speed motor of sufficient capacity for torque, hp, and rpm?

                            This same scheme can be accomplished by using a planetary gear where the output could be the sun gear shaft, and motors would be attached to the ring and planet gears and driven at various relative speeds including reverse rotation of either motor.


                            • #15
                              Joe is right.
                              Just a differential gear (you already have that in your rear axle). The output speed is the difference of the input speeds. If output power is zero, the input power on both shafts will be zero too (disregarding losses). But if output power is 100%, input powers on both shafts will be 50%.

                              That's just a nonsense invention. It will keep alive in the "free energy"-department of YouTube for 17 decades.

                              <edit> With Joe, I meant the "Optics Curmudgeon"-Joe</edit>

                              Last edited by MuellerNick; 05-16-2010, 05:04 AM.