David- This is a nice concept too, especially if you have the controls to pull it off. Unfortunately, this and most variants are patented. Although enforcement seems to be spotty at best (worst?). Perhaps it is the low volume. You also still have to have a balance of motor(s)and ratios to make sure you don't exceed physical limits like RPM or gear tooth strength.
Seth David Brandt wrote: > > I've been reading all the debate on transmissions with some interest, but > let me throw another fly in the puch bowl...if you do need the variable > ratios (which is another debate I will not venture into), why not do it like > the prius does? > > You would need a primary drive motor, an output shaft, and a smaller "ratio > motor" interconnected through a differential. You could even use two > identical motors, though you may not need to. The electronics could decide > how to vary the ratios, and what motor needs to spin which direction, at > what speed, etc., and if one or both needs to regenerate. > > >From a viewpoint of drive system design this is harder, and prevents using > an entirely off the shelf unit. Although possibly Victor's drives could be > configured with an additional "control box" to run in this setup...Victor? > The advantage would be that the software would continually be determining > what the "best" ratio would be and the driver wouldn't have to worry about > it. You could even select a "best efficiency" mode or a "best performance" > mode from a dash mounted selector switch. > > But from a viewpoint of assembly labor hours is where it really shines. > These make the difference in cost to a production run of anything. You > would have fewer parts, no clutches, (potentially) very easy attachment of > the motors, and the ability to get "just the right" ratios at the right > times. Just connect the wiring harnesses and forget it. I don't know if > the weight would be a prohibitive factor, though. > > Anyway, just a thought.
