Audi is advertising multitronic transmission, saying that there are no gears, so there is no shifting. Wouldn’t you still have to shift into drive, reverse, park?
Darn it astro,same article I was gonna link:p
Yes,**flowers **, you still use F, R and P.
Great link! I was dissapointed by the modest increase in fuel efficiency though. I thought that a cvt would have been more of an improvement.
Maybe someone can help me understand this. I understand that there is a chain drive and that it uses friction force alone. That’s about as far as I got.
“The Variator has two tapered disc pairs - a set of primary drive pulleys and a set of secondary driven pulleys. A special chain runs between the two pulleys to transmit power to the drive wheels.”
Which 2 pulleys? Do they mean between the 2 sets of pulleys?
Can anyone tell which are the drive and which are the driven from the illustration?
Yes. By moving the two half-pulleys closer or farther from each other, each set acts like a resizable gear.
The cross-section looks like this: > <
The chain rides between the two halves. As the halves move closer together, the chain is forced to ride on the outer rim, as if it were a larger gear. When the halves move apart, the chain slides down so it’s riding on the inside, like a smaller gear.
I believe the larger set is connected to the wheels; the other way around, it’d be a huge overdrive ratio.
Thanks. Very helpful. I think I pretty much get it now.
Since this question is pretty much answered, can I ask a few other questions?
There have been some strange transmissions in the past which I do not understand. The manual for my '74 Beetle gave instructions for a semi-automatic transmission (which I did not have) which had a standard gearshift, but no clutch. Apparently, the driver would just let off the gas, depress a button on the shifter, select the gear, and push the go-pedal. How did this work?
And there was (if I recall correctly) a Packard, which had some sort of single-gear transmission which I don’t understand at all. I’m pretty curious about that as well. Anyone know anything at all about this one?
Nothing useful to add to this thread, but I do have yet another question:
Are these infinitely variable gearing systems still used on bicycles?
I remember seeing one in a cycling book in the early 80s. I can’t remember if the rear gears were conventional, but at the front, the chain ran over a series of little cogwheels arranged in a radial fashion around a disk where the front sprocket normally would be. The small cogs could travel in and out, using a spring mechanism, in a groove along the disk. It was, IIRC, operated manually by a regular lever and cable set-up.