Zero gear!!

[schumiGO]

http://www.racecar-engineering.com/imag ... _14_N2.pdf

this is link, that i'am very interesting to see you point of view and some other simple-understand pictures)))

Document linked to is copyright of http://www.racecar-engineering.com. It is put here only for your information. F1technical is not responsible for its content

[Monstrobolaxa]

Well just read the document....and I still have to think about it like always....(I never have a definitive answer for everything sometimes I take a while to find it )

So here is my opinion for the moment...like mentioned in the article you can't have 2 gears engaged at the same time...which would cause a lot of stress on the "dogs" (those who know about transmissions will understand....for those who don't...a F1 cog has a few teeth on the side where the dog ring engages....these are called the dogs) it would cause a lot of fatigue besides this since you'd always have a clutch for stopping and starting the roll it would also cause some stress here.

But in any case dogs are mostly found in race cars...in road cars usually one of the shafts with the cogs has sections which move to engage the gears....the do the same kind of work as the dogs....but the diference is that in a race car the ratios are aligned at all time and the dog rings engages the out put shaft cog....in most road cars the sytem has to slide the ratios into allignment.

Now knowing that we can have all ratios alligned at the same time the engagement of a determined gear is down to the dog ring.

Since in the article they say it isn't electronic, hidraulic, etc.....it must be mechanical.....for those who have a manual gearbox have you ever tried to select first gear at 100km/h.....in nearly impossible....or selecting reverse at the same speed....impossible. Road car gearboxes have a mechnical protection against this...it's a kind of mechanical safety pin. So my opinion would be that all the ratios are alligned...and when the driver moves the gear knob this kind of safety pin is released and the gear is selected. (but this is basicly not do-able....according to what I read in the article....cause in this case there is a time lapse).

Now if this safety pin has a kind of on-off mecanism it is possible that the selection in done at the same instant as the de-selection.

A little confusing I might say.....at least I can see it in my head....hard to pass down to words.....but most engineers (or futur engineers like me) usually have a hard time in explaining it in words....a piece of paper and a pen usually is much easier....

[schumiGO]

Sorry ... can't read you post- have no time)) Train to home))




Happy new year!!!!


See you next year!!

[Reca]

http://www.zeroshift.com

for those who have a manual gearbox have you ever tried to select first gear at 100km/h.....

This reminded me a story I read... when the Jag XJ220 was released (early 90s) I read the review on an Italian magazine (AutoCapital IIRC) and the journalist described the effect of a “tiny” mistake by another journalist driving the car on the track. Actually driving could be the wrong word because it implicitly requires that the human being sitting on the drivers’ seat knows what he’s doing and that guy obviously didn’t... In fact while upshifting the idio... ehm... journalist selected the reverse instead of the right gear. A sinister little noise was heard while the car smoothly continued his run with the gears “dancing” in pieces inside the case... Right after that a way louder noise was heard for miles in the track’s neighbourhood, that was the scream of the Jaguar man on the passenger seat...

Anyway I’ve experienced many times while sitting on the grandstand during open track days very “creative” shifting made by brilliant guys driving their “Fast& Furious” like cars on the track. The day people will understand that driving ability (and IQ) aren’t proportional to the number of aftermarket parts mounted on the car, most of tuners will go out of business. But honestly I wouldn’t hold my breath for that...

[West]

www.zeroshift.com

for those who have a manual gearbox have you ever tried to select first gear at 100km/h.....

This reminded me a story I read... when the Jag XJ220 was released (early 90s) I read the review on an Italian magazine (AutoCapital IIRC) and the journalist described the effect of a “tiny” mistake by another journalist driving the car on the track. Actually driving could be the wrong word because it implicitly requires that the human being sitting on the drivers’ seat knows what he’s doing and that guy obviously didn’t... In fact while upshifting the idio... ehm... journalist selected the reverse instead of the right gear. A sinister little noise was heard while the car smoothly continued his run with the gears “dancing” in pieces inside the case... Right after that a way louder noise was heard for miles in the track’s neighbourhood, that was the scream of the Jaguar man on the passenger seat...

Anyway I’ve experienced many times while sitting on the grandstand during open track days very “creative” shifting made by brilliant guys driving their “Fast& Furious” like cars on the track. The day people will understand that driving ability (and IQ) aren’t proportional to the number of aftermarket parts mounted on the car, most of tuners will go out of business. But honestly I wouldn’t hold my breath for that...

Over here we call those drivers "ricers."

[DaveKillens]

I do have a theory.
In typical transmissions, the gear dogs slide on straight cut channels. But how about a sleeve, that joins two sets of gears. On the outside, it is spiral cut, thus making each gear sensitive to torque. On the inside of the sleeve, make it straight cut, so it just slides from side to side, maybe just a millimeter or two. So if one gear, being engaged, senses a miniscule amount of torque, and thus slides the sleeve over a little bit. That little bit is enough to disengage the other dog, which was in the process of being disengaged.
In this scenario, precision machining covers most of the shift process. For the last, tiny bit where torque transfer begins to occur, this little sleeve just moves the disengaging gear at just the right time, as the engaging gear was accepting torque.
Lots of flaws in this theory, the worse is making the shift between non-interlinked gears.
Anyone else?

[DaveKillens]

I don't think my first attempt to describe my idea was very clear.
In a typical gearshift operation, one gear is being disengaged, and once that operation is complete, another gear is being engaged. But since this type of gearbox promises near seamless operation, I am assuming that the time spent between deselecting one gear and selecting another is very small, a tolerance that is almost impossible to achieve in the real world. But I expect the tolerances in the zero shift to be close, but definitely reasonable for day to day real world operation.
The gear being deselected is on a shaft, but the slots/grooves on the gear shaft and gear are not cut in a straight line down the length of the shaft, but spiral. They are in a direction so that on the onset of torque, the shaft will have a tendency to move to the side. As this gear moves sideways, it will push against the selector forks, and they will push the engaging gear the last distance to full engagement. A lever arm, some kind of linkage would be required for a purely mechanical system. But I can easily see where hydraulics or electronics could be used to assist in the gearchange operation.
So, in summary, the gear being selected is torque sensitive, and on onset of torque it will move so as to trigger the completion of the shift process... total deselection of one gear, and full engagement of another.

[Monstrobolaxa]

Basicly I think your idea is similar to mine....your idea is a kind of spiral mechanism that has 1 gear selected and another one more or less pre-selected that is definitly selected with a kind of "torque-selection device"....well all ideas are might be valid the only diferences come in the selection device...which in the end tend to be quite similar in a theoretical approah though the design is slightly diferent.

About this kind of shifting I've heard that it only give an advantage when shifting up not down....so from that point of view your mechanism and mine seem to work!

[DaveKillens]

I love reverse engineering. I will now have to wait and see if I was close, or a fool.

God loves fools, he made so many of us.

[effuno]

has there been any updates on zeroshift?

[Reca]

Go to the http://www.zeroshift.com , there’s an animation showing how it works.