Seamless Shift

[Cogs]

I have read most of the data on the zero shift system and also designed similar systems.

Just to clarify a point. I have neither worked for, or had access to any F1 transmission team or technology but purely from a mechanical understanding and an appreciation of the physics involved clearly see a flaw in your claims.

Such systems can smooth the shift and increare shift speed (so long as the engine inertia is low enough).

I proposed that the engine inertia has been isolated through clutch slip.

There is no way to get over the time it takes for the engine to change rpm between gears however no matter how hard you market such mechanisms.

True, I proposed this as a positive feature of the shift not a problem.

Electric vehicles need far more efficient powertrains and the future will see totaly new gearbox technology with far higher efficiency than layshaft boxes seamless or otherwise.

Hallelujah! you do accept seamlessness. =D>

[autogyro]

Here we see you totaly missing the fundamental point.

No sir, YOU have completely missed the fundamental point. The new gear has caused the input shaft to synchronise the previous gear has become instantaneously unloaded. There is no "time delay".

To even mention the function of a conventional synchroniser ring in this context is yet another example applying old principles to modern technology.

The ONLY way that this is possible is if the input and the output of both gears is rotating at exactly the same speed. In which case there would be no ratio change.

[Cogs]

The ONLY way that this is possible is if the input and the output of both gears is rotating at exactly the same speed. In which case there would be no ratio change.

Lets take this one step at a time...........the transmission is engaged in first gear on the output shaft of a layshft transmission.

The free running second gear on the output is rotating faster than 1st.

Engage 2nd while still applying torque to 1st.

Impact at 2nd gear causes 2nd gear to synchronise with the output shaft.

Because of constant mesh all components also reduce speed.

1st gear decelerates and unloads = instant torque transfer.

Input shaft has decelerated compared to engine speed through pre-conditioned clutch slip.

Engine torque is retarded via management but input torque is maintained through clutch modulation until near synchronisation at which point engine torque is resumed.

Output torque as a result changes from 1st gear torque to 2nd gear torque without a 'gap'

Dare I say it......a seamless shift.

[autogyro]

You can say what you like.
How long does it take?
Faster than earlier methods maybe, seamless NO.

[Cogs]

You can say what you like.
How long does it take?

How long does what take?

Faster than earlier methods maybe

There realy are NO modern mechanisms for gear shifting in a layshaft gearbox

Yet another contradiction!

[Cogs]

Before we continue and to get this thread back on topic, can you confirm that you believe the following STILL to be true?

autogyro wrote:
The 'gap' is a time period where there is little or no torque to be measured at the output shaft. This 'gap' is always present in a stepped gearbox and is the reason why the description 'seamless' is untrue and simply a marketing term.
If so I will make the effort to get my point across

Now?

[autogyro]

?
Sorry I did not write that, you did.

[Cogs]

I know, my question was whether you still stand by your claim?

[autogyro]

You can say what you like.
How long does it take?

How long does what take?

Faster than earlier methods maybe

There realy are NO modern mechanisms for gear shifting in a layshaft gearbox

Yet another contradiction!

What contradiction?

[autogyro]

I know, my question was whether you still stand by your claim?

There can be no such thing as a layshaft 'seamless' gearbox.
The term is meaningless other than as a marketing gimmick.

[Cogs]

You accepted that the principle I proposed was "faster than earlier methods" and therefore contradicted a previous statement that "there are NO modern mechanisms for gear shifting in a layshaft gearbox"

I have a few questions regarding the similar systems that you claim to have designed.

What is the current status of these designs?

Did they adopt a similar shift strategy to the one I proposed?

Do you still stand by your previous statement?

"The 'gap' is a time period where there is little or no torque to be measured at the output shaft. This 'gap' is always present in a stepped gearbox and is the reason why the description 'seamless' is untrue and simply a marketing term."

[Cogs]

There can be no such thing as a layshaft 'seamless' gearbox.

So if I can prove that there is no 'gap' and output torque does not have to equal zero or a negligible value (as this is YOUR definition) am I right in assuming that you will then accept that the shift is seamless?

[autogyro]

You are now clutching at straws cogs.
I have confirmed my statement.
If you disagree please stick to the issue and give reasons.
So far you have failed to explain the time gap between being engaged in one gear and being engaged in the next gear.
To be seamless, there needs to be no time between the two states.

[Cogs]

So far you have failed to explain the time gap between being engaged in one gear and being engaged in the next gear.

That's because there is no time!

For simplicity imagine 2 dog rings sitting on one hub between 1st and 2nd.

One is engaged in 1st gear and the other in neutral.

I can freely move the ring in neutral as there is no torque being applied.

I slide the free ring into 2nd.

At the instant of engagement both rings are in contact (no time between states)

The synchronisation of 2nd gear to the output shaft causes 1st gear to decelerate away from the other ring (because of constant mesh through the layshaft).

The previously driven ring can either be extracted or "ramped" from causing a conflict.

Simple enough??????

[autogyro]

Yep absolutely correct.
One ramps down, the other ramps up, brilliant you understand how it works.
Now tell me how long it takes to ramp up one ring and ramp down the other.
Ipso facto a time gap. Not seamless.