Planetary gearboxes?

[g-force_addict]

Wouldn't planetary gearboxes great in F1?

There have been plenty transmission failures recently.
Planetary gearboxes (PG) are more reliable and sturdy. They can handle 3000 hp dragsters.

With PGs no time is waster while the tranny shifts.

Smoother shifitng.
They work by braking or releasing gears, thus as the gear is accelerating or braking it is already changing the net gear ratio.

PGs are mostly a tube so its easier to use them as a stressed member.

PGs are quite efficient, they have been used in bicycles.
The higher the gear the more efficient they become as ratio becomes 1:1 for some tranny stages.
Thus the tranny is less efficient at low gears (where tire spin limit using full engine power anyhow) and become more efficient at higher gears where full power is needed the most.

[bettonracing]

Weight & power consumption.

Regards,

Kurt

[xpensive]

Inside gears like in planetary gearboxes does not have a perfect involute profile, why there is an element of power consuming sliding between the teeth, which limits the efficiency and causes high lubrication temperatures not suitable for racing.

http://en.wikipedia.org/wiki/Involute_gear

[autogyro]

The problems so far stated did not prevent the ERA's fitted with the Wilson pr-selector planetary gearboxes from winning races.
Planetary gearboxes can consume far less power than any layshaft stepped gearbox.
In the above case, zero losses whatsoever from gear engagement in direct top gear.

[autogyro]

Inside gears like in planetary gearboxes does not have a perfect involute profile, why there is an element of power consuming sliding between the teeth, which limits the efficiency and causes high lubrication temperatures not suitable for racing.

http://en.wikipedia.org/wiki/Involute_gear

http://www.youtube.com/watch?v=Hvfytr7DuGk

No problem with involute tooth profiles for planetary gear sets.
There are also many more advantages using planetary gear sets.
Equalised burst loads which allow for lighter and better balanced gears and components.
Far better bearing support in the caseings.
No offset torque paths.
The capability of only needing gears to actualy move in mesh when that particular gear ratio is needed and no need for ANY gears to rotate in mesh in direct top gear ratio if designed using modern electronic gear shift control systems.
The result is a gearbox that is better in every way to those in current use.

[machin]

just read through the rules again and I can't see anything that prohibits planetary gearboxes in F1 unless I'm mistaken... so Auto, if they're so much better, why don't they use them already? What is causing the teams to use (in your opinion) "inferior" technology?

[mep]

As planetary gearboxes build more radial they probably have higher rotational moment of inertia due to the mass on a higher radius.

[autogyro]

As planetary gearboxes build more radial they probably have higher rotational moment of inertia due to the mass on a higher radius.

84 mm diameter as projected in this case for F1 is not much bigger than the current clutch packs and about the same size as a diff crownwheel.
Any single component with a 'slightly' higher moment of radial inertia within this geartrain helps to make energy recovery in over run brakeing more efficient and makes any traansition from a connected ic engine to disconnected on over run more controllable. The effect of feel to the driver remains constant.

In this case the conventional clutch is not needed at all anyway and neither is any form of flywheel. Over all rotating mass is lower in the powertrain.

[autogyro]

just read through the rules again and I can't see anything that prohibits planetary gearboxes in F1 unless I'm mistaken... so Auto, if they're so much better, why don't they use them already? What is causing the teams to use (in your opinion) "inferior" technology?

I know this will sound like an old record and sour grapes, I hope you will see through it and find the truth for yourselves.

Ferrari (as just one example but probably the most obvious)have stated in public that ALL their future road cars will be hybrid.
They have to be, because even though Ferrari can use the Fiat 500 as part of the CO2 calculation, there is no way a V12 ic engined Ferrari will be allowed into a European Town or City in the future with its engine running. The regulations just wont allow it to happen.
Ferrari have what they believe is a modern powertrain with electric motors and the latest (state of the art) layshaft gearboxes. They believe this is the future for their hybrid range. I think it is the PAST using obsolete geartrain design and first generation electric motor and control systems technology.
The designs look like a hugely complex block of flats.
Other 'supercar' manufacturers are following suit because they are being forced to do so by the regulations, not because they consider hybrid or electric traction as the future, which it is and they should.
This attitude permeates to all levels of vehicle manufacture and the attitude it produces in the general public is the cause of the huge delay in the transition to hybrid and electric vehicles and the cost reductions that should by now have created a level playing field in the market and might even have had a major effect in repairing the financial base of some fossil based economies.

F1 is an 'old boys network'. It might appear to be high technology and it certainly uses the latest techniques and sciences but only when these disciplines suit its financial base.
The ONLY technology given almost a free reign in F1 is aero.
All other areas of F1 potential development are strangled by FIA regulations and any meaningful development or diversity is very effectively prevented.
Energy recovery has been added but only within very exact definitions. There is little area available for new ideas if at all and for anyone with new ideas the risk is not worth taking because anything that looks like a potential breakthrough is always banned before it has a chance. A look into F1 history will prove this without doubt. F1 cars are designed today by a commitee of regulators.
No gearbox company or car manufacturer is prepared to fund a completely new geartrain concept that they know will be outlawed before it races and they sure as hell do not want a new system in road production that will make their current stuff obsolete over night. Far easier to suppress the idea when ever it appears.
In this case it even extends to certain other tech forums when it rattles their OBN and upsets their childish status quo. They dare not even speak its name.

[machin]

come on Auto... do you really believe that? look for yourself; there's no rule against planetaries in F1 and companies like Hewland and Xtrac don't sell 1000's of road cars so they're not trying to promote their own existing technology... its not even a new technology... been around for years and years, so I don't believe there is any particular extra costs involved in designing a planetary gearbox...

I don't believe this "old boys" club argument either; don't you think that if there's an advantage to be had someone (possibly at the back of the grid) would take up the challenge and develope one? F1 is all about trying to find small advantages in the rules and to hell with the fact it might be outlawed the following season... (the Driver operated F-duct was never going to last more than a season was it?!).

So, conspiracy theories aside... why aren't they used? Xpensive, can you find a link which confirms the problem of internal gear efficiency?

[autogyro]

come on Auto... do you really believe that? look for yourself; there's no rule against planetaries in F1 and companies like Hewland and Xtrac don't sell 1000's of road cars so they're not trying to promote their own existing technology... its not even a new technology... been around for years and years, so I don't believe there is any particular extra costs involved in designing a planetary gearbox...

I don't believe this "old boys" club argument either; don't you think that if there's an advantage to be had someone (possibly at the back of the grid) would take up the challenge and develope one? F1 is all about trying to find small advantages in the rules and to hell with the fact it might be outlawed the following season... (the Driver operated F-duct was never going to last more than a season was it?!).

So, conspiracy theories aside... why aren't they used? Xpensive, can you find a link which confirms the problem of internal gear efficiency?

Teams at the back of the grid have no choice other than to use the available powertrain technology, they can hardly afford off the shelf gearboxes and KERS systems. Some cannot even afford to use KERS, let alone develop new geartrains.

A conventional planetary geartrain requires an operating system and a direct engagement clutch. If the system chosen is mechanical, pneumatic or hydraulic then it will be heavier, bulkier and more complex than the current layshaft control systems. This thread is in general terms and in such terms the planetary geartrain would not be chosen.

However, there is another way to control a stepped ratio planetary geartrain.
I am not going into it and have no intention of running around trying to sell anything, in fact I am going to pull all reference to my ideas from any forums.
If the industry wants the technology, then they will have to come to me with money.

[mep]

As much as I like planetary gearboxes myself they clearly have higher rotational inertia which is never a good thing. It doesn't even help with energy recovery because those masses also need to be accelerated when the energy is feed back to the vehicle. The higher inertia makes the response of the engine worse. Also I can clearly see the point of expensive. Just by looking at a picture of the gears I can see that those must slide more.

[Tommy Cookers]

I too like planetary gearboxes, being an automtic driver, so to speak.

IMO we are overdue for a transmission revolution, the CVT is ruinously handicapped by being forced to be an exact substitute for the manual transmission, the traditional automatic also suffers.
The original DAF was the only application ever to be given a fair chance.
Later , metal CVTs were magic (apart from the fake creep which wore the clutch and cost £3000 to fix)

Microprocessor/software control has transformed all automatics.

We need a creeper (non-friction) electromagnetic clutch stage for traffic use, in series with a software controlled full torque friction clutch for thrashing ......
the advantages of both semiautomatics and proper automatics.


In F1 we are in need also of an integrated approach.....

a mechanical CVT/ flybar energy storage&recovery system allowing 100% KERS for a start, not the 2% pretend KERS allowed in recent times

We have 750 bhp engines active for 50% of the time and 3000bhp brakes active for 15%. We need 400bhp engines full time ... etc ... etc

Planetries and CVTs to integrate the large variable energy flows, you know the rest .....

Electrics will never cut it at this level (I should know !), but the thin end of the commercial wedge went in a while ago.

Such fun !

[autogyro]

I too like planetary gearboxes, being an automtic driver, so to speak.

IMO we are overdue for a transmission revolution, the CVT is ruinously handicapped by being forced to be an exact substitute for the manual transmission, the traditional automatic also suffers.
The original DAF was the only application ever to be given a fair chance.
Later , metal CVTs were magic (apart from the fake creep which wore the clutch and cost £3000 to fix)

Microprocessor/software control has transformed all automatics.

We need a creeper (non-friction) electromagnetic clutch stage for traffic use, in series with a software controlled full torque friction clutch for thrashing ......
the advantages of both semiautomatics and proper automatics.


In F1 we are in need also of an integrated approach.....

a mechanical CVT/ flybar energy storage&recovery system allowing 100% KERS for a start, not the 2% pretend KERS allowed in recent times

We have 750 bhp engines active for 50% of the time and 3000bhp brakes active for 15%. We need 400bhp engines full time ... etc ... etc

Planetries and CVTs to integrate the large variable energy flows, you know the rest .....

Electrics will never cut it at this level (I should know !), but the thin end of the commercial wedge went in a while ago.

Such fun !

It could be the best fun in automobile development since the wheel Tommy.
I have answers to all the above, I just need a budget big enough to do it.
I think it unlikely that F1 will be the area for real developments however.
More likely the sports car area, race and road.
F1 is now to far removed from reality.

I have yet to see a CVT or TVT transmission that does not use far to much energy just to operate the ratio changing mechanism and geartrains/cones/disks friction needs.
This is the biggest down side to the Prius hybrid 'triple input to output' juggling act using a planetary system. Efficiency is not that good.
For energy recovery to electric, it is far better to spin up a flywheel through induction for rapid storage. I agree for larger amounts of energy a mechanical connection might be needed, depends on the application. Road cars on motorways dont need energy recovery, they just need to coast further to achieve higher energy efficiency. KERS is not the magick bullet on its own.
Hybrid powertrains with a range of ratios both for ic and electric use is the direction to take. At present the technology is stuck stareing at the flat torque curve of electric motors and loseing its way.

With the system I have in mind you would not need a high torque friction clutch of any sort, even with thousands of ic bhp to deal with. In fact you dont need any clutches at all.

[autogyro]

As much as I like planetary gearboxes myself they clearly have higher rotational inertia which is never a good thing. It doesn't even help with energy recovery because those masses also need to be accelerated when the energy is feed back to the vehicle. The higher inertia makes the response of the engine worse. Also I can clearly see the point of expensive. Just by looking at a picture of the gears I can see that those must slide more.

How can a planetary gear set running in direct top gear where NO gears are turning in mesh and its whole assembly of gears which weighs less is rotating as ONE piece, have a higher rotational moment of inertia than a seven speed stepped layshaft gearset that weighs more and that has ALL its gears rotating in this condition?
The planetary diameter would be approx 84 mm, which is the 'minimum' distance between the shaft centers of the current single layshaft designs.
It is the layshaft gearbox that is harder to accelerate because of all those gears washing machining around in a bath of oil for no purpose other than to create torque loss.
The planetary geartrain would only need oil for the time each set is running in engagement and not at all in direct top, just support bearing lube and only ONE of them right in the middle of a perfectly stressed caseing less than half the weight of a current layshaft bent to one side case.
Engine response would be no problem the shift over lap would be pure electric with the engine rpm and torque available augmented at all times by energy harvesting and application directly through the planetary sets. There would be NO torque loss, either directly from windage or parasitic losses or from gear shifting, in fact toque can be increased during the shifts, just as full energy harvesting can be smoothly controlled even during shifting.

I think a better look into involute gearing is to be advised.
Such geometry does not 'slide'.