Clutch mounting?

[747heavy]

ZF-Sachs F1 clutch internals, it´s not the latest model, but the concept is similar

[autogyro]

Looks exactly the same as an automatic transmission clutch as used in many auto transmissions since the 1930's. It is just dry friction materials rather than wet.
No big deal at all.
Build a transmission casing out of light exotic materials.
Fill it with conventional but light weight gears in a combination based on an 1899 design. Operate the selectors with hydraulic or pneumatic rams electronicaly controled and you have an F1 gearbox.
Join a fully regulation controlled engine design to it and you have the complete F1 powertrain.
Now where on earth is the on going technical development in that?

[Edis]

xpensive,

Heat transfer and friction with carbon is a tricky subject.

As I noted, carbon-carbon definitely has an oxidation temperature limit. With a clutch pack, the heat is being generated at the sliding interface and must be transferred away from that surface. Pitch based carbon has good heat transfer in the axial direction, but poor heat transfer in radial direction. So getting a good heat conduction path out of a thick stack of rotors and stators can be troublesome.

With regards to Mu, carbon has a friction coeff. that varies with temperature. It is the opposite of most materials in that its Mu increases with temperature. Carbon clutches tend to slip very briefly until they heat up. Then the Mu increases and they quickly grab, almost like an on/off switch. That's why even very good drivers still occasionally stall leaving the pits.

Regards,
riff_raff

Wear caused by oxidation is less of a problem with a clutch since it will soon cool off after the start.

It has been said that the friction materials in the F1 clutch approach 1000 degC during a start. I suspect there are other limitations than the wear caused by oxidation, such as the limits of the titanium clutch cage and the steel spring.

Looks exactly the same as an automatic transmission clutch as used in many auto transmissions since the 1930's. It is just dry friction materials rather than wet.
No big deal at all.
Build a transmission casing out of light exotic materials.
Fill it with conventional but light weight gears in a combination based on an 1899 design. Operate the selectors with hydraulic or pneumatic rams electronicaly controled and you have an F1 gearbox.
Join a fully regulation controlled engine design to it and you have the complete F1 powertrain.
Now where on earth is the on going technical development in that?

The F1 clutch is just an ordinary dry multiple plate clutch with carbon/carbon in all friction faces.

Automatic gearboxes with few exceptions use fluid couplings instead of a clutch, the clutches they use are only used to lock or unlock the series of planetary gears for gear selection.

In a F1 gearbox the selector forks also aren't operated directly by hydraulics (although I believe that was tested in the past), they are driven by a rotating drum which have machined groves which the selector forks follow. The configuration of which is such that when the drum if moved a step the next gear is engaged.

The semi automatic sequential gearbox also uses dog clutches, or a seamless shift mechanism for the gearchanges. Not exactly what you find in a gearbox from 1899.

[mx_tifoso]

What's the life expectancy in terms of races and/or km's for F1 clutches?



Post 2700.

[autogyro]

'Automatic gearboxes with few exceptions use fluid couplings instead of a clutch, the clutches they use are only used to lock or unlock the series of planetary gears for gear selection'.

Fluid clutches have been used for many other things in automatic gearboxes as well as connecting epicyclic gear sets. Locking up torque converters, direct fluid clutch drives etc. I even worked on electro fluid clutches, where the fluid becomes solid when a current is passed through it.

'In a F1 gearbox the selector forks also aren't operated directly by hydraulics (although I believe that was tested in the past), they are driven by a rotating drum which have machined groves which the selector forks follow. The configuration of which is such that when the drum if moved a step the next gear is engaged'.

Problems with over engineering of these rotating scrole drums to increase shift speeds has been my suggestion to a number of teams this year for gearbox failures.

'The semi automatic sequential gearbox also uses dog clutches, or a seamless shift mechanism for the gearchanges. Not exactly what you find in a gearbox from 1899'.

I am assisting with the rebuild of a 1908 Panhard at the moment that has both cone and dog clutches. The 1899 Panhard in the museum down the road that a friend of mine engineers also has dog clutches. It was raced by a gentleman called Rolls.

Seamless shift is an untrue description as there is no such thing. Using two layshafts with two clutches goes back to the 1930s on machinery applications. There is always a gap of disengagement with layshaft gearboxes. Twin clutch boxes also sap far more torque. Very wasteful IMO.

[riff_raff]

mx_tifosi,

I'd guess that the life of an F1 carbon clutch varies among the individual components. The carbon rotor/stator plates might last 2 or 3 races, while the rest of the metallic parts would last substantially longer.

As the carbon rotor/stator plates wear, the stack must be shimmed so that the belleville springs give a consistent release point and clamping force. This is probably done several times each weekend.

The wire EDM'd titanium cage shown in 747heavy's picture is a very impressive piece of work. I'd bet that one single part costs over $20K to make!

Regards.
riff_raff

[747heavy]

gearbox mounted clutch
Hispania F1