F1 regulations seriously restrict any worthwhile development in torque vectoring diffs.
I dont think Patrick has much to do with F1 at present.
I may be wrong but I was told he became dissilusioned after his flywheel storage systems were outlawed.
I dont blame him at all if this is the case.
autogyro wrote:Nice compact design Brian.
Can you show us the assembly that connect to it giving the locking action?
Auto,
Im sorry, I cant - Im not withholding info, I simply dont know and just had the images to hand. Im an engine guy and know very little in comparison when transmissions are involved,
Regards,
Brian,
If you think you cant, you wont, If you think you can, you will
Personally I think with the cockpit adjustability of the Diffs to today, a true Torsen type diff wouldn't be the ideal solution, as it is totally autonomous in how it vectors torque.
I believe that a combined viscous coupling, or a true viscous coupling diff would be a better proposition. As I understand it the drivers can adjust lock up under braking, freewheel, and under acceleration, both part and full throttle, are the areas that control any mechanical diffs action. Some Diffs are torque sensitive while hydraulic Diffs are wheel speed sensitive. Therefore you can use either or a combination of each to alter the diff characteristics.
Seeing as hydraulics are very precise, and with electronic servo valves quickly adjustable, it makes sense to use hydraulic pressure variation to adjust lock up.
So as not to be considered 'active' Diffs, you essentially require as switch, so that the system is open circuit and doesn't feedback.
Under braking this could be a pressure sensor on the braking circuit, and you can vary the lock up under brakes. If the car is inherently unstable there, you could add more lock up to settle it down, or vies versa to aid initial turn in.
Freewheel condition could be any amount of lock up whether the car under or over steers mid corner, and dependant upon corner speed, as faster corners have less speed differential between the inner and outer wheels.
Once the accelerator is applied, and detected via the TPS or torque sensor on the input shaft, the part throttle (and probably most crucial) characteristic is altered in regard whether car under steers ( less lock up) of over steers ( more lock up). As the engine produces more torque as more throttle is opened, the lock up can be increased again ( much like a ramp diff does, I believe.
I remember watching on TV a Grand Prix at the A1 Ring in the late 90's, early 2000's, and see a Ferrari smoking the inside rear out of a tight uphill right hander for many laps, until something was tweaked, and it stopped. So even back then they were all onto it!!!
It is a fairley simple design job to produce a differential that vectors a controlled range of torque from one side of the axle to the other, without ever bothering with 'lock'.
bigpat wrote:I don't mean lock as in no differential action at all, rather alter the amount of diff lock up.
Remember that a actively vectoring diff isn't legal, it must emulate the characteristics of a mechanical diff...
'Characteristics of a mechanical diff'?
Exactly so torque vectoring is legal.
A conventional mechanical diff vectors torque (badly) from one side to the other depending on tyre traction and turn.
A 'locked' mechanical diff does not.
In between we have torque vectoring.
I believe the definition of an active boils down to the fact that there is a feedback loop to constant vary the torque vectoring. Open loop requires a switch to provide a defined point of engaging the said control system, hence why I described what I would think the 'switches' in the system.....
The problem is that the regulations do not appear on the surface at least, to show a knowlege of how a differential works.
The regulations are written with one aim and that is to outlaw traction limiting.
However a differential is of itself a traction limiting device with built in torque vectoring.
Another example of the F1 regulations stifleing technical development for the sake of maintaining a 'spec' formula.
It is possible to develop an electro hydraulic diff that would be better than any diff currently in use.
Hmm, I seem to remember doing that in the early 90s.
