bernif2003 wrote:Does anybody know if BAR 006 uses a carbone fibre gearbox?
I heared it in a TV program ... but I think it is false. What do you think about it?
Thanks SpeedTech and Scrabs!!
It is really a great steep forward... I think that the big problem building a CF gearbox, is to mount the bearings and other mechanical devices.... Bacause the CF can't be machined i think.
Does anybody know how do they solve this problem?
BAR wont tell me how they mount the bearings, there's soem metalic components in the casing, but in exactly what material isnt clear.
I know Renautl didnt opt for a CF case as the weight was marginally higher than for a Ti case, plus the extra capacity required to make so many complex CF cases in house. Making a investment cast Ti gearbox is easy, quick and cheap (relatively speaking) and the casing returns fully machined ready to go, so little production capacity is required.
There are lots of obstacles in using graphite/epoxy for a transmission housing. Most importantly, it must have metal (titanium) inserts that can be machined for a close tolerance fit with the bearings. It will also probably need a metal flange where it splits to allow the guts of the transmission (gears, bearings, dogs, etc.) to be installed. And finally, graphite/epoxy has very poor strength at the temperatures that it will experience from the gearbox oil splashing on it.
The attractive thing about using graphite/epoxy for a (stressed) transaxle housing is that it is light, has a CTE close to the steel gears, and has a stiffness similar to the composite tub structure.
If some one is building composite transaxle housings, I'm sure they have some sort of metallic inner liner/sub-structure, and they're probably using a very expensive, high grade of resin like a polyimide.
Pure composite structures always work great. The difficulty arises when you have to attach a non-composite part to it.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
thanks for posting those pic's of the Honda. The most interesting thing I saw in there was that the engine block appeared to be machined from billet instead of cast. I can't imagine how much that must cost! Of course, the mechanical properties of wrought/forged aluminum are far superior to those of any cast aluminum, so I guess it makes sense.
Here in the US, top fuel drag racers have been using billet cylinder heads for a couple of years. But they don't require any coolant jackets, so it's not too difficult to machine them. But it must cost a fortune, as well as taking a massive amount of hours on the machine, to produce a block from solid! Cubic dollars.
"Q: How do you make a small fortune in racing?
A: Start with a large one!"
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