Dual clutch transmission: who? 1

[gpetersc]

Hello,

does someone exactly which OEM/supplier (except VW) is developping dual clutch transmissions, and where I can find infos about it (specs, progress...).

Thanks for your answer.

 

[crysta1c1ear]

There is information on GM's website about them developing clutch to clutch transmissions. Ford had one on display in the Ford Bronco concept. Powertrain Limited have taken out a licence to develop a particular dual clutch design. Getrag listed dual clutch transmissions as offering the most benefit to customers in their Frankfurt motorshow presentation, a copy of which is on their website. Borg Warner state taht three major OEMs are/will be using their technology in Europe. I believe LuK will be presenting something at a forthcoming transmission symposium.

The general trend is wet dual clutch transmissions in large cars for heat disperssion, and dry clutches in smaller vehicles.

Your question smacks of market research which this forum is not really about.

Operation (of a normal 6-speed dual clutch transmission say) is like two 3-speed transmissions, one with gears {1,3,5} and the other with {2,4,6}, so gear ratios can be chosen arbitrarily and mechanical efficiency is about the same as a manual. In practice, vehicle efficiency can be improved by using aggressive shift logic.

There are variations in development, eg transmissions with 6 sets of friction disks, one per gear ratio so that a car can powershift from any gear ratio to an other. They will probably hit the market in early 2006.

Its maybe fair to ask who is not looking at the technology rather than who is. Dual clutch transmissions fall into the category of automated manuals. Automated manuals have to go to powershift long term due to the inherent jerkyness of interrupted power.

To leave the big three on an even pegging, I should say that I know of a dual clutch transmission being designed for a DC vehicle too; and having mentioned Europe and US companies, I am pretty confident work is being done for India, China, Asia, too.

Specs

VW
Length 405 mm
Weight 80 kg
Ratios 6
Gears 16
Teeth contacts 10
Bearings 21
Synchro cones 7

Alternative
Length 350 mm
Weight 73 kg
Ratios 7
Gears 18
Teeth contacts 12
Bearings 20
Synchro cones 8

Both use BW dual clutch device.

 

[crysta1c1ear]

I neglected to mention that there is stuff on the internet about various cars using the Ricardo 7-speed dual clutch, the Chrysler ME4-12 and the Bugatti Veyron are examples if my memory serves me right.