QUOTE(isr25 @ Dec 5 2017, 10:43 AM)
Rumour mill says Civic facelift will come out in 2019 in the US, and might come with wet DCT, similar to Civic in China. Take it with a grain of salt of course.
I looked into the patent office submission, this 8 speed DCT is technically not a common DCT. It is neither a conventional AT with with planetary gears. It is something of its own - Parallel Axes Automatic Transmission with Torque Converter. Patented by Honda, and never use by any other car makers.
In theory, it will not provide the direct shift performance shift feel of the DCT, but it will be more smooth and less mechanically complicated than the planetary gears in conventional AT. Something simple to manufacture and cost effective, but difficult for mortal like me to understand its operation.
http://www.freepatentsonline.com/7421921.html
http://www.freepatentsonline.com/7421921.pdf
Below is the key features of Honda DCT vs common DCT. I'm still trying to understand how which one is gear 1,2,3 etc, merely figured out the concept for now.
- Honda DCT have the gears like MT.
- It has 3 input shafts and one output shaft.
- It doesn't have dog tooth nor synchronizer, and doesn't use mechatronic to lock the gear to the shaft.
- It use wet clutches to select gear (this replace the mechatronic, and make sense without synchronizer needed).
- So far I calculated 6 clutches from the figures, probably more.
- How it connect the engine crankshaft to the gearbox where the common DCT have clutches? Torque converter!
- I don't know which input shaft the torque converter connected to yet.
- So it does have clutches, but it uses it for different purpose. The clutches sits in common DCT/MT are replaced with torque converter.
Common DCT is sequential, it is slower when you do a double downshift because pre-select doesn't work in the same shaft.
Looks like this thing can jump whatever gears as it wish like magic by flipping the the 6 clutches (6 for now).
My only doubt is the clutch plates likely to be smaller in order to fit so many of them in the gear box casing. Probably max torque it can handle will be limited.
This post has been edited by constant_weight: Dec 6 2017, 12:17 AM
Dec 6 2017, 12:00 AM

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