sc-driver

iTrader: (7)

Hey check out this new idea for a CVT transmission. It doesn't use cones like current CVT transmission and can handle larger amounts of torque as well.

This should definitely be interesting once implemented onto a vehicle.

http://www.youtube.com/watch?v=F6zE_...ure=popt02us00

Fixed Ratio Transmission


Cone Type CVT


D-Drive CVT concept

Hoovey689

iTrader: (16)

Very interesting

Mister Two

Absolutely genius!! This is effectively Toyota's E-CVT that uses the MG1 as a mediator but without the need for the MG2. In automotive application, however, the downside is that it'll require a bigger car battery and an electric motor so in the end there probably will be a weight gain and an increase in cost compared to a conventional transmission.

MR_F1

Impressive. Interesting.

I have a lot questions though, for instance, what would the power losses be like, but the concept does seem sound.

One thing is that I believe Lexus' planetary gear Transmission would effectively do the same thing that this is no?

Blackraven

You seem to be knowledgeable on CVT gearboxes. Hence I do have a question:

The neat point of CVT gearboxes is that they have "infinite drive and gear ratios". The possibilities are endless in this aspect.

HOWEVER

AFAIK, it appears that the problem for CVTs is that they can't handle higher amounts of engine torque IF IT IS NOT MATED TO AN ELECTRIC MOTOR/BATTERY.

Examples:
The Lexus LS Hybrid uses a V8 engine. Typically, current CVT technologies would not allow for this set-up. Thankfully, a CVT tranny is used here as the CVT tranny forms a "BOND" or "RELATIONSHIP" with the electric motor (and I think the main engine as well). Hence, why I think they call it as E-CVT.....

However, if you look at the other cars (in the Toyota Group stable), the highest NON-HYBRID car that uses a CVT is the Toyota Estima/Previa.....with a 2.4 liter engine (2AZ-FE).

Atm, their CVT can't be used on non-hybrid vehicles beyond four cylinders.

In the case of Nissan, the highest for non-hybrid is 3.5 V6. The Murano is the best example of this and comes with four-wheel drive. Indeed, that JATCO CVT gearbox module is tough as nails.

However, the CVT has not been used on their V8 engines as of the moment.

Now as for Audi
They have multitronic CVT......BUT ONLY FOR FRONT-WHEEL DRIVE vehicles. Audi said that their CVT is not yet compatible with quattro drivetrain.

With that said, my question is this:
Will this new CVT gearbox be capable of high torque and 4WD/AWD applications?

Meaning, can this type of CVT be placed in an S65 AMG or R8 V10 quattro for example.........and still run?

MR_F1

I know your question was not directed at me, however, Most CVTs use a v belt system, where as Lexus uses a helical gear system, which can hold a lot more torque. It does not need to be mounted with an electric motor AFAIK. Care to contribute Mister Two?

sc-driver

iTrader: (7)

What I've been understanding is that this D-drive IVT can hold just as much torque or more as a fixed ratio transmission that's in gear.

Like said, most CVT's use a V-belt system. The problem with this is that under large amounts of torque the system is vulnerable to slipping. What Lexus did to help this was to mate the CVT with a planetary gear system effectively creating an IVT. This combination of CVT and planetary gearing helped improve torque capabilities.

What the D-Drive is doing is that it is deleting the v-belt system and introducing an IVT designed with gears AND a planetary gearing at the end.

This D-Drive has the benefits of a CVT with the torque capabilities of a fixed ratio transmission because there is no slipping or "shifting" in the system.

PhantomZX

The motor used to change the ratios looks like it needs to have a similar power output as the input source in order for it to work properly. That's a big problem. The entire demonstration was done with a negligible load on the output.

sc-driver

iTrader: (7)

^^not necessarily, all it has to do is change its angular velocity. It doesn't need to match the power input. The forces are still being transferred even with it spinning like that.