Infintely Variable Geared Transmission (D-Drive)

[thepeganator]

You have to remember that the second motor needed to drive that second shaft doesn't need to be that powerful, it only needs the torque to spin a cog and small shaft, unlike the main power drive which needs the torque to move the whole car/etc.

 

[Dogbreath]

You have to remember that the second motor needed to drive that second shaft doesn't need to be that powerful, it only needs the torque to spin a cog and small shaft, .

And what do you think is at the other end of this shaft? It must experience some torque reaction.

 

[BigglesPiP]

You have to remember that the second motor needed to drive that second shaft doesn't need to be that powerful, it only needs the torque to spin a cog and small shaft.

If the torque from the engine can move said small gear and shaft backwards, rather than moving the car, it will.

Imaging a see saw, stick a fat kid on one end and the see saw's pivot will be driven into the ground? No, the other end just goes up. You need another lardy MacDonald's fed kid on the other end. The same applies to the planet gear.

I think I'm right in saying that you don't need the same torque on the inner gear resisting reverse rotation, but you do need the same "power".

 

[malfunkshun]

From the looks of things it won't be very efficent at anything other than full speed though

Nope, think of it like this..
If the optimum efficiency RPM of an engine is 4k RPM, then you set the engine to only run at 4K RPM and use this system to vary road speed instead of the engine.

As for ratio, as I understand it then changing the ring gear at the input end can change the ratio from 1:1.

 

[Hotwired]

Hum.

A combustion engine would have to power an electric motor to do the speed control.

Oh well, still be decades before a car manufacturer sticks its neck out to use it even if it does turn out to be efficient enough.

 

[Jonnycoupe]

Hum.

A combustion engine would have to power an electric motor to do the speed control.

Oh well, still be decades before a car manufacturer sticks its neck out to use it even if it does turn out to be efficient enough.

They already have...

 

[Hotwired]

They already have...

So who's using the D-drive?

 

[Jonnycoupe]

I doubt the patent this guy has will go much further than controlling use of the name. So obviously no one has D-drive, he wouldnt have called it that in the first place anyway.

Try MG1 and MG2 on a Prius though for a combustion engine powering a generator (MG1) which then provides the load resistance/drive output for the power split (MG2).

 

[Gribs]

Nope, think of it like this..
If the optimum efficiency RPM of an engine is 4k RPM, then you set the engine to only run at 4K RPM and use this system to vary road speed instead of the engine.

As for ratio, as I understand it then changing the ring gear at the input end can change the ratio from 1:1.

I understand the constant engine rpm bit as it's just the same principal used with cvt's to make them more efficent. However at anything other than a 1:1 output where the shaft can be mechanically locked it'll need quite a bit of power to keep the second shaft moving at the appropriate speed to generate the required gear ratio.

Normal grearboxes are very efficent so it'll depend if the increase in efficency of being able to run an engine at constant rpm can make up for the decreased efficency of the gearbox.

 

[theo]

I feel in cars this would be much more suited to replacethe Clutch in a car, otherwise it locks then feeds power through to a more conventional gearbox, maybe an all in one system.

 

[Fantom]

Also, surely if the drive can be set for maximum efficiency, it can be set for maximum performance...

afaik in terms of gearboxes maximum efficiency means maximum performance!

Does look great though, looks like it could be packed down into something the size of a clutch too! which means smaller power units