The D-Drive Infinitely Variable Geared Transmission

This brain-bending invention could be the holy grail of transmission technology - it allows you to smoothly move through gear ratios from top gear all the way through neutral and into reverse without ever disengaging the engine. Plus, there's no friction drive component, so the power is always transmitted through gear teeth - there's never any slip or friction losses.

In fact, the D-Drive's main difficulty is that it's so damn hard to understand that people don't really know what to do with it. So here's a close-up look, which will hopefully get a few people thinking.

Read the complete article here: http://www.gizmag.com/steve-durnin-ddrive-d-drive-infinitely-variable-transmi... and a follow up to the response here: http://www.gizmag.com/d-drive-redux/15120/

Category:

Autos & Vehicles

Tags:

• d-drive
• transmission
• CVT
• steve durnin
• gizmag

[dreamdiction]

All I'm seeing is a differential. Nothing more.

[1krr]

Bad engineering. Basically he is bleeding off engine speed by spinning the sun gear in the opposite direction. As output speed comes closer to input speed, you would have to apply an more reactant torque to the variable speed(ed) sun gear to hold it in place. He does this with two separate motors applying torque. 50% of the input power would be needed for this transmission to work at top speed. Newton for the win...

[jatigre1]

This is a sound invention and I don't know why some people don't understand it. It's principle is based in gear ratio, so it's applications will depend only on the size of the gears, motor and output shaft. There's nothing wrong with the design, in fact is quite revolutionary. I hope to see this implemented soon.

[brizig000]

I agree with flyboy3633 and springhill1958. and I would like to see this intigrated in my upcoming invention sprockets with lazer disk reader stablizers in robotics.

[gavincurtis]

But wouldn't this design be limited as the DC motor "gear selector drive" requires a lot of power to overcome torque.

This concept only works at virtually no torque level. Otherwise the gear selector would have to have the same HP as the main drive motor for the entire system? So you have one motor constant speed, a 2nd similar HP motor that has to vary its speed. So what is gained?

[flyboy3633]

This would work fine for low-load systems as he mentioned, but the narrator is wrong when he says that the speed controlling motor can be much smaller than the force being applied to the input shaft. The force applied to the first spur gear in the planetary will apply its load to BOTH sides - the inner ring of the planetary AND the inner speed-controlling gear.. That inner gear must have the strength to resist the spur gear forcing it around the opposite direction.

[sleddog123]

@EurekaThis Please respond, message me if necessary. Thanks.

[joshrhofer]

from a loaded operation I would like to see the calculations on the power needed from the two "gear selector drives" in ratio to the drive motor. Then we will see how good it is .

[obscureanimations]

It's very hard to create a useful, novel device from about 8 gears in the year 2012. In fact, it was hard in the year 1512.

[volodymyrm1]

a double differential for electric cars, nothing beats a 5 speed twin turbocharged gas guzzler on everyday performance, and as far as energy recovery- the new KERS are electric using around 150 watt electric hybrid motor generator and LI-Ion battery pack used to be available only to F1 teams now they packed it up in new volvo SUVs

[sleddog123]

@EurekaThis So any news on your invention? It's been 6 months and I've thought about our discussion here many times. Please let me know because I'm super curious!