Clutchless, Beltless Infinitely Variable Transmission

GA

In fact, I don't yet see any reason for the average 'control' shaft power over the full range of speeds to be significantly different than the 'input' shaft power. Clearly, if the 'control' shaft is stopped, it's input power is zero; at 'neutral', both shafts spin at the same speed, and the only power required is to overcome friction, so the power can be minimum, but not zero. Between those minimums, there will be pairs of torque, velocity, and power curves. To attain full reverse, I get the impression that the 'input' shaft would be completely stopped. If that is the case, then all the power would have to be supplied by the 'control' shaft.

I see this as a torque-summing device. Interesting, but I'll need a lot of ketchup with my hat if the concept achieves an 'order of magnitude improvement' over any current well-made CVT. Since he already has electric motors on both shafts, it should not be difficult to add some form of braking to the output, and measure the 2 motor powers as a function of output shaft speed.

Here's one that will work:

(WO/2008/030535) CURVILINEAR GEAR AND METHOD

This system is truly variable and scalable. Makes a great universal joint, too.

The inventor claims to have the interest of the US Army and the U Mass. at Lowell is working with him on proof of concept models.

I think it's an elegant design!

Mr. Bernier was kind enough to send a detailed set of drawings to me.

I'm having a GREAT difficulty visualizing a 'hemispherical gear'. To me, if it doesn't have teeth, its not a gear. If the teeth are on a hemispherical surface, the spacing MUST vary from inside to outside. Please post an illustration of part of the gear surface!

If there are no teeth, it shouldn't be called a 'gear box'.

I agree.

If it has teeth, it can't work.

If it has no teeth, then it's a friction drive, like Torotrak etc.

About 15 years ago there was a similar idea in one of the automotive mags. If I understand either idea correctly, the movable spacings between the cones (or hemispheres or paraboloids or whatever) will give a continuously variable drive ratio. The device depends on friction (as does a snowmobile belt or SEW-Eurodrive friction disk or cone). The driving elements can be pressed together hard enough to make the engagement all but positive, but it takes large force and heavy bearings. Even then, the engagement is not as positive as with gears. The D-drive achieves positive engagement, but it fails to distinguish the torque contributions of the input shaft versus the control shaft.

Variable displacement piston pump and motor hydraulic drive systems still have the market on this application tied up and here is why.

Scalable from fractional HP to multi thousand HP.

Presently already mass produced.

98+ % efficiency in properly manufactured designs.

Life expectancy with little maintenance often times equal to or greater than the power source its driven from.

Clutch less, Belt less, direct drive capability at either end of the system.

infinitely variable ratio of speed and or torque from true zero to maximum design point.

Can be configured for multiple outputs with independently variable speed and or torque ratios for each output.

hydraulic sistems require lot of hydraulic oil, you cant avoid leackage which contaminates terribly ground watter!

The variable speed principal is the same as any automatic gear box, but what is new as far as I can see is access to control the outer ring gear coupled to the inner drive with any variability resulting in the planetary gears providing the output. But if you where thinking of a hybrid, then electric drive motors could do the same? but how the gear box works is interesting.

Regards JD.

interesting the link works on the daily digest, but not here?

maybe could use a hydraulic rig to run the Durmin drive

I think was demonstrated such a device will always requires some energy spent by friction for example ,so doesnt mater if it is hidraulic or "mechanics" by cones etc.(may be a lot about in the several volume of Artobolvski) or even more efficient like Audi,on purpose Audi A6 havent it already working?.-

We Morons sometimes find this stuff puzzling, so this Moron dug a little.

There was a write up done by an engineering firm, which said that "The Durnin transmission is operating as a conventional epicyclic gear set, combining power flows from three shafts in various combinations."

"The Durnin transmission requires some external means of varying the speed of the Control shaft (and providing power through that shaft) to serve as a true IVT."

(bolding by MoronicBumble)

So this is not the holy grail, by any stretch. It is not an IVT; it could be part of an IVT, as the engineering report says. It is an ordinary epicyclic gear set.

One might wonder who the foolers, the users, the stretchers of truth might be here. It is possible that the inventor has paid various people a chunk of money to evaluate his idea, and has been led along. Have the evaluators been completely forthcoming? There are countries in which pretty slick businesses exist to sell inventors on their own ideas, extracting money from the inventor in the process.

This Moron wonders why the Gizmag seems to be actively presenting this as a breakthrough and too complex to describe... It is as if the intent was to obfuscate rather than elucidate. If the intent were to elucidate, the video would have shown how an epicyclic gear set works.

Any curious mechanic who has played with differentials or conventional automatic transmissions would understand the functioning of this gearbox...

The comments on the Gizmag site are encouraging in the sense that even if the Gizmag editors may be clueless, at least some of the readers are not.

A key paragraph was the one beginning with "One might wonder who....")

I gratefully accept the implied title of "Honorary Moron" from a few posts above. After all, it was just a kid who pointed out that the emperor is naked.

Anyone thought of the old Variable pitch dynaflow?

Try '55 Buick.....

In case you haven't seen it yet,

http://www.gizmag.com/d-drive-redux/15120/?utm_source=Gizmag+Subscribers&utm_campaign=906814a135-UA-2235360-4&utm_medium=email

Gizmag essentially retracted the article.