very cool infinite drive

[HBWC]

i think this has huge capability
YouTube- The D-Drive Infinitely Variable Geared Transmission

[adonuff]

Hi that looks great, I think the inventor is onto something good, imagine a variable speed gearbox with very low to overdrive simple design with far fewer things to break, email it to Land Rover?:)

Andrew

[Blknight.aus]

no so simple....

listen carefully at 4:33
the next potential problem comes in at 4:46

but while its not the answer as it is what it is is the first small step.

what it leads to will be outstanding.

[stuee]

no so simple....

listen carefully at 4:33
the next potential problem comes in at 4:46

but while its not the answer as it is what it is is the first small step.

what it leads to will be outstanding.

Expand please?

Non powered = full speed output and powered = neutral? What do you see as the potential issues that couldn't easily be overcome?

The main issues I see with the design is if the D-Drive motor fails while in neutral which would mean full speed output. The sudden increase in torque would most likely stall the primary engine, if not a simple safety system could quite easily stop the the engine before any movement is achieved.

Or have I missed your points?

The only challenging issue I see is the possible size of the unit once suitable gears are selected that can transmit decent amounts of torque.

[HBWC]

well theirs always going to be teething issues gut i can see this evolving and able to use more fuel efficient motors

[Blknight.aus]

to maintain nuetral you must put power into 2 seperate inputs and you must balance them Ok not a big problem with electronic control but any excess drag or lag produces drive. the next point is how much torque do you need at the secondary input to make the gearbox maintain nuetral. a failure on either input causes drive.

Hes taking advantage of the laws of compound planetaries where (very basically) the output follows the direction of the drive gear with the superior speed at half the mean difference. its a technically very clever solution with the major problem of a minor failure in one of a couple of areas will produce very unwanted results.

What hes managed to do is pretty much this...

YouTube- Double Differential Steering

but instead of having a Left and Right output hes netted back one ouput in such a way as it doesnt change the remaining outputs speed. This ties into my next point.

torque reaction

to actually achieve drove there will be parasitic load on the shafts as a minimum and I'll bet the small drive motor thats turning the "direction control" shaft will wind up dealing with a fair whack of power. Whats potentially going to kill it at this point is providing enough power to overcome the torque reaction, to come up with a single power feed to drive both shafts may cost more power than you loose through not being able to maintain optimum power settings on the power source. Remember that even if the direction control shaft is powered by hydraulics or electrics the power still has to come from somewhere.

In the setup in the vid that Ive posted the torque required to change speed is balanced out one side versus the other. IF your not trying to turn then theres no power requirement on the speed differential shaft. In the setup hes running there is. What you may not have picked up on is all the electric motors hes got driving things have gearboxes on them these have a high torque resistance and while hes got no load on the output its enough to hold everything just where he wants it.

BUT...

Its still very very clever.

lets put it this way...

Its at the beginning of its tech tree. by comparison its like looking at one of Rudolph diesels first engines and saying "this will one day power a car at over 180KPH". the basic concept of suck squeeze bang blow and compression ignition are there but it needs some help from other fields to reach its true potential.

[stuee]

Awesome.

I love learning about this stuff.

So really he is failing to expand on the following:

to actually achieve drive there will be parasitic load on the shafts as a minimum and I'll bet the small drive motor thats turning the "direction control" shaft will wind up dealing with a fair whack of power

I've only ever covered gear theory briefly in machine dynamics at uni. I'd like to know more about planetary gear arrangements and the loads involved but not enough to dig out my old notes on the issue :p

Cheers Blknight.aus :thumbsup:

[Milkman Dan]

Planetary gears, just look into any auto-gearbox, it rare for the gears to give problems, clutches go first, old oil, etc.

[Hardchina]

see this thread.. http://www.aulro.com/afvb/technical-chatter/102631-new-type-gearbox.html

he has some patent issues..

[vnx205]

An acquaintance of mine is way ahead of this bloke with a similar idea. Rather than just a plastic toy version to prove the concept, he has built a version which he fitted to a Holden ute to test it. He is working on producing something for big trucks, so his prototype weighs half a tonne.

It is a couple of years since he showed me the drawings and explained it to me, but my recollection is that he uses hydraulic pumps and motors to control the relative speeds of the planetary gears.

I believe he knows what he is doing. He devised a way of setting up a lathe to produce submarine propellors. His system could be set up in just a few hours rather than the sixty hours it used to take. He has a gold medal from some Swiss society for inventions. I think it was for the lathe setup.

So this bloke with his D-Drive is not the only one working on a transmission that uses this principle.