Outer Limits 4x4 Board

http://www.youtube.com/watch?v=F6zE__J0 ... r_embedded


Looks pretty cool IMO.
Discuss.






Mods, feel free to move if this turns into a shitfight or is not tech enough. Cheers.

very cool. ud want strong gears though or something stopping u from accidentaly putting it in reverse haha

v840 wrote:http://www.youtube.com/watch?v=F6zE__J0 ... eddedLooks pretty cool IMO.
Discuss.

thanks I had a head ache before I watched this now I need to lie down

That is cool and simple but most transmissions nowadays have an over drive as well. To provide an overdrive they will need another planetary drive at the back (or front) just for the overdrive factor. Very simple when you think about and he is a plumber not an engineer or a mechanic.

It was also be interesting on how they plan to power the second shaft, whether from the engine or say electric motor.

Now hooked into a transfer you could also have a pto of the side of the transmission that could also be adjustable in speed if run from one the shafts.

Very cool I think.

I saw that on the New Inventors, and couldn't quite figure out how it varied the speed of the two shafts - this video does a better job of explaining it.

I'm a little dubious about how it will transmit power. Demonstrating it like that, with no load on the output shaft, it's easy for the sun & planet gears to operate as he requires.

Once the system tries to drive a load, I believe it will be a competition between the load resisting being driven, and the strength of the drive system that is varying the speed of the second shaft.

I can't get my head around the gearing issues, but I suspect that significant torque will be required to drive the second shaft at the correct speed to achieve the desired output torque and speed combination. Without enough torque on the second shaft the load may "back drive" the second shaft, and achieve undesirable results. This could be overcome by the use of a worm drive, but they are notoriously inefficient.

Or not. It would be cool if it works.

simkell wrote:That is cool and simple but most transmissions nowadays have an over drive as well. To provide an overdrive they will need another planetary drive at the back (or front) just for the overdrive factor.

In an automotive sense, yes - or they could simply run taller final drive, and underdrive the trans most of the time.

Very clever idea.
Curious how the second motor will go. Could the main engine over drive it. Would you have to up the size of the second motor if you upgraded main motor.
Will be intresting to see how the idea evolves

Very clever system. But looking at the way the gearbox operates, I wonder if it would have vibration issues due to the off centre rotating shafts, but I'm sure this possibility could be refined in the final design with counter weights.

If it works it will be great for the car industry and would be a massive seller if it could suit the high torque loads of a heavy vehicle application.

Clutches would become obsolete, you wouldn't have issues with drivetrain damage caused by harsh gearchanging, in heavy vehicle applications especially as driver error (eg: monkey behind wheel) is a major factor for drivetrain failures

It would be tricky to start a piston motor in "neutral". The electric (or other) "counter motor" would have to match the stuttering start of a normal engine to allow a stationary output shaft. I feel it would still need some sort of disconnect mechanism to start the piston engine.

thats very cool i can see alot of very efficient motors being used ie some of the commercial stationary motors with no rev range

DAMKIA wrote:It would be tricky to start a piston motor in "neutral". The electric (or other) "counter motor" would have to match the stuttering start of a normal engine to allow a stationary output shaft. I feel it would still need some sort of disconnect mechanism to start the piston engine.

Output is zero when both intermediate shafts are turning at the same speed - so simply connect them with a 1:1 drive, and you're in neutral, irrespective of engine speed.

i like what i am seein' that is pimp!

thats unbelievably awesome!!!

-Scott- wrote:I can't get my head around the gearing issues, but I suspect that significant torque will be required to drive the second shaft at the correct speed to achieve the desired output torque and speed combination. Without enough torque on the second shaft the load may "back drive" the second shaft, and achieve undesirable results. This could be overcome by the use of a worm drive, but they are notoriously inefficient.

They seemed to imply in that vid that this wasn't really the case - that only a small amount of power was required for the "second shaft". But obviously they are operating it without a load in their model. It does seem like this would be the key issue, does the second shaft experience the same kind of torque loads as the main shaft. If so it seems a bit screwed. But then that is so obvious that you'd like to think they'd have thought it through.

i like....very interesting.

interesting....BUT

It needs multiple motors to control it and exactly how much torque the controlling motors require to make it all happen is the question....you want a car with 3 engines??

To give a really simple idea of what is basically happening: get a car differential with a typical open centre, put a drive engine on one axle and an electric motor on the other axle, and the otherwise input shaft is now the output. If you run the engine clockwise and the electric motor clockwise you get zero output. If you stop the electric drive you get half the engines speed to the output shaft......you should get the drift

Ive seen much simpler transmissions than this called an orbital transmission. This has the main engine driving a sun gear in a planetary gear set, the output shaft is the planetary gears and the annulus also has a worm gear on the outside and an electric motor is driving the worm gear....now go figure, the output is controlled by whatever the electric motor does - you can go backwards, forwards, neutral and overdrive with minimal torque from an electric motor. You actually use the electric motor to start the engine .....just keep the hand brake on.

bigbear wrote:interesting....BUT

It needs multiple motors to control it and exactly how much torque the controlling motors require to make it all happen is the question....you want a car with 3 engines??

To give a really simple idea of what is basically happening: get a car differential with a typical open centre, put a drive engine on one axle and an electric motor on the other axle, and the otherwise input shaft is now the output. If you run the engine clockwise and the electric motor clockwise you get zero output. If you stop the electric drive you get half the engines speed to the output shaft......you should get the drift

Ive seen much simpler transmissions than this called an orbital transmission. This has the main engine driving a sun gear in a planetary gear set, the output shaft is the planetary gears and the annulus also has a worm gear on the outside and an electric motor is driving the worm gear....now go figure, the output is controlled by whatever the electric motor does - you can go backwards, forwards, neutral and overdrive with minimal torque from an electric motor. You actually use the electric motor to start the engine .....just keep the hand brake on.

Isn't it only two motors, one for the D-Drive and one representing the primary engine? Dont know where you get three from?

This is nothing more than stacked planetaries. It's not a CVT, but it actually requires a real CVT to drive the variable input shaft.

Toyota's Prius gearbox works the same, but they use a large electric motor on the other shaft.

No revolutionary here, time to move on.

stuee wrote:

bigbear wrote:interesting....BUT

It needs multiple motors to control it and exactly how much torque the controlling motors require to make it all happen is the question....you want a car with 3 engines??

To give a really simple idea of what is basically happening: get a car differential with a typical open centre, put a drive engine on one axle and an electric motor on the other axle, and the otherwise input shaft is now the output. If you run the engine clockwise and the electric motor clockwise you get zero output. If you stop the electric drive you get half the engines speed to the output shaft......you should get the drift

Ive seen much simpler transmissions than this called an orbital transmission. This has the main engine driving a sun gear in a planetary gear set, the output shaft is the planetary gears and the annulus also has a worm gear on the outside and an electric motor is driving the worm gear....now go figure, the output is controlled by whatever the electric motor does - you can go backwards, forwards, neutral and overdrive with minimal torque from an electric motor. You actually use the electric motor to start the engine .....just keep the hand brake on.

Isn't it only two motors, one for the D-Drive and one representing the primary engine? Dont know where you get three from?

Yeh it uses three motors: the main drive you see clearly and the 2 shafts each with a bevel gear set both have an electric motor/stepper motor on them. They are needed to control whether its a forward/reverse/neutral of the output.

Cheers

if this was in a car i would think you would have a hand throttle then your accelerator pedal would control the gearbox eg. set your revs to, say 2100rpm with, for arguments sake a td42 for on the highway and with your foot off the pedal it would sit in neutral and as you put your foot down the gear ratio get taller and you go faster.

it would take a bit of getting used to, especially having to back off the pedal when you come to a hill.

thinking more about it as i'm typing, it would never go that way because if your foot slipped off the pedal doing 100km/h the gearbox would shorten up the ratio quickly forcing the engine to over rev until it hit neutral.

so i've just faulted my idea before you guys could, but i'll still post it up anyway to get more mechanical minds ticking.....

It has too many large out of balanced parts with sudden movements to really be any good, even if you scaled it up and put balance weights in, its still a very complicated machine for little benefit, considering a 9speed dual clutch transmission will still be less complicated and cheaper to make and live with, let alone training a whole new generation of mechanics about another over complicated device for a car. We might see this in specialty vehicles and machines.

Sorry to put a downer on it

A CVT transmission have been around for a long time, I work with them in my job. Most defferently the way of the future and are currently making there way into cars already.
And there is many different designs of a CVT transmission, weather its belt driven, hydro-mechanical, mechanically gear driven, torodial so for someone to make a different style CVT was always going to happen.

macarthur 4x4 wrote:<snip>
so for someone to make a different style CVT was always going to happen.

But he hasn't. There is no CVT action in that gearbox, all speed variation is provided by the electric motor.

All of the known CVT methods have been known for a very long time. Most of the ones not in common use feature high contact stress and haven't been viable until metallurgy caught up with the requirements.

gu town wrote:if this was in a car i would think you would have a hand throttle then your accelerator pedal would control the gearbox eg. set your revs to, say 2100rpm with, for arguments sake a td42 for on the highway and with your foot off the pedal it would sit in neutral and as you put your foot down the gear ratio get taller and you go faster.

it would take a bit of getting used to, especially having to back off the pedal when you come to a hill.

thinking more about it as i'm typing, it would never go that way because if your foot slipped off the pedal doing 100km/h the gearbox would shorten up the ratio quickly forcing the engine to over rev until it hit neutral.

so i've just faulted my idea before you guys could, but i'll still post it up anyway to get more mechanical minds ticking.....

So what if the engine run with a governer OR the vehicles speed actuated the ratio OR both???? This could work IMO. You would still however need to manually select neutral and reverse though.

John Deere have been doing it in their tractors for years.

bubs wrote:John Deere have been doing it in their tractors for years.

So has Case New Holland as that is were i deal with them on a day to day basis. Thus saying previously this is the way of the future, quiet reliable and would be orsome off road

It's a Prius (Hybrid Synergy Drive)

Wonder how long till Toyota reinforces their patent?

I love the Prius gearbox - marvellous idea.

a bit of extra info

http://www.gizmag.com/d-drive-redux/15120/

me3@neuralfibre.com wrote:It's a Prius (Hybrid Synergy Drive)

Wonder how long till Toyota reinforces their patent?

I love the Prius gearbox - marvellous idea.

Looks to me like your close to the mark there. As far as results go its just a HSD with no electric drive/regenerative braking funtions/EDIT: and generation at cruise (MG2) and with MG1 relegated to ratio control (where it used to also do power generation and engine starting).

I wonder how hard Toyota will come down on him. Or just buy him out so that they can use any novel concepts in his design.

me3@neuralfibre.com wrote:
Wonder how long till Toyota reinforces their patent?

I love the Prius gearbox - marvellous idea.

Would they care? car makers copy each other all the time.

Plus this bloke has only build a proof of concept model. It's not as if he's mass producting direct replacement gearboxes for toyota's and other makes.

Toyota might be concerned about who's taking credit, but if this bloke plans on waiting for a big manufacutrer to come along and buy his design, well he might be waiting a while.

The other think i'm not convinced of is if this design is merely a copy of a prius box, and is capable of handling huge torque, why has toyota, or another manufacturer not yet implemented it in their own designs?