Emerging transportation technologies

[MountainManJoe]

You can see here where the couplings have actually been used:
http://www.thompsoncouplings.com/site/p ... rofile.php

Apparently they have a development contract with Boeing.

[Kabey's Van]

I don't doubt that, it a pretty cool idea. Check out this US pat. application from 1976, apparently it's an idea thats been around a while.
http://www.freepatentsonline.com/3965700.pdf

Peter

[blacknome]

There are 2 things on the automotive front that have been evolving and have me going.
Albeit maybe not 100% percent on-topic it's relevant

The CVT trans have always fascinated me. Over the years they are making them stronger to accept more power. The rental I have been driving has one ( 2010 Altima ) and it's pretty cool to see the theory used in snowmobiles, drill presses, and lawn tractors for years applied to something much stronger.

http://auto.howstuffworks.com/cvt.htm

The second is that I seen them review the Honda FCX on Top Gear USA and I must admit I was impressed ( or at least the kid who did his grade 7 science Fair Project on hydrogen powered vehicle was ). In case you haven't seen one it's a Hydrogen / Electric hybrid and something I would actually consider as a commuter car if it wasn't so expensive. Some day ( the grade 7 kid in me anyways ) would like to see a Hydrogen / Electric vehicle where you fill the tank with water and it will produce hydrogen on-site and have solar recharge the batteries. Something larger like a Sprinter would be great for this.

http://automobiles.honda.com/fcx-clarity/

a little background on the use of solar power to create hydrogen for anyone interested.
http://www.nmsea.org/Curriculum/7_12/el ... olysis.htm

[MountainManJoe]

It's totally relevant!

I would love to try a CVT just to see what it feels like. What type did the Altima have?

[Cobra]

CVT + Hydrogen hybrid = Win in my books

[Kabey's Van]

A CVT is very cool and they do make them for larger vehicles.
Case 450 and 850 bulldozers use CVT's.
It's a perfect application as you can set your throttle high for full torque and vary the speed of the machine with the speed controller for the tranny, because of the rpms being so high the blade is more responsive at slower speeds as well.
On other dozers without a CVT you have to disengage the drive clutchs to articulate the hydraulic attachments at high rpm, you also have to disengage the drive clutches when shifting gears or when changing direction, and blade movement at slow speeds is in direct relation to engine revs, the slower the revs the less responsive your blade is.

Hydrogen takes more energy to make than you get out of it. It takes massive amounts of electricity to make hydrogen on the scale that would be needed.
Electric vehicles are the way of the future, hydrogen vehicles are to expensive to fuel.

Peter

[blacknome]

It's totally relevant!

I would love to try a CVT just to see what it feels like. What type did the Altima have?

dunno, I noticed that it shifted kind of weird the first couple of days I drove it then seen the CVT badge on the trunklid when I was gassing up D'oh !.

When driving and you are hard on the throttle it's like you have a bad clutch plate ( more revs and noise than actual forward movement ) but after a small lag it grabs and pulls hard. If you suddenly back off the throttle it holds that engine speed ( like a standard trans left in gear while decelerating ).

However if you can keep your foot out of it the engine only revs from 800-1200 rpms with no apparent gear changes and I would suppose you would obtain excellent fuel mileage. Really, cruising at 40 kph turns about the same revs as cruising at 140 kph. Strange feeling expecting a gear shift to come but they never really do LOL. Another thing is that the trans has a tap-shift function as well where pick, shift or hold a gear to accelerate or decelerate, my brain hurts to think about the calculations that need to be made for that to work with CVT.

I wonder what a retro-fit application would be like for the Van or something like my 84 Monte as they are both absolute pigs on fuel in the city. Something like a cvt would drastically bring my economy up from the 12 or so MPG I get driving in the city.

[doyoulikeithere]

The guy is a bit vague on where he plans to use the u-joint on a helicopter, but he does leave you with the impression that the helicopter is going to hang from one of these u-joints, meaning the main shaft. There is no u-joint in the main shaft of a helicopter. It's a solid shaft straight through from the transmission to the rotor head.
Most automotive u-joint applications are good to 5-6000 ft./lbs. of torque (approx. 8000Nm) maximum, heavy trucks have u-joints capable of handling 20,000 ft./lbs. of torque or more.
These guys have a way's to go yet.

If he is using it on a helicopter it must either be the engine to Main Gearbox driveshaft couplings, or the tail rotor driveshaft couplings to intermediate or tail rotor gearboxes.
They take a lot of abuse and are always on the list of airworthiness parts.

[MountainManJoe]

I would have thought there would be no feeling of shifting at all, and that it would be smooth acceleration from 0 to top speed. The revs are supposed to feel higher than normal, because the CVT tries to keep the engine revolutions where it produces the most torque.

I read somewhere that some car makers will will program the CVT to "tug" artificially, because some people weren't comfortable with a car that didn't feel like their old automatic. This to me is dumb. I'd rather have a smoother, more fuel efficient car.

[doyoulikeithere]

Ok, Now I've seen it.
He said he wants to be able to build a helicopter with a fully tilt-able rotor head.
That makes sense since you would need an articulating main rotor shaft to do that.
It would be super beneficial to helicopters as the controls would be simplified a lot and more efficient.
The rotor head could tilt, so the simplified swash-plate would need only 1 link for collective blade pitch.
Cyclic would be controlled somehow by angling the articulating main rotor shaft. Very Nice!

[MountainManJoe]

Clearly you need to know something about helicopters to know what he's talking about, and it's not just crazy talk. Being does make helicopters, like the Chinook.

[doyoulikeithere]

Being does make helicopters, like the Chinook.

timeless BEING, You make Chinooks? where at?
I spend all day every workin day studying Aircraft Maintenance Manuals AD's and IPCs, but havent done the chinook yet, almost everything else though.

[MountainManJoe]

I make them at my timelessboeing factory of course.

[doyoulikeithere]

Oh, I sea ... Lol. Du-Ohh!

[Kabey's Van]

To understand how the controls work one needs to understand how a helicopter flies. I will try to keep it as simple as I can as there are many other factors involved, but you will get the idea.
A helicopters blades change pitch constantly, depending on where they are in relation to the fuselage and what you are asking the machine to do.
The rotor blades pitch horns are attached to the swash plate. The swash plate is controlled by the collective and cyclic controls via the pilot.
There is only one control arm for the collective, it moves the entire swash plate up and down on a plane that is determind by the cyclic's input. The collective is a stick not unlike a hand brake in appearance, it usually has a twist grip throttle and you are able to pull up on it to increase pitch and lift.
The cyclic is the stick you fly the machine with. There are three or more cyclic control arms attached to the swash plate and the pilots controls. The cyclic control arms determine flight direction by altering blade pitch via the swash plate in a cyclic fashion.
The cyclic will alter the rotor discs attitude by changing the rotors pitch cyclically to create flight.
If you want the machine to fly forward the blades will mimic what the swash plate is doing by increasing pitch while over the rear of the fuselage and flattening out the pitch toward the front of the fuselage. This in turn tilts the entire machine and rotor disc and creates forward flight.
While all of this is going on, the pilot is constantly altering the tail rotors pitch to conteract the torque produced by the main rotors rotation and pitch variances.
We all know that to change the plane of a spinning disc takes energy. Anyone who's held a spinning wheel in science class knows how hard it is to alter a spinning wheels plane.
If you had main shaft that articulates you would never be able to alter the plane of the rotor disc in order to create forward flight. There is nothing to hold the fuselage still in order to alter the rotor disc's plane.
Physics will not allow for an articulated rotor head to work, let alone the dangers.
As far as using these couplers in the tail rotor drive assembly they are big, heavy and weak, not to mention that they will prematurally fail when used in a 2 degree or less deflection.
I'm surprized they don't teach a bit of theory in your Aircraft Maintenance Course. You would think that would be very helpful in your chosen career.

Peter the pilot