Emerging transportation technologies

[MountainManJoe]

Lets start a thread about advances in technology that you find interesting. Keep it on the topic of transportation though.

I'll start off...


Thompson coupling. The makers claim that it renders CV and U joints obsolete.

http://www.youtube.com/watch?v=coXB3xd6VK8

[chartman]

Your link is for an engine.

This one looks more like it. Very cool invention.
http://www.youtube.com/watch?v=xgQgm3GwaFs

[MountainManJoe]

Thanks for catching that, chartman. I meant to post the video that you have just provided. (looks like few people are interested in this topic.)

I must have mixed up my links, but the one I ended up posting is very impressive too and I think it can be considered emerging as well. (I also posted it in the "Other cool vehicles" topic). It's a Wankel (rotary) engine with 4 rotors and a turbocharger. It produces 1664 horsepower and 1158 ft-lbs of torque. The exhaust gets so hot, the air around it bursts into flame.

[Cobra]

oh... that coupling is way more interesting then the engine i'm going to have to look into it more

[MountainManJoe]

The Thompson coupling is basically a double cardan rolled into one joint, with a pantograph linkage to keep it in phase.

[Cobra]

i noticed the one in the video was rather large i wonder how small they are currently able to make it

[MountainManJoe]

I'm not sure, but they used the one in the video to support and palette full of concrete mix, so maybe it can be smaller for automotive use.

[Kabey's Van]

Torque is what I was wondering about.
The size of joint they show is about the size of an automotive u-joint but it looks a little week.
I wonder how that particular joint would hold up against 5-600 ft/lbs. of torque.
Also, I'm not to sure why this would be so beneficial to helicopters as they use swash plates to control the blades for directional flight and no tail rotor machines are the way to go as it eliminates the tail shaft, and therefore no u-joints.
I can see where this would be beneficial with some light weight applications but not in anything where it would have to deal with high torque.

[MountainManJoe]

iI wonder how small they are currently able to make it

Torque is what I was wondering about.

It's right on their website and they're quite strong.

This is their smallest version next to a pen for comparison.

Nominal torque rating of 500Nm (370 ft-lbs). Peak torque rating of 1,200 Nm (885 ft-lbs)

They also have 2,000Nm and 8,000Nm rated ones.

Also, I'm not to sure why this would be so beneficial to helicopters.

This video mentions the helicopters
http://www.youtube.com/watch?v=2qmpiblP9oA

[Kabey's Van]

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.

[MountainManJoe]

Our engines only produce 339 Nm.

[Kabey's Van]

Your engine may produce 247ft./lbs. of torque, but that seems a bit high.
Anyway, after it's gone through the transmissions first gear of 3.06 to 1, that torque figure measured at your transmission's tail shaft is now 755 ft./lbs. of torque.
Spin your wheels in the dirt and then hit some dry pavement and that torque figure can double or triple momentarally to the point where your engine may even stall due to the high loads of anti-torque applied to the driveline via the rear wheels.
I know I would want a bit of safty margine of say two or three times the breaking point, so with a maximum anti-torque of 1500-2250 ft./lbs. possible on the drive line that u-joint of 370 ft./lbs. is looking a little weak and dangerous.
So, like I said, "They have a way's to go yet".

[chevymaher]

Not seeing a problem.For its size it stonger than same size conventional joints.Make it bigger.The mere fact it does not bind means it dont have to be as strong to hold the same load.They getting it worked out nothing happened overnite.

[MountainManJoe]

Hm, good point. I think the niche for this coupling is where efficient energy transfer, and longevity are most critical. It seems to be used more in precision machinery than heavy duty applications.

[Kabey's Van]

This is the biggest one they make.
http://www.thompsoncouplings.com/8C_das ... ing/pd.php
The torque specs would work on a driveshaft but not the maximum rpms.
They don't mention that it is 39 cm. long and weighs 80 kgs. It also does not work well with less than a 2 degree deflection.