Ultimate Flexible Drive Shaft

[crazyryan]

id like to design a flying contraption in a y pattern tricopter using flexible shafts that can rotate the pitch controlled props.

[swb31763]

Any idea when it will be available?



[low6road]

The hoses limit the pressure. Could be 3,000 psi, or a lot more.

Torque at this size around 40 pound-feet.

Efficiency depends on a lot of factors, like operating speed, hose diameters etc, but it should be OK because there are no fluid losses.

There have been attempts to change speed/torque, but those mechanisms use cams, so it's difficult to make them compact and efficient. It's probably simpler to use a gears outside the motor.

Reversal only needs a simple crossover valve.

[meandmyevo]

what kind of pressure will those...hydraulic potentiometers(?) tolerate safely?

what kind of torque does that translate to?

what kind of efficiency can it offer?

would you be able to build it with a reduction system for torque/speed amplification?

can it be easily plumbed differently(like with just one valve) to offer counter-rotating and regular rotating heads?

[J1I9M7M4Y]

Wow, thats awsome! How much torque can it handle? There must be a lot of applications where that kind of drive shaft is usable!

[mibars]

What's the efficensy?

[ericsbraun]

Is this really a new invention?

It looks like two hydraulic motors--the type that can also be used as a pump-- with fittings, in a configuration that is effective to produce this result.

Is there something REALLY novel to the design? Or, is it just a really nice, elegant design utilizing existing technology?

[low6road]

@ericsbraun

Yes. Quite new. The end units are not hydraulic pump/motors. Hydraulic pump/motors have valves to direct the flow of fluid. There are no valves in the end units.

Each end unit has three cylinders and pistons, and a mechanism to translate the piston motion into rotary shaft motion. That's all there is to it.

[MrBrey1]

how can you get those (hydraulic pumps is basically all the are) to i guess you could say "grab" so good?

[low6road]

@MrBrey1 They are not hydraulic pumps. There are no valves, so there is no fluid leakage.

[wreschly]

Are two of the hoses for input/output and the third a bypass?

[low6road]

@wreschly No. All three are input/output.

[hyydrasteeeth]

This would be a cool substitue for a steering linkage.

[2005motley]

@hyydrasteeeth That would be great for right hand or cend drive conversion

[low6road]

@hyydrasteeeth Yes. could be used for that.

[natep246]

Seems pretty legit.. but I dought they'll withstand much torque.

[low6road]

@natep246  Don't worry. They'll withstand a lot of torque. That's what it was designed for.

[natep246]

@low6road Possibly, but still seems limited to how much torque... are you telling me it will withstand about 300-750ft lbs. of torque from factory vehicles now adays, like a solid driveline will?

[low6road]

@natep246 The one in the video would not support that much torque, but it can be scaled up to support any torque you like. The torque capacity increases with the cube of the dimensions, so if you make one twice that size, the torque increases eight times. There are no valves in the system, so the torque is only limited by the pressure capacity of the hydraulics.

[natep246]

@low6road Then why don't vehicles came factory with these type of drivelines? nor are there any companies that produce these type of drivelines for vehicles, if there so great why arent they in production?

[low6road]

@natep246 Because that's what new inventions are all about. All systems have some advantages and some disadvantages. The main advantage of this one is that it's a lot more flexible than traditional drivelines. If you don't need that amount of flexibility, a conventional driveline might be a better way to go. BTW - a company is developing this, so you might see it as a product fairly soon.

[natep246]

@low6road Its not that new if the video you posted was over a year ago, might be okay but its not going to revolutionize the way standard drivelines are.. there's no vehicles that are going to use them, except maybe rockcrawlers and prerunners, and even then there flexible driveshafts with u-joints bend partly through them are just as good and probably still stronger than the one your showing. but I'd really like to know what company your talking about is developing these? I've never heard of it

[low6road]

@natep246 I don't understand how can you be so sure of that when you really don't know how it works. Sorry, but I can't tell you who the company is. They are responsible for their own PR. Do you work for a driveline company?

[low6road]

@natep246 BTW, did you happen to notice that, in the video, the two ends are turning in opposite directions? Bet you don't know of another driveshaft that can do that! Oh, and do you know of any that have a built in clutch?

[canuckscottsmen]

i have never thought of hydraulics like that, i can see that working really great in odd areas

[55seddel]

Do you make these custom? I need a small one to convert a drill press into a flex shaft.

[elbrutto]

are you usin pair of gears like a hidaulic pump?

I`m planning some kind of hidraulic transmision for a garden tractor. Here in Argentina theese kind of tractors are not what you would call "Cheap", imagine what all hte accesories might cost. So, I`m pushing my mind as far as it can go, to create averything from scratch.

Again, congratulations.

[elbrutto]

good Idea, are thode hydraulic drives a design of yours?

[low6road]

Thanks! Yes. It's something I cooked up.

[sundrain]

nice job dad.

ill take a pair on my mazda!