Gearbox Design: Increasing Torque and Speed?

[cosmarchy]

I suspect I already know the answer to this question but I want to ask in case anyone has any ideas on how to improve things.

What I am looking for is a gearbox design that will increase both torque and speed at its output. I don't think this is possible as I believe one is traded off against the other but as I said I could be wrong.

Is this possible? Are there any ways around this?

Thanks

 

[c0re]

You're correct, it can't be done because of this formula (well not because of the formula, but the formula results from the physical reality that prevents it):

Power = ( rpm x torque ) / constant

The constant will change depending on what units you select for power and torque.

So yes, that's the tradeoff you mentioned... The only thing that might come close depending on your application is possibly a continually variable transmission (CVT)? That would allow you to run your motor at a fixed RPM while changing the output speed. As it has an effectively infinite number of gear ratios you can tune your setup for either, say, peak efficiency for peak power output, etc.

Absolutely not going to fit all applications, however.

 

[cosmarchy]

Ok thanks for confirming this :) that's what I thought.

I'll have a look at the CVT and see how this works and whether it'll fit in some where.

Thanks

 

[Lsos]

Right...you trade off rpm for speed. One or the other, but not both.

No way around it without violating a very fundamental property of our universe.