NASA's 57 mile range EV...and "Harmonic Drives"

[Shannow]

Watched Apollo 18 last night, and ended up looking up the lunar vehicles, and what they could do with 1960s technology.

Here's Wiki...
https://en.wikipedia.org/wiki/Lunar_Roving_Vehicle

Pretty neat, but I'd never heard of a harmonic drive gearbox before...
https://en.wikipedia.org/wiki/Harmonic_drive

Input (green) expands the internal gear ring to mesh with the ring gear...advancing (well retarding) the blue ring gear...zero backlash.

 

[123Saab]

So the red is output and the blue is stationary? Interesting.

 

[Shannow]

Yeah, it "walks" backwards

 

[Shannow]

http://www.harmonicdrive.net/technology

 

[123Saab]

What is the "red output" made of you think? And would this be dry or wet?

I'm guessing the red could be made of a Timing belt type of material and would be dry?

EDIT: Never mind, read your link...

 

[JLTD]

Cool stuff.

 

[123Saab]

Also via Shannows link:

 

[andyd]

A glorified centrifugal clutch. Less friction. Would the 1/6 G help efficiency? The stiff,yet flexible, thingy, How many flex cycles before it splits? And the larger question, why isn't the moon being utilized to reach Mars?

 

[KrisZ]

Very cool and looks like a very precise way to control rotation.

 

[Schmoe]

I was going to say to that it sure resembles a centrifugal clutch. That flex spine...wonder how long that would hold up before failing??