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When humans or animals walk, the legs work like spokes of a wheel. Highly articulated spokes, but spokes nonetheless. So, I imagine a wheel comprising 2 spokes placed side-by-side. Each spoke ends in a short piece of tye, it rotates through an arc while in contact with the ground then retracts and swings
forward. As it does so, the other spoke goes through its arc phase.
This design might make the wheel and the vehicle smaller than today's foldable bikes. The wheel might be lighter too, as it uses less material. But the mechanisms to drive the spokes may reduce this benefit.
In trying to design this wheel, I (not being a mechanical engineer) consulted a handbook of mechanical mechanisms. I found some linkage-type mechanisms, but either the working end's path is not quite a circular arc, or the arc's angular speed is not constant. So, I'd be grateful if you'd help with some ideas. For example, have you seen such mechanisms elsewhere? Or is there a CAD software that'd be useful?
like this? [xenzag, Dec 12 2008]
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||With only two legs, the motion is not even, so tough to replicate. To explain, if you take the bake as the frame of reference, the leg in contact with the ground moves backwards in a straight line. Before it lifts, the second leg must already be in contact with the ground. When the first leg leaves the ground it must move up, forward and down in the time that the other leg just moves back. The speed difference will require a complex motion and create vibration issues.
||Also this idea is as old as time and the only reason it isn't baked is no one can solve the basic mechanics involved.
||The main problem with this is that legs reciprocate, and you
waste a lot of effort accelerating and decelerating each leg.
||Reminds me of the deliverator's skateboard wheels in Neil Stephenson's "Snowcrash".
||many of the designs for extra-terrestrial vehicles are like this... baked.... I have one myself (currently on the back-burner) using spiral wires... but I haven't found a use for a wheel that actually gets bigger the faster you go... yet.