Regenerative shock absorber

[RedDevil]

If rigids were as good as tubes, why would they have invented those then?
See John Boyd Dunlop - Wikipedia, the free encyclopedia for an answer.
In a race tubes beat rigids hands down.

When a tire meets a little bump, just a tiny part of the thread will flex in while the rest of the tire, the rim and suspension hardly move. With rigids the tire, rim and suspension all will have to cope with the bump, moving 100 times as much mass.
If the suspension system does not return at least 99% of the energy the wheel puts in, the rigid will not have a chance.

[Galane]

The biggest problem with stiffer tires is reduction in the size of the contact patch, the distorted flat area in contact with the road.

A perfectly rigid tire would have next to zero contact patch and very little traction in all directions.

Something I've thought about is using the concept of those "faraday flashlights" to capture some energy from vibrations that make it past the suspension damping. In the really good ones of those lights, the magnet will levitate within the coil, held there by the counter EMF generated by its presence within the coil. Add a plastic spring under the magnet with just enough force to keep the magnet fully inside the coil when the vehicle is at rest, then the magnet will oscillate up and down from vibration when the vehicle is in motion.

The coils, magnets and electronics would need to be adjusted to produce a useful voltage. Gang a bunch together in a box and you have a "Jiggle Jenerator" (TM) ;-) How many Jigglewatts to keep a 12 volt car battery charged?

[88hf]

The Acura ZDX has Magneto-Rheological fluid-filled dampers as well.

[NeilBlanchard]

Here's the Energy Return Wheel - watch the "50% Better Coast" video.

Demo Video Player

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

http://ecomodder.com/forum/showthrea...res-19321.html

So, maybe the ERW is already maximized for low rolling resistance, and it just needs to be aerodynamically smoothed?

[Blue Angel]

I don't want to derail this thread, but that tire concept and its associated website and media seems very heavy on marketing and very light on facts... there's a lot of fancy graphics and interesting looking dyno time, but not much in the way of results to prove their theory. They are also looking for your donations to "Fight Big Oil".

50% coast down improvement video is completely fact-less, other than a timer. I also notice the outside diameter of the tires is far greater than their prototype wheels.

It would be nice if it were real. If everything is patented I'm not sure why they wouldn't share more on their tech, especially if they're looking for investors.

Anyway, back on topic...

[NeilBlanchard]

Some news on regenerative shock absorbers:

Green Car Congress: ZF and start-up Levant Power partnering on first fully active, regenerative suspension for automobiles

These are a variation on what Levant Power has shown us in the past - the electric generator is attached to the top of the shock absorber:



Instead of just generate heat when your car travels over bumps in the road - you can get some energy "back" from that. A good thing, in my opinion.

[night9]

Really cool! I hope they get stuff like this to work with existing tech. I like the thought or the possibility that it could be set up as a aftermarket add on for just about any application to counter electrical consumption or possible boost an ev's range.

[Daox]

Looks really cool. Also looks really expensive...

[Galane]

Extra complexity with more moving parts. Would be far simpler to have a coil inside with a strong magnet on the piston rod, just like those "Faraday Flashlights". Add a big enough bridge rectifier and a smoothing capacitor and bumpy roads get you back a bit of juice.

The best ones of those flashlights will levitate the magnet partway in the coil. Something to do with the way their circuitry is done so the counter-EMF generated by the magnet moving through the coil is strong enough to hold up the magnet instead of letting it drop. (Sort of a useless perpetual non-motion machine. With the flashlight on end the magnet will levitate forever, but one can't get any energy or work out of it.)

It takes just a bit of force to overcome the suspension and generate power. Done right, the levitation feature would aid in suspension damping.

[RedDevil]

Oh, I dig that design.
Moving the magnet in a straight coil works fine for the milliWatts a flashlight needs, but we want several thousand times as much from the shock, while it usually travels far less than the flashlight magnet does.

This new design will spin up a rotating coil.
It has double merit; this way it converts the extreme high pressure but low travel of the shock to a fast moving coil, which will keep spinning once the shock stops. Instead of a sharp peak of several hundreds of kW that the batteries can't handle it gets smeared out over a longer period; the coils will not deliver more energy than the system can take, and just spin a bit longer then.