Suspension Efficiencies

[NeilBlanchard]

Here's how an ideal suspension could work:

Hydraulic springs and dampening to gain regenerative electrical power, and get ride height and leveling all in the same system.

Ride leveling is important especially in a low aerodynamic drag car -- if the "angle of attack" is wrong then much of the low drag benefits are lost. Ride leveling is also important for aspects of drag, and stability. Citroën has these features in many of their cars.

The Citroën 2CV also has a feature that could be a useful example: it uses a centralized dampener for both the front and rear suspension. If this was combined with a hydraulic *spring* system that also does the dampening, then much more energy could be regained, maybe?

So, how could this work? How much energy could be regained do you think?

[DonR]

Neil,

Somewhere on here there was an article about a shock absorber that generated electricity using a coil in the body & magnets on the shaft. Not unlike what you are describing. In that article it stated that a commercial truck could generate in the neighborhood of 1kW of power at highway speeds. I believe MIT was involved.

Don

[NeilBlanchard]

Yep, the company that makes those is called Levant Power:

Levant Power Corp.

They are shock absorbers; not springs; and as far as I know, they do not provide ride leveling or height adjustment.

[gone-ot]

...sounds like a 'suspension' application of the old drum brake double-ended, piston cylinder...accommodates slightly different movement of forward and trailing "shoes."

[darcane]

Originally Posted by NeilBlanchard

Here's how an ideal suspension could work:

Hydraulic springs ...

This makes some sense... but what is a "Hydraulic Spring"?

Hydraulic fluids are typically incompressible, so you can't use a hydraulic cylinder as a spring. If you are thinking of just a hydraulic cylinder replacing the spring and routing the fluid to a some device to harness the power generated... well, the suspension will just collapse once and the car will stay on the ground. You still need an actual spring in the system.

Mike

[Arragonis]

Originally Posted by NeilBlanchard

The Citroën 2CV also has a feature that could be a useful example: it uses a centralized dampener for both the front and rear suspension. If this was combined with a hydraulic *spring* system that also does the dampening, then much more energy could be regained, maybe?

So, how could this work? How much energy could be regained do you think?

The 2CV system was designed to keep the car level with the long suspension travel designed to cope with the rural roads of 1930s France - the original design spec said a basket of eggs should be placed on the rear seat and driven across a ploughed field. So the energy gained at one end when the suspension was compressed was used at the other end to raise the suspension - result = car stays level = better ride.

The 2cv was also very light, so if you captured the energy how would this be done ? Batteries are heavy although I have read the posts on aero vs weight for better MPG ?