Promising New Shock Absorber Technology

FROM AUTOBLOG.COM

On the Rebound: Scientists invent regenerative shocks

by Jonathon Ramsey on Feb 1st, 2009 at 11:20AM


Scientists at Tufts University have patented a shock absorber that converts compressive energy into electricity, which can then be stored in a hybrid vehicle's batteries. Called the Power-Generating Shock Absorber (PGSA), actually an electromagnetic linear generator, it uses "magnet arrays, high magnetic permeability spaces, coil winding arrays," and a linear electric motor to capture the energy of its motion and use it to charge the batteries.

The movement of a standard shock absorber creates heat, which is neutralized by the oil in the shock. In a PGSA, a linear electric motor converts the magnetic field created by the repetitive motion into electricity. Or, if you like your technology to sound science-y, it "uses an electromagnetic linear generator to convert variable frequency, repetitive intermittent linear displacement motion to useful electrical power."

The technology can be used on any vehicle that uses shocks and batteries, but its greatest application could be on trucks due to their higher mass and electricity-generation potential. Electric Truck, LLC has licensed the shock technology, which is predicted to generate between 2kW and 17kW of energy on an average road. According to the men who created it, "the percentage of recoverable power/energy for a 2,500 lb vehicle that employs four optimized design regenerative magnetic shock absorbers and whose average speed is 45 mph on a typical US highway is likely to be between 20% and 70%." Put four of those on a Prius and stay in town, and all of a sudden you're talking about interstellar gas mileage. Thanks for the tip, Paul

[Source: Gizmag via iCars]

Missing here is that the recoverable energy is only the percentage of what is now wasted in the shocks - which is only about 2% of the traction power. So 20-70% of 2% of the energy you put into the system could be recovered. And that is without taking into account the added weight/complexity/cost of installing this system. I can't make this work out to any more of an advantage than putting a solar panel on the roof.

On The Other Hand, they could have an effectively infinite lifetime, and they could be made adjustable while in use. Those might well be bigger advantages than the energy recovered.

And: oh hell. You mean this hadn't been patented yet? I thought of it years ago. Argghh...

Not the first linear e-shock (that was Bose), but there is plenty of room to change things a little bit and get your own patent. Whoever gets the weight and cost out will have a marketable product.

I'd also guess that the energy available is not much (except during the Baja 1000) but it is intriguing to be able to change vehicle handling characteristics while en route.

Apparently Bose took out all the body roll on turns which allowed drivers to overestimate tire adhesion. Spinouts and hilarity ensued, and a compromise amount of body roll was dialed back in.

This would work well on South Australian roads.

You have roads?

Well we learn something new every day.

You could call them roads I guess.
This is how my car looked on my last long trip


The main highway from my house to the city 22km away


So yeah we have roads.

Actually, that looks a lot like the gravel sideroad on the way to my hobby farm. Ever since they started a small logging operation on Crown Land a few miles north of my place, the road has been a disaster

Perhaps a bigger advantage to electronic shocks would be longer life and the ability to tune them underway.

Tom

Electrically tunable shocks have been around for years. Lately they have been connected to computers for "on the fly" adjusting, rather than just a switch the driver throws. They worked differently from these of course. They electrically controlled the shock valving. The latest type uses ferromagnetic fluid, which changes viscosity with magnetic field strength.

I wonder how much unsprung weight -these- devices add? Perhaps that's the real reason they are first considering trucks.

Very interesting concept.

Especially if it makes energy on compression and well as when it relaxes.

I wonder how much energy is lost on a 2000lb vehicle traveling down a perfectly smooth road verses one that is slightly bumpy, verses one that is very bumpy.
How much energy of gas would it take to travel say 20 miles for instance.

Next, I wonder if the application of those shocks would pay back anywhere near enough energy to warrant having them?

The other concern is if the price is astronomical, when its time to replace them... have they paid for the price difference in saving?

This could be a situation similar to solar panels that take 20 years to get your money back and then its time to replace them anyway.. so its a wash.

This technology has to start somewhere, and if they can figure out a way to make it cost effective right off the bat, then they will have a winner.