Dutch Invention Uses Electric Engines For Wheels

Makarand writes "A Dutch invention is promising to make vehicles atleast 50% more efficient and also bring down the soot and carbon dioxide emissions. This is made possible by replacing the conventional wheels by 'in-wheel' electric engines which are normal electric engines turned inside out. No transmission is necessary as the in-wheel engines are powered by battery-packs installed on the vehicle. A diesel-powered generator which replaces the original engine on the vehicle charges the battery-pack continuously. The Dutch company E-Traction has built a bus using this technology that will undergo testing for the next six months."

Comments

Oh puLEASe

[chessie]

this is news how? the idea was built and proven over 100 years ago. ferdinand porsche, who was an ENGINE man, did this in like 1900 and won lots of races with his hybrid car. this feat alone put his name on the map beginging his career.
see this this page

Re:Oh puLEASe

[kfg]

You could put it that way, yes. The issue is inertia. The function of the suspesion system is to move as freely as possible so that the wheels follow the uneven contours of the road leaving the chassis stable and keeping the tires in full contact with the surface for optimum traction.

As the weight of the wheel goes up so does its inertia. It starts to resist movement more and more. This is a Bad Thing. When you hit the right bump at the right speed the wheel hops off the ground rather than moving the suspension up with the irregularity, upsetting the entire car and losing traction at that corner. The sprung to unsprung mass ratio becomes important because with heavy wheels and a light chassis the mass of the wheel reacts more strongly on the mass of the chassis. The suspension can't move with the bump but the chassis does. A loaded bus chassis is much more massive compared to the wheels than a loaded car is.

The people in the car experience this as ride harshness.

Active suspension systems are ones that use sensors and mechanical actuators to move the suspension ( as opposed to springs). They can "anticipate" the movement needed and partially compensate for the added mass, but only partially.

I can'na change the laws of physics.

A heavier wheel rim also takes more energy to accelerate, more so than the same mass on the chassis does, and increases gyroscopic effects.

This is why the solid spoked wheel gave way to the tensioned wire spoked wheel, than the pressed steel wheel and ultimately the "mag" ( which is really only a mag if it's actually made of magnesium. The aluminum wheels you get in the dress up stores are actually often heavier than the cheaper steel wheels they are purchased to replace). The lighter the wheel the higher the ultimate performance of the vehicle in every catagory (this is why bicyclists are absolutely rabid about wheel weight).

Is this system feasable for a car? Oh, absolutely. But you have to be careful to at least keep the motors as low weight and compact as possible. The GM Sunracer managed to contain them within something that looked very much like a standard bicycle hub, although rather heavier. Copper and magnets aren't light.

KFG

Re:electric engines

[Da Fokka]

To quote the Slashdot synopsis (not even TFA)
A diesel-powered generator which replaces the original engine on the vehicle charges the battery-pack continuously.

The electro motors are not used as an engine but just as a clever way of transmission. This system has been in diesl-electric trains for ages, since most diesel engines can operate quite efficiently if they always run at the same RPM.

Re:If I know something about batteries...

[Mr. Slippery]

Won't this create cleaner air AND dumps filled with highly toxic battery-waste?

Lead-acid batteries are highly recyclable. (Though, like computers, because of poor regulation such batteries are often just dumped on third-world nations.)

Re:A quiet bus in a busy city...

[Reziac]

Actually, MOST of the "indicator noise" (as distinguished from a vehicle's general noise level) you hear is not engine noise anyway, but from its tires contacting the pavement. And that's partly a function of the tire (heavier-grade tires tend to be noisier), partly of how smooth the pavement is (rough pavement makes for more noise). You don't need the roar of a diesel engine to tell you a bus is coming; the plentiful tire/pavement noise is sufficient. In fact, you're more likely to hear that *correctly* if it's not diluted by engine noise, plus tire noise gives you better auditory indication of speed and motion.

I'd wondered about using wheel revolutions as a charging source for onboard electric systems myself -- good to see engineers applying it. (IANAE :)

Re:This isn't anything new.

[blargorama]

Massive dump trucks used in mining and made by manufacturers like Euclid (http://www.hcmac.com/) have used this technology for as long as I can remember. At least the early 60's and maybe earlier.

Two more words:

[osjedi]

Unsprung weight.

Making a wheel that is an electric motor would make such a heavy wheel thtat the vehicle would handle and drive like total crap. The huge weight of the wheels would require shock absorbers with huge dampening ability to keep the wheel planted on the road over uneven surfaces. It would ride like a dump-truck.

Re:Will it stand the test of time?

[sjames]

Interesting idea, but the real test will be with long term cost of operation.

While any new tech carries risks, this one has a lot going for it.

Diesel-electric is well proven as a technology. All diesel train engines use it. The difference is in the batteries. No battery pack could contribute much to storing the kinetic energy of a train. However, they do brake electrically. The big grid on the top of the engine is a simple resistance heater to dump the energy from the motors operating as generators.

Electric motors are simple things. The only moving part is a bering, a well understood part. Because of that, industrial motors tend to run for a very long time with minimal maintainance. These motors are not THAT different than other motors, so will likely have the same desirable characteristic.

Transmissions and differentials DO have a lot of moving parts subject to wear and tear. The generator/motor combo replaces all of that.

Engines running at constant RPM and load experiance less wear then on that runs at variable speeds and loads. The engine is smaller as well, so cheaper.

Because of th nature of the system, it doesn't need the latest and greatest cutting edge batteries. I don't know what they're using, but it probably isn't finniky expensive LiIon polymer.

A later generation could easily switch to composite flywheel once that's better proven and manufacturing costs come down. Because of the system design, it would likely be a drop-in replacement.

Even without the fuel savings and quiet operation, the new design might be worthwhile due to savings in maintainance and improved reliability.