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

Will it stand the test of time?

[earthforce_1]

Interesting idea, but the real test will be with long term cost of operation. The cost of diesel fuel may be insignificant if this thing spends significantly more time in the garage, or costs more to build.

Not that I want to be a naysayer. I hope it pans out, but don't be too surprised if it quietly goes away never to be heard from again lot a lot of other great ideas. (I remember a british high speed train that leaned into curves, that was quietly taken out of service after much initial fanfare)

Re:Will it stand the test of time?

[nick_davison]

Will it stand the test of time? Of course not...

"...bring down the soot and carbon dioxide emissions."

Sounds like vapourware to me.

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.

Re:Will it stand the test of time?

[canadian_right]

All modern train locomotives use a similar setup. That is why they are called diesal-electric locomotives. This is tried and true technology that works great year after year.
How Diesal-electric loco's work

It is interesting that this old technology is being used with a bus, and they are adding batteries, but it certainly is not a break through.

Ugly website

[LakeSolon]

Thank god it just got posted to slashdot. That frontpage-template of a website will be gone shortly.

~Lake

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

Perfect 4-wheel drive

[thepuma]

I've heard about this invention, and it promises to make the ultimate 4-wheel dive vehicle! I can now take my old Land Cruiser and remove the engine, replace the wheels with these motors, and load the trunk up with batteries!

It also promises to make auto repair much easier...just swap out a wheel.

If I know something about batteries...

[Mr2cents]

..then they will all die the day after the waranty voids. Won't this create cleaner air AND dumps filled with highly toxic battery-waste?

Re:If I know something about batteries...

[bennomatic]

I can just picture the phone calls:

Customer: My batteries won't hold a charge.

Appl^H^H^Huto Maker Support: Well, the batteries cost, like, $25,000. You may as well just get a new car.

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.)

A quiet bus in a busy city...

[DeepDarkSky]

...can be bad because of its lack of noise, there's less warnings to the pedestrians that the bus is coming. It may seem like a silly problem, but the next time you walk on the streets, check to see how often you use the sound as a cue to determine when a car is coming. Of course, you'd still look to be sure, but for jaywalkers, it could be a bad thing.

The other thing is, since the motor is now the wheel, I wonder what the costs will be to maintain these wheels. I think it's still better to have traditional electric motors with the rotor on the inside, since there's really not that much to gain from having an inside out motor, and more to lose when you need to get at it to fix it. Using traditional motors rather than the inside-out motor also means less change need to be made, since the wheels and tires can be used from currently available parts.

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

[bennomatic]

>bad because of its lack of noise, there's less warnings to the pedestrians

So THAT'S why I keep getting run over by bicyclists! You know, I've been lobbying to make it a legal requirement for kids to start putting playing cards back in their spokes for just that reason!

I can't smell bikes coming, either. Gosh darned quiet, clean-running vehicles!

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 :)

Old idea

[swfranklin]

This is a new application of an old idea - diesel locomotive engines use this exact approach (well, their motors aren't "In" the wheel, but otherwise similar).

Diesel locos use a Diesel powerplant to generate electricity, which is then used to run the electric motors powering the drive wheels. It's very effective and proven technology.

terrible idea

[treat]

They put the engine in the wheel, massively increasing the amount of unsprung weight. The benefits from this layout can't possibly outweigh the huge drawbacks.

This idea will never be marketable, as the vehicle will handle terribly and have a terrible ride.

Re:Just an improvement of standard hybrid technolo

[sparkhead]

Why is this anything more than just a slightly more efficient way of doing a hybrid gas-electric system by putting the engine in the wheel.

Well, I believe most hybrid cars today are parallel hybrids - the (gas/diesel) engine can power the drivetrain directly, and the car will use the engine or the electric motor or both depending on conditions and demand.

This bus (and potential other hybrid cars today) is a series hybrid. The only thing powering the drivetrain is the electric motor. The engine either charges the batteries or powers the motor, but never directly powers the drivetrain.

Power/size and other statistics

[GillBates0]

I happened to get an electrical set as a b'day gift a long time back when I was a kid...and one of the parts was a small electric motor.

Among one of my personal projects was an electric car, which I tried to make out toothpaste boxes/etc. The most natural way to move the car was, ofcourse to attach the electric motor (I had only one) to one of the wheels. I did this by attaching a small wheel to the motor shaft. Ofcourse, it didn't work out right: because of only one moving wheel, the car moved in circles, rather than straight as desired.

My point is: doesn't attaching the engine to the wheel seem like the *most* logical choice in the first place? Why build complicated transmission mechanisms and a centralized engine in the first place? The reason, I think was to use only one big powerful engine to power all wheels (or two, incase of a 2 wheel drive) simultaneously. Since the engine is the single most expensive component of a vehicle, it made sense to use only one of them, especially so, because most of them have a very high space:power ratio.

Electric motors seem to suffer from the same problem (high traction motors are incredibly huge). I would like to see figures on the size/power of these engines, and ofcourse, the size/weight of the batteries which the vehicle would need to haul along.

Re:Just an improvement of standard hybrid technolo

[bennomatic]

You're right; it is just a natural progression. But they also took the next step (another "natural progression") from thinking about it, and actually built the darn thing, so I say kudos to them.

I, for one, will welcome the results of the real-world tests of this thing. If it works as well as they claim, they could put those wheel-gines in all sorts of vehicles. And based on the size of them, I'd say they're going in large vehicles first. Can you imagine the Hummer ad campaign when the release a vehicle that is more fuel efficient than a Toyota Echo?

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.

The Mechanical Engineers sleep late at /.

[neBelcnU]

Wow, all these cogent thoughts from the EE's and CE's, but where are the ME's?!

-Too quiet for a bus?
Round my midwestern city, the noisy, stinky buses are, oh, let's say 30' long, with the engine at the stern. If you're depending on hearing them for avoidance, you're gonna be meat on the front bumper 100% of the time.

-Gyro-effect?
Intersting, a REAL ME (I only play one on /.) could calculate the precession-force but I think the more pressing problem is called "UNSPRUNG WEIGHT." For decades, wheel and tire manufacturers have made huge strides toward lighter products to reduce the UW. Lowering UW allows a more agile suspension. (Perhaps "Unsprung MASS" would be more scientifically accurate?) All that having been said, I think the benefits in design would outweigh this one problem...

-Various comments on Diesel Hybrids.
MIT's done the math, and I've ranted about this before: Forget Hydrogen as a transportation fuel (for a while), a high acceptance rate of Diesel hybrids would save the world. (Soot? Darkening of the earth? All soluble, and still more manageable problems than the far larger emissions from gasoline as a transport-fuel.)

These are a fairly logical solution to the problem, especially for allowing car-designers to make the car do what you want/need it to do: Carry your self and stuff in safety and comfort.

I, for one, welcome our new motor-in-wheel overlords. (Sorry 'bout that)

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.

Unsprung mass as proportion of vehicle mass

[Porag_Spliffing]

All I can say is flat flat flat, not the tire the Netherlands ;-). Unsprung weight is not to important in a low performance vehicle running on good roads (Apeldoorn has well maintained roads, you should see the taxes here). In a bus the unsprung mass will still be rather a small proportion of the total mass even for rather massive wheel motors. The big bastard springs that carry all that bus will not have to much trouble holding the wheels on the road.

Nadolig llawen,
R.

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.