Slashdot Mirror
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."
Back in the ol' Apollo days, NASA's lunar rover operated in exactly the same fashion, if I recall correctly.
l o/ lrv/lrv.htm
http://www.nasm.si.edu/collections/imagery/apol
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
No drivetrain worries...just steering and maybe suspension. I want to get a few and mount them on my couch.
Blar.
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)
My rights don't need management.
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. It's a good idea, but I can't say I hadn't thought of it too. If it's technically sound it's a natural progression.
set softtabstop=4 shiftwidth=4 expandtab nocp worlddomination
Thank god it just got posted to slashdot. That frontpage-template of a website will be gone shortly.
~Lake
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
Too long sad to say. It seems like every good gas saving product that comes out just mysteriously disappears. Like the cars that run on used vegi oil, or the car that get 80+ MPG. I hope this car makes it else where in the world.
This SIG pulled due to lack of funding. (This damn war is costing too much!)
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.
Free your ecomony and enact the FairTax
..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?
"It's too bad that stupidity isn't painful." - Anton LaVey
...for some Oil Giant to buy the company off?
I've noticed that everyone who is for abortion has already been born - Ronald Reagan
...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.
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.
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.
I got the impression that one significant benefit is the flexibility of electric engines in terms of size and manoeuverability. Being able to have your thrusters turn 360 is critical for ocean going cranes, bow thrusters, and such, and is less complicated using an electric engine than would be required for a direct mechanical linkage.
In the cruise ship example, I kind of got the impression that so much electricity is required for the ship in general, that large generators were a given to start with, so powering the thrust of the ship from the same makes a lot of sense.
Very interesting to see this technology potentially cross over to the consumer. It will be interesting to see if the efficiency makes it feasible.
Love many, trust a few, do harm to none.
Not notpicking at all as they are two very different things: the term "electric engine" commonly refers to a reciprocating device with a crankshaft to convert linear to rotary motion. On the other hand, "electric motor" is generally reserved for purely rotary machines. Edison used to market a stationary electric engine for industrial use.
The higher the technology, the sharper that two-edged sword.
While having the motor built into the hub reduces the number of parts and connectors (shafts, u-joints) that rob efficiency, it would seem the major item for efficiency is not so much because of the "inside out" motor, but because of the direct drive on the wheel with fewer parts.
This same company has a similar motor for smaller vehicles here. It uses short axles so the motor is not direct on the wheel.
There are some space considerations with this motor, but while it would work on a bus, such a large amount of unsprung weight on a smaller vehicle would not promote a great ride or handling.
The energy savings comes from lack of friction in the drive shaft and the battery bank can store power so you need an engine big enough to supply the average power, not peak power which results in a smaller engine. This is good for larger vehicles like busses and some trucks. It also means more effecent engines can be used. A modern internal combustion engine as found in cars and trucks is designed to work over a wide range of speeds that aren't need if your just running an generator. Once an engine is running on a consistant load and output, efficiency can be improved even more.
This will not work so well for cars beause the high unsprung weight will make a car handle very poorly and the friction losses in a u-shaft would be better than extra weight in the wheels.
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.
RTFA, it says there is no drivetrain. Everything is in wheel, it is more efficient that way. No gear changing, less heat loss.
:)
Stop contributing to heat death!
-- Having a Creationist Museum is like having an Atheist place of worship
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.
An Indian-American Hindu committed to non-violent thought/speech/action alarmed by the global explosion of radical Islam
The reasons it is so efficient:
- the diesel engine runs at it's optimal speed (that gives an easy 50-70% gain - engines usually run on sub-optimal speed)
- losses only occur in the electrical cirquits (the current regulaters and so), can cost like 10% of the energy
- and a significant energy gain is made by reversing the enige to generator when braking! (though I assume also a mechanical break for emergency stops). As it is a city bus, it will spend most time either accellerating or decellerating.
Wouter.
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?
The CB App. What's your 20?
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.
Wow, all these cogent thoughts from the EE's and CE's, but where are the ME's?!
/.) 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...
-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
-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)
They can give you another 5-10% efficiency on top of Diesel, are much quieter and require far less servicing due to the external combustion. They're not ideal for automotive applications normally because they can't respond instantly, but make good generators. The down side is the development cost, you can go out and just buy a Diesel generator of X size, that isn't quite true of Stirlings.
Government of the people, by corporate executives, for corporate profits.
Nearly every disk drive on the market uses this same "invention". Have been using it for many many years. tb
I'm sure that the passengers will be gutted that the driver won't be able to take his favourite corners flat out at 90mph.
And the parent got modded up as interesting. Says quite a bit about the value of moderators. Either that or "Fuckwitted" should be a moderation option.
Government of the people, by corporate executives, for corporate profits.
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.
Maybe you live in interesting times
Diesel-electric technology has been used to power locomotives for 60 years. D-E locomotives have no mechanical transmission and the motors drive the axles directly. This electric transmission affords good efficiency, a very wide range of torque conversion, and allows the engine to operate within its optimal RPM range. Almost all of the efficiency benefits that this article attributes to the wheel motor can be had by this 60-year-old design.
There's also nothing new about regenerative braking, though it isn't practical for locomotives.
The real novelty here is that the motor turns with the wheel, rather than being stationary and transmitting its torque through a half-shaft. The benefit is the elimination of these half-shafts and a couple of CV joints. The cost is huge size and tremendous unsprung weight of the motors, plus significant engineering challenges of running high-current wires across a sprung connection, and the concern about competition with the brakes for the limited space and heat-dissipation capacity of the wheel area.
Have a look at the rear wheels of the bus in the photo. They're HUGE - the bus has obviously been modified to fit them.
In summary, the only novelty in this design is in transmitting the power the last 2 feet to the wheels. A conventional design would use half-shafts and CV joints while this design uses high-current electrical transmission. It may be that the engineering challenges of the latter can be overcome, but I remain to be convinced that there's any overall advantage. The company's interests would be better served by an article with more restrained hyperbole.
Although we're still a long ways away from mandatory mass transit or fully automated "cars" (a la Minority Report), I still fear that in my lifetime gasoline burning vehicles may be severely restricted in some parts of the world.
This doesn't bother me in principle, except that no one has made a feasible hybrid/alternative motorcycle. Reasonable bikes these days get 50-60 miles per gallon, so it hasn't been a concern, but with "vehicles" like the Honda Insight getting 70+ mpg in the city, bikes may soon need to worry about having a reputation as gas guzzlers.
Anyway, here's to hoping Janklow gets the maximum sentence.
This means that even if increased the gas engine efficiency to 0 cents per kWHr (through smaller engine run at peak efficiency to only charge batteries) but ran all the power flows through the lead acid batteries, you costs would increase from 40 cents to 60 cents per kWHr delivered to the wheels.
Anyway, this argument is for series power flows. The traditional automatic transmission is a series power flow, at best 80 percent efficient. The automotive industry has latched on to parallel power flows as a way to boost efficiency. Modern automatic transmissions use split-torque direct drive and torque converter together with direct-drive clutches to boost this efficiency. The commercial hybrids today are parallel electric and gas engine drive. The Toyota Prius is gear shift free, but instead of the Diesel locomotive series drive of engine-generator-traction motor, the Prius has the gas engine, generator, and traction motor tied to a planetary gear set so there are parallel mechanical and electric torque paths, again to boost the efficiency.
If you have a parallel hybrid, obviously you need to use your 60 cents/kWHr battery electricity under circumstances where the gas engine electricity costs more than 60 cents/kWHr, or perhaps use it to resize the gas engine for greater efficiency while consuming the minimum of expensive 60 cents/kWHr juice. But given that batteries are 1) expensive, and 2) wear out (think laptop or cellphone or iPod battery), the hybrid vehicle is not a slam dunk.
I remember some years ago reading an article about the potential hazard to careless pedestrians of virtually silent electric vehicles, the obvious solution being to put a loudspeaker on them and play a suitable sound. One suggestion was the sound of horses' hooves.
Using HTML in email is like putting sound effects on your phone calls. Just say <strong>no</strong>.
The problem with adapting this sort of tech to an off-road vehicle is that the motors will be right where the vehicle takes the most abuse. With the engine on the vehicle's body it's buffered by the shock absorbers; but inside the wheel the only thing between it and the rocks it's going over is a pneumatic tire. The tire will certainly provide some protection, but it may not be enough.
One thing though, if you ever did it, you'd have a monster truck. Take a look at the size of those back wheels, and imagine 'em mounted on a Dodge pick-up.
It's actually not technically sound at all. It drastically raises the unsprung weight at each wheel- the thing will ride like crap, and contact with the road will be extremely poor. It might be OK for slow moving busses, but certainly not passenger cars, SUVs, or light trucks.
The difference between a 15lb rim and a 30lb rim(rim= wheel minus tire, ie, the metal part) on your car is extremely noticeable, and racers/performance enthusiasts will go to all lengths to find lighter rims, and even braking systems made up of higher-tech, lighter materials(hence Porsche's ceramic brakes, for example.) Even suspension components themselves are usually made up of carefully designed aluminum components to be lightweight. Less unsprung weight means that it's easier for the suspension to keep the wheel firmly planted to the ground, to grossly simplify the situation.
This thing will eat tires like no tomorrow, too; it'll cause a lot of stress in the tire because the tire will need to flex a lot more than normal. Flexing takes energy, by the way- and that can add up fast. Improperly inflating your tires causes more flexing in the tire than usual, and can have a noticeable effect on your mileage.
Putting an electric motor inside the wheel is about the stupidest thing I've ever heard of- it should, if anything, be in the center of the car, with a traditional half-shaft and CV joints(slight loss)...or instead of using a standard automatic transmission, they should be using a CVT(constantly variable transmission) or something like Audi's DSG(Direct Shift Gearbox).
Please help metamoderate.
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.
-=-=-=-=- osjedi uses Debian GNU/Linux. -=-=-=-=-
What happens when the bus gets a flat? That does happen every now and again. It seems like the weight of the bus will fall on the engine. Are they planning on putting 2 tires in each wheel well (like a truck) in case this happens. Also, will you need to keep a spare engine in the trunk in case you do get a flat and you need to change the tire.
I guess this might not be a big deal for a city bus company, since they can just radio HQ and get someone to drive out with a new engine. But if this technology were ever used in real cars, that would be a major drawback.
I'll buy one when they support *.ogg
Way before ... it was the Lohner -Porsche (N.B. The date at the top of this page is a typo).
"There is nothing so simple that works so well that it can't be made to work better by making it more complicated" - ?
They are selling the motor-wheel, you can find more information about it on the web site of a Hydro-Quebec subsidary M4.
The project of building a complete car from scratch was abandonned because it needs massive investments. They figured it would be easier to find partners and license this technology. GM bought a license.
Another reason why they prefer licensing the technology is that is may be not a great idea to put all this weight in the wheel. Taking a bump could easily destroy the suspension.
Virtually identical designs were used almost a century ago.
OTOH, this is why inventions eventually enter the public domain...
Ferdinand Porsches first patent IIRC was an electric car with motors-in-wheels, regenerative braking. all wheel drive, etc.
Had lead acid batteries, which made it impractical, which is still the case for the most part.
A hybrid is , has been, and will be, the only sensible solution for a LONG time.
Absolutely nothing new here.
The fan on your processor is a spindleless, inside-out electric motor: the stator, with an electromagnet coil, is in the middle and the armature, with ceramic magnets, is on the outside. There is no commutator: the reversal of the current in the stator coil is done by means of a bridge of four transistors, and timed by one of the magnetic poles passing a sensor. So there is nothing particularly new in putting the armature on the outside of the stator.
..... and being a Diesel engine, it'll run quite happily on cooking fat, so the Dutch won't have to go to war with anybody when the oil wells run dry!
Nor is there anything new in the way the control system would work. In Europe, most washing machines are front-loaders. The drum has to be able to revolve at a low speed in both directions for washing, and at a high speed for spin drying. Instead of using a gearbox, the motor's windings are split so they can be connected in various series and parallel combinations. Electronically there is no difference {a motor doing 300 watts of work is using 300 watts of electricity and just looks like a resistance dissipating 300 watts of heat} -- mechanically there may be an improvement {the speed-changer need only be a set of relay contacts, not a solenoid-operated or electro-hydraulic gearbox}.
Many trains in Britain {where not all railways are electrified} use a Diesel engine to spin a generator at constant RPM {everyone knows this is the most efficiengt way to run any sort of engine}, which then drives several small electric motors via an electronic control system which actually depends on the waveform of freshly-generated, as opposed to stored, electricity. I think this was invented by our baguette-munching neighbours at the SNCF {Societe/ Nationale de Cattle Freight by my own experience} but not sure so don't quote me on that.
So, all in all it's not much new. But hey, it's an interesting application anyway
Je fume. Tu fumes. Nous fûmes!
If you take a look at that graph, you'll see that even a lead-acid battery can last many thousands of cycles as long as they are shallow. The Yellow Tops in question are, I believe, rated at 55 AH (20-hour rate, don't ask me what discharge rate was used for the test) or about 660 WH nominal. The total throughput over 4500 cycles to 25% depth of discharge is over 600 KWH.
Let's make an assumption here. Let's assume that mass-production batteries like the Yellow Tops would cost about the same per AH as a deep-cycle trolling/starting battery does now. I bought a 105 AH unit for about $65 a couple years ago, assume $70 today or $0.66/AH or $55/KWH nominal. 4500 cycles to 25% depth would cost $(55/1125) or 4.9 cents per KWH. Depending where you're buying your juice, this is somewhere between one-third to one times the cost of your off-peak electricity.
Gasoline costs quite a bit more. At 6.67 lb/gallon and 0.4 lb/HP-hr, you'd get 16.7 HP-hr/gallon or 12.7 KWH/gallon; this is about 36.5% of the 119,000 BTU/gallon of energy that gasoline really carries. At $1.50/gallon you're already talking 19 cents per KWH. Hybrid propulsion using reclaimed (regenerated) energy appears to be quite a bit cheaper than making power from scratch, and charging from the grid when opportunity allows would be cheaper than buying fuel even at today's US prices. At typical European prices, it's a no-brainer.
That said, it makes you wonder why the in-wheel-motor hybrid scheme hasn't been done for the last 50 years. I recall seeing one of Ferdinand Porsche's early attempts to power a string of trailers using in-wheel electric motors... for World War One, to move war materiel. There is very little that's truly new under the sun.
Time is Nature's way of keeping everything from happening at once... the bitch.
Well pal, "Give me a '59 Alfa Romeo any day.", this isnt exactly a matter of personal-satisfaction or fashion. Have you ever heard of *pollution*? fuck, the shortsighted selfishness people are capable of is astounding. Do you have want humanity to have a future? Stop thinking of yourself and consider the bigger picture for a second....