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Dutch Invention Uses Electric Engines For Wheels 380

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."
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Dutch Invention Uses Electric Engines For Wheels

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    I guess we need to look back at more Steve Jackson games for future technology ideas? Or perhaps he patented the idea and stands to make a killing now?
    • Two more words: (Score:4, Informative)

      by osjedi ( 9084 ) on Saturday December 27, 2003 @12:42PM (#7817474)

      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.
      • 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.

        In addition, you wouldn't be able to buy aftermarket wheels (no rims that spin at the traffic light), so no buying a set for winter. The obvious solution is to move the motor inboard and connect it w

      • Re:Two more words: (Score:3, Interesting)

        by ericspinder ( 146776 )

        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.

        The extreme weight of the wheel will be a consideration in the design of the suspention, but I don't think that it will drive like a "dump truck". First without a moter in the tradtional place, the w

      • Re:Two more words: (Score:3, Interesting)

        by Russ Nelson ( 33911 )
        Yes, this is a problem. The solution might be a shaft, but then you have two universals to deal with. How about something even more radical: fix the wheel and put the springs into the tire. Wheel diameter has always been limited by the shaft necessary to drive it. If the wheel drives itself, you don't need the shaft. Why not make the wheel larger in diameter, and build springs and shock absorbers into the tire? For that matter, why not make the shock absorbers be electromagnets which dump current into
  • by NeuroManson ( 214835 ) on Saturday December 27, 2003 @11:11AM (#7817113) Homepage
    Back in the ol' Apollo days, NASA's lunar rover operated in exactly the same fashion, if I recall correctly.

    http://www.nasm.si.edu/collections/imagery/apoll o/ lrv/lrv.htm

    • 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.
  • No drivetrain worries...just steering and maybe suspension. I want to get a few and mount them on my couch.
  • by earthforce_1 ( 454968 ) <earthforce_1@[ ]oo.com ['yah' in gap]> on Saturday December 27, 2003 @11:12AM (#7817121) Journal
    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)
    • What, you mean these [bbc.co.uk]?

      The problem with them is that they need specially re-inforced track. When the track management was privatised to RailTrack they wouldn't upgrade the Track as it would cut into their profits. Now that the Government has returned the track management to the public sector the works are (gradually) going ahead and we will soon have the APTs being able to work on all mainline track.

      The French have, of course, used this concept for years as the TGV [o-keating.com], and the italian Pendulino [madeinfiat.com] follows the sam
      • The French have, of course, used this concept for years as the TGV,

        The TGV is not a tilting train. And therefore it requires an exceptionally flat, straight and stable track for high-speed (300 km/h) operation (though it achieves a decent speed even on regular tracks).

    • by nick_davison ( 217681 ) on Saturday December 27, 2003 @12:04PM (#7817340)
      Will it stand the test of time? Of course not...

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

      Sounds like vapourware to me.
    • Cost of batteries (Score:3, Informative)

      by Latent Heat ( 558884 )
      The main issue I have with these hybrid drive systems is the cost of electricity extracted from a battery. Pulling some electric car numbers out of the air, a $3000 lead-acid battery pack stores 10 kWHr per charge times 300-500 charges or 60 cents to a dollar per kilowatt hour. Lets say a gasoline engine averages 1 lb fuel/hp-hour (it might peak at .45 lb fuel/hp-hour at peak load and optimum RPM). Lets say $2/gallon gas (yeah, yeah, I know people in the world pay more, but that is mainly tax policy -- t
      • Lemme see if I can find that old link.... ah, here [commutercars.com] we go.

        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

    • a british high speed train that leaned into curves

      It was pretty much doomed after the first real-world journey, when it induced vomiting in the assorted dignitaries and members of the press who had been invited along.

      Another great British idea which died (at least as far as Britain is concerned) was the world's first magnetically levitating high-speed train, [suttononline.org] developed by Eric Laithwaite. [bbc.co.uk] I remember seeing his Royal Institution [rigb.org] Christmas Lectures [rigb.org] in 1974 (I think I'm too young to remember the 1966 o

    • by sjames ( 1099 ) on Saturday December 27, 2003 @12:57PM (#7817525) Homepage Journal

      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.

    • by canadian_right ( 410687 ) <alexander.russell@telus.net> on Saturday December 27, 2003 @02:56PM (#7818000) Homepage
      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 [howstuffworks.com]

      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.

  • by egarland ( 120202 ) on Saturday December 27, 2003 @11:13AM (#7817123)
    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.
    • by sparkhead ( 589134 ) on Saturday December 27, 2003 @11:23AM (#7817179)
      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! :)
    • This would be a true hybrid. The present hybrids the gas engine changes speed and load as the car moves. the electric motors just provide braking and power assist. In a true hybrid the gas engine always runs at the same speed and load. This means that it can be tuned and fitted for that speed and load. This also has another advantage in that the gas engine can be used as a mobile generator, like during a power failure or if you need to use power tools off the grid.
    • by Anonymous Coward
      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.

    • by bennomatic ( 691188 ) on Saturday December 27, 2003 @11:32AM (#7817225) Homepage
      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?

  • by LakeSolon ( 699033 ) on Saturday December 27, 2003 @11:13AM (#7817124) Homepage
    Thank god it just got posted to slashdot. That frontpage-template of a website [e-traction.com] will be gone shortly.

  • Oh puLEASe (Score:4, Informative)

    by chessie ( 22669 ) * on Saturday December 27, 2003 @11:13AM (#7817125) Homepage
    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 [porsche.com]
    • The electric motor in the wheel hub was also the basis of the GM Sunracer that won the solar car race across Australia, although that one obviously wasn't a diesel hybrid.

      I've been promoting this system quietly for the past 30 years and built a few prototypes. The only real hold up has been the computing power to make it work up to its true potential.

      The primary downside is the increase in unsprung weight. That much mass in the wheels is an issue for vehicles smaller than a bus. This can be partially offs
  • 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.
    • Actually you can do vegi oil if you have a diesel engine. You can make your own fuel if you have a good source and if not all diesel fuel in the midwest uses vegi oil as a 10% additive.

      Last time I checked they were damn close to 80mpg cars. Go buy one from Honda or Toyota.

  • by thepuma ( 721283 ) * on Saturday December 27, 2003 @11:13AM (#7817131) Homepage
    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.
    • Yup, and instead of one engine you need to look after 4. win-win situ.. or not.

    • Bus [www.rnw.nl].
      Those are some monster wheels.

      And what is the actual cost of this wheel?
      • Yes they are some monsters, but then again if they built a computer with the same power as the one you are sitting at now back in the day it would have covered probably half of the town you live in.

        I bet you they could come up with something that doesn't weigh all that much more than some of the heavier rims available today for full size cars/trucks.

    • ..parking! There's no more reason why you couldn't move your wheels 180 degrees! On the other hand, have you seen the size of that wheel? Cars would have a monster-truck appearance!
    • 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 imag
  • by Mr2cents ( 323101 ) on Saturday December 27, 2003 @11:14AM (#7817135)
    ..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?
  • ...for some Oil Giant to buy the company off?
  • by DeepDarkSky ( 111382 ) on Saturday December 27, 2003 @11:14AM (#7817139)
    ...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.

    • It's a wheel, you can just take it off, put on a new one and send the old one off to a factory for servicing and reconditioning. That suggests potentially lower costs than having the whole bus off the road and out of service for servicing the engine.

    • City pedestrians already have to deal with gas/electric hybrid vehicles that are nearly silent, so these luddites will simply have to evolve. Less noise in the world is a good thing.

      On your second point about traditional versus inside-out electric motor -- I'm no mechanical engineer, but my guess is that this tech allows you to have a fixed axle (or perhaps even no axle) versus the old tech which requires a long rotating heavy axle to drive the wheels.
    • by bennomatic ( 691188 ) on Saturday December 27, 2003 @11:42AM (#7817262) Homepage
      >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!

    • Good point. But still, it's always better if noise is a choice and not obligatory :)
    • since buses have their engines in the back, and they are rather long vehicles, you recieve little noise from a bus coming at you anyway, especially when it is rolling to a stop, with open clutch.
    • by Reziac ( 43301 ) on Saturday December 27, 2003 @11:58AM (#7817325) Homepage Journal
      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 :)

    • ...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.

      That's why they always tell little children to always look both ways before crossing the street. Someone needs to go back to kindergarten so the rest of us

  • Old idea (Score:4, Insightful)

    by swfranklin ( 578324 ) on Saturday December 27, 2003 @11:16AM (#7817143) Journal
    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 (Score:4, Interesting)

    by treat ( 84622 ) on Saturday December 27, 2003 @11:16AM (#7817146)
    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.
    • This holds true for smaller vehicles. But for a city bus (which will not have to negotiate rough terrain) it won't be such a huge problem.

      Furthermore, a lot can be done to reduce the weight of engines, thereby reducing your problem.

      Although I agree it might be a problem I think it can be overcome, and that - especially with fuel prices on the rise - the idea will be very marketable.
      • You clearly have never driven in the northeast US. We have potholes that will swallow buses whole. I've found smoother terrain in the woods.
    • They ARE testing it on a BUS, not a race car :)
    • 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.

    • by Porag_Spliffing ( 66509 ) on Saturday December 27, 2003 @12:09PM (#7817358) Homepage
      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,
  • by PhotoGuy ( 189467 ) on Saturday December 27, 2003 @11:17AM (#7817148) Homepage
    Due to my wonderful education from the "Frontiers of Construction" marathon on Christmas Eve, there seemed to be many examples in the marine industry where the generator/electric motor approach is used instead of the traditional approach is used.

    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.

  • Wheel drive (Score:3, Interesting)

    by sparkhead ( 589134 ) on Saturday December 27, 2003 @11:18AM (#7817157)
    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 [e-traction.com]. 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.
  • pros/cons (Score:3, Informative)

    by thogard ( 43403 ) on Saturday December 27, 2003 @11:20AM (#7817165) Homepage
    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.
  • I read about a Swedish hybrid a few years ago, and have been patiently waiting for something like it to appear in the States. It had a motor for each wheel, and a turbine powered generator to produce electricity (mediated by a battery pack).

    The neat thing about the turbine was that it could burn a wide variety of liquid fuels with no modification: gin, diesel, gasoline, kerosene, methyl alchohol. The fuel didn't have to be especially pure.

    Fuel cells are nice, but each type of fuel cell burns only one

  • I love how new tech is always claimed to be so environment friendly. Reading the article went like this for me:

    - Electric motors in the wheels. Environment friendly... Cool!

    - Ok... Battery packs... Yeah. Enviro PC. Bitchin'...

    - DIESEL ENGINE to power the whole thing...


    They're full of shit! :)

    • As far as I've heard, modern diesel engines are actually very clean - i.e. they can be better than natural gas..
    • Uhhhh... but it uses less energy and has lower emissions. How is this bad?

    • Since in-wheel engines are so highly efficient, the generator's diesel engine can be very small, about the size of the compact city car's engine. Because charging the batteries is all it needs to do, the tiny engine consumes very little fuel and can run continuously at a speed of 1700 revs per minute, the most efficient rev count.

      The efficiency of the system means a smaller engine to acheive the same effect, because the electric engines have a greater range of optimum efficiency.

  • are the new big thing. To look at two totally seperate domains, check out the YS Tech TMD fan [dansdata.com] (Dan's review) and Canon's Ring USM [photo.net] (Photo net review). This is clearly a technology with potential for anyone working in a certain formfactor who thinks they're making a high enough quantity that they can do custom motors instead of just buying the oldfashioned barrels... and now, it seems, it scales as well. I think we'll be seeing a lot more of this. (Is it so bad of me to want a monocycle driven with this kind
  • by GillBates0 ( 664202 ) on Saturday December 27, 2003 @11:30AM (#7817214) Homepage Journal
    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.

  • No, I'm not talking about pastry design, I'm talking about real engineering.

    I worked for a Danish company for 2 years in the R&D Dept. I learned that Danish engeineering is done differently than in America. They are very thourough, and documentation and research will be complete before they ever begin making the tangible object.

    That is a sharp contrast from how things are done here. They call us 'cowboys' because we'll go off and come back with it either done, or a working (tho sometimes failed) proof
  • Back in the 70's, I developed a WindGenerator that used a similar approach for a class.
  • Please insert all your jokes under this thread....

    the environmental impact will be dramatically reduced when using TheWheel(TM)

    Sounds like someone stole an advertising campaign from 55 hundred years ago [about.com]
    I especially love this page [e-traction.com] with the heading "The Wheel - What It Is, and What It Does"


    I've actually read the article.
    IANAE (I am not an engineer) but it sounds to me like they're re-inventing the wheel.


    In Communist Russia, The Wheel turns The Engine.


    1. Re-Invent Wheel
    2. ???
    3. P
  • by neBelcnU ( 663059 ) on Saturday December 27, 2003 @11:39AM (#7817245) Journal
    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.

    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)
  • Let's see, if they ran the diesel engines on Biodiesel, they could totally wean the mass transit system off of petroleum.

    Biodiesel -- fuel from the southeast, not the middle east.

  • This is essentially what trains have been doing for years. An engineer I met once explained to me that converting the energy from the diesel engine directly into electricity which through a series of batteries drove electric motors uses 70% less energy than a mechanical transmission.
  • by Moderation abuser ( 184013 ) on Saturday December 27, 2003 @11:43AM (#7817265)
    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.

  • All I can say is, thisis obviously aimed at large/fleet vehicles, and not your family small-car.

    With the wheel-integrated-with-the-engine concept, there's NO WAY that MaryJane Q Citizen (or even JimBOB SixPack truckdriver) is going to be changing a tire on his/her own.
  • A working prototype? Undergoing testing right now? What the hell is this doing on Slashdot? We're only interested in vague vaporware!

    --grendel drago
  • Nearly every disk drive on the market uses this same "invention". Have been using it for many many years. tb
  • this was the original Aerovironment design for the GM Impact - one motor in each front wheel.

    GM nixed it because they said if one motor failed, the car would do endlesss tight donuts.

    Of course, millions of cars will do this anyway if their traditional IC motor mounts fail, but hey.

    The resulting Impact was less of a performer or as efficient as originally designed.

  • I'm not convinced (Score:3, Informative)

    by gvc ( 167165 ) on Saturday December 27, 2003 @12:10PM (#7817363)
    I would be more impressed if the article were to concentrate on the novel aspects of wheel motors.

    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 nee
  • What the hell is new about this? This type of hybrid vehicle has been around for years.

    The most common are Diesel-electric railroad engines. However over the years the idea of Diesel-electric has been used in buses and cars. There is nothing novel about this "invention".
  • As if jacking your rims in a pothole wasn't expensive enough...
  • by SuperBanana ( 662181 ) on Saturday December 27, 2003 @12:35PM (#7817451)
    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

    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).

  • by Charles Kerr ( 568574 ) on Saturday December 27, 2003 @01:06PM (#7817557) Homepage
    A Oct 2 article [google.com] in the New York Times about e-Traction included a countering opinion:
    But plenty of technological and economic hurdles must be overcome before such motors gain widespread use in transportation. "It is the future," said James Worden, founder and chief executive of Solectria, a company in Woburn, Mass., that has produced drivetrains for more than 100 hybrid electric buses. "Whether it is 10 years out, 20 years out or 30 years out."

    Yet Mr. Worden of Solectria said that one drawback in the bus design was that the electronics in the motor were in direct contact with the road, not protected like the rest of the bus is by shock absorbers. If the tire hits a bump, he said, "it beats the living daylights out of any motor or electronics."

  • by ajs318 ( 655362 ) <`sd_resp2' `at' `earthshod.co.uk'> on Saturday December 27, 2003 @01:52PM (#7817737)
    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.

    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 ..... 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!

If graphics hackers are so smart, why can't they get the bugs out of fresh paint?