Mitsubishi testing Lancer EVO with in-wheel electric motors
It's called the Lanver Evolution MIEV, which stands for Mitsubishi In-wheel Electric Vehicle. Like its name indicates, the EVO MIEV has four electric motors located in the wheels packaged neatly with the brake assemblies and steering hardware. We posted on Mitsu developing this technology on one of its Colts, but the system on this EVO is different in that it features a hollow-doughnut construction that locates the rotor outside the stator, as opposed to vice-versa in a common electric motor. This offers benefits in terms of power output, space efficiency and weight, the latter of which directly affects the vehicle's handling. The all-electric EVO MIEV will be competing in the Shikoku EV Rally 2005 being held August 27-28 on the island of Shikoku, Japan. Mitsubishi is using the event to test the system's range and durability in various environments. Currently the company is one of the few researching in-wheel electric motors, the development and mass-production of which could help draw positive attention to Mitsubishi the same way the Prius did for Toyota. And just imagine a real hybrid EVO with in-wheel electric motors and a 350+hp 2.0T. Mmm… that'd be fun.
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Reader Comments (Page 1 of 1)
Joel A 11:06PM (12/18/2005)
That's a bit of good news for Mitsubishi especially with this downer:
Fleet managers set to dump Mitsubishi
http://www.theaustralian.news.com.au/common/story_page/0,5744,16359624%255E643,00.html
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gnome 11:06PM (12/18/2005)
Are there concerns about this increasing the unsprung weight of these cars? I know for the sake of handling and ride there is usually a lot of work to put as much of the weight as possible on the shocks.
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Peter W. 11:06PM (12/18/2005)
Definitely looks like a cool system. I imagine one of the big pluses of four independant motors would be that more power/torque could be applied to the outside tires in a turn &c.
Buy why the brake rotors/calipers? Wouldn't the electric motors be able to do regen braking or otherwise provide slowing force as effectively as a brake rotor? Then there won't be all the extra heat and brake dust around the electric components.
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Robert Brodrecht 11:06PM (12/18/2005)
I love the idea of an in-wheel electric motor, but not for a sports car... unless they can decrease the weights of the entire wheel/break/electric motor assembly to what the current weight is now.
Adding one pound of unsprung weight (according to a "general" ratio) is worth about 20 pounds of sprung weight. Having even 5 additional pounds in each wheel will make a difference, especially in a rally car where handling is 50% of the game.
So, it's a good idea for saving space on a car that doesn't require superb handling (dragsters, econo boxes, etc) but I'm not so sure about on a rally car.
But, I'll trust Mitsubishi did a good job. It'd be stupid of them to risk the Lancer on this sort of project. If they did a really nice job, I'd consider getting one (or at least the EV assembly).
Side thoughts: they could reduce the weight of the entire assembly by building some of the electric components onto/into the wheel hub (which would also reduce spinning unsprung weight), but would pretty much prevent after-market wheels.
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Eric Bryant 11:06PM (12/18/2005)
Whoa - that is seriously cool. I hope to see more news like this.
Yes, the whole unsprung-weight issue is problematic. I'm optimistic that it can be overcome by taking a clean-sheet approach to the design, as well as by employing advanced materials (magnets get better every year, and aluminum windings might be a great alternative to copper).
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Tman 11:06PM (12/18/2005)
#3, For regen to work properly, it needs some form of torque, and brakes normally provide the necesary torque. The fact that they do less work means that the brakes would much smaller.
For a sports car, mounting the motors on the vehicle and linking them to the wheels is better to combat unsprung weight. This setup, on the other hand would good for a luxury car.
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Rocket Punch 11:06PM (12/18/2005)
In addition to the increased unsprung weight issue. How will the massive heat generated from the brakes affect the motor efficiency and the additional weight of the battery to the car.
I can see how these sort of technology as a retrofit solution to existing public transpotartion (like buses).
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michael parker 11:06PM (12/18/2005)
Keep in mind that with electric wheels they don't need the axle or transmission. That might save them enough weight (both sprung and unsprung) to make it work well.
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Lee Gibson 11:06PM (12/18/2005)
Tman, regenerative braking requires no "torque". Basically, all you have to do (in a simple motor) is reverse its polarity, so it is a voltage source rather than a voltage sink. The power comes from the rotation of the wheel, which is retarded by the electromagnetic force of the generator (that used to be your motor).
I would wager, however, that large dump currents from electromagnetic braking would require a capacitor, because if you try to dump the power into batteries they'll, like, melt.
I would also guess that you'd want friction brakes to augment the regenerative system, for aggressive braking and panic stops. It'd be interesting if you could modulate the regenerative braking system to act as ABS, though...
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RV Buyer 11:06PM (12/18/2005)
Hybrid tech is cool ! An electric car CAN be powerfull !
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gnome 11:06PM (12/18/2005)
What happens when you drive through a puddle?
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Monkey Wrench 11:06PM (12/18/2005)
3500HP, coupled with a couple of electric motors can move more than 300 tons:
https://www.getransportation.com/general/mining/mining_default.asp?SMSESSION=NO
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Monkey Wrench 11:06PM (12/18/2005)
3500HP, coupled with a couple of electric motors can move more than 300 tons:
https://www.getransportation.com/general/mining/mining_default.asp?SMSESSION=NO
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Alistair 11:06PM (12/18/2005)
You could use the four-wheel electric motors to handle ABS, stability control, and traction control. You could also drop the mechanical connection between the motor and the rear wheels to save weight. Eventually, you could decouple the gasoline (or diesel) motor entirely from the drive wheels, and run it at it's most efficient RPM level as a generator to keep the batteries/capacitors topped up. Going somewhat exotic on materials (ceramic brake rotors, forged wheels) could offset some of the unsprung weight penalty. Inboard electric motors with driveshafts would sidestep the issue, but wouldn't be as elegant. Any way you slice it, though, this is an exciting development!
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G 11:06PM (12/18/2005)
Mitsubishi Engineer #1-"So, guys, we've got a cheap, great handling sportscar. The only major advantage to competition has is reliability, and a little in comfort. How can we make it better in the future?"
Mitsubishi Engineer #2-"Let's add a complicated, expensive, and heavy hybrid system!"
Mitsubishi Executive-"Well, we are in dire financial straits, soooo.... Let's go for it!!!
Mitsubishi Engineers-"YAAAAYY!!!!
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Jay White 11:06PM (12/18/2005)
If you reread this article, you will see it states, "The all-electric EVO MIEV will be competing in the Shikoku EV Rally 2005". This is an Electric Vehicle Rally. Don't get your panties in a bunch just yet, Mitsu isn't abandoning gasoline engines, just finding a "fun" way to develope & test new products & technology.
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Paperkite 11:06PM (12/18/2005)
Does anyone know any link with what happenned at Shikoku? Did the rally took place?
Pleased to hear.
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Paul 11:06PM (12/18/2005)
I WANT ONE!!!
4WD and 50Kw per wheel! Plus electric motors produce max torque from 0 rpm to max rpm so we're talking about 200Kw and over 2000Nm of torque in this small four seater from the second you mash the throttle! What's that? 8 x the torque of the proper Evo 9 turbo version? That's more torque than your average Kenworth!
All braking can be done with the elecric motors but it would be much easier to control if they were AC. (these are perminant magnet DC) Regular friction brakes are flat out generating 90Nm of stopping torque, these electric wheel motors can apply 2000Nm!!
Forget about unsprung weight affecting handling, go and pick up up a suspension assembly? there's nothing light weight about them, cast iron disc brake, forged lower control arms, they're built to take a pounding on pot holed public roads and could never be described as 'light weight'. According to the pictures I've seen of these motors they're pretty light weight conpared to your average electric motor which is usually stuffed with as much iron in it's core as possible to increase the magnetic field of the coils.
But just try to imagine the 0-60 mph times this thing might be capable of... 4WD, 200Kw, 2000Nm and full torque from 0 rpm in a small car... I bet sub 2 secs is EASY, this Evo9 will make the rally evo look slow!!!
Check here to see an electric can blow off a Ferrari F355 by a truck length.
http://www.acpropulsion.com/tzero_pages/tzero_home.htm
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Bill Stanton 11:06PM (12/18/2005)
So, one of my clients in the Netherlands built a hybrid city bus with wheel motors and regenerative braking. The energy from regenerative braking (one stop every 1/4 mile from 30 mph)was so great they had to mount a resistor pack on the roof to get rid of power that the batteries couldn't handle, in the form of heat. Unfortunately, during a very strenuous acceleration/braking test at the local airport, the resistor pack overheated and burst into flames! The bus body was foam-reinforced fibreglass and the engineers forgot about adding antimony trioxide as a flame retardent, so the bus burned to the floor in less than 30 minutes.
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Gris Tuckker 11:06PM (12/18/2005)
If you will go for different alloy wheels then it will lok amazing.
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