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Gadgets Michelin Reinvents the Wheel
Shane McGlaun (Blog) - December 1, 2008 2:39 PM
Print 69 comment(s) - last by Chipper Smoltz.. on Dec 5 at 2:23 PM

Michelin Active Wheel  (Source: Michelin)
Active Wheel houses motor, brake, and suspension inside the wheel.

In 1895, Andre and Edouard Michelin, the founding brothers of the Michelin tire group, changed the automotive landscape by adding a tire to the car wheel. Before that, the wheel of a vehicle lacked a tire.

Michelin says that more than a century later it has reinvented the wheel again with a system it calls the Michelin Active Wheel. All essential components to an electric drive train are integrated into the wheel itself.

Inside the Active Wheel resides a brake rotor, brake caliper, suspension components, and the electric drive motor. The electric drive motor produces 30kW of continuous power and vehicles can have Active Wheel's on both front wheels or on all four wheels of the car. Michelin says that these configuration options allow carmakers to continue making front wheel drive and all wheel drive vehicles.

The electric motors can be powered by any electrical source including lithium ion batteries, fuel cells, or supercapacitors. Active Wheel powered vehicles are extremely quiet according to Michelin for the passengers inside the car and pedestrians.

The silence of the system could be an issue in the U.S. though with congress reportedly considering legislation to mandate minimum noise levels so electric vehicles are easier for pedestrians to spot. The suspension system used in the Active Wheel is electrically powered and offers a response rate of 3/1000ths of a second. Michelin says that pitching and rolling motion is automatically corrected.

Two vehicles debuted at the Paris Motor Show that use the Michelin Active Wheel. One of the vehicles is known as the Venturi Volage and uses four of the Active Wheels. The other vehicle is the WILL and uses two Active Wheels in a front drive configuration.

By moving all of the drive, braking, and suspension components into the wheels of the car, designers will have more room inside the car itself to add batteries and passenger space. These wheels could make it easier for designers to develop attractive electric vehicles that are smaller and offer higher performance.

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Unsprung weight
By Spyvie on 12/1/2008 2:49:05 PM , Rating: 5
A motor in the wheel is an obvious idea that has always ran into the problem of unsprung weight severely affecting the vehicles handling. Maybe Michelin has overcome this with the suspension components contained within the wheel assembly, cool! …though it remains to be seen how well a car with this power train would perform, especially on a less than optimum road surface.




RE: Unsprung weight
By Spyvie on 12/1/2008 2:52:26 PM , Rating: 1
My grammar fails


RE: Unsprung weight
By Amiga500 on 12/1/2008 3:18:42 PM , Rating: 3
Indeed, unsprung weight is a killer for handling.

It is actually possible that Michelin have reduced the unsprung weight here - as the motor would need to be mounted on the stationary wheel centre, and not the rotating wheel rim. There are no suspension arms which add inertia to the unsprung system.


RE: Unsprung weight
By Motoman on 12/1/2008 3:25:36 PM , Rating: 3
...if that little diagram is accurate, there's not really any room for suspended wheel movement anyway... An inch of travel isn't going to help much.

There have been motor-in-the-wheel designs before...on motorcycles (with a radial motor turning the crank/axle direclty) for example.

But the concern here is on the money...unsprung weight and the applicability of meaningful suspension.

Surely they don't think they'd suspend the entire motor/wheel assembly? That'd be a huge amount of weight to suspend.


RE: Unsprung weight
By tastyratz on 12/1/2008 4:09:36 PM , Rating: 4
I was just going to post that.

Absolutely - this is a novelty. While it sounds good on paper ultimately it will have WAY too much unsprung weight to handle satisfactory on a vehicle - even for a standard consumer. Standard rule of thumb in relation to handling is 1lb unsprung weight equates to 6lbs sprung weight. only 1lb each wheel x4 wheels x 6 = equivalent 24lbs. Doesn't sound like much but with somesort of assembly of that stature it would add up quickly.

I do support per wheel electric motors which are SPRUNG and not UNSPRUNG... I think its an excellent way to make a car hybrid while adding all wheel drive to any 2wd vehicle.


RE: Unsprung weight
By Gzus666 on 12/1/2008 4:24:10 PM , Rating: 4
This is meant for most of you guys. Take a good look at the picture, the amount of weight actually on the spindle is quite small. This is different since there is no control arms for the suspension, so geometry and other things are not really an issue. The motors are mounted to an outside "cage" if you will, and the spring, shock and spindle at connected to each other.

I hope this explains it well, as I can explain it better in person while showing the diagram piece by piece. Either way, really look at the picture and you should see why this isn't an issue.


RE: Unsprung weight
By tastyratz on 12/1/2008 5:42:49 PM , Rating: 5
This is no way thats a realistic drawing of a true product implementation in a consumer product.

There are several flaws with this. This entire design is around compromise - how much of one will you sacrifice for the other:

1. Geometry. All of those multilink arms exist for a reason. A wheel is not supposed to travel in a straight motion up and down for optimal driving conditions. Camber, Caster, Toe - They all play their role in optimal suspension design. If all wheels remaining parallel was the way to go we would just have springs and shocks at 90 degree angles and be done with it. I cant see the "suspension" on this existing for anything more than a helper to a real suspension - and in that case oscillations would make handling unpredictable.

2. effective suspension travel. You simply cannot package something like that in a reasonably sized wheel while retaining an effective stroke and suspension travel. Either compromises in travel or in wheel size are made.

3. Polar mass. Because you have such a big package to stuff inside the wheels you have to run larger diameter wheels to accommodate. Larger wheels are heavier, and the wheel itself will become an issue when considering sheer weight. That the polar mass is farther away from the center line requiring much more force to rotate. This is the reason low profile wheels/tires make a car slower even if the diameter is the same as well as the weight - all the weight is at the outside edge.

4. Heat. Brakes... electrical motors... suspension components... They can each produce a significant amount of heat, that small area doesn't give it many places to go.

They had an unbelievably excellent idea when they created the tweel.

http://www.michelin.com/corporate/actualites/en/ac...

This is not one of those ideas.


RE: Unsprung weight
By JediJeb on 12/1/2008 6:29:40 PM , Rating: 2
1. Geometry. All of those multilink arms exist for a reason. A wheel is not supposed to travel in a straight motion up and down for optimal driving conditions . Camber, Caster, Toe - They all play their role in optimal suspension design. If all wheels remaining parallel was the way to go we would just have springs and shocks at 90 degree angles and be done with it. I cant see the "suspension" on this existing for anything more than a helper to a real suspension - and in that case oscillations would make handling unpredictable.

Actually I believe the purpose of a multilink suspension is to make the wheel travel as much in a straight up and down motion as possible. If an old fashion straight axle is used you get a tilt of the wheels when one move up or down, which was unwanted, so the multilink was invented to allow the wheels to move vertically with no deflection. When multi links were first introduced they brought in a new problem of bump-steer, where one wheel moving caused it to deflect left or right because the geometry of the tie rods did not extend as the wheel moved. This was overcome by changing the design of the tie rods later.

I remember reading this as a teenager from a book I have called Smokey Yunik's Power Tricks, really good at explaining everything from engines to suspensions in building you own race car.


RE: Unsprung weight
By ziggo on 12/1/2008 10:25:02 PM , Rating: 2
Well designed multilinks do not move straight up and down perpendicular to the chassis. They have uncreasing camber to adjust to the body roll of the vehicle to ensure that the wheel remains perpendicular or has positive camber when the suspension compresses during cornering.


RE: Unsprung weight
By Gzus666 on 12/1/2008 7:22:36 PM , Rating: 1
1. The goal of suspension geometry is to maintain a 90 degree angle for camber, obviously this is never perfect with the current way things are done. From what I read in their press release, the whole thing is active and can be adjusted on the fly, which should mean optimum suspension geometry the entire stroke no matter what angle the wheels are turned or moved. Mercedes has done this with one of their vehicles where they have active camber adjustment in the control arms which handles amazingly.

2. You have maybe 10 inches tops of needed spring travel required for normal cars, if more is really needed, a spring/shock combo could be added to the connection point on the vehicle itself, but I doubt it would be needed.

3. Larger wheels maybe be slightly heavier, but they usually have lower profile tires, that is reduced weight from less rubber, cords and steel belts. On top of that, rotational weight isn't going to be that big of a deal when you are talking about a few pounds at most.

An example, on my old 2002 Trans Am, I changed from the factory flywheel (connected in a similar fashion in simplistic terms as the wheel/motor above) to an aftermarket aluminum version that was half the weight. This is a reduction from 25 pounds to 12.5 pounds. This increased power by about 5hp maybe and slightly increased rev up. That is on a gas engine, which by nature are more affected by weight for initial start than electric motors.

Now, we are effectively adding maybe a pound or two for the motor at each wheel to deal with, electric motors benefit from instant torque, no rev up required. Once the initial friction is broken, the momentum of the additional weight is pretty much unnoticed. Even better is we are dropping the driveshaft, transmission, differential and all the joints and axles that joint them which as you can imagine will make a substantial difference in power to the wheels as this is normally 15-17% for manual transmission vehicles and about 20-25% for automatics. Honestly this whole portion of it is rather silly as it won't be an issue.

Now, granted having the weight on the outside wheels will not be the greatest, but it still isn't rotational weight, so it matters very little for speed and if done correctly, will still handle fantastically.

4. You have LOTS of air flow through there and plumbing cooling ducts to them would do a fantastic job of helping if needed.


RE: Unsprung weight
By mindless1 on 12/1/2008 10:53:07 PM , Rating: 3
1. Oops, this active adjustment is another complexity that, while great if it works, means more wear, failures, expense.

2. 10 inches of spring travel is a huge amount to have inside a wheel.

3. Larger wheels are more than slightly heavier. It is not lower weight from less rubber, because there had to be structural aluminum or carbon fiber and based on how it's designed, brake rotor diameter. Rotational weight of a few pounds is significant when you consider a wheel doesn't normally weigh near even 100 lbs. Remember, this is not an exercise in meeting ICE car efficiency, it's about beating it.

4. Replacing a steel part with an aluminum one has no bearing on replacing a totally different design with parts that will be steel, like the rotor and spring.

5. A pound or two for the motor? Did you by chance check to see what a motor with this torque weighs if it's built to last more than a few thousand hours?

6. YOu don't want lots of airflow (maximized) through there, because this is not a lab this is all-season road driving where lots of flow means even more salt water and road debris pelted upon prototype parts with no track record for survival. Of course they can be engineered to survive it, at a cost premium thus far unseen.


RE: Unsprung weight
By tastyratz on 12/2/2008 12:22:17 AM , Rating: 2
bingo on 1. btw much of this is directed towards gzus666, some are just general comments.

10 inches sounds like nothing but that's MINIMUM clearance beyond the scope of the entire assemblies size so it doesn't touch the wheel. Are we ready for 32 inch wheels on passenger cars? Are we really going to all start driving donks?
Let's try this on Suv's and see what happens.

Again gzus you cant add a strut/spring to this setup due to unpredictable suspension oscillations and unreliable handling. A suspension on a suspension would be dangerous and geometry couldn't be reliably retained over such a wide scope. If you travel 4 inches on the wheel suspension and 2 inches on the car suspension and froze it in time the wheel would not be in the same place it would be in if the wheel suspension traveled 1 inch and the car suspension traveled 5 inches.

Also to back up the tire weight statement - the lower profile tires require the same load rating so more material reinforcement is needed to compensate for the reduced compression area in the sidewall.
Also consider that a wheel itself's weight is either in the face or in the shell - by expanding the shell (larger diameter) you shift a majority of the weight to the outer edge (polar mass again)

An honest realistic minimum expectation from me on this: I would be shocked if this could be pulled off with less than a 22inch wheel in the standard consumer space. I would also suspect as an assembly this adds a minimum of 50lbs to each corner. Way to make a corolla drive like a hummer.

Also to comment on earlier posts about suspension geometry: Camber will compensate for pitch and roll of the vehicle. As the body changes angle the required tire angle for parallel surface contact changes. Also, as side loads increase on the bottom of the wheel it pushes the outside wheels into positive camber making for less contact with the road. This is another reason for camber under compression. Tires flex and roll under load as well but resist with negative camber

If you are running full speed in a small diameter circle (think car not 3 stooges) do you remain parallel to the ground or do you lean?

I could write a book on suspension geometry and barely scratch the surface.

Suspension sees incredibly high forces under load - for a truly effective active suspension you would need massive heavy duty electrical draw. Just how does that impact the range and effectiveness of the electrical motors there in the first place?


RE: Unsprung weight
By Gzus666 on 12/2/2008 10:04:34 AM , Rating: 2
10 inches is hardly minimum for a small vehicle, you could get away with that on small trucks. You are blowing this out of proportion, do you think this did not come up when they engineered this? Michelin makes some of the best tires in the world, do you not think they know what they are doing?

quote:
Again gzus you cant add a strut/spring to this setup due to unpredictable suspension oscillations and unreliable handling.


It won't be unpredictable if you engineer it properly and make it active rather than passive just like the existing setup. Oscillations? That is what shocks prevent, not sure what exactly you are trying to say here, but I have a feeling some of this is based on ignorance to the subject. Honestly I said it would be possible, but really not needed as stated above anyway. Could it be done? Sure.

As I said on the wheel and tire, I understand it will add some weight, but it is negligible compared to the weight and friction you are dropping from drive train anyway.

If it required a 22 inch wheel minimum, they wouldn't be even wasting their time as most electric vehicles right now are quite small anyway.

You aren't compensating you are trying to have the tire as flat to the road as possible ie. 90 degree angle with the road. This gives the highest contact patch possible. The problem with passive suspension is the camber will move negative or positive depending on the conditions and you will lose contact patch which will cause handling to suffer. Tires roll, you build it into the design to compensate with load sensors (same as they use for stability control systems), all vehicles will suffer this same issue, so it is moot.

As for the 50 pounds per wheel, so? It isn't rotational weight. The weight is low so center of gravity is unaffected, the only real issue might be turning, but even then, with a properly designed pivot and steering gear, the issue is gone.

Also, the car leaning (body roll) will be less of an issue with active suspension, just take a look at any sport suspension vehicle with active suspension, they will destroy their passive counterparts due to being able to reduce roll while still maintaining ride quality.

You seem to forget mechanical advantage would run rampant here and active suspension systems exist and destroy their passive counterparts. I agree battery power would be an issue, but it is a hurdle that seems to be an issue with electric vehicles anyway.

Not trying to be a jerk, but I really don't think you could write a book on suspension geometry as I have met many people who have a heavier grasp on it. You seem to be making up problems that would be of little issue to get past with current technology.


RE: Unsprung weight
By tastyratz on 12/2/2008 1:23:10 PM , Rating: 2
You seem to see the picture only as rotational weight as a whole, and devalue the weight as a polar change, and as an unsprung change.

Sprung weight low to the ground is the weight we need the least concern of. It's what matters the least as far as priorities go.

UNSprung weight is precious and every lb counts. The wheel and brake assembly as well as the spring/shock would count as unsprung. Thats a HUGE amount of weight to change. Any arms in a typical setup are half sprung half unsprung obviously as you move closer to the pivot points. I would be surprised if this didn't DOUBLE unsprung weight.

As far as rotational mass: You will certainly not really notice it once its in motion as you have raised in other points, but you will require additional force to brake and accelerate changing the moment of inertia. To very crudely calculate moment of inertia you use the following formula
I=mr2(squared)
Much of this is just for arguments sake.
Lets say the tire is 21lbs on a 15 inch wheel vs a 20 inch wheel even. Lets also pretend all other factors are constant even though impossible such as wheel weights, and tire weight changes from a larger diameter tire which is an obvious given.

The number I come up with is 4725 vs 8400... a 77% increase in force required to turn that same 21lbs effectively almost doubling its weight. Considering the realistic change in weight for the wheel shell, the wheel itself, and everything else - that is a significant change. If a standard wheel and tire might be 40-50lbs, and this ADDS 50lbs that's double before you even consider its location.

That also doesn't consider what appears to be prettymuch ineffective show brakes off a motorcycle. Leveraging against the rotor from a distance farther than the center will give more braking force from a smaller/lighter caliper which is good. Rotors are essentially heatsinks - you cant get away from that and they work off of mass. This shifts all the mass to the outer edge. - it could also work negatively raising rotor weight so a reasonable thickness could be kept to avoid warpage.

Even if something like this could operate without any form of transmission (which it wont), Driveline loses are a couple hundred lbs usually split over 2 wheels - The extra force required for this assembly in comparison per wheel would probably not be any drastic savings in application.

Absolutely suspension would be unpredictable if you essentially add a knee (Fixed mounting point for the wheels suspension) to the middle of the total suspension system. Top to bottom stroke and travel will be different based on the position in each suspension. Anything can be done, but it would be terrible at best.

Having the wheel as flat to the road as possible IS the ultimate goal, however when the chassis is not parallel to the ground, flat to the road is not parallel to the chassis. When cornering hard having negative camber on the outside wheel, and positive camber on the inside wheel is optimal in keeping the tire square with the ground. Camber is in relation to the chassis to make the tire remain neutral to the ground. I will admit, this is not optimal with fore and aft suspension load (under no side load forces) Straight line braking and acceleration maximum traction would be achieved with a setup like this one (which is a positive for it) - but we don't only drive in straight lines. I think electronically controlled link arms are a magnificent idea allowing the best of both worlds. This setup just does not appear to be optimal for controlling camber, caster, and toe. You really would need to be able to dynamically pivot the wheel on its axis in 4 directions which I see no provision for in that picture... nevermind the massive motor that would be required to overcome the staggering forces it would see.

Active suspension as part of a McPherson setup is good such as magnetic dampers, electrically adjustable multilink arms, etc. This is a different class.
You mention sports cars with active suspension like this which have better handling - show me 1 production vehicle.


RE: Unsprung weight
By Gzus666 on 12/2/2008 9:42:12 AM , Rating: 1
1. So? The argument is that it is possible, reliability is dependent on the parts used, it could easily last the life of the vehicle if properly engineered.

2. So? Look at the design, it shouldn't be an issue and I'm pretty sure Michelin engineers have thought this through.

3. Right, but as I said, you are dropping rotational weight anyway. Do you think axles weigh nothing on a conventional car? Do you think drive train weight adds nothing? Do you think that conventional design doesn't have rotor weight to worry about? What about all that friction that is no longer a problem?

4. Huh? The point was weight loss, not the material. Spring is not part of the rotational weight, please look at the picture more closely and you should be able to see how it works.

5. I didn't say that it was a pound or two for the motor, I said it was an additional pound or two for the motor to turn, the motor itself is not part of rotational weight as it is fixed.

6. Air flow ducts are quite common on high performance cars and help cool these systems, why you think all this stuff would flow through these ducts is confusing me, but I have a feeling by the rest of this you have very little mechanical understanding.


RE: Unsprung weight
By Suntan on 12/4/2008 4:19:02 PM , Rating: 1
quote:
I have a feeling by the rest of this you have very little mechanical understanding.


I have more than just a feeling that this statement applies to you more than he.

Just because *you* don’t understand why these things are non-starters does not mean that they are anything other than non-starters.

Anyway, if you can’t grasp the realities of why this is nothing more than marketing gimmickry that will never go beyond a couple of fantasy concept cars at the goofball Tokyo autoshow (where there seems to be an unwritten contest to show off the weirdest shite you can) ask yourself this. Is it realistic to think that a tire company has successfully developed a complete, turn-key propulsion system that fits inside the space that is currently taken up by just a conventional brake, when all the automotive companies across the world have not been able to do the same even though they have all been working on various wheel motor projects for quite a few years?

Now if your answer to that question is still “yes” after you think about it a little more, congratulations, you are truly in a world of your own.

-Suntan


RE: Unsprung weight
By Samus on 12/3/2008 1:45:00 AM , Rating: 2
It's a good idea...I just don't wanna own a vehicle with one and hit a $2000 pothole.


RE: Unsprung weight
By InsaneGain on 12/1/2008 4:00:27 PM , Rating: 2
It looks like this wheel has a fully active suspension system. Doesn't active suspension make unsprung weight much less relevant to handling? The suspension motor actively handles the movement of the wheel, and you wouldn't even know you hit a bump.


RE: Unsprung weight
By mindless1 on 12/1/2008 10:57:33 PM , Rating: 2
You will always know you hit a bump, a suspension reacts to the bump, not proactively acting against it till we have some kind of sonar or other detection to act ahead of time.

This is not a true active suspension. It's an electric reactive suspension. That doesn't make it terrible by any stretch, it just means idealizing about it against suspension tech that is mature and had undergone equivalent scrutiny for dozens of times as long would be premature at best.


RE: Unsprung weight
By Omega215D on 12/1/2008 8:37:01 PM , Rating: 2
WHatever happened to Michelin's other reinvention of the wheel known as the Tweel? It's basically just tread connected to some kind of flexible material, no air or tubes required which makes flats a thing of the past.


RE: Unsprung weight
By Suntan on 12/4/2008 4:26:15 PM , Rating: 2
Its more than just that. You can tailor the dynamic characteristics of it to best suit the application, more so even than the newer advances in radial wound pneumatic tires.

Imagine a tire that gives extremely compliant motion in the radial direction, but extremely stiff resistance to axial motion. A tire that rides as smooth as a floaty old person’s car, but can corner flat like a car that has rock hard rubberband wheels.

-Suntan


RE: Unsprung weight
By slawless on 12/1/2008 9:46:50 PM , Rating: 2
I remember they tried this in the 80's. they ran into a problem controlling the motors speed during a turn as each wheel is turning at a different rate. computers are a little better today so mayby they have that solved.

As far as unsprung weight. these cars will not be designed for performance.


Suspension Travel
By Sanity on 12/1/2008 2:59:02 PM , Rating: 2
I can't quite tell where the wheel would anchor to the vehicle, but to get the maximum suspension travel (up and down) you'd want the anchor point to be mid-way up the wheel. Or above that point, assuming that the wheel wouldn't need to travel down as far as it would up. It looks like that flange near the bottom is the anchor (could be wrong), and it wouldn't be any good for anything other than a near smooth surface.




RE: Suspension Travel
By mindless1 on 12/1/2008 3:36:53 PM , Rating: 2
You don't generally need the same travel both up and down, moreso (the wheel) up relative to the frame, but of course it depends on the terrain, this obviously isn't an off-road wheel.


RE: Suspension Travel
By mindless1 on 12/1/2008 3:44:02 PM , Rating: 2
I should elaborate a bit. The typical suspension spring arrangement, and how it looks to be on this wheel as well, fixes the weight of the vehicle through the frame or adjoining rigid metal, to rest on a top plate sitting on the top of the spring with empty space above it for upwards travel. Stops and a shock or strut (as well as gravity) limit travel in this direction. The bottom of the spring sits in a tray rigidly coupled to the wheel, or actually a connected portion of the wheel with rigidity in respect to vertical movement.

In other words, it's a gravity versus compression and dampening situation, not the weight being held in the middle of two sections of spring opposing each other. Perhaps that is what you meant and I simply misunderstood.


RE: Suspension Travel
By Sanity on 12/1/2008 4:42:45 PM , Rating: 2
Yes, that's essentially what I was getting at. I was looking at the system from the frame's point of view, with the wheel itself moving up or down.

Just looking at the wheel, if that flange is the place where the wheel bolts to the frame, the weight of the car settling on the suspension would drop that flange to the rim of the wheel. (this is assuming that the flange is the correct anchor) This wouldn't allow any upwards travel of the wheel (going over a speed bump) at all. Even if it's stiff enough to not settle with the weight of the car, there's not enough travel room. I wouldn't want my cars frame that close the the pavement either. Unless I'm driving a race car.

Maybe that picture is upside down. o.0

Eh, I'm sure they know what they're doing. I was just making an observation.


cost?
By 4wardtristan on 12/1/2008 5:05:02 PM , Rating: 2
good idea for many reasons, but how much will these cost?

i just had to get replacement tyres for my commodore, at 80$ AUD per tyre

will these cost 80$ a tyre? try quadrupling that...




RE: cost?
By cokbun on 12/2/2008 1:07:24 AM , Rating: 2
most cars have 2 wheels powered by an engine, the other 2 are just for turning.

but a 80$ unimotocycle ? cool!


RE: cost?
By Gzus666 on 12/2/2008 10:07:51 AM , Rating: 3
The tires are no different from conventional tires, why would they cost more than their normal counterparts? Speculation is running rampant here.


A great idea in 2006...
By austinag on 12/1/2008 3:05:40 PM , Rating: 2
I like this application of the tech better:

http://www.autoblog.com/2006/07/21/pml-s-mini-qed-...




RE: A great idea in 2006...
By foolsgambit11 on 12/1/2008 7:18:05 PM , Rating: 2
I had an old back issue of Popular Mechanics, or maybe Popular Science, I don't remember. It was from the early 60's, and along with an explanation of the transistor, there was a bit about a military truck (a 5-ton, I think) with a motor in each wheel. It's not new tech at all....


RE: A great idea in 2006...
By cokbun on 12/2/2008 1:20:02 AM , Rating: 2
I was expecting the Tweel
By KingstonU on 12/1/2008 4:48:07 PM , Rating: 2
The Tweel has been in development by Michelin forever, I got excited to think that this was the big news. The Tweel is much better than today's conventional tire. It can never get a flat so it is safer. The treads can be replaced so it last longer. There is less maintenance or effect of temperature. The resistance of the rubber spokes can be made to work in all vehicle types. The thing is that is it cheaper for the consumer, so less profit for Michelin. Hence why they scrapped it.

This Active Wheel is underwhelming and will likely just be more expensive and require more maintenance = more money for Michelin.




RE: I was expecting the Tweel
By austinag on 12/1/2008 6:13:59 PM , Rating: 2
Did the really scrap the tweel, or is it still in development? Anyone?


RE: I was expecting the Tweel
By Suntan on 12/4/2008 4:30:39 PM , Rating: 2
We’ve looked at using it off and on for off-road/turf tire applications. Then Michelin quotes a price for the application and it goes no farther when compared to a conventional pneumatic tire.

-Suntan


Interesting, but...
By Jimbo1234 on 12/1/2008 10:37:37 PM , Rating: 2
The unsprung mass appears to be quite large. This should not be much of an issue due to the active suspension. However, there is quite a bit of mass to move for steering. The spindle that attaches near the active motor is where the wheel pivots for steering. This will require some extra assist and make feedback horrible.

The other issue is rigidity. The spindle is a single cantilevered beam. It will bend and twist. This will be bad during acceleration, braking, and cornering; basically in all aspects of driving. Conventional suspension systems with multiple links are more like a truss: very rigid and precise.

Active suspension was used on the Infinity I or J or whatever that was in the 90's. If I recall correctly, it was also used in Formula 1 for a few years. Guess how many cars use it today? Active suspension lead to the development of much better conventional mechanisms with magnetic damping, etc.

The hubless wheel is a much better invention in my opinion. This application may be useful for small urban commuter cars and not much else. 30kW per wheel is 40hp per wheel. 160 total horsepower is not that much foy a typical midsize car.

Also the disadvantage of wheel motors is that each wheel is limited to 40hp. If I substitued for these 4 motors a single 160hp motor with drive shafts and differentials, I could then send 160hp to a single wheel if needed (assuming 0 driveline losses - in reality this would be less but still much more than 40).

The bottom line is that I do not see this being a revolutionary design that will change the way cars are built, but it is thinking outside the box that will bring forth other new ideas. And that is never a bad thing.




RE: Interesting, but...
By Gzus666 on 12/2/2008 10:21:55 AM , Rating: 2
It seems like you answer a lot of your own questions here, but as for the electric motors being better through a normal drive train, normal drive train losses are around 15-20% plus the added weight (normally a CVT automatic that is used for electrics is around 250-350 pounds depending on it being a transmission or a transaxle) Also take into account weight of drive shafts and torsion through them. On top of that, you also drop the need for transmission and differential fluid maintenance and the costly repairs associated with them.

All in all, it is really a well thought out design. Power is efficiently pushed to the wheels with minimal parts needed and pretty much no maintenance.


RE: Interesting, but...
By tastyratz on 12/2/2008 11:17:49 AM , Rating: 2
It doesn't eliminate the need for a transmission though.

There is a reason they typically use cvt's on electrical drivetrain's - the electric motor has a point of operation efficiency it should stay in. You cant really use them in a practical direct drive scenario so there has to be at least SOME form of transmission there for the system to work well at any given speed.


Dyson Wheel
By Mitch101 on 12/1/2008 5:00:46 PM , Rating: 2
I'm waiting for Dyson to make a new wheel then run commercials that make us feel stupid we didn't think of it sooner.




RE: Dyson Wheel
By Suntan on 12/4/2008 4:32:51 PM , Rating: 2
I’m waiting for someone to make a new wheel… and then run that Dyson guy over with it.

Come to think of it, it doesn’t even have to be a new wheel.

-Suntan


Ohh, spare tire? Nasty
By lemonadesoda on 12/1/2008 5:53:31 PM , Rating: 2
1./ I dont think the wife would be able to change a flat tire. Imagine the weight of that thing. And the price of each wheel, plus the spare in the boot. I wouldnt want to come back to the car and see it standing on bricks... the wheels stolen by an enterprising chop-shop.

2./ Perfect for golf buggies, fork lifts, and other low-speed low-suspension-needs vehicles. Lots of industrial, enclosed cover, or airport applications.




RE: Ohh, spare tire? Nasty
By mindless1 on 12/1/2008 11:04:30 PM , Rating: 2
I don't have all the info, but I expect that the outer rim and tire are bolted to a center plate such that changing a tire is not so different than it always was, except possibly a few more lug nuts than in the past.

On the other hand, if you're parked in a high crime area with multi-hundred, let alone thousands of dollars worth of electric wheels that can be unbolted, there will definitely be a few cars sitting on blocks without wheels. If they're modularized such that the wheel can be reused on multiple vehicles, it raise the value and lowers the difficulty in reselling it all the more except in the case of exotic car parts... cars that don't park in higher crime areas so much.


Ugh
By Spivonious on 12/1/2008 2:42:29 PM , Rating: 3
I just hope they make the "Active Wheel" modularized, so if one piece of it breaks, I don't have to buy a whole new wheel.

It does open up the interesting situation of getting a loaner wheel when getting work done on your car.




Here is a thought to chew on
By Imaginer on 12/1/2008 2:49:59 PM , Rating: 2
highways with integrated fields that will induce power to these active wheels. You have the benefits of public transportation but your own private vehicle running on these highways.




Reinvent the wheel again?
By spread on 12/1/2008 6:44:55 PM , Rating: 2
I'm still waiting for the Tweel.




Damn it Michelin
By Howard on 12/1/2008 9:59:11 PM , Rating: 2
I was hoping for news about the tweel.




Modular
By abitofgo on 12/2/2008 6:35:50 AM , Rating: 2
I like this.

Hopefully all the wheels will be the same. With standard connectors. If there is a problem with the wheel swop it out. Then you pay a small flat fee for maintenance.

When you reach a certain mileage go to a shop and get a whole set of new wheels then the existing wheels get sent off for refurbising, to be used by someone else.

As the wheels increase in quality get more refined you could then just upgrade the wheel. But they would still be backwards compatible. (A bit like putting DDR2 400 and DDR2 800 it will go to DDR2 400 Speeds)




Silence is safer
By nomentanus on 12/3/2008 2:54:09 PM , Rating: 2
Risk homeostasis suggests that silent vehicles will eventually result in fewer pedestrians being injured, because we'll stop unconsciously relying on our hearing (quite a fallible choice in urban settings, or once you buy an MP3 player) and being so lazy about looking around us. I'm a lot more attentive all the time, now that I wear an MP3 player some of the time: I have much better, and more uniform safety habits.

They thought ABS brakes would be a safely marvel, too. But it wasn't so. People adapt.




30 kw motor
By Andrwken on 12/3/2008 6:04:05 PM , Rating: 2
I find it hard to believe that the motor in that picture can generate 30kw continuous. If so, that is the smallest 40 hp electric motor I have ever seen. Most of my experience is on the 3 phase AC side of things and a 40hp electric would barely fit in the trunk much less in the wheel. I have heard of 30kw mounted on the rear axle but not in the wheel. Anyone have any info to back up this miniature marvel?




By Chipper Smoltz DT on 12/5/2008 2:23:07 PM , Rating: 2
Maybe a car with auto pilot could be invented instead. Just input the coordinates of the city that you would want to travel to and with the help of a GPS, the car should be able to manuever just by itself without the aid of a driver (or if the driver is sleeping or inebriated). Sensors mounted in the front and rear would alert the "sleeping" driver or automatically make the car stop, drive slower or accelerate depending on the proximity of the obstacle. At least that would save alot of trouble and further alleviate some potential accidents.

Only problem is glitches that might occur once the car is in motion and if it is to be controlled by an aritificial intelligent computer. Anyways, no one wants to buy a car nowadays since the economy is doing bad but in time this might be a very popular vehicle to have. Or is this idea has too many flaws? Just trying to help guys. Sorry =(




By Chipper Smoltz DT on 12/5/2008 2:23:12 PM , Rating: 2
Maybe a car with auto pilot could be invented instead. Just input the coordinates of the city that you would want to travel to and with the help of a GPS, the car should be able to manuever just by itself without the aid of a driver (or if the driver is sleeping or inebriated). Sensors mounted in the front and rear would alert the "sleeping" driver or automatically make the car stop, drive slower or accelerate depending on the proximity of the obstacle. At least that would save alot of trouble and further alleviate some potential accidents.

Only problem is glitches that might occur once the car is in motion and if it is to be controlled by an aritificial intelligent computer. Anyways, no one wants to buy a car nowadays since the economy is doing bad but in time this might be a very popular vehicle to have. Or is this idea has too many flaws? Just trying to help guys. Sorry =(




Just what I'd expect
By mindless1 on 12/1/2008 3:25:38 PM , Rating: 1
... from Michelin, a large more expensive tire which from it's width will have more drag. Perfect for an electric fake muscle car, not so good for the goal of high efficiency. Granted that's only my impression at first glimpse, but it looks a lot like several compromises were made to get it all to fit in the wheel.




backward compatibility
By Screwballl on 12/1/2008 4:46:20 PM , Rating: 1
ok once they get this perfected, I hope they release mod kits starting with existing compact cars and work their way up. Imagine power assistance for a full size truck pulling a load (with 2 of these up front and normal engine power at the rear). Would be easy enough to have a flat stack of batteries either under the truck bed or take up a front/side/corner of the truck bed being recharged by a second high output alternator/generator.

Oh wait, big oil with squash this before it ever reaches the US shores...




No thanks
By FITCamaro on 12/1/08, Rating: -1
RE: No thanks
By Gzus666 on 12/1/2008 2:48:33 PM , Rating: 5
If you look, the bottom piece that lips out should be what would best be called a "spindle". Wiring most likely is run through there since it is fixed and can be run up to the controller.

As for the 2nd part, come on, don't be silly. Clearly they are separate pieces that can be changed out.


RE: No thanks
By mindless1 on 12/1/08, Rating: 0
RE: No thanks
By Gzus666 on 12/1/2008 3:56:43 PM , Rating: 3
Of course it will, cause it isn't a conventional wheel. It will be setup to support and be fitted with all these items. There are tons of parts that you can only get from dealers for a while. Last I checked most every car comes with a 36/36 warranty or better, which gives them that much time to make aftermarket replacement parts. Being that most of the parts in there are quite simple, there will most likely be a low amount of failures anyway.

Springs and shocks aren't going to be much of an issue on this, nor should much else there it seems. Electric motors are usually quite sturdy and easily repaired if need be. Brakes look like your usual hydraulics, which rarely fail. Seriously, what are you expecting to fail here?


RE: No thanks
By mindless1 on 12/1/2008 10:35:47 PM , Rating: 2
LOL. You think because a part is simple it won't fail? Let me tell you about the $250 door latch spring a Ford dealership once wanted to charge me. A hardware store, $1, and an hour later it was fixed. Not so with parts like this wheel which are specially designed.

The warranty is not a consolation. I don't want to be ferried around or take a loner car instead of what I chose to buy and I doubt you do either. That's also typically drivetrain not suspension parts so we'll see what kind of warranty coverage new tech has.

There will be higher failures, as always on a radically new design. That's what further revisions are for. If car engineering tech was to the standards you propose, few parts would ever fail already, not be waiting for a total shift to electric drive to come to pass.

Shocks and springs aren't an issue? Based on what, your guesses? I can replace a shock for $15 and 20 minutes of my time. It may take more time than that to figure out how to get access to the bolts on this wheel. The point is, yeah I'm heavily into DIY, for good reason. People doing the grunt work at most shops don't pay attention do detail because it's not their car. I've never had a repair I did end up as bad on average as one done at a shop, at that at about 1/4th the price and the piece of mind not having to guess about what they did... and I have plenty of stories about parts that didn't need replaced and hack jobs instead of proper repairs to other people's cars that they begged me to correct.

Electric motors are sturdy enough, but "quite easily" repaired is nonsense. They're a new part with limited availability. Do you know of any motor winding shops in your area that do electric car motors? You are making up nonsense.

Seriously, I'm expecting every single part that hasn't had years of real world testing to fail. Think about it, none of the parts on a conventional ICE automobile weren't refined several times over many years. It's not that I want to stay with ICE vehicles, but it's just as important to recognize the negative issues as the positive ones. Repair cost is an issue, if it isn't considered then the sticker price is worthless as an indicator of TCO over the desired lifespan of the vehicle.

Brakes look like hydraulics which rarely fail? Nonsense. Over the useful life of a car, if it's otherwise maintained, it is expected the calipers will need either rebuilt or replaced. After a certain age the brake lines including final rubber extensions too for safety reasons. Just putting brake pads on and turning the rotors and/or replacing them is bound to cost quite a bit and this happens every year for anyone who drives a lot.

Perhaps you were only thinking in terms of the first couple years of ownership then putting the car in a landfill. Ok, it's your money and if that's what you want then ok so long as you don't mind living next to one of these landfills. More reasonably, we have to consider what the average age of a vehicle on the road is and what parts will need attention during that period, but then we're still only considering lifespan of parts matured through generations of refinements, not a new prototype that probably hasn't even seen a single winter with salt on the roads, let alone a teenager doing doughnuts in someone's front yard.

Basically, you are idealizing without any evidence to support the theories, with only evidence to the contrary when it comes to past efforts by the automobile industry.

In the end, what WON'T fail? If we want a green future, we have the beginnings of that if thinking in terms of every small factor that can pose a problem over a timeline even longer than today's automobiles are expected to last. That's a key thing to think about, if we modularize cars to the point where swapping an engine is about putting different wheels on, a different battery pack in, or even swapping the seats out when the cushions get worn, all those little things so easily ignored weigh against the cost:benefit ratio and determine when a car goes to a landfill vs being reused.

Reusing a car is green given some forethought about being able to do it. That is not in automaker's best interests, but it can be swayed in that direction if your buying choices reflect this preference... even if it only means you want more resale value because it's expected to last longer.


RE: No thanks
By mindless1 on 12/1/2008 3:33:49 PM , Rating: 3
Also, yes it can cost a few grand to replace a wheel and suspension parts... on a conventional car. Replacing the lower control arm alone can be near $1000 at a shop.


RE: No thanks
By FITCamaro on 12/1/08, Rating: -1
RE: No thanks
By FITCamaro on 12/1/2008 3:55:53 PM , Rating: 3
Also with all that weight on the wheels, rotating your tires is gonna be a b*tch. Guess that's one way to insure that you bring your car to the dealership.

All I know is I'm getting tired of cars becoming ever more difficult to fix on your own. The average Joe used to be able to wrench on a car and fix it with a bare minimum of tools. Now days you practically need a mechanical and electrical engineering degree. Not to mention far more tools and expensive devices to hook into the computer to diagnose simple issues. As much as I love the power and efficiency these new V8s have, you just can't beat the simplicity of the old Gen I V8. Tuning involves a flat head screw driver and changing jets in the carb. Now days you're lucky if you can change the spark plugs on your own with how tight the engine bays are.


RE: No thanks
By Gzus666 on 12/1/2008 4:18:51 PM , Rating: 2
Well, looks like it is an inner ring, most likely the spindle portion stays mounted and the wheel will dismount with a ring. Remember, they still have to be able to get this stuff off to balance, rotate and change wheels/tires.

They are only difficult to fix if you don't keep up with the times. My pop seems to have no issues fixing any of his newer vehicles short of transmission tear downs cause of lack of space and tools. A friend of mine who used to be a mechanic turned machinist who worked for GM in the 70s seems to do just fine with his newer stuff.

Fixing electrical problems just requires a wiring diagram and some basic testing tools, which aren't that expensive and come in handy for pretty much anything electrical anyway. Granted I'm not your average guy, I'm an ex-mechanic with ASE master certification and about $25k in tools, but my pop has none of that and can trace an electrical problem without much issue and do just about any work himself. In other words, if you don't keep up with the times, you get left behind.

Think about it another way, most of us here have a pretty in depth understanding of computers, we can work on our own, build our own and do lots of other things with them. Think of the laymen or the people who haven't stuck with PCs over the years, they surely get left in the dust with the new technology, so they are at the mercy of repair persons just like others with cars.

I mean, hell, I can't program. I stuck my nose into it some, but it bored me to tears so I put it up. I am at the mercy of programmers to make things I want because of this. If the people who can didn't update their programming skill, they would be that guy complaining about how easy it was to program before, but now it is so complicated you have to have a degree in it to do it.

I guess more food for thought, but give the stuff a chance, it really is easy to work on if you realize how it should be worked on.


RE: No thanks
By Gzus666 on 12/1/2008 3:58:29 PM , Rating: 2
Why would they throw wiring everywhere in a press release that is meant to "ooo" and "ahhh"?


RE: No thanks
By mindless1 on 12/1/2008 10:42:47 PM , Rating: 3
To continually remind people this is oooh, ahhh, greeeen, tech. Most tree-huggers, if you show them a picture of a brake caliper, spring, shock and tire, they yawn. Show them a motor with a wire that goes to a battery and they jump up and down.


RE: No thanks
By andrinoaa on 12/2/2008 12:52:17 AM , Rating: 2
For anyone who cares, Seimens has had the idea on the books for years, do a search on gizmag.
This wheel is expensive to replace, doh. Just the fact it replaces what we already have plus THE MOTOR plus THE TRANSMISSION, makes it cheaper to manufacture. The only real problem is cabling. I read somewhere that fatigue from all movement limits its life. Now this may need to be replaced every now and then, similar to brake pads. Lack of verticle movement means larger diameter tyres/wheels. I for one can accept this compromise, after all larger tyre/wheels give us better grip, braking and fills the wheel arch better, lol!
Mindless1, you do have a sense of humour, I nearly missed it!


RE: No thanks
By undermined on 12/2/2008 4:59:56 AM , Rating: 2
Also must heavy wheeled vehicles like catapillar loaders and those huge house sized dumps use electric drive moters mounted in the hub of the wheel.

So it is not a new idea by far. I think they want to downscale this thech for regenrative braking and also because it makes more room for batteries within the chassis of the vehicle.


RE: No thanks
By Jimbo1234 on 12/2/2008 11:19:41 PM , Rating: 2
Not exactly. I used to be a design engineer at one of those. The traction motors do not fit into the wheel. They are in an unsprung axle housing, aka live axle, aka solid rear axle. There is no steering to worry about and the suspension is not inside the wheel.

On top of that there are also 2 sets of planetary gears for torque multiplication and wet disc brakes in case of electrical failure.

The loaders you speak of are articulated. Again, there are no steering components at the wheels.


RE: No thanks
By undermined on 12/3/2008 1:30:21 AM , Rating: 2
yeah I ment to more clearly suggest that the idea that this is a totally new invention or idea on michlin's part is false not to suggest that those loaders were using the same systems.

If I recall the humvee used a type of hub mounted drive system of something too. So it's more just me not thinking the article's title being accurate enough.


RE: No thanks
By Suntan on 12/4/2008 4:42:16 PM , Rating: 2
The Humvee has a gearset in the hub of the wheel such that the drive axel comes into the wheel hub assembly above the center of the wheel. This has more to do with increased ground clearance than anything else. That way you are not as likely to hit the drive axels on things you straddle as you drive over them. It also elevates the drive axel higher off the ground from shrapnel from a mine, etc. (you can drive away on a busted up wheel after a mine hit, but if you lose the driveshafts you are SOL.)

-Suntan


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