A new breed of tire has been developed that won’t go flat, even if it gets bombed. Resilient Technologies L.L.C. has started making these decidedly cool looking tires for the military. The honeycomb of stiff but flexible plastic acts as a shock absorber just as an air filled tire would. Unlike a normal tire, it won’t pop. You would have to completely destroy the tire to stop these. The article mentions that this isn’t the first of its kind. Michelin has made the “tweel” for industrial uses, but you may recall the video of the Audi driving around a course using them. If not, check it out after the break.
[youtube=http://www.youtube.com/watch?v=fqRJ9GfIJtI]
[via Mark’s Technology News]
Will bees make honey in it?
Just Kidding
1 pointless michelin video, WTF is this parkour wheelchair? isnt that one of the brain dead “revolutionary” designs by the same dude that made segway?
2 cars can sit on a parking lot for days if not months, michelin design was deforming under load quite significantly, I imagine this deformation could get semi permanent with time.
The comb design is nicer, draws from natures old blueprint for rigid structure. One drawback is being open, a ton of rock is going to end up inside the wheel (I think one of Mars rovers ended up with a rock inside open wheel)
now they need to make some for wheeling, maybe with replaceable tread? but not having to worry about rims or side walls would be awesome! i wonder if these will ever be available for the public i want some for my jeep!
1 well maybe
2 This is meant do deform !! This gives the tire its Flexibility. The hardest riddle that they had to solve for this tire must have been the material, and i dont think they are stupid enough to use someting that will be damaged by having some pressure on it over time.
3 … i dont think its that hard to make a rubber wall on these tires.
@ rasz
My thoughts exactly – I imagine the deformations not a problem, would work itself out after a few rotations. What it needs, is to be made like a regular air tire, sealed hermetically, but not pressurized. That way, it would keep dirt and snow out, like the rubber on a cv joint.
(imagine if you parked in a puddle which froze overnight?!)
The problem with sidewalls will be the necessary deformation. By its nature, the honeycomb design has to flex, but fusing an ‘end’ onto the open ‘tubes’ its made out of will cause the ends to deform. Conversely, its possible the sidewalls would make the whole tire more rigid and less effective.
Ah yes – The crims will have a field day with this one…
@rasz
how stupid, a wheelchair that might make things more accessible for people with disabilities. that is so much like that device which allows americans to be lazier!
Actually it allows people with disabilities to be more active not lazy.
The ice issue is a non-issue as it would get crashed or just fall out as the tire deforms. Getting rocks out would be as simple as poking a stick in the holes.
@Zanzee
Why would it get crushed? There is obviously no force being exerted in the open spaces when not below the wheel axle. If the support of the tire is in the “Webing” then there is a good chance that any moderately strong material stuck in the openings would cause the car to “bump” rather than destroy the material.
It is a non issue though, they will put sides on these tires, it’s a PR thing to leave them open.
The real issue is how these actually work in a friction environment. We already know that the current generation of run-flat tires are horrible performers in both a comfort and performance arena. Being able to change tire pressure on the fly, or depending on the weight of the car, or suspension setup is paramount to the performance of said tire. These will not have this ability.
Bro… these ain’t even new. Just new for cars. My forklift has used these for a long time. Ice, non issue. Crushes, and what’s a PR issue? We never put “sides” on it. These are amazing and work flawlessly
I personally know the man who invented the tweel.
It is a compliant wheel which means it is designed to deform to some extent.
The tread on the tweel is replaceable.
The tweel also uses some neat polymers, one version even uses glass composites.
The tweel is going to be used on ATHLETE which is a lunar rover in the works.
I don’t know what junk the guy talking about the tweel deforming under large loads is saying, I have personally seen it in action on construction equipment, like bobcats, heavy lifters, cranes, and tehre were no problems. Remember it is a compliant device, which means in this case it must deform to some extent. It is a very durable device, for instance, we had placed the composites for the composite tweel in liquid nitrogen and the thing still performed better than any wheel…
Pneumatic tires are great at shock absorption, but that only half of what they are good at, when they deform they store that potential energy and return a large percentage when rolling down the other side of that bump or whatnot.
Ive played with pneumatic tires and solid ones on bikes, and the solid ones feel like you are riding a lead sled!
I wonder how good the energy return of this spring/comb system is?
The pictured use (offroad) would be a poor one. Matching tire pressure to terrain is a time tested means of keeping moving and getting un-stuck. At low pressure the wide spread of the tire is what gives flotation. These features are important enough that the pictured Humvee would normally come equipped with on-the-fly central inflation system. Air filled tires are not going away any time soon.
I worked with the guy that helped develop these while I was at Dow Chemcical. Originally they were supposed to be run flat inserts, but I guess there must have been some sort of logistics problem getting these to wrap around a standard rim. Pretty cool either way.
The Segway didn’t live up to the hype Kamen help put out there, but to call Kamen brain dead, is brain dead in itself. The wheel chair was brilliant. I understand building the Segway to use the technology used in the wheel chair for a larger market.
Looking at the top photo, there is not much noticable deflection of the cells, if any. Maybe flat spotting may not be a problem. Though road and other debris in the cells may be.
If I recall correctly there were two problems with the Tweel. It would become excessively loud when speed exceeded 50mph. And the tires became too hot when reaching such speeds. I wonder if these will fare better.
alan in right about the off road applications. one of the things you will always hear off road guys talk about is tire pressure vs traction. i think we will see future generations of tweels where the spokes come with adjustable tension or have tweels with different stiffness ratings like snow boards.
come to think of it, there’s a book called “snow crash” by Neil Stephenson where they have smart wheels with telescoping spokes instead of rims and side walls to provide suspension. tweels might be the first step in that direction.
As far as offroading is concerned, that’s not exactly relevant to the application here. The point is that in the context of a hostile environment, a significant vulnerability of the vehicle–being disabled by gun fire or shrapnel puncturing its tires–has been overcome.
This will benefit convoys following Iraqi highways or other predictable routes. No doubt pneumatic tires or treads will continue to serve for off-road conditions, but presumably if you are going where there is no road you will not have to worry about waiting IEDs or ambushes.
In addition to what has already been said, if done right the tweel would be ideal for both high-speed and off road; depending on the compounds used, of course.
In the high-speed environment, the tweel would simply require a more rigid heat-tolerant outer edge because keeping the round shape would be very important to maintain speed and predictability of steering. Conversely off road would benefit from a more flexible outer edge, where it could act more like the tread of a tank and would deform when ‘stuck’ between obstacles in order to get beter traction and leverage on each adjacent object.
I think this honeycomb structure and adjustable air pressure aren’t necessarily mutually exclusive; when there is no air pressure (tire deflated or punctured), they would be soft for off-road use. On regular road, pressurizing the tire would make them harder and more suitable for higher speeds.
In essence, this could be an improved run-flat system. You can drive quite fast on soft tires, but the handling sucks, it’s very fuel-inefficient, and the tires wear very quickly. It would seem to me these are all things you don’t really care about when you’re trying to get out of a ambush situation.
I think the reason that letting the air out in sand is so common, is that it enlarges the contact area and provides enough traction to move the vehicle.
Of course, with standard pneumatic tires, that reduction in pressure comes at the cost of rigidity when turning on pavement or at higher speeds.
Thats what makes these different. You can tune the plastics to provide a large contact patch, and still have better roll and stiffness than an old tire.
Win win to me, I say. When can I buy a set for a land cruiser? :D
As/400 out
Didn’t I see toys with these wheels very long ago? I wonder if a suit will follow.
I fully embrace this idea.
I recall seeing something about a similar wheel in the late 90’s, it was an airless tire. I think it was being pushed as an emergency spare at the time, but I hadn’t heard anything about it since.
I am a mechanical engineer, and for the record I have to point out a very basic element of statics. By lowering the pressure inside a tire, the square area of contact between the tire and the road increases, but the mass stays the same. Therefore, the friction per unit area goes down at the same rate that the unit area goes up. This means that friction and traction stay the exact same when you lower pressure. All it does is increases stability by putting more of the road contact area perpendicular to the direction of motion. Lowering pressure does not increase
Aren’t you presuming a perfect surface underneath the tire when you say that davido? That’s hardly realistic, that’s the problem with going too theoretical.
I heard about these a few years ago, and they were having problems with air going through the honeycomb, and resonating like a musical instrument when it got to certain speeds. made them noisy as hell, and increased vibration. I’m sure they’ve fixed the problem though.
Davido, simple intuition should demonstrate to you that your model is not realistic. What is the purpose of using continuous tracks on vehicles such as tanks? Is it not precisely because of their larger contact area?
The primary problem with off-roading is that you *do not have a fixed surface.* That means that everything you learned in physics 101 about coefficients of kinetic friction, etc., goes straight out the window.
Frequently, when you apply too much lateral force and not enough normal force, you end up propelling the surface instead of the vehicle. Furthermore, because the surface is deformable, you often rely treads on digging in and creating an interlocking substrate with the surface, rather than simple friction between the surface of the ground and the surface of the tire.
Your deduction is only valid for smooth, fixed surfaces. (and even then the event of significant heat transfer during braking can obliterate the expected coefficient of friction if there is not enough contact distribution)
You could insert light foam in the gaps to prevent rocks and grit getting in, and since it’s light, it’d have no extra impact on the structure of the wheel.
You’d probably have to glue it in, and watch out for vandals
Well, they can just use the same material and make a weblike structure over it. Besides, even if a rock went in, it shouldnt do any damage to the twheel.
In defense of davido, I think all he was getting at, is that the term “traction” wasn’t entirely accurate.
It stands to reason that deflating tires is going to give you an advantage off road, because of the increased contact area and ability to contour, even if the total friction is unchanged.
As for tanks, I think beyond a larger contact area, a tread gives you the ability to “bridge” irregularity in rough terrain, as well as reducing overall pressure exerted by gigantic heavily armored vehicles.
davido is right, so is insipid melon and mike. i am too a mechanical/electrical engineer and both terms and arguments are both theoretically sound. The one thing i would like to see is how well they take pot holes, speed bumps, small mammals, and other debris without damaging the honeycomb structure at low speed and high speed. A good number of pneumatic tires will blow out if you hit a good sized pot hole above 40, *happened to me*, id like to know if these bad boys could handle a decent sized pot hole at high speed without severe consequences so i could continue to drive where i want and how i want.
I have a great idea for this – what if they put rubber sidewalls on it, took the structure out of it and then filled it with some sort of pressurized gas?
I am barack obama and I approve this article
The only question I have, other than where can I get a set, is how do these twheels adhere to the rim? Looks as if you’d have to have a two-part rim or something. With any horsepower, it looks like the seal could be broken easily and the rim would spin inside the twheel.
can’t wait to see it on our humvees
You could probably cover the sides in some sort of doughnut material with a high amount of elasticity. It’d significantly increase the size of the wheel, and break the aerodynamics, but you would still get the same movement in the wheel.
Surely everyone has seen the latest ‘low profile’ wheels. A 24″ rim with barely an inch of rubber looks much like the Tweel [depending on rim design].
A wall solves the problem of liquids and solids invading the tyre space, but makes a problem due to trapped air. The rims would need a filtered valve to equalize the internal pressure.
The Honeycomb Wheel does look cool tho.
With the question of the open cells causing all sorts of auditory mayhem I have a possible solution.
Instead of solid elastomer covers why not use closed cell foam inserts as plugs for the cells. The nominal pneumatic pressure should not add to much of an effect. as an added bonus, if a cell plug blows out from normal use the whole wheel would not be compromised.
The cells blowing out from interaction with an IED would be the least of your worries when dealing with the aftereffects of an IED..
The possible cool factor for civilian use would be using translucence / transparent materials for the plugs and light sources embedded into the plugs.
Though it is true that the “tweel” was affected by the force of the car over time and that this could become semiperminant or perminant, it wont happen. Why? These aren’t really meant for everyday people’s cars. They are meant for professional racers / military vehicles where they are used almost constantly, and also on small vehicles like motorcycles and wheelchairs where the load is not heavy enough to cause a perminant or semiperminant dent.
Nice post. By the way i heard that in 2010 michelin plans to make some supper tires. Which saves energy and valid longer time then nowday tires, and this tires will be perfect for electorcars.
Where are you getting your facts? Great site.
Can I get a set of these Honey Comb tiers anywhere? I’d like to try them out for rock crawling and see how they do.
I would like to try them on my Jeep patriot 2012 and to feel them when I’m driving my car .