Airless Tires: A Promising Curiosity

Passenger car with wheels company Protos, Germany. Photo Strangernn.livejournal.com

The general appearance of a car wheel with a central disk and a tire filled with air has been formed for a long time and has proved its effectiveness. However, regular attempts are made to radically restructure such a structure in order to increase its technical or economic characteristics. The so-called. airless tire with elastic elements and without compressed gas ..

Long story

The first options for airless tires appeared almost at the beginning of the last century. Often the reason for the appearance of such projects was a shortage of materials. Designers tried to replace hard-to-reach and expensive rubber with more profitable wood or metal. To date, the deficit problem has been resolved, and new projects are associated only with the desire to improve the performance of the chassis.

Earlier designs of airless tires most often offered a metal disk and an outer rim with a tread, connected by a set of springs of various shapes and configurations. At different times, cylindrical or leaf springs were used. Such designs generally solved the tasks, but they turned out to be too complicated and inconvenient to operate. As a result, they did not go into a large series and did not receive wide distribution.

Combined metal-wooden construction of the wheel of J. Martin, USA 30s. Photo Strangernn.livejournal.com

Relative success came to airless tires only with the development of space programs. It turned out that planet rovers of the Soviet Lunokhod or American LRV type should be equipped with wheels without cameras and air. So, the LRV product from the Apollo system received an elastic tire from a metal mesh with a riveted tread. This design was lightweight, dampened impacts, did not require maintenance, and was characterized by high survivability.

Part of the design of airless tires at various stages attracted the attention of the military and even reached the proving ground. In recent years, interest in such developments has been again observed, and this is not only about projects for the armies. Leading tire manufacturers see the airless design as a real alternative to traditional wheels.

Apollo LRV lunar rover with metal mesh wheels. NASA Photos

However, so far none of the known models has reached the mass production and operation in the military or civilian sphere. Revolutions in the field of running gears are hindered by objective factors.

Modern designs

Consider some of the modern designs of airless tires created in recent decades. So, in the past, the Airless: Resilient NPT project by Resilient Technologies gained wide popularity. It has been developed since 2002 and reached testing at the end of the decade. Using modern polymeric materials, inaccessible in the distant past, American engineers were able to create a very interesting design.

The Airless: Resilient NPT tire is a unified design that includes a central mounting disk, an external rim with a tread, and a special frame between them. The latter is made in the form of a lattice structure of irregular hexagons and trapezoids. The weight of the car is distributed between a relatively rigid rim and grille. At the same time, the elasticity of the structure makes it possible to absorb shock.

Airless tire: Resilient NPT on an HMMWV when hitting an obstacle. Demo video frame

During the tests, it was possible to show that the Airless: Resilient NPT tire is comparable to traditional pneumatic in depreciation. It is not afraid of punctures and can be used if 30% of the frame elements are damaged. Also received a small gain in mass. However, the product was quite difficult to manufacture, required special materials and had a number of other disadvantages. As a result, tires from Resilient Technologies have still not been included in the army.

In 2005, Michelin introduced the Tweel (Tire + Wheel) tire concept. In this design, the central disk and the outer rim are connected using V-shaped “spokes” extending across the entire width of the tire. The developer talked about reducing weight in comparison with traditional products, increasing the resource, etc.

After testing and refinement, the Tweel tire was developed. Modifications of this product to the technology of different classes have appeared. In 2012, the supply of such tires intended for construction and agricultural machinery began. In the future, new models of such products with a different configuration of elastic elements appeared.

Michelin Tweel. Photo Michelinmedia.com

Bridgestone has its own variant of airless tires. She proposes to connect the disk and the rim with curved "knitting needles" arranged crosswise. Such depreciation allowed to increase elasticity while maintaining other characteristics. However, the finished samples had a limited carrying capacity, which reduced the scope.

Other types of airless tires of various kinds are known, which have reached the test or even to production. The search for new solutions continues. Designers try different materials, configurations of elastic elements, etc. However, there are only limited successes.

Advantages and disadvantages

An airless tire with integrated resilient elements offers several important advantages over a traditional pneumatic wheel. It is they that cause the increased interest in such structures, observed so far.

Tweel when hitting an obstacle. Photo Michelin / michelinmedia.com

The main plus is increased survivability. The airless tire has no air chamber and is not afraid of punctures. She is also not afraid of side impacts. Depending on the architecture, operability is maintained even with severe damage to the supporting structure. There is no need for pumping and pressure monitoring, which simplifies operation. There is the possibility of rejecting a large and relatively heavy wheel disk. As a result, the complete wheel assembly is lighter, which reduces unsprung mass.

However, there are a number of problems due to which such tires are not widespread. First of all, this is increased demands on materials. It requires rubber or polymer with sufficient elasticity, high rigidity and resistance to various loads. There are also high requirements for the absorption of mechanical energy and its conversion into heat, followed by dispersion.

All this complicates and increases the cost of production. In addition, most tires have a speed limit - usually not more than 70-80 km / h. Further acceleration increases mechanical stress, and also leads to unacceptable overheating.

A later sample, Michelin Uptis with a different configuration of elastic "spokes." Photo Michelin / michelinmedia.com

Unlike pneumatic tires, airless tires have constant stiffness, and wheels must be changed to change them. At the same time, the ingress of dirt into the structure through the open sidewalls can adversely affect stiffness and other characteristics. Pneumatic constructions from these points of view are much more profitable.

As a result, airless tires so far find application mainly in the field of light engineering with limited speeds and loads. They are put on golf carts, some buggies, compact construction equipment, etc. The production of tires for bicycles, scooters and other light products has also been launched. The provision of larger samples is still in question.

Promising Curiosity

A specific combination of technical, operational and economic characteristics, as well as a number of significant restrictions, do not yet allow airless tires to enter a wide market and seriously compete with traditional designs. As a result, the tire market does not change - although different companies regularly present various “promising” products.

Wheel with a Bridgestone tire. Photo bridgestonetire.com

However, it should be noted that some products of the original design still entered the market and even found their customers. Successes are observed in several rather narrow niches, while the conquest of the main sectors of the market is impossible. There are no objective prerequisites for changing this situation.

Thus, a variety of options for airless tires with integrated elastic elements in general retain the status of a curious solution to an important technical problem - without special prospects in the context of real application.

On the other hand, such projects can have positive results that are not related to the direct use of finished products. The development of such tires is now being carried out by recognized industry leaders with a good scientific and technical base. During the development of airless tires, new materials, technologies and designs can be created. And they can find application in the development and improvement of traditional tires that have real practical and commercial prospects.

Comments

[16112014nk]

... "Will that wheel reach, if it happened, will it reach Moscow or will it not? - Will it, -... And I think it won't reach Kazan? It won't reach Kazan." ©

[Vol4ara]

One question worries what will happen to the wheel when gravel and dirt cram into it.

[Katanikotael]

the same as when accelerating more than 70 km / h - unacceptable for operation loads.

[KVU-NSVD]

All this is of course technological and can even be made fashionable for city cars - this is just a matter of advertising and promoting the device. But for military equipment with high cross-country requirements, there is a significant drawback - in traditional tires you can apply a pressure control system (even on the go) for maximum efficiency on different soils and coatings. A very important off-road option.

[Nyrobsky]

Quote: KVU-NSVD

All this is of course technological and can even be made fashionable for city cars - this is just a matter of advertising and promoting the device. But for military equipment with high cross-country requirements, there is a significant drawback - in traditional tires you can apply a pressure control system (even on the go) for maximum efficiency on different soils and coatings. A very important off-road option.

As for me, this is generally a narrow-profile application. it is not clear how to solve the problem of balancing the wheels, because soil will fall into these voids, and in quantities of different weights for each individual wheel.

[psiho117]

Quote: Nyrobsky

since soil will fall into these voids,

Add a banal low-resilience foam filler to the voids between the "spokes". It will not let dirt through, it will not affect the har-ki, it weighs almost nothing.

[blackice]

Different characteristics in terms of the number of compression-extensions and the same foam will start to fly out of these wheels.
Do you really think that it only occurred to you?
Google it. There is a lot of material on this topic.

[Herman 4223]

And why these voids cannot be closed like in a traditional wheel? This is clearly a solvable problem.

[blackice]

Google.
As it turned out - not entirely solvable.

[Herman 4223]

Googled solved. There are already closed and high-speed ones up to 170 km / h.
http://mir-auto24.ru/kupit-bezvozdushnye-shiny-ili-net-testy-bezvozdushnyx-shin/

[blackice]

Photos from the link.
Well, very closed.

[Herman 4223]

What kind of people went, they learned to look at pictures, but they can’t read the text. There are no pictures with closed tires, but this is written in the text.

[blackice]

Self cleaned? Well, read it!
Only self-cleaning where? Were there trials in the Russian taiga or in the Arabian desert?
Volkswagen also touted its diesel engines as the most environmentally friendly. Like almost oxygen clean exhaust. Then what happened?
Well, if these tires are so cool, where are they on the road? Ahhh no? Well, that means a bullshit article written for a small share, as an advertisement.

[blackice]

And this is the article of 2016. 4 years have passed. Where is the prevalence of airless tires?

[Herman 4223]

I think this is a matter of the future. Such tires are already being produced on special equipment and they work.
Why is there no dominance? I think here the answer is simple, to establish the production of something you need to invest money. In mass production, this is a lot of money, and how the buyer will react to this, whether it will be possible to cram a new product, is a question. It’s just a risk, and the issue with the high-speed mode has not yet been resolved. You need a wheel so that you can ride at a speed of 200 and a long time. Now the limit is 130-170, and as I understand it, not for long because of the warm-up. This will scare away many buyers, because on the track will not really be dispersed. It won’t go to the masses right away, but slowly the issue will be resolved.

[blackice]

So what is there for 4 years, a lot of equipment on special tires?
I work as a mechanic for a construction company. 380 units of equipment at the facility. From small loaders to dumpers. Not a single "reliable, long-lived" airless tire.
Or are we only able to set cons?

[Herman 4223]

I did not give you ratings, no minuses or pluses. You may not have equipment with such rubber, but it has been produced and applied for a long time. You can easily find this information on the Internet.

[Herman 4223]

I will put you a couple of advantages if you are offended.

[t7310]

Quote: Herman 4223

And why these voids cannot be closed like in a traditional wheel? This is clearly a solvable problem.

why are these "spokes" a hard rim and in the middle there is normal rubber without any voids, you can make several layers to find the optimal solution

[Pivot]

These are wheels in a section, for clarity of design, and so these tires are no different from classic tires.

[blackice]

Seriously?
You are mistaken. Google to the rescue.

[Pivot]

I’m not mistaken, we tested such tires.

[blackice]

Well, let's take a look at the points.
1. Enclosing in a shell, you make an ordinary tire, without pressure inside, which replaces special springs. That is, the same eggs, only the view from the side. Well and more expensive.
2. If you make it partially closed, you get dirt getting inside the tire, without the ability to clean it normally.
I like to argue with people who are not related to wheeled vehicles as an operator and who do not have a specialized education.
Otherwise, I did not have to explain the elementary things that our teacher ridiculed back in 1995. (Tashkent Automobile and Road Institute)

[Pivot]

I did not understand your post, I initially said the tires presented in the article are presented in a section to demonstrate the design, but in reality we tested such wheels with closed sidewalls and such tires, what does the teacher from Tashkent from 1995 have to do with it.

[blackice]

What closed sidewalls?
Are we reading commas in general or the last sentence only?
The teacher, despite the fact that the topic of airless tires has been discussed for a long time, but there was no sense, and there will not be until the whole globe is rolled into concrete, and he chewed it up in detail. I tried to convey to "your bright head", but apparently you don't particularly bother to read. Or are there no arguments against?

[Pivot]

The concept of airless tires is excellent, in some industries tires filled with foamed polyurethane have long been used and they have undeniable advantages over air tires. When the whole world is rolled into concrete, there will be no need for airless tires. Your teacher broadcast in the last century and training materials were based on the experience of the 50s and unfortunately our tires are inferior in quality even to Chinese, thanks to the lectures, large tire companies invest a lot of money in creating airless tires and eventually there will be such serial tires, but they will be not used everywhere. I was always surprised by such teachers back in the days of my training, when I said that the future lies with laser machines in metalworking, my teachers looked at me like a fool and said maybe in 100 years it will be, and now these machines at any small-scale production, so just what your teacher said the day before yesterday does not mean that it will be relevant tomorrow.

[The leader of the Redskins]

For some reason, the author forgot the most widespread airless tires in the army - filled with a gusmatik. The guns and armored cars can be said to be tested by God forbid!

[Blacksmith 55]

How such a wheel behaves when cornering, especially at high speeds. After all, one thing, if you put on special equipment at low speed, or a military machine, where you often need to squeeze everything that it is capable of.

[merkava-2bet]

Now there is a more advanced technology, polymers with memory when applying an electric current of a certain frequency and voltage, the same effect as the adjustable tire pressure, and of course more expensive, much, but for now.

[blackice]

More expensive. More difficult. It was and will be.
Remember the T-34 and the Tiger from the Second World War. While the T-34 was treated on its knee in the field, it did not roll with the Tiger.
Especially if it concerns the chassis, which is especially vulnerable not only from enemy fire.

[t7310]

Quote: blackice

Remember the T-34 and the Tiger from the Second World War. While the T-34 was treated on its knee in the field, it did not roll with the Tiger. .

remember the nokiu 3110 and the smartphone ... and where are our t34s now? T72 came and it’s more complicated ... probably even a tiger, and you definitely don’t look at the number of produced tanks of Germany and the Allies, I’m afraid I’m not afraid to lie, but about 7000 including t1 and t2 against 200000 T34 and Sherman and others, the Germans wanted to defeat tactics and not only tanks

[blackice]

So tactics?
Making 10 T-34 1 Tiger for a place, Hitler lost not only tactically.
History has proven this.
As for the Sherman and other blah blah blah, then recall when they entered the total figure of 200000 against Germany?
And I did not understand the comparison of Nokia and a smartphone. These are phones of different electronic eras. Like the T-72.
T-34 and Tiger were at one time, in one place.

[t7310]

I certainly could have stuck your nose on every point, but why do I need it ... I wanted to say that many would prefer to ride a new Mercedes or a new fret than a completely repairable on the knee Lada from 1 to 7 models, well, Regarding of course Nokia 3310 and not 3110, I still say that in the light of recent events, the era of Nokia 3310 has not yet ended

[blackice]

All right.
Only if equated to the conditions of hostilities, then the Lada win.
Well, according to Nokia, then in the light of recent events TAB will be preferable

[t7310]

well, I'm talking about the same thing - 3310 and smartphones are still found, they are from the same era, 3310 is t34 and a smartphone is tigers,
and what is the advantage of Lada in the war? not in comparison with tigers, Merciers break less often, comfort, but in general, in war, cars made for the army, lynx hummers, etc. are better.

[blackice]

We read carefully: In the conditions of hostilities. That is, in the absence of normal roads, spare parts, services and fuel.
Hammer? Controversial issue. So are the lynxes and the rest. I don't like UAZ, but here it is like a cockroach, it will outlive all its off-road brothers.
I myself am an opponent of the Russian car industry, but in a war, I can easily change my Delika to Niva or UAZ.

[t7310]

which car is better in war, of course, depends on which car parts are in allied warehouses and with which machine those who will work with it are trained. But if the Germans had T34 and we had tigers, the result of the war did not change from this. to each his own who was trained by some tigers. By the way, the Germans also fought on trophy 34kas. and ours then made an is34 car similar to a tiger. but the tiger still seemed more interesting to me. they are majors. but in general I like object 2 more in mass production, there would be spare parts and craftsmen

[blackice]

IS similar to Tiger ?????
This is what?
Stop smoking crap, but rather learn the history and economic aspects of wars.

[knn54]

Payload is lower than pneumatic.

[Ross xnumx]

Airless tires will undoubtedly be in demand in some special cars. It is very entertaining and interesting.

[Free wind]

There is another drawback, the tread, its wear resistance is probably the same as that of conventional tires. . And throw the tread erased. Although, for sure, well-protected machines will not be constantly used. And we, as a child, were watering hoses, they put them in the tires of the bicycle, we were not afraid of punctures either.

[garri-lin]

We stuffed "construction sausage" such insulation. Heavy. Riding such a bike was problematic. But the legs swayed like an athlete's.

[Pessimist22]

Yes, this is a sealant for the panels from which they were assembled.

[Ross xnumx]

Quote: garri-lin

We stuffed the "construction sausage" with such insulation

... rubber. My friend and I collected two bicycles from school scrap metal and drove them ...

[bbss]

Winter, dirt. Everything will freeze and turn into stone. Let the Führer consult.

[fa2998]

Yes, you can ride at the exhibition, but on our roads anything can get into these wheels. And in winter, dirt, snow porridge, then it freezes, what are the characteristics? In a warm garage, rinse with a karcher and dry it.

[really]

I liked the article, but the time for these developments has not yet come. As LEDs, they have been used as indicators for so many years, then they developed white, and the LED era has come.

[Proctologist]

Today, electric vehicles (personal mobility aids) are a testing ground for technology where many innovations like aliexpress are quickly and cheaply tried. For scooters in bulk cast tires of various types, including hole ones, which have been sold for several years. With success in light transport, I think it will not be difficult to scale and adapt to cars or military applications. When there is confidence in the tested result, it is easy to find investments and specialists.

[srha]

Have you tried switching to magnetic springs? A standard neodymium magnet disk of 70x50 mm can, with the right design, provide 200 kilos at a stroke of 170 mm (I saw such a calculation). The truth is a little expensive ... very much.

And yes, if you build the airless wheel correctly (as in the last photo in the article, but they roll in the wrong direction), then hitting an obstacle causes additional force to overcome it, and the congress is reduced, which is not possible in the cracks.

[KSVK]

Quote: Herman 4223

And why these voids cannot be closed like in a traditional wheel? This is clearly a solvable problem.

Because these are all prototypes. No more.

Quote: ROSS 42

Airless tires will undoubtedly be in demand in some special cars. It is very entertaining and interesting.

They are. And for a long time. Loaders / stackers have long been using “superelastics”. Only now they have a price ... Somewhere it is profitable, more often not. So all these developments are like Tesla (car). It seems to be fashionable / publicized / innovative, but in reality, no one but the budget cutters is not interested. Highly specialized things exist and work where they have economic feasibility. And do not forget that the modernization potential of the good old “dutik” is far from exhausted.

[riwas]

Cable shock absorbers are known in which cables simultaneously work on bending and torsion
http://www.sinor.ru/~bukren27/amortizator_ATK.doc
It may be possible to create cable airless tires.

[Andrei Nikolaevich]

The idea is interesting. The article is instructive. But why reinvent the wheel? Air, too, like a communal apartment, will rise in price? ..

[Proctologist]

well, the reason is obvious - much greater resistance to damage than the inflatable wheel, any breakdown of which causes a loss of pressure in the entire wheel, loss of functionality. Countermeasures, such as pressure maintenance systems, are mechanical, that is, complex, imperfect, vulnerable, expensive.

[trahterist]

I have been observing Tweel-like slopes for more than a year, on completely serial Bobcats, dummers by road workers in England.
And, judging by their appearance, they have been exploited for a long time.
On tractors, something similar is used in the drive wheels of half-track "triangles", both on articulated a la Kirovets (Case, John Deere, Massey Ferguson), and on workaholics of the classic layout (rear "triangles").
Considering the fact that the load on the wheels is much more serious on such a technique, on cars I do not see any obstacles for widespread adoption.
The only exception can be high-speed passenger carriages, where the slightest flaw in the "honeycomb" structure of such a wheel leads to a wild imbalance and all the chances of suspension destruction and subsequent flight into a ravine / pole / oncoming car.

[Observer2014]

It looks impressive. Especially on construction equipment. Who will gouge out dirt from these tires !? And to whom does a kamenyuk get stuck in such a wheel fly into a lobeshnik? No, for development of other planets, yes, please. A promising business is probably and necessary Although there it can fly into the lobeshnik in the lung. Literally. Who will not even go behind a vehicle with such wheels. And just stand in the affected area. The only applications where it is possible are non-speed robots. There are all kinds of moon rovers. Well, or some spare wheel.

[acetophenone]

Tires in which cushioning is ensured by the elasticity of the polymer should have problems in good frost.