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VIP alllll the way
Join Date: Aug 2003
Location: Roanoke, Virginia. Attend School @ VCU in Richmond
Posts: 4,587
Car 1: 92 L Rosewood Brown Sedan
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No air tires [Michelin's Tweel can never go flat]
- thanks to brian for being such a google master... more pics further down
Check out this article: Michelin's Tweel can never go flat
http://greenvilleonline.com/news/bus...5010856370.htm
The iBot wheelchair that climbs stairs, industrial equipment and military vehicles might be the first to use no-air Tweels, but passenger cars could roll on the new technology in a decade or so, said Terry Gettys, president of Greenville-based Michelin Americas Research Corp.
Michelin is introducing no-air combination tire-and-wheel technology, developed in Greenville, at Detroit's North American International Automobile Show today.
Gettys said the Tweel — a name created to represent the fusion of tire and wheel — is "one of the most exciting breakthroughs in tire technology in my lifetime."
The Tweel's development to date is similar to a concept car made by an automaker, he said. It presents the technology in a way that can be seen.
The Tweel now is a big wheel with spokes and a rubber tread glued on, he said. It doesn't look like any conventional tire, but customers tend to like large, low profile tires, and this fits those criteria.
"You can see through the tire," said Lynn Mann, Michelin North America spokeswoman.
The U.S. military has expressed interest in the technology, Gettys said, because stopping to repair flats can be dangerous for soldiers. Stopping makes them vulnerable to ambushes, and landmines and other explosives can disable trucks and put military personnel in peril because of damage to tires.
Preliminary tests show that no-air tires on slow-moving vehicles can run over explosives that break some of the spokes and even tear off some of the tread, but the vehicle "keeps rolling. It looks ragged, but it continues to move," Gettys said.
The Tweel also directs the blast energy of land mines and other explosives outward rather than up through traditional tires and into the vehicle.
"Our concept works well in segments where mobility is important," he said.
The Tweel also is being tested on the iBOT, a new wheelchair, and the Centaur prototype, a four-wheeled scooter, both developed by Dean Kamen, inventor of the Segway scooter. It is being used in real-world conditions with Skidsteers in industrial situations and has decreased the amount of downtime because of tire problems.
"It's showing a lot of advantages for low speed," Gettys said. "It's less bouncy and more controllable."
But "we are moving up the technology ladder," he said, and Michelin is testing the Tweel on an Audi A4, a high-performance luxury sedan.
"The Tweel automotive application, as demonstrated on the Audi, is definitely a concept, a stretch application with strong future potential," Gettys said. "We see a tremendous advantage for handling. We are seeing some limitations for noise and some types of comfort on rough roads. It envelops obstacles, but it's not ready for the automobile."
Despite today's reliable tires, an automotive application is expected to come in the future.
"Today's radials are pretty reliable," Gettys said. A motorist can expect, on average, one flat for every 80,000 miles driven — or about once every five years.
"When it does occur, it can be a serious nuisance or a dangerous situation," he said.
The Tweel also would free motorists from worry about underinflated tires, Mann said. The National Highway Traffic Safety Administration estimates that three out of four vehicles have at least one tire underinflated. That can cause blowouts and affect load-carrying capacity, wear life of the tires and performance.
An advantage of the research is that Michelin can use knowledge learned from the new technology to its current tire technologies, he said.
The Tweel performs like a pneumatic tire but without any need for air pressure, Gettys said. The Tweel structure supports the load mechanically but flexes to absorb shock. It also generates an adequate contact patch — currently almost twice that found with original equipment tires.
Furthermore, its performance can be tuned. Vertical stiffness, which affects ride comfort, and lateral stiffness, which affects handling and cornering, can both be optimized. The Tweel currently is within 1 percent of the fuel economy of original-equipment tires, Gettys said.
New technology doesn't come quickly, but "we are a company where technology breakthroughs are important," he said. "We're in it for the long-term."
The company, known for its secrecy, is introducing the new technology so "we can immediately start exchanging ideas and working with key players in the mobility market," he said.
Research on Michelin's nonpneumatic tire took off in 1997 as the company became interested in run-flat tires and self-supporting tires with stiff sidewalls.
"Our researchers observed that with load reduction on those tires, you could go a lot farther," he said. "They thought, 'Why not make a tire that runs all the time with no air?'"
With that breakthrough, the design approach to tires and mobility solutions changed tremendously, he said.
The tire became more of a mechanical structure. Although the first no-air tires had sidewalls, that was eliminated and spokes were used, he said. The Tweel is a single unit that replaces the traditional tire, wheel, valve and pressure-monitoring unit.
Although the Tweel is already being tested in real-world situations, Michelin has no timeline for its introduction into the mass market, Gettys said. Right now, researchers are still overcoming some of the technology's limitation.
"It's hard to predict when we'll be ready for the auto segment," he said. But it should be within the next decade. The company also has no estimates on the cost of a production Tweel.
However, a Tweel with the same tread depth as a conventional tire currently appears to last twice as long, Mann said. And the Tweel can be retreaded, lengthening its useful life.
In the future, "it could be a good candidate to replace radials," Gettys said of the tire technology Michelin perfected 50 years ago. If that were to occur, however, it would be several decades in the future.
"We try to bring options of mobility" to the market, he said.
Tweel is one of the three new technologies being introduced to the public at the Detroit car show. The company also is introducing the Michelin Airless, a tire that doesn't have to stop if one or more of its radial bands break or are damaged.
The third new technology is the Michelin Active Wheel, an integrated unit made up of a conventional tire plus an active electric suspension, a disc brake and an electric motor to provide traction. The Active Wheel's compact size offers considerable design flexibility to auto designers.
Last edited by Cole Austin : 01-11-05 at 06:18 PM.
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