Saturday, October 14, 2006
The pneumatic tyre has been around for over a hundred years. The original wheel was straight off the buggy. Wooden spokes and wooden rim with a solid rubber covering the rim. The tongas in India still use this.
The Michelin brothers, Andre and Edouard, were the first to use an air-filled tyre. It was used for the first time on a race car built by the Michelin brothers.
After the introduction of the pneumatic tyre, with a cross ply construction, the Michelin company came out with the radial tyre. This was further improved by the tubeless tyre, which is the ultimate in tyre technology today.
Michelin engineers at their Technology Center in the US are working on a revolutionary concept called the ‘tweel’. It is a combination of a tyre and a wheel and, guess what, it is not pneumatic — it contains no air.
The advantage with this is that you will neither have to carry a spare wheel nor will you be changing a dirty muddy wheel on the way to a cocktail party on a dark rainy night. No more punctures!
The tweel, Michelin’s newest invention, is a rubber tread, bonded to the hub with flexible spokes. It is a single unit but is in four pieces. The hub is made of polyurethane as one unit and the spokes are flexible, (see picture). The flexible spokes are fused with the tread which can change shape and absorb shocks and retain its original shape with the greatest of ease and almost instantly. Then a sheer band and finally a rubber layer is wrapped around the circumference. This is what touches the tarmac and provides the grip expected of a tyre.
Even without air, tweel still has all the characteristics of conventional tyres, like road holding, load-carrying capacity, comfortable ride and resistance to real hazards. The tweel has been driven over the spikes that the police use at road blocks, and it kept going. Of course, the torture test will be Indian road conditions.
The tread will last two to three times longer than the current radial tyres we are used to. And now hear this. When they do wear out they can be retreaded, claims Michelin.
Michelin has high expectations from the tweel. Apart from its acceptance by manufacturers of passenger cars, the tweel will find usage in the aircraft as well.
Since a typical tyre in use today has 23 components, the tweel has four. This could reduce the cost of production eventually. Certainly, three times the lifespan of today’s tyres, the tweel will be cost-effective too. It will also eliminate the installation of air-pressure monitors (aircheckers) which will soon be mandatory on all new vehicles in the US.
In 2005, Time magazine selected the non-pneumatic tweel as "one of the most amazing invention of 2005". Popular Science awarded it the "Best of What’s New" in the Automotive Technology category.
This year the Intermat Innovation Council in Paris awarded a gold medal for "Innovation of the tweel". It is the shape of things to come.