Today for Tomorrow Future look In celebration of SAE’s Centennial in 2005, industry executives discuss the future of mobility technology. PassionPassion forfor anan airlessairless futurefuture

friend once told me, “Show me Still, continues to look to- your checkbook and your calen- wards the future to seek better mobility. A dar and I’ll tell you what you’re Last fall at the Paris Auto Show, Michelin passionate about.” It’s true. Passion re- introduced two examples of new tech- quires commitment of both time and re- nologies that are non-pneumatic— source. without air—the Michelin Airless and Michelin is passionate about technol- Michelin Tweel. The fusion of and by Terry Gettys, President, ogy and innovation, which have been into a single component, Michelin Michelin Americas Research bred into the company’s culture since its Tweel technology was developed in North Corporation founding more than 100 years ago. America at the company’s technology Michelin sustains its dedication to tech- center in Greenville, SC. nology and innovation with R&D spend- Tweel is one of the most exciting ad- ing that is second to none in the industry, vances in tire technology in my lifetime: both in total dollars and as a percentage tires operating without air—on purpose. of gross sales. Without the need to retain air, there is no Nearly 60 years ago, Michelin in- longer a need for a rigid wheel. A fl exible vented the , which is now the wheel using new polyurethane and glass- recognized standard for most tire seg- reinforced plastics can start to provide ments. Some companies might have been suspension-like functions to the new tempted to hold that ground, focusing Tweel design. simply on manufacturing and distribut- And by fusing the tire and wheel to- ing that one range of technology. But gether, some complex systems can be Michelin continues working to improve eliminated. The traditional tire, wheel, the performance of the radial because valve, and tire pressure-monitoring sys- there is still more ground to be gained in tem is replaced with a single Tweel as- Michelin’s Tweel automotive application on fuel economy, , traction, sembly. This innovation eliminates the an Audi A4 wear life, and other properties. That drive need for mounting and dismounting and comes from a passion for continuous simplifi es the logistics. A fl exible wheel improvement. also eliminates the possibility of pinch Over the last several years, Michelin’s shock, sidewall damage, and wheel strike- commitment to innovation has centered on through, all hazards of conventional tire- continued-mobility options, where Michelin wheel assembly. Zero Pressure tires and the Michelin PAX One of the most amazing aspects of System continue to gain acceptance in the Tweel unit is that it performs like a Europe and North America. Last year, the pneumatic tire. Tweel architecture sup- Honda Odyssey Touring Edition became ports the load mechanically, yet it de- the first mainstream vehicle in North forms to absorb bumps and road hazards America to use the PAX System. for ride comfort, and generates a contact

The non-pneumatic Tweel unit replaces the traditional tire/wheel/valve/pressure monitoring assembly

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patch. In fact, the on the which reduces driver fatigue. prototype passenger-car application is The U.S. military’s interest in Tweel almost twice as large as the contact patch technology centers on its unique contin- of the original OE fi tment. ued mobility, even after multiple hits from As the Tweel unit began to take shape, land mines and incoming artillery. The fi tment opportunities quickly became ap- Tweel assembly does not have a single parent. Michelin has a long history of point of failure. It also has high blast re- Michelin’s approach to the market collaboration with Segway, which led to sistance, directing the explosive energy of the fi rst real-world fi tments for the new land mines and other direct hits outward, Segway Concept Centaur and iBOT wheel- rather than up through traditional tires chair from Independence Technology. and into the vehicle itself. The Tweel non-pneumatic solution for First applications for Tweel—iBOT, the iBOT wheelchair provides consistent Centaur, skid steer, and multiple military performance and maintenance-free op- uses—are reality for this new airless tech- eration. Additionally, the use of small nology. In the realm of long-term future Tweel assemblies on the front casters applications, Michelin is experimenting allowed designers to eliminate the need with Tweel fi tments on passenger cars. for a complicated suspension device. The Engineers have found that some proper- adaptation of non-pneumatic Tweel units ties can be tuned independently of each complements the Centaur’s off-highway other, which is a signifi cant change from capability. conventional tires. Vertical stiffness— Both iBOT and Centaur are on the which primarily affects ride comfort—and lower end of the vehicle maturity curve lateral stiffness—which affects handling in terms of speed and weight. The next and cornering—can be optimized inde- steps up the vehicle curve are low-speed pendently. applications on much heavier industrial The Tweel prototype offers responsive and military vehicles. handling while staying within 5% of the The Tweel assembly has completed a rolling resistance and mass levels of to- second round of fi eld testing on skid day’s tires. That translates to being within 1% of the fuel economy of a com- steer machines at working locations in Non-pneumatic Tweel assemblies the U.S., Italy, France, and the parable OE fi tment of the test application. complement Segway Centaur’s off- Netherlands. The elimination of air pres- Additionally, lateral stiffness is increased highway capability sure has drastically reduced down- by a factor of fi ve in this application. time—a critical issue for the construction The radial tire will continue to be the industry. The Tweel fi tment is more sta- undisputed standard for some time to ble than traditional skid steer tire solu- come. Tweel is a stretch application for tions, and enables the equipment to work the future. aei faster with more comfort for the operator,

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