Nexteer Automotive, the only tier one automotive supplier committed exclusively to wheel-to-wheel advanced steering and driveline systems, has invented a plastic flexible coupling that solves NVH challenges previously associated with column electric power steering systems (EPS). The part, currently in production, has won the Society of Plastics Engineers Innovation Award in the chassis/hardware category. The company accepted the award yesterday at the Innovation Awards Competition and Gala in Livonia, Mich.
“Because a column EPS unit is positioned inside the driver compartment, a common drawback to the environmentally friendly system is interior vehicle noise,” said Kevin Ross, global engineering manager of electric power steering at Nexteer Automotive and co-inventor of the coupling. “By replacing a rigid stainless steel part with a robust, flexible design, we created the quietest column EPS system available on the market. This is a solution that helps make green vehicles even more attractive to consumers.”
Nexteer Automotive’s complete line of EPS systems are in demand because they eliminate hydraulic fluid, reduce weight, improve fuel economy by up to 4 percent and reduce emissions. Since 1999, Nexteer Automotive (the former steering division of Delphi) has put more than 12 million EPS units on the road globally, saving more than 500 million gallons of fuel. The company’s first EPS application with the new plastic coupling is on the 2010 Fiat 500 that is available in Europe and other global markets.
“One of our goals is to develop products that help automakers achieve weight reduction without having to sacrifice in other areas,” said Dan Diffin, associate product engineer at Nexteer Automotive and co-inventor and engineer of the coupling. “The flexible coupling design achieves 17 percent more weight savings over the previous part. Plus, the noise and vibration is eliminated so that the vehicle’s driver has a more enjoyable driving experience.”
The component is the first usage of an engineering thermoplastic in a high-performance EPS flexible coupling. It is unique because of the flexible ribs that connect and transfer torque from one rotating shaft to another so that it strokes axially, stretching and compressing the coupling. It also has a fully compliant constant-velocity joint that eliminates torsional lash, grease and all sliding interfaces. The product’s design aids in lean-process assembly.
“For the steering system to be totally quiet, we knew we had to do something innovative and different,” said Ross. “The thrill of new technology is that ‘a-ha’ moment that comes after working with a challenge over and over again. The solution, no matter how small, just hits you.”
Ross and Diffin hold the patent. Diffin, Troy Strieter, senior product engineering supervisor, and Michael Augustine, senior product engineer, engineered the part. Nexteer Automotive collaborated with suppliers DSM and Forteq for materials and molding, respectively.
Nexteer Automotive is a multi-billion dollar global steering and driveline business solely dedicated to electric and hydraulic steering systems, steering columns and driveline products for original equipment manufacturers. Its 6,200 employees serve more than 60 customers in every major region of the world with 15 manufacturing sites, six engineering and 14 customer service centers strategically located in North and South America, Europe and Asia. Nexteer Automotive’s customers include GM, Fiat, Ford, Toyota, Chrysler, and PSA Peugeot Citroen, as well as automakers in India, China and South America. www.nexteer.com.