TRW Automotive recently unveiled its Electrically Powered Steering (EPS) Belt Drive system that will launch on North American models in 2008, according to a TRW Automotive press release.
Belt-drive steering technology, also referred to as "rack drive," brings the fuel efficiency and carbon-dioxide reduction benefits of an electric steering system to higher rack load vehicles as compared to TRW's current Column Drive EPS system, already launched on more than 30 vehicle models, the company notes. As with all TRW electromechanical steering systems, the Belt Drive system only consumes noticeable power when steering assist is needed, providing considerable fuel-consumption benefits and reduced CO2 emissions.
As the name implies, the EPS system requires no hydraulic pump, hoses or fluid. The assist power is applied directly to the rack with a belt and ball-nut mechanism. In addition, the energy consumption of an EPS system is just 10% of a conventional hydraulic power steering (HPS) system as power assist engages only when needed, helping to improve fuel economy of an EPS-equipped vehicle.
TRW's EPS Belt Drive system can provide premium performance across a wide range of vehicle platforms with rack assist forces of 11 kilonewtons (kN), the company says. Power assist is applied directly to the rack allowing for a responsive, low- inertia, low-friction steering system with a direct-steering feel.
Dr. Aly Badawy, vice president engineering, steering and suspension, said: "The product is delivered as a fully tested, ready-to-install unit, and all steering belt, pulley, pump, reservoir and hydraulic lines are eliminated, making the product easy to install and maintain."
"The Belt Drive EPS system can be programmed with steering-assist functions in line with vehicle manufacturer's requirements; options include speed sensitive, positive and responsive steering feel and the possibility for vehicle manufacturers to fine-tune the steering characteristics. And with a Belt Drive system, these benefits are now available for small- and medium-size sport-utility vehicles, minivans and light trucks."
Source: TRW Automotive Holdings Corp. (May 22, 2007). "TRW Automotive To Launch Belt Drive Electrically Powered Steering in North America & Europe." TRW Automotive Holdings Corp. Press release courtesy of PR Newswire.