Innovative air suspension technology is helping Land Rover combine the legendary off-road ability of its vehicles with exceptional refinement and driving dynamics. A key part in the development of the airspring modules was played by Delphi Corp (NYSE: DPH), which manufactures the units at its facility in Luton, UK. The new technology will be available on the Discovery 3 (called LR3 in North America), launched at the Mondial de l’Automobile (Paris autoshow) in September.
"The Discovery has always had an outstanding reputation for off-road ability, which had to be maintained with the new vehicle," explains Guy Hachey, vice president Delphi Corporation and president Delphi Energy & Chassis. "The challenge was to combine this with levels of suspension refinement that would normally be expected in conventional luxury vehicles."
Land Rover also set tough targets for packaging, durability and the air spring’s ability to maintain vehicle trim height even when left fully laden for long periods with the engine off. The packaging requirement dictated the use of small volume air springs, which made the refinement target more challenging because the smaller air volume drives very high internal operating pressures, introducing the possibility of suspension harshness.
The vehicle’s ability to travel quickly on poor surfaces presented further challenges because air springs have a natural tendency to become stiffer under low amplitude / high frequency road inputs, again potentially leading to suspension harshness.
The solution chosen uses front and rear airspring modules with integral twin-tube gas dampers, controlling the vehicle’s four-wheel independent suspension. Delphi’s engineers developed a new generation of compact, very high-pressure airspring unit and new manufacturing and testing techniques to ensure consistently high quality.
The new airspring modules allow Delphi to meet the packaging targets and, compared with conventional coil springs, also reduce vehicle weight by around 7 kg. The units are designed to withstand the most demanding burst pressure and temperature range requirements set by any vehicle manufacturer.