Tenneco Automotive Inc., working closely with DaimlerChrysler, has developed a weight- and space-saving elastomer-based suspension system for the carmaker's highly fuel efficient prototype.
The DaimlerChrysler development, mounted on the recently unveiled Dodge ESX3 concept car, replaces traditional springs and associated mounts and brackets with a simple axle tube with elastomeric spring elements. The patented Elastomeric Torsional Axle on the ESX3 reduces the complexity of rear axle design by up to 40 percent to achieve a 25 percent to 35 percent weight saving over metal spring suspension systems, Tenneco claims.
The Lake Forest, Ill., auto supplier developed the system for DaimlerChrysler in connection with the Partnership for a New Generation of Vehicles, a joint government/industry-sponsored initiative.
For its ESX3 concept, Daimler-Chrysler charged Tenneco with manufacturing an independent rear suspension in which the stability of one tire would not affect the stability of the opposite tire.
'Independent rear suspensions are on a lot of cars,' Tenneco spokesman Brad Nixon said, but DaimlerChrysler wanted a lightweight version with minimized packaging to reduce vehicle size and weight, allowing for better gas mileage.
The front-wheel-drive Dodge ESX3 concept, introduced last month in Washington, uses an elastomeric torsional axle on the rear suspension. Bonded inside a 3-inch diameter piece of boxed steel between the two rear wheels, the axle acts as a torsional spring.
'As the wheel goes up and down, it twists the shaft,' Nixon explained. 'Because the rubber (inside the shaft) wants to go back to its original shape, it forces the tire back down on the road.'
The complete torsional axle system tucks underneath the vehicle, reducing the width of wheel well intrusion into the cockpit or trunk compartment.
The system trims extra pounds from total vehicle weight. The ESX3 is rated at 72 mpg in combined city/highway driving.