Meritor's Trailer Air Suspension in Five-Phase Evolution
ArvinMeritor says its Meritor RHP11 parallelogram-type integrated air suspension for trailers is undergoing a five-phase "evolution" that will result in a product that will exceed industry benchmarks in durability, while remaining very weight competitive. The first three phases were introduced over the last year and two more are due in coming months.
Now included in the Meritor-brand suspension is a new lighter axle design the Meritor5000 series axle. Unlike trailing arm suspensions, the parallelogram approach causes no roll torque on the axles, explained Bob Zirlin, director of product planning for Trailer Systems. This allows the new lighter 5-inch round beam axles to be integrated into the suspension system. The 5000 series is available with a full range of spindle profiles such as the packaged-bearing TL system, as well as the popular TN and TP.
Other changes are a new upper control arm assembly, with five-inch round, 1/4-inch thick tubing. The new control arm saves weight compared to four-inch round, 7/16 inch thick tubing in the older design, while continuing to offer outstanding durability. Bonded rubber upper control arm bushing, based on more than 15 years' experience with demanding European duty cycles, offer extra wear resistance protection against corrosion.
The final two phases of the RHP11 improvement program include a new slider design, and more compact, weight-reduced axle seats. Zirlin emphasized, "For extra strength and resistance to impact, we've optimized the suspension's slider with integrated lateral plates and we've protected the pin mechanism with the crossmembers. We've also moved the pin handle to the front for easy access." The slider was developed through advanced design optimization combined with data from operational experience.
Meritor's new parallelogram system will be "competitive in weight but possess best-in-class durability," Zirlin said. He declined to provide weight figures to avoid counterclaims by trailer-suspension competitors in what has become a war of pounds. "But we will provide figures to our customer,' he said.
The system's other advantages, he said, remain as before: No "Dock walk" and exceptionally smooth ride due to parallelogram design; superior roll stability and resistance to curbing damage; and a "complete undercarriage" product that integrates slider, trailer axles, and brakes.
Meritor suspensions are available through most trailer builders.
Equipment continued...
