TrelleborgVibracoustic, a supplier of vibration control technology, has developed a bellows technology for air springs. The “ZAX bellows” combines the advantages of the cross-ply and axial bellows previously used in passenger cars.
TrelleborgVibracoustic has previously produced cross-ply and axial types of bellows. They differ in terms of the structure of the reinforcing fibers embedded in the bellows. With an axial bellows, the fibers embedded in the elastomer run axially to the deflection direction. In contrast to this, the cross-ply bellows has two intersecting layers of reinforcing members, but they are not connected as opposed to a fabric. The newly developed cross-axial bellows, or ZAX bellows, combine the good torsion decoupling capability of the axial bellows with the dimensional stability of the cross-ply bellows.
The new technology will go into series production in 2015 on the rear axle of a number of new SUVs. Since the air springs in this stand-alone application, are not guided by the integrated vibration dampers, they need to absorb high gimbal and torsional forces. TrelleborgVibracoustic states that cross-ply bellows previously used on the rear axle usually require an elastomeric element or a plain bearing for torsion decoupling. The claimed upshot of this is reduced tension and improved initial suspension response. TrelleborgVibracoustic states an additional benefit of eliminating the torsion-decoupling element, is a reduction in production costs for the ZAX bellows.
TrelleborgVibracoustic states that every second passenger car that runs on air springs is equipped with its products.