Air Springs
Section Through Air Spring
| ITEM | DESCRIPTION |
|---|---|
| 1 | Top mount assembly |
| 2 | Polyurethane damper mounting |
| 3 | Pressure retaining valve |
| 4 | Damper mounting seal |
| 5 | Air spring isolator |
| 6 | Air spring rolling sleeve |
| 7 | Air spring piston |
| 8 | Air spring rolling sleeve to piston crimp ring |
| 9 | Decoupled air spring guide |
The air springs take the place of conventional coil springs on the rear suspension. In the air spring, a piston compresses the air as the suspension moves into bump/jounce, which cushions the movement. A rubber rolling sleeve is guided by an outer metal support sleeve and assembled around the damper. The metal support sleeve is decoupled from the top mount assembly, which allows greater damper articulation without trapping the air sleeve. This design delivers improved ride characteristics compared to a non-guided air spring, and reduces high frequency generated inputs such as those produced by a coarse road surface, for example.
The key sealing points for the air spring are between the:
- piston and damper body
- spring unit and top mount.
The method of achieving a pressure-tight seal between the air spring and the damper means that spring and damper assemblies must be replaced as a complete unit.
The air-tight top mount assembly isolates the damper from the body structure while maintaining pressure within the spring. A pressure retaining valve in the top mount ensures that air cannot be exhausted from the air spring when the pressure is less than 3.0 bar (43.5 lbf/in2). This ensures that the rolling sleeve does not crease and become damaged. The maximum pressure in the full-bump condition at GVW (gross vehicle weight) is approximately 20 bar (290 lbf/in2).