air suspension

Air suspension is a vehicle suspension system that utilizes pressurized air instead of traditional metal springs. It is a load-carrying component found in machines, automobiles, and buses. An air suspension system typically includes an air compressor, an air-supply tank, leveling valves, check valves, and bellows, which are essentially columns of air contained within a rubber and fabric casing.12

These systems maintain a fixed vehicle height regardless of load by admitting more air when the load increases and venting excess air when the vehicle unloads. Unlike metal springs, air springs can have a controllable spring rate, becoming progressively stiffer under increased load due to air compression. While air suspension was introduced in luxury cars in the late 1950s, it has seen renewed development with modern leveling systems.23