airspring

An airspring is a type of mechanical spring that uses compressed gas, typically air, inside a flexible chamber to provide a restoring force. When the loaded component moves, the gas is compressed or expanded, creating resistance. The force and effective stiffness can be adjusted by changing the gas pressure, and stiffness generally increases with pressure and can vary with temperature.

Construction typically involves a rigid cylinder and a movable piston or a flexible bladder (bellows) that contains the gas. The gas space is sealed and connected to a valve or regulator to set the pressure. Some designs use a bladder connected to a piston, while others use a metal bellows. The assembled unit may include a regulator, inflator/vent valve, and sometimes a secondary chamber to tailor the response.

Operation and performance rely on gas compression and expansion. As displacement occurs, the gas stores and releases energy, producing a spring-like force. Many airsprings offer progressive stiffness, which can be tuned for specific applications. In automotive use, compressors and controls maintain ride height and spring rate; in furniture and equipment, manual or passive adjustments set the desired feel.

Applications are widespread. Automotive air suspension systems use airsprings to adjust ride height and handling characteristics. Office chairs, industrial machinery isolators, and stage or laboratory equipment often employ airsprings for smooth support and vibration isolation. They are chosen for lightweight, compact form, and the ability to vary stiffness without mechanical springs.

Advantages include adjustable stiffness, wide force range, and smooth operation. Limitations include sensitivity to temperature, potential gas leakage, and reliance on seals and valves; damping must be provided separately in many systems. See also gas spring, pneumatic cylinder, and vibration isolation.