According to wikipedia,
A hydropneumatic system combines the advantages of two technological principles:
- Hydraulic systems use torque multiplication in an easy way, independent of the distance between the input and output, without the need for mechanical gears or levers
- Pneumatic systems are based on the fact that gas is compressible, so equipment is less subject to shock damage.
- Gas absorbs excessive force, whereas fluid in hydraulics directly transfers force
What purpose do the hydraulics serve? I understand that the air would serve as a cushion, but why the hydraulics?