How Do Air Shocks Function as Both Springs and Dampers in Cars?

[csiddharthn]

Hi,

I see people using air shocks (eg. Fox float, etc) in cars, which function as a spring as well as a damper. The point I do not understand is, how do they function as both a spring and a damper? Correct me if I am wrong, but isn't the spring he thing that absorbs the energy from let's say a bump and the damper the thing that is used for dissipating the energy into? How does an air spring perform these functions? A spring has a spring rate and a damper has a damping coefficient, so I am guessing air has both, although I cannot see how those two parameters can be quantified independently in an air spring - but that must be the point surely? - that air has both an appropriate spring rate and an appropriate damping coefficient, suitable for use in a vehicle's suspensipn with a high degree of tunability? And also, what does the extra volume air chamber found in certain (all?) Air shocks do? Please reply!

Thanks.

 

[mfb]

You can design a system that can quickly compress or expand air (=spring) and slowly change the total air volume (=damping), for example with a small hole in the cylinder.

And also, what does the extra volume air chamber found in certain (all?) Air shocks do?

I guess that is the damping part.

 

[Ranger Mike]

on mechanical engineering forum please look at post - Air Suspension Mar22-11 ..we had a good discussion on this subject