Single-tube gas-filled shock absorbers work along the same principle as a conventional hydraulic shock absorber, but also have a gas cushion that be compressed, therefore creating space for the compressed oil...
Single-tube gas-filled shock absorbers work along the same principle as a conventional hydraulic shock absorber, but also have a gas cushion that be compressed, therefore creating space for the compressed oil. A floating piston separates oil and gas, thus preventing them from mixing. If the oil is displaced when the spring is compressed, the piston compresses the gas cushion. When the spring then extends, the gas pushes the oil back, similar to a spring. The gas pressure is very high and ensures that even the smallest movements are damped.