MONO-TUBE SHOCK ABSORBERS 

The main components are:

• (pressure) cylinder, also called housing

• piston (2)* connected to a piston rod (1)*

• floating piston, also called separating piston (15)*

• piston guide (3)*

How Does a Mono-Tube Shock Absorber Work?

Bump stroke.
Unlike the twin-tube damper, the mono-tube shock has no reservoir tube. There is still a need to store the oil that is displaced by the rod when entering the cylinder. This is achieved by making the oil capacity of the cylinder adaptable. Therefore the cylinder is not completely filled with oil; the lower part contains (nitrogen) gas under 20-30 bar. Gas and oil are separated by the floating piston (15)*.

When the piston rod is pushed in, the floating piston is also forced down by the displacement of the piston rod, thus slightly increasing pressure in both gas and oil section. Also, the oil below the piston is forced to flow through the piston. The resistance encountered in this manner generates the bump damping.

Rebound stroke.
When the piston rod is pulled out, the oil between piston and guide is forced to flow through the piston. The resistance encountered in this manner generates the rebound damping. At the same time, part of the piston rod will emerge from the cylinder and the free (floating) piston will move upwards.