Flow Circuit at Rebound Cycle
Below is a description of how the oil flows from the rebound side to the compression side of the piston. The rebound cycle is very similar to the compression cycle, but the flow will be in the opposite direction and the oil will move through other valves. During the rebound stroke, the pressure of the rebound side of the main piston is increased, while the pressure of the compression side is kept almost constant.
First the oil has to get to the rebound valves. The ports between the end cap and the inner tube (Figure 3.5-A) will lead the oil to the volume between the tubes (Figure 3.5-B) from where the oil will reach the chamber below the rebound valves (Figure 3.5-C). The pressure here will be roughly the same as in the rebound side of the cylinder tube due to small restrictions of the oil flow. The pressure will help to close the check valve in this camber. Flow circuit at compression cycle for more detailed information as the rebound valves are identical to the compression valves. Unless the low speed rebound valve is fully closed, the oil will first pass through this valve (Figure 3.5-D).
The second valve to open is normally the nose shim stack (Figure 3.4-E and Figure 3.5-E). If the pressure level reaches the opening pressure of the poppet valve, the poppet valve will open (Figure 3.4-F and Figure 3.5-F).
Now the oil has reached the low-pressure zone at the gas reservoir (Figure 3.5-G), where the pressure is equal to the gas pressure. The oil will now flow through the rebound check valve (Figure 3.5-H) positionedat the compression valves. Some oil can, in the same way as described above in Flow circuit at compression cycle, flow backwards through the low speed compression valve (Figure 3.5-I) unless it is set to the fully closed position. Finally the oil re-enters the main tube on the compression side through a port in the separating plate (Figure 3.5-J). The rebound circuit is completed.