Shock Absorber, Basic Function - GF32.25-P-1001A

Model All (4xWD) 

Model All (CAR) 

Overview 

This document contains information on: 

• General 
• Function 
  • Monotube gas-filled shock absorber 
  • Twin-tube gas-filled shock absorber 

General 

The shock absorbers convert the impacts and vibrations of unsprung masses into thermal energy. The shock absorbers ensure that the wheels remain in contact with the floor in all driving situations. The shock absorbers increase ride comfort and contribute substantially to driving safety.

Function 

Monotube gas-filled shock absorber 

In a monotube gas-filled shock absorber, the working chamber is filled with oil that is under a system pressure of 20 to 30 bar. Oil and gas are separated from each other by the floating dividing piston.

Damping valves are each located on the piston for the pulling and compression phase. The vibration is dampened in both directions via the multi-stage piston valve.

• Compression stage: The immersed piston rod displaces the corresponding oil volume. The volume is absorbed by the gas cushion.
• Rebound stage: The gas cushion is relaxed when the piston rod moves out and it pushes the dividing piston back.

Twin-tube gas-filled shock absorber 

For precise dampening and a low noise level at high compression speeds, the twin-tube gas pressure shock absorber is filled with a gas pressure that lies between 6 to 8 bar.

During the compression phase, the piston rod moves in and so part of the oil flows from the lower working chamber into the upper working chamber through the piston valve.

During the rebound phase, the piston rod moves out and the piston valve takes over the dampening while the oil flows back through the bottom valve.