Based on the damping material, there are three types: hydraulic, pneumatic, and variable damping.
Hydraulic shock absorbers are widely used in automotive suspension systems. Their principle is that as the vehicle frame and axle reciprocate, a piston moves within a cylinder. Oil repeatedly flows from one chamber through pores into another, generating damping force through friction between the fluid and the inner wall and intramolecular friction.
Pneumatic shock absorbers are a new type of shock absorber developed in the 1960s. A floating piston forms a sealed chamber at the bottom of the cylinder, filled with high-pressure nitrogen. The compression and expansion valves on the working piston change the cross-sectional area of the channel with the speed of movement.
From a functional perspective, they can be broadly classified into shock absorbers designed to eliminate vibrations of specific frequencies, rubber couplings, and rubber buffers used as mechanical components to support various equipment and absorb shock.
Rubber shock absorbers are categorized by shape. There are two types: reduced-profile types, used for compression and high load capacity; cylindrical-profile types, suitable for multi-directional damping, such as those perpendicular to the axis, and high load capacity; compound-profile types, used for combined compression and shear, combining the characteristics of both reduced-profile and shear types. Shear-profile types are primarily used in shear and have low load capacity, but a narrower range of spring rates.
From a structural perspective, they are categorized as single-tube and twin-tube types. Single-tube types, such as single tube, mono tube, and De Carbon, have a free piston structure with high-pressure air enclosed underneath. Damping force is generated by a piston assembly at the end of the shaft, with changes in shaft volume absorbed by the expansion and compression of the gas. Compound-tube types, also known as twin-tube dampers, have a dual-tube structure, generating damping force between the piston at the end of the shaft and the bottom assembly of the tube.
Alternatively, you can verify proper operation by checking the shock absorber housing to see if it is sufficiently warm after driving the car on a poor road surface for 10 kilometers. If it is not warm enough, it indicates no internal resistance and is not functioning.
