Experimental investigations on the effect of rod surface roughness on lubrication characteristics of a hydraulic O-ring seal

The surface roughness of friction pairs plays a significant role in the formation of hydrodynamic fluid film between rod-seal interface. To investigate the influence of rod surface roughness on lubrication characteristics of hydraulic reciprocating seal, the friction force and the net leakage of seal under quasi-constant speed conditions and variable speed conditions are compared and analyzed, by using a self-designed experimental device. The results show that the rod surface roughness has an important influence on seal behavior and cannot be ignored. The rougher the rod surface is, the greater the friction force and the net leakage are, and the seal is more prone to meet with the rolling torsion or fatigue failures under the conditions of frequent start-up and shut-down.