Effect Of Laser Textured Shaft Surfaces On The Reverse Pumping And Frictional Properties Of Lip Seals

Rotary shaft lip seals have many advantages, such as small form, simple structure,good sealing performance and low price, thus they are widely used in industry. With therapid development of vehicle, machinery, aviation and other industries, the requirementon the performance of rotary shaft lip seal is higher and higher. The research about effect ofsurface morphology of rotary shaft on sealing effect and seal life has attracted wideattention.In order to study the influence of shaft’s surface topography on the reverse pumpingeffect and frictional properties of lip seals, the method we choose for research is texturingon the surface of rotary shaft to control its surface topography in this paper. Firstly, lasermarker YLP-F10is used to mark laser texturing on the cylindrical surface of rotary shaftspecimens with the help of the special rotary worktable E-RSC100. Consequently, theproblem that laser marker YLP-F10textures on curved surface is solved. Two sets ofspecimens which have same surface roughness Ra, but different laser texturing on thesurface are obtained: one set of the specimens are circular, which have the same surfaceroughness Ra by keeping the diameter constant and controlling the distance, depth and areadensity of the micro cavity, the others are triangular, which have the same parameters of themicro cavity, only change the direction of the micro cavity. Then a serious of comparisonexperiments under different rotational speed, different surface topographies were conductedon an oil seal tester. Some lip surfaces after experiments were analyzed by using scanningelectron microscopy image. The results show that: the specimens with triangular microcavity towards oil side can promote the reverse pumping effect effectively which makes thesealing performance enhanced. At the same time it can reduce the friction under somespeeds. In contrast with the surface without laser texturing, the surfaces with circle microcavity of which area density are7%and21%respectively show better friction reducing,and with triangular micro cavity lagging and leading can reduce the friction.To take the rubbing pair of rotary shaft-lip seal as the object of the study, thelubrication model was established to do some exploratory researches about their frictionaland lubrication properties. It lays a good foundation for further researching the frictionaland lubrication properties of the micro cavity surface.