Optimization Of Surface Texture And Its Effect On Oil Seal Performance

Oil seals are widely used in rotating machinery due to their simple structure,reliable performance,easy installation and low price.When the oil seal is running,the lubrication and friction state of the seal interface directly affect its sealing performance.In recent years,the application of surface micro texture to improve the lubrication performance of sealing interface has been paid more and more attention.But the existing lip surface texture layout and texture geometric parameters are designed by experience.In order to provide the best surface texture design of lubrication and friction characteristics for the sealing performance of oil seal,this paper studies the influence of lip surface texture optimization on the sealing performance of oil seal.The research results have important guiding significance for promoting the reasonable application of surface texture in sealing parts and improving the sealing performance of oil seal.The main research contents of this paper are as follows :The three-dimensional finite element model of oil seal under precompression was established by ABAQUS software,and the relationship between the maximum contact pressure of oil seal lip and the interference amount and the theoretical contact width was obtained.According to the stress results obtained by ABAQUS,the fatigue analysis software FE-SAFE is used to predict the change trend of oil seal cycle life under different interference and different theoretical contact width.The results show that with the increase of interference,the maximum contact pressure of oil seal lip increases first and then decreases,and the cycle life continues to decrease.With the increase of theoretical contact width,the maximum contact pressure of lip gradually decreases,and the cycle life of oil seal gradually increases.Considering the simulation results,when the interference is controlled in the range of 0.35 mm ～ 0.45 mm and the theoretical contact width is controlled in the range of 0.3 mm ～ 0.5mm,the oil seal can obtain better sealing ability and cycle life.The optimized lip surface of oil seal was optimized with isosceles triangle,ellipse and rectangular micro-pit texture.Based on the elastohydrodynamic lubrication theory,the numerical calculation model of oil seal was established by coupling the texture parameters of lip micro-pits and considering the surface roughness,and using the two-dimensional average Reynolds equation.Based on MATLAB programming,the numerical equation is solved iteratively,and the influence of texture depth,rotation angle,shape factor and texture spacing on the performance index of oil seal is obtained.The texture of each shape is optimized,and the optimal parameter values of texture depth,rotation angle,shape factor and texture spacing arrangement of three kinds of micro-concave textures are obtained.The isosceles triangle micro-concave texture is 6 μm,120 °,1.4 and 2 mm,the elliptical microconcave texture is 7 μm,140 °,1.4 and 2 mm,and the rectangular micro-concave texture is7 μm,130 °,1.5 and 2 mm.Under different working parameters of roughness,working pressure and rotational speed,the effects of three different shape texture optimization schemes on the sealing performance of oil seal were explored.The results show that the variation trends of pump suction rate and friction torque with roughness,working pressure and rotational speed are basically the same for oil seals with different shapes and textures.The influence of isosceles triangle pits texture on pump suction rate is the most obvious,and rectangular texture can obtain smaller friction torque.