表面粗糙度对滑阀式液压阀缝隙流动特性的影响

Effect of Surface Roughness on Gap Flow of Hydraulic Slide Valve

基于W-M函数建立滑阀式液压阀阀芯与阀腔微观表面各向异性的三维形貌模型,并建立阀芯与阀腔间缝隙流动模型;运用Fluent软件分析液压油在压差与剪切共同作用下在缝隙中流动时油压和流速的变化。结果表明:当油液在压差与剪切共同作用下缝隙中流动时,阀芯表面的剪切力大于阀腔,阀芯与阀腔的表面粗糙度越大,剪切力的波动程度越大,油液受到的阻碍作用越大,油液的流速越小;阀芯的表面粗糙度越大,其径向不平衡力越加剧,从而会造成阀芯与阀腔的磨损加快。

Based on the fractal characteristic of spool and valve chamber’s microscopic surface for hydraulic excavatormulti-way valve, a three-dimensional surface topography model with anisotropy was established via the function of W-M.According to the gap flow between the spool and valve chamber, the model of gap flow was established. The change of oilpressure and oil velocity when hydraulic oil flowing in the gap under pressure and shear interaction was analyzed by Fluentsoftware. The results show that when the oil flow in the gap under pressure and shear interaction, the shear stress on thespool surface is larger than that on the valve chamber surface, the larger the surface roughness of spool and valve chamber,the greater the volatility of the shear stress, the greater the hindrance to oil, and the smaller the oil velocity.The larger thesurface roughness of spool, the greater the radial unbalanced force of the spool surface, which will accelerate the wear of spool and valve chamber.