表面粗糙度对配流副润滑特性的影响

为研究表面粗糙度对轴向液压柱塞泵马达配流副润滑特性的影响，引入Weierstrass-Mandelbort分形函数，对不同幅值的表面粗糙度的表面形貌进行二维和三维模拟，建立考虑表面粗糙度的流固热耦合下的配流副油膜润滑模型，采用中差分形式的有限差分法和松弛迭代法对其进行数值求解，并分析油膜厚度、油膜压力、油膜承载力、摩擦因数等性能参数随着表面粗糙度幅值变化的规律。通过盘-盘形式的配流盘-缸体摩擦磨损试验，得到不同幅值的表面粗糙度下配流副摩擦因数，对所建立的数学模型进行验证。数值计算结果表明，表面粗糙度幅值的增大会引起油膜承载力增大，但也会引起最大油膜压力和摩擦因数的增大，导致摩擦性能下降。摩擦磨损试验发现，表面粗糙度增大，配流盘表面摩擦磨损情况加剧，配流副润滑性能和耐磨性能整体降低。因此在配流盘表面加工处理中，应适当降低其表面粗糙度。

Effect of Surface Roughness on Lubrication Characteristics of Port Plate Pair

In order to study the influence of surface roughness on the lubrication characteristics of the valve pair of axial hydraulic piston pump motor,the Weierstrass-Mandelbort fractal function was introduced to simulate the surface topography of the surface roughness with different amplitudes.The oil film lubrication model of the valve pair with fluid-solid thermal coupling considering the surface roughness was established,and was solved by the finite difference method and relaxation iteration method.The variation of oil film thickness,oil film pressure,oil film bearing capacity,friction coefficient and other performance parameters with the amplitude of surface roughness were calculated and analyzed.Through the disk-disc friction and wear test of the valve plate cylinder block,the friction coefficient of the valve pair under different surface roughness amplitudes was obtained,and the mathematical model was verified.The numerical calculation results indicate that an increase in surface roughness amplitude can cause an increase in oil film bearing capacity,but it can also lead to an increase in maximum oil film pressure and friction coefficient,resulting in a decrease in friction performance.The results of friction and wear test show that as the surface roughness increases,the friction and wear on the surface of the valve plate is intensified,and the overall lubrication and wear resistance of the valve pair decreases.Therefore,in the processing of the valve plate surface,the surface roughness should be appropriately reduced.