静压支承导轨密封边的油膜特性

Characteristics of oil film between sealing sides in hydrostatic support slideway

基于理论分析,研究静压支承系统中静压油垫的承载力和刚度特性。利用Coons曲面法建立壁面粗糙形貌符合高斯分布的油膜三维模型,采用数值模拟手段从微观的角度分析粗糙度对密封边油膜性能的影响。研究结果表明:设计参数ηo存在1个理论最优值使得油垫承载刚度达到最大。受粗糙度影响,油膜压力分布呈现随机波动性。油膜承载力与流动速度保持线性增加关系,但随厚度的增加逐渐降低,降低幅度不断减小。相对粗糙度越大油膜承载力越高,且承载力的增加量几乎不受油膜厚度变化的影响,而流动速度变化时,承载力的增加表现为变化率基本相等。

Based on theoretical analysis, carrying capacity and stiffness characteristics of oil pad in hydrostatic support system were investigated. A three-dimensional model of oil film with profile of rough surfaces in accordance with Gaussian distribution was established by using Coons surface method. The effects of roughness on characteristics of oil film between sealing sides were numerically simulated from the microscopic perspective. The results show that the designed parameter ηo has a theoretical optimal value which can make the oil pad bear stiffness to reach the maximum. The pressure distribution of oil film fluctuates randomly under the influence of the roughness. The carrying capacity of oil film increases approximately linearly with flow velocity, but gradually decreases with the increase of the thickness, and the magnitude of decrease reduces continuously as well. Carrying capacity increases with the increase of relative roughness, and the effect becomes more and more distinct. More specifically, the increase of carrying capacity is equal. Additionally, the increase of the carrying capacity remains almost invariable with the change of the thickness, and the increase rates of carrying capacity under different flow velocities are nearly equal.