基于CFD的齿轮泵实际最优端面间隙确定方法

Determination Method of Actual Optimal End Clearance of Gear Pump Based on CFD

齿轮泵端面间隙是内泄漏和黏性摩擦损失最重要的影响因素,其大小主要由浮动侧板背面高压油压紧力与其所受端面油膜反推力平衡状态确定。针对某型号齿轮泵,考虑了端面间隙、油液含气量和油液蒸发等因素对反推力压力分布的影响,采用CFD方法计算获得常用工况下5组给定端面间隙对应的端面油膜反推力,由最小二乘法拟合得到间隙小范围变化时的端面油膜平均反推力线性化方程,求解现有总功率损失最小条件下最优端面间隙值,将其代入端面油膜平均反推力方程,反解出浮动侧板背面所需高压油压紧力。据此,通过调整浮动侧板背面高压区形状,使齿轮泵的实际端面间隙在常用工况下处于最优值。对实际工程中确定齿轮泵最优端面间隙具有重要的参考价值。

The end face clearance of gear pump is the most important influencing factor of internal leakage and viscous friction loss, and its size is mainly determined by the equilibrium state between the high-pressure oil pressure on the back of floating side plate and oil film thrust on the end face. For a certain type of gear pump, the influence of end face clearance, oil gas content, and oil evaporation on the pressure distribution of the thrust force is considered. The CFD method is used to calculate the thrust force of oil film at the end face corresponding to five given end face clearances under rated conditions. The linear equation of average thrust force of oil film at the end face when the clearance varies in a small range is fitted by the least square method. The optimal end face clearance value under the condition of the minimum total power loss is solved, which is substituted into the average thrust force equation of oil film at the end face, and the high-pressure oil pressure required on the back of floating side plate is inversely solved. Accordingly, by adjusting the shape of the high-pressure zone on the back of floating side plate, the actual end face clearance of gear pump is at the optimal value under the rated working condition. This method has an important reference value for determining the optimal end face clearance of gear pump in practical engineering.