内啮合齿轮泵轴向摩擦副的动压润滑研究

Research on hydrodynamic lubrication of axial friction pair in internal gear pump

确定轴向摩擦副动润滑效果的最佳条件并计算油楔面的最佳倾斜角和最佳油膜力。将浮动侧板的内侧面分成左中右3个区域,左右2区域为具有动压润滑效应的油楔斜面,中间区域为起密封和同轴支撑的平行面;由动油膜力的最大条件,建立左右2油楔斜面的倾斜角和油膜力的计算公式;定性比较轴向摩擦副内各种泄漏流量的大小。结果表明:2油楔斜面使总油膜力得到了大幅度提高,案例参数下提高了195.4%;内齿轮端面内的动油膜力相对较小,可忽略不计;采用外齿轮外圈半径处的最佳收敛比,油膜力最大;2油楔斜面还有利于外齿轮外圈、轴-轴孔等摩擦副间的润滑供油和困油现象的充分缓解。

To determine the best condition of hydrodynamic lubrication effect of the axial friction pair,and calculate the best tilt angle and the best oil film force of oil wedge structure,the inner endface of floating endplate was divided into three sub regions of the left,the right and the middle.The left and right sub regions had tilted surface with oil wedge structure for forming hydrodynamic lubrication effect,and the middle sub region was parallel surface for reducing axial leakage and supporting coaxiality.From the best condition of oil film force on the left and right regions,the formula for calculating the two tilted angles and oil film forces were derived.Basing on the qualitative analysis of possible fluid flows within the axial gap,it was found that the total oil film force would be significantly improved because of the two oil wedge structures,and it would be increased by 195.4%in an example;the hydrodynamic oil film force on the axial endface of driving gear was relatively small and might be neglected;the total oil film force would get to the largest value when the best convergence rate was used in the outer radius of driven gear;the two oil wedge structures were also advantageous to supply lubrication oil to axis-bearing friction pair and outer ring friction pair of driven gear,and to effectively relieve the trapped oil.