外啮合齿轮泵齿轮副的偏心设计

Eccentric Design of Gear Pairs in External Gear Pumps

为提高泵齿顶间隙内的润滑性能,提出了旨在强化其内动压润滑效应的齿轮副偏心设计方法,通过综合考虑泵体变形、轴-轴承不同心等因素,建立了压差流与剪切流组合下的齿顶泄漏公式,并由该泄漏的最小化条件计算出齿轮副相对于泵壳中心的偏心距。结果表明,转速越高,偏心距越小,泄漏越小,容积效率提升明显;出口压力越大,偏心距越接近上限值,泄漏越大,容积效率提升不明显等。最终,得出了通过齿轮副的偏心,齿顶间隙内动润滑效应明显的重要结论。

To improve the lubrication performance in radial clearance of gear addendum in external gear pumps,the eccentric design method of gear pairs relative to the center of pump case was put forward to strengthen dynamic pressure lubrication effect in the radial clearance. Based on comprehensive consideration of the relative factors such as pump case deformation and the decentraction of shaft and bearing,under the combination effect of differential pressure and dynamic pressure in the radial clearance,the leakage rate through the radial clearance from discharge side of pump to suction side was calculated; and from the minimized condition of the leakage rate,the eccentric distance of gear pairs relative to the center of pump case was derived. All results showed that the higher the rotating speed was,the smaller the eccentric distance was,then the smaller the leakage rate was,so the more obvious the increased volumetric efficiency of pump was; the greater the discharge pressure was,the bigger the eccentric distance was,so the bigger the leakage rate was,then the less obvious the increased volumetric efficiency was,and so on. Finally,the important conclusion is drawn that the dynamic lubrication effect improvement obtained by the eccentric distance is more obvious.