齿轮泵入口侧的空化性能研究与分析

Research on Cavitation Performance on the Inlet Side of the Gear Pump

为有效避免齿轮泵吸油腔内的空化现象,基于扫过面积法,以主、从动齿轮上的两条啮合半径为边界,构建包含啮合点和啮合半径在内的密闭空间吸油腔,并推导出对应的体积变化率;基于困油的充分卸荷,依据吸油腔的体积变化率等于与腔外的交换流量,推导吸油腔内介质动态压力及其最小值的计算公式,并建立避免空化现象的判别式,进行实例运算和结果分析。结果表明:啮合位置的变化,导致了吸油腔内介质压力的动态变化;节点啮合位置处,压力取最小值;入口半径是有效避免空化现象的主要因素等,其正确选择能有效避免空化现象。计算最小压力时考虑了众多因素,为齿轮泵后续进一步提高空化性能的研究提供了理论基础。

In order to avoid cavitation phenomenon effectively in oil suction chamber of gear pump,taking the two meshing radius of the driving gear and the driven gear as the boundary,a closed space of oil suction chamber,which included the meshing point and meshing radius,was constructed,the corresponding volume change rate was derived according to the method of swept area.According to the volume change rate of the oil suction chamber was equal to the exchange flow outside the chamber,the formula for dynamic pressure change and minimum value of medium in the oil suction chamber was derived based on full unloading of trapped-oil,and the discriminant was established to avoid cavitation.Finally,instance operation and result analysis were done.The results show that dynamic change of the medium pressure in the chamber is caused by the change of the meshing position,the minimum value of pressure is obtained at the position of node and meshing coincidence;the inlet radius is the main factor to avoid cavitation phenomenon,and the correct choice can avoid cavitation effectively.Many factors are considered in the calculation of the minimum pressure,which provides a theoretical basis for the further study of the cavitation performance of the gear pump.