不同卸荷槽影响下外啮合齿轮泵空化特性

Cavitation characteristics of external gear pump under the influence of different relief grooves

为改善外啮合齿轮泵在开式液压系统中空化严重的问题,对齿轮泵空化现象发生的过程及解决齿轮泵空化现象的措施进行了研究.通过分析泵内油液的流动状况得出了导致泵空化现象发生的原因;根据空化原因提出了运用矩形卸荷槽、渐开线型卸荷槽、异型卸荷槽降低齿轮泵空化现象的措施,并运用数值仿真进行了对比分析;最后分析了3种卸荷槽的卸荷作用下泵的困油现象及容积效率.结果表明:吸油腔内的高速旋流和吸空现象与齿轮泵空化现象的发生有很大关系;齿轮处于不同啮合状态时泵的空化强度和空化范围不同;增加卸荷槽是降低齿轮泵空化现象的有效措施,不同类型卸荷槽对空化现象的影响程度不同;3种卸荷槽的卸荷能力及其作用下泵容积效率有一定的差异.本研究为解决齿轮泵空化现象及卸荷槽外形的选择提供了一种新的参考.

In view of the serious problem of cavitation of external gear pump in open hydraulic system,the process of cavitation and the measures to solve the cavitation phenomenon are studied.By analyzing the flow of oil in the pump,the causes of cavitation of the pump are obtained.According to the reasons of cavitation,measures to reduce the cavitation of the gear pump by rectangular relief groove,involute relief groove and special relief groove are proposed,and the performance is compared by numerical simulation.Finally,the oil trapping phenomenon and volumetric efficiency of the pump under different relief groove are analyzed.The results show that the high-speed swirling and suction in the oil suction chamber is closely related to the occurrence of cavitation in the gear pump;The cavitation intensity and range are different when the gears are in different meshing states;There are between the trapped oil phenomenon and the volumetric efficiency of the pump under the action of three different unloading tanks.The conclusion investigated in this study will provide much scientific information for the solving cavitation phenomenon of gear pump and choosing relief groove shape.