通过实验发现 ,离心式水泵平衡孔和口环密封间隙处的汽蚀对泵的性能和寿命有十分不利的影响。研究了离心水泵平衡孔和叶轮入口密封间隙的汽蚀过程和产生机理 ,以及其几何结构和回流对汽蚀的影响。并讨论了平衡孔汽蚀和间隙汽蚀与回流之间的关系。 It is found through experiments that the cavitation at the balance hole between the centrifugal pump and the mouth ring seal has a very adverse effect on the performance and life of the pump. The cavitation process and mechanism of the balance between the centrifugal pump impeller and the impeller inlet seal gap were studied, and the influence of geometrical structure and backflow on cavitation was also studied. The relationship between cavitation in balance hole and interstitial cavitation and backflow is also discussed.