Impeller is an important component of vacuum pump. The liquid in the vacuum pump rotates with the impeller, and the volume of the chamber between the impeller and the liquid ring varies with the position of the impeller. Thus, the shape of the impeller has an important influence on the operation of the vacuum pump. In order to ensure the good operation of the vacuum pump, the impeller in the pump also needs to meet the following requirements:
       1. Stress requirement is determined by material strength limit. Therefore, it is necessary to accurately predict the steady state of impeller in vacuum pump and the vibration stress of impeller under complex shape and high speed.
       2. Hydrodynamic requirements: to solve the problem of large turning and large diffuser of impeller at high flow speed, and to solve other troubles when passing through small channel with high efficiency and high pressure.
       Although the impeller can achieve high efficiency, the component matching of vacuum pump is a basic direction of design. Often due to inappropriate matching, the impeller has to be redesigned. Sometimes, in order to achieve ideal matching, the high efficiency of the impeller is preferred to be sacrificed.