The impeller, also known as the runner or working wheel, is the most important component of a water pump. It transmits external mechanical energy to the water being pumped, increasing the pressure and kinetic energy of the water flow. The form of the impeller basically determines the type and performance of the water pump, and its manufacturing accuracy has a significant impact on the performance and efficiency of the water pump.
There are three forms of centrifugal pump impellers: those with covers on both sides are called closed, those with covers on one side are called semi open, and those without covers on both sides are called open. There are 2-12 nearly cylindrical blades that bend backwards between the closed impeller cover, and the blades and the inner wall of the cover form a series of curved channels called blade grooves. Large centrifugal pumps often use enclosed impellers with 8 blades, which have a relatively high head and efficiency.
The impeller of the single suction pump leaves a water inlet in the center of the wheel cover on the inlet side. Due to single-sided water inflow, the axial force generated in the pump points towards the inlet side. Generally, small centrifugal pumps adopt this form.
The impeller of a double suction pump is equivalent to two back-to-back single suction pump impellers, with a large flow rate. Due to double-sided water ingress, the axial thrust can basically cancel out each other, thereby reducing the bearing burden and extending the bearing life.
