Centrifugal pumps are composed of many parts. They can be roughly divided into three categories according to the working state of each part during operationType: rotating part, fixed part J4: and connecting part. Take the single-stage single suction horizontal diaphragm pump as an example, as shown in Figure 2.4The function, composition, structure and material of each part under.2.2.1 Rotating parts1 Impeller (also called working wheel)The barking wheel is the main part of the water pump, or even the core part of the water pump. The centrifugal system depends on the high-speed rotation of the impellerTransferring water for energy calibration.The wheel rubber of the gear pump is composed of two circular covers. If there is a curved blade between the coversThe two cover plates are connected together, and the space groove enclosed by the two adjacent blades and the front and rear cover plates is generally referred to as the flow of water.The shape and size of the impeller are determined by test and calculation, which can be generally divided into leather suction impeller and double suction impeller.The front cover plate of the impeller with a round hole for water inlet is called a single suction impeller, and the front and rear cover plates of the impeller with a round 7L water inlet are called double suction impellerSuction impeller.It is a teaching suction impeller. It is equipped with a single-sided chock wheel cover plate for water intake, while the rear cover plate is H without the cover plate of the wheel intake; Symmetrical shape. It is a double suction impeller. The front and rear cover plates of the impeller are equipped with round water inletsThe cover plate is symmetrical and generally used for large flow centrifugal pumps.In addition to sufficient mechanical strength, wear resistance and corrosion resistance of materials shall also be consideredPerformance. Recently, most impellers of screw pumps are made of cast iron, cast steel and bronze, and hard plastic and alloy steel are also used.