First, the basic structure of self-priming centrifugal pump The basic structure of self-priming centrifugal pump is composed of six parts are the impeller, pump body, pump shaft, bearings, seal ring, stuffing box. 1, the impeller is the core part of the self-priming centrifugal pump, it is higher than the speed, impeller blades play a major role in the impeller before the assembly through the static balance experiment. The inner and outer surfaces of the impeller require smoothness to reduce the frictional loss of water flow. 2, also known as the pump casing, it is the main pump. To support the role of fixed, and with the bearing bracket to connect. 3, the role of the pump shaft is connected by a coupling and motor, the motor torque to the impeller, so it is the main component of mechanical energy transfer. 4, the bearing is set on the pump shaft supporting the pump shaft components, there are two types of rolling bearings and plain bearings. Rolling bearings using butter as a lubricant to the appropriate general size of 2/3 ~ 3/4 Too much heat, too little sound and fever! Sliding bearings are used as a transparent oil lubricant, refueling to the oil level line. Too much oil to bleed along the pump shaft and cheap, too little bearing but also overheating and burn accident! In the process of running the pump bearing temperature up to 85 degrees generally run at 60 degrees, if high, we must find out the reason (whether impurities, whether the oil is black, whether the water) and timely treatment! 5, seal ring, also known as leakage ring. The gap between the impeller inlet and the pump casing is too large, causing the water in the high-pressure area of ​​the pump to flow to the low-pressure area through this gap, affecting the output of the pump and reducing the efficiency. The gap is too small will cause the impeller and the pump shell friction wear. In order to increase the backflow resistance to reduce internal leakage, delay the service life of the impeller and the pump housing, the inner edge of the pump housing and the impeller is provided with a sealing ring at the joint of the outer support, and the sealed clearance is maintained at between 0.25 and 1.10mm. 6, stuffing box mainly by the filler, water seal ring, packing tube, packing gland, water seal tube. The purpose of the stuffing box is to close the gap between the pump housing and the pump shaft so that the water inside the pump does not flow outside and the outside air does not enter the pump. Always keep the pump vacuum! When the pump shaft friction with the filler to generate heat will depend on the water seal to live in the water seal ring so that the filler cooling! Maintain the normal operation of the pump. Therefore, during the inspection of the pump running inspection of stuffing box is a special note! Filler needs to be replaced after about 600 hours of operation. Second, self-priming centrifugal pump components Self-priming centrifugal pump over-current components are: suction chamber, impeller, pressure chamber three parts. The impeller chamber is the heart of the pump and the heart of the flow component. Pump through the impeller on the liquid work, to increase its energy. Impeller according to the direction of the liquid is divided into three categories: (1) Radial impeller (centrifugal impeller) Liquid is along the axis of the vertical direction out of the impeller. (2) Diagonal impeller (Francis impeller) The liquid flows out of the impeller in a direction inclined to the axis. (3) Axial impeller The direction of liquid flow parallel to the axis. Impeller by inhalation is divided into two categories: (1) single-suction impeller (ie impeller from the side of the inhalation of liquid). (2) double suction impeller (ie impeller suction fluid from both sides). Impeller by cover form is divided into three categories: (1) closed impeller. (2) open impeller. (3) Semi-open impeller. One closed impeller is widely used, the aforementioned single suction impeller double suction impeller belongs to this form. Third, the self-priming centrifugal pump working principle Self-priming centrifugal pump working principle is: self-priming centrifugal pump so that water can be sent out due to the role of centrifugal force. Pump before work, the pump body and the inlet pipe must be filled with water into a vacuum state, when the impeller is rapidly rotating, the blade to promote rapid rotation of water, rotating water from the impeller in the centrifugal force of the fly, the pump After the water is thrown out, the central part of the impeller forms a vacuum area. Suwon's water pressure in the air pressure (or water pressure) under pressure through the pipe into the water pipe. This endless cycle, you can achieve continuous pumping. It is worth mentioning that: Self-priming centrifugal pump must be started before the pump housing full of water before starting, otherwise it will cause the pump heat, vibration, reduce the amount of water, causing damage to the pump (referred to as "cavitation ") Equipment accident! Many types of self-priming centrifugal pumps, classification methods are common in the following ways: 1 according to the impeller inhalation points: single-suction self-priming centrifugal pump double-suction self-priming centrifugal pump. 2 according to the number of impeller points: single-stage self-priming centrifugal pump multi-stage self-priming centrifugal pump. 3 according to the structure of the impeller points: Open-impeller self-priming centrifugal pump semi-open impeller self-priming centrifugal pump closed impeller self-priming centrifugal pump. 4 according to the working pressure points: low pressure self-priming centrifugal pump pressure self-priming centrifugal pump high-pressure self-priming centrifugal pump side vertical self-priming centrifugal pump.