Clean water centrifugal pump is mainly composed of pump body, pump cover, impeller, shaft, sealing ring, shaft sleeve and suspension bearing parts. The advantage is that the maintenance is convenient. The pump body, suction pipeline, discharge pipeline and motor are not moved during maintenance, and only the middle connecting piece of the extension coupling is removed, and the rotor part can be withdrawn for maintenance.
Take IS type horizontal single-stage clean water centrifugal pump as an example, its structure diagram is as follows:
Housing: The housing is used to collect the liquid from the impeller and convert part of the kinetic energy of the fluid into pressure energy, and finally direct the fluid evenly to the discharge port. The housings of single-suction and single-stage clean water pumps are mostly spiral volute type, and some have fixed guide vanes in the housing.
The main components of the impeller pump: divided into open impeller, semi-open impeller (only with rear disc) and closed impeller (with front and rear discs). Open impellers are mostly used to transport liquids containing impurities, such as sewage pumps. All clean water pumps use closed impellers, and most of them are backward impellers
Sealing ring: In order to reduce the amount of liquid leaking from the high-pressure zone to the low-pressure zone in the casing, seal rings (also called leakage reduction devices) are usually installed on the pump body and the impeller respectively. Since the gap between the moving ring and the fixed ring of the sealing ring is small, it is easy to wear and reduce the efficiency of the pump, so it should be checked or replaced regularly.
Suction chamber: The function of the suction chamber of the pump is to minimize the flow loss of liquid into the pump body. The structural shape of the suction chamber has a great influence on the suction performance of the wall-mounted pump. The commonly used suction chambers are cone tube type and ring type. Cone tube type is more commonly used, and its taper is about 70-180.
Shaft seal: where the pump shaft extends out of the pump body, a shaft seal is set between the rotating pump shaft and the fixed pump body to reduce the leakage of fluid with higher pressure inside the pump to the outside of the pump and prevent air from entering the pump. Commonly used shaft seals include packing shaft seals, skeleton rubber shaft seals, mechanical shaft seals and floating ring shaft seals.
Axial force balance device: the impeller shafts of single-suction single-stage pumps and some multi-stage pumps have axial thrust. The main cause is the imbalance of fluid pressure acting on the ears on both sides of the impeller. If no measures are taken to eliminate it, it will cause the pump shaft and impeller to move, and cause friction and damage to components due to force. Generally, a balance pipe is set or a balance hole is opened on the rear plate and a thrust bearing is used to balance the remaining pressure
In addition to the main components mentioned above, the water centrifugal pump also has pump shafts, brackets, couplings, bearings, etc.
