MULTISTAGE CENTRIFUGAL PUMP Russian patent published in 2022 - IPC F04D1/06 

FIELD: hydraulics.

SUBSTANCE: invention relates to the field of hydraulic engineering, namely, to multistage high-pressure centrifugal pumps, and can be used in pumps for pumping feed water to CHP plants, as well as state regional power plants with 200 and 210 MW power units. Multistage centrifugal pump comprises an outer body, an inlet cover, and a pressure cover. The rotor of the pump includes a shaft with one-way inlet impellers and a hydraulic unloading apparatus installed thereon and with a radial gap δ_p. The shaft is supported by bearing supports. The inner body consists of sections accommodating guiding apparatus, an additional bearing formed by a ring with increased surface hardness on the inner diameter, installed on the intermediate stage guiding apparatus, and a sleeve I with a surface layer of high-temperature anti-friction composite material, forming a radial gap δ_n. Radial gaps δ₁ are made in the pump in the front seals of the impellers, in the inter-stage seals δ₂, wherein the bearing support on the outlet side of the pump is formed by an insert set on the body of the support and a sleeve II abutting on the shaft of the pump by a hub, has a chamber B intended for supplying water under pressure P_w from an external source for lubrication of the bearing, and an annular bore is made radially in the hub of the sleeve II of the bearing support on the side of the inner diameter, communicating, on the one hand, with chamber B by the axial holes in the end surface of sleeve II and connected, on the other hand, with the radial holes in the shaft, communicating with the blind central axial a hole in the shaft, also plugged on the side of the free end of the shaft by a plug set along the outer thread into the outer thread on the shaft with a gasket. The central axial hole in the shaft therein overlaps, along the entire length thereof, with sleeve I of the additional bearing, wherein radial holes are made, communicating the radial gap δ_n with the radial holes in the shaft, communicating through the annular bore in the shaft with the central axial hole in the shaft, wherein a check valve is installed on the side of the free end of the shaft, supplying water from chamber B into the radial gap δ_n and shutting off the reverse flow of water.

EFFECT: ensured pumping of feed water to power plants.

4 cl, 3 dwg