A vertical submerged liquid metal magnetic pump

Abstract

The present invention discloses a vertical submerged liquid metal magnetic pump, comprising a motor, a pump cover, an upper pump body, a lower pump body and a guide ring arranged in sequence from top to bottom, the lower end of the motor is connected with a pump shaft, the lower end of the pump shaft extends into the guide ring, an impeller connected to the pump shaft is arranged in the guide ring, a cooling circuit is arranged in the pump cover, an upper bearing assembly corresponding to the pump shaft is arranged between the upper pump body and the lower pump body, a lower bearing assembly corresponding to the pump shaft is arranged in the guide ring, the upper bearing assembly includes a combined bearing structure formed by a guide bearing structure and a thrust bearing structure, an installation cavity corresponding to the combined bearing structure is arranged between the upper pump body and the lower pump body, and a liquid supply tank corresponding to the thrust bearing structure is arranged in the installation cavity. The advantage of the present invention is that the need for configuring an auxiliary lubrication system is eliminated, system damage and cost are reduced, and it can be better applied to small system installation occasions with small radial dimensions and compact structure requirements.

Description

Technical Field

[0001] The present application relates to the technical field of vertical magnetic pumps, and in particular to a vertical immersed liquid metal magnetic pump. Background Art

[0002] At present, magnetic pumps are commonly used to transport liquid metals in the range of 280~550℃. The traditional structure generally consists of motors, couplings, dynamic seals, maintenance static seals, rotating parts, hydraulic parts, support parts, etc. The rotor support is designed as a structure supported by upper and lower guide bearings. The lower bearing is usually immersed in high-temperature liquid metal as a whole, and static or dynamic sliding bearings lubricated by liquid metal are commonly used. For example, in the Chinese patent literature, patent number CN2020100118742 disclosed a magnetic pump bearing box structure on April 21, 2020. The application includes: a bearing box, a first rolling bearing, an external magnetic rotor, a second rolling bearing, a drive shaft and a drive shaft baffle. The first rolling bearing and the second rolling bearing are fixedly mounted at both ends of the bearing box, and the first rolling bearing and the second rolling bearing are sleeved on the drive shaft. The bearing box above the first rolling bearing is provided with a first horizontal oil return groove, and the bearing box below is provided with a second horizontal oil return groove. The bearing box above the second rolling bearing is provided with a third horizontal oil return groove, and the bearing box below is provided with a fourth horizontal oil return groove. The external magnetic rotor is sleeved at one end of the drive shaft, and the inner ring of the first rolling bearing is sleeved on the end of the external magnetic rotor. The drive shaft baffle fixes the external magnetic rotor on the drive shaft by fastening screws. The disadvantage of the prior art is that the upper bearing is generally arranged above the liquid level and cannot be lubricated by liquid metal. If a magnetic pump type is used, additional lubricating medium must be added to the upper bearing, which poses a risk of the lubricating medium leaking into the core. Summary of the invention

[0003] Based on the above-mentioned deficiencies in the prior art, the present invention provides a vertical submerged liquid metal magnetic pump, in which the upper bearing is located below the liquid level, eliminating the need for configuring an auxiliary lubrication system, reducing system damage and cost, and being better suitable for small system installation occasions with small radial dimensions and compact structure requirements.

[0004] Another purpose of the present invention is to use a magnetic coupling to connect the motor and the pump shaft, thereby changing the complex dynamic seal into a reliable static seal, reducing the risk of liquid metal leakage and greatly improving reliability.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions.

[0006] A vertical submerged liquid metal magnetic pump, characterized in that it includes a motor, a pump cover, an upper pump body, a lower pump body and a guide ring which are arranged in sequence from top to bottom, a pump shaft is connected to the lower end of the motor, the lower end of the pump shaft extends into the guide ring, an impeller connected to the pump shaft is arranged in the guide ring, a cooling circuit is arranged in the pump cover, an upper bearing assembly corresponding to the pump shaft is arranged between the upper pump body and the lower pump body, a lower bearing assembly corresponding to the pump shaft is arranged in the guide ring, the upper bearing assembly includes a combined bearing structure formed by a guide bearing structure and a thrust bearing structure, an installation cavity corresponding to the combined bearing structure is arranged between the upper pump body and the lower pump body, and a liquid supply groove corresponding to the thrust bearing structure is arranged in the installation cavity.

[0007] Compared with the traditional vertical pump with rolling bearings in the upper bearing, the pump shaft of the present application adopts the corresponding support structure of the upper bearing assembly and the lower bearing assembly. The traditional rolling bearing is eliminated above the liquid level. Both bearings are below the working liquid level and are completely immersed in the liquid metal. The upper bearing adopts a combined structural bearing combining thrust bearing and radial bearing. The dynamic pressure lubrication effect is generated between the bearings to support the shaft system. It can operate at high and low temperatures without replenishing the lubricating medium, fully meeting the safety requirements of the reactor; at the same time, it eliminates the need to configure an auxiliary lubrication system, reduces system losses and auxiliary system maintenance and replacement costs, and improves system life and reliability; it has stronger size applicability and can be better applied to small system installation occasions with small radial dimensions and compact structure requirements.

[0008] Preferably, the shape of the mounting cavity is a stepped cylindrical hole with an inverted "T" shape in the axial cross section, and the two sides of the thrust bearing structure correspond to the bottom side of the upper pump body and the upper side of the lower pump body respectively. The stepped wall surface of the mounting cavity corresponds to the outer peripheral side wall of the guide bearing structure and the upper and lower end surfaces of the thrust bearing structure respectively, providing reliable axial and radial support, and reliable transmission.

[0009] Preferably, the motor is connected to the pump shaft via a magnetic coupling; the magnetic coupling includes an outer magnet and an inner magnet located in the inner cavity of the outer magnet, a shielding cover is provided between the outer magnet and the inner magnet, the outer magnet is fixedly connected to the motor shaft of the motor, the inner magnet is fixedly connected to the upper end of the pump shaft, and the shielding cover is fixedly arranged on the bottom surface of the pump cover. The motor and the pump shaft are connected via a magnetic coupling, which changes the complex dynamic seal into a reliable static seal, reduces the risk of liquid metal leakage, and greatly improves reliability.

[0010] Preferably, the cooling circuit includes a first cooling circuit corresponding to the lower end of the pump cover wall and a second cooling circuit corresponding to the magnetic coupling, and the outer magnet of the magnetic coupling is provided with a plurality of air guide grooves corresponding to the second cooling circuit. This plays a reliable cooling role for the pump cover and the magnetic coupling, and the provision of the air guide groove enables the cooling medium of the second cooling circuit to enter the outer magnet, thereby achieving forced air cooling for the shielding cover and ensuring cooling efficiency.

[0011] Preferably, the combined bearing structure adopts a carbide bushing, and the surface of the carbide bushing is provided with a surfacing layer. The combined bearing structure can be made by surfacing or spraying carbide, or can be formed by integral casting of carbide. After the integral casting of carbide in the present application, a surfacing layer is further provided to improve the wear resistance and corrosion resistance of the bushing surface, and the high strength can ensure its support and rotation limit function.

[0012] Preferably, the pump shaft is provided with a shaft shoulder and a locking piece corresponding to the combined bearing structure, and the upper and lower ends of the combined bearing structure abut against the locking piece and the shaft shoulder of the pump shaft respectively, so as to realize axial locking of the combined bearing structure.

[0013] Preferably, the locking member includes a fixing nut fixed on the pump shaft, and a stop washer is provided between the fixing nut and the guide bearing structure. Preferably, the pump cover adopts a sunken structure, a connecting flange is provided at the upper end of the pump cover, a mounting platform is supported on the lower side of the connecting flange, and the lower end of the pump cover extends below the mounting platform. The pump cover adopts a sunken structure, which reduces the length of the upper shaft extension section and improves the stability of the shaft system.

[0014] The present invention has the following beneficial effects: eliminating the need for configuring an auxiliary lubrication system, reducing system damage and costs; being better suited for installation in small systems with small radial dimensions and compact structures; using a magnetic coupling to connect the motor and the pump shaft, replacing complex dynamic seals with reliable static seals, reducing the risk of liquid metal leakage, and significantly improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the present invention.

[0016] Figure 2 yes Figure 1 A magnified schematic diagram of center A.

[0017] In the figure: motor 1 pump cover 2 upper pump body 3 lower pump body 4 guide ring 5 connecting flange 6 mounting platform 7 pump shaft 8 magnetic coupling 9 external magnet 10 air guide groove 11 internal magnet 12 shielding cover 13 impeller 14 first cooling circuit 15 second cooling circuit 16 upper bearing assembly 17 guide bearing structure 18 thrust bearing structure 19 cladding layer 20 shaft shoulder 21 fixing nut 22 locking washer 23 mounting cavity 24 liquid supply groove 25 lower bearing assembly 26. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Embodiment 1,

[0020] like Figure 1 to Figure 2As shown, a vertical submerged liquid metal magnetic pump comprises a motor 1, a pump cover 2, an upper pump body 3, a lower pump body 4 and a guide ring 5 arranged in sequence from top to bottom. The pump cover 2 adopts a sinking structure. A connecting flange 6 is provided at the upper end of the pump cover 2. The lower side of the connecting flange 6 is fixedly supported on the mounting platform 7 by screws. The lower end of the pump cover 2 extends below the mounting platform 7 to form a sinking structure. The housing of the motor 1 is directly fixed to the flange surface at the upper end of the pump cover 2 by bolts. A pump shaft 8 is connected to the lower end of the motor 1, and the motor 1 and the pump shaft 8 are connected by a magnetic coupling 9; the magnetic coupling 9 comprises an external magnet 10 and an inner magnet 12 located in the inner cavity of the external magnet 10, a shielding cover 13 is provided between the external magnet 10 and the inner magnet 12, the external magnet 10 is fixedly connected to the motor 1 shaft of the motor 1, the inner magnet 12 is fixedly connected to the upper end of the pump shaft 8, and the shielding cover 13 is fixedly arranged on the bottom surface of the pump cover 2. The lower end of the pump shaft 8 extends into the guide ring 5, and the guide ring 5 is provided with an impeller 14 connected to the pump shaft 8. The pump cover 2 is provided with a cooling circuit, which includes a first cooling circuit 15 corresponding to the lower end of the pump cover 2 wall and a second cooling circuit 16 corresponding to the magnetic coupling 9. The outer magnet 10 of the magnetic coupling 9 is provided with a plurality of air guide grooves 11 corresponding to the second cooling circuit 16. An upper bearing assembly 17 corresponding to the pump shaft 8 is provided between the upper pump body 3 and the lower pump body 4, and a lower bearing assembly 26 corresponding to the pump shaft 8 is provided in the guide ring 5. The upper bearing assembly 17 includes a combined bearing structure formed by a guide bearing structure 18 and a thrust bearing structure 19. The combined bearing structure adopts a hard alloy bushing, and a surfacing layer 20 is provided on the friction pair surface corresponding to the hard alloy bushing. The pump shaft 8 is provided with a shoulder 21 and a locking member corresponding to the combined bearing structure, and the upper and lower ends of the combined bearing structure abut against the locking member and the shoulder 21 of the pump shaft 8 respectively. The locking member includes a fixing nut 22 threadedly fixed on the pump shaft 8, and a stop washer 23 is provided between the fixing nut 22 and the guide bearing structure 18. A mounting cavity 24 corresponding to the combined bearing structure is provided between the pump body and the lower pump body 4. The mounting cavity 24 is in the shape of a stepped cylindrical hole with an inverted "T" shape in the axial cross-section. The upper end of the guide bearing structure 18 extends out of the mounting cavity 24 and extends into the upper pump body 3. The two sides of the thrust bearing structure 19 correspond to the bottom side of the upper pump body 3 and the upper side of the lower pump body 4, respectively. A liquid supply groove 25 corresponding to the thrust bearing structure 19 is provided in the mounting cavity 24. The liquid supply groove 25 is provided corresponding to the side surface and the upper and lower end surfaces of the thrust bearing structure 19. In this embodiment, the lower bearing assembly 26 is a single part, and a circular ring bushing made of hard alloy fixed on the pump shaft 8 is adopted. Through holes corresponding to the clearance fit of the pump shaft 8 are respectively provided in the upper pump body 3 and the lower pump body 4.

[0021] The pump shaft 8 of the present application is supported by an upper and lower guide bearing support structure. The traditional rolling bearing is eliminated above the liquid level. Both bearings are below the working liquid level and are completely immersed in the liquid metal. The bearing friction pair can be made of hard alloy surfacing, spraying or integrally cast. The upper bearing structure adopts a combined bearing structure combining a thrust bearing and a radial bearing. A dynamic pressure lubrication effect is generated between the bearings to support the shaft system.

[0022] The motor 1 part structure and the motor 1 shaft sink into the pump cover 2 cavity and are connected to the pump shaft 8 through the magnetic coupling 9. The motor 1 is directly seated on the upper flange surface of the sunken pump cover 2; the shielding cover 13 of the magnetic coupling 9 is seated on the flange surface of the pump cover 2, and the static sealing structure is used to ensure that the inner and outer cavities are completely separated; the pump cover 2 structure has two cooling circuits, one for cooling the magnetic coupling 9 and other components in the outer cavity, and the other for cooling the structure below the pump cover 2 to enhance the heat shielding effect; the structure below the pump cover 2 is connected in a multi-stage segmented form, which is the upper pump body 3 (including the upper bearing assembly 17), the lower pump body 4, the guide ring 5 (including the lower bearing assembly 26) and the impeller 14 in turn; to meet the system heat shielding requirements, a heat shielding plate and other structures can be set in the upper pump body 3. In order to reduce the vibration of the upper shaft system, strengthen the stability of the shaft system, and reduce the cantilever distance of the main shaft above the liquid level, the pump cover 2 adopts a sunken structure, which cooperates with the magnetic coupling 9 sunk into the pump cover 2 and part of the motor 1 structure to drive the operation of the main shaft and stabilize the shaft system. The pump cover 2 is processed with deep holes, and two cooling circuits are constructed by drilling holes in the base, which can ensure high sealing performance below the pump cover 2 and cool the structure below the pump cover 2 and the magnetic coupling 9 side respectively.

[0023] Compared with the traditional vertical pump represented by the upper bearing using rolling bearings and the seal using mechanical seals, the sinking liquid metal magnetic pump has the following advantages:

[0024] 1) No auxiliary system, high reliability: It can operate at high and low temperatures without the need to replenish lubricating media, fully meeting the safety requirements of the reactor. At the same time, it eliminates the need to configure an auxiliary lubrication system, reduces system losses and auxiliary system maintenance and replacement costs, and improves system life and reliability;

[0025] 2) No leakage risk, high risk controllability: The magnetic coupling 9 and the shielding cover 13 are used to change the complex dynamic seal into a reliable static seal, which reduces the risk of liquid metal leakage and greatly improves reliability;

[0026] 3) Stronger size applicability: It can be better applied to small system installation occasions with small radial size and compact structure requirements.

Claims

1. A vertical submerged liquid metal magnetic pump, characterized in that: It includes a motor, a pump cover, an upper pump body, a lower pump body and a guide ring which are arranged in sequence from top to bottom. The lower end of the motor is connected to a pump shaft, the lower end of the pump shaft extends into the guide ring, an impeller connected to the pump shaft is arranged in the guide ring, a cooling circuit is arranged in the pump cover, an upper bearing assembly corresponding to the pump shaft is arranged between the upper pump body and the lower pump body, a lower bearing assembly corresponding to the pump shaft is arranged in the guide ring, the upper bearing assembly includes a combined bearing structure formed by a guide bearing structure and a thrust bearing structure, an installation cavity corresponding to the combined bearing structure is arranged between the upper pump body and the lower pump body, a liquid supply groove corresponding to the thrust bearing structure is arranged in the installation cavity, and the upper bearing assembly is arranged below the working liquid level.

2. A vertical submerged liquid metal magnetic pump according to claim 1, characterized in that: The shape of the installation cavity is a stepped cylindrical hole with an axial cross-section in an inverted "T" shape, and the two sides of the thrust bearing structure correspond to the bottom side of the upper pump body and the upper side of the lower pump body respectively.

3. A vertical submerged liquid metal magnetic pump according to claim 1, characterized in that: The motor is connected to the pump shaft through a magnetic coupling; the magnetic coupling includes an external magnet and an internal magnet located in the inner cavity of the external magnet, a shielding cover is provided between the external magnet and the internal magnet, the external magnet is fixedly connected to the motor shaft of the motor, the internal magnet is fixedly connected to the upper end of the pump shaft, and the shielding cover is fixedly arranged on the bottom surface of the pump cover.

4. A vertical submerged liquid metal magnetic pump according to claim 3, characterized in that: The cooling circuit comprises a first cooling circuit corresponding to the interior of the lower end of the pump cover wall and a second cooling circuit corresponding to the magnetic coupling. The outer magnet of the magnetic coupling is provided with a plurality of air guide grooves corresponding to the second cooling circuit.

5. A vertical submerged liquid metal magnetic pump according to claim 1, characterized in that: The combined bearing structure adopts a hard alloy bushing, and a surfacing layer is provided on the surface of the hard alloy bushing.

6. A vertical submerged liquid metal magnetic pump according to claim 5, characterized in that: The pump shaft is provided with a shaft shoulder and a locking piece corresponding to the combined bearing structure, and the upper and lower ends of the combined bearing structure abut against the locking piece and the shaft shoulder of the pump shaft respectively.

7. A vertical submerged liquid metal magnetic pump according to claim 6, characterized in that: The locking member comprises a fixing nut fixed on the pump shaft, and a stop washer is arranged between the fixing nut and the guide bearing structure.

8. A vertical submerged liquid metal magnetic pump according to claim 1 or 4, characterized in that: The pump cover adopts a sunken structure, the upper end of the pump cover is provided with a connecting flange, the lower side of the connecting flange is supported by a mounting platform, and the lower end of the pump cover extends below the mounting platform.

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