CN216665929U - Multistage self-balancing centrifugal pump - Google Patents

Abstract

The utility model discloses a multistage self-balancing centrifugal pump which comprises a stator part, a rotor part and a balancing water pipe, wherein the stator part comprises a driving side bearing body, a driving side pump cover, a pump body, a non-driving side pump cover and a non-driving side bearing body which are axially arranged; the pump body comprises an outer shell and an inner shell; an inlet flange and an outlet flange are arranged on the outer shell; a sealing cavity is arranged on the non-driving side pump cover; the rotor part comprises a pump shaft and two impeller assemblies, two ends of the pump shaft are respectively rotatably connected with the bearing bodies on two sides, the impeller assemblies are arranged in the inner shell, and the impeller assemblies are symmetrically sleeved on the pump shaft back to back; the two ends of the balance water pipe are respectively connected with the sealing cavity and the inlet flange. According to the multistage self-balancing centrifugal pump provided by the utility model, the two impeller assemblies on the pump shaft are symmetrically arranged back to back, so that the axial force can be self-balanced, the operation efficiency is improved, the safety and stability are improved, meanwhile, the balance water pipe is balanced, the pressure in the sealing cavity is reduced, and the service life of a mechanical seal is prolonged.

Description

Multistage self-balancing centrifugal pump

Technical Field

The utility model relates to the technical field of centrifugal pumps, in particular to a multi-stage self-balancing centrifugal pump.

Background

At present, a PTA device is adopted in a polyester engineering project by part of petrochemical enterprises, and residual high-pressure PTA condensate in the device is discharged into a boiler system after being boosted by a centrifugal pump so as to achieve the purpose of fully utilizing the PTA condensate.

The conventional multistage centrifugal pump needs to be provided with a balance mechanism in the inner cavity of the centrifugal pump for balancing the axial force, for example: balance disk or balanced drum structure etc. come most axial force of balance with the help of balance mechanism, nevertheless because the wearing and tearing trouble often appears in the balance disk, and balance mechanism's spare part has supply of material cycle length, and spare part provides untimely scheduling problem, has not only reduced centrifugal pump's work efficiency, still can influence the safety and stability of pump unit operation, and simultaneously, the multistage centrifugal pump of traditional structure can influence mechanical seal's life at the sealed chamber pressure of non-drive side too big.

Therefore, a multistage self-balancing centrifugal pump capable of balancing axial force and prolonging the service life of mechanical seal by means of a self structure needs to be researched urgently.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects in the prior art, the utility model provides a multistage self-balancing centrifugal pump, which solves the problems that the centrifugal pump in the prior art balances axial force by a balancing mechanism, the balancing mechanism is easy to damage, and the service life of a mechanical seal is influenced by overlarge pressure of a seal cavity.

The utility model provides a multistage self-balancing centrifugal pump, comprising:

the stator part comprises a driving side bearing body, a driving side pump cover, a pump body, a non-driving side pump cover and a non-driving side bearing body which are sequentially arranged along the axial direction; the pump body comprises an outer shell and an inner shell; an inlet flange and an outlet flange are arranged on the outer shell; a sealing cavity is arranged on the non-driving side pump cover;

the rotor part comprises a pump shaft and two impeller components, two ends of the pump shaft are respectively rotatably connected with the drive side bearing body and the non-drive side bearing body, the two impeller components are arranged in the inner shell, and the two impeller components are symmetrically sleeved on the pump shaft back to back;

and one end of the balance water pipe is connected with the sealing cavity through a through hole in the non-driving side pump cover, and the other end of the balance water pipe is connected with the inlet flange.

Further, the inner shell comprises a suction section, an overflowing section and a middle section which are sequentially arranged along the axial direction, the impeller assembly close to the bearing body on the driving side is arranged in the suction section, the impeller assembly close to the bearing body on the non-driving side is arranged in the middle section, a water inlet is formed in the suction section, and the water inlet and the inlet flange are arranged oppositely.

Furthermore, the overflowing section comprises a first overflowing channel and a second overflowing channel, the first overflowing channel and the second overflowing channel are uniformly distributed along the circumference of the overflowing section, the first overflowing channel is used for transferring media, and an outlet of the second overflowing channel corresponds to the outlet flange.

Furthermore, the two impeller assemblies are connected through a shaft sleeve, and the shaft sleeve is sleeved on the pump shaft; still the cover is equipped with the bush on the axle sleeve, just the bush with it overflows section fixed connection.

Furthermore, the outer shell is respectively sealed with the driving side pump cover, the non-driving side pump cover and the overflowing section through metal winding pads; and the middle section and the pump cover on the non-driving side are sealed by a metal winding pad.

Furthermore, the impeller assembly and the pump shaft are in clearance fit, and the impeller assembly is positioned step by step through a clamping ring.

Furthermore, the driving side bearing body and the non-driving side bearing body both comprise a radial bearing and a thrust bearing, and two ends of the pump shaft are respectively supported on the driving side bearing body and the non-driving side bearing body through the radial bearing and the thrust bearing.

Further, a balance piece is sleeved on the pump shaft close to one side of the non-driving side bearing body, and the balance piece is connected with the non-driving side pump cover.

Furthermore, one side of the pump shaft, which is close to the driving side bearing body, is provided with a conical shaft head for connecting with a coupling of a driving motor.

Further, the shell body is a cylindrical integral forging, and the inlet flange and the outlet flange are both welded on the shell body.

According to the multistage self-balancing centrifugal pump provided by the utility model, the two impeller assemblies on the pump shaft are symmetrically arranged back to back, so that the axial force can be self-balanced, the operation efficiency of the pump is improved, the safety and stability of the pump are increased, the problems that the axial force is balanced by adopting a balancing mechanism in the traditional centrifugal pump, the safe operation of the pump is influenced by the abrasion fault of the balancing mechanism and the like are solved, meanwhile, the balance of the water pipe is balanced, the pressure in the sealing cavity is reduced, and the service life of a mechanical seal is prolonged.

Additional features and advantages of the utility model will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model. The objectives and other advantages of the utility model will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the principles of the utility model and not to limit the utility model. In the drawings:

fig. 1 is a structural sectional view of a multistage self-balancing centrifugal pump of the present application;

FIG. 2 is a side view of the multistage self-balancing centrifugal pump of the present application;

FIG. 3 is a block diagram of an impeller assembly of the multistage self-balancing centrifugal pump of the present application;

FIG. 4 is a structural sectional view of the flow-through section of the multistage self-balancing centrifugal pump of the present application;

fig. 5 is a side view of the flow-through section of the multistage self-balancing centrifugal pump of the present application.

In the figure:

1-pump shaft, 2-drive side bearing body, 3-drive side pump cover, 4-inlet flange, 5-balance water pipe,

6-outlet flange, 7-outer shell, 8-non-driving side pump cover, 9-non-driving side bearing body,

10-balance piece, 11-middle section, 12-flow passage section, 13-impeller component, 14-suction section, 15-bushing, 16-shaft sleeve, 17-primary impeller, 18-secondary impeller, 19-first flow passage, 20-second flow passage and 21-seal cavity.

Detailed Description

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The utility model provides a multistage self-balancing centrifugal pump, which is shown in a figure 1 and a figure 2 and comprises a stator part, a rotor part and a balancing water pipe 5, wherein the stator part comprises a driving side bearing body 2, a driving side pump cover 3, a pump body, a non-driving side pump cover 8 and a non-driving side bearing body 9 which are sequentially arranged along the axial direction; the pump body comprises an outer shell 7 and an inner shell; an inlet flange 4 and an outlet flange 6 are arranged on the outer shell 7; a sealing cavity 21 is arranged on the pump cover 8 at the non-driving side; the rotor part comprises a pump shaft 1 and two impeller assemblies 13, two ends of the pump shaft 1 are respectively rotatably connected with the drive side bearing body 2 and the non-drive side bearing body 9, the two impeller assemblies 13 are both arranged in the inner shell, and the two impeller assemblies 13 are symmetrically sleeved on the pump shaft 1 back to back; one end of the balance water pipe 5 is connected with the sealing cavity 21 through a through hole on the non-driving side pump cover 8, and the other end is connected with the inlet flange 4.

According to the multistage self-balancing centrifugal pump provided by the utility model, the two impeller assemblies 13 on the pump shaft 1 are symmetrically arranged back to back, so that the self-balancing axial force can be balanced, the operation efficiency of the pump is improved, the safety and stability of the pump are increased, the problems that the traditional centrifugal pump adopts a balancing mechanism to balance the axial force, the abrasion failure of the balancing mechanism easily occurs to influence the safe operation of the pump and the like are solved, meanwhile, the balance water pipe 5 is balanced, the pressure in the sealing cavity 21 is reduced, and the service life of a mechanical seal is prolonged.

Specifically, the driving side pump cover 3 and one side of the non-driving side pump cover 8 are both combined with the outer shell 7 by using main bolts, so that the outer shell 7 can bear 1.5 times of maximum allowable working pressure, forging and processing are facilitated, cost is saved, the main bolts and the nuts are made of high-strength alloy steel, the stud is provided with stretching threads, and a worker can disassemble by using a bolt stretcher, so that the threads are protected, and the same and uniform tension generated by each bolt on the pump is ensured; and on the other side, the driving side pump cover 3 and the non-driving side pump cover 8 are positioned with the sealing box body and the bracket through the rabbets and then are welded into a whole, and the driving side pump cover and the non-driving side pump cover are respectively connected with the driving side bearing body 2 and the non-driving side bearing body 9 through connecting flanges to form a whole ring structure, so that the vibration of the pump is reduced, and the stability of the operation of the pump is improved.

Specifically, in the above embodiment, the inner housing includes the suction section 14, the flow passage section 12, and the middle section 11, which are sequentially arranged along the axial direction, the impeller assembly 13 near the drive-side bearing body 2 is disposed in the suction section 14, the impeller assembly 13 near the non-drive-side bearing body 9 is disposed in the middle section 11, and the suction section 14 is provided with the water inlet, which is disposed opposite to the inlet flange 4. In the embodiment, the inner shell is a multi-stage segment structure, when the pump starts to operate, the rotor part rotates under the drive of the drive motor, mechanical energy is converted into pressure energy to enable the medium to flow into the water inlet of the suction section 14 from the inlet flange 4 and reach the middle section 11 through the overflowing section 12, and in the process, two impeller assemblies 13 are used for carrying out step-by-step pressurization, and finally the medium is discharged from the outlet flange 6; the impellers are precisely cast by using wax molds, and the guide vanes in the suction section 14 and the middle section 11 are in an open type, so that the operation efficiency of the pump can be effectively improved; simultaneously, be equipped with the casing sealing ring on suction segment 14 and middle section 11 near impeller subassembly 13 one side for reduce the running clearance between impeller subassembly 13 and the interior casing, reduce inside leakage loss, improve the operating efficiency of pump, inlay the casing sealing ring in suction segment 14 and middle section 11, can in time dismantle and change the sealing ring.

Further, referring to fig. 4 and 5, the flow passage section 12 includes a first flow passage 19 and a second flow passage 20, the first flow passage 19 and the second flow passage 20 are uniformly distributed along the circumferential direction of the flow passage section 12, the first flow passage 19 is used for transferring a medium, and an outlet of the second flow passage 20 is arranged corresponding to the outlet flange 6. In the present embodiment, the flow passage section 12 is uniformly distributed with 24 flow passing holes along the circumferential direction, wherein 12 flow passing holes are used as a first flow passing channel 19, and one impeller assembly arranged in the suction end 14 transfers a medium to another impeller assembly arranged in the middle section 11 through the first flow passing channel 19; in addition, 12 overflowing holes are used as second overflowing channels 20, the impeller assembly 13 arranged in the middle section 11 discharges media to the outlet flange 6 through the second overflowing channels 20, the overflowing hole of each second overflowing channel 20 is arranged between the overflowing holes of the two adjacent first overflowing channels 19, the overflowing section 12 is designed in a double-flow channel mode, the situation that a traditional structure utilizes a transition pipe to connect a front cavity of a water outlet section and a rear water inlet section is avoided, leakage points are reduced, and the operation of the pump is more stable and reliable.

Specifically, in the above embodiment, the two impeller assemblies 13 are connected by the shaft sleeve 16, and the shaft sleeve 16 is sleeved on the pump shaft 1; the bushing 16 is further sleeved with a bushing 15, and the bushing 15 is fixedly connected with the flow passage section 12. In the embodiment, the shaft sleeve 16 is arranged between the two impeller assemblies 13, the shaft sleeve 16 and the bush 15 are matched to play a role in throttling and pressure reducing and also play a role in auxiliary supporting, the impeller assemblies 13 and the shell sealing ring can be prevented from being worn too fast, the rotor part is always in a pulled state due to axial force in opposite directions, the rigidity of the pump shaft 1 is improved, and the operation of the pump is more stable.

Specifically, in the above embodiment, the outer casing 7 is sealed with the drive-side pump cover 3, the non-drive-side pump cover 8, and the flow-passing section 12 by metal gaskets; and the middle section 11 and the non-driving side pump cover 8 are sealed through a metal winding pad. In the embodiment, the outer shell 7 and the adjacent components are sealed by adopting metal winding gaskets and are positioned through rabbets; the middle section 11 and the non-driving side pump cover 8 can be adjusted during assembly according to actual conditions on site, the total compression amount of the metal winding pad ranges from 5mm to 6mm, and the problem of thermal expansion asynchronism caused by temperature difference between the outer shell 7 and the inner shell can be solved by the method of arranging the metal winding pad.

Specifically, in the above embodiment, referring to fig. 3, the impeller assembly 13 and the pump shaft 1 are in clearance fit, and the impeller assembly 13 is positioned step by the snap ring. In this embodiment, the impeller assembly 13 disposed in the suction section 14 includes a primary impeller 17 and a plurality of secondary impellers 18, and the impeller assembly 13 disposed in the middle section 11 includes secondary impellers 18 equal to the total number of impellers of another impeller assembly 13, wherein the primary impeller 17 is positioned by a shaft shoulder, the shaft sleeve 16 and all the other secondary impellers 18 are positioned step by a snap ring, and the snap ring adopts a half-divided structure, so that the snap ring is convenient for workers to disassemble and assemble.

Specifically, in the above-described embodiment, the drive-side bearing body 2 and the non-drive-side bearing body 9 each include the radial bearing and the thrust bearing, and both ends of the pump shaft 1 are supported by the drive-side bearing body 2 and the non-drive-side bearing body 9 through the radial bearing and the thrust bearing, respectively. In the present embodiment, the driving-side bearing body 2 and the non-driving-side bearing body 9 are combined by a radial bearing and a thrust bearing to support the pump shaft 1, wherein the radial bearing is a sliding bearing shell, the thrust bearing is a back-to-back centripetal thrust ball bearing, and the thrust bearing has the same thrust capability in both directions and has a longer service life; copper labyrinth dustproof disks are adopted in the driving side bearing body 2 and the non-driving side bearing body 9, and backflow holes are formed in grooves of a labyrinth, so that accumulated media cannot leak, and oil and water are prevented from being mixed; the driving side bearing body 2 and the non-driving side bearing body 9 are cooled by an oil pool, so that the bearings can be lubricated and radiated in the operation process, and the service life of the bearings is prolonged.

Specifically, in the above embodiment, the pump shaft 1 on the side close to the non-drive-side bearing body 9 is sleeved with the balance member 10, and the balance member 10 is connected to the non-drive-side pump cover 8. In this embodiment, two impeller assemblies 13 are symmetrically mounted back to back on the pump shaft 1, and can balance most of the axial force, and the remaining small part of the residual axial force, by providing a balance member 10 on the pump shaft 1 at the non-drive side bearing body 9, wherein the balance member 10 includes a balance drum and a balance sleeve.

Specifically, in the above embodiment, one side of the pump shaft 1 close to the driving side bearing body 2 is a conical shaft head for connecting with a coupling of the driving motor. In the embodiment, the multistage self-balancing centrifugal pump is connected with the driving motor through the diaphragm type coupling with the lengthened section, the non-spark protective cover is arranged, the shaft head of the pump shaft 1 close to one side of the driving side bearing body 2 is set to be the conical shaft head, the coupling of the driving motor is convenient to disassemble and assemble, and a worker can repair and replace vulnerable parts such as mechanical seals without moving the multistage self-balancing centrifugal pump and the driving motor.

Specifically, in the above embodiment, the outer casing 7 is a cylindrical integral forging, and the inlet flange 4 and the outlet flange 6 are welded to the outer casing 7. In the embodiment, the inlet flange 4 and the outlet flange 6 are welded on the outer shell 7 in a socket welding mode, so that the distance between the inlet flange 4 and the outlet flange 6 is ensured to the maximum extent, and meanwhile, penetration detection is carried out on the welded seam and the welded seam passes acceptance according to the standard; the socket welding connection mode is adopted, so that the welding is simpler and more convenient, the cost is lower, and the socket welded socket has a reinforcing effect in a high-pressure working state.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the utility model. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (10)

1. A multi-stage self-balancing centrifugal pump, comprising:

the stator part comprises a driving side bearing body (2), a driving side pump cover (3), a pump body, a non-driving side pump cover (8) and a non-driving side bearing body (9) which are sequentially arranged along the axial direction; the pump body comprises an outer shell (7) and an inner shell; an inlet flange (4) and an outlet flange (6) are arranged on the outer shell (7); a sealing cavity (21) is arranged on the non-driving side pump cover (8);

the rotor part comprises a pump shaft (1) and two impeller assemblies (13), two ends of the pump shaft (1) are respectively and rotatably connected with the drive side bearing body (2) and the non-drive side bearing body (9), the two impeller assemblies (13) are arranged in the inner shell, and the two impeller assemblies (13) are symmetrically sleeved on the pump shaft (1) back to back;

and one end of the balance water pipe (5) is connected with the sealing cavity (21) through a through hole on the non-driving side pump cover (8), and the other end of the balance water pipe is connected with the inlet flange (4).

2. The multistage self-balancing centrifugal pump according to claim 1, wherein the inner housing includes a suction section (14), a flow passage section (12), and a middle section (11) which are arranged in this order in the axial direction, the impeller assembly (13) near the drive-side bearing body (2) is provided in the suction section (14), the impeller assembly (13) near the non-drive-side bearing body (9) is provided in the middle section (11), and a water inlet is provided on the suction section (14), the water inlet being arranged opposite to the inlet flange (4).

3. The multistage self-balancing centrifugal pump of claim 2, wherein the flow passing section (12) comprises a first flow passing channel (19) and a second flow passing channel (20), the first flow passing channel (19) and the second flow passing channel (20) are uniformly distributed along the circumferential direction of the flow passing section (12), the first flow passing channel (19) is used for transferring a medium, and an outlet of the second flow passing channel (20) is arranged corresponding to the outlet flange (6).

4. The multistage self-balancing centrifugal pump according to claim 2, wherein the two impeller assemblies (13) are connected through a shaft sleeve (16), and the shaft sleeve (16) is sleeved on the pump shaft (1); still the cover is equipped with bush (15) on axle sleeve (16), just bush (15) with overflow section (12) fixed connection.

5. The multistage self-balancing centrifugal pump of claim 2, wherein the outer casing (7) is sealed with the drive-side pump cover (3), the non-drive-side pump cover (8), and the flow-passing section (12) by metal-wound gaskets; and the middle section (11) and the non-driving side pump cover (8) are sealed through a metal winding pad.

6. The multistage self-balancing centrifugal pump of claim 1, wherein the impeller assembly (13) is in clearance fit with the pump shaft (1), and the impeller assembly (13) is positioned stage by snap rings.

7. The multistage self-balancing centrifugal pump according to claim 1, wherein the drive-side bearing body (2) and the non-drive-side bearing body (9) each include a radial bearing and a thrust bearing, and both ends of the pump shaft (1) are supported by the drive-side bearing body (2) and the non-drive-side bearing body (9) through the radial bearing and the thrust bearing, respectively.

8. The multistage self-balancing centrifugal pump of claim 1, wherein a balance member (10) is sleeved on the pump shaft (1) near one side of the non-driving side bearing body (9), and the balance member (10) is connected with the non-driving side pump cover (8).

9. The multistage self-balancing centrifugal pump of claim 1, wherein one side of the pump shaft (1) close to the drive side bearing body (2) is a conical shaft head for connecting with a coupling of a drive motor.

10. The multistage self-balancing centrifugal pump of claim 1, wherein the outer casing (7) is a cylindrical monolithic forging, the inlet flange (4) and the outlet flange (6) being welded to the outer casing (7).

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