Axial force balancing structure of multi-stage pump

Abstract

The utility model relates to the technical field of multi-stage pumps, in particular to an axial force balancing structure of a multi-stage pump, which comprises a balancing structure body, a last-stage impeller arranged on one side of the balancing structure body, a rotating shaft fixedly sleeved in the last-stage impeller, a bearing seat rotatably sleeved at one end of the rotating shaft, and a sealing piece mounted on one side of the bearing seat. A balance disc is arranged on one side of the sealing piece, a balance plate is installed on one side of the balance disc, a radial gap is formed in one side of the balance plate, and an axial gap is formed in the other side of the balance plate. The centrifugal pump has the advantages that liquid with pressure from the last-stage impeller flows into the water chamber between the balance plates through the radial gaps between the balance plates and the balance discs, so that the water chamber is in a high-pressure state, the balance pipe arranged on one side of the balance disc is connected with an inlet of the pump, the pressure of the balance pipe is approximate to the pressure of the inlet of the pump, and the pressures on the two sides of the balance disc are not equal; and through the matching of the radial clearance and the axial clearance, the axial force is balanced by means of the pressure difference generated by the radial clearance and the axial clearance on the leakage of water.

Description

Technical Field

[0001] The utility model relates to the technical field of multistage pumps, and particularly to an axial force balance structure of a multistage pump. Background Technique

[0002] A multistage pump is a centrifugal pump, which is characterized by having multiple impellers connected in series. These impellers are connected in series by a shaft to form a multistage structure. When each impeller rotates, it generates a centrifugal force that throws the liquid towards the pump casing, thereby transferring energy to the liquid. The design of the multistage pump enables it to lift the liquid to a higher height or apply a greater pressure through the relay of multiple impellers during a single water intake and drainage process. This type of pump is usually used in occasions that require high pressure and large flow rate, such as mine drainage, high-rise building water supply, etc.

[0003] In the prior art, during the operation of a multistage centrifugal pump, a large axial force will be generated along its axis. This axial force will drive the rotor to move axially, affecting the normal operation of the multistage centrifugal pump. If the axial force generated by the pump group cannot be neutralized, it will cause friction between the static and moving parts of the pump, reducing the efficiency. In severe cases, the pump rotor will jam with each static part, resulting in pump damage. Therefore, this application provides an axial force balance structure for a multistage pump to meet the requirements. Content of the Utility Model

[0004] The purpose of the utility model is to provide an axial force balance structure for a multistage pump to solve the problems raised in the above background technique.

[0005] To achieve the above purpose, the utility model provides the following technical solution: an axial force balance structure for a multistage pump, including: a balance structure body, a final-stage impeller is arranged on one side of the balance structure body, a rotating shaft is fixedly sleeved inside the final-stage impeller, one end of the rotating shaft is rotatably sleeved inside a bearing seat, and a sealing piece is installed on one side of the bearing seat.

[0006] A balance disk is arranged on one side of the sealing piece, a balance plate is installed on one side of the balance disk, a radial clearance is arranged on one side of the balance plate, and an axial clearance is arranged on the other side of the balance plate.

[0007] Preferably, a housing is sleeved outside the final-stage impeller, the rotating shaft is rotatably sleeved inside the housing, an installation hole is opened on one side of the housing, and a wear-resistant and smooth layer is coated on the outer circumferential surface of the rotating shaft.

[0008] Preferably, one side of the sealing piece abuts against the housing, the other side of the sealing piece abuts against the bearing seat, and the bearing seat and the housing are fixedly connected by an internal hexagonal bolt.

[0009] Preferably, a wear-resistant sleeve is fixedly sleeved on the inner circumferential surface of the balance disk, the wear-resistant sleeve is sleeved on the rotating shaft and is slidably connected to the rotating shaft.

[0010] Preferably, the balancing plate is fixedly connected to the inner wall of the shell, a balancing chamber is provided on one side of the balancing plate, a balancing pipe is installed on one side of the balancing chamber, and one end of the balancing pipe is fixedly sleeved in the shell.

[0011] Compared with the prior art, the utility model has the following beneficial effects: the pressurized liquid coming out of the last-stage impeller flows into the cavity in front of the balancing disk through the radial gap between the balancing plate and the balancing disk, and the cavity is in a high-pressure state. A balancing pipe is connected to the inlet of the pump body behind the balancing disk, and its pressure is approximately the inlet pressure. In this way, the pressures on both sides of the balancing disk are not equal, because a backward axial thrust is generated. An axial gap is formed between the lower side of the balancing plate and the balancing disk, and a radial gap is formed between the side of the balancing plate and the balancing disk. The high-pressure liquid behind the last-stage impeller flows into the axial gap, and the pressure drops from P to P′. Since the pressure of P′ is greater than P″ (the pressure in the balancing chamber), a certain pressure difference is generated on both sides of the balancing disk. The pressure P′ causes the liquid to push the balancing disk backward and flow to the balancing chamber through the radial gap. The force pushing the balancing disk away is opposite to the axial thrust of the rotor, thereby achieving axial force balance, thereby avoiding the generation of a large axial force along the axial direction of the multi-stage centrifugal pump during operation, affecting the normal operation of the multi-stage centrifugal pump, and also avoiding the friction of the dynamic and static parts of the pump to reduce the efficiency. In severe cases, the pump rotor and the static parts are stuck and the pump is damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0013] Figure 2 It is a top view schematic diagram of the overall structure of the utility model;

[0014] Figure 3 This is a bottom view schematic diagram of the internal structure of the utility model;

[0015] Figure 4 It is a schematic cross-sectional view of the overall structure of the utility model;

[0016] Figure 5 It is a schematic diagram of the internal structure of the utility model.

[0017] In the figure: 1. Balance structure body; 2. Final impeller; 3. Rotating shaft; 4. Bearing seat; 5. Sealing sheet;

[0018] 6. Balance disc; 7. Balance plate; 8. Radial clearance; 9. Axial clearance; 10. Housing; 11. Mounting hole; 12. Wear-resistant smooth layer; 13. Hexagon socket bolt; 14. Wear-resistant sleeve; 15. Balance chamber; 16. Balance pipe. DETAILED DESCRIPTION

[0019] In order to make the purpose and technical solution of the utility model clearly and completely described, and the advantages more clearly understood, the embodiments of the utility model are further described in detail in conjunction with the accompanying drawings. It should be understood that the specific embodiments described here are part of the embodiments of the utility model, not all of the embodiments, and are only used to explain the embodiments of the utility model, and are not used to limit the embodiments of the utility model. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0020] Example 1: Please refer to Figures 1 - 5 The utility model provides a technical solution: an axial force balancing structure of a multi-stage pump, comprising: a balancing structure body 1, a final-stage impeller 2 is arranged on one side of the balancing structure body 1, a rotating shaft 3 is fixedly sleeved in the final-stage impeller 2, one end of the rotating shaft 3 is rotatably sleeved in a bearing seat 4, a sealing sheet 5 is installed on one side of the bearing seat 4, a balancing disc 6 is arranged on one side of the sealing sheet 5, a balancing plate 7 is installed on one side of the balancing disc 6, a radial gap 8 is arranged on one side of the balancing plate 7, and an axial gap 9 is arranged on the other side of the balancing plate 7.

[0021] The shaft 3 is stably supported by the bearing seat 4. The sealing sheet 5 installed on one side of the bearing seat 4 can ensure the sealing of the housing 10. The rotation of the shaft 3 drives the final impeller 2 to rotate, so that the water is continuously transported through the final impeller 2. The pressurized liquid coming out of the final impeller 2 flows into the water chamber between the balancing plate 7 and the balancing disc 6 through the radial gap 8 between the balancing plate 7 and the balancing disc 6, so that the water chamber is in a high-pressure state. The balancing pipe 16 arranged on one side of the balancing disc 6 is connected to the inlet of the pump, and its pressure is approximately the inlet pressure of the pump. In this way, the pressures on both sides of the balancing disc 6 are not equal, and a backward axial force is generated. Through the cooperation of the radial gap 8 and the axial gap 9, the axial force is balanced by the pressure difference generated by the leakage of the water, thereby avoiding friction between the dynamic and static parts of the pump and reducing the efficiency. In severe cases, the pump rotor and the dynamic and static parts are stuck together, resulting in damage to the pump.

[0022] Embodiment 2: On the basis of embodiment 1, the outer cover of the last-stage impeller 2 is provided with a shell 10, and the rotating shaft 3 is rotatably sleeved in the shell 10. A mounting hole 11 is opened on one side of the shell 10, and the outer ring surface of the rotating shaft 3 is coated with a wear-resistant smooth layer 12. The shell 10 is the end part of the pump body, and the rotating shaft 3 is stably supported by the shell 10 and the bearing seat 4. The outer ring surface of the rotating shaft 3 is coated with a wear-resistant smooth layer 12, and the wear-resistant smooth layer can be made of tungsten carbide coating. One side of the sealing sheet 5 abuts against the shell 10, and the other side of the sealing sheet 5 abuts against the bearing seat 4. The bearing seat 4 and the shell 10 are fixedly connected by the hexagon socket bolts 13. The sealing sheet 5 is installed between the shell 10 and the bearing seat 4, so as to ensure the sealing of the shell 10, and the bearing seat 4 is fixedly installed on one side of the shell 10 through the cooperation of the mounting hole 11 and the hexagon socket bolts 13.

[0023] Through the cooperation of the mounting hole 11 and the socket head cap screw 13, the bearing housing 4 and the sealing piece 5 are fixedly installed on one side of the housing 10, so as to stably support the rotating shaft 3 through the housing 10 and the bearing housing 4, thereby ensuring the stability of the rotation of the last-stage impeller 2. Then, the sealing piece 5 is used to seal one side of the housing 10, thereby avoiding liquid leakage. The wear-resistant and smooth layer 12 coated on the outer circumferential surface of the rotating shaft 3 can reduce the wear of the rotating shaft 3, thereby extending the service life of the rotating shaft 3.

[0024] Embodiment 3: On the basis of Embodiment 2, a wear-resistant sleeve 14 is fixedly sleeved on the inner circumferential surface of the balance disk 6. The wear-resistant sleeve 14 is sleeved on the rotating shaft 3 and is slidably connected to the rotating shaft 3. The wear-resistant sleeve 14 fixedly sleeved on the inner circumferential surface of the balance disk 6 can increase the wear resistance between the wear-resistant sleeve 14 and the rotating shaft 3. The balance plate 7 is fixedly connected to the inner wall of the housing 10. A balance chamber 15 is arranged on one side of the balance disk 6. A balance pipe 16 is installed on one side of the balance chamber 15. One end of the balance pipe 16 is fixedly sleeved inside the housing 10. The balance plate 7 is fixedly installed on the inner circumferential surface of the housing 10. The balance pipe 16 communicates between the inlet of the pump body and the balance chamber 15.

[0025] The wear-resistant sleeve 14 fixedly sleeved on the inner circumferential surface of the balance disk 6 can increase the wear resistance when the wear-resistant sleeve 14 slides on the rotating shaft 3, thereby extending the service life of the balance disk 6 and facilitating the sliding of the balance disk 6 on the rotating shaft 3. One end of the balance pipe 16 is connected to the inlet of the pump body, and the other end of the balance pipe 16 is fixedly sleeved inside the housing 10 and communicates with the balance chamber 15, thereby facilitating the generation of a pressure difference between the water chamber and the balance chamber 15.

[0026] In actual use, through the cooperation of the mounting hole 11 and the socket head cap screw 13, the bearing seat 4 and the sealing piece 5 are fixedly installed on one side of the housing 10, so as to stably support the rotating shaft 3 through the housing 10 and the bearing seat 4, thereby ensuring the stability of the rotation of the last-stage impeller 2. Then, the sealing piece 5 is used to seal one side of the housing 10 to avoid liquid leakage. The wear-resistant and smooth layer 12 coated on the outer circumferential surface of the rotating shaft 3 can reduce the wear of the rotating shaft 3, thereby prolonging the service life of the rotating shaft 3. At the same time, in cooperation with the sliding fit between the wear-resistant sleeve 14 fixedly sleeved in the balance disk 6 and the rotating shaft 3, the service time of the balance disk 6 can be prolonged. The pressurized liquid coming out of the last-stage impeller 2 flows into the cavity in front of the balance disk 6 through the radial clearance 8 between the balance plate 7 and the balance disk 6. The cavity is in a high-pressure state. There is a balance pipe 16 behind the balance disk 6 connected to the inlet of the pump body, and its pressure is approximately the inlet pressure. In this way, the pressures on both sides of the balance disk 6 are not equal, so an axial thrust backward is generated. An axial clearance 9 is formed between the lower side of the balance plate 7 and the balance disk 6, and a radial clearance 8 is formed between the side surface of the balance plate 7 and the balance disk 6. The high-pressure liquid behind the last-stage impeller 2 flows to the axial clearance 9, and the pressure drops from P (the pressure generated by the high-pressure liquid behind the last-stage impeller 2) to P' (the pressure after the high-pressure liquid flows to the axial clearance 9). Since the pressure of P' is greater than P'' (the pressure in the balance chamber 15), a certain pressure difference is generated on both sides of the balance disk 6. The pressure P' causes the liquid to push the balance disk 6 backward and flow through the radial clearance 8 into the balance chamber 15. The force pushing the balance disk 6 is opposite to the direction of the axial thrust of the rotor, thereby achieving the balance of the axial force. Furthermore, it is avoided that during the operation of the multistage centrifugal pump, a large axial force will be generated along its axis, affecting the normal operation of the multistage centrifugal pump, and it is also avoided that the friction between the static and dynamic components of the pump reduces the efficiency, and in severe cases, the pump rotor bites with each component, resulting in pump damage.

[0027] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An axial force balance structure for a multi-stage pump, comprising a balance structure body (1), characterized in that: On one side of the balance structure body (1), a final-stage impeller (2) is provided. A rotating shaft (3) is fixedly sleeved inside the final-stage impeller (2). One end of the rotating shaft (3) is rotatably sleeved inside a bearing seat (4), and a sealing piece (5) is installed on one side of the bearing seat (4). On one side of the sealing piece (5), a balance disk (6) is provided. On one side of the balance disk (6), a balance plate (7) is installed. On one side of the balance plate (7), a radial clearance (8) is provided, and on the other side of the balance plate (7), an axial clearance (9) is provided.

2. The axial force balance structure of a multi-stage pump according to claim 1, characterized in that: The outside of the final-stage impeller (2) is covered with a housing (10). The rotating shaft (3) is rotatably sleeved inside the housing (10). An installation hole (11) is formed on one side of the housing (10), and a wear-resistant smooth layer (12) is coated on the outer circumferential surface of the rotating shaft (3).

3. The axial force balance structure of a multi-stage pump according to claim 2, characterized in that: One side of the sealing piece (5) abuts against the housing (10), and the other side of the sealing piece (5) abuts against the bearing seat (4). The bearing seat (4) and the housing (10) are fixedly connected by an internal hexagonal bolt (13).

4. The axial force balance structure of a multi-stage pump according to claim 3, characterized in that: A wear-resistant sleeve (14) is fixedly sleeved on the inner circumferential surface of the balance disk (6). The wear-resistant sleeve (14) is sleeved on the rotating shaft (3) and is slidably connected to the rotating shaft (3).

5. The axial force balance structure of a multi-stage pump according to claim 4, characterized in that: The balance plate (7) is fixedly connected to the inner wall of the housing (10). On one side of the balance disk (6), a balance chamber (15) is provided. On one side of the balance chamber (15), a balance pipe (16) is installed. One end of the balance pipe (16) is fixedly sleeved inside the housing (10).

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