Multistage pump with axially adjustable rotor

Abstract

The utility model provides a multi-stage pump with an axially adjustable rotor, which relates to the technical field of multi-stage pumps and comprises a pump body, a rotor structure, a first bearing structure, a second bearing structure, an end cover and an adjusting component. The pump body is provided with an internal space, a water inlet and a water outlet; the rotor structure comprises a pump shaft and a multi-stage impeller; the pump shaft is arranged in the inner space of the pump body in a penetrating mode, and the multiple stages of impellers are sequentially arranged on the pump shaft. The first bearing structure and the second bearing structure are both assembled between the pump shaft and the pump body so as to form rotary support for the pump shaft; the end cover is arranged at one end of the pump body and is connected with the first bearing structure; the adjusting part is installed between the end cover and the pump body and can adjust the installation position of the end cover in the axial direction of the pump shaft, and therefore the axial installation position of the rotor structure is adjusted. During maintenance, a maintainer can adjust the axial installation position of the rotor structure through the adjusting part to carry out position compensation, so that the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-stage pump, in particular to a multi-stage pump with adjustable axial rotor. BACKGROUND

[0002] Pump is a machine for conveying fluid or pressurizing fluid, and multi-stage pump refers to a pump with two or more than two impellers. Multi-stage pump can be used in many industrial departments such as petroleum, chemical industry, machinery, mining, light industry, medicine and food. In the internal structure of multi-stage pump, the gap sealing structure between pump body and rotor structure will be worn out with the use of pump, which will cause the gap to gradually increase and result in sealing failure. Gap sealing is to use the small gap between moving parts to play a sealing role, and the size of the gap has a great influence on the sealing performance.

[0003] In the current multi-stage pump, the axial position of the rotor structure is fixed after assembly, and it is very inconvenient to adjust the axial position of the rotor structure during maintenance. CONTENT OF THE INVENTION

[0004] The technical problem to be solved by the present application is to provide a multi-stage pump with adjustable axial rotor in view of the above-mentioned deficiencies of the prior art.

[0005] A multi-stage pump with adjustable axial rotor, comprising:

[0006] A pump body provided with an internal space, an inlet and an outlet;

[0007] A rotor structure comprising a pump shaft and multi-stage impellers, wherein the pump shaft is arranged in the internal space of the pump body, and the multi-stage impellers are arranged on the pump shaft in sequence;

[0008] A first bearing structure and a second bearing structure are assembled between the pump shaft and the pump body to form a rotating support for the pump shaft;

[0009] An end cover is arranged at one end of the pump body and connected with the first bearing structure;

[0010] An adjusting component is installed between the end cover and the pump body, which can adjust the installation position of the end cover along the axial direction of the pump shaft, so as to adjust the axial installation position of the rotor structure.

[0011] Optionally, the adjusting component comprises a plurality of first adjusting bolts and a plurality of second adjusting bolts, and the plurality of first adjusting bolts and the plurality of second adjusting bolts are installed on the threaded connection holes of the end cover and distributed at different circumferential positions of the pump shaft; wherein the first adjusting bolts are threadedly connected with the first bearing structure to pull the first bearing structure, and the second adjusting bolts abut against the first bearing structure.

[0012] Optionally, a limiting ring is arranged inside the first bearing structure; a tension bolt is arranged between the end cover and the limiting ring; the tension bolt passes through the opening on the pump body to connect the end cover and the limiting ring, so that the end cover and the limiting ring clamp the first bearing structure located therebetween; an adjusting gap is arranged between the end cover, the limiting ring and the pump body to allow the end cover and the limiting ring to be adjusted in axial position relative to the pump body.

[0013] Optionally, the first bearing structure comprises a bearing and a bearing sleeve; the bearing sleeve is sleeved in the inner ring of the bearing sleeve; the bearing sleeve is sleeved in the inner ring of the pump body; a plurality of sealing rings are arranged between the pump body and the bearing sleeve.

[0014] Optionally, the first bearing structure comprises two rolling bearings arranged side by side.

[0015] Optionally, the tension bolt, the first adjusting bolt and the second adjusting bolt are sequentially and alternately distributed along the circumference of the pump shaft.

[0016] Optionally, a nut is further arranged at the end of the pump shaft; the nut is assembled on the pump shaft through threaded cooperation, and the bearing is limited on the pump shaft between the nut and the bearing sleeve.

[0017] Optionally, a plurality of gap seals are arranged between the pump body and the rotor structure; at least part of the gap seals adopts a conical sealing structure; the conical sealing structure has a conical sealing surface, and the directions of the conical sealing surfaces of all the conical sealing structures are consistent, so that the gap sizes of all the conical sealing structures can be wear-compensated by adjusting the axial installation position of the rotor structure.

[0018] Optionally, the pump body is provided with a water inlet end guide body corresponding to each stage of impeller; a first gap seal is arranged between the water inlet end guide body and the impeller; at the position of the first gap seal, a first conical sealing surface is arranged on the water inlet end guide body, and a second conical sealing surface is arranged on the impeller; the first conical sealing surface and the second conical sealing surface cooperatively form a conical sealing structure; the directions of the conical sealing surfaces of all the first gap seals are the same.

[0019] The pump body is provided with a guide vane body corresponding to each stage of impeller; a second gap seal is arranged between the guide vane body and the bearing sleeve on the pump shaft; at the position of the second gap seal, a third conical sealing surface is arranged on the guide vane body, and a fourth conical sealing surface is arranged on the bearing sleeve on the pump shaft; the third conical sealing surface and the fourth conical sealing surface cooperatively form a conical sealing structure; the directions of the conical sealing surfaces of all the second gap seals are the same as those of the first gap seals.

[0020] Optionally, a first annular support and a second annular support are arranged on the pump body in the internal space; a balance body is arranged on the rotor structure; the first support is wrapped around the outer periphery of the balance body, forming a first gap between the first support and the balance body; a second gap is formed between the second support and the balance body; a balance cavity is formed by the balance body and the internal structure of the pump body; the first gap is connected to the drainage port of the multi-stage impeller and the balance cavity; the second gap is connected to the inside and outside of the balance cavity for pressure relief of the balance cavity; the matching surfaces of the first support and the balance body for forming the first gap are arranged as tapered sealing surfaces; the matching surfaces of the second support and the balance body for forming the second gap are radial end surfaces; the matching surfaces of the first gap are in the same direction as the tapered sealing surfaces of the tapered sealing structure.

[0021] In the multi-stage pump provided in the application, the end cover is arranged at one end of the pump body and connected with the first bearing structure, and is provided with an adjusting component installed between the end cover and the pump body, which can adjust the installation position of the end cover in the axial direction of the pump shaft, so as to adjust the axial installation position of the rotor structure. Therefore, during maintenance, the maintenance personnel can adjust the axial installation position of the rotor structure through the adjusting component to compensate the position, thereby reducing the maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of the multi-stage pump in the embodiment of the application.

[0023] Figure 2 is a schematic diagram of the partial structure of the multi-stage pump in the embodiment of the application.

[0024] Figure 3 is a schematic diagram of another partial structure of the multi-stage pump in the embodiment of the application.

[0025] Figure 4 is a schematic diagram of another partial structure of the multi-stage pump in the embodiment of the application.

[0026] Figure 5 is a schematic diagram of another partial structure of the multi-stage pump in the embodiment of the application.

[0027] Figure 6 is a schematic diagram of another partial structure of the multi-stage pump in the embodiment of the application.

[0028] Figure 7 is a schematic diagram of another partial structure of the multi-stage pump in the embodiment of the application.

[0029] REFERENCE SIGNS:

[0030] Pump body 10, inner space 11, water inlet 12, water outlet 13, water inlet end flow guide 14, guide vane body 15, first support 16, second support 17, rotor structure 20, pump shaft 21, impeller 22, nut 23, balance body 24, first bearing structure 30, bearing 31, bearing sleeve 32, second bearing structure 40, end cover 51, limiting ring 52, first adjusting bolt 53, second adjusting bolt 54, tension bolt 55, first gap seal 60, first conical sealing surface 61, second conical sealing surface 62, second gap seal 70, third conical sealing surface 71, fourth conical sealing surface 72, first gap 81, second gap 82, balance cavity 83. DETAILED DESCRIPTION

[0031] The following is a specific embodiment of the present application and further describes the technical solutions of the present application in conjunction with the drawings, but the present application is not limited to these embodiments. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present application. Therefore, it should be clear to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope of protection of the present application. In addition, in order to be clear and concise, the description of known functions and structures is omitted.

[0032] It should be noted that the embodiments and features in the embodiments can be combined with each other without conflict.

[0033] The present application provides a rotor axially adjustable multi-stage pump, during maintenance, the maintenance personnel can adjust the axial installation position of the rotor structure through the adjusting component to make position compensation, thereby reducing the maintenance cost.

[0034] Figure 1 The overall structure of the multi-stage pump provided by the embodiment of the present application is shown. Referring to Figure 1 , the multi-stage pump comprises a pump body 10, a rotor structure 20, a first bearing structure 30 and a second bearing structure 40. The pump body 10 is provided with an inner space 11, a water inlet 12 and a water outlet 13. The rotor structure 20 comprises a pump shaft 21 and a multi-stage impeller; the pump shaft 21 is arranged in the inner space 11 of the pump body 10, and the multi-stage impeller is arranged on the pump shaft 21 in sequence; the first bearing structure 30 and the second bearing structure 40 are both assembled between the pump shaft 21 and the pump body 10 to form a rotating support for the pump shaft 21.

[0035] The multi-stage pump can adopt a centrifugal pump or a mixed flow pump, and therefore, the multi-stage impeller can be a centrifugal pump impeller or a mixed flow pump impeller. The centrifugal pump works by rotating the impeller to make water move in a centrifugal manner. Before starting, the pump body and the water suction pipe are filled with water. Then, the motor is started to make the pump shaft drive the impeller and water to rotate at a high speed. The water moves in a centrifugal manner and is thrown to the outer edge of the impeller, and then flows into the water pressure pipeline of the water pump through the flow channel of the volute pump body. The mixed flow pump has both centrifugal force and axial thrust on the liquid during the working process of the impeller. In a specific technical scheme, the multi-stage pump is a multi-stage centrifugal pump, and the multi-stage impeller is a centrifugal pump impeller. When working, the liquid delivered through the water inlet enters the pump body. Due to the action of the impeller, the kinetic energy and potential energy of the liquid are both increased. After the liquid enters the guide vane, part of the kinetic energy is converted into potential energy (each stage of the impeller is provided with a guide vane). The reverse blades of the guide vane deliver the liquid to the inlet of the next stage of the impeller under favorable hydraulic characteristics. Each stage increases the same pressure. After passing through the last stage of the guide vane, the liquid is discharged from the water outlet. The water pressure of the multi-stage centrifugal pump is the superposition of the stages of the impeller, and therefore, a larger outlet pressure can be obtained. In addition, it should be noted that the rotor structure is the rotating part in the pump body, which includes the pump shaft, the multi-stage impeller, and other components that rotate with the pump shaft.

[0036] The first bearing structure 30 and the second bearing structure 40 are used to rotationally support the rotor structure 20. One or more bearings can be arranged in the first bearing structure 30 and the second bearing structure 40, and the type of the bearing can be a rolling bearing. Figure 1 In the structure shown, the first bearing structure 30 and the second bearing structure 40 are arranged near the two sides of the pump body 10, respectively.

[0037] In the embodiment of the present application, the multi-stage pump further comprises an end cover 51 and an adjusting component. The end cover 51 is arranged at one end of the pump body 10 and connected with the first bearing structure 30. The adjusting component is installed between the end cover 51 and the pump body 10 and can adjust the installation position of the end cover 51 in the axial direction of the pump shaft 21, so as to adjust the axial installation position of the rotor structure 20.

[0038] Specifically, the end cover 51 is connected with the first bearing structure 30 and forms a connection relationship with the rotor structure 20 through the first bearing structure 30. When the axial position of the end cover 51 is adjusted, the rotor structure 20 will also be adjusted. Therefore, during maintenance, the maintenance personnel can adjust the axial installation position of the end cover and the rotor structure through the adjusting component to compensate the position, so as to reduce the maintenance cost.

[0039] Reference Figure 2In an embodiment of the present application, the adjusting component includes a plurality of first adjusting bolts 53 and a plurality of second adjusting bolts 54, and the plurality of first adjusting bolts 53 and the plurality of second adjusting bolts 54 are installed on the threaded connection holes of the end cover 51 and are distributed at different circumferential positions of the pump shaft 21; wherein the first adjusting bolts 53 are threadedly connected with the first bearing structure 30 to pull the first bearing structure 30, and the second adjusting bolts 54 abut against the first bearing structure 30. During adjustment, the maintenance personnel can adjust the axial position of the end cover 51 by screwing the first adjusting bolts 53 and the second adjusting bolts 54.

[0040] In Figure 1 and Figure 2 the structure shown, exemplarily, when it is required to adjust the axial installation position of the end cover and the rotor structure to the left, first loosen the second adjusting bolts 54 so that the ends thereof are out of contact with the first bearing structure 30, then screw the first adjusting bolts 53 to pull the end cover 51 and the rotor structure 20 to move to the left, after moving to the position, tighten the second adjusting bolts 54 to abut against the first bearing structure 30 again. When it is required to adjust the axial installation position of the end cover and the rotor structure to the right, first loosen the first adjusting bolts 53 so that the end cover 51 is relaxed, then screw the second adjusting bolts 54 to drive the end cover 51 and the rotor structure 20 to move to the right, after moving to the position, tighten the first adjusting bolts 53 to pull the bearing structure 30 again.

[0041] Continuing to refer to Figure 2 In an embodiment of the present application, a limiting ring 52 is arranged inside the first bearing structure 30; a tension bolt 55 is arranged between the end cover 51 and the limiting ring 52; the tension bolt 55 passes through the opening on the pump body 10 to connect the end cover 51 and the limiting ring 52, so as to clamp the first bearing structure 30 between the end cover 51 and the limiting ring 52; an adjusting gap is arranged between the end cover 51, the limiting ring 52 and the pump body 10 to allow the end cover 51 and the limiting ring 52 to adjust the axial position relative to the pump body 10.

[0042] Specifically, the tension bolt 55 passes through the opening on the pump body 10 to connect the end cover 51 and the limiting ring 52, so as to clamp the first bearing structure 30 between the end cover 51 and the limiting ring 52. In Figure 2 the structure shown, the limiting ring 52 is located at the left side of the first bearing structure 30, and the end cover 51 is located at the right side of the first bearing structure 30, and the end cover 51 and the first bearing structure 30 are tightly combined together by the tensioning action of the tension bolt 55. In this structure, the end cover 51, the first bearing structure 30, the limiting ring 52 and the rotor structure 20 form an associated structure, which can be adjusted as a whole in the axial position. Therefore, when the first adjusting bolts 53 and the second adjusting bolts 54 adjust the axial displacement of the end cover 51, the first bearing structure 30 and the rotor structure 20 will also be adjusted in position.

[0043] With reference to the drawings Figure 2 The first bearing structure 30 comprises a bearing 31, a bearing sleeve 32, the bearing sleeve 32 is sleeved in the inner ring of the bearing sleeve 32, the bearing sleeve 32 is sleeved in the inner ring of the pump body 10, and a plurality of sealing rings are arranged between the pump body 10 and the bearing sleeve 32. Figure 2 In the structure shown in the figure, two sealing rings are arranged between the bearing 31 and the bearing sleeve 32. Further, the first bearing structure 30 comprises two rolling bearings arranged side by side, which can be deep groove ball bearings in particular.

[0044] With reference to the drawings Figure 3 In an embodiment of the present application, the tensioning bolts 55, the first adjusting bolts 53 and the second adjusting bolts 54 are alternately distributed along the circumferential direction of the pump shaft 21. In the structure shown in the figure, the four tensioning bolts 55, the four first adjusting bolts 53 and the four second adjusting bolts 54 are alternately arranged along the circumferential direction of the pump shaft 21. Figure 3 In the structure shown in the figure, two sealing rings are arranged between the bearing 31 and the bearing sleeve 32. Further, the first bearing structure 30 comprises two rolling bearings arranged side by side, which can be deep groove ball bearings in particular.

[0045] With reference to the drawings Figure 1 A nut 23 is further arranged at the end of the pump shaft 21, the nut 23 is assembled on the pump shaft 21 through threaded cooperation, and the bearing is limited on the pump shaft 21 between the nut 23 and the sleeve, so that the first bearing structure 30 is limited at a fixed axial position of the pump shaft 21.

[0046] In an embodiment of the present application, a plurality of gap seals are arranged between the pump body 10 and the rotor structure 20, at least part of the gap seals adopt a conical sealing structure, the conical sealing structure has a conical sealing surface, and the directions of the conical sealing surfaces of all the conical sealing structures are consistent, so that the gap sizes of all the conical sealing structures can be compensated for wear by adjusting the axial installation position of the rotor structure 20.

[0047] It should be noted that, in operation, due to natural wear, solid particles in the medium, impeller shaking and other reasons, the radial gap between the impeller and the pump body becomes larger or the seal ring breaks, which cannot play a sealing role and can cause a large amount of backflow, reducing the actual flow of the pump. Therefore, in the internal structure of the multi-stage pump, the gap sealing structure between the pump body and the rotor structure will be worn with the use of the pump, causing the gap to gradually increase and leading to sealing failure. Based on the conical sealing structure, maintenance personnel can compensate for the wear of the gap sizes of all the conical sealing structures by adjusting the axial installation position of the rotor structure, without the need to replace related components (for example, the impeller), and the maintenance cost is lower.

[0048] With reference to the drawings Figure 4 and Figure 5, the pump body 10 is arranged with an inlet guide vane 14 corresponding to each stage impeller 22 at the inlet end of the impeller 22, and a first gap seal 60 is arranged between the inlet guide vane 14 and the impeller 22; at the position of the first gap seal 60, a first tapered sealing surface 61 is arranged on the inlet guide vane 14, and a second tapered sealing surface 62 is arranged on the impeller 22, and the first tapered sealing surface 61 and the second tapered sealing surface 62 cooperatively form a tapered sealing structure; the tapered sealing surfaces of each first gap seal 60 are in the same direction.

[0049] With reference to Figure 4 and Figure 6 , the pump body 10 is arranged with a guide vane 15 corresponding to each stage impeller 22 at the outlet end of the impeller 22, and a second gap seal 70 is arranged between the guide vane 15 and the shaft sleeve on the pump shaft 21; at the position of the second gap seal 70, a third tapered sealing surface 71 is arranged on the guide vane 15, and a fourth tapered sealing surface 72 is arranged on the shaft sleeve on the pump shaft 21, and the third tapered sealing surface 71 and the fourth tapered sealing surface 72 cooperatively form a tapered sealing structure; the tapered sealing surfaces of each second gap seal 70 are in the same direction as the tapered sealing surfaces of the first gap seal 60.

[0050] The gap seal between the pump body 10 and the rotor structure 20 includes the first gap seal 60 and the second gap seal 70. Figure 4- Figure 6 The structure at the stage impeller is shown, including the first gap seal 60 and the second gap seal 70.

[0051] With reference to Figure 4 and Figure 5 , the inlet guide vane 14 is arranged on the pump body 10, a first tapered sealing surface 61 is arranged on the inlet guide vane 14, and a second tapered sealing surface 62 is arranged on the impeller 22, and the first tapered sealing surface 61 and the second tapered sealing surface 62 cooperatively form a tapered first gap seal 60. When the inlet guide vane 14 or the impeller 22 is excessively worn, the gap between the first tapered sealing surface 61 and the second tapered sealing surface 62 increases, resulting in failure of the first gap seal 60. During maintenance, the gap size between the first tapered sealing surface 61 and the second tapered sealing surface 62 can be reduced by adjusting the axial installation position of the rotor structure 20 to compensate for the wear of the gap of the first gap seal 60, thereby restoring the sealing function of the first gap seal 60.

[0052] With reference to Figure 4 and Figure 6The guide vane body 15 is arranged on the pump body 10, the third tapered sealing surface 71 is arranged on the guide vane body 15, the shaft sleeve on the pump shaft 21 is provided with a fourth tapered sealing surface 72, and the third tapered sealing surface 71 and the fourth tapered sealing surface 72 cooperatively form the tapered second gap seal 70. When the guide vane body 15 or the shaft sleeve on the pump shaft 21 is excessively worn, the gap between the third tapered sealing surface 71 and the fourth tapered sealing surface 72 is increased, and the second gap seal 70 is lost. During maintenance, the gap between the third tapered sealing surface 71 and the fourth tapered sealing surface 72 can be reduced by adjusting the axial installation position of the rotor structure 20, the gap of the second gap seal 70 is compensated by wear, and the sealing function of the second gap seal 70 is restored.

[0053] It should be noted that the tapered sealing surfaces of the second gap seals 70 are in the same direction as the tapered sealing surfaces of the first gap seal 60, that is, the first tapered sealing surface 61 and the second tapered sealing surface 62, and the third tapered sealing surface 71 and the fourth tapered sealing surface 72 are in the same direction. Therefore, during maintenance, the gap between the first tapered sealing surface 61 and the second tapered sealing surface 62 and the gap between the third tapered sealing surface 71 and the fourth tapered sealing surface 72 can be reduced by adjusting the axial installation position of the rotor structure 20.

[0054] Reference Figure 7 In an embodiment of the present application, in the internal space 11 of the pump body 10, the first support 16 and the second support 17 are arranged on the pump body 10 in a ring shape, the balance body 24 is arranged on the rotor structure 20, the first support 16 is wrapped around the outer periphery of the balance body 24, the first gap 81 is formed between the first support 16 and the balance body 24, the second gap 82 is formed between the second support 17 and the balance body 24, the balance cavity 83 is formed by the balance body 24 and the internal structure of the pump body 10, the first gap 81 communicates the drain port of the multi-stage impeller 22 and the balance cavity 83, and the second gap 82 communicates the inside and outside of the balance cavity 83 for pressure relief of the balance cavity 83. The matching surfaces of the first support 16 and the balance body 24 for forming the first gap 81 are tapered sealing surfaces, the matching surfaces of the second support 17 and the balance body 24 for forming the second gap 82 are radial end surfaces, and the matching surfaces of the first gap 81 are in the same direction as the tapered sealing surfaces of the tapered sealing structure.

[0055] The first gap 81 communicates the drain port of the multi-stage impeller and the balance cavity 83, the high-pressure water of the drain port can enter the balance cavity 83 through the first gap 81, and the water in the balance cavity 83 can be leaked through the second gap 82. Based on Figure 1 and Figure 7As shown in the structure, when the pump is working, the impeller 22 of the rotor structure 20 is subjected to an axial force to the left, and the balancing body 24 is subjected to an axial force to the right to balance the force of the impeller 22. The axial force of the rotor structure changes constantly with the working condition. When the force of the rotor structure 20 moves to the right along the axial direction, the balancing body 24 is close to the second support 17, the second gap 82 is reduced, the leakage of the balancing cavity 83 is reduced, the water pressure is increased, the leftward pressure of the liquid in the balancing cavity 83 on the balancing body 24 is increased, and thus the force direction of the rotor structure 20 is changed to the left. At this time, with the force direction of the whole rotor structure 20 changed to the left, the rotor structure 20 is changed to move to the left. When the force of the rotor structure 20 moves to the left along the axial direction, the balancing body 24 is away from the second support 17, the second gap 82 is increased, the leakage of the balancing cavity 83 is increased, the water pressure is reduced, the leftward pressure of the liquid in the balancing cavity 83 on the balancing body 24 is reduced, and thus the force direction of the rotor structure 20 is changed to the right. At this time, with the force direction of the whole rotor structure 20 changed to the right, the rotor structure 20 is changed to move to the right. Therefore, when the force of the rotor structure 20 moves axially, with the size of the second gap 82 changed, the force of the rotor structure 20 is reversely changed to facilitate the reverse movement of the rotor structure 20. In this way, the rotor structure 20 can keep dynamic balance.

[0056] The matching surfaces of the first support 14 and the balancing body 24 for forming the first gap 81 are tapered, so that when the matching surfaces on both sides of the first gap 81 are worn, the size of the first gap 81 can be compensated by adjusting the axial installation position of the rotor structure 20 as a whole, and the related parts do not need to be replaced, so that the maintenance cost is lower.

[0057] In the above embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0058] In addition, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" are used only for descriptive purposes and are not to be construed as indicating or implying relative importance or a specific number of technical features indicated. Therefore, the features defined with "first", "second", "third", "fourth", "fifth", "sixth", "seventh" and "eighth" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly specified. It should be noted that the terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. Furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, it means that there is a feature, step, work, device, component and / or combination thereof.

[0059] The specific embodiments described herein are merely illustrative of the application. Various modifications or changes can be made to the described embodiments without departing from the scope of the application as defined in the claims.

Claims

1. A multi-stage pump with axial adjustment of the rotor, characterized in that, The multi-stage pump comprises: a pump body provided with an internal space, an inlet and an outlet; a rotor structure comprising a pump shaft and multi-stage impellers, the pump shaft being arranged in the internal space of the pump body, and the multi-stage impellers being arranged on the pump shaft in sequence; a first bearing structure and a second bearing structure, both of which are assembled between the pump shaft and the pump body to provide rotational support for the pump shaft; an end cover arranged at one end of the pump body and connected with the first bearing structure; an adjusting component installed between the end cover and the pump body, capable of adjusting the installation position of the end cover along the axial direction of the pump shaft, thereby adjusting the axial installation position of the rotor structure.

2. A multi-stage pump with axially adjustable rotor according to claim 1, characterized in that The adjusting component comprises a plurality of first adjusting bolts and a plurality of second adjusting bolts, and the first adjusting bolts and the second adjusting bolts are both installed on the threaded connection holes of the end cover and distributed at different circumferential positions of the pump shaft; the first adjusting bolts are in threaded connection with the first bearing structure to pull the first bearing structure, and the second adjusting bolts abut against the first bearing structure.

3. A rotor axially adjustable multi-stage pump according to claim 2, characterized in that, A limiting ring is arranged inside the first bearing structure; a tension bolt is arranged between the end cover and the limiting ring; the tension bolt passes through the opening on the pump body to connect the end cover and the limiting ring, so that the end cover and the limiting ring clamp the first bearing structure therebetween; an adjusting gap is arranged between the end cover, the limiting ring and the pump body to allow the end cover and the limiting ring to adjust the axial position relative to the pump body.

4. A multi-stage pump with axially adjustable rotor according to claim 3, characterized in that The first bearing structure comprises a bearing and a bearing sleeve; the bearing sleeve is sleeved in the inner ring of the bearing sleeve; the bearing sleeve is sleeved in the inner ring of the pump body; a plurality of sealing rings are arranged between the pump body and the bearing sleeve.

5. A rotor axially adjustable multi-stage pump according to claim 4, characterized in that The first bearing structure comprises two parallel arranged rolling bearings.

6. The rotor axially adjustable multi-stage pump according to claim 3, characterized in that, The tension bolt, the first adjusting bolt and the second adjusting bolt are sequentially and alternately distributed along the circumferential direction of the pump shaft.

7. The axial adjustable multi-stage pump of claim 2, wherein, A nut is further arranged at the end of the pump shaft; the nut is assembled on the pump shaft through threaded cooperation, and the bearing is limited on the pump shaft between the nut and the bearing sleeve.

8. A multi-stage pump with axially adjustable rotor according to any of claims 1-7, characterized in that A plurality of gap seals are arranged between the pump body and the rotor structure; at least part of the gap seals adopt a conical sealing structure; the conical sealing structure has a conical sealing surface, and the directions of the conical sealing surfaces of all the conical sealing structures are consistent, so that the gap sizes of all the conical sealing structures can be worn and compensated by adjusting the axial installation position of the rotor structure.

9. The rotor axially adjustable multi-stage pump according to claim 8, wherein the pump body is provided with an inlet end flow guide corresponding to each inlet end of the impellers, a first gap seal is arranged between the inlet end flow guide and the impeller, a first conical sealing surface is arranged on the inlet end flow guide at the position of the first gap seal, a second conical sealing surface is arranged on the impeller, the first conical sealing surface and the second conical sealing surface cooperatively form a conical sealing structure, and the directions of the conical sealing surfaces of all the first gap seals are the same. The pump body is provided with a guide vane body corresponding to each stage of impeller at the water outlet end, and a second gap seal is arranged between the guide vane body and the shaft sleeve on the pump shaft; a third tapered sealing surface is arranged on the guide vane body at the position of the second gap seal, a fourth tapered sealing surface is arranged on the shaft sleeve of the pump shaft, and the third tapered sealing surface and the fourth tapered sealing surface cooperatively form a tapered sealing structure; the tapered sealing surfaces of the second gap seals are in the same direction as the tapered sealing surface of the first gap seal.

10. The rotor-axially-adjustable multi-stage pump according to claim 8, characterized in that, In the internal space of the pump body, a first support and a second support are arranged on the pump body in a ring shape; a balance body is arranged on the rotor structure; the first support is wrapped around the outer periphery of the balance body, and a first gap is formed between the first support and the balance body; a second gap is formed between the second support and the balance body; a balance cavity is formed by the balance body and the internal structure of the pump body; the first gap is connected to the drainage port of the multi-stage impeller and the balance cavity; the second gap is connected between the inside and outside of the balance cavity for pressure relief of the balance cavity; wherein the mating surfaces of the first support and the balance body for forming the first gap are tapered sealing surfaces; the mating surfaces of the second support and the balance body for forming the second gap are radial end surfaces; and the mating surfaces of the first gap are in the same direction as the tapered sealing surfaces of the tapered sealing structure.

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