Water outlet section assembly of self-balancing multi-stage pump and self-balancing multi-stage pump

Abstract

The utility model provides a water outlet section assembly of a self-balancing multi-stage pump and the self-balancing multi-stage pump, a water outlet section (1), a balancing shaft sleeve (5) and a balancing bush (4) jointly form the water outlet section assembly, the balancing shaft sleeve (5) and the balancing bush (4) jointly form a sealing structure of the water outlet section (1), the balancing shaft sleeve (5) is installed on a pump shaft of the self-balancing multi-stage pump in an interference fit mode, and the balancing bush (4) is installed on the pump shaft of the self-balancing multi-stage pump. The longitudinal section cutting plane of the balance bushing (4) is in an L shape, the balance bushing (4) is fixed to the water outlet section (1) through a fastening screw at the end of the balance bushing (4), two balance bushing pressure relief holes (3) are formed in the middle of the balance bushing (4), and a water outlet section pressure relief hole (2) is formed between a hollow cavity of the water outlet section (1) and a left high-pressure cavity of the water outlet section (1). The water outlet section assembly is installed between a positive flow passage component and a negative flow passage component of the self-balancing multi-stage pump, and the problems of erosion and residual axial force of the self-balancing multi-stage pump are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a self -balancing multistage pump technical field, concretely relates to a water outlet section subassembly of self -balancing multistage pump and self -balancing multistage pump. BACKGROUND

[0002] The impeller of the self-balancing multistage pump adopts a back-to-back installation mode. During the operation of the self-balancing multistage centrifugal pump, the pump shaft rotates under the driving of the motor. The fluid medium of the self-balancing multistage pump flows out from one side of the water outlet section after passing through the forward impeller, and then enters the reverse impeller. After the rotation of the reverse impeller, the fluid medium is discharged from the other side of the water outlet section to the drain pipeline. Therefore, a high-pressure area with a certain pressure difference is formed on both sides of the water outlet section of the self-balancing multistage pump, causing the fluid on the side of the high-pressure cavity with high pressure to leak along the gap of the intermediate sealing assembly of the water outlet section to the side of the high-pressure cavity with low pressure, directly eroding the intermediate sealing assembly of the self-balancing multistage pump, and seriously affecting the operation stability and reliability of the self-balancing multistage pump.

[0003] On the other hand, the impeller of the self-balancing multistage pump adopts a back-to-back installation mode. During the operation of the self-balancing multistage centrifugal pump, the axial forces generated by the forward impeller and the reverse impeller can basically cancel each other out. However, due to the fact that the outlet pressures of each forward impeller and reverse impeller are not equal, residual axial forces still exist during the operation of the self-balancing multistage pump. Since the residual axial forces of the self-balancing multistage pump will directly act on the bearings at both ends of the pump shaft, especially the bearing at the end of the self-balancing multistage pump, it will further cause the bearing at the end of the self-balancing multistage pump to generate heat, and even cause damage, affecting the service life of the bearing of the self-balancing multistage pump and the operation stability of the entire machine.

[0004] Therefore, in order to reduce the erosion risk of the intermediate sealing assembly of the self-balancing multistage pump, reduce the impact of residual axial forces on the end bearing during the operation of the self-balancing multistage pump, and improve the operation stability of the self-balancing multistage pump and the service life of the bearing, a water outlet section assembly with a pressure relief channel and a self-balancing multistage pump with the same are urgently needed. SUMMARY

[0005] The utility model provides a water outlet section assembly of self -balancing multistage pump and self -balancing multistage pump, through the pressure relief channel set up on the water outlet section assembly of self -balancing multistage pump, effectively solve the problem of the erosion of the balance bush and the balance shaft sleeve and the problem of the residual axial force of the self -balancing multistage pump.

[0006] To achieve the above object, the technical scheme of the utility model is as follows: a water outlet section assembly of a self-balancing multi-stage pump, comprising a water outlet section, a balance shaft sleeve and a balance bush, wherein the balance shaft sleeve and the balance bush jointly constitute a water outlet section sealing structure, the balance shaft sleeve is installed on a pump shaft of the self-balancing multi-stage pump through interference fit, a longitudinal section of the balance bush is L-shaped, the balance bush is fixed on the water outlet section through fastening screws at the end thereof, two balance bush pressure relief holes are arranged at the middle position of the balance bush, the two balance bush pressure relief holes are symmetrically arranged, and the axes of the two balance bush pressure relief holes are in a horizontal state, a groove is arranged on the outer circular surface of the balance shaft sleeve, and a water outlet section pressure relief hole is arranged between the hollow cavity of the water outlet section and the left high-pressure cavity of the water outlet section, and the axis of the water outlet section pressure relief hole is in a horizontal state.

[0007] Further, the diameter of the balance bush pressure relief hole is 25-35mm, and the diameter of the water outlet section pressure relief hole is 30-35mm.

[0008] Further, the outer circular surface of the balance shaft sleeve and the inner hole surface of the balance bush are cladded with wear-resistant layers, and the material of the wear-resistant layers is nickel-based alloy or silicon carbide ceramic or silicon nitride ceramic or diamond.

[0009] Further, the utility model also discloses a self-balancing multi-stage pump, which comprises a shaft coupling arranged at the end of a pump shaft, a positive flow component arranged on the left side of the water outlet section assembly, a water inlet section and a bearing assembly, and a reverse flow component arranged on the right side of the water outlet section assembly, wherein the left side of the water outlet section assembly is connected with the right side of the positive guide vane of the last stage of the positive flow component, and the right side of the water outlet section assembly is connected with the left side of the reverse guide vane of the last stage of the reverse flow component.

[0010] Compared with the prior art, the water outlet section assembly of the self-balancing multi-stage pump and the self-balancing multi-stage pump have the advantages that by arranging the balance bush pressure relief hole and the water outlet section pressure relief hole, the erosion and wear of the balance shaft sleeve caused by the high-pressure fluid medium in the right side cavity of the water outlet section can be solved, and the residual axial force generated during the operation of the self-balancing multi-stage pump can be effectively reduced, so that the structure is simple and easy to process. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a whole structure schematic view of the utility model;

[0012] Figure 2 It is Figure 1 the A place local enlarged view of;

[0013] Figure 3 It is a structure schematic view of the water outlet section of the utility model.

[0014] Marked as: 1: water outlet section; 2: water outlet section pressure relief hole; 3: balance bushing pressure relief hole; 4: balance bushing; 5: balance shaft sleeve. DETAILED DESCRIPTION

[0015] In the description of the utility model, it needs to explain that the orientation or position relation indicated by the terms "left", "right", "front", "back", "inner", "outer", "two ends", "one end", "the other end" and the like is the orientation or position relation based on the orientation or position relation shown in the drawings, and is only for the convenience of describing the utility model, and is not indicative or suggestive of the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0016] In order to make the technical problems, technical solutions and implementation effects to be solved by the utility model more clear, the following will be combined with the drawings of the utility model Figures 1-3 , and a further description will be made on one embodiment of the utility model.

[0017] Referring to the drawings of the utility model Figures 1-3 , the water outlet section assembly of the self-balancing multi-stage pump comprises a water outlet section 1, a balance shaft sleeve 5 and a balance bushing 4, wherein the balance shaft sleeve 5 and the balance bushing 4 jointly constitute a sealing structure of the water outlet section 1, the balance shaft sleeve 5 is installed on the pump shaft of the self-balancing multi-stage pump in a manner of interference fit, the longitudinal section of the balance bushing 4 is in an L shape, the balance bushing 4 is fixed to the water outlet section 1 through the fastening screw at the end thereof, two balance bushing pressure relief holes 3 are arranged at the middle position of the balance bushing 4, the two balance bushing pressure relief holes 3 are symmetrically arranged, the axes of the two balance bushing pressure relief holes 3 are in a horizontal state, the outer circular surface of the balance shaft sleeve 5 is provided with a groove, one water outlet section pressure relief hole 2 is arranged between the hollow cavity of the water outlet section 1 and the left high-pressure cavity of the water outlet section 1, and the axis of the water outlet section pressure relief hole 2 is in a horizontal state.

[0018] When installing, as shown in the drawings, Figure 1 , the balance bushing 4 is fixed in the inner hole of the water outlet section 1 through the screw at the end thereof, and when fixing the balance bushing 4, the angle of the balance bushing 4 needs to be rotated to ensure that the axes of the two balance bushing pressure relief holes 3 of the balance bushing 4 are in a horizontal state, that is, the axes of the two balance bushing pressure relief holes 3 are in the horizontal section of the pump shaft of the self-balancing multi-stage pump, the balance shaft sleeve 5 and the last-stage impeller of the normal flow part share one common flat key to be fixed on the pump shaft, and the radial gap between the balance bushing 4 and the balance shaft sleeve 5 is 0.5mm-0.8mm.

[0019] As a preferred embodiment, the diameter of the balance bushing pressure relief hole 3 is 25-35mm, and the diameter of the water outlet section pressure relief hole 2 is 30-35mm.

[0020] As shown in the drawings, Figure 2 and 3As shown, when machining the pressure relief hole 3 of the balance bushing 4, a radial drilling machine or machining center can be used to drill through the entire balance bushing 4 from the outer circular surface of the balance bushing 4, thereby ensuring the symmetry of the two pressure relief holes 3 of the balance bushing; when machining the pressure relief hole 2 of the water outlet section, a machining method of pre-reserving casting holes or pre-reserving forging holes can be used to ensure that the axis of the pressure relief hole 2 of the water outlet section is within the horizontal tangent of the pump shaft of the self-balancing multistage pump.

[0021] In a preferred embodiment, the outer circular surface of the balance bushing 5 and the inner hole surface of the balance bushing 4 are clad with a wear-resistant coating, the material of which is a nickel-based alloy, silicon carbide ceramic, silicon nitride ceramic, or diamond.

[0022] To further improve the strength and erosion resistance of the rotating mating surfaces between the balance bushing 5 and the balance bushing 4, wear-resistant coatings are applied to the outer circular surface of the balance bushing 5 and the inner bore surface of the balance bushing 4 using laser cladding, plasma welding, or supersonic spraying. The thickness of the wear-resistant coating needs to be determined based on the model of the self-balancing multistage pump and its operating conditions. Typically, the thickness of the wear-resistant coating is between 0.5 mm and 1 mm.

[0023] like Figure 1 As shown, this utility model also discloses a self-balancing multistage pump, including a coupling disposed at the end of the pump shaft, a positive flow component installed on the left side of the outlet section assembly, an inlet section and bearing assembly, and a reverse flow component installed on the right side of the outlet section assembly, a secondary inlet section and bearing assembly, wherein the left side of the outlet section assembly is connected to the right side of the positive guide vane of the last stage of the positive flow component, and the right side of the outlet section assembly is connected to the left side of the reverse guide vane of the last stage of the reverse flow component.

[0024] The utility model discloses a water outlet section assembly of self-balancing multistage pump and self-balancing multistage pump, when the self-balancing multistage pump normal operation, the left side cavity and right side cavity of water outlet section 1 all form high pressure area, and the fluid medium pressure of right side cavity is greater than the fluid medium pressure of left side cavity, the fluid medium of water outlet section 1 right side cavity will enter between balance bushing 4 and balance shaft sleeve 5 along the sealing gap between balance bushing 4 and balance shaft sleeve 5, and then the fluid medium of balance bushing 4 and balance shaft sleeve 5 sealing gap will enter the internal cavity of water outlet section 1 along balance bushing pressure relief hole 3, can reduce the pressure of fluid medium in the sealing gap of balance bushing 4 and balance shaft sleeve 5 to the maximum limit, and the fluid medium of water outlet section 1 internal cavity will flow back to the left side cavity of water outlet section 1 along water outlet section pressure relief hole 2. Based on balance bushing pressure relief hole 3 and water outlet section pressure relief hole 2, can effectively reduce the fluid medium pressure of balance bushing 4 and balance shaft sleeve 5 sealing gap, avoid the high pressure fluid medium in water outlet section 1 right side cavity to the erosion wear of balance shaft sleeve 5, also reduced the fluid medium pressure of water outlet section 1 right side cavity, make the fluid medium pressure that acts on the rear cover plate of self-balancing multistage pump anti-impeller also reduce, play the purpose of balance self-balancing multistage pump residual axial force.

[0025] The above is only the preferred embodiment of the utility model, and does not limit the utility model, and any modification, equivalent replacement and improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A discharge section assembly of a self-balancing multistage pump, comprising a discharge section (1), a balance shaft sleeve (5), and a balance bushing (4), characterized in that: The balance bushing (5) and the balance bushing (4) together constitute the sealing structure of the outlet section (1). The balance bushing (5) is installed on the pump shaft of the self-balancing multistage pump by means of interference fit. The longitudinal section of the balance bushing (4) is L-shaped. The balance bushing (4) is fixed to the outlet section (1) by the fastening screw at its end. Two balance bushing pressure relief holes (3) are opened in the middle position of the balance bushing (4). The two balance bushing pressure relief holes (3) are arranged symmetrically, and the axes of the two balance bushing pressure relief holes (3) are horizontal. The outer circular surface of the balance bushing (5) is provided with a groove. An outlet section pressure relief hole (2) is opened between the hollow cavity of the outlet section (1) and the high pressure cavity on the left side of the outlet section (1). The axis of the outlet section pressure relief hole (2) is horizontal.

2. The outlet section assembly of a self-balancing multistage pump according to claim 1, characterized in that: The diameter of the pressure relief hole (3) of the balance bushing is 25-35 mm, and the diameter of the pressure relief hole (2) of the water outlet section is 30-35 mm.

3. The outlet section assembly of a self-balancing multistage pump according to claim 1, characterized in that: The outer circular surface of the balance bushing (5) and the inner hole surface of the balance bushing (4) are clad with a wear-resistant coating. The material of the wear-resistant coating is nickel-based alloy, silicon carbide ceramic, silicon nitride ceramic, or diamond.

4. A self-balancing multistage pump, comprising a coupling disposed at the end of the pump shaft, an outlet section assembly as described in any one of claims 1-3, a forward flow component installed on the left side of the outlet section assembly, an inlet section and a bearing assembly, and a reverse flow component, a secondary inlet section and a bearing assembly installed on the right side of the outlet section assembly, characterized in that: The left side of the outlet section assembly is connected to the right side of the positive guide vane of the last stage of the positive flow component, and the right side of the outlet section assembly is connected to the left side of the reverse guide vane of the last stage of the reverse flow component.

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