Small-axial-force multi-stage centrifugal pump

Abstract

The utility model discloses a small axial force multi-stage centrifugal pump which comprises a vertically arranged pump shell, a main shaft extending to the two sides is arranged in the pump shell, the upper end of the main shaft is provided with a balance drum, the balance drum is sleeved with a balance sleeve, and the outer curved surface of the balance sleeve is connected with the pump shell. A plurality of guide vanes are arranged at the upper end and the lower end of the interior of the pump shell, impellers are arranged at the upper end and the lower end of the main shaft, the upper impeller and the lower impeller are symmetrically arranged, and the multiple lower impellers correspond to the multiple lower guide vanes one to one and are located on the inner sides of the lower guide vanes one to one. The multiple upper impellers correspond to the multiple upper guide vanes one to one and are located on the inner sides of the multiple upper guide vanes one to one, a partition block is arranged at the middle end of the inner side of the pump shell, the lower end of the main shaft penetrates to the position below the partition block, and two first flange openings located on the upper side and the lower side of the partition block respectively are formed in the outer side of the pump shell. The small-axial-force multi-stage centrifugal pump has the advantages of being small in axial force and long in service life.

Description

Technical Field

[0001] The utility model relates to the technical field of multi-stage centrifugal pumps, in particular to a small axial force multi-stage centrifugal pump. Background Art

[0002] There are many types of pumps, which can be divided into vane pumps, volumetric pumps and other types of pumps according to their working principles. Centrifugal pumps are a type of vane pump. Compared with single-stage centrifugal pumps, multi-stage centrifugal pumps have a wider range of uses and a larger market share.

[0003] The traditional multi-stage centrifugal pump is designed in a way that the impellers are arranged one by one. The pump will generate axial force during use. The balancing force is usually handled by a balancing disc or a balancing drum mechanism for balancing. However, since the balancing force cannot be completely eliminated, the balancing mechanism is mainly composed of a balancing drum and a balancing sleeve. The balancing mechanism will always wear during the use of the pump, which will lead to wear of other rotor parts, thereby affecting the normal service life of the pump. At the same time, since the parts of the balancing mechanism are wearing parts, they need to be replaced frequently, which increases the user's equipment maintenance costs. Secondly, the traditional self-balancing multi-stage centrifugal pump uses back-to-back impellers to offset each other's axial forces to achieve axial force balance, but no measures are taken to eliminate or reduce the axial force of the impellers in the same direction. As the pump wears out during use, the internal sealing gap increases, which increases the residual axial force and shortens the life of the pump.

[0004] Therefore, a small axial force multi-stage centrifugal pump is proposed to solve the above problems. Utility Model Content

[0005] The utility model aims to provide a small axial force multi-stage centrifugal pump to solve the above problems.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A small axial force multistage centrifugal pump, comprising a vertically arranged pump casing, wherein a main shaft extending to both sides is arranged inside the pump casing, a balancing drum is arranged at the upper end of the main shaft, a balancing sleeve with an outer curved surface connected to the pump casing is sleeved on the balancing drum, a plurality of guide vanes are arranged at the upper and lower ends of the pump casing, an impeller is arranged at the upper and lower ends of the main shaft, the upper and lower impellers are symmetrically arranged, the number of the lower impellers is multiple and one-to-one corresponds to the multiple guide vanes at the lower side and is located on the inner side thereof, the number of the upper impellers is multiple and one-to-one corresponds to the multiple guide vanes at the upper side and is located on the inner side thereof, a spacer is arranged at the middle end of the inner side of the pump casing, the lower end of the main shaft passes through the lower side of the spacer, two flange openings 1 are arranged on the outer side of the pump casing and are respectively located on the upper and lower sides of the spacer, a flange opening 2 is arranged at the upper and lower ends of the pump casing, a reversing flow channel is connected between the lower flange opening 1 and the upper flange opening 2, and balancing holes are opened on the opposite sides of the upper and lower impellers.

[0008] Preferably, the number of the balancing holes is equal to the number of the impeller blades, and the balancing holes correspond to the impeller blades one by one and are located at their starting points.

[0009] Preferably, a suction side shaft is provided at the bottom of the pump housing, a stuffing box is provided at the top of the pump housing, a discharge side shaft is provided at the top of the stuffing box, the lower end of the main shaft passes through to the bottom of the suction side shaft, and bearings are provided between the main shaft and the discharge side shaft and the suction side shaft.

[0010] Preferably, a sealing sleeve is sleeved on the main shaft, the outer curved surface of which is connected to the inner side of the spacer block, and there is a clearance fit between the sealing sleeve and the main shaft.

[0011] Preferably, a pump foot is provided on the outer side of the pump housing, and a mounting hole is opened on the pump foot.

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows: each impeller has a rear cover plate with a balancing hole, and the pressure of the front and rear cover plates of the impeller is balanced through the balancing hole, so that the axial force of each impeller is very small, and the impellers are arranged in a symmetrical manner in the pump casing, thereby achieving self-balancing of the impeller in the axial direction, that is, the axial forces generated by the impellers of each stage offset each other, reducing the mechanical friction caused by the axial force during the operation of the pump, and the axial load on the bearing will not increase, thereby extending the trouble-free working time of the pump and reducing the user's equipment maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings further illustrate the present invention, but the contents in the accompanying drawings do not constitute any limitation to the present invention.

[0014] Figure 1 It is a front sectional view of the utility model.

[0015] In the attached figure: 1. Main shaft; 2. Suction side shaft; 3. Flange opening 2; 4. Impeller; 5. Balance hole; 6. Pump casing; 7. Sealing sleeve; 8. Discharge side shaft; 9. Bearing; 10. Flange opening 1; 11. Reversing flow channel; 12. Guide vane; 13. Balance drum; 14. Balance sleeve; 15. Stuffing box body; 16. Spacer. DETAILED DESCRIPTION

[0016] The following describes the embodiments of the utility model in detail, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, and "several" means one or more, unless otherwise clearly and specifically defined.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0019] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0020] In this embodiment, Figure 1 A small axial force multistage centrifugal pump is given. The utility model includes a vertically arranged pump casing 6, a main shaft 1 extending to both sides is arranged inside the pump casing 6, a balancing drum 13 is arranged on the upper end of the main shaft 1, a balancing sleeve 14 with an outer curved surface connected to the pump casing 6 is sleeved on the balancing drum 13, a plurality of guide vanes 12 are arranged at the upper and lower ends of the pump casing 6, an impeller 4 is arranged at the upper and lower ends of the main shaft 1, the upper and lower impellers 4 are symmetrically arranged, the number of the lower impellers 4 is multiple and one-to-one corresponds to the multiple guide vanes 12 below and is positioned On its inner side, there are multiple impellers 4 above, which correspond one by one to the multiple guide vanes 12 above and are located on its inner side. A spacer 16 is provided at the middle end of the inner side of the pump casing 6. The lower end of the main shaft 1 passes through the bottom of the spacer 16. Two flange openings 10 are provided on the outer side of the pump casing 6 and are respectively located on the upper and lower sides of the spacer 16. Flange openings 2 3 are provided at the upper and lower ends of the pump casing 6. A reversing flow channel 11 is connected between the lower flange opening 10 and the upper flange opening 2 3. Balance holes 5 are provided on the opposite sides of the upper and lower impellers 4.

[0021] In this embodiment, when the impeller 4 is working, the liquid pressure of the rear cover plate of the impeller 4 is large, and the liquid pressure of the suction port is small, and there is a pressure difference to generate an axial force, and the balancing hole 5 balances the pressure of the front and rear cover plates of the impeller, does not generate a pressure difference, and does not generate a large axial force, so that the axial force of a single impeller is basically balanced, and finally the axial force of the main shaft 1 and the impeller 4 is balanced, and the liquid can be transported from the lower end of the pump casing 6 to the upper end of the interior through the reversing flow channel 11, and multiple impellers 4 are arranged in a symmetrical manner in the pump casing 6, so that the impeller 4 is self-balanced in the axial direction, and the mechanical friction caused by the axial force during the operation of the pump is reduced, the trouble-free working time of the pump is extended, and the equipment maintenance cost of the user is reduced. Even if the sealing gap that affects the axial force increases after the pump has been used for a period of time, because there is a balancing hole 5, the balancing hole 5 balances the pressure of the front and rear cover plates of the impeller 4, does not generate a pressure difference, does not generate a large axial force, and does not generate a large axial force change due to leakage of high-pressure liquid, thereby extending the life of the pump and improving the reliability of the pump.

[0022] Preferably, as another embodiment of the present invention, the number of the balancing holes 5 is equal to the number of the impeller 4 blades, and the balancing holes 5 correspond one-to-one to the impeller 4 blades and are located at their starting points.

[0023] In this embodiment, the number of the balancing holes 5 and the impeller 4 blades is 5 to 7, so that the flow of the liquid in the impeller 4 is more uniform and stable, the turbulent loss of the fluid is reduced, and the efficiency and performance of the impeller 4 are improved. The balancing holes are provided at the beginning of each blade to ensure that the force on each blade is relatively balanced, which helps to reduce the uneven force on the impeller 4 and improve the stability and operating efficiency of the centrifugal pump. Therefore, in order to ensure the balance and stability of the impeller during operation, the balancing holes are provided at the beginning of each blade.

[0024] Preferably, as another embodiment of the utility model, a suction side shaft body 2 is provided at the bottom of the pump housing 6, a stuffing box body 15 is provided at the top of the pump housing 6, a discharge side shaft body 8 is provided at the top of the stuffing box body 15, the lower end of the main shaft 1 passes through the bottom of the suction side shaft body 2, and bearings 9 are provided between the main shaft 1 and the discharge side shaft body 8 and the suction side shaft body 2.

[0025] In this embodiment, the stuffing box body 15 is a component for accommodating the stuffing seal, which is a sealing structure of the pump and is used to prevent liquid from leaking from the inside of the pump to the outside. The suction side shaft body 2 and the discharge side shaft body 8 are connected to the main shaft 1 through the bearing 9, which can support and fix the main shaft 1, so that the main shaft 1 remains stable during rotation and reduces the vibration and deviation of the pump shaft.

[0026] Preferably, as another embodiment of the utility model, a sealing sleeve 7 is sleeved on the main shaft 1, and the outer curved surface is connected to the inner side of the spacer block 16. The sealing sleeve 7 and the main shaft 1 are clearance-fitted. The sealing sleeve 7 serves to separate and seal the two sides to prevent liquid from leaking to one side from the gap between the spacer block 16 and the main shaft 1. A pump foot is provided on the outer side of the pump casing 6, and a mounting hole is opened on the pump foot. The pump foot can support the weight of the pump, and the mounting hole can cooperate with fasteners to install and fix the pump to maintain the stability of the pump casing 6, prevent the pump casing 6 from shaking or shifting during operation, and ensure the normal operation of the pump.

[0027] Working principle: The external motor is connected to the main shaft 1 and drives it to rotate, and the impeller 4 rotates. In this process, the liquid pressure of the rear cover of the impeller 4 is large, and the liquid pressure of the suction port is small. The pressure difference generates an axial force, and the suction port of the impeller 4 is connected with the rear cover of the impeller 4 through the balance hole 5. The balance hole 5 balances the pressure of the front and rear covers of the impeller, does not generate a pressure difference, does not generate a large axial force, and makes the axial force of a single impeller basically balanced. Finally, the axial force of the main shaft 1 and the impeller 4 is balanced. The liquid can be transported from the lower end of the pump casing 6 to the upper end of the interior through the reversing flow channel 11, and multiple impellers 4 are arranged in a symmetrical manner in the pump casing 6. The arrangement realizes the self-balancing of the impeller 4 in the axial direction, reduces the mechanical friction caused by the axial force during the operation of the pump, prolongs the trouble-free working time of the pump, and reduces the equipment maintenance cost of the user. Even if the sealing gap that affects the axial force increases after the pump has been used for a period of time, because of the balancing hole 5, the balancing hole 5 balances the pressure of the front and rear cover plates of the impeller 4, and does not generate a pressure difference, does not generate a large axial force, and does not generate a large axial force change due to the leakage of high-pressure liquid. The axial load on the bearing 9 will not increase, and the life and reliability of the pump will not be affected, thereby extending the life of the pump and improving the reliability of the pump.

[0028] In the description of this specification, the description with reference to the terms "embodiment", "one embodiment", "certain embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0029] The technical principle of the present invention is described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the protection scope of the present invention in any way. Based on the explanations here, technicians in this field can think of other specific implementations of the present invention without creative work, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A small axial force multistage centrifugal pump, comprising a vertically arranged pump housing (6), wherein a main shaft (1) extending to both sides is provided inside the pump housing (6), a balancing drum (13) is provided at the upper end of each main shaft (1), and a balancing sleeve (14) having an outer curved surface connected to the pump housing (6) is sleeved on the balancing drum (13), wherein: A plurality of guide vanes (12) are provided at both upper and lower ends of the pump casing (6), and an impeller (4) is provided at both upper and lower ends of the main shaft (1). The upper and lower impellers (4) are symmetrically arranged. The number of the lower impellers (4) is multiple and corresponds one-to-one with the multiple guide vanes (12) at the lower side and is located on the inner side thereof. The number of the upper impellers (4) is multiple and corresponds one-to-one with the multiple guide vanes (12) at the upper side and is located on the inner side thereof. A spacer (16) is provided at the middle end of the inner side of the pump casing (6), and the lower end of the main shaft (1) passes through the lower side of the spacer (16). Two flange openings (10) are provided on the outer side of the pump casing (6) and are respectively located on the upper and lower sides of the spacer (16). A flange opening (2) (3) is provided at both upper and lower ends of the pump casing (6), and a reversing flow channel (11) is connected between the lower flange opening (10) and the upper flange opening (3). Balance holes (5) are provided on opposite sides of the upper and lower impellers (4).

2. A small axial force multistage centrifugal pump according to claim 1, characterized in that: The number of the balancing holes (5) is equal to the number of the blades of the impeller (4), and the balancing holes (5) correspond one-to-one to the blades of the impeller (4) and are located at their starting points.

3. A small axial force multistage centrifugal pump according to claim 1, characterized in that: The bottom of the pump housing (6) is provided with a suction side shaft body (2), the top of the pump housing (6) is provided with a stuffing box body (15), the top of the stuffing box body (15) is provided with a discharge side shaft body (8), the lower end of the main shaft (1) passes through the bottom of the suction side shaft body (2), and bearings (9) are provided between the main shaft (1) and the discharge side shaft body (8) and the suction side shaft body (2).

4. A small axial force multistage centrifugal pump according to claim 1, characterized in that: The main shaft (1) is sleeved with a sealing sleeve (7) whose outer curved surface is connected to the inner side of the spacer (16); there is a clearance fit between the sealing sleeve (7) and the main shaft (1).

5. The small axial force multistage centrifugal pump according to claim 1, characterized in that: A pump foot is provided on the outer side of the pump housing (6), and a mounting hole is provided on the pump foot.

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