Vertical multi-stage magnetic pump

Abstract

A vertical multi-stage magnetic pump comprises a connecting section, a liquid storage section and a pump body connected in sequence. The pump body has a fluid inlet and a fluid outlet. The liquid storage section is provided with an impeller assembly comprising an impeller and a pump shaft. The connecting section is connected to a driving mechanism. The connecting section is also fixed with a magnetic coupling for connecting a power output shaft of the driving mechanism and the pump shaft. The driving mechanism drives the pump shaft to rotate, thereby driving the impeller to rotate, so as to pump the fluid flowing into the liquid storage section from the fluid inlet out of the fluid outlet. The connecting section is provided with a first interface and a second interface communicating with the interior of the magnetic coupling. The first interface is connected to the fluid inlet through a first cooling return pipe, and the second interface is connected to the fluid outlet through a liquid supply pipe. The first cooling return pipe and the liquid supply pipe can realize the large circulation of the fluid in the vertical multi-stage magnetic pump, so as to balance the internal axial force. The first cooling return pipe can also cool the magnetic coupling, which is conducive to the stable operation of the vertical multi-stage magnetic pump.

Description

Technical Field

[0001] This application relates to the field of magnetic pump technology, and more particularly to a vertical multistage magnetic pump. Background Technology

[0002] A typical centrifugal pump consists of a pump body, impeller, bearing housing, bearing assembly, pump shaft, seals, and drive motor. The pump body is the main load-bearing component, storing the medium and connected to the bearing housing for support and fixation. The impeller, the core of the pump's operation, is installed inside the pump body and circulates and pressurizes the medium through high-speed rotation. The bearing housing provides a high-strength support structure for the bearings, and its internal cavity can accommodate the storage and circulation of lubricating media. The bearings, mounted on the bearing housing, support the pump shaft. Insufficient lubricating media can cause abnormal noise and overheating, leading to burnout. The pump shaft of a typical centrifugal pump is usually coaxial with the motor shaft. When multiple impellers are installed simultaneously, the pump shaft length increases. Alternatively, the pump shaft can be connected to the motor shaft via a coupling to transmit torque to the impellers. Typical centrifugal pumps require auxiliary seals for isolation and leakage prevention, commonly including mechanical seals and stuffing boxes. Mechanical seals use a combination of static and dynamic sealing surfaces to achieve ultra-low leakage in the centrifugal pump section, preventing the internal pumped medium from entering the pump shaft and causing corrosion. The stuffing box, located in the gap between the sealed pump casing and the pump shaft, mainly consists of packing, water seal rings, packing sleeves, packing glands, and water seal pipes. It is used to isolate the pump's internal space from contact with the external medium. During operation, the high-speed rotation of the pump shaft and friction with the seals generate heat. Therefore, water needs to be injected to cool the seals and maintain the normal operation of the centrifugal pump. After a certain period of use, the seals should be replaced to prevent functional damage.

[0003] The difference between magnetic drive pumps and ordinary centrifugal pumps lies in the way they transmit power torque. Ordinary centrifugal pumps are commonly used for pumping common media and typically employ a direct connection between the motor shaft and the impeller, or an intermediate coupling, to drive the motor. In this case, seals are required to prevent media leakage and damage to the motor. Magnetic drive pumps, on the other hand, transmit torque through a magnetic coupling. The internal and external magnets conduct torque non-contactly, and the pump head is completely isolated from the motor using a secondary insulating material. Therefore, magnetic drive pumps can transport a wide variety of media, including corrosive ones.

[0004] In the field of multistage magnetic pumps, conventional multistage magnetic pumps are available in horizontal and vertical structures. Horizontal structures require more installation space and have higher manufacturing costs. Vertical multistage magnetic pumps, on the other hand, have a smaller overall size and are easier to install, making them more common and widely applicable. If the pump head of a vertical multistage magnetic pump uses a back-to-back structure, its internal construction is complex and its overall dimensions are large. If the pump head uses a normal impeller stacking structure, the coaxiality of its rotating parts is poor, requiring higher support capacity and structural strength at the installation location, and the resulting axial force is large and difficult to balance.

[0005] Therefore, how to improve the technical defects in the existing technology and design a vertical multistage magnetic pump with axial force self-balancing capability has always been a problem that ordinary people skilled in the art need to solve. Summary of the Invention

[0006] The purpose of this application is to provide a vertical multistage magnetic pump that, combined with a media circulation structure, can achieve internal axial force self-balancing, meet the equipment's requirements for safe and reliable operation, and has a lightweight, small size, and low manufacturing cost.

[0007] The technical solution provided by this invention is as follows:

[0008] A vertical multistage magnetic pump, comprising:

[0009] The connecting section, the liquid storage section, and the pump body are connected in sequence;

[0010] The pump body has a fluid inlet and a fluid outlet. An impeller assembly is provided in the liquid storage section. The impeller assembly includes an impeller and a pump shaft. The connecting section is used to connect to the drive mechanism, and a magnetic coupling is fixed in the connecting section. The magnetic coupling is used to connect the power output shaft of the drive mechanism and the pump shaft. The operation of the drive mechanism drives the pump shaft to rotate, thereby driving the impeller to rotate, so as to pump the fluid flowing into the liquid storage section from the fluid inlet out through the fluid outlet.

[0011] The connecting section has a first interface and a second interface that connect to the inside of the magnetic coupling. The first interface is connected to the fluid inlet via a first cooling return pipe, and the second interface is connected to the fluid outlet via a liquid supply pipe.

[0012] In some embodiments, the pump body has an inflow channel connecting the fluid inlet and the liquid storage section, and an outflow channel connecting the fluid outlet and the liquid storage section;

[0013] The pump body has an assembly hole in the inflow channel, and the end of the pump shaft away from the connecting section is rotatably installed in the assembly hole, and an end bearing is provided between the assembly hole and the pump shaft.

[0014] In some embodiments, the assembly hole is connected to a second cooling return pipe, the end of the second cooling return pipe away from the assembly hole being connected to the outflow channel.

[0015] In some embodiments, the magnetic coupling includes an outer magnetic assembly, an inner magnetic assembly, and an isolation sleeve;

[0016] The external magnetic assembly is driven to the power output shaft, the internal magnetic assembly is driven to the pump shaft, and the isolation sleeve is installed on the side of the connecting section away from the liquid storage section to isolate the external magnetic assembly and the internal magnetic assembly.

[0017] In some embodiments, the vertical multistage magnetic pump further includes:

[0018] The mounting bracket is installed on the connecting section and sleeved on the magnetic coupling for connecting the drive mechanism.

[0019] In some embodiments, a bearing housing is also installed on the side of the connecting section away from the liquid storage section. The bearing housing contains a bearing assembly, and the pump shaft passes through the bearing assembly. The bearing housing also contains two flow holes, which are respectively connected to the first interface and the second interface.

[0020] In some embodiments, the bearing assembly includes an upper bearing and a lower bearing, which are sequentially mounted on the bearing housing, and a bushing is provided between the pump shaft and the upper bearing and the lower bearing.

[0021] In some embodiments, the vertical multistage magnetic pump further includes:

[0022] Upper thrust plate and balance assembly;

[0023] The upper thrust plate is sleeved on the pump shaft and located above the upper bearing; the balancing assembly includes a lower thrust plate and a balancing drum connected to each other, both the lower thrust plate and the balancing drum are sleeved on the pump shaft, the lower thrust plate is located below the lower bearing, and the balancing drum is located below the lower thrust plate.

[0024] When the vertical multistage magnetic pump is subjected to an overall downward axial force, the end faces of the upper thrust plate and the upper bearing come into contact, and a liquid film is formed between the upper thrust plate and the upper bearing; and when the vertical multistage magnetic pump is subjected to an overall upward axial force, the end faces of the lower thrust plate and the lower bearing come into contact, and a liquid film is formed between the lower thrust plate and the lower bearing.

[0025] In some embodiments, the number of impellers is multiple, forming a multi-stage impeller, and the impeller assembly further includes guide vanes corresponding to the impellers;

[0026] The pump shaft is fitted with multiple spacer plates and multiple spacer sleeves. The guide vanes, impellers, spacer sleeves, and spacer plates are installed sequentially at each stage. The guide vanes and spacer plates are installed via a stop fit, and the impellers and spacer sleeves are connected by a key to achieve power transmission.

[0027] The connecting section has a final stage guide vane mounting hole on the side facing the liquid storage section for mounting the final stage guide vane. The inner diameter of the final stage guide vane is within the same dimensional tolerance range as the inner diameter of the bearing assembly to form a throttling gap on the side wall of the balance assembly. The pump body has a first stage spacer plate mounting position for mounting the first stage spacer plate.

[0028] In some embodiments, the first cooling return pipe is equipped with a pressure gauge for monitoring the return pressure;

[0029] The liquid supply pipe is equipped with a pressure reducing valve and a pressure gauge, the pressure gauge being used to monitor the liquid supply pressure.

[0030] The technical advantages of this application are as follows:

[0031] 1. In this application, the liquid supply pipe connects the fluid outlet and the second interface on the connecting section, allowing high-pressure fluid to enter the magnetic coupling and realize the process of fluid changing from high pressure to low pressure. The first cooling return pipe connects the fluid inlet and the first interface on the connecting section, enabling the return flow of fluid inside the magnetic coupling, thereby completing the medium circulation and achieving the function of balancing the internal axial force. In addition, the fluid circulation return can also cool the magnetic coupling, which is beneficial to the long-term stable operation of the vertical multistage magnetic pump. This application achieves the self-balancing of the internal axial force of the vertical multistage magnetic pump by simply setting the first cooling return pipe and the liquid supply pipe, integrating the medium circulation structure into the vertical multistage magnetic pump. The overall structure is simple, lightweight, small in size, and low in manufacturing cost.

[0032] 2. In this application, by setting a second cooling return pipe to connect the inflow channel and the outflow channel, the pressure difference can be used to allow the fluid in the outflow channel to flow to the end bearing and then return to the inflow channel, realizing a small-scale fluid circulation, which is more conducive to the self-balancing of the axial force inside the vertical multistage magnetic pump. At the same time, during the fluid return process, the end bearing can also be cooled and lubricated. The structure is reasonably designed and has a high utilization rate, which is not only conducive to the long-term stable operation of the vertical multistage magnetic pump, but also allows for a smaller size design of the vertical multistage magnetic pump, making it highly practical.

[0033] 3. In this application, a bearing assembly is provided inside the isolation sleeve, which is beneficial to the stable rotation of the pump shaft. At the same time, the aforementioned first cooling return pipe and liquid supply pipe can also achieve cooling and lubrication of the bearing assembly, resulting in a reasonable structural design and high utilization rate.

[0034] 4. In this application, the bearing assembly includes an upper bearing and a lower bearing. By setting an upper thrust plate and a lower thrust plate on opposite sides of the upper and lower bearings, it helps to balance the axial force and improve the self-balancing performance of the axial force inside the vertical multistage magnetic pump. Simultaneously, due to the arrangement of the first cooling return pipe and the liquid supply pipe, the internal fluid can form a liquid film between the upper bearing and the upper thrust plate, and between the lower bearing and the lower thrust plate, thereby preventing dry friction.

[0035] 5. In this application, by arranging pressure gauges on the first cooling return pipe and the liquid supply pipe, it is beneficial for users to monitor the return pressure and the liquid supply pressure, ensuring safety and reliability. In addition, a pressure reducing valve is also arranged on the liquid supply pipe, which can adjust the pressure in the low-pressure zone according to the actual situation, making it highly practical and widely applicable. Attached Figure Description

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] Figure 1 This is a cross-sectional view of a vertical multistage magnetic pump provided in one embodiment of this application;

[0038] Figure 2 This is a three-dimensional structural diagram of the connecting segment provided in one embodiment of this application;

[0039] Figure 3 This is a cross-sectional view of the connection segment provided in one embodiment of this application;

[0040] Figure 4 This is a cross-sectional view of the pump body provided in one embodiment of this application.

[0041] Explanation of icon numbers:

[0042] 100. Connecting section; 110. First interface; 120. Second interface; 130. Bearing housing mounting hole; 140. Isolation sleeve mounting hole; 150. Mounting bracket mounting hole; 160. Tensioner bolt mounting hole; 170. Last stage guide vane mounting hole;

[0043] 200. Liquid storage section;

[0044] 300, Pump body; 310, Fluid inlet; 320, Inflow channel; 321, Assembly hole; 330, Fluid outlet; 340, Outflow channel; 350, Third interface; 360, Fourth interface; 370, First stage partition plate mounting position; 380, End bearing;

[0045] 400. Drive mechanism; 410. Power take-off shaft;

[0046] 510 Impeller; 520 Guide vane; 530 Pump shaft; 540 Spacing plate; 550 Spacing sleeve;

[0047] 610. External magnetic assembly; 620. Internal magnetic assembly; 630. Isolation sleeve; 640. Bearing housing; 641. Flow hole; 650. Upper bearing; 660. Lower bearing; 670. Bushing; 680. Upper thrust plate; 690. Balance assembly;

[0048] 701. Install the bracket;

[0049] 801. First cooling return pipe; 802. Liquid supply pipe; 803. Second cooling return pipe; 804. Pressure gauge; 805. Pressure reducing valve;

[0050] 901. Assembly guide groove for liquid storage section. Detailed Implementation

[0051] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0053] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0054] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0055] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various components of this application are relative rather than absolute. These descriptions are appropriate when these components are in the positions shown in the drawings. If the description of the positions of these components changes, these directional indications also change accordingly.

[0057] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0058] This application addresses the limitations of conventional multistage magnetic pump installation methods, such as large overall size, heavy weight, large installation space requirements, and significantly increased construction difficulty and cost. It provides a vertical multistage magnetic pump with advantages such as light weight, small size, low manufacturing cost, and the ability to self-balance internal axial forces.

[0059] According to a specific embodiment provided in this application, see [link to specific embodiment]. Figure 1 A vertical multistage magnetic pump includes a connecting section 100, a liquid storage section 200, and a pump body 300 connected in sequence. The pump body 300 has a fluid inlet 310 and a fluid outlet 330. The liquid storage section 200 is equipped with an impeller 510 assembly, which specifically includes an impeller 510 and a pump shaft 530. The connecting section 100 is used to connect to a drive mechanism 400, and a magnetic coupling is fixed to the connecting section 100. The magnetic coupling is used to connect the power output shaft 410 of the drive mechanism 400 and the pump shaft 530. When the drive mechanism 400 is running, it drives the pump shaft 530 to rotate, thereby driving the impeller 510 to rotate, pumping the fluid flowing into the liquid storage section 200 from the fluid inlet 310 out through the fluid outlet 330.

[0060] Among them, see Figure 1 and Figure 3 The connecting section 100 has a first interface 110 and a second interface 120 that connect to the inside of the magnetic coupling. The first interface 110 is connected to the fluid inlet 310 via the first cooling return pipe 801, and the second interface 120 is connected to the fluid outlet 330 via the liquid supply pipe 802.

[0061] In this embodiment, the liquid supply pipe 802 connects the fluid outlet 330 and the second interface 120 on the connecting section 100, allowing the high-pressure fluid, pressurized by the impeller 510, to enter the magnetic coupling, realizing the process of fluid changing from high pressure to low pressure. The first cooling return pipe 801 connects the fluid inlet 310 and the first interface 110 on the connecting section 100, enabling the fluid inside the magnetic coupling to flow back to the fluid inlet 310, thereby completing the medium circulation and achieving the function of balancing the internal axial force. In addition, the fluid circulation return can also cool the magnetic coupling, which is beneficial to the long-term stable operation of the vertical multistage magnetic pump. This embodiment achieves the self-balancing of the internal axial force of the vertical multistage magnetic pump by simply setting the first cooling return pipe 801 and the liquid supply pipe 802 and combining the medium circulation structure with the vertical multistage magnetic pump. The overall structure is simple, lightweight, small in size, and low in manufacturing cost.

[0062] Specifically, see Figure 1 and Figure 4 The pump body 300 has a third port 350 and a fourth port 360. The third port 350 is connected to the fluid inlet 310. The two ends of the first cooling return pipe 801 are connected to the first port 110 and the third port 350 respectively through a connector assembly to achieve an overall connection. At the same time, O-rings and gaskets are used to form an overall internal seal. Conversely, the fourth port 360 is connected to the fluid outlet 330. The two ends of the liquid supply pipe 802 are connected to the second port 120 and the fourth port 360 respectively through a connector assembly to achieve an overall connection. At the same time, O-rings and gaskets are used to form an overall internal seal.

[0063] As a preferred option, see Figure 1 Both the first cooling return pipe 801 and the liquid supply pipe 802 are equipped with pressure gauges 804, which are used to monitor the return pressure and the liquid supply pressure, respectively. The liquid supply pipe 802 is also equipped with a pressure reducing valve 805. The pressure reducing valve 805 is located in front of the pressure gauge 804 and is installed with a compression fitting. It is used to regulate the fluid pressure in the liquid supply pipe 802 so as to adjust the pressure in the low-pressure zone according to the actual operating conditions. It is highly practical and has a wide range of applications.

[0064] Further, see Figure 3The pump body 300 has an inflow channel 320 connecting the fluid inlet 310 and the liquid storage section 200, and an outflow channel 340 connecting the fluid outlet 330 and the liquid storage section 200, thereby separating the fluid inflow path and the pump outflow path and preventing them from communicating with each other. The pump body 300 has a mounting hole 321 within the inflow channel 320. The end of the pump shaft 530 away from the connecting section 100 is rotatably mounted in this mounting hole 321, and an end bearing 380 is provided between the mounting hole 321 and the pump shaft 530 to allow the pump shaft 530 to rotate more stably and smoothly, improving the pumping performance of the vertical multistage magnetic pump. In this embodiment, the end bearing 380 is secured with small screws to prevent loosening, ensuring the stability of the vertical multistage magnetic pump operation.

[0065] In one specific embodiment, the pump body 300 adopts a two-end flange configuration, with the two flanges being an inlet flange and an outlet flange, and the inlet flange and outlet flange are not interconnected. The fluid inlet 310, inflow channel 320, and third interface 350 are all located on the inlet flange, while the fluid outlet 330, outflow channel 340, and fourth interface 360 ​​are all located on the outlet flange. When the vertical multistage magnetic pump is running, the fluid is drawn in through the inlet flange, pressurized by the impeller 510, and then output to the storage section 200, before being discharged through the outlet flange.

[0066] Preferably, the mounting hole 321 is connected to a second cooling return pipe 803, and the end of the second cooling return pipe 803 away from the mounting hole 321 is connected to the outflow channel 340. In this way, the pressure difference allows the fluid in the outflow channel 340 to flow to the end bearing 380 and then back to the inflow channel 320, achieving a small-scale fluid circulation, which is more conducive to the self-balancing of the axial force inside the vertical multistage magnetic pump. Simultaneously, during the fluid return process, the end bearing 380 can also be cooled and lubricated. The structure is rationally designed and has a high utilization rate, which is beneficial for the long-term stable operation of the vertical multistage magnetic pump and allows for a smaller size design, making it highly practical.

[0067] Specifically, the two ends of the second cooling return pipe 803 are respectively connected to the assembly hole 321 and the outflow channel 340 through connector assemblies to achieve an overall connection. At the same time, O-rings and gaskets are used to form an overall internal seal. Furthermore, the interface structures on the pump body 300 used to connect the first cooling return pipe 801, the second cooling return pipe 803, and the liquid supply pipe 802 (e.g., the third interface 350, the fourth interface 360, the assembly hole 321, etc.) are all threaded interfaces, which makes the connection more secure and is conducive to the long-term stable circulation of fluid.

[0068] In one example embodiment, there are multiple impellers 510, forming a multi-stage impeller 510 to meet the performance requirements of low flow rate and high head. Furthermore, the impeller 510 assembly also includes guide vanes 520 corresponding to the impellers 510, and multiple spacer plates 540 and multiple spacer sleeves 550 are fitted onto the pump shaft 530. The guide vanes 520, impellers 510, spacer sleeves 550, and spacer plates 540 are installed sequentially. The guide vanes 520 and spacer plates 540 are installed with a stop fit and a static seal is formed using O-rings; the impellers 510 and spacer sleeves 550 are connected by a key for transmission, and double nuts and anti-loosening washers are used at the shaft ends for tightening and anti-loosening.

[0069] Specifically, in the multi-stage impeller 510, the impeller 510 closest to the pump body 300 is the first-stage impeller, and the impeller 510 furthest from the pump body 300 is the last-stage impeller. Similarly, in the multi-stage guide vanes 520, the guide vane 520 closest to the pump body 300 is the first-stage guide vane, and the guide vane 520 furthest from the pump body 300 is the last-stage guide vane. And so on, the partition plate 540 and partition sleeve 550 closest to the pump body 300 are the first-stage partition plate and first-stage partition sleeve, respectively, while the partition plate 540 and partition sleeve 550 furthest from the pump body 300 are the last-stage partition plate and last-stage partition sleeve, respectively. The last-stage guide vane serves as the final fluid outlet. Fluid enters the storage section 200 from the fluid inlet 310, is pressurized by the multi-stage impeller 510, and is then output to the fluid outlet 330 by the last-stage guide vane.

[0070] In this embodiment, see Figure 3 and Figure 4 The connecting section 100 has a final stage guide vane mounting hole 170 on the side facing the liquid storage section 200. A countersunk screw passes through the final stage guide vane mounting hole 170 to fix the final stage guide vane to the connecting section 100. The pump body 300 has a first stage spacer mounting position 370 for mounting the first stage spacer.

[0071] Specifically, see Figure 1 The magnetic coupling includes an outer magnetic assembly 610, an inner magnetic assembly 620, and an isolation sleeve 630. The outer magnetic assembly 610 is drivenly connected to the power output shaft 410, and the inner magnetic assembly 620 is drivenly connected to the pump shaft 530. The isolation sleeve 630 is installed on the side of the connecting section 100 away from the liquid storage section 200 to isolate the outer magnetic assembly 610 and the inner magnetic assembly 620. The outer magnetic assembly 610 is connected to the motor shaft via a flat key and secured with a set screw. The connecting section 100 has an isolation sleeve mounting hole 120, through which bolts pass to secure the isolation sleeve 630 to the connecting section 100, forming a static seal with the help of a sealing gasket.

[0072] This embodiment uses a magnetic coupling and utilizes the isolation sleeve 630 to form a fully enclosed pump head structure, completely separating the pump head from the motor, making it safer and more reliable. It can transport new energy media such as methanol, which have strong acid, strong alkali, flammable and explosive characteristics.

[0073] In one specific embodiment, the vertical multistage magnetic pump further includes a mounting bracket 701, which is mounted on the connecting section 100 and sleeved on the magnetic coupling for connecting the drive mechanism 400. Specifically, the connecting section 100 has mounting holes 150 for the mounting bracket, through which bolts pass to secure the drive mechanism 400 to the mounting bracket 701. The drive mechanism 400 includes a motor with a power output shaft 410 as described above. The mounting bracket 701 is connected to the motor via a stop fit and bolts. Preferably, a three-phase asynchronous motor is used, as it is a standard motor capable of stable speed. In practical use, different models of three-phase asynchronous motors can be replaced according to the required performance of the vertical multistage magnetic pump; this replacement can be achieved simply by using a mounting bracket 701 with the corresponding interface.

[0074] Specifically, see Figures 2 to 4 The lower part of the connecting section 100 (the side away from the drive mechanism 400) and the upper part of the pump body 300 (the side facing the connecting section 100) are both provided with liquid storage section assembly guide grooves, which are used to install the liquid storage section 200 using a stop fit. A sealing gasket is used in conjunction with the liquid storage section assembly guide groove to achieve a seal of the fluid within the liquid storage section 200. Several tension bolt mounting holes 160 are arranged on the flat surface of the lower part of the connecting section 100 for passing tension bolts to tighten and seal the pump body 300 below.

[0075] Further, see Figure 1 and Figure 2 A bearing housing 640 is installed on the side of the connecting section 100 away from the liquid storage section 200. Specifically, a bearing housing mounting hole 130 is provided on the connecting section 100, and bolts pass through the bearing housing mounting hole 130 to fix the bearing housing 640 and the connecting section 100. A bearing assembly is provided inside the bearing housing 640, and the pump shaft 530 passes through the bearing assembly. In addition, there are two flow holes 641 in the bearing housing 640, which are respectively connected to the first interface 110 and the second interface 120. When the vertical multistage magnetic pump is running, the fluid enters the area covered by the isolation sleeve 630 from the outlet flange through the second interface 120 in the connecting section 100 and the flow holes 641 in the bearing housing 640, providing cooling for the magnetic coupling and the bearing assembly, and also providing lubricating medium for the bearing assembly, so that the pump shaft 530 can rotate more stably and smoothly. Conversely, the fluid flowing into the area covered by the isolation sleeve 630 flows back to the inlet flange of the pump body 300 through the flow hole 641 in the bearing housing 640 and the first interface 110 in the connecting section 100.

[0076] In this embodiment, see Figure 2 The connecting section 100 is provided with different stepped end faces for placing and installing the isolation sleeve 630, bearing seat 640 and mounting bracket 701, which are used in conjunction with sealing gaskets and O-rings to form a seal.

[0077] In one specific embodiment, see Figure 1 The bearing assembly includes an upper bearing 650 and a lower bearing 660, which are sequentially installed on a bearing housing 640, and a bushing 670 is provided between the pump shaft 530 and the upper bearing 650 and the lower bearing 660. The upper bearing 650 and the lower bearing 660 are installed on the bearing housing 640 through a locating fit and are fixed with set screws.

[0078] The vertical multistage magnetic pump also includes an upper thrust plate 680 and a balancing assembly 690. The upper thrust plate 680 is sleeved on the pump shaft 530 and located above the upper bearing 650. The balancing assembly 690 includes a lower thrust plate and a balancing drum connected to each other. Both the lower thrust plate and the balancing drum are sleeved on the pump shaft 530 and are prevented from rotating by pins. The lower thrust plate is located below the lower bearing 660, and the balancing drum is located below the lower thrust plate.

[0079] In multistage centrifugal pumps, due to the inconsistent gas forces on both sides of each impeller 510, the rotor experiences a resultant force pointing towards the low-pressure end; this resultant force is called axial force. Axial force is detrimental to the normal operation of the pump, causing the rotor to shift to one side and potentially colliding with the casing, leading to an accident. Therefore, an upper thrust plate 680 and a lower thrust plate are needed to balance this axial force.

[0080] When the axial force of the vertical multistage magnetic pump is downward, the end faces of the upper thrust plate 680 and the upper bearing 650 come into contact, achieving downward thrust of the entire rotor assembly. At this time, a liquid film is formed between the end faces of the upper thrust plate 680 and the upper bearing 650 due to the presence of fluid in the isolation sleeve 630, preventing dry friction. When the axial force of the vertical multistage magnetic pump is upward, the end faces of the lower thrust plate and the lower bearing 660 come into contact, achieving upward thrust of the entire rotor assembly. At this time, a liquid film is also formed between the end faces of the lower thrust plate and the lower bearing 660 due to the presence of fluid in the isolation sleeve 630, thus preventing dry friction.

[0081] In this embodiment, fluid enters the area covered by the isolation sleeve 630 through the second interface 120 in the connecting section 100 and the flow hole 641 in the bearing seat 640 from the outlet flange. While providing cooling for the magnetic coupling, it can also provide lubrication for the contact points between the upper thrust assembly and the end face of the upper bearing 650, as well as the contact points between the lower thrust assembly and the end face of the lower bearing 660.

[0082] Specifically, the inner magnetic assembly 620, the upper thrust plate 680, the bushing 670, and the balance assembly 690 are sequentially installed at one end of the pump shaft 530 and connected by a flat key for transmission. The inner diameter of the final stage guide vane and the inner diameter of the bearing assembly should be within the same dimensional tolerance range to form a throttling gap on the sidewall of the balance assembly 690.

[0083] Preferably, the balance assembly 690 and the upper thrust plate 680 are combined components, made of metal and wear-resistant materials. The metal material of the balance assembly 690 is usually copper, while the metal material of the upper thrust plate 680 can be stainless steel. The wear-resistant material can be selected from materials with high surface hardness and wear resistance, such as cemented carbide and SiC.

[0084] The magnetic pump disclosed in this application has a compact, smooth, and well-integrated structure with complete functions. It is lightweight, small in size, easy to assemble and operate, and its installation method is not limited. It is independent and can be flexibly designed according to actual placement needs. It is versatile and can not only reduce manufacturing costs, but also be portable, reliable in operation, and ensure stable operation during work.

[0085] This application also proposes a combination of a vertical multistage magnetic pump and a media circulation structure, along with a balancing component 690 and an upper thrust plate 680, to achieve internal axial force self-balancing and meet the equipment's requirements for safe and reliable operation. A three-phase asynchronous motor solution is adopted, ensuring stable speed and a universal interface, accommodating model changes under various performance requirements and meeting the pump's diverse functions and operating conditions. The design of the connecting section 100 satisfies structural strength and installation interface requirements for all mating components, while also achieving overall sealing of the pump head and ensuring the installation functionality of the media circulation structure. Through the media circulation structure solution, a three-stage circulation is formed at the supply pipe 802, the first cooling return pipe 801, and the second cooling return pipe 803, achieving the functions of cooling the magnetic coupling, lubricating the bearings, and balancing internal axial forces.

[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0087] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A vertical multistage magnetic pump, characterized in that, include: The connecting section, the liquid storage section, and the pump body are connected in sequence; The pump body has a fluid inlet and a fluid outlet. An impeller assembly is provided in the liquid storage section. The impeller assembly includes an impeller and a pump shaft. The connecting section is used to connect to the drive mechanism, and a magnetic coupling is fixed in the connecting section. The magnetic coupling is used to connect the power output shaft of the drive mechanism and the pump shaft. The operation of the drive mechanism drives the pump shaft to rotate, thereby driving the impeller to rotate, so as to pump the fluid flowing into the liquid storage section from the fluid inlet out through the fluid outlet. The connecting section has a first interface and a second interface that connect to the inside of the magnetic coupling. The first interface is connected to the fluid inlet via a first cooling return pipe, and the second interface is connected to the fluid outlet via a liquid supply pipe. A bearing housing is also installed on the side of the connecting section away from the liquid storage section. A bearing assembly is provided inside the bearing housing, and the pump shaft passes through the bearing assembly. The bearing housing is also provided with two flow holes, which are respectively connected to the first interface and the second interface. The bearing assembly includes an upper bearing and a lower bearing, which are sequentially installed in the bearing housing, and a bushing is provided between the pump shaft and the upper bearing and the lower bearing; The vertical multistage magnetic pump also includes an upper thrust plate and a balancing assembly. The upper thrust plate is sleeved on the pump shaft and located above the upper bearing. The balancing assembly includes a lower thrust plate and a balancing drum connected to each other. Both the lower thrust plate and the balancing drum are sleeved on the pump shaft. The lower thrust plate is located below the lower bearing, and the balancing drum is located below the lower thrust plate. When the vertical multistage magnetic pump is subjected to an overall downward axial force, the end faces of the upper thrust plate and the upper bearing come into contact, and a liquid film is formed between the upper thrust plate and the upper bearing; and when the vertical multistage magnetic pump is subjected to an overall upward axial force, the end faces of the lower thrust plate and the lower bearing come into contact, and a liquid film is formed between the lower thrust plate and the lower bearing.

2. The vertical multistage magnetic pump according to claim 1, characterized in that, The pump body has an inflow channel connecting the fluid inlet and the liquid storage section, and an outflow channel connecting the fluid outlet and the liquid storage section. The pump body has an assembly hole in the inflow channel, and the end of the pump shaft away from the connecting section is rotatably installed in the assembly hole, and an end bearing is provided between the assembly hole and the pump shaft.

3. The vertical multistage magnetic pump according to claim 2, characterized in that, The assembly hole is connected to a second cooling return pipe, and the end of the second cooling return pipe away from the assembly hole is connected to the outflow channel.

4. The vertical multistage magnetic pump according to any one of claims 1-3, characterized in that, The magnetic coupling includes an outer magnetic assembly, an inner magnetic assembly, and an isolation sleeve; The external magnetic assembly is driven to the power output shaft, the internal magnetic assembly is driven to the pump shaft, and the isolation sleeve is installed on the side of the connecting section away from the liquid storage section to isolate the external magnetic assembly and the internal magnetic assembly.

5. The vertical multistage magnetic pump according to claim 4, characterized in that, Also includes: The mounting bracket is installed on the connecting section and sleeved on the magnetic coupling for connecting the drive mechanism.

6. The vertical multistage magnetic pump according to claim 1, characterized in that, The number of impellers is multiple, forming a multi-stage impeller, and the impeller assembly also includes guide vanes corresponding to the impellers; The pump shaft is fitted with multiple spacer plates and multiple spacer sleeves. The guide vanes, impellers, spacer sleeves, and spacer plates are installed sequentially at each stage. The guide vanes and spacer plates are installed via a stop fit, and the impellers and spacer sleeves are connected by a key to achieve power transmission. The connecting section has a final stage guide vane mounting hole on the side facing the liquid storage section for mounting the final stage guide vane. The inner diameter of the final stage guide vane is within the same dimensional tolerance range as the inner diameter of the bearing assembly to form a throttling gap on the side wall of the balance assembly. The pump body has a first stage spacer plate mounting position for mounting the first stage spacer plate.

7. The vertical multistage magnetic pump according to any one of claims 1-3, characterized in that, The first cooling return pipe is equipped with a pressure gauge for monitoring the return pressure; The liquid supply pipe is equipped with a pressure reducing valve and a pressure gauge, the pressure gauge being used to monitor the liquid supply pressure.

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