A centrifugal pump with built-in magnetohydrodynamic seal structure

Abstract

This invention provides a centrifugal pump with a built-in magnetic fluid seal structure, including a pump body, pump shaft, bearings, shaft sleeve, and magnetic fluid seal mechanism. The magnetic fluid seal mechanism includes a magnetic fluid sealing cavity and an annular permanent magnet component. During operation, the annular permanent magnet generates a magnetic field to attract magnetic fluid, forming a sealing barrier to prevent media leakage. A magnetic fluid adsorption reinforcing ring, in conjunction with an axial displacement compensation cavity, compensates for axial displacement of the pump shaft, ensuring stable sealing. An impeller balance hole plug balances the impeller, reducing vibration and noise. Flange joints are provided for the magnetic fluid inlet and outlet for easy maintenance. This centrifugal pump offers excellent sealing performance, adapts to complex working conditions, operates stably, is easy to maintain, has a compact structure, and also boasts environmental and energy-saving advantages. It can effectively improve work efficiency, reduce costs, and extend service life, making it suitable for various scenarios requiring liquid transportation.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal pumps, and more specifically, to a centrifugal pump with a built-in magnetohydrodynamic sealing structure. Background Technology

[0002] Centrifugal pumps, as a common fluid transport device, play a vital role in many fields such as chemical engineering, power generation, and water conservancy. Their working principle primarily relies on the centrifugal force generated by the rotation of the impeller to transport liquids. However, existing centrifugal pumps face numerous problems in actual operation.

[0003] In the operation of centrifugal pumps, axial displacement of the pump shaft is an unavoidable and significant problem. Under the influence of high-speed rotation and various complex forces such as liquid pressure, the pump shaft will experience axial movement. Existing centrifugal pump sealing mechanisms, such as traditional mechanical seals and ordinary magnetohydrodynamic seals, cannot effectively compensate for the axial displacement generated during pump shaft operation.

[0004] While traditional mechanical seals can achieve a certain level of sealing, axial displacement of the pump shaft alters the pressure distribution between the sealing surfaces, potentially leading to increased wear and even leakage. Seal failure not only causes media leakage and environmental contamination but can also trigger equipment malfunctions, disrupting the entire production process.

[0005] The centrifugal pump magnetohydrodynamic sealing device proposed in Chinese Utility Model Patent Application No. CN97213606.1 comprises two inner and outer cylindrical sealing sleeves nested together. The inner diameter of the outer sealing sleeve is equal to the outer diameter of the inner sealing sleeve in a clearance fit. An annular groove is formed on the end face and outer circumference of the inner sealing sleeve, along the circumferential direction. An annular permanent magnet is placed within this annular groove. A ring of magnetohydrodynamic fluid is adsorbed on the circumference of the groove opening containing the annular permanent magnet. This utility model is used for sealing centrifugal pumps, maintaining a magnetohydrodynamic sealing ring in the gap between the centrifugal pump shaft and the housing, thus ensuring a seal between the shaft and the housing during operation.

[0006] However, existing magnetohydrodynamic (MHD) seals primarily utilize the properties of MHDs under a magnetic field to achieve sealing, but they have poor adaptability to axial displacement of the pump shaft. When the axial displacement is too large, the distribution of the MHDs is disrupted, the sealing gap changes, and the sealing effect is compromised. This compromised sealing allows external impurities to easily enter the pump body, accelerating the wear of internal components, increasing the equipment failure rate, and significantly shortening the centrifugal pump's service life. Existing centrifugal pumps lack a MHD adsorption enhancement ring structure that can connect to the axial displacement compensation chamber to effectively compensate for axial displacement of the pump shaft and maintain the stability of the MHD sealing mechanism. Therefore, we propose an improvement: a centrifugal pump with an integrated MHD sealing structure. Utility Model Content

[0007] The purpose of this utility model is to address the problems raised in the existing background technology. To achieve the above-mentioned utility model objective, this utility model provides the following technical solution: a centrifugal pump with a built-in magnetohydrodynamic sealing structure, including a centrifugal pump body, the centrifugal pump body being connected to a pump shaft, the pump shaft being sleeved on the inner ring of a bearing, a bushing being provided on the outer surface of the pump shaft, and the centrifugal pump body being connected to a magnetohydrodynamic sealing mechanism.

[0008] As a preferred technical solution of this utility model, the magnetic fluid sealing mechanism includes a magnetic fluid sealing cavity, an annular permanent magnet, a permanent magnet fixing groove, a magnetic fluid limiting ring, a magnetic fluid injection port, a magnetic fluid discharge port, and a magnetic fluid adsorption enhancement ring.

[0009] As a preferred technical solution of this utility model, an annular permanent magnet is provided in the magnetic fluid sealing cavity, the annular permanent magnet is set in the permanent magnet fixing groove, a magnetic fluid limiting ring is provided on the side of the annular permanent magnet, a magnetic fluid injection port and a magnetic fluid discharge port are provided on the outside of the magnetic fluid sealing cavity, and a magnetic fluid adsorption enhancement ring is provided in the magnetic fluid sealing cavity.

[0010] As a preferred embodiment of this invention, an isolation ring is provided on the side of the magnetohydrodynamic adsorption enhancement ring, and an exhaust valve is provided on the outside of the magnetohydrodynamic adsorption enhancement ring.

[0011] As a preferred technical solution of this utility model, both the front ends of the magnetic fluid injection port and the magnetic fluid discharge port are provided with flange joints, and a channel cavity is provided between the magnetic fluid injection port and the magnetic fluid discharge port.

[0012] As a preferred technical solution of this utility model, the magnetohydrodynamic adsorption enhancement ring is connected to the axial displacement compensation cavity.

[0013] As a preferred technical solution of this utility model, an impeller housing is provided on the side of the axial displacement compensation cavity, and impeller blades are provided inside the impeller housing. The impeller blades are connected to the impeller hub.

[0014] As a preferred technical solution of this utility model, the impeller housing is provided with an impeller balance hole plug.

[0015] As a preferred technical solution of this utility model, a pump body rear cover is provided on the rear side of the centrifugal pump body, a pump body front cover is provided on the front side of the centrifugal pump body, and a pump body mounting foot is provided at the bottom of the centrifugal pump body.

[0016] As a preferred technical solution of this utility model, the pump body mounting feet are connected to the pump body mounting base.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model's magnetic fluid sealing mechanism utilizes the magnetic field generated by a ring-shaped permanent magnet to attract magnetic fluid around the magnetic fluid attraction enhancement ring, forming a tight sealing barrier. This effectively prevents liquid or gas from leaking from the gap between the pump shaft and the centrifugal pump body. Compared with traditional sealing methods, the sealing effect is more reliable, greatly improving the sealing performance and working efficiency of the centrifugal pump.

[0018] This invention relates to a magnetic fluid adsorption enhancement ring connected to an axial displacement compensation cavity, which effectively compensates for the axial displacement generated by the pump shaft during operation. This helps maintain the stability of the magnetic fluid sealing mechanism, prevents damage to the sealing effect due to excessive axial displacement, thereby reducing the failure rate of the equipment and extending the service life of the centrifugal pump.

[0019] The impeller balance hole plug on the impeller housing of this invention can balance the unbalanced forces generated by the impeller during rotation, reducing vibration and noise. Smooth operation not only improves the working efficiency of the centrifugal pump, but also reduces the impact on the surrounding environment, while also reducing equipment wear and improving the reliability and stability of the equipment.

[0020] The exhaust valve located on the outside of the magnetic fluid adsorption enhancement ring of this invention makes it simple and easy to discharge gas from the magnetic fluid sealing cavity. This helps to maintain the pressure balance inside the magnetic fluid sealing cavity, avoids the sealing performance of the magnetic fluid due to gas accumulation, and improves the convenience and effectiveness of maintenance. Attached Figure Description

[0021] Figure 1 This is a structural schematic diagram of the present invention; Figure 2 This is a partial structural schematic diagram of the present invention; Figure 3A schematic diagram of the isolation ring structure provided by this utility model; Figure 4 A schematic diagram of the channel cavity structure provided by this utility model; Figure 5 A schematic diagram of the axial displacement compensation cavity structure provided by this utility model; Figure 6 This is a partial structural diagram of the magnetohydrodynamic sealing mechanism provided by this utility model; Figure 7 This is a schematic diagram of the main structure of the present invention.

[0022] The image shows: 1. Centrifugal pump body; 101. Pump body rear cover; 102. Pump body front cover; 103. Pump body mounting feet; 2. Pump shaft; 3. Shaft sleeve; 4. Bearing; 5. Magnetic fluid sealing mechanism; 501. Magnetic fluid sealing cavity; 502. Annular permanent magnet; 503. Permanent magnet fixing groove; 504. Magnetic fluid limiting ring; 505. Magnetic fluid inlet; 506. Magnetic fluid outlet; 507. Magnetic fluid adsorption reinforcing ring; 6. Isolation ring; 7. Exhaust valve; 8. Flange joint; 9. Channel cavity; 10. Axial displacement compensation cavity; 11. Impeller housing; 12. Impeller blades; 13. Impeller hub; 14. Impeller balance hole plug; 15. Pump body mounting base. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model.

[0024] Therefore, the following detailed description of the embodiments of this utility model is not intended to limit the scope of the claimed utility model, but merely illustrates some embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of this utility model can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0025] Example 1: A centrifugal pump with a built-in magnetic fluid sealing structure includes a centrifugal pump body 1, which is connected to a pump shaft 2. The pump shaft 2 is fitted inside a bearing 4, and a bushing 3 is provided on the outer surface of the pump shaft 2. The centrifugal pump body 1 is connected to a magnetic fluid sealing mechanism 5. The magnetic fluid sealing mechanism 5 includes a magnetic fluid sealing cavity 501, an annular permanent magnet 502, a permanent magnet fixing groove 503, a magnetic fluid limiting ring 504, a magnetic fluid inlet 505, a magnetic fluid outlet 506, and a magnetic fluid adsorption reinforcing ring 507. The annular permanent magnet 502 is disposed inside the magnetic fluid sealing cavity 501 and is located within the permanent magnet fixing groove 503. A magnetic fluid limiting ring 504 is provided on the side of the annular permanent magnet 502. The magnetic fluid inlet 505 and the magnetic fluid outlet 506 are provided on the outside of the magnetic fluid sealing cavity 501. The magnetic fluid adsorption reinforcing ring 507 is provided inside the magnetic fluid sealing cavity 501. An isolation ring 6 is provided on the side of the magnetic fluid adsorption enhancement ring 507, and an exhaust valve 7 is provided on the outside of the magnetic fluid adsorption enhancement ring 507. A flange joint 8 is provided at the front end of both the magnetic fluid injection port 505 and the magnetic fluid discharge port 506, and a channel cavity 9 is provided between the magnetic fluid injection port 505 and the magnetic fluid discharge port 506.

[0026] The magnetohydrodynamic adsorption enhancement ring 507 is connected to the axial displacement compensation cavity 10. An impeller housing 11 is provided on the side of the axial displacement compensation cavity 10, and impeller blades 12 are provided inside the impeller housing 11. The impeller blades 12 are connected to the impeller hub 13. An impeller balance plug 14 is provided on the impeller housing 11. A pump body rear cover 101 is provided on the rear side of the centrifugal pump body 1, a pump body front cover 102 is provided on the front side of the centrifugal pump body 1, and a pump body mounting foot 103 is provided at the bottom of the centrifugal pump body 1. The pump body mounting foot 103 is connected to the pump body mounting base 15.

[0027] The working principle of a centrifugal pump with a built-in magnetic fluid seal structure: When the centrifugal pump starts, the motor drives the pump shaft 2 to rotate, and the impeller blades 12 connected to the pump shaft 2 rotate at high speed. When the impeller blades 12 rotate within the impeller housing 11, they generate centrifugal force on the liquid inside. Under the action of centrifugal force, the liquid is thrown from the center of the impeller to the edge of the impeller, increasing both the flow velocity and pressure. The liquid is then transported to the required location through the flow channel of the pump body. Simultaneously, a low-pressure zone is formed at the center of the impeller, allowing external liquid to continuously enter the impeller through the pump body inlet under atmospheric pressure, thus achieving continuous liquid delivery. The annular permanent magnet 502 within the magnetic fluid seal cavity 501 is a key component; it is installed within the permanent magnet fixing groove 503. The annular permanent magnet 502 can generate a stable magnetic field, providing the basic conditions for the adsorption and sealing of the magnetic fluid.

[0028] Magnetic fluid is injected into the magnetic fluid sealing cavity 501 through the magnetic fluid injection port 505. The magnetic fluid limiting ring 504 is disposed on the side of the annular permanent magnet 502. Its function is to limit the flow range of the magnetic fluid, ensure that the magnetic fluid plays a sealing role in a proper position, and prevent the magnetic fluid from flowing randomly and affecting the sealing effect.

[0029] The magnetic fluid adsorption enhancement ring 507 installed inside the magnetic fluid sealing cavity 501 can enhance the adsorption force on the magnetic fluid. Under the action of the magnetic field generated by the annular permanent magnet 502, the magnetic fluid is adsorbed around the magnetic fluid adsorption enhancement ring 507, forming a sealing barrier to prevent liquid or gas from leaking from the gap between the pump shaft 2 and the centrifugal pump body 1.

[0030] When the magnetic fluid needs to be replaced or maintained, it can be discharged through the magnetic fluid outlet 506. The channel cavity 9 provided between the magnetic fluid inlet 505 and the magnetic fluid outlet 506 facilitates the smooth injection and discharge of the magnetic fluid. An exhaust valve 7 is provided on the outside of the magnetic fluid adsorption reinforcing ring 507, which is used to discharge the gas in the magnetic fluid sealing cavity 501, ensuring the pressure balance inside the magnetic fluid sealing cavity 501 and preventing the sealing performance of the magnetic fluid from being affected by gas accumulation.

[0031] The magnetic fluid adsorption enhancement ring 507 is connected to the axial displacement compensation chamber 10. During the operation of the centrifugal pump, the pump shaft 2 may experience axial displacement due to rotation and liquid flow. The axial displacement compensation chamber 10 can compensate for this axial displacement, ensuring the stability and reliability of the magnetic fluid sealing mechanism 5 and preventing damage to the magnetic fluid sealing effect due to excessive axial displacement.

[0032] The impeller blades 12 inside the impeller housing 11 are connected to the impeller hub 13. When the impeller rotates, a certain unbalanced force is generated. The impeller housing 11 is provided with an impeller balance hole plug 14, which can play a role in balancing the impeller. By adjusting the balance of the impeller, vibration and noise are reduced, and the operating efficiency and service life of the centrifugal pump are improved.

[0033] A pump body mounting foot 103 is provided at the bottom of the centrifugal pump body 1. The pump body mounting foot 103 is connected to the pump body mounting base 15, which securely installs the centrifugal pump in the working position and provides stable support for the normal operation of the centrifugal pump. At the same time, a pump body rear cover 101 is provided on the rear side of the centrifugal pump body 1, and a pump body front cover 102 is provided on the front side. They can protect the internal components of the centrifugal pump and prevent external dust and debris from entering the pump body and affecting the performance of the centrifugal pump.

[0034] The working process of the centrifugal pump with built-in magnetic fluid sealing structure: The centrifugal pump body 1 is securely installed on the pump body mounting base 15 via the pump body mounting feet 103, ensuring that the entire device is in a stable state. The external magnetic fluid supply device and the collection device are connected respectively through the flange joints 8 at the front end of the magnetic fluid inlet 505 and the magnetic fluid outlet 506.

[0035] Connect the centrifugal pump to the motor drive device via pump shaft 2 to ensure smooth power transmission. Open the valve of the magnetic fluid injection port 505 and inject an appropriate amount of magnetic fluid into the magnetic fluid sealing cavity 501 through the external magnetic fluid supply device. During injection, the magnetic fluid is constrained in a suitable position by the magnetic fluid limiting ring 504. Simultaneously, the magnetic fluid adsorption enhancement ring 507, under the action of the magnetic field generated by the annular permanent magnet 502, enhances the adsorption of the magnetic fluid, causing the magnetic fluid to surround the magnetic fluid adsorption enhancement ring 507, initially forming a sealing barrier. Open the exhaust valve 7 outside the magnetic fluid adsorption enhancement ring 507 to discharge the gas inside the magnetic fluid sealing cavity 501, ensuring pressure balance within the cavity and creating favorable conditions for subsequent sealing work.

[0036] The motor is started, driving the pump shaft 2 to rotate. The pump shaft 2 is fitted inside the bearing 4, and the bushing 3 protects the outer surface of the pump shaft 2. As the pump shaft 2 rotates, the impeller blades 12 connected to the pump shaft 2 rotate at high speed within the impeller housing 11. The rotation of the impeller blades 12 generates centrifugal force on the liquid, throwing it from the center of the impeller to the edge. The liquid's velocity and pressure increase during this process, and it is then transported to the desired location through the flow channel of the centrifugal pump body 1. Because a low-pressure zone is formed after the liquid at the center of the impeller is thrown out, external liquid continuously enters the impeller through the pump body inlet under atmospheric pressure, achieving continuous liquid delivery.

[0037] During the operation of the centrifugal pump, the pump shaft 2 may experience axial displacement due to rotation and liquid flow. The magnetohydrodynamic adsorption reinforcing ring 507 is connected to the axial displacement compensation chamber 10, which compensates for the axial displacement of the pump shaft 2, ensuring the stability of the magnetohydrodynamic sealing mechanism 5 and maintaining the effectiveness of the magnetohydrodynamic seal. The unbalanced force generated when the impeller rotates may affect the operation of the centrifugal pump. The impeller balance hole plug 14 on the impeller housing 11 serves to balance the impeller. By adjusting the impeller balance, vibration and noise are reduced, improving the operating efficiency and reliability of the centrifugal pump.

[0038] Continuously observe the sealing effect of the magnetic fluid sealing mechanism 5 and check for any liquid or gas leaks. If a decrease in sealing effect is found, it may be necessary to check the amount of magnetic fluid, the adsorption condition of the magnetic fluid adsorption reinforcing ring 507, and the status of the magnetic fluid limiting ring 504. Monitor the inlet and outlet pressures and temperatures of the centrifugal pump to ensure they are within the normal operating range. Abnormal pressure or temperature may indicate a malfunction in the centrifugal pump, requiring immediate shutdown and inspection.

[0039] Depending on the usage of the magnetic fluid, old magnetic fluid is periodically discharged through the magnetic fluid outlet 506, and new magnetic fluid is injected through the magnetic fluid inlet 505 to ensure the sealing performance of the magnetic fluid. The motor is then turned off, stopping the rotation of the pump shaft 2, and the impeller blades 12 also stop rotating, ending the liquid transport process. The magnetic fluid in the magnetic fluid sealing cavity 501 is discharged through the magnetic fluid outlet 506 for cleaning or replacement maintenance. Simultaneously, all components of the centrifugal pump are inspected for damage or wear to prepare for the next operation.

[0040] The above embodiments are only used to illustrate the present utility model and are not intended to limit the technical solutions described in the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, the present utility model is not limited to the specific embodiments described above. Therefore, any modifications or substitutions to the present utility model, and all technical solutions and improvements that do not depart from the spirit and scope of the utility model, are covered within the scope of the claims of the present utility model.

Claims

1. A centrifugal pump with a built-in magnetohydrodynamic seal structure, comprising a centrifugal pump body (1), characterized in that, The centrifugal pump body (1) is connected to the pump shaft (2), the pump shaft (2) is sleeved on the inner ring of the bearing (4), and the outer surface of the pump shaft (2) is provided with a bushing (3). The centrifugal pump body (1) is connected to the magnetic fluid sealing mechanism (5), the magnetic fluid sealing mechanism (5) includes a magnetic fluid sealing cavity (501), an annular permanent magnet (502), a permanent magnet fixing groove (503), a magnetic fluid limiting ring (504), a magnetic fluid injection port (505), a magnetic fluid discharge port (506), and a magnetic fluid adsorption enhancement ring (507).

2. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 1, characterized in that, The magnetic fluid sealing cavity (501) is provided with an annular permanent magnet (502), which is located in a permanent magnet fixing groove (503). A magnetic fluid limiting ring (504) is provided on the side of the annular permanent magnet (502). A magnetic fluid injection port (505) and a magnetic fluid discharge port (506) are provided on the outside of the magnetic fluid sealing cavity (501). A magnetic fluid adsorption enhancement ring (507) is provided inside the magnetic fluid sealing cavity (501).

3. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 2, characterized in that, An isolation ring (6) is provided on the side of the magnetic fluid adsorption enhancement ring (507), and an exhaust valve (7) is provided on the outside of the magnetic fluid adsorption enhancement ring (507).

4. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 3, characterized in that, The front ends of the magnetic fluid injection port (505) and the magnetic fluid discharge port (506) are both provided with flange joints (8), and a channel cavity (9) is provided between the magnetic fluid injection port (505) and the magnetic fluid discharge port (506).

5. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 4, characterized in that, The magnetohydrodynamic adsorption enhancement ring (507) is connected to the axial displacement compensation cavity (10).

6. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 5, characterized in that, The axial displacement compensation cavity (10) is provided with an impeller housing (11) on its side, and an impeller blade (12) is provided inside the impeller housing (11). The impeller blade (12) is connected to the impeller hub (13).

7. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 6, characterized in that, The impeller housing (11) is provided with an impeller balance hole plug (14).

8. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 7, characterized in that, The centrifugal pump body (1) is provided with a pump body rear cover (101) on the rear side, a pump body front cover (102) on the front side, and a pump body mounting foot (103) on the bottom of the centrifugal pump body (1).

9. A centrifugal pump with a built-in magnetohydrodynamic seal structure according to claim 8, characterized in that, The pump body mounting foot (103) is connected to the pump body mounting base (15).

Images