Magnetic suspension mechanical sealing device

Abstract

A magnetic suspension mechanical sealing device comprises a shell (1), a moving ring (6) and a static ring (7), the moving ring (6) and the static ring (7) are contained in the shell (1), a moving ring sealing ring (5) is arranged between the moving ring (6) and a rotating shaft, a static ring sealing ring (8) is arranged between the static ring (7) and an installation part of corresponding equipment, and a sealing face is formed on the contact face between the moving ring (6) and the static ring (7). Wherein a pair of movable ring lower magnetic steel (4) and movable ring upper magnetic steel (3) is arranged above the upper surface, deviating from the static ring (7), of the movable ring (6), and the magnetic polarities of the opposite surfaces of the movable ring lower magnetic steel (4) and the movable ring upper magnetic steel (3) are the same, so that the sealing surface between the movable ring (6) and the static ring (7) is sealed. The movable ring upper magnetic steel and the movable ring lower magnetic steel are arranged above the movable ring, the movable ring is pressed towards the static ring through magnetic repulsive force between the movable ring upper magnetic steel and the movable ring lower magnetic steel, good sealing between the movable ring and the static ring is achieved, mechanical sealing reliability is improved, the service life is prolonged, and maintenance is more convenient.

Description

Technical Field

[0001] The utility model relates to the field of mechanical seals, and particularly to a magnetic levitation mechanical seal device, which realizes reliable sealing between a dynamic ring and a static ring by using the principle of magnetic field repulsion of the same sex to replace the ordinary mechanical seal in the prior art. The magnetic levitation mechanical seal device of the utility model can be widely applied to submersible pumps, deep well pumps, pipeline pumps, sewage pumps and other fluid equipment. Prior Art

[0002] In the prior art, mechanical seals are adopted as sealing components on fluid equipment such as submersible pumps, deep well pumps, pipeline pumps, sewage pumps, etc. For traditional mechanical seals, the mechanical seal between the dynamic ring and the static ring is mainly realized by relying on the spring pressure to squeeze the dynamic ring and the static ring.

[0003] Figure 1 Shown is a traditional mechanical seal device, which includes a housing 1, a dynamic ring 6, a static ring 7, a pressure spring 10, a dynamic ring pressing plate 11, a dynamic ring sealing ring 5, a static ring sealing ring 8, a main shaft locking screw 2, etc. Among them, the pressure spring 10 is accommodated in the axial groove of the housing 1, and its spring tension acts on the dynamic ring pressing plate 11 above the dynamic ring 6. Through the dynamic ring pressing plate 11, the dynamic ring 6 is pressed against the static ring 7, and a sealing surface is formed on the contact surface between the dynamic ring 6 and the static ring 7 to realize the seal between the dynamic ring 6 and the static ring 7, so as to isolate the external water quality from the inside of the mechanical equipment to avoid mechanical equipment failure due to water ingress.

[0004] Again, Figure 2 Shown is a utility model patent with an application number of 201220289899.X, an application date of June 20, 2012, an invention name of "Submersible Pump Mechanical Seal Device", a patentee of "Chengdu Kexing Sealing Technology Co., Ltd.", and an authorization announcement date of March 20, 2013. The submersible pump mechanical seal device includes a housing 1 (i.e., a pump body), a dynamic ring 6, a static ring 7, a dynamic ring sealing ring 5, a static ring sealing ring 8, a rotating shaft 9, a pressure spring 10, a dynamic ring pressing plate 11 (i.e., a push ring), a spring seat 12, an impeller 13, a transmission pin 14 and a locking and positioning spring 15. Among them, the static ring sealing ring 8 is fixed between the static ring 7 and the housing 1, the static ring 7 is hinged to the dynamic ring 6, the locking and positioning spring 15 is arranged in the card slot on the impeller 13 and connected to the dynamic ring 6, the dynamic ring 6 is connected to the dynamic ring pressing plate 11 through the dynamic ring sealing ring 5, the dynamic ring pressing plate 11 is connected to the spring seat 12 through the pressure spring 10, the spring seat 12 is connected to the impeller 13 through the transmission pin 14, and the impeller 13 is installed on the rotating shaft 9 of the submersible pump. The submersible pump mechanical seal device prevents leakage by pressing the static ring 7 and the dynamic ring 6 through the pressure spring 10, has little influence on the shaft and the medium, and has the advantages of simple structure, low cost and convenient installation.

[0005] Again, Figure 3Shown is a utility model patent with the application number 201720675489.1, the application date of June 12, 2017, the invention title of "A Sealing Structure in a Deep Well Pump", the patentee of "Wenling Hand Pump Industry Co., Ltd.", and the authorization announcement date of January 5, 2018. The sealing structure in this deep well pump includes a seal seat 16, a rotating shaft 9 (i.e., the motor shaft), and a shaft sleeve 17 arranged on the rotating shaft. A dynamic ring seat 18, a dynamic ring 6, a static ring 7, and a static ring seat 19 are successively arranged in the shaft sleeve 17. A push ring (i.e., the dynamic ring pressing plate 11) is arranged on the static ring seat 19. A guide sleeve 20 is arranged in the seal seat 16. A pressure spring 10 is arranged between the push ring and the guide sleeve 20. A gland 21 is also arranged on the seal seat 16. An anti-rotation pin 22 for preventing the guide sleeve 20 from rotating is arranged between the gland 21 and the guide sleeve 20. This traditional mechanical sealing structure has relatively stable performance and good sealing effect.

[0006] For the above-mentioned traditional mechanical seal devices, they all rely on the stretching force of the pressure spring to urge the dynamic ring to press against the static ring for sealing. Their common defect is that when the pressure spring is corroded by corrosive fluid or damaged by external force, it is extremely easy to be corroded by the fluid or damaged, or the pressure spring is prone to fatigue due to long-term use, the stretching force of the pressure spring weakens or even fails, resulting in a gap in the sealing surface, causing leakage of the sealing surface, so that the corresponding equipment (such as a water pump, etc.) will not be able to work normally, and further will affect the service life of the equipment. It can be seen that these traditional mechanical seal devices not only have poor reliability and short service life, but also are inconvenient to repair, resulting in high use costs for the corresponding equipment.

[0007] In view of the problems and defects existing in the above-mentioned prior art, the inventor has conducted more than two years of research and countless tests on the structure of mechanical seals in production practice, and finally found a solution. After testing the test products, the technical effects are good. Utility Model Content

[0008] In order to completely solve the above-mentioned technical problems existing in the traditional prior art, the present utility model provides a magnetic levitation mechanical seal device, aiming to improve the reliability and stability of the mechanical seal, extend the service life of the product, keep the equipment in the best working state all the time, and be convenient to repair and reduce the use cost by changing the structural form for realizing the seal between the dynamic ring and the static ring.

[0009] The technical solution provided by the present utility model to solve the above-mentioned technical problems is as follows:

[0010] A magnetic levitation mechanical seal device includes a housing, a rotating ring and a stationary ring; the rotating ring and the stationary ring are accommodated in the housing, the rotating shaft sequentially passes through the stationary ring, the rotating ring and the main shaft hole of the housing, a rotating ring sealing ring is provided between the rotating ring and the rotating shaft, a stationary ring sealing ring is provided between the stationary ring and the installation component of the corresponding equipment, and a sealing surface is formed on the contact surface between the rotating ring and the stationary ring; it is characterized in that: a lower rotating ring magnet and an upper rotating ring magnet are provided above the upper surface of the rotating ring facing away from the stationary ring, and the magnetic polarities of the opposite surfaces of the lower rotating ring magnet and the upper rotating ring magnet are the same; a radial locking member is provided at the upper end of the housing, and the housing is locked with the rotating shaft by using this locking member.

[0011] Further, the materials of the upper rotating ring magnet and the lower rotating ring magnet are both magnets, selected from alnico magnets, ferrite magnets or neodymium iron boron magnets.

[0012] Further, the designed range of the magnetic flux density of the magnet is 1.0 - 300T, and it can be selected as 1.0 - 50T, 50 - 100T, 100 - 150T, 150 - 200T, 200 - 250T, 250 - 300T, including the end values of the above ranges; it can also be selected as the intermediate values 25T, 75T, 125T, 175T, 225T, 275T of the above ranges.

[0013] Further, the repulsive force range between the upper rotating ring magnet and the lower rotating ring magnet is 100 - 50000N, and it can be selected as 100 - 2500N, 2500 - 5000N, 5000 - 7500N, 7500 - 10000N, 10000 - 12500N, 12500 - 15000N, 15000 - 17500N, 17500 - 20000N, 20000 - 22500N, 22500 - 25000N, 25000 - 27500N, 27500 - 30000N, 30000 - 32500N, 32500 - 35000N, 35000 - 37500N, 37500 - 40000N, 40000 - 42500N, 42500 - 45000N, 45000 - 47500N, 47500 - 50000N, including the end values of the above ranges; it can also be selected as the intermediate values 1250N, 3750N, 6250N, 8750N, 11250N, 13750N, 16250N, 18750N, 21250N, 23750N, 26250N, 28750N, 31250N, 33750N, 36250N, 38750N, 41250N, 43750N, 46250N, 48750N of the above ranges.

[0014] Further, the suspension air gap between the upper magnetic steel and the lower magnetic steel on the moving ring is generally 0.2 - 3 mm, preferably 0.3 - 2 mm, more preferably 0.5 - 1.2 mm, and most preferably 0.3 - 0.5 mm.

[0015] Further, the surfaces of the upper magnetic steel and the lower magnetic steel on the moving ring are both covered with a magnetic steel protective layer, and the magnetic steel protective layer is an electroplated nickel layer, zinc layer, gold layer, or chromium layer; or, the magnetic steel protective layer is a sprayed epoxy resin layer.

[0016] Further, the magnetic steel is made by splicing and assembling laminated, assembled, or slotted magnetic steel sheets.

[0017] Further, the upper magnetic steel and the lower magnetic steel on the moving ring are demagnetized.

[0018] Further, the moving ring uses a stainless - steel main body inlaid with a high - density composite alloy material, and the static ring uses a high - density hot - pressed composite material, both selected from composite low - temperature silicon carbide, silicon nitride, boron carbide, antimony - impregnated graphite, YG5, or W1.

[0019] Further, the materials of the moving - ring seal ring and the static - ring seal ring are elastomers or rubbers, selected from polytetrafluoroethylene, nitrile rubber, fluororubber, silicone rubber, or ordinary rubber.

[0020] The magnetic - levitation mechanical seal device provided by the present utility model realizes good sealing between the moving ring and the static ring by arranging an upper magnetic steel and a lower magnetic steel above the moving ring and using the magnetic repulsive force between the upper magnetic steel and the lower magnetic steel on the moving ring to press the moving ring against the static ring. This not only improves the reliability of the mechanical seal but also extends the service life of the product and makes maintenance more convenient. Description of the Drawings

[0021] Figure 1 is a traditional mechanical seal device in the prior art;

[0022] Figure 2 is a mechanical seal device of a submersible pump in the prior art;

[0023] Figure 3 is a sealing structure in a deep - well pump in the prior art;

[0024] Figure 4 is a structural schematic diagram of the magnetic - levitation mechanical seal device of the present utility model.

[0025] In the figure, the corresponding relationship between the reference numerals and the components, assemblies, and structures:

[0026] 1 - Outer shell, 2 - Locking screw, 3 - Upper magnet on the moving ring, 4 - Lower magnet on the moving ring, 5 - Sealing ring on the moving ring, 6 - Moving ring, 7 - Static ring, 8 - Sealing ring on the static ring, 9 - Rotating shaft, 10 - Pressure spring, 11 - Pressure plate on the moving ring, 12 - Spring seat, 13 - Impeller, 14 - Transmission pin, 15 - Locking and positioning spring, 16 - Sealing seat, 17 - Bush, 18 - Seat of the moving ring, 19 - Seat of the static ring, 20 - Flow guide sleeve, 21 - gland, 22 - Anti - rotation pin. Detailed implementation mode

[0027] The following combines the attached drawings to further elaborate and describe specific embodiments of the present utility model in detail.

[0028] As Figure 4 shown, the magnetic levitation mechanical seal device of the present utility model includes an outer shell 1, a moving ring 6 and a static ring 7. Among them, the moving ring 6 and the static ring 7 are accommodated in the outer shell 1 (the outer shell can be the pump body of a pump or the housing of similar equipment, etc.). The rotating shaft (such as a motor shaft, etc.) sequentially passes through the static ring 7, the moving ring 6 and the main shaft hole of the outer shell 1. A sealing ring 5 on the moving ring is provided between the moving ring 6 and the rotating shaft, and a sealing ring 8 on the static ring is provided between the static ring 7 and the installation component of the corresponding equipment (for example, the housing or bearing seat of a submersible pump motor, etc.). In this way, a sealing surface is formed on the contact surface between the moving ring 6 and the static ring 7. A radial locking screw hole is also provided at the upper end of the outer shell 1, and the outer shell 1 is locked with the rotating shaft by using the locking screw 2.

[0029] The improvement of the magnetic levitation mechanical seal device of the present utility model mainly lies in: above the upper surface of the moving ring 6 facing away from the static ring 7, a lower magnet 4 on the moving ring and an upper magnet 3 on the moving ring are provided. The magnetic polarities of the opposite surfaces of the lower magnet 4 on the moving ring and the upper magnet 3 on the moving ring are the same (both N - poles or both S - poles). A strong relative repulsive force is generated between the lower magnet 4 on the moving ring and the upper magnet 3 on the moving ring. The upper magnet 3 on the moving ring is in a suspended state, and the repulsive force is transmitted to the moving ring 6 through the lower magnet 4 on the moving ring, so that the moving ring 6 is pressed against the static ring 7, and a sealing surface is formed on the contact surface between the moving ring 6 and the static ring 7, realizing the seal between the moving ring 6 and the static ring 7, thereby isolating the external fluid medium (such as water) from the inside of the outer shell (such as the pump body) to avoid water ingress into the outer shell (pump body) and cause failures.

[0030] The materials of the upper magnet 3 on the moving ring and the lower magnet 4 on the moving ring are both selected as magnets (permanent magnets). Using this permanent magnetic material of the magnet can effectively avoid the occurrence of failure caused by demagnetization of general magnets or power - off of electromagnets, etc.

[0031] The magnet adopted in the present utility model is a super - hard permanent magnetic alloy (permanent magnet), selected from alnico magnets, ferrite magnets or neodymium - iron - boron magnets, and the neodymium - iron - boron magnets are further divided into sintered neodymium - iron - boron and bonded neodymium - iron - boron.

[0032] As a most preferred technical solution of the present utility model, the upper magnet 3 and the lower magnet 4 on the moving ring are made of neodymium iron boron magnets to generate strong magnetic force, and the magnetic induction intensities of the two should be equal so as to achieve the balance of axial repulsive force, enabling the lower magnet 4 on the moving ring to be continuously and tightly pressed on the moving ring 6 for a long time and in a balanced manner, and making the axial position of the rotating shaft fixed and not deviated, so as to achieve good sealing.

[0033] For example, specifically, the present utility model can use neodymium iron boron magnets with the following grades and properties to manufacture the upper magnet and the lower magnet on the moving ring:

[0034]

[0035]

[0036] For example, the maximum working temperatures of N35H, N35SH, and N35UH can reach 120°C, 150°C, and 180°C - 400°C respectively.

[0037] Note: (1) Each grade such as N35 - N52, N56, N62, etc. is applicable to the present utility model, not limited to the grades listed in the above table.

[0038] (2) Among each grade, six types of products with low coercivity N, medium coercivity M, high coercivity H, extra high coercivity SH, ultra high coercivity UH, and extremely high coercivity EH are all applicable to the present utility model.

[0039] In the present utility model, the surfaces of the upper magnet and the lower magnet on the moving ring are both covered with a magnet protective layer to protect the upper magnet and the lower magnet on the moving ring from being damaged by collision. Surface coating treatment is carried out on the upper magnet and the lower magnet on the moving ring, such as electroplating nickel (Ni), zinc (Zn), gold (Au), chromium (Cr), or spraying (coating) epoxy resin (Epoxy) on their surfaces, etc., to form their respective magnet protective layers.

[0040] The repulsive force range between the upper magnet 3 and the lower magnet 4 on the moving ring can be very wide and is designed to be 100 - 50000 N according to the usage environment of the magnetic levitation mechanical seal device and the requirements of the equipment used. For example, it can be selected as 100 - 2500 N, 2500 - 5000 N, 5000 - 7500 N, 7500 - 10000 N, 10000 - 12500 N, 12500 - 15000 N, 15000 - 17500 N, 17500 - 20000 N, 20000 - 22500 N, 22500 - 25000 N, 25000 - 27500 N, 27500 - 30000 N, 30000 - 32500 N, 32500 - 35000 N, 35000 - 37500 N, 37500 - 40000 N, 40000 - 42500 N, 42500 - 45000 N, 45000 - 47500 N, 47500 - 50000 N, including the endpoint values of the above ranges. And it can also be selected as the midpoint values of the above ranges. For example, 1250 N, 3750 N, 6250 N, 8750 N, 11250 N, 13750 N, 16250 N, 18750 N, 21250 N, 23750 N, 26250 N, 28750 N, 31250 N, 33750 N, 36250 N, 38750 N, 41250 N, 43750 N, 46250 N, 48750 N, etc.

[0041] The design range of the magnetic flux density of the magnet is generally selected as 1.0 - 300 T and can be selected as 1.0 - 50 T, 50 - 100 T, 100 - 150 T, 150 - 200 T, 200 - 250 T, 250 - 300 T, including the endpoint values of the above ranges. And it can also be selected as the midpoint values of the above ranges, such as 25 T, 75 T, 125 T, 175 T, 225 T, 275 T, etc.

[0042] There should be an appropriate gap (levitation air gap) between the upper magnet 3 and the lower magnet 4 on the moving ring. The size of the levitation air gap needs to be selected and designed according to parameters such as the product specifications and models (for example, the flow rate, head, motor power, and maximum outer diameter of the pump body) of the product. Generally, it is 0.2 - 3 mm, can be selected as 0.3 - 2 mm, preferably 0.5 - 1.2 mm, and most preferably 0.3 - 0.5 mm. Since the upper magnet on the moving ring is in a levitation state relative to the lower magnet on the moving ring, the rotational frictional resistance and frictional loss between the two can be eliminated, mutual frictional wear can be avoided, the service life of the upper magnet and the lower magnet on the moving ring as well as the product can be extended, and the operating cost of the equipment can be reduced.

[0043] After long-term use, the permanent magnet may be partially ineffective. Generally, the permanent magnet can be integral. For occasions that require a large bearing capacity, the upper permanent magnet on the moving ring and the lower permanent magnet on the moving ring can be made by splicing and assembling laminated, assembled or slotted permanent magnet sheets, which will facilitate the replacement of some laminations of the permanent magnet and the change (or improvement) of the magnetic properties of the permanent magnet in the future.

[0044] Both the upper permanent magnet 3 on the moving ring and the lower permanent magnet 4 on the moving ring are demagnetized to maintain the stability of their magnetic density, thereby extending their service life.

[0045] As a preferred mode, both the upper permanent magnet 3 on the moving ring and the lower permanent magnet 4 on the moving ring are disc-shaped.

[0046] The lower permanent magnet 4 on the moving ring can be fixed to the upper surface of the moving ring 6 by means of bonding or the like.

[0047] The material selection of the moving ring and the stationary ring: The moving ring adopts a stainless steel main body inlaid with a high-density composite alloy material, such as composite low-temperature silicon carbide, silicon nitride, boron carbide, antimony-impregnated graphite, YG5, or W1 and other alloys. It has a higher density, stronger hardness, and good sealing performance. The stationary ring adopts a high-density hot-pressed composite material, such as composite low-temperature silicon carbide, silicon nitride, boron carbide, antimony-impregnated graphite, YG5, or W1 and other alloys. The combination of the two results in less frictional heat energy generated between the moving ring and the stationary ring during the high-speed rotation of the rotating shaft, higher wear resistance, better sealing performance, and thus extended service life.

[0048] The materials of the moving ring seal 5 and the stationary ring seal 8 are elastomers or rubbers, such as polytetrafluoroethylene, nitrile rubber, fluororubber, silicone rubber, or ordinary rubber. In this way, the corrosion resistance, high-temperature resistance, and friction resistance of the product can be improved.

[0049] The magnetic levitation mechanical seal device of the present invention can also be provided with a sand protection cover ( Figure 4 not shown in the figure), which covers the magnetic levitation mechanical seal device inside it, and is connected and sealed through the outer shell 1 to isolate the magnetic levitation mechanical seal device from the external fluid. Especially when applied to submersible pumps, deep well pumps, etc., it can prevent sundries such as sand, stones, and mud in the water from entering the magnetic levitation mechanical seal device.

[0050] According to the detailed description above, the magnetic levitation mechanical seal device of the present invention presses the moving ring against the stationary ring by generating a strong magnetic repulsive force between the upper permanent magnet on the moving ring and the lower permanent magnet on the moving ring, realizing good sealing between the moving ring and the stationary ring, changing the technical means of achieving sealing between the moving ring and the stationary ring, and providing a new solution for mechanical seals.

[0051] The magnetic levitation mechanical seal device of the present utility model replaces the pressure spring or electromagnet in the prior art with the upper magnetic steel and lower magnetic steel on the moving ring, fundamentally avoiding the product failure problem caused by the easy failure of the pressure spring or electromagnet. It not only improves the reliability of the mechanical seal, extends the service life of the product, but also makes the maintenance more convenient, reduces the maintenance cost, and saves energy and reduces consumption. After adopting this sealing method, it also helps to increase the rotational speed of the corresponding equipment (such as motors, etc.) and makes the operation more stable.

[0052] The specific embodiments described above are only the preferred embodiments of the present utility model. The preferred embodiments do not elaborate on all structures and details, but only to clearly explain the design principle, inventive concept and practical application of the present utility model, so that those skilled in the art can better understand and utilize it. According to the content of this specification, corresponding modifications and variations can be made. Any technical solution obtained by making modifications without creative efforts based on the design principle and inventive concept of the present utility model shall be regarded as within the protection scope required by the present utility model.

Claims

1. A magnetic levitation mechanical seal device, comprising a housing (1), a rotating ring (6) and a stationary ring (7); the rotating ring (6) and the stationary ring (7) are accommodated in the housing (1), a rotating shaft sequentially passes through a main shaft hole of the stationary ring (7), the rotating ring (6) and the housing (1), a rotating ring sealing ring (5) is arranged between the rotating ring (6) and the rotating shaft, a stationary ring sealing ring (8) is arranged between the stationary ring (7) and an installation component of a corresponding device, and a sealing surface is formed on a contact surface between the rotating ring (6) and the stationary ring (7); characterized in that: Above the upper surface of the moving ring (6) facing away from the stationary ring (7), there is a lower moving-ring magnet (4) and an upper moving-ring magnet (3). The magnetic polarities of the opposite faces of the lower moving-ring magnet (4) and the upper moving-ring magnet (3) are the same. At the upper end of the housing (1), there is a radial locking member for locking the housing (1) and the rotating shaft using this locking member.

2. The magnetic levitation mechanical seal device according to claim 1, characterized in that: The materials of the upper moving-ring magnet (3) and the lower moving-ring magnet (4) are both magnets, selected from alnico magnets, ferrite magnets or neodymium iron boron magnets.

3. The magnetic levitation mechanical seal device according to claim 2, wherein: The range of the magnetic flux density of the magnet is 1.0 - 300 T.

4. The magnetic levitation mechanical seal device according to claim 3, wherein: The magnetic flux density of the magnet is 1.0 - 50 T, including the end values 1.0 T and 50 T of this range and the intermediate value 25 T.

5. The magnetic levitation mechanical seal device according to claim 3, characterized in that: The magnetic flux density of the magnet is 50 - 100 T, including the end value 100 T of this range and the intermediate value 75 T.

6. The magnetic levitation mechanical seal device according to claim 3, characterized in that: The magnetic flux density of the magnet is 100 - 150 T, including the end value 150 T of this range and the intermediate value 125 T.

7. The magnetic levitation mechanical seal device according to claim 3, characterized in that: The magnetic flux density of the magnet is 150 - 200 T, including the end value 200 T of this range and the intermediate value 175 T.

8. The magnetic levitation mechanical seal device according to claim 3, wherein: The magnetic flux density of the magnet is 200 - 250 T, including the end value 250 T of this range and the intermediate value 225 T.

9. The magnetic levitation mechanical seal device according to claim 3, characterized in that: The magnetic flux density of the magnet is 250 - 300 T, including the end value 300 T of this range and the intermediate value 275 T.

10. The magnetic levitation mechanical seal device according to any one of claims 3-9, characterized in that: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) ranges from 100 to 50000 N.

11. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 100 - 2500 N, including the end values 100 N and 2500 N of this range and the intermediate value 1250 N.

12. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 2500 - 5000 N, including the end value 5000 N of this range and the intermediate value 3750 N.

13. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 5000 - 7500 N, including the end value 7500 N of this range and the intermediate value 6250 N.

14. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 7500 - 10000 N, including the end value 10000 N of this range and the intermediate value 8750 N.

15. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 10000 - 12500 N, including the end value 12500 N of this range and the intermediate value 11250 N.

16. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 12500 - 15000 N, including the end value 15000 N of this range and the intermediate value 13750 N.

17. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 15000 - 17500 N, including the end value 17500 N of this range and the intermediate value 16250 N.

18. The magnetic suspension mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper moving-ring magnet (3) and the lower moving-ring magnet (4) is 17500 - 20000 N, including the end value 20000 N of this range and the intermediate value 18750 N.

19. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 20000 - 22500 N, including the endpoint value 22500 N and the midpoint value 21250 N of this range.

20. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 22500 - 25000 N, including the endpoint value 25000 N and the midpoint value 23750 N of this range.

21. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 25000 - 27500 N, including the endpoint value 27500 N and the midpoint value 26250 N of this range.

22. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 27500 - 30000 N, including the endpoint value 30000 N and the midpoint value 28750 N of this range.

23. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 30000 - 32500 N, including the endpoint value 32500 N and the midpoint value 31250 N of this range.

24. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 32500 - 35000 N, including the endpoint value 35000 N and the midpoint value 33750 N of this range.

25. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 35000 - 37500 N, including the endpoint value 37500 N and the midpoint value 36250 N of this range.

26. The magnetic suspension mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 37500 - 40000 N, including the endpoint value 40000 N and the midpoint value 38750 N of this range.

27. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 40000 - 42500 N, including the endpoint value 42500 N and the midpoint value 41250 N of this range.

28. The magnetic levitation mechanical seal device according to claim 10, wherein: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 42500 - 45000 N, including the endpoint value 45000 N and the midpoint value 43750 N of this range.

29. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 45000 - 47500 N, including the endpoint value 47500 N and the midpoint value 46250 N of this range.

30. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The repulsive force between the upper magnet (3) and the lower magnet (4) on the moving ring is 47500 - 50000 N, including the endpoint value 50000 N and the midpoint value 48750 N of this range.

31. The magnetic levitation mechanical seal device according to claim 10, characterized in that: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.2 - 3 mm.

32. The magnetic levitation mechanical seal device according to any one of claims 11-30, characterized in that: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.2 - 3 mm.

33. The magnetic levitation mechanical seal device according to claim 31, wherein: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.3 - 2 mm.

34. The magnetic suspension mechanical seal device according to claim 32, wherein: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.3 - 2 mm.

35. The magnetic levitation mechanical seal device according to claim 33 or 34, characterized in that: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.5 - 1.2 mm.

36. The magnetic levitation mechanical seal device according to claim 33 or 34, characterized in that: The suspension air gap between the upper magnet (3) and the lower magnet (4) on the moving ring is 0.3 - 0.5 mm.

37. The magnetic levitation mechanical seal device according to claim 31, characterized in that: The surfaces of the upper magnet (3) and the lower magnet (4) on the moving ring are both covered with a magnet protective layer, and the magnet protective layer is an electroplated nickel layer, zinc layer, gold layer or chromium layer, or a sprayed epoxy resin layer.

38. The magnetic suspension mechanical seal device according to claim 32, wherein: The surfaces of the upper magnet (3) and the lower magnet (4) on the moving ring are both covered with a magnet protective layer, and the magnet protective layer is an electroplated nickel layer, zinc layer, gold layer or chromium layer, or a sprayed epoxy resin layer.

39. The magnetic levitation mechanical seal device according to claim 33 or 34, characterized in that: The surfaces of the upper magnet (3) and the lower magnet (4) on the moving ring are both covered with a magnet protective layer, and the magnet protective layer is an electroplated nickel layer, zinc layer, gold layer or chromium layer, or a sprayed epoxy resin layer.

40. The magnetic levitation mechanical seal device according to claim 35, wherein: The surfaces of the upper magnet (3) and the lower magnet (4) on the moving ring are both covered with a magnet protective layer, and the magnet protective layer is an electroplated nickel layer, zinc layer, gold layer or chromium layer, or a sprayed epoxy resin layer.

41. The magnetic levitation mechanical seal device according to claim 36, wherein: The surfaces of the upper magnet (3) and the lower magnet (4) on the moving ring are both covered with a magnet protective layer, and the magnet protective layer is an electroplated nickel layer, zinc layer, gold layer or chromium layer, or a sprayed epoxy resin layer.

42. The magnetic levitation mechanical seal device according to claim 37 or 38, characterized in that: The magnet is made by splicing and assembling laminated, assembled or slotted magnet sheets.

43. The magnetic levitation mechanical seal device according to claim 39, wherein: The magnet is made by splicing and assembling laminated, assembled or slotted magnet sheets.

44. The magnetic levitation mechanical seal device according to claim 40 or 41, characterized in that: The magnet is made by splicing and assembling laminated, assembled or slotted magnet sheets.

45. The magnetic levitation mechanical seal device according to claim 42, wherein: The upper magnet (3) and the lower magnet (4) on the moving ring are demagnetized.

46. The magnetic levitation mechanical seal device according to claim 43, characterized in that: The upper magnet (3) and the lower magnet (4) on the moving ring are demagnetized.

47. The magnetic levitation mechanical seal device according to claim 44, characterized in that: The upper magnet (3) and the lower magnet (4) on the moving ring are demagnetized.

48. The magnetic levitation mechanical seal device according to any one of claims 45 to 47, characterized in that: The moving ring (6) is made of a stainless steel main body inlaid with a high-density composite alloy material, and the static ring (7) is made of a high-density hot-pressed composite material, both selected from composite low-temperature silicon carbide, silicon nitride, boron carbide, antimony-impregnated graphite, YG5 or W1.

49. The magnetic levitation mechanical seal device according to claim 48, wherein: The materials of the moving ring seal (5) and the static ring seal (8) are elastomers or rubbers, selected from polytetrafluoroethylene, nitrile rubber, fluororubber, silicone rubber or ordinary rubber.

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