Micro-nano magnetic medium combined sealing device

Abstract

The invention discloses a micro-nano magnetic medium combined sealing device which comprises a rotating shaft, a first sealing assembly, a second sealing assembly and a shell. The first sealing assembly comprises a pole shoe body, a first magnet and a second magnet which are arranged on the rotating shaft in a sleeving mode. A first sealing gap used for being filled with magnetofluid is formed between the pole shoe body and the rotating shaft. The second sealing assembly comprises a first pole shoe and a second pole shoe which are arranged on the rotating shaft in a sleeving mode, the first pole shoe and the second pole shoe are arranged at the two ends of the first sealing assembly respectively, and second sealing gaps used for being filled with magnetic lubricating grease are formed between the first pole shoe and the rotating shaft and between the second pole shoe and the rotating shaft; the shell sleeves the pole shoe body, the first pole shoe and the second pole shoe, and the pole shoe body, the first pole shoe and the second pole shoe are all connected to the shell and can rotate relative to the rotating shaft. According to the micro-nano magnetic medium combined sealing device, zero leakage of the sealed medium can be guaranteed, and meanwhile the probability that the magnetic fluid is emulsified and the probability that the sealed medium is polluted due to leakage of the magnetic fluid are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing devices, and particularly to a micro-nano magnetic medium combined sealing device. Background Art

[0002] Micro-nano magnetic medium is a new type of functional material. Usually, magnetic particles in the micron or nano scale are surface-treated and then dispersed into base oil or grease to form a magnetic material, including magnetic fluid, magnetic grease, magnetorheological fluid, etc.

[0003] Magnetic fluid sealing technology is a new type of sealing form, which has significant advantages such as zero leakage, long service life, high reliability, and no wear, and plays an important role in the fields of aviation, aerospace, nuclear energy, military, chemical industry, etc.

[0004] However, the magnetic fluid of the magnetic fluid sealing device is exposed during use, and phenomena such as magnetic fluid leakage and magnetic fluid emulsification are likely to occur, which will further lead to a decrease in sealing performance or even failure. Moreover, magnetic fluid leakage will also cause problems such as contamination of the sealed medium. For example, in the field of aviation, when equipment such as unmanned aerial vehicles works at high altitude, the magnetic fluid sealing is washed by condensed water, and the magnetic fluid emulsifies, resulting in sealing failure; in the field of nuclear energy, nuclear equipment requires zero leakage of sealing, and magnetic fluid leakage will cause problems of contamination of the sealed medium; in the fields of optical instruments and some high-end equipment manufacturing, the working temperature is relatively high, and the base carrier liquid in the magnetic fluid volatilizes, which is also likely to cause problems of contamination of the sealed medium. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0006] Therefore, an embodiment of the present invention provides a micro-nano magnetic medium combined sealing device, which can combine the performance advantages of different micro-nano magnetic media, and while ensuring zero leakage of the sealed medium, reduce the probability of magnetic fluid emulsification and the probability of magnetic fluid leakage contaminating the sealed medium.

[0007] The micro-nano magnetic medium combined sealing device according to an embodiment of the present invention includes a rotating shaft, a first sealing assembly, a second sealing assembly, and a housing; the first sealing assembly includes a pole shoe body, a first magnet, and a second magnet, all of which are sleeved on the rotating shaft. The first magnet and the second magnet are respectively arranged at both ends of the pole shoe body, and a first sealing gap for filling magnetic fluid is formed between the pole shoe body and the rotating shaft; the second sealing assembly includes a first pole shoe and a second pole shoe, both of which are sleeved on the rotating shaft. The first pole shoe and the second pole shoe are respectively arranged at both ends of the first sealing assembly, and a second sealing gap for filling magnetic grease is formed between the first pole shoe and the second pole shoe and the rotating shaft; the housing is sleeved on the pole shoe body, the first pole shoe, and the second pole shoe, and the pole shoe body, the first pole shoe, and the second pole shoe are all connected to the housing and are rotatable relative to the rotating shaft.

[0008] In some embodiments, the size of the first sealing gap in the radial direction of the rotating shaft is smaller than the size of the second sealing gap in the radial direction of the rotating shaft.

[0009] In some embodiments, the pole shoe body has a liquid injection hole for injecting magnetic fluid, and the liquid injection hole is communicated with the first sealing gap.

[0010] In some embodiments, the pole shoe body includes a plurality of first pole teeth, and a plurality of first sealing gaps are formed between the plurality of first pole teeth and the rotating shaft. The inner wall of the pole shoe body has a liquid storage tank, and the liquid storage tank is arranged between two adjacent first sealing gaps. The liquid injection hole and the first sealing gap are both communicated with the liquid storage tank.

[0011] In some embodiments, the liquid storage tank has a first tank wall and a second tank wall, and the first tank wall and the second tank wall gradually move away from each other from the outside to the inside along the radial direction of the rotating shaft.

[0012] In some embodiments, the first tank wall forms a first included angle with the center line of the liquid injection hole, and the first included angle is 30° to 60°; and / or the second tank wall forms a second included angle with the center line of the liquid injection hole, and the second included angle is 30° to 60°.

[0013] In some embodiments, the first included angle and the second included angle are equal.

[0014] In some embodiments, the housing has a liquid injection port arranged therethrough, the liquid injection port is communicated with the liquid injection hole, and a plug is detachably connected in the liquid injection port.

[0015] In some embodiments, the pole shoe body includes a third pole shoe and a fourth pole shoe. The third pole shoe and the fourth pole shoe are arranged in a fitting manner. The third pole shoe has a first half-hole, and the fourth pole shoe has a second half-hole. The first half-hole and the second half-hole form the liquid injection hole.

[0016] In some embodiments, a sealing ring is provided between at least one of the first pole shoe, the second pole shoe, the third pole shoe, and the fourth pole shoe and the housing.

[0017] The micro-nano magnetic medium combined sealing device according to the embodiment of the present invention can combine the performance advantages of different micro-nano magnetic media. By filling the magnetic fluid in the first sealing gap, a magnetic fluid sealing ring can be formed to achieve the sealing performance of the sealing device and ensure zero leakage of the medium to be sealed. By providing second sealing components at both ends of the first sealing component to form a second sealing gap and filling magnetic grease in the second sealing gap, magnetic grease sealing rings can be formed on both sides of the magnetic fluid. Since the magnetic grease has the characteristics of low volatility and high viscosity, the magnetic fluid can be isolated in the sealing cavity (the sealing cavity refers to the cavity formed by the housing and the rotating shaft, mainly used for installing the first sealing component), preventing the condensed water outside the sealing cavity from flushing the magnetic fluid and reducing the probability of the magnetic fluid emulsifying, playing a protective role for the magnetic fluid in the sealing cavity and improving the service life of the magnetic fluid; at the same time, since the magnetic grease has a spatial network structure, when the base carrier liquid in the magnetic fluid volatilizes in a high-temperature environment or the magnetic fluid flows out, the magnetic grease can prevent the volatilized base carrier liquid or the flowing-out magnetic fluid from leaking and polluting the medium to be sealed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a micro-nano magnetic medium combined sealing device according to an embodiment of the present invention.

[0019] Figure 2 is Figure 1 an enlarged schematic view of part A in

[0020] Figure 3 is Figure 1 an enlarged schematic view of part B in

[0021] Figure 4 is Figure 1 an enlarged schematic view of part C in

[0022] REFERENCE SIGNS:

[0023] 100, combined sealing device;

[0024] 1, rotating shaft;

[0025] 2. First sealing assembly; 21. Pole shoe body; 211. First pole tooth; 2111. First sealing gap; 212. Liquid injection hole; 213. Liquid storage tank; 2131. First tank wall; 2132. Second tank wall; 214. Third pole shoe; 215. Fourth pole shoe; 22. First magnet; 23. Second magnet;

[0026] 3. Second sealing assembly; 31. First pole shoe; 32. Second pole shoe; 33. Second pole tooth; 331. Second sealing gap;

[0027] 4. Outer shell; 41. Liquid injection port;

[0028] 5. Sealing ring; 51. Sealing ring groove. Specific embodiments

[0029] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] As Figures 1-3 shown, the micro-nano magnetic medium combined sealing device 100 of the embodiment of the present invention includes a rotating shaft 1, a first sealing assembly 2, a second sealing assembly 3 and an outer shell 4; the first sealing assembly 2 includes a pole shoe body 21, a first magnet 22 and a second magnet 23 all sleeved on the rotating shaft 1. The first magnet 22 and the second magnet 23 are respectively arranged at both ends of the pole shoe body 21. A first sealing gap 2111 for filling magnetic fluid is formed between the pole shoe body 21 and the rotating shaft 1; the second sealing assembly 3 includes a first pole shoe 31 and a second pole shoe 32 all sleeved on the rotating shaft 1. The first pole shoe 31 and the second pole shoe 32 are respectively arranged at both ends of the first sealing assembly 2. A second sealing gap 331 for filling magnetic grease is formed between both the first pole shoe 31 and the second pole shoe 32 and the rotating shaft 1; the outer shell 4 is sleeved on the pole shoe body 21, the first pole shoe 31 and the second pole shoe 32. The pole shoe body 21, the first pole shoe 31 and the second pole shoe 32 are all connected to the outer shell 4 and are rotatable relative to the rotating shaft 1.

[0031] The micro-nano magnetic medium combined sealing device 100 according to the embodiment of the present invention can combine the performance advantages of different micro-nano magnetic media. By filling the magnetic fluid in the first sealing gap 2111, a magnetic fluid sealing ring can be formed to achieve the sealing performance of the combined sealing device 100 and ensure zero leakage of the medium to be sealed. By arranging the second sealing component 3 at both ends of the first sealing component 2 to form a second sealing gap 331 and filling magnetic grease in the second sealing gap 331, magnetic grease sealing rings can be formed on both sides of the magnetic fluid. Since the magnetic grease has the characteristics of low volatility and high viscosity, it can isolate the magnetic fluid in the sealing cavity (the sealing cavity refers to the cavity formed by the outer shell 4 and the rotating shaft 1, mainly used for installing the first sealing component 2), prevent the condensed water outside the sealing cavity from flushing the magnetic fluid, reduce the probability of the magnetic fluid emulsification phenomenon, protect the magnetic fluid in the sealing cavity, and improve the service life of the magnetic fluid; at the same time, since the magnetic grease has a spatial network structure, when the base carrier liquid in the magnetic fluid volatilizes in a high-temperature environment or the magnetic fluid flows out, the magnetic grease can prevent the volatilized base carrier liquid or the flowing-out magnetic fluid from leaking and polluting the medium to be sealed.

[0032] It can be understood that the magnetic fluid is a stable colloidal solution formed by dispersing nano-magnetic particles into a base carrier liquid. Optionally, the volume fraction of the nano-magnetic particles in the magnetic fluid is 5% - 25%, and the base carrier liquid is a lubricating oil with excellent performance. Preferably, the base carrier liquid is a fully synthetic engine oil, and the volume fraction of the nano-magnetic particles in the magnetic fluid is 20%, that is, the magnetic fluid is formed by dispersing nano-magnetic particles with a volume fraction of 20% into the fully synthetic engine oil.

[0033] Optionally, the magnetic grease is formed by dispersing magnetic particles with a volume fraction of 15% into vacuum silicone grease.

[0034] Optionally, the outer shell 4 is made of a non-magnetic conductive material.

[0035] Optionally, both the first magnet 22 and the second magnet 23 are made of a permanent magnetic material with good magnetic properties, for example: neodymium iron boron permanent magnet of grade N38.

[0036] As Figure 1 shown, the magnetic pole directions of the first magnet 22 and the second magnet 23 are opposite and both are parallel to the axial direction of the rotating shaft 1. The first magnet 22 is arranged between the first pole shoe 31 and the pole shoe body 21, and the second magnet 23 is arranged between the second pole shoe 32 and the pole shoe body 21.

[0037] Optionally, the first pole shoe 31, the second pole shoe 32 and the pole shoe body 21 are all made of a stainless steel material with good magnetic conductivity, for example: GCr15.

[0038] Optionally, the rotating shaft 1 is made of a stainless steel with good magnetic conductivity.

[0039] Thus, a magnetic circuit can be formed between the first magnet 22, the second magnet 23, the pole shoe body 21 and the rotating shaft 1, so that the magnetic fluid is filled in the first sealing gap 2111 to form a magnetic fluid sealing ring, thereby achieving zero leakage of the sealing medium. In addition, magnetic circuits can also be formed between the first magnet 22, the first pole shoe 31 and the rotating shaft 1, and between the second magnet 23, the second pole shoe 32 and the rotating shaft 1, so that the magnetic grease is filled in the second sealing gap 331 to form a magnetic grease sealing ring, thereby reducing the probability of emulsification and leakage of the magnetic fluid.

[0040] As an example, as Figure 1 shown, the rotating shaft 1 is a solid shaft, and the first pole shoe 31, the first magnet 22, the pole shoe body 21, the second magnet 23, and the second pole shoe 32 are all sleeved on the rotating shaft 1 and arranged in sequence along the axial direction of the rotating shaft 1.

[0041] As Figure 1 and Figure 2 shown, the pole shoe body 21 includes a plurality of first pole teeth 211 provided on its inner wall. The cross-section of the first pole teeth 211 is rectangular. The inner side surface of the first pole teeth 211 and the outer side surface of the rotating shaft 1 enclose an annular first sealing gap 2111. The plurality of first sealing gaps 2111 are arranged in sequence along the axial direction of the rotating shaft 1. The magnetic fluid filled in the plurality of first sealing gaps 2111 can form a plurality of magnetic fluid sealing rings, thereby achieving a better sealing effect and ensuring zero leakage of the sealed medium.

[0042] As Figure 1 and Figure 3 shown, both the first pole shoe 31 and the second pole shoe 32 include a plurality of second pole teeth 33 provided on their inner walls. The cross-section of the second pole teeth 33 is also rectangular. The inner side surface of the second pole teeth 33 and the outer side surface of the rotating shaft 1 enclose an annular second sealing gap 331. The magnetic grease filled in the plurality of second sealing gaps 331 forms a plurality of magnetic grease sealing rings to isolate the magnetic fluid in the sealing cavity.

[0043] Of course, in other embodiments, the rotating shaft 1 can also be formed as a stepped shaft, a hollow shaft, a shaft sleeve, etc.

[0044] In some embodiments, the dimension of the first sealing gap 2111 in the radial direction of the rotating shaft 1 is smaller than the dimension of the second sealing gap 331 in the radial direction of the rotating shaft 1.

[0045] It is known that the fluidity of the magnetic grease is poor. Setting the dimension of the second sealing gap 331 to be larger than the dimension of the first sealing gap 2111 is more conducive to filling the second sealing gap 331 with the magnetic grease, thereby forming a magnetic grease sealing ring with better sealing performance.

[0046] As Figure 2As shown, the dimension of the first sealing gap 2111 in the radial direction of the rotating shaft 1 is L1, the radius of the inner side surface of the first pole tooth 211 surrounding the rotating shaft 1 in the circumferential direction is R1, the radius of the outer side surface of the rotating shaft 1 is r, and L1 = R1 - r.

[0047] As Figure 3 shown, the dimension of the second sealing gap 331 in the radial direction of the rotating shaft 1 is L2, the radius of the inner side surface of the second pole tooth 33 surrounding the rotating shaft 1 in the circumferential direction is R2, and L1 = R2 - r.

[0048] Optionally, L1 is 0.1 mm to 0.2 mm.

[0049] Optionally, L2 is 0.5 mm to 1 mm.

[0050] In some embodiments, as Figure 1 shown, the pole shoe body 21 has a liquid injection hole 212 for injecting magnetic fluid, and the liquid injection hole 212 is communicated with the first sealing gap 2111.

[0051] After the combined sealing device 100 is used for a long time, the phenomenon of insufficient magnetic fluid may occur, resulting in reduced sealing performance. At this time, the magnetic fluid can be replenished into the first sealing gap 2111 by using the liquid injection hole 212 to ensure the sealing performance of the combined sealing device 100, thereby solving the problem of difficult maintenance of magnetic fluid sealing. In addition, after the combined sealing device 100 is assembled, magnetic fluid can also be filled into the first sealing gap 2111 through the liquid injection hole 212.

[0052] As Figure 1 shown, the liquid injection hole 212 is provided through the pole shoe body 21 in the radial direction and is arranged at the middle position of the pole shoe body 21 in the axial direction.

[0053] Since the magnetic pole directions of the first magnet 22 and the second magnet 23 are opposite, and the first pole tooth 211 is arranged on the inner wall of the pole shoe body 21, the first pole tooth 211 has a magnetic focusing effect, so that the magnetic field intensity gradually decreases from the inside to the outside along the radial direction of the rotating shaft 1, that is, the magnetic field intensity at the liquid injection hole 212 gradually increases along the direction close to the first sealing gap 2111. Thus, power can be provided for the magnetic fluid injected into the liquid injection hole 212 to drive the magnetic fluid to flow in the direction close to the first sealing gap 2111, which is more conducive to injecting magnetic fluid into the first sealing gap 2111.

[0054] In some embodiments, as Figure 1 and Figure 4 shown, the inner wall of the pole shoe body 21 has a liquid storage tank 213, the liquid storage tank 213 is arranged between two adjacent first sealing gaps 2111, and both the liquid injection hole 212 and the first sealing gap 2111 are communicated with the liquid storage tank 213.

[0055] After the combined seal device 100 is assembled, magnetic fluid is injected into the multiple first seal gaps 2111 through the liquid injection hole 212. To ensure that the magnetic fluid fills the multiple first seal gaps 2111, an excessive amount of magnetic fluid needs to be injected. Under the action of the magnetic field, the magnetic fluid first flows into the multiple first seal gaps 2111. When the multiple first seal gaps 2111 are all filled with magnetic fluid, the excessive magnetic fluid can be stored in the liquid storage tank 213 and automatically replenished when the magnetic fluid in the first seal gaps 2111 is insufficient.

[0056] It can be understood that during the assembly process of the first pole shoe 31 and the second pole shoe 32, an excessive amount of magnetic grease also needs to be evenly applied to the multiple second pole teeth 33 to ensure that after the combined seal device 100 is assembled, the magnetic grease can fill the second seal gap 331, thereby isolating the magnetic fluid in the seal cavity.

[0057] In some embodiments, as Figure 4 shown, the liquid storage tank 213 has a first tank wall 2131 and a second tank wall 2132, and the first tank wall 2131 and the second tank wall 2132 gradually move away from each other radially inward along the axis of the rotating shaft 1.

[0058] Exemplarily, as Figure 1 and Figure 4 shown, the liquid storage tank 213 extends in a ring shape along the circumferential direction of the pole shoe body 21. The liquid storage tank 213 is arranged between two adjacent first pole teeth 211. The two first pole teeth 211 arranged on both sides of the liquid storage tank 213 are named intermediate pole teeth, and the first tank wall 2131 and the second tank wall 2132 respectively form the end faces of the two intermediate pole teeth.

[0059] In some embodiments, as Figure 4 shown, the first tank wall 2131 forms a first included angle α with the center line of the liquid injection hole 212, and the first included angle α is 30° to 60°; and / or the second tank wall 2132 forms a second included angle β with the center line of the liquid injection hole 212, and the second included angle β is 30° to 60°.

[0060] It is known that the magnetic field intensity is concentrated at the sharp corners of the pole shoe body 21. If a sharp corner structure appears at the liquid storage tank 213, the magnetic fluid will tend to concentrate at the sharp corners, hindering the flow of the magnetic fluid into the first seal gaps 2111.

[0061] With the above settings, the cross-section of the liquid storage tank 213 is in a "V" shape and the opening faces the rotating shaft 1, which can prevent the appearance of a sharp corner structure in the liquid storage tank 213, so that the magnetic fluid can flow from the liquid storage tank 213 into the first seal gaps 2111 on both sides.

[0062] In some embodiments, the first included angle and the second included angle are equal.

[0063] With the above settings, the liquid storage tank 213 is symmetrically arranged with respect to the center line of the liquid injection hole 212, so that the magnetic field is symmetrically arranged on both sides of the liquid storage tank 213, enabling the magnetorheological fluid to flow evenly to the first sealing gaps 2111 on both sides, improving the uniformity of the magnetorheological fluid distribution, and thus achieving a better sealing effect. In addition, the symmetrical arrangement of the liquid storage tank 213 is also more conducive to the processing and assembly of the pole shoe body 21.

[0064] Of course, in other embodiments, the first included angle and the second included angle may also be unequal, as long as the above-mentioned liquid storage tank 213 can be formed.

[0065] As an example, as Figure 4 shown, the first tank wall 2131 and the second tank wall 2132 are symmetrically arranged, both the first included angle and the second included angle are 30°, the distance between the side of the first tank wall 2131 close to the rotating shaft 1 and the center line of the liquid injection hole 212 is L3, the distance between the side of the second tank wall 2132 close to the rotating shaft 1 and the center line of the liquid injection hole 212 is L4, and both L3 and L4 are 2 mm.

[0066] In some embodiments, as Figure 1 shown, the housing 4 has a liquid injection port 41 penetrating therethrough, the liquid injection port 41 is communicated with the liquid injection hole 212, and a plug (not shown in the figure) is detachably connected in the liquid injection port 41.

[0067] When the combined sealing device 100 needs to be maintained, the plug is removed, the liquid injection port 41 is opened, an excessive amount of magnetorheological fluid is injected into the liquid injection hole 212 through a syringe, and then the liquid injection port 41 is sealed with the plug.

[0068] In other embodiments, a sealant can also be used instead of the plug to block the liquid injection port 41.

[0069] In some embodiments, the pole shoe body 21 includes a third pole shoe 214 and a fourth pole shoe 215, the third pole shoe 214 and the fourth pole shoe 215 are arranged in a fitting manner, the third pole shoe 214 has a first half hole, the fourth pole shoe 215 has a second half hole, and the first half hole and the second half hole form the liquid injection hole 212.

[0070] By making the pole shoe body 21 a split type, it is more conducive to the production and processing of the liquid injection hole 212 and the liquid storage tank 213, and reduces the production cost of the pole shoe body 21.

[0071] As an example, as Figure 1As shown, the third pole shoe 214 is disposed in contact with the first magnet 22, the fourth pole shoe 215 is disposed in contact with the second magnet 23. The end face of the third pole shoe 214 in contact with the fourth pole shoe 215 has a first semi-hole with a semi-circular cross-section, and the end face of the fourth pole shoe 215 in contact with the third pole shoe 214 has a second semi-hole with a semi-circular cross-section, thereby forming a liquid injection hole 212 with a circular cross-section. The center line of the liquid injection hole 212 is its axis. The inner sides of the end faces of the third pole shoe 214 and the fourth pole shoe 215 close to each other both have chamfers, so as to form the above-mentioned first groove wall 2131 on the third pole shoe 214 and the above-mentioned second groove wall 2132 on the fourth pole shoe 215. The third pole shoe 214 and the fourth pole shoe 215 are symmetrically arranged, thereby forming the above-mentioned liquid storage tank 213.

[0072] Optionally, the third pole shoe 214 and the fourth pole shoe 215 are bonded to each other. Specifically, when assembling the third pole shoe 214 and the fourth pole shoe 215, a layer of sealant is evenly applied to the end faces of the third pole shoe 214 and the fourth pole shoe 215 in contact with each other. Align the liquid injection holes 212 of the third pole shoe 214 and the fourth pole shoe 215, and then fit the third pole shoe 214 and the fourth pole shoe 215 together to form the pole shoe body 21.

[0073] Of course, in other embodiments, the pole shoe body 21 can also be set as an integral structure.

[0074] In some embodiments, as Figure 1 shown, a sealing ring 5 is provided between at least one of the first pole shoe 31, the second pole shoe 32, the third pole shoe 214 and the fourth pole shoe 215 and the outer shell 4.

[0075] By providing the sealing ring 5, the sealing performance between the first pole shoe 31, the second pole shoe 32, the third pole shoe 214 and the fourth pole shoe 215 and the outer shell 4 can be ensured.

[0076] Exemplarily, as Figure 1 shown, the annular outer walls of the first pole shoe 31, the second pole shoe 32, the third pole shoe 214 and the fourth pole shoe 215 all have sealing ring grooves 51. The sealing ring 5 is disposed in the sealing ring grooves 51, and the sealing ring 5 is closely attached to the inner wall of the outer shell 4, thereby ensuring the sealing performance between the first pole shoe 31, the second pole shoe 32, the third pole shoe 214 and the fourth pole shoe 215 and the outer shell 4.

[0077] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.

[0078] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0079] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0081] In the present invention, terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0082] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A micro-nano magnetic medium combined sealing device (100), characterized in that: include: A rotating shaft (1); A first sealing component (2), the first sealing component (2) comprising a pole shoe body (21), a first magnet (22) and a second magnet (23) which are both mounted on the rotating shaft (1), the first magnet (22) and the second magnet (23) being arranged at two ends of the pole shoe body (21) respectively, and a first sealing gap (2111) for filling a magnetic fluid is formed between the pole shoe body (21) and the rotating shaft (1); A second sealing assembly (3), the second sealing assembly (3) comprising a first pole shoe (31) and a second pole shoe (32) both mounted on the rotating shaft (1), the first pole shoe (31) and the second pole shoe (32) being arranged at two ends of the first sealing assembly (2), respectively, and a second sealing gap (331) for filling magnetic grease is formed between the first pole shoe (31) and the second pole shoe (32) and the rotating shaft (1); A housing (4), wherein the housing (4) is mounted on the pole shoe body (21), the first pole shoe (31) and the second pole shoe (32); the pole shoe body (21), the first pole shoe (31) and the second pole shoe (32) are all connected to the housing (4) and are rotatable relative to the rotating shaft (1).

2. The micro-nano magnetic medium combined sealing device (100) according to claim 1, characterized in that: The dimension of the first sealing gap (2111) in the radial direction of the rotating shaft (1) is smaller than the dimension of the second sealing gap (331) in the radial direction of the rotating shaft (1).

3. The micro-nano magnetic medium combined sealing device (100) according to claim 1, characterized in that: The pole shoe body (21) has an injection hole (212) for injecting magnetic fluid, and the injection hole (212) is connected to the first sealing gap (2111).

4. The micro-nano magnetic medium combined sealing device (100) according to claim 3, characterized in that: The pole shoe body (21) comprises a plurality of first pole teeth (211), a plurality of first sealing gaps (2111) are formed between the plurality of first pole teeth (211) and the rotating shaft (1), the inner wall of the pole shoe body (21) comprises a liquid storage tank (213), the liquid storage tank (213) is arranged between two adjacent first sealing gaps (2111), and the liquid injection hole (212) and the first sealing gap (2111) are both connected to the liquid storage tank (213).

5. The micro-nano magnetic medium combined sealing device (100) according to claim 4, characterized in that: The liquid storage tank (213) comprises a first tank wall (2131) and a second tank wall (2132), wherein the first tank wall (2131) and the second tank wall (2132) gradually move away from the outside to the inside along the radial direction of the rotating shaft (1).

6. The micro-nano magnetic medium combined sealing device (100) according to claim 5, characterized in that: The first groove wall (2131) and the center line of the liquid injection hole (212) form a first angle, and the first angle is 30° to 60°; and / or The second groove wall (2132) and the center line of the liquid injection hole (212) form a second angle, and the second angle is 30° to 60°.

7. The micro-nano magnetic medium combined sealing device (100) according to claim 6, characterized in that: The first angle is equal to the second angle.

8. The micro-nano magnetic medium combined sealing device (100) according to claim 3, characterized in that: The housing (4) has a liquid injection port (41) extending therethrough, the liquid injection port (41) being in communication with the liquid injection hole (212), and a plug is detachably connected to the inside of the liquid injection port (41).

9. The micro-nano magnetic medium combined sealing device (100) according to any one of claims 3 to 8, characterized in that: The pole shoe body (21) comprises a third pole shoe (214) and a fourth pole shoe (215), wherein the third pole shoe (214) and the fourth pole shoe (215) are arranged in close contact with each other, the third pole shoe (214) has a first half hole, and the fourth pole shoe (215) has a second half hole, and the first half hole and the second half hole constitute the injection hole (212).

10. The micro-nano magnetic medium combined sealing device (100) according to claim 9, characterized in that: A sealing ring (5) is provided between at least one of the first pole shoe (31), the second pole shoe (32), the third pole shoe (214) and the fourth pole shoe (215) and the housing (4).

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