Micro-nano magnetic medium combination sealing device

Abstract

The application 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 sleeved on the rotating shaft, and a first sealing gap for filling magnetic fluid 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 sleeved on the rotating shaft, and the first pole shoe and the second pole shoe are arranged at two ends of the first sealing assembly respectively, and a second sealing gap for filling magnetic lubricating grease is formed between the first pole shoe and the second pole shoe and the rotating shaft. The shell 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 connected to the shell and can rotate relative to the rotating shaft. The micro-nano magnetic medium combined sealing device can ensure zero leakage of the sealed medium, reduce the probability of emulsification of the magnetic fluid and the probability of pollution of the sealed medium caused by leakage of the magnetic fluid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing devices, and in particular to a micro-nano magnetic medium combined sealing device. BACKGROUND

[0002] Micro-nano magnetic medium is a new type of functional material, which is usually formed by dispersing micron or nanometer magnetic particles treated on the surface into base oil or grease to form a magnetic material, including magnetic fluid, magnetic grease, and magneto-rheological fluid.

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

[0004] However, the magnetic fluid of the magnetic fluid sealing device is exposed during use, which is prone to magnetic fluid leakage, magnetic fluid emulsification, and other phenomena, thereby reducing the sealing performance and even causing failure. In addition, magnetic fluid leakage can also cause contamination of the sealed medium. For example, in the field of aviation, unmanned aerial vehicles and other equipment work in high altitudes, and the magnetic fluid sealing is subjected to the scouring of condensed water, causing the magnetic fluid to emulsify and resulting in sealing failure. In the field of nuclear energy, nuclear equipment requires zero leakage, and magnetic fluid leakage can cause contamination of the sealed medium. In the field of optical instruments and some high-end equipment manufacturing, the working temperature is relatively high, and the base fluid in the magnetic fluid volatilizes, which can also cause contamination of the sealed medium. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art.

[0006] To this end, an embodiment of the present application provides a micro-nano magnetic medium combined sealing device, which can combine the performance advantages of different micro-nano magnetic media, ensure zero leakage of the sealed medium, and reduce the probability of magnetic fluid emulsification and the probability of magnetic fluid leakage causing contamination of the sealed medium.

[0007] The micro-nano magnetic medium combined sealing device 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 sleeved on the rotating shaft; the first magnet and the second magnet are arranged at two ends of the pole shoe body respectively, and a first sealing gap for filling magnetic fluid 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 sleeved on the rotating shaft; the first pole shoe and the second pole shoe are arranged at two ends of the first sealing assembly respectively, and a second sealing gap for filling magnetic lubricating grease is formed between the first pole shoe and the rotating shaft and between the second pole shoe and the rotating shaft; the shell 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 connected to the shell and can rotate 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 in communication with the first sealing gap.

[0010] In some embodiments, the pole shoe body comprises a plurality of first pole teeth, a plurality of first sealing gaps are formed between the plurality of first pole teeth and the rotating shaft, an inner wall of the pole shoe body has a liquid storage groove, the liquid storage groove is arranged between two adjacent first sealing gaps, and the liquid injection hole and the first sealing gap are in communication with the liquid storage groove.

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

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

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

[0014] In some embodiments, the shell has a liquid injection port arranged therethrough, the liquid injection port is in communication 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 being fitted together, the third pole shoe having a first half-hole, the fourth pole shoe having a second half-hole, the first half-hole and the second half-hole forming the injection hole.

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

[0017] The micro-nano magnetic media combined sealing device of this invention combines the performance advantages of different micro-nano magnetic media. By filling the first sealing gap with magnetic fluid, a magnetic fluid sealing ring can be formed, achieving the sealing performance of the sealing device and ensuring zero leakage of the sealed medium. By setting second sealing components at both ends of the first sealing component to form a second sealing gap, and filling the second sealing gap with magnetic grease, magnetic grease sealing rings can be formed on both sides of the magnetic fluid. Due to the low volatility and high viscosity of the magnetic grease, it can isolate the magnetic fluid in the sealing cavity (the sealing cavity refers to the chamber formed by the outer shell and the rotating shaft, mainly used to install the first sealing component), preventing condensate outside the sealing cavity from washing away the magnetic fluid, reducing the probability of emulsification of the magnetic fluid, protecting the magnetic fluid in the sealing cavity, and improving the service life of the magnetic fluid. At the same time, because the magnetic grease has a spatial network structure, when the base liquid in the magnetic fluid evaporates in a high-temperature environment or the magnetic fluid flows out, the magnetic grease can prevent the evaporated base liquid or the outflowing magnetic fluid from leaking and contaminating the sealed medium. Attached Figure Description

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

[0019] Figure 2 yes Figure 1 Enlarged diagram of point A in the middle.

[0020] Figure 3 yes Figure 1 Enlarged diagram of point B in the middle.

[0021] Figure 4 yes Figure 1 Enlarged diagram of point C in the middle.

[0022] Figure label:

[0023] 100. Combined sealing device;

[0024] 1. Shaft;

[0025] 2. First sealing assembly; 21. Pole shoe body; 211. First pole tooth; 2111. First sealing gap; 212. 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 casing; 41. Liquid inlet;

[0028] 5. Sealing ring; 51. Sealing ring groove. Detailed Implementation

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

[0030] like Figures 1-3 As shown, the micro / nano magnetic medium combined sealing device 100 of this embodiment includes a rotating shaft 1, a first sealing assembly 2, a second sealing assembly 3, and a housing 4. The first sealing assembly 2 includes pole shoes 21, a first magnet 22, and a second magnet 23, all fitted onto the rotating shaft 1. The first magnet 22 and the second magnet 23 are respectively arranged at both ends of the pole shoes 21, and a first sealing gap 2111 for filling magnetic fluid is formed between the pole shoes 21 and the rotating shaft 1. The second sealing assembly 3 includes a first pole shoe 31 and a second pole shoe 32, all fitted onto 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, and a second sealing gap 331 for filling magnetic grease is formed between the first pole shoe 31 and the rotating shaft 1. The housing 4 is fitted onto the pole shoes 21, the first pole shoe 31, and the second pole shoe 32. The pole shoes 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.

[0031] The micro-nano magnetic medium combined sealing device 100 can combine the performance advantages of different micro-nano magnetic media, fill the magnetic fluid in the first sealing gap 2111, form a magnetic fluid sealing ring, realize the sealing performance of the combined sealing device 100, and ensure zero leakage of the sealed medium. The second sealing assembly 3 is arranged at both ends of the first sealing assembly 2 to form a second sealing gap 331, and the magnetic grease is filled in the second sealing gap 331, so that a magnetic grease sealing ring is formed on both sides of the magnetic fluid. Because 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 shell 4 and the rotating shaft 1, which is mainly used for mounting the first sealing assembly 2), so that the condensed water outside the sealing cavity cannot wash away the magnetic fluid, the probability of emulsification of the magnetic fluid is reduced, the magnetic fluid in the sealing cavity is protected, and the service life of the magnetic fluid is prolonged. At the same time, because the magnetic grease has a space 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 leaked magnetic fluid from polluting the sealed medium.

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

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

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

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

[0036] As shown in Figure 1 , 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 stainless steel with good magnetic conductivity, for example, GCr15.

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

[0039] Thus, a magnetic circuit is 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 fills in the first sealing gap 2111 to form a magnetic fluid sealing ring, thereby achieving zero leakage of the sealed medium. In addition, a magnetic circuit is also 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 lubricating grease fills in the second sealing gap 331 to form a magnetic grease sealing ring, thereby reducing the probability of emulsification of the magnetic fluid and leakage of the magnetic fluid.

[0040] As an example, as shown in Figure 1 , 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 shown in Figure 1 and Figure 2 , the pole shoe body 21 includes a plurality of first pole teeth 211 arranged on the inner wall thereof, 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 form a ring-shaped first sealing gap 2111, and a 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 better sealing effect and ensuring zero leakage of the sealed medium.

[0042] As shown in Figure 1 and Figure 3 , the first pole shoe 31 and the second pole shoe 32 each include a plurality of second pole teeth 33 arranged on the inner wall thereof, 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 form a ring-shaped second sealing gap 331, and the magnetic lubricating grease filled in the plurality of second sealing gaps 331 forms a plurality of magnetic grease sealing rings, thereby isolating 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 size of the first sealing gap 2111 in the radial direction of the rotating shaft 1 is smaller than the size of the second sealing gap 331 in the radial direction of the rotating shaft 1.

[0045] It is known that the flowability of the magnetic lubricating grease is poor, and setting the size of the second sealing gap 331 to be larger than the size of the first sealing gap 2111 is more conducive to filling the magnetic lubricating grease in the second sealing gap 331, thereby forming a magnetic grease sealing ring with better sealing performance.

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

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

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

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

[0050] In some embodiments, such as Figure 1 As shown, 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.

[0051] After prolonged use, the combined sealing device 100 may experience insufficient magnetic fluid, leading to reduced sealing performance. In this case, magnetic fluid can be added to the first sealing gap 2111 through the injection hole 212 to ensure the sealing performance of the combined sealing device 100, thereby solving the problem of difficult maintenance of the magnetic fluid seal. Furthermore, after the combined sealing device 100 is assembled, magnetic fluid can also be filled into the first sealing gap 2111 through the injection hole 212.

[0052] like Figure 1 As shown, the injection hole 212 is arranged radially through the pole shoe body 21 and is located at the middle position of the pole shoe body 21 along the axial direction of the pole shoe body 21.

[0053] Since the magnetic poles of the first magnet 22 and the second magnet 23 are opposite, and the first pole tooth 211 is located on the inner wall of the pole shoe body 21, the first pole tooth 211 has a magnetic focusing effect, which makes the magnetic field strength gradually decrease from the inside to the outside along the radial direction of the rotating shaft 1. That is, the magnetic field strength at the injection hole 212 gradually increases along the direction close to the first sealing gap 2111. This can provide power for the magnetic fluid injected into the injection hole 212, driving the magnetic fluid to flow towards 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, such as Figure 1 and Figure 4 As shown, the inner wall of the pole shoe body 21 has a liquid storage tank 213, which is located between two adjacent first sealing gaps 2111. The injection hole 212 and the first sealing gaps 2111 are both connected to the liquid storage tank 213.

[0055] After the assembly of the combined sealing device 100 is completed, the magnetic fluid is injected into the plurality of first sealing gaps 2111 through the liquid injection hole 212. In order to ensure that the magnetic fluid fills the plurality of first sealing gaps 2111, an excess of magnetic fluid needs to be injected. Under the action of the magnetic field, the magnetic fluid first flows into the plurality of first sealing gaps 2111. When the plurality of first sealing gaps 2111 are filled with magnetic fluid, the excess magnetic fluid can be stored in the liquid storage groove 213. When the magnetic fluid in the first sealing gap 2111 is insufficient, it is automatically replenished.

[0056] It can be understood that during the assembly of the first pole shoe 31 and the second pole shoe 32, an excess of magnetic lubricating grease also needs to be uniformly applied to the plurality of second pole teeth 33 to ensure that the magnetic lubricating grease can fill the second sealing gap 331 after the assembly of the combined sealing device 100 is completed, thereby isolating the magnetic fluid in the sealing cavity.

[0057] In some embodiments, as shown in Figure 4 , the liquid storage groove 213 has a first groove wall 2131 and a second groove wall 2132. The first groove wall 2131 and the second groove wall 2132 gradually move away from each other along the radial direction of the rotating shaft 1.

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

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

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

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

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

[0063] Through the above setting, the liquid storage tank 213 is symmetrically arranged about 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, so that the magnetic fluid can uniformly flow to the first sealing gap 2111 on both sides, improve the uniformity of the magnetic fluid distribution, so as to achieve better sealing effect. In addition, the symmetrical arrangement of the liquid storage tank 213 is also more conducive to the machining and assembly of the pole shoe body 21.

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

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

[0066] In some embodiments, as shown in Figure 1 , the shell 4 has a liquid injection port 41 arranged through, the liquid injection port 41 communicates 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, the excess magnetic fluid is injected into the liquid injection hole 212 through the syringe, and then the liquid injection port 41 is sealed by the plug.

[0068] In other embodiments, a sealing glue can also be used instead of the plug to seal 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 close contact, the third pole shoe 214 has a first half hole, and the fourth pole shoe 215 has a second half hole, the first half hole and the second half hole constitute the liquid injection hole 212.

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

[0071] As an example, as shown in Figure 1As shown, the third pole shoe 214 is attached to the first magnet 22, and the fourth pole shoe 215 is attached to the second magnet 23. The end face of the third pole shoe 214 attached to the fourth pole shoe 215 has a first semi-circular cross-section, and the end face of the fourth pole shoe 215 attached to the third pole shoe 214 has a second semi-circular cross-section, thus forming a circular liquid injection hole 212. 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 that are close to each other have chamfers to form the first groove wall 2131 on the third pole shoe 214 and the second groove wall 2132 on the fourth pole shoe 215. The third pole shoe 214 and the fourth pole shoe 215 are symmetrically arranged to form the liquid storage tank 213.

[0072] Optionally, the third pole shoe 214 and the fourth pole shoe 215 are bonded together. 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 that are in contact with each other. The injection holes 212 of the third pole shoe 214 and the fourth pole shoe 215 are aligned, and then the third pole shoe 214 and the fourth pole shoe 215 are bonded together to form the pole shoe body 21.

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

[0074] In some embodiments, such as Figure 1 As shown, 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 is provided with a sealing ring 5 between itself and the outer casing 4.

[0075] By setting the sealing ring 5, the sealing 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 guaranteed.

[0076] As an example, such as Figure 1 As 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, and sealing rings 5 ​​are disposed in the sealing ring grooves 51. The sealing rings 5 ​​are tightly fitted to the inner wall of the outer shell 4, thereby ensuring the sealing 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 application, it is to be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements indicated thereby must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0078] In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated thereby. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0079] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication or interaction relationship of two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0080] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it can only mean that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it can only mean that the horizontal height of the first feature is less than that of the second feature.

[0081] In this disclosure, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic is included in at least one embodiment or example of the present disclosure. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily referred to the same embodiment or example. Moreover, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Furthermore, the terminology "comprising" is used in the disclosure as comprising but not limited to, that is, it is open-ended and does not exclude the presence of additional features, structures, materials, or characteristics.

[0082] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be interpreted as limiting the present disclosure, and the ordinary skilled person in the art can make changes, modifications, replacements, and variations to the above-described embodiments within the scope of the present disclosure.

Claims

1. A micro / nano magnetic medium combined sealing device (100), characterized in that, include: Rotating shaft (1); The first sealing assembly (2) includes a pole shoe (21), a first magnet (22), and a second magnet (23) all fitted onto the rotating shaft (1). The first magnet (22) and the second magnet (23) are respectively arranged at both ends of the pole shoe (21). A first sealing gap (2111) for filling with magnetic fluid is formed between the pole shoe (21) and the rotating shaft (1). The second sealing assembly (3) includes a first pole shoe (31) and a second pole shoe (32) both fitted onto 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). The first pole shoe (31) and the second pole shoe (32) both form a second sealing gap (331) with the rotating shaft (1) for filling magnetic grease. The outer shell (4) is fitted onto 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). The pole shoe body (21) has an injection hole (212) for injecting magnetic fluid, and the injection hole (212) communicates with the first sealing gap (2111); The pole shoe body (21) includes a plurality of first pole teeth (211), and 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) has a liquid storage tank (213), and the liquid storage tank (213) is located between two adjacent first sealing gaps (2111). The injection hole (212) and the first sealing gaps (2111) are both connected to the liquid storage tank (213). The liquid storage tank (213) has a first tank wall (2131) and a second tank wall (2132), which gradually move away from the outside to the inside along the radial direction of the rotating shaft (1).

2. The micro / nano magnetic medium combined sealing device (100) according to claim 1, characterized in that, The size of the first sealing gap (2111) in the radial direction of the rotating shaft (1) is smaller than the size 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 first tank wall (2131) and the centerline of the injection hole (212) form a first angle, the first angle being 30°~60°; and / or The second tank wall (2132) and the center line of the injection hole (212) form a second included angle, which is 30°~60°.

4. The micro / nano magnetic medium combined sealing device (100) according to claim 3, characterized in that, The first included angle and the second included angle are equal.

5. The micro / nano magnetic medium combined sealing device (100) according to claim 1, characterized in that, The outer casing (4) has a through-hole (41) for injecting liquid, which is connected to the injection hole (212). A plug is detachably connected inside the injection port (41).

6. The micro / nano magnetic medium combined sealing device (100) according to any one of claims 1-5, characterized in that, The pole piece (21) includes a third pole piece (214) and a fourth pole piece (215). The third pole piece (214) and the fourth pole piece (215) are fitted together. The third pole piece (214) has a first half-hole and the fourth pole piece (215) has a second half-hole. The first half-hole and the second half-hole together form the injection hole (212).

7. The micro / nano magnetic medium combined sealing device (100) according to claim 6, characterized in that, 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) is provided with a sealing ring (5) between itself and the outer shell (4).

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