Follow-up micro-nano magnetic medium sealing device

Abstract

The application provides a kind of servo micro-nano magnetic medium sealing device, relating to sealing device technical field, including shell, rotating shaft, floating seal seat and first sealing assembly, shell has chamber;Rotating shaft, first sealing assembly and floating seal seat are sequentially set from inside to outside, floating seal seat and first sealing assembly are all matched in chamber and movably connected with chamber along the radial direction of rotating shaft, first sealing assembly includes first pole shoe, first permanent magnet and second pole shoe, the magnetic pole direction of first permanent magnet is consistent with the axial direction of rotating shaft;The inner circumferential surface of each of first pole shoe and second pole shoe is defined with the outer circumferential surface of rotating shaft first gap, and micro-nano magnetic medium is adsorbed in first gap, the outer circumferential surface of floating seal seat is defined with the inner circumferential surface of chamber second gap, which is communicated with the outside.The application can make sealing assembly jump radially under the action of fluid dynamic pressure effect, to change the gap between sealing assembly and rotating shaft, reduce the influence of rotating shaft radial jump.

Description

TECHNICAL FIELD

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

[0002] Micro-nano magnetic medium sealing is to form a continuous and stable liquid sealing ring of micro-nano magnetic medium in a sealing gap by magnetic field control to realize non-contact sealing, so that the micro-nano magnetic medium sealing has the characteristic of "zero leakage", but the radial runout of the rotating shaft will cause the pressure resistance and service life of the micro-nano magnetic medium sealing to decrease, and even cause the micro-nano magnetic medium sealing pole teeth to be damaged by rubbing with the rotating shaft.

[0003] In order to reduce the influence of the radial runout of the rotating shaft on the performance of the micro-nano magnetic medium sealing, the related technology adopts a floating type micro-nano magnetic medium sealing structure, which specifically includes the following two types:

[0004] 1. A magnetic floating ring is arranged between the shell and the rotating shaft, and a liquid film is formed between the magnetic floating ring and the rotating shaft by continuously supplying micro-nano magnetic medium to the magnetic floating ring from outside, so as to seal the leaked gas, but in this way, the distribution state of the micro-nano magnetic medium is difficult to guarantee under the action of gravity, and the continuous supply of micro-nano magnetic medium from outside also increases the cost;

[0005] 2. A floating ring is arranged between the shell and the rotating shaft, a plurality of springs are installed between the floating ring and the shell in the circumferential direction, and the eccentric force is offset by the springs, but the springs are easy to reduce the reliability of the sealing device, and the structure is complex, it is difficult to guarantee the coaxial degree during processing, and it is also easy to affect the sealing performance and service life. SUMMARY

[0006] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0007] To this end, an embodiment of the present application provides a follow-up type micro-nano magnetic medium sealing device, which can make the sealing assembly follow the radial runout of the rotating shaft under the action of fluid dynamic pressure effect, so as to change the gap between the sealing assembly and the rotating shaft, reduce the influence of the radial runout of the rotating shaft, and improve the pressure resistance and service life.

[0008] According to an embodiment of the present application, a sealing device for micro-nano magnetic medium comprises a housing, a rotating shaft, a floating sealing seat and a first sealing assembly. The housing has a cavity. The rotating shaft is pivotally connected to the cavity and at least one end of the rotating shaft is located outside the housing. The rotating shaft, the first sealing assembly and the floating sealing seat are sequentially sleeved from inside to outside. The floating sealing seat and the first sealing assembly are both fitted in the cavity and movably connected to the cavity along the radial direction of the rotating shaft. The first sealing assembly comprises a first pole shoe, a first permanent magnet and a second pole shoe which are sequentially arranged along the axial direction of the rotating shaft. The magnetic pole direction of the first permanent magnet is consistent with the axial direction of the rotating shaft. The inner circumferential surface of each of the first pole shoe and the second pole shoe and the outer circumferential surface of the rotating shaft define a first gap. The micro-nano magnetic medium is adsorbed in the first gap. The outer circumferential surface of the floating sealing seat and the inner circumferential surface of the cavity define a second gap which is connected to the outside.

[0009] According to an embodiment of the present application, the floating sealing structure is formed by the floating sealing seat and the first sealing assembly. The floating sealing structure is movably connected to the cavity along the radial direction of the rotating shaft. When the rotating shaft is in the radial run-out state, that is, the rotating shaft is eccentric relative to the first pole shoe and the second pole shoe, the first gap is uneven in the circumferential direction and there are large gaps and small gaps in the circumferential direction. When the sealing device is installed on the sealed equipment, the high-pressure gas in the sealed equipment enters the first gap. At this time, the fluid dynamic pressure effect of the high-pressure gas makes the pressure on the small gap side of the first gap very large, and a pressure difference is formed between the small gap side and the second gap. Under the action of the pressure difference, the first pole shoe and the second pole shoe are pushed to the small gap side, that is, the first pole shoe and the second pole shoe move towards the direction of increasing the size of the gap. The first pole shoe and the second pole shoe are followed by the rotating shaft, so as to adaptively adjust the concentricity between the rotating shaft and the first pole shoe and the second pole shoe, reduce the influence of the radial run-out of the rotating shaft on the sealing of the micro-nano magnetic medium, and improve the pressure resistance and service life.

[0010] In some embodiments, each of the first pole shoe and the second pole shoe is provided with a first pole tooth. The first pole tooth has a plurality of first pole teeth which are spaced apart along the axial direction of the rotating shaft. All the first pole teeth and the outer circumferential surface of the rotating shaft define the first gap.

[0011] Further, the first gap is smaller than the second gap.

[0012] Further, the outer circumferential surface of at least one of the first pole shoe and the second pole shoe and the inner circumferential surface of the floating sealing seat are provided with a first sealing ring.

[0013] In some embodiments, the sealing device further comprises a first end cover and a magnetic conductive ring, both of which are sleeved on the rotating shaft and arranged on two sides of the first sealing assembly along the axial direction of the rotating shaft, the first end cover is connected with the floating seal seat, the end surface of the first pole shoe away from the first permanent magnet abuts against the first end cover, and the inner circumferential surface of the floating seal seat is provided with a first annular shoulder, the magnetic conductive ring is located between the second pole shoe and the first annular shoulder and abuts against the first annular shoulder.

[0014] In some embodiments, the sealing device further comprises a first magnetic isolation ring, which is sleeved on the rotating shaft and located in the inner cavity of the floating seal seat, and the opposite end surfaces of the first magnetic isolation ring along the axial direction of the rotating shaft abut against the second pole shoe and the magnetic conductive ring, respectively.

[0015] In some embodiments, the sealing device further comprises a second sealing assembly, which is fitted in the chamber and sleeved on the rotating shaft, and the second sealing assembly is arranged along the axial direction of the rotating shaft and closer to the high-pressure side than the first sealing assembly, so as to separate the first sealing assembly from the high-pressure side by the second sealing assembly.

[0016] In some embodiments, the second sealing assembly and the second pole shoe are arranged on two sides of the magnetic conductive ring along the axial direction of the rotating shaft, and the floating seal seat and the magnetic conductive ring are movably connected with the second sealing assembly along the radial direction of the rotating shaft.

[0017] The second sealing assembly comprises a third pole shoe, a second permanent magnet and a fourth pole shoe which are sleeved in sequence from inside to outside, each of the third pole shoe and the fourth pole shoe is provided with a second pole tooth adjacent to the end surface of the magnetic conductive ring, the second pole tooth and the magnetic conductive ring are adsorbed with micro-nano magnetic medium therebetween, and the magnetic pole direction of the second permanent magnet is perpendicular to the axial direction of the rotating shaft.

[0018] Further, the magnetic pole of the first permanent magnet adjacent to the second pole shoe is the same as the magnetic pole of the second permanent magnet adjacent to the fourth pole shoe.

[0019] Further, the outer circumferential surface of the fourth pole shoe and the inner circumferential surface of the chamber are clamped with a second sealing ring therebetween.

[0020] In some embodiments, the magnetic conductive ring is provided with a boss adjacent to the end surface of the second sealing assembly, the boss is spaced apart from the first annular shoulder in the radial direction of the rotating shaft, and the second pole tooth is located between the boss and the first annular shoulder.

[0021] The second pole tooth is multiple and is arranged along the radial direction of the rotating shaft, the second pole tooth closest to the boss defines a third gap with the boss, the second pole tooth closest to the first annular shoulder defines a fourth gap with the first annular shoulder, the third gap and the fourth gap are both larger than the first gap.

[0022] In some embodiments, the sealing device further comprises a labyrinth seal ring, an airflow passage for accommodating the labyrinth seal ring is defined between the inner circumferential surface of the third pole shoe and the outer circumferential surface of the rotating shaft, the labyrinth seal ring is sleeved on the rotating shaft and connected with the third pole shoe, the inner circumferential surface of the labyrinth seal ring is provided with a sealing tooth, the sealing tooth and the outer circumferential surface of the rotating shaft define a fifth gap, the inner circumferential surface of the magnetic conducting ring and the outer circumferential surface of the rotating shaft define a sixth gap, the fifth gap is smaller than the sixth gap.

[0023] Further, the sealing tooth is multiple and is arranged along the axial direction of the rotating shaft.

[0024] Further, the sealing tooth is a sawtooth, wherein the sealing tooth closest to the magnetic conducting ring is inclined in the direction from the second pole shoe to the first pole shoe, and the remaining sealing teeth are inclined in the direction from the first pole shoe to the second pole shoe.

[0025] In some embodiments, the sealing device further comprises a second end cover, the second end cover is sleeved on the rotating shaft and connected with the shell, and the second end cover is adapted to cover the chamber.

[0026] In some embodiments, the sealing device further comprises a second magnetic isolation ring, the second magnetic isolation ring is fitted in the chamber and sleeved on the rotating shaft, the second magnetic isolation ring is located between the second end cover and the floating seal seat, and the end surface of the second magnetic isolation ring away from the floating seal seat abuts against the second end cover.

[0027] In some embodiments, the floating seal seat has a first end surface and a second end surface opposite along the axial direction of the rotating shaft, and the outer circumferential edge of each of the first end surface and the second end surface of the floating seal seat is provided with a ball retainer, and the ball retainer and the floating seal seat enclose an annular groove.

[0028] The annular groove is provided with balls, at least part of the balls protrude out of the annular groove along the axial direction of the rotating shaft and are in rolling contact with the second magnetic isolation ring or the fourth pole shoe, so as to facilitate the floating seal seat to move along the radial direction of the rotating shaft relative to the chamber.

[0029] Further, the balls are multiple and are arranged along the circumferential direction of the annular groove, and any two adjacent balls are in rolling contact.

[0030] In some embodiments, the sealing device further comprises a first bearing and a second bearing, each of the first bearing and the second bearing being fitted in the chamber and sleeved on the rotating shaft, each of the first bearing and the second bearing being closer to the high-pressure side than the second sealing assembly;

[0031] The rotating shaft is provided with a shaft shoulder, an inner circumferential surface of the shell is provided with a second annular shoulder, the shaft shoulder is respectively abutted against the first bearing and the second bearing along two end surfaces of the rotating shaft in the axial direction, an end surface of the first bearing away from the shaft shoulder is abutted against the fourth pole shoe through a third magnetic isolation ring, the third magnetic isolation ring is fitted in the chamber and sleeved on the rotating shaft, and an end surface of the second bearing away from the shaft shoulder is abutted against the second annular shoulder.

[0032] In some embodiments, the shell is adapted to be connected with a sealed device and is provided with a third sealing ring, the third sealing ring is clamped between the shell and the sealed device.

[0033] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic view of a follow-up type micro-nano magnetic medium sealing device according to an embodiment of the present application.

[0035] Figure 2 is Figure 1 is a partial enlarged structural schematic view of A in FIG. 1.

[0036] Figure 3 is Figure 1 is a partial enlarged structural schematic view of B in FIG. 1.

[0037] Figure 4 is Figure 1 is a partial enlarged structural schematic view of C in FIG. 1.

[0038] Figure 5 is a schematic view of an air flow force on a floating sealing structure of a follow-up type micro-nano magnetic medium sealing device according to an embodiment of the present application in a rotating shaft radial run-out state.

[0039] REFERENCE SIGNS:

[0040] 1, shell; 11, chamber; 12, second end cover; 13, second magnetic isolation ring; 14, first bearing; 15, second bearing; 16, second annular shoulder; 17, third magnetic isolation ring; 18, third sealing ring;

[0041] 2, rotating shaft; 21, first gap; 22, shaft shoulder;

[0042] 3. Floating seal seat; 31. Second gap; 32. First annular shoulder; 33. Ball retainer; 34. Ball;

[0043] 4. First sealing assembly; 41. First pole shoe; 42. First permanent magnet; 43. Second pole shoe; 44. First pole tooth; 45. First sealing ring;

[0044] 5. First end cover;

[0045] 6. Magnetic ring; 61. Boss; 62. Sixth gap;

[0046] 7. The first magnetic isolation ring;

[0047] 8. Second sealing assembly; 81. Third pole shoe; 82. Second permanent magnet; 83. Fourth pole shoe; 84. Second pole tooth; 85. Second sealing ring; 86. Third gap; 87. Fourth gap;

[0048] 9. Labyrinth sealing ring; 91. Sealing teeth; 92. Fifth gap. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0050] like Figures 1 to 5 As shown, a follow-up micro-nano magnetic medium sealing device according to an embodiment of the present invention includes a housing 1, a rotating shaft 2, a floating seal seat 3 and a first sealing component 4. The housing 1 has a chamber 11, and the rotating shaft 2 is pivotally connected to the chamber 11 and at least one end is located outside the housing 1; the rotating shaft 2, the first sealing component 4 and the floating seal seat 3 are sequentially sleeved from the inside to the outside, and the floating seal seat 3 and the first sealing component 4 are both matched with the chamber 11 and are movably connected to the chamber 11 along the radial direction of the rotating shaft 2. The first sealing component 4 includes a first pole shoe 41, a first pole shoe 42 and a first pole shoe 43 arranged in sequence along the axial direction of the rotating shaft 2. The permanent magnet 42 and the second pole shoe 43, the magnetic pole direction of the first permanent magnet 42 is consistent with the axial direction of the rotating shaft 2; the inner circumference of each of the first pole shoe 41 and the second pole shoe 43 and the outer circumference of the rotating shaft 2 define a first gap 21, and the first gap 21 is adsorbed with micro-nano magnetic medium. The outer circumference of the floating seal seat 3 and the inner circumference of the chamber 11 define a second gap 31 connected to the outside world, and the pressure of the first gap 21 is higher than the pressure of the second gap 31, so that the floating seal seat 3 and the first sealing assembly 4 can adjust the radial position relative to the chamber 11 with the rotating shaft 2 under the action of the pressure difference.

[0051] According to the floating type micro-nano magnetic medium sealing device, the floating sealing structure is movably connected to the chamber 11 along the radial direction of the rotating shaft 2, the first gap 21 is smaller than the second gap 31, and the pressure of the first gap 21 is higher than the pressure of the second gap 31. Therefore, when the rotating shaft 2 is in a radial runout state, that is, the rotating shaft 2 is eccentric relative to the first pole shoe 41 and the second pole shoe 43, the first gap 21 is uneven in the circumferential direction, and there are large gaps and small gaps in the circumferential direction. When the sealing device is installed on the sealed equipment, the high-pressure gas in the sealed equipment enters the first gap 21. At this time, the fluid dynamic pressure effect of the high-pressure gas makes the pressure on the small gap side of the first gap 21 very large, and a pressure difference is formed between the small gap side and the second gap 31. Under the action of the pressure difference, the first pole shoe 41 and the second pole shoe 43 are pushed to the small gap side, that is, the first pole shoe 41 and the second pole shoe 43 move towards the direction of increasing the size of the gap, so as to realize the follow-up of the first pole shoe 41 and the second pole shoe 43 relative to the rotating shaft 2, thereby adaptively adjusting the concentricity between the rotating shaft 2 and the first pole shoe 41 and the second pole shoe 43, reducing the influence of the radial runout of the rotating shaft 2 on the micro-nano magnetic medium sealing. Compared with the related art, the sealing assembly (that is, the first sealing assembly 4) can follow the radial runout of the rotating shaft 2 under the action of the fluid dynamic pressure effect, so as to change the gap between the sealing assembly and the rotating shaft 2, reduce the influence of the radial runout of the rotating shaft 2, and improve the pressure resistance and service life.

[0052] Specifically, the chamber 11 can extend along the axial direction of the rotating shaft 2. The axial direction of the rotating shaft 2 can be the left-right direction in the figure. The rotating shaft 2, the first sealing assembly 4 and the floating sealing seat 3 can be coaxially arranged. The first pole shoe 41 and the second pole shoe 43 can adopt the same structure and specification. The first permanent magnet 42 can be a ring-shaped permanent magnet. The magnetic pole direction of the first permanent magnet 42 is consistent with the axial direction of the rotating shaft 2, that is, the N pole and the S pole of the first permanent magnet 42 are arranged along the left-right direction in the figure. For example, in the figure, the first pole shoe 41 is located on the left side of the second pole shoe 43.

[0053] It can be understood that the first sealing assembly 4 forms an axial micro-nano magnetic medium sealing in the sealing device. The inner circumferential surface of the chamber 11 is the inner circumferential surface of the housing 1 used to surround the chamber 11. The magnetic circuit of the first sealing assembly 4 is that the magnetic field emitted from the N pole of the first permanent magnet 42 passes through the first pole shoe 41, the rotating shaft 2 and the second pole shoe 43, and returns to the S pole of the first permanent magnet 42.

[0054] The second gap 31 is in communication with the outside, so that low-pressure gas outside the shell 1 enters the second gap 31, and after the high-pressure gas in the sealed device enters the first gap 21, the pressure difference between the low-pressure gas in the second gap 31 and the fluid dynamic pressure generated by the high-pressure gas in the first gap 21 can stabilize the floating sealing structure in the chamber 11, ensure the sealing performance, and actively center the floating sealing structure with the radial jumping of the rotating shaft 2, so that the sealing device can adaptively adjust the concentricity between the floating sealing structure and the rotating shaft 2. Compared with the related art, the present application can ensure the sealing performance based on the existing conditions of the sealing device, has good micro-nano magnetic medium distribution state, low cost, simple overall structure, and high reliability.

[0055] It should be noted that after the sealing device is installed on the sealed device, high-pressure gas needs to be filled into the sealing chamber of the sealed device before starting, so that a high-pressure side and a low-pressure side are formed outside the shell 1 in the sealing device, wherein the high-pressure gas on the high-pressure side enters the first gap 21, and the low-pressure gas (which can also be said to be the outside atmosphere) on the low-pressure side enters the second gap 31.

[0056] At this time, the force generated by the fluid dynamic pressure effect of the high-pressure gas in the first gap 21 on the floating sealing structure is directed towards the outer peripheral surface of the first sealing assembly 4, and the force generated by the gas pressure of the second gap 31 on the floating sealing structure is directed towards the inner peripheral surface of the first sealing assembly 4, but since the former is the fluid dynamic pressure effect of high-pressure gas and the latter is low-pressure gas, the force generated by the former is much greater, so the overall resultant force is outward, and therefore when the rotating shaft 2 radially jumps to cause a small gap in the circumferential direction of the first gap 21, the first pole shoe 41 and the second pole shoe 43 will move towards the direction of increasing the small gap side of the first gap 21, so as to adjust the concentricity of the floating sealing structure relative to the rotating shaft 2 and improve the pressure resistance of the sealing device.

[0057] In addition, the present application is not limited to application in a nuclear reactor main pump, and can also be applied to other sealing occasions where the rotating shaft 2 radially jumps.

[0058] Figure 5 O is the geometric center of the floating sealing structure, O' is the geometric center of the rotating shaft 2, ω is the rotational angular velocity of the rotating shaft 2, p is the gas flow pressure distribution between the floating sealing structure and the rotating shaft 2, and F is the gas flow force on the floating sealing structure.

[0059] Further, the first pole shoe 41 and the second pole shoe 43 can be mirror-symmetric relative to a reference surface, the reference surface is perpendicular to the axial direction of the rotating shaft 2, and the center of the first permanent magnet 42 is coplanar with the reference surface, that is, the first permanent magnet 42 is mirror-symmetric relative to the reference surface.

[0060] As Figure 1As shown, in some embodiments, each of the first pole shoe 41 and the second pole shoe 43 is provided with a first pole tooth 44, and there are multiple first pole teeth 44 and they are arranged at intervals along the axial direction of the rotating shaft 2, and a first gap 21 is defined between all the first pole teeth 44 and the outer peripheral surface of the rotating shaft 2, wherein the multiple first pole teeth 44 are preferably arranged at equal intervals along the axial direction of the rotating shaft 2 to ensure uniform force on all the pole teeth in the first pole shoe 41 and the second pole shoe 43.

[0061] Furthermore, the first gap 21 is smaller than the second gap 31. In other words, the maximum distance from the inner circumference of each of the first pole shoe 41 and the second pole shoe 43 to the outer circumference of the rotating shaft 2 is smaller than the minimum distance from the outer circumference of the floating seal seat 3 to the inner circumference of the chamber 11. That is to say, the first gap 21 is smaller than the second gap 31 at all locations in the circumferential direction of the rotating shaft 2.

[0062] Furthermore, a first sealing ring 45 is sandwiched between the outer circumference of each of the first pole shoe 41 and the second pole shoe 43 and the inner circumference of the floating seal seat 3 to further ensure the sealing performance.

[0063] For example, taking the figure as an example, annular grooves can be provided on the outer circumference of the first pole shoe 41 and the outer circumference of the second pole shoe 43 , and the first sealing ring 45 can be fitted in the annular grooves and abut against the inner circumference of the floating seal seat 3 .

[0064] like Figure 1 As shown, in some embodiments, the sealing device also includes a first end cover 5 and a magnetic ring 6, which are both sleeved on the rotating shaft 2 and are respectively arranged on both sides of the first sealing component 4 along the axial direction of the rotating shaft 2, the first end cover 5 is connected to the floating seal seat 3, the end face of the first pole shoe 41 facing away from the first permanent magnet 42 abuts against the first end cover 5, and the inner circumferential surface of the floating seal seat 3 is provided with a first annular boss 32, the magnetic ring 6 is located between the second pole shoe 43 and the first annular boss 32 and abuts against the first annular boss 32, so that the first sealing component 4 is axially positioned by the first end cover 5 and the first annular boss 32, and the first sealing component 4 is limited in the inner cavity of the floating seal seat 3 along the axial direction of the rotating shaft 2.

[0065] Specifically, the first end cap 5 and the magnetic ring 6 can be located in the inner cavity of the floating seal seat 3. The first end cap 5 can be threadedly connected to the floating seal seat 3 to ensure the connection reliability between the two, while facilitating the disassembly and assembly of the floating seal structure and reducing the subsequent maintenance cost.

[0066] like Figure 1 As shown, in some embodiments, the sealing device also includes a first magnetic isolation ring 7, which is sleeved on the rotating shaft 2 and located in the inner cavity of the floating sealing seat 3. The two end surfaces of the first magnetic isolation ring 7 opposite to each other along the axial direction of the rotating shaft 2 are respectively in contact with the second pole shoe 43 and the magnetic conductive ring 6. In other words, the first magnetic isolation ring 7 is clamped between the second pole shoe 43 and the magnetic conductive ring 6.

[0067] like Figure 1 As shown, in some embodiments, the sealing device also includes a second sealing component 8, which is matched with the chamber 11 and is sleeved on the rotating shaft 2. The second sealing component 8 and the first sealing component 4 are arranged along the axial direction of the rotating shaft 2 and are closer to the high-pressure side than the first sealing component 4, so that the second sealing component 8 separates the first sealing component 4 from the high-pressure side, reduces the influence of the high-pressure gas on the high-pressure side on the sealing performance of the first sealing component 4, and improves the sealing reliability of the sealing device.

[0068] For example, taking the figure as an example, the right side of the housing 1 in the sealing device can be the high-pressure side, and the left side of the housing 1 can be the low-pressure side.

[0069] like Figure 1 and Figure 3 As shown, in some embodiments, the second sealing assembly 8 and the second pole shoe 43 are arranged on both sides of the magnetic ring 6 along the axial direction of the rotating shaft 2. In other words, the second sealing assembly 8 is closer to the high-pressure side than the second pole shoe 43, and the floating sealing seat 3 and the magnetic ring 6 are both movably connected to the second sealing assembly 8 along the radial direction of the rotating shaft 2.

[0070] The second sealing assembly 8 includes a third pole shoe 81, a second permanent magnet 82 and a fourth pole shoe 83 which are sequentially arranged from the inside to the outside. Each of the third pole shoe 81 and the fourth pole shoe 83 is provided with a second pole tooth 84 on the end face adjacent to the magnetic ring 6. A micro-nano magnetic medium is adsorbed between the second pole tooth 84 and the magnetic ring 6. The magnetic pole direction of the second permanent magnet 82 is perpendicular to the axial direction of the rotating shaft 2.

[0071] It can be understood that the second sealing component 8 forms an end face micro-nano magnetic medium seal in the sealing device, and the first magnetic isolation ring 7 can separate the axial micro-nano magnetic medium seal and the end face micro-nano magnetic medium seal so that the two micro-nano magnetic medium sealing forms do not interfere with each other, thereby ensuring the working performance of both. Among them, the magnetic circuit of the second sealing component 8 is: the magnetic field emitted from the N pole of the second permanent magnet 82 passes through the third pole shoe 81, the magnetic conductive ring 6 and the fourth pole shoe 83 and returns to the S pole of the second permanent magnet 82.

[0072] Specifically, the second permanent magnet 82 can be an annular permanent magnet. The magnetic pole direction of the second permanent magnet 82 is perpendicular to the axial direction of the rotating shaft 2, that is, the north pole and the south pole of the second permanent magnet 82 are arranged along the radial direction of the rotating shaft 2, such as the south pole of the second permanent magnet 82 is located outside the north pole, or the north pole of the second permanent magnet 82 is located outside the south pole.

[0073] Furthermore, the magnetic pole of the first permanent magnet 42 adjacent to the second pole shoe 43 is the same as the magnetic pole of the second permanent magnet 82 adjacent to the fourth pole shoe 83. Since air will leak magnetic flux, the first permanent magnet 42 and the second permanent magnet 82 adopt the aforementioned layout structure, which will not weaken the magnetic properties of the magnets.

[0074] For example, the installation direction of the first permanent magnet 42 is left N pole and right S pole, and the corresponding installation direction of the second permanent magnet 82 is inner N pole and outer S pole; or, the installation direction of the first permanent magnet 42 is left S pole and right N pole, and the corresponding installation direction of the second permanent magnet 82 is inner S pole and outer N pole.

[0075] Furthermore, a second sealing ring 85 is sandwiched between the outer circumference of the fourth pole shoe 83 and the inner circumference of the chamber 11 to further ensure the sealing performance of the sealing device.

[0076] For example, taking the figure as an example, an annular groove may be provided on the outer circumference of the fourth pole shoe 83 , and the second sealing ring 85 may be fitted in the annular groove and abut against the inner circumference of the chamber 11 .

[0077] like Figure 1 and Figure 4 As shown, in some embodiments, the end surface of the magnetic ring 6 adjacent to the second sealing assembly 8 is provided with a boss 61 , the boss 61 is spaced apart from the first annular shoulder 32 in the radial direction of the rotating shaft 2 , and the second pole tooth 84 is located between the boss 61 and the first annular shoulder 32 .

[0078] There are multiple second pole teeth 84, spaced apart in the radial direction of the rotating shaft 2. A third gap 86 is defined between the second pole tooth 84 closest to the boss 61 and the boss 61. This means that the first second pole tooth 84 near the inner circumference of the third pole shoe 81 is spaced apart from the magnetic ring 6 in the radial direction of the rotating shaft 2. A fourth gap 87 is defined between the second pole tooth 84 closest to the first annular shoulder 32 and the first annular shoulder 32. This means that the first second pole tooth 84 near the outer circumference of the fourth pole shoe 83 is spaced apart from the floating seal seat 3 in the radial direction of the rotating shaft 2. Both the third gap 86 and the fourth gap 87 are larger than the first gap 21. In other words, each of the third gap 86 and the fourth gap 87 is larger than the first gap 21 at all locations along the circumference of the rotating shaft 2.

[0079] It can be understood that when the floating sealing structure moves radially along the rotating shaft 2 (i.e. floats), based on the above conditions, the second pole tooth 84 in the third pole shoe 81 closest to the boss 61 will not collide with the boss 61, nor will the second pole tooth 84 in the fourth pole shoe 83 closest to the first annular shoulder 32 collide with the first annular shoulder 32.

[0080] Preferably, the plurality of second pole teeth 84 are arranged at equal intervals along the radial direction of the rotating shaft 2 to ensure uniform force on all the pole teeth in the third pole shoe 81 and the fourth pole shoe 83 .

[0081] like Figure 1 and Figure 4 As shown, in some embodiments, the sealing device further includes a labyrinth sealing ring 9, an air flow channel for accommodating the labyrinth sealing ring 9 is defined between the inner circumference of the third pole shoe 81 and the outer circumference of the rotating shaft 2, the labyrinth sealing ring 9 is sleeved on the rotating shaft 2 and connected to the third pole shoe 81, the inner circumference of the labyrinth sealing ring 9 is provided with sealing teeth 91, a fifth gap 92 is defined between the sealing teeth 91 and the outer circumference of the rotating shaft 2, a sixth gap 62 is defined between the inner circumference of the magnetic ring 6 and the outer circumference of the rotating shaft 2, the fifth gap 92 is smaller than the sixth gap 62, in other words, the maximum distance from the sealing teeth 91 to the outer circumference of the rotating shaft 2 is smaller than the minimum distance from the inner circumference of the magnetic ring 6 to the outer circumference of the rotating shaft 2, or in other words, the sealing teeth 91 are closer to the rotating shaft 2 than the magnetic ring 6.

[0082] It is understood that the use of the labyrinth seal ring 9 effectively increases the flow resistance to the airflow during the unsteady flow process of pressurization (i.e., filling the sealed chamber of the sealed device with high-pressure gas). The seal teeth 91 reduce the pressure of the high-pressure gas, allowing the micro-nano magnetic medium to contact the lower-energy airflow, thereby effectively preventing the micro-nano magnetic medium film from being ruptured during the pressurization process. Furthermore, because the fifth gap 92 is smaller than the sixth gap 62, the labyrinth seal ring 9 will contact the rotating shaft 2 before the magnetic ring 6 when the rotating shaft 2 experiences radial runout, thus ensuring that the second sealing assembly 8 (i.e., the end-face micro-nano magnetic medium sealing structure) has excellent anti-wear performance.

[0083] Furthermore, there are multiple sealing teeth 91 and they are spaced apart along the axial direction of the rotating shaft 2. Preferably, the multiple sealing teeth 91 are equally spaced apart along the axial direction of the rotating shaft 2 to ensure uniform force on all the sealing teeth 91 in the labyrinth sealing ring 9.

[0084] Furthermore, the sealing teeth 91 are serrated, wherein the sealing teeth 91 closest to the magnetic ring 6 are inclined in the direction from the second pole shoe 43 toward the first pole shoe 41, and the remaining sealing teeth 91 are inclined in the direction from the first pole shoe 41 toward the second pole shoe 43. In other words, taking the figure as an example, there are three sealing teeth 91, that is, the sealing tooth 91 on the far left is a conical bevel tooth inclined toward the left, and the two sealing teeth 91 on the right are conical bevel teeth inclined toward the right.

[0085] It can be understood that, in the unsteady process of gas flow during the pressurization, the two sealing teeth 91 on the right side of the labyrinth seal ring 9 are used to increase the flow resistance of the gas flow, so as to reduce the pressure of the high-pressure gas, thereby protecting the micro-nano magnetic medium from being impacted by the gas flow with small energy, that is, avoiding the micro-nano magnetic medium from being "blown away" by the high-energy gas flow, and thereby the artificial pressurization can increase the gas flow and reduce the artificial pressurization time. The first sealing tooth 91 on the left side can guide more gas flow into the axial micro-nano magnetic medium seal, so that less gas flow enters the end face micro-nano magnetic medium seal. At the same time, the chamber 11 formed between the first sealing tooth 91 on the left side and the magnetic conducting ring 6 can form a rotational flow of the gas flow, so that the energy of the gas flow entering the end face micro-nano magnetic medium seal is lower, thereby improving the pressure resistance of the end face micro-nano magnetic medium seal during the pressurization process, and then isolating the second gap 31 (that is, the chamber formed by the outer shell 1 and the floating seal seat 3) from the high-pressure side.

[0086] As shown in Figure 1 and Figure 2 , in some embodiments, the sealing device further comprises a second end cover 12, which is sleeved on the rotating shaft 2 and connected with the outer shell 1, and the second end cover 12 is adapted to cover the chamber 11.

[0087] Specifically, the second end cover 12 can be located in the chamber 11. The second end cover 12 can be threadedly connected with the outer shell 1 to ensure the reliability of the connection between the two, while facilitating the disassembly of the sealing device and reducing the later maintenance cost.

[0088] As shown in Figure 1 and Figure 2 , in some embodiments, the sealing device further comprises a second magnetic shielding ring 13, which is fitted in the chamber 11 and sleeved on the rotating shaft 2. The second magnetic shielding ring 13 is located between the second end cover 12 and the floating seal seat 3, and the end surface of the second magnetic shielding ring 13 away from the floating seal seat 3 abuts against the second end cover 12.

[0089] As shown in Figures 1 to 3 , in some embodiments, the floating seal seat 3 has a first end surface and a second end surface opposite along the axial direction of the rotating shaft 2. The outer periphery of each of the first end surface and the second end surface of the floating seal seat 3 is provided with a ball retainer 33, and the ball retainer 33 and the floating seal seat 3 form an annular groove.

[0090] The annular groove is provided with a plurality of balls 34, at least part of which protrudes out of the annular groove along the axial direction of the rotating shaft 2 and is in rolling contact with the second magnetic shielding ring 13 or the fourth pole shoe 83, so as to facilitate the floating seal seat 3 to move along the radial direction of the rotating shaft 2 relative to the chamber 11.

[0091] It can be understood that, by installing the ball retainer 33 and the ball 34 structure on the floating seal seat 3, the friction between the floating seal structure and the second magnetic isolation ring 13 and the fourth pole shoe 83 when the floating seal structure self-adapts and adjusts the concentricity with the radial jump of the rotating shaft 2 can be effectively reduced, so that the floating seal structure is more easily moved (i.e., floating).

[0092] Further, the balls 34 are multiple and arranged along the circumferential direction of the annular groove, and any two adjacent balls 34 are in rolling contact.

[0093] Specifically, the balls 34 can be made of a material that has both self-lubricating properties and high hardness.

[0094] As shown in Figure 1 some embodiments, the sealing device further includes a first bearing 14 and a second bearing 15, both of which are fitted in the chamber 11 and sleeved on the rotating shaft 2, and each of the first bearing 14 and the second bearing 15 is closer to the high-pressure side than the second sealing assembly 8.

[0095] The rotating shaft 2 is provided with a shaft shoulder 22, and the inner circumferential surface of the housing 1 is provided with a second annular shoulder 16, the shaft shoulder 22 abuts against the first bearing 14 and the second bearing 15 respectively at the two axially opposite end surfaces of the rotating shaft 2, the end surface of the first bearing 14 away from the shaft shoulder 22 abuts against the fourth pole shoe 83 through a third magnetic isolation ring 17, the third magnetic isolation ring 17 is fitted in the chamber 11 and sleeved on the rotating shaft 2, and the end surface of the second bearing 15 away from the shaft shoulder 22 abuts against the second annular shoulder 16.

[0096] It can be understood that, by cooperation of the second end cover 12 and the second annular shoulder 16, the floating seal structure, the second sealing assembly 8, the labyrinth seal ring 9, the first bearing 14 and the second bearing 15 can be axially positioned to limit the aforementioned components in the chamber 11.

[0097] Specifically, the first bearing 14 and the second bearing 15 can both be deep groove ball bearings.

[0098] As shown in Figure 1 some embodiments, the housing 1 is adapted to be connected with a sealed device and is provided with a third sealing ring 18, the third sealing ring 18 is clamped between the housing 1 and the sealed device to seal the connection gap therebetween, further ensuring the sealing reliability of the sealing device.

[0099] For example, the housing 1 can be connected with the sealed device through a flange plate, the end surface of the flange plate can be provided with an annular groove, and the third sealing ring 18 can be fitted in the annular groove.

[0100] It should be noted that the floating seal seat 3, the first end cover 5, the first magnetic isolation ring 7, the ball retainer 33 and the ball 34 can be made of light non-magnetic material; the shell 1, the labyrinth seal ring 9, the second end cover 12, the first bearing 14 and the second bearing 15 can be made of non-magnetic material, or the shell 1, the labyrinth seal ring 9, the second end cover 12, the first bearing 14 and the second bearing 15 can be provided with a non-magnetic material coating; the first pole shoe 41, the second pole shoe 43 and the magnetic ring 6 can be made of light magnetic material; the rotating shaft 2, the third pole shoe 81 and the fourth pole shoe 83 can be made of magnetic material; the first permanent magnet 42 and the second permanent magnet 82 can adopt neodymium iron boron material.

[0101] Therefore, the present application has the following advantages compared with the related art:

[0102] 1) Under the action of fluid dynamic pressure effect, the axial micro-nano magnetic medium seal has follow-up, which changes the gap between the rotating shaft 2 and the rotating shaft 2, improves the concentricity of the rotating shaft 2 relative to the first sealing assembly 4, reduces the influence of the radial jump of the rotating shaft 2, and improves the pressure resistance and service life of the sealing device;

[0103] 2) The setting of the labyrinth seal ring 9 can protect the micro-nano magnetic medium from being impacted by a smaller energy airflow during the pressure charging process, which can reduce the artificial pressure charging time and improve the production efficiency.

[0104] In the description of the present application, it should be understood that 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" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0105] In addition, the terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" 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 specifically limited.

[0106] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connecting", "fixed", "fixedly connected", "connection", "fixedly connected", "connected", "fixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. 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.

[0107] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be 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 only indicates that the first feature is higher than the second feature in horizontal height. 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 only indicates that the first feature is lower than the second feature in horizontal height.

[0108] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 application. In the present specification, the illustrative expressions 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 any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0109] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A follow-up micro-nano magnetic medium sealing device, characterized in that: include: A housing and a rotating shaft, wherein the housing has a chamber, the rotating shaft is pivotally connected to the chamber and has at least one end located outside the housing; as well as A floating seal seat and a first seal assembly, wherein the rotating shaft, the first seal assembly, and the floating seal seat are sequentially sleeved from the inside to the outside, the floating seal seat and the first seal assembly are both fitted into the chamber and movably connected to the chamber along the radial direction of the rotating shaft, the first seal assembly comprising a first pole shoe, a first permanent magnet, and a second pole shoe sequentially arranged along the axial direction of the rotating shaft, the magnetic pole direction of the first permanent magnet being consistent with the axial direction of the rotating shaft; A first gap is defined between the inner circumference of each of the first pole shoe and the second pole shoe and the outer circumference of the rotating shaft, wherein a micro-nano magnetic medium is adsorbed in the first gap, and a second gap communicating with the outside is defined between the outer circumference of the floating seal seat and the inner circumference of the chamber; The floating seal seat has a first end face and a second end face that are opposite to each other along the axial direction of the rotating shaft, and a ball retainer is provided on the outer periphery of each of the first end face and the second end face of the floating seal seat, and the ball retainer and the floating seal seat form an annular groove; A ball is arranged in the annular groove.

2. The follow-up micro-nano magnetic medium sealing device according to claim 1, characterized in that: Each of the first pole shoe and the second pole shoe is provided with a first pole tooth, wherein the first pole teeth are provided in plurality and are arranged at intervals along the axial direction of the rotating shaft, and the first gap is defined between all the first pole teeth and the outer peripheral surface of the rotating shaft; And / or, the first gap is smaller than the second gap.

3. The follow-up micro-nano magnetic medium sealing device according to claim 1, characterized in that: Also includes: a first end cover and a magnetic conductive ring, wherein the first end cover and the magnetic conductive ring are both sleeved on the rotating shaft and are respectively arranged on both sides of the first sealing assembly along the axial direction of the rotating shaft; the first end cover is connected to the floating seal seat; the end surface of the first pole shoe facing away from the first permanent magnet abuts against the first end cover; the inner circumferential surface of the floating seal seat is provided with a first annular shoulder; the magnetic conductive ring is located between the second pole shoe and the first annular shoulder and abuts against the first annular shoulder; and / or The first magnetic isolation ring is sleeved on the rotating shaft and located in the inner cavity of the floating seal seat. The first magnetic isolation ring has two opposite axial ends along the rotating shaft that are in contact with the second pole shoe and the magnetic conductive ring respectively.

4. The follow-up micro-nano magnetic medium sealing device according to claim 3, characterized in that: It also includes a second sealing component, which is matched with the chamber and sleeved on the rotating shaft. The second sealing component and the first sealing component are arranged along the axial direction of the rotating shaft and are closer to the high-pressure side than the first sealing component.

5. The follow-up micro-nano magnetic medium sealing device according to claim 4, characterized in that: The second sealing assembly and the second pole shoe are respectively arranged on both sides of the magnetic conductive ring along the axial direction of the rotating shaft, and the floating sealing seat and the magnetic conductive ring are both movably connected to the second sealing assembly along the radial direction of the rotating shaft; The second sealing assembly includes a third pole shoe, a second permanent magnet and a fourth pole shoe which are sequentially arranged from the inside to the outside. Each of the third pole shoe and the fourth pole shoe is provided with a second pole tooth adjacent to the end face of the magnetic conductive ring. A micro-nano magnetic medium is adsorbed between the second pole tooth and the magnetic conductive ring. The magnetic pole direction of the second permanent magnet is perpendicular to the axial direction of the rotating shaft.

6. The follow-up micro-nano magnetic medium sealing device according to claim 5, characterized in that: The magnetic conductive ring is provided with a boss on an end surface adjacent to the second sealing assembly, the boss is spaced apart from the first annular shoulder in the radial direction of the rotating shaft, and the second pole tooth is located between the boss and the first annular shoulder; There are multiple second pole teeth and they are arranged at intervals along the radial direction of the rotating shaft. A third gap is defined between the second pole tooth closest to the boss and the boss. A fourth gap is defined between the second pole tooth closest to the first annular shoulder and the first annular shoulder. Both the third gap and the fourth gap are larger than the first gap.

7. The follow-up micro-nano magnetic medium sealing device according to claim 5, characterized in that: It also includes a labyrinth sealing ring, an air flow channel for accommodating the labyrinth sealing ring is defined between the inner circumference of the third pole shoe and the outer circumference of the rotating shaft, the labyrinth sealing ring is sleeved on the rotating shaft and connected to the third pole shoe, the inner circumference of the labyrinth sealing ring is provided with sealing teeth, a fifth gap is defined between the sealing teeth and the outer circumference of the rotating shaft, a sixth gap is defined between the inner circumference of the magnetic ring and the outer circumference of the rotating shaft, and the fifth gap is smaller than the sixth gap.

8. The follow-up micro-nano magnetic medium sealing device according to claim 7, characterized in that: There are a plurality of sealing teeth which are spaced apart along the axial direction of the rotating shaft; And / or, the sealing teeth are saw teeth, wherein the sealing teeth closest to the magnetic ring are inclined in the direction from the second pole shoe toward the first pole shoe, and the remaining sealing teeth are inclined in the direction from the first pole shoe toward the second pole shoe.

9. The follow-up micro-nano magnetic medium sealing device according to claim 7, characterized in that: Also includes: a second end cover, the second end cover being sleeved on the rotating shaft and connected to the housing, the second end cover being suitable for sealing the chamber; and / or The second magnetic isolation ring is matched with the chamber and is sleeved on the rotating shaft. The second magnetic isolation ring is located between the second end cover and the floating seal seat. The end surface of the second magnetic isolation ring facing away from the floating seal seat abuts against the second end cover.

10. The follow-up micro-nano magnetic medium sealing device according to claim 9, characterized in that: At least part of the ball protrudes out of the annular groove along the axial direction of the rotating shaft and is in rolling contact with the second magnetic isolation ring or the fourth pole shoe, so that the floating seal seat moves radially along the rotating shaft relative to the chamber.

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