Compensation type wide-speed-range magnetic medium sealing device

Abstract

The invention provides a compensation type wide-speed-range magnetic medium sealing device and relates to the technical field of sealing devices, the compensation type wide-speed-range magnetic medium sealing device comprises a shell, a hollow shaft, a first sealing assembly and a second sealing assembly, the shell is provided with a containing cavity, and the hollow shaft divides the containing cavity into an inner cavity and an outer cavity which are arranged in a sleeved mode; the first sealing assembly is matched with the outer cavity and arranged on the hollow shaft in a sleeving mode, and a first sealing gap is defined between the inner circumferential face of the first sealing assembly and the outer circumferential face of the hollow shaft. The second sealing assembly is matched with the inner cavity and connected with the shell, and a second sealing gap is defined between the outer circumferential face of the second sealing assembly and the inner circumferential face of the inner cavity. The first sealing gap and the second sealing gap attract magnetic media, and the first sealing gap is larger than the second sealing gap. The magnetic medium sealing structure can meet the pressure resistance of magnetic medium sealing when the hollow shaft is in a static state and a low-speed operation state, space allowance can be reserved for radial extension of the hollow shaft in a high-speed operation state, and the sealing reliability under the full-speed-domain working condition is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing devices, and in particular to a compensating wide-speed range magnetic medium sealing device. Background Art

[0002] Magnetic medium seal is a type of seal that uses non-uniform magnetic field force to bind magnetic medium to prevent leakage of working fluid. It has the advantage of "zero leakage". Therefore, magnetic medium seal can effectively improve the working efficiency and safety of equipment. However, the rotating shafts in aerospace equipment are mainly thin-walled hollow shafts. Thin-walled hollow shafts will radially extend under high-speed rotation, and the radial extension will change under variable speed conditions. Therefore, the design of thin-walled hollow shaft wide-speed range magnetic medium seals is crucial.

[0003] When the hollow shaft in the related technology is sealed with magnetic media, if the sealing gap is designed to be small, it can meet the pressure resistance at low speeds, but the radially extended hollow shaft will rub against the pole shoe at high speeds, which may easily cause the magnetic media seal to be damaged and fail. On the contrary, if the sealing gap is designed to be large, the hollow shaft can be prevented from rubbing against the pole shoe under high-speed centrifugal extension, but it cannot meet the pressure resistance requirements at low speeds. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention proposes a compensating wide-speed range magnetic medium sealing device, which can meet the pressure resistance of the magnetic medium seal of the hollow shaft under static and low-speed operation conditions, and can reserve space margin for the radial extension of the hollow shaft under high-speed operation conditions, thereby ensuring the sealing reliability under full-speed range working conditions.

[0006] According to an embodiment of the present invention, a compensating wide-speed magnetic medium sealing device includes a shell, a hollow shaft, a first sealing component and a second sealing component. The shell has a accommodating chamber, the hollow shaft is pivotally connected to the accommodating chamber and is at least partially located outside the shell, and the hollow shaft divides the accommodating chamber into an inner chamber and an outer chamber that are nested with each other; the first sealing component is matched with the outer chamber and is sleeved on the hollow shaft, and a first sealing gap is defined between the inner circumference of the first sealing component and the outer circumference of the hollow shaft; the second sealing component is matched with the inner chamber and is connected to the shell, and a second sealing gap is defined between the outer circumference of the second sealing component and the inner circumference of the inner chamber; the first sealing gap and the second sealing gap both adsorb magnetic media, and the first sealing gap is larger than the second sealing gap.

[0007] According to the compensated wide-speed range magnetic medium sealing device of the embodiment of the present invention, a magnetic medium sealing structure is formed by the cooperation of a housing, a hollow shaft, a first sealing component and a second sealing component. When the hollow shaft is in a stationary or low-speed state, the first sealing gap is larger than the second sealing gap. The magnetic medium seal of the second sealing gap can ensure sufficient pressure resistance in the stationary state and low-speed state. When the hollow shaft is in a high-speed state, the hollow shaft will undergo radial elongation, the first sealing gap will decrease and the second sealing gap will increase. The magnetic medium seal of the first sealing gap will provide sufficient pressure resistance in the high-speed state. The radially extended hollow shaft will not rub against the first sealing component. That is to say, the second sealing component and the first sealing component arranged inside and outside the hollow shaft can cooperate to reserve space margin for the changing radial extension of the hollow shaft, and meet the pressure resistance requirements of the magnetic medium seal, and can effectively overcome the problem of incompatibility of the sealing gap of the hollow shaft under static, low-speed and high-speed operation states. Therefore, compared with the relevant technology, the present invention can meet the pressure resistance of the magnetic medium seal of the hollow shaft under static and low-speed operation states, and can reserve space margin for the radial extension of the hollow shaft under high-speed operation, thereby ensuring the sealing reliability under full-speed working conditions.

[0008] In some embodiments, the first end of the hollow shaft is located in the accommodating cavity, and the housing further has a mounting surface facing the first end surface of the hollow shaft;

[0009] The sealing device also includes an end face sealing assembly, which is fitted into the accommodating cavity and located between the first end face of the hollow shaft and the mounting surface. A third sealing gap is defined between the end face sealing assembly and the first end face of the hollow shaft, and the third sealing gap adsorbs magnetic medium.

[0010] In some embodiments, the first sealing assembly includes a first pole shoe and a first permanent magnet arranged along the axial direction of the hollow shaft, and the first sealing gap is defined between the inner circumference of the first pole shoe and the outer circumference of the hollow shaft;

[0011] The second sealing assembly includes a second pole shoe and a second permanent magnet arranged along the axial direction of the hollow shaft, and the second sealing gap is defined between the outer circumferential surface of the second pole shoe and the inner circumferential surface of the inner chamber;

[0012] The end face sealing assembly includes a third permanent magnet, and the first permanent magnet, the second permanent magnet and the third permanent magnet are all installed on the mounting surface. The third sealing gap is defined between the side of the third permanent magnet facing away from the mounting surface and the first end face of the hollow shaft. The magnetic pole direction of the first permanent magnet is the same as the magnetic pole direction of the second permanent magnet and is consistent with the axial direction of the hollow shaft. The magnetic pole direction of the third permanent magnet is opposite to the magnetic pole direction of the first permanent magnet.

[0013] In some embodiments, the sealing device further includes a magnetic conductive plate, which is fitted into the accommodating cavity and connected to the mounting surface, and the first permanent magnet, the second permanent magnet, and the third permanent magnet are all connected to the end of the magnetic conductive plate facing away from the mounting surface.

[0014] In some embodiments, the mounting surface is provided with a support portion, the support portion is matched with the inner cavity, and the second pole shoe, the second permanent magnet and the magnetic conductive plate are all sleeved on the support portion;

[0015] The supporting portion is a hollow structure.

[0016] In some embodiments, the outer circumference of the hollow shaft is provided with first pole teeth, there are multiple first pole teeth and they are arranged at intervals along the axial direction of the hollow shaft, and the first sealing gap is defined between the inner circumference of the first pole shoe and all the first pole teeth.

[0017] In some embodiments, the outer circumference of the second pole shoe is provided with second pole teeth, there are multiple second pole teeth and they are arranged at intervals along the axial direction of the hollow shaft, and the second sealing gap is defined between the inner circumference of the inner chamber and all the second pole teeth.

[0018] In some embodiments, the first end face of the hollow shaft is provided with a third pole tooth, and the third pole teeth are multiple and arranged at intervals along the radial direction of the hollow shaft. The third sealing gap is defined between the side of the third permanent magnet facing away from the mounting surface and all the third pole teeth.

[0019] In some embodiments, the sealing device further comprises an outer sleeve and an inner sleeve.

[0020] The outer sleeve is sleeved on the hollow shaft and matched with the outer chamber, the first sealing assembly is sleeved on the outer sleeve, and the first sealing gap is defined between the inner circumference of the first sealing assembly and the outer circumference of the outer sleeve;

[0021] The inner sleeve is fitted in the inner chamber and its outer circumference abuts against the inner circumference of the inner chamber, and the second sealing gap is defined between the outer circumference of the second sealing assembly and the inner circumference of the inner sleeve.

[0022] In some embodiments, the first sealing gap is δ1, and the centrifugal elongation of the hollow shaft at the rated speed is G C , 0.05mm≤δ1-G C ≤0.15mm.

[0023] In some embodiments, the second sealing gap is δ2, 0.05 mm ≤ δ2 ≤ 0.15 mm.

[0024] In some embodiments, the third sealing gap is δ3, 0.05 mm ≤ δ3 ≤ 0.1 mm.

[0025] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The structure of the compensation type wide speed range magnetic medium sealing device in the static state according to the embodiment of the present invention is shown in FIG. Figure 1 .

[0027] Figure 2 yes Figure 1 Schematic diagram of the locally enlarged structure in .

[0028] Figure 3 This is a schematic diagram of the structure of the compensation type wide speed range magnetic medium sealing device in the high speed state according to an embodiment of the present invention. Figure 1 .

[0029] Figure 4 yes Figure 3 Schematic diagram of the locally enlarged structure in .

[0030] Figure 5 The structure of the compensation type wide speed range magnetic medium sealing device in the static state according to the embodiment of the present invention is shown in FIG. Figure 2 .

[0031] Figure 6 yes Figure 5 Schematic diagram of the locally enlarged structure in .

[0032] Figure 7 This is a schematic diagram of the structure of the compensation type wide speed range magnetic medium sealing device in the high speed state according to an embodiment of the present invention. Figure 2 .

[0033] Figure 8 yes Figure 7 Schematic diagram of the locally enlarged structure in .

[0034] Reference numerals:

[0035] 1. Housing; 11. Accommodating cavity; 111. Inner chamber; 112. Outer chamber; 12. Mounting surface; 13. Support portion;

[0036] 2. Hollow shaft; 21. First pole tooth; 22. Third pole tooth;

[0037] 3. First sealing assembly; 31. First sealing gap; 32. First pole shoe; 33. First permanent magnet; 34. First retaining spring; 35. First sealing member;

[0038] 4. Second sealing assembly; 41. Second sealing gap; 42. Second pole shoe; 421. Second pole tooth; 43. Second permanent magnet; 44. Second retaining spring; 45. Second sealing member;

[0039] 5. End face sealing assembly; 51. Third sealing gap; 52. Third permanent magnet; 53. Third sealing member;

[0040] 6. Magnetic plate; 61. First positioning slot; 62. Middle positioning slot; 63. Second positioning slot;

[0041] 7. Fourth seal;

[0042] 8. Outer sleeve; 81. Outer retaining ring; 82. Fifth seal;

[0043] 9. Inner sleeve; 91. Inner retaining ring; 92. Sixth sealing element. DETAILED DESCRIPTION

[0044] 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.

[0045] like Figures 1 to 4 As shown, a compensating wide-speed range magnetic medium sealing device according to an embodiment of the present invention includes a shell 1, a hollow shaft 2, a first sealing component 3 and a second sealing component 4. The shell 1 has a accommodating chamber 11, the hollow shaft 2 is pivotally connected to the accommodating chamber 11 and is at least partially located outside the shell 1, and the hollow shaft 2 divides the accommodating chamber 11 into an inner chamber 111 and an outer chamber 112 that are nested with each other; the first sealing component 3 is matched with the outer chamber 112 and is sleeved on the hollow shaft 2, and a first sealing gap 31 is defined between the inner circumference of the first sealing component 3 and the outer circumference of the hollow shaft 2; the second sealing component 4 is matched with the inner chamber 111 and is connected to the shell 1, and a second sealing gap 41 is defined between the outer circumference of the second sealing component 4 and the inner circumference of the inner chamber 111; the first sealing gap 31 and the second sealing gap 41 are both adsorbed with magnetic media, and the first sealing gap 31 is larger than the second sealing gap 41.

[0046] According to an embodiment of the present invention, a compensating wide-speed magnetic medium sealing device is formed by a housing 1, a hollow shaft 2, a first sealing component 3 and a second sealing component 4, which cooperate to form a magnetic medium sealing structure. When the hollow shaft 2 is in a stationary or low-speed state, the first sealing gap 31 is larger than the second sealing gap 41. The magnetic medium seal of the second sealing gap 41 can ensure sufficient pressure resistance in the stationary state and low-speed state. When the hollow shaft 2 is in a high-speed state, the hollow shaft 2 will undergo radial elongation, the first sealing gap 31 will decrease and the second sealing gap 41 will increase. The magnetic medium seal of the first sealing gap 31 will provide sufficient pressure resistance in the high-speed state. capacity, and at the same time, the radially extended hollow shaft 2 will not rub against the first sealing component 3. That is to say, the second sealing component 4 and the first sealing component 3 arranged inside and outside the hollow shaft 2 can cooperate with each other to reserve space margin for the changing radial extension of the hollow shaft 2, and meet the pressure resistance requirements of the magnetic medium seal, and can effectively overcome the problem of incompatibility of the sealing gap of the hollow shaft 2 in static, low-speed and high-speed operation states. Therefore, compared with the relevant technology, the present invention can meet the pressure resistance capacity of the magnetic medium seal of the hollow shaft 2 in static and low-speed operation states, and can reserve space margin for the radial extension of the hollow shaft 2 in the high-speed operation state, thereby ensuring the sealing reliability under full-speed working conditions.

[0047] Specifically, both the housing 1 and the accommodating chamber 11 extend axially along the hollow shaft 2. The inner circumference of the inner chamber 111 corresponds to the inner circumference of the hollow shaft 2 that surrounds the inner chamber 111. The hollow shaft 2 is pivotally connected to the accommodating chamber 11 coaxially. The first sealing assembly 3 is used to seal the outer chamber 112, and the second sealing assembly 4 is used to seal the inner chamber 111.

[0048] It should be noted that the "magnetic medium" is not limited to magnetic particles, magnetic liquid, magnetorheological fluid, magnetic grease, and other magnetic media. Furthermore, a sufficient amount of magnetic medium must be injected into the first sealing gap 31 and the second sealing gap 41. The amount of magnetic medium used can be determined based on the designed sealing gap volume.

[0049] like Figures 1 to 4 As shown, in some embodiments, the first end of the hollow shaft 2 is located in the accommodating cavity 11 , and the housing 1 further has a mounting surface 12 facing the first end surface of the hollow shaft 2 .

[0050] The sealing device also includes an end face sealing assembly 5, which is fitted in the accommodating cavity 11 and located between the first end face of the hollow shaft 2 and the mounting surface 12. A third sealing gap 51 is defined between the end face sealing assembly 5 and the first end face of the hollow shaft 2, and the third sealing gap 51 adsorbs magnetic medium.

[0051] It can be understood that magnetic medium seals are provided on the outer circumference, inner circumference and end face of the hollow shaft 2, and the same leakage path is formed. When medium leakage occurs, the medium needs to pass through the first sealing gap 31, the third sealing gap 51 and the second sealing gap 41 in sequence, thereby extending the leakage path. Therefore, the pressure resistance of the magnetic medium seal can be improved, and the leakage risk can be greatly reduced.

[0052] Specifically, the axial direction of the hollow shaft 2 may be the left-right direction in the figure. The first end of the hollow shaft 2 may correspond to the right end of the hollow shaft 2 in the figure.

[0053] Similarly, a sufficient amount of magnetic medium needs to be injected into the third sealing gap 51 , and the amount of magnetic medium used can be determined according to the designed sealing gap volume.

[0054] like Figures 1 to 4 As shown, in some embodiments, the first sealing assembly 3 includes a first pole shoe 32 and a first permanent magnet 33 arranged along the axial direction of the hollow shaft 2, the first pole shoe 32 and the first permanent magnet 33 are both matched with the outer chamber 112, the first pole shoe 32 is sleeved on the hollow shaft 2, and the first permanent magnet 33 is spaced apart on the outer peripheral side of the hollow shaft 2, and a first sealing gap 31 is defined between the inner peripheral surface of the first pole shoe 32 and the outer peripheral surface of the hollow shaft 2.

[0055] The second sealing assembly 4 includes a second pole shoe 42 and a second permanent magnet 43 arranged along the axial direction of the hollow shaft 2. The second pole shoe 42 and the second permanent magnet 43 are both fitted in the inner chamber 111 and connected to the outer shell 1. A second sealing gap 41 is defined between the outer peripheral surface of the second pole shoe 42 and the inner peripheral surface of the inner chamber 111. The second permanent magnet 43 is spaced apart on the inner peripheral side of the hollow shaft 2.

[0056] The end face sealing assembly 5 includes a third permanent magnet 52. The first permanent magnet 33, the second permanent magnet 43 and the third permanent magnet 52 are all mounted on the mounting surface 12. A third sealing gap 51 is defined between the side of the third permanent magnet 52 facing away from the mounting surface 12 and the first end face of the hollow shaft 2. The magnetic pole direction of the first permanent magnet 33 is the same as the magnetic pole direction of the second permanent magnet 43 and is consistent with the axial direction of the hollow shaft 2. The magnetic pole direction of the third permanent magnet 52 is opposite to that of the first permanent magnet 33.

[0057] It can be understood that integrating the first sealing component 3, the second sealing component 4 and the end face sealing component 5 into the above structure simplifies the overall structure of the sealing device and reduces its overall weight while ensuring the sealing performance of the three sets of magnetic medium seals on the hollow shaft 2.

[0058] In addition, compared with the method in the related art of increasing the number of pole shoes along the axial direction of the outer peripheral surface of the hollow shaft 2 to improve the pressure resistance of the magnetic medium seal, the present invention adopts a method of arranging pole shoes in the inner cavity of the hollow shaft 2, that is, arranging the second sealing component 4 in the inner chamber 111, so as to ensure the pressure resistance of the sealing device under full-speed working conditions based on the cooperation of the first sealing component 3 and the second sealing component 4. Among them, because the pole shoes added by the present invention are located in the inner cavity of the hollow shaft 2, the overall size of the pole shoes added by the present invention is smaller than the size of the pole shoes added to the outside of the hollow shaft 2 in the related art. Therefore, the above-mentioned structure of the present invention can make the axial size and weight of the present invention smaller, which is more conducive to the application of the sealing device in fields such as aerospace that have high requirements on the size, weight, cost, etc. of the sealing device.

[0059] Specifically, the first pole shoe 32 may be located on the left side of the first permanent magnet 33 and abut against the left end of the first permanent magnet 33. The second pole shoe 42 may be located on the left side of the second permanent magnet 43 and abut against the left end of the second permanent magnet 43. The third permanent magnet 52 may be located on the right side of the hollow shaft 2. The first permanent magnet 33 and the second permanent magnet 43 may both be annular permanent magnets or permanent magnets of other shapes. The third permanent magnet 52 may be annular permanent magnets to facilitate reliable fixation of the third permanent magnet 52 on the mounting surface 12. The first permanent magnet 33, the second permanent magnet 43, and the third permanent magnet 52 may all be permanent magnet materials with good magnetic properties.

[0060] For example, in the figure, the left end of each of the first permanent magnet 33 and the second permanent magnet 43 is an N pole, and the right end is an S pole; while the left end of the third permanent magnet 52 is an S pole, and the right end is an N pole.

[0061] like Figure 1 As shown, in some embodiments, the sealing device further includes a magnetic conductive plate 6, which is fitted into the accommodating cavity 11 and connected to the mounting surface 12, and the first permanent magnet 33, the second permanent magnet 43 and the third permanent magnet 52 are all connected to the end of the magnetic conductive plate 6 facing away from the mounting surface 12.

[0062] It can be understood that, by adopting the above-mentioned structural design, the magnetic lines of force starting from the N pole of the first permanent magnet 33 can reach the S pole of the third permanent magnet 52 via the first pole shoe 32 and the hollow shaft 2, and at the same time, the magnetic lines of force starting from the N pole of the third permanent magnet 52 return to the first permanent magnet 33 via the magnetic plate 6 to form a closed magnetic circuit, while the magnetic lines of force starting from the N pole of the second permanent magnet 43 can reach the S pole of the third permanent magnet 52 via the second pole shoe 42 and the hollow shaft 2, and at the same time, the magnetic lines of force starting from the N pole of the third permanent magnet 52 return to the second permanent magnet 43 via the magnetic plate 6 to form a closed magnetic circuit, thereby realizing the magnetic sealing of the sealing device on the hollow shaft 2.

[0063] Specifically, the hollow shaft 2, first pole shoe 32, second pole shoe 42, and magnetic plate 6 can all be made of materials with excellent magnetic conductivity. The magnetic plate 6 can be removably connected to the mounting surface 12, facilitating assembly and disassembly between the magnetic plate 6 and the housing 1 and reducing costs. For example, in the figure, the right end of each of the first permanent magnet 33, the second permanent magnet 43, and the third permanent magnet 52 is connected to the left end of the magnetic plate 6.

[0064] It should be noted that in order to ensure that the sealing device can form a magnetic seal on the hollow shaft 2, the magnetic plate 6 can be replaced by providing a magnetic conductive material coating on the mounting surface 12. The specific design can be based on the actual working conditions and will not be expanded here.

[0065] like Figure 1 As shown, in some embodiments, the end of the magnetic conductive plate 6 facing away from the mounting surface 12 is provided with a first positioning groove 61, an intermediate positioning groove 62 and a second positioning groove 63, and the first positioning groove 61, the intermediate positioning groove 62 and the second positioning groove 63 are sequentially arranged from the outside to the inside, the first permanent magnet 33 cooperates with the first positioning groove 61, the third permanent magnet 52 cooperates with the intermediate positioning groove 62, and the second permanent magnet 43 cooperates with the second positioning groove 63.

[0066] It can be understood that the first permanent magnet 33 can be positioned through the first positioning groove 61, the third permanent magnet 52 can be positioned through the middle positioning groove 62, and the second positioning groove 63 can be positioned for the second permanent magnet 43, thereby facilitating the disassembly, assembly and maintenance of the first permanent magnet 33, the second permanent magnet 43 and the third permanent magnet 52 on the outer casing 1, thereby improving the assembly efficiency of the sealing device.

[0067] For example, taking the figure as an example, the left end of the magnetic conductive plate 6 is provided with a first positioning groove 61 , a middle positioning groove 62 and a second positioning groove 63 in sequence from the outside to the inside.

[0068] like Figure 1 As shown, in some embodiments, the mounting surface 12 is provided with a support portion 13 , the support portion 13 is matched with the inner cavity 111 , and the second pole shoe 42 , the second permanent magnet 43 and the magnetic conductive plate 6 are all sleeved on the support portion 13 .

[0069] The support portion 13 is a hollow structure.

[0070] It can be understood that the support portion 13 can support and limit the second sealing assembly 4 in the inner chamber 111. At the same time, since the support portion 13 is a hollow structure, the overall weight of the sealing device can be further reduced.

[0071] Specifically, the support portion 13 can be integrally formed at the middle position of the mounting surface 12. The support portion 13 can extend in the left-right direction. The second pole piece 42, the second permanent magnet 43 and the magnetic conductive plate 6 can be coaxially sleeved on the support portion 13.

[0072] like Figures 1 to 4 As shown, in some embodiments, the outer circumference of the hollow shaft 2 is provided with first pole teeth 21 , there are multiple first pole teeth 21 and they are arranged at intervals along the axial direction of the hollow shaft 2 , and a first sealing gap 31 is defined between the inner circumference of the first pole shoe 32 and all the first pole teeth 21 .

[0073] It can be understood that, compared with the solution in which the first pole teeth 21 are arranged on the inner circumference of the first pole shoe 32, arranging the first pole teeth 21 on the outer circumference of the hollow shaft 2 can reduce the influence of centrifugal force on the morphology of the magnetic medium and further improve the pressure resistance of the magnetic medium seal under high speed conditions.

[0074] Preferably, the plurality of first pole teeth 21 are arranged at equal intervals along the axial direction of the hollow shaft 2 to ensure uniform force on all the pole teeth.

[0075] like Figures 1 to 4 As shown, in some embodiments, the outer circumference of the second pole shoe 42 is provided with second pole teeth 421, and there are multiple second pole teeth 421 that are arranged at intervals along the axial direction of the hollow shaft 2, and a second sealing gap 41 is defined between the inner circumference of the inner chamber 111 and all the second pole teeth 421.

[0076] It can be understood that, compared with the solution in which the second pole teeth 421 are arranged on the inner circumference of the hollow shaft 2, arranging the second pole teeth 421 on the outer circumference of the second pole shoe 42 can reduce the influence of centrifugal force on the morphology of the magnetic medium and further improve the pressure resistance of the magnetic medium seal under high speed conditions.

[0077] Preferably, the plurality of second pole teeth 421 are arranged at equal intervals along the axial direction of the hollow shaft 2 to ensure uniform force on all the pole teeth.

[0078] It should be noted that the arrangement of pole teeth generates a non-uniform magnetic field. Due to the edge effect, the magnetic field at the pole teeth is stronger, far stronger than the "axial gap between the pole teeth." In the scheme where the first pole teeth 21 are arranged on the outer circumference of the hollow shaft 2 and the second pole teeth 421 are arranged on the outer circumference of the second pole shoe 42, because the outer wall forming the sealed gap is not provided with pole teeth (with the axis of the hollow shaft 2 as the reference, the side wall farther from the axis of the hollow shaft 2 in the sealed gap is the outer wall), when the hollow shaft 2 rotates to generate centrifugal force that throws the magnetic medium outward, the majority of the magnetic medium is confined between the pole teeth and the outer wall. Therefore, compared to schemes where the outer wall is provided with pole teeth (where the rotation of the hollow shaft 2 generates centrifugal force that throws the magnetic medium outward, which can easily cause the magnetic medium to enter the axially adjacent pole tooth gap on the outer wall, thereby changing the shape of the magnetic medium in the sealed gap), the present invention adopts the above-mentioned structure to effectively avoid the influence of centrifugal force on the shape of the magnetic medium.

[0079] like Figure 1 As shown, in some embodiments, the first sealing assembly 3 also includes a first retaining spring 34 and a first seal 35. The first retaining spring 34 is arranged at intervals on the outer peripheral side of the hollow shaft 2 and is connected to the inner peripheral surface of the outer chamber 112. The first pole shoe 32 is respectively in contact with the first retaining spring 34 and the first permanent magnet 33 at two opposite ends along the axial direction of the hollow shaft 2; the first seal 35 is clamped between the outer peripheral surface of the first pole shoe 32 and the inner peripheral surface of the outer chamber 112.

[0080] It can be understood that the first retaining spring 34 and the first permanent magnet 33 cooperate to limit the first pole shoe 32 in the outer chamber 112, that is, to limit the axial sliding of the first pole shoe 32 along the hollow shaft 2, and the first seal 35 can form a static seal between the first pole shoe 32 and the outer chamber 112.

[0081] like Figure 1 As shown, in some embodiments, the second sealing assembly 4 also includes a second retaining spring 44 and a second sealing member 45. The second retaining spring 44 is sleeved on the outer peripheral surface of the support portion 13, and the second pole shoe 42 is respectively abutted against the second retaining spring 44 and the second permanent magnet 43 at two opposite ends along the axial direction of the hollow shaft 2; the second sealing member 45 is clamped between the inner peripheral surface of the second pole shoe 42 and the outer peripheral surface of the support portion 13.

[0082] Similarly, the second retaining spring 44 and the second permanent magnet 43 cooperate to limit the second pole shoe 42 to the support portion 13, thereby limiting the axial sliding of the second pole shoe 42 along the hollow shaft 2, and the second seal 45 can form a static seal between the second pole shoe 42 and the support portion 13.

[0083] like Figures 1 to 4 As shown, in some embodiments, a third pole tooth 22 is provided on the first end face of the hollow shaft 2, and there are multiple third pole teeth 22 that are arranged at intervals along the radial direction of the hollow shaft 2. A third sealing gap 51 is defined between the side of the third permanent magnet 52 facing away from the mounting surface 12 and all the third pole teeth 22. Taking the figure as an example, a third sealing gap 51 is defined between the left side of the third permanent magnet 52 and all the third pole teeth 22.

[0084] Preferably, the plurality of third pole teeth 22 are arranged at equal intervals along the radial direction of the hollow shaft 2 to ensure uniform force on all the pole teeth.

[0085] like Figure 1 As shown, in some embodiments, the end face sealing assembly 5 also includes a third sealing member 53, which is clamped between the third permanent magnet 52 and the end of the magnetic conductive plate 6 facing away from the mounting surface 12 to form a seal therebetween, further ensuring the sealing reliability of the end face sealing assembly 5.

[0086] like Figures 1 to 4As shown, in some embodiments, the sealing device further includes a fourth sealing member 7, which is provided on the housing 1 and is suitable for sealing the connection gap between the housing 1 and the sealed equipment.

[0087] Specifically, the housing 1 , the first clamping spring 34 , the first sealing member 35 , the second clamping spring 44 , the second sealing member 45 , the third sealing member 53 and the fourth sealing member 7 may all be made of non-magnetic materials.

[0088] like Figures 5 to 8 As shown, in some embodiments, the sealing device further includes an outer sleeve 8 and an inner sleeve 9 .

[0089] The outer sleeve 8 is sleeved on the hollow shaft 2 and matched with the outer chamber 112 . The first sealing assembly 3 is sleeved on the outer sleeve 8 . A first sealing gap 31 is defined between the inner circumference of the first sealing assembly 3 and the outer circumference of the outer sleeve 8 .

[0090] The inner sleeve 9 is fitted in the inner chamber 111 and its outer circumference abuts against the inner circumference of the inner chamber 111 . A second sealing gap 41 is defined between the outer circumference of the second sealing assembly 4 and the inner circumference of the inner sleeve 9 .

[0091] Each of the outer sleeve 8, the hollow shaft 2 and the inner sleeve 9 is arranged axially spaced apart from the third permanent magnet 52 along the hollow shaft 2, and a third sealing gap 51 is defined between the end face of each of the outer sleeve 8 and the inner sleeve 9 adjacent to the third permanent magnet 52 and the third permanent magnet 52.

[0092] It can be understood that the inner sleeve 9 and the outer sleeve 8 can protect the hollow shaft 2 .

[0093] In addition, when the hollow shaft 2 is not suitable for providing pole teeth or is non-magnetic, an outer sleeve 8 with a first pole tooth 21 and a third pole tooth 22 can be installed on the hollow shaft 2, and an inner sleeve 9 with a third pole tooth 22 can be installed thereon, wherein the third pole teeth 22 on the outer sleeve 8 and the third pole teeth 22 on the inner sleeve 9 together form a pole tooth structure in the end face sealing assembly 5.

[0094] Specifically, the first pole shoe 32 is sleeved on the outer sleeve 8, and the first permanent magnet 33 and the first retaining spring 34 are spaced apart on the outer circumference of the outer sleeve 8. A first sealed gap 31 is defined between the inner circumference of the first pole shoe 32 and the outer circumference of the outer sleeve 8. In combination with the above structure, the outer circumference of the outer sleeve 8 is provided with first pole teeth 21. A second sealed gap 41 is defined between all second pole teeth 421 of the second pole shoe 42 and the inner circumference of the inner sleeve 9. Third pole teeth 22 are provided on the end surface of each of the outer sleeve 8 and the inner sleeve 9, adjacent to the magnetic conductive plate 6.

[0095] Meanwhile, in this embodiment, the hollow shaft 2 can be made of non-magnetic material, while the outer sleeve 8 and the inner sleeve 9 can be made of materials with good magnetic conductivity, and the materials of the remaining components are the same as those in the above embodiment.

[0096] like Figure 5 As shown, in some embodiments, the sealing device also includes an external retaining spring 81 and a fifth sealing member 82. The external retaining spring 81 is sleeved on the outer peripheral surface of the hollow shaft 2, and the end of the outer sleeve 8 facing away from the third permanent magnet 52 abuts against the external retaining spring 81 to limit the outer sleeve 8 on the hollow shaft 2; the fifth sealing member 82 is clamped between the inner peripheral surface of the outer sleeve 8 and the outer peripheral surface of the hollow shaft 2 to form a static seal between the outer sleeve 8 and the hollow shaft 2.

[0097] like Figure 5 As shown, in some embodiments, the sealing device also includes an inner retaining spring 91 and a sixth sealing member 92. The inner retaining spring 91 is installed on the inner circumference of the inner chamber 111, and the end of the inner sleeve 9 facing away from the third permanent magnet 52 abuts against the inner retaining spring 91 to limit the inner sleeve 9 on the hollow shaft 2; the sixth sealing member 92 is clamped between the outer circumference of the inner sleeve 9 and the inner circumference of the inner chamber 111 to form a static seal between the inner sleeve 9 and the inner chamber 111.

[0098] Specifically, to ensure reliable installation of the first seal 35, the second seal 45, the third seal 53, the fourth seal 7, the fifth seal 82, and the sixth seal 92 in the sealing device, groove structures may be provided at the locations where the aforementioned seals are arranged in the sealing device, and the aforementioned seals may be fitted into the grooves. For example, a groove may be provided on the outer circumferential surface of the first pole shoe 32 to install the first seal 35, a groove may be provided on the inner circumferential surface of the second pole shoe 42 to install the second seal 45, a groove may be provided on the end surface of the third permanent magnet 52 adjacent to the magnetic conductive plate 6 to install the third seal 53, a groove may be provided on the end surface of the first end of the housing 1 facing away from the hollow shaft 2 to install the fourth seal 7, a groove may be provided on the inner circumferential surface of the outer sleeve 8 to install the fifth seal 82, and a groove may be provided on the outer circumferential surface of the inner sleeve 9 to install the sixth seal 92. The outer retaining spring 81, the fifth seal 82, the inner retaining spring 91, and the sixth seal 92 may all be made of non-magnetic materials.

[0099] In addition, the first seal 35, the second seal 45, the third seal 53, the fourth seal 7, the fifth seal 82 and the sixth seal 92 are not limited to O-rings. Other sealing structures that can perform sealing functions can also be applicable to the present invention and will not be expanded upon here.

[0100] like Figures 1 to 8 As shown, in some embodiments, the first sealing gap 31 is δ1, and the centrifugal elongation of the hollow shaft 2 at the rated speed is G C , 0.05mm≤δ1-GC ≤0.15mm, that is, the first sealing gap 31δ1=G C +(0.05mm~0.15mm), that is, the size of the first sealing gap 31 is determined according to the centrifugal elongation of the hollow shaft 2 at the rated speed, wherein the first sealing gap 31 is the distance from the inner circumference of the first pole shoe 32 to the first pole tooth 21.

[0101] It should be noted that the centrifugal elongation G of the hollow shaft 2 at rated speed is C " can be calculated using the following formula:

[0102]

[0103] Among them, ρ r is the density of the hollow shaft 2; ω is the rotational angular velocity of the hollow shaft 2; R s is the radius of the hollow shaft 2; r is the Poisson's ratio of the hollow shaft 2; E r is the Young's modulus of the hollow shaft 2.

[0104] Of course, for the centrifugal extension G of the hollow shaft 2 at rated speed C , is not limited to the calculation using the above formula, and can also be obtained through finite element simulation calculation or experimental measurement, which is not specifically limited here.

[0105] like Figures 1 to 8 As shown, in some embodiments, the second sealing gap 41 is δ2, 0.05mm≤δ2≤0.15mm, where δ2 can be, for example, 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0106] It should be noted that the size of the second sealing gap 41 can be determined based on processing and assembly errors. The smaller the second sealing gap 41, the better. In addition, the second sealing gap 41 is the distance from the inner circumference of the inner chamber 111 to the second pole teeth 421.

[0107] like Figures 1 to 8 As shown, in some embodiments, the third sealing gap 51 is δ3, 0.05mm≤δ3≤0.1mm, wherein δ3 can be, for example, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0108] It is understandable that by designing the values ​​of the first sealing gap 31 , the second sealing gap 41 and the third sealing gap 51 to be within the above parameter range, the pressure resistance of the magnetic medium seal can be ensured and the leakage risk can be reduced.

[0109] It should be noted that the size of the third sealing gap 51 can be determined based on the optimal gap value for magnetic medium sealing in the prior art. In addition, the third sealing gap 51 is the distance from the side of the third permanent magnet 52 facing away from the mounting surface 12 to the third pole tooth 22.

[0110] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0111] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0112] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0113] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0114] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic 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 one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0115] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A compensating wide-speed magnetic medium sealing device, characterized in that: include: A housing and a hollow shaft, wherein the housing has a receiving cavity, the hollow shaft is pivotally connected to the receiving cavity and is at least partially located outside the housing, and the hollow shaft divides the receiving cavity into an inner chamber and an outer chamber that are nested with each other; a first sealing assembly, the first sealing assembly being fitted into the outer chamber and sleeved on the hollow shaft, wherein a first sealing gap is defined between an inner circumferential surface of the first sealing assembly and an outer circumferential surface of the hollow shaft; a second sealing assembly, the second sealing assembly being fitted in the inner chamber and connected to the outer shell, wherein a second sealing gap is defined between an outer circumferential surface of the second sealing assembly and an inner circumferential surface of the inner chamber; Magnetic media is adsorbed on both the first sealing gap and the second sealing gap, and the first sealing gap is larger than the second sealing gap.

2. The compensating wide-speed magnetic medium sealing device according to claim 1, characterized in that: The first end of the hollow shaft is located in the accommodating cavity, and the housing further has a mounting surface facing the first end surface of the hollow shaft; The sealing device also includes an end face sealing assembly, which is fitted into the accommodating cavity and located between the first end face of the hollow shaft and the mounting surface. A third sealing gap is defined between the end face sealing assembly and the first end face of the hollow shaft, and the third sealing gap adsorbs magnetic medium.

3. The compensating wide-speed magnetic medium sealing device according to claim 2, characterized in that: The first sealing assembly includes a first pole shoe and a first permanent magnet arranged along the axial direction of the hollow shaft, and the first sealing gap is defined between the inner circumferential surface of the first pole shoe and the outer circumferential surface of the hollow shaft; The second sealing assembly includes a second pole shoe and a second permanent magnet arranged along the axial direction of the hollow shaft, and the second sealing gap is defined between the outer circumferential surface of the second pole shoe and the inner circumferential surface of the inner chamber; The end face sealing assembly includes a third permanent magnet, and the first permanent magnet, the second permanent magnet and the third permanent magnet are all installed on the mounting surface. The third sealing gap is defined between the side of the third permanent magnet facing away from the mounting surface and the first end face of the hollow shaft. The magnetic pole direction of the first permanent magnet is the same as the magnetic pole direction of the second permanent magnet and is consistent with the axial direction of the hollow shaft. The magnetic pole direction of the third permanent magnet is opposite to the magnetic pole direction of the first permanent magnet.

4. The compensating wide-speed magnetic medium sealing device according to claim 3, characterized in that: It also includes a magnetic conductive plate, which is matched with the accommodating cavity and connected to the mounting surface. The first permanent magnet, the second permanent magnet and the third permanent magnet are all connected to the end of the magnetic conductive plate away from the mounting surface.

5. The compensating wide-speed magnetic medium sealing device according to claim 4, characterized in that: The mounting surface is provided with a support portion, the support portion is matched with the inner cavity, and the second pole shoe, the second permanent magnet and the magnetic conductive plate are all sleeved on the support portion; The supporting portion is a hollow structure.

6. The compensating wide-speed range magnetic medium sealing device according to claim 3, characterized in that: The outer circumference of the hollow shaft is provided with first pole teeth, and there are a plurality of first pole teeth arranged at intervals along the axial direction of the hollow shaft. The first sealing gap is defined between the inner circumference of the first pole shoe and all the first pole teeth.

7. The compensating wide-speed range magnetic medium sealing device according to claim 3, characterized in that: The outer circumference of the second pole shoe is provided with second pole teeth, and there are a plurality of second pole teeth arranged at intervals along the axial direction of the hollow shaft. The second sealing gap is defined between the inner circumference of the inner chamber and all the second pole teeth.

8. The compensating wide-speed range magnetic medium sealing device according to claim 3, characterized in that: The first end surface of the hollow shaft is provided with a third pole tooth. There are multiple third pole teeth arranged at intervals along the radial direction of the hollow shaft. The third sealing gap is defined between the side of the third permanent magnet facing away from the mounting surface and all the third pole teeth.

9. The compensating wide-speed range magnetic medium sealing device according to claim 1, characterized in that: Also includes: an outer sleeve, the outer sleeve being sleeved on the hollow shaft and fitting into the outer chamber, the first sealing assembly being sleeved on the outer sleeve, the first sealing gap being defined between an inner circumferential surface of the first sealing assembly and an outer circumferential surface of the outer sleeve; An inner sleeve is fitted in the inner chamber and its outer circumference abuts against the inner circumference of the inner chamber, and the second sealing gap is defined between the outer circumference of the second sealing assembly and the inner circumference of the inner sleeve.

10. The compensating wide-speed range magnetic medium sealing device according to claim 2, characterized in that: The first sealing gap is δ1, and the centrifugal elongation of the hollow shaft at the rated speed is G C , 0.05mm≤δ1-G C ≤0.15mm; and / or, the second sealing gap is δ2, 0.05mm≤δ2≤0.15mm; And / or, the third sealing gap is δ3, 0.05mm≤δ3≤0.1mm.

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