High-speed-resistant magnetic liquid sealing device

Abstract

The invention discloses a high-speed-resistant magnetic liquid sealing device which comprises a shell, a shaft sleeve assembly, a sealing assembly and a liquid supplementing assembly. The sealing assembly comprises a pole shoe, a permanent magnet and a flux sleeve, and the inner surface of the pole shoe is provided with a stepped structure which comprises a stepped platform and a stepped inclined surface; stepped pole teeth are arranged on the periphery of the flux sleeve, and a sealing gap filled with magnetic liquid is formed between the stepped pole teeth and the inner surface of the pole shoe. The liquid supplementing assembly comprises a liquid storage disc made of a capillary porous material, a liquid collecting ring and a flow guide ring, and the liquid storage disc can release magnetic liquid at a high speed; capillary micro-textures are arranged on the end face, making contact with the flow guide ring, of the pole shoe and the inner circumferential face of the pole shoe. The liquid collecting ring, the flow guide ring and the capillary micro-textures convey magnetic liquid to a sealing gap through capillary force gradient. According to the device, centrifugal force can be converted into axial component force resisting gas pressure under the high-speed working condition, self-adaptive liquid supplementing is achieved, and the high-speed-resistant performance and the pressure-resistant capacity of the sealing device are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of sealing device technology, and in particular to a high-speed magnetic liquid resistant sealing device. Background Technology

[0002] Magnetic fluid seals achieve sealing by balancing the forces of a magnetic fluid under the influence of a magnetic field gradient and pressure difference. Due to their advantages such as "zero leakage" and low frictional resistance, they are widely used in advanced equipment such as high-speed motors and aerospace. However, for traditional magnetic fluid seals, under high linear velocity conditions, the magnetic fluid within the sealing gap is radially thrown outward by centrifugal force to the pole piece groove region where the magnetic field strength and gradient are lower. This makes it highly susceptible to being blown out of the sealing gap by high-pressure gas, leading to a continuous decrease in the amount of magnetic fluid within the sealing gap and ultimately causing seal failure.

[0003] As modern equipment develops towards higher parameters, higher demands are placed on the high-speed performance and pressure resistance of magnetic fluid sealing devices. Therefore, effectively overcoming centrifugal force while constructing an adaptive fluid replenishment system adapted to the rotational speed has become the key to solving the problem of insufficient performance of magnetic fluid seals under high-speed conditions, and is also a technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

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

[0005] Therefore, embodiments of the present invention propose a high-speed magnetic liquid sealing device that can convert centrifugal force into a beneficial component force to resist the pressure of the sealed gas, and can achieve adaptive liquid replenishment under high-speed conditions, thereby significantly improving the high-speed performance and reliability of the device.

[0006] According to an embodiment of the present invention, a high-speed magnetic liquid sealing device includes a housing, a bushing assembly, a sealing assembly, and a liquid replenishment assembly. The housing has a chamber. The bushing assembly is pivotally connected to the chamber, with at least one end located outside the housing. The sealing assembly includes pole shoes fixed inside the housing, permanent magnets sandwiched between the pole shoes, and a magnetically conductive sleeve fixed to the bushing assembly. The outer circumference of the magnetically conductive sleeve extends outward to form a plurality of annular stepped pole teeth, and a sealing gap is formed between the stepped pole teeth and the inner surface of the pole shoes. The gap is filled with a magnetic liquid; the inner surface of the pole shoe has a stepped structure, including at least one stepped platform and at least one stepped inclined surface connected to the stepped platform; the liquid replenishment assembly includes a reservoir, a collection ring, and a guide ring made of capillary porous material; the liquid replenishment assembly is sleeved on the bushing assembly and disposed on both axial sides of the sealing assembly; the collection ring is disposed on the radially outer side corresponding to the reservoir, and the guide ring is located between the collection ring and the pole shoe; the end face of the pole shoe that contacts the guide ring and / or the inner circumferential surface of the pole shoe is provided with a capillary microtexture.

[0007] According to an embodiment of the present invention, a high-speed magnetic liquid sealing device comprises a housing, a bushing assembly, a sealing assembly, and a liquid replenishment assembly to form a magnetic liquid sealing structure. Airflow proceeds from the high-pressure side to the low-pressure side. The sealing gap is a stepped structure with a downward-stepping shape, meaning the inner diameter of the pole shoe decreases along the airflow direction, and the outer diameter of the stepped pole teeth also decreases along the airflow direction. Under low-speed conditions, the centrifugal force is small and insufficient to propel the magnetic liquid under the magnetic field radially outward. Therefore, the magnetic liquid is held at the stepped platform by the magnetic field to achieve sealing. Under high-speed conditions, the magnetic liquid moves radially outward along the stepped slope under the action of centrifugal force, possessing a velocity component and a force component pointing towards the axial high-pressure side. This force component can offset part of the gas pressure, converting the harmful centrifugal force into a component force resisting the high-pressure gas pressure, thus improving the high-speed resistance of the magnetic liquid sealing device.

[0008] Under low-speed conditions, the centrifugal force generated by the rotation of the reservoir is insufficient to overcome its capillary force, and the spare magnetic liquid is stored in the reservoir. Under high-speed conditions, the centrifugal force generated by the rotation of the reservoir overcomes its capillary force and throws the stored magnetic liquid radially outward to the collecting ring. The collecting ring, with its higher porosity, quickly absorbs the magnetic liquid. The guide ring, with its lower porosity, has a greater capillary force than the collecting ring, meaning it can transport the magnetic liquid from the collecting ring to the guide ring. The end face of the pole shoe and the inner circumferential surface of the pole shoe, which are in contact with the guide ring, have a capillary microtexture. The capillary force of this microtexture is greater than that of the guide ring, meaning it can transport the magnetic liquid from the guide ring to the sealing gap for replenishment, achieving adaptive replenishment at the target speed and improving the high-speed performance of the magnetic liquid sealing device.

[0009] In some embodiments, the stepped structure on the inner surface of the pole shoe is a step-down structure; under low-speed conditions, the magnetic fluid is maintained at the stepped platform under the action of the magnetic field to achieve sealing; the stepped inclined surface forms an acute angle with the axis of the sealing device, and its inclined direction is towards the high-pressure side; under high-speed conditions, the magnetic fluid moving radially outward under the action of centrifugal force moves along the stepped inclined surface, thereby generating an axial component force pointing towards the high-pressure side to offset part of the gas pressure.

[0010] Wherein, the diameter of the inner surface of the stepped pole shoe decreases along the airflow direction; the diameter of the stepped inclined surface decreases along the airflow direction.

[0011] In some embodiments, the liquid collecting ring has a first porosity and the flow guiding ring has a second porosity, wherein the first porosity is greater than the second porosity, such that the capillary force of the liquid collecting ring is less than the capillary force of the flow guiding ring, thereby forming a capillary force gradient from the liquid collecting ring to the flow guiding ring, driving the magnetic liquid to be transported from the liquid collecting ring to the flow guiding ring.

[0012] Both the liquid collecting ring and the flow guiding ring are made of capillary porous material. The liquid collecting ring has a large porosity to quickly absorb the magnetic liquid thrown out of the liquid storage pan; the flow guiding ring has a small porosity to efficiently transport the magnetic liquid in the liquid collecting ring to the flow guiding ring.

[0013] In some embodiments, the capillary force generated by the capillary microtexture on the pole shoe is greater than the capillary force of the guide ring, forming a capillary force gradient from the guide ring to the sealing gap, driving the magnetic fluid to be transported from the guide ring through the channel formed by the capillary microtexture to the sealing gap, replenishing the magnetic fluid loss under high-speed conditions.

[0014] The capillary microtexture is disposed on the inner circumferential surface of the pole shoe and the end face that contacts the guide ring.

[0015] In some embodiments, the porosity of the liquid storage tray is adapted to the magnitude of the centrifugal force corresponding to the target operating speed of the sealing device; when the speed is below the target operating speed, the capillary force of the liquid storage tray can stably bind the magnetic liquid; when the target operating speed is reached, the centrifugal force overcomes the capillary force and releases the stored magnetic liquid into the liquid collection ring, thereby achieving adaptive liquid replenishment at the target operating speed.

[0016] In some embodiments, the liquid collection ring is disposed on the radially outer side of the liquid storage pan, adapting to the movement path of the magnetic liquid being thrown outward radially under centrifugal force, and the axial position of the liquid collection ring corresponds to the liquid throwing area of ​​the liquid storage pan, thereby achieving efficient collection of the magnetic liquid.

[0017] There is a radial gap between the liquid storage tray and the liquid collection ring.

[0018] In some embodiments, the liquid collecting ring is made of a capillary porous material with high porosity relative to the flow guiding ring, and has a groove on the side facing the liquid storage tray to increase the contact area with the magnetic liquid and accelerate the absorption rate of the magnetic liquid.

[0019] The groove and the guide ring are smoothly transitioned, allowing any unabsorbed magnetic fluid to flow along the guide ring to the sealing gap, thus improving design tolerance. In some embodiments, one end of the guide ring is fitted with the liquid collecting ring in the axial direction, and the other end is fitted with the end face of the pole shoe with the capillary microtexture, forming a continuous capillary transport path of liquid collecting ring-guide ring-pole shoe capillary microtexture-sealing gap, ensuring that the magnetic liquid is directionally transported to the sealing gap.

[0020] In some embodiments, the sealing device further includes a dustproof assembly comprising dustproof seals disposed axially outside the fluid replenishment assembly, each dustproof seal comprising at least two dustproof rings for preventing external contaminants from clogging the capillary channels.

[0021] The dustproof seal is sleeved on the bushing assembly, and the dustproof seal is arranged symmetrically about the sealing assembly along the axial direction.

[0022] The dustproof seal forms a labyrinth flow channel through the non-contact engagement of the sealing teeth, resulting in no increase in frictional torque and making it suitable for high-speed dustproof sealing.

[0023] The dust seal on the equipment side includes a first dust seal and a second dust seal, which are non-contactly fitted together to form the first dust seal. The dust seal on the atmospheric environment side includes a third dust seal and a fourth dust seal, which are non-contactly fitted together to form the second dust seal.

[0024] The dustproof rings all have sealing teeth, and the non-contact engagement is a non-contact meshing of the sealing teeth.

[0025] In some embodiments, the stepped structure on the inner surface of the pole shoe and the stepped pole teeth corresponding to the structure are arranged in multiple groups along the axial direction of the sealing device to form a multi-stage seal.

[0026] The stepped pole teeth are disposed on the outer circumferential surface of the magnetic sleeve, and the magnetic sleeve is sleeved on the bushing assembly and disposed on the radial inner side of the pole shoe.

[0027] The fifth sealing ring is sandwiched between the inner circumferential surface of the magnetic sleeve and the outer circumferential surface of the bushing assembly.

[0028] In some embodiments, the bushing assembly includes a bushing, a first snap ring, a second snap ring, and a second sealing ring.

[0029] The first retaining ring and the second retaining ring are both sleeved on the bushing. The first retaining ring abuts against the end of the first dust ring that is away from the sealing assembly, and the second retaining ring abuts against the end of the fourth dust ring that is away from the sealing assembly.

[0030] The inner circumferential surface of the bushing is provided with a second sealing ring for sealing connection between the bushing and the sealed rotating shaft.

[0031] In some embodiments, the sealing assembly includes a first pole shoe, a permanent magnet, a second pole shoe, a third sealing ring, and a fourth sealing ring.

[0032] The first pole shoe, the permanent magnet, and the second pole shoe are arranged sequentially along the axial direction of the bushing assembly, and a sealing gap is defined between the stepped inner surface of each of the first pole shoe and the second pole shoe and the stepped pole teeth of the magnetic sleeve.

[0033] The third sealing ring and the fourth sealing ring are respectively sandwiched between the outer peripheral surface of each of the first pole shoe and the second pole shoe and the inner peripheral surface of the outer shell.

[0034] In some embodiments, the housing includes a shell, an end cap, and a first sealing ring. The shell and the end cap are connected by fasteners and enclose a cavity. The first sealing ring is provided on the connection surface between the shell and the sealed equipment to ensure static sealing.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a high-speed magnetic liquid sealing device according to an embodiment of the present invention.

[0037] Figure 2 yes Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0038] Figure 3 This is a cross-sectional view of the pole shoe in a high-speed magnetic liquid sealing device according to an embodiment of the present invention.

[0039] Figure 4 This is a right view of the first pole shoe in a high-speed magnetic liquid sealing device according to an embodiment of the present invention.

[0040] Figure label: 100. Sealing device; 1. Outer shell; 11. Housing; 12. End cap; 13. First sealing ring; 2. Bushing assembly; 21. Bushing; 22. First snap ring; 23. Second snap ring; 24. Second sealing ring; 3. Sealing assembly; 31. First pole shoe; 311. Stepped platform; 312. Stepped slope; 313. Capillary microtexture; 32. Second pole shoe; 33. Permanent magnet; 34. Magnetic sleeve; 341. Stepped pole teeth; 342. Sealing gap; 343. Magnetic fluid; 35. Third sealing ring; 36. Fourth sealing ring; 37. Fifth sealing ring; 4. Liquid replenishment assembly; 41. First liquid collection ring; 42. Second liquid collection ring; 43. First guide ring; 44. Second guide ring; 45. First liquid storage tray; 46. Second liquid storage tray; 5. Dustproof assembly; 51. First dustproof seal; 511. First dustproof ring; 5111. Sealing tooth; 512. Second dustproof ring; 52. Second dustproof seal; 521. Third dustproof ring; 522. Fourth dustproof ring. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0042] like Figures 1 to 4 As shown, an embodiment of the present invention provides a high-speed magnetic liquid sealing device, comprising a housing 1, a bushing assembly 2, a sealing assembly 3, and a liquid replenishment assembly 4. The housing 1 has a chamber; the bushing assembly 2 is pivotally connected to the chamber and at least one end is located outside the housing 1; the sealing assembly 3 includes pole shoes fixed inside the housing 1, permanent magnets 33 sandwiched between the pole shoes, and a magnetically conductive sleeve fixed to the bushing assembly 2; the outer circumference of the magnetically conductive sleeve extends outward to form a plurality of annular stepped pole teeth 341, and a sealing gap 342 is formed between the stepped pole teeth 341 and the inner surface of the pole shoes. The gap 342 is filled with magnetic liquid 343; the inner surface of the pole shoe has a stepped structure, including at least one stepped platform 311 and at least one stepped inclined surface 312 connected to the stepped platform; the liquid replenishment assembly 4 includes a liquid storage tray, a liquid collection ring and a flow guide ring made of capillary porous material; the liquid replenishment assembly 4 is sleeved on the bushing assembly 2 and disposed on both axial sides of the sealing assembly 3; the liquid collection ring is disposed on the radially outer side corresponding to the liquid storage tray, and the flow guide ring is disposed between the liquid collection ring and the pole shoe; the end face of the pole shoe that contacts the flow guide ring and / or the inner circumferential surface of the pole shoe is provided with a capillary microtexture 313.

[0043] According to an embodiment of the present invention, a high-speed magnetic liquid sealing device is formed by the cooperation of a housing 1, a bushing assembly 2, a sealing assembly 3, and a liquid replenishment assembly 4 to form a magnetic liquid sealing structure. For the airflow direction, the sealing gap 342 is a stepped structure with a downward step, meaning the inner diameter of the pole shoe decreases along the airflow direction, and the outer diameter of the stepped pole teeth 341 also decreases along the airflow direction. Under low-speed conditions, the centrifugal force is small and insufficient to push the magnetic liquid 343 under the magnetic field to move radially outward. Therefore, the magnetic liquid 343 is held at the stepped platform 311 by the magnetic field to achieve sealing. Under high-speed conditions, the magnetic liquid 343 moves radially outward along the stepped inclined surface 312 under the action of centrifugal force, possessing a velocity component and a force component pointing towards the axial high-pressure side. This force component can offset part of the gas pressure, that is, converting the harmful centrifugal force into a component force resisting the high-pressure gas pressure, thereby improving the high-speed resistance of the magnetic liquid sealing device.

[0044] Under low-speed conditions, the centrifugal force generated by the rotation of the reservoir is insufficient to overcome its capillary force, and the spare magnetic liquid 343 is stored in the reservoir. Under high-speed conditions, the centrifugal force generated by the rotation of the reservoir overcomes its capillary force and throws the stored magnetic liquid 343 radially outward to the collecting ring. The collecting ring, with its higher porosity, quickly absorbs the magnetic liquid 343. The guide ring, with its lower porosity, has a greater capillary force than the collecting ring, meaning that the guide ring can transport the magnetic liquid 343 from the collecting ring to the guide ring. The end face of the pole shoe in contact with the guide ring and the inner circumferential surface of the pole shoe have a capillary microtexture 313. The capillary force of the capillary microtexture 313 is greater than that of the guide ring, meaning that the capillary microtexture 313 can transport the magnetic liquid 343 from the guide ring to the sealing gap 342 for replenishment, achieving adaptive replenishment at the target speed and improving the high-speed performance of the magnetic liquid sealing device.

[0045] Specifically, the sealing assembly 3 includes a first pole shoe 31, a permanent magnet 33, a second pole shoe 32, and a magnetic sleeve 34. The inner surface of the first pole shoe 31 and / or the second pole shoe 32 is stepped, with a stepped platform 311 and a stepped inclined surface 312. The outer peripheral surface of the magnetic sleeve has stepped pole teeth 341 extending radially outward at positions corresponding to the first pole shoe 31 and the second pole shoe 32 along the axial direction.

[0046] The first pole piece 31, the permanent magnet 33, and the second pole piece 32 are arranged sequentially along the axial direction of the bushing assembly 2. The lower stepped inner surface of each of the first pole piece 31 and the second pole piece 32 defines a sealing gap 342 between the stepped pole teeth 341 of the magnetic sleeve.

[0047] Specifically, the diameter of the inner surface of the stepped pole shoe decreases along the airflow direction, the diameter of the stepped inclined surface 312 decreases along the airflow direction, and the diameter of the outer peripheral surface of the stepped pole tooth 341 decreases along the airflow direction. That is, for the first pole shoe 31, the diameter of the inner surface of the pole shoe and the diameter of the stepped pole tooth 341 corresponding to the high-pressure sealing gap 342 are greater than the diameter of the inner surface of the pole shoe and the diameter of the stepped pole tooth 341 corresponding to the low-pressure sealing gap 342. It can be understood that the same applies to the second pole shoe 32.

[0048] Preferably, the axial length of the stepped platform 311 is the same as the axial length of the stepped pole tooth 341.

[0049] Preferably, the sealing gaps 342 corresponding to the first pole shoe 31 and the second pole shoe 32 are the same, the sealing gaps 342 corresponding to each stepped platform 311 of the first pole shoe 31 are the same, and the sealing gaps 342 corresponding to each stepped platform 311 of the second pole shoe 32 are the same. like Figure 1 and Figure 2 As shown, in some embodiments, the stepped structure on the inner surface of the pole shoe is a step-down structure; under low-speed conditions, the magnetic liquid 343 is maintained at the stepped platform 311 under the action of the magnetic field to achieve sealing; the stepped inclined surface 312 forms an acute angle with the axis of the sealing device 100, and its inclined direction is towards the high-pressure side. Under high-speed conditions, the magnetic liquid 343, which moves radially outward under the action of centrifugal force, moves along the stepped inclined surface 312, thereby generating an axial component force pointing towards the high-pressure side to offset part of the gas pressure.

[0050] In some embodiments, the collecting ring has a first porosity and the guiding ring has a second porosity, the first porosity being greater than the second porosity, such that the capillary force of the collecting ring is less than the capillary force of the guiding ring, thereby forming a capillary force gradient from the collecting ring to the guiding ring, driving the magnetic liquid 343 to be transported from the collecting ring to the guiding ring.

[0051] Both the liquid collecting ring and the flow guiding ring are made of capillary porous material. The liquid collecting ring has a large porosity to quickly absorb the magnetic liquid 343 thrown out of the liquid storage plate; the flow guiding ring has a small porosity to efficiently transport the magnetic liquid 343 in the liquid collecting ring to the flow guiding ring.

[0052] Specifically, the liquid collecting ring includes a first liquid collecting ring 41 and a second liquid collecting ring 42, and the flow guiding ring includes a first flow guiding ring 43 and a second flow guiding ring 44. The first liquid collecting ring 41 and the second liquid collecting ring 42 are arranged symmetrically about the sealing assembly 3 along the axial direction, and the first flow guiding ring 43 and the second flow guiding ring 44 are arranged symmetrically about the sealing assembly 3 along the axial direction.

[0053] Optionally, the first liquid collecting ring 41, the second liquid collecting ring 42, the first flow guiding ring 43, and the second flow guiding ring 44 are made of porous materials such as porous powder metallurgy materials, foamed metals, porous ceramics, and polymer porous materials.

[0054] It is understandable that the first liquid collecting ring 41, the second liquid collecting ring 42, the first flow guiding ring 43, and the second flow guiding ring 44 have very low magnetic permeability due to their porous internal structure.

[0055] Preferably, the first liquid collecting ring 41, the second liquid collecting ring 42, the first flow guiding ring 43, and the second flow guiding ring 44 are made of non-magnetic materials.

[0056] like Figure 3 and Figure 4 As shown, in some embodiments, the capillary force generated by the capillary microtexture 313 on the pole shoe is greater than the capillary force of the guide ring, forming a capillary force gradient from the guide ring to the sealing gap 342, driving the magnetic fluid 343 to be transported from the guide ring through the channel formed by the capillary microtexture 313 to the sealing gap 342, replenishing the loss of magnetic fluid 343 under high-speed conditions.

[0057] Among them, the capillary microtexture 313 is provided on the inner circumferential surface of the pole shoe and the end face that contacts the guide ring.

[0058] Alternatively, the microtexture 313 can be processed by laser processing, etching, embossing, or other methods.

[0059] Preferably, the capillary microtexture 313 is processed into a continuous plurality of grooves, and the capillary microtexture 313 on the end face of the pole shoe is continuous with the capillary microtexture 313 on the inner surface, ensuring that the magnetic liquid 343 transport channel is unobstructed.

[0060] Optionally, the capillary microtexture 313 on the inner surface of the pole shoe can be a straight line along the axial direction or a spiral line.

[0061] In some embodiments, the porosity of the liquid storage tray is adapted to the magnitude of the centrifugal force corresponding to the target operating speed of the sealing device 100; when the speed is lower than the target operating speed, the capillary force of the liquid storage tray can stably bind the magnetic liquid; when the target operating speed is reached, the centrifugal force overcomes the capillary force and releases the stored magnetic liquid 343 into the liquid collection ring, thereby achieving adaptive liquid replenishment at the target speed.

[0062] Understandably, the larger the diameter of the liquid storage tray, the greater the centrifugal force, and the lower the rotation speed at which the magnetic liquid 343 is released.

[0063] Optionally, the liquid storage tray is made of porous materials such as porous powder metallurgy materials, foamed metal, porous ceramics, and polymer porous materials.

[0064] It is understandable that the liquid storage pan has a very low magnetic permeability due to its porous internal structure.

[0065] Preferably, the liquid storage tray is made of a non-magnetic material.

[0066] Optionally, the liquid storage tray can be processed into various forms such as impeller type and disc type.

[0067] Specifically, the liquid storage tray includes a first liquid storage tray 45 and a second liquid storage tray 46, which are arranged symmetrically about the sealing assembly 3 along the axial direction.

[0068] In some embodiments, the liquid collection ring is disposed on the radial outer side of the liquid storage pan, adapting to the movement path of the magnetic liquid 343 being thrown outward radially under centrifugal force, and the axial position of the liquid collection ring corresponds to the liquid throwing area of ​​the liquid storage pan, thereby achieving efficient collection of the magnetic liquid 343.

[0069] There is a radial gap between the liquid storage pan and the liquid collection ring.

[0070] like Figure 1 As shown, in some embodiments, the liquid collecting ring is made of a high-porosity capillary porous material, and has a groove 411 on the side facing the liquid storage tray to increase the contact area with the magnetic liquid 343 and accelerate the absorption rate of the magnetic liquid 343.

[0071] Optionally, the groove 411 can be processed into an arc-shaped, V-shaped, or other shaped groove; preferably, it is processed into an arc shape.

[0072] The groove 411 and the guide ring are smoothly transitioned, allowing the unabsorbed magnetic fluid 343 to flow along the guide ring to the sealing gap 342, thus improving design tolerance. Preferably, the radial section of the guide ring is machined into a trapezoidal shape, and the groove 411 smoothly transitions to the trapezoidal inclined side of the guide ring.

[0073] like Figure 1 As shown, in some embodiments, one end of the guide ring is attached to the liquid collecting ring in the axial direction, and the other end is attached to the end face of the pole shoe with capillary microtexture 313, forming a continuous capillary transport path of liquid collecting ring-guide ring-pole shoe capillary microtexture-sealing gap, ensuring that the magnetic liquid 343 is directionally transported to the sealing gap 342.

[0074] It is understandable that the magnetic liquid 343 collected and stored by the liquid collecting ring can reach the sealing gap 342 by passing through the liquid collecting ring, the guide ring, and the capillary microtexture 313 in sequence by capillary force.

[0075] Preferably, the guide ring, the liquid collecting ring, and the end face with capillary microtexture 313 are precision machined.

[0076] like Figure 1 As shown, in some embodiments, the sealing device 100 further includes a dustproof component 5, which includes dustproof seals respectively disposed on the axial outer side of the liquid replenishment component 4. Each dustproof seal includes at least two dustproof rings for preventing external contaminants from clogging the capillary channels.

[0077] The dustproof seal is fitted onto the bushing assembly 2, and the dustproof seal is symmetrically arranged about the sealing assembly 3 along the axial direction.

[0078] Among them, the dustproof seal forms a labyrinth flow channel through the non-contact meshing of the sealing teeth, which increases frictional torque and is suitable for high-speed dustproof sealing.

[0079] The dust seal on the equipment side includes a first dust ring 511 and a second dust ring 512, which are non-contactly fitted together to form a first dust seal 51; the dust seal on the atmospheric environment side includes a third dust ring 521 and a fourth dust ring 522, which are non-contactly fitted together to form a second dust seal 52.

[0080] Specifically, each dust ring has multiple sealing teeth 5111, and the non-contact engagement is a non-contact meshing of the sealing teeth 5111.

[0081] Preferably, the first dust seal 51 and the second dust seal 52 are arranged symmetrically about the sealing assembly 3 along the axial direction.

[0082] Specifically, the first dustproof ring 511 and the third dustproof ring 521 are sleeved on the outer circumferential surface of the bushing 21, and the second dustproof ring 512 and the fourth dustproof ring 522 are sleeved on the inner circumferential surface of the housing 11.

[0083] In some embodiments, the stepped structure on the inner surface of the pole shoe and the stepped pole teeth 341 corresponding to the structure are arranged in multiple groups along the axial direction of the sealing device to form a multi-stage seal.

[0084] Among them, the stepped pole teeth 341 are disposed on the outer peripheral surface of the magnetic sleeve, and the magnetic sleeve is sleeved on the bushing assembly 2 and disposed on the radial inner side of the pole shoe.

[0085] A fifth sealing ring 37 is provided between the inner circumferential surface of the magnetic sleeve and the outer circumferential surface of the bushing assembly 2.

[0086] In some embodiments, the bushing assembly 2 includes a bushing 21, a first retaining ring 22, a second retaining ring 23, and a second sealing ring 24.

[0087] The first retaining ring 22 and the second retaining ring 23 are both sleeved on the bushing 21. The first retaining ring 22 abuts against the end of the first dustproof ring 511 away from the sealing assembly 3, and the second retaining ring 23 abuts against the end of the fourth dustproof ring 522 away from the sealing assembly 3.

[0088] Understandably, the first retaining ring 22 and the second retaining ring respectively limit the first dustproof ring 511 and the third dustproof ring 521, restricting the first dustproof ring 511 and the third dustproof ring 521 from sliding axially along the bushing 21.

[0089] The inner circumferential surface of the bushing 21 is provided with a second sealing ring 24 for sealing connection between the bushing 21 and the sealed rotating shaft.

[0090] like Figure 1 As shown, in some embodiments, the housing includes a shell, an end cap, and a first sealing ring. The shell and the end cap are connected by fasteners and enclose a cavity. The first sealing ring is provided on the connection surface between the shell and the equipment being sealed to ensure static sealing.

[0091] like Figure 1 As shown, and in conjunction with the above structural design, the end face of the first dustproof ring 511 facing the sealing assembly 3 abuts against the first liquid storage tray 45, and the end face of the first dustproof ring 511 away from the sealing assembly 3 abuts against the first retaining ring 22; the end face of the second dustproof ring 512 facing the sealing assembly 3 abuts against the first liquid collection ring 41, and the end face of the second dustproof ring 512 away from the sealing assembly 3 abuts against the inner end face of the housing 11 on the side away from the end cover 12; the end face of the third dustproof ring 521 facing the sealing assembly 3 abuts against the second liquid storage tray 45, and the end face of the third dustproof ring 521 away from the sealing assembly 3 abuts against the second retaining ring 23; the end face of the fourth dustproof ring 522 facing the sealing assembly 3 abuts against the second liquid collection ring 42, and the end face of the fourth dustproof ring 522 away from the sealing assembly 3 abuts against the end cover 12.

[0092] In addition, the first liquid storage tray 45 and the second liquid storage tray 46 are axially sleeved on the bushing 21. The end face of the first liquid storage tray 45 facing the sealing assembly 3 abuts against the magnetic sleeve 34, and the end face of the first liquid storage tray 45 away from the sealing assembly 3 abuts against the first dustproof ring 511. The end face of the second liquid storage tray 46 facing the sealing assembly 3 abuts against the magnetic sleeve 34, and the end face of the second liquid storage tray 46 away from the sealing assembly 3 abuts against the third dustproof ring 521.

[0093] like Figure 1 As shown, in some embodiments, the sealing assembly 3 further includes a third sealing ring 35 and a fourth sealing ring 36.

[0094] Specifically, a third sealing ring 35 and a fourth sealing ring 36 are respectively provided between the outer peripheral surface of the first pole shoe 31 and the inner peripheral surface of the outer shell 1.

[0095] Therefore, the present invention has the following advantages compared with related technologies: 1) Under high-speed conditions, the magnetic fluid is guided to the stepped slope by centrifugal force, generating an axial component force pointing towards the high-pressure side, which offsets part of the gas pressure, thereby converting the harmful centrifugal force into a beneficial sealing force and improving the pressure resistance of the sealing device under high-speed conditions. 2) It integrates a complete liquid replenishment structure for magnetic liquid release, collection and delivery, which adaptively replenishes magnetic liquid at the target speed. The structure is compact and highly integrated, and further improves the pressure resistance of the sealing device under high-speed conditions. 3) Non-contact dustproof seals are set on both sides of the liquid replenishment component, which are frictionless, suitable for high-speed operation, and have high reliability.

[0096] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0097] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0099] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0100] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0101] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A high-speed magnetic liquid sealing device, characterized in that, include: The outer casing has a cavity; A bushing assembly, the bushing assembly being pivotally connected to the chamber and having at least one end located outside the housing; A sealing assembly includes pole shoes fixed inside the housing, permanent magnets sandwiched between the pole shoes, and a magnetic sleeve fixed on the bushing assembly; the outer circumferential surface of the magnetic sleeve extends outward to form a plurality of annular stepped pole teeth, and a sealing gap is formed between the stepped pole teeth and the inner surface of the pole shoes, the sealing gap being filled with magnetic fluid; The inner surface of the pole shoe has a stepped structure, including at least one stepped platform and at least one stepped inclined surface connected to the stepped platform. A fluid replenishment assembly includes a reservoir, a collection ring, and a guide ring made of a capillary porous material; the fluid replenishment assembly is sleeved on the bushing assembly and disposed on both axial sides of the sealing assembly; the collection ring is disposed on the radially outer side of the reservoir, and the guide ring is located between the collection ring and the pole shoe; The end face of the pole shoe that contacts the guide ring and / or the inner circumferential surface of the pole shoe are provided with a capillary microtexture.

2. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The stepped structure on the inner surface of the pole shoe is a step-down structure. Under low-speed conditions, the magnetic fluid is maintained at the stepped platform under the action of the magnetic field to achieve sealing. The stepped inclined surface forms an acute angle with the axis of the sealing device, and its inclined direction is towards the high-pressure side. Under high-speed conditions, the magnetic fluid moving radially outward under the action of centrifugal force moves along the stepped inclined surface, thereby generating an axial component force pointing towards the high-pressure side to offset part of the gas pressure.

3. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The liquid collecting ring has a first porosity, and the flow guiding ring has a second porosity. The first porosity is greater than the second porosity, so that the capillary force of the liquid collecting ring is less than that of the flow guiding ring, thereby forming a capillary force gradient from the liquid collecting ring to the flow guiding ring, driving the magnetic liquid to be transported from the liquid collecting ring to the flow guiding ring.

4. The high-speed magnetic liquid sealing device according to claim 3, characterized in that, The capillary force generated by the microtexture on the pole shoe is greater than that of the guide ring, forming a capillary force gradient from the guide ring to the sealing gap. This drives the magnetic fluid to be transported from the guide ring through the channel formed by the microtexture to the sealing gap, replenishing the magnetic fluid loss under high-speed conditions.

5. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The porosity of the liquid storage tray is set to be adapted to the magnitude of the centrifugal force corresponding to the target operating speed of the sealing device. When the speed is lower than the target operating speed, the capillary force of the liquid storage tray can stably bind the magnetic liquid. When the target operating speed is reached, the centrifugal force overcomes the capillary force and releases the stored magnetic liquid into the liquid collection ring, thereby achieving adaptive liquid replenishment at the target speed.

6. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The liquid collection ring is located on the radial outer side of the liquid storage pan, which is adapted to the movement path of the magnetic liquid being thrown outward radially under centrifugal force. The axial position of the liquid collection ring corresponds to the liquid throwing area of ​​the liquid storage pan, thereby achieving efficient collection of the magnetic liquid.

7. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The liquid collecting ring is made of a capillary porous material with high porosity relative to the flow guiding ring, and it has a groove on the side facing the liquid storage plate to increase the contact area with the magnetic liquid and accelerate the absorption rate of the magnetic liquid.

8. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, One end of the guide ring is in contact with the liquid collecting ring in the axial direction, and the other end is in contact with the end face of the pole shoe with the capillary microtexture, forming a continuous capillary transport path of liquid collecting ring-guide ring-pole shoe capillary microtexture-sealing gap, ensuring that the magnetic liquid is directionally transported to the sealing gap.

9. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, It also includes a dustproof component, which includes dustproof seals respectively disposed on the axial outer side of the liquid replenishment component, each dustproof seal including at least two dustproof rings for preventing external contaminants from clogging the capillary channels.

10. The high-speed magnetic liquid sealing device according to claim 1, characterized in that, The stepped structure on the inner surface of the pole shoe and the corresponding stepped pole teeth are arranged in multiple groups along the axial direction of the sealing device to form a multi-stage seal.

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