Magnetic liquid sealing device capable of realizing self-supply of magnetic liquid

Abstract

The embodiment of the present application discloses a magnetic liquid sealing device capable of realizing self-supply of magnetic liquid, comprising a shell, a rotating shaft and at least one pole shoe, the rotating shaft is provided with at least one first magnetic liquid storage groove for accommodating standby magnetic liquid, and / or part of the pole teeth is provided with a second magnetic liquid storage groove for accommodating standby magnetic liquid. The magnetic liquid sealing device of the embodiment of the present application can self-supply the magnetic liquid in the sealing gap, effectively solve the problem of evaporation of the magnetic liquid, improve the sealing reliability and service life of the magnetic liquid sealing device, and automatically supply the magnetic liquid in the sealing gap without an additional sensor, thereby improving the reliability of the device. The magnetic liquid storage groove is designed on the rotating shaft or the pole tooth, axial installation space is saved, the magnetic liquid can be automatically supplied or replaced without disassembling or opening the sealing device, maintenance cost and downtime are reduced, and sealing effect and equipment safety are improved.

Description

Technical Field

[0001] This invention belongs to the field of mechanical engineering sealing technology, and in particular relates to a magnetic liquid sealing device that can realize self-replenishment of magnetic liquid. Background Technology

[0002] A magnetic liquid sealing device is a device that utilizes the properties of magnetic liquids to achieve a dynamic seal between a rotating shaft and a sealed container. Magnetic liquid is a colloidal liquid composed of nanoscale magnetic solid particles, surfactants, and a carrier liquid, capable of forming a liquid "O"-ring seal under the influence of a magnetic field. Magnetic liquid sealing devices offer advantages such as zero leakage, high vacuum, long lifespan, low torque loss, pressure differential resistance, high temperature resistance, and corrosion resistance, and are widely used in many fields.

[0003] However, the magnetic liquid sealing devices in related technologies suffer from the problem of magnetic liquid evaporation. Because the carrier liquid of the magnetic liquid has a certain degree of volatility, the amount of magnetic liquid decreases over time, affecting sealing performance and service life. This evaporation is particularly severe under extreme conditions such as high temperature, high pressure, and high speed, requiring regular replenishment or replacement of the magnetic liquid, increasing maintenance costs and downtime. Furthermore, due to the complex structure and strong sealing properties of the magnetic liquid sealing device, replenishing or replacing the magnetic liquid requires disassembling or opening the sealing device, exposing the rotating shaft and sealing container, which may cause leakage or contamination of the sealing medium, affecting the sealing effect and equipment safety. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a magnetic liquid sealing device capable of achieving self-replenishment of magnetic liquid.

[0005] The magnetic liquid sealing device for self-replenishment of magnetic liquid according to an embodiment of the present invention includes: a housing; a rotating shaft that passes through the housing and is rotatable relative to the housing; at least one pole shoe that is fitted onto the rotating shaft and located within the cavity of the housing, the pole shoe being connected to the housing, and the inner circumferential surface of the pole shoe having a plurality of pole teeth spaced apart along the axial direction of the rotating shaft, the pole teeth forming a sealing gap with the outer circumferential surface of the rotating shaft, the pole shoe being magnetic and adsorbing magnetic liquid in the sealing gap; wherein, the rotating shaft has at least one first magnetic liquid storage tank for accommodating spare magnetic liquid, the circumferential surface of the rotating shaft has a first opening of the first magnetic liquid storage tank, the first opening being radially opposite to at least one pole tooth of the rotating shaft, and a first cover plate being provided at the first opening, when the sealing gap is saturated with magnetic liquid... When the magnetic liquid is in the sealing gap, the first cover plate is pressed to close the first opening. When the magnetic liquid in the sealing gap is unsaturated and the shaft rotates, the first cover plate opens the first opening, and the magnetic liquid flows out from the first opening under the action of centrifugal force and replenishes the sealing gap; and / or, some of the pole teeth are provided with a second magnetic liquid storage tank for accommodating spare magnetic liquid. The tooth end face of the pole teeth is provided with a second opening of the second magnetic liquid storage tank. The second opening faces downward and towards the sealing gap. A second cover plate is provided at the second opening. When the sealing gap is saturated with magnetic liquid, the second cover plate is pressed to close the second opening. When the magnetic liquid in the sealing gap is unsaturated and the shaft rotates, the second cover plate opens the second opening, and the magnetic liquid flows out from the second opening under the action of gravity and replenishes the sealing gap.

[0006] The magnetic liquid sealing device of this invention can automatically replenish the magnetic liquid in the sealing gap, effectively solving the problem of magnetic liquid evaporation, improving the sealing reliability and service life of the magnetic liquid sealing device. It automatically replenishes the magnetic liquid in the sealing gap without the need for external sensors, thus improving the reliability of the device. Designing the magnetic liquid storage tank on the rotating shaft or pole teeth saves axial installation space, allowing for automatic replenishment or replacement of the magnetic liquid without disassembling or opening the sealing device, reducing maintenance costs and downtime, and improving sealing effect and equipment safety.

[0007] In some embodiments, the first magnetic liquid storage tank is provided with a first elastic member, which is supported between the first cover plate and the bottom surface of the first magnetic liquid storage tank, and the first elastic member is used to apply a pushing force to the first cover plate toward the open position; and / or, the second magnetic liquid storage tank is provided with a second elastic member, which is supported between the second cover plate and the bottom surface of the second magnetic liquid storage tank, and the second elastic member is used to apply a pushing force to the second cover plate toward the open position.

[0008] In some embodiments, the pole teeth are radially opposite to the first opening of at least one of the first magnetic liquid storage tanks on the rotating shaft.

[0009] In some embodiments, there are multiple first magnetic liquid storage tanks, which are divided into multiple groups. The multiple groups of first magnetic liquid storage tanks are spaced apart along the axial direction of the rotating shaft, and each group includes a plurality of first magnetic liquid storage tanks spaced apart along the circumferential direction of the rotating shaft.

[0010] In some embodiments, the rotating shaft extends horizontally, and the upper half of the pole teeth is provided with a plurality of second magnetic liquid storage tanks spaced apart in the circumferential direction of the rotating shaft.

[0011] In some embodiments, the angle between the orientation of the second opening of the second magnetic liquid storage tank and the vertical direction is less than or equal to 60°.

[0012] In some embodiments, the rotating shaft is provided with at least one of the first magnetic liquid storage tanks, and the first opening of the first magnetic liquid storage tank is opposite to the pole tooth in the middle of the corresponding pole shoe in the radial direction of the rotating shaft. The magnetism of the plurality of pole teeth of the pole shoe increases in a stepwise manner away from the first magnetic liquid storage tank.

[0013] In some embodiments, the width of the sealing gap between the plurality of pole teeth of the pole shoe and the rotating shaft decreases sequentially in the direction away from the first magnetic liquid storage tank; or the width of the plurality of pole teeth of the pole shoe decreases sequentially in the direction away from the first magnetic liquid storage tank; or the height of the plurality of grooves formed by the plurality of pole teeth of the pole shoe in the radial direction of the rotating shaft increases sequentially in the direction away from the first magnetic liquid storage tank; or the tooth end faces of the plurality of pole teeth of the pole shoe are beveled, and the distance between the tooth end faces of the plurality of pole teeth and the rotating shaft in the radial direction of the rotating shaft decreases sequentially in the direction away from the first magnetic liquid storage tank.

[0014] In some embodiments, the pole teeth in the middle of the pole shoe are provided with the second magnetic liquid storage tank, and the magnetism of the plurality of pole teeth of the pole shoe increases in a stepwise manner away from the second magnetic liquid storage tank.

[0015] In some embodiments, the width of the sealing gap between the plurality of pole teeth of the pole shoe and the rotating shaft decreases sequentially in the direction away from the second magnetic liquid storage tank; or the width of the plurality of pole teeth of the pole shoe decreases sequentially in the direction away from the second magnetic liquid storage tank; or the height of the plurality of tooth grooves formed by the plurality of pole teeth of the pole shoe in the radial direction of the rotating shaft increases sequentially in the direction away from the second magnetic liquid storage tank; or the tooth end faces of the plurality of pole teeth of the pole shoe are beveled, and the distance between the tooth end faces of the plurality of pole teeth and the rotating shaft in the radial direction of the rotating shaft decreases sequentially in the direction away from the second magnetic liquid storage tank. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the sealing device for achieving self-replenishment of magnetic fluid using thermal conductivity, according to an embodiment of the present invention.

[0017] Figure 2 yes Figure 1 Enlarged view of point A (first cover plate in open position).

[0018] Figure 3 yes Figure 1 Enlarged view of point A (first cover plate in closed position).

[0019] Figure 4 This is an enlarged schematic diagram of the polar teeth of the sealing device according to another embodiment of the present invention (the second cover plate is in the open position).

[0020] Figure 5 This is an enlarged schematic diagram of the polar teeth of the sealing device according to another embodiment of the present invention (the second cover plate is in the closed position).

[0021] Figure 6 This is an enlarged schematic diagram of the polar teeth of the sealing device according to another embodiment of the present invention (the first cover plate and the second cover plate are in the open position).

[0022] Figure 7 This is an enlarged schematic diagram of the polar teeth of the sealing device according to another embodiment of the present invention (the first cover plate and the second cover plate are in the closed position).

[0023] Figure 8 This is a cross-sectional view of the rotating shaft and the pole shoe of a sealing device according to an embodiment of the present invention.

[0024] Figure 9 This is a cross-sectional view of the rotating shaft and pole shoe of the sealing device according to another embodiment of the present invention.

[0025] Figure 10 This is another cross-sectional view of the rotating shaft and pole shoe of the sealing device according to another embodiment of the present invention.

[0026] Figure 11 This is a schematic diagram of a sealing device for achieving self-replenishment of magnetic fluid using thermal conductivity, according to another embodiment of the present invention.

[0027] Figure label:

[0028] Sealing device 100

[0029] Shell 1, Chamber 11

[0030] 2. Rotating shaft; 21. First magnetic liquid storage tank; 22. First opening; 23. First cover plate; 24. First elastic element.

[0031] 3. Pole shoe; 31. First pole shoe; 32. Second pole shoe; 33. Pole tooth; 34. Magnetic fluid; 35. Second magnetic fluid storage tank; 36. Second opening; 37. Second cover plate; 38. Second elastic element.

[0032] Permanent magnet 4, first bearing 51, second bearing 52, first sleeve 61, second sleeve 62. Detailed Implementation

[0033] 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.

[0034] like Figures 1-11 As shown, the magnetic liquid sealing device 100 capable of self-replenishing magnetic liquid according to an embodiment of the present invention includes a housing 1, a rotating shaft 2, and at least one pole shoe 3.

[0035] The housing 1 contains a chamber 11. A rotating shaft 2 passes through the chamber 11 and is rotatable relative to the housing 1, with both ends of the shaft 2 extending from the sides of the chamber 11. A pole shoe 3 is fitted onto the rotating shaft 2 and located within the chamber 11. The pole shoe 3 is connected to the housing 1. The inner circumferential surface of the pole shoe 3 has multiple pole teeth 33 spaced apart along the axial direction of the rotating shaft 2. Grooves are formed between adjacent pole teeth 33, and a sealing gap is formed between the pole teeth 33 and the outer circumferential surface of the rotating shaft 2. The pole teeth 33 are magnetic, and a magnetic liquid 34 is adsorbed within the sealing gap. The magnetic liquid 34 is adsorbed onto the tooth end faces of the pole teeth 33 and contacts the outer circumferential surface of the rotating shaft 2, thereby achieving a sealing effect.

[0036] The rotating shaft 2 is provided with at least one first magnetic liquid storage tank 21 for holding spare magnetic liquid, and / or, some of the pole teeth 33 are provided with a second magnetic liquid storage tank 35 for holding spare magnetic liquid.

[0037] Specifically, the rotating shaft 2 is provided with at least one first magnetic liquid storage tank 21, and the circumferential surface of the rotating shaft 2 is provided with a first opening 22 of the first magnetic liquid storage tank 21. The first opening 22 is opposite to at least one pole tooth 33 in the radial direction of the rotating shaft 2. A first cover plate 23 is provided at the first opening 22, and the first cover plate 23 can move between an open position and a closed position. When the sealed gap is saturated with magnetic liquid 34, the first cover plate 23 is in the closed position due to the pressure of the magnetic liquid 34, and the first cover plate 23 closes the first opening 22. When the magnetic liquid in the sealed gap is unsaturated and the rotating shaft 2 rotates, the first cover plate 23 moves from the closed position to the open position, the first opening 22 opens, and the magnetic liquid in the first magnetic liquid storage tank 21 flows out from the first opening 22 under the action of centrifugal force and replenishes the sealed gap. As the amount of magnetic liquid in the sealed gap continues to increase, the pressure of the magnetic liquid on the first cover plate 23 increases, and the first cover plate 23 moves from the open position to the closed position.

[0038] A second magnetic liquid storage tank 35 is provided within a portion of the pole teeth 33. A second opening 36 of the second magnetic liquid storage tank 35 is provided on the tooth end face of the pole teeth 33. The second opening 36 faces downwards and towards the sealing gap. A second cover plate 37 is provided at the second opening 36, and the second cover plate 37 moves between an open position and a closed position. When the sealing gap is saturated with magnetic liquid, the second cover plate 37 is in the closed position due to the pressure of the magnetic liquid, and the second cover plate 37 closes the second opening 36. When the magnetic liquid in the sealing gap is unsaturated and the rotating shaft 4 rotates, the second cover plate 37 moves from the closed position to the open position, the second opening 36 opens, and the magnetic liquid in the second magnetic liquid storage tank 35 flows downwards from the second opening 36 under the action of gravity, replenishing the sealing gap. As the amount of magnetic liquid in the sealing gap increases, the pressure of the magnetic liquid on the second cover plate 37 increases, and the second cover plate 37 moves from the open position to the closed position.

[0039] The magnetic liquid sealing device of this invention can automatically replenish the magnetic liquid in the sealing gap, effectively solving the problem of magnetic liquid evaporation, improving the sealing reliability and service life of the magnetic liquid sealing device. It automatically replenishes the magnetic liquid in the sealing gap without the need for external sensors, thus improving the reliability of the device. Designing the magnetic liquid storage tank on the rotating shaft or pole teeth saves axial installation space, allowing for automatic replenishment or replacement of the magnetic liquid without disassembling or opening the sealing device, reducing maintenance costs and downtime, and improving sealing effect and equipment safety.

[0040] In some embodiments, such as Figures 1-3As shown, the rotating shaft 2 is provided with a plurality of first magnetic liquid storage tanks 21, and a first elastic element 24 is provided in the first magnetic liquid storage tank 21. The first elastic element 24 is supported between the first cover plate 23 and the bottom surface of the first magnetic liquid storage tank 21. The first elastic element 24 is used to apply a pushing force to the first cover plate 23 toward the open position.

[0041] For example, the first elastic element 24 is a first spring, and the first end of the first spring (e.g.) Figure 2 The top end of the first spring is connected to the first cover plate 23, and the second end of the first spring (e.g., Figure 2 The bottom end of the first spring is connected to the bottom surface of the first magnetic liquid storage tank 21.

[0042] When the sealed gap is filled with saturated magnetic fluid 34, such as Figure 2 As shown, under the pressure of the magnetic liquid 34, the first cover plate 23 is in the closed position, the first spring is compressed, and the magnetic liquid in the first magnetic liquid storage tank 21 cannot flow out. When the magnetic liquid 34 in the sealed gap decreases and becomes unsaturated due to evaporation or other reasons, the pressure exerted by the magnetic liquid 34 decreases, and the first cover plate 23 moves to the open position under the thrust of the first spring, opening the first opening 22. Due to the rotation of the shaft 2, the magnetic liquid in the first magnetic liquid storage tank 21 flows out from the first opening 22 under the action of centrifugal force and replenishes the sealed gap. As the amount of magnetic liquid 34 in the sealed gap increases, the pressure of the magnetic liquid 34 on the first cover plate 23 increases, and the first cover plate 23 moves from the open position to the closed position.

[0043] In some embodiments, such as Figure 4 and Figure 5 As shown, a second elastic member 38 is provided in the second magnetic liquid storage tank 35. The second elastic member 38 is supported between the second cover plate 37 and the bottom surface of the second magnetic liquid storage tank 35. The second elastic member 38 is used to apply a pushing force to the second cover plate 37 toward the open position.

[0044] For example, the second elastic element 38 is a second spring, and the second end of the first spring (e.g.) Figure 4 The bottom end of the second spring is connected to the second cover plate 37, and the second end of the second spring (e.g.) Figure 4 The top of the second spring is connected to the bottom surface of the second magnetic liquid storage tank 35.

[0045] When the sealed gap is filled with saturated magnetic fluid 34, such as Figure 4As shown, under the pressure of the magnetic fluid 34, the second cover plate 37 is in the closed position, the second spring is compressed, and the magnetic fluid in the second magnetic fluid storage tank 35 cannot flow out. When the magnetic fluid 34 in the sealed gap decreases and becomes unsaturated due to evaporation or other reasons, the pressure exerted by the magnetic fluid 34 decreases, and the second cover plate 37 moves to the open position under the thrust of the second spring, opening the second opening 36. The magnetic fluid in the second magnetic fluid storage tank 35 flows out from the second opening 36 under the action of gravity and replenishes the sealed gap. As the amount of magnetic fluid 34 in the sealed gap increases, the pressure of the magnetic fluid 34 on the second cover plate 37 increases, and the second cover plate 37 moves from the open position to the closed position.

[0046] In some embodiments, such as Figure 6 and Figure 7 As shown, the rotating shaft 2 has a first magnetic liquid storage tank 21, and the pole tooth 33 has a second magnetic liquid storage tank 35. The first magnetic liquid storage tank 21 has a first elastic element 24, and the second magnetic liquid storage tank 35 has a second elastic element 38. Figure 6 As shown, the sealed gap is filled with saturated magnetic liquid 34, and both the first cover plate 23 and the second cover plate 37 are in the closed position. Figure 7 As shown, when the magnetic liquid 34 in the sealed gap decreases and becomes unsaturated due to evaporation or other reasons, both the first cover plate 23 and the second cover plate 37 are in the open position.

[0047] In some embodiments, such as Figure 1 As shown, there are multiple first magnetic liquid storage tanks 21, which are divided into multiple groups. These groups of first magnetic liquid storage tanks 21 are spaced apart along the axial direction of the rotating shaft 2. Each group includes several first magnetic liquid storage tanks 21 spaced apart along the circumferential direction of the rotating shaft 2. Furthermore, multiple pole teeth 33 of the pole shoe 3 correspond one-to-one with the multiple groups of first magnetic liquid storage tanks 21, and the pole teeth 33 and the first openings 22 of the corresponding multiple first magnetic liquid storage tanks 21 are radially opposite each other on the rotating shaft 2.

[0048] In other embodiments, the rotating shaft 2 is provided with a plurality of first magnetic liquid storage tanks 21, which are spaced apart in the axial direction of the rotating shaft 2. Furthermore, each pole tooth 33 of the pole shoe 3 is radially opposite to the first opening 22 of a first magnetic liquid storage tank 21.

[0049] As an example, such as Figure 8 As shown, the rotating shaft 2 is provided with at least one first magnetic liquid storage tank 21, and the pole tooth 33 is provided with a second magnetic liquid storage tank 35.

[0050] As an example, such as Figure 9 and Figure 10As shown, the rotating shaft 2 is provided with a plurality of first magnetic liquid storage tanks 21 spaced apart in the circumferential direction, and the pole teeth 33 is provided with a plurality of second magnetic liquid storage tanks 35 spaced apart in the circumferential direction. When the rotating shaft 2 extends in the horizontal direction, in order to ensure that the magnetic liquid in the second magnetic liquid storage tanks 35 can flow out smoothly under the action of gravity, the plurality of second magnetic liquid storage tanks 35 are provided in the upper half of the pole teeth 33, and the second opening 36 of the second magnetic liquid storage tanks 35 faces downward. Here, the second opening 36 facing downward does not only mean that the opening of the second opening 36 is vertically downward.

[0051] It is understandable that the first magnetic liquid storage tank 21 rotates with the rotating shaft 2. Therefore, as Figure 9 and Figure 10 As shown, the relative positions of the first magnetic liquid storage tank 21 and the second magnetic liquid storage tank 35 change.

[0052] Optionally, the angle between the orientation of the second opening 36 of the second magnetic liquid storage tank 35 and the vertical direction is less than or equal to 60°, so as to better ensure that the magnetic liquid in the second magnetic liquid storage tank 35 can flow out smoothly under the action of gravity.

[0053] exist Figure 1 and Figure 11 In the illustrated embodiment, the sealing device 100 has two pole shoes 3, including a first pole shoe 31 and a second pole shoe 32. The first pole shoe 31 and the second pole shoe 32 are spaced apart axially on the rotating shaft 2, with the first pole shoe 31 located to the left of the second pole shoe 32. Both the first pole shoe 31 and the second pole shoe 32 are annular, with their outer circumferential surfaces connected to the housing 1 and relatively stationary. When the rotating shaft 2 rotates, relative movement occurs between the rotating shaft 2 and the first pole shoe 31 and the second pole shoe 32. The magnetic fluid is maintained in the sealing gap between the first pole shoe 31 and the rotating shaft 2, and in the sealing gap between the second pole shoe 32 and the rotating shaft 2.

[0054] The sealing device 100 includes a permanent magnet 4, which is located axially between the first pole piece 31 and the second pole piece 32 of the rotating shaft 2. Since the first pole piece 31 and the second pole piece 32 are made of magnetically conductive materials, the magnetic field lines of the permanent magnet 4 pass through the first pole piece 31 and the second pole piece 32, making both the first pole piece 31 and the second pole piece 32 magnetic. As a result, the magnetic liquid 34 used for sealing can be adsorbed at the pole teeth 33 of the first pole piece 31 and the second pole piece 32.

[0055] Specifically, the permanent magnet 4 has a first end (left end) and a second end (right end) opposite each other along the axial direction of the rotating shaft 2. The first end of the permanent magnet 4 abuts against the first pole piece 31, making the first pole piece 31 magnetic. The second end of the permanent magnet 4 abuts against the second pole piece 32, making the second pole piece 32 magnetic. In other words, a magnetic circuit is formed between the permanent magnet 4, the first pole piece 31, the second pole piece 32, and the rotating shaft 2. Under the action of the magnetic field, the magnetic fluid is adsorbed into the sealed gap.

[0056] Optionally, the permanent magnet 4 is ring-shaped, or the permanent magnet 4 is multiple permanent magnet blocks arranged sequentially around the circumference of the rotating shaft 2, and each permanent magnet block abuts against each of the first pole piece 31 and the second pole piece 32 to provide magnetism to the pole piece 3.

[0057] In other alternative embodiments, the number of pole shoes 3 and their arrangement with the permanent magnets 4 can be different, and the present invention does not limit this.

[0058] Furthermore, such as Figure 1 and Figure 11 As shown, the sealing device 100 also includes a first bearing 51, a second bearing 52, a first sleeve 61, and a second sleeve 62. The first bearing 51, the second bearing 52, the first sleeve 61, and the second sleeve 62 are all located within the chamber 11 of the housing 1.

[0059] The first bearing 51 and the second bearing 52 are both supported between the housing 1 and the rotating shaft 2, and are used to support the rotation of the rotating shaft 2 relative to the housing 1. Each of the first pole shoe 31, the permanent magnet 4 and the second pole shoe 32 is located between the first bearing 51 and the second bearing 52 in the axial direction of the rotating shaft 2, and the second bearing 52 is away from the sealed container relative to the first bearing 51.

[0060] like Figure 1 and Figure 11 As shown, the first sleeve 61 is axially supported between the first pole shoe 31 and the first bearing 51 on the rotating shaft 2, and the first sleeve 61 is made of a non-magnetic material. The second sleeve 62 is axially supported between the second pole shoe 32 and the second bearing 52 on the rotating shaft 2, and the second sleeve 62 is also made of a non-magnetic material. The arrangement of the first sleeve 61 and the second sleeve 62 prevents the first bearing 51 and the second bearing 52 from affecting the magnetic field and causing magnetic field leakage.

[0061] In some embodiments, such as Figure 11As shown, the rotating shaft 2 is provided with a plurality of first magnetic liquid storage tanks 21. The first opening 22 of at least one first magnetic liquid storage tank 21 is opposite to the pole tooth 33 at the middle of the first pole shoe 31 in the radial direction of the rotating shaft 22. The first opening 22 of at least one first magnetic liquid storage tank 21 is opposite to the pole tooth 33 at the middle of the second pole shoe 32 in the radial direction of the rotating shaft 22. The magnetism of the plurality of pole teeth 33 of the pole shoe 3 increases in a stepped manner away from the corresponding first magnetic liquid storage tank 21.

[0062] As described above, the magnetism of the multiple pole teeth 33 of the pole shoe 3 increases in a stepped manner towards the direction away from the corresponding first magnetic liquid storage tank 21. In other words, the magnetism of the multiple pole teeth 33 of the pole shoe 3 increases in a stepped manner, and the magnetism of the pole teeth 33 farther away from the corresponding first magnetic liquid storage tank 21 is greater than that of the pole teeth 33 relatively adjacent to the first magnetic liquid storage tank 21. When the magnetic liquid 34 in the sealing gap decreases, under the action of centrifugal force, the magnetic liquid flows out from the first magnetic liquid storage tank 21. Under the action of gradient magnetic field force, the magnetic liquid is preferentially adsorbed into the sealing gap of the pole tooth 33 farthest from the first magnetic liquid storage tank 21, that is, the sealing gap of the pole tooth 33 with the strongest magnetism, until the magnetic liquid in the sealing gap reaches a saturated state. Then, the sealing gaps of the remaining pole teeth 33 of the pole shoe 3 are gradually filled in sequence until a saturated state is reached.

[0063] By utilizing the magnetic field strength gradient to fill the sealed gap with magnetic liquid, the number of openings in the first magnetic liquid storage tank 21 is reduced, the processing and manufacturing difficulty is lowered, and the reliability of the device is improved.

[0064] In some alternative embodiments, the width of the sealing gap between the plurality of pole teeth 33 of the pole shoe 3 and the rotating shaft 2 decreases sequentially in the direction away from the corresponding first magnetic liquid storage tank 21. Here, the width of the sealing gap refers to the radial dimension of the sealing gap on the rotating shaft 2.

[0065] by Figure 11 Taking the first pole shoe 31 in the sealing device 100 as an example, the width of the sealing gap formed by the pole teeth 33 located on the right side of the first magnetic liquid storage tank 21 gradually decreases from left to right, while the width of the sealing gap formed by the pole teeth 33 located on the left side of the first magnetic liquid storage tank 21 gradually decreases from right to left. The smaller the width of the sealing gap, the greater the magnetic field strength generated at the sealing gap.

[0066] The pole teeth 33 located on the left side of the first magnetic liquid storage tank 21 form a gradient magnetic field that increases progressively from right to left, while the pole shoes 33 located on the right side of the first magnetic liquid storage tank 21 form a gradient magnetic field that increases progressively from left to right. A gradient magnetic field, centered on the central pole teeth 33 and increasing in intensity towards both sides, is formed between the first pole shoes 31 and the rotating shaft 2. When the magnetic liquid in the sealed gap between the first pole shoes 31 and the rotating shaft 2 decreases, the magnetic liquid in the first magnetic liquid storage tank 21 flows out through the opened first opening 22 under the action of centrifugal force. Under the action of the gradient magnetic field of the first pole shoes 31, a portion of the magnetic liquid flows from left to right, and another portion flows from right to left, ensuring that the sealed gap of each pole tooth 33 is filled with magnetic liquid.

[0067] The second pole shoe 32 also forms a gradient magnetic field with the central pole tooth 33 as the center, and the intensity gradually increases to both sides, which will not be elaborated here.

[0068] In some alternative embodiments, the width of the plurality of pole teeth 33 of the pole shoe 3 decreases sequentially in the direction away from the corresponding first magnetic liquid storage tank 21. The width of the pole tooth 33 refers to the dimension of the pole tooth 33 in the axial direction of the rotating shaft 2.

[0069] by Figure 11 Taking the first pole shoe 31 in the sealing device 100 as an example, the width of the pole teeth 33 located on the right side of the first magnetic liquid storage tank 21 gradually decreases from left to right. The width of the pole teeth 33 located on the left side of the first magnetic liquid storage tank 21 gradually decreases from right to left. The smaller the width of the pole teeth 33, the greater the magnetic field strength generated at the sealing gap. A gradient magnetic field is formed between the first pole shoe 31 and the rotating shaft 2, with the central pole tooth 33 as the center and the strength gradually increasing to both sides. When the magnetic liquid in the sealing gap between the first pole shoe 31 and the rotating shaft 2 decreases, the magnetic liquid in the first magnetic liquid storage tank 21 flows out from the first opening 22 of the first magnetic liquid storage tank 21 under the action of centrifugal force. Under the action of the gradient magnetic field of the first pole shoe 31, part of the magnetic liquid flows from left to right and the other part flows from right to left, ensuring that the sealing gap of each pole tooth 33 is filled with magnetic liquid.

[0070] In some alternative embodiments, the height of the multiple grooves formed by the multiple pole teeth 33 of the pole shoe 3 in the radial direction of the rotating shaft 2 increases sequentially in the direction away from the corresponding first magnetic liquid storage tank 21. The height of the groove is its dimension in the radial direction of the rotating shaft 2.

[0071] by Figure 11Taking the first pole shoe 31 in the sealing device 100 as an example, the height of the grooves on the right side of the first magnetic liquid storage tank 21 gradually increases from left to right, while the height of the grooves on the left side of the first magnetic liquid storage tank 21 gradually increases from right to left. A gradient magnetic field is formed between the first pole shoe 31 and the rotating shaft 2, with the central pole tooth 33 as the center and the intensity gradually increasing towards both sides. When the magnetic liquid in the sealing gap between the first pole shoe 31 and the rotating shaft 2 decreases, the magnetic liquid in the first magnetic liquid storage tank 21 flows out from the first opening 22 of the first magnetic liquid storage tank 21 under the action of centrifugal force. Under the action of the gradient magnetic field of the first pole shoe 31, part of the magnetic liquid flows from left to right and the other part flows from right to left, ensuring that the sealing gap of each pole tooth 33 is filled with magnetic liquid.

[0072] In some optional embodiments, the tooth tips of the multiple pole teeth 33 of the pole shoe 3 are beveled, and the distance between the tooth tips of the multiple pole teeth 33 and the rotating shaft 2 in the radial direction of the rotating shaft decreases sequentially away from the first magnetic liquid storage tank 21. In other words, the width (radial dimension of the rotating shaft 2) of the sealing gap formed between the pole teeth 33 and the rotating shaft 2 decreases sequentially away from the corresponding first magnetic liquid storage tank 21; the smaller the width, the greater the magnetic field strength generated at the sealing gap. Therefore, a gradient magnetic field with increasing strength towards both sides is formed between the pole shoe 3 and the rotating shaft 2, centered on the central pole tooth 33.

[0073] In some embodiments, a second magnetic liquid storage tank 35 is provided within the pole teeth 33 in the middle of the pole shoe 3. The magnetism of the multiple pole teeth 33 of the pole shoe 3 increases in a stepped manner away from the second magnetic liquid storage tank 35. In other words, the magnetism of the multiple pole teeth 33 of the pole shoe 3 increases in a stepped manner, and the magnetism of the pole teeth 33 farther away from the corresponding second magnetic liquid storage tank 35 is greater than that of the pole teeth 33 relatively adjacent to the second magnetic liquid storage tank 35. When the magnetic liquid 34 in the sealing gap decreases, the magnetic liquid flows out from the second magnetic liquid storage tank 35 under the action of gravity. Under the action of the gradient magnetic field force, the magnetic liquid is preferentially attracted to the sealing gap of the pole tooth 33 furthest from the second magnetic liquid storage tank 35, that is, the sealing gap of the pole tooth 33 with the strongest magnetism, until the magnetic liquid in the sealing gap reaches a saturated state. Then, the sealing gaps of the remaining pole teeth 33 of the pole shoe 3 are gradually filled in sequence until a saturated state is reached. This reduces the number of second magnetic liquid storage tanks 35, reduces the manufacturing difficulty, and improves the reliability of the device.

[0074] In some alternative embodiments, the width of the sealing gap between the plurality of pole teeth 33 of the pole shoe 3 and the rotating shaft 2 decreases sequentially in the direction away from the second magnetic liquid storage tank 35.

[0075] In some alternative embodiments, the width of the plurality of pole teeth 33 of the pole shoe 3 decreases sequentially in the direction away from the second magnetic liquid storage tank 35.

[0076] In some alternative embodiments, the height of the multiple grooves formed by the multiple pole teeth 33 of the pole shoe 3 in the radial direction of the rotating shaft increases sequentially in the direction away from the second magnetic liquid storage tank 35.

[0077] In some alternative embodiments, the tooth end faces of the plurality of pole teeth 33 of the pole shoe 3 are inclined, and the distance between the tooth end faces of the plurality of pole teeth 33 and the rotating shaft 2 in the radial direction of the rotating shaft 2 decreases sequentially in the direction away from the second magnetic liquid storage tank 35.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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 magnetic liquid sealing device capable of self-replenishing magnetic liquid, characterized in that, include: case; A rotating shaft that passes through the housing and is rotatable relative to the housing; At least one pole shoe, the pole shoe is fitted onto the rotating shaft and located in the cavity of the housing, the pole shoe is connected to the housing, the inner circumferential surface of the pole shoe is provided with a plurality of pole teeth spaced apart in the axial direction of the rotating shaft, the pole teeth and the outer circumferential surface of the rotating shaft form a sealing gap, the pole shoe is magnetic and magnetic liquid is adsorbed in the sealing gap; The rotating shaft includes at least one first magnetic liquid storage tank for accommodating spare magnetic liquid. A first opening of the first magnetic liquid storage tank is located on the circumferential surface of the rotating shaft. This first opening is radially opposite at least one pole tooth. A first cover plate is located at the first opening. When the sealed gap is saturated with magnetic liquid, the first cover plate is pressed to close the first opening. When the magnetic liquid in the sealed gap is unsaturated and the rotating shaft rotates, the first cover plate opens the first opening, allowing the magnetic liquid to flow out from the first opening under centrifugal force and replenish the sealed gap. The pole teeth are provided with a second magnetic liquid storage tank for holding spare magnetic liquid. The tooth end face of the pole teeth is provided with a second opening of the second magnetic liquid storage tank. The second opening faces downward and toward the sealing gap. A second cover plate is provided at the second opening. When the sealing gap is saturated with magnetic liquid, the second cover plate is pressed to close the second opening. When the magnetic liquid in the sealing gap is unsaturated and the shaft rotates, the second cover plate opens the second opening, and the magnetic liquid flows out from the second opening under the action of gravity and replenishes the sealing gap. The first magnetic liquid storage tank is provided with a first elastic element, which is supported between the first cover plate and the bottom surface of the first magnetic liquid storage tank. The first elastic element is used to apply a pushing force to the first cover plate toward the open position. The rotating shaft is provided with at least one first magnetic liquid storage tank. The first opening of the first magnetic liquid storage tank is opposite to the pole tooth in the middle of the corresponding pole shoe in the radial direction of the rotating shaft. The magnetism of the multiple pole teeth of the pole shoe increases in a stepwise manner away from the first magnetic liquid storage tank. The width of the sealing gap between the plurality of pole teeth of the pole shoe and the rotating shaft decreases sequentially in the direction away from the first magnetic liquid storage tank; or The width of the plurality of pole teeth of the pole shoe decreases sequentially in the direction away from the first magnetic liquid storage tank; or, The height of the grooves formed by the multiple pole teeth of the pole shoe in the radial direction of the rotating shaft increases sequentially in the direction away from the first magnetic liquid storage tank; or, The tooth end faces of the plurality of pole teeth of the pole shoe are beveled, and the distance between the tooth end faces of the plurality of pole teeth and the rotating shaft in the radial direction of the rotating shaft decreases sequentially in the direction away from the first magnetic liquid storage tank.

2. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 1, characterized in that, The second magnetic liquid storage tank is provided with a second elastic element, which is supported between the second cover plate and the bottom surface of the second magnetic liquid storage tank. The second elastic element is used to apply a pushing force to the second cover plate toward the open position.

3. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 1, characterized in that, The pole teeth are radially opposite to the first opening of at least one of the first magnetic liquid storage tanks on the rotating shaft.

4. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 1, characterized in that, There are multiple first magnetic liquid storage tanks, which are divided into multiple groups. The multiple groups of first magnetic liquid storage tanks are spaced apart along the axial direction of the rotating shaft. Each group includes several first magnetic liquid storage tanks spaced apart along the circumferential direction of the rotating shaft.

5. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 1, characterized in that, The rotating shaft extends horizontally, and the upper half of the pole teeth is provided with a plurality of second magnetic liquid storage tanks spaced apart in the circumferential direction of the rotating shaft.

6. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 5, characterized in that, The angle between the orientation of the second opening of the second magnetic liquid storage tank and the vertical direction is less than or equal to 60°.

7. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 1, characterized in that, The pole teeth in the middle of the pole shoe are provided with the second magnetic liquid storage tank, and the magnetism of the multiple pole teeth of the pole shoe increases in a stepwise manner away from the second magnetic liquid storage tank.

8. The magnetic fluid sealing device capable of self-replenishing magnetic fluid according to claim 7, characterized in that, The width of the sealing gap between the plurality of pole teeth of the pole shoe and the rotating shaft decreases sequentially in the direction away from the second magnetic liquid storage tank; or The width of the plurality of pole teeth of the pole shoe decreases sequentially in the direction away from the second magnetic liquid storage tank; or, The height of the grooves formed by the multiple pole teeth of the pole shoe in the radial direction of the rotating shaft increases sequentially in the direction away from the second magnetic liquid storage tank; or, The tooth end faces of the plurality of pole teeth of the pole shoe are inclined, and the distance between the tooth end faces of the plurality of pole teeth and the rotating shaft in the radial direction of the rotating shaft decreases sequentially in the direction away from the second magnetic liquid storage tank.

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