Ultra-high vacuum magnetic liquid seal
By using a two-stage magnetic liquid sealing structure, the problem of sealing failure and contamination in traditional magnetic liquid sealing devices in ultra-high vacuum environments is solved, achieving ultra-high vacuum sealing with low leakage rate and low gas permeability, suitable for high-temperature environments up to 400℃.
Patent Information
- Application Number
- CN202310043539.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-01-29
- Publication Date
- 2026-01-02
- Estimated Expiration
- 2043-01-29
AI Technical Summary
Traditional magnetic liquid sealing devices are not suitable for ultra-high vacuum environments. The rubber sealing rings are prone to aging and failure, and the evaporation of lubricating grease contaminates the vacuum environment, affecting sealing performance and equipment reliability.
It adopts a two-stage magnetic fluid sealing structure, including a first-stage and a second-stage magnetic fluid sealing structure. Multiple sealing gaps are formed by permanent magnets and pole shoes, avoiding the use of rubber O-rings. The bearing is placed outside the ultra-high vacuum to prevent lubricant contamination.
It achieves low leakage rate, low gas permeability, and no vacuum contamination in ultra-high vacuum environments, with excellent sealing performance, long service life, and is suitable for high-temperature baking at 400℃, ensuring the safety and reliability of the equipment.
Smart Images
Figure CN116066566B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of mechanical engineering sealing, and relates to the technical field of magnetic liquid sealing, in particular to a magnetic liquid sealing transmission device for ultra-high vacuum. BACKGROUND
[0002] Magnetic liquid is a nano functional material, and its main components include surfactant, magnetic nanoparticles and base carrier liquid. The particles can be uniformly dispersed in the base carrier liquid by modifying the particles with a suitable surfactant, so as to obtain a magnetic liquid with magnetic field responsiveness and fluidity. The magnetic liquid sealing is one of the most mature application ways of the magnetic liquid in industry, and its basic structure includes a permanent magnet, a pole shoe processed with a tooth and groove structure and a magnetic liquid. An appropriate amount of magnetic liquid is injected into the sealing gap, a specific magnetic field distribution is formed by the permanent magnet and the pole shoe, and a plurality of "O" shaped liquid sealing rings can be formed in the sealing gap, which has excellent anti-leakage capacity and certain pressure resistance, and has long sealing life and low friction torque.
[0003] The conventional magnetic liquid sealing device shaft uses a rubber O-ring for auxiliary sealing on the outer circumferential surface of the pole shoe and the inner circumferential surface of the shell, and bearings are arranged on the left and right sides of the sealing structure. The conventional magnetic fluid sealing transmission device is not suitable for an ultra-high vacuum environment below 1x10 -5 Pa. On the one hand, since the rubber O-ring sealing ring used therein usually has a relatively high gas permeation rate, it is not suitable for sealing in an ultra-high vacuum environment, and the ultra-high vacuum equipment needs to be baked at a high temperature of about 400 DEG C for a long time for outgassing. Such a high temperature can easily cause residual deformation of the rubber, accelerate aging of the rubber, and affect the sealing performance. In addition, the rubber will gradually age and become brittle when stored for a long time at room temperature and normal pressure or used in a vacuum, thereby leading to sealing failure. Moreover, the rubber sealing ring has a quality loss problem in a vacuum environment, that is, as the filler and volatile components are lost, the mass of the rubber sealing ring gradually decreases, and when the quality loss exceeds the initial compression amount, the rubber sealing ring loses the sealing performance. On the other hand, from the structure of the above two devices, the bearings are arranged between the vacuum cavity and the sealing assembly composed of the O-shaped sealing ring, the permanent magnet, the magnetic pole and the magnetic fluid. The lubricating grease in the bearings has a volatilization phenomenon in a vacuum or at a high temperature, which not only causes the bearings to be damaged prematurely due to poor lubrication, but also pollutes the vacuum environment, thereby affecting the achievement of the ultra-high vacuum. SUMMARY
[0004] The present application aims to at least solve one of the technical problems in the related art to some extent. To this end, an embodiment of the present application provides an ultra-high vacuum magnetic liquid sealing device with good sealing performance, long service life and safety and reliability.
[0005] The magnetic liquid sealing device according to the embodiment of the present application comprises a housing, a rotating shaft, a plurality of sleeves, a plurality of pole shoes and a plurality of permanent magnets. The sealing assembly is arranged between the ultra-high vacuum side and all the bearings.
[0006] The housing has a chamber, a left part of the housing is a first half housing, the first half housing is non-magnetic conductive, a right part of the housing is a second half housing, the second half housing is magnetic conductive, the first half housing and the second half housing are integrated by welding. The rotating shaft is rotatably arranged in the chamber, a left part of the rotating shaft is a first half shaft, the first half shaft is magnetic conductive, a right part of the rotating shaft is a second half shaft, the second half shaft is non-magnetic conductive, the first half shaft and the second half shaft are integrated by welding.
[0007] The first pole shoe and the second pole shoe are arranged in the axial direction of the rotating shaft, the first pole shoe and the second pole shoe are sleeved on the rotating shaft, an outer circumferential surface of the first pole shoe is in contact with an inner circumferential surface of the housing and is integrated by welding, an inner circumferential surface of the first pole shoe is provided with a plurality of first pole teeth, the inner circumferential surface of the first pole teeth is arranged in the radial direction of the rotating shaft to form a first sealing gap, the plurality of first pole teeth are arranged in the axial direction of the first pole shoe, the first sealing gap is filled with magnetic liquid, an outer circumferential surface of the second pole shoe is in contact with the inner circumferential surface of the housing, an inner circumferential surface of the second pole shoe is not provided with pole teeth, the inner circumferential surface of the second pole shoe is arranged in the radial direction of the rotating shaft to form a first small gap, the second pole shoe does not have a sealing function and only has a magnetic conductive function. The first permanent magnet is sleeved on the rotating shaft, and the first permanent magnet is located between the first pole shoe and the second pole shoe in the axial direction of the rotating shaft.
[0008] The first sleeve is arranged in the chamber and is sleeved on the rotating shaft, and the first sleeve is located between the second pole shoe and the third pole shoe in the axial direction of the rotating shaft.
[0009] The third pole shoe and the fourth pole shoe are arranged in the axial direction of the rotating shaft, and the third pole shoe and the fourth pole shoe are sleeved on the rotating shaft, the inner circumferential surface of the third pole shoe is in contact with the outer circumferential surface of the rotating shaft, the outer circumferential surface of the third pole shoe is free of pole teeth, and the outer circumferential surface of the third pole shoe is arranged in the radial direction of the rotating shaft and spaced from the inner circumferential surface of the shell to form a second small gap, the third pole shoe does not have a sealing function but only has a magnetic conducting function, the inner circumferential surface of the fourth pole shoe is in contact with the outer circumferential surface of the rotating shaft and is integrated by welding, the outer circumferential surface of the fourth pole shoe is provided with a plurality of second pole teeth, the outer circumferential surface of the second pole teeth is arranged in the radial direction of the rotating shaft and spaced from the inner circumferential surface of the shell to form a second sealing gap, the plurality of second pole teeth are arranged in the axial direction of the fourth pole shoe, and the fourth sealing gap is filled with the magnetic liquid. The second permanent magnet is arranged around the rotating shaft, and the second permanent magnet is located between the third pole shoe and the fourth pole shoe in the axial direction of the rotating shaft.
[0010] The first pole shoe, the first permanent magnet, the second pole shoe and the first half shell constitute a first-stage magnetic liquid sealing structure, and the third pole shoe, the second permanent magnet, the fourth pole shoe and the second half shell constitute a second-stage magnetic liquid sealing structure. The two-stage magnetic liquid sealing structure guarantees the sealing effect and prolongs the leakage channel. The two-stage magnetic liquid sealing structures are arranged in opposite directions in the radial direction of the rotating shaft, so that the two-stage magnetic liquid sealing structures can be assembled and disassembled.
[0011] The magnetic liquid sealing device according to the embodiment of the present application has the sealing assembly arranged between the ultra-high vacuum side and all the bearings, that is, the bearings are arranged outside the ultra-high vacuum environment, and the volatilized lubricating oil in the bearings cannot enter the ultra-high vacuum side, so that the problem that the ultra-high vacuum environment is easily polluted is solved. The present application does not use rubber O-rings, and the quality loss problem of the rubber sealing rings does not exist. The present application can not only meet the requirements of the ultra-high vacuum environment, such as high ultimate vacuum degree, low leakage rate, low gas permeation rate, fast pumping speed and no vacuum pollution, but also can guarantee long-time reliable sealing.
[0012] In some embodiments, the rotating shaft has a shaft ring, the shaft ring is in contact with the right end surface of the fourth pole shoe, and the left bearing inner ring is axially fixed through the shaft ring.
[0013] In some embodiments, the second sleeve is connected with the shell and is sleeved on the rotating shaft, and the second sleeve is located between the left bearing and the right bearing in the axial direction of the rotating shaft.
[0014] In some embodiments, the rotating shaft has a threaded shaft segment, and the circular nut is connected with the rotating shaft through the thread. The end cover is connected with the shell through bolts, the right bearing outer ring is axially fixed through the end cover, and the right bearing inner ring is axially fixed through the circular nut. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is a schematic diagram of a super-high vacuum magnetic liquid sealing device of the present application;
[0016] Figure 2 is Figure 1 is a partial enlarged schematic diagram of the super-high vacuum magnetic liquid sealing device shown at A;
[0017] Figure 3 is Figure 1 is a partial enlarged schematic diagram of the super-high vacuum magnetic liquid sealing device shown at B;
[0018] Reference signs:
[0019] The housing 1, the first half housing 1A, the second half housing 1B, the chamber 101, the flange 102, the shaft 2, the first half shaft 2A, the second half shaft 2B, the shaft ring 201, the shaft segment 202, the cover 3, the first pole shoe 4, the first sealing gap 401, the first pole tooth 402, the first permanent magnet 5, the second pole shoe 6, the first pole small gap 601, the first sleeve 7, the third pole shoe 8, the second pole small gap 801, the second permanent magnet 9, the fourth pole shoe 10, the second sealing gap 1001, the second pole tooth 1002, the left bearing 11, the second sleeve 12, the right bearing 13, the round nut 14. DETAILED DESCRIPTION
[0020] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.
[0021] The following description refers to the accompanying drawings, which are meant to be exemplary and not limiting. Figure 1 A super-high vacuum magnetic liquid sealing device according to an embodiment of the present application is described below.
[0022] The magnetic liquid sealing device according to an embodiment of the present application comprises: a housing, a first half housing, a second half housing, a chamber, a flange, a shaft, a first half shaft, a second half shaft, a shaft ring, a shaft segment, a cover, a first pole shoe, a first sealing gap, a first pole tooth, a first permanent magnet, a second pole shoe, a first pole small gap, a first sleeve, a third pole shoe, a second pole small gap, a second permanent magnet, a fourth pole shoe, a second sealing gap, a second pole tooth, a left bearing, a second sleeve, a right bearing, a round nut.
[0023] The housing 1 has the chamber 101 therein. As shown in FIG. 1, the chamber 101 is a cylindrical cavity. Figure 1As shown, the left end of the outer casing 1 is provided with a flange 102, which has multiple threaded holes and is suitable for connection to external equipment. The left side of the outer casing 1 is the first half-shell 1A, which is non-magnetic, and the right side is the second half-shell 1B, which is magnetic. The first half-shell 1A and the second half-shell 1B are integrated by welding.
[0024] The rotating shaft 2 is rotatably disposed within the chamber 101. The left portion of the rotating shaft 2 is the first half-shaft 2A, which is magnetically conductive, and the right portion is the second half-shaft 2B, which is non-magnetically conductive. The first half-shaft 2A and the second half-shaft 2B are integrally welded together. Figure 1 As shown, the rotating shaft 2 passes horizontally through the outer casing 1 in the left-right direction, and the left and right ends of the rotating shaft 2 extend out of the outer casing 1.
[0025] The first pole shoe 4 and the second pole shoe 6 are axially aligned with the first half-shaft 2A (e.g., Figure 1 The first pole shoe 4 is disposed within the chamber 101 and sleeved on the first half-shaft 2A. The outer peripheral surface of the first pole shoe 4 contacts the inner peripheral surface of the first half-shell 1A and is integrally welded together. The inner peripheral surface of the first pole shoe 4 is provided with multiple first pole teeth 402. The inner peripheral surface of the first pole teeth 402 and the outer peripheral surface of the first half-shaft 2A are arranged radially (e.g., in the left-right direction shown) of the first half-shaft 2A. Figure 1 The first sealing gap 401 is formed by the arrangement of multiple first pole teeth 402 in the axial direction of the first pole shoe 4 at intervals. Magnetic liquid is adsorbed in the first sealing gap 401.
[0026] The second pole shoe 6 is disposed within the chamber 101 and sleeved on the first half-shaft 2A. The outer peripheral surface of the second pole shoe 6 contacts the inner peripheral surface of the first half-shell 1A. The inner peripheral surface of the second pole shoe 6 has no pole teeth. The inner peripheral surface of the second pole shoe 6 and the outer peripheral surface of the first half-shaft 2A are in radial direction (e.g., ...) of the first half-shaft 2A. Figure 1 The first minimum gap 601 is formed by the arrangement of the pole pieces (in the vertical direction shown). The second pole piece 6 does not have a sealing function, but only a magnetic conduction function.
[0027] The first permanent magnet 5 is disposed within the chamber 101 and sleeved on the first half-shaft 2A. The first permanent magnet 5 is located axially between the first pole shoe 4 and the second pole shoe 6 of the first half-shaft 2A. Figure 1 As shown, the left end face of the first permanent magnet 5 is in contact with the right end face of the first pole shoe 4, the right end face of the first permanent magnet 5 is in contact with the left end face of the second pole shoe 6, the outer peripheral surface of the first permanent magnet 5 is in contact with the inner peripheral surface of the first half-shell 1A, and the inner peripheral surface of the first permanent magnet 5 and the outer peripheral surface of the first half-shaft 2A are spaced apart in the vertical direction.
[0028] The first sleeve 7 is located inside the chamber 101 and is fitted onto the rotating shaft 2. The second pole shoe 6, the first sleeve 7, and the third pole shoe 8 are aligned axially along the rotating shaft 2 (e.g., ...). Figure 1 Arranged sequentially in the left and right directions (as shown). Figure 1 As shown, the left end face of the first sleeve 7 is in contact with the right end face of the second pole shoe 6, the right end face of the first sleeve 7 is in contact with the left end face of the third pole shoe 9, the outer peripheral surface of the first sleeve 7 is in contact with the inner peripheral surface of the outer shell 1, and the inner peripheral surface of the first sleeve 7 and the outer peripheral surface of the second sleeve 12 are spaced apart in the vertical direction.
[0029] The third pole shoe 8 and the fourth pole shoe 10 are axially aligned with the second half-shaft 2B (e.g., Figure 1 The third pole shoe 8 is disposed within the chamber 101 and fitted onto the second half-shaft 2B. The inner circumferential surface of the third pole shoe 8 contacts the outer circumferential surface of the second half-shaft 2B. The outer circumferential surface of the third pole shoe 8 has no pole teeth. The outer circumferential surface of the third pole shoe 8 and the inner circumferential surface of the second half-shell 1B are arranged radially (e.g., in the left-right direction) of the second half-shaft 2B. Figure 1 The upper and lower parts are arranged at intervals to form the second minimum gap 801. The third pole shoe 8 does not have a sealing function, but only a magnetic conduction function.
[0030] The fourth pole shoe 10 is disposed within the chamber 101 and sleeved on the second half-shaft 2B. The inner circumferential surface of the fourth pole shoe 10 contacts the outer circumferential surface of the second half-shaft 2B and is integrally welded together. The outer circumferential surface of the fourth pole shoe 10 is provided with a plurality of second pole teeth 1002. The outer circumferential surface of the second pole teeth 1002 and the inner circumferential surface of the second half-shell 1B are radially (e.g., ...) of the second half-shaft 2B. Figure 1 The second sealing gap 1001 is formed by the teeth arranged at intervals in the vertical direction shown. Multiple second pole teeth 1002 are arranged at intervals in the axial direction of the fourth pole shoe 11. Magnetic liquid is adsorbed in the second sealing gap 1001.
[0031] The second permanent magnet 9 is disposed within the chamber 101 and sleeved on the second half-shaft 2B. The second permanent magnet 9 is located axially between the third pole shoe 8 and the fourth pole shoe 10 of the second half-shaft 2B. Figure 1 As shown, the left end face of the second permanent magnet 9 is in contact with the right end face of the third pole shoe 8, the right end face of the second permanent magnet 9 is in contact with the left end face of the fourth pole shoe 11, the inner circumferential surface of the second permanent magnet 9 is in contact with the outer circumferential surface of the second half-shaft 2B, and the outer circumferential surface of the second permanent magnet 9 and the inner circumferential surface of the second half-shell 1B are spaced apart in the vertical direction.
[0032] like Figure 1, the first pole shoe 4, the first permanent magnet 5, the second pole shoe 6 and the first half shaft 2A form a first-stage magnetic liquid sealing structure. The third pole shoe 8, the second permanent magnet 9 and the fourth pole shoe 10 form a second-stage magnetic liquid sealing structure. The two-stage magnetic liquid sealing structure guarantees the sealing effect and prolongs the leakage channel. The two-stage magnetic liquid sealing structures are in opposite directions in the radial direction of the rotating shaft 2, which guarantees the assembly and disassembly.
[0033] In the magnetic liquid sealing device according to the embodiment of the present application, in the assembly, the first pole shoe 4 and the first half shell 1A are integrated by welding, then the first permanent magnet 5, the second pole shoe 6 are sequentially put in, then the first half shell 1A and the second half shell 1B are integrated by welding, then the first sleeve 7, the third pole shoe 8 and the second permanent magnet 9 are sequentially put in, then the first half shaft 2A and the second half shaft 2B and the fourth pole shoe 10 are integrated by welding, then the integrated rotating shaft 2 is inserted into the center of the third pole shoe 8 and the second permanent magnet 9.
[0034] In the magnetic liquid sealing device according to the embodiment of the present application, when the magnetic liquid sealing device works, the first permanent magnet 5, the second pole shoe 6, the first sleeve 7, the third pole shoe 8 and the second permanent magnet 9 are sequentially pressed in the axial direction (such as the left-right direction shown in the figure) by the first pole shoe 4 and the fourth pole shoe 10.
[0035] In the magnetic liquid sealing device according to the embodiment of the present application, when the magnetic liquid sealing device works, the left side of the device is the ultra-high vacuum side I and the right side is the atmospheric side II.
[0036] In some embodiments, the rotating shaft 2 has a shaft ring 201, the shaft ring 201 is adjacent to the right end surface of the fourth pole shoe 10, and the inner ring of the left bearing 11 is axially fixed through the shaft ring 201.
[0037] In some embodiments, the second sleeve 12 is arranged in the cavity 101 and is sleeved on the rotating shaft 2, and the second sleeve 12 is located between the left bearing 11 and the right bearing 13 in the axial direction of the rotating shaft 2. The outer circumferential surface of the second sleeve 12 is in contact with the inner circumferential surface of the shell 1, and the inner circumferential surface of the second sleeve 12 and the outer circumferential surface of the rotating shaft 2 have a spacing distance in the up-down direction.
[0038] In some embodiments, the shaft segment 202 has a thread, and the circular nut 14 is connected to the rotating shaft 2 through the thread. The end cover 3 is connected to the shell 1 through bolts, the outer ring of the right bearing 13 is axially fixed through the end cover 3, and the inner ring of the right bearing is axially fixed through the circular nut 14.
[0039] In addition, the terms "first", "second", etc. are used only for the purpose of description and do not imply or imply relative importance or imply the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified.
[0040] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or communicate with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0041] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.
[0042] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification and the features of different embodiments or examples, without contradiction.
[0043] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and cannot be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.
Claims
1. A high-vacuum magnetic liquid sealing device, characterized in that, The sealing device includes: a housing, a chamber, a flange, a rotating shaft, a cover, a first pole shoe, a first sealing gap, a first pole tooth, a first permanent magnet, a second pole shoe, a first minimum gap, a first sleeve, a third pole shoe, a second minimum gap, a second permanent magnet, a fourth pole shoe, a second sealing gap, a second pole tooth, a left bearing, a second sleeve, a right bearing, and a round nut; The outer shell has a cavity inside. The left part of the outer shell is the first half shell, which is non-magnetic. The right part of the outer shell is the second half shell, which is magnetic. The first half shell and the second half shell are integrated by welding. The rotating shaft is rotatably disposed in the cavity. The left part of the rotating shaft is the first half-shaft, which is magnetically conductive. The right part of the rotating shaft is the second half-shaft, which is non-magnetically conductive. The first half-shaft and the second half-shaft are integrated by welding. The first sleeve is disposed in the cavity and sleeved on the rotating shaft. The first sleeve is connected to the outer shell. The first sleeve is located in the axial direction of the rotating shaft between the second pole shoe and the third pole shoe. The first pole shoe and the second pole shoe are respectively sleeved on the rotating shaft. The outer peripheral surface of the first pole shoe is in contact with the inner peripheral surface of the outer shell and is integrated by welding. The inner peripheral surface of the first pole shoe is provided with a plurality of first pole teeth. The inner peripheral surfaces of the first pole teeth and the outer peripheral surface of the rotating shaft are arranged at intervals in the radial direction of the rotating shaft to form a first sealing gap. The plurality of first pole teeth are arranged at intervals in the axial direction of the first pole shoe. Magnetic liquid is adsorbed in the first sealing gap. The outer peripheral surface of the second pole shoe is in contact with the inner peripheral surface of the outer shell. The inner peripheral surface of the second pole shoe has no pole teeth. The inner peripheral surface of the second pole shoe and the outer peripheral surface of the rotating shaft are arranged at intervals in the radial direction of the rotating shaft to form a first minimum gap. The second pole shoe does not perform a sealing function, but only a magnetic conduction function. The third and fourth pole shoes are respectively sleeved on the rotating shaft. The inner circumferential surface of the third pole shoe is in contact with the outer circumferential surface of the rotating shaft. The outer circumferential surface of the third pole shoe has no pole teeth. The outer circumferential surface of the third pole shoe and the inner circumferential surface of the outer shell are arranged radially on the rotating shaft to form a second minimum gap. The third pole shoe does not serve a sealing function, but only a magnetic conduction function. The inner circumferential surface of the fourth pole shoe is in contact with the outer circumferential surface of the rotating shaft and is integrally welded. The outer circumferential surface of the fourth pole shoe is provided with multiple second pole teeth. The outer circumferential surfaces of the second pole teeth and the inner circumferential surface of the outer shell are arranged radially on the rotating shaft to form a second sealing gap. The multiple second pole teeth are arranged axially on the fourth pole shoe. Magnetic liquid is adsorbed in the second sealing gap. The first permanent magnet is wrapped around the shaft and is located between the first pole shoe and the second pole shoe in the axial direction of the shaft; The second permanent magnet is wrapped around the shaft and is located axially between the third and fourth pole shoes.
2. The ultra-high vacuum magnetic liquid sealing device according to claim 1, characterized in that: The first pole shoe, the first permanent magnet, and the second pole shoe form a first-stage magnetic liquid sealing structure, which forms a closed magnetic circuit with the first half-shaft; the third pole shoe, the second permanent magnet, and the fourth pole shoe form a second-stage magnetic liquid sealing structure, which forms a closed magnetic circuit with the second half-shell.
Citation Information
Patent Citations
Peltier cooling type magnetic liquid sealing device
CN103925371A
Finned tube cooled magnetic fluid sealing device
CN204852353U