Magnetic liquid sealing device and method

Abstract

The invention discloses a magnetic liquid sealing device and method. The magnetic liquid sealing device comprises a shell, a left half rotating shaft, a right half rotating shaft, an elastic pad, a pole shoe, a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet; the left half rotating shaft and the right half rotating shaft are tightly fitted and rotatably arranged in the shell, the elastic pad is arranged at the connecting end surface of the left half rotating shaft and the right half rotating shaft, the first permanent magnet and the second permanent magnet, the third permanent magnet and the fourth permanent magnet respectively correspond to opposite polarities to form a corresponding magnetic circuit; the invention solves the technical problems that the existing magnetic liquid sealing device has a complex structural design and is inconvenient to disassemble, which leads to difficulty in replacing magnetic liquid and cleaning pole shoe pole teeth.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical engineering sealing, and in particular to a magnetic liquid sealing device and method. Background Art

[0002] Magnetic liquid is a new type of functional material that has emerged with the development of science and technology. It has the magnetizable properties of magnetic materials and the fluidity of liquids. Magnetic liquid sealing technology is used by more and more industries due to its advantages such as zero leakage, no wear, long life, and simple structure. The magnetic liquid sealing device in the related technology includes a housing, a pole shoe, a permanent magnet, and a rotating shaft. A sealing gap is formed between the pole shoe and the rotating shaft, and the sealing gap is 0.1 mm to 0.2 mm. Under the action of the magnetic field, the magnetic liquid is filled in the sealing gap, and the nano-scale ferromagnetic particles in the magnetic liquid can be suspended stably for a long time and evenly dispersed in the base carrier liquid, so that the magnetic liquid sealing device has good sealing and pressure resistance performance.

[0003] The magnetic liquid sealing device is installed on the sealing cavity of the equipment to seal the fluid in the sealing cavity. The equipment can be a reactor. When the equipment is in working state, there is generally a high pressure between two adjacent pole teeth, and the pressure between the two adjacent pole teeth closer to the sealing cavity is greater. When the equipment is stopped, the external pressure of the sealing device near the sealing cavity suddenly decreases. Therefore, the pressure between the two adjacent pole teeth near the sealing cavity is greater than the external pressure, and the pressure difference on both sides of the axial direction of the pole teeth closer to the sealing cavity is greater, that is, the pressure difference on both sides of the magnetic liquid in the sealing gap closer to the sealing cavity is greater. This pressure difference can easily flush the magnetic liquid in the sealing gap out of the sealing gap, resulting in a reduction of the magnetic liquid in the sealing gap, which ultimately affects the sealing pressure resistance of the magnetic liquid sealing device and even causes the problem of sealing failure.

[0004] In order to meet the overall sealing requirements, the magnetic liquid sealing device in the prior art usually has a complex structural design, which brings many inconveniences to disassembly and assembly, resulting in inconvenience in use and maintenance (such as replacing the magnetic liquid and cleaning the pole shoes are very difficult), resulting in the high cost of using the magnetic liquid sealing device.

[0005] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a magnetic liquid sealing device and method to solve the technical problems that the existing magnetic liquid sealing device has complex structural design and is inconvenient to disassemble, resulting in inconvenience in use and maintenance (such as difficulty in replacing magnetic liquid and cleaning pole shoes and pole teeth, etc.), and the sealing performance and compressive strength need to be improved.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] Design a magnetic liquid sealing device, including:

[0009] A shell, the shell comprising an inner peripheral wall and left and right end covers, the inner peripheral wall and the left and right end covers enclose a chamber;

[0010] A rotating shaft, the rotating shaft comprising a left half rotating shaft and a right half rotating shaft, the left half rotating shaft and the right half rotating shaft are fixedly arranged in the shell and rotate relative to the shell;

[0011] An elastic pad, wherein the elastic pad is arranged between the left half rotating shaft and the right half rotating shaft, and the end surfaces of the left half rotating shaft and the right half rotating shaft extend beyond the elastic pad by the same length;

[0012] A pole shoe, the pole shoe is installed in the housing, a plurality of pole teeth are arranged on the inner side of the pole shoe along the axial direction of the rotating shaft, and a plurality of grooves are opened on the inner side of the pole shoe on both sides of the pole teeth;

[0013] A permanent magnet, wherein the permanent magnet is fixed in the groove;

[0014] A locking sleeve is fixedly arranged on the butt end surfaces of the left half rotating shaft and the right half rotating shaft, and the outer diameter of the locking sleeve is smaller than the inner diameter of the shell.

[0015] Preferably, the permanent magnet includes a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet arranged in the pole shoe groove; the first permanent magnet and the second permanent magnet have opposite polarities, and the third permanent magnet and the fourth permanent magnet have opposite polarities to form a magnetic circuit to enhance the sealing performance.

[0016] Preferably, a sealing groove is correspondingly provided on the outer side of the pole shoe, and a sealing ring is sleeved in the sealing groove to prevent leakage of the magnetic liquid.

[0017] Preferably, threaded holes are provided on the corresponding end surfaces of the left half shaft and the right half shaft, and the left half shaft and the right half shaft are tightly connected by bolts to ensure the overall structural strength of the shaft.

[0018] Preferably, the rotating shaft is at least partially located in the chamber, and the axial direction of the rotating shaft is consistent with the length direction of the outer peripheral wall of the shell.

[0019] Preferably, a protective sleeve is provided between the locking sleeve and the rotating shaft, so that the locking force of the locking sleeve acts on the rotating shaft in a buffering manner, thereby preventing the rotating shaft from being damaged due to stress concentration.

[0020] Preferably, the outer diameter of the locking sleeve is spaced 5 to 8 mm from the inner diameter of the housing in a radial direction.

[0021] Preferably, the left end cover and the right end cover are both stepped structures, so that the bearing can be respectively clamped in the left end cover and the right end cover.

[0022] Preferably, magnetic isolation sleeves are respectively provided on the axial end faces of the pole shoes.

[0023] A maintenance method for a magnetic liquid sealing device is designed, which is implemented based on the above magnetic liquid sealing device and includes the following steps:

[0024] S1, open the left end cover or the right end cover, remove the corresponding locking sleeve, protective sleeve and bearing;

[0025] S2, tighten the fixing bolts between the left half shaft and the right half shaft, clamp the left half shaft or the right half shaft and stretch it axially outward, until the right end face or the left end face of the left half shaft or the right half shaft coincides with the right end face or the left end face of the elastic pad;

[0026] S3, the elastic pad is deformed radially by the gravity of the left half shaft or the right half shaft, so that the left half shaft or the right half shaft is radially away from the pole shoe pole teeth on the corresponding side, and the left half shaft or the right half shaft is continuously stretched axially outward until it is completely pulled out;

[0027] S4, starting to clean the pole shoes and pole teeth on the corresponding side of the left half shaft or the right half shaft or / and replacing the magnetic fluid;

[0028] S5, rotating the right half shaft or the left half shaft to the cleaning completed side, starting to clean the pole shoes and pole teeth on the uncleaned side of the right half shaft or the left half shaft or / and replacing the magnetic fluid;

[0029] S6, push the left or right half shaft axially, tighten the fixing bolts, and install the bearing, locking sleeve, protective sleeve and end cover on the corresponding side.

[0030] Compared with the prior art, the main beneficial technical effects of the present invention are:

[0031] 1. The present invention transforms the integral shaft design into a split shaft structure and an elastic pad combination, which effectively avoids the complexity of the sealing device structure while ensuring the strength and stability of the overall shaft structure, solves the problems of inconvenient replacement of magnetic liquid and difficulty in cleaning the pole shoes and pole teeth, makes it easy to maintain during use, and does not cause damage to the pole shoes and pole teeth during replacement, thereby extending the service life of the device.

[0032] 2. The design structure of the permanent magnets of the present invention with opposite polarities is conducive to forming a magnetic circuit between adjacent permanent magnets, so that the magnetic liquid is more tightly adsorbed on the corresponding pole shoe pole teeth and permanent magnets, thereby enhancing the sealing performance and compressive strength of the sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a cross-sectional schematic diagram of the overall structure of the magnetic liquid sealing device of the present invention.

[0034] In the figure, 1 is the left end cover, 2 is the left bearing, 3 is the left locking sleeve, 4 is the left magnetic isolation sleeve, 5 is the first permanent magnet, 6 is the sealing ring, 7 is the pole shoe, 8 is the second permanent magnet, 9 is the right locking sleeve, 10 is the shell, 11 is the right end cover, 12 is the right protective sleeve, 13 is the right half shaft, 14 is the right bearing, 15 is the right magnetic isolation sleeve, 16 is the third permanent magnet, 17 is the fourth permanent magnet, 18 is the left half shaft, 19 is the left protective sleeve, 20 is the elastic pad, and 21 is the magnetic liquid. DETAILED DESCRIPTION

[0035] The specific implementation modes of the present invention are described below in conjunction with the accompanying drawings and examples. However, the following examples are only used to illustrate the present invention in detail and do not limit the scope of the present invention in any way.

[0036] In the description of the technical solution of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. The terms "first", "second", etc., etc., are used to distinguish similar objects, rather than to limit a specific order or sequence.

[0037] Example 1: A magnetic liquid sealing device, see Figure 1 , comprising a shell 10, the shell 10 is a hollow cylinder with a certain thickness, the two ends of the shell 10 are respectively fixed with a left end cover 1 and a right end cover 11 by bolts, and the inner circumferential wall of the hollow cylindrical shell 10 and the left end cover 1 and the right end cover 11 form a chamber with a certain space;

[0038] The inner side of the left end cover 1 and the right end cover 11, i.e., the side corresponding to the inner peripheral wall of the housing 10, is provided with a stepped structure, so that the stepped structure can be used to clamp the bearings that facilitate the rotation of the shaft. The bearing corresponding to the left end cover 1 is the left bearing 2, and the bearing corresponding to the right end cover 11 is the right bearing 14. The inner diameters of the left bearing 2 and the right bearing 14 are slightly larger than the outer diameter of the shaft, so that the shaft can be fixed in the bearings for rotation and can be easily disassembled;

[0039] The rotating shaft is sleeved between the left bearing 2 and the right bearing 14. The rotating shaft is different from the integral structure in the prior art. The rotating shaft in the magnetic liquid sealing device of the present invention is a split structure, including a left half rotating shaft 18 and a right half rotating shaft 13; the end faces of the joints between the left half rotating shaft 18 and the right half rotating shaft 13 are both provided with bolt holes for convenient fixing by bolts, so that the left half rotating shaft 18 and the right half rotating shaft 13 maintain the integrity, stability and strength of the structure in the working state; at least a part of the rotating shaft is located in the chamber, and the part of the rotating shaft that exceeds the chamber is consistent with the length direction of the inner peripheral wall of the shell, To ensure the structural sealing between the rotating shaft and the chamber; the docking end faces of the left half rotating shaft 18 and the right half rotating shaft 13 are set as a stepped structure, and an elastic pad 20 is provided in the middle of the docking end faces, and the elastic pad 20 has the function of being able to undergo elastic deformation to a certain extent when subjected to force, and the lengths of the left half rotating shaft 18 and the right half rotating shaft 13 exceeding the elastic pad 20 are equal, so that when the left half rotating shaft 18 or the right half rotating shaft 13 is axially stretched, the elastic pad 20 is elastically deformed radially under the influence of the rotating shaft's own gravity, so that the left half rotating shaft 18 or the right half rotating shaft 13 is radially away from the pole shoe 7 during the stretching process, to ensure that the pole shoe is not damaged.

[0040] The pole shoe 7 is sleeved in the shell 10 and symmetrically arranged along the axis of the rotating shaft; both ends of the pole shoe 7 are provided with magnetic isolation sleeves, including a left magnetic isolation sleeve 4 and a right magnetic isolation sleeve 15; the pole shoe 7 is provided with a plurality of pole teeth arranged along the axial direction of the rotating shaft corresponding to the rotating shaft side, and a plurality of grooves for fixing permanent magnets are provided on both sides of the pole teeth; the first permanent magnet 5, the second permanent magnet 8, the third permanent magnet 16 and the fourth permanent magnet 17 are fixedly arranged in the grooves in the pole shoe 7; the polarities of the first permanent magnet 5 and the second permanent magnet 8 are opposite, and the polarities of the third permanent magnet 16 and the fourth permanent magnet 17 are opposite, that is, the N pole of the first permanent magnet 5 corresponds to the N pole of the second permanent magnet 8 The S pole of the third permanent magnet 16 corresponds to the N pole of the fourth permanent magnet 17. This arrangement is conducive to forming a magnetic circuit, so that the magnetic liquid is more closely adsorbed on the pole teeth, the permanent magnets and the magnetic circuit formed between the permanent magnets, thereby increasing the overall sealing effect of the magnetic liquid sealing device. The first permanent magnet 5, the second permanent magnet 8, the third permanent magnet 16 and the fourth permanent magnet 17 are all cylindrical structures, and there are multiple of them, which are arranged along the axial direction of the rotating shaft; the outer circumferential surface of the pole shoe 7 is processed with a sealing groove, and a sealing ring 6 for preventing leakage of the magnetic liquid is installed in the sealing groove, and the sealing ring 6 is tightly fitted with the inner side of the shell 10.

[0041] A locking sleeve is provided at the joint end surface of the left half rotating shaft 18 and the right half rotating shaft 13, and the locking sleeve includes a left locking sleeve 3 and a right locking sleeve 9 which are symmetrically arranged on the left and right sides; the locking sleeve is sleeved on the rotating shaft, and the outer diameter of the locking sleeve is smaller than the inner diameter of the shell 10, and the radial interval between the two is 5 to 8 mm, and the center position of the locking sleeve corresponds to the joint end surface of the left half rotating shaft 18 and the right half rotating shaft 13, so that the left half rotating shaft 18 and the right half rotating shaft 13 are tightly connected to maintain the integrity and stability of the structure; and in order to prevent the left locking sleeve 3 and the right locking sleeve 9 from being directly connected to the rotating shaft, resulting in stress concentration on the rotating shaft and destroying the strength and stability of the rotating shaft, a protective sleeve is provided between the locking sleeve and the rotating shaft, and the protective sleeve includes a left protective sleeve 19 and a right protective sleeve 12 with the same structural dimensions.

[0042] Embodiment 2: Maintenance method of magnetic liquid sealing device. Taking the magnetic liquid sealing device described in Embodiment 1 as an example, when it needs maintenance, the following steps are implemented:

[0043] S1, tighten the fastening bolts on the left end cover 1 or the right end cover 11 connected to the housing 10, and remove the left end cover 1 or the right end cover 10;

[0044] S2, remove the left bearing 2 or the right bearing 14 sleeved on the left half shaft 18 or the right half shaft 13;

[0045] S3, screw the left locking sleeve 3 or the right locking sleeve 9, and remove the corresponding protective sleeve;

[0046] S4, opening the fastening bolts fixedly connected to the left half shaft 18 and the right half shaft 13, so that the left half shaft 18 and the right half shaft 13 can move relative to each other, and axially stretching the left half shaft 18 or the right half shaft 13;

[0047] S5, when the right end face or left end face of the left half shaft 18 or the right half shaft 13 is stretched to coincide with the right end face or left end face of the elastic pad 20, the supporting force of the left half shaft 18 or the right half shaft 13 is completely placed on the elastic pad 20, and the elastic pad 20 is elastically deformed in the radial direction under the force, so that the left half shaft 18 or the right half shaft 13 is radially away from the pole teeth on the pole shoe, so as to prevent the pole shoe and the pole teeth from being damaged during the stretching process, thereby causing damage to the device;

[0048] S6, continue to stretch the left half shaft 18 or the right half shaft 13 until it is completely pulled out and stretched, and start cleaning the pole shoes and pole teeth and / or replacing the magnetic fluid 21;

[0049] S7, after one side is cleaned, the right half shaft 13 or the left half shaft 18 is rotated to the side where the cleaning is completed, and the operation of cleaning the uncleaned pole shoes, pole teeth or / and replacing the magnetic liquid 21 on the other side is started;

[0050] S8, axially push the left half shaft 18 or the right half shaft 13 until the end faces of the two half shafts are butted, use fastening bolts to fasten the connection, and install the corresponding protective sleeves, locking sleeves, bearings and end covers to complete the operation of cleaning the pole shoes and pole teeth or / and replacing the magnetic fluid 21.

[0051] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. However, those skilled in the art will appreciate that, without departing from the concept of the present invention, the specific parameters in the above embodiments may be changed, or related components, structures, methods, steps, etc. may be replaced by equivalents, thereby forming multiple specific embodiments, which are all common variations of the present invention and will not be described in detail herein.

Claims

1. A magnetic liquid sealing device, characterized in that: include: A shell, the shell comprising an inner peripheral wall and left and right end covers, the inner peripheral wall and the left and right end covers enclose a chamber; A rotating shaft, the rotating shaft comprising a left half rotating shaft and a right half rotating shaft, the left half rotating shaft and the right half rotating shaft are fixedly arranged in the shell and rotate relative to the shell; An elastic pad, wherein the elastic pad is arranged between the left half rotating shaft and the right half rotating shaft, and the end surfaces of the left half rotating shaft and the right half rotating shaft extend beyond the elastic pad by the same length; A pole shoe, the pole shoe is installed in the housing, a plurality of pole teeth are arranged on the inner side of the pole shoe along the axial direction of the rotating shaft, and a plurality of grooves are opened on the inner side of the pole shoe on both sides of the pole teeth; A permanent magnet, wherein the permanent magnet is fixed in the groove; A locking sleeve is fixedly arranged on the butt end surfaces of the left half rotating shaft and the right half rotating shaft, and the outer diameter of the locking sleeve is smaller than the inner diameter of the shell.

2. The magnetic liquid sealing device according to claim 1, characterized in that: The permanent magnets include a first permanent magnet, a second permanent magnet, a third permanent magnet and a fourth permanent magnet arranged in the pole shoe groove; the first permanent magnet and the second permanent magnet have opposite polarities, and the third permanent magnet and the fourth permanent magnet have opposite polarities to form a magnetic circuit to enhance sealing performance.

3. The magnetic liquid sealing device according to claim 1, characterized in that: A sealing groove is correspondingly provided on the outer side of the pole shoe, and a sealing ring is sleeved in the sealing groove to prevent leakage of the magnetic liquid.

4. The magnetic liquid sealing device according to claim 1, characterized in that: The end surfaces corresponding to the left half shaft and the right half shaft are provided with threaded holes, and the left half shaft and the right half shaft are tightly connected by bolts to ensure the overall structural strength of the shaft.

5. The magnetic liquid sealing device according to claim 1, characterized in that: The rotating shaft is at least partially located in the chamber, and the axial direction of the rotating shaft is consistent with the length direction of the outer peripheral wall of the shell.

6. The magnetic liquid sealing device according to claim 1, characterized in that: A protective sleeve is provided between the locking sleeve and the rotating shaft so that the locking force of the locking sleeve acts on the rotating shaft in a buffering manner, thereby preventing the rotating shaft from being damaged due to stress concentration.

7. The magnetic liquid sealing device according to claim 6, characterized in that: The outer diameter of the locking sleeve is spaced 5 to 8 mm from the inner diameter of the housing in a radial direction.

8. The magnetic liquid sealing device according to claim 1, characterized in that: The left end cover and the right end cover are both stepped structures, so that the bearing is respectively clamped in the left end cover and the right end cover.

9. The magnetic liquid sealing device according to claim 1, characterized in that: Magnetic isolation sleeves are respectively provided on the axial end surfaces of the pole shoes.

10. A method for maintaining a magnetic liquid sealing device, characterized in that: Based on the magnetic liquid sealing device according to claim 1, The following steps are involved: S1, open the left end cover or the right end cover, remove the corresponding locking sleeve, protective sleeve and bearing; S2, tighten the fixing bolts between the left half shaft and the right half shaft, clamp the left half shaft or the right half shaft and stretch it axially outward, until the right end face or the left end face of the left half shaft or the right half shaft coincides with the right end face or the left end face of the elastic pad; S3, the elastic pad is deformed radially by the gravity of the left half shaft or the right half shaft, so that the left half shaft or the right half shaft is radially away from the pole shoe pole teeth on the corresponding side, and the left half shaft or the right half shaft is continuously stretched axially outward until it is completely pulled out; S4, starting to clean the pole shoes and pole teeth on the corresponding side of the left half shaft or the right half shaft or / and replacing the magnetic fluid; S5, rotating the right half shaft or the left half shaft to the cleaning completed side, starting to clean the pole shoes and pole teeth on the uncleaned side of the right half shaft or the left half shaft or / and replacing the magnetic fluid; S6, push the left or right half shaft axially, tighten the fixing bolts, and install the bearing, locking sleeve, protective sleeve and end cover on the corresponding side.

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