Magnetic liquid sealing device

Abstract

The magnetic liquid sealing device comprises a bottom plate, a through hole is formed in the center of the bottom plate, a rotating shaft is arranged in the through hole, the upper portion of the rotating shaft is rotationally sleeved with a rotating disc, a magnetic beam groove with an opening facing the rotating disc is formed in the position, on the periphery of the through hole, of the bottom plate, and a magnetic conducting ring is fixedly connected into the magnetic beam groove. A plurality of permanent magnets are fixedly connected in the magnetic conductive ring and attracted to the bottom wall of the rotary disc, pole teeth arranged in the radial direction are arranged on the top wall of the magnetic conductive ring and distributed on the two sides of the inner periphery and the outer periphery of the permanent magnets, magnetic liquid used for sealing is attracted to the top faces of the pole teeth, and the bottom plate, the magnetic conductive ring and the rotary disc are all made of magnetic conductive materials. The device is simple and novel, a bearing is replaced by the balls, the adsorption effect of the permanent magnets on the rotating disc is fully utilized, the mechanical structure of the device is simplified, the anti-swing capacity and the sealing capacity of the whole device under rotation of the rotating shaft are improved, and the adaptability and the flexibility of installation and application of the device when the axial space is insufficient are improved.

Description

Technical Field

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

[0002] Magnetic liquid sealing technology, also known as magnetic fluid sealing, is an advanced technology that uses magnetic liquid (ferrofluid) with high saturation magnetic strength for sealing. Magnetic liquid is a colloid formed by the fusion of nano-scale magnetic conductive materials, dispersants and carriers. It has the fluidity, lubricity and sealing properties of liquid carriers, and the strong magnetism of solid nanoparticles. These characteristics make magnetic liquid have unique application advantages in the field of sealing.

[0003] The existing magnetic liquid sealing device is mainly composed of magnetic fluid and a specially designed sealing device, including a magnetic shaft, magnetic poles, non-magnetic seats, bearings, permanent magnets and other parts. Under the action of the magnetic field, the magnetic liquid will form a "liquid O-ring" in the sealing gap, thereby sealing the medium. This sealing method has the characteristics of no leakage, no wear, no pollution, no directionality, low loss and long life. However, in order to achieve better sealing performance, the existing magnetic liquid sealing device needs to arrange multiple sets of pole teeth, and the bearings need to bear the radial load when the shaft rotates. These complex structures are all arranged axially inside the magnetic liquid sealing device, resulting in the installation of the magnetic liquid sealing device requiring a large amount of axial space, reducing the flexibility and convenience of the installation and application of the magnetic liquid sealing device.

[0004] Therefore, it is necessary to propose a low-cost magnetic liquid sealing device which occupies less axial space, has a simple structure and has sufficient sealing performance. Summary of the invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a magnetic liquid sealing device, which reasonably arranges the position of the pole teeth, uses balls between the turntables instead of bearings to bear the radial load, and fully utilizes the adsorption effect of the permanent magnet on the turntable, simplifies the device structure, and improves the overall anti-swing ability and sealing ability of the device under the rotation of the shaft, thereby reducing the axial space occupied and achieving the purpose of magnetic liquid sealing at a low cost.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is as follows: a magnetic liquid sealing device comprises a bottom plate, a through hole is opened in the center of the bottom plate, a rotating shaft is arranged in the through hole, a turntable is rotatably sleeved on the upper part of the rotating shaft, a magnetic flux groove is opened in the bottom plate at the outer periphery of the through hole, a magnetic conductive ring is fixedly connected in the magnetic flux groove, a plurality of permanent magnets are fixedly connected in the magnetic conductive ring, the magnetic conductive ring is adsorbed on the bottom wall of the turntable, a radially arranged pole teeth is opened on the top wall of the magnetic conductive ring, the pole teeth are distributed on both sides of the inner and outer peripheries of the permanent magnets, and a magnetic liquid for sealing is adsorbed on the top surfaces of the pole teeth, and the bottom plate, the magnetic conductive ring and the turntable are all made of magnetic conductive materials.

[0007] The principle of the basic solution is: a closed magnetic circuit is formed between the permanent magnet in the magnetic ring and the magnetic base plate and the turntable, generating a non-uniform magnetic field with alternating strong and weak strengths in the gap between the pole teeth and the turntable, constraining the magnetic liquid to gather in the gap between the top surface of the pole teeth and the turntable to form a radially arranged magnetic liquid "O"-shaped sealing ring, thereby forming a magnetic liquid seal on the end face of the turntable.

[0008] The beneficial effects of the basic scheme are: 1. A closed magnetic circuit is formed between the base plate and the turntable through the magnetic field of the permanent magnet, and the magnetic liquid is confined in a non-uniform magnetic field to achieve a magnetic liquid sealing effect, thereby achieving a pollution-free and leak-free seal. Compared with ordinary mechanical sealing devices, the structure is simpler, the possible failure points are reduced, the reliability of the equipment is improved, and the frequency and cost of replacing seals are reduced.

[0009] 2. Through the radial arrangement of magnetic liquid "O"-shaped sealing rings, low-loss and multi-directional sealing is achieved in the radial direction, improving the overall sealing strength and enhancing the anti-swing effect.

[0010] 3. Through the radial arrangement of magnetic liquid "O"-shaped sealing rings, the motion state between the turntable and the bottom plate is separated, the friction loss caused by the relative movement between the turntable and the bottom plate is reduced, and the service life of the sealing device is extended.

[0011] 4. The magnetic ring is used to absorb the turntable to bear the axial load for the shaft, thereby improving the utilization rate of the permanent magnet magnetic field in the sealing process, simplifying the device structure, and saving production and installation costs.

[0012] Furthermore, the inner wall of the rotating disk is provided with an axially arranged first groove, and a first "O" ring for sealing is installed between the first groove and the rotating shaft.

[0013] The beneficial effect of the basic solution is that the first "O" ring made of rubber forms a sealing effect in the axial section in the gap between the turntable and the rotating shaft. Since the turntable rotates with the rotating shaft, the sealing effect of the first "O" ring will not affect the rotation performance of the rotating shaft, nor will it cause unnecessary friction loss.

[0014] Furthermore, a second groove opening toward the mounting surface is formed on the bottom wall of the bottom plate at the periphery of the magnetic flux groove, and a second "O" ring for sealing is installed between the second groove and the mounting surface.

[0015] The beneficial effects of the basic solution are: a second "O" ring made of rubber forms a sealing effect on the mounting end face in the gap between the second groove and the mounting surface, changing the existing axial sealing structure into a radial structure, saving axial space, and improving the adaptability and flexibility of the device installation application when the axial space is insufficient.

[0016] Furthermore, a pole shoe spacer is provided between the permanent magnet and the rotating disk.

[0017] The beneficial effect of the basic solution is: the permanent magnet is separated from the turntable by the pole shoe spacer, preventing the permanent magnet from adsorbing the turntable and being driven to rotate to generate friction with the inner wall of the magnetic beam slot, thereby improving the overall stability of the device, reducing internal wear of the device, and extending the service life of the device.

[0018] Furthermore, the permanent magnet is radiation magnetized.

[0019] The beneficial effects of the basic scheme are: by radiating magnetization for the permanent magnet, the magnetization method and the magnetic field distribution are flexible and diverse, and it can be magnetized by single-pole radiation, multi-pole direct charging and multi-pole oblique charging. The integral structure of the radiation-magnetized permanent magnet makes it easier to control the dimensional accuracy and simplify the assembly process. The surface field of the permanent magnet is sinusoidal and evenly distributed, the transition zone between the poles is small, and the operation is more stable.

[0020] Furthermore, a first ball rolling groove opening toward the turntable is formed on the bottom plate of the outer periphery of the magnetic flux groove, a second ball rolling groove corresponding to the first ball rolling groove is formed on the bottom wall of the turntable, and a plurality of balls are arranged between the first ball rolling groove and the second ball rolling groove.

[0021] The beneficial effects of the basic solution are: the radial load of the rotating shaft is borne by the bearings instead of the balls between the base plate and the turntable, making the bearings no longer necessary, simplifying the device structure while saving axial space, reducing the production and installation costs of the device, and improving the flexibility and adaptability of the device installation application.

[0022] Furthermore, a driving sleeve is fixedly sleeved on the upper part of the rotating shaft, and a conical rectangular wedge-shaped tooth is provided on the bottom wall of the driving sleeve to mesh and tightly hold the top wall of the rotating disk.

[0023] The beneficial effects of the basic scheme are: through the conical rectangular wedge teeth engaging the drive sleeve and the turntable, the torque is transmitted for synchronous rotation, and the axial and radial swing between the drive sleeve and the turntable is constrained, thereby improving the stability of the shaft rotation, improving the anti-swing ability of the device, simplifying the device structure, and reducing production and installation costs.

[0024] Furthermore, the number of the pole teeth is at least 3.

[0025] The beneficial effects of the basic scheme are: through the magnetic liquid "O"-shaped sealing ring formed between the pole teeth and the turntable, and distributed on the inner and outer peripheries of the permanent magnet, the sealing effect of the gap between the turntable and the bottom plate is improved, while the permanent magnet is prevented from being corroded by the sealing medium, the friction between the magnetic ring and the bottom wall of the turntable is reduced, and the sealing effect of the device is enhanced.

[0026] Furthermore, the number of the conical rectangular wedge teeth on the bottom wall of the driving sleeve is at least 2 and they are symmetrically distributed.

[0027] The beneficial effect of the basic scheme is that the number of conical rectangular wedge teeth on the bottom wall of the drive sleeve is at least 2, so the conical rectangular wedge teeth on the bottom wall of the drive sleeve and the top wall of the turntable are meshed in pairs, so as to evenly share the torque of the drive sleeve to drive the turntable to rotate, reduce the risk of metal fatigue, and extend the operating life of the device.

[0028] Furthermore, the volume of the magnetic liquid is at least V1, which is specifically expressed by the formula:

[0029] V1=v(R1+r1)(R1-r1)h1

[0030] Among them, π is the pi, R1 is the outer circle radius of the pole tooth, r1 is the inner circle radius of the pole tooth, and h1 is the distance from the top surface of the pole tooth to the bottom wall of the turntable.

[0031] The beneficial effect of the basic solution is: since the magnetic liquid will leak and lose in the process of forming the magnetic liquid "O"-ring, when adding magnetic liquid, it is necessary to calculate the space between the pole tooth and the sealing surface and fill a sufficient amount of magnetic liquid to ensure the smooth formation of the magnetic liquid "O"-ring and maintain the stability of the sealing effect of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is an axonometric view of a magnetic liquid sealing device according to an embodiment of the present invention.

[0033] Figure 2 It is a front cross-sectional view of a magnetic liquid sealing device according to an embodiment of the present invention.

[0034] Figure 3 The figure is a top view of the bottom plate of the magnetic liquid sealing device according to an embodiment of the present invention.

[0035] The figure marks in the drawings of the specification include: 1. rotating shaft; 2. bottom plate; 3. magnetic flux groove; 4. magnetic conductive ring; 5. second groove; 6. second "O" ring; 7. mounting surface; 8. first ball groove; 9. ball; 10. second ball groove; 11. turntable; 12. drive sleeve; 13. conical rectangular wedge tooth; 14. first groove; 15. first "O" ring; 16. pole shoe spacer; 17. permanent magnet; 18. pole tooth; 19. magnetic liquid. DETAILED DESCRIPTION

[0036] The following is further described in detail through specific implementation methods:

[0037] Basically as attached Figure 1 , Figure 2 and Figure 3As shown: a magnetic liquid sealing device, including a bottom plate 2, a through hole is opened in the center of the bottom plate 2, a rotating shaft 1 is arranged in the through hole, a rotating disk 11 is rotatably sleeved on the upper part of the rotating shaft 1, a magnetic flux groove 3 with an opening facing the rotating disk 11 is opened on the bottom plate 2 at the outer periphery of the through hole, a magnetic flux ring 4 is welded in the magnetic flux groove 3, a plurality of permanent magnets 17 are welded in the magnetic flux ring 4, the permanent magnet 17 is radiantly magnetized, the magnetic flux ring 4 is adsorbed on the bottom wall of the rotating disk 11, a pole shoe spacer 16 is separated between the permanent magnet 17 and the rotating disk 11, and a radially arranged pole tooth 18 is opened on the top wall of the magnetic flux ring 4, and the pole teeth 18 are arranged on the top wall of the magnetic flux ring 4. The number is at least 3, the pole teeth 18 are distributed on both sides of the inner and outer peripheries of the permanent magnet 17, and the top surfaces of the pole teeth 18 are adsorbed with magnetic liquid 19 for sealing; the inner wall of the turntable 11 is provided with an axially arranged first groove 14, and a first "O" ring 15 for sealing is installed between the first groove 14 and the rotating shaft 1; the bottom wall of the bottom plate 2 at the outer periphery of the magnetic flux groove 3 is provided with a second groove 5 with an opening facing the mounting surface 7, and a second "O" ring 6 for sealing is installed between the second groove 5 and the mounting surface 7, and the bottom plate 2, the magnetic ring 4 and the turntable 11 are all made of magnetic conductive materials.

[0038] The bottom plate 2 on the outer periphery of the magnetic flux groove 3 is provided with a first ball groove 8 opening toward the turntable 11, and the bottom wall of the turntable 11 is provided with a second ball groove 10 corresponding to the first ball groove 8, and a plurality of balls 9 are installed between the first ball groove 8 and the second ball groove 10. A driving sleeve 12 is clamped on the upper part of the rotating shaft 1, and the bottom wall of the driving sleeve 12 is provided with conical rectangular wedge teeth 13 which mesh and clamp with the top wall of the turntable 11, and the number of the conical rectangular wedge teeth 13 is at least 2 and is symmetrically distributed.

[0039] The specific implementation process is as follows: after installation on the mounting surface 7, the rotating shaft 1 starts to rotate, and the magnetic field of the permanent magnet 17 in the magnetic ring 4 forms a closed magnetic circuit through the magnetic base plate 2, the magnetic ring 4 and the turntable 11. The gap between the pole teeth 18 and the turntable 11 generates a strong and weak alternating non-uniform magnetic field, and the magnetic liquid 19 is constrained to form a radially arranged magnetic liquid "O"-shaped sealing ring in the gap between the top surface of the pole teeth 18 and the turntable 11 to prevent the medium from leaking from the radial gap between the magnetic ring 4 and the turntable 11; the first "O"-shaped ring 15 installed in the gap between the first groove 14 and the rotating shaft 1 seals to prevent the medium from leaking along the axial gap between the drive sleeve 12 and the rotating shaft 1; the second "O"-shaped ring 6 installed in the gap between the second groove 5 and the mounting surface 7 seals to prevent the medium from leaking along the radial gap between the base plate 2 and the mounting surface 7.

[0040] The driving sleeve 12 rotates together with the rotating shaft 1, and the driving sleeve 12 is meshed and tightly held with the rotating disk 11 through the conical rectangular wedge teeth 13, driving the rotating disk 11 to rotate while restraining the axial and radial swings between the driving sleeve 12 and the rotating disk 11, thereby enhancing the rotation stability of the rotating shaft 1. Since the rotating disk 11 moves synchronously with the rotating shaft 1, the rotating shaft 1 will not be subjected to the rotation wear of the first "O"-shaped sealing ring when rotating, and the magnetic liquid "O"-shaped sealing ring reduces the friction between the magnetizer 4 and the rotating disk 11, thereby extending the service life of the device. When the rotating disk 11 rotates, it is adsorbed by the permanent magnet 17 in the magnetic ring 4, thereby restraining the axial swing of the rotating disk 11 when rotating with the rotating shaft 1, thereby improving the utilization efficiency of the magnetic field of the permanent magnet 17 in the device, and simplifying the restraint structure of the device. The turntable 11 and the magnetic ring 4 are separated by a pole shoe spacer 16 and a magnetic liquid "O"-shaped sealing ring to prevent the permanent magnet 17 in the magnetic ring 4 from adsorbing the turntable 11 so that the magnetic ring 4 rotates with the turntable 11, causing friction between the magnetic ring 4 and the inner wall of the magnetic beam groove 3, reducing wear and aging inside the device. The balls 9 between the first ball groove 8 of the bottom plate 2 and the second ball groove 10 of the turntable 11 bear the axial structural pressure inside the device while restricting the radial swing of the turntable 11 caused by the rotation of the shaft 1, thereby enhancing the overall anti-swing ability and sealing ability of the device. At the same time, the balls 9 replace the bearings to simplify the structure of the device, reduce the axial space required for sealing, and improve the adaptability and flexibility of the device in installation and application when the axial space is insufficient.

[0041] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0042] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A magnetic liquid sealing device, characterized in that: The invention comprises a bottom plate (2), a through hole is formed in the center of the bottom plate (2), a rotating shaft (1) is arranged in the through hole, a rotating disk (11) is rotatably sleeved on the upper part of the rotating shaft (1), a magnetic flux groove (3) is formed on the bottom plate (2) at the outer periphery of the through hole and the opening faces the rotating disk (11), a magnetic conductive ring (4) is fixedly connected in the magnetic flux groove (3), a plurality of permanent magnets (17) are fixedly connected in the magnetic conductive ring (4), the magnetic conductive ring (4) is adsorbed on the bottom wall of the rotating disk (11), a radially arranged polar teeth (18) are formed on the top wall of the magnetic conductive ring (4), the polar teeth (18) are distributed on both sides of the inner and outer peripheries of the permanent magnets (17), a magnetic liquid (19) for sealing is adsorbed on the top surfaces of the polar teeth (18), and the bottom plate (2), the magnetic conductive ring (4) and the rotating disk (11) are all made of magnetic conductive material.

2. The magnetic liquid sealing device according to claim 1, characterized in that: The inner wall of the rotating disk (11) is provided with a first groove (14) arranged axially, and a first "O" ring (15) for sealing is installed between the first groove (14) and the rotating shaft (1).

3. The magnetic liquid sealing device according to claim 1, characterized in that: A second groove (5) with an opening facing the mounting surface (7) is formed on the bottom wall of the bottom plate (2) at the periphery of the magnetic flux groove (3), and a second "O"-shaped ring (6) for sealing is installed between the second groove (5) and the mounting surface (7).

4. The magnetic liquid sealing device according to claim 1, characterized in that: A pole shoe spacer (16) is provided between the permanent magnet (17) and the rotating disk (11).

5. The magnetic liquid sealing device according to claim 1, characterized in that: The permanent magnet (17) is magnetized by radiation.

6. The magnetic liquid sealing device according to claim 1, characterized in that: A first ball rolling groove (8) opening toward the turntable (11) is formed on the bottom plate (2) at the periphery of the magnetic beam groove (3); a second ball rolling groove (10) corresponding to the first ball rolling groove (8) is formed on the bottom wall of the turntable (11); and a plurality of balls (9) are arranged between the first ball rolling groove (8) and the second ball rolling groove (10).

7. The magnetic liquid sealing device according to claim 1, characterized in that: A driving sleeve (12) is fixedly sleeved on the upper part of the rotating shaft (1), and a conical rectangular wedge tooth (13) is provided on the bottom wall of the driving sleeve (12) to mesh and tightly hold the top wall of the rotating disk (11).

8. The magnetic liquid sealing device according to claim 2, characterized in that: The number of the pole teeth (18) is at least three.

9. The magnetic liquid sealing device according to claim 6, characterized in that: The number of the conical rectangular wedge teeth (13) on the bottom wall of the driving sleeve (12) is at least 2 and they are symmetrically distributed.

10. The magnetic liquid sealing device according to claim 2, characterized in that: The volume of the magnetic liquid (19) is at least V1, which is specifically expressed by the formula: V1=π(R1+r1)(R1-r1)h1 Wherein, π is the circumference of a circle, R1 is the outer radius of the pole tooth (18), r1 is the inner radius of the pole tooth (18), and h1 is the distance between the top surface of the pole tooth (18) and the bottom wall of the rotating disk (11).

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