Multi-layer magnetic fluid sealing element

Abstract

The utility model relates to the technical field of magnetic fluid sealing, in particular to a multilayer magnetic fluid sealing element which comprises a sealing cylinder and a rotating shaft, a protective shell is arranged at one end of the sealing cylinder, a supporting structure is arranged at the other end of the sealing cylinder, and the rotating shaft penetrates through the sealing cylinder, the protective shell and the supporting structure. And a magnetic component is arranged in the protective shell. According to the multi-layer magnetic fluid sealing piece, the sealing cylinder, the protective shell, the rotating shaft, the supporting structure, the end cover, the material storage cavity, the groove, the magnetic component, a conveying hole, a clamping ring, an elastic piece, a threaded sleeve, a threaded groove, a sealing block, an elastic telescopic piece and a liquid injection pipe are used in cooperation, and the liquid injection pipe is designed and reserved to serve as a supplementing channel; and a magnetic fluid supplement way can be provided for the magnetic fluid sealing element in the later period. Therefore, when the magnetic fluid is supplemented, the sealing element does not need to be physically damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetic fluid sealing, in particular to a multi-layer magnetic fluid seal. Background Technique

[0002] A magnetic fluid seal is a device that uses magnetic fluid (magnetic liquid) for sealing. Magnetic fluid is a fluid formed by suspending magnetic nanoparticles in a liquid, and it will exhibit obvious physical property changes under the action of an external magnetic field. The working principle of a magnetic fluid seal is to form a stable sealing interface at the sealing location through an external magnetic field, so as to achieve the purpose of preventing liquid or gas leakage.

[0003] A magnetic fluid seal disclosed in Chinese Patent with the publication number CN212080171U includes a sealing cylinder, a rotating shaft partially inserted into the sealing cylinder, a magnetic member arranged outside the sealing cylinder, and a protective shell sleeved outside the magnetic member; the magnetic member is sleeved outside the rotating shaft, and magnetic fluid is filled between the magnetic member and the rotating shaft. This utility model utilizes the principle that the magnetic force is the strongest at the magnetic field air gap, and by providing a storage chamber, a conveying chamber, a first groove and a second groove for the rotating shaft, the automatic replenishment of magnetic fluid between the magnetic member and the rotating shaft is realized, ensuring the airtightness of the magnetic fluid seal.

[0004] Regarding the above related technologies, there are some deficiencies in this seal. During actual use, the replenishment method of the magnetic fluid seal requires injecting magnetic fluid with superparamagnetic properties into the storage chamber through a syringe needle, and this process requires inserting the needle into the elastic member. This will cause physical damage to the structure of the elastic member, possibly resulting in tearing or deformation on the surface or inside of the elastic member, thereby destroying its sealing performance. As a result, the sealing effect of the seal is affected, the use stability is reduced, and it may lead to liquid leakage or performance degradation of the equipment. Therefore, it is necessary to provide a multi-layer magnetic fluid seal to solve the above technical problems. Content of the Utility Model

[0005] The purpose of this utility model is to provide a multi-layer magnetic fluid seal to solve the problems raised in the above background technique.

[0006] To achieve the above purpose, this utility model provides the following technical solutions:

[0007] A multi-layer magnetic fluid seal, which includes:

[0008] Sealing cylinder and rotating shaft. One end of the sealing cylinder is provided with a protective shell, and the other end of the sealing cylinder is provided with a support structure. The rotating shaft penetrates through the inside of the sealing cylinder, the protective shell and the support structure. A magnetic component is arranged inside the protective shell, and magnetic fluid is filled between the magnetic component and the rotating shaft. An elastic member is slidably installed inside the rotating shaft. A storage chamber is arranged inside the rotating shaft. A groove is arranged on the outer wall of the rotating shaft, and symmetrically distributed conveying holes are formed on the inner wall of the rotating shaft, and the conveying holes are communicated with the inside of the groove;

[0009] A snap ring is arranged inside the storage chamber. One end of the rotating shaft close to the support structure is a sealed structure. A liquid injection pipe is fixedly inserted and installed at one end of the rotating shaft close to the support structure. A threaded groove is formed at one end of the rotating shaft close to the support structure. The rotating shaft is threadedly connected with a threaded sleeve through the threaded groove;

[0010] One side of the threaded sleeve is fixedly installed with an end cover, and one end of the liquid injection pipe extends to the inside of the end cover through an opening on one side of the end cover. A sealing block is arranged on one side inside the end cover, and the sealing block abuts against the end of the liquid injection pipe located outside the rotating shaft.

[0011] Preferably, annular protrusions are fixedly installed on the outer walls at the connection between the end cover and the rotating shaft. A limiting hoop is clamped on the outer wall of the annular protrusion. A positioning groove is formed on the inner surface of the limiting hoop, and the positioning groove is clamped with the annular protrusion.

[0012] Preferably, the cross-section of the positioning groove is composed of a rectangular groove and a trapezoidal groove, and the rectangular groove is located outside the trapezoidal groove. The rectangular groove is adapted to the annular protrusion.

[0013] Preferably, a plurality of elastic telescopic members are fixedly installed between the sealing block and the inner wall of the end cover.

[0014] Preferably, the magnetic component is composed of a circular ring permanent magnet and two annular disc magnetic poles.

[0015] Preferably, the rotating shaft is made of a magnetic conductive material.

[0016] Preferably, a protective sleeve is fixedly installed on the outer wall of the rotating shaft inside the sealing cylinder. Symmetrically distributed bearings are fixedly installed inside the sealing cylinder, and the bearings are movably sleeved on the outer wall of the protective sleeve.

[0017] Preferably, the limiting hoop is composed of two semi-circular metal parts, and the rear ends of the two semi-circular metal parts are hinged. The front ends of the two semi-circular metal parts are connected by bolts.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. By the combined use of a sealing cylinder, a protective shell, a rotating shaft, a support structure, an end cap, a material storage chamber, a groove, a magnetic component, a conveying hole, a snap ring, an elastic member, a threaded sleeve, a threaded groove, a sealing block, an elastic telescopic member, and a liquid injection pipe, a reserved liquid injection pipe is designed as a supplementary channel, which can provide a way to supplement magnetic fluid for the magnetic fluid seal in the later stage. When supplementing the magnetic fluid, no physical damage needs to be done to the seal itself. The liquid injection pipe can be operated outside the seal, without affecting the structural integrity or sealing performance of the elastic member. This not only ensures the sealing effect of the seal, but also improves its use stability, avoiding the problem of decreased sealing performance caused by damage to the elastic member.

[0020] 2. By the combined use of a limiting hoop, a positioning groove, and an annular protrusion, after the end cap is fixed to the end of the rotating shaft by means of threaded connection, the limiting hoop can be clamped on the outer wall of the annular protrusion at the connection between the end cap and the rotating shaft, and the front end of the limiting hoop is fixed by bolts, further improving the stability of the installation of the end cap at the end of the rotating shaft. In addition, relying on the design of the trapezoidal groove inside the positioning groove, the trapezoidal groove will generate a squeezing force on the two annular protrusions, making the fixation of the end cap at the end of the rotating shaft more firm and not prone to loosening and displacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a front view structural schematic diagram of the present utility model.

[0022] Figure 2 is a front view sectional structural schematic diagram of the present utility model.

[0023] Figure 3 is a structural schematic diagram of the limiting hoop in the present utility model.

[0024] Figure 4 is a connection structural schematic diagram of the end cap and the threaded sleeve in the present utility model.

[0025] Figure 5 is of the present utility model Figure 2 the enlarged structural schematic diagram at A.

[0026] In the figure: 1. Sealing cylinder; 2. Protective shell; 3. Rotating shaft; 4. Support structure; 5. End cap; 6. Limiting hoop; 7. Protective sleeve; 8. Bearing; 9. Material storage chamber; 10. Groove; 11. Magnetic component; 12. Conveying hole; 13. Snap ring; 14. Elastic member; 15. Positioning groove; 16. Annular protrusion; 17. Threaded sleeve; 18. Threaded groove; 19. Sealing block; 20. Elastic telescopic member; 21. Liquid injection pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the technical means, creative features, achieved purposes and effects realized by the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0028] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", "the other end", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model 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 should not be construed as a limitation of the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0030] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0031] Please refer to Figures 1 - 5 , an embodiment provided by the present utility model:

[0032] A multi-layer magnetic fluid seal, which includes:

[0033] A sealing cylinder 1 and a rotating shaft 3. One end of the sealing cylinder 1 is provided with a protective shell 2, and the other end of the sealing cylinder 1 is provided with a support structure 4. The rotating shaft 3 penetrates through the inside of the sealing cylinder 1, the protective shell 2 and the support structure 4. A magnetic member 11 is arranged inside the protective shell 2. Magnetic fluid is filled between the magnetic member 11 and the rotating shaft 3. An elastic member 14 is slidably installed inside the rotating shaft 3. A storage chamber 9 is arranged inside the rotating shaft 3. A groove 10 is arranged on the outer wall of the rotating shaft 3. Symmetrically distributed conveying holes 12 are formed on the inner wall of the rotating shaft 3, and the conveying holes 12 are communicated with the inside of the groove 10;

[0034] Inside the storage chamber 9, a snap ring 13 is provided. One end of the rotating shaft 3 close to the support structure 4 is a sealing structure. A liquid injection pipe 21 is fixedly inserted and installed at one end of the rotating shaft 3 close to the support structure 4. A threaded groove 18 is formed at one end of the rotating shaft 3 close to the support structure 4. The rotating shaft 3 is threadedly connected with a threaded sleeve 17 through the threaded groove 18;

[0035] One side of the threaded sleeve 17 is fixedly installed with an end cover 5. One end of the liquid injection pipe 21 extends to the inside of the end cover 5 through an opening on one side of the end cover 5. A sealing block 19 is arranged on one side inside the end cover 5, and the sealing block 19 abuts against the end of the liquid injection pipe 21 located outside the rotating shaft 3.

[0036] Annular protrusions 16 are fixedly installed on the outer walls at the connection between the end cover 5 and the rotating shaft 3. A limit hoop 6 is clamped on the outer wall of the annular protrusion 16. A positioning groove 15 is formed on the inner surface of the limit hoop 6, and the positioning groove 15 is clamped with the annular protrusion 16.

[0037] In one embodiment, the cross-section of the positioning groove 15 is composed of a rectangular groove and a trapezoidal groove, and the rectangular groove is located outside the trapezoidal groove. The rectangular groove is adapted to the annular protrusion 16. The design of the positioning groove 15 composed of the rectangular groove and the trapezoidal groove provides stable positioning, fixing effects and assembly accuracy through precise cooperation and reasonable stress distribution.

[0038] In one preferred embodiment, a plurality of elastic telescopic members 20 are fixedly installed between the sealing block 19 and the inner wall of the end cover 5, improving the sealing effect of the sealing block 19 on the liquid injection pipe 21.

[0039] In one embodiment, the magnetic member 11 is composed of a circular permanent magnet and two annular disc magnetic poles. The arrangement of the two annular disc magnetic poles helps to generate a uniform magnetic field distribution around the circular permanent magnet. This uniformity can reduce the influence of magnetic field non-uniformity on the performance of the device, improving the overall stability and accuracy.

[0040] In one preferred embodiment, the rotating shaft 3 is made of a magnetic conductive material. The magnetic conductive material can effectively conduct and concentrate the magnetic field, enabling the rotating shaft 3 to better interact with the magnetic field in the application of magnetic fluid, improving the driving effect or control accuracy of the magnetic fluid.

[0041] In one embodiment, a protective sleeve 7 is fixedly installed on the outer wall of the rotating shaft 3 inside the sealing cylinder 1. Symmetrically distributed bearings 8 are fixedly installed inside the sealing cylinder 1, and the bearings 8 are movably sleeved on the outer wall of the protective sleeve 7, improving the stability of the rotating shaft 3 during rotation.

[0042] In one of the preferred embodiments, the limiting hoop 6 is composed of two semi-circular metal pieces, and the rear ends of the two semi-circular metal pieces are hinged, and the front ends of the two semi-circular metal pieces are connected by bolts. Since the limiting hoop 6 is divided into two semi-circular metal pieces, it can be installed and disassembled more easily, especially in the case of narrow space or complex assembly. This split design allows for flexible adjustment during installation and simplifies the operation.

[0043] The working principle of the present utility model is as follows: The parts not involved in this seal are the same as or can be implemented by the prior art. During use, the seal cylinder 1 is stationary, and the rotating shaft 3 rotates around its own axis. When the magnetic fluid decreases, under the action of the magnetic field, the magnetic fluid is attracted out of the storage chamber 9, enters the groove 10 communicated with it through the conveying hole 12, and the magnetic fluid entering the groove 10 spreads over the groove 10 under the rotation of the rotating shaft 3. At the same time, the external air pressure will push the elastic member 14 to move inward, and so on, automatically replenishing the evaporated magnetic fluid during use. When the elastic member 14 contacts the snap ring 13, it is necessary to replenish the magnetic fluid at this time. The end cap 5 can be directly rotated. The rotation of the end cap 5 drives the threaded sleeve 17 and the threaded groove 18 to generate a threaded drive, so that the threaded sleeve 17 is removed from the inside of the threaded groove 18, thereby completing the disassembly of the end cap 5 at the end of the rotating shaft 3. After the end cap 5 is disassembled, the sealing block 19 inside the end cap 5 will lose the sealing effect on the liquid injection pipe 21. At this time, the magnetic fluid can be directly replenished into the storage chamber 9 through the liquid injection pipe 21. After the replenishment is completed, the end cap 5 is directly fixed at the end of the rotating shaft 3, and the liquid injection pipe 21 can be sealed. By designing and reserving the liquid injection pipe 21 as a replenishment channel, a way to replenish the magnetic fluid for the magnetic fluid seal can be provided in the later stage. When replenishing the magnetic fluid, it is not necessary to perform any physical damage to the seal itself. The liquid injection pipe 21 can be operated outside the seal, without affecting the structural integrity or sealing performance of the elastic member 14. In this way, both the sealing effect of the seal is ensured, and its use stability is improved, avoiding the problem of the decrease in sealing performance caused by the damage of the elastic member 14.

[0044] After the end cap 5 is fixed to the end of the rotating shaft 3 by means of threaded connection, the limiting hoop 6 can be clamped on the outer wall of the annular protrusion 16 at the connection between the end cap 5 and the rotating shaft 3, and the front end of the limiting hoop 6 is fixed by bolts, further improving the stability of the installation of the end cap 5 at the end of the rotating shaft 3. In addition, relying on the design of the trapezoidal groove inside the positioning groove 15, the trapezoidal groove will generate a squeezing force on the two annular protrusions 16, making the fixation of the end cap 5 at the end of the rotating shaft 3 more firm and not prone to looseness and displacement.

[0045] It should be noted that in a magnetic fluid seal of the present utility model, the arrangement of its internal structure is a prior art and will not be elaborated herein. The present utility model is only directed to solving the problem that in the existing magnetic fluid seal, the internal structure of the fluid seal may be damaged during the process of replenishing the magnetic fluid, which may lead to liquid leakage or performance degradation of the equipment.

[0046] The foregoing has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present utility model and are not used to limit the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and all these changes and improvements fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A multi-layer magnetic fluid seal, characterized in that: It includes: A sealing cylinder (1) and a rotating shaft (3), wherein a protective shell (2) is disposed at one end of the sealing cylinder (1), and a supporting structure (4) is disposed at the other end of the sealing cylinder (1); the rotating shaft (3) passes through the interior of the sealing cylinder (1), the protective shell (2) and the supporting structure (4); a magnetic component (11) is disposed inside the protective shell (2); a magnetic fluid is filled between the magnetic component (11) and the rotating shaft (3); an elastic component (14) is slidably mounted inside the rotating shaft (3); a material storage chamber (9) is disposed inside the rotating shaft (3); a groove (10) is disposed on the outer wall of the rotating shaft (3); symmetrically distributed conveying holes (12) are opened on the inner wall of the rotating shaft (3), and the conveying holes (12) are communicated with the interior of the groove (10); A snap ring (13) is arranged inside the material storage chamber (9); one end of the rotating shaft (3) close to the supporting structure (4) is a sealing structure; an injection pipe (21) is fixedly installed and inserted into the one end of the rotating shaft (3) close to the supporting structure (4); a thread groove (18) is formed at the one end of the rotating shaft (3) close to the supporting structure (4); and the rotating shaft (3) is threadedly connected to a threaded sleeve (17) via the thread groove (18); An end cover (5) is fixedly mounted on one side of the threaded sleeve (17), and one end of the injection tube (21) extends to the interior of the end cover (5) through an opening on one side of the end cover (5). A sealing block (19) is provided on one side of the interior of the end cover (5), and the sealing block (19) abuts against one end of the injection tube (21) located outside the rotating shaft (3).

2. A multi-layer magnetic fluid seal according to claim 1, characterized in that: An annular protrusion (16) is fixedly mounted on the outer wall of the connection between the end cover (5) and the rotating shaft (3); a limiting hoop (6) is clamped on the outer wall of the annular protrusion (16); a positioning groove (15) is provided on the inner surface of the limiting hoop (6); and the positioning groove (15) is clamped with the annular protrusion (16).

3. A multi-layer magnetic fluid seal according to claim 2, characterized in that: The cross section of the positioning groove (15) is composed of a rectangular groove and a trapezoidal groove, and the rectangular groove is located outside the trapezoidal groove. The rectangular groove is matched with the annular protrusion (16).

4. The multi-layer magnetic fluid seal according to claim 1, characterized in that: A plurality of elastic telescopic parts (20) are fixedly installed between the sealing block (19) and the inner wall of the end cover (5).

5. The multi-layer magnetic fluid seal according to claim 1, characterized in that: The magnetic component (11) is composed of a circular permanent magnet and two annular disk magnetic poles.

6. The multi-layer magnetic fluid seal according to claim 1, characterized in that: The rotating shaft (3) is made of magnetic conductive material.

7. The multi-layer magnetic fluid seal according to claim 1, characterized in that: A protective sleeve (7) is fixedly mounted on the outer wall of the rotating shaft (3) inside the sealing cylinder (1), and symmetrically distributed bearings (8) are fixedly mounted inside the sealing cylinder (1), and the bearings (8) are movably sleeved on the outer wall of the protective sleeve (7).

8. The multi-layer magnetic fluid seal according to claim 2, characterized in that: The limiting hoop (6) is composed of two semi-arc-shaped metal parts, the rear ends of the two semi-arc-shaped metal parts are hingedly connected, and the front ends of the two semi-arc-shaped metal parts are connected by bolts.

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