Magnetic liquid sealing device for shaft

Abstract

The utility model relates to a magnetic liquid sealing device for a shaft. The magnetic liquid sealing device comprises a magnetic sleeve, an end cover and a sealing system, the periphery of the shaft is coaxially sleeved with the magnetic sleeve; the periphery of the magnetic sleeve is coaxially sleeved with the end cover, the end cover comprises a fixing system used for fixing the end cover to a shell, and a containing cavity used for containing magnetic liquid is formed between the end cover and the magnetic sleeve; the sealing system comprises a first sealing ring and a second sealing ring, wherein the first sealing ring is arranged on the inner periphery of the magnetic sleeve to guarantee sealing of the magnetic sleeve and the shaft, and the second sealing ring is arranged on the outer periphery of the end cover to guarantee sealing of the end cover and the shell. The magnetic liquid is filled in the accommodating cavity formed by the end cover and the magnetic sleeve, and the magnetic sleeve is fixed on the shaft, so that when the shaft rotates at a high speed, the magnetic liquid can be firmly adsorbed on the magnetic sleeve due to the action of a magnetic field, and a gap formed between the end cover and the magnetic sleeve can be filled to play a sealing role. The device is stable, reliable, simple in structure, economical and practical.

Description

Technical Field

[0001] The utility model belongs to the technical field of sealing devices, and particularly relates to a magnetic fluid sealing device for a shaft. Background Art

[0002] In the prior art, rubber seals are mostly used for static seals and reciprocating motion seals, and mechanical seals are mostly used for rotary seals. In recent years, with the rapid development of technology, a new type of sealing method has emerged and been widely used. Magnetic fluid sealing is a sealing method that utilizes the property that magnetic fluid can be attracted by a magnetic field. By designing a suitable magnetic circuit, the magnetic fluid forms a liquid "O" ring in the sealing gap for sealing.

[0003] As a fluid, magnetic fluid can also play a lubricating role when a suitable base carrier liquid is selected. Therefore, using magnetic fluid as a lubricant can design the magnetic gap smaller. Reducing the magnetic gap can greatly improve the pressure resistance of magnetic fluid sealing, and it is very suitable for scenarios that require rotary sealing.

[0004] Due to the advantages of zero leakage, long life, and little influence from environmental changes of magnetic fluid sealing, magnetic sealing has been widely used in high-end industries such as aerospace, artificial intelligence, and biomedicine in recent years; some magnetic sealing structures on the market are relatively complex in design, which is not conducive to processing and assembly, and there is an urgent need for a simple and reliable magnetic sealing structure to replace. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide a magnetic fluid sealing device for a shaft, which is suitable for rotary sealing at the shaft end, has a simple structure, and is convenient for processing, assembly, and maintenance.

[0006] The technical solution adopted by the utility model to solve its technical problem is: to provide a magnetic fluid sealing device for a shaft, which is used for sealing a shell with a hole and a shaft rotatably arranged in the hole, and includes: a magnetic sleeve coaxially sleeved on the outer periphery of the shaft; an end cover coaxially sleeved on the outer periphery of the magnetic sleeve, including a fixing system for fixing it on the shell, and a receiving cavity for accommodating magnetic fluid is formed between the end cover and the magnetic sleeve; a sealing system, including a first sealing ring arranged on the inner periphery of the magnetic sleeve to ensure the sealing between the magnetic sleeve and the shaft, and a second sealing ring arranged on the outer periphery of the end cover to ensure the sealing between the end cover and the shell.

[0007] Preferably, the magnetic sleeve is in the shape of a hollow cylinder, one end abuts against the shaft shoulder of the shaft, and the other end is limited by a retaining ring arranged on the shaft.

[0008] Preferably, a first threaded hole communicating the outside with the receiving cavity is provided on the surface of the end cover, and a plug is provided in the first threaded hole.

[0009] Preferably, the magnetic sleeve is a permanent magnet.

[0010] Preferably, the fixing system includes a second threaded hole provided on the surface of the end cover, and a screw is screwed into the surface of the housing in the second threaded hole.

[0011] Preferably, the magnetic sleeve and the shaft are in interference fit.

[0012] Preferably, the end cover includes a first baffle and a second baffle arranged in parallel, and there is a gap between the first baffle and the second baffle and the magnetic sleeve.

[0013] The beneficial effects are as follows: By filling magnetic liquid into the accommodating cavity formed by the end cover and the magnetic sleeve, and fixing the magnetic sleeve on the shaft, when the shaft rotates at a high speed, due to the action of the magnetic field, the magnetic liquid will firmly adsorb on the magnetic sleeve, and the gap formed between the end cover and the magnetic sleeve will be filled, playing a sealing role. Subsequently, the first sealing ring in the sealing system prevents the medium from leaking through the gap between the magnetic sleeve and the shaft; the second sealing ring prevents the medium from leaking through the gap between the end cover and the housing. The utility model is stable and reliable, and has a simple structure, being economical and practical. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a magnetic fluid sealing device for a shaft.

[0015] Wherein, 1. Shaft; 11. Shaft shoulder; 12. Sealing ring groove; 13. Chamfer; 14. Retaining ring groove; 2. Retaining ring; 3. Plug; 4. End cover; 41. Through hole; 42. First baffle; 43. First threaded hole; 44. Second baffle; 5. Screw; 6. Housing; 61. Second threaded hole; 7. Second sealing ring; 8. Magnetic sleeve; 9. First sealing ring; 10. Magnetic liquid. Detailed Embodiments

[0016] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0017] Such as Figure 1As described above, the present utility model provides a magnetic fluid seal device for shafts, which is used to seal a housing with a hole and a shaft rotatably disposed in the hole. It includes a magnetic sleeve 8, an end cover 4 and a sealing system. The magnetic sleeve 8 is coaxially sleeved on the outer periphery of the shaft 1; the end cover 4 is coaxially sleeved on the outer periphery of the magnetic sleeve 8 and includes a fixing system for fixing it on the housing 6. A receiving cavity for accommodating the magnetic fluid 10 is formed between the end cover 4 and the magnetic sleeve 8; the sealing system includes a first sealing ring 9 provided on the inner periphery of the magnetic sleeve 8 to ensure the seal between the magnetic sleeve 8 and the shaft 1 and a second sealing ring 7 provided on the outer periphery of the end cover 4 to ensure the seal between the end cover 4 and the housing 6.

[0018] The magnetic sleeve 8 is in the shape of a hollow cylinder. The end of the shaft 1 is provided with a chamfer 13, which facilitates the installation of the magnetic sleeve 8. A snap ring groove 14 is provided on the surface of the shaft 1, and a snap ring 2 is installed inside the snap ring groove 14. The snap ring 2 is used to limit the magnetic sleeve 8. A sealing ring groove 12 is also provided on the surface of the shaft 1, and a first sealing ring 9 is installed in the sealing ring groove 12 to seal the gap generated between the magnetic sleeve 8 and the shaft 1. The other end of the shaft 1 is provided with a shaft shoulder 11, which is used for the positioning of the magnetic sleeve 8.

[0019] A through hole 41 is provided on the end face of the end cover 4. A first baffle 42 is provided at one end inside, and a second baffle 44 is provided at the other end. The first baffle 42 and the second baffle 44 are arranged parallel to each other and do not directly contact the magnetic sleeve 8, and there is a gap in the middle. This setting ensures that there is no friction between the magnetic sleeve 8 and the shaft 1 when they rotate together and the end cover 4. A first threaded hole 43 is provided on the first baffle 42, which is used for filling the magnetic fluid 10. A plug 3 is installed on the first threaded hole 43, and there is a seal between the plug 3 and the first baffle 42. The length of the magnetic sleeve 8 is greater than the distance between the first baffle 42 and the second baffle 44, which helps to prevent the magnetic fluid 10 from leaking out of the gap.

[0020] The magnetic sleeve 8 is a permanent magnet, and the end cover 4 is made of a magnetic conductive material. When the magnetic sleeve 8 and the end cover 4 are jointly provided, a magnetic field circuit is formed, which helps to control the magnetic fluid 10 to adsorb on the magnetic sleeve 8 to achieve magnetic fluid sealing when the shaft 1 rotates.

[0021] Threaded holes two 61 are provided on the end face of the housing 6. The number of the threaded holes two 61 is three, and they are evenly distributed in a circumferential manner on the end face of the housing 6. The number of the threaded holes two 61 is the same as that of the through holes 41 and their positions match. A second sealing ring 7 is installed between the housing 6 and the end cover 4 to seal the gap formed between the end cover 4 and the housing 6, and the two are fixed by screws 5. The threaded holes two 61 and the through holes 41 serve as the fixing system to fix the end cover 4 on the housing 6, and screws 5 are screwed into the surface of the housing 6 in the threaded holes two 61.

[0022] The sealing ring grooves 12 and the first sealing rings 9 are provided in two groups, respectively provided at both ends inside the magnetic sleeve 8.

[0023] In the utility model, by providing a cavity formed by the end cover 4 and the magnetic sleeve 8, magnetic fluid 10 can be filled inside. By fixing the magnetic sleeve 8 on the shaft 1, when the shaft 1 rotates at a high speed, due to the action of the magnetic field, the magnetic fluid 10 will firmly adsorb on the magnetic sleeve 8, and the gap formed between the end cover 4 and the magnetic sleeve 8 will be filled, playing a sealing role. By providing the first sealing rings 9, it can prevent the medium from leaking through the gap between the magnetic sleeve 8 and the shaft 1. By providing the second sealing rings 7, it can prevent the medium from leaking through the gap between the end cover 4 and the housing 6. This structure is applicable to media whether they are liquid, gas, or powder, is stable and reliable, and has a simple structure, being economical and practical.

Claims

1. A magnetic fluid sealing device for a shaft, used for sealing a housing with a hole and a shaft rotatably arranged in the hole, characterized in that: include: A magnetic sleeve coaxially sleeved on the outer circumference of the shaft; An end cap is coaxially sleeved on the outer periphery of the magnetic sleeve and includes a fixing system for fixing the end cap to the housing, and a receiving cavity for receiving magnetic liquid is formed between the end cap and the magnetic sleeve; The sealing system comprises a sealing ring 1 arranged on the inner periphery of the magnetic sleeve to ensure the sealing between the magnetic sleeve and the shaft, and a sealing ring 2 arranged on the outer periphery of the end cover to ensure the sealing between the end cover and the housing.

2. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The magnetic sleeve is in the shape of a hollow cylinder, one end of which is against the shoulder of the shaft, and the other end is limited by a retaining ring arranged on the shaft.

3. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The surface of the end cover is provided with a threaded hole 1 for connecting the outside with the accommodating cavity, and a plug is arranged in the threaded hole 1.

4. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The magnetic sleeve is a permanent magnet.

5. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The fixing system comprises a second threaded hole arranged on the surface of the end cover, and a screw which is screwed into the surface of the shell body is arranged in the second threaded hole.

6. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The magnetic sleeve and the shaft are in interference fit.

7. A magnetic fluid sealing device for a shaft according to claim 1, characterized in that: The end cover comprises a baffle plate 1 and a baffle plate 2 which are arranged in parallel with each other, and a gap is left between the baffle plate 1 and the baffle plate 2 and the magnetic sleeve.

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