Magnetic fluid sealing device

Abstract

The invention discloses a magnetofluid sealing device which comprises a rotating shaft, a sealing assembly, a shell and a collecting assembly. The sealing assembly can rotate relative to the rotating shaft and comprises a first pole shoe, a first magnet and a second pole shoe which are sequentially arranged on the rotating shaft in a sleeving mode in the axial direction of the rotating shaft, and sealing gaps used for being filled with magnetic fluid are formed between the first pole shoe and the rotating shaft and between the second pole shoe and the rotating shaft. The shell sleeves the sealing assembly and is connected with the sealing assembly; the collecting assembly comprises a collector and a second magnet opposite to the magnetic pole direction of the first magnet, the collector is arranged between the rotating shaft and the shell and connected to the rotating shaft or the shell, the second magnet is connected with the collector, and the collector is provided with a liquid collecting groove used for collecting magnetic fluid. According to the magnetic fluid sealing device, the liquid collecting groove can collect the magnetic fluid flowing out of the sealing gap, so that the probability that the magnetic fluid leaks is reduced, the probability that a sealing medium is polluted is reduced, and the magnetic fluid sealing device is suitable for sealing equipment with the high requirement for sealing cleanliness.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing devices, and particularly relates to a magnetic fluid sealing device. Background Art

[0002] Magnetic fluid sealing devices have been widely used in various equipment in the fields of aviation, aerospace, nuclear energy, military, chemical industry, etc. due to their significant advantages such as reliable sealing, no leakage, no mechanical wear, long service life, and high working efficiency.

[0003] In special scenarios, the magnetic fluid of the magnetic fluid sealing device may leak, resulting in the contamination of the sealed medium. For example, for the magnetic fluid sealing device used in the airborne optoelectronic pod of an unmanned aerial vehicle in the aviation field, when working at high altitude, the condensed water flushes the magnetic fluid, which may cause the magnetic fluid to flow out and contaminate the optical elements, resulting in irreparable consequences; for another example, for the magnetic fluid sealing device used in a chemical reaction kettle in the chemical industry, the magnetic fluid works in a high-temperature environment, which causes the magnetic particles to accelerate oxidation. After the magnetic fluid deteriorates, the base carrier liquid flows out from the sealing gap, contaminating the reactants. This makes the magnetic fluid sealing device still face challenges when applied to equipment with high requirements for sealing cleanliness. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent.

[0005] To this end, an embodiment of the present invention provides a magnetic fluid sealing device. The liquid collecting tank can collect the magnetic fluid flowing out from the sealing gap, thereby reducing the probability of magnetic fluid leakage and the probability of contamination of the sealed medium, and is suitable for sealing equipment with high requirements for sealing cleanliness.

[0006] The magnetic fluid sealing device according to the embodiment of the present invention includes a rotating shaft, a sealing assembly, a housing, and a collecting assembly; the sealing assembly is rotatable relative to the rotating shaft, and the sealing assembly includes a first pole shoe, a first magnet, and a second pole shoe that are sequentially sleeved on the rotating shaft along the axial direction of the rotating shaft. The first pole shoe includes first pole teeth, the second pole shoe includes second pole teeth, and a sealing gap for filling magnetic fluid is formed between the first pole teeth and the second pole teeth and the rotating shaft; the housing is sleeved on the sealing assembly and connected to the sealing assembly; the collecting assembly includes a collector and a second magnet, the magnetic pole direction of the second magnet is opposite to that of the first magnet, the collector is disposed between the rotating shaft and the housing and is connected to the rotating shaft or the housing, the second magnet is connected to the collector, and the collector has a liquid collecting tank for collecting magnetic fluid.

[0007] In some embodiments, the number of the liquid collecting tanks is multiple, and the multiple liquid collecting tanks are arranged in sequence.

[0008] In some embodiments, the collection assembly further includes a positioning ring disposed on a side of the collector away from the sealing assembly and abutting against the collector. When the collector is connected to the rotating shaft, the positioning ring is connected to the rotating shaft. When the collector is connected to the housing, the positioning ring is connected to the housing.

[0009] In some embodiments, the first pole teeth and the second pole teeth are respectively disposed on the inner walls of the first pole shoe and the second pole shoe, and are both arranged facing the outer side surface of the rotating shaft. A sealing gap is formed between both the first pole teeth and the second pole teeth and the outer side surface of the rotating shaft; the collector is connected to the rotating shaft.

[0010] In some embodiments, the rotating shaft includes a shaft body and a shaft sleeve. The shaft sleeve is sleeved on the shaft body and connected to the shaft body. The shaft sleeve includes a convex ring disposed between the first pole shoe and the second pole shoe. The first pole teeth are disposed on the end surface of the first pole shoe facing the convex ring, and the second pole teeth are disposed on the end surface of the second pole shoe facing the convex ring. The sealing gap is formed between the first pole teeth and the convex ring and between the second pole teeth and the convex ring; the collector is connected to the housing.

[0011] In some embodiments, a second channel is defined by the inner wall of the second pole shoe and the outer wall of the shaft sleeve, and the second channel communicates with the sealing gap; the collection assembly further includes a retaining ring connected to the rotating shaft. The liquid collection groove is arranged radially inward along the rotating shaft. A liquid collection channel is defined by the outer wall of the retaining ring and the groove wall of the liquid collection groove, and the liquid collection channel communicates with the second channel.

[0012] In some embodiments, the positioning ring is connected to the housing, and the projection of the positioning ring on the cross-section of the rotating shaft completely covers the projection of the liquid collection channel on the cross-section of the rotating shaft.

[0013] In some embodiments, the sealing assembly has a liquid injection hole for injecting magnetic fluid, and the liquid injection hole communicates with the sealing gap.

[0014] In some embodiments, the sealing assembly further includes a first abutting ring and a second abutting ring. The first abutting ring is connected to the housing and abuts against the first pole shoe, and the second abutting ring is connected to the housing and abuts against the second pole shoe; the collector is arranged on a side of the second pole shoe away from the first pole shoe, and the liquid injection hole is provided on the first pole shoe or the first abutting ring.

[0015] In some embodiments, the collector is made of a porous fiber material.

[0016] In the magnetic fluid sealing device according to the embodiment of the present invention, the magnetic fluid filled in a plurality of sealing gaps can form a plurality of sealing rings, so that the magnetic fluid sealing device has good sealing performance. Under the magnetic force of the second magnet, the collector has a magnetic field force to attract the magnetic fluid. When the magnetic fluid flows out of the sealing gap, the liquid collecting tank can collect the flowing magnetic fluid, increasing the collection rate of the magnetic fluid, thereby reducing the probability of magnetic fluid leakage and reducing the probability of contamination of the sealing medium, and can be adapted to seal equipment with high requirements for sealing cleanliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 FIG. is a schematic structural diagram of a magnetic fluid sealing device according to an embodiment of the present invention.

[0018] Figure 2 FIG. is a schematic structural diagram of a magnetic fluid sealing device according to another embodiment of the present invention.

[0019] REFERENCE SIGNS:

[0020] 100, magnetic fluid sealing device;

[0021] 1, rotating shaft; 11, shaft body; 12, shaft sleeve; 121, convex ring;

[0022] 2, sealing assembly; 21, first pole shoe; 211, first pole tooth; 212, first channel; 22, first magnet; 23, second pole shoe; 231, second pole tooth; 232, second channel; 24, liquid injection hole; 25, first stop ring; 26, second stop ring;

[0023] 3, housing; 32, liquid injection port; 33, hole plug;

[0024] 4, collection assembly; 41, collector; 411, liquid collecting tank; 412, liquid collecting channel; 42, second magnet; 43, positioning ring; 431, positioning screw; 44, retaining ring; 441, first ring portion; 442, second ring portion;

[0025] 51, first sealing ring; 52, second sealing ring; 53, third sealing ring;

[0026] 61, first retaining ring; 62, second retaining ring; 63, third retaining ring. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation of the present invention.

[0028] As Figure 1 and Figure 2As shown in the figure, the magnetic fluid sealing device 100 according to an embodiment of the present invention includes a rotating shaft 1, a sealing assembly 2, a housing 3, and a collecting assembly 4; the sealing assembly 2 is rotatable relative to the rotating shaft 1, and the sealing assembly 2 includes a first pole shoe 21, a first magnet 22, and a second pole shoe 23 that are sequentially sleeved on the rotating shaft 1 along the axial direction of the rotating shaft 1. The first pole shoe 21 includes a first pole tooth 211, and the second pole shoe 23 includes a second pole tooth 231. A sealing gap for filling magnetic fluid is formed between both the first pole tooth 211 and the second pole tooth 231 and the rotating shaft 1; the housing 3 is sleeved on the sealing assembly 2 and connected to the sealing assembly 2; the collecting assembly 4 includes a collector 41 and a second magnet 42. The magnetic pole direction of the second magnet 42 is opposite to that of the first magnet 22. The collector 41 is disposed between the rotating shaft 1 and the housing 3 and is connected to the rotating shaft 1 or the housing 3. The second magnet 42 is connected to the collector 41, and the collector 41 has a liquid collecting groove 411 for collecting magnetic fluid.

[0029] For the magnetic fluid sealing device 100 according to an embodiment of the present invention, the magnetic fluid filled in multiple sealing gaps can form multiple sealing rings, so that the magnetic fluid sealing device 100 has good sealing performance. Since the magnetic pole direction of the second magnet 42 is opposite to that of the first magnet 22, a magnetic field force for attracting magnetic fluid can be provided for the collector 41 of the collecting assembly 4 without affecting the magnetic field distribution of the sealing assembly 2. Under the magnetic force of the second magnet 42, when the magnetic fluid flows out of the sealing gap, the liquid collecting groove 411 of the collector 41 can collect the flowing magnetic fluid, increasing the collection rate of the magnetic fluid, thereby reducing the probability of magnetic fluid leakage and reducing the probability of the sealing medium being contaminated, and can be adapted to seal equipment with high requirements for sealing cleanliness.

[0030] When the rotational speed of the rotating shaft 1 is low, the collector 41 can be connected to the rotating shaft 1, and the distance between the collector 41 and the sealing gap is relatively close, which can improve the collection rate of the magnetic fluid; when the rotational speed of the rotating shaft 1 is high, the collector 41 can be connected to the housing 3, and the collector 41 does not rotate with the rotating shaft 1, which can prevent the collected magnetic fluid from being thrown out by the high-speed rotation of the collector 41 with the rotating shaft 1.

[0031] Optionally, both the first magnet 22 and the second magnet 42 are permanent magnets and are made of permanent magnetic materials with good magnetic properties.

[0032] Optionally, as Figure 1 and Figure 2 shown, the outer side walls of both the first pole shoe 21 and the second pole shoe 23 have first sealing ring grooves, and first sealing rings 51 are provided in the first sealing ring grooves.

[0033] Thus, when the housing 3 is sleeved on the outer sides of the first pole shoe 21 and the second pole shoe 23, the first sealing rings 51 are closely attached to the inner wall of the housing 3, thereby ensuring the sealing performance between the first pole shoe 21 and the second pole shoe 23 and the housing 3.

[0034] In some embodiments, such as Figure 1 and Figure 2 shown, the number of the liquid collecting grooves 411 is multiple, and the multiple liquid collecting grooves 411 are arranged in sequence.

[0035] It is known that after the magnetorheological fluid flows out of the sealing gap, it jets outwards at a high speed and leaks.

[0036] By arranging multiple liquid collecting grooves 411, the multiple liquid collecting grooves 411 are sequentially arranged on the collector 41 to form a labyrinth seal structure. The labyrinth seal structure can change the leakage jet direction of the magnetorheological fluid flowing out of the sealing gap, prevent the magnetorheological fluid from leaking outwards, and at the same time can effectively reduce the leakage speed of the magnetorheological fluid, thereby increasing the collection rate of the magnetorheological fluid and reducing the probability of the sealing medium being contaminated.

[0037] In some embodiments, the collector 41 is made of a porous fiber material, such as high-density polyester fiber, sponge.

[0038] The magnetorheological fluid flowing out of the sealing gap can penetrate into the interior of the collector 41, increasing the storage amount of the magnetorheological fluid in the collector 41, thereby increasing the collection rate of the magnetorheological fluid; in addition, it is also possible to judge whether the magnetorheological fluid working in the sealing gap is sufficient by observing the penetration amount of the magnetorheological fluid in the collector 41 (for example, observing the color of the collector 41).

[0039] It can be understood that when observing the penetration amount of the magnetorheological fluid in the collector 41, the operator can directly observe or remove the collector 41 for observation, and can select according to the actual working conditions.

[0040] In some embodiments, such as Figure 1 and Figure 2 shown, the collecting assembly 4 further includes a positioning ring 43. The positioning ring 43 is arranged on the side of the collector 41 away from the sealing assembly 2 and abuts against the collector 41. When the collector 41 is connected to the rotating shaft 1, the positioning ring 43 is connected to the rotating shaft 1. When the collector 41 is connected to the housing 3, the positioning ring 43 is connected to the housing 3.

[0041] The collector 41 can be positioned through the positioning ring 43, which is more conducive to the assembly work of the collecting assembly 4.

[0042] In some embodiments, such as Figure 1 shown, the first pole teeth 211 and the second pole teeth 231 are respectively arranged on the inner walls of the first pole shoe 21 and the second pole shoe 23, and are both arranged towards the outer side surface of the rotating shaft 1. Sealing gaps are formed between the first pole teeth 211 and the second pole teeth 231 and the outer side surface of the rotating shaft 1; the collector 41 is connected to the rotating shaft 1.

[0043] The sealing assembly 2 adopts the above structure, and a plurality of sealing gaps are arranged in sequence along the axial direction of the rotating shaft 1. Under the influence of the magnetic field force provided by the first magnet 22, the magnetorheological fluid filled in the sealing gaps forms a plurality of sealing rings arranged in sequence along the axial direction of the rotating shaft 1, thereby playing a sealing role.

[0044] The above structure is applicable to low rotational speed working conditions, and is applicable to the sealing of optical systems in the aviation field and high-end reactors in the chemical and nuclear energy fields, etc. Under low rotational speed working conditions, the collector 41 is connected to the rotating shaft 1, and the distance between the collector 41 and the sealing gap is relatively close. The collector 41 has a high collection rate of the magnetorheological fluid, and the collected magnetorheological fluid will not be thrown out as the rotating shaft 1 rotates. When the magnetorheological fluid flows out of the sealing gap, under the action of the magnetic field force of the second magnet 42, the flowing-out magnetorheological fluid is absorbed by the porous fiber material of the collector 41, thereby preventing the magnetorheological fluid from leaking and polluting the sealed medium.

[0045] As an example, as Figure 1 shown, the collecting assembly 4 is arranged on the side of the second pole shoe 23 away from the first pole shoe 21. The collector 41 is sleeved on the rotating shaft 1 and rotates synchronously with the rotating shaft 1. The liquid collecting groove 411 is arranged on the end face of the collector 41 facing the second pole shoe 23 and is arranged facing the second pole shoe 23. The cross-sectional shape of the liquid collecting groove 411 is semicircular, rectangular and other shapes. A plurality of liquid collecting grooves 411 are arranged in sequence along the radial direction of the rotating shaft 1 to form a labyrinth seal, thereby being able to effectively reduce the speed of the magnetorheological fluid and increase the collection rate of the magnetorheological fluid.

[0046] The end face of the collector 41 away from the liquid collecting groove 411 has an embedding groove, and the second magnet 42 is arranged in the embedding groove. Thus, the second magnet 42 can provide a magnetic field force for the collector 41 to adsorb the magnetorheological fluid.

[0047] The positioning ring 43 is arranged on the side of the collector 41 away from the second pole shoe 23. The positioning ring 43 is sleeved on the rotating shaft 1. The positioning ring 43 has a plurality of countersunk holes evenly distributed along its circumferential direction, and the countersunk holes penetrate through the positioning ring 43. The rotating shaft 1 has a plurality of threaded holes evenly distributed along its circumferential direction, and the threaded holes correspond to the countersunk holes one by one. The positioning ring 43 is sleeved on the rotating shaft 1 and the countersunk holes are aligned with the threaded holes. The positioning screws 431 are sequentially passed through the countersunk holes and the threaded holes, and the connection between the positioning ring 43 and the rotating shaft 1 can be realized. Furthermore, by the positioning ring 43 abutting against the collector 41, the positioning of the collector 41 can be realized.

[0048] Optionally, as Figure 1 shown, the outer wall of the rotating shaft 1 has a groove, and a first retaining ring 61 is arranged in the groove. The first retaining ring 61 is arranged on the side of the collector 41 close to the second pole shoe 23 and abuts against the collector 41.

[0049] Thus, the first retaining ring 61 can further limit the collector 41 axially, thereby ensuring the stability of the collector 41 during operation.

[0050] In some embodiments, the rotating shaft 1 includes a shaft body 11 and a shaft sleeve 12. The shaft sleeve 12 is sleeved on the shaft body 11 and connected to the shaft body 11. The shaft sleeve 12 includes a convex ring 121. The convex ring 121 is disposed between the first pole shoe 21 and the second pole shoe 23. The first pole teeth 211 are disposed on the end face of the first pole shoe 21 facing the convex ring 121, and the second pole teeth 231 are disposed on the end face of the second pole shoe 23 facing the convex ring 121. A sealing gap is formed between the first pole teeth 211 and the convex ring 121 and between the second pole teeth 231 and the convex ring 121; the collector 41 is connected to the housing 3.

[0051] The structure of the above-mentioned sealing assembly 2 is a centrifugal magneto-rheological fluid sealing structure. The first pole teeth 211 and the second pole teeth 231 are respectively disposed on the end faces of the first pole shoe 21 and the second pole shoe 23 that are oppositely arranged, and the shaft sleeve 12 has a "convex" structure. This centrifugal magneto-rheological fluid sealing structure is suitable for working conditions with high rotational speeds and for working conditions where the radial runout of the rotating shaft 1 is relatively large. The magneto-rheological fluid is affected by the centrifugal force and accumulates at the outer diameter of the rotating shaft 1, thereby forming a centrifugal seal, which has a good sealing effect.

[0052] Under the working condition of high rotational speed, the collector 41 is connected to the housing 3, that is, the collector 41 does not rotate with the rotating shaft 1, thereby preventing the collected magneto-rheological fluid from being thrown out of the collector 41 due to high centrifugal force, so as to improve the collection rate of the magneto-rheological fluid under high-speed working conditions.

[0053] Optionally, the shaft sleeve 12 is made of a non-magnetic material.

[0054] As an example, as Figure 2 shown, the shaft sleeve 12 is sleeved on the rotating shaft 1 and rotates with the rotating shaft 1. A plurality of first pole teeth 211 are disposed on the end face of the first pole shoe 21 facing the convex ring 121 and are evenly arranged along its radial direction. A plurality of second pole teeth 231 are disposed on the end face of the second pole shoe 23 facing the convex ring 121 and are evenly arranged along its radial direction.

[0055] Optionally, as Figure 2 shown, the inner wall of the shaft sleeve 12 has two second sealing ring grooves, and second sealing rings 52 are disposed in the second sealing ring grooves.

[0056] Thus, when the shaft sleeve 12 is fitted to the rotating shaft 1, the second sealing rings 52 are closely attached to the outer wall of the rotating shaft 1, thereby ensuring the sealing performance between the rotating shaft 1 and the shaft sleeve 12.

[0057] In some embodiments, an inner wall of the second pole shoe 23 and an outer wall of the shaft sleeve 12 define a second channel 232, and the second channel 232 communicates with the sealing gap; the collecting assembly 4 further includes a retaining ring 44, the retaining ring 44 is connected to the rotating shaft 1, the liquid collecting groove 411 is arranged radially inward along the rotating shaft 1, and an outer wall of the retaining ring 44 and a wall of the liquid collecting groove 411 define a liquid collecting channel 412, and the liquid collecting channel 412 communicates with the second channel 232.

[0058] When the magnetic fluid flows out of the sealing gap, it needs to flow through the second channel 232 to the liquid collecting channel 412, and the magnetic fluid is adsorbed and collected by the collector 41 when passing through the liquid collecting channel 412; the retaining ring 44 is connected to the rotating shaft 1, and the distance between the retaining ring 44 and the second channel 232 is small, which can block the magnetic fluid flowing out of the second channel 232, so that the magnetic fluid flowing out of the sealing gap flows to the liquid collecting channel 412, thereby reducing the leakage channel area of the magnetic fluid and improving the collection rate of the magnetic fluid.

[0059] Exemplarily, as Figure 2 shown, the collector 41 is provided at an end of the second pole shoe 23 away from the first pole shoe 21 and abuts against the second pole shoe 23, the collecting groove faces the rotating shaft 1, the cross-sectional shape of the liquid collecting groove 411 is semicircular, rectangular or the like, and a plurality of liquid collecting grooves 411 are arranged in sequence along the axial direction of the rotating shaft 1 to form a labyrinth seal structure; the retaining ring 44 includes a first ring portion 441 and a second ring portion 442, an outer wall of the first ring portion 441 is flush with an outer wall of the shaft sleeve 12, and the first ring portion 441 abuts against the shaft sleeve 12 to position the shaft sleeve 12; an outer diameter of the second ring portion 442 is greater than an outer diameter of the first ring portion 441, and an outer wall of the second ring portion 442 and a wall of the liquid collecting groove 411 define the above-mentioned liquid collecting channel 412.

[0060] Optionally, as Figure 2 shown, an end face of the collector 41 facing the second pole shoe 23 has a third seal ring groove, and a third seal ring 53 is provided in the third seal ring groove.

[0061] Thus, after the magnetic fluid sealing device 100 is assembled, the third seal ring 53 is closely attached to the end face of the second pole shoe 23, thereby ensuring the sealing performance between the second pole shoe 23 and the collector 41 and preventing the magnetic fluid from leaking through the connection between the second pole shoe 23 and the collector 41.

[0062] Optionally, as Figure 2 shown, the rotating shaft 1 has two grooves, a second retaining ring 62 and a third retaining ring 63 are respectively provided in the two grooves, the second retaining ring 62 is provided on a side of the shaft sleeve 12 away from the retaining ring 44, the third retaining ring 63 is provided on a side of the retaining ring 44 away from the shaft sleeve 12, and the retaining ring 44 abuts against the shaft sleeve 12.

[0063] Thus, the positioning and installation of the bushing 12 and the retaining ring 44 can be achieved through the second retaining ring 62 and the third retaining ring 63.

[0064] In some embodiments, as Figure 2 shown, the positioning ring 43 is connected to the housing 3, and the projection of the positioning ring 43 on the cross-section of the rotating shaft 1 completely covers the projection of the liquid collecting channel 412 on the cross-section of the rotating shaft 1.

[0065] It is known that the positioning ring 43 can achieve the positioning and installation of the collector 41. Through the above settings, the positioning ring 43 has a relatively large size in the radial direction of the rotating shaft 1, and its projection on the cross-section of the rotating shaft 1 can completely cover the projection of the liquid collecting channel 412 on the cross-section of the rotating shaft 1. Thus, when the magnetic fluid passes through the liquid collecting channel 412 and is not completely collected by the collector 41, the leaked magnetic fluid can be ejected onto the positioning ring 43 and reflected into the liquid collecting channel 412, and then collected by the collector 41 again, thereby improving the collection rate of the magnetic fluid.

[0066] Optionally, as Figure 2 shown, the second magnet 42 is embedded in the positioning ring 43.

[0067] Thus, under the magnetic force of the second magnet 42, when the magnetic fluid flowing out of the liquid collecting channel 412 is ejected onto the positioning ring 43, it can also adhere to the positioning ring 43, preventing the magnetic fluid from leaking and causing pollution to the sealed medium.

[0068] Of course, in other embodiments, the second magnet 42 can also be disposed in the collector 41, as long as the second magnet 42 can provide the power to adsorb the magnetic fluid for the collector 41.

[0069] In some embodiments, as Figure 1 and Figure 2 shown, the sealing assembly 2 has a liquid injection hole 24 for injecting magnetic fluid, and the liquid injection hole 24 is communicated with the sealing gap.

[0070] It is known that by observing the color of the collector 41, it can be judged whether the magnetic fluid working in the sealing gap is sufficient; by providing the liquid injection hole 24, when the magnetic fluid working in the sealing gap is insufficient, a syringe can be used to supplement the magnetic fluid into the sealing gap, thereby ensuring the sealing performance of the magnetic fluid sealing device 100.

[0071] Optionally, as Figure 1 and Figure 2 shown, the housing 3 has a liquid injection port 32 communicated with the liquid injection hole 24, and the liquid injection port 32 is a countersunk threaded hole; the magnetic fluid sealing device 100 further includes a hole plug 33, the hole plug 33 is an internal hexagonal threaded hole plug 33, the hole plug 33 is detachably disposed at the liquid injection port 32, and the hole plug 33 can block the liquid injection port 32; when it is necessary to supplement the magnetic fluid, the hole plug 33 can be removed.

[0072] In some embodiments, such as Figure 1 and Figure 2 shown, the sealing assembly 2 further includes a first abutting ring 25 and a second abutting ring 26. The first abutting ring 25 is connected to the outer shell 3 and abuts against the first pole shoe 21, and the second abutting ring 26 is connected to the outer shell 3 and abuts against the second pole shoe 23; the collector 41 is arranged on the side of the second pole shoe 23 away from the first pole shoe 21, and the liquid injection hole 24 is provided on the first pole shoe 21 or the first abutting ring 25.

[0073] Through the first abutting ring 25 and the second abutting ring 26, the positioning and installation of the first pole shoe 21, the second pole shoe 23 and the first magnet 22 can be realized, making the assembly work of the sealing assembly 2 more convenient.

[0074] Optionally, when the collector 41 is connected to the rotating shaft 1, the liquid injection hole 24 is provided on the first abutting ring 25.

[0075] As an example, such as Figure 1 shown, the magnetic fluid sealing device 100 is applicable to low rotational speed working conditions; the outer wall of the first abutting ring 25 fits against and is connected to the outer shell 3. The first pole shoe 21 includes a body and a first pole tooth 211. The first pole tooth 211 is provided on the inner wall of the body. The inner diameter of the first abutting ring 25 is smaller than the inner diameter of the body of the first pole shoe 21. The liquid injection hole 24 is provided on the first abutting ring 25 and penetrates along the radial direction of the first pole shoe 21, so that the end of the liquid injection hole 24 facing the rotating shaft 1 is closer to the sealing gap, which is more conducive to injecting magnetic fluid into the sealing gap through the liquid injection hole 24; when installing the first abutting ring 25, the liquid injection hole 24 on the first abutting ring 25 needs to be aligned with the liquid injection port 32 on the outer shell 3.

[0076] Such as Figure 1 shown, the second abutting ring 26 is sleeved on the outside of the collector 41, and there is a small gap between the inner wall of the second abutting ring 26 and the outer wall of the collector 41, so that the collector 41 can rotate with the rotating shaft 1; at the same time, the area where the collector 41 extends along the radial direction of the rotating shaft 1 is relatively large, which can reduce the area of the magnetic fluid leakage channel, thereby reducing the probability of magnetic fluid leakage.

[0077] Optionally, when the collector 41 is connected to the outer shell 3, the liquid injection hole 24 is provided on the first pole shoe 21.

[0078] As an example, such as Figure 2As shown, an inner wall of the first pole shoe 21 and the bushing 12 form a first channel 212. The first channel 212, the sealing gap, and the second channel 232 are communicated in sequence. The liquid injection hole 24 penetrates through the first pole shoe 21 in the radial direction, such that one end of the liquid injection hole 24 close to the bushing 12 is directly communicated with the first channel 212. When injecting the magnetic fluid into the sealing gap, the hole plug 33 can be removed, and the magnetic fluid is injected into the liquid injection hole 24 through a syringe. After flowing through the liquid injection hole 24 and the first channel 212 in sequence, the magnetic fluid is filled into a plurality of sealing gaps in sequence.

[0079] As Figure 2 shown, the second abutting ring 26 is sleeved on the outer side of the collector 41 and connected to the housing 3. Both the collector 41 and the positioning ring 43 are connected to the second abutting ring 26. An inner wall of the second abutting ring 26 has an annular step. An end face of the positioning ring 43 away from the collector 41 abuts against the annular step, whereby the positioning of the positioning ring 43 can be realized, and further the positioning installation of the collector 41 can be realized, making the assembly work of the collection assembly 4 more convenient.

[0080] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are 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 thus should not be construed as a limitation to the present invention.

[0081] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] In the present invention, unless otherwise clearly defined or limited, a first feature being "on" or "under" a second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "over" and "on top of" a second feature may be that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. A first feature being "under", "below" and "beneath" a second feature may be that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0084] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0085] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A magnetic fluid sealing device (100), characterized in that: include: A rotating shaft (1); A sealing assembly (2), wherein the sealing assembly (2) is rotatable relative to the rotating shaft (1), and the sealing assembly (2) comprises a first pole shoe (21), a first magnet (22), and a second pole shoe (23) which are sequentially mounted on the rotating shaft (1) along the axial direction of the rotating shaft (1), wherein the first pole shoe (21) comprises a first pole tooth (211), and the second pole shoe (23) comprises a second pole tooth (231), and a sealing gap for filling a magnetic fluid is formed between the first pole tooth (211) and the second pole tooth (231) and the rotating shaft (1); A housing (3), the housing (3) being sleeved on the sealing assembly (2) and connected to the sealing assembly (2); A collecting assembly (4), the collecting assembly (4) comprising a collector (41) and a second magnet (42), the magnetic pole direction of the second magnet (42) being opposite to that of the first magnet (22), the collector (41) being arranged between the rotating shaft (1) and the housing (3), and being connected to the rotating shaft (1) or the housing (3), the second magnet (42) being connected to the collector (41), and the collector (41) having a liquid collecting tank (411) for collecting magnetic fluid.

2. The magnetic fluid sealing device (100) according to claim 1, characterized in that: There are multiple liquid collecting tanks (411), and the multiple liquid collecting tanks (411) are arranged in sequence.

3. The magnetic fluid sealing device (100) according to claim 1, characterized in that: The collecting assembly (4) further comprises a positioning ring (43), wherein the positioning ring (43) is arranged on a side of the collector (41) away from the sealing assembly (2) and abuts against the collector (41); when the collector (41) is connected to the rotating shaft (1), the positioning ring (43) is connected to the rotating shaft (1); and when the collector (41) is connected to the outer shell (3), the positioning ring (43) is connected to the outer shell (3).

4. The magnetic fluid sealing device (100) according to any one of claims 1 to 3, characterized in that: The first pole tooth (211) and the second pole tooth (231) are respectively arranged on the inner walls of the first pole shoe (21) and the second pole shoe (23), and are both arranged toward the outer side surface of the rotating shaft (1), and the sealing gap is formed between the first pole tooth (211) and the second pole tooth (231) and the outer side surface of the rotating shaft (1); The collector (41) is connected to the rotating shaft (1).

5. The magnetic fluid sealing device (100) according to claim 3, characterized in that: The rotating shaft (1) comprises a shaft body (11) and a shaft sleeve (12), wherein the shaft sleeve (12) is sleeved on the shaft body (11) and connected to the shaft body (11), wherein the shaft sleeve (12) comprises a convex ring (121), wherein the convex ring (121) is arranged between the first pole shoe (21) and the second pole shoe (23), wherein the first pole tooth (211) is arranged on the end surface of the first pole shoe (21) facing the convex ring (121), and the second pole tooth (231) is arranged on the end surface of the second pole shoe (23) facing the convex ring (121), and wherein the sealing gap is formed between the first pole tooth (211) and the convex ring (121) and between the second pole tooth (231) and the convex ring (121); The collector (41) is connected to the housing (3).

6. The magnetic fluid sealing device (100) according to claim 5, characterized in that: The inner wall of the second pole shoe (23) and the outer wall of the shaft sleeve (12) form a second channel (232), and the second channel (232) is connected to the sealing gap; The collecting assembly (4) further comprises a retaining ring (44), wherein the retaining ring (44) is connected to the rotating shaft (1), the liquid collecting groove (411) is arranged radially inwardly along the rotating shaft (1), and the outer wall of the retaining ring (44) and the groove wall of the liquid collecting groove (411) form a liquid collecting channel (412), and the liquid collecting channel (412) is connected to the second channel (232).

7. The magnetic fluid sealing device (100) according to claim 6, characterized in that: The positioning ring (43) is connected to the housing (3), and the projection of the positioning ring (43) on the cross section of the rotating shaft (1) completely covers the projection of the liquid collecting channel (412) on the cross section of the rotating shaft (1).

8. The magnetic fluid sealing device (100) according to claim 1, characterized in that: The sealing component (2) has an injection hole (24) for injecting magnetic fluid, and the injection hole (24) is communicated with the sealing gap.

9. The magnetic fluid sealing device (100) according to claim 8, characterized in that: The sealing assembly (2) further comprises a first stop ring (25) and a second stop ring (26), wherein the first stop ring (25) is connected to the housing (3) and stops at the first pole shoe (21), and the second stop ring (26) is connected to the housing (3) and stops at the second pole shoe (23); The collector (41) is arranged on a side of the second pole shoe (23) away from the first pole shoe (21), and the injection hole (24) is provided on the first pole shoe (21) or the first stop ring (25).

10. The magnetic fluid sealing device (100) according to claim 1, characterized in that: The collector (41) is made of porous fiber material.

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