Magnetic fluid seal device

Abstract

The application discloses a magnetic fluid sealing device, which comprises a rotating shaft, a sealing assembly, a shell and a collecting assembly. The sealing assembly is rotatable relative to the rotating shaft. The sealing assembly comprises a first pole shoe, a first magnet and a second pole shoe which are sequentially sleeved on the rotating shaft along the axial direction of the rotating shaft. The first pole shoe and the second pole shoe form a sealing gap for filling the magnetic fluid between the rotating shaft and the sealing assembly. The shell is sleeved on the sealing assembly and connected with the sealing assembly. The collecting assembly comprises a collector and a second magnet which is opposite to the magnetic pole direction of the first magnet. The collector is arranged between the rotating shaft and the shell and connected with the rotating shaft or the shell. The second magnet is connected with the collector. The collector has a liquid collecting groove for collecting the magnetic fluid. The magnetic fluid sealing device of the embodiment can collect the magnetic fluid flowing out of the sealing gap, thereby reducing the probability of the leakage of the magnetic fluid, reducing the probability of the pollution of the sealing medium and being suitable for sealing the equipment with high sealing cleanliness requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing devices, and in particular to a magnetic fluid sealing device. BACKGROUND

[0002] The magnetic fluid sealing device has been widely applied in various devices in the fields of aviation, aerospace, nuclear energy, military industry, and chemical industry, due to its advantages of 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, which may contaminate the sealed medium. For example, the magnetic fluid sealing device used in an airborne optoelectronic pod of an unmanned aerial vehicle may cause the magnetic fluid to flow out and contaminate the optical elements when the condensate washes the magnetic fluid at high altitudes, which may cause irreparable consequences. For another example, the magnetic fluid sealing device used in a chemical reaction kettle in the chemical industry may cause the magnetic particles to accelerate oxidation in a high-temperature environment, and the base carrier liquid may flow out from the sealing gap after the magnetic fluid deteriorates, which may contaminate the reactants. This makes the magnetic fluid sealing device still face challenges when it is applied to devices with high sealing cleanliness requirements. SUMMARY

[0004] The present application aims to at least partially solve one of the problems in the related art.

[0005] To this end, an embodiment of the present application provides a magnetic fluid sealing device, and a liquid collecting groove can collect the magnetic fluid flowing out from the sealing gap, so as to reduce the probability of leakage of the magnetic fluid and the probability of contamination of the sealed medium, and the magnetic fluid sealing device is suitable for sealing devices with high sealing cleanliness requirements.

[0006] The magnetic fluid sealing device provided by the embodiment of the present application comprises a rotating shaft, a sealing assembly, a shell, and a collecting assembly. The sealing assembly is rotatable relative to the rotating shaft. The sealing assembly comprises a first pole shoe, a first magnet, and a second pole shoe which are sequentially sleeved on the rotating shaft in the axial direction of the rotating shaft. The first pole shoe comprises first pole teeth, and the second pole shoe comprises second pole teeth. The first pole teeth and the second pole teeth form a sealing gap for filling the magnetic fluid between the rotating shaft and the first pole teeth and between the rotating shaft and the second pole teeth. The shell is sleeved on and connected with the sealing assembly. The collecting assembly comprises a collector and a second magnet. The second magnet is opposite to the first magnet in the direction of the magnetic pole. The collector is arranged between the rotating shaft and the shell and is connected to the rotating shaft or the shell. The second magnet is connected to the collector. The collector has a liquid collecting groove for collecting the magnetic fluid.

[0007] In some embodiments, the number of the liquid collecting grooves is multiple, and the multiple liquid collecting grooves are sequentially arranged.

[0008] In some embodiments, the collecting assembly further comprises a positioning ring, which is arranged on a side of the collector away from the sealing assembly and abuts against the collector, the positioning ring is connected with the rotating shaft when the collector is connected with the rotating shaft, and the positioning ring is connected with the housing when the collector is connected with the housing.

[0009] In some embodiments, the first and second pole teeth are arranged on inner walls of the first and second pole shoes respectively and face the outer side surface of the rotating shaft, and the first and second pole teeth are arranged on the outer side surface of the rotating shaft to form the sealing gap; the collector is connected with the rotating shaft.

[0010] In some embodiments, the rotating shaft comprises a shaft body and a shaft sleeve, the shaft sleeve is sleeved on and connected with the shaft body, the shaft sleeve comprises a convex ring, the convex ring is arranged between the first and second pole shoes, the first pole tooth is arranged on an end surface of the first pole shoe facing the convex ring, the second pole tooth is arranged on an end surface of the second pole shoe facing the convex ring, and the sealing gap is formed between the first pole tooth and the convex ring and between the second pole tooth and the convex ring; the collector is connected with the housing.

[0011] In some embodiments, an inner wall of the second pole shoe and an outer wall of the shaft sleeve form a second channel, and the second channel is communicated with the sealing gap; the collecting assembly further comprises a blocking ring, which is connected with the rotating shaft, and the liquid collecting groove is arranged inward along the radial direction of the rotating shaft, an outer wall of the blocking ring and a groove wall of the liquid collecting groove form a liquid collecting channel, and the liquid collecting channel is communicated with the second channel.

[0012] In some embodiments, the positioning ring is connected with the housing, and a projection of the positioning ring on a cross section of the rotating shaft completely covers a projection of the liquid collecting 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 is communicated with the sealing gap.

[0014] In some embodiments, the sealing assembly further comprises a first abutting ring and a second abutting ring, the first abutting ring is connected with the housing and abuts against the first pole shoe, and the second abutting ring is connected with 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 arranged on the first pole shoe or the first abutting ring.

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

[0016] The magnetic fluid filled in the plurality of sealing gaps can form a plurality of sealing rings, so that the magnetic fluid sealing device has better sealing performance. Under the magnetic force of the second magnet, the collector has a magnetic field force attracting the magnetic fluid, when the magnetic fluid flows out of the sealing gap, the liquid collecting groove can collect the flowed-out magnetic fluid, increase the collection rate of the magnetic fluid, thereby reducing the probability of leakage of the magnetic fluid, reducing the probability of pollution of the sealing medium, and the magnetic fluid sealing device can be suitable for sealing equipment with higher sealing cleanliness requirements. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of a magnetic fluid sealing device of one embodiment of the present application.

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

[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, collecting assembly; 41, collector; 411, liquid collecting groove; 412, liquid collecting channel; 42, second magnet; 43, positioning ring; 431, positioning screw; 44, blocking ring; 441, first ring part; 442, second ring part;

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

[0026] 61, first blocking ring; 62, second blocking ring; 63, third blocking ring. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0028] As Figure 1 and Figure 2As shown, the magnetic fluid sealing device 100 of the embodiment of the present application comprises a rotating shaft 1, a sealing assembly 2, a shell 3 and a collecting assembly 4; 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 sleeved on the rotating shaft 1 along the axial direction of the rotating shaft 1; the first pole shoe 21 comprises first pole teeth 211, and the second pole shoe 23 comprises second pole teeth 231; the first pole teeth 211 and the second pole teeth 231 form sealing gaps for filling the magnetic fluid between the rotating shaft 1; the shell 3 is sleeved on the sealing assembly 2 and connected with the sealing assembly 2; the collecting assembly 4 comprises a collector 41 and a second magnet 42; the second magnet 42 is opposite to the first magnet 22 in the magnetic pole direction; the collector 41 is arranged between the rotating shaft 1 and the shell 3 and connected with the rotating shaft 1 or the shell 3; the second magnet 42 is connected with the collector 41; and the collector 41 has a liquid collecting groove 411 for collecting the magnetic fluid.

[0029] The magnetic fluid filled in the plurality of sealing gaps can form a plurality of sealing rings, so that the magnetic fluid sealing device 100 has better sealing performance. Since the second magnet 42 is opposite to the first magnet 22 in the magnetic pole direction, the collector 41 of the collecting assembly 4 can be provided with a magnetic field force for attracting the magnetic fluid without affecting the magnetic field distribution of the sealing assembly 2; under the magnetic force of the second magnet 42, the liquid collecting groove 411 of the collector 41 can collect the magnetic fluid flowing out of the sealing gaps when the magnetic fluid flows out of the sealing gaps, so as to increase the collection rate of the magnetic fluid, thereby reducing the probability of leakage of the magnetic fluid and the probability of pollution of the sealing medium, and the magnetic fluid sealing device 100 can be suitable for sealing equipment with high sealing cleanliness requirement.

[0030] When the rotating speed of the rotating shaft 1 is low, the collector 41 can be connected with the rotating shaft 1, and the distance between the collector 41 and the sealing gaps is short, so that the collection rate of the magnetic fluid can be improved; when the rotating speed of the rotating shaft 1 is high, the collector 41 can be connected with the shell 3, and the collector 41 does not rotate with the rotating shaft 1, so that the collector 41 can be prevented from throwing out the collected magnetic fluid due to high-speed rotation with the rotating shaft 1.

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

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

[0033] Therefore, when the shell 3 is sleeved on the outer side walls of the first pole shoe 21 and the second pole shoe 23, the first sealing rings 51 are tightly attached to the inner wall of the shell 3, so that the sealing performance between the first pole shoe 21, the second pole shoe 23 and the shell 3 can be ensured.

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

[0035] It is known that the magnetic fluid flows out of the sealing gap and is ejected outward at high speed.

[0036] By arranging multiple sumps 411, the multiple sumps 411 are arranged in sequence on the collector 41 to form a labyrinth seal structure, which can change the leakage direction of the magnetic fluid flowing out of the sealing gap, prevent the magnetic fluid from leaking outward, and effectively reduce the leakage speed of the magnetic fluid, thereby increasing the collection rate of the magnetic fluid and reducing the probability of contamination of the sealing medium.

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

[0038] The magnetic fluid flowing out of the sealing gap can penetrate into the interior of the collector 41, increasing the storage capacity of the collector 41 and thus improving the collection rate of the magnetic fluid; in addition, the amount of penetration of the magnetic fluid in the collector 41 (for example, the color of the collector 41) can be observed to determine whether the magnetic fluid in the sealing gap is sufficient.

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

[0040] In some embodiments, as shown in Figure 1 and Figure 2 , the collection assembly 4 further comprises a positioning ring 43, which 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 shaft 1, the positioning ring 43 is connected to the shaft 1; when the collector 41 is connected to the housing 3, the positioning ring 43 is connected to the housing 3.

[0041] The positioning ring 43 can be used to position the collector 41, thereby facilitating the assembly of the collection assembly 4.

[0042] In some embodiments, as shown in Figure 1 , the first and second pole teeth 211 and 231 are arranged on the inner walls of the first and second pole shoes 21 and 23, respectively, and face the outer side of the shaft 1. The first and second pole teeth 211 and 231 form a sealing gap with the outer side of the shaft 1; the collector 41 is connected to the shaft 1.

[0043] The sealing assembly 2 adopts the above structure, and the 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 magnetic 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 suitable for low-rotation-speed working conditions and is suitable for sealing of optical systems in the aviation field and high-end reaction kettles in the chemical and nuclear energy fields. In the low-rotation-speed working condition, the collector 41 is connected to the rotating shaft 1, the distance between the collector 41 and the sealing gap is relatively close, the collection rate of the magnetic fluid by the collector 41 is relatively high, and the collected magnetic fluid will not be thrown out with the rotating shaft 1. When the magnetic fluid flows out of the sealing gap, the flowing-out magnetic fluid is absorbed by the porous fiber material of the collector 41 under the action of the magnetic field force of the second magnet 42, thereby preventing the magnetic fluid from leaking and polluting the sealed medium.

[0045] As shown in Figure 1 , 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 towards the second pole shoe 23, 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 radial direction of the rotating shaft 1 to form a labyrinth seal, thereby effectively reducing the speed of the magnetic fluid and increasing the collection rate of the magnetic 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, so that the second magnet 42 can provide the collector 41 with a magnetic field force for absorbing the magnetic 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 uniformly distributed along the circumferential direction thereof, the countersunk holes penetrate through the positioning ring 43; the rotating shaft 1 has a plurality of threaded holes uniformly distributed along the circumferential direction thereof, 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, and the positioning screws 431 are sequentially inserted through the countersunk holes and the threaded holes, so as to realize the connection between the positioning ring 43 and the rotating shaft 1; and then the collector 41 is abutted against the positioning ring 43, so as to realize the positioning of the collector 41.

[0048] Optionally, as shown in Figure 1 , the outer wall of the rotating shaft 1 has a groove, the first retaining ring 61 is arranged in the groove, and 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] Therefore, the first retaining ring 61 can further limit the collector 41 in the axial direction, 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 bushing 12. The bushing 12 is fitted onto and connected to the shaft body 11. The bushing 12 includes a convex ring 121, which is disposed between a first pole shoe 21 and a second pole shoe 23. A first pole tooth 211 is disposed on the end face of the first pole shoe 21 facing the convex ring 121, and a second pole tooth 231 is 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 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 outer casing 3.

[0051] The aforementioned sealing assembly 2 has a centrifugal magnetohydrodynamic (MHD) seal structure. The first pole tooth 211 and the second pole tooth 231 are respectively located on the opposite end faces of the first pole shoe 21 and the second pole shoe 23. The bushing 12 has a "convex" shaped structure. This centrifugal MHD seal structure is suitable for high rotational speed conditions and conditions where the radial runout of the rotating shaft 1 is large. The magnetohydrodynamic fluid is affected by centrifugal force and accumulates at the outer diameter of the rotating shaft 1, thereby forming a centrifugal seal with good sealing effect.

[0052] Under high rotational speed conditions, the collector 41 is connected to the housing 3, meaning that the collector 41 does not rotate with the shaft 1, thereby preventing the collected magnetic fluid from being thrown out of the collector 41 due to high centrifugal force, thus improving the collection rate of magnetic fluid under high rotational speed conditions.

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

[0054] As an example, such as Figure 2 As shown, the bushing 12 is fitted onto the rotating shaft 1 and rotates with the rotating shaft 1. A plurality of first pole teeth 211 are provided 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 provided 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, such as Figure 2 As shown, the inner wall of the bushing 12 has two second sealing ring grooves, and a second sealing ring 52 is provided in the second sealing ring groove.

[0056] Therefore, when the bushing 12 is fitted to the rotating shaft 1, the second sealing ring 52 fits tightly against the outer wall of the rotating shaft 1, thereby ensuring the sealing between the rotating shaft 1 and the bushing 12.

[0057] In some embodiments, the inner wall of the second pole shoe 23 and the outer wall of the shaft sleeve 12 form a second channel 232, which is in communication with the sealing gap; the collecting assembly 4 further comprises a baffle ring 44, which is connected to the rotating shaft 1, and the liquid collecting groove 411 is arranged inwardly along the radial direction of the rotating shaft 1, and the outer wall of the baffle ring 44 and the groove wall of the liquid collecting groove 411 form a liquid collecting channel 412, which is in communication 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 passing through the liquid collecting channel 412 is adsorbed and collected by the collector 41; the baffle ring 44 is connected to the rotating shaft 1, and the distance between the baffle 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] As an example, as shown in Figure 2 , the collector 41 is arranged at the end of the second pole shoe 23 away from the first pole shoe 21 and abuts against the second pole shoe 23, and the collecting groove is arranged towards the rotating shaft 1, and 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 baffle ring 44 comprises a first ring portion 441 and a second ring portion 442, the outer wall of the first ring portion 441 is flush with the outer wall of the shaft sleeve 12, and the first ring portion 441 abuts against the shaft sleeve 12 to realize positioning of the shaft sleeve 12; the outer diameter of the second ring portion 442 is greater than that of the first ring portion 441, and the outer wall of the second ring portion 442 and the groove wall of the liquid collecting groove 411 form the above-mentioned liquid collecting channel 412.

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

[0061] Therefore, after the magnetic fluid sealing device 100 is assembled, the third sealing ring 53 tightly abuts against the end face of the second pole shoe 23, so as to ensure the sealing between the second pole shoe 23 and the collector 41, and prevent the magnetic fluid from leaking through the connection between the second pole shoe 23 and the collector 41.

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

[0063] Thus, the positioning and installation of the shaft sleeve 12 and the blocking ring 44 can be realized by the second blocking ring 62 and the third blocking ring 63.

[0064] In some embodiments, as shown in Figure 2 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 realize the positioning and installation of the collector 41. Through the above arrangement, the size of the positioning ring 43 in the radial direction of the rotating shaft 1 is large, and the projection of the positioning ring 43 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, the magnetic fluid that is not completely collected by the collector 41 can be sprayed on the positioning ring 43 and reflected into the liquid collecting channel 412 and be collected by the collector 41 again, thereby improving the collection rate of the magnetic fluid.

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

[0067] Thus, when the magnetic fluid flowing out of the liquid collecting channel 412 is sprayed on the positioning ring 43 under the magnetic field force of the second magnet 42, the magnetic fluid can also be attached to the positioning ring 43, preventing the leakage of the magnetic fluid from polluting the sealed medium.

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

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

[0070] It is known that the color of the collector 41 can be observed to determine whether the magnetic fluid working in the sealing gap is sufficient; through the arrangement of 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 in the sealing gap, thereby ensuring the sealing performance of the magnetic fluid sealing device 100.

[0071] Optionally, as shown in Figure 1 and Figure 2 The housing 3 has a liquid injection port 32 in communication with the liquid injection hole 24, and the liquid injection port 32 is a counter-sunk threaded hole; the magnetic fluid sealing device 100 further comprises a plug 33, which is an internal hexagonal threaded plug 33, and the plug 33 is detachably arranged in the liquid injection port 32. The plug 33 can block the liquid injection port 32; when it is necessary to supplement the magnetic fluid, the plug 33 can be removed.

[0072] In some embodiments, as shown in Figure 1 and Figure 2 , the sealing assembly 2 further comprises a first stop ring 25 connected with the housing 3 and stopping at the first pole shoe 21, and a second stop ring 26 connected with the housing 3 and stopping at the second pole shoe 23; the collector 41 is arranged at the side of the second pole shoe 23 away from the first pole shoe 21, and the liquid injection hole 24 is arranged at the first pole shoe 21 or the first stop ring 25.

[0073] Through the first stop ring 25 and the second stop 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, so that the assembly work of the sealing assembly 2 is more convenient.

[0074] Optionally, when the collector 41 is connected with the rotating shaft 1, the liquid injection hole 24 is arranged at the first stop ring 25.

[0075] As an example, as shown in Figure 1 , the magnetic fluid sealing device 100 is suitable for low rotation speed working condition; the outer wall of the first stop ring 25 is fitted to and connected with the housing 3, the first pole shoe 21 comprises a body and a first pole tooth 211, the first pole tooth 211 is arranged at the inner wall of the body, the inner diameter of the first stop ring 25 is smaller than the inner diameter of the body of the first pole shoe 21, the liquid injection hole 24 is arranged at the first stop ring 25 and penetrates along the radial direction of the first pole shoe 21, so that the end of the liquid injection hole 24 towards the rotating shaft 1 is closer to the sealing gap, thereby being more conducive to injecting the magnetic fluid into the sealing gap through the liquid injection hole 24; when the first stop ring 25 is installed, the liquid injection hole 24 on the first stop ring 25 needs to be aligned with the liquid injection hole 32 on the housing 3.

[0076] As shown in Figure 1 , the second stop ring 26 is sleeved on the outside of the collector 41, and the inner wall of the second stop ring 26 and the outer wall of the collector 41 have a gap therebetween and the gap is small, so that the collector 41 can rotate with the rotating shaft 1; at the same time, the collector 41 extends along the radial direction of the rotating shaft 1 with a larger area, 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 with the housing 3, the liquid injection hole 24 is arranged at the first pole shoe 21.

[0078] As an example, as shown in Figure 2 , the magnetic fluid sealing device 100 is suitable for high rotation speed working condition; the outer wall of the first stop ring 25 is fitted to and connected with the housing 3, the first pole shoe 21 comprises a body and a first pole tooth 211, the first pole tooth 211 is arranged at the inner wall of the body, the inner diameter of the first stop ring 25 is smaller than the inner diameter of the body of the first pole shoe 21, the liquid injection hole 24 is arranged at the first stop ring 25 and penetrates along the radial direction of the first pole shoe 21, so that the end of the liquid injection hole 24 towards the rotating shaft 1 is closer to the sealing gap, thereby being more conducive to injecting the magnetic fluid into the sealing gap through the liquid injection hole 24; when the first stop ring 25 is installed, the liquid injection hole 24 on the first stop ring 25 needs to be aligned with the liquid injection hole 32 on the housing 3.As shown, the inner wall of the first pole shoe 21 and the shaft sleeve 12 form a first channel 212, the first channel 212, the sealing gap and the second channel 232 are sequentially communicated; the liquid injection hole 24 penetrates along the radial direction of the first pole shoe 21, so that the end of the liquid injection hole 24 close to the shaft sleeve 12 is directly communicated with the first channel 212; when the magnetic fluid is injected into the sealing gap, the hole plug 33 can be removed, the magnetic fluid is injected into the liquid injection hole 24 through the syringe, and the magnetic fluid sequentially flows through the liquid injection hole 24 and the first channel 212 and is sequentially filled into the plurality of sealing gaps.

[0079] As shown in the drawings, Figure 2 As shown, the second stop ring 26 is sleeved on the outside of the collector 41 and connected with the shell 3, and the collector 41 and the positioning ring 43 are connected with the second stop ring 26; the inner wall of the second stop ring 26 has an annular step, and the end face of the positioning ring 43 away from the collector 41 is stopped on the annular step, so that the positioning of the positioning ring 43 is realized, and the positioning and installation of the collector 41 are realized, so that the assembly work of the collecting assembly 4 is more convenient.

[0080] In the description of the present application, it should be understood that the orientation or positional relationship indicated by 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" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

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

[0082] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected or in communication with each other; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0083] In the present application, unless specifically stated and limited otherwise, a first feature is "on" or "under" a second feature can mean that the first and second features are in direct contact, or the first and second features are in indirect contact with an intervening medium. Also, a first feature "over", "above" and "on top of" a second feature can mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0084] In the present application, the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" mean that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the present application. The illustrative appearances of the above-mentioned terms in various places in the specification are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. Moreover, the terms "first", "second", "third", etc. are used herein merely as identifiers for different elements, regions, or layers, and are not intended to be taken literally, unless otherwise specified.

[0085] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary, and are not to be interpreted as limiting the present application, and that changes, modifications, substitutions and variations can be made therein without departing from the scope of the present application.

Claims

1. A magnetohydrodynamic sealing device (100), characterized in that, include: Rotating shaft (1); A sealing assembly (2) is rotatable relative to the rotating shaft (1). The sealing assembly (2) includes a first pole shoe (21), a first magnet (22), and a second pole shoe (23) sequentially fitted onto the rotating shaft (1) along its axial direction. The first pole shoe (21) includes a first pole tooth (211), and the second pole shoe (23) includes a second pole tooth (231). Both the first pole tooth (211) and the second pole tooth (231) form a sealing gap with the rotating shaft (1) for filling with magnetic fluid. The outer casing (3) is fitted onto the sealing assembly (2) and connected to the sealing assembly (2); The collection component (4) includes a collector (41) and a second magnet (42), the second magnet (42) having a magnetic pole direction opposite to that of the first magnet (22), the collector (41) being disposed between the rotating shaft (1) and the outer shell (3) and connected to the rotating shaft (1) or the outer shell (3), the second magnet (42) being connected to the collector (41), and the collector (41) having a collection tank (411) for collecting magnetic fluid. The collecting assembly (4) further includes a positioning ring (43), which is located 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 outer shell (3), the positioning ring (43) is connected to the outer shell (3). The rotating shaft (1) includes a shaft body (11) and a bushing (12). The bushing (12) is fitted onto the shaft body (11) and connected to it. The bushing (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 tooth (211) is disposed on the end face of the first pole shoe (21) facing the convex ring (121). The second pole tooth (231) is disposed on the end face of the second pole shoe (23) facing the convex ring (121). 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 outer shell (3). The inner wall of the second pole shoe (23) and the outer wall of the bushing (12) form a second channel (232), which is connected to the sealing gap; the collection assembly (4) also includes a retaining ring (44), which is connected to the rotating shaft (1), and the liquid collection tank (411) is arranged radially inward along the rotating shaft (1). The outer wall of the retaining ring (44) and the tank wall of the liquid collection tank (411) form a liquid collection channel (412), which is connected to the second channel (232); The positioning ring (43) is connected to the outer shell (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 collection channel (412) on the cross-section of the rotating shaft (1).

2. The magnetohydrodynamic sealing device (100) according to claim 1, characterized in that, The number of liquid collection tanks (411) is multiple, and the multiple liquid collection tanks (411) are arranged in sequence.

3. The magnetohydrodynamic sealing device (100) according to claim 1, characterized in that, The sealing assembly (2) has an injection hole (24) for injecting magnetic fluid, the injection hole (24) being in communication with the sealing gap.

4. The magnetohydrodynamic sealing device (100) according to claim 3, characterized in that, The sealing assembly (2) further includes a first stop ring (25) and a second stop ring (26), the first stop ring (25) being connected to the outer shell (3) and abutting against the first pole shoe (21), and the second stop ring (26) being connected to the outer shell (3) and abutting 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 injection hole (24) is located on the first pole shoe (21).

5. The magnetohydrodynamic sealing device (100) according to claim 1, characterized in that, The collector (41) is made of porous fiber material.

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