A multi-magnetic source sleeve type magnetic fluid seal device

Abstract

The application discloses a kind of multi-magnetic source sleeve type magnetic fluid sealing devices, including shaft, and shell and end cap are spaced sleeve on the shaft;The lateral surface of shaft is sleeved with sleeve, and sleeve is provided with two and is left-right symmetrical distribution, and two sleeves are all sleeved with inner blocking structure and outer blocking structure, and two outer blocking structures are respectively located in the outside of two inner blocking structures;Locking structure is installed in the inside of shaft, and locking structure is provided with two and is left-right symmetrical setting, and two locking structures are respectively passed through the outer lateral surface of shaft and are connected with two outer blocking structures;Two permanent magnet rings are jointly installed between sleeve inner blocking structure, and one permanent magnet ring is jointly installed between outer blocking structure and inner blocking structure.The application can realize the integral type sleeve installation of one permanent magnet ring and two permanent magnet rings, avoids embedding, avoids split type embedding, so that the installation of one permanent magnet ring and two permanent magnet rings can be more convenient, reduces installation difficulty, shortens installation time consumption, and installation efficiency is higher.

Description

Technical Field

[0001] This invention relates to the field of magnetic fluid sealing technology, and in particular to a multi-magnetic-source sleeve-type magnetic fluid sealing device. Background Technology

[0002] Magnetohydrodynamic (MHD) sealing technology has been widely used in rotating sealing devices, such as in vacuum equipment, high-temperature and high-pressure equipment, and equipment with stringent environmental requirements, to improve product quality and achieve significant economic benefits. However, as the sealing gap increases, the sealing capacity gradually decreases or even fails. Therefore, improving the pressure resistance of MHD seals under large gaps is a pressing issue today.

[0003] Magnetofluid sealing utilizes the magnetic field generated by a permanent magnet within a sealing gap to firmly fix the magnetofluid within the gap, resisting the pressure difference between the two sides, thereby achieving a sealing effect. Existing multi-magnetic-source sleeve-type magnetofluid sealing devices, such as the one disclosed in CN108799507B, consist of one or more magnetofluid sealing units. Each magnetofluid sealing unit includes a shell, a left pole shoe ring, a right pole shoe ring, a sleeve, a left first permanent magnet ring, a left second permanent magnet ring, a middle permanent magnet ring, a right first permanent magnet ring, and a right second permanent magnet ring. This invention solves the problem of low pressure resistance in existing single-magnetic-source magnetofluid sealing devices.

[0004] However, in the aforementioned magnetohydrodynamic sealing device, the left and right permanent magnet rings (first and second from the left, first and second from the right) are inserted into the grooves of the sleeve in a segmented manner. Due to the influence of magnetic force, the magnet segments interfere with each other. This means that when the magnet segments are continuously inserted into the grooves, the first inserted segment will hinder the subsequent inserted segment, requiring greater pressure to be pressed into the groove. Therefore, the segmented installation of the permanent magnet rings is inconvenient, difficult, and time-consuming, resulting in low installation efficiency. Therefore, we propose a multi-magnetic-source sleeve-type magnetohydrodynamic sealing device. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-magnetic-source sleeve-type magnetohydrodynamic sealing device, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A multi-magnetic-source sleeve-type magnetohydrodynamic sealing device includes a shaft, on which a housing and an end cap are spaced apart. The housing is barrel-shaped, and the end caps are installed at the opening of the housing. The two outer end faces of the shaft extend to the outer sides of the housing and the end caps, respectively. Two sleeves are fitted onto the circumferential side of the shaft, symmetrically arranged. Each sleeve has an inner retaining structure and an outer retaining structure, with the two outer retaining structures located outside the two inner retaining structures. Two locking structures are installed on the inner side of the shaft, symmetrically arranged, passing through the outer circumferential side of the shaft and connecting to the two outer retaining structures. A second permanent magnet ring is installed between the inner retaining structures of the sleeves, and a second permanent magnet ring is installed between the outer and inner retaining structures. It is equipped with a No. 1 permanent magnet ring; the inner wall of the outer shell is equipped with a No. 3 permanent magnet ring, a left pole shoe ring, a right pole shoe ring, an outer magnetic isolation ring, and bearings. The No. 3 permanent magnet ring is spaced out on the outside of the two sleeves; the left pole shoe ring is spaced out on the outside of the No. 1 and No. 2 permanent magnet rings on the left side; the right pole shoe ring is spaced out on the outside of the No. 1 and No. 2 permanent magnet rings on the right side; there are two outer magnetic isolation rings, which abut against the outer end face of the left pole shoe ring and the outer end face of the right pole shoe ring respectively; an inner magnetic isolation ring abuts against the outer end face of each of the two outer baffle structures, and both inner magnetic isolation rings are sleeved on the shaft; two bearings are also sleeved on the shaft, and the two bearings abut against the outer end face of the two outer magnetic isolation rings and the outer end face of the two inner magnetic isolation rings respectively.

[0008] Preferably, the shaft includes two shafts symmetrically arranged on the left and right, with the large ends of the two shafts abutting together. Each of the large ends of the two shafts has an annular groove. Two sliding grooves are opened laterally on the groove walls of each of the two grooves. A guide groove is opened on one side of the peripheral side of each of the two shafts, and the guide groove passes through the other side of the peripheral side of the shaft along the radial direction of the shaft. The guide groove on the same shaft is connected to the two sliding grooves on the same shaft. The narrow ends of the two shafts extend to the outer side of the outer shell and the end cap, respectively.

[0009] Preferably, a connecting screw hole is provided in the middle of the large end of one shaft, and a connecting stud is fixed in the middle of the large end of the other shaft. The connecting stud is threadedly connected to the connecting screw hole to tightly fit the large ends of the two shafts together.

[0010] Preferably, the sleeve includes a main sleeve fitted onto the shaft body, the abutting surfaces of the two main sleeves being flush with the abutting surfaces of the two shaft bodies respectively, a first mounting sleeve fixedly connected to the other end face of the main sleeve, a second mounting sleeve fixedly connected to the other end of the first mounting sleeve, both the first and second mounting sleeves being fitted onto the shaft body, a slot being provided at the other end of the second mounting sleeve, the slot extending toward and through the end face of the first mounting sleeve, and a second keyway being provided on the inner wall of the main sleeve, the inner wall of the first mounting sleeve, and the inner wall of the second mounting sleeve.

[0011] Preferably, the inner retaining structure includes an inner retaining ring, which is sleeved on the second mounting cylinder and abuts against the end face of the first mounting cylinder. An inner retaining ring is integrally sleeved on the outer peripheral side of the inner retaining ring. An insertion hole is opened at the end of the inner retaining ring away from the first mounting cylinder. An insertion plate is fixedly connected to the inner peripheral side of the inner retaining ring and is inserted into the slot.

[0012] Preferably, the outer retaining structure includes an outer retaining ring, one end of which is fixedly connected to a pin, and two oppositely arranged locking grooves are opened on the inner circumferential side of the outer retaining ring. A third keyway is also opened on the inner circumferential side of the outer retaining ring. The end of the outer retaining ring on which the pin is installed abuts against the end of the inner retaining ring away from the first mounting cylinder and the outer end face of the second mounting cylinder. The pin is inserted into the insertion hole.

[0013] Preferably, a first keyway is provided on the circumferential side of both shafts. The first keyway is arranged along the axial direction of the shaft, and a transmission key is jointly engaged in both first keyways. The transmission key is engaged in the second keyway and the third keyway.

[0014] Preferably, the second permanent magnet ring is fitted onto the first mounting cylinder and abuts against the main cylinder and the inner retaining ring; the first permanent magnet ring is fitted onto the inner retaining ring and abuts against the inner retaining ring and the outer retaining ring.

[0015] Preferably, the locking structure includes two locking plates and two locking blocks. The two locking plates are slidably disposed in two grooves on the same shaft, and the two locking blocks are disposed opposite each other in guide grooves on the same shaft. The two locking blocks are respectively connected to the outer surfaces of the two locking plates and form an inclined transmission structure. The two locking blocks are respectively engaged with two locking grooves. A connecting arc rod is fixedly connected between the two locking plates, and the two connecting arc rods together form a transmission ring, which engages with the groove. A spring column is fixedly connected between the two locking blocks.

[0016] Preferably, when the two locking plates slide towards the narrow end of the shaft in the slide groove, they push the two locking blocks to slide to both sides in the guide groove, and a portion of the two locking blocks slide into the two locking grooves respectively, and the spring column is stretched.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By setting a sleeve, the sleeve includes a main sleeve, a No. 1 mounting sleeve fixed to one end of the main sleeve, and a No. 2 mounting sleeve fixed to one end of the No. 1 mounting sleeve. The No. 2 permanent magnet ring is sleeved on the No. 1 mounting sleeve and abuts against the main sleeve and the inner retaining ring. By setting an inner retaining structure and an outer retaining structure, the inner retaining structure includes an inner retaining ring and an inner retaining ring sleeved on the inner retaining ring, and the inner retaining ring is sleeved on the No. 2 mounting sleeve. The outer retaining structure includes an outer retaining ring, and the outer retaining ring abuts against the inner retaining ring and the No. 2 mounting sleeve after installation. The No. 1 permanent magnet ring is sleeved on the inner retaining ring and abuts against the inner retaining ring and the outer retaining ring. Through the above, the No. 1 permanent magnet ring and the No. 2 permanent magnet ring can be installed as a whole, avoiding the need for inserting or segmented inserting. This makes the installation of the No. 1 permanent magnet ring and the No. 2 permanent magnet ring more convenient, reduces the installation difficulty, shortens the installation time, and increases the installation efficiency.

[0019] 2. By setting a locking structure in conjunction with two outer retaining structures, when part of the locking block slides into the locking groove, the outer retaining ring can be in close contact with the inner retaining ring and the outer retaining ring, locking the position of the outer retaining ring and preventing the outer retaining ring from moving along the axis of the shaft, thereby ensuring the firmness of the first permanent magnet ring and the second permanent magnet ring.

[0020] 3. By setting a shaft and dividing it into two shaft bodies, and installing two locking structures on each shaft body, the two locking structures abut against each other during the process of connecting the two shaft bodies together through connecting studs and connecting screw holes. As the two shaft bodies approach each other, the locking plates on the two locking structures slide along the slide grooves into the shaft bodies, pushing the locking blocks to slide outward along the guide grooves, so that a part of the locking blocks slides into the locking grooves. This allows the outer retaining ring to be locked at the same time as the connection of the two shaft bodies is completed, further improving the convenience of installation.

[0021] 4. The locking block and locking groove work together to prevent the outer retaining ring from moving relative to the shaft. The shaft, main cylinder, first mounting cylinder, second mounting cylinder, and outer retaining ring are connected by a connecting key. The inner retaining ring is connected to the first and second mounting cylinders by the cooperation of the insert plate and the slot. The inner retaining ring is connected to the outer retaining ring by the cooperation of the insert post and the slot. This ensures the stability and firmness of the installation, while improving the convenience of installation, enabling quick installation, ensuring proper installation, guaranteeing installation accuracy, and thus improving installation efficiency. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the overall structure of a multi-magnetic source sleeve-type magnetofluid sealing device according to the present invention;

[0023] Figure 2 This is a partial structural cross-sectional view of a multi-magnetic source sleeve-type magnetofluid sealing device according to the present invention;

[0024] Figure 3This is a cross-sectional view of the internal structure of a multi-magnetic-source sleeve-type magnetofluid sealing device according to the present invention;

[0025] Figure 4 This is a schematic diagram showing the setup of the transmission key;

[0026] Figure 5 This is a schematic diagram showing the arrangement of the shaft and the connecting screw hole;

[0027] Figure 6 A schematic diagram showing the shaft and connecting studs;

[0028] Figure 7 This is a schematic diagram of the sleeve structure;

[0029] Figure 8 This is a schematic diagram of the inner retaining structure;

[0030] Figure 9 This is a structural diagram of the outer retaining structure;

[0031] Figure 10 This is a schematic diagram of the locking structure.

[0032] In the diagram: 1. Outer shell; 2. Shaft; 3. End cap; 4. Connecting stud; 41. Connecting screw hole; 5. Sleeve; 6. Inner retaining structure; 7. Outer retaining structure; 8. Locking structure; 9. Transmission key; 10. No. 1 permanent magnet ring; 11. No. 2 permanent magnet ring; 12. No. 3 permanent magnet ring; 13. Left pole shoe ring; 14. Right pole shoe ring; 15. Outer magnetic isolation ring; 16. Inner magnetic isolation ring; 17. Bearing; 21. Shaft body; 22. 23. Groove; 24. Slide groove; 25. Guide groove; 26. Keyway No. 1; 51. Main cylinder; 52. Mounting cylinder No. 1; 53. Mounting cylinder No. 2; 54. Slot; 55. Keyway No. 2; 61. Inner retaining ring; 62. Inner retaining ring; 63. Insertion hole; 64. Insertion plate; 71. Outer retaining ring; 72. Insertion post; 73. Lock groove; 74. Keyway No. 3; 81. Locking plate; 82. Locking block; 83. Connecting arc rod; 84. Spring post. Detailed Implementation

[0033] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0034] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] like Figure 1-10As shown, a multi-magnetic-source sleeve-type magnetohydrodynamic sealing device includes a shaft 2, on which a housing 1 and an end cap 3 are fitted at intervals. The housing 1 is barrel-shaped, and the end cap 3 is installed at the opening of the housing 1. The two outer end faces of the shaft 2 extend to the outer sides of the housing 1 and the end cap 3, respectively. A sleeve 5 is fitted on the circumferential side of the shaft 2. Two sleeves 5 are provided and are symmetrically distributed from left to right. Each sleeve 5 is fitted with an inner baffle structure 6 and an outer baffle structure 7. The two outer baffle structures 7 are located outside the two inner baffle structures 6, respectively. A locking structure 8 is installed on the inner side of the shaft 2. Two locking structures 8 are provided and are symmetrically arranged from left to right. The two locking structures 8 pass through the outer circumferential side of the shaft 2 and are connected to the two outer baffle structures 7. A second permanent magnet ring 11 is installed between the inner baffle structures 6 of the sleeves 5. A first permanent magnet ring 10 is installed between the outer retaining structure 7 and the inner retaining structure 6; a third permanent magnet ring 12, a left pole shoe ring 13, a right pole shoe ring 14, an outer magnetic isolation ring 15, and a bearing 17 are installed on the inner wall of the outer shell 1. The third permanent magnet ring 12 is spaced out on the outside of the two sleeves 5; the left pole shoe ring 13 is spaced out on the outside of the first permanent magnet ring 10 and the second permanent magnet ring 11 on the left side; the right pole shoe ring 14 is spaced out on the outside of the first permanent magnet ring 10 and the second permanent magnet ring 11 on the right side; the gap between the third permanent magnet ring 12 and the sleeve 5 is filled with magnetic fluid material, and the gaps between the first permanent magnet ring 10, the second permanent magnet ring 11 and the left pole shoe ring 13, and the gaps between the first permanent magnet ring 10, the second permanent magnet ring 11 and the right pole shoe ring 14 are also filled with magnetic fluid material. The magnetofluid material is magnetized by the No. 3 permanent magnet ring 12, the No. 1 permanent magnet ring 10, and the No. 2 permanent magnet ring 11, and is limited by the No. 3 permanent magnet ring 12, the No. 1 permanent magnet ring 10, and the No. 2 permanent magnet ring 11, thereby achieving a seal for the magnetofluid material.

[0037] Two outer magnetic isolation rings 15 are provided, which respectively abut against the outer end face of the left pole shoe ring 13 and the outer end face of the right pole shoe ring 14; an inner magnetic isolation ring 16 abuts against the outer end face of each of the two outer blocking structures 7, and the two inner magnetic isolation rings 16 are sleeved on the shaft 2; two bearings 17 are also sleeved on the shaft 2, and the two bearings 17 abut against the outer end face of the two outer magnetic isolation rings 15 and the outer end face of the two inner magnetic isolation rings 16 respectively.

[0038] As a further explanation of the above technical solution, the shaft 2 includes two shaft bodies 21 arranged symmetrically on the left and right sides. The large ends of the two shaft bodies 21 abut together. Each of the large ends of the two shaft bodies 21 is provided with an annular groove 22. Two sliding grooves 23 are provided laterally on the groove walls of the two grooves 22. A guide groove 24 is provided on one side of the peripheral side of each of the two shaft bodies 21. The guide groove 24 passes through the other side of the peripheral side of the shaft body 21 along the radial direction. The guide groove 24 on the same shaft body 21 is connected to the two sliding grooves 23 on the same shaft body 21. The narrow ends of the two shaft bodies 21 extend to the outside of the outer shell 1 and the end cover 3, respectively.

[0039] As a further explanation of the above technical solution, the sleeve 5 includes a main sleeve 51 sleeved on the shaft 21. The surfaces of the two main sleeves 51 that abut against each other are flush with the surfaces of the two shafts 21 respectively. A first mounting sleeve 52 is fixedly connected to the other end of the main sleeve 51, and a second mounting sleeve 53 is fixedly connected to the other end of the first mounting sleeve 52, making the entire sleeve 5 have a stepped bushing structure, which facilitates the installation of the structure on the sleeve 5. Both the first mounting sleeve 52 and the second mounting sleeve 53 are sleeved on the shaft 21. The other end of the second mounting sleeve 53 has a slot 54 that extends toward the first mounting sleeve 52 and penetrates the end face of the first mounting sleeve 52.

[0040] As a further explanation of the above technical solution, the inner retaining structure 6 includes an inner retaining ring 61, which is sleeved on the second mounting cylinder 53 and abuts against the end face of the first mounting cylinder 52. An inner retaining ring 62 is integrally sleeved on the outer peripheral side of the inner retaining ring 61. An insertion hole 63 is opened at the end of the inner retaining ring 61 away from the first mounting cylinder 52. An insertion plate 64 is fixedly connected to the inner peripheral side of the inner retaining ring 61 and inserted into the slot 54. Through the cooperation of the insertion plate 64 and the slot 54, the inner retaining ring 61 can be connected to the second mounting cylinder 53 and the first mounting cylinder 52, and the relative rotation between the inner retaining structure 6 and the sleeve 5 will not occur, which facilitates the installation and alignment between the inner retaining structure 6 and the sleeve 5 and improves the speed of installation.

[0041] As a further explanation of the above technical solution, the outer retaining structure 7 includes an outer retaining ring 71, one end of which is fixedly connected to a pin 72. Two oppositely arranged locking grooves 73 are opened on the inner circumferential side of the outer retaining ring 71, and a third keyway 74 is also opened on the inner circumferential side of the outer retaining ring 71. The end of the outer retaining ring 71 on which the pin 72 is installed abuts against the end of the inner retaining ring 61 away from the first mounting cylinder 52 and the outer end face of the second mounting cylinder 53. The pin 72 is inserted into the insertion hole 63. Through the cooperation of the pin 72 and the insertion hole 63, the outer retaining ring 71 and the inner retaining ring 61 can be connected together, and the inner retaining structure 6 and the outer retaining structure 7 will not rotate relative to each other, which facilitates the installation and alignment between the inner retaining structure 6 and the outer retaining structure 7 and further improves the speed of installation.

[0042] Furthermore, a first keyway 25 is formed on the circumferential surface of each of the two shafts 21. The first keyway 25 is arranged along the axial direction of the shaft 21, and a transmission key 9 is engaged in both first keyways 25. A second keyway 55 is formed on the inner wall of the main cylinder 51, the inner wall of the first mounting cylinder 52, and the inner wall of the second mounting cylinder 53. The transmission key 9 is engaged in the second keyway 55 and the third keyway 74. The shaft 21, the main cylinder 51, the first mounting cylinder 52, the second mounting cylinder 53, and the outer retaining ring 71 are connected together by the transmission key 9, ensuring that the sleeve 5 and the outer retaining structure 7 on the shaft 2 will not rotate relative to the shaft 2. This ensures the secure installation and strength of the sleeve 5, the inner retaining structure 6, and the outer retaining structure 7 on the shaft 2, allowing the sleeve 5, the inner retaining structure 6, and the outer retaining structure 7 to rotate with the shaft 2.

[0043] Furthermore, the second permanent magnet ring 11 is fitted onto the first mounting cylinder 52 and abuts against the main cylinder 51 and the inner retaining ring 61; the first permanent magnet ring 10 is fitted onto the inner retaining ring 61 and abuts against the inner retaining ring 62 and the outer retaining ring 71. Through the above, the first permanent magnet ring 10 and the second permanent magnet ring 11 can be installed as a whole, avoiding embedded installation and segmented embedded installation, making installation more convenient, thereby reducing installation strength and improving installation efficiency. At the same time, the first permanent magnet ring 10 and the second permanent magnet ring 11 are limited and fixed by the sleeve 5, the inner retaining structure 6 and the inner and outer retaining structures 7, which can ensure the installation firmness of the first permanent magnet ring 10 and the second permanent magnet ring 11 and prevent axial displacement of the first permanent magnet ring 10 and the second permanent magnet ring 11.

[0044] More specifically, the installation process of the first permanent magnet ring 10 and the second permanent magnet ring 11 is as follows: First, two sleeves 5 are symmetrically fitted onto two shafts 21, with the large ends of the two sleeves 5 facing each other. Then, the two second permanent magnet rings 11 are respectively fitted onto two first mounting cylinders 52 and abut against the circular surface of the main cylinder 51. Then, the two inner retaining structures 6 are respectively fitted onto two first mounting cylinders 52 and abut against the second permanent magnet rings 11. Then, the two first permanent magnet rings 10 are respectively fitted onto two inner retaining rings 61 and abut against the outer side of the inner retaining rings 62. Then, the two outer retaining structures 7 are respectively fitted onto two shafts 21 and abut against the outer side of the first permanent magnet rings 10.

[0045] As a further explanation of the above technical solution, the locking structure 8 includes two locking plates 81 and two locking blocks 82. The two locking plates 81 are slidably disposed in two grooves 23 on the same shaft 21, and the two locking blocks 82 are disposed opposite to each other in guide grooves 24 on the same shaft 21. The two locking blocks 82 are respectively connected to the outer surfaces of the two locking plates 81 and form an inclined transmission structure. The two locking blocks 82 are respectively engaged with two locking grooves 73. A connecting arc rod 83 is fixedly connected between the two locking plates 81. The two connecting arc rods 83 together form a transmission ring, so that the surfaces of the two locking structures 8 that abut against each other are arc surfaces, so that the two locking structures 8 can abut against each other and rotate relative to each other, so that the two locking structures 8 can be pushed to move towards the two outer stop structures 7 by the mutual approach of the two shafts 21. The transmission ring engages with the groove 22. After the locking structure 8 and the outer retaining structure 7 are locked together, the transmission ring is engaged in the groove 22 and will not protrude from the groove 22, allowing the large ends of the two shafts 21 to fit tightly together, ensuring a secure installation. A spring post 84 is fixedly connected between the two locking blocks 82. The spring post 84 connects the two locking blocks 82 together and stretches and accumulates elastic potential energy when the two locking blocks 82 move away from each other. When the two locking blocks 82 need to come together, the elastic potential energy released by the spring post 84 is used to bring them together, making it more convenient to use.

[0046] Furthermore, when the two locking plates 81 slide towards the narrow end of the shaft 21 within the slide groove 23, pushing the two locking blocks 82 to slide to both sides within the guide groove 24, and causing a portion of the two locking blocks 82 to slide into the two locking grooves 73 respectively, the locking structure 8 and the outer stop structure 7 can be locked together, so that the outer stop structure 7 will not rotate relative to the shaft 21 or undergo axial displacement relative to the shaft 21. This allows the outer stop structure 7 to fix the first permanent magnet ring 10, the second permanent magnet ring 11, and the inner stop structure 6 onto the sleeve 5. Simultaneously, through the symmetrical arrangement of the two locking structures 8 on the left and right, the two sleeves 5, the two inner stop structures 6, the two outer stop structures 7, the two first permanent magnet rings 10, and the two second permanent magnet rings 11 can be connected as a whole without misalignment. When a portion of the locking block 82 slides into the locking groove 73, the spring column 84 is stretched.

[0047] It should be further explained that a connecting screw hole 41 is provided in the middle of the large end of one shaft 21, and a connecting stud 4 is fixed in the middle of the large end of the other shaft 21. The connecting stud 4 is threaded to the connecting screw hole 41, which tightly fits the large ends of the two shafts 21 together, which can easily connect and fix the two shafts 21 together. After the two shafts 21 are connected, the sliding grooves 23 on the two shafts 21 are connected. At the same time, by gradually screwing the connecting stud 4 into the connecting screw hole 41, the two locking structures 8 that abut against each other are activated while connecting the two shafts 21, realizing the movement of the locking block 82 towards the locking groove 73. When the large ends of the two shafts 21 abut against each other, a part of the locking block 82 slides into the locking groove 73 and cooperates with the locking groove 73, applying a locking force pointing towards the sleeve 5 to the outer retaining ring 71. Thus, the locking force received by the two outer retaining rings 71 is directed towards the sleeve 5, thereby realizing the pressing from the outside to the inside.

[0048] It should be further noted that the transmission key 9 is installed after the connection between the lock block 82 and the lock groove 73 is completed.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A multi-magnetic-source sleeve-type magnetohydrodynamic sealing device, comprising a shaft, characterized in that: A housing and an end cap are fitted onto the shaft at intervals, with the two outer end faces of the shaft extending to the outer sides of the housing and end cap, respectively. Two sleeves are fitted onto the circumferential side of the shaft, arranged symmetrically from left to right. Each sleeve has an inner and an outer retaining structure, with the two outer retaining structures located outside the two inner retaining structures. A second permanent magnet ring is installed between the sleeves and the inner retaining structures, and a first permanent magnet ring is installed between the outer and inner retaining structures. A third permanent magnet ring, a left pole shoe ring, a right pole shoe ring, an outer magnetic shielding ring, and a bearing are installed on the inner wall of the housing. The third permanent magnet ring is fitted onto the outer sides of the two sleeves at intervals. The left pole shoe ring is fitted onto the outer sides of the first and second permanent magnet rings on the left side. The right pole shoe ring is fitted onto the outer sides of the first and second permanent magnet rings on the right side. The shaft comprises two symmetrically arranged shaft bodies, with their large ends abutting together. The sleeve includes a main sleeve fitted onto the shaft body. The surfaces of the two main sleeves that abut against each other are flush with the surfaces of the two shaft bodies respectively. A first mounting sleeve is fixedly connected to the other end of the main sleeve. A second mounting sleeve is fixedly connected to the other end of the first mounting sleeve. Both the first and second mounting sleeves are fitted onto the shaft body. A slot is provided at the other end of the second mounting sleeve. The slot extends toward the first mounting sleeve and penetrates the end face of the first mounting sleeve. A second keyway is provided on the inner wall of the main sleeve, the inner wall of the first mounting sleeve, and the inner wall of the second mounting sleeve. The inner retaining structure includes an inner retaining ring, which is sleeved on the second mounting cylinder and abuts against the end face of the first mounting cylinder. An inner retaining ring is integrally sleeved on the outer peripheral side of the inner retaining ring. An insertion hole is opened at the end of the inner retaining ring away from the first mounting cylinder. An insertion plate is fixedly connected to the inner peripheral side of the inner retaining ring, and the insertion plate is inserted into the slot. The outer retaining structure includes an outer retaining ring, one end of which is fixedly connected to a pin. Two oppositely arranged locking grooves are formed on the inner circumferential side of the outer retaining ring, and a third keyway is also formed on the inner circumferential side of the outer retaining ring. The end of the outer retaining ring on which the pin is installed abuts against the end of the inner retaining ring away from the first mounting cylinder and the outer end face of the second mounting cylinder. The pin is inserted into the insertion hole.

2. The multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 1, characterized in that: The outer casing is barrel-shaped, and the end cap is installed at the opening of the outer casing; a locking structure is installed on the inner side of the shaft, and two locking structures are provided and arranged symmetrically on the left and right. The two locking structures pass through the outer peripheral side of the shaft and are connected to two outer stop structures respectively. Two outer magnetic isolation rings are provided, each abutting against the outer end face of the left pole shoe ring and the outer end face of the right pole shoe ring, respectively. Inner magnetic isolation rings abut against the outer end faces of both outer baffle structures, and both inner magnetic isolation rings are sleeved on the shaft. Two bearings are also sleeved on the shaft, abutting against the outer end faces of the two outer magnetic isolation rings and the two inner magnetic isolation rings, respectively. Annular grooves are formed on the large ends of both shafts, and two sliding grooves are formed laterally on the groove walls of each groove. A guide groove is formed on one side of the circumferential surface of each shaft, extending radially through the other side of the circumferential surface of the shaft. The guide groove on the same shaft communicates with the two sliding grooves on that shaft. The narrow ends of the two shafts extend to the outer sides of the outer shell and end cap, respectively.

3. The multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 2, characterized in that: A connecting screw hole is provided in the middle of the large end of one of the shafts, and a connecting stud is fixed in the middle of the large end of the other shaft. The connecting stud is threaded to the connecting screw hole to tightly fit the large ends of the two shafts together.

4. The multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 3, characterized in that: A first keyway is formed on the peripheral side surface of both shafts. The first keyway is arranged along the axial direction of the shaft. A transmission key is commonly engaged in both first keyways. The transmission key is engaged in the second keyway and the third keyway.

5. The multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 4, characterized in that: The second permanent magnet ring is fitted onto the first mounting cylinder and abuts against the main cylinder and the inner retaining ring; the first permanent magnet ring is fitted onto the inner retaining ring and abuts against the inner retaining ring and the outer retaining ring.

6. The multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 5, characterized in that: The locking structure includes two locking plates and two locking blocks. The two locking plates are slidably disposed in two grooves on the same shaft, and the two locking blocks are disposed opposite each other in guide grooves on the same shaft. The two locking blocks are respectively connected to the outer surfaces of the two locking plates and form an inclined transmission structure. The two locking blocks are respectively engaged with two locking grooves. A connecting arc rod is fixedly connected between the two locking plates, and the two connecting arc rods together form a transmission ring, which engages with the groove. A spring column is fixedly connected between the two locking blocks.

7. A multi-magnetic-source sleeve-type magnetohydrodynamic sealing device according to claim 6, characterized in that: As the two locking plates slide toward the narrow end of the shaft within the slide groove, they push the two locking blocks to slide to both sides within the guide groove.

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