A multi-pole recessed tooth type magnetic fluid sealing device

Abstract

This invention aims to provide a multi-pole grooved toothed magnetohydrodynamic sealing device, comprising a housing, a stepped shaft, a left pole shoe ring, a right pole shoe ring, and permanent magnet rings. The stepped shaft is located on a rotating shaft and is coaxially arranged with the rotating shaft. The stepped shaft includes a middle step with the largest diameter and a set of secondary steps with successively decreasing diameters. The left and right pole shoe rings are installed on the inner circular surface of the housing by an interference fit, and the inner circular surfaces of the left and right pole shoe rings correspond to the outer circular surfaces of the first secondary steps on both sides of the middle step, respectively. The left and right pole shoe rings are provided with pole teeth A, B, and C, which cooperate with the stepped shaft to achieve magnetohydrodynamic sealing. Multiple sets of permanent magnet rings are arranged between the outer side of the right end face of the left pole shoe ring and the left end face of the right pole shoe ring. The permanent magnet rings are stacked radially, and a gap is left between the stacked permanent magnet rings and the outer circular surface of the middle step and the inner circular surface of the housing. The sealing device of this invention has significant advantages in high-speed sealing.

Description

Technical Field

[0001] This invention relates to the field of mechanical engineering sealing technology, and in particular to a multi-pole groove toothed magnetohydrodynamic sealing device. Background Technology

[0002] Magnetofluidic sealing devices utilize the unique response of magnetofluids to magnetic fields. Under the influence of a strong magnetic field, the magnetofluid forms a multi-layered sealing liquid film, thereby isolating the pressure difference across the device. Recent research has shown that creating radial sealing channels can reduce magnetic leakage and fully utilize magnetic energy. However, in high-speed rotating operating environments, the magnetofluid in radial sealing channels is prone to sealing failure under the influence of centrifugal force, making it difficult to achieve stable sealing standards.

[0003] In the prior art, the sealing devices in Document 1 (Publication No. CN107620799B) and Document 2 (Publication No. CN108061163B) are as follows: Document 1 provides a magnetofluid sealing structure for high vacuum. This structure is symmetrical, with a secondary shaft and stepped pole shoes, and pole teeth designed on the secondary shaft, with a permanent magnet ring located in the middle. This structure can fully utilize the difference between the magnetic force and magnetic flux density generated by the permanent magnet ring. However, the magnetic energy generated by the permanent magnet ring in this structure is limited, making it difficult to fix the magnetofluid in the radial sealing channel when the shaft rotates at high speed, especially under pressure, the reliability drops sharply. In addition, this structure, due to the multiple steps in the sealing channel, forces an axial length increase, which is not conducive to saving axial space. Document 2 provides a stepped magnetofluid sealing structure, which has multiple pole shoes and a permanent magnet ring, and also has a secondary stepped shaft. Under high-speed rotation of the shaft, the multiple permanent magnet rings can generate a stronger magnetic force to fix the magnetofluid, improving the sealing reliability. While this structure utilizes multiple annular permanent magnets to improve sealing pressure resistance, this method also occupies a significant amount of axial space. Furthermore, under the influence of centrifugal force and pressure, the magnetohydrodynamic fluid is also difficult to stably fix at the pole tooth position, making it unsuitable for high-speed rotating seals.

[0004] Current research suggests two approaches to improving sealing pressure resistance: one is to increase the number of steps to form multiple stepped surfaces, fully utilizing these surfaces to set the pole teeth; the other is to increase the number of annular permanent magnets axially, thereby increasing the number of pole shoes and thus the number of pole teeth. However, both methods consume a significant amount of axial space in the device, making it impossible to achieve the desired sealing effect using the existing axial space. Furthermore, when the magnetic fluid in the radial sealing channel is subjected to centrifugal force during high-speed rotation of the shaft, it is difficult to fix it at the position of the rectangular pole teeth, leading to seal failure. Summary of the Invention

[0005] In view of the technical problems existing in the background art, the present invention aims to provide a multi-pole groove toothed magnetohydrodynamic sealing device. The sealing device has a scientific structural design, occupies less space, has great advantages in high-speed sealing, and enhances the reliability in actual working conditions.

[0006] To solve the above problems, the technical solution of the present invention is as follows: The multi-pole groove toothed magnetohydrodynamic sealing device includes a housing, a stepped shaft, a left pole shoe ring, a right pole shoe ring, and a permanent magnet ring; The stepped axis is located on the rotating shaft and is coaxial with the rotating shaft; the stepped axis includes a middle step with the largest diameter and a group of more than one set of secondary steps with successively decreasing diameters. The secondary steps are arranged sequentially to both sides along the side of the middle step, and are symmetrical about left and right with the middle step as the dividing line. The left and right pole shoe rings are installed on the inner circular surface of the housing by interference fit. The inner circular surfaces of the left and right pole shoe rings correspond to the outer circular surfaces of the first-level steps on both sides of the middle step. The inner circular surfaces of the left and right pole shoe rings are provided with multiple sets of pole teeth A. The pole teeth A extend radially toward the outer circular surface of the first-level step and leave a gap with the outer circular surface. The gap is filled with magnetic fluid. The inner sides of the right end face of the left pole shoe ring and the left end face of the right pole shoe ring correspond to the left and right end faces of the intermediate step, respectively. Multiple sets of annular grooves are evenly spaced on the left and right end faces of the intermediate step. Multiple sets of pole teeth B are respectively provided on the right end face of the left pole shoe ring and the left end face of the right pole shoe ring at the corresponding annular groove positions. The pole teeth B extend axially towards the end face of the intermediate step, leaving a gap between them. The end face of the pole teeth B completely covers its corresponding annular groove area, and the width of the pole teeth B is greater than the width of the annular groove. A set of pole teeth C is provided in the middle of the end face of each set of pole teeth B. The pole teeth C extend into the annular groove, with gaps between their end face and upper and lower side faces and the bottom and side faces of the annular groove, respectively. The pole teeth B, pole teeth C, and their corresponding left and right end faces of the intermediate step and the annular groove are all filled with magnetofluid. Multiple sets of permanent magnet rings are provided between the right end face of the left pole shoe ring and the outer side of the left end face of the right pole shoe ring. The permanent magnet rings are stacked on each other radially, and there is a gap between the stacked permanent magnet rings and the outer circular surface of the intermediate step and the inner circular surface of the shell.

[0007] The left and right pole shoe rings are interference-fitted onto the inner circular surface of the housing.

[0008] The axial length of each group of permanent magnet rings decreases sequentially from the outside to the inside. The right end face of the left pole shoe ring and the outer side of the left end face of the right pole shoe ring are respectively provided with continuous stepped structures corresponding to each group of permanent magnet rings. Each group of permanent magnet rings is an axially magnetized permanent magnet with the same magnetic field line direction.

[0009] The secondary staircase has two levels: a first-level staircase and a second-level staircase located outside the first-level staircase.

[0010] The inner circular surface of the shell is divided into a first stepped ring and a second stepped ring; the inner circular surface of the second stepped ring corresponds to the left side of the second step and the left side of the first step; the inner circular surface of the first stepped ring corresponds to the range from the right side of the first step to the right side of the second step.

[0011] The inner circular surface of the second step ring is fitted with a left deep groove ball bearing through an transition fit, and the inner ring of the left deep groove ball bearing is fitted onto the second step through an transition fit. The left and right pole shoe rings are both installed on the inner circular surface of the first stepped ring, and the left end of the left pole shoe ring is in contact with the right end face of the second stepped ring. The left end of the housing is closed by a left end plate, and the right end is an open structure. The right end of the inner circular surface of the first stepped ring is fitted with a right end cover by a threaded connection. The second step at the right end protrudes beyond the right end cover, and the second step at the left end protrudes beyond the left end plate. Both of these are clearance fits. A right sleeve is provided between the right end cap and the right pole shoe ring; the outer circular surface of the right sleeve is fitted onto the inner circular surface of the first stepped ring through a transition fit, and fits against the right end face of the right pole shoe ring, with a gap between the inner circular surface of the right sleeve and the outer circular surface of the stepped shaft.

[0012] The inner ring of the right deep groove ball bearing is installed on the second-stage step on the right end through an transition fit, and the outer ring of the right deep groove ball bearing is installed on the inner circular surface of the right sleeve through an transition fit. A retaining ring is provided on the left end of the inner circular surface of the right sleeve. The retaining ring is in close contact with the left end of the right deep groove ball bearing, and its height is equal to or less than the thickness of the outer ring of the right deep groove ball bearing. The left end face of the right end cover is provided with a protruding ring at the corresponding position of the retaining ring. The protruding ring is close to the right end of the right deep groove ball bearing. Neither the left end face of the right end cover nor the protruding ring contacts the right sleeve.

[0013] The second stepped ring has a left sleeve on the right side of its inner circular surface. The two ends of the left sleeve are respectively attached to the left deep groove ball bearing and the left pole shoe ring. There is a distance between the left sleeve and the stepped shaft.

[0014] The outer surfaces of the left and right pole shoe rings are respectively provided with sealing ring grooves, and sealing rings are provided in the sealing ring grooves.

[0015] The beneficial effects of this invention are as follows: This invention proposes a multi-pole grooved toothed sealing structure. This structure employs a radially layered, progressively expanding method for stacking the magnetic source. This approach enhances magnetic energy by increasing the number of radially arranged annular permanent magnets. Compared to increasing the number of steps or axially increasing the number of annular permanent magnets, this method directly increases the magnetic energy at a single pole tooth position, improving the ability of a single pole tooth to fix the magnetofluid. Simultaneously, it reduces the axial space occupied by increasing the radial axial diameter slightly. Furthermore, the progressively expanding and stacking of three permanent magnet rings allows for full utilization of the pole shoe space compared to a single permanent magnet ring of the same volume. When a single annular permanent magnet with a rectangular axial cross-section acts as the magnetic source, the magnetic lines of force generated at the lower end of the magnet cannot fully occupy the cross-sectional space of the pole shoe, while leakage magnetic field occurs at the upper end. This structure, utilizing progressive expansion, prevents leakage magnetic field at the uppermost end of the cross-section due to the repulsion between like poles of the lower permanent magnets. The uppermost permanent magnet, due to its width, also ensures that a large number of magnetic lines of force are distributed only at the bottom. This method fully utilizes the volume of the pole shoe and improves magnetic field utilization.

[0016] This invention also designs an axial combination of pole teeth B and C, forming a grooved tooth sealing structure. Pole tooth C is embedded inside an annular groove, increasing the meandering nature of the sealing gap. At high speeds, the magnetofluid on traditional axial rectangular pole teeth tends to deviate away from the axis due to centrifugal force. However, the grooved tooth sealing structure can actively resist the centrifugal force by utilizing the meandering inner wall of the tooth groove, thus preserving more sealing performance for the magnetofluid inside the radial sealing gap. Therefore, this invention has significant advantages at high speeds, enhancing reliability during actual operation. Attached Figure Description

[0017] The following description, in conjunction with the accompanying drawings, details the embodiments and working process of the present invention.

[0018] Figure 1 This is a schematic diagram of the structure of the multi-pole groove toothed magnetohydrodynamic sealing device in Example 1; Figure 2 This is a schematic diagram of the mating structure of the pole tooth AC, the stepped shaft, and the annular groove in Example 1; Figure 3 This is a comparative schematic diagram of the prior art and the grooved tooth sealing structure of the present invention at high speeds; in the figure, a is the magnetohydrodynamic state on the axial pole teeth of the prior art at high speeds; b is the magnetohydrodynamic state on the axial grooved tooth sealing structure of the present invention at high speeds.

[0019] The names and numbers of the parts in the diagram are as follows: 1-Housing, 2-Left pole shoe ring, 3-Right pole shoe ring, 4-Permanent magnet ring, 5-Rotating shaft, 6-Intermediate step, 7-First stage step, 8-Pole tooth A, 9-Annular groove, 10-Pole tooth B, 11-Pole tooth C, 12-Step structure, 13-Second stage step, 14-First stage ring, 15-Second stage ring, 16-Left deep groove ball bearing, 17-Left end plate, 18-Right end cover, 19-Right sleeve, 20-Retaining ring, 21-Right deep groove ball bearing, 22-Convex ring, 23-Left sleeve, 24-Sealing ring. Detailed Implementation

[0020] like Figures 1-2 The multi-pole groove toothed magnetohydrodynamic sealing device described in this embodiment includes a housing 1, a stepped shaft, a left pole shoe ring 2, a right pole shoe ring 3, and a permanent magnet ring 4. The stepped axis is located on the rotating shaft 5 and is coaxial with the rotating shaft 5; the stepped axis includes the middle step 6 with the largest diameter and two sets of secondary steps with successively decreasing diameters, namely the first-level step 7 and the second-level step 13 located outside the first-level step 7; the secondary steps are arranged sequentially to both sides along the side of the middle step 6, and are symmetrical about left and right with the middle step 6 as the dividing line. The left pole shoe ring 2 and the right pole shoe ring 3 are installed on the inner circular surface of the housing 1 by interference fit. The inner circular surfaces of the left pole shoe ring 2 and the right pole shoe ring 3 correspond to the outer circular surfaces of the first-stage steps 7 on both sides of the intermediate step 6. The inner circular surfaces of the left pole shoe ring 2 and the right pole shoe ring 3 are provided with multiple sets of pole teeth A8. The pole teeth A8 extend radially toward the outer circular surface of the first-stage step 7, and there is a gap between them and the outer circular surface. The gap is filled with magnetic fluid. The inner sides of the right end face of the left pole shoe ring 2 and the left end face of the right pole shoe ring 3 correspond to the left and right end faces of the intermediate step 6, respectively. Multiple sets of annular grooves 9 are evenly spaced on the left and right end faces of the intermediate step 6. Multiple sets of pole teeth B10 are respectively provided on the right end face of the left pole shoe ring 2 and the left end face of the right pole shoe ring 3 at the positions corresponding to the annular grooves 9. The pole teeth B10 extend axially towards the end face of the intermediate step 6, leaving a gap between them. The end face of the pole teeth B10 completely covers the area of ​​its corresponding annular groove 9, and the width of the pole teeth B10 is greater than the width of the annular groove 9. A set of pole teeth C11 is provided in the middle of the end face of each set of pole teeth B10. The pole teeth C11 extend into the annular groove 9, and their end face and upper and lower side faces leave gaps with the bottom and side faces of the annular groove 9, respectively. The pole teeth B10, pole teeth C11, and their corresponding left and right end faces of the intermediate step 6 and the annular groove 9 are all filled with magnetofluid. Multiple sets of permanent magnet rings 4 are provided between the right end face of the left pole shoe ring 2 and the outer side of the left end face of the right pole shoe ring 3. The permanent magnet rings 4 are stacked on each other radially, and there is a gap between the stacked permanent magnet rings 4 and the outer circular surface of the intermediate step 6 and the inner circular surface of the shell 1.

[0021] The left pole shoe ring 2 and the right pole shoe ring 3 are interference-fitted onto the inner circular surface of the housing 1.

[0022] The axial length of each group of permanent magnet rings 4 decreases sequentially from the outside to the inside. The right end face of the left pole shoe ring 2 and the outer side of the left end face of the right pole shoe ring 3 are respectively provided with continuous stepped structures 12 corresponding to each group of permanent magnet rings 4. Each group of permanent magnet rings 4 are axially magnetized permanent magnets with the same magnetic field line direction.

[0023] The inner circular surface of the shell 1 is divided into a first stepped ring 14 and a second stepped ring 15; the inner circular surface of the second stepped ring 15 corresponds to the left side of the second step 13 and the left side of the first step 7; the inner circular surface of the first stepped ring 14 corresponds to the range from the right side of the first step 7 to the right side of the second step 13.

[0024] The inner surface of the second step ring 15 is fitted with a left deep groove ball bearing 16 through a transition fit, and the inner ring of the left deep groove ball bearing 16 is fitted on the second step 13 through a transition fit. The left pole shoe ring 2 and the right pole shoe ring 3 are both installed on the inner circular surface of the first stepped ring 14, and the left end of the left pole shoe ring 2 is in contact with the right end face of the second stepped ring 15. The left end of the housing 1 is closed by a left end plate 17, and the right end is an open structure. The right end of the inner circle of the first stepped ring 14 is fitted with a right end cover 18 by a threaded fit. The second step 13 on the right end protrudes out of the right end cover 18, and the second step 13 on the left end protrudes out of the left end plate 17. Both of these are clearance fits. A right sleeve 19 is provided between the right end cap 18 and the right pole shoe ring 3; the outer circular surface of the right sleeve 19 is fitted onto the inner circular surface of the first stepped ring 14 through a transition fit, and is in contact with the right end face of the right pole shoe ring 3, with a gap between the inner circular surface of the right sleeve 19 and the outer circular surface of the stepped shaft.

[0025] The inner ring of the right deep groove ball bearing 21 is installed on the second-stage step 13 at the right end through an transition fit, and the outer ring of the right deep groove ball bearing 21 is installed on the inner circular surface of the right sleeve 19 through an transition fit. A retaining ring 20 is provided on the left end of the inner circular surface of the right sleeve 19. The retaining ring 20 is in close contact with the left end of the right deep groove ball bearing 21, and its height is equal to or less than the thickness of the outer ring of the right deep groove ball bearing 21. The left end face of the right end cover 18 is provided with a protruding ring 22 corresponding to the position of the retaining ring 20. The protruding ring 22 is close to the right end of the right deep groove ball bearing 21. Neither the left end face of the right end cover 18 nor the protruding ring 22 is in contact with the right sleeve 19.

[0026] The second stepped ring 15 has a left sleeve 23 on the right side of its inner circular surface. The two ends of the left sleeve 23 are respectively attached to the left deep groove ball bearing 16 and the left pole shoe ring 2. There is a distance between the left sleeve 23 and the stepped shaft.

[0027] The outer surfaces of the left pole shoe ring 2 and the right pole shoe ring 3 are respectively provided with sealing ring grooves, and sealing rings 24 are provided in the sealing ring grooves.

[0028] The working principle of this invention is as follows: When the sealing device of the present invention is in operation, a sealing structure is formed between the outer circular surfaces of the left and right pole shoes and the inner wall of the housing, which, together with the magnetohydrodynamic seal formed between the pole teeth A8 and the first-stage step 7, constitutes an axial sealing structure; and, as Figure 3 As shown in Figure b, a magnetohydrodynamic (MHD) sealing structure is formed between the pole teeth B10 and C11 and the annular groove 9. This structure actively resists centrifugal force based on the meandering inner wall of the groove, thereby preserving more sealing performance for the MHD within the radial sealing gap. Figure 3 As shown in Figure a, the magnetohydrodynamic fluid on the conventional axial rectangular pole teeth in the prior art will deviate away from the axis under the action of centrifugal force, and in severe cases, magnetic leakage will occur.

Claims

1. A multi-pole grooved toothed magnetohydrodynamic sealing device, comprising a housing (1), a stepped shaft, a left pole shoe ring (2), a right pole shoe ring (3), and a permanent magnet ring (4), characterized in that: The stepped shaft is located on the rotating shaft (5) and is coaxial with the rotating shaft (5); the stepped shaft includes the largest diameter intermediate step (6) and a group of more than one set of secondary steps with successively decreasing diameters. The secondary steps are arranged sequentially on both sides along the side of the intermediate step (6) and are symmetrical about left and right with the intermediate step (6) as the dividing line. The left pole shoe ring (2) and the right pole shoe ring (3) are installed on the inner circular surface of the housing (1) by interference fit. The inner circular surfaces of the left pole shoe ring (2) and the right pole shoe ring (3) correspond to the outer circular surfaces of the first-level steps (7) on both sides of the middle step (6). The inner circular surfaces of the left pole shoe ring (2) and the right pole shoe ring (3) are provided with multiple sets of pole teeth A (8). The pole teeth A (8) extend radially toward the outer circular surface of the first-level step (7) and leave a gap between them. The gap is filled with magnetic fluid. The inner sides of the right end face of the left pole shoe ring (2) and the left end face of the right pole shoe ring (3) correspond to the left and right end faces of the intermediate step (6), respectively. Multiple sets of annular grooves (9) are evenly spaced on the left and right end faces of the intermediate step (6). Multiple sets of pole teeth B (10) are provided on the right end face of the left pole shoe ring (2) and the left end face of the right pole shoe ring (3) corresponding to the positions of the annular grooves (9), respectively. The pole teeth B (10) extend axially toward the end face of the intermediate step (6) and leave a gap between them. The end face of the pole tooth B (10) is completely covered by the corresponding annular groove (9) area. The width of the pole tooth B (10) is greater than the width of the annular groove (9). Each set of pole teeth B (10) has a set of pole teeth C (11) in the middle of its end face. The pole teeth C (11) extend into the annular groove (9). Its end face and upper and lower side faces are respectively separated from the bottom and side faces of the annular groove (9). The left and right end faces of the pole teeth B (10), pole teeth C (11) and their corresponding intermediate steps (6) and the annular groove (9) are filled with magnetic fluid. Multiple sets of permanent magnet rings (4) are provided between the right end face of the left pole shoe ring (2) and the outer side of the left end face of the right pole shoe ring (3). The permanent magnet rings (4) are stacked together radially. There is a gap between the outer circular surface of the stacked permanent magnet rings (4) and the middle step (6) and the inner circular surface of the shell (1).

2. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 1, characterized in that: The left pole shoe ring (2) and the right pole shoe ring (3) are interference-fitted onto the inner circular surface of the housing (1).

3. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 1, characterized in that: The axial length of each group of permanent magnet rings (4) decreases sequentially from the outside to the inside. The right end face of the left pole shoe ring (2) and the outer side of the left end face of the right pole shoe ring (3) are respectively provided with a continuous stepped structure (12) corresponding to each group of permanent magnet rings (4). Each group of permanent magnet rings (4) are axially magnetized permanent magnets with the same magnetic field line direction.

4. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 1, characterized in that: The secondary staircase has two levels: the first level staircase (7) and the second level staircase (13) located outside the first level staircase (7).

5. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 4, characterized in that: The inner circular surface of the shell (1) is divided into a first step ring (14) and a second step ring (15); the inner circular surface of the second step ring (15) corresponds to the left side of the second step (13) and the left side of the first step (7); the inner circular surface of the first step ring (14) corresponds to the range from the right side of the first step (7) to the right side of the second step (13).

6. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 5, characterized in that: The inner surface of the second step ring (15) is fitted with a left deep groove ball bearing (16) through a transition fit, and the inner ring of the left deep groove ball bearing (16) is fitted on the second step (13) through a transition fit. The left pole shoe ring (2) and the right pole shoe ring (3) are both installed on the inner circular surface of the first stepped ring (14), and the left end of the left pole shoe ring (2) is in contact with the right end face of the second stepped ring (15). The left end of the housing (1) is closed by a left end plate (17), and the right end is an open structure. The right end of the inner circle of the first stepped ring (14) is fitted with a right end cover (18) by a threaded fit. The second step (13) on the right end protrudes out of the right end cover (18), and the second step (13) on the left end protrudes out of the left end plate (17). Both of these are clearance fits. A right sleeve (19) is provided between the right end cap (18) and the right pole shoe ring (3); the outer circular surface of the right sleeve (19) is fitted onto the inner circular surface of the first stepped ring (14) through a transition fit, and is in contact with the right end face of the right pole shoe ring (3), with a gap between the inner circular surface of the right sleeve (19) and the outer circular surface of the stepped shaft.

7. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 6, characterized in that: The inner ring of the right deep groove ball bearing (21) is installed on the second step (13) at the right end through an transition fit, and the outer ring of the right deep groove ball bearing (21) is installed on the inner circular surface of the right sleeve (19) through an transition fit. A retaining ring (20) is provided on the left end of the inner circular surface of the right sleeve (19). The retaining ring (20) is close to the left end of the right deep groove ball bearing (21), and its height is equal to or less than the thickness of the outer ring of the right deep groove ball bearing (21). The left end face of the right end cover (18) is provided with a protruding ring (22) corresponding to the position of the retaining ring (20). The protruding ring (22) is close to the right end of the right deep groove ball bearing (21). Neither the left end face of the right end cover (18) nor the protruding ring (22) is in contact with the right sleeve (19).

8. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 6, characterized in that: The second stepped ring (15) has a left sleeve (23) on the right side of its inner circular surface. The two ends of the left sleeve (23) are respectively attached to the left deep groove ball bearing (16) and the left pole shoe ring (2); there is a distance between the left sleeve (23) and the stepped shaft.

9. The multi-pole groove toothed magnetohydrodynamic sealing device as described in claim 1, characterized in that: The outer circular surfaces of the left pole shoe ring (2) and the right pole shoe ring (3) are respectively provided with sealing ring grooves, and sealing rings (24) are provided in the sealing ring grooves.

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