Magnetic powder sealing device and assembly method thereof

Abstract

The present invention discloses a magnetic powder sealing device and an assembly method thereof. The magnetic powder sealing device includes a rotating shaft, a housing, and a pole shoe. The housing is mounted on the rotating shaft and is rotatable relative to the rotating shaft. The inner wall of the housing and the outer side surface of the rotating shaft form a mounting cavity. The pole shoe includes a seat body and multiple pole tooth groups spaced apart along the axial direction of the rotating shaft. The seat body is inserted into the mounting cavity and connected to the housing. The seat body has multiple threaded holes arranged circumferentially along the rotating shaft. At least one pole tooth group is a first pole tooth group, which includes multiple first pole teeth. A first sealing gap for filling magnetic powder is formed between the first pole teeth and the rotating shaft. The size of the first pole teeth in the axial direction of the rotating shaft gradually decreases from the outside to the inside along the radial direction of the rotating shaft. The magnetic powder sealing device of the embodiment of the present invention can improve the density of magnetic powder filling in the first sealing gap and reduce the leakage rate of the magnetic powder sealing device.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing devices, and in particular to a magnetic powder sealing device and an assembling method thereof. Background Art

[0002] A magnetic powder seal utilizes the properties of magnetic materials and magnetic fields to achieve a seal. It is a non-contact seal with advantages such as zero friction and wear, a long service life, and low maintenance costs. The magnetic powder seal comprises a rotating shaft, pole shoes, and magnets. The pole shoes include pole teeth, which form a sealed gap between the pole teeth and the rotating shaft for filling with magnetic powder. Under the influence of a magnetic field, the pole shoes and the rotating shaft form a magnetic circuit, magnetizing the magnetic powder in the sealed gap. The magnetized magnetic powder forms a structure similar to "magnetic chains" under the influence of the magnetic field. These chains are tightly arranged and fill the sealed gap, thereby preventing media such as gas or liquid from leaking through the gap and achieving the desired seal.

[0003] In the related technology, the pole teeth are rectangular. Due to the large gradient of magnetic induction intensity at the tip of the pole teeth, magnetic powder easily adheres to the two tip positions of the pole teeth, resulting in a small amount of magnetic powder filling in the gap between the two tips, loose magnetic powder filling and insufficient density. As the working time of the magnetic powder sealing device increases, the magnetic powder in the sealing gap becomes less and less, resulting in an increase in the leakage rate. Summary of the Invention

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

[0005] To this end, an embodiment of the present invention provides a magnetic powder sealing device, which can improve the density of magnetic powder filling in the first sealing gap and reduce the leakage rate of the magnetic powder sealing device.

[0006] The magnetic powder sealing device of an embodiment of the present invention includes a rotating shaft, a shell and a pole shoe; the shell is mounted on the rotating shaft and is rotatable relative to the rotating shaft, and the inner wall of the shell and the outer side surface of the rotating shaft form a mounting cavity; the pole shoe includes a seat body and a plurality of pole tooth groups arranged at intervals along the axial direction of the rotating shaft, the seat body is inserted into the mounting cavity and connected to the shell, and the seat body has a plurality of threaded holes arranged along the circumference of the rotating shaft; at least one of the pole tooth groups is a first pole tooth group, the first pole tooth group includes a plurality of first pole teeth, and a first sealing gap for filling magnetic powder is formed between the first pole teeth and the rotating shaft, and the size of the first pole teeth in the axial direction of the rotating shaft gradually decreases from the outside to the inside along the radial direction of the rotating shaft.

[0007] In some embodiments, the first pole tooth has a first side surface and a second side surface arranged opposite to each other along the axial direction of the rotating shaft, the first side surface and the second side surface are both planes, the first side surface is arranged inclined from outside to inside along the radial direction of the rotating shaft; and / or the second side surface is arranged inclined from outside to inside along the radial direction of the rotating shaft.

[0008] In some embodiments, at least one of the pole tooth groups is a second pole tooth group, the second pole tooth group includes a plurality of second pole teeth, and the size of the second pole teeth in the axial direction of the rotating shaft remains unchanged from outside to inside along the radial direction of the rotating shaft.

[0009] In some embodiments, the first pole tooth group and the second pole tooth group are alternately arranged in sequence along the axial direction of the rotating shaft.

[0010] In some embodiments, the outer side surface of the seat body has a groove, the groove and the pole tooth group are arranged alternately along the axial direction of the rotating shaft, and a magnet is provided in the groove; the groove has a groove bottom wall, and the wall thickness of the groove bottom wall is 0.8mm to 1.2mm.

[0011] In some embodiments, the outer shell includes a shell portion, a first connecting portion and a second connecting portion, the first connecting portion and the second connecting portion are respectively arranged at both ends of the shell portion and are both connected to the shell portion, and the inner wall of the shell portion and the outer side surface of the rotating shaft form the installation cavity; the magnetic powder sealing device also includes a first end cover and a second end cover, the first end cover and the second end cover are arranged relatively at the two ends of the outer shell, the first end cover is connected to the first connecting portion, and the second end cover is connected to the second connecting portion.

[0012] In some embodiments, the seat body includes a sleeve portion and a flange portion that are connected to each other, the sleeve portion has an inner hole, the rotating shaft has a first end face, the rotating shaft is passed through the inner hole and the first end face is located in the inner hole, the first end face is arranged toward the first end cover, the first connecting portion, the flange portion and the first end cover are arranged in sequence along the axial direction of the rotating shaft, the flange portion is connected to the first connecting portion, and the first end cover is connected to the flange portion.

[0013] In some embodiments, the first end cover has a plurality of bolt holes uniformly distributed along the circumference of the rotating shaft, and the plurality of threaded holes are arranged on the flange portion and uniformly distributed along the circumference of the flange portion. The bolt holes correspond to the threaded holes one by one and are coaxially arranged to connect the first end cover to the flange portion through a bolt assembly.

[0014] In some embodiments, the magnetic powder sealing device further includes a bearing, the inner wall of the housing has a limiting protrusion, the bearing is arranged between the limiting protrusion and the second end cover, and respectively stops at the limiting protrusion and the second end cover.

[0015] The magnetic powder sealing device assembly method of the embodiment of the present invention is applicable to assembling the magnetic powder sealing device described in any of the above embodiments, and the magnetic powder sealing device assembly method includes the following steps:

[0016] Sleeve the housing onto the rotating shaft to form the mounting cavity;

[0017] Installing mounting bolts into the plurality of threaded holes of the seat body;

[0018] Placing the pole shoe with the mounting bolts installed on one end of the housing, aligning the seat with the mounting cavity and with the mounting bolts abutting against the end surface of the housing;

[0019] Rotating the mounting bolts to slowly insert the pole shoe into the mounting cavity to form a sealed gap between the pole tooth assembly and the rotating shaft;

[0020] While the pole shoe is slowly inserted into the installation cavity, magnetic powder is filled into the sealing gap in batches.

[0021] In the magnetic powder sealing device of the embodiment of the present invention, sealing gaps for filling magnetic powder are formed between the multiple pole tooth groups and the rotating shaft. For example, a first sealing gap is formed between the first pole tooth and the rotating shaft. Since the width of the first pole tooth gradually decreases from the outside to the inside along the radial direction of the rotating shaft (the width of the first pole tooth refers to the size of the first pole tooth in the axial direction of the rotating shaft), the distance between the two tips of the first pole tooth is small, which can weaken the phenomenon that the amount of magnetic powder filling in the sealing gap is small due to the large induction intensity gradient at the pole tooth tip. In other words, even if magnetic powder adheres to the two tip positions of the first pole tooth, it will not cause the filling amount of the first sealing gap to become smaller, thereby improving the density of the magnetic powder filling in the first sealing gap and reducing the leakage rate of the magnetic powder sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a magnetic powder sealing device according to an embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Enlarged schematic diagram of point A in the middle.

[0024] Figure 3 The figure is a schematic diagram of the assembly process of the pole shoe of the magnetic powder sealing device according to one embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of the assembled pole piece of the magnetic powder sealing device according to one embodiment of the present invention.

[0026] Figure 5 yes Figure 1 Enlarged schematic diagram of point B in the middle.

[0027] Figure 6 Schematic diagram of the distribution of magnets in a magnetic powder sealing device according to an embodiment of the present invention.

[0028] Reference numerals:

[0029] 100. Magnetic powder sealing device;

[0030] 1. Rotating shaft; 11. First end surface;

[0031] 2. Outer shell; 21. Shell portion; 22. First connecting portion; 23. Second connecting portion; 24. Position limiting protrusion;

[0032] 3. Pole shoe; 31. Base; 311. Bushing; 3111. Groove; 3112. Groove bottom wall; 312. Flange; 3121. Threaded hole; 32. First pole tooth group; 321. First pole tooth; 3211. First side surface; 3212. Second side surface; 33. Second pole tooth group; 331. Second pole tooth;

[0033] 4. Magnetic powder;

[0034] 5. Install the bolts;

[0035] 6. Magnet;

[0036] 71, first end cover; 711, first boss; 712, bolt hole; 72, second end cover; 721, second boss;

[0037] 8. Sealing ring;

[0038] 9. Bearing; 91. Circlip. DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention in detail. Figure 1-6 The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0040] like Figure 1 and Figure 2As shown, the magnetic powder sealing device 100 of the embodiment of the present invention includes a rotating shaft 1, a shell 2 and a pole shoe 3; the shell 2 is mounted on the rotating shaft 1 and is rotatable relative to the rotating shaft 1, and the inner wall of the shell 2 and the outer side surface of the rotating shaft 1 form a mounting cavity; the pole shoe 3 includes a seat body 31 and a plurality of pole tooth groups arranged at intervals along the axial direction of the rotating shaft 1, the seat body 31 is inserted into the mounting cavity and connected to the shell 2, and the seat body 31 has a plurality of threaded holes 3121 arranged along the circumference of the rotating shaft 1; at least one pole tooth group is a first pole tooth group 32, the first pole tooth group 32 includes a plurality of first pole teeth 321, and a first sealing gap for filling magnetic powder 4 is formed between the first pole teeth 321 and the rotating shaft 1, and the size of the first pole teeth 321 in the axial direction of the rotating shaft 1 gradually decreases from the outside to the inside along the radial direction of the rotating shaft 1.

[0041] In the magnetic powder sealing device 100 of the embodiment of the present invention, sealing gaps for filling magnetic powder 4 are formed between the multiple pole tooth groups and the rotating shaft 1. For example, a first sealing gap is formed between the first pole tooth 321 and the rotating shaft 1. Since the width of the first pole tooth 321 gradually decreases from the outside to the inside along the radial direction of the rotating shaft 1 (the width of the first pole tooth 321 refers to the size of the first pole tooth 321 in the axial direction of the rotating shaft 1), the distance between the two tips of the first pole tooth 321 is small, which can weaken the phenomenon that the amount of magnetic powder 4 filling in the sealing gap is small due to the large induction intensity gradient at the pole tooth tip. In other words, even if the magnetic powder 4 adheres to the two tip positions of the first pole tooth 321, it will not cause the filling amount of the first sealing gap to become smaller, thereby improving the density of the magnetic powder 4 filling in the first sealing gap and reducing the leakage rate of the magnetic powder sealing device 100.

[0042] In addition, by providing the threaded hole 3121 on the seat body 31 , the pole shoe 3 of the magnetic powder sealing device 100 can be assembled and disassembled by using a bolt assembly and disassembly method.

[0043] Specifically, if Figure 3 As shown, when assembling the magnetic powder sealing device 100, the shell 2 is first mounted on the rotating shaft 1 to form the above-mentioned mounting cavity; then the mounting bolts 5 are installed in the multiple threaded holes 3121 of the seat body 31, and the pole shoe 3 equipped with the mounting bolts 5 is placed on one end of the shell 2, and the seat body 31 is aligned with the mounting cavity and the mounting bolts 5 are stopped at the end face of the shell 2; the mounting bolts 5 are rotated so that the pole shoe 3 is slowly and smoothly inserted into the mounting cavity to form a sealing gap between the pole tooth group and the rotating shaft 1 (for example, a first sealing gap is formed between the first pole tooth 321 and the rotating shaft 1), and while the pole shoe 3 is inserted into the mounting cavity, the sealing gap is filled with magnetic powder 4 in batches; after the pole shoe 3 is fully inserted into the mounting cavity, the mounting bolts 5 are removed.

[0044] Similarly, if Figure 4As shown, when disassembling the pole shoe 3, the mounting bolts 5 are installed in the multiple threaded holes 3121 of the seat body 31, and the mounting bolts 5 are rotated to slowly and smoothly remove the pole shoe 3 from the installation cavity.

[0045] It is known that in the related art, when installing the pole shoe 3, the pole shoe 3 must be installed first before the magnetic powder 4 can be filled into the sealing gap, resulting in uneven distribution of the magnetic powder 4 in multiple sealing gaps, and further resulting in insufficient density of the magnetic powder 4 in some sealing gaps.

[0046] The magnetic powder sealing device 100 of the embodiment of the present invention can fill the sealing gap in batches during the process of inserting the pole shoe 3 into the installation cavity, thereby improving the uniformity of the distribution of magnetic powder 4 in multiple sealing gaps, thereby further improving the density of the magnetic powder 4 and reducing the leakage rate; specifically, during the process of inserting the pole shoe 3 into the installation cavity, the rotation of the mounting bolt 5 is stopped so that the pole shoe 3 is positioned at a certain position, and the filling of magnetic powder 4 can be implemented.

[0047] At the same time, during the process of inserting the pole shoe 3 into the installation cavity, the pole shoe 3 can be controlled to be inserted into the installation cavity slowly and smoothly through multiple installation bolts 5, reducing the probability of damage to the pole tooth group during the installation process, thereby ensuring the sealing of the magnetic powder sealing device 100 and reducing the leakage rate.

[0048] like Figure 1 As shown, the rotating shaft 1 is rotatable relative to the housing 2, and the pole shoe 3 is connected to the housing 2, so the rotating shaft 1 is rotatable relative to the pole shoe 3; the pole tooth group is arranged in a ring shape along the circumference of the rotating shaft 1, and multiple pole tooth groups are evenly distributed along the axial direction of the rotating shaft 1, and multiple sealing gaps are formed between the multiple pole tooth groups and the rotating shaft 1. The sealing gaps are filled with magnetic powder 4, so that the sealing effect of the magnetic powder sealing device 100 can be achieved.

[0049] In some embodiments, the first pole tooth 321 has a first side surface 3211 and a second side surface 3212 arranged opposite to each other along the axial direction of the rotating shaft 1, the first side surface 3211 and the second side surface 3212 are both planes, the first side surface 3211 is arranged inclined from outside to inside along the radial direction of the rotating shaft 1; and / or the second side surface 3212 is arranged inclined from outside to inside along the radial direction of the rotating shaft 1.

[0050] The distance between the first side surface 3211 and the second side surface 3212 is the width of the first pole tooth 321. The first side surface 3211 and the second side surface 3212 are both set as planes, so that the cross-section of the first pole tooth 321 is trapezoidal. Compared with setting the first side surface 3211 and the second side surface 3212 as arc surfaces or other irregular surfaces, the processing difficulty of the first pole tooth 321 in the embodiment of the present invention is lower, which can reduce the processing cost of the magnetic powder sealing device 100.

[0051] The cross section of the first pole tooth 321 refers to a cross section formed by cutting the first pole tooth 321 with a plane passing through the axis of the rotating shaft 1 as a reference.

[0052] As an example, Figure 2 As shown, a plurality of first pole teeth 321 are evenly distributed along the axial direction of the rotating shaft 1 to form a first pole tooth group 32; the cross-section of the first pole tooth 321 is a right-angled trapezoid, the first side surface 3211 is perpendicular to the axial direction of the rotating shaft 1, and the second side surface 3212 is arranged obliquely relative to the first side surface 3211, and gradually approaches the first side surface 3211 from the outside to the inside along the radial direction of the rotating shaft 1, so that the distance between the two tips of the first pole tooth 321 is small; therefore, by only setting the second side surface 3212 obliquely, the processing difficulty of the first pole tooth group 32 can be reduced while improving the density of the magnetic powder 4.

[0053] In some embodiments, as Figure 1 and Figure 5 As shown, at least one pole tooth group is a second pole tooth group 33 , and the second pole tooth group 33 includes a plurality of second pole teeth 331 . The size of the second pole teeth 331 in the axial direction of the shaft 1 remains constant from outside to inside along the radial direction of the shaft 1 .

[0054] Through the above arrangement, the width of the second pole tooth 331 remains unchanged from the outside to the inside along the radial direction of the rotating shaft 1 (the width of the second pole tooth 331 refers to the size of the second pole tooth 331 in the axial direction of the rotating shaft 1), that is, the two side surfaces of the second pole tooth 331 arranged relatively along the circumference of the rotating shaft 1 are parallel to each other and both perpendicular to the axial direction of the rotating shaft 1, and the processing difficulty of the second pole tooth group 33 is lower than that of the first pole tooth group 32; the embodiment of the present invention combines the first pole tooth group 32 and the second pole tooth group 33 to ensure the sealing while further reducing the processing cost of the pole shoe 3.

[0055] Optionally, the width of the second pole tooth 331 is 0.1 mm to 0.2 mm.

[0056] A second sealing gap is formed between the second pole tooth 331 and the rotating shaft 1. By limiting the width of the second pole tooth 331 as described above, the second pole tooth 331 is made into an extremely narrow pole tooth, and the distance between the two tips of the second pole tooth 331 is small, thereby improving the density of the magnetic powder 4 in the second sealing gap and reducing the leakage rate of the magnetic powder sealing device 100.

[0057] Alternatively, as Figure 2 As shown, the width of the first pole tooth 321 gradually decreases from the outside to the inside along the radial direction of the rotating shaft 1, and the maximum width of the first pole tooth 321 is 0.1 mm to 0.2 mm.

[0058] Therefore, the minimum width of the first pole tooth 321 (ie, the distance between the two tips of the first pole tooth 321 ) is smaller than the width of the second pole tooth 331 . In other words, the magnetic powder 4 in the first sealing gap is more compact.

[0059] As an example, Figure 5 As shown, the cross section of the second pole tooth 331 is rectangular, and multiple second pole teeth 331 are evenly distributed along the axial direction of the rotating shaft 1 to form a second pole tooth group 33; the cross section of the second pole tooth 331 refers to: the cross section formed by cutting the second pole tooth 331 with a plane passing through the axis of the rotating shaft 1 as the reference plane.

[0060] In some embodiments, the first pole tooth set 32 ​​and the second pole tooth set 33 are alternately arranged in sequence along the axial direction of the rotating shaft 1 .

[0061] The first pole tooth group 32 and the second pole tooth group 33 are alternately and equidistantly distributed along the axial direction of the rotating shaft 1, so that the first sealing gap and the second sealing gap are alternately and equidistantly distributed in the form of groups along the axial direction of the rotating shaft 1. The density of the magnetic powder 4 in the first sealing gap is higher than that of the magnetic powder 4 in the second sealing gap, thereby ensuring the sealing performance of the magnetic powder sealing device 100 and reducing the leakage rate while reducing the processing cost of the magnetic powder sealing device 100.

[0062] In some embodiments, as Figure 1 As shown, the outer side surface of the seat body 31 has a groove 3111, and the groove 3111 and the pole tooth group are alternately arranged along the axial direction of the rotating shaft 1. A magnet 6 is provided in the groove 3111; the groove 3111 has a groove bottom wall 3112, and the wall thickness of the groove bottom wall 3112 is 0.8mm~1.2mm.

[0063] The grooves 3111 and the pole tooth groups are arranged alternately along the axial direction of the rotating shaft 1, so that the magnets 6, the pole tooth groups, the magnetic powder 4, and the rotating shaft 1 form a magnetic circuit, achieving the sealing effect of the magnetic powder sealing device 100. Because the magnetic lines of force forming the magnetic circuit must pass through the bottom wall 3112 of the groove 3111, the thickness of the bottom wall 3112 restricts the weakening of the magnetic lines of force by the bottom wall 3112, ensuring that the magnetic powder 4 can be tightly arranged and filled in the sealing gap, thereby improving the sealing effect of the magnetic powder sealing device 100.

[0064] Preferably, the wall thickness of the groove bottom wall 3112 is no more than 1 mm.

[0065] As an example, Figure 1 As shown, there is one first tooth group 32 and two second tooth groups 33. The first tooth group 32 is arranged between the two second tooth groups 33, and there is a gap between the first tooth group 32 and the two second tooth groups 33. There are two grooves 3111, and the two grooves 3111 are respectively arranged in the gap area formed by the first tooth group 32 and the second tooth groups 33 on both sides of it.

[0066] Alternatively, as Figure 6As shown, the magnet 6 is a cylindrical magnet 6 , and there are multiple magnets 6 . The multiple magnets 6 are arranged in sequence along the circumference of the rotating shaft 1 , and two adjacent magnets 6 are in contact with each other.

[0067] This makes it easier to install the magnet 6 .

[0068] In some embodiments, as Figure 1 As shown, the housing 2 includes a shell portion 21, a first connecting portion 22 and a second connecting portion 23. The first connecting portion 22 and the second connecting portion 23 are respectively arranged at both ends of the shell portion 21 and are both connected to the shell portion 21. The inner wall of the shell portion 21 and the outer side surface of the rotating shaft 1 form the above-mentioned installation cavity; the magnetic powder sealing device 100 also includes a first end cover 71 and a second end cover 72. The first end cover 71 and the second end cover 72 are arranged at the two ends of the housing 2 relatively, the first end cover 71 is connected to the first connecting portion 22, and the second end cover 72 is connected to the second connecting portion 23.

[0069] Through the above arrangement, the first end cover 71 and the second end cover 72 can block both ends of the housing 2, reducing the probability of debris in the external environment entering the installation cavity and contacting the pole shoe 3, thereby protecting the pole shoe 3 and other structures.

[0070] In some embodiments, as Figure 1 and Figure 3 As shown, the seat body 31 includes a sleeve portion 311 and a flange portion 312 that are connected to each other. The sleeve portion 311 has an inner hole. The rotating shaft 1 has a first end face 11. The rotating shaft 1 is inserted into the inner hole and the first end face 11 is located in the inner hole. The first end face 11 is arranged toward the first end cover 71. The first connecting portion 22, the flange portion 312 and the first end cover 71 are arranged in sequence along the axial direction of the rotating shaft 1. The flange portion 312 is connected to the first connecting portion 22, and the first end cover 71 is connected to the flange portion 312.

[0071] Through the above arrangement, when assembling the magnetic powder sealing device 100, the pole shoe 3 is first inserted into the installation cavity, and the flange portion 312 of the pole shoe 3 is connected to the first connecting portion 22 of the shell 2 to achieve the installation of the pole shoe 3. Then, the first end cover 71 is connected to the flange portion 312, and the assembly operation is relatively simple.

[0072] As an example, Figure 1 As shown, the first connecting portion 22 and the second connecting portion 23 are both flanges and are integrally arranged with the shell portion 21. The first end cover 71 and the second end cover 72 are arranged at the two ends of the shell 2 relatively to each other. The second end cover 72 has a through hole arranged along its axial direction. The rotating shaft 1 passes through the through hole and extends to the interior of the shell 2, thereby forming the above-mentioned installation cavity for inserting the pole shoe 3 between the rotating shaft 1 and the shell 2.

[0073] The first end cover 71 is sealed in the inner hole of the pole shoe 3, the flange portion 312 of the pole shoe 3 is connected to the first connecting portion 22, and the first end cover 71 is connected to the flange portion 312 of the pole shoe 3, thereby achieving a stable connection between the housing 2, the pole shoe 3 and the first end cover 71.

[0074] A first boss 711 is provided on the side of the first end cap 71 facing the first end face 11. The dimensions of the first boss 711 match those of the inner hole. The first boss 711 is inserted into the inner hole to position the first end cap 71 and achieve connection between the first end cap 71 and the pole piece 3. The end face of the housing 2 facing the first end cap 71 has an annular groove, within which a sealing ring 8 is disposed. This sealing ring 8 seals the connection between the end cap and the pole piece 3, preventing debris from entering the sealed gap and thereby ensuring the sealing performance of the magnetic powder sealing device 100.

[0075] A second boss 721 is provided on the side of the second end cover 72 facing the pole shoe 3. The size of the second boss 721 matches the inner wall size of the shell 2. The second boss 721 is inserted into the interior of the shell 2 to position the second end cover 72 to achieve the connection between the second end cover 72 and the shell 2.

[0076] In some embodiments, the first end cover 71 has a plurality of bolt holes 712 evenly distributed along the circumference of the rotating shaft 1, and a plurality of threaded holes 3121 are arranged on the flange portion 312 and evenly distributed along the circumference of the flange portion 312. The bolt holes 712 correspond one-to-one to the threaded holes 3121 and are coaxially arranged to connect the first end cover 71 to the flange portion 312 through a bolt assembly.

[0077] By passing the bolts of the bolt assembly through the bolt holes 712 of the first end cover 71 and then screwing them into the threaded holes 3121 of the flange portion 312, the first end cover 71 and the pole shoe 3 can be connected, which is relatively convenient to operate. In addition, the first end cover 71 and the flange portion 312 of the pole shoe 3 are connected by multiple bolt assemblies, and the stability of the connection is also relatively high.

[0078] In addition, the threaded holes 3121 on the flange portion 312 can also play an auxiliary role in the assembly and disassembly process of the magnetic powder sealing device 100, allowing the operator to use the bolt disassembly method to install and disassemble the pole shoe 3, thereby improving the stability of the disassembly of the pole shoe 3.

[0079] Optionally, the number of the bolt holes 712 of the first end cover 71 is at least three, and the number of the threaded holes 3121 of the flange portion 312 is the same as the number of the bolt holes 712 .

[0080] As an example, Figure 1As shown, the flange portion 312 of the pole shoe 3 and the first connecting portion 22 of the housing 2 are also connected by multiple bolt assemblies; specifically, the bolts of the bolt assembly pass through the flange portion 312 and the first connecting portion 22, and are threadedly engaged with the first connecting portion 22, thereby achieving a stable connection between the pole shoe 3 and the housing 2.

[0081] Similarly, the second end cover 72 and the second connecting portion 23 are also firmly connected by a plurality of bolt assemblies.

[0082] In some embodiments, as Figure 1 As shown, the magnetic powder sealing device 100 further includes a bearing 9. The inner wall of the housing 2 has a limiting protrusion 24. The bearing 9 is arranged between the limiting protrusion 24 and the second end cover 72 and respectively stops at the limiting protrusion 24 and the second end cover 72.

[0083] The bearing 9 can be installed through the limiting protrusion 24 and the second end cover 72. The bearing 9 can play a supporting role between the rotating shaft 1 and the housing 2, so that the rotating shaft 1 can rotate stably relative to the housing 2, thereby improving the stability of the magnetic powder sealing device 100.

[0084] like Figure 1 As shown, the rotating shaft 1 has two slots arranged at intervals along its axial direction, and the slots are used to install the retaining springs 91; the bearing 9 is mounted on the rotating shaft 1, and the bearing 9 is installed between the two slots, and then the retaining springs 91 are respectively installed in the two slots to realize the connection between the bearing 9 and the rotating shaft 1.

[0085] The magnetic powder sealing device assembly method of the embodiment of the present invention is applicable to assembling the magnetic powder sealing device 100 of any of the above embodiments. The magnetic powder sealing device assembly method includes the following steps:

[0086] The housing 2 is mounted on the rotating shaft 1 to form a mounting cavity;

[0087] Install the mounting bolts 5 into the multiple threaded holes 3121 of the seat body 31;

[0088] Place the pole shoe 3 with the mounting bolts 5 on one end of the housing 2, align the base 31 with the mounting cavity, and stop the mounting bolts 5 against the end surface of the housing 2;

[0089] Turn the mounting bolt 5 to slowly insert the pole shoe 3 into the mounting cavity to form a sealing gap between the pole tooth assembly and the rotating shaft 1;

[0090] While the pole shoe 3 is slowly inserted into the installation cavity, the sealing gap is filled with magnetic powder 4 in batches.

[0091] The magnetic powder sealing device 100 of the embodiment of the present invention can fill the sealing gap in batches during the process of inserting the pole shoe 3 into the installation cavity, thereby improving the uniformity of the distribution of magnetic powder 4 in multiple sealing gaps, thereby further improving the density of the magnetic powder 4 and reducing the leakage rate; specifically, during the process of inserting the pole shoe 3 into the installation cavity, the rotation of the mounting bolt 5 is stopped so that the pole shoe 3 is positioned at a certain position, and the filling of magnetic powder 4 can be implemented.

[0092] At the same time, during the process of inserting the pole shoe 3 into the installation cavity, the pole shoe 3 can be controlled to be inserted into the installation cavity slowly and smoothly through multiple installation bolts 5, reducing the probability of damage to the pole tooth group during the installation process, thereby ensuring the sealing of the magnetic powder sealing device 100 and reducing the leakage rate.

[0093] As an example, the method for assembling a magnetic powder sealing device includes the following steps:

[0094] S1: Install the bearing 9 on the rotating shaft 1 and use the retaining ring 91 to position the bearing 9. Then, insert the rotating shaft 1 with the bearing 9 into the housing 2, and make the bearing 9 stop at the limiting protrusion 24 to form a mounting cavity between the rotating shaft 1 and the housing 2.

[0095] S2: Install the magnet 6 into the groove 3111 of the pole shoe 3, and then install multiple mounting bolts 5 into the multiple threaded holes 3121 of the base 31. The multiple mounting bolts 5 are evenly distributed along the circumference of the rotating shaft 1 and pass through the threaded holes 3121;

[0096] S3: Place the pole shoe 3 with the mounting bolt 5 on one end of the housing 2 so that the sleeve portion 311 of the seat 31 is aligned with the mounting cavity and the mounting bolt 5 abuts against the end surface of the housing 2;

[0097] S4: Turn the mounting bolt 5 to control the mounting bolt 5 to gradually screw out of the threaded hole 3121. At this time, the pole shoe 3 is slowly inserted into the mounting cavity to form a sealed gap between the pole tooth assembly and the rotating shaft 1. While the pole shoe 3 is slowly inserted into the mounting cavity, the sealed gap is filled with magnetic powder 4 in batches.

[0098] S5: After the pole shoe 3 is completely installed in the installation cavity, the plurality of mounting bolts 5 are unscrewed from the pole shoe 3, and the pole shoe 3 is connected to the housing 2 using a bolt assembly;

[0099] S6: Install the sealing ring 8 in the annular groove of the pole shoe 3, and use a bolt assembly to connect the first end cover 71 to the pole shoe 3;

[0100] S7: Use a bolt assembly to connect the second end cover 72 to the housing 2.

[0101] It is understandable that the description of the magnetic powder sealing device 100 in the above embodiment is also applicable to the assembly method of the magnetic powder sealing device, and will not be repeated here.

[0102] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0104] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0105] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0106] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0107] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A magnetic powder sealing device (100), characterized in that: include: Rotating shaft (1); A housing (2), the housing (2) being fitted onto the rotating shaft (1) and rotatable relative to the rotating shaft (1), the inner wall of the housing (2) and the outer side surface of the rotating shaft (1) forming a mounting cavity; A pole shoe (3), the pole shoe (3) comprising a seat body (31) and a plurality of pole tooth groups arranged at intervals along the axial direction of the rotating shaft (1); the seat body (31) is inserted into the mounting cavity and connected to the housing (2); the seat body (31) has a plurality of threaded holes (3121) arranged along the circumference of the rotating shaft (1); At least one of the pole tooth groups is a first pole tooth group (32), the first pole tooth group (32) includes a plurality of first pole teeth (321), a first sealing gap for filling magnetic powder (4) is formed between the first pole teeth (321) and the rotating shaft (1), and the size of the first pole teeth (321) in the axial direction of the rotating shaft (1) gradually decreases from the outside to the inside along the radial direction of the rotating shaft (1); the first pole teeth (321) have a first side surface (3211) and a second side surface (3212) arranged opposite to each other along the axial direction of the rotating shaft (1), the first side surface (3211) and the second side surface (3212) are both planes, and the first side surface (3211) is arranged obliquely from the outside to the inside along the radial direction of the rotating shaft (1); and / or The second side surface (3212) is arranged obliquely from outside to inside along the radial direction of the rotating shaft (1); At least one of the pole tooth groups is a second pole tooth group (33), the second pole tooth group (33) comprises a plurality of second pole teeth (331), and the dimensions of the second pole teeth (331) in the axial direction of the rotating shaft (1) remain constant from outside to inside along the radial direction of the rotating shaft (1); The first pole tooth group (32) and the second pole tooth group (33) are alternately arranged in sequence along the axial direction of the rotating shaft (1).

2. The magnetic powder sealing device (100) according to claim 1, characterized in that: The outer side surface of the seat body (31) has a groove (3111), the groove (3111) and the pole tooth group are arranged alternately in sequence along the axial direction of the rotating shaft (1), and a magnet (6) is provided in the groove (3111); The groove (3111) has a groove bottom wall (3112), and the wall thickness of the groove bottom wall (3112) is 0.8 mm to 1.2 mm.

3. The magnetic powder sealing device (100) according to claim 1 or 2, characterized in that: The housing (2) comprises a shell portion (21), a first connecting portion (22) and a second connecting portion (23), wherein the first connecting portion (22) and the second connecting portion (23) are respectively arranged at two ends of the shell portion (21) and are both connected to the shell portion (21), and the inner wall of the shell portion (21) and the outer side surface of the rotating shaft (1) form the installation cavity; The magnetic powder sealing device (100) further comprises a first end cover (71) and a second end cover (72), wherein the first end cover (71) and the second end cover (72) are arranged at two ends of the housing (2) relative to each other, the first end cover (71) is connected to the first connecting portion (22), and the second end cover (72) is connected to the second connecting portion (23).

4. The magnetic powder sealing device (100) according to claim 3, characterized in that: The seat body (31) includes a sleeve portion (311) and a flange portion (312) connected to each other, the sleeve portion (311) has an inner hole, the rotating shaft (1) has a first end face (11), the rotating shaft (1) is passed through the inner hole and the first end face (11) is located in the inner hole, the first end face (11) is arranged toward the first end cover (71), the first connecting portion (22), the flange portion (312) and the first end cover (71) are arranged in sequence along the axial direction of the rotating shaft (1), the flange portion (312) is connected to the first connecting portion (22), and the first end cover (71) is connected to the flange portion (312).

5. The magnetic powder sealing device (100) according to claim 4, characterized in that: The first end cover (71) has a plurality of bolt holes (712) uniformly distributed along the circumference of the rotating shaft (1), and a plurality of threaded holes (3121) are arranged on the flange portion (312) and uniformly distributed along the circumference of the flange portion (312). The bolt holes (712) correspond to the threaded holes (3121) one by one and are coaxially arranged, so that the first end cover (71) is connected to the flange portion (312) through a bolt assembly.

6. The magnetic powder sealing device (100) according to claim 3, characterized in that: The housing (2) further comprises a bearing (9), wherein the inner wall of the housing (2) has a limiting protrusion (24), and the bearing (9) is arranged between the limiting protrusion (24) and the second end cover (72), and respectively stops at the limiting protrusion (24) and the second end cover (72).

7. A method for assembling a magnetic powder sealing device, characterized in that: Suitable for assembling the magnetic powder sealing device (100) according to any one of claims 1 to 6, the magnetic powder sealing device assembly method comprises the following steps: The housing (2) is fitted onto the rotating shaft (1) to form the installation cavity; Mounting bolts (5) are installed in each of the plurality of threaded holes (3121) of the seat body (31); The pole shoe (3) equipped with the mounting bolt (5) is placed at one end of the housing (2), and the seat (31) is aligned with the mounting cavity and the mounting bolt (5) is stopped at the end surface of the housing (2); Rotating the mounting bolt (5) causes the pole shoe (3) to be slowly inserted into the mounting cavity, thereby forming a sealing gap between the pole tooth assembly and the rotating shaft (1); While the pole shoe (3) is slowly inserted into the installation cavity, magnetic powder (4) is filled into the sealing gap in batches.

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