Magnetic powder sealing device and assembling method thereof

Abstract

The invention discloses a magnetic powder sealing device and an assembling method thereof. The magnetic powder sealing device comprises a rotating shaft, a shell and a pole shoe. The shell sleeves the rotating shaft and can rotate relative to the rotating shaft; a mounting cavity is defined by the inner wall of the shell and the outer side surface of the rotating shaft; the pole shoe comprises a seat body and a plurality of pole tooth groups arranged at intervals in the axial direction of the rotating shaft, the seat body is inserted into the mounting cavity and connected with the shell, and the seat body is provided with a plurality of threaded holes formed in the circumferential direction of the rotating shaft; at least one pole tooth set is a first pole tooth set, the first pole tooth set comprises a plurality of first pole teeth, a first sealing gap used for being filled with 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 is gradually reduced from outside to inside in the radial direction of the rotating shaft. According to the magnetic powder sealing device, the compactness of magnetic powder filling of the first sealing gap can be improved, and the leakage rate of the magnetic powder sealing device is reduced.

Description

Technical Field

[0001] The 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] The magnetic powder sealing device is a sealing device that uses magnetic materials and magnetic field characteristics to achieve the sealing function. It is a non-contact seal with the advantages of no friction and wear, long service life, and low maintenance cost. The magnetic powder sealing device includes a rotating shaft, a pole shoe, and a magnet. The pole shoe includes a pole tooth. A sealing gap for filling magnetic powder is formed between the pole tooth and the rotating shaft. Under the action of the magnetic field, the pole shoe and the rotating shaft form a magnetic circuit. The magnetic powder filled in the sealing gap will be magnetized. The magnetized magnetic powder forms a structure similar to a "magnetic chain" under the action of the magnetic field force. These magnetic chains are closely arranged and filled in the sealing gap, thereby preventing the gas or liquid and other media from leaking through the gap to achieve the purpose of sealing.

[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 is easily attached 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 compactness of the 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 the embodiment of the present invention comprises a rotating shaft, a shell and a pole shoe; the shell is sleeved 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 comprises 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 comprises a plurality of first pole teeth, 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 shaft remains constant from outside to inside along the radial direction of the shaft.

[0009] In some embodiments, the first polar tooth group and the second polar 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 in sequence along the axial direction of the rotating shaft, and a magnet is arranged 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 two 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 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 evenly distributed along the circumference of the rotating shaft, and the plurality of threaded holes are arranged on the flange portion and evenly distributed along the circumference of the flange portion. The bolt holes correspond to the threaded holes one by one and are coaxially arranged so that the first end cover is connected 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 stops at the limiting protrusion and the second end cover respectively.

[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 comprises the following steps:

[0016] The housing is mounted on 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 body with the mounting cavity and stopping the mounting bolts against the end surface of the housing;

[0019] Rotating the mounting bolts to slowly insert the pole shoe into the mounting cavity, so as to form a sealing gap between the pole tooth set 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 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 magnetic powder filling amount of the sealing gap is small due to the large induction intensity gradient at the tip of the pole tooth. In other words, even if the 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 compactness of the magnetic powder filling of 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 A magnified schematic diagram of center A.

[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 completed assembly of the pole shoe of the magnetic powder sealing device according to one embodiment of the present invention.

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

[0027] Figure 6 The figure is a 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. limiting protrusion;

[0032] 3. pole shoe; 31. seat body; 311. sleeve portion; 3111. groove; 3112. groove bottom wall; 312. flange portion; 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 in detail embodiments of the present invention. Examples of the embodiments are shown in the attached 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 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, a sealing gap for filling magnetic powder 4 is 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 compactness 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, Figure 3 As shown, when assembling the magnetic powder sealing device 100, first, the shell 2 is mounted on the rotating shaft 1 to form the above-mentioned installation cavity; then, the installation bolts 5 are installed in the multiple threaded holes 3121 of the seat body 31, and the pole shoe 3 equipped with the installation bolts 5 is placed at one end of the shell 2, and the seat body 31 is aligned with the installation cavity and the installation bolts 5 are stopped at the end surface of the shell 2; the installation bolts 5 are rotated so that the pole shoe 3 is slowly and smoothly inserted into the installation 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 installation cavity, the magnetic powder 4 is filled into the sealing gap in batches; after the pole shoe 3 is completely inserted into the installation cavity, the installation bolts 5 are removed.

[0044] Similarly, if Figure 4As shown, when the pole shoe 3 is disassembled, 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 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 compactness 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 magnetic powder 4 filling 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 the 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 magnetic powder 4 is filled into the sealing gap, 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 which are 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 to be inclined from outside to inside along the radial direction of the rotating shaft 1; and / or the second side surface 3212 is arranged to be 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, 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, only the second side surface 3212 is inclined, which can reduce the processing difficulty of the first pole tooth group 32 while improving the density of the magnetic powder 4.

[0053] In some embodiments, 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 , and the size of the second pole teeth 331 in the axial direction of the rotating shaft 1 remains constant from outside to inside along the radial direction of the rotating shaft 1 .

[0054] Through the above arrangement, the width of the second pole tooth 331 remains unchanged from outside to 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 circumferential direction of the rotating shaft 1 are parallel to each other and 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 further reduce the processing cost of the pole shoe 3 while ensuring the sealing performance.

[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 above, the second pole tooth 331 is an extremely narrow pole tooth, and the distance between the two tips of the second pole tooth 331 is small, thereby improving the compactness of the magnetic powder 4 in the second sealing gap and reducing the leakage rate of the magnetic powder sealing device 100.

[0057] Alternatively, if 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 has a higher density.

[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 the 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 a group along the axial direction of the rotating shaft 1, and 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, Figure 1 As shown, the outer side of the seat body 31 has a groove 3111, and the groove 3111 and the pole tooth group are arranged alternately in the axial direction of the rotating shaft 1, and a magnet 6 is arranged 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 teeth groups are arranged alternately in the axial direction of the rotating shaft 1, so that the magnet 6, the pole teeth group, the magnetic powder 4 and the rotating shaft 1 form a magnetic circuit, thereby achieving the sealing effect of the magnetic powder sealing device 100. Since the magnetic lines of force forming the magnetic circuit need to pass through the groove bottom wall 3112 of the groove 3111, the thickness of the groove bottom wall 3112 is used to limit the weakening of the magnetic lines of force by the groove bottom wall 3112, thereby ensuring that the magnetic powder 4 can be closely 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, the number of the first pole tooth group 32 is one, the number of the second pole tooth group 33 is two, the first pole tooth group 32 is arranged between the two second pole tooth groups 33, and there is a gap between the first pole tooth group 32 and the two second pole tooth groups 33; the number of the grooves 3111 is two, and the two grooves 3111 are respectively arranged in the gap area formed by the first pole tooth group 32 and the second pole tooth groups 33 on both sides thereof.

[0066] Alternatively, if 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, Figure 1 As shown, the outer shell 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, and 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 both ends of the outer shell 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, 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, and 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 housing 2 to achieve the installation of the pole shoe 3, and 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 relatively arranged at the two ends of the outer shell 2. 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 outer shell 2, thereby forming the above-mentioned installation cavity for inserting the pole shoe 3 between the rotating shaft 1 and the outer 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 among the housing 2, the pole shoe 3 and the first end cover 71.

[0074] A first boss 711 is provided on one side of the first end cover 71 facing the first end face 11. The size of the first boss 711 matches the size of the inner hole. The first boss 711 is inserted into the inner hole to position the first end cover 71 to achieve the connection between the first end cover 71 and the pole shoe 3. The end face of the housing 2 facing the first end cover 71 has an annular groove, and a sealing ring 8 is provided in the annular groove. The sealing ring 8 can play a sealing role at the connection between the end cover and the pole shoe 3 to prevent debris from entering the sealing gap, 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, 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 with the threaded holes 3121 and are coaxially arranged so that the first end cover 71 is connected to the flange portion 312 through a bolt assembly.

[0077] By passing the bolt of the bolt assembly through the bolt hole 712 of the first end cover 71 and screwing it into the threaded hole 3121 of the flange portion 312, the first end cover 71 and the pole shoe 3 can be connected, and the operation is relatively convenient; moreover, 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, so that the operator can 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 a plurality of bolt assemblies; specifically, the bolts of the bolt assembly pass through the flange portion 312 and the first connecting portion 22, and are threadedly matched 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, 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 stops at the limiting protrusion 24 and the second end cover 72 respectively.

[0083] The bearing 9 can be installed by 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 spring 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 spring 91 is installed in the two slots respectively, so that the bearing 9 and the rotating shaft 1 can be connected.

[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 comprises 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 bolt 5 at one end of the housing 2, align the seat 31 with the mounting cavity, and stop the mounting bolt 5 against the end surface of the housing 2;

[0089] The mounting bolt 5 is rotated to slowly insert the pole shoe 3 into the mounting cavity, so as to form a sealing gap between the pole tooth assembly and the rotating shaft 1;

[0090] While the pole piece 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 compactness 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 magnetic powder 4 filling 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 a plurality of mounting bolts 5 into a plurality of threaded holes 3121 of the seat body 31, wherein the plurality of mounting bolts 5 are evenly distributed along the circumference of the rotating shaft 1, and the mounting bolts 5 pass through the threaded holes 3121;

[0096] S3: placing the pole shoe 3 equipped with the mounting bolt 5 at one end of the housing 2, so that the shaft sleeve portion 311 of the seat body 31 is aligned with the mounting cavity and the mounting bolt 5 stops at 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, and then slowly insert the pole shoe 3 into the mounting cavity to form a sealing gap between the pole tooth group and the rotating shaft 1. While the pole shoe 3 is slowly inserted into the mounting cavity, the magnetic powder 4 is filled into the sealing gap in batches;

[0098] S5: After the pole shoe 3 is completely installed in the installation cavity, the plurality of installation bolts 5 are screwed out of 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 is to 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”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element 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] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0104] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0105] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0106] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

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

Claims

1. A magnetic powder sealing device (100), characterized in that: include: A rotating shaft (1); A housing (2), the housing (2) being mounted on 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) being inserted into the installation cavity and connected to the housing (2), the seat body (31) having 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) comprising 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 outside to inside along the radial direction of the rotating shaft (1).

2. The magnetic powder sealing device (100) according to claim 1, characterized in that: The first pole tooth (321) comprises a first side surface (3211) and a second side surface (3212) which are arranged opposite to each other in 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 outside to inside in 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).

3. The magnetic powder sealing device (100) according to claim 1, characterized in that: At least one of the pole tooth groups is a second pole tooth group (33), the second pole tooth group (33) comprising a plurality of second pole teeth (331), the dimensions of the second pole teeth (331) in the axial direction of the rotating shaft (1) remaining constant from outside to inside along the radial direction of the rotating shaft (1).

4. The magnetic powder sealing device (100) according to claim 3, characterized in that: The first pole tooth group (32) and the second pole tooth group (33) are arranged alternately in sequence along the axial direction of the rotating shaft (1).

5. The magnetic powder sealing device (100) according to claim 1, characterized in that: The outer side surface of the seat body (31) is provided with 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 arranged 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.

6. The magnetic powder sealing device (100) according to any one of claims 1 to 5, characterized in that: The housing (2) comprises 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 two 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 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 oppositely at two ends of the housing (2), 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).

7. The magnetic powder sealing device (100) according to claim 6, characterized in that: The seat body (31) comprises a shaft sleeve portion (311) and a flange portion (312) which are connected to each other, the shaft sleeve portion (311) having an inner hole, the rotating shaft (1) having a first end face (11), the rotating shaft (1) passing through the inner hole and the first end face (11) being located in the inner hole, the first end face (11) being arranged toward the first end cover (71), the first connecting portion (22), the flange portion (312) and the first end cover (71) being arranged in sequence along the axial direction of the rotating shaft (1), the flange portion (312) being connected to the first connecting portion (22), and the first end cover (71) being connected to the flange portion (312).

8. The magnetic powder sealing device (100) according to claim 7, 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 the 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 as to connect the first end cover (71) to the flange portion (312) through a bolt assembly.

9. The magnetic powder sealing device (100) according to claim 6, characterized in that: The housing (2) further comprises 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 stops at the limiting protrusion (24) and the second end cover (72), respectively.

10. 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 9, the magnetic powder sealing device assembly method comprises the following steps: The housing (2) is mounted on the rotating shaft (1) to form the mounting 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 body (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) so that the pole shoe (3) is slowly inserted into the mounting cavity, thereby forming a sealing gap between the pole tooth group 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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