Magnetic liquid sealing device with controllable magnetic field

Abstract

The utility model belongs to the technical field of magnetic liquid sealing, and particularly relates to a magnetic field controllable magnetic liquid sealing device which comprises a shaft and a shell arranged on the outer side, a static sealing structure is installed between the shaft and the shell, a pole shoe module is further installed between the shaft and the shell, a permanent magnet is installed in the pole shoe module, and a threading hole is reserved in the permanent magnet. Coils are wound on the inner side and the outer side of the permanent magnet, and the coils penetrate through the threading holes at intervals in a reciprocating mode to be wound on the inner wall and the outer wall of the permanent magnet. According to the utility model, the purposes of reducing the magnetic field intensity in the magnetic fluid and reducing the sealing starting torque of the magnetic fluid can be realized, the applicability and the reliability of the magnetic fluid sealing are improved, and the coil is wound on the inner wall and the outer wall of the permanent magnet through the threading hole, and the magnetic field generated by the electrified coil mainly passes through the permanent magnet; and the magnetic field intensity is flexibly regulated and controlled by controlling the number of turns of the coil, the magnitude of the current and other parameters.

Description

Technical Field

[0001] The utility model belongs to the technical field of magnetic liquid sealing, and in particular relates to a magnetic liquid sealing device with controllable magnetic field. Background Art

[0002] In mechanical equipment, sealing technology is one of the key factors to ensure the normal operation of equipment and extend its service life. The performance of seals directly affects the sealing effect and working efficiency of the equipment. According to the relationship between movement, seals can be divided into two categories: static seals and dynamic seals. In the field of dynamic seals, common sealing methods include packing seals, lip seals, mechanical seals, magnetic fluid seals, dry gas seals, etc.

[0003] Magnetic fluid sealing is a technology that uses magnetic force to achieve sealing. It forms a magnetic circuit by designing a specific magnetic circuit to concentrate magnetic energy, and uses the magnetic field to bind the magnetic fluid between the pole piece (pole tooth) and the shaft. The basic principle of magnetic fluid sealing is to use magnetic force to overcome the pressure difference force to achieve the sealing effect, and the fluidity of the magnetic fluid helps to reduce frictional resistance. Compared with other sealing methods, magnetic fluid seals have significant advantages such as low frictional resistance and good sealing effect.

[0004] However, existing magnetic fluid sealing technology has some shortcomings, especially the problem of large starting torque. This problem is mainly due to the fact that after the magnetic fluid seal is shut down for a long time, the magnetic fluid solidifies under the action of the non-uniform magnetic field, resulting in a significant increase in the starting torque. For equipment that requires low starting torque, such as rotary drum water ring vacuum pumps, the magnetic fluid seal is difficult to start, thus affecting the normal operation of the equipment. Reducing the magnetic field strength inside the magnetic fluid is an effective way to solve the problem of magnetic fluid solidification.

[0005] In order to solve the problems existing in the prior art, the present invention proposes a new magnetic fluid sealing device with adjustable magnetic field. Utility Model Content

[0006] The purpose of the utility model is to provide a magnetic fluid sealing device with controllable magnetic field, which can improve the applicability and reliability of magnetic fluid sealing. By setting the threading holes, the coil is wound around the inner and outer walls of the permanent magnet through the threading holes. The magnetic field generated by the energized coil mainly passes through the permanent magnet and is superimposed with the magnetic field vector generated by the permanent magnet. By controlling parameters such as the number of coil turns and the current size, the magnetic field strength can be flexibly controlled.

[0007] The technical solutions adopted by this utility model are as follows:

[0008] A magnetic fluid sealing device with controllable magnetic field comprises a shaft, with a shell provided on the outer side of the shaft;

[0009] A sealing structure is further installed between the shaft and the housing, and is used to seal the space between the shaft and the housing. The sealing structure allows either the shaft or the housing to rotate while the other remains stationary.

[0010] A pole shoe module is further installed between the shaft and the housing. The pole shoe module includes a first pole shoe and a second pole shoe. A permanent magnet is installed between the first pole shoe and the second pole shoe. Threading holes are evenly distributed on the circumferential side of the permanent magnet. Coils are wound around the inner and outer sides of the permanent magnet.

[0011] The threading holes are arranged in an annular stepped shape on the permanent magnet, and the coils are intermittently and reciprocally passed through the threading holes and wound around the inner and outer walls of the permanent magnet, with a gap left at any position of the permanent magnet.

[0012] The pole shoe module is part of the sealing structure. Static sealing rings are provided on the outer sides of the first pole shoe and the second pole shoe. The first pole shoe and the second pole shoe are connected to the housing through the static sealing rings.

[0013] Pole teeth are provided on the inner sides of the first pole shoe and the second pole shoe, and magnetic fluid is provided between the pole teeth on the first pole shoe and the second pole shoe and the shaft;

[0014] The sealing structure also includes a bearing module assembled between the shaft and the shell, the bearing module includes a first bearing and a second bearing, and the shaft and the shell are rotatably connected through the first bearing and the second bearing. The sealing structure causes the shaft to rotate while the shell is stationary.

[0015] The sealing structure includes a third bearing and a fourth bearing assembled on the outside of the shaft, and a base is installed on the outside of the third bearing and the fourth bearing. The pole shoe module is part of the sealing structure. The outside of the first pole shoe and the second pole shoe are provided with pole teeth. Magnetic fluid is provided between the pole teeth on the first pole shoe and the second pole shoe and the shell;

[0016] Static sealing rings are provided on the inner sides of the first pole shoe and the second pole shoe, and the first pole shoe and the second pole shoe are connected to the base through the static sealing rings;

[0017] The sealing structure also includes a bearing module assembled between the shell and the base, the bearing module includes a first bearing and a second bearing, and the shell and the base are rotatably connected through the first bearing and the second bearing. The sealing structure makes the base stationary while the shaft and the shell rotate.

[0018] A first sleeve and a second sleeve are installed between the shaft and the housing, and the first bearing and the second bearing are assembled in the first sleeve and the second sleeve.

[0019] A third sleeve is mounted on the inner wall of the shell, a baffle is fixed to one end of the third sleeve away from the pole shoe module, and the baffle is fixedly connected to the shell.

[0020] The technical effects achieved by this utility model are:

[0021] The utility model can achieve the purpose of reducing the magnetic field strength in the magnetic fluid and reducing the starting torque of the magnetic fluid seal by changing the structure of the permanent magnet and the coil, thereby overcoming the shortcomings of the existing technology and improving the applicability and reliability of the magnetic fluid seal. In addition, by setting the threading holes, the coil is wound around the inner wall and the outer wall of the permanent magnet through the threading holes. The magnetic field generated by the energized coil mainly passes through the permanent magnet and is superimposed with the magnetic field vector generated by the permanent magnet. By controlling parameters such as the number of coil turns and the current size, the magnetic field strength can be flexibly adjusted, and beneficial effects such as low starting torque, low friction resistance, and high sealing can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of Example 1 of the present utility model;

[0023] Figure 2 This is a schematic diagram of the permanent magnet and threading hole in the utility model;

[0024] Figure 3 This is a schematic structural diagram of Example 2 of the present utility model;

[0025] Figure 4 It is a schematic diagram of the coil wound around the permanent magnet in the utility model.

[0026] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0027] 1. Shaft; 2. Shell; 3. Bearing module; 31. First bearing; 32. Second bearing; 33. Third bearing; 34. Fourth bearing; 41. First sleeve; 42. Second sleeve; 43. Third sleeve; 51. First pole shoe; 52. Second pole shoe; 6. Coil; 61. Power module; 7. Permanent magnet; 71. Threading hole; 8. Baffle; 9. Base. DETAILED DESCRIPTION

[0028] In order to make the purpose and advantages of the present invention more clearly understood, the present invention is described in detail below with reference to the following embodiments. It should be understood that the following text is only used to describe one or several specific embodiments of the present invention and does not strictly limit the scope of protection of the present invention.

[0029] Example 1:

[0030] like Figures 1-4 As shown, a magnetic fluid sealing device with controllable magnetic field includes a shaft 1, and a shell 2 is provided on the outer side of the shaft 1;

[0031] It is also equipped with a power module 61, which is used to power the device. A sealing structure is also installed between the shaft 1 and the shell 2. The sealing structure is used to seal the space between the shaft 1 and the shell 2. The sealing structure allows either the shaft 1 or the shell 2 to rotate while the other remains stationary.

[0032] A pole shoe module 5 is also installed between the shaft 1 and the housing 2. Figure 2 , a permanent magnet 7 is installed between the first pole shoe 51 and the second pole shoe 52, and threading holes 71 are evenly distributed on the circumferential side of the permanent magnet 7, and the threading holes 71 can be 2-10. The inner and outer sides of the permanent magnet 7 are wound with a coil 6 through the threading holes 71. The coil 6 is wound around the inner and outer walls of the permanent magnet 7 through the threading holes 71. When the coil 6 is energized, the magnetic field generated by the coil 6 mainly passes through the permanent magnet 7 and is superimposed with the magnetic field vector generated by the permanent magnet 7. The threading holes 71 are evenly distributed in the circumferential direction of the permanent magnet 7 and are evenly distributed in the axial direction of the permanent magnet 7. The threading holes 71 are arranged in an annular stepped shape on the permanent magnet 7, thereby ensuring the threading efficiency and the magnetic effect. The coil 6 is wound around the inner and outer walls of the permanent magnet 7 through the threading holes 71 at intervals and reciprocatingly, and a gap is left at any position of the permanent magnet 7 for the coil 6.

[0033] like Figure 4 As shown, the coil 6 follows the principle of "first winding around the outer wall of the permanent magnet 7, and then winding around the inner wall of the permanent magnet 7 through the threading hole 71". Each threading hole 71 can be wound multiple times, and the coil wound on the permanent magnet 7 presents a "ring with a gap" shape;

[0034] When winding, the coil 6 needs to be completely fixed to the inner and outer walls of the permanent magnet 7 with wires, steel wires, screws or other structures to prevent it from deformation and falling off. A third sleeve 43 is installed on the inner wall of the shell 2. A baffle 8 is fixed at one end of the third sleeve 43 away from the pole shoe module 5, and the baffle 8 is fixed to the shell 2. The third sleeve 43 can install the baffle 8 and ensure that the position of the baffle 8 will not deviate or tilt.

[0035] Refer to the attached Figure 1 Static sealing rings are provided on the outside of the first pole shoe 51 and the second pole shoe 52. The first pole shoe 51 and the second pole shoe 52 are connected to the housing 2 through the static sealing rings. The static sealing rings can seal the first pole shoe 51 and the second pole shoe 52 with the housing 2 and prevent the housing 2 from rotating.

[0036] Pole teeth are provided on the inner sides of the first pole shoe 51 and the second pole shoe 52. A magnetic fluid is provided between the pole teeth on the first pole shoe 51 and the second pole shoe 52 and the shaft 1. The magnetic fluid allows the shaft 1 and the first pole shoe 51 and the second pole shoe 52 to rotate and be sealed.

[0037] The sealing structure also includes a bearing module 3 assembled between the shaft 1 and the housing 2. The bearing module 3 includes a first bearing 31 and a second bearing 32. The shaft 1 and the housing 2 are rotatably connected via the first bearing 31 and the second bearing 32. The arrangement of the first bearing 31 and the second bearing 32 reduces the friction force on the shaft 1 when it rotates. A first sleeve 41 and a second sleeve 42 are installed between the shaft 1 and the housing 2. The first bearing 31 and the second bearing 32 are assembled within the first sleeve 41 and the second sleeve 42. The arrangement of the first sleeve 41 and the second sleeve 42 facilitates the assembly of the first bearing 31 and the second bearing 32.

[0038] Through the above-mentioned arrangement, the shaft 1 can rotate while the shell 2 does not rotate, thereby achieving the function of "moving inside and still outside". In this embodiment, the shell 2 is provided with a through hole or other guiding structure for connecting electricity between the power module 61 and the coil 6.

[0039] The following are the installation steps for this embodiment. Figure 1 For example:

[0040] S1: Install the bearing module 3 on the shaft 1, and position the bearing modules 3 through the first sleeve 41;

[0041] S2: Install the housing 2 on the bearing module 3, and then install the second sleeve 42;

[0042] S3: Install the first pole shoe 51 in the housing 2;

[0043] S4: Wind the coil 6 around the permanent magnet 7, install the permanent magnet 7 in the housing 2 and make it contact with the first pole piece 51;

[0044] S5: Install the second pole piece 52 in the housing 2;

[0045] S6: Install and fix the third sleeve 43 and the baffle 8 in sequence;

[0046] S7: Connect the power module 61.

[0047] Example 2:

[0048] The difference between this embodiment and embodiment 1 is that embodiment 1 can achieve the function of "inner movement and outer stillness", while this embodiment can achieve the function of "inner stillness and outer movement", as follows:

[0049] Refer to the attached Figure 3The sealing structure includes a third bearing 33 and a fourth bearing 34 assembled on the outside of the shaft 1, and a base 9 is installed on the outside of the third bearing 33 and the fourth bearing 34. The base 9 is a fixed part. The pole shoe module 5 is part of the sealing structure. Pole teeth are provided on the outside of the first pole shoe 51 and the second pole shoe 52. Magnetic fluid is provided between the pole teeth on the first pole shoe 51 and the second pole shoe 52 and the shell 2. Through the provision of the magnetic fluid, the shell 2 and the first pole shoe 51 and the second pole shoe 52 can rotate and can be sealed.

[0050] Static sealing rings are provided on the inner sides of the first pole shoe 51 and the second pole shoe 52. The first pole shoe 51 and the second pole shoe 52 are connected to the base 9 through the static sealing rings. The static sealing rings can not only seal the first pole shoe 51 and the second pole shoe 52 with the base 9, but also prevent the base 9 from rotating.

[0051] The sealing structure also includes a bearing module 3 assembled between the shell 2 and the base 9. The bearing module 3 includes a first bearing 31 and a second bearing 32. The shell 2 and the base 9 are rotatably connected via the first bearing 31 and the second bearing 32. The arrangement of the first bearing 31 and the second bearing 32 reduces the friction force on the shell 2 when it rotates. A first sleeve 41 and a second sleeve 42 are installed between the shaft 1 and the shell 2. The first bearing 31 and the second bearing 32 are assembled in the first sleeve 41 and the second sleeve 42. The arrangement of the first sleeve 41 and the second sleeve 42 facilitates the assembly of the first bearing 31 and the second bearing 32.

[0052] Through the above-mentioned arrangement, the shell 2 can rotate while the base 9 does not rotate, thereby achieving the function of "static inside and moving outside". In this embodiment, there are no electrical connection structures such as through holes on the shell 2. All electrical connection structures are arranged on the base 9 for connecting electricity between the power module 61 and the coil 6.

[0053] When the device is started, the present application supplies power through the power module 61, and uses the magnetic field generated in the coil 6 in the opposite direction to the permanent magnet 7 to achieve the purpose of reducing the magnetic field strength in the magnetic fluid, which has the effect of reducing the starting torque of the magnetic fluid seal. In addition, different magnetic fields are provided for different sealing requirements to achieve the purpose of reducing resistance, thereby solving the problem of large starting force of the magnetic fluid seal. By controlling parameters such as the number of turns of the coil 6 and the current size, the magnetic field strength can be flexibly controlled, which can achieve beneficial effects such as low starting torque, low friction resistance, and high sealing.

[0054] The following are the installation steps for this embodiment. Figure 3 For example:

[0055] S1: Install the third bearing 33 and the fourth bearing 34 on the shaft 1, and install the base 9 on the third bearing 33 and the fourth bearing 34;

[0056] S2: Mount the bearing modules 3 on the base 9, and position the bearing modules 3 by the first sleeve 41;

[0057] S3: Install the housing 2 on the bearing module 3, and then install the second sleeve 42;

[0058] S4: Install the first pole shoe 51 in the housing 2;

[0059] S5: Wind the coil 6 around the permanent magnet 7, install the permanent magnet 7 in the housing 2 and make it contact with the first pole piece 51;

[0060] S6: Install the second pole piece 52 in the housing 2;

[0061] S7: Install and fix the third sleeve 43 and the baffle 8 in sequence;

[0062] S8: Connect the power module 61.

[0063] The following are the steps for the device to adjust the magnetic field:

[0064] S1: Before the magnetic fluid seal is started, the current is adjusted by the power module 61 to obtain an electromagnetic field opposite to the static magnetic field of the permanent magnet 7;

[0065] S2: Start the equipment and the magnetic fluid seal starts to operate;

[0066] S3: After the device is started, the current of the coil 6 is reduced or the power module 61 is turned off, and the magnetic fluid seal is performed by relying on the magnetic field generated by the permanent magnet 7.

[0067] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications should be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention shall, unless otherwise specified or limited, be implemented in accordance with conventional means in the art.

Claims

1. A magnetic fluid sealing device with controllable magnetic field, comprising a shaft (1), characterized in that: A shell (2) is provided on the outer side of the shaft (1); A sealing structure is also installed between the shaft (1) and the housing (2), and the sealing structure is used to seal the space between the shaft (1) and the housing (2). The sealing structure allows either the shaft (1) or the housing (2) to rotate while the other remains stationary. A pole shoe module (5) is also installed between the shaft (1) and the housing (2), the pole shoe module (5) comprising a first pole shoe (51) and a second pole shoe (52), a permanent magnet (7) being installed between the first pole shoe (51) and the second pole shoe (52), threading holes (71) being evenly distributed on the circumferential side surface of the permanent magnet (7), and a coil (6) being wound around the inner and outer sides of the permanent magnet (7); The threading holes (71) are arranged in an annular stepped manner on the permanent magnet (7), and the coil (6) is wound around the inner wall and outer wall of the permanent magnet (7) in an interval and reciprocating manner through the threading holes (71), and a gap is left at any position of the permanent magnet (7) for the coil (6).

2. The magnetic fluid sealing device with controllable magnetic field according to claim 1, characterized in that: The pole shoe module (5) is a part of the sealing structure, and static sealing rings are provided on the outer sides of the first pole shoe (51) and the second pole shoe (52), and the first pole shoe (51) and the second pole shoe (52) are connected to the housing (2) through the static sealing rings; Pole teeth are provided on the inner sides of the first pole shoe (51) and the second pole shoe (52), and magnetic fluid is provided between the pole teeth on the first pole shoe (51) and the second pole shoe (52) and the shaft (1); The sealing structure further comprises a bearing module (3) assembled between the shaft (1) and the housing (2), the bearing module (3) comprising a first bearing (31) and a second bearing (32), and the shaft (1) and the housing (2) are rotatably connected via the first bearing (31) and the second bearing (32), and the sealing structure enables the shaft (1) to rotate while the housing (2) remains stationary.

3. The magnetic fluid sealing device with controllable magnetic field according to claim 1, characterized in that: The sealing structure comprises a third bearing (33) and a fourth bearing (34) assembled on the outside of the shaft (1), and a base (9) is installed on the outside of the third bearing (33) and the fourth bearing (34), the pole shoe module (5) is part of the sealing structure, the outside of the first pole shoe (51) and the second pole shoe (52) are provided with pole teeth, and magnetic fluid is provided between the pole teeth on the first pole shoe (51) and the second pole shoe (52) and the shell (2); Static sealing rings are provided on the inner sides of the first pole shoe (51) and the second pole shoe (52), and the first pole shoe (51) and the second pole shoe (52) are connected to the base (9) through the static sealing rings; The sealing structure further comprises a bearing module (3) assembled between the shell (2) and the base (9), the bearing module (3) comprising a first bearing (31) and a second bearing (32), and the shell (2) and the base (9) are rotatably connected via the first bearing (31) and the second bearing (32), and the sealing structure enables the base (9) to be stationary while the shaft (1) and the shell (2) to rotate.

4. A magnetic fluid sealing device with controllable magnetic field according to any one of claims 2 or 3, characterized in that: A first sleeve (41) and a second sleeve (42) are installed between the shaft (1) and the housing (2), and the first bearing (31) and the second bearing (32) are assembled in the first sleeve (41) and the second sleeve (42).

5. A magnetic fluid sealing device with controllable magnetic field according to any one of claims 2 or 3, characterized in that: A third sleeve (43) is mounted on the inner wall of the shell (2), a baffle (8) is fixed to one end of the third sleeve (43) away from the pole shoe module (5), and the baffle (8) is fixedly connected to the shell (2).

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