Magnetic fluid transmission device

Abstract

The application discloses a magnetic fluid transmission device, comprising: a rotating shaft; a shell sleeved outside the rotating shaft and rotationally connected with the rotating shaft, an end cover fixedly connected with the shell is further arranged on the rotating shaft, and a containing cavity is arranged between the end cover and the shell; a magnetic fluid sealing mechanism arranged in the containing cavity is arranged between the shell and the rotating shaft; a first spiral groove is arranged at the connecting position of the shell and the shell, and the rotating shaft is driven to rotate by a driving piece, so that the first spiral groove drives air to be transmitted in a direction away from the magnetic fluid sealing mechanism. The magnetic fluid transmission device provided by the application can form a vacuum in the cavity between the magnetic fluid sealing mechanism and the first spiral groove through high-speed rotation of the rotating shaft, reduce the contact between low-temperature air and the magnetic fluid sealing mechanism and low-temperature conduction, and better complete the dynamic sealing of gas in a low-temperature or ultralow-temperature environment.

Description

Technical Field

[0001] This application relates to the technical field of magnetohydrodynamic sealing, and more specifically, to a magnetohydrodynamic transmission device. Background Technology

[0002] With the rapid development of the economy, the requirements for sealing performance in industrial equipment and related fields are becoming increasingly stringent. Traditional sealing methods are no longer sufficient to meet the sealing requirements of certain special occasions. The development of magnetic fluid technology has driven the development of magnetic fluid sealing technology, which is playing an increasingly important role in the sealing field.

[0003] After decades of development, magnetohydrodynamic (MHD) sealing technology has been widely applied in numerous fields, including national defense, aerospace, machinery, electronics, instrumentation, nuclear energy, chemical industry, and pharmaceuticals, particularly excelling in dustproof sealing, vacuum sealing, and differential pressure sealing. Applications include sealing critical rotating parts of machinery, sealing computer hard drives for dust and oil mist, sealing radioactive gases in nuclear equipment, preventing bacterial contamination in fermenter agitators, sealing under ultra-high and extra-high vacuum conditions in vacuum coating machines, vacuum heat treatment furnaces, and single-crystal silicon furnaces, and sealing under differential pressure conditions in reactors, fans, and air pumps. It is especially advantageous as a dynamic leak-proof component in rotating shafts. MHD sealing technology achieves leak prevention without affecting the movement of rotatable components.

[0004] Magnetofluids possess both the fluidity of liquids and the magnetism of solid magnetic materials. However, they are difficult to stabilize at low temperatures. The operating temperature of magnetofluid sealing technology is generally between -30°C and 120°C. In low-temperature or ultra-low-temperature environments, existing magnetofluid sealing technologies are limited by the magnetic properties of the magnetofluid, resulting in increased magnetic sealing resistance and an inability to effectively perform the functions of transmission and sealing.

[0005] Therefore, there is an urgent need for a magnetohydrodynamic transmission device that can better achieve dynamic sealing of gases in low-temperature or ultra-low-temperature environments. Summary of the Invention

[0006] To solve the above-mentioned technical problems, this application provides a magnetic fluid transmission device. By setting a first spiral groove between the outer shell and the rotating shaft, the high-speed rotation of the rotating shaft causes the cavity between the magnetic fluid sealing mechanism and the first spiral groove to form a vacuum, reducing the contact between low-temperature air and the magnetic fluid sealing mechanism and the conduction of low temperature, thus enabling better dynamic sealing of gas in low-temperature or ultra-low-temperature environments.

[0007] The technical solution provided in this application is as follows:

[0008] A magnetohydrodynamic transmission device, comprising:

[0009] Shaft;

[0010] A housing fitted on the outside of the rotating shaft and rotatably connected to the rotating shaft, with a receiving cavity provided between the rotating shaft and the housing;

[0011] A magnetic fluid sealing mechanism is disposed within the accommodating cavity, and the magnetic fluid sealing mechanism is disposed between the rotating shaft and the outer casing;

[0012] A first helical groove is provided at the connection between the outer casing and the rotating shaft. The driving member drives the rotating shaft to rotate, so that the first helical groove drives air to be transported away from the magnetohydrodynamic sealing mechanism.

[0013] Preferably, the first spiral groove is located at the end of the rotating shaft away from the driving component.

[0014] The first helical groove is disposed on the outer wall of the rotating shaft, and the direction of the first helical groove is opposite to the direction of rotation of the rotating shaft; or,

[0015] The first spiral groove is disposed on the outer wall of the housing, and the direction of the first spiral groove is the same as the direction of rotation of the shaft.

[0016] Preferably, it further includes:

[0017] A second spiral groove used in conjunction with the first spiral groove, wherein the spiral direction of the second spiral groove is opposite to that of the first spiral groove;

[0018] in,

[0019] The second spiral groove is disposed on the inner wall of the housing, or the second spiral groove is disposed on the outer wall of the rotating shaft.

[0020] Preferably, it further includes:

[0021] A heat exchange cavity is disposed within the outer casing, the heat exchange cavity being located outside the first spiral groove;

[0022] It is installed on the outer shell, communicates with the heat exchange cavity, and serves as a channel for delivering the heat-insulating medium into the heat exchange cavity.

[0023] Preferably, it further includes:

[0024] A temperature sensor is installed on the outer casing to detect the temperature inside the heat exchange chamber.

[0025] Preferably, the rotating shaft includes:

[0026] mandrel;

[0027] A bushing is fitted on the outside of the mandrel, the bushing is fixedly connected to the mandrel, a vacuum cavity is provided between the bushing and the mandrel, and the outer shell is rotatably fitted on the outside of the bushing.

[0028] Preferably, the magnetohydrodynamic sealing mechanism includes:

[0029] A magnetic pole is disposed between the rotating shaft and the outer casing, and sleeved on the rotating shaft. The magnetic pole is in clearance fit with the rotating shaft, and a magnetic fluid is disposed between the magnetic pole and the mounting gap of the rotating shaft.

[0030] The magnetic poles are at least two in number and are spaced apart along the axis of the rotating shaft. A permanent magnet is provided between adjacent magnetic poles.

[0031] Preferably, the magnetohydrodynamic sealing mechanism further includes:

[0032] A first heat-insulating groove and a first sealing element are disposed between the magnetic pole and the outer shell. Two first sealing elements are disposed on both sides of the first heat-insulating groove.

[0033] The outlet of the channel is connected to the first insulation tank and is used to deliver the insulation medium into the first insulation tank.

[0034] Preferably, the magnetohydrodynamic sealing mechanism further includes magnetic pole teeth;

[0035] The magnetic pole teeth are disposed on the inner wall of the magnetic pole; or the magnetic pole teeth are disposed on the outer surface of the rotating shaft.

[0036] Preferably, the magnetohydrodynamic sealing mechanism further includes:

[0037] A first heat dissipation ring is disposed inside the first heat insulation tank and connected to the magnetic pole, wherein the outer diameter of the first heat dissipation ring is smaller than the outer diameter of the magnetic pole.

[0038] Preferably, the magnetohydrodynamic sealing mechanism further includes:

[0039] A first bearing and a second bearing are disposed within the accommodating cavity, with the second bearing disposed at one end of the rotating shaft near the outer casing.

[0040] A first spacer is provided between the first bearing and the magnetic pole, a second spacer is provided between the second bearing and the magnetic pole, and a third spiral groove is provided at the connection between the rotating shaft and the second spacer;

[0041] in,

[0042] The third helical groove is disposed on the outer wall of the rotating shaft, and the direction of the third helical groove is opposite to the direction of rotation of the rotating shaft; or,

[0043] The third spiral groove is disposed on the inner hole of the second spacer, and the direction of the third spiral groove is the same as the direction of rotation of the shaft.

[0044] Preferably, it further includes:

[0045] A fourth spiral groove is used in conjunction with the third spiral groove, wherein the direction of rotation of the fourth spiral groove is opposite to that of the third spiral groove;

[0046] in,

[0047] The fourth spiral groove is disposed on the inner hole of the second spacer, or the fourth spiral groove is disposed on the outer wall of the rotating shaft.

[0048] Preferably, the magnetohydrodynamic sealing mechanism further includes:

[0049] A second heat-insulating groove is disposed on the outer surface of the second spacer and communicates with the channel;

[0050] A second heat dissipation ring is disposed inside the second insulation groove and connected to the second spacer, wherein the outer diameter of the second heat dissipation ring is smaller than the outer diameter of the second spacer.

[0051] The magnetohydrodynamic (MHD) transmission device provided by this invention, firstly, comprises a rotating shaft, a housing, and a MHD sealing mechanism. The housing is fitted onto the rotating shaft, and the housing and rotating shaft are rotatably connected. A receiving cavity is provided between the housing and the rotating shaft. The MHD sealing mechanism is disposed within the receiving cavity and between the rotating shaft and the housing. The function of the MHD sealing mechanism is to ensure that the transported gas does not exchange with the outside air and to drive the fan blades to rotate. However, because the sealing medium in the MHD sealing mechanism is easily affected by temperature and is difficult to stabilize at low temperatures, it cannot effectively perform the transmission and sealing functions. To prevent heat exchange between the connection between the housing and the rotating shaft and the air in the receiving cavity due to low temperatures, a first spiral groove is also provided. The first spiral groove is located at the connection between the housing and the rotating shaft. A driving component drives the rotating shaft to rotate, so that the first spiral groove drives the air away from the MHD sealing mechanism. By providing a first helical groove at the connection between the outer shell and the rotating shaft, the first helical groove, the outer shell, and the rotating shaft work together to push the cryogenic gas away from the magnetic fluid sealing mechanism when the rotating shaft rotates at high speed. This creates a vacuum in the cavity between the magnetic fluid sealing mechanism and the first helical groove, reducing the contact between the cryogenic gas and the magnetic fluid sealing mechanism, as well as reducing cryogenic conduction. Compared with the prior art, the magnetic fluid transmission device in this embodiment of the invention can better achieve dynamic sealing of gases in cryogenic or ultra-crescent environments. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of a magnetohydrodynamic transmission device provided in an embodiment of the present invention;

[0054] Figure 2 A schematic diagram of a rotating shaft provided in an embodiment of the present invention;

[0055] Figure 3 for Figure 2 The first sectional view at point AA;

[0056] Figure 4 for Figure 2 The second sectional view at point AA;

[0057] Figure 5 A schematic diagram of a magnetic pole structure provided in an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of a second spacer provided in an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram of the outer casing provided in an embodiment of the present invention.

[0060] Reference numerals: 1. Outer shell; 2. Rotating shaft; 21. Mandrel; 22. Bushing; 23. Vacuum chamber; 3. Magnetofluid sealing mechanism; 5. Channel; 31. Magnetic pole; 32. Magnetofluid; 33. Permanent magnet; 34. Magnetic pole tooth; 35. First bearing; 36. Second bearing; 38. First spacer; 39. Second spacer; 311. First insulation groove; 312. First heat dissipation ring; 313. First seal; 391. Second insulation groove; 392. Second heat dissipation ring; 393. Second seal; 61. First spiral groove; 62. Second spiral groove; 63. Heat exchange chamber; 64. Temperature sensor; 65. Third spiral groove; 66. Fourth spiral groove; 11. Shell; 12. End cap. Detailed Implementation

[0061] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly set on the other component; when a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to the other component.

[0063] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0064] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" or "several" means two or more, unless otherwise explicitly specified.

[0065] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0066] The embodiments of this invention are written in a progressive manner.

[0067] like Figures 1 to 7As shown, this embodiment of the invention provides a magnetohydrodynamic transmission device, including: a rotating shaft 2; a housing 1 fitted on the outside of the rotating shaft 2 and rotatably connected to the rotating shaft 2, with a receiving cavity provided between the rotating shaft 2 and the housing 1; a magnetohydrodynamic sealing mechanism 3 disposed in the receiving cavity, the magnetohydrodynamic sealing mechanism 3 being disposed between the rotating shaft 2 and the housing 1; a first spiral groove 61 disposed at the connection between the housing 1 and the rotating shaft 2, and a driving member (not shown in the figure) driving the rotating shaft 2 to rotate, so that the first spiral groove 61 drives air to be conveyed in a direction away from the magnetohydrodynamic sealing mechanism 3.

[0068] It should be noted that the driving component driving the rotating shaft 2 to rotate specifically means that the driving component drives the rotating shaft 2 to rotate around the axis of the rotating shaft 2.

[0069] When existing magnetohydrodynamic sealing transmission devices encounter operating conditions with temperatures below -50°C, such as when air temperature control systems require magnetohydrodynamic sealing, the magnetic properties of the magnetohydrodynamic fluid limit the process. In low-temperature environments, the magnetohydrodynamic fluid used for dynamic sealing eventually solidifies, rendering it unable to perform its transmission and sealing functions.

[0070] The magnetohydrodynamic (MHD) transmission device provided by this invention, firstly, comprises a rotating shaft 2, a housing 11, and a MHD sealing mechanism 3. The housing 1 is fitted onto the rotating shaft 2, and the housing 1 and rotating shaft 2 are rotatably connected. A receiving cavity is provided between the housing 1 and the rotating shaft 2. The MHD sealing mechanism 3 is disposed within the receiving cavity and between the rotating shaft 2 and the housing 1. The function of the MHD sealing mechanism 3 is to ensure that the transported gas does not exchange with the outside air, providing a sealing effect and a transmission effect that drives the fan blades to rotate. However, since the sealing medium in the MHD sealing mechanism 3 is easily affected by temperature and is difficult to stabilize at low temperatures, it cannot effectively perform the transmission and sealing functions. To prevent heat exchange between the connection between the housing 1 and the rotating shaft 2 and the air in the receiving cavity due to low temperatures, a first spiral groove 61 is also provided. The first spiral groove 61 is located at the connection between the housing 1 and the rotating shaft 2. A driving component drives the rotating shaft 2 to rotate around its axis, so that the first spiral groove 61 drives the air to be transported away from the MHD sealing mechanism 3. By providing a first spiral groove 61 at the connection between the outer shell 1 and the rotating shaft 2, the rotating shaft 2, in cooperation with the first spiral groove 61, the outer shell 1, and the rotating shaft 2, pushes the cryogenic gas away from the magnetic fluid sealing mechanism 3 when the rotating shaft 2 rotates at high speed. This creates a vacuum in the cavity between the magnetic fluid sealing mechanism 3 and the first spiral groove 61, reducing the contact between the cryogenic gas and the magnetic fluid sealing mechanism 3, as well as reducing cryogenic conduction. Compared with the prior art, the magnetic fluid transmission device in this embodiment of the invention can better achieve dynamic sealing of gases in cryogenic or ultra-crescent environments.

[0071] In the above structure, as one embodiment, one end of the rotating shaft 2 is connected to a driving component such as a motor in the atmospheric environment, and the other end of the rotating shaft 2 is connected to a fan blade inside the sealed cavity. If the temperature of the gas transmitted inside the sealed cavity is too low, the low-temperature gas will exchange heat with the cavity through the connection between the outer shell 1 and the rotating shaft 2. In this case, the first spiral groove 61 in this embodiment of the invention is provided on the side of the outer shell 1 away from the driving component. The first spiral groove 61 is provided on the outer wall of the rotating shaft 2, and the direction of rotation of the first spiral groove 61 is opposite to the direction of rotation of the rotating shaft 2; or, the first spiral groove 61 is provided on the inner wall of the outer shell 1, and the direction of rotation of the first spiral groove 61 is the same as the direction of rotation of the rotating shaft 2.

[0072] In the above structure, during the high-speed rotation of the shaft 2, the low-temperature gas is transported away from the magnetic fluid sealing mechanism 3 through the cooperation between the first spiral groove 61, the shaft 2, and the outer shell 1. However, the low-temperature gas is prone to liquefaction during transport, and the space within the first spiral groove 61 is limited, thus hindering the discharge of the low-temperature gas from the first spiral groove 61. To solve this problem, the magnetic fluid transmission device in this embodiment of the invention further includes a second spiral groove 62, which works in conjunction with the first spiral groove 61. The rotation direction of the second spiral groove 62 is opposite to that of the first spiral groove 61, and the pitch and groove depth of the second spiral groove 62 and the first spiral groove 61 are the same, increasing the air transport space between the outer shell 1 and the shaft 2. Even if the low-temperature gas liquefies, it can still be transported. Both the first spiral groove 61 and the second spiral groove 62 can transport low-temperature air or liquefied gas away from the magnetic fluid sealing mechanism 3, resulting in higher efficiency.

[0073] Specifically, in one embodiment, the first spiral groove 61 is provided on the outer wall of the rotating shaft 2, and the direction of rotation of the first spiral groove 61 is opposite to the direction of rotation of the rotating shaft 2. Then, the second spiral groove 62 is provided on the inner wall of the outer shell 1, and the direction of rotation of the second spiral groove 62 is the same as that of the rotating shaft 2. In another embodiment, the second spiral groove 62 is provided on the outer wall of the rotating shaft 2, and the direction of rotation of the second spiral groove 62 is opposite to that of rotation of the rotating shaft 2. Then, the first spiral groove 61 is provided on the inner wall of the outer shell 1, and the direction of rotation of the first spiral groove 61 is the same as that of rotation of the rotating shaft 2.

[0074] In the above structure, as one embodiment, the outer shell 1 of the present invention includes a shell 11 and an end cap 12. The shell 11 and the end cap 12 are both fitted on the rotating shaft 2, and the accommodating cavity is disposed between the shell 11 and the end cap 12. The end cap 12 and the shell 11 are fixedly connected by screws. In the present invention, the end cap 12 is disposed at the end of the rotating shaft 2 near the drive component, and the shell is disposed at the end of the rotating shaft 2 near the fan blade, which makes installation easier.

[0075] In the above structure, as a preferred embodiment, the magnetohydrodynamic transmission device in this embodiment of the invention further includes a heat exchange chamber 63 and a channel 5. The heat exchange chamber 63 is disposed inside the outer shell 1 and is located outside the first spiral groove 61. The channel 5 is disposed on the outer shell 1 and communicates with the heat exchange chamber 63, allowing the heat-insulating medium to be supplied into the heat exchange chamber 63. By providing the heat exchange chamber 63 on the outer shell 1 and supplying the heat-insulating medium into the heat exchange chamber 63, heat conduction from low-temperature gas outside the outer shell 1 through the components inside the outer shell 1 is prevented, thus ensuring the operating temperature of the magnetohydrodynamic sealing mechanism 3.

[0076] Furthermore, as one embodiment, the heat-insulating medium in this invention includes, but is not limited to, heating media such as high-temperature steam, hot air, and water. Through heat exchange between the heat-insulating medium and the low-temperature air, the working temperature of the magnetic fluid sealing mechanism 3 is guaranteed, and the sealing and transmission effect of the magnetic fluid sealing mechanism 3 is prevented from being affected by the low-temperature air.

[0077] In the above structure, as one embodiment, the magnetohydrodynamic transmission device in this invention further includes a temperature sensor 64, wherein the temperature sensor 64 is disposed on the outer shell 1 and is used to detect the temperature inside the heat exchange chamber 63. When the temperature inside the heat exchange chamber 63 exceeds the preset range, the temperature, flow rate, pressure and other parameters of the heat insulation medium can be adjusted so that the temperature inside the heat exchange chamber 63 is adjusted to the preset range.

[0078] In the above structure, as one embodiment, the magnetohydrodynamic transmission device in this invention further includes a controller and a heating element. The heating element is disposed in the channel and is used to heat the insulation medium. The heating element is connected to the controller. When the temperature of the insulation medium detected by the temperature sensor 64 is too low, the heating element can heat the insulation medium. When the temperature of the insulation medium detected by the temperature sensor 64 reaches a preset range, the heating element stops heating.

[0079] Please Figure 2As shown, the rotating shaft 2 in this embodiment of the invention includes: a spindle 21; a bushing 22 fitted on the outside of the spindle 21, the bushing 22 being fixedly connected to the spindle 21, a vacuum cavity 23 being provided between the bushing 22 and the spindle 21, and a housing 1 being rotatably fitted on the outside of the bushing 22. Specifically, the magnetohydrodynamic transmission device provided by the present invention includes a spindle 21, a bushing 22, and a vacuum cavity 23. The bushing 22 is fitted on the outside of the spindle 21 and is fixedly connected to the spindle 21. A vacuum cavity 23 is provided between the bushing 22 and the spindle 21. The device also includes a housing 1 and a magnetohydrodynamic sealing mechanism 3. The housing 1 is fitted on the outside of the bushing 22 and is rotatably connected to the bushing 22. A magnetohydrodynamic sealing mechanism 3 is provided between the housing 1 and the bushing 22. Since the vacuum chamber 23 is a vacuum environment and contains no medium for temperature conduction, low temperatures are prevented from reaching the sealing area through conduction, thus reducing the impact of low temperatures on the sealing effect. Compared with the prior art, the magnetic fluid transmission device in this embodiment of the invention provides a vacuum chamber 23 between the mandrel 21 and the bushing 22, reducing the conduction of low temperatures to the magnetic fluid sealing mechanism 3 through the mandrel 21, and thus better achieving dynamic sealing of gases in low-temperature or ultra-low-temperature environments.

[0080] In this embodiment of the invention, a vacuum chamber 23 is provided between the mandrel 21 and the bushing 22. There is no heat-conducting medium in the vacuum chamber 23. Temperature is conducted through the extremely small area at the joint between the bushing 22 and the mandrel 21, making it difficult for low temperature to be conducted to the sealing part, thereby ensuring the working temperature of the sealing material magnetic fluid.

[0081] As one of the first implementation methods, please refer to Figure 3 As shown, in this embodiment of the invention, both ends of the bushing 22 are sealed to the spindle 21.

[0082] In the above structure, as a second implementation method, please refer to... Figure 4 As shown, in this embodiment of the invention, one end of the mandrel 21 is connected to the blades in the vacuum equipment, and the end of the bushing 22 away from the vacuum equipment is sealed to the mandrel 21. When the mandrel 21 is connected to the blades in the vacuum equipment, since the vacuum equipment itself is a vacuum environment, the end of the bushing 22 near the vacuum equipment can be set to an open form, that is, the end of the vacuum chamber 23 near the vacuum equipment is connected to the vacuum environment, thereby reducing the conduction of low temperature through the vacuum chamber 23 between the bushing 22 and the mandrel 21. This configuration can reduce the manufacturing difficulty of the mandrel 21 and the bushing 22.

[0083] More specifically, the sealed connection between the bushing 22 and the spindle 21 includes the following embodiments: In a first embodiment, the bushing 22 and the spindle 21 are specifically welded together. In another embodiment, the bushing 22 and the spindle 21 are sealed together using a sealing element.

[0084] In the above structure, as one embodiment, the magnetohydrodynamic transmission device of the present invention further includes a heat insulation layer disposed on the outer surface of the mandrel 21. By providing a heat insulation layer on the outer surface of the mandrel 21, the heat exchange between the mandrel 21 and the bushing 22 is reduced. As a specific embodiment, the heat insulation layer in the present invention includes coating the outer surface of the mandrel with a heat-insulating coating, or covering the outside of the mandrel 21 with heat-insulating material.

[0085] Furthermore, as one embodiment, the outer shell 1 is rotatably mounted on the rotating shaft 2 in this embodiment of the invention, and the outer shell 1 is fixed to the customer equipment, thus achieving a static seal.

[0086] In the above structure, the magnetic fluid sealing mechanism 3 in this embodiment of the invention includes magnetic poles 31, magnetic fluid 32, and permanent magnets 33. Magnetic poles 31 are disposed between the outer shell 1 and the bushing 22, and are fitted onto the bushing 22. The inner hole of the magnetic poles 31 is clearance-fitted with the bushing 22. Magnetic fluid 32 is disposed within the installation gap between the magnetic poles 31 and the bushing 22. At least two magnetic poles 31 are provided, and they are spaced apart along the axial direction of the bushing 22. A permanent magnet 33 is disposed between two adjacent magnetic poles 31. The permanent magnet 33 generates a magnetic field, which forms a magnetic circuit through the magnetic poles 31, the installation gap, and the bushing 22, thereby confining the magnetic fluid 32 and forming a liquid O-ring between the bushing 22 and the magnetic poles 31, thus achieving a dynamic seal.

[0087] Furthermore, in the above structure, the N and S poles of the permanent magnet 33 in this embodiment of the invention are distributed along the axial direction of the bushing 22. The bushing 22 and the magnetic poles 31 are made of magnetically conductive material. The magnetic field reaches the S pole of the permanent magnet 33 from the N pole through the magnetic poles 31, the mounting gap, and the bushing 22, forming a closed magnetic circuit. The magnetic fluid 32 is disposed between the bushing 22 and the magnetic poles 31. Under the action of the magnetic field, the magnetic fluid 32 is stably attracted between the bushing 22 and the magnetic poles 31, realizing the separation of the space at both ends of the magnetic field and forming a reliable seal.

[0088] Furthermore, as one embodiment, the magnetic poles 31 in this invention are provided with at least two sets, so that at least two sets of liquid O-rings are formed between the outer surface of the bushing 22 and the inner hole of the magnetic pole 31, resulting in a better dynamic sealing effect.

[0089] In the above structure, as one embodiment, the magnetic fluid sealing mechanism 3 in this embodiment of the invention further includes magnetic pole teeth 34, wherein the magnetic pole teeth 34 are disposed on the inner wall of the magnetic pole 31, or the magnetic pole teeth 34 are disposed on the outer surface of the bushing 22.

[0090] Please Figure 5 As shown, furthermore, in order to prevent the influence of low temperature on the sealing performance of the magnetic fluid, as a preferred embodiment, the magnetic fluid transmission device in this invention further includes a first heat preservation groove 311 and a first sealing element 313. The first heat preservation groove 311 and the first sealing element 313 are disposed between the magnetic pole 31 and the outer shell 1. There are two first sealing elements, which are respectively disposed on both sides of the first heat preservation groove. Since the first sealing element 313 is disposed at both ends of the first heat preservation groove 311, the heat preservation effect of the first heat preservation groove 311 is better. The first sealing element 313 can also play a static sealing role, and its sealing effect is better. The channel 5 is connected to the first heat preservation groove. The heat preservation medium can be transported into the first heat preservation groove through the channel 5. The heat preservation medium can be transported into the first heat preservation groove 311 through the channel 5. Heat exchange occurs between the heat preservation medium and the magnetic pole 31 and the magnetic fluid 32, thereby avoiding the effect of the dynamic sealing of the magnetic fluid 32 due to excessively low temperature.

[0091] Furthermore, the magnetic fluid sealing mechanism 3 in this embodiment of the invention also includes a first heat dissipation ring 312, wherein the first heat dissipation ring 312 is disposed in the first heat insulation groove 311 and is connected to the magnetic pole 31. The outer diameter of the first heat dissipation ring 312 is smaller than the outer diameter of the magnetic pole 31, so it will not affect the installation of the magnetic pole 31. Due to the provision of the first heat dissipation ring 312, the contact area between the heat insulation medium and the magnetic pole 31 is increased, and the heat exchange effect between the heat insulation medium and the magnetic fluid 32 is better.

[0092] Furthermore, as one embodiment, the magnetohydrodynamic sealing mechanism 3 in this invention further includes a first bearing 35 and a second bearing 36. The first bearing 35 and the second bearing 36 are mounted on the rotating shaft 2, and are disposed between the rotating shaft 2 and the outer casing 1 to support the outer casing 1. The first bearing is disposed at the end of the rotating shaft 2 near the drive component, and the second bearing is disposed at the end of the rotating shaft 2 near the fan blade. Furthermore, in order to position the magnetic pole 31 axially and prevent axial movement of the magnetic pole 31 within the accommodating cavity, a first spacer 38 is disposed between the first bearing 35 and the magnetic pole 31, and a second spacer 39 is disposed between the second bearing 36 and the magnetic pole 31. The axial positioning of the magnetic pole 31 is achieved through the first spacer 38 and the second spacer 39. Furthermore, the first spacer 38 and the second spacer 39 are made of non-magnetic material, which can be used to isolate the magnetic field and prevent the bearing from being magnetized.

[0093] To further prevent the influence of low-temperature air on the magnetic fluid sealing mechanism 3, as one embodiment of the invention, the magnetic fluid sealing mechanism 3 further includes a third spiral groove 65. The third spiral groove 65 is disposed at the connection between the second spacer and the rotating shaft 2. The third spiral groove 65 is located on the outer wall of the rotating shaft 2, and its rotation direction is opposite to the rotation direction of the rotating shaft 2. Alternatively, the third spiral groove 65 is disposed on the inner hole of the second spacer 39, and its rotation direction is the same as the rotation direction of the rotating shaft 2. The rotation direction and function of the third spiral groove 65 are the same as those of the first spiral groove 61, both aiming to push the low-temperature air away from the magnetic fluid sealing mechanism 3, thus preventing heat exchange between the low-temperature air and the magnetic fluid sealing mechanism 3 and affecting its sealing and transmission performance.

[0094] Furthermore, the magnetohydrodynamic sealing mechanism 3 in this embodiment of the invention also includes a fourth helical groove 66, which cooperates with the third helical groove 65, and the direction of rotation of the fourth helical groove 66 is opposite to that of the third helical groove 65, and the pitch and groove depth of the fourth helical groove 66 and the third helical groove 65 are the same. In a first embodiment, when the third helical groove 65 is disposed on the outer wall of the rotating shaft 2 and its direction of rotation is opposite to that of the rotating shaft 2, the fourth helical groove 66 is disposed on the inner hole of the second spacer 39, and its direction of rotation is the same as that of the rotating shaft 2. In a second embodiment, when the third helical groove 65 is disposed on the inner hole of the second spacer 39 and its direction of rotation is the same as that of the rotating shaft 2, the fourth helical groove 66 is disposed on the outer wall of the rotating shaft 2, and its direction of rotation is opposite to that of the rotating shaft 2.

[0095] Furthermore, as one embodiment, in this invention, the side of the rotating shaft 2 near the first bearing 35 is connected to the drive component in the atmospheric environment, and the end of the rotating shaft 2 near the second bearing 36 is connected to the fan blade. To prevent the low-temperature air on the sealed chamber side from affecting the sealing performance of the magnetofluid 32, as one embodiment, please refer to... Figure 6As shown, the magnetic fluid sealing mechanism 3 in this embodiment of the invention further includes a second heat-insulating groove 391 and a second heat-dissipating ring 392. The second heat-insulating groove 391 is disposed on the outside of the second spacer 39 and is connected to the channel 5. The heat-insulating medium is conveyed into the second heat-insulating groove 391 through the channel 5. In order to further increase the heat-insulating effect of the second spacer 39, a second heat-dissipating ring 392 is provided in the second heat-insulating groove 391. The outer diameter of the second heat-dissipating ring 392 is smaller than the outer diameter of the second spacer 39. Due to the presence of the second heat-dissipating ring 392, the contact area between the heat-insulating medium and the second spacer 39 is further increased, resulting in a better heat-insulating effect.

[0096] In the above structure, as one embodiment, the second heat preservation groove 391 in this embodiment of the invention is specifically ring-shaped.

[0097] In the above structure, at least two second heat dissipation rings 392 are provided in the embodiments of the present invention, and the second heat dissipation rings 392 are spaced apart along the axial direction of the second spacer 39.

[0098] Furthermore, as one embodiment, the magnetic fluid sealing mechanism 3 in this invention further includes a second sealing element 393. The second sealing element 393 is disposed between the second spacer 39 and the outer shell 1. At least two second sealing elements 393 are provided, respectively disposed on both sides of the second insulation groove 391. On one hand, since the second sealing element 393 is provided at both ends of the second insulation groove 391, the insulation effect of the second insulation groove 391 is better. On the other hand, the second sealing element 393 can play a static sealing role, preventing cold air from entering the accommodating cavity through the gap between the second spacer 39 and the outer shell 1, thus improving its sealing effect.

[0099] Furthermore, as one embodiment, the first spacer 38 in this invention is specifically an annular spacer, which serves to axially position the end of the magnetic pole 31 away from the second spacer 39.

[0100] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A magnetohydrodynamic transmission device, characterized in that, include: Shaft (2); A housing (1) is fitted on the outside of the rotating shaft (2) and rotatably connected to the rotating shaft (2), and a receiving cavity is provided between the rotating shaft (2) and the housing (1); A magnetic fluid sealing mechanism (3) is disposed within the accommodating cavity, and the magnetic fluid sealing mechanism (3) is disposed between the rotating shaft (2) and the outer shell (1); A first spiral groove (61) is provided at the connection between the outer shell (1) and the rotating shaft (2). The driving member drives the rotating shaft (2) to rotate, so that the first spiral groove (61) drives the air to be transmitted away from the magnetic fluid sealing mechanism (3). The first helical groove is located at the end of the rotating shaft away from the driving member. The first helical groove (61) is disposed on the outer wall of the rotating shaft (2), and the direction of rotation of the first helical groove (61) is opposite to the direction of rotation of the rotating shaft (2); or, The first spiral groove (61) is provided on the outer wall of the outer shell (1), and the direction of the first spiral groove (61) is the same as the direction of the rotation of the shaft (2); Also includes: A second spiral groove (62) used in conjunction with the first spiral groove (61) has a spiral direction opposite to that of the first spiral groove (61); in, The second spiral groove (62) is provided on the inner wall of the outer casing (1), or the second spiral groove (62) is provided on the outer wall of the rotating shaft (2); Also includes: A heat exchange cavity (63) is disposed within the outer casing (1), the heat exchange cavity (63) being located outside the first spiral groove (61); A channel (5) is provided on the outer shell (1) and communicates with the heat exchange chamber (63) to deliver the heat insulation medium into the heat exchange chamber (63). Also includes: A temperature sensor (64) is disposed on the outer casing (1) for detecting the temperature inside the heat exchange chamber (63). The rotating shaft (2) includes: mandrel (21); A bushing (22) is fitted on the outside of the mandrel (21), the bushing (22) is fixedly connected to the mandrel (21), a vacuum cavity (23) is provided between the bushing (22) and the mandrel (21), and the outer shell (1) is rotatably fitted on the outside of the bushing (22); The magnetic fluid sealing mechanism (3) includes: A magnetic pole (31) is disposed between the rotating shaft (2) and the outer shell (1) and sleeved on the rotating shaft (2). The magnetic pole (31) is in clearance fit with the rotating shaft (2). A magnetic fluid (32) is disposed between the magnetic pole (31) and the mounting gap of the rotating shaft (2). There are at least two magnetic poles (31), and the magnetic poles (31) are spaced apart along the axis of the rotating shaft (2), and a permanent magnet (33) is provided between adjacent magnetic poles (31).

2. The magnetohydrodynamic transmission device according to claim 1, characterized in that, The magnetic fluid sealing mechanism (3) further includes: A first heat-insulating groove (311) and a first sealing member (313) are provided between the magnetic pole and the outer shell. There are two first sealing members (313), which are respectively provided on both sides of the first heat-insulating groove (311). The outlet of the channel (5) is connected to the first insulation tank (311) and is used to deliver the insulation medium into the first insulation tank (311).

3. The magnetohydrodynamic transmission device according to claim 2, characterized in that, The magnetic fluid sealing mechanism (3) further includes: A first heat dissipation ring (312) is disposed in the first heat insulation groove (311) and connected to the magnetic pole (31). The outer diameter of the first heat dissipation ring (312) is smaller than the outer diameter of the magnetic pole (31).

4. The magnetohydrodynamic transmission device according to claim 1, characterized in that, The magnetic fluid sealing mechanism (3) further includes magnetic pole teeth (34). The magnetic pole teeth (34) are disposed on the inner wall of the magnetic pole (31); or the magnetic pole teeth (34) are disposed on the outer surface of the rotating shaft (2).

5. The magnetohydrodynamic transmission device according to any one of claims 1 to 4, characterized in that, The magnetic fluid sealing mechanism (3) further includes: A first bearing (35) and a second bearing (36) are disposed within the accommodating cavity, the second bearing being disposed at one end of the rotating shaft (2) near the outer casing (1); A first spacer (38) is provided between the first bearing (35) and the magnetic pole (31), a second spacer (39) is provided between the second bearing (36) and the magnetic pole (31), and a third spiral groove (65) is provided at the connection between the rotating shaft (2) and the second spacer (39). in, The third spiral groove (65) is disposed on the outer wall of the rotating shaft (2), and the direction of rotation of the third spiral groove (65) is opposite to the direction of rotation of the rotating shaft (2); or, The third spiral groove (65) is provided on the inner hole of the second spacer (39), and the direction of the third spiral groove (65) is the same as the direction of rotation of the shaft (2).

6. The magnetohydrodynamic transmission device according to claim 5, characterized in that, Also includes: A fourth spiral groove (66) is used in conjunction with the third spiral groove (65), the direction of rotation of the fourth spiral groove (66) being opposite to that of the third spiral groove (65); in, The fourth spiral groove (66) is provided on the inner hole of the second spacer (39), or the fourth spiral groove (66) is provided on the outer wall of the rotating shaft (2).

7. The magnetohydrodynamic transmission device according to claim 6, characterized in that, The magnetic fluid sealing mechanism (3) further includes: A second heat insulation groove (391) is disposed on the outer surface of the second spacer (39) and communicates with the channel (5). A second heat dissipation ring (392) is disposed inside the second heat insulation groove (391) and connected to the second spacer (39). The outer diameter of the second heat dissipation ring (392) is smaller than the outer diameter of the second spacer (39).

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