A shell-driven magnetic fluid sealing transmission device and its manufacturing method

Abstract

The present invention discloses a shell-driven magnetic fluid seal transmission device, comprising: an integrated inner shaft, a shaft member for connecting to a central stationary component within a vacuum chamber; a magnetic fluid seal assembly integrated on the integrated inner shaft; an outer shaft, a shaft body for fixedly connecting to a mounting portion of the vacuum chamber, the outer shaft being fixedly connected to the integrated inner shaft and forming a transmission cavity radially with the integrated inner shaft; and a transmission housing, a component for transmitting power from the atmosphere to the interior of the vacuum chamber. The transmission housing is rotatably disposed between the integrated inner shaft and the outer shaft via a transmission member, and forms a magnetic fluid seal structure with the magnetic fluid seal assembly. A manufacturing method for the transmission device is also disclosed. By using an integrated inner shaft and outer shaft in combination, the transmission housing is disposed and rotated between the inner and outer shafts, achieving single-axis transmission and a transmission method in which the rotating component rotates while the central component remains stationary, resulting in good transmission efficiency and high sealing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic fluid sealing, and in particular to a shell-driven magnetic fluid sealing transmission device and a manufacturing method thereof. Background Art

[0002] Magnetic fluid seals are widely used in vacuum-related equipment, such as semiconductors, optical fibers, medical devices, and satellites. Their primary purpose is to transfer power or specific gases from outside the vacuum chamber to the inside, maintaining the required vacuum level. The core component is the magnetic fluid, which acts like a liquid seal in a magnetic fluid seal, providing a dynamic seal.

[0003] A magnetic fluid sealed transmission generally consists of a housing, a sealing assembly, and bearings. The magnetic seal assembly primarily comprises a spindle, a magnet, magnetic poles 1 and 2, and magnetic fluid (also called magnetic fluid). The magnet is located between magnetic poles 1 and 2. Spindle teeth are machined into the mating areas between the spindle, the magnet, and the magnetic poles. The gaps between the spindle teeth and the magnetic poles are filled with magnetic fluid, which acts as a seal under the influence of the magnetic field. Because the spindle tooth profile is limited by the spindle structure and machining conditions, this introduces significant inconvenience during machining. Furthermore, the overall structure of the magnetic fluid sealed transmission cannot meet the requirements of vacuum transmissions in confined spaces, particularly for transmissions where the spindle assembly is stationary.

[0004] Conventional magnetic fluid sealed transmission devices have a housing installed at the interface of the vacuum chamber, and the main shaft transmits power to the interior of the vacuum chamber. However, sometimes the vacuum chamber requires the central component of the chamber to remain stationary, while the vacuum chamber requires rotation around the central component. In this way, the conventional magnetic fluid sealed transmission device cannot achieve transmission. In order to achieve the goal of keeping the central component of the chamber stationary while the vacuum chamber requires rotation around the central component, the currently adopted technical solution is to use two magnetic fluid sealed transmission devices or a dual-axis magnetic fluid sealed transmission device to achieve this special transmission requirement. However, two magnetic fluid sealed transmission devices or a dual-axis magnetic fluid sealed transmission device have problems such as complex structure, large transmission error, and poor sealing performance.

[0005] Therefore, it is urgent to design a magnetic fluid sealing transmission device with simple structure, good transmission effect and strong sealing performance to achieve the transmission of this special requirement. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of complex structure, large transmission error and poor sealing performance of the existing magnetic fluid sealing transmission device, and to provide a shell-driven magnetic fluid sealing transmission device with a simple structure, good transmission effect and strong sealing performance, which can meet the installation requirements of narrow equipment installation space, meet the requirements that the central component is stationary while the rotating components outside the central component are driven around the central component, and can realize single-axis transmission and a manufacturing method thereof.

[0007] The technical solution adopted by the present invention to achieve the first invention object is: a shell-driven magnetic fluid sealing transmission device, comprising:

[0008] An integrated inner shaft is a shaft member connected to the central component inside the vacuum chamber; the integrated inner shaft is integrated with a magnetic fluid sealing component;

[0009] The outer shaft is a shaft body fixedly connected to the mounting portion of the true cavity, the outer shaft is fixedly connected to the one-piece integrated inner shaft, and forms a transmission cavity in the radial direction with the one-piece integrated inner shaft;

[0010] The transmission housing is a component used to transmit power from the atmospheric side to the inside of the vacuum cavity. The transmission housing is rotatably arranged in the transmission cavity through a transmission member and forms a magnetic fluid sealing structure with the magnetic fluid sealing assembly.

[0011] The shell-driven magnetic fluid sealed transmission device adopts an integrated inner shaft and outer shaft to form a transmission chamber, and a transmission housing is arranged in the transmission chamber. The transmission housing plays the function of a single-axis transmission, which is used to transmit power from the atmospheric side to the vacuum side. Moreover, the transmission housing is connected to the vacuum chamber and the rotating component outside the central component inside it, realizing the transmission mode of the outer rotating component being driven while the central component is stationary. This effectively solves the requirement that the existing magnetic fluid sealed transmission device can only realize the transmission of the central component being stationary and the rotating component outside the central component being driven by two magnetic fluid sealed transmission devices or dual-axis transmission. The magnetic fluid sealing component is integrated on the inner shaft to form a magnetic fluid sealing structure between the magnetic fluid sealing component and the external transmission housing. Due to the use of an integrated inner shaft, the overall structure is more compact and simple. It is only necessary to combine the transmission housing and the outer shaft according to the transmission requirements to realize the setting of the entire magnetic fluid sealing transmission device. This structural setting in which the inner and outer shafts are stationary and the power is transmitted through the transmission housing realizes the stationary center component inside the vacuum cavity by using a single-axis magnetic fluid sealing transmission, and drives the rotating component outside the center component to rotate around the center component through the transmission housing. This transmission structure not only simplifies the structure of the device, but also makes the force transmission effect of the magnetic fluid sealing transmission better and improves the transmission effect. At the same time, due to the less assembly between components and the reduction of assembly errors, the sealing performance is greatly improved, and the axial length can be shortened in the axial direction to meet the installation requirements of a small space.

[0012] Preferably, the one-piece integrated inner shaft further comprises an inner shaft body and a sleeve, wherein the magnetic fluid seal assembly is sleeved on one end of the inner shaft body facing the vacuum side, and the sleeve is sleeved on one end of the inner shaft body facing the atmosphere side and is fixedly connected to the inner shaft body by welding. The one-piece integrated inner shaft is mainly composed of the inner shaft body and the sleeve that is welded and fixed to the inner shaft body as one, so as to form an one-piece integrated inner shaft, which serves as a fixed shaft for connecting to the central component produced in the vacuum chamber and playing a supporting role in power transmission. The integrated structure makes the inner shaft, the magnetic fluid seal assembly and the sleeve an integral whole. The overall structure can not only reduce the installation error of the transmission components, but also reduce the transmission error and improve the sealing performance. In the design of the magnetic fluid seal, it is only necessary to ensure the sealing performance between the magnetic pole seal teeth on the magnetic pole and the magnetic fluid and the transmission housing, making the transmission device more convenient to manufacture.

[0013] Preferably, the inner shaft body is a non-magnetic shaft body. An inner shaft flange is provided at the end of the inner shaft body facing the vacuum chamber. A sealing ring body is integrally connected to the inner shaft flange, and a sealing convex ring is provided on the circumferential surface of the sealing ring body. A welding end is provided at the end of the inner shaft body facing the atmosphere, and an inner shaft welding bevel is provided on the outer diameter of the welding end. The inner shaft body is a non-magnetic shaft body. The inner shaft flange is used to achieve docking with the central component within the vacuum chamber. The sealing ring body and the sealing convex ring are provided to cooperate with the transmission housing to achieve connection, while ensuring the sealing performance of the magnetic fluid seal.

[0014] Preferably, the sleeve is a non-magnetic component, and the end of the sleeve facing the vacuum side is provided with a magnetic pole fixing end, the sleeve is provided with a bearing mounting seat, the end of the sleeve facing the atmosphere side is provided with an outer shaft connecting end, and the inner diameter of the outer shaft connecting end is provided with a sleeve welding bevel. The sleeve is not only a positioning member for the bearing mounting seat and the magnetic fluid sealing assembly, but also a transition member that connects the inner shaft and the outer shaft as one. Therefore, the magnetic pole fixing end is provided at the end of the sleeve facing the vacuum side for positioning and fixing the magnetic fluid sealing assembly, while the bearing mounting seat is used to install the transmission member to achieve a transmission connection between the transmission housing and the inner shaft, and the outer shaft connecting end is used to achieve a fixed connection with the outer shaft, thereby forming a transmission structure design in which the transmission housing is located between the inner shaft and the outer shaft. The sleeve welding bevel is provided on the inner diameter of the outer shaft connecting end to facilitate the welding connection with the inner shaft body.

[0015] Preferably, the magnetic fluid seal assembly includes a magnetic pole assembly and a magnetic fluid coated on the magnetic pole assembly. The magnetic pole assembly includes a plurality of magnetic poles and magnetic blocks disposed between adjacent magnetic poles. A plurality of magnetic pole sealing teeth are evenly distributed on the outer diameter of the magnetic poles, and the magnetic fluid is coated on the magnetic pole sealing teeth. A static seal is disposed on the inner diameter of the magnetic poles. The magnetic fluid seal assembly is a key component in forming a magnetic fluid seal. The magnetic pole assembly primarily comprises a plurality of magnetic poles and a plurality of magnetic blocks. The magnetic pole assembly cooperates with the magnetic transmission housing to form a magnetic field, concentrating the magnetic fluid disposed on the magnetic poles to form a so-called "O" ring, which blocks the gap channel and achieves a sealing effect. This magnetic fluid seal assembly disposes the magnetic pole sealing teeth on the magnetic poles, resolving the structural limitations and processing difficulties associated with disposing the magnetic pole sealing teeth on the transmission main shaft. The magnetic pole seal teeth can be configured in various shapes, such as rectangular, trapezoidal, and circular, depending on the inner diameter of the transmission housing, rotational speed, and other operating conditions. To achieve a more compact axial structure, the length of the sealing area can be minimized. To minimize the sealing area, trapezoidal teeth can be used, and the number of teeth can be reduced compared to existing rectangular teeth. To achieve a better sealing effect, the magnetic pole seal teeth can adopt an inwardly concave arc shape. This structure allows the magnetic fluid above them to form a more effective magnetic fluid seal under the influence of the magnetic field.

[0016] Preferably, the transmission housing is made of magnetic stainless steel material, and the transmission housing includes an integral vacuum insertion end, a sealing cavity and a bearing cavity. The vacuum insertion end cooperates with the integral inner shaft, and the inner diameter of the sealing cavity and the magnetic fluid sealing assembly form the magnetic fluid sealing structure. The transmission member is arranged inside the bearing cavity, and a non-magnetic housing end cover is provided at the end of the bearing cavity. The transmission housing is used to cooperate with the magnetic fluid sealing assembly to form a magnetic fluid seal. Therefore, the transmission housing is made of magnetic conductive material. The vacuum insertion end of the transmission housing extends into the vacuum cavity when installed, and the end face of the sealing cavity is connected to the transmission member outside the central component of the vacuum cavity. The interior of the sealing cavity cooperates with the magnetic fluid sealing assembly to form a magnetic field, thereby forming a magnetic fluid sealing structure. The bearing cavity is for accommodating the transmission member, and the housing end cover is for achieving axial positioning of the bearing.

[0017] Preferably, the transmission element is an angular contact bearing or a crossed ball bearing. Conventional angular contact bearings can be used as transmission elements, as they have a strong ability to withstand external forces, are inexpensive, and have a short procurement cycle, effectively reducing the cost of the magnetic fluid sealed transmission device. Alternatively, a crossed ball bearing can be used as the transmission element, which is suitable for low-speed, high-torque operating conditions and can shorten the axial length of the magnetic fluid sealed transmission device to accommodate installation requirements in confined equipment installation spaces.

[0018] Preferably, the outer shaft is a non-magnetic body, and the outer shaft includes an integral outer shaft flange, an outer shaft cavity, and a connection and positioning inner shaft seat. The connection and positioning inner shaft seat cooperates with the end of the integral inner shaft facing the atmosphere, and is fixedly connected as a whole by fasteners. The outer shaft is used to connect to the equipment installation port, so a non-magnetic body is used. The outer shaft cavity is provided to cooperate with the inner shaft to form a transmission cavity for installing the transmission housing, and the connection and positioning inner shaft seat is used to achieve a fixed connection with the inner shaft. Several connection holes are axially provided on the upper side of the outer shaft cavity for connection with the installation equipment.

[0019] The technical solution adopted by the present invention to achieve the second invention object is: a method for manufacturing a shell-driven magnetic fluid sealing transmission device, comprising the following steps:

[0020] Step 1: Fabricate the inner shaft body, outer shaft, sleeve, transmission housing, housing end cover, and magnetic pole assembly; and leave a finishing allowance on the inner shaft body and sleeve end facing the atmosphere;

[0021] Step 2: Assemble the integrated inner shaft. Sleeve the magnetic pole assembly onto the inner shaft body and make close contact with the end face of the sealing ring body. Sleeve the sleeve onto the inner shaft with its magnetic pole fixed end in close contact with the magnetic pole sealing assembly. Then, fix and protect the magnetic pole assembly with the tooling. Use electron beam welding equipment to weld the inner shaft body and the left end face of the sleeve at the welding bevel. After welding, fine-machine the welding end face. After machining, disassemble the tooling and clean the magnetic pole assembly.

[0022] Step 3: After the one-piece integrated inner shaft is manufactured, a certain amount of magnetic fluid is applied to the magnetic pole sealing teeth of the magnetic pole;

[0023] Step 4: Assemble the transmission parts on the bearing mounting seat of the sleeve, install the transmission housing outside the magnetic pole assembly from the vacuum side, and install the fixed housing end cover at one end on the atmosphere side;

[0024] Step 5: Finally, install the outer shaft from the atmospheric side, and connect the outer shaft, sleeve, and inner shaft body into one piece through fasteners to complete the production of the shell-driven magnetic fluid sealing transmission device.

[0025] The manufacturing method of the shell-driven magnetic fluid sealed transmission device makes the overall structure of the transmission device more compact, more convenient to install, and low in manufacturing cost, and realizes the transmission requirement of using a single-axis magnetic fluid transmission to meet the transmission requirements of keeping the central component inside the vacuum chamber stationary while the outer rotating component rotates.

[0026] The beneficial effects of the present invention are as follows: the shell-driven magnetic fluid sealed transmission device adopts an integrated inner shaft and outer shaft to form a transmission chamber, and a transmission housing is set in the transmission chamber. The transmission housing plays the role of a single-axis transmission, which is used to transmit power from the atmospheric side to the vacuum side, realizing the transmission of the outer rotating component while the central component is stationary. This effectively solves the requirement that the existing magnetic fluid sealed transmission device can only realize the transmission of the outer rotating component of the central component by a dual-axis transmission. This transmission structure not only simplifies the structure of the device, makes the force transmission effect of the magnetic fluid sealed transmission better, and improves the transmission effect, but also, due to the less assembly between components and the reduction of assembly errors, the sealing performance is greatly improved, and the axial length can be shortened in the axial direction to meet the installation requirements of a small space. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural schematic diagram of a shell-driven magnetic fluid sealing transmission device of the present invention;

[0028] Figure 2 This is a structural schematic diagram of the shell-driven magnetic fluid sealing transmission device of the present invention from another angle;

[0029] Figure 3 This is a cross-sectional view of the shell-driven magnetic fluid sealing transmission device of the present invention;

[0030] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0031] Figure 5 This is a structural schematic diagram of the one-piece integrated inner shaft in the present invention;

[0032] Figure 6 This is a structural diagram of the outer shaft in the present invention;

[0033] Figure 7 This is a structural diagram of the transmission housing in the present invention;

[0034] Figure 8 This is a structural schematic diagram of a shell-driven magnetic fluid sealing transmission device in Example 2 of the present invention;

[0035] Figure 9 yes Figure 8 Enlarged view of point B in the middle;

[0036] Figure 10 This is a schematic diagram of an installation of a shell-driven magnetic fluid sealing transmission device of the present invention;

[0037] In the figure: 1. One-piece integrated inner shaft, 2. Magnetic fluid sealing assembly, 3. Outer shaft, 31. Outer shaft flange, 32. Outer shaft cavity, 33. Connecting and positioning inner shaft seat, 34. Connecting hole, 4. Transmission cavity, 5. Transmission housing, 51. Vacuum inlet end, 52. Sealing cavity, 53. Bearing cavity, 54. Housing end cover, 6. Inner shaft body, 61. Inner shaft flange, 62. Sealing ring body, 63. Sealing convex ring, 64. Inner shaft welding end, 65. Inner shaft welding bevel, 7. Sleeve, 71. Magnetic pole fixed end, 72. Bearing mounting seat, 73. Outer shaft connecting end, 74. Sleeve welding bevel, 8. Magnetic pole assembly, 9. Magnetic fluid, 10. Magnetic pole, 101. Magnetic pole sealing tooth, 102. Sealing groove, 103. Groove, 104. Magnetic block mounting groove, 11. Magnetic block, 12. Static seal, 13. Transmission part, 14. Vacuum chamber installation part, 15. Center component, 16. Vacuum chamber, 17. Rotating component, 18. Pulley. DETAILED DESCRIPTION

[0038] The various aspects of the present invention are described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0039] Example 1:

[0040] exist Figure 1 、 Figure 2 、 Figure 3 In the illustrated embodiment, a shell-driven magnetic fluid seal transmission device includes: an integrated inner shaft 1 for connecting to a central component 15 within a vacuum chamber 16, with a magnetic fluid seal assembly 2 integrated thereon; an outer shaft 3 for fixedly connecting to a vacuum chamber mounting portion 14, the outer shaft 3 being fixedly connected to the integrated inner shaft 1 and forming a transmission cavity 4 radially therewith;

[0041] The transmission housing 5 is used to transmit power from the atmospheric side to the inside of the vacuum chamber 16. The transmission housing 5 is rotatably arranged in the transmission chamber 4 formed by the integrated inner shaft 1 and the outer shaft 3 through the transmission member 13 and extends to one side of the vacuum chamber. A magnetic fluid sealing structure is formed between the transmission housing 5 and the magnetic fluid sealing assembly 2.

[0042] like Figure 5 As shown, the one-piece integrated inner shaft 1 also includes an inner shaft body 6 and a sleeve 7. The magnetic fluid sealing assembly 2 is sleeved on one end of the inner shaft body 6 facing the vacuum side, and the sleeve 7 is sleeved on one end of the inner shaft body 6 facing the atmosphere side and is fixedly connected to the inner shaft body 6 by welding.

[0043] The inner shaft body 6 is used to connect to the central component 15 within the vacuum chamber. It adopts a hollow shaft structure and is made of austenitic stainless steel, making it a non-magnetic shaft. An inner shaft flange 61 is provided on the end of the inner shaft body 6 facing the vacuum side. A sealing ring body 62 is integrally connected to the inner shaft flange 61. A sealing protrusion 63 is provided on the circumference of the sealing ring body 62. The sealing protrusion 63 is located at the end of the sealing ring body away from the inner shaft flange 61, forming a groove between the sealing protrusion and the sealing ring body on both sides. The diameter of the sealing protrusion 63 is larger than the diameter of the sealing ring body 62, which is larger than the diameter of the inner shaft flange 61. The diameter of the inner shaft flange 61 is larger than the diameter of the inner shaft body 6. The end surface of the sealing ring body 62 facing the atmosphere is provided with a magnetic pole assembly mounting surface 64. The end of the inner shaft body 6 facing the atmosphere is provided with an inner shaft welding end 64, which is provided with an inner shaft welding bevel 65. A 0.7mm machining allowance is left on the inner shaft welding end face of the inner shaft body.

[0044] The sleeve 7 is made of austenitic stainless steel and is a non-magnetic component. The sleeve 7 is welded to the inner shaft body 6 to form an integrated structure. The end of the sleeve 7 facing the vacuum side is provided with a magnetic pole fixing end 71, and the sleeve adjacent to the magnetic pole fixing end 71 is provided with a bearing mounting seat 72. The end of the sleeve 7 facing the atmosphere side is provided with an outer shaft connecting end 73, and the inner diameter of the outer shaft connecting end 73 is provided with a sleeve welding bevel 74. A 0.7mm processing allowance is left at the end of the sleeve 7 facing the atmosphere side. The sleeve 7 is not only a positioning member for the bearing mounting seat and the magnetic fluid sealing assembly, but also a transition piece that connects the inner shaft and the outer shaft into one. Therefore, the sleeve 7 adopts a welded sleeve structure. Such a design structure is more conducive to forming an integrated inner shaft.

[0045] The magnetic fluid sealing assembly 2 includes a magnetic pole assembly 8 and a magnetic fluid 9 coated on the magnetic pole assembly 8. The magnetic pole assembly 8 includes a plurality of magnetic poles 10 and a plurality of magnetic blocks 11 uniformly distributed along the circumferential direction between adjacent magnetic poles 10. The magnetic poles 10 are made of magnetic conductive stainless steel. In this embodiment, two magnetic poles 10 and a plurality of magnetic blocks 11 uniformly distributed in a cylindrical structure are used. A plurality of magnetic pole sealing teeth 101 are provided on the outer circumference of the magnetic pole 10, a sealing groove 102 is provided on the inner circumference of the magnetic pole 10, and a static seal 12 is provided inside the sealing groove 102. The static seal 12 adopts an O-ring. A groove 103 is provided at one axial end of the magnetic pole 10. The grooves 103 of the two adjacent magnetic poles are relatively arranged to form a magnetic block mounting groove 104. The magnetic block 11 is arranged inside the magnetic block mounting groove 104.

[0046] like Figure 4As shown, the magnetic pole seal teeth 101 can have different tooth shapes, such as rectangular, trapezoidal, and circular, depending on the inner diameter of the transmission housing, rotational speed, and other operating conditions. To achieve a more compact structure in the axial direction, the length of the sealing area can be minimized. To minimize the sealing area, trapezoidal teeth can be used, and the number of teeth can be reduced compared to conventional rectangular teeth. In this embodiment, the magnetic pole seal teeth 101 have a concave arc-shaped tooth top. This structure allows the magnetic fluid above them to form a more effective magnetic fluid seal under the influence of the magnetic field.

[0047] To form the one-piece integrated inner shaft 1, first, the magnetic pole assembly 8 is sleeved on the inner shaft body 6 and is in close contact with the end face of the sealing ring body 62. The sleeve 7 is sleeved on the inner shaft body 6 and its magnetic pole fixed end 71 is tightly attached to the magnetic pole assembly 8. Then, the magnetic pole assembly is fixed and protected by a tool, and electron beam welding equipment is used to weld the inner shaft welding bevel 65 and the sleeve welding bevel 74 at the junction. After welding, the welding end face is fine-machined to remove the 0.7mm machining allowance. After machining, the tool is disassembled and the magnetic assembly is cleaned to form the one-piece integrated inner shaft 1. After the one-piece integrated inner shaft 1 is manufactured, a certain amount of magnetic fluid 9 is applied to the magnetic pole sealing teeth 101 of the magnetic pole 10. In this embodiment, since the magnetic pole sealing teeth adopt an inwardly concave arc structure, after the magnetic fluid is applied, after the magnetic pole assembly forms a magnetic field with the transmission housing, the magnetic fluid fills the entire gap in the magnetic field, forming a liquid O-ring. Under the action of the magnetic field, the magnetic fluid placed in the gap at the top of the pole sealing teeth 101 is concentrated and concentrated on the pole sealing teeth with a concave arc structure, forming a fluid seal, blocking the gap channel and achieving the purpose of sealing.

[0048] like Figure 7As shown, the transmission housing 5 is made of magnetically conductive stainless steel and includes an integral vacuum inlet 51, a sealing cavity 52, and a bearing cavity 53. The vacuum inlet 51 is annular, with its inner diameter rotatably mating with the outer diameter of the sealing ring 62 on the inner shaft body 6. The inner diameter of the vacuum inlet, the sealing ring, and the sealing cam form an end labyrinth seal. The sealing cavity 52 is in a driving engagement with the sealing cam 63 on the inner shaft body and the magnetic pole seal teeth 101 on the magnetic pole 10. A transmission member 13 is disposed within the bearing cavity 53. The transmission member 13 utilizes a transmission bearing, either an angular contact bearing or a cross-ball bearing. In this embodiment, the transmission bearings utilize a pair of angular contact bearings, which can withstand strong external forces and reduce the cost of the magnetic fluid seal transmission. A housing end cap 54 is disposed outside the bearing cavity 53 to provide axial restraint and fixation for the bearing. The housing end cap 54 is made of austenitic stainless steel and is non-magnetic. The design structure, in which the transmission housing 5 is positioned between the inner and outer shafts, utilizes a single-axis magnetic fluid-sealed transmission device to achieve a transmission in which the central component 15 within the vacuum chamber remains stationary while the rotating component 17 outside the central component 15 rotates around it. Compared to a dual-axis transmission, this greatly simplifies the sealing device structure, reduces transmission errors, and makes the transmission device more compact, enabling widespread application in smaller spaces where vacuum transmission is required. This achieves the universal design requirements of magnetic fluid-sealed transmission devices, extending their application range and improving transmission performance and sealing.

[0049] like Figure 6 As shown, the outer shaft 3 is made of austenitic stainless steel and is non-magnetic. The outer shaft 3 includes an integral outer shaft flange 31, an outer shaft cavity 32, and a connecting and positioning inner shaft seat 33. The connecting and positioning inner shaft seat 33 mates with the end of the inner shaft body facing the atmosphere and is fixedly connected as a whole by fasteners. The outer diameter of the transmission housing 5 is configured to be in a transmission-coordinated manner with the inner diameter of the outer shaft cavity 32. A plurality of connecting holes 34 are provided axially on the outer shaft cavity 32 for connection to the mounting equipment.

[0050] The shell-driven magnetic fluid sealing transmission device is characterized in that after the integrated inner shaft is installed, the bearing, the transmission shell, the shell end cover and finally the outer shaft are installed, and the outer shaft, the sleeve and the inner shaft are connected into one by screws.

[0051] The specific manufacturing and installation process of the shell-driven magnetic fluid sealing transmission device is as follows:

[0052] First, the integrated inner shaft is assembled and integrated. The magnetic pole assembly is placed on the inner shaft and in close contact with the end face of the sealing ring body. The sleeve is placed on the inner shaft with its magnetic pole fixed end tightly attached to the magnetic pole sealing assembly. Then, the magnetic pole assembly is fixed and protected by tooling, and electron beam welding equipment is used to weld the welding bevel at the junction of the inner shaft and the left end face of the sleeve. After welding, the welding end face is fine-machined to remove the 0.7mm machining allowance. After machining, the tooling is disassembled and the magnetic pole assembly is cleaned. After the integrated inner shaft is completed, a certain amount of magnetic fluid is applied to the magnetic pole sealing teeth of the magnetic pole. Then, a pair of angular contact bearings, a transmission housing, and a housing end cover are assembled. Finally, the outer shaft is installed and the outer shaft, sleeve, and inner shaft are connected into one by screws.

[0053] like Figure 10 As shown, when the shell-driven magnetic fluid sealing transmission device is installed on the vacuum equipment, the outer shaft 3 is connected to the vacuum chamber installation part 14, the one-piece integrated inner shaft 1 is connected to the central component 15 inside the vacuum chamber 16, and the transmission shell 5 is connected to the vacuum chamber 16. At the same time, the vacuum chamber 16 is connected to the rotating component 17 outside the central component 15. When the external power drives the transmission shell 5 to rotate through the pulley 18, the transmission shell 5 drives the vacuum chamber 16 and the rotating component 17 to rotate around the central component 15, thereby achieving the purpose of keeping the central component 15 inside the vacuum chamber 16 stationary and the rotating component rotating.

[0054] Example 2:

[0055] exist Figure 8 The illustrated embodiment features a housing-driven magnetic fluid sealed transmission device. Its technical solution is essentially the same as that of Example 1, differing in that this sealed transmission device is suitable for installation in narrower spaces. To reduce the overall axial dimension of the sealed transmission device, the transmission member 13 in this embodiment utilizes a transmission bearing, which is a crossed ball bearing. The use of a crossed roller bearing is suitable for low-speed, high-torque operating conditions and reduces the axial length of the magnetic fluid sealed transmission device, making it suitable for equipment installation in confined spaces.

[0056] like Figure 9 As shown, in this embodiment, to achieve a more compact structure in the axial direction and minimize the length of the sealing area, the magnetic pole seal teeth 101 are selected to adopt asymmetric trapezoidal teeth, that is, a trapezoidal tooth structure with one right angle and one beveled edge, and the number of teeth is set to four. This structure achieves a better magnetic fluid sealing effect.

[0057] The specific manufacturing and installation process of the shell-driven magnetic fluid sealing transmission device is as follows:

[0058] First, the integrated inner shaft is assembled. The magnetic pole assembly is placed on the inner shaft, in close contact with the end face of the sealing ring. The sleeve is placed on the inner shaft, with its magnetic pole fixed end in close contact with the magnetic pole seal assembly. The magnetic pole assembly is then secured and protected using tooling. Electron beam welding is performed at the weld bevel at the junction of the inner shaft and the left end face of the sleeve. After welding, the weld end face is fine-machined to remove a 0.7mm machining allowance. After machining, the tooling is disassembled and the magnetic pole assembly is cleaned. Once the integrated inner shaft is fabricated, a fixed amount of magnetic fluid is applied to the magnetic pole seal teeth. The cross-roller bearing, transmission housing, and housing end cap are then assembled. Finally, the outer shaft is installed, and the outer shaft, sleeve, and inner shaft are connected together using screws.

[0059] When the shell-driven magnetic fluid sealing transmission device is installed on the vacuum equipment, the outer shaft 3 is connected to the vacuum chamber installation part 14, the one-piece integrated inner shaft 1 is connected to the central component 15 inside the vacuum chamber 16, and the transmission shell 5 is connected to the vacuum chamber 16. At the same time, the vacuum chamber 16 is connected to the rotating component 17 outside the central component 15. When the external power drives the transmission shell 5 to rotate through the pulley 18, the transmission shell 5 drives the vacuum chamber 16 and the rotating component 17 to rotate around the central component 15, thereby achieving the purpose of keeping the central component 15 inside the vacuum chamber 16 stationary and the rotating component rotating.

[0060] It should be noted that the above embodiments are merely illustrative of the principles of the present invention. Various variations and improvements are possible without departing from the scope of the present invention, and all such variations and improvements fall within the scope of the claimed invention. Based on the embodiments described herein, all other embodiments derived by persons of ordinary skill in the art on the basis of the technical solutions of this application without inventive effort shall fall within the scope of protection of the present invention.

Claims

1. A shell-driven magnetic fluid sealing transmission device, characterized in that include: An integrated inner shaft (1) is a shaft member connected to a central component inside a vacuum chamber; a magnetic fluid sealing assembly (2) is integrated on the integrated inner shaft (1); the integrated inner shaft (1) further comprises an inner shaft body (6) and a sleeve (7); An outer shaft (3) is a shaft body fixedly connected to a mounting portion of the vacuum chamber, wherein the outer shaft (3) is fixedly connected to the one-piece integrated inner shaft (1) and forms a transmission cavity (4) with the one-piece integrated inner shaft (1) in a radial direction; A transmission housing (5) is a component for transmitting power from the atmospheric side to the interior of the vacuum chamber. The transmission housing (5) is rotatably disposed in the transmission chamber (4) via a transmission member (13) and forms a magnetic fluid sealing structure with the magnetic fluid sealing assembly (2); The transmission housing (5) includes an integrally arranged vacuum insertion end (51), a sealing cavity (52), and a bearing cavity (53); the vacuum insertion end (51) cooperates with the integrally integrated inner shaft (1) to form an end labyrinth seal structure; the transmission member (13) is arranged inside the bearing cavity (53); and a non-magnetic housing end cover (54) is provided at the end of the bearing cavity (53).

2. The shell-driven magnetic fluid sealing transmission device according to claim 1, characterized in that: The magnetic fluid sealing component (2) is sleeved on one end of the inner shaft body (6) facing the vacuum side, and the sleeve (7) is sleeved on one end of the inner shaft body (6) facing the atmosphere side and is fixedly connected to the inner shaft body (6) by welding.

3. The shell-driven magnetic fluid sealing transmission device according to claim 2, characterized in that: The inner shaft body (6) is a non-magnetic shaft body. The inner shaft body (6) is provided with an inner shaft flange (61) at one end facing the vacuum side, and a sealing ring body (62) is provided in an integral manner connected to the inner shaft flange (61). A sealing convex ring (63) is provided on the circumferential surface of the sealing ring body (62); the inner shaft body (6) is provided with an inner shaft welding end (64) at one end facing the atmosphere side, and an inner shaft welding bevel (65) is provided on the outer diameter of the inner shaft welding end.

4. The shell-driven magnetic fluid sealing transmission device according to claim 3, characterized in that: The sleeve (7) is a non-magnetic component. The end of the sleeve (7) facing the vacuum side is provided with a magnetic pole fixing end (71), the sleeve (7) is provided with a bearing mounting seat (72), the end of the sleeve (7) facing the atmosphere side is provided with an outer shaft connecting end (73), and the inner diameter of the outer shaft connecting end (73) is provided with a sleeve welding bevel (74).

5. The shell-driven magnetic fluid sealing transmission device according to claim 4, characterized in that: The magnetic fluid sealing assembly (2) includes a magnetic pole assembly (8) and a magnetic fluid (9) coated on the magnetic pole assembly (8), the magnetic pole assembly (8) includes a plurality of magnetic poles (10) and a magnetic block (11) arranged between adjacent magnetic poles (10), a plurality of magnetic pole sealing teeth (101) are evenly distributed on the outer diameter of the magnetic pole (10), and the magnetic fluid (9) is coated on the magnetic pole sealing teeth (101); a static seal (12) is provided on the inner diameter of the magnetic pole (10).

6. The shell-driven magnetic fluid sealing transmission device according to claim 5, characterized in that: The magnetic pole sealing teeth (101) are concave arc-shaped teeth or asymmetric trapezoidal teeth.

7. The shell-driven magnetic fluid sealing transmission device according to any one of claims 1 to 6, characterized in that: The transmission housing (5) is made of magnetic stainless steel.

8. The shell-driven magnetic fluid sealing transmission device according to any one of claims 1 to 6, characterized in that: The transmission member (13) is an angular contact bearing or a cross ball bearing.

9. The shell-driven magnetic fluid sealing transmission device according to any one of claims 1 to 6, characterized in that: The outer shaft (3) is a non-magnetic body, and the outer shaft (3) includes an outer shaft flange (31), an outer shaft cavity (32) and a connecting and positioning inner shaft seat (33) that are integrally arranged. The connecting and positioning inner shaft seat (33) cooperates with one end of the integral integrated inner shaft facing the atmosphere, and is fixedly connected as a whole by fasteners.

10. A method for manufacturing a shell-driven magnetic fluid sealing transmission device according to claim 6, characterized in that The following steps are involved: Step 1: Fabricate the inner shaft body, outer shaft, sleeve, transmission housing, housing end cover, and magnetic pole assembly; and leave a finishing allowance on the inner shaft body and sleeve end facing the atmosphere; Step 2: Assemble the integrated inner shaft. Sleeve the magnetic pole assembly onto the inner shaft body and make close contact with the end face of the sealing ring body. Sleeve the sleeve onto the inner shaft with its magnetic pole fixed end in close contact with the magnetic pole sealing assembly. Then, fix and protect the magnetic pole assembly with the tooling. Use electron beam welding equipment to weld the inner shaft body and the left end face of the sleeve at the welding bevel. After welding, fine-machine the welding end face. After machining, disassemble the tooling and clean the magnetic pole assembly. Step 3: After the one-piece integrated inner shaft is manufactured, a certain amount of magnetic fluid is applied to the magnetic pole sealing teeth of the magnetic pole; Step 4: Assemble the transmission parts on the bearing mounting seat of the sleeve, install the transmission housing outside the sealing assembly from the vacuum side, and install the fixed housing end cover on one end of the atmosphere side; Step 5: Finally, install the outer shaft from the atmospheric side, and connect the outer shaft, sleeve, and inner shaft body into one piece through fasteners to complete the production of the shell-driven magnetic fluid sealing transmission device.

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