A flexible connection magnetic fluid dynamic seal device

Abstract

This invention discloses a flexible connection magnetohydrodynamic sealing device, including a magnetohydrodynamic seal and a flexible coupling. The invention uses an arc-shaped rolling guide rail to position the housing and rotor pole shoes, achieving precise control of the gap between the fixed pole shoes and the rotor pole shoes, resulting in a sufficiently small sealing gap. Unlike traditional rolling bearing connections, the arc-shaped rolling guide rail can be assembled by splicing multiple arc-shaped sub-guide rails, facilitating the creation of ultra-large diameter guide rails. This allows for the positioning of ultra-large diameter rotor pole shoes and the connection of ultra-large diameter spindles. The sliders in the arc-shaped rolling guide rail only need to be arranged in multiple local areas along the circumference, resulting in a small space occupation, light weight, low cost, and easy installation. The flexible coupling connects the rotor pole shoes and the spindle, ensuring torque transmission between them while achieving a seal. It also allows for radial yaw and axial movement of the spindle relative to the rotor pole shoes.

Description

Technical Field

[0001] This invention relates to the field of dynamic sealing technology, and in particular to a flexible connection magnetohydrodynamic sealing device. Background Technology

[0002] Magnetofluidic sealing utilizes the magnetic force generated by a permanent magnet to confine the magnetofluid within a tiny annular gap between the annular pole shoe and the rotating shaft, forming a liquid seal ring to achieve the sealing purpose. Magnetofluidic shaft dynamic sealing technology features zero leakage, no solid friction, low energy consumption, no mechanical wear, long service life, and suitability for transmitting high speeds. It has been widely used in aerospace, defense, chemical, petroleum, instrumentation, and other fields.

[0003] To ensure sufficient load-bearing capacity of the magnetohydrodynamic fluid, the magnetic field strength within the sealed gap between the pole shoe and the shaft needs to be as high as possible. Under the same permanent magnet conditions, the sealed gap between the pole shoe and the shaft needs to be controlled to be sufficiently small.

[0004] Dynamic sealing devices with small diameters and stable spindle operation generally use high-precision rolling bearings to ensure the tiny sealing gap between the pole shoe and the shaft. However, for shafts with large diameters and a certain degree of radial and axial float, using rolling bearings to control the sealing gap not only has disadvantages such as high cost, large space occupation, and heavy weight, but also cannot meet the radial and axial float requirements of the shaft.

[0005] Therefore, there is an urgent need to develop a flexible connection magnetohydrodynamic sealing device to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to design a flexible connection magnetohydrodynamic sealing device to solve the above-mentioned problems.

[0007] The present invention achieves the above objectives through the following technical solutions:

[0008] A flexible connection magnetohydrodynamic sealing device, comprising:

[0009] Magnetohydrodynamic seals;

[0010] Magnetohydrodynamic seals include:

[0011] Housing; the housing is formed in a circular shape; the main shaft passes through the housing;

[0012] At least one set of permanent magnets; a set of permanent magnets includes multiple permanent magnets arranged in a circular ring.

[0013] At least two fixed pole shoes; at least one set of permanent magnets and at least two fixed pole shoes are alternately distributed in the axial direction; the fixed pole shoes are formed in a ring shape;

[0014] Arc-shaped rolling guide rail; the arc-shaped rolling guide rail includes a guide rail and multiple sliders, the guide rail is formed into a circular ring, and the multiple sliders slide in conjunction with the guide rail; multiple sliders and at least two sets of fixed pole shoes are fixedly installed on the inner wall of the housing.

[0015] Rotor pole shoe; the rotor pole shoe is formed in a circular ring; the first end of the rotor pole shoe is connected to a set of guide rails;

[0016] Magnetofluid; the magnetofluid is placed in the gap between the stationary pole shoe and the rotor pole shoe;

[0017] Flexible couplings;

[0018] Flexible couplings include:

[0019] Spindle threaded ring; the spindle threaded ring is formed into a ring shape, the inner wall of the spindle threaded ring is provided with internal thread, the corresponding shoulder is provided on the spindle, and the outer wall of the spindle is provided with external thread; the spindle threaded ring is threaded to the spindle.

[0020] Flexible tube; the first end of the flexible tube is fixed between one end face of the main shaft screw ring and one end face of the shaft shoulder; the second end of the flexible tube is connected to the second end of the rotor pole shoe.

[0021] Preferably, the guide rail comprises multiple arc sub-guide rails.

[0022] Specifically, the upper end of the housing is provided with an outward second annular protrusion, and the lower end of the housing is provided with an inward first annular protrusion. The housing is fixed in position by the outward second annular protrusion, and the slider is installed on the upper part of the inward first annular protrusion. The slider's groove is arranged upward.

[0023] Preferably, the flexible connection magnetohydrodynamic sealing device further includes a permanent magnet positioning ring, which is circular and has multiple circular holes evenly arranged along the circumference, with the center line of the circular holes parallel to the center line of the main shaft; the permanent magnet is cylindrical, and multiple permanent magnets are installed in the multiple circular holes, with the permanent magnet positioning ring installed between two adjacent fixed pole shoes.

[0024] Preferably, the flexible connection magnetohydrodynamic sealing device further includes multiple sealing rings, with toothed protrusions on the inner side of the fixed pole shoe and an annular sealing groove on the outer side, and the sealing rings are installed in the sealing groove.

[0025] Furthermore, the flexible connection magnetohydrodynamic sealing device also includes a first cover plate and a second cover plate. The first cover plate is formed into an annular shape and has an axial third annular protrusion on its inner side. The second cover plate is formed into an annular shape. An inward fourth annular protrusion is provided on the inner wall of the housing. The lower end of the fixed pole shoe is placed on the fourth annular protrusion. The second cover plate covers the upper end of the fixed pole shoe and is placed inside the housing. The first cover plate is fixed to the upper end of the housing by cover plate screws. The third annular protrusion of the first cover plate is connected to the upper end of the second cover plate.

[0026] Preferably, the flexible connection magnetohydrodynamic sealing device further includes an adjusting shim, which is placed between the first cover plate and the end of the housing.

[0027] Furthermore, the flexible connection magnetohydrodynamic sealing device also includes a pole shoe pressure ring, a main shaft pressure ring, and multiple connecting screws. Both the pole shoe pressure ring and the main shaft pressure ring are formed into annular rings. The main shaft pressure ring is placed between the first end of the flexible tube and the main shaft screw ring. The second end of the flexible tube is clamped between the pole shoe pressure ring and the second end of the rotor pole shoe. The pole shoe pressure ring and the rotor pole shoe are connected by multiple connecting screws.

[0028] Furthermore, multiple fifth annular protrusions for heat dissipation are provided on the outer wall of the casing.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. The positioning between the housing and the rotor pole shoes is achieved through the circular arc rolling guide, enabling precise control of the gap between the fixed pole shoes and the rotor pole shoes, and the sealing gap can be small enough. Unlike traditional rolling bearing connections, the guide rail in the circular arc rolling guide can be assembled by splicing multiple circular arc sub-guide rails, which facilitates the realization of ultra-large diameter guide rails. It can be used for positioning ultra-large diameter rotor pole shoes and can connect ultra-large diameter spindles. The slider in the circular arc rolling guide only needs to be arranged in multiple local areas in the circumferential direction, which has a small space occupation, light weight, low cost, and convenient installation.

[0031] 2. The rotor pole shoes and the main shaft are connected by a flexible coupling, which not only ensures the transmission of torque between the rotor pole shoes and the main shaft, but also achieves sealing between the rotor pole shoes and the main shaft, while allowing the main shaft to oscillate radially and move axially relative to the rotor pole shoes.

[0032] Therefore, the present invention can effectively solve the problem of rotary dynamic sealing of large-diameter floating spindles, and the sealing capacity and sealing stability can be greatly improved compared with the prior art. Attached Figure Description

[0033] Figure 1 This is a schematic diagram (sectional view) of the structure of the present invention.

[0034] Figure 2This is a schematic diagram (sectional view) of the magnetic fluid seal in this invention.

[0035] Figure 3 This is a schematic diagram (sectional view) of the flexible coupling in this invention.

[0036] In the diagram: 1. Magnetofluid seal; 1-1. Housing; 1-2. Circular arc rolling guide rail; 1-3. Fixed pole shoe; 1-4. Sealing ring; 1-5. Permanent magnet; 1-6. Permanent magnet positioning ring; 1-7. Adjusting shim; 1-8. First cover plate; 1-9. Second cover plate; 1-10. Magnetofluid; 1-11. Rotor pole shoe; 1-12. Cover plate screw; 1-13. Guide rail screw; 2. Flexible coupling; 2-1. Flexible tube; 2-2. Pole shoe pressure ring; 2-3. Main shaft pressure ring; 2-4. Main shaft threaded ring; 3. Connecting screw; 4. Main shaft. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0039] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0040] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to 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 invention.

[0041] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0042] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0044] like Figure 1-3 As shown, a flexible connection magnetohydrodynamic sealing device includes:

[0045] Magnetohydrodynamic seal 1;

[0046] The magnetohydrodynamic seal 1 includes:

[0047] Housing 1-1; Housing 1-1 is formed in a circular shape; Main shaft 4 is disposed through housing 1-1;

[0048] At least one set of permanent magnets 1-5; a set of permanent magnets 1-5 includes multiple permanent magnets arranged in a circular ring.

[0049] At least two fixed pole shoes 1-3; at least one set of permanent magnets 1-5 and at least two fixed pole shoes 1-3 are alternately distributed in the axial direction; the fixed pole shoes 1-3 are formed in a ring shape;

[0050] Arc-shaped rolling guide rail 1-2; Arc-shaped rolling guide rail 1-2 includes a guide rail and multiple sliders, the guide rail is formed in a circular ring, and the multiple sliders slide in cooperation with the guide rail; Multiple sliders and at least two sets of fixed pole shoes 1-3 are fixedly installed on the inner wall of housing 1-1;

[0051] Rotor pole shoe 1-11; Rotor pole shoe 1-11 is formed into a circular ring; The first end of rotor pole shoe 1-11 is connected to a set of guide rails by multiple guide rail screws 1-13;

[0052] Magnetofluid 1-10; Magnetofluid 1-10 is placed in the gap between the fixed pole shoe 1-3 and the rotor pole shoe 1-11;

[0053] Flexible coupling 2;

[0054] Flexible coupling 2 includes:

[0055] Spindle threaded ring 2-4; The spindle threaded ring 2-4 is formed into a ring shape, and an internal thread is provided on the inner wall of the spindle threaded ring 2-4. Correspondingly, a shoulder is provided on the spindle 4, and an external thread is provided on the outer wall of the spindle 4; The spindle threaded ring 2-4 is threadedly connected to the spindle 4.

[0056] Flexible tube 2-1; the first end of flexible tube 2-1 is fixed between one end face of the main shaft screw ring 2-4 and one end face of the shaft shoulder; the second end of flexible tube 2-1 is connected to the second end of the rotor pole shoe 1-11.

[0057] Preferably, the guide rail comprises multiple arc sub-guide rails.

[0058] like Figure 2 As shown, specifically, the upper end of the housing 1-1 is provided with an outward second annular protrusion, and the lower end of the housing 1-1 is provided with an inward first annular protrusion. The housing 1-1 is fixedly installed through the outward second annular protrusion, and the slider is installed on the upper part of the inward first annular protrusion. The slider's groove is arranged upward.

[0059] Preferably, the flexible connection magnetic fluid 1-10 dynamic sealing device further includes a permanent magnet positioning ring 1-6. The permanent magnet positioning ring 1-6 is formed into a ring shape, and multiple circular holes are evenly arranged on the permanent magnet positioning ring 1-6 along the circumferential direction. The center line of the circular holes is parallel to the center line of the main shaft 4. The permanent magnets 1-5 are formed into cylinders, and multiple permanent magnets 1-5 are correspondingly installed in multiple circular holes. The permanent magnet positioning ring 1-6 is installed between two adjacent fixed pole shoes 1-3. The permanent magnet positioning ring 1-6 is used for the installation and positioning of multiple permanent magnets 1-5.

[0060] like Figure 2 As shown, the flexible connection magnetic fluid 1-10 dynamic sealing device also includes multiple sealing rings 1-4. The inner side of the fixed pole shoe 1-3 has toothed protrusions, and the outer side has an annular sealing groove. The sealing rings 1-4 are installed in the sealing groove. The fixed pole shoe 1-3 and the housing 1-1 are sealed by the sealing rings 1-4.

[0061] like Figure 2 As shown, the flexible connection magnetic fluid 1-10 dynamic sealing device further includes a first cover plate 1-8 and a second cover plate 1-9. The first cover plate 1-8 is formed in an annular shape, and an axial third annular protrusion is formed on its inner side. The second cover plate 1-9 is formed in an annular shape. An inward fourth annular protrusion is provided on the inner wall of the housing 1-1. The lower fixed pole shoe 1-3 is placed on the fourth annular protrusion. The second cover plate 1-9 covers the upper fixed pole shoe 1-3 and is placed inside the housing 1-1. The first cover plate 1-8 is fixed to the upper end of the housing 1-1 by cover plate screws 1-12. The third annular protrusion of the first cover plate 1-8 is connected to the upper end of the second cover plate 1-9. The second cover plate 1-9 is preferably an aluminum cover plate.

[0062] like Figure 2 As shown, the flexible connection magnetic fluid 1-10 dynamic sealing device also includes an adjusting shim 1-7, which is placed between the end of the first cover plate 1-8 and the housing 1-1.

[0063] like Figure 2 As shown, the flexible connection magnetic fluid 1-10 dynamic sealing device further includes a pole shoe pressure ring 2-2, a main shaft pressure ring 2-3, and multiple connecting screws 3. Both the pole shoe pressure ring 2-2 and the main shaft pressure ring 2-3 are formed as annular rings. The main shaft pressure ring 2-3 is positioned between the first end of the flexible tube 2-1 and the main shaft screw ring 2-4. The second end of the flexible tube 2-1 is clamped between the pole shoe pressure ring 2-2 and the second end of the rotor pole shoe 1-11. The pole shoe pressure ring 2-2 and the rotor pole shoe 1-11 are connected by multiple connecting screws 3. In some embodiments, the flexible tube 2-1 has a flexible corrugated structure with lip-shaped flanges at both ends. A set of mounting holes evenly distributed along the circumferential direction is opened on the lower flange. The pole shoe pressure ring 2-2 is an annular structure with a set of mounting holes evenly distributed along the circumferential direction.

[0064] like Figure 1 As shown, in some embodiments, a plurality of fifth annular protrusions for heat dissipation are provided on the outer side wall of the housing 1-1. The plurality of fifth annular protrusions are parallel to each other.

[0065] In this application, the magnetohydrodynamic seal 1 achieves a sealing chain through a housing 1-1, a fixed pole shoe 1-3, a sealing ring 1-4, a permanent magnet 1-5, a magnetohydrodynamic fluid 1-10, and a rotor pole shoe 1-11. The rotor pole shoe 1-11 is mounted on the housing 1-1 via an arc-shaped rolling guide rail 1-2, achieving precise positioning of the rotor pole shoe 1-11 and allowing it to rotate freely relative to the housing 1-1. Therefore, only a small gap is allowed between the rotor pole shoe 1-11 and the fixed pole shoe 1-3. The magnetohydrodynamic fluid 1-10, within the small gap formed between the rotor pole shoe 1-11 and the fixed pole shoe 1-3, is constrained within the sealing gap by the magnetic force generated by the permanent magnet 1-5, thus creating a sealing effect.

[0066] The flexible coupling 2 achieves a sealing chain through the rotor pole shoe 1-11, the flexible tube 2-1, and the main shaft 4.

[0067] The lower flange of the flexible tube 2-1 is pressed against the rotor pole shoe 1-11 by the pole shoe pressure ring 2-2 and the connecting screw 3 to achieve a seal.

[0068] The outer edge of the upper end face of the spindle screw ring 2-4 has evenly distributed notches. The notches on the outer edge of the upper end face of the spindle screw ring 2-4 can apply external torque. Under the action of torque, the spindle screw ring 2-4 can move axially and push the spindle pressure ring 2-3 to move, thereby pressing the upper flange of the flexible tube 2-1 onto the shoulder of the spindle 4 to form a sealing effect.

[0069] The flexible tube 2-1 is made of a thin layer of rubber or metal, possessing both a certain circumferential stiffness and relatively low radial and axial stiffness. The sufficient circumferential stiffness allows torque to be transmitted from the main shaft 4 through the flexible tube 2-1 to the rotor pole shoes 1-11, driving them to rotate at high speed. The relatively low radial and axial stiffness allows the main shaft 4 to exhibit radial yaw and axial movement relative to the rotor pole shoes 1-11.

[0070] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flexible connection magnetohydrodynamic sealing device, characterized in that, include: Magnetohydrodynamic seals; Magnetohydrodynamic seals include: Housing; the housing is formed in a circular shape; the main shaft passes through the housing; At least one set of permanent magnets; a set of permanent magnets includes multiple permanent magnets arranged in a circular ring. At least two fixed pole shoes; at least one set of permanent magnets and at least two fixed pole shoes are alternately distributed in the axial direction; the fixed pole shoes are formed in a ring shape; Arc-shaped rolling guide rail; the arc-shaped rolling guide rail includes a guide rail and multiple sliders, the guide rail is formed into a circular ring, and the multiple sliders slide in conjunction with the guide rail; multiple sliders and at least two sets of fixed pole shoes are fixedly installed on the inner wall of the housing. Rotor pole shoe; the rotor pole shoe is formed in a circular ring; the first end of the rotor pole shoe is connected to a set of guide rails; Magnetofluid; the magnetofluid is placed in the gap between the stationary pole shoe and the rotor pole shoe; Flexible couplings; Flexible couplings include: Spindle threaded ring; the spindle threaded ring is formed into a ring shape, the inner wall of the spindle threaded ring is provided with internal thread, the corresponding shoulder is provided on the spindle, and the outer wall of the spindle is provided with external thread; the spindle threaded ring is threaded to the spindle. Flexible tube; the first end of the flexible tube is fixed between one end face of the main shaft screw ring and one end face of the shaft shoulder; the second end of the flexible tube is connected to the second end of the rotor pole shoe.

2. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The guide rail consists of multiple arc sub-rails.

3. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The upper end of the housing is provided with an outward second annular protrusion, and the lower end of the housing is provided with an inward first annular protrusion. The housing is fixed in position by the outward second annular protrusion, and the slider is installed on the upper part of the inward first annular protrusion. The slider's groove is arranged upward.

4. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The flexible connection magnetohydrodynamic sealing device also includes a permanent magnet positioning ring, which is circular and has multiple circular holes evenly arranged along the circumference. The center line of the circular holes is parallel to the center line of the main shaft. The permanent magnet is cylindrical, and multiple permanent magnets are installed in the multiple circular holes. The permanent magnet positioning ring is installed between two adjacent fixed pole shoes.

5. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The flexible connection magnetohydrodynamic sealing device also includes multiple sealing rings. The inner side of the fixed pole shoe has toothed protrusions, and the outer side has an annular sealing groove. The sealing rings are installed in the sealing groove.

6. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The flexible connection magnetohydrodynamic sealing device also includes a first cover plate and a second cover plate. The first cover plate is formed into a ring and has an axial third annular protrusion on its inner side. The second cover plate is formed into a ring. An inward fourth annular protrusion is provided on the inner wall of the housing. The lower fixed pole shoe is placed on the fourth annular protrusion. The second cover plate covers the upper fixed pole shoe and is placed inside the housing. The first cover plate is fixed to the upper end of the housing by cover plate screws. The third annular protrusion of the first cover plate is connected to the upper end of the second cover plate.

7. The flexible connection magnetohydrodynamic sealing device according to claim 6, characterized in that, The flexible connection magnetohydrodynamic sealing device also includes an adjusting shim, which is placed between the first cover plate and the end of the housing.

8. The flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, The flexible connection magnetohydrodynamic sealing device also includes a pole shoe pressure ring, a main shaft pressure ring, and multiple connecting screws. Both the pole shoe pressure ring and the main shaft pressure ring are formed into annular rings. The main shaft pressure ring is placed between the first end of the flexible tube and the main shaft screw ring. The second end of the flexible tube is clamped between the pole shoe pressure ring and the second end of the rotor pole shoe. The pole shoe pressure ring and the rotor pole shoe are connected by multiple connecting screws.

9. A flexible connection magnetohydrodynamic sealing device according to claim 1, characterized in that, Multiple fifth annular protrusions for heat dissipation are provided on the outer wall of the casing.

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