Inner and outer double-layer magnetic ring structure and preparation method thereof

Abstract

The application discloses an inner-outer double-layer magnetic ring structure, which comprises an outer magnetic ring and an inner magnetic ring, wherein the outer shape of the outer magnetic ring is a cylinder, a center air gap is arranged at the axial position of the outer magnetic ring, and the center air gap is a working space of a magnetic field system; and the inner magnetic ring is installed in the center air gap. The application further discloses a preparation method of the inner-outer double-layer magnetic ring structure. The application solves the magnetic leakage problem of a magnetic refrigeration test system, the magnetic field formed by the inner magnetic ring and the outer magnetic ring has multiple levels and no magnetic leakage in the center, and the magnetic field direction and size of the magnetic refrigeration test system are adjusted through the rotation of the inner-outer double-layer magnetic field.

Description

TECHNICAL FIELD

[0001] The application relates to the field of magnetic refrigeration, in particular to an inner-outer double-layer magnetic ring structure and a preparation method thereof. BACKGROUND

[0002] At present, the research on room-temperature magnetic refrigerators mainly concentrates on reciprocating and rotary types, the reciprocating magnetic refrigerator uses a partially closed magnetic circuit magnetic field, and the rotary magnetic refrigerator uses a fully closed magnetic circuit magnetic field.

[0003] Based on the material gene engineering research method, around the key scientific problems of improving the performance of rare earth magnetic refrigeration materials, it is necessary to carry out the whole chain of collaborative innovation research work from high-throughput calculation and material design, multi-field regulation and performance optimization, high-throughput preparation and characterization to magnetic refrigerator operation. The problems to be solved in the research of rare earth magnetic refrigeration materials include: developing a high-throughput preparation platform for rare earth magnetic refrigeration materials, mastering the key forming technology of magnetic refrigeration materials, preparing high-performance rare earth magnetic refrigeration materials, developing a 0-1T adjustable magnetic field test platform, and applying rare earth magnetic refrigeration materials to room-temperature and liquid helium temperature magnetic refrigerators. However, the existing magnetic refrigeration test system has simple magnetic field structure, no airtight space, serious magnetic leakage, and the magnetic field size cannot be adjusted. SUMMARY

[0004] The application aims to provide an inner-outer double-layer magnetic ring structure and a preparation method thereof, solve the magnetic leakage problem of the magnetic refrigeration test system, and the magnetic field formed by the inner magnetic ring and the outer magnetic ring has multiple levels and no magnetic leakage in the center. The magnetic field direction and size of the magnetic refrigeration test system are adjusted through the rotation of the inner-outer double-layer magnetic field.

[0005] To achieve the above-mentioned purposes, the technical solution used by the application is:

[0006] The inner-outer double-layer magnetic ring structure comprises an outer magnetic ring and an inner magnetic ring, the outer shape of the outer magnetic ring is a cylinder, a center air gap is arranged at the axial position, and the center air gap is the working space of the magnetic field system; the inner magnetic ring is sleeved in the center air gap, and the outer magnetic ring and the inner magnetic ring are coaxial.

[0007] Further, the outer magnetic ring comprises: an outer shell, a first support plate, a first side plate, an outer magnetic ring monomer, and an end plate; the outer shell is a cylindrical structure, and two end plates are arranged at two ends of the outer shell; the end plate is provided with a shaft hole for mounting a rotating shaft, eight first side plates are located inside the first side plate, the side edges of the first side plate are connected at the connection of the two first side plates, and the outer wall of the first side plate is connected with the inner wall of the outer shell; eight first support plates are arranged inside the outer shell, and the side edges of the eight first support plates are sequentially connected to form an octagonal barrel structure; the outer magnetic ring monomer is a trapezoidal column structure with an arc-shaped inner side surface and a flat outer side surface, the outer magnetic ring monomer is mounted in a trapezoidal groove formed by the first support plate and the two first side plates, and the magnetization angles of the eight outer magnetic ring monomers are different.

[0008] Further, the material of the outer shell is an alloy, the thickness of the outer shell is greater than 1 mm, the outer magnetic ring monomer is an NdFeB magnet, the working point Ji of the NdFeB magnet is greater than or equal to 0.9Br, and the demagnetization curve squareness is close to 1.

[0009] Further, the magnetization angles of the eight outer magnetic ring monomers are 90°, 45°, 0°, 45°, 90°, and -45°, respectively.

[0010] Further, the first support plate has a rectangular shape and is provided with a plurality of fixing through holes, and the outer magnetic ring monomer is provided with a threaded counterbore at the back, and a fixing screw passes through the fixing through hole to fix the outer magnetic ring monomer on the first support plate.

[0011] Further, the inner magnetic ring comprises: an inner magnetic ring monomer, a fixing cylinder, and a second side plate; the fixing cylinder is a regular octahedral cylindrical structure, the side edges of the second side plate are connected at the bending portions of the inner wall of the fixing cylinder, eight second side plates and the inner wall of the fixing cylinder form eight trapezoidal grooves, eight inner magnetic ring monomers are respectively mounted in the eight trapezoidal grooves, and the magnetization angles of the eight inner magnetic ring monomers are different.

[0012] Further, the inner magnetic ring monomer is a trapezoidal column structure with an arc-shaped inner side edge and a flat outer side, and the arc-shaped surfaces of the eight inner magnetic ring monomers form a cylindrical space; the fixing cylinder is provided with a mounting long hole, the inner magnetic ring monomer is provided with a threaded hole at the back, a screw passes through the mounting long hole to adjust the position and is then connected to the threaded hole to fix the inner magnetic ring monomer on the inner wall of the fixing cylinder.

[0013] Further, the magnetization angles of the eight inner magnetic ring monomers are 90°, 45°, 0°, 45°, 90°, and -45°, respectively.

[0014] 1. A preparation method of an inner-outer double-layer magnetic ring structure, comprising:

[0015] a plurality of outer magnetic ring monomers are mounted in trapezoidal grooves inside an outer shell to assemble an outer magnetic ring, and a central air gap of a magnetic field is formed inside the outer shell by the outer magnetic ring monomers;

[0016] The plurality of inner layer magnetic ring monomers are installed in the trapezoidal grooves inside the fixed cylinder to assemble into the inner layer magnetic ring, the inner layer magnetic ring is placed at the axis position of the center air gap, two end plates are connected at the two ends of the shell, and the double layer magnetic ring magnetic circuit is formed by the outer layer magnetic ring and the inner layer magnetic ring.

[0017] Preferably, eight outer layer magnetic ring monomers are installed in eight trapezoidal grooves according to magnetization angles of 90°, 45°, 0°, 45°, 90° and -45°, and eight inner layer magnetic ring monomers are installed in the trapezoidal grooves inside the fixed cylinder according to magnetization angles of 90°, 45°, 0°, 45°, 90° and -45°.

[0018] The present application at least includes the following beneficial effects:

[0019] The present application is proposed for the existing magnetic refrigeration test system, and the closed magnetic field scheme is adopted to solve the magnetic leakage problem of the magnetic refrigeration test system. The shell and the trapezoidal grooves inside the shell, and the trapezoidal grooves inside the fixed cylinder, install the magnets in the trapezoidal grooves to form a closed magnetic field, and avoid magnetic field leakage.

[0020] To realize the magnetic field size adjustment, the inner and outer double layer magnetic field design is adopted, the inner layer magnetic ring and the outer layer magnetic ring form a double layer magnetic ring magnetic circuit, the magnetic field surrounded by the inner layer magnetic ring and the outer layer magnetic ring has the characteristics of multiple levels, no leakage in the center, adjustable magnetic field strength, rotatable magnetic field direction, etc. Further, the inner layer magnetic ring and the outer layer magnetic ring respectively form a regular octagonal magnetic ring magnetic circuit, the inner layer magnetic ring and the outer layer magnetic ring have eight directions of magnetic field, and the magnetic field direction and size of the magnetic refrigeration test system are adjusted by the rotation of the inner and outer double layer magnetic field which are sleeved together. The magnetic field size can be freely adjusted between 0-1T.

[0021] The magnetic blocks of the inner layer magnetic ring and the outer layer magnetic ring are installed in sequence according to different magnetization angles, a certain strength of magnetic field is generated in the working space, and the design method has the effect of enhancing the 0° direction magnetic field strength. When installing, the trapezoidal grooves in the metal shell are used, the inner hexagon nut is connected with the support plate and the magnetic block to achieve the tightening state, and the NdFeB magnets are installed in sequence according to the angle decreasing rule of 90°, 45°, 0°, 45°, 90° and -45°, so that the 0° direction magnetic field of the regular octagonal double magnetic ring magnetic field is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a cross-sectional structure schematic view of the inner and outer double layer magnetic ring structure in the present application;

[0023] Figure 2 is a cross-sectional structure schematic view of the outer layer magnetic ring in the present application;

[0024] Figure 3is a cross-sectional structure diagram of the outer magnetic ring without the outer magnetic ring monomer in the application;

[0025] Figure 4 is a structure diagram of the first support plate in the application;

[0026] Figure 5 is a structure diagram of the inner magnetic ring in the application;

[0027] Figure 6 is a structure diagram of the fixed cylinder in the application DETAILED DESCRIPTION

[0028] The following description fully illustrates specific embodiments of the application to enable one of ordinary skill in the art to practice and reproduce the application.

[0029] As shown in Figure 1 , it is a cross-sectional structure diagram of the inner and outer double-layer magnetic ring structure in the application.

[0030] The inner and outer double-layer magnetic ring structure comprises: an outer magnetic ring 1 and an inner magnetic ring 2; the shape of the outer magnetic ring 1 is a cylinder, and a central air gap is arranged at the axial position of the outer magnetic ring 1, and the central air gap is the working space of the magnetic field system; the inner magnetic ring 2 is installed in the central air gap. The outer magnetic ring 1 and the inner magnetic ring 2 can rotate relative to each other, or the outer magnetic ring 1 does not rotate, and the inner magnetic ring 2 rotates; or the outer magnetic ring 1 rotates, and the inner magnetic ring 2 does not rotate.

[0031] As shown in Figure 2 , it is a cross-sectional structure diagram of the outer magnetic ring 1 in the application; as shown in Figure 3 , it is a cross-sectional structure diagram of the outer magnetic ring 1 without the outer magnetic ring monomer 14 in the application.

[0032] The outer magnetic ring 1 comprises: an outer shell 11, a first support plate 12, a first side plate 13, an outer magnetic ring monomer 14, and an end plate; the outer shell 11 is a cylindrical structure, two end plates are arranged at both ends of the outer shell 11 to form a relatively closed structure; the end plate is provided with an axle hole for the convenience of installing the rotating shaft; the first side plate 13 is located inside the first support plate 12 and connected at the joint of the two first support plates 12; the first side plate 13 is connected with the inner wall of the outer shell 11, and eight first support plates 12 are arranged inside the outer shell 11, and the side edges of the eight first support plates 12 are sequentially connected to form an octagonal barrel structure; the inner side surface of the outer magnetic ring monomer 14 is an arc surface, and the outer side surface is a planar trapezoidal cylindrical structure; the outer magnetic ring monomer 14 is installed in the trapezoidal groove formed by the first support plate 12 and the two first side plates 13, and the trapezoidal groove is arranged axially.

[0033] The inner side surfaces of the eight outer magnetic ring monomers 14 form a central air gap, and the central air gap is a cylindrical space.

[0034] The material of the shell 11 is alloy, and the shell 11 mainly functions to seal the magnetic field, and the thickness of the shell 11 is greater than 1 mm.

[0035] The outer magnetic ring monomer 14 is an NdFeB magnet, and the magnetic field surrounded by the eight outer magnetic ring monomers 14 has the characteristics of a central leakage-free magnetic field and a rotatable magnetic field direction. Under the action of the first supporting plate 12, the magnetic field is fixedly installed on the shell 11, the central magnetic field is large, and the external magnetic field is sealed. The working point Ji of the NdFeB magnet is greater than 0.9Br, and the demagnetization curve square degree is close to 1.

[0036] Figure 2 In the figure, the arrow direction represents the magnetization angle, the magnetization angles of the eight outer magnetic ring monomers 14 are different, and according to the Halbach rotation theory, the angles are 90°, 45°, 0°, 45°, 90°, and -45°. The magnetic field formed by the eight outer magnetic ring monomers 14 is a regular octagon magnetic field with a trapezoidal array structure.

[0037] As shown in Figure 4 , it is a structure schematic view of the first supporting plate 12 in the application.

[0038] The first supporting plate 12 has a rectangular shape, and a plurality of fixing through holes 121 are formed in the first supporting plate 12. The outer magnetic ring monomer 14 is provided with a threaded counterbore at the back, a fixing screw passes through the fixing through hole to fix the outer magnetic ring monomer 14 on the first supporting plate 12, and the outer magnetic ring monomer 14 is fixed in the trapezoidal groove.

[0039] The first supporting plate 12 has eight fixing through holes 121, and the back of each outer magnetic ring monomer 14 is provided with two threaded counterbores. The depth of the threaded counterbores is greater than the length of the fixing screw, so that the outer magnetic ring monomer 14 can be tightly fixed.

[0040] As shown in Figure 5 , it is a structure schematic view of the inner magnetic ring 2 in the application; and as shown in Figure 6 , it is a structure schematic view of the fixed cylinder 22 in the application.

[0041] The inner magnetic ring 2 comprises an inner magnetic ring monomer 21, a fixed cylinder 22, and a second side plate 23. The fixed cylinder 22 has a regular octahedral cylinder structure, is made of titanium alloy, and has a thickness greater than 0.5 mm. The side edges of the second side plate 23 are connected to the inner wall of the fixed cylinder 22, eight trapezoidal grooves are formed by the eight second side plates 23 and the inner wall of the fixed cylinder 22, and the eight inner magnetic ring monomers 21 are respectively installed in the eight trapezoidal grooves.

[0042] The inner side of the inner magnetic ring monomer 21 is an arc surface, and the outer side is a flat trapezoidal column structure. The arc surfaces of the eight inner magnetic ring monomers 21 form a cylindrical space. The magnetic field formed by the eight inner magnetic ring monomers 21 has the characteristics of central leakage-free magnetic field and rotatable magnetic field direction. The rotating shaft can be fixed in the cylindrical space formed by the inner side of the inner magnetic ring monomer 21, and the two ends extend out of the shaft hole of the end plate. The rotating shaft can drive the inner magnetic ring 2 to rotate, or it can fix the inner magnetic ring 2 and only make the outer magnetic ring 1 rotate.

[0043] The magnetization angles of the eight inner magnetic ring monomers 21 are different according to the Halbach rotation theory. The angles are 90°, 45°, 0°, 45°, 90°, and -45°, respectively. The inner magnetic ring monomer 21 is an NdFeB magnet, and the magnet operating point Ji is greater than or equal to 0.9Br. The demagnetization curve squareness of the NdFeB magnet is close to 1.

[0044] The fixed cylinder 22 has a mounting long hole, and the inner magnetic ring monomer 21 has a threaded hole on the back. After adjusting the position by passing the screw through the mounting long hole, the screw is connected to the threaded hole to fix the inner magnetic ring monomer 21 at a suitable position on the inner wall of the fixed cylinder 22.

[0045] The central air gap in the middle of the outer magnetic ring 1 is the working space of the magnetic field. The outer magnetic ring 1 and the inner magnetic ring 2 form two inner-outer double-layer coaxial magnetic ring structures. Through the rotation of the inner-outer magnetic rings, the magnetic field is superimposed, and the magnetic field is adjusted in the range of 0T-1T.

[0046] The preparation method of the inner-outer double-layer magnetic ring structure is as follows:

[0047] Step 1: Install multiple outer magnetic ring monomers 14 in the trapezoidal grooves formed by the first support plate 12 and the two first side plates 13 inside the outer shell 11 to assemble the outer magnetic ring 1. The central air gap of the magnetic field is formed in the outer shell 11 by the outer magnetic ring monomers 14.

[0048] Install eight outer magnetic ring monomers 14 in eight trapezoidal grooves, respectively. Install the eight outer magnetic ring monomers 14 in order of decreasing angle. The eight outer magnetic ring monomers 14 form a central air gap at the central axis position. This design method has the effect of enhancing the 0° direction magnetic field strength.

[0049] Step 2: Install multiple inner magnetic ring monomers 21 in the trapezoidal grooves inside the fixed cylinder 22 to assemble the inner magnetic ring 2. Place the inner magnetic ring 2 at the axis position in the central air gap. Connect the two end plates to the two ends of the outer shell. Form a double-layer magnetic ring magnetic circuit by the outer magnetic ring 1 and the inner magnetic ring 2.

[0050] The rotating shaft is installed and fixed in the cylindrical space at the axis position of the inner magnetic ring 2. The end of the rotating shaft extends out of the shaft hole of the end plate for connection with power components such as motors.

[0051] Eight inner layer magnetic ring monomers 21 are respectively installed in eight trapezoidal grooves separated by eight second side plates 23 inside the fixed cylinder 22. The arc surfaces of the eight inner layer magnetic ring monomers 21 enclose a cylindrical space, facilitating installation of the rotating shaft.

[0052] According to the decreasing angle installation mode, the 90° 45° 0° 45° 90° -45° NdFeB magnets are sequentially installed in a decreasing angle order. The outer layer magnetic ring 1 and the inner layer magnetic ring 2 form an enhanced positive octagonal double magnetic ring magnetic field in the 0° direction.

[0053] The terms used in the present application are illustrative and exemplary rather than restrictive terms. Since the present application can be embodied in various forms without departing from the spirit or essential characteristics thereof, it is to be understood that the above-described embodiments are not limited to any particular detailed set of conditions, but are meant to cover all alternatives, modifications, and equivalents falling within the spirit and scope of the claims appended hereto.

Claims

1. A double-layered magnetic ring structure, characterized in that, The application relates to a double-layer magnetic ring, which comprises an outer magnetic ring and an inner magnetic ring. The outer magnetic ring is in the shape of a cylinder, and a central air gap is arranged at the axial position of the outer magnetic ring, the central air gap being the working space of a magnetic field system; the inner magnetic ring is arranged in the central air gap; the outer magnetic ring comprises an outer shell, a first supporting plate, a first side plate, an outer magnetic ring monomer and an end plate; the outer shell is in the shape of a cylinder, and two end plates are arranged at the two ends of the outer shell; the end plate is provided with a shaft hole for mounting a rotating shaft; eight first side plates are arranged on the inner side of the first side plate; the side edge of the first side plate is connected to the connecting position of the two first side plates; the outer wall of the first side plate is connected to the inner wall of the outer shell; the first supporting plate is in the shape of a rectangle, and a plurality of fixing through holes are formed in the first supporting plate; a threaded hole is formed in the back of the outer magnetic ring monomer; a fixing screw passes through the fixing through hole to fix the outer magnetic ring monomer on the first supporting plate; eight first supporting plates are arranged in the inner part of the outer shell; the side edges of the eight first supporting plates are sequentially connected to form an octagonal barrel-shaped structure; the outer magnetic ring monomer is in the shape of a trapezoidal cylinder with an arc-shaped inner side and a flat outer side; the outer magnetic ring monomer is arranged in the trapezoidal groove formed by the first supporting plate and the two first side plates; the magnetization angles of the eight outer magnetic ring monomers are different; the inner magnetic ring comprises an inner magnetic ring monomer, a fixing cylinder and a second side plate; the fixing cylinder is in the shape of an octagonal cylinder; the side edge of the second side plate is connected to the bending position of the inner wall of the fixing cylinder; the eight second side plates and the inner wall of the fixing cylinder form eight trapezoidal grooves; the eight inner magnetic ring monomers are arranged in the eight trapezoidal grooves respectively; the magnetization angles of the eight inner magnetic ring monomers are different; the inner magnetic ring monomer is in the shape of a trapezoidal cylinder with an arc-shaped inner side and a flat outer side; the arc-shaped inner sides of the eight inner magnetic ring monomers form a cylindrical space; the fixing cylinder is provided with a mounting long hole; a threaded hole is formed in the back of the inner magnetic ring monomer; a screw passes through the mounting long hole, is adjusted in position and is connected to the threaded hole to fix the inner magnetic ring monomer on the inner wall of the fixing cylinder.

2. The double-layered magnetic ring structure according to claim 1, wherein, The material of the outer shell is an alloy, the thickness of the outer shell is greater than 1 mm, the outer magnetic ring monomer is an NdFeB magnet, the working point Ji of the NdFeB magnet is greater than 0.9Br, and the squareness of the demagnetization curve is close to 1. The magnetization angles of the eight outer magnetic ring monomers are 90 DEG, 45 DEG, 0 DEG, 45 DEG, 90 DEG and-45 DEG respectively.

3. The double-layered magnetic ring structure according to claim 1, wherein, The magnetization angles of the eight inner magnetic ring monomers are 90 DEG, 45 DEG, 0 DEG, 45 DEG, 90 DEG and-45 DEG respectively.

4. The double-layered magnetic ring structure according to claim 1, wherein, The application further relates to a double-layer magnetic ring assembly method.

5. The method of claim 1-4, wherein the inner and outer double-layer magnetic ring structure is prepared by the steps of: The outer magnetic ring monomers are arranged in the trapezoidal groove formed by the first supporting plate and the two first side plates in the inner part of the outer shell to form the outer magnetic ring; the central air gap of the magnetic field is formed by the outer magnetic ring monomers in the inner part of the outer shell; the inner magnetic ring monomers are arranged in the trapezoidal groove in the inner part of the fixing cylinder to form the inner magnetic ring; the inner magnetic ring is arranged at the axial position of the central air gap; the two end plates are connected to the two ends of the outer shell; the double-layer magnetic ring magnetic circuit is formed by the outer magnetic ring and the inner magnetic ring. ​ ​ ​ 6. The method of claim 5, wherein the inner and outer dual-layer magnetic ring structure is prepared by the steps of: forming a first magnetic layer on a substrate; forming a second magnetic layer on the first magnetic layer; and forming a third magnetic layer on the second magnetic layer. According to the magnetization angle 90°, 45°, 0°, 45°, 90°, -45°, eight outer layer magnetic ring monomers are respectively installed in eight trapezoidal grooves, and the eight outer layer magnetic ring monomers form a center air gap at the center axis position; according to the magnetization angle 90°, 45°, 0°, 45°, 90°, -45°, eight inner layer magnetic ring monomers are respectively installed in the trapezoidal grooves inside the fixed cylinder.

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