CN210223697U - Permanent magnet device for generating space uniform magnetic field - Google Patents
Permanent magnet device for generating space uniform magnetic field Download PDFInfo
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- CN210223697U CN210223697U CN201921505306.7U CN201921505306U CN210223697U CN 210223697 U CN210223697 U CN 210223697U CN 201921505306 U CN201921505306 U CN 201921505306U CN 210223697 U CN210223697 U CN 210223697U
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Abstract
The utility model discloses a produce permanent magnet device in even magnetic field in space belongs to permanent magnetism device technical field, including yoke, two permanent magnets and two pole shoes, its characterized in that: the two permanent magnets are respectively fixed at the center positions of two planes of the magnetic yokes facing each other, and the polarities of the opposite surfaces of the two permanent magnets are opposite; the two pole shoes are fixed on the two permanent magnets in a one-to-one manner, the space between the two pole shoes is an air gap area, and pits are arranged on the two pole shoes; the utility model adopts the method of processing the pits on the pole shoe, so that the pole shoe plays a role of gathering the magnetic field, and the magnetic field uniformity in the space range in the air gap can be obviously improved; the permanent magnet device of the utility model has simple structure, small volume, light weight and convenient batch production; the utility model discloses not only can extensively use widely in the Lorenz magnetic suspension exciter, can also be used to magnetron permanent magnetism device, nuclear magnetic resonance imaging system etc..
Description
Technical Field
The utility model relates to a permanent magnetism device technical field especially relates to a produce permanent magnetism device in space uniform magnetic field.
Background
The permanent magnetic device can provide a static magnetic field or a dynamic magnetic field, a uniform magnetic field or a gradient magnetic field in a specific space range, and can realize specific functions by applying energy conversion and various physical effects of the magnetic field. For example, coulomb's law of force is used to convert magnetostatic energy into mechanical energy, faraday's law is used to convert mechanical energy into electrical energy, lorentz's principle on conductors is used to convert electrical energy into mechanical energy, and so on. The permanent magnetic device has wide application fields, such as microwave communication technology, electrical engineering, magnetic separation technology, nuclear magnetic resonance imaging and particle energy spectrum measurement technology and the like.
In many fields where permanent magnets are used to generate static magnetic fields, it is often desirable to generate highly uniform magnetic fields over a spatial range to produce forces on energized conductors placed in their air gaps or to control the movement of electrons. Such as a lorentz magnetic levitation exciter, and also such as a magnetron, nuclear magnetic resonance, etc. Taking the Lorenz magnetic suspension exciter as an example, when an electrified lead of the Lorenz magnetic suspension exciter displaces in a certain range due to a uniform magnetic field, the total number of magnetic lines of force cut by the lead is kept unchanged, the overall magnetic flux density is unchanged, and the stress of the electrified lead is kept consistent.
There are many reports on various permanent magnet devices, such as chinese patents 201610258521.6,03136672.4, 201110408498.1, 201610639248.1, etc. From the numerous published relevant documents, the existing permanent magnet devices usually consist of a magnetic circuit consisting of permanent magnets, pole shoes and yokes.
Under the premise of fixed distance between the two pole shoes, in order to generate a uniform magnetic field in a certain range of the center of the air gap, the volume and the size of the permanent magnet and the pole shoes are generally increased, but the volume and the weight of the permanent magnet device are increased. For example, in chinese patent application 201110408498.1, the auxiliary magnets are added around the main magnet to compensate the leakage of the field strength at the outer edge of the main magnet to expand the range of the uniform region of the magnetic field, but this method increases the size of the outer edge of the magnet, and introduces a complicated manufacturing process and increases the cost. Chinese patent applications 201320757529.9, 03136672.4 and the like adopt concave pole shoes or magnetic gathering rings and the like to increase the shimming effect.
The common problems of the prior art are as follows: the uniformity within the range of the central plane of the air gap is only realized, a gradient field is formed in the direction vertical to the pole face of the permanent magnet, and the closer the pole face is, the stronger the magnetic induction intensity is.
Disclosure of Invention
An object of the utility model is to provide a produce permanent magnet device in space uniform magnetic field to solve above-mentioned problem.
In order to achieve the above purpose, the utility model adopts the technical scheme that: a permanent magnet device for generating a spatially uniform magnetic field comprises a magnet yoke, two permanent magnets and two pole shoes, wherein the two permanent magnets are respectively fixed at the center positions of two planes of the magnet yoke, which face each other, and the polarities of the opposite faces of the two permanent magnets are opposite; the two pole shoes are fixed on the two permanent magnets in a one-to-one mode, the space between the two pole shoes is an air gap area, and pits are formed in the two pole shoes.
Preferably, the width of the permanent magnet and the pole shoe is consistent with the width of the magnetic yoke.
The pole shoe has the same shape as the permanent magnet, and the pits are arranged on the pole shoe and play a role in converging the magnetic field, so that the uniformity of the magnetic field in an air gap can be obviously improved.
The magnetic yoke and the pole shoe are made of magnetic conductive materials.
As a preferred technical scheme: the concave pits are spherical, drum-shaped, truncated cone-shaped, arc-shaped, square truncated cone-shaped or the combination of two or more of the shapes.
As a preferred technical scheme: the magnetic yoke, the permanent magnet and the pole shoe are bonded and fixed by adhesive.
As a preferred technical scheme: the magnet yoke is square or C-shaped. May be a unitary structure or a splice structure.
As a preferred technical scheme: the permanent magnet is a cube, a cuboid or a cylinder.
As a preferred technical scheme: the permanent magnet is of an integrated structure or a splicing structure.
As a further preferable technical scheme: the permanent magnet is of a splicing structure and is fixed by a non-magnetic material.
Compared with the prior art, the utility model has the advantages of: the utility model adopts the method of processing the pits on the pole shoe, so that the pole shoe plays a role of gathering the magnetic field, and the magnetic field uniformity in the space range in the air gap can be obviously improved; the permanent magnet device has simple structure, small volume and light weight, and is convenient for batch production; the utility model discloses not only can extensively use widely in the Lorenz magnetic suspension exciter, can also be used to magnetron permanent magnetism device, nuclear magnetic resonance imaging system etc..
Drawings
Fig. 1 is an axonometric view of a permanent magnet device for generating a spatially uniform magnetic field according to embodiment 1 of the present invention;
fig. 2 is an axonometric view of pole shoes of the permanent magnet device for generating a spatially uniform magnetic field according to embodiment 1 of the present invention;
fig. 3 is a cross-sectional view of a permanent magnet device for generating a spatially uniform magnetic field according to embodiment 1 of the present invention;
fig. 4 is a three-dimensional 6mm × 6mm × 6mm regional magnetic field distribution diagram in the central region of the air gap magnetic field according to embodiment 1 of the present invention;
fig. 5 is a three-dimensional 6mm × 6mm × 6mm regional magnetic field distribution diagram in the air gap magnetic field central region of comparative example 1 according to example 1 of the present invention;
fig. 6 is a three-dimensional 6mm × 6mm × 6mm regional magnetic field distribution diagram in the air gap magnetic field central region of comparative example 2 according to example 1 of the present invention;
fig. 7 is an axonometric view of the permanent magnet device for generating a spatially uniform magnetic field according to embodiment 2 of the present invention;
fig. 8 is an axonometric view of the pole shoes of the permanent magnet device for generating a spatially uniform magnetic field according to embodiment 2 of the present invention;
fig. 9 is a cross-sectional view of a pole piece of a permanent magnet device for generating a spatially uniform magnetic field according to embodiment 2 of the present invention;
fig. 10 is a cross-sectional view of a permanent magnet apparatus for generating a spatially uniform magnetic field according to embodiment 2 of the present invention;
fig. 11 is a three-dimensional 16mm × 16mm × 6mm regional magnetic field distribution diagram in the air gap magnetic field central region according to embodiment 2 of the present invention;
fig. 12 is a three-dimensional 16mm × 16mm × 6mm regional magnetic field distribution diagram in the air gap magnetic field central region of comparative example 3 according to example 2 of the present invention;
fig. 13 is an isometric view of pole shoes of a permanent magnet apparatus for producing a spatially uniform magnetic field according to embodiment 3 of the present invention;
fig. 14 is a cross-sectional view of a pole piece of a permanent magnet device for generating a spatially uniform magnetic field according to embodiment 3 of the present invention;
fig. 15 is a three-dimensional 16mm × 16mm × 6mm regional magnetic field distribution diagram in the air gap magnetic field central region according to embodiment 3 of the present invention;
fig. 16 is an axonometric view of the permanent magnet device for generating a spatially uniform magnetic field according to embodiment 4 of the present invention;
fig. 17 is an isometric view of pole shoes of a permanent magnet apparatus for producing a spatially uniform magnetic field according to embodiment 4 of the present invention;
fig. 18 is a sectional view of a pole piece of a permanent magnet device for generating a spatially uniform magnetic field according to embodiment 4 of the present invention;
fig. 19 is a three-dimensional 60mm × 5mm × 5mm regional magnetic field distribution diagram in the central region of the air gap magnetic field according to embodiment 4 of the present invention;
fig. 20 is a three-dimensional 60mm × 5mm × 5mm regional magnetic field distribution diagram in the air gap magnetic field central region of comparative example 4 of the present invention;
fig. 21 is an isometric view of a pole piece of a permanent magnet apparatus for producing a spatially uniform magnetic field according to embodiment 5 of the present invention;
fig. 22 is a three-dimensional 60mm × 5mm × 5mm regional magnetic field distribution diagram in the central region of the air gap magnetic field according to embodiment 5 of the present invention;
fig. 23 is an isometric view of a permanent magnet apparatus for generating a spatially uniform magnetic field according to embodiment 6 of the present invention;
fig. 24 is an isometric view of pole pieces of a permanent magnet apparatus for producing a spatially uniform magnetic field according to embodiment 6 of the present invention;
fig. 25 is a cross-sectional view of a permanent magnet apparatus for generating a spatially uniform magnetic field according to embodiment 6 of the present invention;
fig. 26 is a three-dimensional 12mm × 12mm × 9mm regional magnetic field distribution diagram in the air gap magnetic field central region according to embodiment 6 of the present invention;
fig. 27 is a three-dimensional space 12mm × 12mm × 9mm regional magnetic field distribution diagram of the air gap magnetic field central region of comparative example 5 of example 6 of the present invention.
In the figure: 1. a magnetic yoke; 2. a permanent magnet; 3. a pole shoe; 4. a magnetic field homogenizing region; 5. and (4) pits.
Detailed Description
The present invention will be further explained with reference to the accompanying drawings.
Example 1
A permanent magnet device for generating a space uniform magnetic field is disclosed, as shown in figures 1-3, a square magnet yoke 1 and a pair of square permanent magnets 2 are respectively fixed at the center positions of two planes of the magnet yoke 1 facing each other, and the opposite surfaces of the two permanent magnets 2 have opposite polarities; two pole shoes 3 provided with spherical pits 5 are respectively fixed on a pair of permanent magnets 2, the space between the pole shoes 3 is a magnetic field air gap area, and the area forms a magnetic field uniform area 4; FIG. 4 is a graph of the magnetic field distribution of the central region of the gap of FIG. 1 at a maximum magnetic field of 132.336mT, a minimum magnetic field of 131.198mT, and a magnetic field uniformity of + -0.43% in three dimensions. The magnetic field uniformity is calculated by the following equation:
uniformity = ± [ (maximum magnetic field-minimum magnetic field)/(maximum magnetic field + minimum magnetic field) ] × 100%
Comparative example 1
Compared with the embodiment 1, the magnetic field uniformity of the comparison example 1 is tested by adopting the same method as the embodiment 1 except that the pole shoe 3 is not provided with the pits, the other structures are the same as the embodiment 1, the other components, the position relation and the connection relation, the sizes of the components and the like are the same, and fig. 5 is a magnetic field distribution diagram of 6mm multiplied by 6mm in a three-dimensional space in the central area of an air gap, wherein the maximum magnetic field is 167.884mT, the minimum magnetic field is 160.950mT, and the magnetic field uniformity is +/-2.11%.
Comparative example 2
In the comparative example, on the basis of the comparative example 1, the dimension of the surface, perpendicular to the magnetizing direction, of the magnet and the pole shoe is enlarged by 33.3%, and the width dimension of the magnetic yoke is consistent with the dimension of the magnet. The rest of the structure is the same as that of comparative example 1, including the rest of the constituent components, the positional relationship and the connection relationship, the sizes of the components, etc. are the same, and the magnetic field uniformity of comparative example 2 is tested by the same method as that of comparative example 1, and fig. 6 is a magnetic field distribution diagram of 6mm × 6mm × 6mm in the three-dimensional space of the central region of the air gap, the maximum magnetic field 210.444mT, the minimum magnetic field 207.401mT, and the magnetic field uniformity ± 0.73%.
Example 2
A permanent magnet device for generating a spatially uniform magnetic field is disclosed, as shown in fig. 7-10, a square magnet yoke 1 with chamfered edges is provided, a pair of rectangular permanent magnets 2 are respectively fixed at the center positions of two planes of the magnet yoke 1 facing each other, and the polarities of the opposite surfaces of the two permanent magnets 2 are opposite; two pole shoes 3 provided with drum-shaped pits 5 are respectively fixed on a pair of permanent magnets 2, the space between the pole shoes 3 is a magnetic field air gap area, and the area forms a magnetic field uniform area 4; FIG. 11 is a 16mm by 6mm magnetic field distribution plot in three dimensions in the central region of the gap of FIG. 7 with a maximum magnetic field of 230.321mT, a minimum magnetic field of 225.057mT, and a magnetic field uniformity of + -1.16%.
Comparative example 3
Compared with the embodiment 2, the magnetic field uniformity of the comparison example 3 is tested by the same method as the embodiment 2 except that the pole shoe 3 is not provided with the pits, the other structures are the same as the embodiment 2, including the rest components, the position relation and the connection relation, the sizes of the components and the like, and fig. 12 is a magnetic field distribution diagram of 16mm x 6mm in the three-dimensional space of the central area of the air gap, wherein the maximum magnetic field is 260.981mT, the minimum magnetic field is 242.979mT, and the magnetic field uniformity is +/-3.57%.
Example 3
The difference between this embodiment and embodiment 2 is that the pole shoe is provided with truncated cone-shaped pits, as shown in fig. 13 to 14. The magnetic field uniformity of example 3 was tested in the same manner as in example 2, except that the structure was the same as in example 2, including the remaining constituent elements, positional relationship and connection relationship, and the size of the elements, and fig. 15 is a magnetic field distribution diagram of 16mm × 16mm × 6mm in three-dimensional space in the central region of the air gap, in which the maximum magnetic field was 231.548mT, the minimum magnetic field was 226.352mT, and the magnetic field uniformity was ± 1.13%.
Example 4
A permanent magnet device for generating a spatially uniform magnetic field is disclosed, as shown in fig. 16-18, a square magnetic yoke 1 and a pair of rectangular permanent magnets 2 are respectively fixed at the center positions of two planes of the magnetic yoke 1 facing each other, and the polarities of the opposite surfaces of the two permanent magnets 2 are opposite; two rectangular pole shoes 3 provided with spherical and arc-shaped combined pits are respectively fixed on a pair of permanent magnets 2, the space between the pole shoes 3 is a magnetic field air gap area, and the area forms a magnetic field uniform area 4; FIG. 19 is a graph of the magnetic field distribution of the central region of the gap of FIG. 16 in three dimensions 60mm 5mm with a maximum magnetic field of 190.876mT, a minimum magnetic field of 189.111mT, and a magnetic field uniformity of + -0.46%.
Comparative example 4
Compared with the example 4, the magnetic field uniformity of the comparative example 4 is tested by the same method as the example 4 except that the pole shoe 3 is not provided with the spherical and arc-shaped combined pits, the other structures comprise the rest components, the position relation and the connection relation, the sizes of the components and the like, and the magnetic field uniformity of the comparative example 4 is tested, wherein the magnetic field distribution diagram of the three-dimensional space of the central area of the air gap is 60mm multiplied by 5mm, the maximum magnetic field 221.115mT, the minimum magnetic field 214.974mT and the magnetic field uniformity is +/-1.41 percent in the figure 20.
Example 5
This embodiment is different from embodiment 4 in that square frustum-shaped pits are provided on the pole shoe, as shown in fig. 21. The magnetic field uniformity of example 5 was tested in the same manner as in example 4, except that the structure was the same as in example 4, including the remaining constituent elements, positional relationship and connection relationship, and the size of the elements, and fig. 22 is a magnetic field distribution diagram of 60mm × 5mm × 5mm in three-dimensional space in the central region of the air gap, in which the maximum magnetic field was 183.953mT, the minimum magnetic field was 182.567mT, and the magnetic field uniformity was ± 0.38%.
Example 6
The difference between this embodiment and embodiment 1 is that the permanent magnet 2 is cylindrical, the yoke 1 is C-shaped, and the structure is shown in fig. 23-25. FIG. 26 is a graph of the magnetic field distribution of the central region of the air gap of FIG. 23 at a maximum magnetic field of 130.630mT, a minimum magnetic field of 129.353mT, and a magnetic field uniformity of + -0.49% in three dimensions.
Comparative example 5
Compared with the example 6, the magnetic field uniformity of the comparative example 5 is tested by the same method as the example 6 except that the pole piece 3 is not provided with the spherical pits, the other structures are the same as the example 6, the rest components, the position relation and the connection relation, the sizes of the components and the like are the same, and fig. 27 is a magnetic field distribution diagram of 12mm x 9mm in a three-dimensional space in the central area of the air gap, wherein the maximum magnetic field is 147.655mT, the minimum magnetic field is 142.951mT, and the magnetic field uniformity is +/-1.62%.
The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.
Claims (7)
1. The utility model provides a produce permanent magnet device of space uniform magnetic field, includes yoke, two permanent magnets and two pole shoes, its characterized in that: the two permanent magnets are respectively fixed at the center positions of two planes of the magnetic yokes facing each other, and the polarities of the opposite surfaces of the two permanent magnets are opposite; the two pole shoes are fixed on the two permanent magnets in a one-to-one mode, the space between the two pole shoes is an air gap area, and pits are formed in the two pole shoes.
2. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 1, wherein: the concave pits are spherical, drum-shaped, truncated cone-shaped, arc-shaped, square truncated cone-shaped or the combination of two or more of the shapes.
3. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 1, wherein: the magnetic yoke, the permanent magnet and the pole shoe are bonded and fixed by adhesive.
4. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 1, wherein: the magnet yoke is square or C-shaped.
5. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 1, wherein: the permanent magnet is a cube, a cuboid or a cylinder.
6. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 1, wherein: the permanent magnet is of an integrated structure or a splicing structure.
7. A permanent magnet apparatus for generating a spatially uniform magnetic field as defined in claim 6, wherein: the permanent magnet is of a splicing structure and is fixed by a non-magnetic material.
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| CN201921505306.7U CN210223697U (en) | 2019-09-11 | 2019-09-11 | Permanent magnet device for generating space uniform magnetic field |
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| CN201921505306.7U CN210223697U (en) | 2019-09-11 | 2019-09-11 | Permanent magnet device for generating space uniform magnetic field |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110459378A (en) * | 2019-09-11 | 2019-11-15 | 西南应用磁学研究所 | A kind of permanent magnetic device generating space uniform magnetic field |
| CN111865038A (en) * | 2020-07-02 | 2020-10-30 | 中国科学院电工研究所 | High-efficient liquid metal magnetofluid pump |
-
2019
- 2019-09-11 CN CN201921505306.7U patent/CN210223697U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110459378A (en) * | 2019-09-11 | 2019-11-15 | 西南应用磁学研究所 | A kind of permanent magnetic device generating space uniform magnetic field |
| CN111865038A (en) * | 2020-07-02 | 2020-10-30 | 中国科学院电工研究所 | High-efficient liquid metal magnetofluid pump |
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