JP2015027208A - Electromagnetic induction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow for increase in the number of flux interlinking with an armature coil.SOLUTION: An electromagnetic induction device has such a relationship, in a plane parallel with the magnetization direction of permanent magnets 23, 27, that the ratio of the cross-sectional area aof a cavity between the center line II of a field cavity 24 and a permanent magnet array 22 and the cross-sectional area aof a cavity between the center line II of a field cavity 24 and a permanent magnet array 26 is substantially equal to the ratio of the cross-sectional area Aof a permanent magnet array 22 and the cross-sectional area Aof a permanent magnet array 26. Preferably, the cross-sectional area (a+a) of the cavity 24 is 1.2-2.0 of the average value of the cross-sectional area Aof a permanent magnet array 22 and the cross-sectional area Aof a permanent magnet array 26.

Description

  The present invention relates to an electromagnetic induction device, and more particularly to an electromagnetic induction device used as an electric motor or a generator.

  To increase the magnetic field of an electric motor (motor) or generator, there is a permanent magnet arrangement method called Halbach arrangement. If the permanent magnets are arranged so that the north and south poles are alternately arranged, a magnetic field is generated on both the front side and the back side of the magnet arrangement, and the magnetic field cannot be used effectively. On the other hand, in the Halbach arrangement, the magnetic poles of the permanent magnets are arranged while being rotated by 90 °, so that the magnetic field on one side of the magnet arrangement is weakened, and on the other side of the magnet arrangement, the corresponding magnetic field is reduced accordingly. A strong magnetic field can be generated on one side of the array of permanent magnets. A permanent magnet rotating electric machine (see Patent Document 1) and a linear motor (see Patent Document 2) in which armature coils are arranged between two rows of permanent magnet arrays (dual Halbach array) arranged in Halbach are proposed.

JP 2009-201343 A JP 2010-154688 A

  In coreless motors and coreless generators using permanent magnet dual Halbach array fields, it is desirable to increase the number of magnetic fluxes linked to the armature coil as much as possible. However, in the conventional structure, the number of flux linkages is optimized. There is no need to make it larger.

  A main object of the present invention is to provide an electromagnetic induction device capable of increasing the number of magnetic fluxes linked to an armature coil.

According to the present invention,
A first permanent magnet row and a second permanent magnet row arranged opposite to each other, wherein the first permanent magnet row changes the direction of the magnetic pole by an integer equal to 2π in a predetermined direction; A plurality of first permanent magnets arranged in the predetermined direction so that the magnetic field on the second permanent magnet row side is strengthened and the magnetic field on the side opposite to the second permanent magnet row side is weakened; In the second permanent magnet row, the direction of the magnetic poles changes by an integer equal to 2π in the predetermined direction, the magnetic field on the first permanent magnet row side is strengthened, and opposite to the first permanent magnet row side. The first permanent magnet row and the second permanent magnet row having a plurality of second permanent magnets arranged in the predetermined direction so that the magnetic field on the side is weakened;
An armature coil disposed in a field gap between the first permanent magnet row and the second permanent magnet row facing each other,
In the plane parallel to the magnetization direction of the first permanent magnet and the second permanent magnet, the gap cross-sectional area between the center line of the field gap and the first permanent magnet row and the field magnet The ratio of the gap sectional area between the center line of the gap and the second permanent magnet row is substantially equal to the ratio of the sectional area of the first permanent magnet row and the sectional area of the second permanent magnet row. An electromagnetic induction device is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic induction apparatus which can enlarge the magnetic flux number linked with an armature coil is provided.

FIG. 1 is a sectional view of a dual Halbach array field to which the equivalent magnetic circuit method is applied. FIG. 2 is a diagram for explaining the equivalent magnetic circuit of FIG. FIG. 3 is a sectional view of a dual Halbach array field. FIG. 4 is a diagram showing the relationship between the gap length and the number of flux linkages. FIG. 5 is a diagram showing the relationship between the gap length and the number of flux linkages. FIG. 6 is a schematic perspective view for explaining the cylindrical three-phase linear synchronous motor 100 according to the first preferred embodiment of the present invention. 7 is a cross-sectional view taken along line AA in FIG. 8 is a cross-sectional view taken along the line BB in FIG. 9 is a cross-sectional view taken along the line CC of FIG. FIG. 10 is a schematic perspective view for explaining a three-phase synchronous generator 200 according to a preferred second embodiment of the present invention. FIG. 11A is a schematic cross-sectional view of the three-phase synchronous generator 200 in a plane parallel to the magnetization direction, and FIG. 11B is a diagram showing wiring of armature coils. FIG. 12 is a cross-sectional view taken along the line V-V in FIG. 11A and shows a generator having a single-layer field. FIG. 13 is a diagram illustrating a generator having a multilayer field, which is a modification of the generator shown in FIGS. 10 to 12.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  The inventors have determined the average magnetic flux density at the center of the gap between the magnetic poles using an equivalent magnetic circuit for the dual Halbach field formed by rotating the magnetic poles by 90 degrees. In the dual Halbach field, the magnetic flux density is extremely low outside the permanent magnet array. The relative permeability of the permanent magnet is almost the same as that of air. Unless a ferromagnetic material such as iron is used, magnetic saturation due to magnetic flux concentration does not occur. For this reason, a required magnetic flux density can be obtained with an equivalent magnetic circuit.

  FIG. 1 is a cross-sectional view of a dual Halbach array field 10 to which the equivalent magnetic circuit method is applied. The dual Halbach array field 10 includes a permanent magnet array 12 in which the magnetic poles of the permanent magnets 13 are rotated by 90 degrees in the first linear direction, and the magnetic poles of the permanent magnets 17 are parallel to the first straight line. 2 and a permanent magnet array 16 arranged in a Halbach array by rotating 90 degrees in the linear direction.

  In the permanent magnet array 12, the permanent magnets 13 are arranged so that the magnetic field on the permanent magnet array 16 side is strengthened and the magnetic field on the opposite side to the permanent magnet array 16 side is weakened. In the permanent magnet arrangement 16, the permanent magnets 17 are arranged so that the magnetic field on the permanent magnet arrangement 12 side strengthens and the magnetic field on the opposite side to the permanent magnet arrangement 12 side weakens.

  FIG. 1 is a cross-sectional view taken along a plane parallel to the magnetization direction of the permanent magnets 13 and 17. The permanent magnets 13 and 17 both have a square shape within the plane parallel to the magnetization direction of the permanent magnets 13 and 17 (a plane parallel to the paper surface) and have the same cross-sectional area.

  The square root of the cross-sectional area of the permanent magnets 13 and 17 in the plane parallel to the magnetization direction of the permanent magnets 13 and 17 (plane parallel to the paper surface) is normalized as 1. Since the square root of the cross-sectional area is 1, the cross-sectional areas of the permanent magnets 13 and 17 are also 1. In addition, since the permanent magnets 13 and 17 both have a square shape in a plane parallel to the magnetization direction of the permanent magnets 13 and 17, the length of one side of the permanent magnets 13 and 17 is also 1. A distance (gap length) between the permanent magnet array 12 and the permanent magnet array 16 is defined as a.

  The closed curve shown in FIG. 1 is a magnetic flux line. It can be seen from the shape of the magnetic flux lines that the same magnetic flux path exists for each pole pitch. This magnetic flux path is indicated by a dotted line.

The main magnetic flux of the equivalent magnetic circuit of the dual Halbach field shown in FIG. 1 passes through the magnetic flux path of FIG. In addition, since the magnetic circuit exists symmetrically with respect to the magnetic pole center line XX, the magnetic circuit related to one path continues line-symmetrically for each magnetic pole. Now, one magnetic circuit is defined as shown in FIG. In FIG. 2, R is the magnetic resistance of the permanent magnets 13 and 17, where S is the cross-sectional area of the permanent magnet perpendicular to the magnetic pole, l _{m is} the length in the magnetic pole direction of the permanent magnet, and μ ₀ is the permeability of the vacuum. It is expressed by a formula.
Here, the relative magnetic permeability of the permanent magnet is approximated to 1. In FIG. 2, γ is the distance from the magnetic pole surface of the magnet to the longitudinal path, and δ is the ratio of the distance from the magnetic pole surface to the nearest lateral path in the gap to the gap length. The cross-sectional area S _{v of} the longitudinal path and the cross-sectional area S _r of the lateral path in the gap are
Therefore, the three closed circuit main magnetic fluxes φ ₁ , φ ₂ , and φ ₃ satisfy the following circuit equation.

Α from equation (2)
As
It becomes.
Therefore, the average magnetic flux density _Bav between the NS magnetic poles on the gap center line YY is expressed by the following equation.
Here, _Br is the residual magnetic flux density of the permanent magnet.

  FIG. 3 is a cross-sectional view of another dual Halbach array field 20 to which the equivalent magnetic circuit method is applied. The dual Halbach array field 20 rotates the magnetic poles of the permanent magnets 23 by approximately 90 degrees in the circumferential direction and rotates the magnetic poles of the permanent magnets 27 by approximately 90 degrees in the circumferential direction. And a permanent magnet array 26 arranged in a Halbach array.

  In the permanent magnet array 22, the permanent magnets 23 are arranged so that the magnetic field on the permanent magnet array 26 side is strengthened and the magnetic field on the side opposite to the permanent magnet array 26 side is weakened. In the permanent magnet array 26, the permanent magnets 27 are arranged so that the magnetic field on the permanent magnet array 22 side is strengthened and the magnetic field on the opposite side to the permanent magnet array 22 side is weakened.

  FIG. 3 is a cross-sectional view taken along a plane parallel to the magnetization direction of the permanent magnets 23 and 27. The permanent magnets 23 and 27 are both trapezoidal in a plane parallel to the magnetization direction of the permanent magnets 23 and 27 (a plane parallel to the paper surface). The number of permanent magnets 23 and the number of permanent magnets 27 are the same. When the number of permanent magnets 23 and the number of permanent magnets 27 is, for example, 64, adjacent permanent magnets 23 or adjacent permanent magnets 27 are joined at an angle of approximately 174 degrees close to 180 degrees. become. Therefore, it can be considered that the permanent magnet 23 and the permanent magnet 27 are substantially square.

  Therefore, as in the case of FIG. 1, the square root of the sectional area of the permanent magnets 23 and 27 in the plane parallel to the magnetization direction of the permanent magnets 23 and 27 (plane parallel to the paper surface) is normalized as 1. Since the square root of the cross-sectional area is 1, the cross-sectional areas of the permanent magnets 23 and 27 are also 1. In addition, since the permanent magnets 23 and 27 can be regarded as having a substantially square shape in a plane parallel to the magnetization direction of the permanent magnets 23 and 27, The length can also be approximated as 1. An interval (gap length) between the permanent magnet array 22 and the permanent magnet array 26 is a.

  Thus, as shown in FIG. 3, the permanent magnet arrangements 22 and 26 in which the magnetic poles of the permanent magnets 23 and 27 are rotated by approximately 90 degrees in the circumferential direction to form a ring-shaped Halbach arrangement are also used approximately. The equivalent magnetic circuit of FIG. 2 is obtained, and the above discussion can be applied as it is. (However, as will be described later, when the electromagnetic induction device of FIG. 3 is discussed based on FIG. 1, the amount of permanent magnets of the outer and inner permanent magnet arrays 22, 26 is set to the outside of the center line II of the field gap 24. And the volume ratio of the inner gap is desirable.)

When the gap length a is set to 0.25, 0.5, _1.0 , 1.5, and 2.0, the average values B ₀ , γ, and δ of the y-direction magnetic flux density B _y on the straight line YY are parameters. Table 1 shows the values of B _av obtained from the equation (4).
In Table 1, γ = 0.25 and δ = 0.25 correspond to the case where the geometric center is selected as the path of the magnetic circuit. Further, γ = 0.10, δ = 0.25 is _{B 0} value to minimize the error _{B av,} B _tau is the average value between the pole pitch of the _{B y} in the analysis value by two-dimensional finite element method field analysis is there. Here, assuming that the magnetic flux density between the pole pitches is distributed in a sine wave shape, the magnetic flux density average value B _avτ is 1 / √2 times B _av . Error of B _tau and _{B Avtau} is minimized by γ = 0.20, δ = 0.22.

As shown in FIG. 1, the permanent magnet array 12 is arranged in a Halbach array by rotating the magnetic poles of the permanent magnet 13 by 90 degrees in the first linear direction, and the magnetic poles of the permanent magnet 17 are parallel to the first straight line. The permanent magnet 13 and the permanent magnet 17 are square-shaped and have the same cross-sectional area, and the dual Halbach array field is provided. 10 and FIG. 3, the permanent magnet array 22 is rotated by 90 degrees in the circumferential direction by rotating the magnetic poles of the permanent magnet 23 by 90 degrees in the circumferential direction, and the magnetic pole of the permanent magnet 27 is rotated by 90 degrees in the circumferential direction. In the dual Halbach array field 20 having the Halbach array permanent magnet array 26, the permanent magnet 23 and the permanent magnet 27 having a substantially square shape and the same cross-sectional area, as described above, the gap During ~ The average magnetic flux density _{B Avtau} between NS pole pitch on line YY is
It becomes. Here, _Br is the residual magnetic flux density of the permanent magnet, and α is
It is.

The number of interlinkage magnetic fluxes Φ of the armature coil arranged in the gap of the dual Halbach field is S and the number of coil turns is N.
It becomes.

When the armature coil arranged in the gap is manufactured so as to fill the gap with the width of the pole pitch, the maximum number of turns can be obtained. Therefore, the square root of the cross-sectional area of the permanent magnet in the plane parallel to the magnetization direction is set to 1. When the permanent magnet is square, the length of one side of the square is 1, and when the permanent magnet is approximately square and can be approximated as a square, the length of one side of the approximated square is 1. In this case, S is proportional to the depth of the field (the length of the permanent magnet in the direction perpendicular to the square cross section) l, and N is proportional to the gap length a. Now, if the proportionality constant is k,
given that,
Therefore, by substituting Equations (7) and (8) into Equation (6), the number of flux linkages Φ can be expressed by the following equation.

On the other hand, as described above, when γ = 0.20 and δ = 0.22 in the equation (5), _{Bavτ in the} equation (4) is a calculation equation representing the actual average magnetic flux density between the magnetic pole pitches. Therefore, the actual flux linkage can be calculated by equation (9) when γ = 0.20 and δ = 0.22. Here, k and l in the equation are predetermined constants.
If there is a value of the gap length a that maximizes the function f (a) defined by (2), the maximum number of interlinkage magnetic fluxes can be obtained by configuring a dual Halbach array field with that gap length.

FIG. 4 shows a graph of f (a). Since there is a maximum value,
If a is obtained, a = 1.2. That is, 1.2 times the square root of the cross-sectional area of the permanent magnet in a plane parallel to the magnetization direction, and when the permanent magnet is square, the permanent magnet is approximately 1.2 times the length of one side of the square. If it is a square and can be approximated as a square, the maximum interlinkage magnetic flux can be obtained for a predetermined number of turns if the gap length is 1.2 times the length of one side of the approximated square. Can do.

  Since the Halbach array field and armature coils move relative to each other, a certain amount of clearance is required when the armature coils are actually placed in the field gap so that the permanent magnets of the field and the armature coils do not contact each other. And The armature coil is formed by winding an electric wire around a bobbin or fixing the wound electric wire by a mold. Therefore, the entire thickness of the coil is not occupied by the conductor, and if the length of one side of the square cross section of the permanent magnet is 1 cm, the surface facing the field is about 1 mm between the field magnet and the coil conductor. The non-conductor is present.

In this case, the square root of the cross-sectional area of the permanent magnet in the plane parallel to the magnetization direction is 1, and when the permanent magnet is square, the length of one side of the square is 1, and the permanent magnet is substantially square. When it can be approximated as a square, when the length of one side of the approximated square is set to 1, the number of turns N of the armature coil arranged in the field gap is as in the case of Equation (7). Similarly,
It can be expressed as Therefore, the gap length that maximizes the flux linkage is
The gap length that maximizes the function g (a) defined by

FIG. 5 is a graph of g (a). Since there is a maximum value,
If a is obtained, a = 1.5. That is, 1.5 times the square root of the cross-sectional area of the permanent magnet in a plane parallel to the magnetization direction, and when the permanent magnet is square, the permanent magnet is approximately 1.5 times the length of one side of the square. If it is a square and can be approximated as a square, the maximum flux linkage can be obtained for a given number of turns if the gap length is 1.5 times the length of one side of the approximated square. Can do.

Thus, when the gap length of the dual Halbach array field is 1.2 to 1.5 times the square root of the cross section of the permanent magnet in a plane parallel to the magnetization direction, and the permanent magnet is square, When the length of one side of the square is 1.2 to 1.5 times, and the permanent magnet is substantially square and can be approximated as a square, the length of one side of the approximate square is 1.2 to 1.5. When set to double, a large number of flux linkages can be obtained in the armature coil.
Furthermore, the gap of FIG. 1 is linear, whereas the field gap 24 is curved. When a rectangular parallelepiped coil is inserted into the gap to form an armature, the corner of the coil is the field. 20 and a gap is generated between the coil and the field even if contact is made.
For this reason, the gap length of the dual Halbach array field is 1.2 to 2.0 times the square root of the cross-sectional area of the permanent magnet in the plane parallel to the magnetization direction. 1.2 to 2.0 times the length of one side, and if the permanent magnet is approximately square and can be approximated as a square, 1.2 to 2.0 times the length of one side of the approximated square When set to, a large number of flux linkages can be obtained in the armature coil.

  However, when a circular permanent magnet array is used as shown in FIG. 3, the outer gap is larger in cross section than the outer gap and the inner gap from the center line II of the ring-shaped field gap 24. (Volume considering depth) increases. On the other hand, in FIG. 1, the cross-sectional areas of the upper half gap and the lower half gap from the gap center line YY are equal. Therefore, when discussing the electromagnetic induction device of FIG. 3 based on FIG. 1, the amount of permanent magnets of the outer and inner permanent magnet rows 22, 26 is set to the outer and inner gaps of the center line II of the field gap 24. It is desirable to match the volume ratio.

Specifically, in the electromagnetic induction device of the present invention, in the plane parallel to the magnetization direction of the permanent magnets 23 and 27 as shown in FIG.
The ratio of the air gap cross-sectional area a ₁ between the center line II of the field air gap 24 and the permanent magnet row 22 and the air gap cross-sectional area a ₂ between the center line II of the field air gap 24 and the permanent magnet row 26 is
The relationship is approximately equal to the ratio of the cross-sectional area A ₁ of the permanent magnet row 22 and the cross-sectional area A ₂ of the permanent magnet row 26.

In this case, the sectional area (a ₁ + a ₂ ) of the field gap 24 is 1.2 times or more and 2.0 times the average value of the sectional area A ₁ of the permanent magnet array 22 and the sectional area A ₂ of the permanent magnet array 26. The following is desirable.

(First embodiment)
The first preferred embodiment of the present invention is a cylindrical three-phase linear synchronous motor. FIG. 6 is a schematic perspective view for explaining the cylindrical three-phase linear synchronous motor 100 according to the first preferred embodiment of the present invention. 7 is a cross-sectional view taken along line AA in FIG. 6, FIG. 8 is a cross-sectional view taken along line BB in FIG. 6, and FIG. 9 is a cross-sectional view taken along line CC in FIG.

  A cylindrical three-phase linear synchronous motor 100 includes a cylindrical stator 105, a cylindrical movable element 107 that is movable in the axial direction of the stator 105, and has a notch, and an external power source 108 connected to the movable element 107. And a driving device 109 for supplying the electric power.

  The stator 105 is an outer permanent magnet as a first permanent magnet array configured by adjoining the permanent magnet 112 so that the magnetic pole of the ring-shaped permanent magnet 112 rotates approximately 90 degrees in a cross section including the central axis. An inner permanent magnet row as a second permanent magnet row configured by adjoining the permanent magnet 116 such that the magnetic poles of the row 111 and the ring-shaped permanent magnet 116 rotate approximately 90 degrees in a cross section including the central axis thereof. 115, an outer pipe 113 as a first annular fixing member to which the first permanent magnet row 111 is fixed to the inner inner surface, and a second annular fixing member to which the inner permanent magnet row 115 is fixed to the outer surface. And an outer pipe 113 and a fixing plate 123 for fixing the inner pipe 117 so as not to interfere with the mover 107.

  Further, in the stator 105, guide rods 121 are attached to the outer upper portion and the outer lower portion of the outer pipe 113 via guide rod support members 211 and 213. Electrodes 203, 205, 207, and 209 that are divided into two portions in the range from the end on the guide rod support member 211 side to the guide rod support member 211 are fixed to the surface of the guide rod 121. The lead wires 141 are bundled and introduced into the driving device 109 via a lead-out path 143 provided in the guide rod support member 211.

  The mover 107 includes a winding ring 133 around which the three-phase coil 131 is wound, an output ring 137 having a notch fixed to both ends of the winding ring 133, and a notch for fixing the notch of the output ring 137. A notch fixing plate 139 and a linear bush 135 attached to the end of the output ring 137 and guiding the winding ring 133 along the guide rod 121 are provided. The linear bush 135 includes a sliding electrode 201 that contacts each of the electrodes 203, 205, 207, and 209 provided on the surface of the guide rod 121, and a lead wire 141 having one end connected to the three-phase coil 131. The output ring 137 and the linear bush 135 are connected to the sliding electrode 201 via a lead-out path 143. As a result, the three-phase coil 131 is electrically connected to the driving device 109 via the electrodes 203, 205, 207, and 209 on the stator 105 side. Here, the U-phase, V-phase, W-phase, and neutral point current of the three-phase AC current corresponding to the three-phase AC voltage generated by the drive device 109 flows through each of the electrodes 203, 205, 207, and 209. The three-phase coil 131 is excited and the mover 107 moves in the axial direction with a predetermined thrust.

  The number of permanent magnets 112 in the outer permanent magnet array 111 and the number of permanent magnets 116 in the inner permanent magnet array 115 are the same, and the magnetic poles of the permanent magnets 112 magnetized in the radial direction among the permanent magnets 112 in the outer permanent magnet array 111. The direction and the magnetic pole direction of the permanent magnet 116 magnetized in the radial direction among the permanent magnets 116 of the permanent magnet array 115 are the same when arranged on the same radius. The magnetic pole direction of the permanent magnet 112 magnetized in the axial direction among the permanent magnets 112 in the outer permanent magnet array 111 and the magnetic pole direction of the permanent magnet 116 magnetized in the axial direction among the permanent magnets 116 in the inner permanent magnet array 115 are: Those arranged on the same radius are opposite.

  In the outer permanent magnet arrangement 111, the magnetic poles of the permanent magnets 112 are arranged while being rotated approximately 90 degrees in the axial direction, so that the magnetic field on one side of the arrangement (outside in the present embodiment) is weakened. On the other side (in this embodiment, on the inner side, on the inner permanent magnet array 115 side), the magnetic field is increased correspondingly, and a strong magnetic field is generated on one side (in this embodiment, on the inner side) of the outer permanent magnet array 111. Can do. Further, in the inner permanent magnet arrangement 115, the magnetic poles of the permanent magnets 116 are arranged while being rotated approximately 90 degrees in the axial direction, so that the magnetic field on one side of the arrangement (in this embodiment, the inner side) is weakened. On the other side of the array (outside in this embodiment, outside permanent magnet array 111 side), the magnetic field is increased correspondingly, and a strong magnetic field is generated on one side of the inside permanent magnet array 115 (outside in this embodiment). Can be made.

  Since the outer magnet array 111 and the inner permanent magnet array 115 are thus configured, the magnetic field in the space between the outer permanent magnet array 111 and the inner permanent magnet array 115 becomes stronger, while on the other hand, the outer permanent magnet The magnetic field hardly leaks outside the array 111 and inside the inner permanent magnet array 115. Then, an extremely large amount of radial magnetic flux is distributed in the gap between the outer permanent magnet row 111 and the inner permanent magnet row 115. The three-phase coil 131 is disposed in the gap in which a large amount of magnetic flux in the radial direction is distributed, and most of the magnetic flux is linked to the three-phase coil 131 at a right angle, so that the power supplied from the drive device 109 can be efficiently used. Can be converted into thrust well. Thus, since the magnetic field in the region where the three-phase coil 131 is disposed becomes strong, the three-phase coil 131 is strongly excited without using an iron core for the three-phase coil 131, and the movable element 107 is pivoted with a large thrust. Can move in the direction. And since an iron core is not used, cogging can be eliminated or reduced.

  The outer permanent magnet array 111 is configured by stacking ring-shaped permanent magnets 112 each having a substantially square cross section magnetized in the radial direction and the thickness direction. Further, the inner permanent magnet array 115 is configured by stacking ring-shaped permanent magnets 116 each having a substantially square cross section magnetized in the radial direction and the thickness direction. A dual Halbach field is composed of an outer cylindrical field composed of the outer permanent magnet array 111 and an inner cylindrical field composed of the inner permanent magnet array 115. The central axes of the outer cylindrical field and the inner cylindrical field overlap each other. A field gap is formed between the inner surface of the outer cylindrical field and the outer surface of the inner cylindrical field. Then, in a plane parallel to the magnetization direction of the permanent magnets 112 and 116 (a plane parallel to the CC cross section), a gap cross-sectional area and a field between the center line of the field gap and the outer permanent magnet array 111. The ratio of the gap cross-sectional area between the center line of the magnetic gap and the inner permanent magnet array 115 is substantially equal to the ratio of the cross-sectional area of the outer permanent magnet array 111 and the cross-sectional area of the inner permanent magnet array 115. Yes. The relationship of the area ratio is the same as that described above with reference to FIG. The cross-sectional area of the field gap is desirably 1.2 times to 2.0 times the average value of the cross-sectional area of the outer permanent magnet array 111 and the cross-sectional area of the inner permanent magnet array 115.

  In the above-described embodiment, the three-phase coil 131 is arranged in a gap in which a large amount of magnetic flux in the radial direction is distributed. Therefore, most of the magnetic flux is linked to the three-phase coil 131 at a right angle, and is large with less current. Thrust is generated. In the outer permanent magnet array 111, the magnetic poles of the permanent magnets 112 are arrayed while being rotated approximately 90 degrees in the axial direction, and the magnetic field outside the outer permanent magnet array 111 is weakened. The magnetic field is strengthened to generate a strong magnetic field inside the outer permanent magnet array 111. In the inner permanent magnet array 115, the magnetic poles of the permanent magnets 116 are arranged while being rotated approximately 90 degrees in the axial direction, and The magnetic field inside the permanent magnet array 115 is weakened, and the magnetic field is increased correspondingly outside the inner permanent magnet array 115, and a strong magnetic field is generated outside the inner permanent magnet array 115. For example, a plurality of first permanent magnets may be arranged in the axial direction so that the direction of the magnetic poles changes by an integer equal to 2π in the axial direction. Thus, the magnetic field on the inner side of the first permanent magnet array is strengthened and the outer magnetic field is weakened, and the direction of the magnetic pole is opposite to that of the first permanent magnet array in increments of 2π in the axial direction. A plurality of second permanent magnets are arranged in the axial direction so as to change to the inner side of the first permanent magnet array, the magnetic field outside the second permanent magnet array is strengthened, You may arrange | position so that a magnetic field may weaken.

(Second Embodiment)
A preferred second embodiment of the present invention is a three-phase synchronous generator. FIG. 10 is a schematic perspective view for explaining a three-phase synchronous generator 200 according to a preferred second embodiment of the present invention. FIG. 11A is a cross-sectional view in a plane parallel to the magnetization direction, and FIG. 11B is a diagram showing the wiring of the armature coil.

  The generator 200 of this embodiment includes a rotor 250 and a stator 260. If the shaft 240 is attached to the rotor 250 and the shaft 240 is rotated, a generator can be configured. The rotor 250 includes permanent magnet arrays 210 and 220. The stator 260 includes a coil array 230. The permanent magnet arrays 210 and 220 are each configured in a ring shape, and the coil array 230 is also configured in a ring shape. The permanent magnet arrays 210 and 220 and the coil array 230 are arranged concentrically. The permanent magnet array 220 is provided inside the permanent magnet array 20.

  As in the embodiment shown in FIG. 3, the permanent magnet arrays 210 and 220 are Halbach arrays in which the magnetic poles of the permanent magnets 211 and 221 are respectively rotated by approximately 90 °.

  The number of permanent magnets 211 in the permanent magnet array 210 is the same as the number of permanent magnets 221 in the permanent magnet array 220, and the magnetic pole direction of the permanent magnet 211 magnetized in the radial direction among the permanent magnets 211 in the permanent magnet array 210; Among the permanent magnets 221 in the permanent magnet array 220, the magnetic poles of the permanent magnets 221 magnetized in the radial direction are the same as those disposed on the same radius. The magnetic pole direction of the permanent magnet 211 magnetized in the circumferential direction of the permanent magnets 211 of the permanent magnet array 210 and the magnetic pole direction of the permanent magnet 221 magnetized in the circumferential direction of the permanent magnets 221 of the permanent magnet array 220 are the same radius. The ones placed above are the opposite.

  In the permanent magnet arrangement 210, the magnetic poles of the permanent magnets 211 are arranged while being rotated by approximately 90 ° in the circumferential direction, so that the magnetic field on one side (outside in the present embodiment) of the arrangement is weakened, and the other of the arrangement On the other side (inner side in the present embodiment), the magnetic field is increased correspondingly, and a strong magnetic field can be generated on one side (inner side in the present embodiment) of the array 210 of the permanent magnets 211. Further, in the permanent magnet arrangement 220, the magnetic poles of the permanent magnets 221 are arranged while being rotated by approximately 90 ° in the circumferential direction, so that the magnetic field on one side (in the present embodiment) of the arrangement is weakened. On the other side (outside in the present embodiment), the magnetic field is increased correspondingly, and a strong magnetic field can be generated on one side (outside in the present embodiment) of the array 220 of the permanent magnets 221.

  Since the permanent magnet array 210 and the permanent magnet array 220 are thus configured, the magnetic field in the space between the permanent magnet array 210 and the permanent magnet array 220 becomes strong, while the outside of the permanent magnet array 210. The magnetic field hardly leaks inside the permanent magnet array 220. Since the coil array 230 is arranged between the permanent magnet array 210 and the permanent magnet array 220, a high voltage can be generated. Thus, since the magnetic field in the region where the coil array 230 is arranged becomes strong, a high voltage can be generated without using an iron core for the coil 231 constituting the coil array 230. And since an iron core is not used, cogging can be eliminated or reduced. As shown in FIG. 11B, in the coil array 230, a plurality of coils 231 are wound in the order of U phase-V phase-W phase and Y-connected to generate a three-phase alternating current.

  In the present embodiment, the permanent magnets 211 and 221 are arranged around the rotating shaft 240 in a Halbach array, and the dual two Halbach array field is configured by the two outer magnet rows 201 and 220. Each of the permanent magnets 211 and 221 has a radial cross section (a cross section in a plane parallel to the magnetization direction) and has substantially the same area, and forms the inner magnet row 220 and the inner surface of the permanent magnet 211 constituting the outer magnet row 210. The outer surfaces of the permanent magnets 221 are opposed to each other. The individual radial cross sections of the permanent magnet 211 constituting the outer magnet row 210 and the permanent magnet 221 constituting the inner magnet row 220 are both trapezoidal, and 64 pieces each constitute a dual Halbach array field. The armature coil 231 is arranged in the gap of the dual Halbach array field, but the outer magnet array 210 and the inner magnet array 220 are both hexagonal, and a connection angle is formed on the gap surface between the adjacent permanent magnets 211 and 221. Exists. In the three-phase synchronous generator 200 of the present embodiment, the armature coil 231 has a rectangular cross section in the radial direction, and its width is an angle at which two permanent magnets 211 and 221 are expected from the center of the rotation axis. The armature coil 231 is configured by winding an insulating coated copper wire around a flanged bobbin. A field gap is formed between the inner surface of the permanent magnet 211 constituting the outer magnet row 210 and the outer surface of the permanent magnet 221 constituting the inner magnet row 220. Then, in a plane parallel to the magnetization direction of the permanent magnets 211 and 221, the gap cross-sectional area between the center line of the field gap and the outer magnet row 210, the center line of the field gap and the inner magnet row 220, The ratio of the gap cross-sectional area between the outer magnet row 210 and the inner magnet row 220 is approximately equal to the ratio of the cross-sectional area of the outer magnet row 210 and the inner magnet row 220. The relationship of the area ratio is the same as that described above with reference to FIG. The cross-sectional area of the field gap is desirably 1.2 times to 2.0 times the average value of the cross-sectional area of the outer magnet row 210 and the cross-sectional area of the inner magnet row 220.

  In the above-described embodiment, in the permanent magnet arrangement 210 of the generator 200, the magnetic poles of the permanent magnets 211 are arranged while being rotated by approximately 90 ° in the circumferential direction, and the magnetic field outside the arrangement is weakened. Accordingly, the magnetic field becomes stronger, and a strong magnetic field is generated inside the arrangement 210 of the permanent magnets 211. In the permanent magnet arrangement 220, the magnetic poles of the permanent magnets 221 are arranged while being rotated by about 90 ° in the circumferential direction. As a result, the magnetic field inside the array is weakened, and the magnetic field is increased correspondingly outside the array, and a strong magnetic field is generated outside the array 220 of the permanent magnets 221, but the magnetic poles are approximately 90 ° in the circumferential direction. Without rotating, for example, it may be rotated by approximately 45 °, and a plurality of first permanent magnets are arranged in the circumferential direction so that the direction of the magnetic poles changes by an integer equal to 2π in the circumferential direction, Of the first permanent magnet array A plurality of second permanent magnets are formed so that the inner magnetic field is strengthened and the outer magnetic field is weakened, and the direction of the magnetic pole is changed in the opposite direction to the first permanent magnet by an integer equal to 2π in the circumferential direction. May be arranged in the circumferential direction, arranged inside the first permanent magnet arrangement, and arranged such that the magnetic field outside the second permanent magnet arrangement strengthens and the inner magnetic field weakens.

  Further, in the above-described embodiment, the generator 200 is configured to have a single field as shown in the cross-sectional view of FIG. 12 (cross-sectional view taken along the line V-V of FIG. 11A). A generator having a multilayer field as shown in FIG. 13 may be configured, and the present invention may be applied to each field. Further, the present invention can also be applied to a multi-stage field generator including a single-layer field as shown in FIG. 12 or a plurality of multilayer fields as shown in FIG. 13 in the vertical direction.

  As described above, when an electromagnetic induction device having a circular permanent magnet array is manufactured, the center line of the field gap is within the plane parallel to the magnetization direction of the first permanent magnet and the second permanent magnet. The ratio of the gap cross-sectional area between the first permanent magnet row and the gap cross-sectional area between the center line of the field gap and the second permanent magnet row is the first permanent magnet row. By making it equal to the ratio of the cross-sectional area of the second permanent magnet row and the cross-sectional area of the second permanent magnet array, a large number of flux linkages can be obtained in the armature coil. As a result, the generator generates the maximum voltage with the minimum amount of magnets. Further, the motor generates the maximum torque with the minimum magnet amount. Further, since the amount of permanent magnets in the dual Halbach array field can be minimized, it is possible to contribute to cost reduction and resource saving of the apparatus.

  While various typical embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Accordingly, the scope of the invention is limited only by the following claims.

112 Permanent magnet 111 Permanent magnet array 116 Permanent magnet 115 Permanent magnet array 131 Armature coil

Claims (6)

A first permanent magnet row and a second permanent magnet row arranged opposite to each other, wherein the first permanent magnet row changes the direction of the magnetic pole by an integer equal to 2π in a predetermined direction; A plurality of first permanent magnets arranged in the predetermined direction so that the magnetic field on the second permanent magnet row side is strengthened and the magnetic field on the side opposite to the second permanent magnet row side is weakened; In the second permanent magnet row, the direction of the magnetic poles changes by an integer equal to 2π in the predetermined direction, the magnetic field on the first permanent magnet row side is strengthened, and opposite to the first permanent magnet row side. The first permanent magnet row and the second permanent magnet row having a plurality of second permanent magnets arranged in the predetermined direction so that the magnetic field on the side is weakened;
An armature coil disposed in a field gap between the first permanent magnet row and the second permanent magnet row facing each other,
In the plane parallel to the magnetization direction of the first permanent magnet and the second permanent magnet, the gap cross-sectional area between the center line of the field gap and the first permanent magnet row and the field magnet The ratio of the gap sectional area between the center line of the gap and the second permanent magnet row is substantially equal to the ratio of the sectional area of the first permanent magnet row and the sectional area of the second permanent magnet row. An electromagnetic induction device.   2. The electromagnetic induction device according to claim 1, wherein the gap cross-sectional area is 1.2 times or more and 2.0 times or less of an average value of cross-sectional areas of the first permanent magnet row and the second permanent magnet row. The plurality of first permanent magnets are arranged in the predetermined direction so that the direction of the magnetic poles of the plurality of first permanent magnets rotates approximately 90 degrees in the predetermined direction,
The plurality of second permanent magnets are arranged in the predetermined direction so that the direction of the magnetic poles of the plurality of second permanent magnets is rotated approximately 90 degrees in the predetermined direction,
The direction of the magnetic poles of the plurality of first permanent magnets and the direction of the magnetic poles of the plurality of second permanent magnets are the same in the direction perpendicular to the predetermined direction, and the direction of the magnetic poles in the predetermined direction The electromagnetic induction device according to claim 1, which is in the opposite direction.   The electromagnetic induction device according to claim 1, wherein the predetermined direction is a linear direction.   The electromagnetic induction device according to claim 1, wherein the predetermined direction is a circumferential direction.   The electromagnetic induction device according to any one of claims 1 to 5, wherein the electromagnetic induction device is an electric motor or a generator.