JP2021121153A - Halbach field magneton and rotary electric machine equipped with the same - Google Patents

Abstract

To provide a Halbach field magneton and a rotary electric machine equipped with the same capable of reliably holding a Halbach array of a plurality of unit permanent magnets in a desired array and reliably maintaining a function as a Halbach field.SOLUTION: A Halbach field magneton 2 includes: a plurality of unit permanent magnets 50 forming a square pole; and an inner cylinder 3 and an outer cylinder 4 of non-magnetic members forming a hollow cylinder. The inner cylinder 3 and the outer cylinder 4 are arranged coaxially. Additionally, the plurality of unit permanent magnets 50 are arranged in a Halbach array having a cylindrical shape coaxial with the inner cylinder 3 and the outer cylinder 4 so as to be constrained in the facing space between the inner cylinder 3 and the outer cylinder 4 arranged coaxially.SELECTED DRAWING: Figure 3

Description

The present invention relates to a rotary electric machine having a Halbach field magnet.

In a rotating electric machine (motor or generator), in order to increase the magnetic field, a method of arranging a plurality of unit permanent magnets according to a Halbach array is known.
That is, when a plurality of unit permanent magnets are simply arranged so that the north and south poles alternate, magnetic fields are generated on both the front side and the back side of the magnet arrangement, so that the magnetic fields cannot be effectively used. Arranges the magnetic poles of a plurality of unit permanent magnets in order while rotating them by a predetermined angle (for example, 90 °). As a result, the magnetic field on one side of the magnet arrangement is weakened, the magnetic field is strengthened on the other side, and a strong magnetic field can be generated on one side of the magnet arrangement.

For example, Patent Document 1 describes a Halbach field magnet having a single row of unit permanent magnet arrays arranged in a Halbach array. Further, Patent Document 2 describes a Halbach field magnet having two rows of unit permanent magnet arrays (dual Halbach array), each of which is Halbach array. The Halbach field magnets disclosed in these patent documents form the field in a ring shape.

Japanese Unexamined Patent Publication No. 2015-122834 Japanese Unexamined Patent Publication No. 2015-27208 WO / 2019/045017

Here, a unit permanent magnet having an extremely strong magnetic force is used for the Halbach field magnet having a Halbach array of unit permanent magnets. Therefore, extremely strong repulsive force and attractive force are generated between adjacent unit permanent magnets. Therefore, if no measures are taken against this strong repulsive force or attractive force, one of the unit permanent magnets will generate repulsive force or attractive force. Due to the influence of the attractive force, the unit permanent magnet arrangement may be pushed out or tilted, and the intended Halbach array may be disturbed.

Therefore, the present invention has been made by paying attention to such a problem, and can maintain the Halbach array by a plurality of unit permanent magnets in the desired array and maintain the function as the Halbach field. An object of the present invention is to provide a magnet and a rotating electric machine equipped with the magnet.

In order to solve the above problems, the Halbach field magnet according to one aspect of the present invention has a rectangular or fan shape in which two planes at both ends in the axial direction are parallel to each other and congruent, or a shape obtained by combining them in the axial direction. A plurality of hexagonal unit permanent magnets in which the other four surfaces along the line are planes or curved surfaces along the opposite contour lines of the two surfaces, and a hollow cylindrical non-magnetic member. The inner cylinder and the outer cylinder are provided, and the inner cylinder and the outer cylinder are arranged coaxially, and the plurality of the inner cylinder and the outer cylinder are constrained in the facing space between the inner cylinder and the outer cylinder arranged coaxially. Unit Permanent magnets are arranged in a Halbach array in a cylindrical shape coaxial with the inner cylinder and the outer cylinder.

According to the Halbach field magnet according to one aspect of the present invention, the inner cylinder and the outer cylinder of the non-magnetic member forming a hollow cylinder are arranged coaxially, and the space opposite to the inner cylinder and the outer cylinder arranged coaxially. Since multiple unit permanent magnets are arranged in a Halbach array in a cylindrical shape coaxial with the inner and outer cylinders so as to be constrained inside, the Halbach array by multiple unit permanent magnets is maintained in the desired arrangement. However, the function as a Halbach field can be maintained.

Further, in order to solve the above problems, the rotary electric machine according to one aspect of the present invention is characterized by including a Halbach field magnet according to any one aspect of the present invention.

According to the present invention, the Halbach array of a plurality of unit permanent magnets can be maintained in the desired array, and the function as the Halbach field can be maintained.

It is a perspective view of the Halbach motor which is one Embodiment of the rotary electric machine which concerns on one aspect of this invention, and in this figure, a part is broken along the axial direction and is shown. It is explanatory drawing which shows the Halbach motor of FIG. 1 cut along the axial direction. It is a perspective view (a) which shows the field magnet of the Halbach motor of FIG. 1, and the schematic diagram (b) explaining the arrangement of the unit permanent magnet of the field magnet part. It is a perspective view explaining one embodiment (the end face is trapezoidal) of the unit permanent magnet which constitutes the field magnet of the Halbach motor of FIG. It is a perspective view explaining another embodiment (the end face is a fan shape) of the unit permanent magnet which constitutes the field magnet of the Halbach motor of FIG. It is a perspective view explaining another embodiment (the end face is a combination shape of a trapezoid and a fan shape) of the unit permanent magnet which constitutes the field magnet of the Halbach motor of FIG. It is a figure explaining one embodiment of the field magnet which is provided | It is a figure explaining another embodiment of the field magnet which is provided | .. It is a figure explaining another embodiment of the field magnet which is provided | ..

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and there are parts where the relationship and ratio of the dimensions are different between the drawings.
Further, the embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, and arrangement of constituent parts. Etc. are not specified in the following embodiments.

This embodiment is an example in which the present invention is applied to a Halbach motor configured as a three-phase synchronous motor as a rotary electric machine.
As shown in FIGS. 1 and 2, the Halbach motor 1 of the present embodiment includes a cylindrical field magnet 2 configured to include a structure in which a plurality of unit permanent magnets 50 are arranged in a cylindrical shape, and a field magnet. It has a coil holder 12 in which three armature windings 30 are housed so as to be arranged so as to face each other in the radial direction on the outer peripheral surface of 2. The Halbach motor 1 is mounted on the installation target with the lower portion supported by the base 17.

As shown in FIG. 3, the field magnet 2 of the present embodiment is a four-pole NS arranged in a Halbach array by combining a plurality of unit permanent magnets 50 (40 in this example) in a cylindrical shape in the circumferential direction. It has a magnetic field structure. As shown in FIG. 3A, when a plurality of unit permanent magnets are referred to without any particular distinction, they are designated as the representative code 50.

The plurality of unit permanent magnets 50 are combined so that adjacent unit permanent magnets 50 have different magnetic directions so as to have a predetermined Halbach array. In FIG. 3, the arrows shown on the end faces of the permanent magnets 50 of each unit indicate the image of the magnetic direction of each, and the base end side of the arrow is the south pole and the tip end side is the north pole.
Then, in the field magnet 2 of the present embodiment, an annular row of a plurality of unit permanent magnets 50 is fitted with a thin-walled cylindrical field inner holder 3 inside in the radial direction, and a thin-walled cylinder is fitted outside in the radial direction. The field outer holder 4 in the shape is fitted. The inner and outer field holders 3 and 4 are made of carbon fiber.

In the Halbach array, for example, as shown in FIG. 3 (b), any one of the numbers obtained by adding 2 to a multiple of 3 is set as the number of divisions, and the magnetizing direction is set by the angle obtained by dividing one period of the electric angle by the number of divisions. It is preferable that the unit permanent magnets 50, which are changed in order, are arranged. In this case, all the unit permanent magnets 50 have the same cross-sectional area shape parallel to the magnetizing direction.

In the present specification, for convenience of explaining the relative relationship of the four poles arranged in the Halbach array, as shown in FIG. 3 (b), when one S pole is positioned upward, the position of the S pole is set. The S pole located on the opposite side is called the code Ss, the N pole located on the right side is called the code Ne, and the N pole located on the left side is called the code Nw.
Further, in the present specification, a set of unit permanent magnets 50 having a predetermined Halbach array located between these four poles is referred to as a transition portion 50t, and in each transition portion 50t, transitions are made in order from the S pole to the N pole. Each unit permanent magnet 50 is referred to as 50a to 50i in order from the S pole side.

The field magnet 2 of the present embodiment has two unit permanent magnets 50s for the S pole portion, two unit permanent magnets 50n for the N pole portion, and nine types of units for each of the four Halbach transition portions 50t. Four sets of permanent magnets 50a to 50i are arranged. Therefore, in order to assemble one field magnet 2, a total of 11 types and 40 unit permanent magnets 50 are required.
That is, in the present embodiment, since all the unit permanent magnets 50 have the same cross-sectional area shape parallel to the magnetizing direction, the field is formed by a set of 40 unit permanent magnets 50 whose magnetizing directions are changed in order by 18 °. The Halbach array of magnets 2 is configured.
As a result, according to the Halbach motor 1, although the mechanical resonance frequency is passed by the time the rated rotation speed is reached, the torque ripple is suppressed, so that the vibration when passing through the mechanical resonance frequency is suppressed.

The field magnet 2 of the present embodiment includes a plurality of unit permanent magnets 50 having a predetermined hexahedral shape, and an inner cylinder 3 and an outer cylinder 4 of non-magnetic members having a hollow cylindrical shape, and includes the inner cylinder 3 and the outer cylinder 4. A plurality of unit permanent magnets 50 form a Halbach array so that the outer cylinder 4 is coaxially arranged and is constrained in the space opposite to the inner cylinder 3 and the outer cylinder 4 arranged coaxially. It is arranged in a cylindrical shape coaxial with 3 and the outer cylinder 4. In particular, in the field magnet 2 of the present embodiment, the plurality of unit permanent magnets 50 arranged in a cylindrical shape are not adhered to each other, and their radial positions are constrained only by the inner cylinder 3 and the outer cylinder 4. ing. As a matter of course, the position in the circumferential direction is constrained by the number of unit permanent magnets 50 arranged adjacent to each other in the filled state.

Here, the predetermined hexahedral shape of the unit permanent magnet 50 is a rectangle in which the two surfaces 51a and 51b at both ends in the axial direction are parallel to each other and congruent, as shown in FIGS. 4, 5 or 6 (FIG. 4). ) Or a fan shape (FIG. 5) or a combination thereof (FIG. 6), and the other four surfaces 52j, 52k, 53, 54 along the axial direction are contours of the two surfaces 51a, 51b facing each other. A three-dimensional shape that is a flat surface or a curved surface along a line can be adopted.
In the field magnet 2 of the present embodiment, as shown in FIG. 4, the plurality of unit permanent magnets 50 have a hexahedral shape in which the two surfaces 51a and 51b at both ends in the axial direction are parallel to each other and congruent. It has a trapezoidal shape, and the other surfaces 52j, 52k, 53, 54 are all square pillars having a parallelogram shape along the axial direction.

Further, in the field magnet 2 of the present embodiment, each unit permanent magnet 50 is magnetized on at least one end surface of the two surfaces 51a and 51b in the axial direction, as shown by an example in FIG. A mark that distinguishes itself from another different unit permanent magnet 50 is visibly provided by the concave shape.
That is, in FIG. 3, the arrows shown on the end faces of the permanent magnets 50 of each unit indicate the image of the magnetic direction of each permanent magnet 50. However, in the field magnet 2 of the present embodiment, the actual permanent magnets 50 of each unit The end faces 51a and 51b are actually provided with "marks" that match the magnetic directions of the respective end faces 51a and 51b.

Various aspects of this mark can be adopted as long as the other unit permanent magnets 50 having different magnetizing directions can be visually distinguished from themselves. For example, a mark can consist of a color, a symbol, or a combination thereof.
In the present embodiment, as shown in FIG. 7, an arrow corresponding to the magnetic direction of each unit permanent magnet 50 is engraved by a concave mark. Further, the concave portion of the concave marking is filled with paints having different colors from each other in order to further improve the visibility when assembled.

Since the field magnet 2 of the present embodiment has a 4-pole NS magnetic field structure arranged in a Halbach array, the S-pole portion of the end faces of the four unit permanent magnets 50s and 50n corresponding to the poles. The concave portion of the concave marking of the unit permanent magnet 50s located in is filled with, for example, blue paint, and the concave portion of the concave marking of the unit permanent magnet 50n located in the N pole portion is filled with, for example, red paint. Further, the recesses of the concave markings of the unit permanent magnets 50a to 50i of the Halbach transition portion 50t arranged between the poles are not filled with paint or have another color (for example, yellow). It is filled.

Here, the field magnet 2 in which the unit permanent magnet 50 is assembled in a cylindrical shape confirms the mass balance around the axis, and if the balance deviation exceeds a predetermined value, an appropriate balance is obtained by adding a balancer or the like. Need to take.
On the other hand, the unit permanent magnets 50a to 50i constituting the Halbach transition portion 50t tend to attract each other in a state of being assembled in a cylindrical shape, whereas the unit permanent magnets located in the north pole portion and the south pole portion are permanent. The magnets 50s and 50n tend to repel each other with the unit permanent magnet 50 of the adjacent Halbach transition portion 50t, and the gap in which the cumulative error is accumulated is the pole of the unit permanent magnets 50s and 50n. Occurs at the position of.

Therefore, when balancing the mass around the axis in the field magnet 2 assembled in a cylindrical shape, a non-magnetic filler that fills the gap at the positions of both side surfaces 52j and 52k of the pole unit permanent magnets 50s and 50n. It is preferable to adjust the mass balance around the axis of the assembled field magnet 2 by filling the field magnet 2 as a balancer.
Returning to FIGS. 1 and 2, an aluminum inner yoke 5 is coaxially fitted on the inner peripheral surface of the field inner holder 3, and the field magnetism is applied to the fixed female threaded portion on the end surface of the inner yoke 5 in the front-back direction in the axial direction. The child end holder 6 is fixed by a plurality of holder fixing bolts 22, whereby the cylindrical combination state of the plurality of unit permanent magnets 50 is maintained.

The coil holder 12 is formed with an elliptical recess for accommodating the armature winding 30 on the surface facing the outer peripheral side. The elliptical recess of the coil holder 12 is covered by the coil holder lid 14 after the armature winding 30 is accommodated.
The coil holder 12 is held by a pair of housings 15 and 16 provided apart from each other in the front-rear direction in the axial direction at positions separated by an appropriate facing gap with respect to the outer peripheral surface of the field magnet 2. A plurality of yokes 7 made of electrical steel sheets are arranged between the pair of housings 15 and 16.

In this example, as shown in FIGS. 1 and 2, for example, 500 pieces of the plurality of yokes 7 are laminated in a cylindrical shape along the circumferential direction, and the outer side of the plurality of yokes 7 is a cylindrical outer yoke 9. It is supported by a pair of yoke holders 8 from the front and rear in the axial direction.
By fixing the pair of yoke retainers 8 to the outer yoke 9 with a plurality of yoke fixing bolts 23, the arrangement postures of the plurality of yokes 7 are maintained. The pair of housings 15 and 16 are fixed to the end faces of the pair of yoke holders 8 by a plurality of housing fixing bolts 24 from the front and rear in the axial direction, respectively.

At the center of the field magnet 2, a shaft 10 serving as an input or output shaft of a rotary electric machine is coaxially fixed. In the present embodiment, the shaft 10 is provided with a pair of shaft flanges 11 separated from each other in the front-rear direction in the axial direction, and the pair of shaft flanges 11 are provided on the outer surface of the field holder 6 in the front-rear direction in the axial direction. , It is integrated by being fixed by a plurality of holder fixing bolts 22.
The shaft 10 is rotatably supported by a combination bearing 20 provided at the center of each of the pair of housings 15 and 16, and the rear end is held by a C-shaped retaining ring 21 on the rear housing 16. The axial position is specified by.

The armature winding 30 of the present embodiment is an air-core coil having an oval shape in a plan view, and is curved along the circumferential direction as shown in FIG. The oval-shaped armature winding 30 includes a coil side 32 that is radially opposed to the magnet portion of the field magnet 2, and coil ends 31 and 33 that are located in front of and behind the coil side 32 in the axial direction. Has. The coil ends 31 and 33 are circumferential portions that orbit the phase winding in the circumferential direction. By using a litz wire for the armature winding 30, it is possible to suppress an increase in current loss and suppress heat generation of the coil.

The armature winding 30 is resin-molded in the recess of the coil holder 12, and the resin-molded coil ends 31 and 33 are held in close contact with the inner peripheral surfaces of the housings 15 and 16, respectively. A rectangular convex portion is formed in the central portion of the coil holder 12, and the gap portion at the center of the air-core coil is fitted into the outer peripheral surface of the convex portion, so that the armature winding 30 is surely in the desired mounting position. It is supposed to be held in.
The coil end (front) 31 on the front side in the axial direction is arranged so as to be housed inside the front housing 15, and the coil end (rear) 33 on the rear side in the axial direction is housed inside the rear housing 16. Arranged like this.

The outer peripheral surfaces of the housings 15 and 16 are located inward in the radial direction and inward of the end faces of the housings 15 and 16 in the axial direction in a range that faces the coil ends 31 and 33 in the radial direction. A plurality of heat radiation fins 15f and 16f are formed radially outward from the center of the shaft 10 so as to be located.
The three armature windings 30 have terminals at the beginning of winding of each armature winding 30 connected to each other to be a neutral point. A wiring for measurement is connected to the neutral point and extends to the outside of the machine. Then, three-phase alternating current is applied to each terminal at the end of winding of each armature winding 30.

Next, the operation and the effect of the Halbach motor 1 of the present embodiment will be described.
In the Halbach motor 1 of the present embodiment, three-phase alternating current is applied to each terminal at the end of winding of each armature winding 30, and the U-phase is delayed by 120 ° with respect to the three armature windings 30. By passing the alternating current of V phase and W phase in order, the NS magnetic field of the 4-pole field armature 2 is drawn by the moving magnetic field, so that the field armature 2 synchronizes and becomes the frequency of the three-phase alternating current. It can rotate at the corresponding number of rotations.

Here, a unit permanent magnet having an extremely strong magnetic force is used for the Halbach field magnet 2 having a Halbach array of unit permanent magnets. Therefore, extremely strong repulsive force and attractive force are generated between adjacent unit permanent magnets. Therefore, if no measures are taken against this strong repulsive force or attractive force, one of the unit permanent magnets will generate repulsive force or attractive force. Due to the influence of the attractive force, the unit permanent magnet arrangement may be pushed out or tilted, and the intended Halbach array may be disturbed.

On the other hand, according to the Halbach motor 1 of the present embodiment, the inner cylinder 3 and the outer cylinder 4 formed of the non-magnetic member forming a hollow cylinder are arranged coaxially with the inner cylinder 3 arranged coaxially. Since the plurality of unit permanent magnets 50 are arranged in a Halbach array in a cylindrical shape coaxial with the inner cylinder 3 and the outer cylinder 4 so as to be constrained in the space facing the outer cylinder 4, the plurality of unit permanent magnets 50 are permanently arranged. The Halbach array by the magnet 50 can be reliably maintained in the desired array, and the function as the Halbach field magnet can be reliably maintained.
Here, the torque ripple generated in the rotor 2 contributes to the vibration and noise generated in the electric motor. Further, the torque ripple affects the stop position and the operation accuracy of the moving member moved by the motor in the drive device using the motor as the drive source. Therefore, it is desired to suppress torque ripple in a rotary electric machine (motor) or the like.

On the other hand, in the technique described in Patent Document 3, in order to suppress torque ripple, as in the present embodiment, the electromagnetic device uses an armature provided with a three-phase coil and 2 as a multiple of 3. One of the added numbers was defined as the number of divisions, and the magnetizing direction was changed in order by the angle obtained by dividing one period of the electric angle of the coil current by the number of divisions, and a plurality of unit permanent magnets were arranged in a predetermined direction. A field magnet is provided, and one of the armature and the field magnet is configured to be moved relative to the other in the arrangement direction of the unit permanent magnets. According to the technique described in the same document, an excellent effect such as suppression of torque ripple can be obtained in an electric motor or the like.

Here, as in the present embodiment, in the technique described in Patent Document 3, a plurality of unit permanent magnets constituting the field magnets are divided into any one of a multiple of 3 plus 2. A complicated configuration is required in which the magnetizing directions are sequentially changed and arranged in a predetermined direction by the angle obtained by dividing one cycle of the electric current by the number of divisions. Therefore, three or more types of unit permanent magnets whose magnetizing directions are sequentially changed by predetermined angles are required, and a complicated assembly process of arranging them in a predetermined direction is required.

Therefore, in managing the unit permanent magnets for Halbach field magnets and quality control in complicated assembly processes, the field magnets (N-) in which N poles and S poles are alternately arranged as in the past. In the production of Halbach field coils that can suppress torque ripple, it is not possible to simply horizontally deploy the control of unit permanent magnets using S-aligned field and the quality control in the assembly process. , There are still problems to be solved, which are peculiar to Halbach field magnets.
Therefore, in the present embodiment, in order to make a Halbach field magnet capable of suppressing torque ripple while reliably maintaining the Halbach array in the desired array and reliably maintaining the function as the Halbach field magnet, the Halbach field magnet is used. In the child 2, the unit permanent magnet 50 is provided with a mark on at least one end face in the axial direction so as to distinguish itself from other unit permanent magnets having different magnetizing directions.

According to the present embodiment, the square columnar unit permanent magnet 50 shown in FIG. 4 has at least one end face in the axial direction of the end faces 51a and 51b (in the example of the present embodiment, both end faces 51a and 51b). ) Is provided with a mark that can distinguish itself from another unit permanent magnet 50 having a different magnetizing direction, so that the other unit permanent magnet 50 having a different magnetizing direction and itself are provided. Can be easily visually distinguished from.

Therefore, the Halbach field permanent magnet itself can be easily managed, and the mark that can distinguish itself from other unit permanent magnets 50 having different magnetizing directions is at least one end face in the axial direction of the square columnar. Since the end faces 51a and 51b can be visually recognized even after being assembled into a cylindrical shape as the Halbach field magnet 2, it is also effective in performing quality control in the assembling process. Therefore, it is excellent in manufacturing the Halbach field magnet 2 capable of suppressing torque ripple.

As described above, according to the Halbach motor 1 of the present embodiment, the Halbach array composed of a plurality of unit permanent magnets 50 is reliably held in the desired array, and the function as the Halbach field is reliably maintained. can. It should be noted that the rotary electric machine according to the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

For example, in the Halbach motor 1 of the above embodiment, an example of forming a rectangular columnar shape as a unit permanent magnet 50 having a predetermined hexahedral shape is shown, but the present invention is not limited to this, and is as shown in FIGS. 4 to 6. In addition, the two planes at both ends in the axial direction are parallel and congruent rectangles or sectors, or a combination of these, and the other four planes along the axial direction are the contour lines of the two planes facing each other. As long as it is a flat surface or a curved surface along the above, various modes can be used.

For example, as shown in FIG. 5, a plurality of unit permanent magnets have a six-sided shape in which the two surfaces at both ends are parallel to each other and congruent in a fan shape, and the left and right side surfaces of the other surfaces are axes. The inner and outer surfaces of the sector, which have a parallelogram shape along the direction and which face the inner and outer radial directions among the other surfaces, may be formed as curved surfaces along the contour line of the sector.
Even with such a configuration, a plurality of unit permanent magnets form a Halbach array and are coaxial with the inner cylinder and the outer cylinder so as to be constrained in the facing space between the inner cylinder and the outer cylinder arranged coaxially. Can be arranged in a cylindrical shape.

Further, as shown in FIG. 6, for example, the plurality of unit permanent magnets have a hexahedral shape in which the two surfaces at both ends are parallel to each other and are congruent with a combination of a rectangle and a fan shape, and the other surfaces. Of these, the left and right sides form a parallelogram along the axial direction, and the inner and outer radial directions of the other faces are peeled off, and the inner or outer faces of the sector are formed into curved surfaces along the contour of the sector. You may. In the example of the figure, the outer surface of the sector is formed as a curved surface along the contour line of the sector, and the inner surface is parallel that extends in the axial direction along the rectangular side shown in FIG. This is an example of a quadrilateral shape.
Even with such a configuration, a plurality of unit permanent magnets form a Halbach array and are coaxial with the inner cylinder and the outer cylinder so as to be constrained in the facing space between the inner cylinder and the outer cylinder arranged coaxially. Can be arranged in a cylindrical shape.

Further, as for the above-mentioned visible "mark", various modes can be adopted as long as the other unit permanent magnets 50 having different magnetizing directions can be visually distinguished from themselves. For example, a mark can consist of a color, a symbol, or a combination thereof.
In particular, it is preferable to color the entire end faces 51a and 51b of each unit permanent magnet 50 from the viewpoint of rust prevention. Specifically, as shown in FIG. 8, the end faces of the four unit permanent magnets 50s and 50n corresponding to the poles are the end faces 51a and 51b of the unit permanent magnets 50s located at the south pole. Is coated with, for example, a blue paint, and the end faces 51a and 51b of the unit permanent magnet 50n located at the north pole portion are coated with, for example, a red paint. Further, another color (for example, yellow) is applied to the end faces 51a and 51b of the unit permanent magnets 50a to 50i of the Halbach transition portion 50t arranged between the poles.

Even with such a configuration, the unit permanent magnet for the Halbach field magnet itself can be easily managed, and the mark that can distinguish itself from other unit permanent magnets 50 having different magnetizing directions is a square columnar shape. Since it is provided on at least one end face in the axial direction, the end faces 51a and 51b can be visually recognized even after being assembled into a cylindrical shape as the Halbach field magnet 2, which is also effective for quality control in the assembly process. be.

Also, as shown in another example in FIG. 9, marks can be composed of symbols (in this example, numbers and alphabets). In the example of the figure, on the end faces of the four unit permanent magnets 50s and 50n corresponding to the poles, for example, the alphabet S is engraved on the end faces 51a and 51b of the unit permanent magnets 50s located at the S poles. Then, for example, the alphabet N is engraved on the end faces 51a and 51b of the unit permanent magnet 50n located at the N pole portion.
Further, the end faces 51a and 51b of the unit permanent magnets 50a to 50i of the Halbach transition portion 50t arranged between the poles are combined with the alphabet T and a number (integer starting from 1 in this example). Then, T1 to T9 are stamped in order from the S pole side.

Even with such a configuration, the unit permanent magnet for the Halbach field magnet itself can be easily managed, and the mark that can distinguish itself from other unit permanent magnets 50 having different magnetizing directions is a square columnar shape. Since it is provided on at least one end face in the axial direction, the end faces 51a and 51b can be visually recognized even after being assembled into a cylindrical shape as the Halbach field magnet 2, which is also effective for quality control in the assembly process. be.

1 Halbach motor (rotary machine)
2 Field magnet 3 Field inner holder (inner cylinder)
4 Field magnet outer holder (outer cylinder)
5 Inner yoke 6 Field holder (end face lid)
7 Yoke 8 Yoke retainer 9 Outer yoke 10 Shaft 11 Shaft flange 12 Coil holder 14 Coil holder lid 15 Front housing 15f Heat dissipation fin 16 Rear housing 16f Heat dissipation fin 17 Base 20 Bearing 21 C type retaining ring 22 Holder fixing bolt 23 Yoke fixing bolt 24 Housing fixing bolt 30 Armature winding 31 Coil end (front)
32 Coil side 33 Coil end (rear)
50 units permanent magnet

Claims (9)

The two planes at both ends in the axial direction are parallel and congruent to each other in a rectangular or fan shape, or a combination thereof, and the other four planes along the axial direction are along the opposite contour lines of the two planes. It is provided with a plurality of unit permanent magnets having a hexagonal shape that is a flat surface or a curved surface, and an inner cylinder and an outer cylinder that are non-magnetic members having a hollow cylindrical shape.
The plurality of unit permanent magnets are arranged in a Halbach array so that the inner cylinder and the outer cylinder are coaxially arranged and constrained in the facing space between the inner cylinder and the outer cylinder arranged coaxially. A Halbach field magnet characterized by being arranged in a cylindrical shape coaxial with the inner cylinder and the outer cylinder. The Halbach field magnet according to claim 1, wherein the inner cylinder and the outer cylinder are made of carbon fibers. The unit permanent magnet has a trapezoidal shape in which the two surfaces at both ends in the axial direction are parallel and congruent to each other, and the other surfaces are all parallelograms along the axial direction. Item 2. The Halbach field magnet according to Item 1 or 2. The unit permanent magnet has a fan-shaped aspect in which the two surfaces at both ends are parallel to each other and congruent, and the inner and outer surfaces of the fan-shaped surface are peeled in the inner and outer radial directions among the other surfaces. The Halbach field magnet according to claim 1 or 2, wherein is a curved surface along a fan-shaped contour line, and the left and right side surfaces of the other surfaces are parallelograms along the axial direction. The plurality of unit permanent magnets arranged in a cylindrical shape are not adhered to each other, and the positions in the radial direction are constrained by the inner cylinder and the outer cylinder according to any one of claims 1 to 4. The described Halbach field magnet. The item according to any one of claims 1 to 5, wherein the unit permanent magnet is provided with a mark on at least one end face in the axial direction so as to distinguish itself from another unit permanent magnet having a different magnetizing direction. Halbach field magnet. The Halbach field magnet according to claim 6, wherein the mark is set so as to be distinguishable for each group according to the number of poles of the Halbach field magnet. The Halbach field magnet according to claim 6 or 7, wherein the mark comprises a color, a symbol, or a combination thereof. A rotary electric machine comprising the Halbach field magnet according to any one of claims 1 to 8.

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