JP2013123318A - Ring magnet, method of manufacturing ring magnet, and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring magnet capable of reducing usage of magnets.SOLUTION: A cylindrical ring magnet 2 is constituted of an outer peripheral ring part 5 oriented in the same radial direction 5a and an inner peripheral ring part 6 oriented in the same circumferential direction 6a, and arranged so that U-shaped magnetic paths 8a to 8h which start from the outer peripheral ring part 5 and return again to the outer peripheral ring part 5 passing through the inner peripheral ring part 6 are formed at position in an even number and adjacent magnet paths of the respective magnetic paths 8a to 8h are magnetized so as to have mutually opposite directivity.

Description

  The present invention relates to a ring magnet, a method of manufacturing a ring magnet, and a motor that can reduce the amount of magnets used.

  As a conventional ring magnet, a polar anisotropic ring magnet is used which is advantageous for reducing torque unevenness such as cogging torque in a permanent magnet motor. This polar anisotropy ring magnet is a magnet with magnetic anisotropy arranged in such a way that the magnetic poles adjacent to the outer circumference are connected on a circular arc, so that the magnetic force distribution is sinusoidal in the direction of rotation of the magnet. Since the harmonic component becomes smaller, the cogging torque can be suppressed (see, for example, Patent Document 1). In particular, in the prior art, a magnetic circuit configuration of a mold for magnetic field orientation in a magnetic field forming step for imparting polar anisotropy is shown. In other conventional ring magnets, magnetic particles in a mold are oriented so as to impart polar anisotropy by a magnetic field generated by an electromagnetic coil disposed in the mold (for example, patents). Reference 2).

JP 2000-269062 A JP-A-2005-44820

  Conventional ring magnets can reduce torque unevenness such as cogging torque and torque ripple by applying a polar anisotropic ring magnet to a motor. However, in many cases, the torque expected from the magnetic characteristics of the original magnet cannot be obtained. In such a case, when the magnetic force of the magnet alone is measured, it is found that the magnetic flux density is lower than expected from the magnetic characteristics. For example, in the case of a φ30 mm ring magnet, there was a case where it was 20% or more lower than expected. Then, consider the comparison between the measured value and the magnetic field analysis. It was verified that the original magnetic properties of the magnet could not be realized.

  In addition, the polar orientation of the polar anisotropic ring magnet is oriented by the magnetic field generated by the electromagnetic coil in the mold of the magnetic field forming process, but compared to the parallel orientation of the square magnet and the radial orientation of the ring magnet. Since a strong magnetic field cannot be applied to the entire magnet due to orientation, a sufficiently high orientation cannot be provided. Therefore, the effective magnetic force per total weight of the magnet is low. That is, the amount of magnets used is greater than the magnetic force (= the amount of magnetic flux) that can be used as a motor. Therefore, this is particularly a problem with neodymium sintered magnets and neodymium plastic magnets that require a large magnetic force for orientation.

  A typical neodymium sintered magnet used for such a polar anisotropic ring magnet contains 27 to 28 wt% neodymium and 1 to 5 wt% dysprosium. Since these rare earth materials have limited reserves and production areas on the earth, their costs are high, production is limited, and supply is becoming unstable. For this reason, when used in motors that are produced in large quantities, there are problems such as an increase in the cost of the rotating electrical machine and a limited production volume. In addition, there are problems such as a heavy motor and a large motor.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a ring magnet, a method for manufacturing the ring magnet, and a motor that can reduce the amount of the magnet used.

The ring magnet of this invention is
In the cylindrical ring magnet,
An outer peripheral ring portion oriented in the same radial direction;
It is comprised from the inner peripheral ring part orientated in the same circumferential direction.

Further, in the method of manufacturing a ring magnet of the present invention, the outer peripheral ring portion is oriented in the same radial direction by passing a repulsive magnetic field that is in the same radial direction and opposite to the upper and lower sides,
The inner ring portion allows a circumferential magnetic field to pass through the inner ring portion.

The motor of the present invention
In the cylindrical ring magnet,
An outer peripheral ring portion oriented in the same radial direction;
The rotor is composed of inner ring parts oriented in the same circumferential direction and includes a ring magnet, and a stator composed of a stator core and windings.

The ring magnet of this invention is
In the cylindrical ring magnet,
An outer peripheral ring portion oriented in the same radial direction;
Since it is composed of inner ring parts that are oriented in the same circumferential direction,
The amount of magnets used can be reduced.

Further, in the method of manufacturing a ring magnet of the present invention, the outer peripheral ring portion is oriented in the same radial direction by passing a repulsive magnetic field that is in the same radial direction and opposite to the upper and lower sides,
Since the inner ring portion allows a circumferential magnetic field to pass through the inner ring portion,
The amount of magnets used can be reduced.

The motor of the present invention
In the cylindrical ring magnet,
An outer peripheral ring portion oriented in the same radial direction;
Consists of a rotor including a ring magnet and an inner ring portion oriented in the same circumferential direction, and a stator consisting of a stator core and a winding,
The amount of magnets used can be reduced.

It is a figure which shows the structure of the ring magnet of Embodiment 1 of this invention. It is the figure which showed the orientation state of the ring magnet shown in FIG. It is the figure which showed the method of the magnetization of the ring magnet shown in FIG. It is the figure which showed the method of orientation of the outer periphery ring part of the ring magnet shown in FIG. It is the figure which showed the method of orientation of the inner peripheral ring part of the ring magnet shown in FIG. It is the figure which showed the manufacturing method of the ring magnet shown in FIG. It is a figure which shows the structure of the conventional ring magnet. It is a figure for demonstrating the performance of a ring magnet. It is a figure which shows the characteristic of the conventional ring magnet. It is a figure which shows the characteristic of the ring magnet of Embodiment 1 of this invention. It is the figure which showed the structure of the motor using the ring magnet shown in FIG. It is a figure which shows the structure of the ring magnet of Embodiment 2 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 3 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 4 of this invention. It is sectional drawing which shows the manufacturing method of the ring magnet of Embodiment 4 of this invention.

Embodiment 1 FIG.
Embodiments of the present invention will be described below. 1 is a diagram showing a configuration of a ring magnet according to Embodiment 1 of the present invention, FIG. 2 is a diagram showing an orientation state of the ring magnet shown in FIG. 1, and FIG. 3 is a magnetization of the ring magnet shown in FIG. FIG. 4 is a diagram showing the orientation method of the outer ring portion of the ring magnet shown in FIG. 1, and FIG. 5 is the orientation method of the inner ring portion of the ring magnet shown in FIG. FIG. 6 is a diagram showing a manufacturing method of the ring magnet shown in FIG. 1, FIG. 7 is a diagram showing a configuration of a conventional ring magnet, and FIG. 8 is a diagram for explaining the performance of the ring magnet. 9 shows the characteristics of the conventional ring magnet, FIG. 10 shows the characteristics of the ring magnet according to Embodiment 1 of the present invention, and FIG. 11 shows the configuration of the motor using the ring magnet shown in FIG. FIG.

  In FIG. 1, the ring magnet 2 is formed in a cylindrical shape, and an outer peripheral ring portion 5 oriented in the same radial direction (radial) 5a and an inner peripheral ring portion 6 oriented in the same circumferential direction 6a. It is composed of The outer peripheral ring portion 5 is made of, for example, a magnetic powder material oriented in the same radial direction 5a, and the inner peripheral ring portion 6 is made of, for example, a magnetic powder material oriented in the same circumferential direction 6a. The same radial direction 5a and the same circumferential direction 6a are indicated by arrows, and the directions indicate the directions of orientation. And in the ring magnet 2, U-shaped magnetic paths 8a to 8h returning from the outer ring part 5 to the outer ring part 5 through the inner ring part 6 are formed at even numbers, here, eight places, Adjacent ones of the magnetic paths 8a to 8h are magnetized so as to have opposite directions. The magnetic paths 8a to 8h are indicated by arrows, and their directions indicate the directivity of the respective magnetic paths 8a to 8h.

Next, the manufacturing method of the ring magnet in this Embodiment 1 is demonstrated. First, the ring magnet 2 is comprised by the outer peripheral ring part 5 orientated in the same radial direction 5a and the inner peripheral ring part 6 orientated in the same circumferential direction 6a (FIG. 2). This is formed by aligning the magnetic powder material in the same radial direction 5a in the outer peripheral ring portion 5 and aligning the magnetic powder material in the same circumferential direction 6a in the inner peripheral ring portion 6. Next, the ring magnet 2 is inserted into the magnetized yoke 20 composed of the eight coils 21 and the core 22. Next, for example, a magnetizing magnetic field is generated by applying a pulse current of about 10 kA to the coil 21. Therefore, the U-shaped magnetic paths 8a to 8h that return from the outer ring part 5 to the outer ring part 5 through the inner ring part 6 are adjacent to each other, and the adjacent magnetic paths 8a to 8h have opposite directions. The ring magnet 2 is formed by being magnetized so as to have (FIG. 3). Therefore, this ring magnet 2 is formed with eight magnetic poles. In this magnetization, for example, when a neodymium magnet is used, a magnetic flux density of 2T or more is necessary to fully magnetize the magnet. This magnetic flux density corresponds to a magnetic field strength of 2.51 × 10 ⁻⁶ A / m in the case of air.

  Here, the outer peripheral ring portion 5 of the ring magnet 2 having the orientation shown in FIG. 2 fills the cavity 34 of the mold 31 with the magnetic powder material 30 as shown in FIG. And the electromagnetic coils 32a and 32b respectively arrange | positioned at the upper and lower sides of the metal mold | die 31 are arrange | positioned, and an electric current is sent through the rotation direction opposite to these electromagnetic coils 32a and 32b. Then, repulsive magnetic fields 33a and 33b are generated. A magnetic field in the same radial direction is generated in the cavity 34 filled with the magnetic powder material 30 in the mold 31. This magnetic field aligns the magnetic powder material 30 in the same radial direction.

  Further, the inner ring portion 6 of the ring magnet 2 having the orientation shown in FIG. 2 fills the cavity 35 of the mold 38 with the magnetic powder material 30 as shown in FIG. Then, a current 36 a is passed upward through the energizing core 36 formed on the central axis via the insulating core 39 of the mold 38. A magnetic field 37 in the rotational direction is generated in the cavity 35 by the current 36a, and the magnetic powder material 30 is aligned in the same circumferential direction. The insulating core 39 is disposed to electrically insulate the energizing core 36 from other parts.

  In this way, both the same radial direction magnetic field and the same circumferential direction magnetic field can easily generate a strong magnetic field that is uniform in the radial direction and the circumferential direction, so an extremely high orientation ratio can be easily obtained. . In the case of a neodymium sintered magnet, an orientation ratio of 95% is obtained when the magnetic field is 1.5 T or more. Since the generated magnetic field distribution is simple for both the radial magnetic field and the circumferential magnetic field, the former is the arrangement of the electromagnetic coils 32 a and 32 b outside the mold 31, and the latter is the central axis of the mold 28. It can be formed by passing a current through the current-carrying core 36.

  And as shown in FIG. 6, the outer periphery ring part 5 and the inner periphery ring part 6 which were manufactured by these magnetic field shaping | molding processes are combined, and it forms as a ring magnet 2. FIG. At this time, a method in which the outer peripheral ring portion 5 and the inner peripheral ring portion 6 are bonded with an adhesive, a method in which the outer peripheral ring portion 5 and the inner peripheral ring portion 6 are formed by fitting, or the like can be considered. Also, a method of producing a sintered body by subjecting the combined ring magnet 2 to a sintering / heat treatment process. Further, finishing may be performed as necessary. Then, as shown in FIG. 3, a magnetic flux is generated and magnetized with the outer ring portion 5 → the inner ring portion 6 → the outer ring portion 5. As shown in FIG. 11, the motor includes a rotor 1 composed of a ring magnet 2 and a rotor core 3, and a stator 4 composed of a stator core 9 and a winding 10. The ring magnet 2 can be demagnetized when heated to a temperature above the Curie temperature, and therefore can be demagnetized as appropriate.

  Next, the performance of the conventional ring magnet 45 and the ring magnet 2 of the present invention will be described in comparison. As shown in FIG. 7, a conventional polar anisotropic ring magnet 45 is formed using a mold 40 in which a coil 41 and a core 42 are configured. Then, a magnetic flux on an arc as shown in FIG. 7 flows due to the current passed through the coil 41, and the magnetic powder material filled in the mold 40 is oriented to form magnetic paths 43a to 43h. However, the strength of the orientation magnetic field rapidly decreases as the distance from the coil 41 increases. FIG. 8 is a diagram showing an example of magnetic field analysis of the orientation magnetic field in the cross section of the mold 40. In FIG. 8, the solid line indicates the magnetic flux 44.

  FIG. 9 is a diagram showing the distribution relationship between the magnitude of the magnetic flux density of the conventional ring magnet 45 and the distance from the central axis. The distance (radius R) from the central axis and the angle θ are shown in FIG. As can be seen from FIG. 9, in the conventional ring magnet 45, the magnetic flux density decreases sharply toward the inner diameter side. This is because the flow of the magnetic flux 44 is distributed in an arc shape as shown in FIG. In addition, in order to obtain such a magnetic field distribution, in the conventional case, it is necessary to dispose the coils 41 for each pole in the mold 40, and therefore the cross-sectional area of each coil 41 cannot be increased. For this reason, the current that can be passed through the coil 41 is restricted, and a large magnetic field cannot be generated. For this reason, the orientation rate decreases on the inner peripheral side of the magnet. As a result, the magnetic force is reduced in the magnet.

  On the other hand, the ring magnet 2 of the present invention achieves a high orientation ratio using a strong magnetic field in order to make the orientation of the ring magnet 2 uniform. And after combining the magnet (the outer periphery ring part 5 and the inner periphery ring part 6), it magnetizes and the ring magnet 2 of strong magnetic force is comprised. Here, the present invention will be described using specific examples. FIG. 10 shows the distribution of magnetic flux density in the orientation mold when formed in the following cases in the magnetic field forming step as described above. The distribution of the magnetic flux density can be calculated from the magnetic circuit configuration in the mold. This figure also shows the distribution of the orientation magnetic flux density in the same radial direction 5a of the outer peripheral ring portion 5 of the ring magnet 2 and the radial position of the orientation magnetic flux density of the inner peripheral ring portion 6 in the same circumferential direction 6a. . As a specific example, the outer diameter of the outer ring part 5 is φ40 mm, the inner diameter of the inner ring part 6 is φ30 mm, and the thickness of the ring magnet 2 is 5 mm. This is the case.

  In the magnetic field shaping method shown in FIG. 4, the orientation magnetic field of the outer peripheral ring portion 5 can be generated by applying a DC current of several hundreds of A to the electromagnetic coils 32 a and 32 b that have been appropriately wound and cooled. Further, in the magnetic field shaping method shown in FIG. 5, the orientation magnetic field of the inner ring portion 6 is formed by arranging a plurality of coils on the current-carrying core 36 that is a current path (for example, arranging 20 φ2 mm coils). It can be generated by passing a current 36a of about 10 kA. In this case, a pulse current that can suppress the heat generation of the coil is suitable. And the magnetic flux density of the outer periphery ring part 5 and the magnetic flux density of the inner periphery ring part 6 have the minimum value in the radius 17-18 mm vicinity of the ring magnet 2 substantially. The boundary between the inner ring portion 6 and the outer ring portion 5 of the ring magnet 2 is 17 to 18 mm, that is, the boundary is divided so that the ratio between the inner ring portion 6 and the outer ring portion 5 is 40 to 60%. Provided. Thus, the alignment can be performed efficiently.

  The magnetic flux density distribution shown above can be controlled by controlling the value of the current flowing through each of the electromagnetic coils 32a and 32b or the energizing core 36. For example, when the current of the orientation magnetic field of the outer ring portion 5 is increased, the orientation magnetic flux density in the same radial direction 5a of the outer ring portion 5 is increased. However, in that case, the mold 31 is likely to be saturated, which is not efficient in generating a magnetic flux. For this reason, in order to manufacture efficiently, the outer peripheral ring part 5 and the inner peripheral ring part 6 should be carried out with the minimum value required for orientation after making the magnetic flux density the same size. If manufactured in this way, effects such as suppression of heat generation of the manufacturing apparatus can be further obtained.

  According to the ring magnet, the manufacturing method of the ring magnet, and the motor of the first embodiment configured as described above, high orientation is achieved in the same radial direction orientation of the outer ring portion and the same circumferential direction orientation of the inner ring portion. Since the ratio can be easily realized, the orientation ratio of the entire magnet can be increased, and a high magnetic force can be obtained with a small amount of magnet. Therefore, when applied to a motor, the weight of the magnet used can be reduced without reducing the output torque. The amount of neodymium sintered magnets, which are expensive and have a problem in procurement, can be reduced. Therefore, when producing the same motor as the conventional one, it is possible to reduce the cost of the motor and improve the procurement. When the amount of magnets used is the same, a large output motor can be obtained. Moreover, when the same output is obtained, the current supplied to the motor is reduced, copper loss can be reduced, and the efficiency of the motor can be increased.

Embodiment 2. FIG.
According to the first embodiment, an example in which 8 poles are magnetized is shown. However, the present invention is not limited to this. For example, 6 poles can be magnetized. Also in this case, the ring magnet 2 having the same orientation as shown in FIG. 2 is placed in the magnetizing yoke 20 composed of six coils 21 and the core 22 as shown in FIG. Insert and magnetize. In this way, it is possible to easily create 6-pole magnetization and form the magnetic paths 8a to 8f in the same manner as in the first embodiment.

  According to the ring magnet of the second embodiment configured as described above, the number of poles of the polar anisotropic ring magnet is conventionally changed as well as the same effect as the first embodiment. In this case, since the orientation pattern and the number of poles are determined in the magnetic field forming mold, it is necessary to change the mold. This mold is very expensive because a coil for energizing current is disposed in the mold, and it takes time to manufacture. Therefore, even if the magnets have the same external shape, it is necessary to manufacture different molds only in the number of poles.

  On the other hand, in the present invention, since the pole can be formed by magnetization, two types of magnetic field forming molds are necessary as compared with the conventional case, but can be easily manufactured in a short time. When the shapes are the same and only the number of poles is different, ring magnets manufactured with the same magnetic field molding die can be used. Further, only an inexpensive magnetized yoke may be manufactured corresponding to different numbers of poles. Therefore, it is possible to reduce the initial investment cost for manufacturing the ring magnet, and to obtain an effect that a prototype can be made in a short time. In addition, although the example of the number of magnetic poles formed is 8 poles or 6 poles, other even pole numbers can be configured in the same manner, and the same effect can be obtained.

Embodiment 3 FIG.
13 to 16 are views showing a method for manufacturing a ring magnet according to Embodiment 3 of the present invention. In the third embodiment, a method of manufacturing a ring magnet by a manufacturing method different from the above embodiments will be described. However, since the ring magnet is formed in the same manner as each of the above embodiments, the description thereof is omitted as appropriate. To do. In the figure, the third embodiment shows an example of a ring magnet formed by neodymium-based sintering, for example. Also, the same parts as those in the above embodiments are given the same reference numerals, and the description thereof is omitted. The mold 50 includes an outer punch portion 54 that can be vertically divided and vertically movable, and an inner punch portion 53 that is vertically divided and vertically movable. In addition, in this Embodiment 3, the electricity supply core 36 and the insulation core 39 are divided | segmented up and down, and are formed so that the up-and-down is possible.

  Next, a ring magnet manufacturing method using the ring magnet manufacturing apparatus according to Embodiment 3 configured as described above will be described. First, in a state where the upper electromagnetic coil 32a, the outer punch portion 54, the inner punch portion 53, the energizing core 36 and the insulating core 39 are moved upward, the lower outer punch portion 54 is lowered, An outer cavity 56 is formed between the punch portion 53 and the outer punch portion 54, and the magnetic powder material 30 is filled in the outer cavity 56 (FIG. 13). Next, the upper electromagnetic coil 32a, the outer punch portion 54, the inner punch portion 53, the energizing core 36 and the insulating core 39 are lowered, and the repulsive magnetic fields 33a and 33b are moved by the electromagnetic coils 32a and 32b in the same manner as in the above embodiments. And the magnetic powder material 30 in the outer cavity 56 is oriented in the same radial direction 5a (FIG. 14). Next, the upper outer punch portion 54 is lowered, and the magnetic powder material 30 is compression-molded (FIG. 15), and the outer peripheral ring portion 5 is formed.

  Next, the upper electromagnetic coil 32a, the inner punch portion 53, the energizing core 36, and the insulating core 39 are moved upward, and the lower inner punch portion 53 is lowered to form the inner cavity 55 (FIG. 16). Next, the magnetic powder material 30 is filled into the inner cavity 55 (FIG. 17). Next, the upper side of the inner punch portion 53 is lowered, and a current 36 a is supplied to the energizing core 36. With this electric current 36a, the magnetic powder material 30 in the inner cavity 55 is oriented in the same circumferential direction 6a, and in this state, the inner punch portion 53 is pressurized and compression molded to form the inner circumferential ring portion 6 (FIG. 18). At this time, since the molded body of the outer peripheral ring portion 5 is already compressed and formed, the circumferential magnetic field does not disturb the orientation. Next, after molding in this way, the upper outer punch portion 54 and inner punch portion 53 are raised and taken out as a ring magnet 2 of the molded body. In the method for manufacturing the ring magnet, portions that can be performed in the same manner as in the past, such as powder supply operation and take-out operation, are omitted as appropriate. Also, the processes before and after, such as alloy casting, pulverization, sintering / heat treatment, processing, and surface treatment are omitted.

  According to the third embodiment configured as described above, the ring magnet having a strong magnetic force and polar anisotropy can be efficiently obtained in a short time, as well as the same effects as the above-described embodiments. Can be manufactured. Moreover, since the yield is also improved, rare earth materials such as neodymium and dysprosium used in neodymium sintered magnets can reduce the amount of rare earth metals used on earth, where reserves and production areas are limited. Therefore, the cost of the motor using the ring magnet can be reduced. In addition, as shown in FIG. 5, FIG. 6, you may assemble after manufacturing separately the outer peripheral ring part and inner peripheral ring part of a ring magnet.

Embodiment 4 FIG.
19 and 20 are views showing a method of manufacturing a ring magnet in the fourth embodiment of the present invention. In the fourth embodiment, a method for manufacturing a ring magnet by a manufacturing method different from that in each of the above embodiments will be described. However, since the ring magnet is formed in the same manner as in each of the above embodiments, the description thereof is omitted as appropriate. To do. In the figure, in the fourth embodiment, an example of a ring magnet created by, for example, compound sintering is shown. Also, the same parts as those in the above embodiments are given the same reference numerals, and the description thereof is omitted. The mold 60 is formed by injection molding and includes an upper mold 65 and a lower mold 66 that are divided into upper and lower parts. The mold 60 includes an outer cavity 64, an inner cavity 61, and an inner punch portion 63 that moves up and down in the inner cavity 61. The upper mold 65 includes an outer injection port 67 that penetrates the outer cavity 64 and an inner injection port 68 that penetrates the inner cavity 61.

  Next, a ring magnet manufacturing method using the ring magnet manufacturing apparatus according to Embodiment 4 configured as described above will be described. First, the melted compound 64 is injected into the outer cavity 64 from the outer injection port 67. Next, repulsive magnetic fields 33a and 33b are generated by the electromagnetic coils 32a and 32b in the same manner as in the above embodiments, the compound 64 in the outer cavity 64 is oriented in the same radial direction 5a, cured, and the outer ring portion 5 (FIG. 19). Next, the inner punch portion 63 is lowered to form the inner cavity 61. Then, the melted compound 64 is injected into the inner cavity 61 from the inner injection port 68. Next, an electric current 36a is passed through the energizing core 36, the orientation is formed in the same circumferential direction 6a, and the inner circumferential ring portion 6 is formed by curing (FIG. 20). And the ring magnet 2 is taken out and manufactured.

  According to the ring magnet of the fourth embodiment configured as described above, it is possible to further increase the orientation ratio of the ring magnet as well as to achieve the same effects as those of the above embodiments. The magnetic force can be further improved, and the amount of use can be further reduced.

  In each of the above-described embodiments, the orientation direction of the outer peripheral ring portion is the same radial direction facing inward, and the orientation direction of the inner peripheral ring portion is an example of the same circumferential direction counterclockwise. However, the present invention is not limited to this. For example, the direction of orientation of the outer peripheral ring portion may be the same radial direction outward, and the direction of orientation of the inner peripheral ring portion may be the same clockwise direction. These can be formed in the same manner as the above embodiments, and the same effects can be obtained.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Rotor, 2 Ring magnet, 4 Stator, 5 Outer ring part, 5a Same radial direction, 6 Inner ring part, 6a Same circumferential direction, 8a-8h Magnetic path, 9 Stator core,
10 winding, 30 magnetic powder material, 32a, 32b electromagnetic coil,
33a, 33b Repulsive magnetic field, 36 conducting core, 36a current.

Claims (7)

In the cylindrical ring magnet,
An outer peripheral ring portion oriented in the same radial direction;
A ring magnet comprising an inner ring portion oriented in the same circumferential direction. The outer ring part is formed of a magnetic powder material oriented in the same radial direction,
The ring magnet according to claim 1, wherein the inner ring portion is formed of a magnetic powder material oriented in the same circumferential direction. U-shaped magnetic paths that return from the outer ring part to the outer ring part through the inner ring part are formed at even numbers, and adjacent magnetic paths have mutually opposite directions. The ring magnet according to claim 1, wherein the ring magnet is magnetized so as to have a magnetic field. The outer peripheral ring portion and the inner peripheral ring portion are formed by bonding with an adhesive or formed by sintering. The ring magnet according to item 1. In the manufacturing method of the ring magnet of any one of Claims 1 thru | or 4,
The outer ring portion is oriented in the same radial direction by passing a repulsive magnetic field that is in the same radial direction and opposite to the upper and lower sides,
The method of manufacturing a ring magnet, wherein the inner ring portion is oriented in the same circumferential direction by passing a circumferential magnetic field in the inner ring portion. The repulsive magnetic field is formed by arranging a pair of ring-shaped electromagnetic coils at the upper and lower positions of the outer peripheral ring portion, and flowing currents in opposite directions to the pair of electromagnetic coils,
6. The method of manufacturing a ring magnet according to claim 5, wherein the circumferential magnetic field is formed by flowing a current in a vertical direction on the central axis of the inner ring portion. A motor comprising: a rotor including the ring magnet according to any one of claims 1 to 4; and a stator including a stator core and a winding.

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