Motor magnet, field element, and motor

Abstract

This motor magnet is provided in a rotor disposed side by side with a stator in the radial direction, and comprises an N magnet and an S magnet arranged adjacent to each other in the circumferential direction. The N magnet and the S magnet have an orientation (OR) including a radial orientation component and a circumferential orientation component. The electrical angle that increases or decreases as the position in the circumferential direction changes, with the magnetic pole center of one of the N and S magnets arranged adjacent to each other in the circumferential direction as a 0° base point, is denoted by θ; a fundamental amplitude is denoted by A0; a first amplitude having an absolute value smaller than A0 is denoted by A1; and multiplication is denoted by ×. Then, the radial orientation component is expressed by a waveform including at least a fundamental periodic wave A0 × cosθ and a third-harmonic periodic wave A1 × cos3θ.

Description

Motor magnet, field element, and motor Cross-Reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-068376 filed in Japan on April 17, 2025, the entire contents of which are incorporated herein by reference.

[0002] The disclosure in the present specification relates to a motor magnet, a field element, and a motor.

[0003] Patent Document 1 describes a segment magnet for constituting a 6-pole pole-anisotropic ring magnet.

[0004] Japanese Unexamined Patent Application Publication No. 2017-99071

[0005] The magnetization direction of the segment magnet described in Patent Document 1 is determined such that the surface magnetic flux density distribution has a sinusoidal shape. However, in the case of such a configuration, there is a limit to achieving both improvement of rotational torque and suppression of cogging torque.

[0006] One object of the present disclosure is to provide a motor magnet, a field element, and a motor that can easily achieve improvement of rotational torque and suppression of cogging torque.

[0007] A motor magnet according to the disclosed aspect is a motor magnet provided in a field element arranged side by side with an exciter in a first direction, the motor magnet comprising an N magnet and an S magnet arranged adjacent to each other in a second direction that intersects the first direction and in which either one of the exciter and the field element moves, wherein the N magnet and the S magnet have an orientation including a first orientation component along the first direction and a second orientation component along the second direction, where θ is an electrical angle that increases and decreases as the position in the second direction varies with the magnetic pole center of one of the N magnet and the S magnet arranged adjacent to each other in the second direction set as a base point of 0°, A0 is a fundamental amplitude, A1 is a first amplitude having an absolute value smaller than A0, and × represents multiplication, the first orientation component is represented by a waveform including at least an equal-magnitude periodic wave A0×cosθ and a triple periodic wave A1×cos3θ.

[0008] The field of the disclosed embodiment is a field aligned with an exciter in a first direction, and comprises an extension magnet extending in a second direction intersecting the first direction and in which one of the exciter and the field moves, wherein the extension magnet comprises an N magnet and an S magnet aligned adjacent to each other in the second direction, and the N magnet and the S magnet have an orientation including a first orientation component along the first direction and a second orientation component along the second direction, and if the electrical angle that increases or decreases as the position in the second direction changes with respect to the pole center of one of the N magnets and S magnets aligned adjacent to each other in the second direction as the base point of 0°, and the fundamental amplitude is A0, and the first amplitude having an absolute value smaller than A0 is A1, and the multiplication is ×, then the first orientation component is represented by a waveform that includes at least a 1x period wave A0 × cosθ and a 3x period wave A1 × cos3θ.

[0009] A motor in a disclosed embodiment comprises an exciter and a field element aligned in a first direction, the field element comprising an extension magnet extending in a second direction intersecting the first direction and in which one of the exciter and the field element moves, the extension magnet comprising an N magnet and an S magnet aligned adjacent to each other in the second direction, the N magnet and the S magnet having an orientation including a first orientation component along the first direction and a second orientation component along the second direction, and if θ is the electric angle that increases or decreases as the position in the second direction changes with respect to the pole center of one of the N magnets and S magnets aligned adjacent to each other in the second direction as the base point of 0°, A0 is the fundamental amplitude, A1 is the first amplitude with an absolute value smaller than A0, and × is the multiplication, then the first orientation component is represented by a waveform that includes at least a regular-period wave A0 × cosθ and a triple-period wave A1 × cos3θ.

[0010] As will be explained in detail in "Modes for Carrying Out the Invention," these disclosures make it easier to improve rotational torque and suppress cogging torque.

[0011] The reference numbers in parentheses above merely indicate the correspondence with the configurations described in the embodiments below, and do not limit the technical scope in any way.

[0012] This is a top view of the motor. This is a perspective view of the rotor. This is a schematic diagram showing three-dimensional polar coordinates. This is a cross-sectional view along the line IV-IV shown in Figure 2. This is a cross-sectional view of the motor. This is a schematic diagram showing orientation. This is a schematic diagram for explaining orientation. This is a graph showing the relationship between amplitude and torque ratio. This is a graph showing the relationship between electrical angle and orientation component ratio. This is a graph showing the relationship between amplitude and pulsation strength. This is a graph showing the relationship between electrical angle and rotational torque. This is a graph showing the relationship between electrical angle and cogging torque. This is a top view of the motor. This is a graph showing the relationship between electrical angle and rotational torque. This is a graph showing the relationship between electrical angle and cogging torque. This is a schematic diagram showing orientation. This is a top view of the motor. This is a top view of the motor. This is a top view of the motor. This is a top view of the motor. This is a perspective view of the motor. This is a cross-sectional view of the motor. This is a top view of the motor. This is a cross-sectional view of the motor. This is a cross-sectional view of the motor. This is a cross-sectional view of the motor. This is a cross-sectional view of the motor.

[0013] The following describes several embodiments for implementing this disclosure with reference to the drawings. In later embodiments, parts corresponding to matters described in earlier embodiments may be given the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the description of the earlier embodiment may be applied to the other parts of the configuration.

[0014] It is possible to combine parts that are explicitly shown to be combinable in each form. Furthermore, if there are no particular problems with the combination, it is also possible to partially combine multiple forms with each other, a form with a modified form, and multiple modified forms with each other, even if it is not explicitly shown that they can be combined.

[0015] <First Embodiment> <Motor> The motor 100 shown in Figure 1 has a magnet 600. This motor 100 can be applied to consumer, commercial, industrial, and medical products. The motor 100 can be applied to mobility products that move people or objects, robotic products involved in the production and control of goods, and equipment that generates energy such as electricity. In addition, the motor 100 can be applied to a wide range of general products without being specifically exemplified. The motor 100 functions as a power source for the applied product.

[0016] The motor 100 in this embodiment is a multi-phase AC motor. The motor 100 can perform both power generation and regeneration. The motor 100 can be used as a motor generator. However, the motor 100 does not necessarily have to be able to perform regeneration. The motor 100 may also be a DC motor or a stepping motor.

[0017] In the following, the three mutually orthogonal directions are referred to as axial AD, radial RD, and circumferential CD. Axial AD and radial RD are linear directions, while circumferential CD is the circumferential direction. AD stands for Axial Direction, RD for Radial Direction, and CD for Circumferential Direction. The circumferential direction can also be called the rotational direction. In this embodiment, radial RD corresponds to the first direction, circumferential CD to the second direction, and axial AD to the third direction.

[0018] Furthermore, the line that runs along the axial direction AD and passes through the center of the motor 100 is defined as the motor axis MA. MA is an abbreviation for Motor Axis. Unless otherwise specified, in the following, the direction that intersects and is perpendicular to this motor axis MA will be simply referred to as the radial direction RD. The direction around the motor axis MA will be simply referred to as the circumferential direction CD.

[0019] The motor 100 comprises a housing 200, a shaft 300, a rotor 400, and a stator 500. The housing 200 is made of a metal material. The housing 200 is cylindrical in shape. At least a portion of the shaft 300, the rotor 400, and the stator 500 are housed in the space enclosed by the inner wall surface of the housing 200.

[0020] The shaft 300 extends axially AD along the motor shaft MA. The shaft 300 is supported by bearing members such as bearings in the housing 200. The shaft 300 is rotatable relative to the housing 200. The shaft 300 is the rotation axis of the motor 100.

[0021] The rotor 400 is fixed to the shaft 300. The motor shaft MA passes through the center of the shaft 300 and the center of the rotor 400. The shaft 300 and rotor 400 rotate around the motor shaft MA as their center of rotation. The shaft 300 and rotor 400 rotate relative to the housing 200.

[0022] The stator 500 is fixed to the housing 200. The overall shape of the stator 500 is annular. The motor shaft MA passes through the space enclosed by the stator 500. The rotor 400 and shaft 300 are located in this space. The stator 500 is aligned with the rotor 400 in the radial direction RD, separated by a radial gap.

[0023] As shown above, the rotor 400 is located closer to the center of the motor 100 than the stator 500. The motor 100 in this embodiment is an inner rotor type radial motor. The motor 100 is also a brushless motor.

[0024] <Stator> The stator 500 is an exciter that is energized by the flow of current. The stator 500 can also be called an armature. The stator 500 has a stator core 510 and a stator coil 520. The stator coil 520 is provided on the stator core 510. The stator 500 is energized by the flow of current to this stator coil 520.

[0025] The stator core 510 is made of iron. The stator core 510 contains a soft magnetic material. Magnetic flux generated by the stator coil 520 and the magnet 600 passes through the stator core 510. A magnetic path (magnetic circuit), which is the path for the magnetic flux, is formed in the stator core 510.

[0026] The stator core 510 has a core support portion 530 and core teeth 540. The overall shape of the core support portion 530 is annular. The core support portion 530 is fixed to the housing 200 directly or indirectly. The outer circumferential surface of the core support portion 530 is located radially RD closer to the housing 200 than its inner circumferential surface. The core teeth 540 are connected to the inner circumferential surface of the core support portion 530.

[0027] The core teeth 540 extend radially RD from the inner circumferential surface of the core support portion 530 toward the motor shaft MA. Multiple core teeth 540 are arranged in the circumferential direction CD. The stator coil 520 is wound around these core teeth 540. The stator coil 520 is an electric wire.

[0028] In this embodiment, 60 core teeth 540 are integrally connected to the core support portion 530. Stator coils 520 are distributed-winding around these 60 core teeth 540. The number of core teeth 540 is not limited to the above example. Furthermore, a configuration in which the stator coils 520 are concentrated-winding around the core teeth 540 can also be adopted.

[0029] <Rotor> The rotor 400 is a field element. The rotor 400 has a rotor core 410 and magnets 600. The magnets 600 are provided on the rotor core 410. Multiple magnets 600 are arranged in the circumferential direction CD. The magnetic field of the rotor 400 is formed by these multiple magnets 600.

[0030] The rotor core 410 is formed of a metallic material. At least a portion of the rotor core 410 contains a soft magnetic material.

[0031] The rotor core 410 has a shaft connecting portion 420, a connecting arm 430, and a magnet support portion 440. The shaft connecting portion 420 is fixed to the shaft 300. The connecting arm 430 connects the shaft connecting portion 420 and the magnet support portion 440. The magnet support portion 440 supports a plurality of magnets 600.

[0032] As shown in Figure 2, the shaft connecting portion 420 is cylindrical. The shaft 300 is inserted through a hole partitioned by the inner wall surface of this shaft connecting portion 420. In this inserted state, the shaft connecting portion 420 is fixed to the shaft 300. The rotor 400 is fixed to the shaft 300.

[0033] The connecting arm 430 extends from the shaft connecting portion 420 toward the magnet support portion 440. Multiple connecting arms 430 are arranged in the circumferential direction CD. The motor shaft MA is located on the extension of the radial direction RD of the multiple connecting arms 430. One end of the connecting arm 430 is connected to the outer circumferential surface of the shaft connecting portion 420. The other end of the connecting arm 430 is connected to the magnet support portion 440.

[0034] The overall shape of the magnet support section 440 is annular. The other ends of multiple connecting arms 430 are connected to the inner circumferential surface of this magnet support section 440. Multiple magnets 600 are provided on the outer circumferential surface of the magnet support section 440. The multiple magnets 600 are fixed to the magnet support section 440 by adhesive or the like.

[0035] The magnet support portion 440 is made of a soft magnetic material. Therefore, magnetic flux passes through the magnet support portion 440. A magnetic path is formed in the magnet support portion 440. The magnet support portion 440 is a back core. The magnet support portion 440 can also be called a yoke or yoke. Note that a magnetic path does not necessarily have to be formed in the magnet support portion 440.

[0036] The magnet 600 is a permanent magnet. Multiple magnets 600 arranged in the circumferential direction CD are connected by an adhesive or the like. These multiple magnets 600 constitute an extension magnet 700 that extends in the circumferential direction CD. The extension magnet 700 is ring-shaped in the circumferential direction CD. The extension magnet 700 is provided on the outer circumferential surface of the magnet support part 440. The extension magnet 700 and the magnet support part 440 are concentric.

[0037] <Magnetic Flux and Magnetic Path> As shown in Figure 1, the magnet 600 and the core teeth 540 are facing each other in the radial direction RD. The magnetic centers of the magnet 600 and the core teeth 540 are aligned in the radial direction RD in the axial direction AD. Furthermore, the length of the magnet 600 in the axial direction AD is longer than that of the core teeth 540.

[0038] When three-phase AC power is supplied to the stator coil 520, a magnetic flux is generated from the stator 500. The magnetic path is determined by the magnetic flux emitted from the stator 500, the magnetic flux emitted from the extension magnet 700 of the rotor 400, and the housing 200 and other components surrounding them.

[0039] The magnetic flux flows from the stator 500 towards the rotor 400, then reverses direction and flows back from the rotor 400 towards the stator 500. To explain it by reversing the subject, the magnetic flux flows from the rotor 400 towards the stator 500, then reverses direction and flows back from the stator 500 towards the rotor 400. On the stator 500 side, the magnetic flux passes through the core teeth 540 and the core support section 530. On the rotor 400 side, the magnetic flux passes through the extension magnet 700 and the magnet support section 440.

[0040] <Magnets> The following provides a detailed explanation of magnet 600. Magnet 600 includes magnetic material and other materials. Magnet 600 includes sintered magnets, bonded magnets, etc.

[0041] As shown in Figures 2 and 4, the magnet 600 has six faces. The magnet 600 has an arc shape extending in the circumferential direction CD. The magnet 600 has an inner surface 600a and an outer surface 600b spaced apart in the radial direction RD, an upper surface 600c and a lower surface 600d spaced apart in the axial direction AD, and a first side surface 600e and a second side surface 600f spaced apart in the circumferential direction CD.

[0042] The inner surface 600a and the outer surface 600b extend in the circumferential direction CD. These are curved surfaces with an arc shape. They are concentric circles. The length of the circumferential direction CD is shorter for the inner surface 600a than for the outer surface 600b. The separation distance in the radial direction RD between the inner surface 600a and the outer surface 600b is the same even if the measurement position differs in a direction perpendicular to the radial direction RD. However, the separation distance in the radial direction RD between the inner surface 600a and the outer surface 600b can also be configured such that, for example, in the axial direction AD, the distance gradually increases from the upper surface 600c or the lower surface 600d toward the axial center 600cd side between the upper surface 600c and the lower surface 600d. When the magnet 600 is assembled to the motor 100, the inner surface 600a is located on the rotor core 410 side, and the outer surface 600b is located on the stator 500 side.

[0043] The upper surface 600c and the lower surface 600d extend in a direction orthogonal to the axial direction AD. The upper surface 600c and the lower surface 600d extend parallel to each other. The separation distance in the axial direction AD between the upper surface 600c and the lower surface 600d is equal even if the measurement positions differ in the direction orthogonal to the axial direction AD. However, the separation distance in the axial direction AD between the upper surface 600c and the lower surface 600d may, for example, increase or decrease from the inner surface 600a side toward the outer surface 600b side in the radial direction RD.

[0044] The first side surface 600e and the second side surface 600f extend in the radial direction RD. The extended line of the first side surface 600e and the extended line of the second side surface 600f intersect at the motor axis MA. The separation distance in the circumferential direction CD between the first side surface 600e and the second side surface 600f increases as the distance from the motor axis MA in the radial direction RD increases. The first side surface 600e and the second side surface 600f are connected via the inner surface 600a, the outer surface 600b, the upper surface 600c, and the lower surface 600d.

[0045] <Orientation> The magnet 600 has an orientation OR. The orientation OR is the easy magnetization direction of the magnetic material contained in the magnet 600. The magnetic material includes magnetic powder. The distribution of the orientation OR is determined by the magnetic material. The orientation OR can also be referred to as magnet orientation. The magnet 600 can also be referred to as an anisotropic magnet.

[0046] In the drawings, representative ones of the innumerably scattered orientations OR are indicated by arrows. When it is desired to show the overall distribution of the orientations OR, a plurality of orientations OR are connected and shown as continuous lines. These continuous lines also represent the magnetic paths within the magnet 600. In the actual magnet 600, some deviation may occur in the distribution of the orientation OR due to manufacturing errors and the like. However, in the drawings, the orientations OR are shown as being distributed as evenly as possible.

[0047] In the present embodiment, the magnitudes of the plurality of scattered orientations OR in one magnet 600 are all the same. The magnitude of the orientation OR is constant even across the plurality of magnets 600. However, the magnitudes of the orientations OR included in one magnet 600 may be different. The magnitudes of the orientations OR of the plurality of magnets 600 may be different.

[0048] Figure 3 shows three-dimensional polar coordinates to explain the orientation OR. The circumferential direction CD is the circumferential direction. However, in Figure 3, the circumferential direction CD is shown as a straight line, representing the tangent direction of the intersection of the radial direction RD and the axial direction AD passing through one of the measurement points of the orientation OR. In other drawings as well, when a representative radial direction RD is shown, the circumferential direction CD is shown as the tangent direction of the circumferential direction perpendicular to it.

[0049] The orientation OR can be decomposed into three orientation components: radial RD, circumferential CD, and axial AD. The radial orientation component ORr is the radial orientation component for RD. The circumferential orientation component ORc is the circumferential orientation component for CD. The axial orientation component ORa is the axial orientation component for AD. When these three types of orientation components are combined, they form the orientation OR. The size and orientation (angle) of the orientation OR are determined by these three orientation components. In this embodiment, the radial orientation component ORr corresponds to the first orientation component, the circumferential orientation component ORc to the second orientation component, and the axial orientation component ORa to the third orientation component.

[0050] The orientation OR angle is expressed by the azimuth angle φ and the elevation angle ζ. The azimuth angle φ is the angle between the radial direction RD and the orientation OR. The elevation angle ζ is the angle between the axial direction AD and the orientation OR.

[0051] When the radial direction RD and the orientation direction OR intersect, two types of angles are formed. The azimuth angle φ is the smaller of these two angles. The magnitude of the azimuth angle φ is 90° or less.

[0052] Similarly, when the axial direction AD and the orientation OR intersect, two types of angles are formed. The elevation angle ζ is the smaller of these two angles. The magnitude of the elevation angle ζ is 90° or less.

[0053] If the orientation OR has an elevation angle ζ, the orientation OR is inclined from the radial direction RD towards the axial direction AD. In other words, the orientation OR is inclined from the axial direction AD towards the radial direction RD. If the orientation OR has an azimuth angle φ, the orientation OR is inclined from the radial direction RD towards the circumferential direction CD. In other words, the orientation OR is inclined from the circumferential direction CD towards the radial direction RD.

[0054] If the magnitude of the orientation OR is A, then the following relationship holds: ORr = Asinζcosφ, ORc = Asinζsinφ, ORa = Acosζ. As described above, in this embodiment, the magnitude of all orientation ORs is constant. Therefore, for example, if the magnitude of the axial orientation component ORa is constant, then if the radial orientation component ORr increases, the circumferential orientation component ORc decreases. Reversing the increase / decrease expression, if the radial orientation component ORr decreases, the circumferential orientation component ORc increases.

[0055] In Figure 2, the first reference line LR1 is shown as a dashed line representing one of the countless radial directions RD. The second reference line LR2 is shown as a dashed line representing one of the countless circumferential directions CD. The third reference line LR3 is shown as a dashed line representing one of the countless axial directions AD.

[0056] The first reference line LR1 passes through the motor shaft MA. The first reference line LR1 is normal to the inner surface 600a and outer surface 600b of the magnet 600. The second reference line LR2 is perpendicular to the first reference line LR1. The second reference line LR2 is tangent to the first reference line LR1 at the intersection in the circumferential direction CD. The second reference line LR2 is spaced radially RD away from the motor shaft MA and passes through the magnet 600. The third reference line LR3 is perpendicular to the first reference line LR1. The third reference line LR3 is spaced radially RD away from the motor shaft MA and passes through the magnet 600. The third reference line LR3 passes through the intersection of the first reference line LR1 and the second reference line LR2.

[0057] The azimuth angle φ of the orientation OR located at the intersection of the first reference line LR1 and the second reference line LR2 is the smaller of the two angles formed between the first reference line LR1 and the orientation OR. The elevation angle ζ of the orientation OR located at the intersection of the first reference line LR1 and the third reference line LR3 is the smaller of the two angles formed between the third reference line LR3 and the orientation OR.

[0058] As shown in Figures 4 to 6, the orientation components of the multiple orientation ORs included in the magnet 600 of this embodiment are of two types: a radial orientation component ORr and a circumferential orientation component ORc. None of the multiple orientation ORs included in the magnet 600 have an axial orientation component ORa. However, at least some of the multiple orientation ORs included in the magnet 600 may have an axial orientation component ORa. Orientation ORs will be explained in detail later.

[0059] <N Magnets and S Magnets> As described above, the rotor 400 equipped with magnets 600 faces the stator 500. As shown in Figures 1 and 2, the magnets 600 include N magnets 600N and S magnets 600S, whose orientation OR directions are opposite in the direction of opposition between the rotor 400 and the stator 500.

[0060] As shown in Figure 5, the orientation OR of the N magnet 600N is toward the stator 500 and away from the motor shaft MA. The orientation OR of the S magnet 600S is away from the stator 500 and toward the motor shaft MA.

[0061] As shown in Figures 1 and 2, the overall shape of the rotor 400 and stator 500 is an arc shape. However, for the sake of clarity, they are shown as rectangular prisms in Figure 5. Similarly, in Figure 6, the N magnet 600N and S magnet 600S are shown as rectangular prisms for the sake of clarity in the orientation OR notation.

[0062] The direction of the radial orientation component ORr of the N magnet 600N is away from the motor shaft MA and towards the stator 500. The direction of the radial orientation component ORr of the S magnet 600S is away from the stator 500 and towards the motor shaft MA.

[0063] The orientation OR of the N magnet 600N is symmetrical in the circumferential direction CD of the magnet 600, with the axis of symmetry being the side center portion 600ef, which is at an intermediate position between the first side surface 600e and the second side surface 600f in the circumferential direction CD of the magnet 600. Therefore, the behavior of the orientation OR between the first side surface 600e and the side center portion 600ef of the N magnet 600N is equivalent to the behavior of the orientation OR between the side center portion 600ef and the second side surface 600f of the N magnet 600N. The direction of the circumferential orientation component ORc of the N magnet 600N is toward the side center portion 600ef of the N magnet 600N. In Figures 5 and 6, the side center portion 600ef is shown as a dashed line.

[0064] The orientation OR of the S magnet 600S is symmetrical in the circumferential direction CD with respect to the side center portion 600ef as the axis of symmetry. Therefore, the behavior of the orientation OR between the first side surface 600e and the side center portion 600ef of the S magnet 600S is equivalent to the behavior of the orientation OR between the side center portion 600ef and the second side surface 600f of the S magnet 600S. The direction of the circumferential orientation component ORc of the S magnet 600S is away from the side center portion 600ef of the S magnet 600S.

[0065] Furthermore, the rate of change of orientation OR between the first side surface 600e and the side center portion 600ef in the N magnet 600N is equivalent to the rate of change of orientation OR between the first side surface 600e and the side center portion 600ef in the S magnet 600S. The difference in the behavior of the orientation OR between the two is that the radial direction RD and the circumferential direction CD are in opposite directions.

[0066] Similarly, the rate of change of orientation OR between the side center portion 600ef and the second side surface 600f in the N magnet 600N is equivalent to the rate of change of orientation OR between the side center portion 600ef and the second side surface 600f in the S magnet 600S. The difference in the behavior of the orientation OR between the two is that the radial direction RD and the circumferential direction CD are in opposite directions.

[0067] Furthermore, in this embodiment, as shown in Figure 5, the radial orientation component ORr and the circumferential orientation component ORc of orientation OR aligned in the radial direction RD are equivalent. Similarly, the radial orientation component ORr and the circumferential orientation component ORc of orientation OR aligned in the axial direction AD are equivalent. However, the orientation components of orientation OR aligned in the radial direction RD may be different. The orientation components of orientation OR aligned in the axial direction AD may also be different.

[0068] <Extension Magnet> As described above, the extension magnet 700 has a plurality of magnets 600 arranged in the circumferential direction CD. The extension magnet 700 of this embodiment has 10 magnets 600. The extension magnet 700 has 5 N magnets 600N and 5 S magnets 600S. Two adjacent magnets 600 in the circumferential direction CD are an N magnet 600N and an S magnet 600S. The extension magnet 700 has 10 magnetic poles.

[0069] N magnets 600N and S magnets 600S are arranged alternately, one at a time, along the circumferential direction CD. Of the N magnets 600N and S magnets 600S that are adjacent to each other along the circumferential direction CD, the first side surface 600e of one magnet and the second side surface 600f of the other magnet are adjacent to each other. An adhesive is interposed between these first side surface 600e and second side surface 600f. However, this adhesive is thin. Therefore, it can be said that these first side surface 600e and second side surface 600f are substantially in contact along the circumferential direction CD.

[0070] Two N magnets 600N are aligned in the circumferential direction CD via one S magnet 600S. Two S magnets 600S are aligned in the circumferential direction CD via one N magnet 600N. To put it simply, two of either the N magnets 600N or the S magnets 600S are aligned in the circumferential direction CD via one of the other.

[0071] The extension magnet 700 has an extension inner surface 700a and an extension outer surface 700b that are spaced apart in the radial direction RD, and an extension upper surface 700c and an extension lower surface 700d that are spaced apart in the axial direction AD. The extension inner surface 700a, extension outer surface 700b, extension upper surface 700c, and extension lower surface 700d are annular in shape.

[0072] The extended inner surface 700a is formed by the inner surfaces 600a of multiple magnets 600 connected in a circumferential direction CD. The extended outer surface 700b is formed by the outer surfaces 600b of multiple magnets 600 connected in a circumferential direction CD. The extended upper surface 700c is formed flush with the upper surfaces 600c of multiple magnets 600. The extended lower surface 700d is formed flush with the lower surfaces 600d of multiple magnets 600. More precisely, the surface of the extended magnet 700 described above is formed not only by the surfaces of the multiple magnets 600, but also by adhesives and the like that connect the multiple magnets 600.

[0073] Both the extended inner surface 700a and the extended outer surface 700b are curved surfaces with an arc shape. They are concentric circles. The length of the circumferential CD is shorter for the extended inner surface 700a than for the extended outer surface 700b. The radial separation distance RD between the extended inner surface 700a and the extended outer surface 700b is the same even if the measurement position differs in the circumferential CD and axial AD. However, the radial separation distance RD between the extended inner surface 700a and the extended outer surface 700b can also be configured such that, for example, in the axial AD, the distance gradually increases towards the center between the extended upper surface 700c and the extended lower surface 700d, starting from the extended upper surface 700c or the extended lower surface 700d.

[0074] When the extension magnet 700 is assembled to the motor 100, the extension inner surface 700a is located on the rotor core 410 side, and the extension outer surface 700b is located on the stator 500 side. In this embodiment, the entire surface of the extension outer surface 700b faces the stator 500 in the radial direction RD.

[0075] The extension magnet 700 has a longer axial length AD than the core teeth 540. The magnetic center of the extension magnet 700 in the axial direction AD and the magnetic center of the stator 500 in the axial direction AD are aligned in the radial direction RD.

[0076] The extended upper surface 700c and the extended lower surface 700d extend in a direction perpendicular to the axial direction AD. The extended upper surface 700c and the extended lower surface 700d extend parallel to each other. The separation distance in the axial direction AD between the extended upper surface 700c and the extended lower surface 700d is the same even if the measurement position differs in a direction perpendicular to the axial direction AD. However, the separation distance in the axial direction AD between the extended upper surface 700c and the extended lower surface 700d may increase or decrease as you move from the extended inner surface 700a side to the extended outer surface 700b side in the radial direction RD.

[0077] The multiple magnets 600 constituting the extension magnet 700 extend in the axial direction A. In this embodiment, the multiple magnets 600 are not aligned in the axial direction A. However, a configuration in which the multiple magnets 600 are aligned in the axial direction A can also be adopted.

[0078] In this embodiment, the magnet 600 is the smallest component of the extension magnet 700. The extension magnet 700 is composed of multiple separate magnets 600. One magnet 600 constitutes one of the multiple magnetic poles included in the extension magnet 700. However, the configuration is not limited to this. The smallest component of the extension magnet 700 may be smaller or larger than the magnet 600 shown in this embodiment. For example, the smallest component may be half the size of the magnet 600, or twice the size. One magnetic pole of the extension magnet 700 may be composed of multiple magnets 600, or multiple magnetic poles may be composed of one magnet 600.

[0079] The extension magnet 700 may be manufactured from a single ring-shaped magnetic material, rather than being manufactured by connecting multiple magnets 600. In this configuration, the extension inner surface 700a is made up of the inner surface 600a of one magnet 600. The extension outer surface 700b is made up of the outer surface 600b of one magnet 600. The extension upper surface 700c is made up of the upper surface 600c of one magnet 600. The extension lower surface 700d is made up of the lower surface 600d of one magnet 600. The orientation OR of the multiple magnetic poles included in the extension magnet 700 is equivalent to the orientation OR of one magnet 600 described in this embodiment.

[0080] <Radial Orientation Component> Next, we will explain the radial orientation component ORr of N magnet 600N and S magnet 600S that are adjacent to each other in the circumferential direction CD. This radial orientation component ORr is represented by a waveform that includes a regular period wave ORr1 and a triple period wave ORr3. The radial orientation component ORr is represented by the sum of the regular period wave ORr1 and the triple period wave ORr3.

[0081] The equal-period wave ORr1 is represented as A0 × cosθ. The triple-period wave ORr3 is represented as A1 × cos3θ. Therefore, the radially oriented component ORr is represented as A0 × cosθ + A1 × cos3θ.

[0082] Here, A0 represents the fundamental amplitude, A1 represents the first amplitude, and × represents multiplication. Then, θ represents the electric angle that increases or decreases as the position of the circumferential CD changes, with the pole center of the N magnet 600N (one of two adjacent N magnets 600N and S magnets 600S) set as the base point at 0°.

[0083] The fundamental amplitude A0 is normalized to 1, and the absolute value of the first amplitude A1 is smaller than the absolute value of the fundamental amplitude A0, which is 1. The electrical angle θ increases clockwise and decreases counterclockwise. The base point for the electrical angle θ may be, for example, the magnetic pole center of the S magnet 600S.

[0084] As shown in Figure 6, the position where the electrical angle θ is -90° indicates the first side surface 600e of the N magnet 600N. The position where the electrical angle θ is 0° indicates the side center 600ef of the N magnet 600N, which is the magnetic pole center. The position where the electrical angle θ is 90° indicates the second side surface 600f of the N magnet 600N and the first side surface 600e of the S magnet 600S. The position where the electrical angle θ is 180° indicates the side center 600ef of the S magnet 600S, which is the magnetic pole center. The position where the electrical angle θ is 270° indicates the second side surface 600f of the S magnet 600S.

[0085] In Figure 7, the equal-period wave ORr1, A0 × cosθ, is shown by a dashed line. The triple-period wave ORr3, A1 × cos3θ, is shown by a dashed line. The radially oriented component ORr, A0 × cosθ + A1 × cos3θ, is shown by a solid line.

[0086] As shown in Figure 7, the value of the radial orientation component ORr becomes nearly constant near the pole center of the N magnet 600N. That is, the value of the radial orientation component ORr becomes nearly constant in the range of electrical angle θ from -40° to +40°. Similarly, the value of the radial orientation component ORr becomes nearly constant near the pole center of the S magnet 600S. That is, the value of the radial orientation component ORr becomes nearly constant in the range of electrical angle θ from +130° to +220°. The change in the radial orientation component ORr near the pole center becomes negligible.

[0087] Figure 8 shows the dependence of the radial orientation component ORr on the first amplitude A1. The horizontal axis of Figure 8 represents the value of the first amplitude A1. The vertical axis of Figure 8 shows the value obtained by dividing the rotational torque when the radial orientation component ORr has both equal-period wave ORr1 and triple-period wave ORr3 by the rotational torque when the radial orientation component ORr has only equal-period wave ORr1. Hereafter, this value on the vertical axis will be referred to as the torque ratio. In the drawing, this torque ratio is represented by T.

[0088] The dashed line in Figure 8 shows the theoretical value of the radial orientation component ORr, which is A0 × cosθ + A1 × cos3θ. As is clear from this theoretical value, if the first amplitude A1 is 0.4 or less, the torque ratio will be greater than 1. Note that 0.4 can also be expressed as 2 / 5.

[0089] The white diamond and dashed line in Figure 8 show the relationship between the rotational torque obtained by the radial orientation component ORr shown in Figure 6 and the first amplitude A1. From these measurements, it can be seen that if the first amplitude A1 is 0.3 or less, the torque ratio will be greater than 1.

[0090] Figure 9 shows the radial orientation component ORr when the value of the first amplitude A1 is varied. The horizontal axis of Figure 9 represents the electrical angle θ. The vertical axis of Figure 9 represents the value obtained by dividing the radial orientation component ORr by the orientation OR. It shows the ratio of the radial orientation component ORr to the orientation OR. Hereafter, this value on the vertical axis will be referred to as the radial orientation ratio ORrR. In the drawing, this radial orientation ratio is represented by ORrR. The equal-frequency wave ORr1 is shown by a dashed line. The radial orientation component ORr when the first amplitude A1 is -2 / 9 is shown by a dashed line. The radial orientation component ORr when the first amplitude A1 is -1 / 9 is shown by a solid line. Note that 1 / 9 is approximately 0.11.

[0091] When the first amplitude A1 is -2 / 9, the radial orientation ratio is smaller near electrical angle θ 0° compared to the equal-frequency wave ORr1. However, as the electrical angle θ increases from 0°, the radial orientation ratio gradually increases, and at an electrical angle θ of approximately 30°, the radial orientation ratio becomes larger than that of the equal-frequency wave ORr1. The radial orientation ratio then reaches its peak value at an electrical angle θ of approximately 40°. After that, the radial orientation ratio decreases as the electrical angle θ approaches 90°.

[0092] Thus, when the first amplitude A1 is -2 / 9, the radial orientation ratio increases as the electrical angle θ moves from 0° to 40° and decreases as it moves from 40° to 90°. This drop in the radial orientation ratio when the electrical angle θ is 0° and the rise in the radial orientation ratio when the electrical angle θ is 40° cause periodic vibrations (pulsations) in the motor 100.

[0093] If we denote the strength of this pulsation as pulsation strength P, then pulsation strength P corresponds to the difference between the radial orientation ratio ORrR0 when the electrical angle θ is 0° and the radial orientation ratio ORrRmax when the electrical angle θ is 40°. The larger this pulsation strength P is, the greater the pulsation and the greater the torque fluctuation. Therefore, a smaller pulsation strength P is preferable.

[0094] In contrast, when the first amplitude A1 is -1 / 9, the radial orientation ratio is almost constant in the range of electrical angle θ from 0° to 40°. The radial orientation ratio decreases slightly as the electrical angle θ approaches 40° from 0°, and decreases further as it approaches 90° from 40°. The pulsation strength P is zero. Thus, the magnitude of the pulsation strength P changes according to the value of the first amplitude A1.

[0095] Figure 10 shows the relationship between pulsation strength P and the first amplitude A1. As can be seen, when the absolute value of the first amplitude A1 is approximately 0.12 or less, the pulsation strength P becomes zero.

[0096] In this embodiment, as shown in Figure 1, the stator coil 520 is distributed-winded around 60 core teeth 540. In this configuration, the rotational torque and cogging torque were verified when the radial orientation component ORr is radially oriented, when it is a constant-period wave, and when it includes a constant-period wave ORr1 and a triple-period wave ORr3. The verification results are shown in Figures 11 and 12. In this verification, the first amplitude A1 was set to -1 / 8.7. 1 / 8.7 is approximately 0.115.

[0097] The horizontal axis in Figures 11 and 12 represents the electrical angle θ. The vertical axis in Figure 11 represents the rotational torque. In the drawing, this rotational torque ratio is represented by TR. The vertical axis in Figure 12 represents the cogging torque. In the drawing, this cogging torque is represented by TC. The rotational torque and cogging torque when the radial orientation component ORr is a wave of equal period is shown by dashed lines. The rotational torque and cogging torque when the radial orientation component ORr is radially oriented is shown by dashed lines. The rotational torque and cogging torque when the radial orientation component ORr includes a wave of equal period ORr1 and a wave of three times the period ORr3 are shown by solid lines. Note that the cogging torque is measured with the current to the stator coil 520 stopped.

[0098] As shown in Figure 11, the rotational torque is lower when the radial orientation component ORr is radially oriented than when the radial orientation component ORr is a single-frequency wave. However, the rotational torque is higher when the radial orientation component ORr includes both a single-frequency wave ORr1 and a triple-frequency wave ORr3 than when the radial orientation component ORr is a single-frequency wave. Specifically, the relative magnitude of the rotational torque is 0.97 when the radial orientation component ORr is radially oriented, 1 when it is a single-frequency wave, and 1.06 when it includes both a single-frequency wave ORr1 and a triple-frequency wave ORr3. Note that the magnitude of the rotational torque is expressed as an average value.

[0099] As shown in Figure 12, the cogging torque is higher when the radial orientation component ORr is radially oriented than when the radial orientation component ORr is a constant-period wave. However, the cogging torque is lower when the radial orientation component ORr includes both a constant-period wave ORr1 and a triple-period wave ORr3 than when the radial orientation component ORr is a constant-period wave. Specifically, the cogging torque is 0.07 Nm when the radial orientation component ORr is radially oriented, 0.007 Nm when it is a constant-period wave, and 0.002 Nm when it includes both a constant-period wave ORr1 and a triple-period wave ORr3. The magnitude of the cogging torque is expressed as the difference between the upper and lower peak values.

[0100] As shown above, when the radial orientation component ORr includes equal-period wave ORr1 and triple-period wave ORr3, the rotational torque increases and the cogging torque decreases. This effect also holds true in a configuration in which the stator coil 520 is concentrated on the core teeth 540, as shown in Figure 13. In the configuration shown in Figure 13, there are 12 core teeth 540 and 8 magnetic poles on the extension magnet 700. The verification results of the rotational torque and cogging torque in this configuration are shown in Figures 14 and 15. In this verification as well, the first amplitude A1 is set to -1 / 8.7.

[0101] In Figures 14 and 15, the rotational torque and cogging torque when the radial orientation component ORr is a wave of equal period are shown by dashed lines, similar to Figures 11 and 12, and the rotational torque and cogging torque when the radial orientation component ORr is radially oriented are shown by dashed lines. The rotational torque and cogging torque when the radial orientation component ORr includes a wave of equal period ORr1 and a wave of three times the period ORr3 are shown by solid lines.

[0102] As shown in Figure 14, the rotational torque when the radial orientation component ORr includes equal-period wave ORr1 and triple-period wave ORr3 is higher than the rotational torque when the radial orientation component ORr is radially oriented and when the radial orientation component ORr is a equal-period wave. Specifically, the relative magnitude of the rotational torque is 1.04 when the radial orientation component ORr is radially oriented, 1 when it is a equal-period wave, and 1.07 when it includes equal-period wave ORr1 and triple-period wave ORr3.

[0103] As shown in Figure 15, the cogging torque when the radial orientation component ORr includes equal-period wave ORr1 and triple-period wave ORr3 is lower than the cogging torque when the radial orientation component ORr is radially oriented and when the radial orientation component ORr is a equal-period wave. Specifically, the cogging torque is 0.37 Nm when the radial orientation component ORr is radially oriented, 0.02 Nm when it is a equal-period wave, and 0.01 Nm when it includes equal-period wave ORr1 and triple-period wave ORr3.

[0104] Furthermore, the radial orientation component ORr may include, in addition to the equal-period wave ORr1 and the triple-period wave ORr3, at least one odd-multiple-period wave represented by An × cos{(2n + 1) × θ}, where n is a natural number of 2 or greater. That is, the radial orientation component ORr may include A2 × cos 5θ, A3 cos 7θ, etc. The radial orientation component ORr may be represented by a waveform that includes multiple types of periodic waves.

[0105] <Measurement of Orientation> The orientation of the OR can be measured by the following method. For example, the measurer takes out the magnet 600 contained in the motor 100 as the object to be measured. The measurer then measures the magnetic flux of the object to be measured and identifies the magnetic path by magnetic circuit analysis. Through such identification, the orientation of the OR can be estimated.

[0106] The operator may measure the orientation OR using electron backscatter diffraction. Electron backscatter diffraction can also be called EBSD. Electron backscatter diffraction is a method for measuring the crystal orientation of magnet 600. By electron backscatter diffraction, the direction of the easy magnetization axis (easy magnetization direction) can be quantitatively evaluated. That is, the direction of the orientation OR can be quantitatively evaluated. As shown above, the orientation OR can be measured by identifying the magnetic path by magnetic circuit analysis and quantitatively evaluating the direction of the easy magnetization axis by electron backscatter diffraction.

[0107] <Effects> As explained above, the radial orientation component ORr includes equal-period wave ORr1 and triple-period wave ORr3. This allows for improved rotational torque and suppression of cogging torque.

[0108] Furthermore, when the radial orientation component ORr includes a constant-period wave A0 × cosθ and a triple-period wave A1 × cos3θ, the surface magnetic flux density distribution formed around the magnet 600 can be achieved not only with orientation OR but also with other configurations.

[0109] The above surface magnetic flux density distribution can be achieved, for example, by individually changing the strength of the radial RD of the magnetism contained in a minute region of the magnet 600. However, in such a configuration, in order to adjust the surface magnetic flux density distribution, it is necessary to adjust the relative strengths of the magnetism in multiple minute regions. The strength of the magnetism must be weakened locally. As a result, the total amount of magnetic flux density emitted from the magnet 600 decreases.

[0110] The above surface magnetic flux density distribution can be achieved, for example, by making the outer shape of the magnet 600 a non-arc shape. However, in this configuration, the volume of the magnet 600 decreases. Therefore, the total amount of magnetic flux density emitted from the magnet 600 decreases.

[0111] As described above, when adjusting the magnetic strength or changing the outer shape to a non-arc shape, the total amount of magnetic flux density emitted from the magnet 600 decreases. Therefore, it becomes difficult to improve the rotational torque.

[0112] In contrast, this disclosure uses orientation OR to form a similar surface magnetic flux density distribution. Therefore, compared to the modified example described above, it is possible to improve the rotational torque.

[0113] As will be detailed later, the particle size of the magnetic powder contained in the magnet 600 can be nanoscale. By using such fine magnetic powder, it became possible to finely adjust the orientation OR as described in this disclosure. Specifically, it was possible to include equal-period wave ORr1 and triple-period wave ORr3 in the radial orientation component ORr.

[0114] The absolute value of the first amplitude A1 should be 0.4 times or less the absolute value of the fundamental amplitude A0. This will improve the rotational torque.

[0115] The absolute value of the first amplitude A1 is set to be 0.3 times or less the absolute value of the fundamental amplitude A0. This improves the rotational torque.

[0116] The absolute value of the first amplitude A1 is set to be 0.12 times or less the absolute value of the fundamental amplitude A0. This reduces the cogging torque.

[0117] <Second Embodiment> This embodiment will be described primarily in terms of its differences from the first embodiment. In subsequent embodiments, the differences from the previously described embodiment will also be described primarily in terms of their differences. Configurations, operations, and effects that are not specifically described in other embodiments are the same as those in the previously described embodiment.

[0118] In the first embodiment, an example was shown in which the radial orientation component ORr and the circumferential orientation component ORc of orientation OR aligned in the radial direction RD are equivalent. In contrast, in this embodiment, as shown in Figure 16, the radial orientation component ORr and the circumferential orientation component ORc of orientation OR aligned in the radial direction RD are different.

[0119] Figure 16 shows the first circumferential line LC1, the second circumferential line LC2, the third circumferential line LC3 extending in the circumferential direction CD, and the radial line LR extending in the radial direction. The first circumferential line LC1, the second circumferential line LC2, and the third circumferential line LC3 are arranged in order from the inner surface 600a to the outer surface 600b. The first circumferential line LC1 is located on the inner surface 600a side in the radial direction RD. The second circumferential line LC2 is located between the inner surface 600a and the outer surface 600b in the radial direction RD. The third circumferential line LC3 is located on the outer surface 600b side in the radial direction RD.

[0120] The orientation OR located at a position passing through the first circumference line LC1 is the orientation OR on the inner surface 600a side. The orientation OR located at a position passing through the second circumference line LC2 is the orientation OR between the inner surface 600a and the outer surface 600b. The orientation OR located at a position passing through the third circumference line LC3 is the orientation OR on the outer surface 600b side.

[0121] For example, as shown by the three orientation ORs passing through the radial line LR in Figure 16, the absolute value of the radial orientation component ORr of the orientation OR on the inner surface 600a side is smaller than the absolute value of the circumferential orientation component ORc of the orientation OR on the outer surface 600b side. The absolute value of the circumferential orientation component ORc of the orientation OR on the inner surface 600a side is larger than the absolute value of the circumferential orientation component ORc of the orientation OR on the outer surface 600b side. As you move from the inner surface 600a side towards the outer surface 600b side, the absolute value of the radial orientation component ORr gradually increases, and the absolute value of the circumferential orientation component ORc gradually decreases.

[0122] Thus, at locations where the radial RD position differs, the radially oriented component ORr and the circumferentially oriented component ORc differ. This makes it easier to improve both rotational torque and cogging torque.

[0123] Furthermore, at locations where the radial RD is in a different position, it is also possible to adopt a configuration in which only one of the radial orientation component ORr and the circumferential orientation component ORc is different.

[0124] <Third Embodiment> In this embodiment, as shown in Figure 17, the rotor 400 has a support portion 450 instead of a rotor core 410. The support portion 450 contains a non-magnetic material such as resin. The support portion 450 supports the extension magnet 700 and also serves to connect the extension magnet 700 to the shaft 300.

[0125] <Fourth Embodiment> In this embodiment, as shown in Figure 18, the extension magnet 700 is manufactured from a single annular magnetic material. In this configuration, the orientation OR of the multiple magnetic poles included in the extension magnet 700 is equivalent to the orientation OR of the single magnet 600 described above.

[0126] <Fifth Embodiment> In the first embodiment, an example was shown in which the motor 100 is an inner rotor type radial motor. In contrast, in this embodiment, as shown in Figure 19, the motor 100 is an outer rotor type radial motor. Note that the housing 200 and shaft 300 are not shown in Figure 19.

[0127] As shown in Figure 19, the stator 500 is located closer to the center of the motor 100 than the rotor 400. The rotor 400 is further away from the motor shaft MA in the radial direction RD than the stator 500.

[0128] The rotor 400 has an annular shape. Multiple magnets 600 are provided on the inner circumferential surface of the magnet support portion 440. An annular extension magnet 700 is formed. The motor shaft MA passes through the space enclosed by the extension magnet 700. The stator 500 is provided in this space. The rotor 400 is aligned with the stator 500 in the radial direction RD across a radial gap.

[0129] The core support portion 530 is annular in shape. Core teeth 540 are connected to the outer circumferential surface of the core support portion 530. The core teeth 540 extend radially RD from the outer circumferential surface of the core support portion 530 toward the rotor 400. Multiple core teeth 540 are arranged in the circumferential direction CD. The stator coil 520 is wound around these multiple core teeth 540.

[0130] In this configuration, the inner surface 600a of the magnet 600 included in the rotor 400 is located closer to the stator 500 than its outer surface 600b. In this embodiment, the relationship between the inner surface 600a and the outer surface 600b described above is reversed. The first surface corresponds to the inner surface 600a. The second surface corresponds to the outer surface 600b.

[0131] <Sixth Embodiment> In the first embodiment, an example was shown in which the stator 500 is the exciter and the rotor 400 is the field element. In contrast, in this embodiment, the rotor 400 is the exciter and the stator 500 is the field element. As shown in Figure 20, the stator 500, not the rotor 400, has the magnet 600. The rotor 400 has a rotor coil 470 instead of the magnet 600. Note that the housing 200 is not shown in Figure 20.

[0132] The stator core 510 has a core support portion 530. The core support portion 530 contains a soft magnetic material. The core support portion 530 is annular in shape. Multiple magnets 600 are provided on the inner circumferential surface of the core support portion 530. The core support portion 530 performs the same function as the magnet support portion 440 described in the first embodiment. The core support portion 530 does not necessarily contain a soft magnetic material.

[0133] A ring-shaped extension magnet 700 is formed by multiple magnets 600. A rotor 400 is provided in the space enclosed by this extension magnet 700.

[0134] The rotor core 410 has a shaft connecting portion 420 and rotor teeth 460. The shaft connecting portion 420 is annular in shape. The rotor teeth 460 are connected to the outer circumferential surface of the shaft connecting portion 420. The rotor teeth 460 extend from the shaft connecting portion 420 toward the stator 500. The motor shaft MA is located on the extension of the radial direction RD of the rotor teeth 460. Multiple rotor teeth 460 are arranged in the circumferential direction CD. A rotor coil 470 is wound around these multiple rotor teeth 460. When current is supplied to this rotor coil 470, the rotor 400 is energized.

[0135] As described above, the motor 100 of this embodiment is an inner rotor type radial motor. However, the motor 100 of this embodiment can also be used as an outer rotor type radial motor as described in the sixth embodiment.

[0136] <Seventh Embodiment> In the previous embodiments, an example was shown where the motor 100 is a radial motor. In contrast, in this embodiment, the motor 100 is an axial motor. The radial direction RD corresponds to the third direction, the circumferential direction CD to the second direction, and the axial direction AD to the first direction. The radial orientation component ORr corresponds to the third orientation component, the circumferential orientation component ORc to the second orientation component, and the axial orientation component ORa to the first orientation component.

[0137] The main difference between a radial motor and an axial motor lies in the direction in which the rotor 400 and stator 500 face each other. In a radial motor, the rotor 400 and stator 500 face each other in the radial direction RD. In contrast, in an axial motor, as shown in Figure 21, for example, the rotor 400 and stator 500 face each other in the axial direction AD.

[0138] Because of these significant differences, when applying the configuration of the radial motor described above to the configuration of the axial motor of this embodiment, the radial RD characteristics of the radial motor are applied to the axial AD characteristics of the axial motor.

[0139] To explain specifically in terms of orientation OR, the characteristics of the radial orientation component ORr of a radial motor can be applied to the characteristics of the axial orientation component ORa of an axial motor. The characteristics of the axial orientation component ORa of a radial motor can be applied to the characteristics of the radial orientation component ORr of an axial motor. However, the characteristics of the circumferential orientation component ORc are the same for both radial and axial motors.

[0140] The configuration of the motor 100 of this embodiment will be outlined below with reference to Figures 21 to 24. Figures 21 to 24 are diagrams illustrating the arrangement of the rotor 400 and stator 500 in an axial motor. For this reason, some components of the axial motor are omitted from the illustration in Figures 21 to 24.

[0141] As shown in Figure 22, the housing 200 has a bottom plate 210 and side walls 220. The bottom plate 210 is a thin plate shape with a thickness in the axial direction AD. The bottom plate 210 has an inner bottom surface and an outer bottom surface aligned in the axial direction AD. The side walls 220 stand upright from this inner bottom surface. The side walls 220 form an annular shape so as to surround the entire inner bottom surface of the bottom plate 210.

[0142] A portion of the shaft 300, the rotor 400, and the stator 500 are housed in the space enclosed by the bottom plate 210 and the side wall 220. Inside this housing 200, the rotor 400 and the stator 500 are aligned in the axial direction AD with an axial gap between them. The bottom plate 210 has a hole formed that penetrates the inner bottom surface and the outer bottom surface in the axial direction AD. The shaft 300 passes through this hole in the bottom plate 210.

[0143] The core support portion 530 of the stator core 510 has an overall disc shape. The core support portion 530 closes the opening of the housing 200, which is partitioned by the tip of the annular side wall 220.

[0144] The core support portion 530 has two main surfaces, a first main surface and a second main surface, aligned in the axial direction AD. A hole is formed in the core support portion 530 that penetrates these first and second main surfaces in the axial direction AD. The shaft 300 passes through this hole in the core support portion 530. The first main surface is located closer to the bottom plate 210 of the housing 200 in the axial direction AD than the second main surface. The core teeth 540 are connected to this first main surface.

[0145] The core teeth 540 extend axially AD from the core support portion 530 toward the bottom plate 210. Multiple core teeth 540 are arranged circumferentially CD around a hole formed in the core support portion 530. The stator coil 520 is wound around these multiple core teeth 540.

[0146] The overall shape of the shaft connecting portion 420 of the rotor core 410 is disc-shaped. The shaft connecting portion 420 has a support surface and a back surface aligned in the axial direction AD. A hole is formed in the shaft connecting portion 420 that penetrates these support surface and back surface in the axial direction AD. The shaft connecting portion 420 is fixed to the shaft 300 with the shaft 300 inserted through this hole.

[0147] With the rotor 400 housed in the housing 200, the back surface of the shaft connecting portion 420 is located closer to the bottom plate 210 of the housing 200 than the support surface. The support surface of the shaft connecting portion 420 is located closer to the stator 500 than the back surface. Multiple magnets 600 are provided on this support surface. In this embodiment, the shaft connecting portion 420 also serves the function of supporting the magnets 600.

[0148] Multiple magnets 600 are arranged in a ring shape in the circumferential direction CD so as to surround a hole formed in the shaft connecting portion 420. This constitutes an annular extension magnet 700. The extended upper surface 700c of this extension magnet 700 is located closer to the support surface of the shaft connecting portion 420 than the extended lower surface 700d. The extended lower surface 700d is located closer to the stator 500 than the extended upper surface 700c. The extension magnet 700 and the multiple core teeth 540 around which the stator coil 520 is wound are aligned in the axial direction AD.

[0149] As shown in Figure 24, the multiple orientations OR contained in one magnet 600 have a circumferential orientation component ORc. This orientation OR has an axial orientation component ORa instead of a radial orientation component ORr. The axial orientation component ORa is expressed as A0 × cosθ + A1 × cos3θ.

[0150] As shown in Figures 21 and 23, in this embodiment, the rotor 400 has four magnets 600 of equal size. N magnets 600N and S magnets 600S are arranged alternately in the circumferential direction CD. Therefore, magnets 600 with the same polarity are arranged in the radial direction RD. Two N magnets 600N are arranged in the radial direction RD. Two S magnets 600S are arranged in the radial direction RD. Depending on the number of magnets 600 that the rotor 400 has, magnets 600 with opposite polarity may be arranged in the radial direction RD. For example, if the rotor 400 has 10 magnets 600, N magnets 600N and S magnets 600S will be arranged in the radial direction RD.

[0151] The elevation angles ζ of the orientation OR of the multiple magnets 600 arranged in the circumferential direction CD are twofold symmetric with respect to the shaft 300. That is, the elevation angles ζ of the orientation OR of the extension magnet 700 are twofold symmetric with respect to the shaft 300.

[0152] All of the multiple orientations OR contained in one magnet 600 have a circumferential orientation component ORc and an axial orientation component ORa, but do not have a radial orientation component ORr.

[0153] As detailed in the first embodiment, the orientation OR can be varied in various ways in the axial motor of this embodiment as well. For example, the orientation OR may have a radial orientation component ORr.

[0154] Furthermore, an axial motor may have multiple rotors 400 and multiple stators 500. For example, motor 100 may have two rotors 400. A stator 500 may be provided between the two rotors 400. This configuration can also be called a double-rotor motor. Alternatively, motor 100 may have two stators 500. A rotor 400 may be provided between the two stators 500. This configuration can also be called a double-stator motor. In such configurations, where an axial motor has multiple rotors 400 and multiple stators 500, the rotational torque can be improved.

[0155] In this embodiment, an example was shown in which the stator 500 is the exciter and the rotor 400 is the field element in an axial motor. However, although not specifically shown, an axial motor can also be configured in which the rotor 400 is the exciter and the stator 500 is the field element.

[0156] <Eighth Embodiment> In the previous embodiments, an example was shown in which the motor 100 rotates. In contrast, the motor 100 in this embodiment is a linear motor that moves in a straight line.

[0157] In the following, in order to explain this embodiment, a new lateral direction LD is defined in addition to the radial direction RD, circumferential direction CD, and axial direction AD. LD is an abbreviation for Lateral Direction. The lateral direction LD is a linear direction perpendicular to the radial direction RD and the axial direction AD.

[0158] The orientation component of orientation OR can be decomposed into three parts by using the newly defined transverse LD instead of the circumferential CD. As shown in Figure 3, orientation OR can be decomposed into three parts: the radial orientation component ORr, the axial orientation component ORa, and the transverse orientation component ORl along the transverse LD.

[0159] The radial direction RD corresponds to the first direction, the axial direction AD to the second direction, and the transverse direction LD to the third direction. The radial orientation component ORr corresponds to the first orientation component, the axial orientation component ORa to the second orientation component, and the transverse orientation component ORl to the third orientation component.

[0160] The main difference between a radial motor and a linear motor lies in the motion of the rotor 400. In a radial motor, the rotor 400 rotates in the circumferential direction CD. In contrast, in a linear motor, the rotor 400 moves linearly in the axial direction AD.

[0161] Because of these significant differences, when applying the configuration of a radial motor to the configuration of a linear motor in this embodiment, the circumferential CD characteristics of the radial motor are adapted to the axial AD characteristics of the linear motor.

[0162] To explain in detail regarding orientation OR, the characteristics of the circumferential orientation component ORc of a radial motor are applicable to the characteristics of the axial orientation component ORa of a linear motor. The characteristics of the axial orientation component ORa of a radial motor are applicable to the characteristics of the lateral orientation component ORl of a linear motor. However, the characteristics of the radial orientation component ORr are equivalent for both radial motors and linear motors. The configuration of the motor 100 of this embodiment will be outlined below.

[0163] As shown in Figure 25, the rotor 400 and stator 500 are aligned radially RD across a radial gap. The motor 100 has a linear motion axis 800 instead of a shaft 300. The rotor 400 is connected to this linear motion axis 800. The linear motion axis 800 is movable axially AD relative to the stator 500. In this embodiment, the radial direction RD is perpendicular to the axial direction AD and is the direction in which the rotor 400 and stator 500 are aligned. Therefore, the radial direction RD can also be described as the alignment direction.

[0164] The linear motion axis 800 is flat in a direction perpendicular to the radial direction RD. The extension direction of the linear motion axis 800 is the axial direction AD. The axial width direction of the linear motion axis 800 is the lateral direction LD. The linear motion axis 800 is longer in the lateral direction LD than in the radial direction RD.

[0165] The core support portion 530 of the stator core 510 extends in the axial direction AD. Core teeth 540 are connected to one surface of this core support portion 530 that extends in the axial direction AD. The core teeth 540 extend in the radial direction RD. Multiple core teeth 540 are arranged in the axial direction AD. Stator coils 520 are wound around these multiple core teeth 540.

[0166] The shaft connection portion 420 of the rotor core 410 extends in the axial direction AD. Multiple magnets 600 are provided on one surface of this shaft connection portion 420 that extends in the axial direction AD. The back side is connected to the linear motion shaft 800. The shaft connection portion 420 also functions as a support portion 450. The multiple magnets 600 and the core teeth 540 are aligned radially RD with a radial gap in between.

[0167] Furthermore, it is also possible to adopt a configuration without a rotor core 410, where multiple magnets 600 are mounted on a linear motion axis 800.

[0168] The multiple magnets 600 are not arc-shaped, but rectangular parallelepipeds. These multiple magnets 600 are arranged in a straight line along the axial direction AD. The upper surface 600c of one of two magnets 600 aligned along the axial direction AD is adjacent to the lower surface 600d of the other magnet 600 along the axial direction AD.

[0169] In this embodiment, an extension magnet 700 is formed by connecting multiple magnets 600 in a straight line. The extension magnet 700 is linear in shape.

[0170] Multiple orientations OR contained in a single magnet 600 have an axial orientation component ORa. This orientation OR has a radial orientation component ORr instead of a transverse orientation component ORl. The radial orientation component ORr is expressed as A0 × cosθ + A1 × cos3θ.

[0171] As explained in detail in the previous embodiments for radial and axial motors, the orientation OR can be varied in various ways in the linear motor of this embodiment as well. For example, multiple orientation ORs may have a lateral orientation component ORl.

[0172] Furthermore, an example is shown in which the rotor 400 and stator 500 extend in the axial direction AD. In this configuration, the motor 100 may take on a cylindrical shape by further extending the rotor 400 and stator 500 in the circumferential direction CD around the axial direction AD. In this configuration, the rotor 400 is provided within the space enclosed by the stator 500. The rotor 400 moves in the axial direction AD within the space enclosed by the stator 500.

[0173] In this embodiment, an example was shown in which the stator 500 is the exciter and the rotor 400 is the field element in a linear motor. However, although not specifically shown, a linear motor can also be configured in which the rotor 400 is the exciter and the stator 500 is the field element.

[0174] <Other Embodiments> The disclosures of this specification are not limited to the exemplary embodiments. The disclosures encompass the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to the combinations of parts and elements shown in the embodiments, but can be implemented in various variations. The disclosures can be implemented in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures encompass embodiments in which parts and elements have been omitted. The disclosures encompass substitutions or combinations of parts and elements between one embodiment and another. The scope of the disclosed technical field is not limited to the descriptions of the embodiments. The scope of the disclosed technical field is indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.

[0175] <Magnet Materials> In the first embodiment, an example was shown in which the magnet 600 includes magnetic powder and other materials. These magnetic powder and other materials can be appropriately selected as long as they satisfy the performance requirements of the motor 100 to which they are applied. The magnet 600 will possess characteristics resulting from the combination of magnetic powder and other materials selected. A magnet 600 with such characteristics will be used in the motor 100. Note that the other materials other than magnetic powder do not necessarily have to be included in the magnet 600. If the motor 100 is a bonded magnet, the other materials other than magnetic powder may be resin materials, etc.

[0176] As the magnetic powder, rare earth magnetic powder containing rare earth elements and rare earth-free magnetic powder not containing rare earth elements can be used. The magnetic powder may contain at least one type of rare earth magnetic powder. The magnetic powder may contain at least one type of rare earth magnetic powder. The magnetic powder may contain at least one type of rare earth magnetic powder and at least one type of rare earth-free magnetic powder.

[0177] When the performance requirements for magnet 600 include miniaturization, weight reduction, and ease of modification, a finer particle size of magnetic powder is preferable. Microscale and nanoscale particle sizes can be used for the magnetic powder. Using such fine magnetic powder increases the design freedom of the orientation OR. When ease of material procurement and high recycling efficiency are required, it is desirable that the composition of the magnetic powder be simple and abundant, and that it does not contain rare earth elements. When it is required to withstand use under harsh conditions, it is desirable that the magnetic powder has high heat resistance and radiation resistance.

[0178] Motor magnets containing magnetic powders exhibiting the characteristics described above—nanoscale, simple and abundant composition, rare-earth-free, high heat resistance, and radiation resistance—are generally expected to possess the properties of such magnetic powders. Therefore, motor magnets containing such magnetic powders are expected to exhibit characteristics such as small size, light weight, ease of modification, easy material procurement, high recycling efficiency, high heat resistance, and radiation resistance. Such motor magnets can be widely used in motors in general. Furthermore, such motor magnets can also be used in motors in specific small-scale technological fields where their characteristics are required.

[0179] Of course, the magnet 600 used in the motor 100 is required to have an output appropriate to its application. The magnetic powder contained in the magnet 600 can be a magnetic powder that is expected to produce an output appropriate to its application.

[0180] Common types of magnets that can be used in Magnet 600 include ceramic magnets such as ferrite magnets, metallic magnets such as rare earth magnets and ordered alloy magnets, and bonded magnets such as rubber magnets and plastic magnets.

[0181] Ferrites include hexagonal ferrites such as barium ferrite and strontium ferrite, and spinel ferrites such as cobalt ferrite. Rare earth elements include R-T systems such as Sm-Co, R-T-B systems such as Nd-Fe-B, and R-T-N systems such as Sm-Fe-N. As for ordered alloys, L1 ０ -FePt, L1 ０ Examples include -FeNi and τ-MnAl. Other metallic materials for metal magnets include Alnico, spinodal decomposition systems such as Fe-Cr-Co, and Fe16N2. Note that R stands for Rare Earth, and includes Nd, Sm, Dy, etc. T stands for Transition metal, and includes Fe, Co, Ni, etc.

[0182] <Applications of the motor> At the beginning of the first embodiment, it was shown that the applications of the motor 100 are not particularly limited and that it can be applied to, for example, mobility products, robot products, and equipment that generates energy such as electricity.

[0183] These mobility products include cars as a means of land travel, aircraft as a means of air travel, ships as a means of water travel, submersibles and other vessels as a means of underwater travel, and spacecraft used for travel in outer space.

[0184] These means of transportation on land, air, water, and space include manned and unmanned aircraft. Vehicles include manned and unmanned vehicles. Specifically for the transport of goods, vehicles include manned and unmanned transport vehicles. Unmanned transport vehicles can also be called AGVs. AGV is an abbreviation for Automated Guided Vehicle. Aircraft include manned and unmanned aircraft. Unmanned aircraft can also be called UAVs. UAV is an abbreviation for Unmanned Aerial Vehicle. Specifically for the operation of goods, ships include manned and unmanned ships. Submarines and underwater vehicles include manned and unmanned underwater vehicles. Spacecraft include manned and unmanned spacecraft. Manned spacecraft can also be called spaceships.

[0185] The power sources for these means of transportation, including manned and unmanned aircraft, can include various energy sources such as thermal energy, electrical energy, light energy, renewable energy, chemical energy, and nuclear energy. The power sources for these means of transportation can utilize one or a combination of these various energy sources.

[0186] Robot products, categorized by application, include industrial robots, household robots, service robots, medical robots, educational robots, agricultural robots, exploration robots, and leisure robots.

[0187] One example of an energy-generating facility is a power plant. A power plant is a facility that generates electrical energy using energy sources such as oil, coal, natural gas, biomass, nuclear power, wind power, hydropower, geothermal energy, solar power, and chemical reactions.

[0188] <Disclosure of Technical Ideas> This specification discloses several technical ideas as described in the following paragraphs. Some paragraphs may be written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs may be written in a multiple dependent form, where they refer to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical ideas.

[0189] <Technical Concept 1> A motor magnet provided on field magnets (400, 500) aligned with an exciter (500, 400) in a first direction (RD, AD), comprising an N magnet (600N) and an S magnet (600S) adjacent to each other in a second direction (CD, AD) that intersects the first direction and in which either the exciter or the field magnet moves, wherein the N magnet and the S magnet have an orientation (OR) including a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, and the electric angle that increases or decreases as the position in the second direction changes, with the pole center of one of the adjacent N magnets and S magnets in the second direction set as the base point at 0°, the fundamental amplitude is A0, the first amplitude with an absolute value smaller than A0 is A1, and multiplication is ×, The motor magnet is represented by a waveform in which the first orientation component includes at least an equal-period wave A0 × cosθ and a triple-period wave A1 × cos3θ.

[0190] <Technical Idea 2> The motor magnet according to Technical Idea 1, wherein the absolute value of A1 is 0.4 times or less the absolute value of A0.

[0191] <Technical Idea 3> The motor magnet according to Technical Idea 2, wherein the absolute value of A1 is 0.3 times or less the absolute value of A0.

[0192] <Technical Idea 4> The motor magnet according to Technical Idea 3, wherein the absolute value of A1 is 0.12 times or less the absolute value of A0.

[0193] <Technical Idea 5> A motor magnet according to any one of Technical Ideas 1 to 4, wherein at locations where the position in the first direction is different, at least one of the first orientation component and the second orientation component is different.

[0194] <Technical Idea 6> The motor magnet according to any one of Technical Ideas 1 to 5, wherein the N magnet and the S magnet contain magnetic powder with a particle size on the nanoscale.

[0195] <Technical Concept 7> A field magnet aligned with an exciter (500, 400) in a first direction (RD, AD), comprising an extension magnet (700) extending in a second direction (CD, AD) intersecting the first direction, in which one of the exciter and the field magnet moves, wherein the extension magnet comprises an N magnet (600N) and an S magnet (600S) adjacent to each other in the second direction, wherein the N magnet and the S magnet have an orientation (OR) including a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, and the electric angle that increases or decreases as the position in the second direction changes, with the pole center of one of the N magnets and the S magnets adjacent to each other in the second direction set as the base point at 0°, the fundamental amplitude is A0, the first amplitude with an absolute value smaller than A0 is A1, and multiplication is ×, The first orientation component is a field field represented by a waveform that includes at least an equal-period wave A0 × cosθ and a triple-period wave A1 × cos3θ.

[0196] <Technical Concept 8> The device comprises an exciter (500, 400) and a field element (400, 500) aligned in a first direction (RD, AD), the field element includes an extension magnet (700) that intersects the first direction and extends in a second direction (CD, AD) in which one of the exciter and the field element moves, the extension magnet includes an N magnet (600N) and an S magnet (600S) aligned adjacent to each other in the second direction, the N magnet and the S magnet have an orientation (OR) that includes a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, A motor in which the first orientation component is represented by a waveform that includes at least a regular period wave A0 × cosθ and a triple period wave A1 × cos3θ, with the center of the magnetic pole of one of the N magnets and S magnets that are adjacent to each other in the second direction being the base point at 0°, the electrical angle that increases or decreases as the position in the second direction changes, the fundamental amplitude being A0, the first amplitude having a smaller absolute value than A0 being A1, and multiplication being ×.

[0197] <Technical Idea 9> The motor according to technical idea 8, wherein the first direction is the radial direction (RD) perpendicular to the rotation axis (300) on which either the exciter or the field element is provided, and the second direction is the circumferential direction (CD) around the rotation axis.

[0198] <Technical Concept 10> The motor according to technical concept 8, wherein the first direction is the axial direction (AD) along the rotation axis (300) on which either the exciter or the field element is provided, and the second direction is the circumferential direction (CD) around the rotation axis.

[0199] <Technical Concept 11> The motor according to technical concept 8, wherein the first direction is the radial direction (RD) perpendicular to the linear motion axis (800) on which either the exciter or the field element is provided, and the second direction is the axial direction (AD) along the linear motion axis.

Claims

1. A motor magnet provided on field magnets (400, 500) aligned with exciters (500, 400) in a first direction (RD, AD), comprising an N magnet (600N) and an S magnet (600S) adjacent to each other in a second direction (CD, AD) that intersects the first direction and in which either the exciters or the field magnets move, wherein the N magnet and the S magnet have an orientation (OR) including a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, and the electric angle that increases or decreases as the position in the second direction changes, with the pole center of one of the adjacent N magnets and S magnets in the second direction set as the base point at 0°, the fundamental amplitude is A0, the first amplitude with an absolute value smaller than A0 is A1, and multiplication is ×, The motor magnet is represented by a waveform in which the first orientation component includes at least an equal-period wave A0 × cosθ and a triple-period wave A1 × cos3θ.

2. The motor magnet according to claim 1, wherein the absolute value of A1 is 0.4 times or less the absolute value of A0.

3. The motor magnet according to claim 2, wherein the absolute value of A1 is 0.3 times or less the absolute value of A0.

4. The motor magnet according to claim 3, wherein the absolute value of A1 is 0.12 times or less the absolute value of A0.

5. The motor magnet according to claim 1, wherein at least one of the first orientation component and the second orientation component is different at locations where the position in the first direction is different.

6. The motor magnet according to any one of claims 1 to 5, wherein the N magnet and the S magnet contain magnetic powder with a particle size on the nanoscale.

7. A field magnet aligned with an exciter (500, 400) in a first direction (RD, AD), comprising an extension magnet (700) extending in a second direction (CD, AD) intersecting the first direction, in which one of the exciter and the field magnet moves, wherein the extension magnet comprises an N magnet (600N) and an S magnet (600S) adjacent to each other in the second direction, wherein the N magnet and the S magnet have an orientation (OR) including a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, and the electric angle that increases or decreases as the position in the second direction changes, with the pole center of one of the adjacent N magnets and the S magnet in the second direction set as the base point at 0°, the fundamental amplitude is A0, the first amplitude with an absolute value smaller than A0 is A1, and multiplication is ×, The first orientation component is a field field represented by a waveform that includes at least an equal-period wave A0 × cosθ and a triple-period wave A1 × cos3θ.

8. The device comprises exciters (500, 400) and field elements (400, 500) aligned in a first direction (RD, AD), the field elements include an extension magnet (700) that intersects the first direction and extends in a second direction (CD, AD) in which one of the exciters and the field elements moves, the extension magnet includes an N magnet (600N) and an S magnet (600S) aligned adjacent to each other in the second direction, the N magnet and the S magnet have an orientation (OR) including a first orientation component (ORr, ORA) along the first direction and a second orientation component (ORc, ORA) along the second direction, A motor in which the first orientation component is represented by a waveform that includes at least a regular period wave A0 × cosθ and a triple period wave A1 × cos3θ, with the center of the magnetic pole of one of the N magnets and S magnets that are adjacent to each other in the second direction being the base point at 0°, the electrical angle that increases or decreases as the position in the second direction changes, the fundamental amplitude being A0, the first amplitude having a smaller absolute value than A0 being A1, and multiplication being ×.

9. The motor according to claim 8, wherein the first direction is the radial direction (RD) perpendicular to the rotation axis (300) on which either the exciter or the field element is provided, and the second direction is the circumferential direction (CD) about the rotation axis.

10. The motor according to claim 8, wherein the first direction is the axial direction (AD) along the rotation axis (300) on which either the exciter or the field element is provided, and the second direction is the circumferential direction (CD) around the rotation axis.

11. The motor according to claim 8, wherein the first direction is the radial direction (RD) perpendicular to the linear motion axis (800) on which either the exciter or the field element is provided, and the second direction is the axial direction (AD) along the linear motion axis.

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