Motor magnet, field element, and motor

Abstract

In the present invention, a magnet (100) is provided to either a stator (500) or a rotor (400) which are arranged in the radial direction (RD). The magnet has a plurality of orientations (OR). The types of structural components of the plurality of orientations include: a radial orientation component (ORr) along the radial direction; a circumferential orientation component (ORc) along the circumferential direction (CD) in which the rotor moves; and an axial orientation component (ORa) along the axial direction (AD) intersecting the radial direction in the circumferential direction. The plurality of orientations include the axial orientation component.

Description

Motor magnet, field element, and motor CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-110577 filed in Japan on July 9, 2024, and the contents of the original application are incorporated by reference in their entirety.

[0002] The disclosure herein relates to a motor magnet, a field element, and a motor.

[0003] Patent Document 1 describes a rotating electric machine including a rotor and a stator arranged radially opposite each other. The rotor has a plurality of permanent magnets arranged in the circumferential direction.

[0004] JP 2022-44204 A

[0005] The magnetic flux density of the permanent magnet described in Patent Document 1 is not uniform but varies from region to region of the permanent magnet, and the orientation direction of the permanent magnet is tilted counterclockwise with respect to the central axis of the permanent magnet.

[0006] This configuration reduces the effect of the magnetic flux generated by the stator on the permanent magnet, improves the demagnetization resistance of the permanent magnet, and improves the counterclockwise torque characteristics.

[0007] However, in the case of the configuration described in Patent Document 1, the torque characteristics differ between counterclockwise and clockwise rotations due to the tilt of the orientation angle toward the counterclockwise direction, which causes a problem in that the ease of movement in a specific direction (movement characteristics) depends on the orientation.

[0008] One object of the present disclosure is to provide a motor magnet, a field element, and a motor in which demagnetization is suppressed and whose motion characteristics are less dependent on orientation.

[0009] The disclosed aspect is a motor magnet provided on a field element aligned with an exciter in a first direction, the motor magnet having a plurality of orientations, the types of components of the plurality of orientations being a first orientation component along the first direction, a second orientation component along a second direction in which either the exciter or the field element moves, and a third orientation component along a third direction intersecting the first and second directions, the plurality of orientations being a motor magnet having the third orientation component.

[0010] The disclosed aspect is a field element aligned with an exciter in a first direction, and including an extension magnet extending in a second direction in which one of the exciter and field element moves, wherein the multiple magnetic poles included in the extension magnet have multiple orientations, and the types of components of the multiple orientations include a first orientation component along the first direction, a second orientation component along the second direction, and a third orientation component along a third direction intersecting the first and second directions, and the multiple orientations are a field element having the third orientation component.

[0011] The disclosed aspect is a motor comprising an exciter and a field element aligned in a first direction, the field element having an extension magnet extending in a second direction in which one of the exciter and field element moves, the extension magnet including a plurality of magnetic poles having a plurality of orientations, the types of components of the plurality of orientations being a first orientation component along the first direction, a second orientation component along the second direction, and a third orientation component along a third direction intersecting the first and second directions, and the plurality of orientations having the third orientation component.

[0012] This suppresses demagnetization and makes the motion characteristics less dependent on the orientation.

[0013] The reference numbers in parentheses above merely indicate the corresponding relationship with the configurations described in the embodiments below, and do not in any way limit the technical scope.

[0014] 19 is a top view of a motor. 20 is a perspective view of a rotor. 21 is a cross-sectional view taken along line III-III in FIG. 2. 22 is a schematic diagram showing three-dimensional polar coordinates. 23 is a top view for explaining the orientation of magnets. 24 is a schematic diagram for explaining the orientation of a cross section taken along line VI-VI in FIG. 2. 25 is a schematic diagram for explaining the orientation of a cross section taken along line VII-VII in FIG. 2. 26 is a schematic diagram for explaining the orientation of a cross section taken along line VIII-VIII in FIG. 2. 27 is a schematic diagram for explaining the orientation of a cross section taken along line VIII-VIII in FIG. 2. 28 is a schematic diagram for outlining the orientation of area A surrounded by a dashed line in FIG. 3. 29 is a cross-sectional view of a rotor. 29 is a perspective view of a rotor. 29 is a cross-sectional view taken along line XII-XII in FIG. 21. 29 is a graph for explaining the holding force of a magnet. 29 is a graph for explaining the holding force of a magnet. 29 is a top view of a motor. 29 is a top view for explaining the orientation of magnets. 29 is a schematic diagram for explaining the orientation of a cross section taken along line XVII-XVII in FIG. 21. 29 is a top view of a motor. 29 is a perspective view of a rotor. 29 is a cross-sectional view taken along line XX-XX in FIG. 22. 31. A top view for explaining the orientation of the magnet. A schematic view for explaining the orientation of a cross section taken along line XXII-XXII shown in FIG. 21. A schematic view for explaining the orientation of a cross section taken along line XXIII-XXIII shown in FIG. 21. A schematic view for explaining the orientation of a cross section taken along line XXIV-XXIV shown in FIG. 21. A schematic cross-sectional view for explaining the position of a rotor and a stator. A cross-sectional view of the rotor. A cross-sectional view of the rotor. A perspective cross-sectional view of the rotor. A top view of the motor. A top view of the motor. A top view of the motor. A cross-sectional view taken along line XXXII-XXXII in FIG. 31. A perspective view of the rotor and stator. A top view of the motor. A cross-sectional view of the motor. A schematic view for explaining polar anisotropic orientation. A perspective cross-sectional view of a magnet. A cross-sectional view of the motor. A cross-sectional view of the motor. A cross-sectional view of the motor. A cross-sectional view of the motor. A cross-sectional view of the motor.

[0015] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. Portions corresponding to matters described in the previous embodiments may be assigned the same reference numerals in the subsequent embodiments, and duplicated descriptions may be omitted. When only a portion of the configuration is described in each embodiment, the description of the previous embodiment may be applied to the remaining portions of the configuration.

[0016] In each embodiment, it is possible to combine parts that are specifically expressly permitted to be combined with each other. Furthermore, even if it is not explicitly stated that a combination is possible, it is also possible to partially combine multiple embodiments, an embodiment and a variation, or multiple variation embodiments, as long as there is no particular problem with the combination.

[0017] <First embodiment> <Motor> The motor 100 shown in FIG. 1 has a magnet 600. The motor 100 can be applied to consumer, commercial, industrial, medical, and other products. The motor 100 can be applied to mobility products that move people and objects, robotic products involved in the production and control of objects, and equipment that generates energy such as electricity. In addition, the motor 100 can be applied to a wide range of general products, even if not specifically exemplified. The motor 100 functions as a power source for the applicable product.

[0018] The motor 100 of this embodiment is a multi-phase AC motor. The motor 100 is capable of power running and regeneration. The motor 100 can be used as a motor generator. Note that the motor 100 does not necessarily have to be capable of regeneration. The motor 100 may also be a DC motor or a stepping motor.

[0019] In the following, the three mutually orthogonal directions are referred to as the axial direction AD, the radial direction RD, and the circumferential direction CD. The axial direction AD and the radial direction RD are linear directions, and the circumferential direction CD is a circumferential direction. AD stands for Axial Direction, RD stands for Radial Direction, and CD stands for Circumferential Direction. The circumferential direction can also be referred to as the rotational direction. In this embodiment, the radial direction RD corresponds to the first direction, the circumferential direction CD corresponds to the second direction, and the axial direction AD corresponds to the third direction.

[0020] The line that runs along the axial direction AD and passes through the center of the motor 100 is referred to as the motor axis MA. MA is an abbreviation for Motor Axis. Unless otherwise specified, the direction that intersects with and is perpendicular to the motor axis MA will hereinafter be referred to simply as the radial direction RD. The direction around the motor axis MA will hereinafter be referred to simply as the circumferential direction CD.

[0021] The motor 100 includes a housing 200, a shaft 300, a rotor 400, and a stator 500. The housing 200 contains a metal material. The housing 200 has a cylindrical shape. At least a portion of the shaft 300, the rotor 400, and the stator 500 are housed in a space surrounded by the inner wall surface of the housing 200.

[0022] The shaft 300 extends in the axial direction AD along the motor axis MA. The shaft 300 is supported by the housing 200 via a bearing or other bearing member. The shaft 300 is rotatable relative to the housing 200. The shaft 300 is the rotation axis of the motor 100.

[0023] The rotor 400 is fixed to the shaft 300. The motor axis MA passes through the center of the shaft 300 and the center of the rotor 400. The shaft 300 and the rotor 400 rotate around the motor axis MA. The shaft 300 and the rotor 400 rotate relative to the housing 200.

[0024] 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 surrounded by the stator 500. The rotor 400 and the shaft 300 are provided in this space. The stator 500 is aligned with the rotor 400 in the radial direction RD via a radial gap.

[0025] As described above, the rotor 400 is located closer to the center of the motor 100 than the stator 500. The motor 100 of this embodiment is an inner rotor type radial motor. The motor 100 is also a brushless motor.

[0026] <Stator> The stator 500 is an exciter that is excited by energization. The stator 500 can also be called an armature. The stator 500 has a stator core 510 and a stator coil 520. The stator core 510 is provided with the stator coil 520. The stator 500 is excited by energization of the stator coil 520.

[0027] The stator core 510 is an iron core. 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) through which the magnetic flux passes is formed in the stator core 510.

[0028] 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 directly or indirectly to the housing 200. The outer peripheral surface side of the core support portion 530 is closer to the housing 200 in the radial direction RD than the inner peripheral surface side of the core support portion 530. The core teeth 540 are connected to the inner peripheral surface side of the core support portion 530.

[0029] The core teeth 540 extend in the radial direction RD from the inner circumferential surface of the core support portion 530 toward the motor shaft MA. A plurality of core teeth 540 are arranged in the circumferential direction CD. The stator coils 520 are wound around these core teeth 540. The stator coils 520 are electric wires. In this embodiment, 60 core teeth 540 are integrally connected to the core support portion 530. The stator coils 520 are distributedly wound around these 60 core teeth 540. The number of core teeth 540 is not limited to the above example. A configuration in which the stator coils 520 are concentratedly wound around the core teeth 540 may also be adopted.

[0030] <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. A plurality of magnets 600 are arranged in the circumferential direction CD. The magnetic field of the rotor 400 is formed by the plurality of magnets 600.

[0031] The rotor core 410 is made of a metal material, and at least a portion of the rotor core 410 includes a soft magnetic material.

[0032] Rotor core 410 has a shaft connecting portion 420, a connecting arm 430, and a magnet support portion 440. Shaft connecting portion 420 is fixed to shaft 300. Connecting arm 430 connects shaft connecting portion 420 and magnet support portion 440. Magnet support portion 440 supports a plurality of magnets 600.

[0033] 2 and 3, the shaft coupling part 420 is cylindrical. The shaft 300 is inserted into a hole defined by the inner wall surface of the shaft coupling part 420. In this inserted state, the shaft coupling part 420 is fixed to the shaft 300. The rotor 400 is fixed to the shaft 300. In FIG. 3, the boundary between the shaft coupling part 420 and the coupling arm 430 and the boundary between the coupling arm 430 and the magnet support part 440 are indicated by dashed lines.

[0034] The connecting arm 430 extends from the shaft connecting portion 420 toward the magnet support portion 440. The multiple connecting arms 430 are aligned in the circumferential direction CD. The motor shaft MA is located on an extension line of the multiple connecting arms 430 in the radial direction RD. One end of the connecting arm 430 is connected to the outer peripheral surface of the shaft connecting portion 420. The other end of the connecting arm 430 is connected to the magnet support portion 440.

[0035] The overall shape of the magnet support portion 440 is annular. The other ends of the multiple connecting arms 430 are connected to the inner circumferential surface of the magnet support portion 440. Multiple magnets 600 are provided on the outer circumferential surface of the magnet support portion 440. The multiple magnets 600 are fixed to the magnet support portion 440 with an adhesive or the like.

[0036] 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 may also be called a yoke.

[0037] The magnet 600 is a permanent magnet. A plurality of magnets 600 are arranged in the circumferential direction CD. The plurality of magnets 600 are connected by adhesive or the like. The plurality of magnets 600 constitute an extension magnet 700 that extends in the circumferential direction CD. The extension magnet 700 is annular in the circumferential direction CD. The extension magnet 700 is provided on the outer peripheral surface of the magnet support portion 440. The extension magnet 700 and the magnet support portion 440 are concentric.

[0038] <Magnetic Flux and Magnetic Path> When three-phase AC power is supplied to the stator coil 520, magnetic flux is generated from the stator 500. A magnetic path is determined by the magnetic flux emitted from the stator 500, the magnetic flux emitted from the extension magnets 700 of the rotor 400, and the housing 200 and other elements surrounding these.

[0039] The magnetic flux flows from the stator 500 toward the rotor 400, then turns back, and flows from the rotor 400 toward the stator 500. Explaining this with the subject reversed, the magnetic flux flows from the rotor 400 toward the stator 500, then turns back, and flows from the stator 500 toward the rotor 400. On the stator 500 side, the magnetic flux passes through the core teeth 540, the core support portion 530, etc. On the rotor 400 side, the magnetic flux passes through the extension magnets 700, the magnet support portion 440, etc.

[0040] <Magnet> The magnet 600 will be described in detail below. The magnet 600 includes a magnetic material and other materials. The magnet 600 is a sintered magnet, a bonded magnet, or the like. The magnet 600 corresponds to a motor magnet.

[0041] 2 and 3, the magnet 600 has six surfaces. The magnet 600 is arc-shaped and extends 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. They are arc-shaped curved surfaces. They are concentric. The inner surface 600a is shorter in the circumferential direction CD than the outer surface 600b. The radial separation distance between the inner surface 600a and the outer surface 600b in the radial direction RD is the same even if the measurement position is different in a direction perpendicular to the radial direction RD. However, the radial separation distance between the inner surface 600a and the outer surface 600b in the radial direction RD may be configured to gradually increase from the upper surface 600c or the lower surface 600d toward the axial center portion 600cd between the upper surface 600c and the lower surface 600d in the axial direction AD. When the magnet 600 is assembled in 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 perpendicular to the axial direction AD. The upper surface 600c and the lower surface 600d extend parallel to each other. The separation distance between the upper surface 600c and the lower surface 600d in the axial direction AD is the same even if the measurement position is different in the direction perpendicular to the axial direction AD. However, the separation distance between the upper surface 600c and the lower surface 600d in the axial direction AD may increase or decrease, for example, 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. An extension line of the first side surface 600e and an extension line of the second side surface 600f intersect at the motor axis MA. The separation distance between the first side surface 600e and the second side surface 600f in the circumferential direction CD increases with increasing distance from the motor axis MA in the radial direction RD. The first side surface 600e and the second side surface 600f are connected via an inner surface 600a, an outer surface 600b, an upper surface 600c, and a lower surface 600d.

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

[0046] In the drawing, a representative of the countless scattered orientations OR is indicated by a white arrow. There can be countless orientations OR contained in one magnet 600, but for convenience, only a certain number are shown in the drawing. In an actual magnet 600, there is a possibility that the distribution of orientations OR may be somewhat biased due to manufacturing errors, etc. However, in the drawing, the orientations OR are shown as being distributed as evenly as possible.

[0047] In this embodiment, the sizes of the multiple orientations OR scattered throughout one magnet 600 are all the same. The size of the orientations OR is also constant across multiple magnets 600. Therefore, in the drawings, the lengths of the arrows indicating the multiple orientations OR are made equal. However, the sizes of the orientations OR included in one magnet 600 may be different. The sizes of the orientations OR of multiple magnets 600 may be different.

[0048] Figure 4 shows three-dimensional polar coordinates for explaining the orientation OR. The circumferential direction CD is the circumferential direction. However, in Figure 4, the circumferential direction CD is shown as a straight line as a tangent direction to the intersection of the radial direction RD and the axial direction AD that pass through the measurement point of one orientation OR. In other drawings, when a representative radial direction RD is shown, the tangent direction to the circumferential direction perpendicular to it is shown as the circumferential direction CD.

[0049] The orientation OR can be decomposed into three orientation components: the radial direction RD, the circumferential direction CD, and the axial direction AD. The radial orientation component ORr is the orientation component in the radial direction RD. The circumferential orientation component ORc is the orientation component in the circumferential direction CD. The axial orientation component ORa is the orientation component in the axial direction AD. When these three types of orientation components are combined, they become the orientation OR. The size and direction (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 corresponds to the second orientation component, and the axial orientation component ORa corresponds to the third orientation component.

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

[0051] When the radial direction RD and the orientation OR intersect, they form two angles. The azimuthal angle φ is the smaller of the two angles. The azimuthal angle φ is less than or equal to 90°.

[0052] Similarly, when the axis direction AD and the orientation OR intersect, they form two angles. The elevation angle θ is the smaller of the two angles. The magnitude of the elevation angle θ is less than or equal to 90°.

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

[0054] If the magnitude of the orientation OR is A, the following relational expression holds: ORr = A sin θ cos φ, ORc = A sin θ sin φ, ORa = A cos θ. As described above, in this embodiment, the magnitude of all orientations OR is constant. Therefore, for example, when the magnitude of the circumferential orientation component ORc is constant, the axial orientation component ORa decreases as the radial orientation component ORr increases. Reversing the increase / decrease expression, the axial orientation component ORa increases as the radial orientation component ORr decreases.

[0055] 2 and 3, a first reference line LR1 is shown by a dashed line as a representative of an infinite number of radial directions RD, a second reference line LR2 is shown by a dashed line as a representative of an infinite number of circumferential directions CD, and a third reference line LR3 is shown by a dashed line as a representative of an infinite number of axial directions AD.

[0056] The first reference line LR1 passes through the motor axis MA. The first reference line LR1 is a normal to the inner surface 600a and the 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 a tangent to the first reference line LR1 at an intersection in the circumferential direction CD. The second reference line LR2 is spaced apart from the motor axis MA in the radial direction RD 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 apart from the motor axis MA in the radial direction RD 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 by the first reference line LR1 and the orientation OR. The elevation angle θ 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 by the third reference line LR3 and the orientation OR.

[0058] <Planar Orientation> As shown in Figure 5, the multiple orientations OR included in magnet 600 of this embodiment are parallel in a plane perpendicular to the axial direction AD. The multiple orientations OR are parallel. Therefore, when one of the multiple orientations OR included in magnet 600 is aligned with the radial direction RD, the other orientations OR are also aligned with the radial direction RD.

[0059] All of the orientations OR included in the magnet 600 of this embodiment have a radial orientation component ORr. If one of the countless possible first reference lines LR1 is taken as the only reference line, the orientations OR along that only reference line do not have a circumferential orientation component ORc. However, the other orientations OR do have a circumferential orientation component ORc.

[0060] <Axial Orientation> As shown in Figures 3 and 6 to 8, the orientations of the multiple orientations OR included in the magnet 600 of this embodiment change in the axial direction AD in a plane perpendicular to the circumferential direction CD. The orientations OR on the upper surface 600c side point from the upper surface 600c toward the axial center 600cd between the upper surface 600c and the lower surface 600d in the axial direction AD. The orientations OR on the lower surface 600d side point from the lower surface 600d toward the axial center 600cd.

[0061] The absolute value of the elevation angle θ of the orientation OR increases from the upper surface 600c toward the axial center 600cd. The absolute value of the elevation angle θ of the orientation OR increases from the lower surface 600d toward the axial center 600cd.

[0062] Therefore, the axial orientation component ORa is smaller on the axial center portion 600cd side than on the upper surface 600c side. The axial orientation component ORa gradually decreases from the upper surface 600c side toward the axial center portion 600cd side.

[0063] Similarly, the axial orientation component ORa is smaller on the axial center portion 600cd side than on the lower surface 600d side. The axial orientation component ORa gradually decreases from the lower surface 600d side toward the axial center portion 600cd side.

[0064] Conversely, the composite component obtained by combining the radially oriented component ORr and the circumferentially oriented component ORc gradually increases from the upper surface 600c toward the axial center portion 600cd. The composite component gradually increases from the lower surface 600d toward the axial center portion 600cd.

[0065] Specifically, the radial orientation component ORr gradually increases from the upper surface 600c toward the axial center 600cd. The radial orientation component ORr gradually increases from the lower surface 600d toward the axial center 600cd.

[0066] As described above, the multiple orientations OR are parallel in a plane perpendicular to the axial direction AD. Due to this configuration, when line VII-VII shown in Fig. 5 is taken as a reference line, the orientation OR shown in Fig. 7 does not have a circumferential orientation component ORc. In contrast, the orientations OR shown in Figs. 6 and 8 have a circumferential orientation component ORc.

[0067] 9, a portion of the magnet 600 is cut out and divided in half in the radial direction RD, and the orientations OR of the divided regions are indicated by white arrows. As shown in this figure, the angles of the orientations OR aligned in the radial direction RD are equal.

[0068] The multiple orientations OR are perpendicular to the axial direction AD and are symmetrical in the axial direction AD with respect to a symmetry plane that divides the motor 100 into two in the axial direction AD at the exact center position between the upper surface 600c and the lower surface 600d. This makes it less likely that a bias will occur in the distribution of the magnetic flux generated from the magnet 600 between the upper surface 600c side and the lower surface 600d side.

[0069] In this embodiment, the absolute value of the elevation angle θ of the orientation OR does not take a value of 0° or 90°. The radial orientation component ORr and the axial orientation component ORa are not zero. All of the multiple orientations OR included in the magnet 600 of this embodiment have a radial orientation component ORr and an axial orientation component ORa.

[0070] Due to the multiple orientations OR shown above, when the magnet 600 is incorporated into the motor 100 as the extension magnet 700, the magnetic flux passing through both the extension magnet 700 and the magnet support portion 440 decreases, and the magnetic flux passing only through the extension magnet 700 increases. In addition, the magnetic flux density increases on the axial center portion 600cd side of the magnet 600. This axial center portion 600cd faces the stator 500 in the radial direction RD.

[0071] In this embodiment, the axial center portion 600cd refers to the exact center position between the upper surface 600c and the lower surface 600d. The axial center portion 600cd and the magnetic center MC of the rotor 400 are located in the same position in the axial direction AD. However, the concept of the axial center portion 600cd is that it is located between the upper surface 600c and the lower surface 600d, and is not very close to the upper surface 600c or very close to the lower surface 600d in the axial direction AD. Therefore, the axial center portion 600cd may refer to just the exact center position between the upper surface 600c and the lower surface 600d, or it may not refer to just the center position itself.

[0072] The axial center portion 600cd may have a certain width in the axial direction AD. This width may be, for example, one to one-third of the length of the magnet 600 in the axial direction AD. When the axial center portion 600cd has a width in the axial direction AD, the axial center portion 600cd includes the exact center position between the upper surface 600c and the lower surface 600d. When the axial center portion 600cd has a width in this way, the range having that width may be expressed as the axial center portion 600cd side. Note that the radial center portion 600ab and the lateral center portion 600ef, which will be described later, may also be in a similar position or may have a similar width. These are indicated by dashed lines in the drawings.

[0073] Additionally, the upper surface 600c side and the lower surface 600d side may have a certain width in the axial direction AD. This width is, for example, one to one-third of several tens of tenths of the length of the magnet 600 in the axial direction AD. This also applies to the inner surface 600a side, the outer surface 600b side, the first side surface 600e side, and the second side surface 600f side.

[0074] <Orientation Components and Rotational Torque> As described above, all of the orientations OR included in the magnet 600 of this embodiment have a radial orientation component ORr and an axial orientation component ORa. Some of the orientations OR have a circumferential orientation component ORc.

[0075] The rotor 400 faces the stator 500 in the radial direction RD, and its rotation direction is the circumferential direction CD. In this configuration, the rotational torque applied to the rotor 400 depends on the radial orientation component ORr and the circumferential orientation component ORc. The circumferential orientation component ORc determines the ease of movement (motion characteristics) of the rotor 400 in a specific rotational direction. The axial orientation component ORa does not contribute to the generation of rotational torque. Furthermore, the magnets 600 provided on the rotor 400 are subject to demagnetization by the magnetic flux emitted from the stator 500, but it is the radial orientation component ORr that is most susceptible to this effect. The circumferential orientation component ORc and the axial orientation component ORa are less susceptible to demagnetization by the magnetic flux emitted from the stator 500.

[0076] To prevent the clockwise and counterclockwise motion characteristics from differing depending on the circumferentially oriented component ORc, the arithmetic mean of the absolute values ​​of the circumferentially oriented component ORc of the multiple orientations OR contained in one magnet 600 is smaller than the arithmetic mean of the absolute values ​​of the axially oriented component ORa. Expressed by switching the subject, the arithmetic mean of the absolute values ​​of the axially oriented component ORa is larger than the arithmetic mean of the absolute values ​​of the circumferentially oriented component ORc. Macroscopically, in short, in one magnet 600, the axially oriented component ORa is larger than the circumferentially oriented component ORc.

[0077] <Modifications of Orientation> The directions of the multiple orientations OR included in one magnet 600 are not limited to the configuration examples described so far.

[0078] For example, the multiple orientations OR may have a radial orientation component ORr and an axial orientation component ORa, but may not have a circumferential orientation component ORc. In such a configuration, the circumferential orientation component ORc becomes zero. Simply put, the axial orientation component ORa becomes larger than the circumferential orientation component ORc.

[0079] Furthermore, locally, the axial orientation component ORa may be smaller than the circumferential orientation component ORc. Locally, the axial orientation component ORa may be zero. In such a modified example, it is sufficient that the arithmetic mean of the absolute values ​​of the axial orientation components ORa of the multiple orientations OR is larger than the arithmetic mean of the absolute values ​​of the circumferential orientation components ORc.

[0080] Furthermore, as long as the radial orientation component ORr is included in the multiple orientations OR so that the rotational torque of the rotor 400 can be obtained, the radial orientation component ORr may be locally zero.

[0081] <Measurement of Orientation> The direction of the orientation OR described above can be measured by the following method. For example, the measurer takes out the magnet 600 included in the motor 100 as the measurement object. Then, the measurer measures the magnetic flux of the measurement object and identifies the magnetic path by magnetic circuit analysis. From this identification, the direction of the orientation OR can be estimated.

[0082] The measurer may measure the direction of the OR orientation 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. Electron backscatter diffraction can quantitatively evaluate the direction of the easy axis of magnetization (direction of easy magnetization). In other words, the direction of the OR orientation can be quantitatively evaluated. As described above, the direction of the OR orientation can be measured by identifying the magnetic path using magnetic circuit analysis and quantitatively evaluating the direction of the easy axis of magnetization using electron backscatter diffraction.

[0083] <Evaluation of the arithmetic mean> There are countless orientations OR in a single magnet 600. It is practically impossible to precisely measure all of these orientations OR and calculate the arithmetic mean of the absolute values ​​of the axial orientation component ORa and the arithmetic mean of the absolute values ​​of the circumferential orientation component ORc. Therefore, these arithmetic means are estimated using the following method.

[0084] One magnet 600 is divided into, for example, 10 parts in the circumferential direction CD. These parts are then further divided into 10 parts in the axial direction AD. In this way, the magnet 600 is divided into 100 pieces. The arithmetic mean of the absolute values ​​of the circumferential orientation component ORc and the axial orientation component ORa that appear on the divided surfaces is then calculated. By comparing the two, the magnitude relationship between the arithmetic mean of the absolute values ​​of the axial orientation component ORa and the arithmetic mean of the absolute values ​​of the circumferential orientation component ORc can be estimated.

[0085] Note that the number of divisions is merely an example. If a significant change is observed in the orientation component, the number of divisions may be increased, or if no significant change is observed, the number of divisions may be decreased. Furthermore, the division intervals may be equal or unequal. There are no particular limitations on the evaluation conditions, as long as the division intervals and number of divisions are suitable for evaluating the tendency of the orientation OR of one magnet 600.

[0086] <North Magnet and South Magnet> As described above, the rotor 400 equipped with the magnet 600 faces the stator 500. As shown in Figures 1 to 3, the magnet 600 includes a North magnet 600N and a South magnet 600S, whose orientations OR in the opposing direction of the rotor 400 and stator 500 are opposite. The orientation OR of the North magnet 600N faces the stator 500 and points away from the motor shaft MA. The orientation OR of the South magnet 600S faces away from the stator 500 and points towards the motor shaft MA.

[0087] <Magnet annular portion> As described above, the extension magnet 700 has a plurality of magnets 600 lined up in the circumferential direction CD. In this embodiment, the extension magnet 700 has ten magnets 600. The extension magnet 700 has five north magnets 600N and five south magnets 600S. Two adjacent magnets 600 in the circumferential direction CD are an north magnet 600N and an south magnet 600S. These north magnets 600N and south magnets 600S are lined up alternately one by one in the circumferential direction CD. The extension magnet 700 has ten magnetic poles.

[0088] Of the N magnet 600N and S magnet 600S that are adjacent to each other in 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 the first side surface 600e and the second side surface 600f. However, this adhesive is thin. Therefore, it can be said that the first side surface 600e and the second side surface 600f are substantially in contact in the circumferential direction CD.

[0089] Although not shown, the extension magnet 700 may include only one of the north magnets 600N and south magnets 600S. In such a configuration, the extension magnet 700 includes a soft magnetic material that functions as a pseudo pole in addition to one of the north magnets 600N and south magnets 600S. For example, if the extension magnet 700 includes multiple north magnets 600N, one soft magnetic material is provided between two north magnets 600N that are adjacent to each other in the circumferential direction CD. Expressed by switching the subject, one north magnet 600N is provided between two soft magnetic materials that are adjacent to each other in the circumferential direction CD. This soft magnetic material may be integrated with the magnet support portion 440 or may be a separate body.

[0090] The extended magnet 700 has an extended inner surface 700a and an extended outer surface 700b spaced apart in a radial direction RD, and an extended upper surface 700c and an extended lower surface 700d spaced apart in an axial direction AD. The extended inner surface 700a, the extended outer surface 700b, the extended upper surface 700c, and the extended lower surface 700d are annular.

[0091] The extended inner surface 700a is formed by the inner surfaces 600a of the multiple magnets 600 connected in the circumferential direction CD. The extended outer surface 700b is formed by the outer surfaces 600b of the multiple magnets 600 connected in the circumferential direction CD. The extended upper surface 700c is formed flush with the upper surfaces 600c of the multiple magnets 600. The extended lower surface 700d is formed flush with the lower surfaces 600d of the multiple magnets 600. Strictly speaking, the surface of the extended magnet 700 shown 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.

[0092] Both the extended inner surface 700a and the extended outer surface 700b are arc-shaped curved surfaces. They are concentric. The extended inner surface 700a has a shorter length in the circumferential direction CD than the extended outer surface 700b. The radial distance RD between the extended inner surface 700a and the extended outer surface 700b is the same even if the measurement position is different in the circumferential direction CD and the axial direction AD. However, it is also possible to adopt a configuration in which the radial distance RD between the extended inner surface 700a and the extended outer surface 700b gradually increases from the extended upper surface 700c or the extended lower surface 700d toward the center between the extended upper surface 700c and the extended lower surface 700d in the axial direction AD.

[0093] When the extended magnet 700 is assembled to the motor 100, the extended inner surface 700a is located on the rotor core 410 side, and the extended outer surface 700b is located on the stator 500 side. The axial center portions 600cd of the multiple outer surfaces 600b that make up the extended outer surface 700b face the stator 500 in the axial direction AD. In this embodiment, the entire surface of the extended outer surface 700b faces the stator 500 in the radial direction RD. The magnetic center MC of the extended outer surface 700b in the axial direction AD and the magnetic center MC of the stator 500 in the axial direction AD are aligned in the radial direction RD. MC stands for Magnetic Core.

[0094] 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 is different in the 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, for example, from the extended inner surface 700a side toward the extended outer surface 700b side in the radial direction RD.

[0095] The multiple magnets 600 that make up the extension magnet 700 extend in the axial direction AD. In this embodiment, the multiple magnets 600 are not aligned in the axial direction AD. However, a configuration in which the multiple magnets 600 are aligned in the axial direction AD may also be employed.

[0096] In this embodiment, the magnet 600 is the smallest component of the extension magnet 700. The extension magnet 700 is made up of a plurality of separate magnets 600. One magnet 600 constitutes one of the plurality of magnetic poles included in the extension magnet 700. However, this 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 or twice the size of the magnet 600. One magnetic pole of the extension magnet 700 may be made up of a plurality of magnets 600, or a plurality of magnetic poles may be made up of a single magnet 600.

[0097] The extended magnet 700 may not be manufactured by connecting multiple magnets 600, but may be manufactured from a single annular magnetic material. In such a configuration, the extended inner surface 700a is formed by the inner surface 600a of one magnet 600. The extended outer surface 700b is formed by the outer surface 600b of one magnet 600. The extended upper surface 700c is formed by the upper surface 600c of one magnet 600. The extended lower surface 700d is formed by the lower surface 600d of one magnet 600. The orientation OR of the multiple magnetic poles included in the extended magnet 700 is the same as the orientation OR of one magnet 600 described in this embodiment.

[0098] <Effects> The multiple orientations OR of the magnet 600 have an axial orientation component ORa. This reduces demagnetization of the magnet 600 compared to a configuration in which the orientations OR have only a radial orientation component ORr. Also, compared to a configuration in which the orientations OR have only a circumferential orientation component ORc as a demagnetization countermeasure, the motion characteristics (rotation characteristics) of the rotor 400 are less dependent on the orientations OR.

[0099] The multiple orientations OR have an axial orientation component ORa and a circumferential orientation component ORc. In this way, the axial orientation component ORa and the circumferential orientation component ORc are used to counteract demagnetization. Therefore, compared to a configuration in which the orientation OR has only the circumferential orientation component ORc as a countermeasure against demagnetization, the rotation characteristics of the rotor 400 are less dependent on the orientation OR. The orientation OR prevents the motor 100 from rotating more easily or less easily in a particular rotation direction. The orientation OR prevents the motor 100 from rotating more easily counterclockwise than clockwise, or more easily clockwise than counterclockwise.

[0100] The arithmetic mean of the absolute values ​​of the axial orientation components ORa of the multiple orientations OR is greater than the arithmetic mean of the absolute values ​​of the circumferential orientation components ORc. Thus, in magnet 600, the relationship between axial orientation components ORa and circumferential orientation components ORc is established to suppress demagnetization and suppress dependence of the rotation characteristics of rotor 400 on the orientation OR. Therefore, unlike a configuration in which magnet 600 simply has axial orientation component ORa without intending such a relationship, it is easy to design motor 100 that effectively achieves the two functional effects of suppressing demagnetization and suppressing dependence of rotation characteristics on the orientation OR.

[0101] All of the multiple orientations OR have an axial orientation component ORa. This prevents localized regions in magnet 600 from being demagnetized by the axial orientation component ORa. It also prevents localized regions in magnet 600 from being demagnetized.

[0102] The radial orientation component ORr is larger and the axial orientation component ORa is smaller on the axial center portion 600cd side between the upper surface 600c and the lower surface 600d than on the upper surface 600c or the lower surface 600d. This increases the density of the magnetic flux generated from the axial center portion 600cd side in the axial direction AD of the magnet 600. This improves torque characteristics such as starting torque, rated torque, and maximum torque.

[0103] In this way, in the case of a configuration that can increase the density of magnetic flux generated from the axial center portion 600cd side in the axial direction AD of the magnet 600, the length in the axial direction AD of the stator 500 may be shorter than the length in the axial direction AD of the magnet 600. In other words, the length in the axial direction AD of the stator 500 may be shorter than the length in the axial direction AD of the extension magnet 700.

[0104] With this configuration, it becomes easier to concentrate the magnetic flux generated from the extension magnets 700 on the stator 500. As a result, it is possible to effectively improve the torque characteristics.

[0105] The orientations OR are symmetrical with respect to the axial direction AD with respect to a plane of symmetry that is perpendicular to the axial direction AD and divides the center between the upper surface 600 c and the lower surface 600 d, thereby improving torque characteristics.

[0106] Second Embodiment In this embodiment, differences from the first embodiment will be mainly described. Hereinafter, other embodiments will also be described, focusing on differences from the previously described embodiment. Configurations, actions, and effects that are not particularly described in other embodiments are the same as those in the previously described embodiment.

[0107] In the first embodiment, an example was shown in which the separation distance between the inner surface 600 a and the outer surface 600 b in the radial direction RD is equivalent even if the measurement position is different in the circumferential direction CD and the axial direction AD. In contrast, in the present embodiment, the separation distance between the inner surface 600 a and the outer surface 600 b in the radial direction RD is equivalent even if the measurement position is different in the circumferential direction CD, but changes when the measurement position is different in the axial direction AD.

[0108] As shown in Figure 10, the radial distance RD between the inner surface 600a and the outer surface 600b gradually increases from the upper surface 600c toward the axial center 600cd. Similarly, the radial distance RD between the inner surface 600a and the outer surface 600b gradually increases from the lower surface 600d toward the axial center 600cd. Simply put, the thickness of the magnet 600 in the radial direction RD gradually increases from the end side toward the center side in the axial direction AD. As a result of this increase in thickness, the magnetic path is longer at the center side of the magnet 600 than at the end side.

[0109] Although the thickness in the radial direction RD changes in this way, the outer surface 600b that faces the stator 500 in the radial direction RD is perpendicular to the radial direction RD. Instead, the inner surface 600a is inclined with respect to the radial direction RD. A support recess 441 formed by a slope similar to the inclination of this inner surface 600a is formed in the magnet support portion 440.

[0110] In this embodiment, similarly to the first embodiment, the radial orientation component ORr increases and the axial orientation component ORa decreases from the upper surface 600c toward the axial center portion 600cd. Similarly, the radial orientation component ORr increases and the axial orientation component ORa decreases from the lower surface 600d toward the axial center portion 600cd.

[0111] Thus, in this embodiment, the smaller the axial orientation component ORa, the greater the radial thickness of magnet 600. In other words, the less the demagnetization countermeasures due to axial orientation component ORa, the greater the demagnetization countermeasures due to the increased radial thickness of magnet 600. The demagnetization countermeasures due to the extension of the magnetic path of magnet 600 are increased. Due to this configuration, demagnetization is suppressed locally in magnet 600.

[0112] In the present embodiment, the thickness of the magnet 600 in the radial direction RD gradually increases from the upper surface 600c or the lower surface 600d toward the axial center portion 600cd. However, the thickness of the magnet 600 in the radial direction RD is not limited to the above example.

[0113] The rate of change of the increase in thickness of magnet 600 in the radial direction RD may be gradual or intermittent. The rate of change of thickness in the radial direction RD is not particularly limited. The rate of increase in thickness and the rate of decrease in the axial orientation component ORa may behave in the same manner.

[0114] Note that the rate of increase in thickness and the rate of decrease in axially oriented component ORa being equal means that they are equal within the range of manufacturing tolerance. Furthermore, if there is a difference in the effectiveness of demagnetization suppression due to thickness and that due to axially oriented component ORa, a difference may be set between the rate of increase in thickness and the rate of decrease in axially oriented component ORa so that localized demagnetization in magnet 600 is suppressed.

[0115] Furthermore, as shown by the length of the white arrows in Figure 10, as the thickness of magnet 600 in the radial direction RD increases, the axial orientation component ORa becomes smaller than the radial orientation component ORr, and the magnitude of the orientation OR itself may increase.

[0116] Third Embodiment In the second embodiment, an example was shown in which a countermeasure against demagnetization was taken by adjusting the thickness of the magnet 600. In contrast to this, in this embodiment, a countermeasure against demagnetization is taken by adjusting the coercive force of the magnet 600.

[0117] 11 and 12, the magnet 600 has a plurality of magnet pieces 610. In this embodiment, the magnet pieces 610 include a first magnet piece 611, a second magnet piece 612, and a third magnet piece 613. These are arranged in order in the axial direction AD.

[0118] The first magnet piece 611 constitutes the upper surface 600c side of the magnet 600. The second magnet piece 612 constitutes the axial center portion 600cd side of the magnet 600. The third magnet piece 613 constitutes the lower surface 600d side of the magnet 600. In this way, the first magnet piece 611 and the third magnet piece 613 constitute the end sides of the magnet 600 in the axial direction AD. The second magnet piece 612 constitutes the center side of the magnet 600 in the axial direction AD.

[0119] The first magnet piece 611 and the third magnet piece 613 are made of the same material. Therefore, their coercive forces are the same. In contrast, the second magnet piece 612 is made of a different material from the first magnet piece 611 and the third magnet piece 613. In this way, the magnet 600 is made up of multiple types of magnet pieces 610 that are different in terms of material.

[0120] The second magnet piece 612 has a higher coercive force than the first magnet piece 611 and the third magnet piece 613. On the other hand, the axial orientation component ORa of the second magnet piece 612 is smaller than the axial orientation components ORa of the first magnet piece 611 and the third magnet piece 613. In this way, the axial orientation component ORa becomes smaller as the coercive force of the magnet piece 610 becomes higher.

[0121] Therefore, the coercive force of the magnet 600 changes in the axial direction AD. Examples of such changes in coercive force are shown in Figures 13 and 14. In this embodiment, the magnet 600 is composed of three magnet pieces 610. Therefore, the coercive force does not change smoothly as shown in Figures 13 and 14. CF in the figures stands for Coercive Force.

[0122] As described above, in this embodiment, the smaller the axial orientation component ORa, the higher the coercivity of the magnet piece 610. In other words, the less the demagnetization countermeasure due to the axial orientation component ORa, the greater the demagnetization countermeasure due to the high coercivity of the magnet piece 610. This configuration suppresses localized demagnetization in the magnet 600.

[0123] In this embodiment, the magnet 600 is configured with three magnet segments 610. However, the number of magnet segments 610 constituting the magnet 600 may be any number as long as it is plural. The number of magnet segments 610 may be two, four or more.

[0124] Two types of magnet pieces 610 are shown. However, the types of magnet pieces 610 are not limited to the above example. There may be three or more types of magnet pieces 610.

[0125] Furthermore, the rate of change in the increase in coercivity due to the combination of magnet pieces 610 with different coercive forces is not particularly limited. Within the range of manufacturing error, the rate of increase in coercivity and the rate of decrease in the axial orientation component ORa may behave in the same manner.

[0126] If there is a difference in effectiveness between the suppression of demagnetization by coercive force and the suppression of demagnetization by the axial orientation component ORa, a difference may be set between the rate of increase in coercive force and the rate of decrease in axial orientation component ORa so as to suppress localized demagnetization in magnet 600. Furthermore, by combining the configurations shown in the second embodiment, measures against demagnetization may be taken by adjusting the thickness of magnet 600, adjusting the coercive force, and adjusting the axial orientation component ORa.

[0127] <Fourth Embodiment> In this embodiment, as shown in Figures 15 and 16, the multiple orientations OR are radially oriented in a plane perpendicular to the axial direction AD. That is, the multiple orientations OR included in the magnet 600 are aligned along the radial direction RD that passes through the orientations OR. In this configuration, the circumferential orientation component ORc of the multiple orientations OR is zero. Therefore, dependence of the rotation characteristics of the rotor 400 on the orientations OR is effectively suppressed. Note that in this configuration, the orientations OR are the same in all of the cross-sectional views taken along three lines XVII-XVII in different locations in the circumferential direction CD, as shown by the dashed dotted lines in Figure 16, as shown in Figure 17.

[0128] Fifth Embodiment In this embodiment, as shown in Figures 18 to 20, the multiple orientations OR are polar anisotropically oriented in a plane perpendicular to the axial direction AD. As shown in Figure 21, from the first side surface 600e toward the side center portion 600ef between the first side surface 600e and the second side surface 600f in the circumferential direction CD, the radial orientation component ORr increases and the circumferential orientation component ORc decreases. Similarly, from the second side surface 600f toward the side center portion 600ef, the radial orientation component ORr increases and the circumferential orientation component ORc decreases. This lengthens the magnetic path within the magnet 600. This makes it easier to suppress demagnetization.

[0129] In this embodiment, the orientations OR have the same elevation angle θ for all of the orientations OR, as shown in Figure 20. However, as described above, the orientation is polar anisotropic in a plane perpendicular to the axial direction AD. Therefore, the orientation of the OR that appears in a cross section cut along a line along the radial direction RD, which differs in the circumferential direction CD, changes as shown in Figures 22 to 24. The azimuth angle φ of the orientations OR changes.

[0130] In this embodiment, the elevation angles θ of the multiple orientations OR are the same. However, even if they are manufactured with the intention of being identical, they are not actually strictly identical due to manufacturing errors, etc. In this specification, "identical" means equal within the range of such manufacturing errors, etc.

[0131] As shown in Figure 20, when the elevation angle θ is finite but constant, the magnetic field emitted from the magnet 600 varies between the upper surface 600c and the lower surface 600d of the magnet 600. As a result, the structural center SC and magnetic center MC of the rotor 400 are misaligned in the axial direction AD. Therefore, the rotor 400 may be moved along the axial direction AD so that the magnetic center MC of the rotor 400 and the magnetic center MC of the stator 500 are aligned in the radial direction RD. SC stands for Structure Center.

[0132] 20 , the magnetic center MC of the rotor 400 moves from the structural center SC toward the top surface 600c. Therefore, the stator 500 may be fixed in position and the rotor 400 may be moved in the axial direction AD from the top surface 600c toward the bottom surface 600d, so that the magnetic center MC of the rotor 400 and the magnetic center MC of the stator 500 are aligned in the radial direction RD. In this configuration, space is created directly above the top surface 600c of the rotor 400 in the axial direction AD. This space can be effectively utilized.

[0133] As shown in FIG. 25 , tapers 600g may be provided on the upper surface 600c and the lower surface 600d of the magnet 600. The upper surface 600c and the lower surface 600d are inclined due to the taper 600g. The shape of a plane perpendicular to the circumferential direction CD of the magnet 600 is a parallelogram. The volume of the magnet 600 on the lower surface 600d side is reduced, while the volume of the magnet 600 on the upper surface 600c side is increased. In FIG. 25 , the areas where this volume increase or decrease occurs are indicated by dashed lines and labeled with the symbol for the taper 600g. The magnet support portion 440 is located in the projection area of ​​the lower surface 600d in the radial direction RD, but the magnet support portion 440 is no longer located in the projection area of ​​the upper surface 600c in the radial direction RD.

[0134] In this configuration, the stator 500, shown simply in Figure 25, and the outer surface 600b of the magnet 600 are arranged opposite each other in the radial direction RD. The magnetic center MC of the rotor 400 and the magnetic center MC of the stator 500 are aligned in the radial direction RD. With this configuration, the area of ​​the magnet 600 that does not contribute to torque is reduced.

[0135] 26 , in this embodiment, the absolute value of the elevation angle θ of the orientation OR increases from the upper surface 600c side or the lower surface 600d side toward the axial center portion 600cd side, and the absolute value of the elevation angle θ is 90° on the axial center portion 600cd side. The axial orientation components ORa of the multiple orientations OR on the axial center portion 600cd side are zero.

[0136] Seventh Embodiment In this embodiment, as shown in Figure 27, the orientation OR is polar anisotropic in a plane perpendicular to the circumferential direction CD. In the axial direction AD, the radial orientation component ORr increases and the axial orientation component ORa decreases from the upper surface 600c side toward the axial center portion 600cd side. Similarly, in the axial direction AD, the radial orientation component ORr increases and the axial orientation component ORa decreases from the lower surface 600d side toward the axial center portion 600cd side. This lengthens the magnetic path within the magnet 600. This makes it easier to suppress demagnetization.

[0137] Although it is not necessary to illustrate this, in this embodiment, as shown in FIG. 28, a configuration can also be adopted in which the orientation OR is polar anisotropic in a plane perpendicular to the axial direction AD.

[0138] Eighth Embodiment In this embodiment, as shown in Fig. 29 , the rotor 400 has a support portion 450 instead of the 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 functions to connect the extension magnet 700 to the shaft 300. Note that the configuration of the orientation OR is not particularly limited in this embodiment, and therefore the orientation OR is not shown in Fig. 29 .

[0139] Ninth Embodiment In the first embodiment, an example was shown in which the motor 100 was an inner rotor type radial motor. In contrast, in this embodiment, as shown in Figure 30, the motor 100 is an outer rotor type radial motor. Note that the configuration of this embodiment is not particularly limited to the configuration of the orientation OR, so the orientation OR is not shown in Figure 30. Furthermore, the housing 200 and the shaft 300 are not shown.

[0140] 30, the stator 500 is located closer to the center of the motor 100 than the rotor 400. The rotor 400 is farther away from the motor axis MA in the radial direction RD than the stator 500.

[0141] The rotor 400 has an annular overall shape. A plurality of magnets 600 are provided on the inner circumferential surface of the magnet support portion 440. An annular extension magnet 700 is configured. The motor shaft MA passes through a space surrounded by the extension magnets 700. The stator 500 is provided in this space. The rotor 400 is aligned with the stator 500 in the radial direction RD via a radial gap.

[0142] The core support portion 530 is annular. The core teeth 540 are connected to the outer peripheral surface of the core support portion 530. The core teeth 540 extend in the radial direction RD from the outer peripheral surface of the core support portion 530 toward the rotor 400. The multiple core teeth 540 are aligned in the circumferential direction CD. The stator coil 520 is wound around these multiple core teeth 540.

[0143] Tenth Embodiment In the first embodiment, an example was shown in which the stator 500 is an exciter and the rotor 400 is a field element. In contrast, in this embodiment, the rotor 400 is an exciter and the stator 500 is a field element. As shown in FIGS. 31 and 32 , the stator 500, not the rotor 400, has a magnet 600. The rotor 400 has a rotor coil 470 instead of the magnet 600. Note that, since the configuration of the OR orientation is not particularly limited in this embodiment, the OR orientation is omitted from FIG. 31 . However, in order to show the magnetic flux formed on the stator 500 side, the OR orientation is illustrated in FIG. 32 . Furthermore, the housing 200 is omitted from the illustration.

[0144] 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. A plurality of magnets 600 are provided on the inner circumferential surface of the core support portion 530. The core support portion 530 performs the same function in forming a magnetic path as the magnet support portion 440 described in the first embodiment.

[0145] A ring-shaped extension magnet 700 is formed by a plurality of magnets 600. The rotor 400 is provided in the space surrounded by this extension magnet 700.

[0146] The rotor core 410 has a shaft connecting portion 420 and rotor teeth 460. The shaft connecting portion 420 is annular. The rotor teeth 460 are connected to the outer peripheral surface of the shaft connecting portion 420. The rotor teeth 460 extend from the shaft connecting portion 420 toward the stator 500. The motor axis MA is located on an extension of the rotor teeth 460 in the radial direction RD. The rotor teeth 460 are aligned in the circumferential direction CD. A rotor coil 470 is wound around the rotor teeth 460. When current is applied to the rotor coil 470, the rotor 400 is excited. In FIG. 32 , the boundary between the shaft connecting portion 420 and the rotor teeth 460 is indicated by a dashed line.

[0147] 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 eighth embodiment.

[0148] Eleventh Embodiment In the previous embodiments, examples were shown in which the motor 100 was 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 corresponds to the second direction, and the axial direction AD corresponds to the first direction. The radial orientation component ORr corresponds to the third orientation component, the circumferential orientation component ORc corresponds to the second orientation component, and the axial orientation component ORa corresponds to the first orientation component.

[0149] The major difference between a radial motor and an axial motor is the opposing direction of the rotor 400 and the stator 500. In a radial motor, the rotor 400 and the stator 500 face each other in the radial direction RD. In contrast, in an axial motor, as shown in Figures 33 and 34, the rotor 400 and the stator 500 face each other in the axial direction AD. Note that Figures 33 and 34 are diagrams for explaining the arrangement of the main parts of the rotor 400 and the stator 500 in an axial motor. For this reason, some of the components of the axial motor are not shown in Figures 33 and 34.

[0150] Because of these significant differences, when the configuration of the radial motor described above is applied to the configuration of the axial motor of this embodiment, the characteristics of the radial direction RD in the radial motor are converted into the characteristics of the axial direction AD in the axial motor, and the characteristics of the axial direction AD in the radial motor are converted into the characteristics of the radial direction RD in the axial motor.

[0151] Specifically, the characteristics of the radial orientation component ORr of a radial motor are transferred 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 are transferred to the characteristics of the radial orientation component ORr of an axial motor. However, the characteristics of the circumferential orientation component ORc are equivalent in both radial and axial motors. The configuration of the motor 100 of this embodiment will now be outlined.

[0152] As shown in FIG. 35 , the housing 200 has a bottom plate 210 and a side wall 220. The bottom plate 210 has 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 that are aligned in the axial direction AD. A side wall 220 stands upright from the inner bottom surface. The side wall 220 is annular so as to surround the entire inner bottom surface of the bottom plate 210. A portion of the shaft 300, the rotor 400, and the stator 500 are housed in the space surrounded by the bottom plate 210 and the side wall 220. Inside the 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 that penetrates from the inner bottom surface to the outer bottom surface in the axial direction AD. The shaft 300 passes through the hole in the bottom plate 210.

[0153] The overall shape of the core support portion 530 of the stator core 510 is a disk shape. The core support portion 530 closes the opening of the housing 200 defined by the tip end side of the annular side wall 220.

[0154] The core support portion 530 has two main surfaces, a first main surface and a second main surface, which are aligned in the axial direction AD. A hole is formed in the core support portion 530, penetrating the first main surface and the second main surface 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.

[0155] The core teeth 540 extend in the axial direction AD from the core support portion 530 toward the bottom plate 210. The multiple core teeth 540 are arranged in the circumferential direction CD so as to surround a hole formed in the core support portion 530. The stator coil 520 is wound around the multiple core teeth 540.

[0156] The overall shape of the shaft connecting portion 420 of the rotor core 410 is a disk shape. The shaft connecting portion 420 has a support surface and a back surface that are aligned in the axial direction AD. A hole is formed in the shaft connecting portion 420, penetrating the support surface and the 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.

[0157] When the rotor 400 is 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. A plurality of magnets 600 are provided on this support surface. The shaft connecting portion 420 of this embodiment also functions to support the magnets 600.

[0158] The multiple magnets 600 are arranged in an annular shape in the circumferential direction CD so as to surround a hole formed in the shaft connecting portion 420. This forms an annular extension magnet 700. An extended upper surface 700c of this extension magnet 700 is located closer to the support surface of the shaft connecting portion 420 than an 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 arranged in the axial direction AD.

[0159] 35, the multiple orientations OR included in one magnet 600 of this embodiment are parallel to each other in a plane perpendicular to the circumferential direction CD.

[0160] In this embodiment, the rotor 400 has four magnets 600 of equal size. The N magnets 600N and S magnets 600S are alternately arranged in the circumferential direction CD. Therefore, as shown in FIG. 35 , magnets 600 of 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. Note that depending on the number of magnets 600 the rotor 400 has, magnets 600 of opposite polarity may be arranged in the radial direction RD. For example, if the rotor 400 has 10 magnets 600, the N magnets 600N and S magnets 600S will be arranged in the radial direction RD.

[0161] 35, the elevation angle θ of the orientation OR of the multiple magnets 600 aligned in the circumferential direction CD is dyad-symmetric with respect to the shaft 300. In other words, the elevation angle θ of the orientation OR of the extension magnet 700 is dyad-symmetric with respect to the shaft 300.

[0162] All of the orientations OR included in one magnet 600 have an axial orientation component ORa and a radial orientation component ORr, but do not have a circumferential orientation component ORc. In this embodiment, the elevation angles θ and azimuth angles φ of all of the orientations OR are equal.

[0163] The above-described configuration suppresses demagnetization of magnet 600 compared to a configuration in which the orientation OR has only axial orientation component ORa. Also, compared to a configuration in which the orientation OR has circumferential orientation component ORc as a demagnetization countermeasure, dependence of the rotation characteristics of rotor 400 on the orientation OR is suppressed. Because all of the multiple orientations OR have radial orientation component ORr, the occurrence of localized regions in magnet 600 where demagnetization suppression by radial orientation component ORr is not achieved is suppressed.

[0164] As explained in detail in the first embodiment, the orientation OR can also be changed in various ways in the axial motor of this embodiment.

[0165] For example, all of the multiple orientations OR may have not only an axial orientation component ORa and a radial orientation component ORr, but also a circumferential orientation component ORc. Furthermore, locally, the radial orientation component ORr may be smaller than the circumferential orientation component ORc. Locally, the radial orientation component ORr may be zero. In such a modified example, it is sufficient that the arithmetic mean of the absolute values ​​of the radial orientation components ORr of the multiple orientations OR is greater than the arithmetic mean of the absolute values ​​of the circumferential orientation components ORc.

[0166] In this modified example, the radial orientation component ORr and the circumferential orientation component ORc are used to counteract demagnetization, which reduces the dependence of the rotation characteristics of the rotor 400 on the orientation OR compared to a configuration in which the orientation OR has only the circumferential orientation component ORc as a countermeasure against demagnetization.

[0167] The arithmetic mean of the absolute values ​​of the radial orientation components ORr of the multiple orientations OR is greater than the arithmetic mean of the absolute values ​​of the circumferential orientation components ORc. Thus, in magnet 600, the relationship between radial orientation components ORr and circumferential orientation components ORc is established to suppress demagnetization and suppress dependence of the rotation characteristics of rotor 400 on orientation OR. Therefore, unlike a configuration in which magnet 600 simply has radial orientation component ORr without intending such a relationship, it becomes easier to design motor 100 that effectively achieves the two functional effects of suppressing demagnetization and suppressing dependence of rotation characteristics on orientation OR.

[0168] As a further example of a modified example, as long as the axial orientation component ORa is included in a plurality of orientations OR so that the rotational torque of the rotor 400 can be obtained, the axial orientation component ORa may be locally zero.

[0169] The orientation OR of one magnet 600 in a plane perpendicular to the circumferential direction CD may be parallel or axial. The absolute value of the elevation angle θ of the orientation OR may increase or decrease as one moves from the inner surface 600a toward the radial center portion 600ab between the inner surface 600a and the outer surface 600b. The absolute value of the elevation angle θ of the orientation OR may increase or decrease as one moves from the outer surface 600b toward the radial center portion 600ab. The orientation OR may be polar anisotropic in either the plane perpendicular to the axial direction AD or the plane perpendicular to the circumferential direction CD.

[0170] 36 shows a simplified polar anisotropic orientation in a plane perpendicular to the circumferential direction CD. In this configuration, the polar anisotropic orientation of two regions aligned in the radial direction RD is symmetrical with respect to the boundary dividing the two regions in the radial direction RD.

[0171] The axial motor may be provided with a plurality of at least one of the rotors 400 and the stators 500. For example, the motor 100 may have two rotors 400. A stator 500 may be provided between the two rotors 400. Such a configuration may also be called a double-rotor motor. The motor 100 may also have two stators 500. A rotor 400 may be provided between the two stators 500. Such a configuration may also be called a double-stator motor. In this way, when the axial motor is provided with a plurality of at least one of the rotors 400 and the stators 500, the rotational torque can be improved.

[0172] In the present embodiment, an example has been shown in which the stator 500 is an exciter and the rotor 400 is a field element in the axial motor. However, although not particularly shown, the axial motor may also employ a configuration in which the rotor 400 is an exciter and the stator 500 is a field element.

[0173] Twelfth Embodiment In the tenth embodiment, an example was shown in which the separation distance in the axial direction AD between the upper surface 600 c and the lower surface 600 d is equivalent even if the measurement position is different in the circumferential direction CD and the radial direction RD, as shown in Fig. 35. In contrast to this, in the present embodiment, as shown in Fig. 37, the separation distance in the axial direction AD between the upper surface 600 c and the lower surface 600 d is equivalent even if the measurement position is different in the circumferential direction CD, but changes when the measurement position is different in the radial direction RD.

[0174] The distance between the upper surface 600c and the lower surface 600d in the axial direction AD gradually increases from the inner surface 600a toward the radial center portion 600ab. Similarly, the distance between the upper surface 600c and the lower surface 600d in the axial direction AD gradually increases from the outer surface 600b toward the radial center portion 600ab. Simply put, the thickness of the magnet 600 in the axial direction AD gradually increases from the end portion toward the center portion in the radial direction RD.

[0175] Although the thickness in the axial direction AD changes in this manner, the lower surface 600d that faces the stator 500 in the axial direction AD is perpendicular to the axial direction AD. Instead, the upper surface 600c is inclined with respect to the axial direction AD. A recess 421 formed by a slope similar to the inclination of the upper surface 600c is formed in the shaft coupling portion 420.

[0176] In this embodiment, the axial orientation component ORa increases and the radial orientation component ORr decreases from the inner surface 600a toward the radial center portion 600ab. Similarly, the axial orientation component ORa increases and the radial orientation component ORr decreases from the outer surface 600b toward the radial center portion 600ab. The orientations OR are symmetrical in the radial direction RD with respect to a symmetry plane that is perpendicular to the radial direction RD and divides the center between the inner surface 600a and the outer surface 600b in the radial direction RD.

[0177] Thus, in this embodiment, the smaller the radial orientation component ORr, the greater the thickness of the axial direction AD of the magnet 600. In other words, the less the demagnetization countermeasures due to the radial orientation component ORr, the greater the demagnetization countermeasures due to the increased thickness of the axial direction AD of the magnet 600. Therefore, localized demagnetization of the magnet 600 is suppressed.

[0178] In this embodiment, the thickness in the axial direction AD of the magnet 600 gradually increases from the inner surface 600 a or the outer surface 600 b toward the radial center portion 600 a b. However, the thickness of the magnet 600 in the axial direction AD is not limited to the above example.

[0179] The rate of change of the increase in thickness of magnet 600 in the axial direction AD may be gradual or intermittent. The rate of change of thickness in the axial direction AD is not particularly limited. The rate of increase in thickness and the rate of decrease in radial orientation component ORr may behave similarly within the range of manufacturing tolerance.

[0180] Furthermore, if there is a difference in the effectiveness of demagnetization suppression due to thickness and that due to the radial orientation component ORr, a difference may be set between the rate of increase in thickness and the rate of decrease in the radial orientation component ORr so that localized demagnetization in the magnet 600 is suppressed.

[0181] Thirteenth Embodiment In this embodiment, similar to the third embodiment, a countermeasure against demagnetization is taken by adjusting the coercive force of the magnet 600.

[0182] As shown in Figure 38, the first magnet piece 611, second magnet piece 612, and third magnet piece 613 that make up the magnet 600 are arranged in this order in the radial direction RD. The first magnet piece 611 makes up the inner surface 600a side of the magnet 600. The second magnet piece 612 makes up the radial center portion 600ab side of the magnet 600. The third magnet piece 613 makes up the outer surface 600b side of the magnet 600. The first magnet piece 611 and the third magnet piece 613 make up the end sides of the magnet 600 in the radial direction RD. The second magnet piece 612 makes up the center side of the magnet 600 in the radial direction RD.

[0183] The second magnet piece 612 has a higher coercivity than the first magnet piece 611 and the third magnet piece 613. Conversely, the radial orientation component ORr of the second magnet piece 612 is smaller than the radial orientation component ORr of the first magnet piece 611 and the third magnet piece 613. In this way, the higher the coercivity of the magnet piece 610, the smaller the radial orientation component ORr. As the demagnetization countermeasure by the radial orientation component ORr decreases, the demagnetization countermeasure by the high coercivity of the magnet piece 610 increases.

[0184] Furthermore, within the range of manufacturing error, the rate of increase in coercivity and the rate of decrease in radial orientation component ORr may behave similarly. If there is a difference in the effectiveness of demagnetization suppression due to high coercivity and that due to radial orientation component ORr, a difference may be set between the rate of increase in coercivity and the rate of decrease in radial orientation component ORr so as to suppress localized demagnetization in magnet 600. Furthermore, measures against demagnetization may be taken by adjusting the thickness and coercivity of magnet 600, and adjusting the radial orientation component ORr.

[0185] Fourteenth Embodiment In the embodiments described so far, examples have been shown in which the motor 100 performs rotational motion. In contrast, the motor 100 of this embodiment is a linear motor that performs linear motion.

[0186] In the following, in order to explain this embodiment, a new lateral direction LD is defined in addition to the radial direction RD, the circumferential direction CD, and the axial direction AD. LD stands for Lateral Direction. The lateral direction LD is a linear direction that is perpendicular to the radial direction RD and the axial direction AD.

[0187] The orientation OR can be decomposed into three components by using the newly defined transverse direction LD instead of the circumferential direction CD. As shown in Figure 4, the orientation OR can be decomposed into a radial orientation component ORr, an axial orientation component ORa, and a transverse orientation component ORl along the transverse direction LD.

[0188] The radial direction RD corresponds to the first direction, the axial direction AD corresponds to the second direction, and the lateral direction LD corresponds to the third direction. The radial orientation component ORr corresponds to the first orientation component, the axial orientation component ORa corresponds to the second orientation component, and the lateral orientation component ORl corresponds to the third orientation component.

[0189] The major difference between a radial motor and a linear motor is the movement of the rotor 400. In a radial motor, the rotor 400 rotates in a circumferential direction CD, whereas in a linear motor, the rotor 400 moves linearly in an axial direction AD.

[0190] Because of this large difference, when the configuration of a radial motor is applied to the configuration of the linear motor of this embodiment, the characteristics of the radial motor in the circumferential direction CD are converted into the characteristics of the linear motor in the axial direction AD.

[0191] Specifically, the characteristics of the circumferential orientation component ORc of a radial motor are transferred 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 transferred to the characteristics of the lateral orientation component ORl of a linear motor. However, the characteristics of the radial orientation component ORr are equivalent in both radial and linear motors. The configuration of the motor 100 of this embodiment will now be outlined.

[0192] As shown in Figure 39, the rotor 400 and the stator 500 are aligned in the radial direction RD with a radial gap between them. The motor 100 has a linear motion axis 800 instead of the shaft 300. The rotor 400 is connected to this linear motion axis 800. The linear motion axis 800 is movable in the axial direction 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 the stator 500 are aligned. Therefore, the radial direction RD can also be referred to as the alignment direction.

[0193] The linear motion shaft 800 is flat in a direction perpendicular to the radial direction RD. The extension direction of the linear motion shaft 800 is the axial direction AD. The axial width direction of the linear motion shaft 800 is the lateral direction LD. The linear motion shaft 800 is longer in the lateral direction LD than in the radial direction RD.

[0194] 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 the core support portion 530 extending in the axial direction AD. The core teeth 540 extend in the radial direction RD. A plurality of core teeth 540 are aligned in the axial direction AD. A stator coil 520 is wound around the plurality of core teeth 540.

[0195] The shaft connecting portion 420 of the rotor core 410 extends in the axial direction AD. A plurality of magnets 600 are provided on one surface of the shaft connecting portion 420 extending in the axial direction AD. The back side of the magnets 600 is connected to the linear motion shaft 800. The shaft connecting portion 420 is configured to also function as a support portion 450. The plurality of magnets 600 and the core teeth 540 are aligned in the radial direction RD with a radial gap interposed therebetween.

[0196] It is also possible to employ a configuration in which the rotor core 410 is not provided, and multiple magnets 600 are mounted on the linear motion shaft 800. In such a modified example, the linear motion shaft 800 functions to form a magnetic path in the same manner as the rotor core 410.

[0197] The magnets 600 are not arc-shaped but rectangular parallelepiped-shaped. The magnets 600 are arranged in a straight line along the axial direction AD. Of two magnets 600 arranged in the axial direction AD, the top surface 600c of one magnet and the bottom surface 600d of the other magnet are adjacent to each other in the axial direction AD.

[0198] In this embodiment, the extension magnet 700 is configured by connecting multiple magnets 600 in a linear fashion. The extension magnet 700 is linear. Note that in the extension magnet 700, two adjacent magnets 600 in the axial direction AD may be spaced apart in the axial direction AD. There may be a gap between the two magnets 600. Therefore, the surface of the extension magnet 700 may be configured by the surfaces of multiple magnets 600 arranged at intervals.

[0199] As shown in Figures 39 and 40, all of the multiple orientations OR included in one magnet 600 are inclined in the radial direction RD, axial direction AD, and lateral direction LD. All of the multiple orientations OR have a radial orientation component ORr, an axial orientation component ORa, and a lateral orientation component ORl. However, the arithmetic mean of the absolute values ​​of the lateral orientation components ORl of the multiple orientations OR is greater than the arithmetic mean of the absolute values ​​of the axial orientation component ORa. In this embodiment, the elevation angles θ and azimuth angles φ of all of the multiple orientations OR are equal.

[0200] The above-described configuration suppresses demagnetization of magnet 600 compared to a configuration in which orientation OR has only radial orientation component ORr. Also, compared to a configuration in which orientation OR has only axial orientation component ORa as a demagnetization countermeasure, dependence of the motion characteristics (linear motion characteristics) of rotor 400 on orientation OR is suppressed.

[0201] Countermeasures against demagnetization are taken with the transverse orientation component ORl and the axial orientation component ORa. Therefore, compared to a configuration in which the orientation OR has only the axial orientation component ORa as a countermeasure against demagnetization, the linear motion characteristics of the rotor 400 are less dependent on the orientation OR. The orientation OR prevents the rotor 400 from easily or difficultly moving linearly in a specific direction.

[0202] The arithmetic mean of the absolute values ​​of the transverse orientation components ORl of the multiple orientations OR is greater than the arithmetic mean of the absolute values ​​of the axial orientation components ORa. Thus, in magnet 600, the relationship between transverse orientation component ORl and axial orientation component ORa is established to suppress demagnetization and suppress dependence of the linear motion characteristics of rotor 400 on orientation OR. Therefore, unlike a configuration in which magnet 600 simply has transverse orientation component ORl without intending such a relationship, it is easy to design motor 100 that effectively achieves the two functional effects of suppressing demagnetization and suppressing dependence of linear motion characteristics on orientation OR.

[0203] As explained in detail with respect to the radial motor and axial motor in the above embodiments, the orientation OR can also be changed in various ways in the linear motor of this embodiment.

[0204] For example, the multiple orientations OR may have a radial orientation component ORr and a transverse orientation component ORl, but may not have an axial orientation component ORa. In such a configuration, the axial orientation component ORa becomes zero. Simply put, the transverse orientation component ORl is greater than the axial orientation component ORa.

[0205] Furthermore, the horizontal alignment component ORl may be locally smaller than the axial alignment component ORa. The horizontal alignment component ORl may be locally zero. In such a modified example, it is sufficient that the arithmetic mean of the absolute values ​​of the horizontal alignment components ORl of the multiple alignments OR is larger than the arithmetic mean of the absolute values ​​of the axial alignment components ORa.

[0206] Furthermore, as long as the radial orientation component ORr is included in the multiple orientations OR so that a driving force for the linear motion of the rotor 400 can be obtained, the radial orientation component ORr may be locally zero.

[0207] The orientation OR of one magnet 600 in a plane perpendicular to the axial direction AD and in a plane perpendicular to the lateral direction LD may be parallel, axial, or polar anisotropic. In any case, the absolute value of the angle of the orientation OR may increase or decrease from the end toward the center.

[0208] Also, an example has been shown in which the rotor 400 and the stator 500 extend in the axial direction AD. In such a configuration, the rotor 400 and the stator 500 may further extend in the circumferential direction CD around the axial direction AD, thereby forming the motor 100 into a cylindrical shape. In such a configuration, the rotor 400 is provided in a space surrounded by the stator 500. The rotor 400 moves in the axial direction AD within the space surrounded by the stator 500.

[0209] In the present embodiment, an example has been shown in which the stator 500 is an exciter and the rotor 400 is a field element in the linear motor. However, although not particularly shown, the linear motor may also employ a configuration in which the rotor 400 is an exciter and the stator 500 is a field element.

[0210] Fifteenth Embodiment As explained in the second and twelfth embodiments, it is possible to take both demagnetization measures based on the orientation OR and on the thickness of the magnet 600. Although this will not be explained in further detail, for example, as shown in Figure 41, as the demagnetization measures based on the horizontal orientation component ORl decrease, the thickness of the magnet 600 in the radial direction RD may be increased in the horizontal direction LD.

[0211] In this embodiment, the thickness in the radial direction RD increases from the first side surface 600e or the second side surface 600f toward the side center 600ef between the first side surface 600e and the second side surface 600f. The thickness of the magnet 600 in the radial direction RD gradually increases from the end side toward the center side in the lateral direction LD.

[0212] Although the thickness in the radial direction RD changes in this way, the outer surface 600b that faces the stator 500 in the radial direction RD is perpendicular to the radial direction RD. Instead, the inner surface 600a is inclined with respect to the radial direction RD. A recess 421 formed by a slope similar to the inclination of this inner surface 600a is formed in the shaft coupling portion 420.

[0213] The plurality of orientations OR are perpendicular to the horizontal direction LD and are symmetrical with respect to the horizontal direction LD, with a symmetry plane dividing the center between the upper surface 600a and the lower surface 600b by the horizontal direction LD as a reference.

[0214] Within the range of manufacturing error, the rate of increase in thickness in the radial direction RD and the rate of decrease in the transverse orientation component ORl may behave similarly. If there is a difference in the effectiveness of demagnetization suppression due to the thickness in the radial direction RD and the transverse orientation component ORl, a difference may be set between the rate of increase in thickness and the rate of decrease in the transverse orientation component ORl so that local demagnetization in magnet 600 is suppressed.

[0215] As explained in the third and thirteenth embodiments, it is possible to take both demagnetization countermeasures using the orientation OR and demagnetization countermeasures using the coercive force of the magnet 600. Although this will not be explained in further detail, for example, as shown in Figure 42, the coercive force of the magnet 600 may be increased as the demagnetization countermeasure using the transverse orientation component ORl decreases.

[0216] Furthermore, within the range of manufacturing error, the rate of increase in coercivity and the rate of decrease in transverse orientation component ORl may behave similarly. If there is a difference in the effectiveness of demagnetization suppression due to high coercivity and that due to transverse orientation component ORl, a difference may be set between the rate of increase in coercivity and the rate of decrease in transverse orientation component ORl so as to suppress localized demagnetization in magnet 600. Furthermore, measures against demagnetization may be taken by adjusting the thickness and coercivity of magnet 600, and by adjusting the transverse orientation component ORl.

[0217] <Other Embodiments> The disclosure of this specification is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and elements shown in the embodiments, and can be implemented in various modifications. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses embodiments in which parts and elements of the embodiments are omitted. The disclosure encompasses the substitution or combination of parts and elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. The disclosed technical scope is defined by the claims, and should be interpreted as including all modifications within the meaning and scope of the claims.

[0218] <Magnet Material> In the first embodiment, an example was shown in which the magnet 600 contains magnetic powder and other materials. The magnetic powder and other materials can be appropriately selected as long as they satisfy the performance of the motor 100 to which they are applied. The magnet 600 will have characteristics that arise from the combination of the selected magnetic powder and other materials. The magnet 600 with such characteristics is used in the motor 100. Note that materials other than the magnetic powder do not necessarily need to be included in the magnet 600. If the motor 100 is a bonded magnet, the materials other than the magnetic powder may be a resin material or the like.

[0219] The magnetic powder may be a rare earth magnetic powder containing a rare earth as a component, or a rare earth-free magnetic powder containing no rare earth as a component. 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-free 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.

[0220] When the performance of the magnet 600 requires at least one of small size and light weight and ease of modification, it is preferable that the magnetic powder has a fine particle size. The particle size of the magnetic powder can be microscale or nanoscale. Using such fine magnetic powder increases the design freedom of the oriented OR. When easy material procurement and high recycling efficiency are required, it is desirable that the magnetic powder has simple and abundant components and does not contain rare earths. When it is required to withstand use under harsh conditions, it is desirable that the magnetic powder has high heat resistance, radiation resistance, etc.

[0221] Motor magnets containing magnetic powders with the above-mentioned properties, such as nanoscale, simple and abundant components, rare earth-free, high heat resistance, and radiation resistance, are expected to generally have the properties of such magnetic powders. Therefore, motor magnets containing such magnetic powders are expected to have properties such as small size and light weight, easy improvement, easy material procurement, high recycling efficiency, high heat resistance, and radiation resistance. Such motor magnets can be widely adopted in motors in general. At the same time, such motor magnets can also be adopted in motors in certain small-scale technical fields where these properties are required.

[0222] Of course, the magnet 600 employed in the motor 100 is required to have an output that is suited to its intended use. As the magnetic powder contained in the magnet 600, magnetic powder that is expected to produce an output suited to the intended use can be employed.

[0223] Common types of magnets that can be used for magnet 600 include ceramic magnets such as ferrite magnets, metal magnets such as rare earth magnets and ordered alloy magnets, and bonded magnets such as rubber magnets and plastic magnets.

[0224] Ferrites include hexagonal ferrites such as barium ferrite and strontium ferrite, and spinel ferrites such as cobalt ferrite. Rare earths 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. Ordered alloys include L10-FePt, L10-FeNi, and τ-MnAl. Other metallic materials for metal magnets include spinodal decomposition systems such as alnico and Fe-Cr-Co, and Fe16N2. Note that the "R" in the above names stands for rare earth, and includes Nd, Sm, and Dy. "T" stands for transition metal, and includes Fe, Co, and Ni.

[0225] <Applications of the Motor> At the beginning of the first embodiment, it was stated that the application of the motor 100 is not particularly limited, and that the motor 100 can be applied to, for example, mobility products, robot products, and facilities that generate energy such as electricity.

[0226] These mobility products include cars as a means of transportation on land, aircraft as a means of transportation in the air, ships as a means of transportation on water, submersible boats and submarines as a means of transportation in water, and spacecraft used for transportation in outer space.

[0227] These means of transportation on land, air, water, and space include manned and unmanned aircraft. Vehicles include manned and unmanned automobiles. Specifically, vehicles include manned and unmanned guided vehicles. Unmanned guided 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, vehicles include transportation of goods, ships include manned and unmanned ships. Submarines and submarines include manned and unmanned submersibles. Spacecraft include manned and unmanned spacecraft. Manned spacecraft can also be called spaceships.

[0228] The power source of these vehicles, including manned and unmanned vehicles, may be various types of energy, such as thermal energy, electrical energy, light energy, renewable energy, chemical energy, nuclear energy, etc. One or a combination of these various types of energy may be used as the power source of the vehicle.

[0229] Robot products, when classified by use, include industrial robots, industrial robots, domestic robots, service robots, medical robots, educational robots, agricultural robots, exploration robots, and leisure robots.

[0230] An example of a facility that generates energy is a power plant, which produces electrical energy using energy sources such as oil, coal, natural gas, biomass, nuclear power, wind power, hydroelectric power, geothermal power, solar power, and chemical reactions.

[0231] <Disclosure of Technical Ideas> This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, where the subsequent clause alternatively refers to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, where the subsequent clause refers to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0232] <Technical Idea 1> A motor magnet provided on a field element (400, 500) aligned with an exciter (500, 400) in a first direction (RD, AD), the motor magnet having a plurality of orientations (OR), the types of components of the plurality of orientations being a first orientation component (ORr, ORa) along the first direction, a second orientation component (ORc, ORa) along a second direction (CD, AD) in which either the exciter or the field element moves, and a third orientation component (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, the plurality of orientations being motor magnets having the third orientation components.

[0233] <Technical Concept 2> The motor magnet according to Technical Concept 1, wherein the arithmetic mean of the absolute values ​​of the third orientation components of the plurality of orientations is greater than the arithmetic mean of the absolute values ​​of the second orientation components.

[0234] <Technical Concept 3> The motor magnet according to Technical Concept 1 or Technical Concept 2, wherein all of the plurality of orientations have the third orientation component.

[0235] <Technical Idea 4> The multiple orientations have not only the third orientation component but also the first orientation component, and the orientation component along the first direction is larger and the orientation component along the third direction is smaller on the central portion (600cd, 600ab, 600ef) between the two end sides than on the two end sides (600c, 600d, 600a, 600b, 600e, 600f) in the third direction. This is a motor magnet described in any one of Technical Ideas 1 to 3.

[0236] <Technical Idea 5> The motor magnet according to Technical Idea 4, wherein the plurality of orientations are symmetrical in the third direction with respect to a plane of symmetry that is perpendicular to the third direction and divides the central portion.

[0237] <Technical Concept 6> A motor magnet according to any one of Technical Concepts 1 to 5, wherein the smaller the orientation component along the third direction, the longer the length in the first direction.

[0238] <Technical Idea 7> A motor magnet described in any one of Technical Ideas 1 to 6, having multiple types of magnet pieces (611, 612, 613) with different coercive forces, the multiple magnet pieces being aligned in the third direction, and the third orientation component of the multiple magnet pieces being smaller as the coercive force increases.

[0239] <Technical Idea 8> A field element aligned with an exciter (500, 400) in a first direction (RD, AD), comprising an extension magnet (700) extending in a second direction (CD, AD) in which one of the exciter and the field element moves, wherein a plurality of magnetic poles (600) included in the extension magnet have a plurality of orientations (OR), and types of components of the plurality of orientations include first orientation components (ORr, ORa) along the first direction, second orientation components (ORc, ORa) along the second direction (CD, AD), and third orientation components (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, and the plurality of orientations have the third orientation components.

[0240] <Technical Idea 9> A motor comprising an exciter (500, 400) and a field element (400, 500) aligned in a first direction (RD, AD), wherein the field element has an extension magnet (700) extending in a second direction (CD, AD) in which one of the exciter and the field element moves, wherein a plurality of magnetic poles (600) included in the extension magnet have a plurality of orientations (OR), and types of components of the plurality of orientations include first orientation components (ORr, ORa) along the first direction, second orientation components (ORc, ORa) along the second direction (CD, AD), and third orientation components (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, and wherein the plurality of orientations have the third orientation components.

[0241] <Technical Idea 10> The motor according to Technical Idea 9, wherein the first direction is a radial direction (RD) perpendicular to a rotation axis (300) on which either the exciter or the field element is provided, the second direction is a circumferential direction (CD) around the rotation axis, and the third direction is an axial direction (AD) along the rotation axis.

[0242] <Technical Idea 11> The motor according to Technical Idea 10, wherein the field element is provided on the rotating shaft, the structural center (SC) and the magnetic center (MC) of the field element are offset in the third direction, and the magnetic center of the field element in the third direction and the magnetic center of the exciter are aligned in the first direction.

[0243] <Technical Idea 12> The motor according to Technical Idea 9, wherein the first direction is an axial direction (AD) along a rotation axis (300) on which either the exciter or the field element is provided, the second direction is a circumferential direction (CD) around the rotation axis, and the third direction is a radial direction (RD) perpendicular to the rotation axis.

[0244] <Technical Concept 13> The motor according to Technical Concept 12, wherein the orientation angles of the extension magnets extending in the circumferential direction are two-fold symmetric about the rotation axis.

[0245] <Technical Idea 14> The motor according to Technical Idea 9, wherein the first direction is a radial direction (RD) perpendicular to a linear motion axis (800) on which either the exciter or the field element is provided, the second direction is an axial direction (AD) along the linear motion axis, and the third direction is a lateral direction (LD) perpendicular to the first direction and the second direction.

Claims

1. A motor magnet provided on a field element (400, 500) aligned with an exciter (500, 400) in a first direction (RD, AD), the motor magnet having a plurality of orientations (OR), the types of components of the plurality of orientations being a first orientation component (ORr, ORa) along the first direction, a second orientation component (ORc, ORa) along a second direction (CD, AD) in which either the exciter or the field element moves, and a third orientation component (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, the plurality of orientations having the third orientation component.

2. A motor magnet according to claim 1, wherein the arithmetic mean of the absolute values ​​of the third orientation components of the plurality of orientations is greater than the arithmetic mean of the absolute values ​​of the second orientation components.

3. A motor magnet according to claim 1 or claim 2, wherein all of the plurality of orientations have the third orientation component.

4. A motor magnet as described in claim 1 or claim 2, wherein the multiple orientations have not only the third orientation component but also the first orientation component, and the orientation component along the first direction is larger and the orientation component along the third direction is smaller on the central portion (600cd, 600ab, 600ef) between the two end sides than on the two end sides (600c, 600d, 600a, 600b, 600e, 600f) in the third direction.

5. A motor magnet according to claim 4, wherein the plurality of orientations are symmetrical in the third direction with respect to a plane of symmetry that is perpendicular to the third direction and divides the central portion.

6. A motor magnet according to claim 1 or 2, wherein the smaller the orientation component along the third direction, the longer the length in the first direction.

7. A motor magnet as described in claim 1 or claim 2, having multiple types of magnet pieces (611, 612, 613) with different coercive forces, the multiple magnet pieces being aligned in the third direction, and the third orientation component of the multiple magnet pieces being smaller the higher the coercive force.

8. A field element aligned with an exciter (500, 400) in a first direction (RD, AD), comprising an extension magnet (700) extending in a second direction (CD, AD) in which one of the exciter and the field element moves, wherein a plurality of magnetic poles (600) included in the extension magnet have a plurality of orientations (OR), and the types of components of the plurality of orientations include first orientation components (ORr, ORa) along the first direction, second orientation components (ORc, ORa) along the second direction (CD, AD), and third orientation components (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, and the plurality of orientations have the third orientation components.

9. A motor comprising an exciter (500, 400) and a field element (400, 500) aligned in a first direction (RD, AD), wherein the field element has an extension magnet (700) extending in a second direction (CD, AD) in which one of the exciter and the field element moves, wherein a plurality of magnetic poles (600) included in the extension magnet have a plurality of orientations (OR), and the types of components of the plurality of orientations include first orientation components (ORr, ORa) along the first direction, second orientation components (ORc, ORa) along the second direction (CD, AD), and third orientation components (ORa, ORr, ORl) along a third direction (AD, RD, LD) intersecting the first direction and the second direction, and wherein the plurality of orientations have the third orientation components.

10. The motor described in claim 9, wherein the first direction is a radial direction (RD) perpendicular to a rotation axis (300) on which either the exciter or the field element is provided, the second direction is a circumferential direction (CD) around the rotation axis, and the third direction is an axial direction (AD) along the rotation axis.

11. The motor according to claim 10, wherein the field element is provided on the rotating shaft, the structural center (SC) and the magnetic center (MC) of the field element are offset in the third direction, and the magnetic center of the field element in the third direction and the magnetic center of the exciter element are aligned in the first direction.

12. The motor described in claim 9, wherein the first direction is an axial direction (AD) along a rotation axis (300) on which either the exciter or the field element is provided, the second direction is a circumferential direction (CD) around the rotation axis, and the third direction is a radial direction (RD) perpendicular to the rotation axis.

13. The motor according to claim 12, wherein the orientation angles of the extension magnets extending in the circumferential direction are two-fold symmetric about the rotation axis.

14. The motor described in claim 9, wherein the first direction is a radial direction (RD) perpendicular to a linear motion axis (800) on which either the exciter or the field element is provided, the second direction is an axial direction (AD) along the linear motion axis, and the third direction is a lateral direction (LD) perpendicular to the first direction and the second direction.

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