Motor magnet, field element including same, and motor

Abstract

In a rotor (40), a plurality of magnets (100) are arranged in the circumferential direction (CD). The magnets (100) each have a hard magnetic body (90) and a soft magnetic body (80). In the hard magnetic body (90), a first surface (91) and a second surface (92) are side by side in the radial direction (RD). The first surface (91) is provided on a stator side. The second surface (92) is provided on the opposite side from the stator. The soft magnetic body (80) is provided on the first surface (91) side of the hard magnetic body (90). The soft magnetic body (80) extends from the first surface (91) and toward the second surface (92). A recess (97) is provided in the hard magnetic body (90). The recess (97) is recessed from the first surface (91) toward the second surface (92). At least part of the soft magnetic body (80) is inside the recess (97).

Description

A motor magnet, a field element including the same, and a motor CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-100647 filed in Japan on June 21, 2024, the contents of which are incorporated by reference in their entirety.

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

[0003] Patent Document 1 describes a permanent magnet motor 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 2011-217517 A

[0005] The orientation of the permanent magnets described in Patent Document 1 is polar anisotropic, which results in a configuration in which magnetic flux is concentrated.

[0006] Increasing the radial thickness of the permanent magnets in this configuration could be considered to increase the magnetic flux, but because the orientation of the permanent magnets is polar anisotropic, increasing the thickness of the permanent magnets may result in the magnetic flux emitted from some of the permanent magnets not contributing as much to generating torque in the motor.

[0007] One object of the present disclosure is to provide a motor magnet, a field element including the same, and a motor with improved torque performance.

[0008] The multiple aspects disclosed in this specification employ different technical means to achieve their respective objectives. Furthermore, the reference symbols in parentheses in the claims and this section are merely examples showing the correspondence between specific means described in the embodiments below as one aspect, and do not limit the technical scope.

[0009] In order to achieve the above object, the disclosed aspect is a motor magnet included in either a field element or an exciter arranged opposite each other in a first direction, the motor magnet comprising: a hard magnetic body having a plurality of orientations; and a soft magnetic body provided on the hard magnetic body, at least a portion of the plurality of orientations having an orientation component along a second direction that intersects with the first direction; the soft magnetic body being provided on a first surface side of the hard magnetic body that faces the field element, and extending from the first surface toward a second surface on the back side thereof.

[0010] With this, the magnetic flux flowing in the second direction inside the ferromagnetic body flows to the first field element side via the soft magnetic body, thereby improving torque performance.

[0011] The disclosed aspect is a field element having a plurality of motor magnets arranged opposite an exciter in a first direction and aligned in a second direction intersecting the first direction, wherein the motor magnets comprise a hard magnetic body having a plurality of orientations and a soft magnetic body provided on the hard magnetic body, at least some of the plurality of orientations having an orientation component along the second direction, and the soft magnetic body is provided on a first surface side of the hard magnetic body facing the exciter, and extends from the first surface toward a second surface on the back side thereof.

[0012] The field element can achieve the same effects as the motor magnet.

[0013] The disclosed aspect is a motor comprising: a field element; and an armature arranged opposite the field element in a first direction; either the field element or the armature has a plurality of motor magnets arranged in a second direction that intersects the first direction; the motor magnets have a hard magnetic body with a plurality of orientations and a soft magnetic body provided on the hard magnetic body; at least some of the plurality of orientations have an orientation component along the second direction; and the soft magnetic body is provided on a first surface side of the hard magnetic body that faces the field element, and extends from the first surface toward a second surface on the back side thereof.

[0014] The motor can achieve the same effects as the motor magnet.

[0015] 1 is a plan view of a motor according to a first embodiment. A perspective view of a rotor. A partial plan view of the rotor and stator unfolded so that the circumferential direction is a linear direction. A view of the rotor unfolded on a plane as seen from the radially outside. A partial plan view of the rotor unfolded so that the circumferential direction is a linear direction. A schematic plan view of an N magnet. A plan view partially showing the shape of the N magnet. A diagram for explaining the magnetization orientation angle γ. A plan view of an S magnet. A diagram for explaining the magnetic flux in the soft magnetic material of the N magnet. A diagram for explaining the magnetic flux in the soft magnetic material of the S magnet. A diagram for explaining the magnetic flux in the soft magnetic material of the N magnet. A plan view of a magnet according to a second embodiment. A plan view of a magnet according to a modification 2-1. A plan view of a magnet according to a modification 2-2. A plan view of a magnet according to a third embodiment. A plan view of a magnet according to a modification 3-1. A plan view of a magnet according to a modification 3-2. A plan view of a magnet according to a fourth embodiment. A plan view of a magnet according to a modification 4-1. A plan view of a magnet according to a modification 4-2. A plan view of a magnet according to a fifth embodiment. 12. A perspective view of a magnet in a sixth embodiment. A perspective view of a magnet in a modified example 6-1. A partial plan view of a rotor in a seventh embodiment, developed so that the circumferential direction is a linear direction. A partial plan view of a rotor in an eighth embodiment, developed so that the circumferential direction is a linear direction. A partial plan view of a rotor in a modified example 8-1, developed so that the circumferential direction is a linear direction. A plan view of a motor in a ninth embodiment. A plan view of a motor in a tenth embodiment. A partial plan view of a rotor in an eleventh embodiment, developed so that the circumferential direction is a linear direction. A plan view of an outer rotor type motor in a twelfth embodiment. A plan view of a brushed motor in a thirteenth embodiment. A schematic longitudinal cross-sectional view of an axial motor in a fourteenth embodiment. A perspective view of an axial motor. A plan view of a rotor. A perspective view of a magnet. A view of a rotor and a stator as viewed from the radially outside, developed on a plane. A partial longitudinal cross-sectional view of a linear motor in a fifteenth embodiment.

[0016] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to matters described in the preceding embodiment will be assigned the same reference numerals, and duplicate descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other previously described embodiments may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically specified as being combinable in each embodiment, it is also possible to partially combine embodiments even if not specified, as long as there is no particular problem with the combination.

[0017] <First embodiment> A motor 10 shown in Fig. 1 is provided in various devices and the like. The motor 10 drives the various devices and the like to operate them. The motor 10 is supplied with power from a power supply unit such as a battery. The motor 10 functions as an electric motor when power is supplied from the power supply unit. The motor 10 is a multi-phase AC motor. The motor 10 is a motor generator. The motor 10 functions as a generator during regeneration. The motor 10 is sometimes referred to as a rotating electric machine.

[0018] In the following description, the three mutually orthogonal directions are referred to as an axial direction AD, a radial direction RD, and a circumferential direction CD. The radial direction RD is sometimes referred to as a radial direction, and the axial direction AD is sometimes referred to as an axial direction.

[0019] An imaginary line that runs along the linear axial direction AD and passes through the center of the motor 10 is referred to as the motor axis Cm. Unless otherwise specified, hereinafter, the direction that intersects with and is perpendicular to the motor axis Cm will be referred to simply as the radial direction RD. The direction around the motor axis Cm will be referred to simply as the circumferential direction CD. Furthermore, of the two directions spaced apart in the radial direction RD, the side farther from the motor axis Cm may be referred to as the radially outer side or outer circumferential side, and the side closer to the motor axis Cm may be referred to as the radially inner side or inner circumferential side.

[0020] The motor 10 has a housing 11, a shaft 12, a stator 30, and a rotor 40. The housing 11 is made of a metal material or the like. The housing 11 is a housing whose outer and inner peripheral surfaces are formed in an annular shape. At least a portion of the shaft 12, the stator 30, and the rotor 40 are housed in the space surrounded by this annular inner peripheral surface.

[0021] 1 and 2, the stator 30 is a stator, and the rotor 40 is a rotor. The shaft 12 is fixed to the rotor 40. The shaft 12 and the rotor 40 rotate relative to the stator 30. The shaft 12 and the rotor 40 rotate about a motor axis Cm. The motor axis Cm extends in the axial direction AD through the center of the shaft 12 and the center of the rotor 40. The motor axis Cm is the rotation axis of the motor 10. The shaft 12 extends in the axial direction AD along the motor axis Cm. The rotor 40 rotates about the shaft 12. The shaft 12 corresponds to the rotation axis. The shaft 12 is rotatably supported by bearing members such as bearings. The motor 10 is sometimes referred to as a rotary motor that performs rotary motion.

[0022] The motor 10 is a radial gap type motor. Radial gap type motors are sometimes called radial motors. In the motor 10, a stator 30 and a rotor 40 are aligned in the radial direction RD. The motor 10 is provided with one stator 30 and one rotor 40. A radial gap 20 is present between the stator 30 and the rotor 40. The radial gap 20 is a gap. The stator 30 and the rotor 40 are aligned in the radial direction RD with the radial gap 20 interposed therebetween.

[0023] In this embodiment, the rotor 40 is provided on the inner periphery of the stator 30. For example, the motor 10 is a brushless motor. The motor 10 in which the rotor 40 is provided on the inner periphery of the stator 30 is sometimes referred to as an inner rotor type motor. The rotor 40 provided on the inner periphery of the stator 30 is sometimes referred to as an inner rotor.

[0024] The stator 30 is fixed to the housing 11. The stator 30 extends in the circumferential direction CD along the inner circumferential surface of the housing 11. For example, the stator 30 is formed in an annular shape as a whole. The stator 30 is an exciter that is excited by passing current through it. The stator 30 is sometimes called an armature. The stator 30 has a stator core 31 and a coil 35. The stator 30 is excited by passing current through the coil 35. The coil 35 is formed from an electric wire or the like and is capable of passing current through it.

[0025] The stator core 31 is an iron core. The stator core 31 is made of a soft magnetic material or the like. The stator core 31 can form a magnetic path through which magnetic flux such as interlinkage magnetic flux passes. The stator core 31 has core teeth 32 and a core outer periphery 33. A plurality of core teeth 32 are arranged in the circumferential direction CD along the inner circumferential surface of the housing 11. Coils 35 are wound around the core teeth 32. The core outer periphery 33 is provided on the outer periphery of the core teeth 32. The core outer periphery 33 supports the core teeth 32. The core outer periphery 33 is fixed directly or indirectly to the housing 11. The core outer periphery 33 extends in the circumferential direction CD so as to be wrapped around the plurality of core teeth 32. For example, the core outer periphery 33 is formed in an annular shape.

[0026] The rotor 40 is a field element. The rotor 40 has a rotor core 51 and magnets 100. In the rotor 40, the magnets 100 generate a magnetic field. The rotor core 51 supports the magnets 100. The rotor core 51 is fixed to the shaft 12. The outer peripheral surface 51a of the rotor core 51 extends annularly in the circumferential direction CD. A plurality of magnets 100 are arranged along the outer peripheral surface 51a. Two magnets 100 that are arranged adjacent to each other in the circumferential direction CD are in contact with each other in the circumferential direction CD. The magnets 100 are affixed to the rotor core 51 by adhesive or the like. The magnets 100 are included in the field element and correspond to motor magnets.

[0027] The rotor core 51 is made of a metal material or the like. The rotor core 51 is made of a soft magnetic material or the like. The rotor core 51 can form a magnetic path through which magnetic flux such as interlinkage magnetic flux passes. The magnetic path is sometimes called a magnetic circuit. The rotor core 51 is a back core for the magnet 100. The rotor core 51 is sometimes called a back yoke.

[0028] In this embodiment, the stator 30 and the rotor 40 are disposed opposite each other in the radial direction RD. The radial direction RD corresponds to the first direction, and the circumferential direction CD corresponds to the second direction. Furthermore, the configuration in which the stator 30 and the rotor 40 are disposed opposite each other in the radial direction RD corresponds to the configuration in which an exciter and a field element are disposed opposite each other in the first direction.

[0029] The rotor 40 has a magnetic pole assembly 70. The magnetic pole assembly 70 has a plurality of magnets 100. The magnetic pole assembly 70 is formed in a ring shape by arranging the plurality of magnets 100 in a ring shape in the circumferential direction CD. In the magnetic pole assembly 70, the plurality of magnets 100 are arranged in a grouped state. The magnetic pole assembly 70 is sometimes referred to as a magnet ring. The magnetic pole assembly 70 is fixed to the rotor core 51. In the magnetic pole assembly 70, the magnets 100 are arranged in the circumferential direction CD, but are not arranged in the axial direction AD or the radial direction RD. Note that a configuration in which the plurality of magnets 100 are arranged in the axial direction AD may also be employed.

[0030] The magnetic pole assembly 70 has a first collective surface 71, a second collective surface 72, a first collective side surface 73, and a second collective side surface 74. The surfaces 71 to 74 are included in the outer surface of the magnetic pole assembly 70. The first collective surface 71 is the outer peripheral surface of the magnetic pole assembly 70. The second collective surface 72 is the inner peripheral surface of the magnetic pole assembly 70. The first collective side surface 73 and the second collective side surface 74 are aligned in the axial direction AD via the first collective surface 71 and the second collective surface 72. The collective side surfaces 73 and 74 extend in a direction perpendicular to the axial direction AD. The collective side surfaces 73 and 74 are bridged between the first collective surface 71 and the second collective surface 72.

[0031] As shown in Figures 1 to 3, the magnet 100 has a hard magnetic body 90 and a soft magnetic body 80. For example, the magnet 100 has one hard magnetic body 90 and one soft magnetic body 80. The hard magnetic body 90 is formed by including a hard magnetic material. For example, the hard magnetic body 90 has a hard magnetic member formed from a hard magnetic material. One hard magnetic body 90 is formed by one hard magnetic member. For example, the hard magnetic member is a magnetic member formed from a magnetic material or the like. Examples of magnetic members include sintered magnets and bonded magnets. One hard magnetic body 90 is formed by one magnetic member. The magnetic material is a material containing magnetic powder. The magnetic powder is sometimes called magnetic powder or magnetic powder. The hard magnetic body 90 is in a magnetized state.

[0032] The orientation OR of the hard magnetic body 90 is set by magnetization or the like. For example, the direction and magnitude of the orientation OR are set by magnetization or the like. Fine magnetic powder is used as the magnetic powder of the hard magnetic body 90. In the hard magnetic body 90, the degree of freedom regarding the orientation OR is increased due to the fine magnetic powder, etc. In the hard magnetic body 90, the arrangement of the orientation OR is complex.

[0033] The magnetic powder forming the hard magnetic body 90 includes magnetic powder made of a metal material. Magnetic powder made of a metal material includes base metal magnetic powder, rare metal magnetic powder, and rare earth magnetic powder. Base metal magnetic powder is magnetic powder made of a base metal. Rare metal magnetic powder is magnetic powder made of a rare metal. Rare earth magnetic powder is magnetic powder made of a rare earth. The magnet 100 is formed including at least one of base metal magnetic powder, rare metal magnetic powder, and rare earth magnetic powder.

[0034] The soft magnetic body 80 is formed to include a soft magnetic material. For example, the soft magnetic body 80 has a soft magnetic member formed from a soft magnetic material. One soft magnetic body 80 is formed from one soft magnetic member. For example, the soft magnetic member is a compact made of an electromagnetic steel sheet or a powder magnetic core. By forming the soft magnetic body 80 from this compact, loss due to eddy current generation in the soft magnetic body 80 can be reduced. The soft magnetic member is also a core member formed from a core material or the like. The soft magnetic body 80 is provided in the hard magnetic body 90. At least a portion of the soft magnetic body 80 is embedded in the hard magnetic body 90.

[0035] 2, the magnet 100, hard magnetic material 90, and soft magnetic material 80 are formed in a columnar shape extending in the axial direction AD. The size and shape of the cross section of each of the magnet 100, hard magnetic material 90, and soft magnetic material 80 are uniform in the axial direction AD. The cross sections of each of the magnet 100, hard magnetic material 90, and soft magnetic material 80 are cross sections obtained by cutting the magnet 100 in a direction perpendicular to the axial direction AD.

[0036] In Figure 3 and other figures, magnet 100 is shown as being approximately rectangular in plan view, but in reality, magnet 100 is approximately fan-shaped in plan view, extending along an arc, as shown in Figures 1 and 7. In Figure 3 and other figures, the curved lines extending along the arc of magnet 100 are shown expanded into straight lines. For example, in Figures 6 and 9, magnet 100 is shown simplified as a rectangle.

[0037] 3 to 5, the hard magnetic body 90 has a first surface 91, a second surface 92, a first end face 93, a second end face 94, a first side face 95, and a second side face 96. The faces 91 to 96 are included in the outer surface of the hard magnetic body 90.

[0038] The surfaces 91, 92 extend in a direction perpendicular to the radial direction RD. The surfaces 91, 92 extend in the circumferential direction CD so as to span between a first end face 93 and a second end face 94. The first surface 91 and the second surface 92 are aligned in the radial direction RD via surfaces 93 to 96. In the magnetic pole assembly portion 70, the first surface 91 is located on the outer circumferential side, and the second surface 92 is located on the inner circumferential side. The first surface 91 is included in the first assembly surface 71. The second surface 92 is included in the second assembly surface 72. The first surface 91 faces the stator 30 across the radial gap 20. The first surface 91 is also the armature-side surface of the hard magnetic body 90. The second surface 92 is on the opposite side to the stator 30 in the radial direction RD. The second surface 92 is also the anti-armature-side surface of the hard magnetic body 90. The second surface 92 is placed over the outer peripheral surface 51 a of the rotor core 51. The second surface 92 is located on the reverse side of the first surface 91.

[0039] The end faces 93, 94 extend in a direction perpendicular to the circumferential direction CD. The end faces 93, 94 extend in the radial direction RD so as to span the first surface 91 and the second surface 92. The first end face 93 and the second end face 94 are aligned in the circumferential direction CD via surfaces 91, 92, 95, and 96. In two magnets 100 adjacent to each other in the circumferential direction CD, the first end face 93 of one hard magnetic body 90 and the second end face 94 of the other hard magnetic body 90 are overlapped with each other.

[0040] The side surfaces 95, 96 extend in a direction perpendicular to the axial direction AD. The first side surface 95 and the second side surface 96 are aligned in the axial direction AD via the end surfaces 93, 94 and the surfaces 91, 92. The first side surface 95 is included in the first collective side surface 73. The second side surface 96 is included in the second collective side surface 74.

[0041] The hard magnetic body 90 has a recess 97. The recess 97 is recessed from the first surface 91 to the second surface 92 in the hard magnetic body 90. The recess 97 is open to both one side and the other side in the axial direction AD. In the recess 97, a concave surface 97a extends in the axial direction AD. The concave surface 97a is the inner surface of the recess 97.

[0042] The soft magnetic body 80 is provided in the recess 97, and is thus embedded in the hard magnetic body 90. The soft magnetic body 80 is provided on the first surface 91 side of the hard magnetic body 90, and extends from the first surface 91 toward the front of the second surface 92. The soft magnetic body 80 is provided on the hard magnetic body 90 at the center side of the first surface 91 in the circumferential direction CD. The soft magnetic body 80 is provided at a position that straddles the center of the hard magnetic body 90 in the circumferential direction CD. For example, the center of the soft magnetic body 80 and the center of the hard magnetic body 90 are aligned in the radial direction RD. The soft magnetic body 80 is disposed at the center of the hard magnetic body 90 in the circumferential direction CD.

[0043] The soft magnetic body 80 has a first opposing surface 81, a second opposing surface 82, a first side surface 83, and a second side surface 84. The surfaces 81 to 84 are included in the outer surface of the soft magnetic body 80. The opposing surfaces 81, 82 extend in the axial direction AD. The first opposing surface 81 extends in a direction perpendicular to the radial direction RD. The first opposing surface 81 faces the stator 30 via the radial gap 20. The first opposing surface 81 is aligned with the first surface 91 in the circumferential direction CD. The first opposing surface 81 and the first surface 91 are provided flush with each other. The first opposing surface 81 and the first surface 91 form a continuous surface.

[0044] The second opposing surface 82 faces the opposite side to the first opposing surface 81 as a whole. The soft magnetic body 80 has a shape in which the second opposing surface 82 bulges out toward the opposite side to the first opposing surface 81. The second opposing surface 82 is curved so that the center of the second opposing surface 82 bulges out. For example, the second opposing surface 82 is a curved surface. The second opposing surface 82 faces the hard magnetic body 90. For example, the second opposing surface 82 faces the concave surface 97a. The second opposing surface 82 is overlapped on the concave surface 97a. The second opposing surface 82 and the concave surface 97a are fixed together with an adhesive or the like.

[0045] The side surfaces 83, 84 extend in a direction perpendicular to the axial direction AD. The first side surface 83 and the second side surface 84 are aligned in the axial direction AD via the opposing surfaces 81, 82. The side surfaces 83, 84 are aligned with the side surfaces 95, 96 in a direction perpendicular to the axial direction AD. The soft magnetic body 80 extends in the axial direction AD so as to bridge between the first side surface 95 and the second side surface 96. For example, the first side surface 83 and the first side surface 95 are flush with each other, and the second side surface 84 and the second side surface 96 are flush with each other.

[0046] As shown in Fig. 6, the length of the soft magnetic material 80 in the circumferential direction CD increases from the second surface 92 toward the first surface 91 in the radial direction RD. The length of the soft magnetic material 80 in the circumferential direction CD is length Xcore. The length Xcore increases as the position in the radial direction RD approaches the first surface 91. In other words, the length Xcore gradually increases from the tip end 82a toward the first opposing surface 81. For example, the length Xcore may increase continuously or stepwise from the tip end 82a toward the first opposing surface 81.

[0047] 0≦Xcore1<Xcore2<Xcore3 Equation 1 Equation 1 holds true for the soft magnetic body 80. In Equation 1, the length in the circumferential direction CD at the tip end 82a of the soft magnetic body 80 is designated Xcore1, the horizontal dimension in the circumferential direction CD at the intermediate portion is designated Xcore2, and the length in the circumferential direction CD at the first opposing surface 81 is designated Xcore3. In reality, the length Xcore1 of the tip end 82a is greater than zero. The tip end 82a is the end of the soft magnetic body 80 on the opposite side from the first opposing surface 81. The intermediate portion is located in the middle of the soft magnetic body 80 between the first opposing surface 81 and the tip end 82a.

[0048] Equation 2 holds true for the relationship between the hard magnetic material 90 and the soft magnetic material 80. In Equation 2, the length of the hard magnetic material 90 in the circumferential direction CD is Xmag, and the length of the hard magnetic material 90 in the radial direction RD is Ymag. For example, the length Xmag is the length of the first surface 91 in the circumferential direction CD. The length Xmag is the distance in the circumferential direction CD between the first end face 93 and the second end face 94 on the first surface 91. The length Ymag is the distance in the radial direction RD between the first surface 91 and the second surface 92. Equation 2 shows the dimensional relationship between the hard magnetic material 90 and the soft magnetic material 80. In the magnet 100, the difference between the length Ymag of the hard magnetic material 90 in the radial direction RD and the length Ycore of the soft magnetic material 80 in the radial direction RD depends on half the length Xmag of the hard magnetic material 90 in the circumferential direction CD.

[0049] Xmag / 2 ≒ Ymag - Ycore ... Equation 2 Equation 2 includes the right-hand side and the left-hand side being the same. Equation 2 also includes the difference between the right-hand side and the left-hand side being smaller than a predetermined value. For example, this predetermined value is smaller than a few percent or several tens of percent of the right-hand side or the left-hand side. The length Ymag is the distance in the radial direction RD between the first surface 91 and the second surface 92. The length Ycore is the distance in the radial direction RD between the first opposing surface 81 and the tip end 82a. The lengths Ymag and Ycore are sometimes referred to as thicknesses. The right-hand side is the distance in the radial direction RD between the second surface 92 and the tip end 82a.

[0050] In the magnet 100, the soft magnetic body 80 extends in the radial direction RD. The length Ycore of the soft magnetic body 80 in the radial direction RD is greater than the length Xcore of the soft magnetic body 80 in the circumferential direction CD. For example, the length Ycore is greater than the length Xcore3 of the first opposing surface 81. The length Xcore3 of the first opposing surface 81 is smaller than half the length Xmag of the hard magnetic body 90.

[0051] In the magnet 100, the relationship between the saturation magnetic flux density Bs of the soft magnetic body 80 and the residual magnetic flux density Br of the hard magnetic body 90 is expressed by Equation 3. The saturation magnetic flux density Bs of the soft magnetic body 80 is the magnetic flux density when the soft magnetic body 80 is magnetically saturated. The residual magnetic flux density Br of the hard magnetic body 90 is the magnetic flux density remaining in the soft magnetic body 80 when the magnetic field is zero, in the hysteresis characteristics of the soft magnetic body 80. For example, the saturation magnetic flux density Bs of the soft magnetic body 80 is greater than the residual magnetic flux density Br of the hard magnetic body 90. The product of the saturation magnetic flux density Bs of the soft magnetic body 80 and the area S1 of the first opposing surface 81 is greater than the product of the residual magnetic flux density Br of the hard magnetic body 90 and the area S2 of the second opposing surface 82.

[0052] Bs×S1≧Br×S2 Equation 3 Area S1 in Equation 3 is the area of ​​the portion of first opposing surface 81 that overlaps with second opposing surface 82 in the axial direction AD. Area S2 is the area of ​​the portion of second opposing surface 82 that is in contact with hard magnetic material 90. Bs×S1 in Equation 3 indicates the amount of magnetic flux that can be released from soft magnetic material 80 at first opposing surface 81. Furthermore, Br×S2 indicates the amount of magnetic flux that flows into soft magnetic material 80 at second opposing surface 82. In magnet 100, by setting magnetic flux densities Bs, Br and areas S1, S2 to satisfy Equation 3, the first opposing surface 81 is made highly magnetic and magnetic saturation is suppressed.

[0053] Furthermore, in the soft magnetic body 80, the area S1 of the first opposing surface 81 is equal to or smaller than the area S2 of the second opposing surface 82. For example, the area S1 is smaller than the area S2. Note that although the first surface 91 and the dimension lines are illustrated as straight lines in FIG. 6, in reality, the first surface 91 and the dimension lines are curved along the circumferential direction CD, as shown in FIG. 7. The area S1 is the area of ​​the first opposing surface 81, which is a curved surface.

[0054] The longitudinal cross-sectional area of ​​the soft magnetic body 80 increases as the position approaches the first surface 91 in the radial direction RD. The longitudinal cross-sectional area is the area of ​​a cross section obtained by cutting the soft magnetic body 80 in a direction perpendicular to the radial direction RD. At the first opposing surface 81, the area S1 is the longitudinal cross-sectional area. At the tip end portion 82a, the area of ​​the tip end portion 82a is the longitudinal cross-sectional area. At the soft magnetic body 80, the length Xcore increases as the position approaches the first surface 91 in the radial direction RD, and therefore the longitudinal cross-sectional area increases as the position approaches the first surface 91 in the radial direction RD.

[0055] When power is supplied to the motor 10 from the power supply unit, a magnetic field is generated as current flows through the coils 35. In this magnetic field, magnetic flux is passed between the stator 30 and the rotor 40. The magnetic path through which this magnetic flux passes is determined by the magnetic flux emitted from each of the stator 30 and the rotor 40, as well as the surrounding housing 11 and other components. On the stator 30 side, the magnetic flux passes through the core teeth 32, the core outer periphery 33, and other components. On the rotor 40 side, the magnetic flux passes through the magnets 100, the rotor core 51, and other components.

[0056] As shown in Figure 5, the magnetic flux on the rotor 40 side includes magnetic flux MF. The magnetic flux MF is magnetic flux that passes through the magnets 100. The magnetic flux MF flows through the hard magnetic bodies 90 and the soft magnetic bodies 80. Of two magnets 100 that are adjacent in the circumferential direction CD, the magnetic flux MF flows from one soft magnetic body 80 to the other soft magnetic body 80. In the hard magnetic body 90, the magnetic flux MF flows overall in the circumferential direction CD. In the soft magnetic body 80, the magnetic flux MF flows overall in the radial direction RD.

[0057] In the magnet 100, the soft magnetic material 80 and the hard magnetic material 90 are configured so as to suppress magnetic saturation in the soft magnetic material 80. For example, the size and shape of the soft magnetic material 80, and the size and shape of the hard magnetic material 90, and the orientation OR are set so as to suppress magnetic saturation in the soft magnetic material 80. For example, as described above, the size and shape of the soft magnetic material 80 and the hard magnetic material 90 are set so as to satisfy Equation 2 and Equation 3. In addition, the orientation OR of the hard magnetic material 90 is set so that magnetic flux MF flows from one soft magnetic material 80 of two magnets 100 adjacent to each other in the circumferential direction CD to the other soft magnetic material 80.

[0058] The orientation OR is oriented in the direction of easy magnetization in the hard magnetic material 90. The easy magnetization direction is the direction in which the hard magnetic material 90 is easily magnetized. The orientation OR is sometimes referred to as a magnet orientation. With respect to the motor 10, the presence of the orientation OR in the hard magnetic material 90 is sometimes expressed as the hard magnetic material 90 having multiple orientations OR. The hard magnetic material 90 is sometimes referred to as an anisotropic magnet.

[0059] As shown in Figures 3 to 5, in the hard magnetic body 90, the orientation OR as a whole faces the circumferential direction CD. As shown in Figures 3 and 5, in the hard magnetic body 90, at least a portion of the orientation OR is inclined toward the radial direction RD with respect to the circumferential direction CD. As shown in Figure 4, the orientation OR is not inclined toward the axial direction AD with respect to the circumferential direction CD. In Figure 3 and other figures, the orientation OR is indicated by a hollow arrow. The hollow arrow indicates the direction of the orientation OR. For convenience, if the orientation OR has a size, the size of all the orientations OR is the same. In other words, in the hard magnetic body 90, the size of the orientation OR is constant. Note that it is conceivable that an infinite number of orientations OR may exist in the hard magnetic body 90, but for convenience, only a predetermined number are illustrated in Figure 3 and other figures. Although some bias may occur in an actual magnet, the illustration shows a predetermined number of orientations OR as being evenly distributed.

[0060] The direction of the orientation OR is expressed by the size and angle of the orientation component. As shown in FIG. 6, the orientation OR has a first orientation component OR1 and a second orientation component OR2. The first orientation component OR1 is an orientation component along the radial direction RD, which is the first direction. The second orientation component OR2 is an orientation component along the circumferential direction CD, which is the second direction. The orientation OR is decomposed into the radial direction RD and the circumferential direction CD, and is decomposed into the first orientation component OR1 and the second orientation component OR2. The orientation OR is obtained by combining the first orientation component OR1 and the second orientation component OR2. The orientation components OR1 and OR2 have sizes according to the direction of the orientation OR. As described above, in the hard magnetic material 90, the magnitude of the orientation OR is constant, so the orientation components OR1 and OR2 have a relationship in which as the second orientation component OR2 increases, the first orientation component OR1 decreases, and as the second orientation component OR2 decreases, the first orientation component OR1 increases.

[0061] The orientation components of the orientation OR include a first orientation component OR1, a second orientation component OR2, and a third orientation component. The third orientation component is an orientation component in the axial direction AD. In this embodiment, a magnet 100 is assumed in which the third orientation component of the orientation OR is zero. The orientation OR is not inclined with respect to the axial direction AD. For example, the orientation OR faces one side in a direction perpendicular to the motor axis Cm. In this embodiment, the axial direction AD corresponds to the third direction. The third orientation component is an orientation component in the third direction.

[0062] The orientation OR may be inclined toward the axial direction AD with respect to the radial direction RD. For example, the third orientation component of the orientation OR may not be zero. Even with this configuration, the magnitude of the orientation OR in a planar view is constant in magnet 100, regardless of the magnitude of the third orientation component. For example, in magnet 100, the magnitude of the orientation OR obtained by combining the first orientation component OR1 and the second orientation component OR2 is constant, regardless of the magnitude of the third orientation component.

[0063] Furthermore, the orientation OR has an orientation angle θ. The orientation angle θ is the angle of the orientation OR. The orientation angle θ is the angle between the radial direction RD and the orientation OR. Two angles are formed by the radial direction RD and the orientation OR, and the orientation angle θ is the smaller of the two angles. The magnitude of the orientation angle θ is 90° or less. The orientation angle θ is the inclination angle of the orientation OR inclined toward the second direction with respect to the first direction. In this embodiment, the orientation angle θ is the inclination angle of the orientation OR inclined toward the circumferential direction CD with respect to the radial direction RD.

[0064] The orientation angle θ is in the range of 0° or more and 90° or less. The relationship of 0°≦θ≦90° holds for the orientation angle θ. The orientation angle θ indicates the tilt angle of the orientation OR relative to the first direction, based on the orientation of the orientation OR. For example, in FIG. 6, the angle between the head of the arrow and the auxiliary dashed-dotted line in the orientation OR is the orientation angle θ. Therefore, for convenience, the orientation angle θ may be the same for multiple orientations OR that are oriented differently from each other. For example, the orientation angle θ may be the same for an orientation OR facing the upper left of the page in FIG. 6 and an orientation OR facing the lower left of the page.

[0065] As described above, since the magnitude of the orientation OR is constant in magnet 100, the orientation angle θ is determined by the magnitude relationship between the first orientation component OR1 and the second orientation component OR2. For magnet 100, Equations 4 and 5 hold true.

[0066] A1=A cos θ (Equation 4) A2=A sin θ (Equation 5) In Equations 4 and 5, for convenience, the magnitude of the orientation OR is designated as A, the magnitude of the first orientation component OR1 is designated as A1, and the magnitude of the second orientation component OR2 is designated as A2.

[0067] In the hard magnetic material 90, at least some of the orientations OR have an orientation component along the circumferential direction CD. That is, at least some of the orientations OR have a second orientation component OR2. In addition, in the hard magnetic material 90, as it approaches the soft magnetic material 80, the orientation component along the circumferential direction CD weakens and the orientation component along the radial direction RD strengthens.

[0068] In the hard magnetic body 90, the second orientation component OR2 of the orientation OR on the end face 93, 94 side is larger than the second orientation component OR2 of the orientation OR on the soft magnetic body 80 side. In the hard magnetic body 90, a plurality of orientations OR are distributed such that the second orientation component OR2 gradually decreases from the end faces 93, 94 toward the soft magnetic body 80. In addition, in the hard magnetic body 90, the second orientation component OR2 of the orientation OR on the central side in the circumferential direction CD is smallest.

[0069] In the hard magnetic body 90, the first orientation component OR1 of the orientation OR on the end face 93, 94 side is smaller than the first orientation component OR1 of the orientation OR on the soft magnetic body 80 side. In the hard magnetic body 90, a plurality of orientations OR are distributed such that the first orientation component OR1 gradually increases from the end faces 93, 94 toward the soft magnetic body 80. In addition, in the hard magnetic body 90, the first orientation component OR1 of the orientation OR on the central side in the circumferential direction CD is the largest.

[0070] In the hard magnetic body 90, the orientation components OR1 and OR2 of the orientation OR on the first surface 91 side are substantially the same as the orientation components OR1 and OR2 of the orientation OR on the second surface 92 side. In the hard magnetic body 90, the orientation components OR1 and OR2 of the plurality of orientations OR aligned in the radial direction RD are substantially the same.

[0071] In the hard magnetic body 90, the orientation angle θ of the orientation OR on the end face 93, 94 side is larger than the orientation angle θ of the orientation OR on the soft magnetic body 80 side. In the hard magnetic body 90, a plurality of orientation ORs are distributed so that the orientation angle θ gradually decreases from the end faces 93, 94 toward the soft magnetic body 80. In addition, in the hard magnetic body 90, the orientation angle θ of the orientation OR on the center side in the circumferential direction CD is the smallest.

[0072] In the hard magnetic body 90, the orientation angle θ of the orientation OR on the first surface 91 side is approximately the same as the orientation angle θ of the orientation OR on the second surface 92 side. In the hard magnetic body 90, the orientation angles θ of the multiple orientations OR aligned in the radial direction RD are approximately the same.

[0073] In magnet 100, the magnetization orientation angle γ shown in Figure 8 is 20° or less. In magnet 100, the shape and size of soft magnetic body 80, and the shape and size of hard magnetic body 90, and the orientation OR are set so that the absolute value of the magnetization orientation angle γ is 20° or less. The magnetization orientation angle γ is an angle that indicates the direction of the orientation OR at the boundary between hard magnetic body 90 and soft magnetic body 80. For example, the magnetization orientation angle γ is an angle that indicates the direction of the orientation OR at concave surface 97a, or the direction of the orientation OR at the concave surface forming portion of hard magnetic body 90 that forms concave surface 97a.

[0074] The magnetization orientation angle γ is the angle of the orientation OR with respect to the second opposing surface 82 of the soft magnetic material 80. The magnetization orientation angle γ is the angle between the reference plane Sp and the orientation OR. The reference plane Sp is perpendicular to the boundary surface between the soft magnetic material 80 and the hard magnetic material 90. The reference plane Sp is an imaginary flat surface that is perpendicular to the tangent to the second opposing surface 82. The reference plane Sp is a surface that extends in the axial direction AD. The reference plane Sp includes a perpendicular line that is perpendicular to the tangent to the second opposing surface 82. The magnitude of the magnetization orientation angle γ is 90° or less. The magnetization orientation angle γ is approximately the same as the angle between the magnetic flux MF that passes through the boundary between the soft magnetic material 80 and the hard magnetic material 90 and the reference plane Sp. In this embodiment, the magnetization orientation angle γ is approximately 0°. In the magnet 100, the shape and size of the soft magnetic material 80, the shape and size of the hard magnetic material 90, and the orientation OR are set so that the magnetization orientation angle γ is approximately 0°.

[0075] Magnet 100 has a south pole and a north pole as magnetic poles. Magnet 100 has a south pole face that forms the south pole and a north pole face that forms the north pole. In magnet 100, magnetic flux MF is generated so as to enter the interior of magnet 100 through the south pole face. In addition, magnetic flux MF is generated so as to exit the interior of magnet 100 through the north pole face.

[0076] As shown in Figures 3 and 5, the multiple magnets 100 include north magnets 100N and south magnets 100S. In the magnetic pole assembly 70, the north magnets 100N and south magnets 100S are arranged alternately one by one in the circumferential direction CD. In the magnetic pole assembly 70, of two magnets 100 adjacent in the circumferential direction CD, one is the north magnet 100N and the other is the south magnet 100S. The multiple orientations OR include orientations ORN and ORS. The orientation ORN is the orientation OR of the hard magnetic material 90 in the north magnet 100N. The orientation ORS is the orientation OR of the hard magnetic material 90 in the south magnet 100S.

[0077] As shown in Figure 6, in the N magnet 100N, at least some of the multiple orientations OR have orientation components that face from the second surface 92 to the first surface 91 in the radial direction RD and approach the soft magnetic material 80 in the circumferential direction CD. For example, in the orientation ORN, the first orientation component OR1 faces the first surface 91. Also, in the orientation ORN, the second orientation component OR2 faces the soft magnetic material 80. In other words, the second orientation component OR2 faces toward the center of the N magnet 100N in the circumferential direction CD. In the N magnet 100N, the first surface 91 is the N pole face. Also, in the N magnet 100N, the second surface 92, the first end face 93, and the second end face 94 are S pole faces.

[0078] As shown in Figure 9, in the S magnet 100S, at least some of the multiple orientations OR have orientation components that point from the first surface 91 to the second surface 92 in the radial direction RD and away from the soft magnetic material 80 in the circumferential direction CD. For example, in the orientation ORS, the first orientation component OR1 faces toward the second surface 92. In addition, in the orientation ORS, the second orientation component OR2 faces away from the soft magnetic material 80. In other words, the second orientation component OR2 faces away from the center of the S magnet 100S in the circumferential direction CD. In the S magnet 100S, the first surface 91 is the S pole face. In addition, in the S magnet 100S, the second surface 92, the first end face 93, and the second end face 94 are N pole faces.

[0079] The plurality of orientations OR may include an orientation OR that does not have either the first orientation component OR1 or the second orientation component OR2. For example, the plurality of orientations OR may include an orientation OR whose orientation angle θ is 0° or 90°.

[0080] On assembly surfaces 71 and 72 of magnetic pole assembly portion 70, north and south pole faces are alternately aligned in the circumferential direction CD. For example, on first assembly surface 71, the first surface 91 of north magnet 100N and the first surface 91 of south magnet 100S are aligned in the circumferential direction CD, so that the north and south pole faces are aligned in the circumferential direction CD. On second assembly surface 72, the second surface 92 of north magnet 100N and the second surface 92 of south magnet 100S are aligned in the circumferential direction CD, so that the south and north pole faces are aligned in the circumferential direction CD.

[0081] Next, measuring the orientation of a motor magnet such as magnet 100 will be described. An operator can measure the orientation of a motor magnet by using a measuring device, for example. For example, the operator measures the orientation OR of hard magnetic material 90. The operator removes at least a portion of the motor magnet from the motor as the measurement object and measures the orientation of the measurement object. The orientation measured by the measuring device is displayed on a display screen or the like of the measuring device, with only multiple positions on the motor magnet sampled.

[0082] The worker may also perform orientation analysis on the motor magnet. In the orientation analysis, tasks and processes are performed to analyze the orientation of the motor magnet. For example, as the orientation analysis, the worker detects the magnetic flux generated in the motor magnet using a detection device or the like, and performs a process to estimate or calculate the orientation of the motor magnet using the detected magnetic flux. The worker may also use the results of the orientation analysis to identify the magnetic path through magnetic circuit analysis. Furthermore, the worker may perform the orientation analysis using electron backscatter diffraction. Electron backscatter diffraction is sometimes referred to as EBSD. Electron backscatter diffraction is a method for measuring the crystal orientation of a motor magnet. Electron backscatter diffraction makes it possible to quantitatively evaluate the extent to which the easy axis of magnetization, which is the orientation of the magnet, is oriented in a given direction.

[0083] According to the present embodiment described so far, the soft magnetic body 80 is provided on the first surface 91 side of the hard magnetic body 90, and extends from the first surface 91 toward the front of the second surface 92. As a result, the magnetic flux MF flowing inside the hard magnetic body 90 along the circumferential direction CD flows toward the stator 30 via the soft magnetic body 80. This improves torque performance.

[0084] In this embodiment, magnetic saturation in the soft magnetic material 80 is suppressed. Therefore, in magnet 100, both the first region P1 and the second region P2 in FIG. 5 can be made to contribute to an increase in torque. Therefore, by adjusting the thickness of soft magnetic material 80, there is no longer any restriction on the magnet thickness that can contribute to an increase in torque. In other words, by adjusting the length Ycore of soft magnetic material 80, the restriction that the second region P2 cannot contribute to an increase in torque can be eliminated.

[0085] The first region P1 and the second region P2 are regions aligned in the radial direction RD on the magnet 100. The first region P1 and the second region P2 are set to divide the magnet 100 in two. The first region P1 is the region on the first surface 91 side, and the second region P2 is the region on the second surface 92 side. For example, in the radial direction RD, the first region P1 is larger than the second region P2. Note that the regions P1 and P2 are set for convenience of explanation, and in reality, they are not clearly separate parts. The regions P1 and P2 are set to explain specific locations on the magnet 100.

[0086] For example, consider a comparative example in which the magnet 100 does not have a soft magnetic body 80, unlike this embodiment. In this comparative example, magnetic saturation is likely to occur because the hard magnetic body 90 is not provided with a soft magnetic body 80. When magnetic saturation occurs in the soft magnetic body 80 of the N magnet 100N in the comparative example, the magnetic flux flowing through the second region P2 is less likely to reach the first surface 91. For this reason, in this comparative example, the magnetic flux flowing between the magnet 100 and the stator 30 is more likely to decrease by the amount of magnetic flux flowing through the second region P2. Therefore, in this comparative example, the first region P1 is more likely to contribute to an increase in torque, while the second region P2 is less likely to contribute to an increase in torque.

[0087] In contrast, in this embodiment, a portion of the hard magnetic material 90 in the comparative example has been replaced with soft magnetic material 80. For this reason, in the N magnet 100N, magnetic saturation is less likely to occur in the soft magnetic material 80 than in the hard magnetic material 90, and as a result, the magnetic flux MF that reaches the soft magnetic material 80 from the second region P2 tends to pass through the soft magnetic material 80 and flow from the first opposing surface 81 toward the stator 30. Therefore, the magnetic flux MF that flows between the magnet 100 and the stator 30 is less likely to decrease by the amount of the magnetic flux MF flowing through the second region P2. This makes it possible to achieve an increase in torque by the magnetic flux MF flowing through the first region P1 and the magnetic flux MF flowing through the second region P2.

[0088] According to this embodiment, the area S1 of the first opposing surface 81 is equal to or smaller than the area S2 of the second opposing surface 82. This allows high-density magnetic flux MF to pass through the first opposing surface 81. For example, in the soft magnetic material 80, the magnetic flux density passing through the first opposing surface 81 tends to be greater than the magnetic flux density passing through the second opposing surface 82. For example, as shown in FIG. 10 , in the N magnet 100N, the magnetic flux MF collected from the second opposing surface 82 on the hard magnetic material 90 side can be made high-flux and released from the first opposing surface 81 to the stator 30 side. Furthermore, as shown in FIG. 11 , in the S magnet 100S, the magnetic flux MF flowing from the first opposing surface 81 on the stator 30 side can be made low-flux and released from the second opposing surface 82, thereby suppressing magnetic saturation in the hard magnetic material 90.

[0089] According to this embodiment, the product of the saturation magnetic flux density Bs of the soft magnetic body 80 and the area S1 of the first opposing surface 81 is equal to or greater than the product of the residual magnetic flux density Br of the hard magnetic body 90 and the area S2 of the second opposing surface 82. This suppresses magnetic saturation on the first opposing surface 81 side of the soft magnetic body 80.

[0090] 10, the magnetic flux density that can be emitted from the first opposing surface 81 toward the stator 30 is greater than the magnetic flux density that flows from the hard magnetic material 90 into the second opposing surface 82. In this configuration, the magnetic flux density that can be emitted from the first opposing surface 81 toward the stator 30 is relatively large, which allows the first opposing surface 81 on the stator 30 side to have a high magnetic flux.

[0091] 11, the magnetic flux density flowing into the first opposing surface 81 from the stator 30 side is greater than the magnetic flux density emitted from the second opposing surface 82 to the hard magnetic material 90. In this configuration, the magnetic flux density flowing into the first opposing surface 81 from the stator 30 side is relatively large, which makes it possible to increase the magnetic flux at the first opposing surface 81 on the stator 30 side.

[0092] According to this embodiment, the length Xcore of the soft magnetic body 80 in the circumferential direction CD increases in the radial direction RD from the second surface 92 toward the first surface 91. This makes it easier for a large amount of magnetic flux to pass through the second opposing surface.

[0093] For example, the magnetic flux MF passing through the soft magnetic body 80 tends to increase as one moves closer to the first opposing surface 81 from the tip end 82a. For this reason, there is a concern that magnetic saturation is more likely to occur in the soft magnetic body 80 at positions closer to the first opposing surface 81. In contrast, in the present embodiment, the length Xcore of the soft magnetic body 80 increases as one moves closer to the first opposing surface 81 in the radial direction RD. This configuration makes it easy to realize a configuration in which the longitudinal cross-sectional area of ​​the soft magnetic body 80 increases as one moves closer to the first opposing surface 81 in the radial direction RD. For this reason, it is possible to suppress the disadvantage that magnetic saturation is more likely to occur in the soft magnetic body 80 at positions closer to the first opposing surface 81.

[0094] Furthermore, with this configuration, it is possible to maximize the area S1 of the first opposing surface 81. This allows the amount of magnetic flux passing through the first opposing surface 81 to be maximized. For example, the N magnet 100N shown in FIG. 12 allows a large amount of magnetic flux MF to be emitted from the first surface 91 toward the stator 30. Furthermore, the S magnet 100S allows a large amount of magnetic flux MF to flow into the first surface 91 from the stator 30.

[0095] Furthermore, in this embodiment, the length Xcore of the soft magnetic body 80 becomes shorter as it approaches the tip end 82a in the radial direction RD. This configuration makes it easy to realize a configuration in which the volume of the soft magnetic body 80 becomes smaller as it approaches the tip end 82a in the radial direction RD. Therefore, in a configuration in which the soft magnetic body 80 is provided on the hard magnetic body 90, it is possible to prevent the volume or amount of the soft magnetic body 80 from becoming too large and resulting in a shortage of the volume or amount of the hard magnetic body 90. Therefore, by increasing the amount of magnetic flux generated in the hard magnetic body 90, it is possible to increase the torque.

[0096] According to this embodiment, the difference between the length Ymag of the hard magnetic body 90 and the length Ycore of the soft magnetic body 80 depends on half the length Xmag of the hard magnetic body 90. This makes it easier for high-density magnetic flux to pass through the first opposing surface 81.

[0097] For example, the hard magnetic material 90 and the soft magnetic material 80 are configured to satisfy Equation 2. This makes it possible to realize a configuration in which the magnetic flux flowing through the second region P2 opposite the stator 30 tends to concentrate in the first region P1 on the stator 30 side, while also achieving high magnetic flux to increase torque. For example, in magnet 100, the distance between the second surface 92 and the tip end 82a in the radial direction RD and the length Xmag of the hard magnetic material 90 are set to values ​​that make it easy for the magnetic flux MF to flow from the second region P2 into the soft magnetic material 80 and that make it easy for the magnetic flux MF to be high at the first opposing surface 81.

[0098] According to this embodiment, in the N-type magnet 100N, at least some of the multiple orientations OR have an orientation component that faces from the second surface 92 to the first surface 91 in the radial direction RD and approaches the soft magnetic material 80 in the circumferential direction CD. In this N-type magnet 100N, the magnetic flux MF that flows into the hard magnetic material 90 from the end faces 93, 94 can be made to flow toward the soft magnetic material 80 in a magnetic path that bulges toward the second surface 92. In the S-type magnet 100S, at least some of the multiple orientations OR have an orientation component that faces from the first surface 91 to the second surface 92 in the radial direction RD and moves away from the soft magnetic material 80 in the circumferential direction CD. In this S-type magnet 100S, the magnetic flux MF that flows into the hard magnetic material 90 from the soft magnetic material 80 can be made to flow toward the end faces 93, 94 in a magnetic path that bulges toward the second surface 92.

[0099] In this embodiment, one of the two magnets 100 adjacent in the circumferential direction CD is an N magnet 100N, and the other is an S magnet 100S. In this configuration, the magnetic path of the magnetic flux MF flowing from the soft magnetic material 80 of the N magnet 100N to the soft magnetic material 80 of the S magnet 100S becomes longer, which tends to create a state in which the magnet 100 is virtually thicker in the radial direction RD. In this way, by realizing a configuration in which the magnet 100 is virtually thicker in the radial direction RD, a high magnetic flux can be ensured.

[0100] According to this embodiment, the orientation component along the circumferential direction CD weakens and the orientation component along the radial direction RD strengthens as one approaches the soft magnetic material 80. This suppresses uneven distribution of magnetic flux density within the soft magnetic material 80. For example, with this configuration, in the N magnet 100N, the magnetic flux MF flowing into the hard magnetic material 90 from the end faces 93, 94 can be made to flow toward the soft magnetic material 80 along a magnetic path that bulges toward the second surface 92. Also, with this configuration, in the S magnet 100S, the magnetic flux MF flowing into the hard magnetic material 90 from the soft magnetic material 80 can be made to flow toward the end faces 93, 94 along a magnetic path that bulges toward the second surface 92.

[0101] When the rotor 40 and the stator 30 face each other, a magnetic path is determined by the magnetic flux emitted from both of them. This magnetic path is not uniquely determined by the orientation OR of the motor magnet 100 provided on the rotor 40. However, the magnetic path within the motor magnet 100 is strongly dependent on the orientation of the motor magnet 100.

[0102] For example, the magnetic path at the boundary between the hard magnetic material 90 and the soft magnetic material 80 in the motor magnet 100 strongly depends on the orientation OR on the boundary side of the hard magnetic material 90. At the boundary, the angle of the magnetic flux MF entering the soft magnetic material 80 from the hard magnetic material 90 and the magnetic flux MF entering the hard magnetic material 90 from the soft magnetic material 80 strongly depends on the orientation OR on the boundary side of the hard magnetic material 90.

[0103] The angle of the magnetic flux MF entering and leaving the boundary is closely related to determining the magnetic flux density distribution within the soft magnetic material 80. The closer the angle is to perpendicular to the boundary, the more the magnetic flux density is prevented from becoming biased within the soft magnetic material 80. This also prevents magnetic saturation from occurring in a portion of the soft magnetic material 80. Conversely, the farther the angle is from perpendicular, the more likely the magnetic flux density is to become biased within the soft magnetic material 80. This also makes it more likely that magnetic saturation will occur in a portion of the soft magnetic material 80.

[0104] Therefore, it is preferable that the angle between the orientation OR of the hard magnetic body 90 on the boundary side with the soft magnetic body 80 and the reference plane Sp that is perpendicular to the boundary and extends in the axial direction AD, which is the third direction, is as close to 0° as possible.

[0105] However, although the magnetic path within the motor magnet 100 is strongly dependent on the orientation OR of the motor magnet 100, the magnetic path also changes depending on the magnetic flux emitted from the stator 30. The angle also changes due to manufacturing errors. Taking these factors into consideration, it is preferable that the angle between the orientation OR and the reference plane Sp be 20° or less.

[0106] 5 , by causing the magnetic flux MF to flow from the second opposing surface 82 into the soft magnetic material 80 so that the magnetization orientation angle γ is 20° or less, more of the magnetic flux MF from the hard magnetic material 90 can flow into the soft magnetic material 80. In other words, the normal direction component tends to act effectively with respect to the second opposing surface 82. Therefore, the magnetic flux MF can be caused to flow in a direction that minimizes the magnetic resistance in the entire magnetic circuit including the stator 30.

[0107] According to this embodiment, two magnets 100 that are adjacent to each other in the circumferential direction CD are in contact with each other in the circumferential direction CD. In this configuration, the magnetic flux MF flows from one soft magnetic body 80 of the two magnets 100 adjacent to each other in the circumferential direction CD toward the other soft magnetic body 80 in the magnetic path, and therefore a high magnetic flux can be ensured because there is no high magnetic resistance portion along the magnetic path.

[0108] Second Embodiment In the second embodiment, the size and shape of the soft magnetic body 80 may be set according to the size and shape of the hard magnetic body 90 in the first embodiment. For example, in the second embodiment, the length Ymag of the hard magnetic body 90 is relatively large. The configuration, action, and effect not specifically described in the second embodiment are the same as those in the first embodiment. In the second embodiment, differences from the first embodiment will be mainly described. Hereinafter, the other embodiments will also be described, focusing on differences from the previously described embodiments.

[0109] As shown in Figure 13, in the magnet 100, the length of the hard magnetic body 90 in the radial direction RD is longer than the length in the circumferential direction CD. The length of the hard magnetic body 90 in the radial direction RD is length Ymag. The length in the circumferential direction CD is length Xmag. For example, in the hard magnetic body 90, length Ymag is greater than length Xmag. In the magnet 100, the distance between the second surface 92 and the tip end 82a in the radial direction RD is length Xcore3 or greater.

[0110] In magnet 100, the rate of change of the length of soft magnetic body 80 in the circumferential direction CD decreases in the radial direction RD from second surface 92 to first surface 91. In soft magnetic body 80, the rate at which length Xcore increases the closer to first opposing surface 81 in the radial direction RD, decreases the closer to first opposing surface 81. In second opposing surface 82, the surface connecting first opposing surface 81 and tip end portion 82a has a curved surface that bulges out toward end faces 93, 94.

[0111] Equation 6 holds true for magnet 100 in which the length Ymag of hard magnetic body 90 is large. Configurations in which length Ymag is large include configurations in which length Ymag is equal to or greater than length Xmag, and configurations in which length Ymag is smaller than length Xmag but the difference between length Ymag and length Xmag is smaller than a predetermined value. For example, this predetermined value is smaller than a few percent or a dozen percent of lengths Xmag and Ymag.

[0112] Xcore3 / Xcore2<Xcore2 / Xcore1 Equation 6 In magnet 100 with a large length Ymag, magnetic flux MF tends to concentrate on the tip end 82a side of soft magnetic material 80. In contrast, by making soft magnetic material 80 have a size and shape that satisfies Equation 6, it is possible to prevent magnetic saturation from occurring at tip end 82a of soft magnetic material 80 or at a position close to tip end 82a.

[0113] According to this embodiment, the rate of change of the length of the soft magnetic material 80 in the circumferential direction CD decreases in the radial direction RD from the second surface 92 to the first surface 91. This suppresses magnetic saturation on the first opposing surface 81 side of the soft magnetic material 80 and makes it easier for high-density magnetic flux MF to pass through the first opposing surface 81.

[0114] In variant 2-1, the length Ymag of the hard magnetic body 90 does not have to be large. For example, as shown in FIG. 14 , the length Ymag is smaller than the length Xmag. For example, in magnet 100, the distance between the second surface 92 and the tip end 82a in the radial direction RD is smaller than at least one of the lengths Xcore3 and Xcore3. In magnet 100, the rate at which the length Xcore increases the closer to the first opposing surface 81 in the radial direction RD is constant regardless of the distance from the first opposing surface 81. In second opposing surface 82, the surface connecting first opposing surface 81 and tip end 82a extends linearly.

[0115] In Modification 2-2, the length Ymag of the hard magnetic body 90 may be small. For example, as shown in FIG. 15 , the length of the hard magnetic body 90 in the radial direction RD is shorter than the length in the circumferential direction CD. For example, in the hard magnetic body 90, the length Ymag is shorter than the length Xmag. In the magnet 100, the distance between the second surface 92 and the tip end 82a in the radial direction RD is equal to or greater than the length Xcore3. Note that in the hard magnetic body 90, the length Ymag may be greater than the length of the second surface 92 in the circumferential direction CD, as long as it is smaller than the length Xmag.

[0116] In magnet 100, the rate of change of the length of soft magnetic body 80 in the circumferential direction CD increases from second surface 92 to first surface 91 in the radial direction RD. In soft magnetic body 80, the rate at which length Xcore increases the closer to the position in the radial direction RD is to first opposing surface 81 also increases the closer to the position is to first opposing surface 81. In second opposing surface 82, the surface connecting first opposing surface 81 and tip end 82a has a curved surface that is concave on the side opposite end faces 93, 94. In plan view, soft magnetic body 80 has a shape that tapers from first opposing surface 81 to tip end 82a.

[0117] Equation 7 holds true for magnet 100 in which the length Ymag of hard magnetic body 90 is small. A configuration in which length Ymag is small includes a configuration in which length Ymag is smaller than length Xmag. In a configuration in which length Ymag is smaller than length Xmag, it is preferable that the difference between length Ymag and length Xmag be greater than a predetermined value. For example, this predetermined value is greater than several tens or even several tens of percent of lengths Xmag and Ymag.

[0118] Xcore3 / Xcore2>Xcore2 / Xcore1 Equation 7 In magnet 100 with a small length Ymag, even if magnetic flux MF concentrates on the tip end 82a side of soft magnetic material 80, the amount of magnetic flux concentrated on tip end 82a is likely to be relatively small. In contrast, by making soft magnetic material 80 have a size and shape that satisfies Equation 7, it is possible to prevent magnetic saturation in hard magnetic material 90 while also preventing the volume or amount of hard magnetic material 90 from becoming insufficient.

[0119] According to the configuration of Modification 2-2, the rate of change of the length of the soft magnetic body 80 in the circumferential direction CD increases in the radial direction RD from the second surface 92 to the first surface 91. This suppresses magnetic saturation on the first opposing surface 81 side of the soft magnetic body 80, and makes it easier for high-density magnetic flux MF to pass through the first opposing surface 81.

[0120] Third Embodiment In a third embodiment, the relative size of the soft magnetic body 80 with respect to the hard magnetic body 90 may be different from that in the first embodiment.

[0121] 16 , in magnet 100, soft magnetic material 80 has a shape that extends in the circumferential direction CD. In soft magnetic material 80, length Ycore in radial direction RD is smaller than length Xcore3 of first opposing surface 81. In magnet 100, the distance between second surface 92 and tip end 82a in radial direction RD is larger than at least one of length Ycore and length Xcore of soft magnetic material 80.

[0122] In Modification 3-1, the length Ycore of the soft magnetic body 80 may be relatively large. For example, as shown in FIG. 17 , the distance between the second surface 92 and the tip end 82a in the radial direction RD is smaller than both the length Ycore and the length Xcore of the soft magnetic body 80. The magnet 100 is configured not to satisfy Equation 1 of the first embodiment. For example, the distance between the second surface 92 and the tip end 82a in the radial direction RD is smaller than half the length Xamg of the hard magnetic body 90.

[0123] In Modification 3-2, the length Ycore of the soft magnetic body 80 may be relatively small. For example, as shown in FIG. 18 , the distance between the second surface 92 and the tip end 82a in the radial direction RD is greater than both the length Ycore and the length Xcore of the soft magnetic body 80. As with Modification 3-1, the magnet 100 is configured not to satisfy Equation 1 of the first embodiment. For example, the distance between the second surface 92 and the tip end 82a in the radial direction RD is greater than half the length Xamg of the hard magnetic body 90.

[0124] Fourth Embodiment In a fourth embodiment, the soft magnetic body 80 may protrude further toward the stator 30 side than the first surface 91 .

[0125] As shown in FIG. 19 , the soft magnetic body 80 protrudes radially outward from the recess 97, thereby protruding from the recess 97 toward the stator 30. The soft magnetic body 80 has an indented portion 85 and a protruding portion 86. The indented portion 85 is indented into the recess 97. The indented portion 85 is housed in the recess 97. The indented portion 85 forms a second opposing surface 82. The protruding portion 86 extends from the indented portion 85 toward the stator 30. The protruding portion 86 protrudes from the first surface 91 and the recess 97 toward the stator 30. The protruding portion 86 forms the first opposing surface 81. The first opposing surface 81 is located away from the first surface 91 toward the stator 30. As in the first embodiment, the first opposing surface 81 extends in a direction perpendicular to the radial direction RD.

[0126] In this embodiment, the first opposing surface 81 of the soft magnetic body 80 that faces the stator 30 is farther away from the second surface 92 in the radial direction RD than the first surface 91 of the hard magnetic body 90. For example, the first opposing surface 81 is provided at a position closer to the stator 30 than the first surface 91. This narrows the radial gap 20, thereby enabling high torque to be achieved.

[0127] In Modification 4-1, the first opposing surfaces 81 may be curved so as to bulge toward the stator 30. For example, as shown in Fig. 20 , the first opposing surfaces 81 are curved surfaces that are curved so that the center of the first opposing surfaces 81 in the circumferential direction CD protrudes toward the stator 30.

[0128] In Modification 4-2, the protruding portion 86 may extend in the circumferential direction CD further than the recessed portion 85. For example, as shown in Fig. 21 , the protruding portion 86 extends from the recessed portion 85 toward both the first end face 93 side and the second end face 94 side.

[0129] Fifth Embodiment In a fifth embodiment, the area S1 of the first opposing surface 81 does not have to be equal to or smaller than the area S2 of the second opposing surface 82 .

[0130] 22 , in the soft magnetic body 80, the area S1 of the first opposing surface 81 is larger than the area S2 of the second opposing surface 82. In the soft magnetic body 80, the first opposing surface 81 is curved so as to bulge toward the stator 30, as in the modified example 4-1, thereby making the area S1 as large as possible. Furthermore, the length Ycore of the soft magnetic body 80 is made as small as possible, thereby making the area S2 as small as possible. Furthermore, as in the modified example 2-1, the surface of the second opposing surface 82 that connects the first opposing surface 81 and the tip end 82 a extends linearly, thereby making the area S2 as small as possible.

[0131] Sixth Embodiment In a sixth embodiment, the size or shape of the cross section of at least one of the magnet 100, the hard magnetic body 90, and the soft magnetic body 80 does not have to be uniform in the axial direction AD.

[0132] 23 , the size and shape of the cross section of the hard magnetic body 90 and the soft magnetic body 80 are not uniform in the axial direction AD. In the soft magnetic body 80, the length Xcore3 of the first opposing surface 81 is not uniform in the axial direction AD. For example, the length Xcore1 increases the farther it is from the side surfaces 83 and 84 in the axial direction AD. In the first opposing surface 81, the length Xcore3 at the side surfaces 83 and 84 is smaller than the length Xcore3 at the center between the first side surface 95 and the second side surface 96.

[0133] In Modification 6-1, at least one of the magnet 100, hard magnetic material 90, and soft magnetic material 80 may extend in a direction inclined with respect to the axial direction AD. For example, as shown in Figure 24, the magnet 100, hard magnetic material 90, and soft magnetic material 80 each extend in a direction inclined in the circumferential direction CD with respect to the axial direction AD. In a skewed magnet 100, the hard magnetic material 90 and soft magnetic material 80 are also each skewed so that the soft magnetic material 80 is positioned in the center of the hard magnetic material 90 in the circumferential direction CD.

[0134] Seventh Embodiment In a seventh embodiment, two magnets 100 adjacent to each other in the circumferential direction CD do not have to be in contact with each other.

[0135] As shown in FIG. 25 , the rotor 40 has an interposition portion 55. The interposition portion 55 is included in the magnetic pole assembly portion 70. The interposition portion 55 is provided between two magnets 100 that are adjacent to each other in the circumferential direction CD. One of the two magnets 100 that are adjacent to each other in the circumferential direction CD via the interposition portion 55 is a north magnet 100N, and the other is a south magnet 100S. The interposition portion 55 is provided between the north magnet 100N and the south magnet 100S. The interposition portion 55 extends in the radial direction RD so as to span between the first surface 91 and the second surface 92. The interposition portion 55 also extends in the axial direction AD so as to span between the first side surface 95 and the second side surface 96.

[0136] The interposed portion 55 is formed to include a soft magnetic material, similar to the soft magnetic body 80. For example, the interposed portion 55 includes a soft magnetic member.

[0137] According to this embodiment, an interposed portion 55 containing a soft magnetic material is provided between two magnets 100 that are arranged adjacent to each other in the circumferential direction CD. This configuration can improve torque generation efficiency compared to a configuration in which a non-magnetic material is provided between the two magnets 100.

[0138] Eighth Embodiment In an eighth embodiment, the magnet 100 may be provided with a gap.

[0139] As shown in Figure 26, the magnet 100 has a gap 58. The gap 58 is formed in the hard magnetic material 90, but is not formed in the soft magnetic material 80. A notch is formed in the magnet 100. The gap 58 is a gap formed by the notch in the magnet 100. The gap 58 is open in the radial direction RD toward the side opposite to the stator 30. For example, the gap 58 extends in the radial direction RD so as to span between the tip end portion 82a and the second surface 92.

[0140] In Modification 8-1, the void 58 may be provided in at least one of the hard magnetic body 90 and the soft magnetic body 80. As shown in Fig. 27 , the void 58 is provided in both the hard magnetic body 90 and the soft magnetic body 80. For example, the void 58 extends in the radial direction RD so as to span between the first surface 91 and the first opposing surface 81.

[0141] Ninth Embodiment In a ninth embodiment, the rotor 40 does not necessarily have to have the rotor core 51 .

[0142] 28, the rotor 40 has a non-magnetic body 151 instead of the rotor core 51. The non-magnetic body 151 is made of a non-magnetic material such as a resin material. The non-magnetic body 151 is provided on the inner periphery of the magnet 100 and the magnetic pole assembly portion 70. In the motor 10, the rotor 40 does not have a rotor core 51, so there is no back core for the magnet 100.

[0143] Tenth Embodiment In a tenth embodiment, the magnetic pole assembly 70 does not necessarily have to include a plurality of magnets 100 .

[0144] As shown in Figure 29, the magnetic pole assembly 70 may be formed from a single magnet member. In the magnetic pole assembly 70, multiple magnet regions 106 are arranged in the circumferential direction CD. The magnet regions 106 are regions in the magnetic pole assembly 70 that correspond to the magnet 100 of the first embodiment. The magnet regions 106 correspond to the motor magnet. The multiple magnet regions 106 include an N magnet region 106N and an S magnet region 106S. The N magnet region 106N and the S magnet region 106S are regions in the magnetic pole assembly 70 that correspond to the N magnet 100N and S magnet 100S of the first embodiment.

[0145] In the magnetic pole assembly 70, a plurality of hard magnetic regions 105 are arranged in the circumferential direction CD. The hard magnetic regions 105 are regions in the magnetic pole assembly 70 that correspond to the hard magnetic bodies 90 in the first embodiment. The hard magnetic regions 105 correspond to the hard magnetic bodies. In the magnetic pole assembly 70, soft magnetic bodies 80 are provided in the hard magnetic regions 105, thereby forming magnet regions 106. The magnet regions 106 include the hard magnetic regions 105 and the soft magnetic bodies 80.

[0146] Eleventh Embodiment In the eleventh embodiment, at least one of the first orientation component OR1 and the second orientation component OR2 may not be uniform in at least one of the plurality of orientations OR aligned in the circumferential direction CD and the plurality of orientations OR aligned in the radial direction RD in the hard magnetic body 90. That is, the orientations of the plurality of orientations OR aligned in the circumferential direction CD may not be the same, and the orientations of the plurality of orientations OR aligned in the radial direction RD may not be the same.

[0147] 30 , similar to the first embodiment, in the hard magnetic body 90, the second orientation component OR2 of the orientation OR on the end surface 93, 94 side is larger than the second orientation component OR2 of the orientation OR on the soft magnetic body 80 side. In addition, in the hard magnetic body 90, the second orientation component OR2 of the orientation OR on the second surface 92 side is larger than the second orientation component OR2 of the orientation OR on the first surface 91 side. Also, similar to the first embodiment, in the hard magnetic body 90, multiple orientations OR are distributed such that the second orientation component OR2 gradually decreases from the end surfaces 93, 94 toward the soft magnetic body 80. In addition, in the hard magnetic body 90, multiple orientations OR are distributed such that the second orientation component OR2 gradually decreases from the second surface 92 toward the first surface 91.

[0148] As in the first embodiment, in the hard magnetic body 90, the first orientation component OR1 of the orientation OR on the end surface 93, 94 side is smaller than the first orientation component OR1 of the orientation OR on the soft magnetic body 80 side. In addition, in the hard magnetic body 90, the first orientation component OR1 of the orientation OR on the second surface side is smaller than the first orientation component OR1 of the orientation OR on the first surface 91 side. Also, as in the first embodiment, in the hard magnetic body 90, multiple orientations OR are distributed such that the first orientation component OR1 gradually increases from the end surfaces 93, 94 toward the soft magnetic body 80. In addition, in the hard magnetic body 90, multiple orientations OR are distributed such that the first orientation component OR1 gradually increases from the second surface 92 toward the first surface 91.

[0149] Twelfth Embodiment In a twelfth embodiment, the magnet 100 may be provided in an outer rotor type motor.

[0150] As shown in Fig. 31 , in this embodiment, a field element of the rotor 40 or the like is provided on the outer periphery of an exciter of the stator 30 or the like. The housing 11 and the shaft 12 are not shown in Fig. 31 . In this embodiment, the magnetic pole assembly 70 and the magnet 100 are provided on the inner periphery of the rotor core 51. The magnetic pole assembly 70 and the magnet 100 are provided on the outer periphery of the stator 30. In the magnet 100, the first surface 91 and the first opposing surface 81 face the inner periphery, and the second surface 92 faces the outer periphery.

[0151] Thirteenth Embodiment In the first embodiment, an example was shown in which the stator 30 is an exciter and the rotor 40 is a field element. In contrast to this, in this embodiment, the rotor 40 is an exciter and the stator 30 is a field element. As shown in Fig. 32 , the stator 30, not the rotor 40, has the magnet 100. The rotor 40 has a rotor coil 135 instead of the magnet 100.

[0152] The stator core 31 has a core support portion 36. The core support portion 36 contains a soft magnetic material. The overall shape of the core support portion 36 is annular. A plurality of magnets 100 are provided on the inner circumferential surface of the core support portion 36. The core support portion 36 performs the same function as the rotor core 51 described in the first embodiment in forming a magnetic path.

[0153] A magnetic pole assembly 200 is formed by a plurality of magnets 100. The rotor 40 is provided in the space surrounded by this magnetic pole assembly 200.

[0154] The rotor core 51 has a shaft connecting portion 52 and rotor teeth 53. The rotor teeth 53 are connected to the outer peripheral surface of the shaft connecting portion 52. The rotor teeth 53 extend from the shaft connecting portion 52 toward the stator 30. The motor axis Cm is located on an extension of the rotor teeth 53 in the radial direction RD. The multiple rotor teeth 53 are aligned in the circumferential direction CD. A rotor coil 135 is wound around these multiple rotor teeth 53. When current is applied to the rotor coil 135, the rotor 40 is excited.

[0155] As described above, the motor 10 of this embodiment is an inner rotor type radial motor. However, the motor 10 of this embodiment can also be used as an outer rotor type radial motor as described in the twelfth embodiment.

[0156] Fourteenth Embodiment In a fourteenth embodiment, the magnet 100 may be provided in an axial gap motor.

[0157] The motor 110 shown in Figures 33 and 34 is an axial gap motor. An axial gap motor is sometimes called an axial motor. The motor 110 is sometimes called a rotary motor. In the motor 110, a stator 130 and a rotor 140 are arranged in the axial direction AD with an axial gap 120 interposed therebetween. The axial gap 120 is a gap between the stator 130 and the rotor 140. The rotor 140 is fixed to a shaft 112. In Figure 34, the rotor core 51 and the shaft 112 are not shown.

[0158] In this embodiment, the motor 110, shaft 112, stator 130, and rotor 140 are configured to correspond to the motor 10, shaft 12, stator 30, and rotor 40 of the first embodiment. The motor 110 of this embodiment differs significantly from the motor 10 of the first embodiment in that the stator 130 and rotor 140 are aligned in the axial direction AD. In this embodiment, the stator 130 corresponds to the exciter, and the rotor 140 corresponds to the field element. The shaft 112 corresponds to the rotation axis. The circumferential direction CD is the direction around the rotation axis.

[0159] As shown in Figures 35, 36, and 37, the magnet 100, hard magnetic body 90, and soft magnetic body 80 are formed in a columnar shape extending in the radial direction RD. In the hard magnetic body 90, a first surface 91 and a second surface 92 are aligned in the axial direction AD. The first surface 91 and the second surface 92 extend in a direction perpendicular to the axial direction AD. In the soft magnetic body 80, a first opposing surface 81 extends in a direction perpendicular to the axial direction AD. In the magnet 100, the first surface 91 and the first opposing surface 81 face the stator 130 via an axial gap 120.

[0160] In this embodiment, the stator 30 and the rotor 40 are arranged opposite each other in the axial direction AD. The axial direction AD corresponds to the first direction, and the circumferential direction CD corresponds to the second direction. Furthermore, the configuration in which the stator 30 and the rotor 40 are arranged opposite each other in the axial direction AD corresponds to the configuration in which an exciter and a field element are arranged opposite each other in the first direction.

[0161] 37 , in the hard magnetic body 90, the second orientation component OR2 of the orientation OR is along the circumferential direction CD. In the hard magnetic body 90, at least a portion of the orientation OR is inclined in the axial direction AD with respect to the circumferential direction CD. The orientation OR is not inclined in the radial direction RD with respect to the circumferential direction CD. The orientations and orientation components of the orientation OR with respect to the first and second directions are configured in the same manner as in the first embodiment.

[0162] An axial motor may be provided with a plurality of stators 130 and rotors 140. For example, in the motor 110, two rotors 140 may be arranged side by side in the axial direction AD with the stator 130 interposed therebetween. This motor 110 is sometimes referred to as a double-rotor motor. Also, two stators 130 may be arranged side by side in the axial direction AD with the rotor 140 interposed therebetween. This motor 110 is sometimes referred to as a double-stator motor.

[0163] Fifteenth Embodiment In a fifteenth embodiment, the magnet 100 may be provided in a linear motor.

[0164] The motor 210 shown in Figure 38 is a linear motor that performs linear motion. In the motor 210, a stator 230 and a mover 240 are aligned in the radial direction RD. The mover 240 and shaft 212 are movable in the axial direction AD relative to the stator 230. The mover 240 is attached to the shaft 212. The shaft 212 moves linearly in the axial direction AD. In the motor 210, the stator 230 and the mover 240 are aligned in the radial direction RD with a linear gap 220 interposed therebetween. The linear gap 220 is a gap between the stator 230 and the mover 240. A plurality of magnets 100 are aligned in a straight line along the axial direction AD. In the mover 240, a rotor core 51 and a magnetic pole assembly 70 extend along the axial direction AD.

[0165] In this embodiment, the motor 210, shaft 212, stator 230, and mover 240 are configured to correspond to the motor 10, shaft 12, stator 30, and rotor 40 of the first embodiment. The motor 210 of this embodiment differs greatly from the motor 10 of the first embodiment in that the mover 240 moves in the axial direction AD relative to the stator 230. In this embodiment, the stator 230 corresponds to the exciter, and the mover 240 corresponds to the field element. The shaft 212 corresponds to the linear motion axis. The axial direction AD is a direction along the linear motion axis. In a linear motor, the stator 30 is sufficiently longer in the axial direction AD than the rotor 40.

[0166] The magnet 100 is provided on the outer periphery of the rotor core 51. The magnet 100 is formed in an annular shape so as to cover the rotor core 51 from the outer periphery. In the magnet 100, the hard magnetic body 90 and the soft magnetic body 80 are formed in an annular shape so as to extend in the circumferential direction CD. In the hard magnetic body 90, the first surface 91 and the second surface 92 are aligned in the radial direction RD. The first surface 91 and the second surface 92 extend in a direction perpendicular to the radial direction RD. In the soft magnetic body 80, the first opposing surface 81 extends in a direction perpendicular to the radial direction RD. In the magnet 100, the first surface 91 and the first opposing surface 81 face the stator 130 via a linear gap 220.

[0167] In this embodiment, the stator 30 and the rotor 40 are disposed opposite each other in the radial direction RD. The radial direction RD corresponds to the first direction, and the axial direction AD corresponds to the second direction. Furthermore, the configuration in which the stator 30 and the rotor 40 are disposed opposite each other in the radial direction RD corresponds to the configuration in which an exciter and a field element are disposed opposite each other in the first direction.

[0168] In the hard magnetic body 90, the second orientation component OR2 of the orientation OR is along the axial direction AD. In the hard magnetic body 90, at least a portion of the orientation OR is inclined in the radial direction RD with respect to the axial direction AD. The orientation OR is not inclined in the circumferential direction CD with respect to the axial direction AD. The directions and orientation components of the orientation OR with respect to the first direction and the second direction are configured in the same manner as in the first embodiment.

[0169] <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 the omission of parts and elements from the embodiments. 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 equivalent to the claims.

[0170] In each embodiment, the soft magnetic material 80 may be provided on the hard magnetic material 90 in any manner as long as the soft magnetic material 80 extends from the first surface 91 toward the front of the second surface 92. In the magnet 100, the hard magnetic material 90 may cover at least a portion of the soft magnetic material 80 from the stator 30 side. For example, the soft magnetic material 80 may be provided at a position away from the first surface 91 toward the second surface 92. The soft magnetic material 80 may be provided at a position closer to the first end surface 93 or the second end surface 94 from the center of the hard magnetic material 90. In the soft magnetic material 80, the length Xcore does not have to increase from the tip end portion 82a toward the first opposing surface 81. For example, the length Xcore1 of the tip end portion 82a and the length Xcore2 of the intermediate portion do not have to be smaller than the length Xcore3 of the first opposing surface 81.

[0171] In each embodiment, the orientation of the OR in the hard magnetic material 90 may be set in any way. For example, in the north magnet 100N, the orientation of the OR may be set so that the first surface 91 is the north pole face. In the south magnet 100S, the orientation of the OR may be set so that the first surface 91 is the south pole face.

[0172] In each embodiment, the magnitude of the orientations OR may not be the same for all orientations OR. For example, one of two orientations OR may be larger than the other orientation OR. In one orientation OR, both the first orientation component OR1 and the second orientation component OR2 may be larger than either the first orientation component OR1 or the second orientation component OR2 in the other orientation OR.

[0173] In each embodiment, the magnet 100, hard magnetic material 90, and soft magnetic material 80 may have any shape. For example, in the first embodiment, the first surface 91, the second surface 92, and the first opposing surface 81 do not have to extend in a direction perpendicular to a first direction such as the radial direction RD. Furthermore, the first end surface 93 and the second end surface 94 do not have to extend in a direction perpendicular to a second direction such as the circumferential direction CD. Furthermore, the first side surface 95, the second side surface 96, the first side surface 83, and the second side surface 84 do not have to extend in a direction perpendicular to a third direction such as the axial direction AD.

[0174] In each embodiment, one hard magnetic body 90 may be formed to include a plurality of hard magnetic members, and one soft magnetic body 80 may be formed to include a plurality of soft magnetic members.

[0175] In each embodiment, two adjacent protrusions 86 in the circumferential direction CD may be connected to each other. Also, a gap may be provided between two adjacent magnets 100 in the circumferential direction CD.

[0176] In each embodiment, a motor magnet such as magnet 100 may be provided in a stator, rotor, or mover, regardless of the type of motor, as long as it is included in the field magnet of the motor.

[0177] In each embodiment, the first direction and the second direction do not have to be orthogonal as long as they intersect with each other. For example, in the first embodiment, the radial direction RD, which is the first direction, and the circumferential direction CD, which is the second direction, do not have to be orthogonal as long as they intersect with each other. In the fifteenth embodiment, the radial direction RD or the Y direction, which is the first direction, and the axial direction AD or the X direction, which is the second direction, do not have to be orthogonal as long as they intersect with each other.

[0178] In each embodiment, the magnetic powder and other materials contained in the motor magnet, such as magnet 100, can be appropriately selected as long as they satisfy the performance of the motor magnet. The motor magnet will have characteristics that arise from the combination of the selected magnetic powder and other materials. A motor magnet with such characteristics is used in a motor. Note that materials other than the magnetic powder do not necessarily need to be included in the motor magnet.

[0179] 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.

[0180] If the motor magnet requires at least one of small size and light weight and ease of modification, then a finer particle size of the magnetic powder is preferable. The particle size of the magnetic powder can be either micro- or nano-scale. If ease of material procurement is required, then it is desirable that the magnetic powder has simple and abundant components and does not contain rare earth elements. If it is required to withstand use under harsh conditions, then it is desirable that the magnetic powder has high heat resistance, radiation resistance, etc.

[0181] 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.

[0182] Of course, motor magnets used in motors are required to produce output appropriate for their intended use. The magnetic powder contained in the motor magnet can be any magnetic powder expected to produce the output appropriate for the intended use. Examples of magnets 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. 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 metal magnet materials include spinodal decomposition systems such as alnico and Fe-Cr-Co, and Fe16N2. The above R stands for rare earth, which includes Nd, Sm, Dy, etc. T stands for transition metal, which includes Fe, Co, Ni, etc.

[0183] In each embodiment, the motor magnet, field element, and various devices in which the motor is installed are not particularly limited. In other words, the application of the motor employing the motor magnet is not particularly limited. The motor can be used for consumer, commercial, industrial, medical, and other purposes. For example, the motor can be used in 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, even if not specifically exemplified, the motor magnet can be widely and generally applied to any device that includes a motor.

[0184] Mobility products include cars for land transportation, aircraft for air transportation, ships for water transportation, submarines and submersibles for underwater transportation, and spacecraft for space travel.

[0185] These means of transportation on land, air, water, and space include manned and unmanned aircraft. Vehicles include manned and unmanned automobiles. Specifically for transporting goods, vehicles include manned and unmanned guided vehicles. Unmanned guided vehicles are sometimes called AGVs. AGV is an abbreviation for Automated Guided Vehicle. Aircraft include manned and unmanned aircraft. Unmanned aircraft are sometimes called UAVs. UAV is an abbreviation for Unmanned Aerial Vehicle. Specifically for transporting goods, ships include manned and unmanned ships. Submarines and submarines include manned and unmanned submersibles. Spacecraft include manned and unmanned spacecraft. Manned spacecraft are sometimes called spaceships.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] In each embodiment, the motor provided with the motor magnet such as the magnet 100 does not have to be an AC motor. For example, the motor provided with the motor magnet may be a DC motor or a stepping motor.

[0190] (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, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0191] (Technical Idea 1) A motor magnet (100) included in either a field element (40; 140; 240) or an exciter (30; 130; 230) arranged opposite each other in a first direction (RD; AD; RD), comprising: a hard magnetic body (90) having a plurality of orientations (OR); and a soft magnetic body (80) provided on the hard magnetic body, at least a portion of the plurality of orientations having an orientation component (OR2) along a second direction (CD; CD; AD) intersecting the first direction, and the soft magnetic body is provided on a first surface (91) side of the hard magnetic body that faces the field element, and extends from the first surface toward a second surface (92) on the back side thereof.

[0192] (Technical Idea 2) A motor magnet according to Technical Idea 1, wherein an area (S1) of a first opposing surface (81) of the soft magnetic material that faces the field element is equal to or smaller than an area (S2) of a second opposing surface (82) of the soft magnetic material that faces the hard magnetic material.

[0193] (Technical Idea 3) A motor magnet according to Technical Idea 2, wherein the product of the saturation magnetic flux density (Bs) of the soft magnetic material and the area of ​​the first opposing surface is equal to or greater than the product of the residual magnetic flux density (Br) of the hard magnetic material and the area of ​​the second opposing surface.

[0194] (Technical Idea 4) A motor magnet according to any one of Technical Ideas 1 to 3, wherein the length (Xcore) of the soft magnetic material in the second direction increases from the second surface toward the first surface in the first direction.

[0195] (Technical Idea 5) A motor magnet according to Technical Idea 4, wherein the length (Ymag) of the hard magnetic material in the first direction is longer than the length (Xmag) of the hard magnetic material in the second direction, and the rate of change of the length of the soft magnetic material in the second direction decreases from the second surface toward the first surface in the first direction.

[0196] (Technical Idea 6) A motor magnet according to Technical Idea 4, wherein the length (Ymag) of the hard magnetic material in the first direction is shorter than the length (Xmag) of the hard magnetic material in the second direction, and the rate of change of the length of the soft magnetic material in the second direction increases from the second surface toward the first surface in the first direction.

[0197] (Technical Idea 7) A motor magnet according to any one of Technical Ideas 1 to 6, wherein the difference between the length (Ymag) of the hard magnetic body in the first direction and the length (Ycore) of the soft magnetic body in the first direction depends on half the length of the hard magnetic body in the second direction.

[0198] (Technical Idea 8) A motor magnet described in any one of Technical Ideas 1 to 7, wherein the soft magnetic material is provided on the center side of the first surface in the second direction, and at least some of the multiple orientations have an orientation component that extends from the second surface to the first surface in the first direction and approaches the soft magnetic material in the second direction, or an orientation component that extends from the first surface to the second surface in the first direction and moves away from the soft magnetic material in the second direction.

[0199] (Technical Concept 9) The motor magnet according to Technical Concept 8, wherein the orientation component along the second direction weakens and the orientation component along the first direction strengthens as the magnet approaches the soft magnetic material.

[0200] (Technical Idea 10) A motor magnet according to Technical Idea 9, wherein the angle (γ) between the orientation of the hard magnetic material on the boundary side between the hard magnetic material and the soft magnetic material and a reference plane (Sp) extending in a third direction (AD; RD; CD) perpendicular to the boundary and orthogonal to the first direction and the second direction is 20° or less.

[0201] (Technical Idea 11) A field element (40; 140; 240) having a plurality of motor magnets (100) arranged opposite an exciter (30; 130; 230) in a first direction (RD; AD; RD) and aligned in a second direction (CD; CD; AD) intersecting the first direction, wherein the motor magnet comprises a hard magnetic body (90) having a plurality of orientations (OR), and a soft magnetic body (80) provided on the hard magnetic body, at least some of the plurality of orientations have an orientation component (OR2) along the second direction, and the soft magnetic body is provided on a first surface (91) of the hard magnetic body on the exciter side, and extends from the first surface toward a second surface (92) on the back side thereof.

[0202] (Technical Concept 12) The field element according to Technical Concept 11, wherein two of the motor magnets arranged adjacent to each other in the second direction are in contact with each other in the second direction.

[0203] (Technical Concept 13) The field element according to Technical Concept 11, wherein an intervening portion (55) including a soft magnetic material is provided between two of the motor magnets arranged adjacent to each other in the second direction.

[0204] (Technical Idea 14) A motor comprising: a field element (40; 140; 240); and an armature (30; 130; 230) arranged opposite the field element in a first direction (RD; AD; RD), wherein either the field element or the armature has a plurality of motor magnets (100) arranged in a second direction (CD; CD; AD) that intersects the first direction, wherein the motor magnet has a hard magnetic body (90) with a plurality of orientations (OR), and a soft magnetic body (80) provided on the hard magnetic body, wherein at least a portion of the plurality of orientations have an orientation component (OR2) along the second direction, and the soft magnetic body is provided on a first surface (91) of the hard magnetic body that faces the field element, and extends from the first surface toward a second surface (92) on the back side thereof.

[0205] (Technical Idea 15) The motor according to Technical Idea 14, wherein the first direction is a radial direction (RD) perpendicular to a rotation axis (12) on which one of the field element and the armature is provided, and the second direction is a circumferential direction (CD) around the rotation axis.

[0206] (Technical Idea 16) The motor according to Technical Idea 14, wherein the first direction is an axial direction (AD) along a rotation axis (112) on which one of the field element and the armature is provided, and the second direction is a circumferential direction (CD) around the rotation axis.

[0207] (Technical Idea 17) A motor according to Technical Idea 14, wherein the first direction is a direction (RD) perpendicular to a linear motion axis (212) along which one of the field element and the armature is provided, and the second direction is an axial direction (AD) along the linear motion axis.

Claims

1. A motor magnet (100) included in either a field element (40; 140; 240) or an exciter (30; 130; 230) arranged opposite each other in a first direction (RD; AD; RD), comprising: a hard magnetic body (90) having a plurality of orientations (OR); and a soft magnetic body (80) provided on the hard magnetic body, at least a portion of the plurality of orientations having an orientation component (OR2) along a second direction (CD; CD; AD) intersecting the first direction, and the soft magnetic body is provided on a first surface (91) side of the hard magnetic body that faces the field element, and extends from the first surface toward a second surface (92) on the back side thereof.

2. A motor magnet as described in claim 1, wherein the area (S1) of a first opposing surface (81) of the soft magnetic material that faces the field element is equal to or smaller than the area (S2) of a second opposing surface (82) of the soft magnetic material that faces the hard magnetic material.

3. A motor magnet according to claim 2, wherein the product of the saturation magnetic flux density (Bs) of the soft magnetic material and the area of ​​the first opposing surface is equal to or greater than the product of the residual magnetic flux density (Br) of the hard magnetic material and the area of ​​the second opposing surface.

4. A motor magnet according to claim 1, wherein the length (Xcore) of the soft magnetic material in the second direction increases from the second surface toward the first surface in the first direction.

5. A motor magnet as set forth in claim 4, wherein the length (Ymag) of said hard magnetic material in said first direction is longer than the length (Xmag) of said second direction, and the rate of change of the length of said soft magnetic material in said second direction decreases from said second surface toward said first surface in said first direction.

6. A motor magnet as set forth in claim 4, wherein the length (Ymag) of said hard magnetic material in said first direction is shorter than the length (Xmag) of said second direction, and the rate of change of the length of said soft magnetic material in said second direction increases from said second surface toward said first surface in said first direction.

7. A motor magnet as described in claim 1, wherein the difference between the length (Ymag) of the hard magnetic material in the first direction and the length (Ycore) of the soft magnetic material in the first direction depends on half the length of the hard magnetic material in the second direction.

8. A motor magnet as described in any one of claims 1 to 7, wherein the soft magnetic material is provided on the central side of the first surface in the second direction, and at least some of the multiple orientations have an orientation component that extends from the second surface to the first surface in the first direction and approaches the soft magnetic material in the second direction, or an orientation component that extends from the first surface to the second surface in the first direction and moves away from the soft magnetic material in the second direction.

9. A motor magnet according to claim 8, wherein the orientation component along the second direction weakens and the orientation component along the first direction strengthens as the magnet approaches the soft magnetic material.

10. A motor magnet as described in claim 9, wherein the angle (γ) formed between the orientation of the hard magnetic material on the boundary side between the hard magnetic material and the soft magnetic material and a reference plane (Sp) that is perpendicular to the boundary and extends in a third direction (AD; RD; CD) orthogonal to the first direction and the second direction is 20° or less.

11. A field element (40; 140; 240) having a plurality of motor magnets (100) arranged opposite an exciter (30; 130; 230) in a first direction (RD; AD; RD) and aligned in a second direction (CD; CD; AD) intersecting the first direction, wherein the motor magnet comprises a hard magnetic body (90) having a plurality of orientations (OR) and a soft magnetic body (80) provided on the hard magnetic body, at least a portion of the plurality of orientations having an orientation component (OR2) along the second direction, and the soft magnetic body is provided on a first surface (91) of the hard magnetic body on the exciter side, and extends from the first surface toward a second surface (92) on the back side thereof.

12. A field element according to claim 11, wherein two of the motor magnets arranged adjacent to each other in the second direction are in contact with each other in the second direction.

13. A field element according to claim 11, wherein an intervening portion (55) containing a soft magnetic material is provided between two of the motor magnets that are arranged adjacent to each other in the second direction.

14. A motor comprising: a field element (40; 140; 240); and an armature (30; 130; 230) arranged opposite the field element in a first direction (RD; AD; RD), wherein either the field element or the armature has a plurality of motor magnets (100) arranged in a second direction (CD; CD; AD) intersecting the first direction, wherein the motor magnet has a hard magnetic body (90) with a plurality of orientations (OR) and a soft magnetic body (80) provided on the hard magnetic body, wherein at least a portion of the plurality of orientations have an orientation component (OR2) along the second direction, and the soft magnetic body is provided on a first surface (91) of the hard magnetic body that faces the field element, and extends from the first surface toward a second surface (92) on the back side thereof.

15. A motor as described in claim 14, wherein the first direction is a radial direction (RD) perpendicular to a rotation axis (12) on which one of the field element and the armature is provided, and the second direction is a circumferential direction (CD) around the rotation axis.

16. The motor of claim 14, wherein the first direction is an axial direction (AD) along a rotation axis (112) on which one of the field element and the armature is provided, and the second direction is a circumferential direction (CD) around the rotation axis.

17. The motor of claim 14, wherein the first direction is a direction (RD) perpendicular to a linear motion axis (212) along which one of the field element and the armature is provided, and the second direction is an axial direction (AD) along the linear motion axis.

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