Iron core piece, stator core, stator, and rotating electrical machine

Abstract

The iron core piece is an iron core piece constituting a stator core for an axial gap type rotating electric machine, and is provided with a columnar first member extending in a direction along an axis of the stator core, and a circumferential surface of the first member has a plurality of slots in a winding direction of a winding wire in at least a part of a surface in contact with the winding wire of a coil.

Description

Technical Field

[0001] The present disclosure relates to a core sheet, a stator core, a stator, and a rotating electric machine.

[0002] This application claims the benefit of priority based on Japanese patent application No. 2022-116664 filed on July 21, 2022, and incorporates by reference all the contents described in the aforementioned Japanese application. Background Art

[0003] Patent Documents 1 to 3 disclose stator cores and stators for axial gap motors. The stator core includes teeth, a yoke portion, and a flange portion. The stator includes coils disposed on the teeth of the stator core. The coils are formed by winding wires around the teeth. Generally, the peripheral surface of the teeth on which the coils are disposed is formed by a flat surface.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-44829

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-124794

[0008] Patent Document 3: Japanese Patent Application Publication No. 2009-142095 Summary of the invention

[0009] The iron core piece involved in the present disclosure,

[0010] It is an iron core sheet that constitutes the stator core of an axial gap type rotating electric machine.

[0011] A columnar first member extending in a direction along the axis of the stator core is provided,

[0012] The peripheral surface of the first member has a plurality of grooves along a direction in which the winding wire is wound, in at least a portion of a surface in contact with the winding wire of the coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a perspective view schematically showing the core sheet according to the first embodiment.

[0014] Figure 2 It is a plan view schematically showing the core sheet according to the first embodiment.

[0015] Figure 3 This is a diagram of the core sheet according to Embodiment 1 as viewed from the inner peripheral surface side.

[0016] Figure 4 is shown along Figure 3This is a cross-sectional view of the state after the core piece is cut along line IV-IV.

[0017] Figure 5 is shown along Figure 3 This is a cross-sectional view of the state after the iron core piece is cut along the VV line.

[0018] Figure 6 is shown along Figure 3 This is a cross-sectional view of the state after the iron core piece is cut along the VI-VI line.

[0019] Fig. 7A This is a schematic cross-sectional view showing a plurality of grooves provided on the inner peripheral surface of the first member in the core sheet according to the first embodiment.

[0020] Figure 7B This is a schematic cross-sectional view showing a modification of the first embodiment, that is, an example in which the cross section of the winding is an elliptical shape.

[0021] Figure 8 This is a schematic cross-sectional view showing a modification of the first embodiment, that is, another example of the plurality of grooves.

[0022] Fig. 9 This is a schematic perspective view showing another modified example of the first embodiment, that is, an iron core sheet having a plurality of grooves on the outer peripheral surface of the first member.

[0023] Fig.10 It is a plan view showing an opening edge of a punching die of a die for manufacturing the core piece according to the first embodiment.

[0024] Fig.11 This is a cross-sectional view schematically showing a mold for manufacturing a first member in the core sheet according to the first embodiment.

[0025] Fig.12 This is a cross-sectional view schematically showing a mold for manufacturing the second member in the core sheet according to the first embodiment.

[0026] Fig.13 This is a cross-sectional view schematically showing a mold for manufacturing the third member in the core sheet according to the first embodiment.

[0027] Fig.14 This is a schematic perspective view showing another modified example of the first embodiment, that is, a core sheet having a groove in which an end portion where winding of the winding wire is to be started is arranged in a protruding portion of the second member.

[0028] Fig.15 This is a schematic perspective view showing another modified example of the first embodiment, that is, a core sheet having a step in which an end portion where winding of the winding wire starts is arranged at a protruding portion of the second member.

[0029] Fig.16This is a perspective view schematically showing a stator core according to the second embodiment.

[0030] Fig.17 This is a perspective view schematically showing a stator according to the third embodiment.

[0031] Fig.18 This is a cross-sectional view schematically showing a rotating electrical machine according to a fourth embodiment.

[0032] Fig.19 This is a cross-sectional view schematically showing a rotating electrical machine according to the fifth embodiment. DETAILED DESCRIPTION

[0033] [Technical Problems to be Solved by the Present Disclosure]

[0034] When the motor is driven, current flows through the coil, causing the coil to generate heat. In order to reduce the size of the motor while maintaining the output of the motor, it is necessary to increase the current flowing through the coil. Since the heat generated by the coil increases, it is desirable to suppress the temperature rise of the coil.

[0035] One object of the present disclosure is to provide a core sheet capable of suppressing a temperature rise of a coil. Another object of the present disclosure is to provide a stator core, a stator, and a rotating electric machine capable of suppressing a temperature rise of a coil.

[0036] [Effects of the present disclosure]

[0037] The core piece according to the present disclosure can suppress a temperature increase of the coil.

[0038] <Description of Embodiments of the Present Disclosure>

[0039] First, embodiments of the present disclosure will be listed and described.

[0040] (1) A core piece according to an embodiment of the present disclosure,

[0041] It is an iron core sheet that constitutes the stator core of an axial gap type rotating electric machine.

[0042] A columnar first member extending in a direction along the axis of the stator core is provided,

[0043] The peripheral surface of the first member has a plurality of grooves along a direction in which the winding wire is wound, in at least a portion of a surface in contact with the winding wire of the coil.

[0044] The iron core sheet disclosed in the present invention can suppress the temperature rise of the coil. In the iron core sheet disclosed in the present invention, a coil is arranged on a first component. The peripheral surface of the first component has a plurality of grooves. The winding is arranged in a state of being embedded in each groove. Therefore, compared with the case where the peripheral surface of the first component is composed of a flat surface, the contact area between the winding and the first component is increased. The heat dissipation from the winding to the first component is improved, and as a result, the coil can be effectively cooled.

[0045] In addition, when the winding is wound on the first member, the winding is held in each groove, so that the winding of the winding can be prevented from being loosened. The winding is wound uniformly along the groove, so that the space factor of the coil is improved. The improvement of the space factor of the coil is effective for miniaturization and high output of the rotating electric machine.

[0046] (2) In the core piece described in (1) above, it may be that:

[0047] The width of each of the plurality of slots is not less than 1 / 4 of the long diameter of the winding and not more than the long diameter.

[0048] The depth of each of the plurality of grooves is not less than 1 / 4 of the minor diameter of the winding and not more than the minor diameter.

[0049] The core piece of (2) described above is sufficiently maintained in a state where the winding wires are fitted into the respective grooves.

[0050] (3) In the core piece described in (1) or (2) above, it may be that:

[0051] The cross section of the winding is circular,

[0052] The cross-section of each of the plurality of grooves is in the shape of an arc.

[0053] The radius of the circle of the cross section of the winding wire is the same as the radius of the arc of the cross section of the groove.

[0054] The core sheet of (3) above can easily ensure a sufficient contact area between the winding and the first member because the cross-sectional shape of the groove corresponds to the cross-sectional shape of the winding.

[0055] (4) In the core piece described in any one of (1) to (3) above, it may be that:

[0056] The plurality of grooves have a connecting surface between two adjacent grooves that is continuous with the inner peripheral surface of the groove.

[0057] The connecting surface is composed of a flat surface or a rounded curved surface.

[0058] The core piece of the above-mentioned (4) does not have a sharp shape because the connecting surface is formed of a flat surface or the above-mentioned curved surface, and thus a defect is less likely to occur on the connecting surface.

[0059] (5) In the core piece described in any one of (1) to (4) above, it may be that:

[0060] The peripheral surface has:

[0061] An inner peripheral surface is arranged close to the axis of the stator core; and

[0062] The outer peripheral surface is arranged at a position away from the axis of the stator core,

[0063] The plurality of grooves are provided on at least one of the inner peripheral surface and the outer peripheral surface.

[0064] The iron core sheet of (5) described above can suppress the temperature rise of the coil by providing a plurality of slots on at least one of the inner circumference and the outer circumference of the first component. In particular, the inner circumference of the iron core sheet is closer to the inner circumference of other adjacent iron core sheets around the axis of the stator core, so that the heat of the coil is easily accumulated. That is, the temperature rise of the winding connected to the inner circumference of the first component is large. Therefore, when a plurality of slots are provided on the inner circumference of the first component, the temperature rise of the coil can be more effectively suppressed. Compared with the inner circumference, the outer circumference of the iron core sheet is longer along the axis around the stator core. Therefore, when a plurality of slots are provided on the outer circumference of the first component, the winding can be easily and stably maintained in each slot.

[0065] (6) The core piece according to any one of (1) to (5) above may include:

[0066] a plate-shaped second member provided at a first end portion of the first member in a direction along the axis; and

[0067] a plate-shaped third member disposed at a second end portion of the first member in a direction along the axis,

[0068] The peripheral surface of the first component is connected to the second component and the third component,

[0069] The second member has a protrusion extending outward from the peripheral surface of the first member,

[0070] The third member has a protrusion extending outward from the peripheral surface of the first member,

[0071] The first member, the second member, and the third member are formed of an integrally molded powder compact.

[0072] The iron core sheet of (6) mentioned above is provided with protrusions of the second component and the third component at each end of the first component, so that the coil arranged on the first component can be held between the two protrusions. In addition, the iron core sheet of (6) mentioned above is composed of a pressed powder molded body formed integrally by the first component, the second component and the third component, and the iron core sheet is easy to manufacture and easy to handle as a single component.

[0073] (7) In the core piece described in (6) above,

[0074] The protruding portion of the second member or the protruding portion of the third member may have a groove or a step at which an end portion of the winding wire is arranged to start winding.

[0075] The core sheet of (7) is arranged at the groove or step at the end where the winding of the wire starts. When the winding of the wire is wound in multiple layers, the winding of the second layer and later layers can avoid interfering with the end where the winding starts. Therefore, compared with the core sheet without the groove or step, the core sheet of (7) can wind the winding one more turn. That is, the space factor of the coil is improved.

[0076] (8) The core piece according to the embodiment of the present disclosure,

[0077] This is an iron core sheet constituting a stator core for an axial gap type rotating electrical machine, and has:

[0078] A first columnar member extending in a direction along the axis of the stator core;

[0079] a plate-shaped second member provided at a first end portion of the first member in a direction along the axis; and

[0080] a plate-shaped third member disposed at a second end portion of the first member in a direction along the axis,

[0081] The first component has a peripheral surface connected to the second component and the third component,

[0082] The second member has a protrusion extending outward from the peripheral surface of the first member,

[0083] The third member has a protrusion extending outward from the peripheral surface of the first member,

[0084] The first component, the second component and the third component are formed of a compact formed by integral molding.

[0085] The peripheral surface of the first component has:

[0086] An inner peripheral surface is arranged close to the axis of the stator core; and

[0087] The outer peripheral surface is arranged at a position away from the axis of the stator core,

[0088] At least one of the inner peripheral surface and the outer peripheral surface has a plurality of grooves along the winding direction of the coil in at least a portion of the surface in contact with the coil winding.

[0089] The width of each of the plurality of slots is not less than 1 / 4 of the long diameter of the winding and not more than the long diameter.

[0090] The depth of each of the plurality of grooves is not less than 1 / 4 of the short diameter of the winding and not more than the short diameter.

[0091] The protruding portion of the second member or the protruding portion of the third member has a groove or a step at which an end portion of the winding wire is arranged to start winding.

[0092] The core sheet of (8) has the configurations described in (1), (2), (5), (6), and (7). The core sheet of (8) has the effects of the configurations described above.

[0093] (9) A stator core according to an embodiment of the present disclosure,

[0094] It is the stator core for axial gap type rotating motor.

[0095] A plurality of core sheets are provided in a ring shape.

[0096] Each of the plurality of core sheets is the core sheet described in any one of (1) to (8) above.

[0097] Since the stator core of the present disclosure includes the core sheet described above, it is possible to suppress a temperature increase of the coil.

[0098] (10) A stator according to an embodiment of the present disclosure,

[0099] This is a stator for an axial gap type rotating electrical machine, having:

[0100] The stator core described in (9) above; and

[0101] A coil is arranged in each of the first components in the stator core.

[0102] Since the stator of the present disclosure includes the above-described stator core, it is possible to suppress a temperature increase of the coil.

[0103] (11) A rotating electrical machine according to an embodiment of the present disclosure,

[0104] An axial gap type rotating electric machine includes a rotor and a stator, wherein the rotor and the stator are arranged facing each other in a direction along an axis.

[0105] The stator is the stator described in (10) above.

[0106] Since the rotating electrical machine of the present disclosure includes the above-described stator, it is possible to suppress a temperature increase of the coil.

[0107] <Details of the embodiments of the present disclosure>

[0108] Hereinafter, the details of the embodiments of the present disclosure will be described with reference to the accompanying drawings. The same reference numerals in the drawings represent the same names.

[0109] Implementation Method 1

[0110] 〔Iron core〕

[0111] Reference Figures 1 to 9 , the core piece 1 according to the first embodiment is described. Fig.16 As described below, a plurality of core sheets 1 are arranged in a ring shape to form a stator core 7. Fig.17 As described below, the stator core 7 is constituted by arranging coils 80 on each first member 10 in each core sheet 1. Fig.18 , Fig.19 As described below, the stator 8 is used in an axial gap type rotating electric machine 9. Figure 1 As shown, the core sheet 1 of this embodiment includes a columnar first member 10. The first member 10 extends in the direction along the axis of the stator core 7. One of the characteristics of the core sheet 1 of this embodiment is that a plurality of slots 40 are provided on the peripheral surface 11 of the first member 10. Fig. 7A As described below, the winding 81 of the coil 80 is wound along the slot 40. Hereinafter, the direction along the axis of the stator core is sometimes referred to as the "axial direction", the direction orthogonal to the axial direction of the stator core is sometimes referred to as the "radial direction", and the direction along the axis around the stator core is sometimes referred to as the "circumferential direction".

[0112] Furthermore, if Figure 1 As shown, the core sheet 1 of this embodiment includes a plate-shaped second member 20 and a plate-shaped third member 30. The second member 20 is provided at the first end portion in the axial direction of the first member 10. The third member 30 is provided at the second end portion in the axial direction of the first member 10.

[0113] Hereinafter, the core piece 1 will be described in detail.

[0114] The direction along the radial direction of the stator core 7 in the core sheet 1 is defined as an X-axis direction.

[0115] The direction along the axial direction of the stator core 7 in the core sheet 1 is defined as a Z-axis direction.

[0116] A direction perpendicular to both the X-axis direction and the Z-axis direction of the core piece 1 is defined as a Y-axis direction.

[0117] In the X-axis direction, the direction of the axis of the core sheet 1 close to the stator core 7 is referred to as an X1 direction, and the direction of the axis away from the stator core 7 is referred to as an X2 direction.

[0118] The X1 direction is the inner circumferential direction of the stator core 7 .

[0119] The X2 direction is the outer circumferential direction of the stator core 7 .

[0120] In the Z-axis direction, a direction from the third member 30 toward the second member 20 in the first member 10 is referred to as a Z1 direction, and a direction from the second member 20 toward the third member 30 in the first member 10 is referred to as a Z2 direction.

[0121] The end portion of the first member 10 in the Z1 direction is a first end portion of the first member 10 .

[0122] The end portion of the first member 10 in the Z2 direction is a second end portion of the first member 10 .

[0123] In the Y-axis direction, a first direction of the stator core 7 in the core sheet 1 is referred to as a Y1 direction, and a second direction of the stator core 7 is referred to as a Y2 direction.

[0124] [First component]

[0125] The first member 10 is a columnar member extending in the Z-axis direction. In either the case where the core sheet 1 constitutes the stator core 7 of the dual-stator and single-rotor type in the axial gap type rotating electrical machine 9 or the stator core 7 of the single-stator and dual-rotor type in the axial gap type rotating electrical machine 9, the first member 10 constitutes teeth. Fig.18 As shown, the axial gap type rotating electric machine 9 of the double stator and single rotor type is assembled in such a way that one rotor 90 is sandwiched between two stators 8. Fig.19 As shown, the single-stator, dual-rotor axial gap type rotating electrical machine 9 is assembled in such a manner that one stator 8 is sandwiched between two rotors 90. Hereinafter, for convenience of explanation, dual stators and single rotors may be referred to as DS / SR, and single stators and dual rotors may be referred to as SS / DR.

[0126] The shape of the first component 10 may be, for example, a prism or a cylinder. The prism may be, for example, a quadrangular prism whose cross-sectional shape after being cut along a plane perpendicular to the Z-axis direction is a quadrilateral. The quadrangular prism may be, for example, a trapezoidal column whose cross-sectional shape is a trapezoid. The cross-sections may be the same or different in the Z-axis direction. "Trapezoidal shape" includes not only geometric trapezoids, but also shapes with rounded corners as in this example, including a range that is essentially regarded as a trapezoid. "Trapezoidal shape" includes not only trapezoids whose two legs are the same length as an isosceles trapezoid, but also trapezoids whose two legs are different lengths as a right trapezoid. This is also the same in the second component 20 and the third component 30 described later.

[0127] like Figure 1 , Figure 4 As shown, the shape of the first component 10 of this embodiment is a trapezoidal column whose cross-sectional shape is a trapezoid. In the cross-sectional shape, the length of the side located in the X2 direction is longer, and the length of the side located in the X1 direction is shorter. The cross-sectional shape of the first component 10 is the same in the Z-axis direction. If the shape of the first component 10 is a trapezoidal column, it is easy to ensure a larger cross-sectional area. In addition, it is easy to reduce the dead zone of the iron core sheet 1, and it is easy to form a stator 8 with a high space factor.

[0128] like Figure 1 , Figure 3 As shown, the first component 10 has a peripheral surface 11 connected to the second component 20 and the third component 30. Figure 4 As shown, the peripheral surface 11 of the first component 10 has an outer peripheral surface 12, an inner peripheral surface 13, a first side surface 14a and a second side surface 14b. The outer peripheral surface 12 is located in the X2 direction. That is, the outer peripheral surface 12 is arranged at a position away from the axis of the stator core 7. The inner peripheral surface 13 is located in the X1 direction. That is, the inner peripheral surface 13 is arranged at a position close to the axis of the stator core 7. The first side surface 14a and the second side surface 14b are located on the side separated from each other in the circumferential direction of the stator core 7 in the core sheet 1. That is, the first side surface 14a is located in the first direction of the circumferential direction of the stator core 7 in the core sheet 1. The second side surface 14b is located in the second direction of the circumferential direction of the stator core 7 in the core sheet 1. The positional relationship between the outer peripheral surface 12, the inner peripheral surface 13, the first side surface 14a and the second side surface 14b is the same in the second component 20 and the third component 30 described later.

[0129] The outer peripheral surface 12 is connected to the outer peripheral edge of the first side surface 14a and the outer peripheral edge of the second side surface 14b. The inner peripheral surface 13 is connected to the inner peripheral edge of the first side surface 14a and the inner peripheral edge of the second side surface 14b. That is, the first side surface 14a and the second side surface 14b are connected to the outer peripheral surface 12 and the inner peripheral surface 13.

[0130] The length between the first side surface 14a and the second side surface 14b in the outer peripheral surface 12, that is, the length of the outer peripheral surface 12 along the Y-axis direction is longer than the length between the first side surface 14a and the second side surface 14b in the inner peripheral surface 13, that is, the length of the inner peripheral surface 13 along the Y-axis direction. In this embodiment, the outer peripheral surface 12 has a curved surface convex toward the X2 direction. It should be noted that the outer peripheral surface 12 can also be composed of a plane. In this embodiment, the inner peripheral surface 13 has a curved surface convex toward the X1 direction. It should be noted that the inner peripheral surface 13 can have a curved surface convex toward the X2 direction or can be composed of a plane. The respective bending radii of the outer peripheral surface 12 and the inner peripheral surface 13 can be the same as each other or different from each other.

[0131] The first side surface 14a and the second side surface 14b respectively have a first parallel surface 141, a second parallel surface 142 and a first inclined surface 143. The first parallel surfaces 141 of the first side surface 14a and the second side surface 14b are parallel to each other. The second parallel surfaces 142 of the first side surface 14a and the second side surface 14b are parallel to each other. The first parallel surface 141 of the first side surface 14a is parallel to the second parallel surface 142 of the first side surface 14a. The first parallel surface 141 and the second parallel surface 142 are surfaces parallel to the X-axis direction in the core sheet 1. The X-axis direction refers to the direction of a straight line that passes through the center of the stator core 7 and divides the core sheet 1 into two equal parts in the circumferential direction of the stator core 7. The first parallel surface 141 is connected to the outer peripheral surface 12. The second parallel surface 142 is connected to the inner peripheral surface 13. The first inclined surface 143 is connected to the first parallel surface 141 and the second parallel surface 142.

[0132] The length of the first parallel surface 141 and the second parallel surface 142 along the X-axis direction is determined by the size of the core piece 1, etc., but is preferably 0.3 mm or more and 25 mm or less, for example. If it is greater than the above lower limit, the reference Fig.10 , Fig.12The damage of the die 5 accompanying the contact between the lower punch 55 and the die 50 described below. This is because, although the manufacturing method of the core sheet 1 will be described below, if it is above the lower limit, the raw material powder constituting the core sheet 1 can be sufficiently pressed. If it is below the upper limit, the cross-sectional area of ​​the first component 10 can be increased, so the torque in the axial gap type rotating electric machine 9 can be improved and the iron loss can be suppressed. The length of the first parallel surface 141 and the second parallel surface 142 along the X-axis direction is more preferably 0.4 mm or more and 20 mm or less, and particularly preferably 0.5 mm or more and 15 mm or less. The above preferred range of the length of the first parallel surface 141 and the second parallel surface 142 of the first side surface 14a and the second side surface 14b of the first component 10 along the X-axis direction is also the same in the first parallel surface 241 and the second parallel surface 242 of the first side surface 24a and the second side surface 24b of the second component 20 described below, and the first parallel surface 341 and the second parallel surface 342 of the first side surface 34a and the second side surface 34b of the third component 30.

[0133] like Figure 4 As shown, the first inclination angle θ11 and the second inclination angle θ12 of the first inclined surface 143 are preferably, for example, not less than 5° and not more than 20°. If the first inclination angle θ11 and the second inclination angle θ12 are not less than 5° and not more than 20°, it is easy to wind the winding 81 described below on the peripheral surface 11 of the first component 10. The first inclination angle θ11 and the second inclination angle θ12 are further preferably not less than 5.5° and not more than 18°, and particularly preferably not less than 6° and not more than 16°. Although the first inclination angle θ11 and the second inclination angle θ12 are preferably the same angle, they may be different. The first inclination angle θ1 refers to the angle formed by the extension surface E11 of the first parallel surface 141 in the first side surface 14a and the first inclined surface 143. The second inclination angle θ12 refers to the angle formed by the extension surface E12 of the first parallel surface 141 in the second side surface 14b and the first inclined surface 143.

[0134] (groove)

[0135] like Figure 1 As shown, the peripheral surface 11 of the first component 10 has a plurality of grooves 40. Fig. 7A As shown, a plurality of grooves 40 may be provided on at least a portion of the surface in contact with the winding 81 of the coil 80. The above-mentioned "at least a portion of the surface in contact with the winding 81 of the coil 80" also includes the corners of two adjacent surfaces in the peripheral surface 11. In this embodiment, a plurality of grooves 40 are provided on the inner peripheral surface 13 in the peripheral surface 11. The grooves 40 are along the direction in which the winding 81 of the coil 80 is wound. Hereinafter, the direction in which the winding 81 is wound is sometimes referred to as the "winding direction". Fig. 7AIt is a cross-sectional view after cutting the inner peripheral surface 13 along a plane that is orthogonal to the inner peripheral surface 13 and parallel to the Z-axis direction. A plurality of grooves 40 are arranged in the Z-axis direction. Each groove 40 extends in a direction orthogonal to the Z-axis direction in the inner peripheral surface 13. The direction in which the groove 40 extends is along the winding direction of the winding 81, and may also be inclined relative to the Z-axis direction. The winding 81 is configured in a state of being embedded in each groove 40. By increasing the contact area between the winding 81 and the first component 10, the heat dissipation from the winding 81 to the first component 10 is improved. As a result, the coil 80 can be effectively cooled and the temperature rise of the coil 80 can be suppressed.

[0136] The cross section of the winding 81 is, for example, circular or elliptical. In the present embodiment, the cross section of the winding 81 is circular. The cross section of the winding 81 is a cross section cut along a plane perpendicular to the direction along the length of the winding 81. The winding 81 has a copper wire and an insulating coating covering the copper wire. The coil 80 is a multi-layer winding coil in which the winding 81 is arranged and wound into multiple layers. The winding 81 has a major diameter 81a and a minor diameter 81b. The major diameter 81a is the longest diameter in the cross section of the winding 81. The minor diameter 81b is the longest diameter among the diameters perpendicular to the major diameter 81a. When the cross section of the winding 81 is circular, the major diameter 81a and the minor diameter 81b are respectively equal to the diameter 81d.

[0137] The cross-sectional shape of the groove 40 may be any shape as long as the winding 81 is in contact with the inner peripheral surface of the groove 40 at two or more points. Fig. 7A As shown, the cross section of the groove 40 of this embodiment is in the shape of an arc. The cross section of the groove 40 is a cross section cut along a plane perpendicular to the extension direction of the groove 40. The inner circumference of the groove 40 is composed of an arc surface. In this embodiment, the radius of the circle of the cross section of the winding 81 is the same as the radius of the arc of the cross section of the groove 40. That is, the cross-sectional shape of the groove 40 is a shape corresponding to the cross-sectional shape of the winding 81. Since the winding 81 is substantially in close contact with the inner circumferential surface of the groove 40, it is easy to fully ensure the contact area between the winding 81 and the first component 10.

[0138] The size of the groove 40 is sufficient as long as it has a size that the winding 81 can enter. When the cross section of the winding 81 is circular, the width 40w of the groove 40 is, for example, more than 1 / 4 of the diameter 81d of the winding 81 and less than the diameter 81d. The width 40w is the opening width of the groove 40 opened on the peripheral surface 11. By making the width 40w more than 1 / 4 of the diameter 81d and less than the diameter 81d, it is easy to fully hold the winding 81. The width 40w may also be more than 1 / 2 of the diameter 81d and less than the diameter 81d. Furthermore, the width 40w may also be more than 3 / 5 of the diameter 81d and less than 4 / 5 of the diameter 81d. The deeper the depth 40d of the groove 40, the easier it is to fully hold the winding 81 in a state of being embedded in the groove 40. The depth 40d of the groove 40 can be determined according to the width 40w of the groove 40 so that the winding 81 is easily accommodated in the groove 40. The depth 40d of the groove 40 is, for example, not less than 1 / 4 of the diameter 81d of the winding 81 and not more than the diameter 81d. The depth 40d is the distance from the opening edge of the groove 40 to the bottom. When the depth 40d is not less than 1 / 4 of the diameter 81d and not more than the diameter 81d, it is easy to fully hold the winding 81. The depth 40d may also be not less than 1 / 3 of the diameter 81d and not more than 1 / 2 of the diameter 81d.

[0139] Fig. 7A The diameter of the winding 81 of the first component 10 shown is the same as the diameter of the groove 40. That is, the cross section of the groove 40 is formed into an arc shape along the circular shape of the winding 81. The outer peripheral surface of the winding 81 is consistent with the inner peripheral surface of the groove 40, and the contact area between the winding 81 and the groove 40 is the largest relative to the width 40w. If the relationship is expressed as a range, the width 40w and the depth 40d of the groove 40 can also satisfy the following relationship (1) or (2) with respect to the diameter 81d of the winding 81. Here, the diameter 81d is simply represented as "D".

[0140] (1) When the width 40w is greater than or equal to 0.25D and less than or equal to D, the depth 40d is greater than or equal to 0.016D and less than or equal to 0.5D.

[0141] (2) When the width 40w is greater than or equal to 0.6D and less than or equal to 0.8D, the depth 40d is greater than or equal to 0.1D and less than or equal to 0.2D.

[0142] In this embodiment, the plurality of grooves 40 have a connecting surface 42 between two adjacent grooves 40 that is continuous with the inner peripheral surface of the groove 40. Fig. 7AAs shown, the connecting surface 42 of this embodiment is composed of a flat surface. Since the connecting surface 42 is composed of a flat surface, no sharp corners are formed between adjacent grooves 40. Since the connecting surface 42 is not in a sharp shape, it is not easy to cause defects on the connecting surface 42. In addition, when the winding 81 is wound on the first component 10, even if the winding 81 sometimes contacts the connecting surface 42, it is possible to suppress damage to the winding 81. Furthermore, the corner between the inner circumferential surface of the groove 40 and the connecting surface 42 can also be rounded. The connecting surface 42 can also be composed of a rounded curved surface. Even if the connecting surface 42 is composed of the above-mentioned curved surface, since the connecting surface 42 is not in a sharp shape, it is not easy to cause defects on the connecting surface 42. In addition, when the winding 81 is wound on the first component 10, it is possible to suppress damage to the winding 81.

[0143] like Figure 7B As shown, the cross-section of the winding 81 may also be an elliptical shape. When the cross-section of the winding 81 is an elliptical shape, the winding 81 is wound, for example, in a manner such that the major diameter 81a is parallel to the peripheral surface 11. The cross-section of the groove 40 is a shape along the elliptical shape of the winding 81. The width 40w of the groove 40 is, for example, greater than 1 / 4 of the major diameter 81a of the winding 81 and less than the major diameter 81a. The width 40w may also be greater than 3 / 5 of the major diameter 81a and less than 4 / 5 of the major diameter 81a. The depth 40d of the groove 40 is, for example, greater than 1 / 4 of the minor diameter 81b of the winding 81 and less than the minor diameter 81b. The depth 40d may also be greater than 1 / 3 of the minor diameter 81b and less than 1 / 2 of the minor diameter 81b. Figure 7B Different from the example shown, the winding 81 may be wound in such a manner that the short diameter 81b is parallel to the peripheral surface 11. Figure 7B In this case, the width 40w of the groove 40 is greater than 1 / 4 of the short diameter 81b of the winding 81 and less than the short diameter 81b, and the depth 40d of the groove 40 can also be greater than 1 / 4 of the long diameter 81a of the winding 81 and less than the long diameter 81a.

[0144] like Figure 8 As shown, the cross section of the groove 40 may also be triangular. The inner peripheral surface of the triangular groove 40 is composed of two linear inclined surfaces. The winding 81 contacts the inner peripheral surface of the groove 40 at two points.

[0145] The plurality of grooves 40 are provided in the peripheral surface 11. Figure 4 Any one of the outer peripheral surface 12, the inner peripheral surface 13, the first side surface 14a and the second side surface 14b shown in the figure can be used. Fig. 9As shown, a plurality of grooves 40 may be provided on the outer peripheral surface 12. Furthermore, a plurality of grooves 40 may be provided on both the inner peripheral surface 13 and the outer peripheral surface 12. A plurality of grooves 40 may also be provided at the corners of two adjacent surfaces. For example, a plurality of grooves 40 may also be provided near the corner between at least one of the first side surface 14a and the second side surface 14b and the inner peripheral surface 13. In addition, a plurality of grooves 40 may also be provided near the corner between at least one of the first side surface 14a and the second side surface 14b and the outer peripheral surface 12.

[0146] When a plurality of grooves 40 are provided on the inner peripheral surface 13, it can be seen from the Fig.12 The lower punch 55 described below is used for forming. When a plurality of grooves 40 are provided on the outer peripheral surface 12, it is possible to Fig.11 The upper punch 54 described below is formed. In the case where a plurality of grooves 40 are provided on at least one of the first side surface 14a and the second side surface 14b, it is possible to refer to Fig.10 The inner circumferential surface of the die hole 50h of the die 50 described below is formed. In the case where a plurality of grooves 40 are provided on at least one of the first side surface 14a and the second side surface 14b, when the core piece 1 is pulled out from the die hole 50h of the die 50, the groove 40 may be damaged due to friction with the inner circumferential surface of the die hole 50h. In addition, the friction resistance between the core piece 1 and the inner circumferential surface of the die hole 50h increases, making it difficult to pull the core piece 1 out of the die hole 50h. In the case where a plurality of grooves 40 are provided on the inner circumferential surface 13, since the grooves 40 are formed by the lower punch 55, the grooves 40 are not easily damaged. In the case where a plurality of grooves 40 are provided on the outer circumferential surface 12, since the grooves 40 are formed by the upper punch 54, the grooves 40 are not easily damaged.

[0147] [Second component]

[0148] like Figure 1 , Figure 3 As shown, the second member 20 is a plate-shaped member provided at the first end portion in the Z-axis direction of the first member 10. When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the DS / SR system, the second member 20 constitutes the yoke. When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the SS / DR system, the second member 20 constitutes the flange portion.

[0149] The shape of the second component 20 is a trapezoidal plate in this embodiment. The cross-sectional shape of the second component 20 cut along a plane perpendicular to the Z-axis direction of the trapezoidal plate is a trapezoidal shape. The above cross-sections may be the same or different in the Z-axis direction. It should be noted that, in the case where the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the SS / DR method, the shape of the second component 20 may also be a rectangular plate.

[0150] like Figures 1 to 3 As shown, the second component 20 has a protrusion 21. The protrusion 21 extends outwards further than the circumferential surface 11 of the first component 10. The protrusion 21 may protrude outwards further than the circumferential surface 11 of the first component 10 in a portion of the circumferential surface 11 of the first component 10, or may protrude outwards further than the circumferential surface 11 of the first component 10 in the entire circumference of the first component 10. In this embodiment, the protrusion 21 has a first protrusion 211 and a second protrusion 212. The first protrusion 211 extends in the second direction of the circumference of the stator core 7. The second protrusion 212 extends in the second direction of the circumference of the stator core 7. It should be noted that the protrusion 21 may not have the first protrusion 211 and the second protrusion 212, but may have a portion extending in the X1 direction and a portion extending in the X2 direction. The protrusion 21 may also have a portion extending in the X1 direction and a portion extending in the X2 direction in addition to the first protrusion 211 and the second protrusion 212. In this case, the protrusion 21 is provided in a ring shape along the circumferential direction of the first member 10 .

[0151] When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the DS / SR system, the protrusion lengths of the first protrusion 211 and the second protrusion 212 of the second member 20 are longer than the protrusion lengths of the first protrusion 311 and the second protrusion 312 of the third member 30 described later. When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the SS / DR system, the protrusion lengths of the first protrusion 211 and the second protrusion 212 of the second member 20 may be the same as the protrusion lengths of the first protrusion 311 and the second protrusion 312 of the third member 30. The protrusion length is the length extending in the direction perpendicular to the peripheral surface 11 of the first member 10. When the peripheral surface 11 has a curved surface, the protrusion length refers to the length along the normal direction of the curved surface.

[0152] like Figure 3 As shown, the second component 20 has a first end surface 26 and a second end surface 27. Figure 5 As shown, the second component 20 has an outer peripheral surface 22, an inner peripheral surface 23, a first side surface 24a and a second side surface 24b. The positional relationship between the outer peripheral surface 22, the inner peripheral surface 23, the first side surface 24a and the second side surface 24b is as described above, and is the same as the positional relationship of the surfaces in the first component 10. The first end surface 26 and the second end surface 27 are arranged at positions facing each other. The first end surface 26 is located in the Z1 direction. The first end surface 26 is located on the opposite side of the first component 10. The second end surface 27 is located in the Z2 direction. The second end surface 27 is located on the first component 10 side. The positional relationship between the first end surface 26 and the second end surface 27 is also the same in the third component 30 described below.

[0153] The outer peripheral surface 22 is connected to the outer peripheral edge of the first side surface 24a, the outer peripheral edge of the second side surface 24b, and the first end surface 26 (see Figure 3 ) and the outer peripheral edge and the second end surface 27 (refer to Figure 3 ) is connected to the outer peripheral side edge of the second component 20. The outer peripheral surface 22 of the second component 20 is connected to the outer peripheral surface 12 of the first component 10 (refer to Figure 4 The inner peripheral surface 23 is connected to the inner peripheral edge of the first side surface 24a, the inner peripheral edge of the second side surface 24b, the inner peripheral edge of the first end surface 26, and the inner peripheral edge of the second end surface 27. The inner peripheral surface 23 of the second component 20 is connected to the inner peripheral surface 13 of the first component 10 (see Figure 4 ). The first side surface 24a and the second side surface 24b are connected to the outer peripheral surface 22 and the inner peripheral surface 23. The first end surface 26 is connected to the outer peripheral surface 22, the first side surface 24a, the second side surface 24b and the inner peripheral surface 23. The second end surface 27 is connected to the outer peripheral surface 22, the first side surface 24a, the second side surface 24b, the inner peripheral surface 23 and the peripheral surface 11 of the first component 10.

[0154] The length between the first side surface 24a and the second side surface 24b in the outer peripheral surface 22 is longer than the length between the first side surface 24a and the second side surface 24b in the inner peripheral surface 23. The length between the first side surface 24a and the second side surface 24b in the outer peripheral surface 22 of the second component 20 is longer than the length between the first side surface 14a and the second side surface 14b in the outer peripheral surface 12 of the first component 10. The length between the first side surface 24a and the second side surface 24b in the inner peripheral surface 23 in the second component 20 is the same as the length between the first side surface 14a and the second side surface 14b in the inner peripheral surface 13 in the first component 10.

[0155] The outer peripheral surface 22 has a curved surface convex toward the X2 direction in this embodiment. It should be noted that the outer peripheral surface 22 can also be composed of a plane. The inner peripheral surface 23 has a curved surface convex toward the X1 direction in this embodiment. It should be noted that the inner peripheral surface 23 can have a curved surface convex toward the X2 direction or can be composed of a plane. The curvature radii of the outer peripheral surface 22 and the inner peripheral surface 23 can be the same as each other or different from each other.

[0156] The first side surface 24a and the second side surface 24b respectively have a first parallel surface 241, a second parallel surface 242 and a first inclined surface 243. The first parallel surfaces 241 of the first side surface 24a and the second side surface 24b are parallel to each other. The second parallel surfaces 242 of the first side surface 24a and the second side surface 24b are parallel to each other. The first parallel surface 241 of the first side surface 24a is parallel to the second parallel surface 242 of the first side surface 24a. The first parallel surface 241 and the second parallel surface 242 are surfaces parallel to the X-axis direction of the core sheet 1. The first parallel surface 241 is connected to the outer peripheral surface 22. The second parallel surface 242 is connected to the inner peripheral surface 23. The first inclined surface 243 is connected to the first parallel surface 241 and the second parallel surface 242.

[0157] like Figure 5 As shown, the first inclination angle θ21 and the second inclination angle θ22 of the first inclined surface 243 are preferably, for example, greater than 5° and less than 20°. If the first inclination angle θ21 and the second inclination angle θ22 are greater than 5° and less than 20°, it is easy to configure the iron core sheet 1 into a ring shape, and it is easy to form the stator core 7. The first inclination angle θ21 and the second inclination angle θ22 are further preferably greater than 5.5° and less than 18°, and particularly preferably greater than 6° and less than 16°. Although the first inclination angle θ21 and the second inclination angle θ22 are preferably the same angle, they may also be different. The first inclination angle θ21 refers to the angle formed by the extension surface E21 of the first parallel surface 241 in the first side surface 24a and the first inclined surface 243. The second inclination angle θ22 refers to the angle formed by the extension surface E22 of the first parallel surface 241 in the second side surface 24b and the first inclined surface 243.

[0158] When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the DS / SR method, in the first core sheet 1 and the second core sheet 1 adjacent in the circumferential direction of the stator core 7, the first side surface 24a in the second part 20 of the first core sheet 1 is in contact with the second side surface 24b in the second part 20 of the second core sheet 1. In this case, it is preferred that the first inclined surface 243 in the first side surface 24a has a portion 244 extending outwardly from the first imaginary plane V21. It is preferred that the first inclined surface 243 in the second side surface 24b has a portion 244 extending outwardly from the second imaginary plane V22.

[0159] The first imaginary plane V21 is a plane connecting the first connection part and the second connection part in the first side surface 24a of the first protrusion 211. The first connection part in the first side surface 24a is the connection part between the first parallel surface 241 of the first side surface 24a and the first inclined surface 243. The second connection part in the first side surface 24a is the connection part between the second parallel surface 242 of the first side surface 24a and the inner peripheral surface 23. The second imaginary plane V22 is a plane connecting the first connection part and the second connection part in the second side surface 24b of the second protrusion 212. The first connection part in the second side surface 24b is the connection part between the first parallel surface 241 of the second side surface 24b and the first inclined surface 243. The second connection part in the second side surface 24b is the connection part between the second parallel surface 242 of the second side surface 24b and the inner peripheral surface 23. The first imaginary plane V21 and the second imaginary plane V22 are Figure 5 The figure is indicated by a two-dot chain line extending in the tilted direction of the paper surface.

[0160] The magnetic path area of ​​the stator core 7 is easily increased by having the first inclined surface 243 of each of the first side surface 24a and the second side surface 24b have a protruding portion 244. The reason is as follows. For example, in the case of an iron core sheet having a first parallel surface 241, a second parallel surface 242 and a first inclined surface 243 on the first side surface 24a and the second side surface 24b, respectively, and the first inclined surface 243 does not have a protruding portion 244, as described below. When the iron core sheet is arranged in an annular shape, if the first side surface 24a of the first iron core sheet adjacent to the circumferential direction of the stator core 7 is brought into contact with the second side surface 24b of the second iron core sheet, the first corner of the first iron core sheet is brought into contact with the second corner of the second iron core sheet. The first corner is the corner between the first side surface 24a and the inner peripheral surface 23. The second corner is the corner between the second side surface 24b and the inner peripheral surface 23. Therefore, the first side surface 24a of the first iron core sheet 1 cannot be brought into full contact with the second side surface 24b of the second iron core sheet. That is, the contact area between the first side surface 24a of the first core sheet 1 and the second side surface 24b of the second core sheet is reduced.

[0161] In contrast, the first side surface 24a of the core sheet 1 has a first parallel surface 241, a second parallel surface 242, and a first inclined surface 243, and the first inclined surface 243 has a portion 244 that extends further than the first imaginary surface V21. In addition, the second side surface 24b of the core sheet 1 has a first parallel surface 241, a second parallel surface 242, and a first inclined surface 243, and the first inclined surface 243 has a portion 244 that extends further than the second imaginary surface V22. When the core sheet 1 is configured in a ring shape, even if the first side surface 24a of the first core sheet 1 is brought into contact with the second side surface 24b of the second core sheet 1, it is possible to prevent the first corner of the first core sheet 1 from contacting the second corner of the second core sheet 1. Thus, the first side surface 24a of the first core sheet 1 can be brought into full contact with the second side surface 24b of the second core sheet 1. That is, the contact area between the first side surface 24a of the first core sheet 1 and the second side surface 24b of the second core sheet 1 is increased.

[0162] When the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the DS / SR method, as described above, in the first core sheet 1 and the second core sheet 1 adjacent in the circumferential direction of the stator core 7, the first side surface 24a of the second part 20 of the first core sheet 1 is in contact with the second side surface 24b of the second part 20 of the second core sheet 1. In this case, Figure 3 As shown, it is preferred that the first side surface 24a and the second side surface 24b of the core piece 1 each have a step 240 that can fit together. In this way, the magnetic path area of ​​the stator core 7 is easily increased. The first core piece 1 and the second core piece 1 adjacent in the circumferential direction of the stator core 7 are made to fit together through the step 240 of the first side surface 24a of the first protrusion 211 in the second component 20 of the first core piece 1 and the step 240 of the second side surface 24b of the second protrusion 212 in the second component 20 of the second core piece 1. Therefore, since the first core piece 1 and the second core piece 1 can be fully in contact, the contact area between the core pieces 1 adjacent in the circumferential direction of the stator core 7 can be increased. The step 240 of the first side surface 24a is provided on the first end surface 26 side. The step 240 of the first side surface 24a is configured to be away from the first side surface 14a of the first component 10 as it moves from the first end surface 26 toward the second end surface 27. On the other hand, the step 240 of the second side surface 24b is provided on the second end surface 27 side. The step 240 of the second side surface 24 b is configured to become more distant from the second side surface 14 b of the first member 10 as it moves from the second end surface 27 toward the first end surface 26 .

[0163] Although omitted from the illustration, the first side 24a of the core piece 1 may have at least one of a concave portion and a convex portion without a step. The second side 24b may have at least one of a convex portion corresponding to the concave portion of the first side 24a and a concave portion corresponding to the convex portion of the first side 24a. That is, both the first side 24a and the second side 24b may have concave and convex portions. In addition, the side of either the first side 24a or the second side 24b may have only a concave portion, and the side of the other may have only a convex portion. The number and shape of the concave and convex portions are not particularly limited.

[0164] Although not shown in the figure, the first side surface 24a and the second side surface 24b of the core piece 1 may each have a second inclined surface connected to each other without having a step or a concave-convex. For example, the second inclined surface of the first side surface 24a may also be inclined outward from the first end surface 26 toward the second end surface 27. In addition, the second inclined surface of the second side surface 24b may also be inclined outward from the second end surface 27 toward the first end surface 26.

[0165] When the core pieces 1 constitute the stator core 7 for the SS / DR type axial gap type rotating electric machine 9, the core pieces 1 are arranged in a ring shape without contacting each other. In this case, the first side surface 24a and the second side surface 24b may not have any of the step 240, the concave portion, the convex portion, and the second inclined surface that can fit each other.

[0166] The corners between the first side surface 24a and the first end surface 26 and the corners between the first side surface 24a and the second end surface 27 are rounded. The corners between the second side surface 24b and the first end surface 26 and the corners between the second side surface 24b and the second end surface 27 are rounded.

[0167] When the core piece 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the DS / SR method, the first end face 26 is constituted by, for example, a plane. When the core piece 1 constitutes the stator core 7 for the axial gap type rotating electric machine 9 of the SS / DR method, the first end face 26 may be constituted by a plane or may be constituted to be convex toward the Z1 direction. Such a core piece 1 can constitute an axial gap type rotating electric machine 9 with low noise and vibration. The reason is as follows. Fig.19 As shown, the stator 8 and the rotor 90 of the SS / DR type axial gap type rotating electric machine 9 are arranged facing each other. Fig.17 As shown in FIG. 8 , the stator 8 includes a stator core 7 and a coil 80. Fig.16 As shown, the stator core 7 is composed of a plurality of core sheets 1 arranged in a ring shape. Fig.17 As shown, the coil 80 is arranged on the first component 10 of each core sheet 1 (see Figure 1 ). If the first end surface 26 of the second component 20 of the core sheet 1 is configured to be convex, then Fig.19In the axial gap type rotating electric machine 9 shown, it is easy to suppress a sudden change in the magnetic flux of the magnet 95 of the rotor 90 received by the core sheet 1. Therefore, it is easy to reduce the cogging torque. Since the cogging torque is small, noise and vibration are not likely to increase.

[0168] It is preferable that the corners between the first end surface 26 and the inner peripheral surface 23 and the corners between the first end surface 26 and the outer peripheral surface 22 are chamfered. Since these corners are chamfered, they are not easily damaged. These chamfers may be C chamfers or R chamfers.

[0169] [Third Component]

[0170] like Figure 1 , Figure 3 As shown, the third member 30 is a plate-shaped member provided at the second end portion in the Z-axis direction of the first member 10. In either the case where the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electrical machine 9 of the DS / SR method or the case where the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electrical machine 9 of the SS / DR method, the third member 30 constitutes the flange portion.

[0171] The shape of the third component 30 is a trapezoidal plate in the present embodiment. The cross-sectional shape of the trapezoidal plate after cutting the third component 30 along a plane orthogonal to the Z-axis direction is a trapezoid. The above cross-sections can be the same or different in the Z-axis direction. It should be noted that the shape of the third component 30 can also be a rectangular plate. For example, in the iron core sheet 1, the first component 10 can also be a trapezoidal column, and at least one of the second component 20 and the third component 30 can be a rectangular plate.

[0172] like Figures 1 to 3 As shown, the third component 30 has a protrusion 31. The protrusion 31 extends outward from the circumferential surface 11 of the first component 10. The protrusion 31 may protrude outward from a portion of the circumferential surface 11 of the first component 10, or may protrude outward from the circumferential surface 11 of the first component 10 over the entire circumference of the first component 10. In this embodiment, the protrusion 31 has a first protrusion 311 and a second protrusion 312. The first protrusion 311 extends in a first direction in the circumferential direction of the stator core 7. The second protrusion 312 extends in a second direction in the circumferential direction of the stator core 7. It should be noted that the protrusion 31 may not have the first protrusion 311 and the second protrusion 312, but may have at least one of a portion extending in the X1 direction and a portion extending in the X2 direction. The protrusion 31 may also have a portion extending in the X1 direction and a portion extending in the X2 direction in addition to the first protrusion 311 and the second protrusion 312. In this case, the protrusion 31 is provided in a ring shape along the circumferential direction of the first member 10 .

[0173] As described above, when the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electrical machine 9 of the DS / SR system, the protruding lengths of the first protrusion 311 and the second protrusion 312 of the third member 30 are shorter than the protruding lengths of the first protrusion 211 and the second protrusion 212 of the second member 20. As described above, when the core sheet 1 constitutes the stator core 7 for the axial gap type rotating electrical machine 9 of the SS / DR system, the protruding lengths of the first protrusion 311 and the second protrusion 312 of the third member 30 may be the same as the protruding lengths of the first protrusion 211 and the second protrusion 212 of the second member 20.

[0174] like Figure 3 As shown, the third component 30 has a first end surface 36 and a second end surface 37. Figure 6 As shown in FIG. 1 , the third component 30 has an outer peripheral surface 32, an inner peripheral surface 33, a first side surface 34a, and a second side surface 34b. As described above, the positional relationship between the outer peripheral surface 32, the inner peripheral surface 33, the first side surface 34a, and the second side surface 34b is the same as the positional relationship between the surfaces in the first component 10. As described above, the positional relationship between the first end surface 36 and the second end surface 37 is the same as the positional relationship between the surfaces in the second component 20.

[0175] The outer peripheral surface 32 is connected to the outer peripheral edge of the first side surface 34a, the outer peripheral edge of the second side surface 34b, and the first end surface 36 (see Figure 3 ) and the outer peripheral edge and the second end surface 37 (refer to Figure 3 The outer peripheral surface 32 of the third component 30 is connected to the outer peripheral surface 12 of the first component 10 (refer to Figure 4 The inner peripheral surface 33 is connected to the inner peripheral edge of the first side surface 34a, the inner peripheral edge of the second side surface 34b, the inner peripheral edge of the first end surface 36, and the inner peripheral edge of the second end surface 37. The inner peripheral surface 33 of the third component 30 is connected to the inner peripheral surface 13 of the first component 10 (see Figure 4 ). The first side surface 34a and the second side surface 34b are connected to the outer peripheral surface 32 and the inner peripheral surface 33. The first end surface 36 is connected to the outer peripheral surface 32, the first side surface 34a, the second side surface 34b and the inner peripheral surface 33. The second end surface 37 is connected to the outer peripheral surface 32, the first side surface 34a, the second side surface 34b, the inner peripheral surface 33 and the peripheral surface 11 of the first component 10.

[0176] The length between the first side surface 34a and the second side surface 34b in the outer peripheral surface 32 is longer than the length between the first side surface 34a and the second side surface 34b in the inner peripheral surface 33. The length between the first side surface 34a and the second side surface 34b in the outer peripheral surface 32 of the third component 30 is longer than the length between the first side surface 14a and the second side surface 14b in the outer peripheral surface 12 of the first component 10. The length between the first side surface 34a and the second side surface 34b in the outer peripheral surface 32 of the third component 30 is shorter than the length between the first side surface 24a and the second side surface 24b in the outer peripheral surface 22 of the second component 20. The length between the first side surface 34a and the second side surface 34b in the inner peripheral surface 33 of the third component 30 is the same as the length between the first side surface 14a and the second side surface 14b in the inner peripheral surface 13 of the first component 10. That is, the length between the first side surface 14a and the second side surface 14b in the inner peripheral surface 13 of the first component 10, the length between the first side surface 24a and the second side surface 24b in the inner peripheral surface 23 of the second component 20, and the length between the first side surface 34a and the second side surface 34b in the inner peripheral surface 33 of the third component 30 are the same as each other.

[0177] The outer peripheral surface 32 has a curved surface convex toward the X2 direction in this embodiment. It should be noted that the outer peripheral surface 32 can also be composed of a plane. The inner peripheral surface 33 has a curved surface convex toward the X1 direction in this embodiment. It should be noted that the inner peripheral surface 33 can have a curved surface convex toward the X2 direction or can be composed of a plane. The curvature radii of the outer peripheral surface 32 and the inner peripheral surface 33 can be the same as each other or different from each other.

[0178] The bending radius of at least two of the outer peripheral surface 12, the outer peripheral surface 22, and the outer peripheral surface 32 may also be the same. Of course, the bending radius of the outer peripheral surface 12, the outer peripheral surface 22, and the outer peripheral surface 32 may all be the same. The bending radius of the outer peripheral surface 12, the outer peripheral surface 22, and the outer peripheral surface 32 may all be different. The bending radius of at least two of the inner peripheral surface 13, the inner peripheral surface 23, and the inner peripheral surface 33 may also be the same. Of course, the bending radius of the inner peripheral surface 13, the inner peripheral surface 23, and the inner peripheral surface 33 may all be the same. The bending radius of the inner peripheral surface 13, the inner peripheral surface 23, and the inner peripheral surface 33 may all be different.

[0179] The first side surface 34a and the second side surface 34b respectively have a first parallel surface 341, a second parallel surface 342 and a first inclined surface 343. The first parallel surfaces 341 of the first side surface 34a and the second side surface 34b are parallel to each other. The second parallel surfaces 342 of the first side surface 34a and the second side surface 34b are parallel to each other. The first parallel surface 341 of the first side surface 34a is parallel to the second parallel surface 342 of the first side surface 34a. The first parallel surface 341 and the second parallel surface 342 are surfaces parallel to the X-axis direction of the core piece 1. The first parallel surface 341 is connected to the outer peripheral surface 32. The second parallel surface 342 is connected to the inner peripheral surface 33. The first inclined surface 343 is connected to the first parallel surface 341 and the second parallel surface 342.

[0180] like Figure 6 As shown, the first inclination angle θ31 and the second inclination angle θ32 of the first inclined surface 343 are preferably, for example, greater than 5° and less than 20°. If the first inclination angle θ31 and the second inclination angle θ32 are greater than 5° and less than 20°, the density deviation of the iron core piece 1 can be suppressed. The first inclination angle θ31 and the second inclination angle θ32 are further preferably greater than 5.5° and less than 18°, and particularly preferably greater than 6° and less than 16°. Although the first inclination angle θ31 and the second inclination angle θ32 are preferably the same angle, they may also be different. The first inclination angle θ31 refers to the angle formed by the extension surface E31 of the first parallel surface 341 in the first side surface 34a and the first inclined surface 343. The second inclination angle θ32 refers to the angle formed by the extension surface E32 of the first parallel surface 341 in the second side surface 34b and the first inclined surface 343.

[0181] At least two of the first inclination angle θ11, the first inclination angle θ21, and the first inclination angle θ31 may also be the same. At least two of the second inclination angle θ12, the second inclination angle θ22, and the second inclination angle θ32 may also be the same. Of course, the first inclination angle θ11, the first inclination angle θ21, and the first inclination angle θ31 may all be the same. The second inclination angle θ12, the second inclination angle θ22, and the second inclination angle θ32 may also all be the same. It should be noted that the first inclination angle θ11, the first inclination angle θ21, and the first inclination angle θ31 may all be different. The second inclination angle θ12, the second inclination angle θ22, and the second inclination angle θ32 may also all be different.

[0182] The corners between the first side surface 34a and the first end surface 36 and the corners between the first side surface 34a and the second end surface 37 are rounded. The corners between the second side surface 34b and the first end surface 36 and the corners between the second side surface 34b and the second end surface 37 are rounded.

[0183] In either the case where the core piece 1 constitutes the stator core 7 for the axial gap type rotating electrical machine 9 of the DS / SR system or the stator core 7 for the axial gap type rotating electrical machine 9 of the SS / DR system, the first end surface 36 may be as follows: Figure 3 As shown in the figure, it is composed of a plane, and it can also be composed of a convex shape toward the Z2 direction. If the first end surface 36 is composed of a convex shape, it is possible to form an axial gap type rotating motor 9 with low noise and vibration. The reason is as follows. Fig.18 or Fig.19 As shown, the stator 8 and the rotor 90 of the axial gap type rotating electric machine 9 are arranged facing each other. Fig.17 As shown in FIG. 8 , the stator 8 includes a stator core 7 and a coil 80. Fig.16 As shown, the stator core 7 is composed of a plurality of core sheets 1 arranged in a ring shape. Fig.17 As shown, the coil 80 is arranged on the first component 10 of each core sheet 1. The first end surface 36 of the third component 30 of the core sheet 1 is set to be convex. Fig.18 , Fig.19 In the axial gap type rotating electric machine 9 shown, it is easy to suppress a sudden change in the magnetic flux of the magnet 95 of the rotor 90 received by the core sheet 1. Therefore, it is easy to reduce the cogging torque. Since the cogging torque is small, noise and vibration are not likely to increase.

[0184] It is preferable that the corners between the first end surface 36 and the inner peripheral surface 33 and the corners between the first end surface 36 and the outer peripheral surface 32 are chamfered. Since these corners are chamfered, they are not easily damaged. These chamfers may be C chamfers or R chamfers.

[0185] [seam]

[0186] like Figure 3 As shown, the first joint between the second end face 27 of the protrusion 21 of the second component 20 and the peripheral surface 11 of the first component 10, and the second joint between the second end face 37 of the protrusion 31 of the third component 30 and the peripheral surface 11 of the first component 10 are rounded. In this embodiment, the first joint includes the joint between the first protrusion 211 of the second component 20 and the peripheral surface 11 of the first component 10, and the joint between the second protrusion 212 of the second component 20 and the peripheral surface 11 of the first component 10. These joints are rounded. The second joint includes the joint between the first protrusion 311 of the third component 30 and the peripheral surface 11 of the first component 10, and the joint between the second protrusion 312 of the third component 30 and the peripheral surface 11 of the first component 10. These joints are rounded. Since each joint is a rounded shape, the core piece 1 is not easily damaged starting from the above joint.

[0187] The bending radius of the first joint and the bending radius of the second joint are preferably 0.2 mm or more and 4.0 mm or less. By making the bending radius of the first joint and the second joint 0.2 mm or more, the load on the mold is small when manufacturing the core piece 1. By making the bending radius of the first joint and the second joint 4.0 mm or less, the reference Fig.17 In the stator 8 described below, it is easy to wind the coil 80, so it is easy to increase the number of turns of the coil 80. The bending radius of the first joint and the bending radius of the second joint are more preferably 0.3 mm or more and 3.0 mm or less, and particularly preferably 0.5 mm or more and 2.0 mm or less. The bending radius of the first joint and the bending radius of the second joint may be the same as or different from each other.

[0188] [Area ratio]

[0189] It is preferred that the total area of ​​the outer circumferential surfaces 12, 22, 32 of each of the first component 10, the second component 20, and the third component 30 is more than 1 time and less than 4 times the total area of ​​the inner circumferential surfaces 13, 23, 33 of each of the first component 10, the second component 20, and the third component 30. The core piece 1 whose total area of ​​the outer circumferential surfaces 12, 22, 32 is more than 1 time the total area of ​​the inner circumferential surfaces 13, 23, 33 is easy to be arranged in a ring shape and easy to form the stator core 7. The core piece 1 whose total area of ​​the outer circumferential surfaces 12, 22, 32 is less than 4 times the total area of ​​the inner circumferential surfaces 13, 23, 33 is easy to manufacture. Since the ratio of the total area of ​​the inner circumferential surfaces 13, 23, 33 is relatively large, the area pushed out by the lower punch 55 when the core piece 1 is pulled out from the die 5 is large. Therefore, it is easy to suppress damage to the core piece 1 when the core piece 1 is pulled out from the die 5. The total area of ​​the outer peripheral surfaces 12 , 22 , and 32 is more preferably 1.2 times or more and 3.8 times or less, and particularly preferably 1.5 times or more and 3.5 times or less, the total area of ​​the inner peripheral surfaces 13 , 23 , and 33 .

[0190] The core piece 1 of this embodiment is composed of a powder compact formed by integrally molding the first component 10, the second component 20 and the third component 30. Integral molding means that, for example, the first component 10, the second component 20 and the third component 30 are continuously formed by molding without mechanical connection using screws or bonding based on bonding agents. The powder compact has a plurality of soft magnetic particles. The powder compact is composed of an aggregate of soft magnetic particles. The powder compact is obtained by compression molding a soft magnetic powder having a plurality of soft magnetic particles. The soft magnetic particles are iron-based particles composed of pure iron or an iron-based alloy. Pure iron refers to iron with a purity of Fe (iron) of 99% by mass or more. The iron-based alloy contains at least one element of Si (silicon) and Al (aluminum), and the remainder is composed of Fe and unavoidable impurities. The iron-based alloy is, for example, at least one selected from the group consisting of Fe-Si alloy, Fe-Al alloy and Fe-Si-Al alloy. Fe-Si alloy is, for example, silicon steel. Fe-Si-Al alloy is, for example, sendustine. Since the above-mentioned material is relatively soft, the soft magnetic particles are easily deformed when the powder compact is formed. Therefore, the iron core sheet 1 has high density and excellent dimensional accuracy. Preferably, the powder compact is composed of an aggregate of multiple coated soft magnetic particles having an insulating coating on the surface of the soft magnetic particles. That is, the preferred powder compact is obtained by compression molding a coated soft magnetic powder having multiple coated soft magnetic particles. If an insulating coating is formed, it is easy to ensure electrical insulation between particles by the insulating coating. Therefore, the iron loss of the powder compact caused by eddy current loss can be reduced. The soft magnetic particles are as described above. As an insulating coating, for example, it is a phosphate coating or a silica coating.

[0191] [Relative density]

[0192] The relative density of the powder compact is preferably 85% or more. The powder compact having a relative density of 85% or more has excellent magnetic properties such as saturation magnetic flux density and mechanical properties such as strength. The relative density of the powder compact is further preferably 90% or more, and particularly preferably 93% or more. The relative density of the powder compact may be less than 100%. "Relative density" refers to the ratio (%) of the density of the actual powder compact to the true density of the soft magnetic particles constituting the powder compact.

[0193] [Difference in relative density]

[0194] In the first part, the second part, and the third part of the core piece 1, the difference in relative density between the first part, the second part, and the third part is preferably 5.0% or less. Since the difference in relative density of the core piece 1 is small, the physical properties such as magnetic properties are substantially uniform in the core piece 1. The smaller the difference in relative density between the first part, the second part, and the third part, the more preferred it is. The difference in relative density between the first part, the second part, and the third part is further preferably 4.0% or less, and particularly preferably 3.0% or less. Here, if Figure 2 As shown, by passing through the second parallel surface 142 along the first side surface 14a (refer to Figure 4 ) and the second parallel surface 142 along the second side surface 14b (refer to Figure 4 ) in the parts obtained by dividing the iron core piece 1 into three parts, the part located in the first circumferential direction is set as the first part, the part located in the second circumferential direction is set as the second part, and the part located between the first part and the second part is set as the third part.

[0195] Preferably, in the first component 10, the second component 20, and the third component 30, the difference in relative density between the component with the highest relative density and the component with the lowest relative density is 5.0% or less. Since the difference in relative density of the core piece 1 is small, the physical properties such as magnetic properties are substantially uniform in the core piece 1. The smaller the difference in relative density between the component with the highest relative density and the component with the lowest relative density, the better. The difference in relative density between the component with the highest relative density and the component with the lowest relative density is further preferably 4.0% or less, and particularly preferably 3.0% or less.

[0196] Preferably, the difference in relative density between the first and second portions and the third portion is 5.0% or less, and the difference in relative density between the member with the highest relative density and the member with the lowest relative density is 5.0% or less.

[0197] [Manufacturing method]

[0198] The core sheet 1 according to the first embodiment can be manufactured by a core sheet manufacturing method including a filling step and a molding step. In the filling step, raw material powder is filled into the cavity of the mold 5. In the molding step, the raw material powder in the cavity is compressed and molded. Figures 10 to 13 , the mold 5 is described, and then each process is described.

[0199] [Mold]

[0200] The die 5 includes a die 50, an upper punch 54, and a lower punch 55. The die 50 and the lower punch 55 constitute a cavity filled with raw material powder.

[0201] (die)

[0202] The die 50 has a die hole 50h. The die hole 50h is arranged facing the upper punch 54 and the lower punch 55. The inner peripheral shape of the die hole 50h is a shape corresponding to the shape of the core sheet 1. The upper punch 54 can be driven independently in the vertical direction relative to the die 50. The lower punch 55 can be driven independently in the vertical direction relative to the die 50.

[0203] Die hole 50h has Fig.10 , Fig.11 The first hole portion 51 shown, Fig.10 , Fig.12 The second hole portion 52 shown, and Fig.10 , Fig.13 The third hole portion 53 is shown. Fig.10 The opening edge of the upper punch 54 side in the die hole 50h of the die 50 is shown. For convenience of explanation, Fig.10 The punch die 50 is hatched. Figures 11 to 13 It is a cross-sectional view showing a state where the raw material powder filled in the cavity is pressure-molded by the upper punch 54 and the lower punch 55 . Fig.11 The cutting position of the cross-sectional view is equivalent to Fig.10 The XI-XI cut line indicates the position. Fig.12 The cutting position of the cross-sectional view is equivalent to Fig.10 The XII-XII cut line is shown at the position. Fig.13 The cutting position of the cross-sectional view is equivalent to Fig.10 The XIII-XIII cut line is shown at the position.

[0204] The first hole portion 51 has an inner circumferential surface that forms the first side surface 14a and the second side surface 14b of the first component 10. The second hole portion 52 has an inner circumferential surface that forms the first side surface 24a, the second side surface 24b, the first end surface 26, and the second end surface 27 of the second component 20. The third hole portion 53 has an inner circumferential surface that forms the first side surface 34a, the second side surface 34b, the first end surface 36, and the second end surface 37 of the third component 30. The first hole portion 51, the second hole portion 52, and the third hole portion 53 are continuously formed in a direction orthogonal to the direction in which the upper punch 54 and the lower punch 55 face each other. Specifically, the second hole portion 52 is connected to the first end side of the first hole portion 51 in the above-mentioned orthogonal direction. In addition, the third hole portion 53 is connected to the second end side of the first hole portion 51 in the above-mentioned orthogonal direction.

[0205] The first hole portion 51 includes a first straight portion 511, a second straight portion 512, and a tapered portion 513. The first straight portion 511, the tapered portion 513, and the second straight portion 512 are formed in sequence from the upper portion where the upper punch 54 is inserted to the lower portion where the lower punch 55 is inserted. Similarly, the second hole portion 52 includes a first straight portion 521, a second straight portion 522, and a tapered portion 523. The first straight portion 521, the tapered portion 523, and the second straight portion 522 are formed in sequence from the upper portion where the upper punch 54 is inserted to the lower portion where the lower punch 55 is inserted. Similarly, the third hole portion 53 includes a first straight portion 531, a second straight portion 532, and a tapered portion 533. The first straight portion 531, the tapered portion 533, and the second straight portion 532 are formed in sequence from the upper portion where the upper punch 54 is inserted to the lower portion where the lower punch 55 is inserted. The first straight portions 511, 521, 531 form portions near the outer circumference of the core sheet 1. The second straight portions 512, 522, 532 form portions near the inner circumference of the core sheet 1. The tapered portions 513, 523, 533 form portions between the outer circumference and the inner circumference of the core sheet 1.

[0206] When a plurality of grooves 40 are formed on the first side surface 14 a or the second side surface 14 b of the first member 10 , it is sufficient that concavities and convexities corresponding to the plurality of grooves 40 are provided on the inner peripheral surface of the first hole portion 51 .

[0207] (Upper punch)

[0208] The upper punch 54 has Fig.11 The first upper punch portion 541 shown, Fig.12 The second upper punch portion 542 shown, and Fig.13 The third upper punch portion 543 shown. The first upper punch portion 541 has a first lower end surface 541e. The first lower end surface 541e forms the outer peripheral surface 12 of the first component 10. The second upper punch portion 542 has a second lower end surface 542e. The second lower end surface 542e forms the outer peripheral surface 22 of the second component 20. The third upper punch portion 543 has a third lower end surface 543e. The third lower end surface 543e forms the outer peripheral surface 32 of the third component 30. The first upper punch portion 541, the second upper punch portion 542, and the third upper punch portion 543 may be formed continuously or independently of each other in a manner that allows them to be independently raised and lowered. When the first upper punch portion 541, the second upper punch portion 542, and the third upper punch portion 543 are formed continuously, the first lower end surface 541e, the second lower end surface 542e, and the third lower end surface 543e are formed continuously. The shape of the first lower end surface 541e corresponds to the shape of the outer peripheral surface 12 of the first component 10. The shape of the second lower end surface 542e corresponds to the shape of the outer peripheral surface 22 of the second member 20. The shape of the third lower end surface 543e corresponds to the shape of the outer peripheral surface 32 of the third member 30.

[0209] like Fig. 9 As shown, when a plurality of grooves 40 are formed on the outer peripheral surface 12 of the first member 10 , it is sufficient to provide projections and depressions corresponding to the plurality of grooves 40 on the first lower end surface 541 e of the first upper punch portion 541 .

[0210] (Lower punch)

[0211] The lower punch 55 has Fig.11 The first lower punch portion 551 shown, Fig.12 The second lower punch portion 552 shown, and Fig.13 The third lower punch portion 553 shown. The first lower punch portion 551 has a first upper end surface 551e. The first upper end surface 551e forms the inner peripheral surface 13 of the first component 10. The second lower punch portion 552 has a second upper end surface 552e. The second upper end surface 552e forms the inner peripheral surface 23 of the second component 20. The third lower punch portion 553 has a third upper end surface 553e. The third upper end surface 553e forms the inner peripheral surface 33 of the third component 30. The first lower punch portion 551, the second lower punch portion 552, and the third lower punch portion 553 may be formed continuously or independently of each other in a manner that allows them to be independently raised and lowered. When the first lower punch portion 551, the second lower punch portion 552, and the third lower punch portion 553 are formed continuously, the first upper end surface 551e, the second upper end surface 552e, and the third upper end surface 553e are formed continuously. The shape of the first upper end surface 551e corresponds to the shape of the inner peripheral surface 13 of the first component 10. The shape of the second upper end surface 552e corresponds to the shape of the inner peripheral surface 23 of the second member 20. The shape of the third upper end surface 553e corresponds to the shape of the inner peripheral surface 33 of the third member 30.

[0212] like Figure 1 As shown, when a plurality of grooves 40 are formed on the inner peripheral surface 13 of the first member 10 , it is sufficient to provide projections and depressions corresponding to the plurality of grooves 40 on the first upper end surface 551 e of the first lower punch portion 551 .

[0213] [Filling process]

[0214] The cavity formed by the die 50 and the lower punch 55 is filled with raw material powder. The raw material powder can be the soft magnetic powder or coated soft magnetic powder mentioned above. The raw material powder may also contain a binder and a lubricant in addition to the soft magnetic powder or the coated soft magnetic powder. The lubricant may also be applied to the inner peripheral surface of the die hole 50h of the die 50.

[0215] [Molding process]

[0216] The raw material powder in the die cavity is compressed and molded by the upper punch 54 and the lower punch 55. The direction in which the raw material powder is compressed is along the radial direction of the stator core 7. The higher the pressure during compression molding, the higher the relative density of the core piece 1 will be. The above pressure is preferably 700 MPa or more, and more preferably 980 MPa or more.

[0217] [Other processes]

[0218] After the forming process, heat treatment may also be performed as needed. For example, by removing strain through heat treatment, a low-loss iron core sheet 1 can be manufactured. Alternatively, for example, a binder or lubricant may also be removed through heat treatment. In the case where the raw material powder contains the above-mentioned coated soft magnetic particles, the heat treatment temperature is preferably below the decomposition temperature of the insulating coating.

[0219] The core piece 1 of this embodiment can suppress the temperature rise of the coil 80. The core piece 1 has a plurality of grooves 40 on the peripheral surface 11 of the first component 10. The winding 81 is arranged in a state of being embedded in each groove 40. By increasing the contact area between the winding 81 and the first component 10, the heat dissipation from the winding 81 to the first component 10 is improved. The coil 80 can be effectively cooled. In addition, when the winding 81 is wound on the first component 10, since the winding 81 is held in each groove 40, it is possible to suppress the winding of the winding 81 from being loose. By winding the winding 81 uniformly along the groove 40, the space factor of the coil 80 is improved. By increasing the space factor of the coil 80, it is possible to achieve miniaturization and high output of the axial gap type rotating electric machine 9.

[0220] 《Variation Example》

[0221] like Fig.14 or Fig.15 As shown, the core piece 1 of the present embodiment may include a groove 61 or a step 62 in which the end portion 81s where the winding of the winding wire 81 starts is arranged, in the protruding portion 21 of the second member 20 or the protruding portion 31 of the third member 30 .

[0222] 《Variant 1》

[0223] In Modification 1, referring to Fig.14 , an example in which the protrusion 21 of the second member 20 has a groove 61 will be described. In this example, the second end surface 27 (refer to Figure 3 ) is provided with a groove 61. The groove 61 extends from the outer peripheral surface 22 in the first protrusion 211 along the peripheral surface 11 of the first member 10. The groove 61 opens on the outer peripheral surface 22. The winding 81 passes through the groove 61 and is wound around the peripheral surface 11. The size of the groove 61 only needs to be large enough for the end 81s where the winding starts to enter. The width and depth of the groove 61 only need to be larger than the diameter of the winding 81.

[0224] 《Variant 2》

[0225] In Modification 2, refer to Fig.15 , an example in which the protrusion 21 of the second component 20 has a step 62 is described. In this example, the protrusion 21 has a third protrusion 213 in addition to the first protrusion 211 and the second protrusion 212. The third protrusion 213 extends in the X2 direction. The step 62 is provided on the third protrusion 213. The step 62 is recessed in the Z1 direction relative to the first protrusion 211 and the second protrusion 212. The winding 81 is wound around the peripheral surface 11 from the step 62. The distance between the first protrusion 211 and the second protrusion 212 and the step 62 in the Z-axis direction only needs to be greater than the diameter of the winding 81.

[0226] By placing the end 81s of the winding start of the winding wire 81 in the above-mentioned groove 61 or step 62, when the winding wire 81 is wound in multiple layers, it is possible to avoid the winding wire 81 after the second layer interfering with the end 81s of the winding start. Therefore, compared with the core piece without the groove 61 or step 62, the winding wire 81 can be wound one more turn.

[0227] Implementation Method 2

[0228] 〔Stator core〕

[0229] Reference Fig.16 , the stator core 7 involved in the second embodiment is described. The stator core 7 of this embodiment has a plurality of core sheets 1 arranged in a ring shape. Each of the plurality of core sheets 1 is the core sheet 1 involved in the first embodiment. The plurality of core sheets 1 are combined into a ring shape in such a way that the step 240 of the first side surface 24a in the second part 20 of the first core sheet 1 in the circumferentially adjacent core sheets 1 and the step 240 of the second side surface 24b in the second part 20 of the second core sheet 1 are interlocked with each other. The stator core 7 is used for Fig.18 An axial gap rotating electrical machine 9 of the DS / SR system is shown.

[0230] Preferably, the deviation in length between the surface on the first end side and the surface on the second end side in the Z-axis direction of each of the plurality of core sheets 1 is less than 0.1 mm. The length between the surface on the first end side and the surface on the second end side in the Z-axis direction refers to the maximum length between the first end face 26 of the second component 20 and the first end face 36 of the third component 30.

[0231] If the deviation of the length between the first end face 26 of the second component 20 and the first end face 36 of the third component 30 of each of the plurality of core sheets 1 is less than 0.1 mm, the deviation of the length is very small. Therefore, the stator core 7 can constitute an axial gap type rotating electric machine 9 with low noise and vibration. The reason is as follows. Fig.18As shown, the stator 8 and the rotor 90 of the axial gap type rotating electric machine 9 are arranged facing each other. Since the deviation of the above-mentioned length of the stator core 7 is small, the deviation of the interval between the stator 8 and the rotor 90 is small. Since the deviation of the above-mentioned interval is small, the torque pulsation becomes small. Since the torque pulsation is small, the noise and vibration are not easy to increase. The deviation of the above-mentioned length is calculated as follows. In each iron core sheet 1, the length from the first end face 26 of the second component 20 to the first end face 36 of the third component 30 is measured. This length is the maximum length of the iron core sheet 1 along the Z-axis direction. Calculate the difference between the maximum value and the minimum value of the above-mentioned length of each of the multiple iron core sheets 1. The difference is taken as the deviation of the above-mentioned length. The deviation of the length between the first end face 26 of the second component 20 and the first end face 36 of the third component 30 of each of the multiple iron core sheets 1 is further preferably less than 0.05 mm, and particularly preferably less than 0.01 mm.

[0232] In the stator core 7 of the present embodiment, each of the plurality of core sheets 1 constituting the stator core 7 is constituted by the core sheets 1 of the first embodiment. Therefore, it is possible to suppress a temperature increase of the coil 80 .

[0233] Implementation Method 3

[0234] 〔stator〕

[0235] Reference Fig.17 , the stator 8 according to the third embodiment is described. The stator 8 of this embodiment includes a stator core 7 and a coil 80. The stator core 7 according to the second embodiment can be used as the stator core 7. The coil 80 is wound around the first member 10 in each core sheet 1 of the stator core 7. The stator 8 is used Fig.18 An axial gap rotating electrical machine 9 of the DS / SR system is shown.

[0236] Each coil 80 has a cylindrical portion formed by winding a winding wire. Fig.17 In FIG. 1 , only the cylindrical portion of each coil 80 is shown in brief, and both ends of the winding wire are omitted from the illustration. The stator core 7 can be manufactured by winding the winding wire around the first member 10 of each core sheet 1 .

[0237] Since the stator 8 according to the third embodiment includes the stator core 7 according to the second embodiment, it is possible to suppress a temperature increase in the coil 80 .

[0238] Implementation Method 4

[0239] 〔Rotating electric machine〕

[0240] Reference Fig.18 , the rotating electrical machine 9 according to the fourth embodiment will be described. Fig.18This is a cross-sectional view taken along a plane parallel to the rotating shaft 91 of the rotating electric machine 9 and passing through the center of the stator 8. This is referred to in the fifth embodiment described below. Fig.19 The same is true in the embodiment. The rotating electric machine 9 of this embodiment is an axial gap type rotating electric machine. The rotating electric machine 9 of this embodiment is a DS / SR type having a rotor 90 and two stators 8. The rotor 90 of the rotating electric machine 9 is arranged facing the stator 8 in the axial direction. It is assembled in a manner in which a rotor 90 is sandwiched by two stators 8. In each stator 8, the stator 8 involved in the above-mentioned embodiment 3 can be used. The rotating electric machine 9 can be used as a motor or a generator. The rotating electric machine 9 has a housing 92.

[0241] The housing 92 has a cylindrical internal space for accommodating the stator 8 and the rotor 90. The housing 92 includes a cylindrical portion 921 and two plates 922. The cylindrical portion 921 surrounds the outer circumference of the stator 8 and the rotor 90. Plates 922 are respectively arranged at both ends of the cylindrical portion 921. The two plates 922 are fixed to the two end surfaces of the cylindrical portion 921 in a manner of sandwiching the stator 8 and the rotor 90 from both sides in the axial direction. The two plates 922 have a through hole in the center portion thereof. A bearing 93 is provided in the through hole. The rotating shaft 91 is inserted into the through hole via the bearing 93. The rotating shaft 91 passes through the housing 92.

[0242] The rotor 90 includes a magnet 95 and a rotor body. The rotor 90 is a flat plate-shaped component in this embodiment. The number of magnets 95 may be multiple as shown in this embodiment, or may be one as is different from this embodiment. When the number of magnets 95 is multiple, the specific number of magnets 95 may be the same as the number of core pieces 1. Multiple magnets 95 are arranged at equal intervals in the circumferential direction of the rotor body. In this embodiment, each magnet 95 is a flat plate having a planar shape corresponding to the planar shape of the first end face 36 of the third component 30 in each core piece 1. It should be noted that each magnet 95 may also be a convex lens having a convex surface toward each stator 8 side. When the number of magnets 95 is one, the shape of the magnet 95 is annular. The S pole and the N pole of one magnet 95 are alternately arranged in the circumferential direction. The rotor body supports multiple magnets 95. The rotor body is annular. The rotor body is supported by the rotating shaft 91 in a rotatable manner. Each magnet 95 is arranged at equal intervals in the circumferential direction of the rotor body. Each magnet 95 is magnetized in the axial direction along the rotating shaft 91. The magnetization directions of magnets 95 adjacent to each other in the circumferential direction of the rotor body are opposite to each other. The magnets 95 and each core piece 1 are repeatedly attracted and repelled by the rotating magnetic field generated by the stator 8, so that the rotor 90 rotates.

[0243] The stator 8 is arranged so that the first end surface 36 of the third member 30 in each core sheet 1 faces the magnet 95 of the rotor 90. When the rotor 90 rotates, the first end surface 36 of the third member 30 in each core sheet 1 receives the magnetic flux from the rotating magnet 95. Figure 3 As shown, if the first end face 36 of the third component 30 in each core sheet 1 is configured as a convex shape as described above, the noise and vibration of the rotating electric machine 9 can be reduced. The reason is as follows. By setting the first end face 36 of the third component 30 of each core sheet 1 to a convex shape, it is easy to suppress the rapid change of the magnetic flux of the magnet 95 of the rotor 90 received by each core sheet 1. Therefore, it is easy to reduce the cogging torque. Since the cogging torque is small, the noise and vibration are not easy to increase.

[0244] Since the rotating electrical machine 9 according to the fourth embodiment includes the stator 8 according to the third embodiment, it is possible to suppress a temperature increase in the coil 80 .

[0245] Implementation Method 5

[0246] 〔Rotating electric machine〕

[0247] Reference Fig.19 , the rotating electric machine 9 involved in the fifth embodiment is described. The rotating electric machine 9 of this embodiment is an axial gap type rotating electric machine. The rotating electric machine 9 of this embodiment is different from the rotating electric machine 9 of the fourth embodiment mainly in that it is an SS / DR type having two rotors 90 and one stator 8. The rotor 90 and the stator 8 of the rotating electric machine 9 are arranged facing each other in the axial direction. They are assembled in a manner in which one stator 8 is sandwiched between two rotors 90. The following description is centered on the differences from the fourth embodiment. The description of the same structure as the fourth embodiment is omitted.

[0248] Each rotor 90 includes a rotor body, a plurality of magnets 95, and a back yoke 98. The rotor body and the plurality of magnets 95 are as described in the above-mentioned embodiment 4. The back yoke 98 is provided between the rotor 90 and the plate 922. The back yoke 98 is a flat plate-shaped member. The back yoke 98 is composed of a powder compact or a laminated steel plate similar to the above-mentioned core sheet 1.

[0249] The stator 8 includes a plurality of core sheets 1 arranged in a ring shape, a coil 80 wound on a first component 10 of each core sheet 1, and a support component for holding the plurality of core sheets 1. The illustration of the support component is omitted. The second component 20 and the third component 30 of each core sheet 1 are configured identically to each other. That is, the protrusion amount of the first protrusion 211 and the second protrusion 212 in the second component 20 of each core sheet 1 is identical to the protrusion amount of the first protrusion 311 and the second protrusion 312 in the third component 30. In addition, the first side surface 24a of the first protrusion 211 and the second side surface 24b of the second protrusion 212 in the second component 20 are not provided with the above-mentioned step. The coil 80 is as shown in the above-mentioned embodiment 3. The support component holds the plurality of core sheets 1 in such a manner that the intervals between the core sheets 1 are equal. Through the support component, the core sheets 1 adjacent to each other in the circumferential direction do not contact each other.

[0250] Since the rotating electrical machine 9 according to the fifth embodiment includes the stator 8 similarly to the rotating electrical machine 9 according to the fourth embodiment, it is possible to suppress a temperature increase in the coil 80 .

[0251] The present invention is not limited to these examples but is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. For example, the rotating electrical machine may be a rotating electrical machine including one rotor and one stator.

[0252] Postscript

[0253] In association with the embodiments of the present disclosure described above, the following supplementary notes are further disclosed.

[0254] [Note 1]

[0255] A core sheet constituting a stator core for an axial gap type rotating electrical machine, comprising:

[0256] A first columnar component extending in the axial direction of the stator core;

[0257] a plate-shaped second component disposed at a first end portion of the first component in the axial direction; and

[0258] a plate-shaped third member, disposed at the second end portion of the first member in the axial direction,

[0259] The first component has a peripheral surface connected to the second component and the third component,

[0260] The second member has a protrusion extending outward from the peripheral surface of the first member,

[0261] The third member has a protrusion extending outward from the peripheral surface of the first member,

[0262] The first component, the second component and the third component respectively have:

[0263] An outer peripheral surface is arranged at a position away from the axis of the stator core;

[0264] An inner peripheral surface is arranged close to the axis of the stator core;

[0265] a first side surface, located in a first circumferential direction of the stator core, connected to the outer circumferential surface and the inner circumferential surface; and

[0266] The second side surface is located in a second circumferential direction of the stator core and is connected to the outer circumferential surface and the inner circumferential surface.

[0267] In each of the first component, the second component, and the third component, a length between the first side surface and the second side surface in the outer peripheral surface is longer than a length between the first side surface and the second side surface in the inner peripheral surface.

[0268] The first side surface and the second side surface of each of the first component, the second component and the third component respectively have:

[0269] A first parallel surface connected to the outer peripheral surface;

[0270] A second parallel surface connected to the inner peripheral surface; and

[0271] a first inclined surface connected to the first parallel surface and the second parallel surface,

[0272] In each of the first component, the second component, and the third component,

[0273] The first parallel surface of the first side surface is parallel to the first parallel surface of the second side surface,

[0274] The second parallel surface of the first side surface is parallel to the second parallel surface of the second side surface,

[0275] The first parallel surface of the first side surface is parallel to the second parallel surface of the first side surface,

[0276] The first component, the second component and the third component are formed of a compact formed by integral molding.

[0277] The peripheral surface of the first member has a plurality of grooves along a winding direction of the coil in at least a portion of a surface in contact with the coil winding.

[0278] The core piece according to Supplementary Note 1 is excellent in productivity.

[0279] The existing iron core sheet is composed of, for example, a powder compact formed by integrally forming a first component and a second component, and a third component formed separately from the powder compact. Alternatively, the existing iron core sheet is composed of, for example, a powder compact formed by integrally forming a first component and a third component, and a second component formed separately from the powder compact. That is, the existing iron core sheet needs to manufacture at least two components and combine them to form it. Therefore, the number of processes required for the manufacture of the existing iron core sheet is large, and the manufacturing time is long. In addition, at least two molds are required for the manufacture of the existing iron core sheet.

[0280] On the other hand, since the iron core sheet involved in Note 1 is composed of a powder compact formed by the first component, the second component and the third component as a whole, there is no need to combine multiple components. Therefore, compared with the existing iron core sheets, the iron core sheet involved in Note 1 can be manufactured with fewer processes and in a short time. In addition, since the iron core sheet involved in Note 1 is composed of a powder compact formed by the first component, the second component and the third component as a whole, it can be manufactured by a single mold. Therefore, the costs required for mold production and maintenance can be reduced, so the iron core sheet involved in Note 1 can be manufactured at low cost.

[0281] The powder compact is manufactured by pressurizing the raw material powder filled in the die hole of the die of the mold using an upper punch and a lower punch. As described in the above-mentioned manufacturing method, the powder compact formed in which the first component, the second component and the third component are integrally formed can be manufactured by setting the pressurization direction and the extraction direction to the radial direction of the stator core. The outer peripheral surface and the inner peripheral surface of the core sheet are formed by the lower end surface of the upper punch and the upper end surface of the lower punch. The first side surface and the second side surface of the core sheet and the axial first end surface and the second end surface of the stator core are formed by the inner peripheral surface of the die hole of the die. In this case, even if the second component and the third component have protrusions respectively, the protrusions will not hook on the inner peripheral surface of the die hole of the die. Therefore, the core sheet can be pulled out of the die.

[0282] Furthermore, the relative density of the iron core sheet involved in Note 1 is relatively high. The reason is as follows. As described above, the first parallel surface and the second parallel surface can be formed by a straight portion along the pressurizing direction of the upper punch and the lower punch in the die hole of the die of the mold. Therefore, it is possible to sufficiently apply pressure to the raw material powder constituting the iron core sheet. Moreover, the first inclined surface can be formed by a tapered portion that intersects the pressurizing direction of the upper punch and the lower punch in the die hole of the die of the mold. By having a straight portion in the die hole of the die, the upper punch and the lower punch can be prevented from contacting the inner circumferential surface of the tapered portion. Therefore, the life of the mold is prolonged, and thus the number of iron core sheets that can be produced by one mold is increased.

[0283] [Note 2]

[0284] According to the core sheet described in Supplementary Note 1, in each of the first component, the second component, and the third component,

[0285] The angle formed by the extension of the first parallel surface of the first side surface and the first inclined surface is greater than or equal to 5° and less than or equal to 20°,

[0286] An angle formed by an extension of the first parallel surface of the second side surface and the first inclined surface is greater than or equal to 5° and less than or equal to 20°.

[0287] The iron core sheet of Appendix 2 meets the above-mentioned range through the angle formed by the first component, so that it is easy to wind the winding around the circumference of the first component and to form the stator. The iron core sheet of Appendix 2 meets the above-mentioned range through the angle formed by the second component, so that it is easy to be arranged in a ring shape and to construct the stator core. The iron core sheet of Appendix 2 meets the above-mentioned range through the angle formed by the third component, which can suppress the deviation of the density in the iron core sheet.

[0288] [Note 3]

[0289] According to the core sheet described in Supplementary Note 1 or Supplementary Note 2, the protruding portion of the second member and the protruding portion of the third member respectively have:

[0290] A first protrusion extending in a first circumferential direction; and

[0291] A second protrusion extends in a second direction of the circumferential direction,

[0292] The protrusion amount of the first protrusion in the second component is greater than the protrusion amount of the first protrusion in the third component,

[0293] The protrusion amount of the second protrusion in the second component is greater than the protrusion amount of the second protrusion in the third component,

[0294] The first inclined surface of the first protrusion in the second member has a portion extending outward from the first imaginary surface.

[0295] The first inclined surface of the second protrusion in the second member has a portion extending outward from the second imaginary surface.

[0296] The first imaginary plane is a plane connecting a connection portion between the first parallel plane and the first inclined plane and a connection portion between the second parallel plane and the inner peripheral surface on the first side surface of the first protrusion in the second member.

[0297] The second imaginary plane is a plane connecting a connection point between the first parallel surface and the first inclined surface and a connection point between the second parallel surface and the inner peripheral surface on the second side surface of the second protruding portion of the second member.

[0298] The core pieces of Supplementary Note 3 can easily constitute a stator core having a large magnetic path area. The reason is as follows.

[0299] The stator core is formed by arranging a plurality of core sheets in a ring shape and is formed by combining a first core sheet and a second core sheet adjacent to each other in a circumferential direction so as to contact each other.

[0300] For example, in the case where the first side surface of the first protrusion and the second side surface of the second protrusion respectively have a first parallel surface, a second parallel surface and a first inclined surface, and the first inclined surface does not have an iron core sheet of the above-mentioned protruding portion, as described below. When the iron core sheets are arranged in a ring shape, if the first side surface of the first protrusion in the second part of the first iron core sheet is brought into contact with the second side surface of the second protrusion in the second part of the second iron core sheet, the first corner of the first iron core sheet is brought into contact with the second corner of the second iron core sheet. The first corner is the corner between the first side surface of the first protrusion in the second part and the inner peripheral surface. The second corner is the corner between the second side surface of the second protrusion in the second part and the inner peripheral surface. Therefore, the first side surface of the first protrusion in the second part of the first iron core sheet cannot be brought into full contact with the second side surface of the second protrusion in the second part of the second iron core sheet.

[0301] In contrast, the first side surface of the first protrusion and the second side surface of the second protrusion of the core sheet of Note 3 respectively have a first parallel surface, a second parallel surface and a first inclined surface, and the first inclined surface has a portion that extends further than the first imaginary surface and the second imaginary line. When the core sheets are arranged in a ring shape, even if the first side surface of the first protrusion in the second part of the first core sheet is brought into contact with the second side surface of the second protrusion in the second part of the second core sheet, the first corner of the first core sheet can be prevented from coming into contact with the second corner of the second core sheet. Thus, the first side surface of the first protrusion in the second part of the first core sheet can be brought into full contact with the second side surface of the second protrusion in the second part of the second core sheet.

[0302] [Note 4]

[0303] According to the core piece described in Supplementary Note 3, the first side surface of the first protrusion in the second member has one selected from the group consisting of at least one of a concave portion and a convex portion, a step, and a second inclined surface.

[0304] The second side surface of the second protrusion in the second component has one selected from the group consisting of at least one of a convex portion corresponding to the concave portion of the first side surface and a concave portion corresponding to the convex portion of the first side surface, a step corresponding to the step of the first side surface, and a second inclined surface corresponding to the second inclined surface of the first side surface.

[0305] The iron core sheet of Supplement 4 can easily form a stator iron core with a large magnetic circuit area, and the reason is as follows. The first iron core sheet and the second iron core sheet adjacent in the circumferential direction of the stator iron core can be interlocked with each other through the above-mentioned steps or the above-mentioned concave and convex parts, or can be in contact with each other through the above-mentioned second inclined surfaces. As a result, the first iron core sheet and the second iron core sheet can be fully in contact, so the contact area between the first iron core sheet and the second iron core sheet can be increased.

[0306] [Note 5]

[0307] According to the core sheet described in Supplementary Note 3 or Supplementary Note 4, the third member has a first end surface arranged on a side opposite to a side facing the second member,

[0308] The first end surface is arranged to be convex toward the opposite side.

[0309] The iron core sheet of Appendix 5 can construct a rotating electric machine with low noise and vibration. The reasons are as follows. The stator and rotor of the rotating electric machine are arranged facing each other. The stator is composed of coils arranged in each first part of the stator core. The stator core is composed of a plurality of iron core sheets arranged in a ring shape. By setting the first end face of the iron core sheet to be convex, it is easy to suppress the sudden change of the magnetic flux of the magnet of the rotor received by the iron core sheet. Since it is easy to suppress the sudden change of the magnetic flux, it is easy to reduce the cogging torque. Since the cogging torque is small, noise and vibration are not easy to increase.

[0310] [Note 6]

[0311] According to the core sheet described in any one of Supplementary Notes 1 to 5, the outer peripheral surface of each of the first component, the second component, and the third component has a curved surface that is convex in a direction away from the axis of the stator core,

[0312] The inner peripheral surface of each of the first member, the second member, and the third member has a curved surface that is convex in a direction approaching the axis of the stator core.

[0313] The core piece of Supplementary Note 6 can suppress the density variation in the core piece.

[0314] [Note 7]

[0315] According to the core sheet described in any one of Supplementary Notes 1 to 6, a first joint between the protruding portion of the second member and the peripheral surface of the first member, and a second joint between the protruding portion of the third member and the peripheral surface of the first member are rounded.

[0316] Since the first joint and the second joint of the core piece of Supplementary Note 7 are rounded, it is not easy to be damaged starting from each joint.

[0317] [Note 8]

[0318] According to the core sheet described in Supplementary Note 7, a bending radius of the first joint and a bending radius of the second joint are equal to or greater than 0.2 mm and equal to or less than 4.0 mm.

[0319] The bending radius of the core piece of note 8 through the first joint and the second joint is 0.2 mm or more, which can reduce the load on the mold when manufacturing the core piece. The bending radius of the core piece of note 8 through the first joint and the second joint is 4.0 mm or less, which makes it easy to wind the coil when forming the stator, so it is easy to increase the number of turns of the coil.

[0320] [Note 9]

[0321] According to the core sheet described in any one of Supplementary Notes 1 to 8, the second member and the third member each have a first end surface arranged on the opposite side to the sides facing each other,

[0322] In each of the second member and the third member, a corner portion between the outer peripheral surface and the first end surface, and a corner portion between the inner peripheral surface and the first end surface are chamfered.

[0323] Since the core piece of Supplementary Note 9 has the corners chamfered, the corners are not easily damaged.

[0324] [Note 10]

[0325] According to the iron core sheet described in any one of Appendix 1 to Appendix 9, the total area of ​​the outer peripheral surfaces of the first component, the second component and the third component is more than 1 time and less than 4 times the total area of ​​the inner peripheral surfaces of the first component, the second component and the third component.

[0326] The total area of ​​the core pieces passing through the outer peripheral surface of Appendix 10 is more than 1 times the total area of ​​the inner peripheral surface, so that it is easy to be arranged in a ring shape and to form a stator core. The total area of ​​the core pieces passing through the outer peripheral surface is less than 4 times the total area of ​​the inner peripheral surface, so that it is easy to manufacture. The ratio of the total area passing through the inner peripheral surface is relatively large, so that when the core pieces are pulled out from the mold, the area of ​​the core pieces pushed out by the lower punch is larger. Therefore, it is easy to suppress damage to the core pieces when the core pieces are pulled out from the mold.

[0327] [Note 11]

[0328] According to the iron core piece recorded in any one of Notes 1 to 10, in the parts obtained by dividing the iron core piece into three by an imaginary plane along the second parallel plane of the first side surface and an imaginary plane along the second parallel plane of the second side surface, the difference in relative density between a first part located in the first direction of the circumference, a second part located in the second direction of the circumference, and a third part located between the first part and the second part is less than 5.0%.

[0329] Since the difference in relative density of the core piece of Supplementary Note 11 is small, the physical properties such as magnetic properties are substantially uniform within the core piece.

[0330] [Note 12]

[0331] According to the core sheet according to any one of Supplementary Notes 1 to 11, among the first member, the second member, and the third member, a difference in relative density between a member having the highest relative density and a member having the lowest relative density is 5.0% or less.

[0332] Since the difference in relative density of the core piece of Supplementary Note 12 is small, the physical properties such as magnetic properties are substantially uniform within the core piece.

[0333] [Note 13]

[0334] The core sheet according to any one of Appendix 1 to Appendix 12, wherein the relative density of the powder compact is 85% or more.

[0335] The core sheet of Supplementary Note 13 has a high density because its relative density is 85% or more. The core sheet of Supplementary Note 13 can construct an axial gap type rotating electric machine having excellent magnetic properties such as saturation magnetic flux density. The core sheet of Supplementary Note 13 also has excellent mechanical properties such as strength.

[0336] [Note 14]

[0337] The core piece according to any one of Supplementary Notes 1 to 13, wherein the powder compact is composed of an aggregate of a plurality of coated soft magnetic particles having an insulating coating on the surface of the soft magnetic particles,

[0338] The soft magnetic particles are iron-based particles composed of at least one metal selected from the group consisting of pure iron, Fe-Si-based alloys, Fe-Al-based alloys, and Fe-Si-Al-based alloys.

[0339] The core piece of Supplementary Note 14 has high density and excellent dimensional accuracy. This is because the material is relatively soft, and therefore the soft magnetic particles are easily deformed when the powder compact is formed.

[0340] Description of Reference Numerals

[0341] 1 Iron chip

[0342] 10. First Part

[0343] 11 circumferential surface, 12 outer circumferential surface, 13 inner circumferential surface

[0344] 14a first side surface, 14b second side surface

[0345] 141 first parallel surface, 142 second parallel surface, 143 first inclined surface

[0346] 20 Second Part

[0347] 21 Protrusion

[0348] 211 first protrusion, 212 second protrusion, 213 third protrusion

[0349] 22 outer peripheral surface, 23 inner peripheral surface, 24a first side surface, 24b second side surface

[0350] 240 steps

[0351] 241 first parallel surface, 242 second parallel surface, 243 first inclined surface

[0352] 244 Extended part

[0353] 26 first end surface, 27 second end surface

[0354] 30 Third Part

[0355] 31 protrusion, 311 first protrusion, 312 second protrusion

[0356] 32 outer surface, 33 inner surface

[0357] 34a first side, 34b second side

[0358] 341 first parallel surface, 342 second parallel surface, 343 first inclined surface

[0359] 36 first end surface, 37 second end surface

[0360] 40 slots

[0361] 40w width, 40d depth

[0362] 42 Connection surface

[0363] 5. Mould

[0364] 50 punch die, 50h die hole

[0365] 51 first hole

[0366] 511 first straight portion, 512 second straight portion, 513 cone portion

[0367] 52 second hole

[0368] 521 first straight portion, 522 second straight portion, 523 tapered portion

[0369] 53 Third hole

[0370] 531 first straight portion, 532 second straight portion, 533 cone portion

[0371] 54 upper punch

[0372] 541 first upper punch head, 541e first lower end surface

[0373] 542 second upper punch head, 542e second lower end surface

[0374] 543 third upper punch head, 543e third lower end surface

[0375] 55 lower punch

[0376] 551 first lower punch head, 551e first upper end surface

[0377] 552 second lower punch head, 552e second upper end surface

[0378] 553 third lower punch head, 553e third upper end surface

[0379] 61 slots, 62 steps

[0380] 7 stator core, 8 stator

[0381] 80 coils

[0382] 81 winding, 81s winding start end

[0383] 81a long diameter, 81b short diameter

[0384] 81d diameter

[0385] 9 Rotating motor

[0386] 90 rotor, 91 rotating shaft, 92 housing

[0387] 921 cylinder, 922 plate

[0388] 93 bearing, 95 magnet, 98 back yoke

[0389] E11, E12, E21, E22, E31, E32 extension surface

[0390] Va, Vb imaginary surface, V21 first imaginary surface, V22 second imaginary surface

[0391] θ11, θ21, θ31 first tilt angle

[0392] θ12, θ22, θ32 are the second inclination angles.

Claims

1. A core sheet constituting a stator core for an axial gap type rotating electrical machine, A columnar first member extending in a direction along the axis of the stator core is provided, The peripheral surface of the first member has a plurality of grooves along a direction in which the coil is wound, in at least a portion of a surface in contact with the coil winding.

2. The core piece according to claim 1, The width of each of the plurality of slots is not less than 1 / 4 of the long diameter of the winding and not more than the long diameter. The depth of each of the plurality of grooves is not less than 1 / 4 of the minor diameter of the winding and not more than the minor diameter.

3. The core piece according to claim 1 or 2, The cross section of the winding is circular, The cross-section of each of the plurality of grooves is in the shape of an arc. The radius of the circle of the cross section of the winding wire is the same as the radius of the arc of the cross section of the groove.

4. The core piece according to any one of claims 1 to 3, The plurality of grooves have a connecting surface between two adjacent grooves that is continuous with the inner peripheral surface of the groove. The connecting surface is composed of a flat surface or a rounded curved surface.

5. The core piece according to any one of claims 1 to 4, The peripheral surface has: an inner peripheral surface disposed close to the axis of the stator core; and The outer peripheral surface is arranged at a position away from the axis of the stator core, The plurality of grooves are provided on at least one of the inner peripheral surface and the outer peripheral surface.

6. The core sheet according to any one of claims 1 to 5, comprising: a plate-shaped second member provided at a first end portion of the first member in a direction along the axis; and a plate-shaped third member disposed at a second end portion of the first member in a direction along the axis, The peripheral surface of the first component is connected to the second component and the third component, and the second component has a protrusion extending outward from the peripheral surface of the first component. The third member has a protrusion extending outward from the peripheral surface of the first member, The first member, the second member, and the third member are formed of an integrally molded powder compact.

7. The core piece according to claim 6, The protruding portion of the second member or the protruding portion of the third member has a groove or a step at which an end portion of the winding wire is arranged to start winding.

8. A core sheet constituting a stator core for an axial gap type rotating electrical machine, comprising: A first columnar member extending in a direction along the axis of the stator core; a plate-shaped second member provided at a first end portion of the first member in a direction along the axis; and a plate-shaped third member disposed at a second end portion of the first member in a direction along the axis, The first component has a peripheral surface connected to the second component and the third component, and the second component has a protrusion extending outward from the peripheral surface of the first component. The third member has a protrusion extending outward from the peripheral surface of the first member, The first component, the second component and the third component are formed of a compact formed by integral molding. The peripheral surface of the first component has: an inner peripheral surface disposed close to the axis of the stator core; and The outer peripheral surface is arranged at a position away from the axis of the stator core, At least one of the inner peripheral surface and the outer peripheral surface has a plurality of grooves along the winding direction of the coil in at least a portion of the surface in contact with the coil winding. The width of each of the plurality of slots is not less than 1 / 4 of the long diameter of the winding and not more than the long diameter. The depth of each of the plurality of grooves is not less than 1 / 4 of the short diameter of the winding and not more than the short diameter. The protruding portion of the second member or the protruding portion of the third member has a groove or a step at which an end portion of the winding wire is arranged to start winding.

9. A stator core, which is a stator core for an axial gap type rotating electrical machine, A plurality of core sheets are provided in a ring shape. Each of the plurality of core sheets is the core sheet according to any one of claims 1 to 8.

10. A stator for an axial gap type rotating electrical machine, comprising: The stator core according to claim 9; and A coil is arranged in each of the first components in the stator core.

11. A rotating electrical machine, which is an axial gap type rotating electrical machine, comprising a rotor and a stator, wherein the rotor and the stator are arranged facing each other in a direction along an axis, The stator is the stator according to claim 10.

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