Core piece and axial gap rotating electrical machine

Abstract

This core piece comprises a first member, a second member, and a third member. A peripheral surface of the first member has a first lateral surface, a second lateral surface, and a connecting surface joining the first lateral surface and the second lateral surface. Each of the second member and the third member has a protruding part. The first member, the second member, and the third member are formed as a monolithically molded, pressed powder compact. Each of the first lateral surface and the second lateral surface has a parallel surface joined to the connecting surface. The connecting surface has, in order from both ends to the center of the connecting surface, orthogonal surfaces respectively joined to a corresponding one of the parallel surfaces, lateral end surfaces respectively joined to a corresponding one of the orthogonal surfaces, and a central surface connected to each of the lateral end surfaces. An arc portion is included in each of the lateral end surfaces and in the central surface. The radius of curvature of the arc portion of each of the lateral end surfaces is less than the radius of curvature of the arc portion of the central surface, and a specific angle is greater than 90° and less than or equal to 150°.

Description

Core piece and axial gap type rotating electric machine

[0001] The present disclosure relates to a core piece and an axial gap type rotating electric machine. This application claims priority to Japanese Patent Application No. 2024-154140 filed on September 6, 2024. The entire contents of said Japanese application are incorporated herein by reference.

[0002] Patent Document 1 discloses core pieces arranged in an annular shape to form a stator core for an axial gap type rotating electric machine. The core piece in Patent Document 1 includes a first member extending in a direction along the axis of the stator core, a second member provided at a first end of the first member in the direction along the axis, and a third member provided at a second end of the first member in the direction along the axis. The first member, second member, and third member are formed as an integrally molded powder compact.

[0003] The first member has a peripheral surface that connects to the second member and the third member. The peripheral surface has an outer peripheral surface, an inner peripheral surface, a first side surface, and a second side surface. The outer peripheral surface is disposed on the outer periphery of the stator core. The inner peripheral surface is disposed on the inner periphery of the stator core. The first side surface is located in a first direction around the central axis of the stator core at the core piece. The second side surface is located in a second direction around the central axis of the stator core at the core piece. Each of the first side surface and the second side surface has a first parallel surface, a second parallel surface, and a first inclined surface. Each of the first parallel surfaces and each of the second parallel surfaces is parallel to a line that passes through the center of the stator core and divides the core piece in half around the central axis of the stator core. Each of the first parallel surfaces is connected to the outer peripheral surface. Each of the second parallel surfaces is connected to the inner periphery. Each of the first inclined surfaces is connected to each of the first parallel surfaces and each of the second parallel surfaces. As shown in FIG. 4 of Patent Document 1, the inner peripheral surface has orthogonal surfaces that are connected to the second parallel surfaces so as to be orthogonal to each other.

[0004] The second member and the third member have protruding portions that protrude outward beyond the peripheral surface of the first member.

[0005] International Publication No. 2021 / 225049

[0006] The core pieces disclosed herein are arranged in an annular arrangement to form a stator core for an axial gap rotating electric machine. The core pieces include a columnar first member extending in a direction along the central axis of the stator core, a plate-shaped second member provided at a first end of the first member in a direction along the central axis, and a plate-shaped third member provided at a second end of the first member in a direction along the central axis. The peripheral surface of the first member has a first side surface disposed in a first direction around the central axis, a second side surface disposed in a second direction around the central axis, and a connecting surface connecting the first side surface and the second side surface. The second member and the third member each have a protruding portion that protrudes outward from the peripheral surface. The first member, the second member, and the third member are formed as an integrally molded powder compact. The first side surface and the second side surface each have a parallel surface that connects to the connecting surface and are parallel to the diameter of the stator core. The connecting surface includes, in order from both ends of the connecting surface toward the center, orthogonal surfaces that connect to each of the parallel surfaces of the first side surface and the second side surface so as to be perpendicular to each of the parallel surfaces, side end surfaces that connect to each of the orthogonal surfaces, and a central surface that connects to each of the side end surfaces. Each of the side end surfaces and the central surface has an arc portion that protrudes outward from the connecting surface. The radius of curvature of the arc portion of each of the side end surfaces is smaller than the radius of curvature of the arc portion of the central surface. An angle between a tangent to the side end surface that passes through a connection point between the orthogonal surface and the side end surface and the orthogonal surface is greater than 90° and not greater than 150°.

[0007] FIG. 1 is a perspective view showing an outline of a core piece of embodiment 1. FIG. 2 is a side view showing an outline of a core piece of embodiment 1. FIG. 3 is a first perspective view showing an outer peripheral surface of a core piece of embodiment 1. FIG. 4 is a second perspective view showing an outer peripheral surface of a core piece of embodiment 1. FIG. 5 is a first perspective view showing an inner peripheral surface of a core piece of embodiment 1. FIG. 6 is a second perspective view showing an inner peripheral surface of a core piece of embodiment 1. FIG. 7 is a cross-sectional view of a first member in the core piece of FIG. 1. FIG. 8 is an enlarged view of region A1 in FIG. 7. FIG. 9 is an enlarged view of region A2 in FIG. 7. FIG. 10 is an enlarged view of region A3 in FIG. 7. FIG. 11 is an enlarged view of region A4 in FIG. 7. FIG. 12 is a cross-sectional view of a second member in the core piece of FIG. 1. FIG. 13 is a cross-sectional view of a third member in the core piece of FIG. 1. FIG. 14 is a cross-sectional view showing an outline of a mold for manufacturing the core piece of embodiment 1. FIG. 15 is a cross-sectional view showing an outline of a mold for manufacturing the first member in the core piece of embodiment 1. Fig. 16 is an enlarged view of region B1 in Fig. 15. Fig. 17 is an enlarged view of region B2 in Fig. 15. Fig. 18 is a first perspective view showing an outline of an upper punch of a die. Fig. 19 is a second perspective view showing an outline of an upper punch of a die. Fig. 20 is a first perspective view showing an outline of a lower punch of a die. Fig. 21 is a second perspective view showing an outline of a lower punch of a die. Fig. 22 is a cross-sectional view showing an outline of a core piece of embodiment 2. Fig. 23 is a cross-sectional view showing an outline of an axial gap type rotating electric machine of embodiment 3. Fig. 24 is a perspective view showing an outline of a stator provided in the axial gap type rotating electric machine of embodiment 3. Fig. 25 is a cross-sectional view of a first member in a core piece of sample No. 101. Fig. 26 is an enlarged view of region A1 in Fig. 25. Fig. 27 is an enlarged view of region A3 in Fig. 25. Fig. 28 is a cross-sectional view of a first member in a core piece of sample No. 102. Fig. 29 is an enlarged view of region A1 in Fig. 28. FIG. 30 is an enlarged view of area A3 in FIG.

[0008] The core piece in Patent Document 1 is manufactured by press-molding raw material powder filled in a die hole of a mold using an upper punch and a lower punch. The outer peripheral surface of this core piece is formed by the lower end surface of the upper punch, and the inner peripheral surface is formed by the upper end surface of the lower punch. This is because the core piece needs to be extracted from the hole without the protrusions on the second and third members getting caught on the inner peripheral surface of the die hole. Having the orthogonal surface on the inner peripheral surface of the first member of the core piece makes it easier to apply pressure to the raw material powder using the upper end surface of the lower punch, facilitating the production of a high-density green compact. Furthermore, large localized stresses are less likely to act on the upper end surface of the lower punch. When the outer peripheral surface has the orthogonal surface, the lower end surface of the upper punch also has the same effect as the upper end surface of the lower punch. This extends the life of the mold and increases the number of core pieces that can be produced using a single mold.

[0009] When forming a rotating electric machine using the core pieces of Patent Document 1, a winding is wound around the circumferential surface of a first member. The winding is typically a covered wire having a conductor and an insulating coating covering the outer periphery of the conductor. When the winding is wound around the circumferential surface of the first member, the winding comes into contact with corners where the first and second side surfaces of the circumferential surface meet the orthogonal surface of the inner circumferential surface. It is desirable for the core pieces to be ones that are less likely to damage the insulating coating of the winding due to this contact.

[0010] One of the objects of the present disclosure is to provide a core piece that is less likely to damage the mold during manufacturing and is less likely to damage the insulating coating of the wound winding.

[0011] The core pieces of the present disclosure are less likely to damage the mold during manufacturing, and are less likely to damage the insulating coating of the wound wire.

[0012] First, embodiments of the present disclosure will be listed and described.

[0013] (1) According to one aspect of the present disclosure, core pieces are arranged in an annular shape to form a stator core for an axial gap rotating electric machine. The core pieces include a columnar first member extending in a direction along the central axis of the stator core, a plate-shaped second member provided at a first end of the first member in a direction along the central axis, and a plate-shaped third member provided at a second end of the first member in a direction along the central axis. The peripheral surface of the first member has a first side surface disposed in a first direction around the central axis, a second side surface disposed in a second direction around the central axis, and a connecting surface connecting the first side surface and the second side surface. The second member and the third member each have a protrusion that protrudes outward from the peripheral surface. The first member, the second member, and the third member are formed as an integrally molded powder compact. The first side surface and the second side surface each have a parallel surface that connects to the connecting surface and is parallel to the diameter of the stator core. The connecting surface includes, in order from both ends of the connecting surface toward the center, orthogonal surfaces that connect to each of the parallel surfaces of the first side surface and the second side surface so as to be perpendicular to each of the parallel surfaces, side end surfaces that connect to each of the orthogonal surfaces, and a central surface that connects to each of the side end surfaces. Each of the side end surfaces and the central surface has an arc portion that protrudes outward from the connecting surface. The radius of curvature of the arc portion of each of the side end surfaces is smaller than the radius of curvature of the arc portion of the central surface. An angle between a tangent to the side end surface that passes through a connection point between the orthogonal surface and the side end surface and the orthogonal surface is greater than 90° and not greater than 150°.

[0014] The core piece (1) above, which is composed of a powder compact formed by integrally molding a first member, a second member, and a third member, is manufactured by pressurizing raw material powder filled in a die hole of a mold with a punch. In the core piece (1), the second member and the third member each have a protrusion. A connecting surface is formed by the end face of the punch so that the core piece can be removed from the mold without the protrusion getting caught on the inner circumferential surface of the die hole. When the connecting surface formed by the end face of the punch has an orthogonal surface, pressure is more easily applied to the raw material powder than when the connecting surface formed by the end face of the punch does not have an orthogonal surface. Therefore, the core piece (1) above is likely to have a high density. Furthermore, since large stress is less likely to act locally on the end face of the punch, the mold is less likely to be damaged during the production of the core piece (1). This extends the mold's lifespan and increases the number of core pieces that can be produced with a single mold.

[0015] In the core piece (1) above, the radius of curvature of the arc portion of the side end face connected to the orthogonal surface is smaller than the radius of curvature of the arc portion of the central surface connected to the side end face, and the angle is greater than 90°, so that the width of the portion of the punch that forms the orthogonal surface does not become too thin. Therefore, the mold, especially the punch, is less likely to be damaged during the production of the core piece (1), and the life of the mold is likely to be extended.

[0016] The core piece (1) described above is used to form a stator core for an axial gap type rotating electrical machine, with a coil winding wound around the circumferential surface of a first member. The winding is typically a coated wire having a conductor and an insulating coating covering the outer periphery of the conductor. In the core piece (1) described above, the radius of curvature of the arc portion of the side end face connected to the orthogonal plane is smaller than the radius of curvature of the arc portion of the central face connected to the side end face, and the angle is 150° or less, so that the winding is less likely to come into excessive contact with the corner between the orthogonal plane and the parallel plane. Therefore, the core piece (1) described above is less likely to damage the insulating coating of the wound winding.

[0017] (2) The core laminations of (1) above may have the following configuration: the connecting surface has an outer peripheral surface disposed on the outer periphery of the stator core and an inner peripheral surface disposed on the inner periphery of the stator core. The parallel surfaces of each of the first side surface and the second side surface have a first parallel surface connected to the outer peripheral surface and a second parallel surface connected to the inner peripheral surface. The orthogonal surfaces have a first orthogonal surface connected to each of the first parallel surfaces and a second orthogonal surface connected to each of the second parallel surfaces. The side end surfaces have first side end surfaces connected to each of the first orthogonal surfaces and a second side end surface connected to each of the second orthogonal surfaces. The central surfaces have a first central surface connected to each of the first side end surfaces and a second central surface connected to each of the second side end surfaces. The radius of curvature of the arc portion of each of the first side end surfaces is smaller than the radius of curvature of the arc portion of the first central surface. The radius of curvature of the arc portion of each of the second side end faces is smaller than the radius of curvature of the arc portion of the second central face. An angle formed by a tangent to the first side end face passing through a connection point between the first orthogonal plane and the first side end face and the first orthogonal plane is greater than 90° and not greater than 150°. An angle formed by a tangent to the second side end face passing through a connection point between the second orthogonal plane and the second side end face and the second orthogonal plane is greater than 90° and not greater than 150°.

[0018] For example, the core piece (2) has an outer peripheral surface formed by the lower end surface of the upper punch and an inner peripheral surface formed by the upper end surface of the lower punch. The radius of curvature of the arc portion of the first side end surface connected to the first orthogonal plane is smaller than the radius of curvature of the arc portion of the first central plane connected to the first side end surface, and the angle is greater than 90°. Therefore, the width of the portion of the upper punch that forms the outer peripheral surface and that forms the first orthogonal plane is not too thin. Similarly, the width of the portion of the lower punch that forms the inner peripheral surface and that forms the second orthogonal plane is not too thin. Therefore, the mold, particularly the upper punch and the lower punch, are less likely to be damaged during the production of the core piece (2), which further extends the mold's lifespan.

[0019] Because the radius of curvature of the arc portion of the first side end face connected to the first orthogonal plane is smaller than the radius of curvature of the arc portion of the first central plane connected to the first side end face and the angle is 150° or less, the winding is less likely to come into excessive contact with the corner between the first orthogonal plane and the first parallel plane. Similarly, the winding is less likely to come into excessive contact with the corner between the second orthogonal plane and the second parallel plane. Therefore, the core piece of (2) above is even less likely to damage the insulating coating of the wound winding.

[0020] (3) In the core piece of (2) above, the width of each of the first orthogonal surfaces and the width of each of the second orthogonal surfaces may be 0.05 mm or more and 0.40 mm or less.

[0021] If the width is 0.05 mm or more, the width of the portion of the lower end surface of the upper punch that forms the first orthogonal plane and the width of the portion of the upper end surface of the lower punch that forms the second orthogonal plane are not too small. Therefore, the stress acting on the above-mentioned portions of the upper punch and the lower punch does not become too high. This tends to extend the life of the die, making it easier to produce a larger number of core pieces with one die. If the width is 0.40 mm or less, the winding is less likely to come into excessive contact with the corners between the first parallel plane and the first orthogonal plane, and the corners between the second parallel plane and the second orthogonal plane. Therefore, the insulating coating of the winding is less likely to be damaged.

[0022] (4) In the core piece of (2) or (3) above, the ratio of the total width of the first orthogonal surface and the width of the first side end surface to the width of the outer circumferential surface may be 3% or more and 50% or less.

[0023] If the ratio is 3% or more, the width of the portion of the lower end face of the upper punch that forms the first orthogonal plane and the first side end face is not too small. Therefore, the stress acting on the portion of the upper punch does not become too high. If the ratio is 50% or less, the winding is less likely to come into excessive contact with the corner between the first parallel plane and the first orthogonal plane.

[0024] (5) In any of the core pieces (2) to (4) above, the ratio of the total width of the second orthogonal surface and the width of the second side end surface to the width of the inner peripheral surface may be 3% or more and 50% or less.

[0025] If the ratio is 3% or more, the width of the portion of the upper end face of the lower punch that forms the second orthogonal plane and the second side end face is not too small. Therefore, the stress acting on the portion of the lower punch does not become too high. If the ratio is 50% or less, the winding is less likely to come into excessive contact with the corner between the second parallel plane and the second orthogonal plane.

[0026] (6) In any of the core pieces (2) to (5) above, the ratio of the radius of curvature of the arcuate portion of the first central surface to the width of the outer circumferential surface may be 0.5 or more.

[0027] With the above configuration, the depth of the portion of the lower end surface of the upper punch that forms the first central surface is not too deep, which makes it difficult for large stresses to act locally on the lower end surface of the upper punch, thereby increasing the life of the upper punch.

[0028] (7) In any of the core pieces (2) to (6) above, the ratio of the radius of curvature of the arcuate portion of the second central surface to the width of the inner circumferential surface may be 0.5 or more.

[0029] With the above configuration, the depth of the portion of the upper end surface of the lower punch that forms the second central surface is not too deep, which makes it difficult for large stresses to act locally on the upper end surface of the lower punch, thereby increasing the life of the lower punch.

[0030] (8) In any of the core pieces described in (2) to (7), the protruding portions of the second member and the third member may each have an outer peripheral protruding portion that protrudes outward from the outer peripheral surface. The outer peripheral surface has an outer peripheral inclined surface at a location connected to the outer peripheral protruding portion of each of the second member and the third member, the outer peripheral surface inclining away from the inner peripheral surface toward the outer peripheral protruding portion of each of the second member and the third member. The width of the outer peripheral inclined surface decreases toward the outer peripheral protruding portion of each of the second member and the third member.

[0031] The core piece (8) having an outer peripheral inclined surface is superior in productivity because it is easier to separate the core piece from the lower end surface of the upper punch than a core piece without an outer peripheral inclined surface.

[0032] Unlike the core piece described in (8) above, if the width of the outer peripheral inclined surface is uniform rather than narrow as described above, when winding the winding around the circumferential surface of the first member, the tension acting on the winding wound around the outer peripheral inclined surface will be greater than the tension acting on the winding wound around the portion of the outer peripheral surface other than the outer peripheral inclined surface. This is because the circumferential length of the circumferential surface of the first member, including the outer peripheral inclined surface, is longer than the circumferential length of the circumferential surface of the first member other than the outer peripheral inclined surface. In contrast, if the width of the outer peripheral inclined surface is narrow as described above, as in the core piece described in (8) above, the tension acting on the winding wound around the outer peripheral inclined surface is likely to be smaller than when the width of the outer peripheral inclined surface is uniform rather than narrow as described above.

[0033] (9) In any of the core pieces (2) to (8), the protruding portions of the second and third members may each have an inner peripheral protruding portion that protrudes outward from the inner peripheral surface. The inner peripheral surface has an inner peripheral inclined surface at a location connected to the inner peripheral protruding portion of each of the second and third members, the inner peripheral surface inclining away from the outer peripheral surface toward the inner peripheral protruding portion of each of the second and third members. The width of the inner peripheral inclined surface decreases toward the inner peripheral protruding portion of each of the second and third members.

[0034] The core piece (9) having an inner peripheral inclined surface is superior in productivity because it is easier to separate the core piece from the upper end surface of the lower punch than a core piece without an inner peripheral inclined surface.

[0035] If the width of the inner circumferential inclined surface is small as described above, as in the core piece (9) above, the tension acting on the winding wound on the inner circumferential inclined surface tends to be smaller than when the width of the inner circumferential inclined surface is not small as described above but is uniform.

[0036] (10) In any of the core pieces (2) to (9) above, the ratio of the width of the outer peripheral surface to the width of the inner peripheral surface may be greater than 1 and equal to or less than 4.

[0037] The core piece (10) has an inner peripheral surface with a width smaller than that of the outer peripheral surface. Even if the width of the inner peripheral surface is smaller than that of the outer peripheral surface, the core piece is less likely to damage the mold during manufacturing and is less likely to damage the insulating coating of the wound wire.

[0038] (11) The core piece according to any one of (1) to (10) above may further include an insulating coating covering the peripheral surface, the insulating coating having an average thickness of 100 μm or less.

[0039] When the core piece (11) is used in a component of an axial gap type rotating electric machine, a coil is disposed on the circumferential surface of the first member. The insulating coating covering the circumferential surface can improve electrical insulation between the core piece and the coil. Even if the coil winding comes into contact with the corners between the parallel and orthogonal surfaces of the first side surface and the corners between the parallel and orthogonal surfaces of the second side surface, the insulating coating of the winding is unlikely to be damaged. Therefore, even if the average thickness of the insulating coating is 100 μm or less, the electrical insulation between the core piece and the coil is unlikely to decrease. An insulating coating with an average thickness of 100 μm or less is unlikely to increase the size of the core pieces.

[0040] (12) In the core piece according to any one of (1) to (11), the powder compact may be composed of an aggregate of a plurality of soft magnetic particles, wherein the soft magnetic particles are iron-based particles made 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.

[0041] The core piece (12) has high density and excellent dimensional accuracy because the material is relatively soft and the soft magnetic particles are easily deformed during molding of the powder compact.

[0042] (13) An axial gap type rotating electric machine according to one aspect of the present disclosure includes a rotor and a stator, wherein the stator includes the stator core formed by arranging the core pieces according to any one of (1) to (12) in an annular shape, and a coil disposed on each of the first members in the stator core.

[0043] The axial gap type rotating electrical machine of (13) above has excellent electrical characteristics and productivity because it includes the core pieces.

[0044] [Details of the embodiment of the present disclosure] Specific examples of core pieces of the present disclosure will be described below with reference to the drawings. The same reference numerals in the drawings indicate the same objects. The shapes, sizes, positional relationships, etc. shown in each drawing are depicted for the purpose of clarifying the description and do not necessarily represent the actual shapes, sizes, positional relationships, etc.

[0045] [Embodiment 1] <Core Laminates> A core laminate 1 according to embodiment 1 will be described with reference to FIGS. 1 to 13. The core laminates 1 of embodiment 1 are arranged in an annular shape to form a stator core 7, as will be described later with reference to FIGS. 23 and 24. The stator core 7 is used in an axial gap type rotating electric machine 9 (hereinafter simply referred to as the rotating electric machine 9). As shown in FIG. 1, the core laminate 1 of embodiment 1 includes a columnar first member 10, a plate-shaped second member 20, and a plate-shaped third member 30. The first member 10 extends along the central axis of the stator core 7. The second member 20 is provided at a first end of the first member 10 in a direction along the axis. The third member 30 is provided at a second end of the first member 10 in a direction along the axis. A peripheral surface 10a of the first member 10 includes a first side surface 14a, a second side surface 14b, and a connecting surface 11. One of the features of the core piece 1 of the first embodiment is that it satisfies the following requirements (a) to (f).

[0046] (a) The second member 20 and the third member 30 have protrusions 21, 31 that protrude outward from the peripheral surface 10a of the first member 10. (b) The first member 10, the second member 20, and the third member 30 are integrally molded into a powder-pressed compact. "Integratedly molded" means that the first member 10, the second member 20, and the third member 30 are formed as a single unit by molding, without mechanical connection using screws or bonding with adhesives. (c) The connecting surface 11 has specific orthogonal surfaces, side end surfaces, and a central surface. (d) Each of the side end surfaces and the central surface has an arc portion that protrudes outward from the connecting surface 11. (e) The curvature of the arc portion of each of the side end surfaces and the curvature of the arc portion of the central surface satisfy a specific magnitude relationship. (f) The angle formed by each of the orthogonal surfaces and a tangent to the side end surface passing through each of the connection points between each of the orthogonal surfaces and each of the side end surfaces satisfies a specific range.

[0047] In the following description, the X1 direction, X2 direction, Y1 direction, Y2 direction, Z1 direction, and Z2 direction defined as follows will be used. The X1 direction is a direction along the diameter of the stator core 7, along a line that passes through the center of the stator core 7 and bisects the core lamination 1 around the central axis of the stator core 7, and is a direction moving away from the center of the stator core 7. The X2 direction is the opposite direction to the X1 direction, and is a direction along the diameter of the stator core 7, along a line that passes through the center of the stator core 7 and bisects the core lamination 1 around the central axis of the stator core 7, and is a direction toward the center of the stator core 7. The Y1 direction is a first direction along the central axis of the stator core 7 in the core lamination 1. The Y2 direction is a second direction along the central axis of the stator core 7 in the core lamination 1, and is opposite to the Y1 direction. The Z1 direction is a direction along the central axis of the stator core 7 in the core lamination 1, from the first member 10 to the second member 20. The Z2 direction is the opposite direction to the Z1 direction, and is a direction along the central axis of the stator core 7 in the core lamination 1 from the first member 10 toward the third member 30.

[0048] <<First Member>> The first member 10 is a columnar member extending along the central axis of the stator core 7. The first member 10 forms teeth in either the case where the core laminations 1 form a stator core 7 of a double stator / single rotor (DS / SR) configuration for the rotating electric machine 9, or the case where the core laminations 1 form a stator core 7 of a single stator / double rotor (SS / DR) configuration for the rotating electric machine 9. As shown in FIG. 23 , the rotating electric machine 9 of the DS / SR configuration is assembled so that one rotor 90 is sandwiched between two stators 8. Although not shown, the rotating electric machine 9 of the SS / DR configuration is assembled so that one stator is sandwiched between two rotors. When the core laminations 1 form teeth, coils 80, which will be described later with reference to FIGS. 23 and 24 , are arranged on the first member 10.

[0049] 7, the cross-sectional shape of the first member 10 is, for example, a fan shape. The cross-section of the first member 10 is a cross section cut along a plane perpendicular to the Z1 direction. If the cross-sectional shape of the first member 10 is a fan shape, it is easy to increase the cross-sectional area of ​​the first member 10, and it is also easy to reduce the dead space of the core laminations 1, making it easy to form a stator 8 with a high space factor.

[0050] As shown in FIG. 1 , the peripheral surface 10a of the first member 10 is connected to the second member 20 and the third member 30. As shown in FIGS. 1 to 6 , the peripheral surface 10a of the first member 10 has a first side surface 14a, a second side surface 14b, and a connecting surface 11. The first side surface 14a is a surface facing the Y1 direction. The second side surface 14b is a surface facing the Y2 direction. The connecting surface 11 is a surface connecting the first side surface 14a and the second side surface 14b. In this example, the connecting surface 11 is both the outer peripheral surface 12 and the inner peripheral surface 13. The outer peripheral surface 12 is a surface facing the X1 direction. The outer peripheral surface 12 is connected to the X1-direction edge of the first side surface 14a and the X1-direction edge of the second side surface 14b. The inner peripheral surface 13 is a surface facing the X2 direction. The inner peripheral surface 13 is connected to the X2-direction edge of the first side surface 14 a and the X2-direction edge of the second side surface 14 b. The positional relationships among the outer peripheral surface 12, the inner peripheral surface 13, the first side surface 14 a, and the second side surface 14 b are the same for the second member 20 and the third member 30 described later.

[0051] As shown in FIG. 7 , each of the first side surface 14a and the second side surface 14b has a first parallel surface 141, a second parallel surface 142, and a first inclined surface 143. Each of the first parallel surfaces 141 and each of the second parallel surfaces 142 are parallel to the X1 direction and the X2 direction. The first parallel surfaces 141 are parallel to each other. The second parallel surfaces 142 are parallel to each other. Each of the first parallel surfaces 141 and each of the second parallel surfaces 142 are parallel to each other. Each of the first parallel surfaces 141 is connected to the outer peripheral surface 12. Each of the second parallel surfaces 142 is connected to the inner peripheral surface 13. Each of the first inclined surfaces 143 is connected to each of the first parallel surfaces 141 and each of the second parallel surfaces 142.

[0052] The length of each first parallel surface 141 and each second parallel surface 142 along the X1 direction depends on the size of the core piece 1, and is, for example, 0.3 mm or more and 25 mm or less. If the length of each first parallel surface 141 and each second parallel surface 142 along the X1 direction is 0.3 mm or more, damage caused by contact between the upper punch 54 and the lower punch 55, which will be described later with reference to FIG. 14 , and the die 50 is reduced. Although the manufacturing method of the core piece 1 will be described later, if the length of each first parallel surface 141 and each second parallel surface 142 along the X1 direction is 0.3 mm or more, even when sufficient pressure is applied to the raw material powder constituting the core piece 1, the upper punch 54 and the die 50 are unlikely to come into contact, and the lower punch 55 and the die 50 are unlikely to come into contact. If the length of each first parallel surface 141 and each second parallel surface 142 along the X1 direction is 25 mm or less, the cross-sectional area of ​​the first member 10 is unlikely to be small. This tends to improve the torque and reduce iron loss in the rotary electric machine 9. The length of each of the first parallel surfaces 141 and each of the second parallel surfaces 142 along the X1 direction may be 0.4 mm or more and 20 mm or less, or 0.5 mm or more and 15 mm or less.

[0053] The above-mentioned ranges of the lengths of each of the first parallel surfaces 141 and each of the second parallel surfaces 142 along the X1 direction also apply to the ranges of the lengths of each of the first parallel surfaces 241 and each of the second parallel surfaces 242 along the X1 direction of the second member 20, which will be described later with reference to Figures 12 and 13, and the ranges of the lengths of each of the first parallel surfaces 341 and each of the second parallel surfaces 342 along the X1 direction of the third member 30. The lengths of each of the first parallel surfaces 241 and each of the second parallel surfaces 242 along the X1 direction and the lengths of each of the first parallel surfaces 341 and each of the second parallel surfaces 342 along the X1 direction may be the same as or different from the lengths of each of the first parallel surfaces 141 and each of the second parallel surfaces 142 along the X1 direction.

[0054] As shown in FIG. 7 , the first inclination angle θ11 and the second inclination angle θ12 of the first inclined surface 143 are, for example, 5° to 20°. The first inclination angle θ11 is the angle between the first inclined surface 143 and an extension E11 of the first parallel surface 141 on the first side surface 14a. The second inclination angle θ12 is the angle between the first inclined surface 143 and an extension E12 of the first parallel surface 141 on the second side surface 14b. If the first inclination angle θ11 and the second inclination angle θ12 are 5° to 20°, the winding of the coil 80 (described later) can be easily wound around the circumferential surface 10a of the first member 10, making it easier to form the stator 8 shown in FIG. 24 . The first inclination angle θ11 and the second inclination angle θ12 may be 5.5° to 18° or 6° to 16°. The first tilt angle θ11 and the second tilt angle θ12 may be the same as or different from each other.

[0055] The ratio W10 / W20 of the width W10 of the outer peripheral surface 12 to the width W20 of the inner peripheral surface 13 is, for example, greater than 1 and equal to or less than 4. The width W20 is the linear length between the second parallel surfaces 142. The width W10 is the linear length between the first parallel surfaces 141. The ratio W10 / W20 may be equal to or greater than 1.05 and equal to or less than 3.9, or equal to or greater than 1.1 and equal to or less than 3.8.

[0056] As shown in Figures 8 and 9, the outer peripheral surface 12 of this example has a first orthogonal surface 12a, a first side end surface 12b, and a first central surface 12c, which are arranged in this order from both ends of the outer peripheral surface 12 toward the center. The two ends of the outer peripheral surface 12 are the connection portion between the outer peripheral surface 12 and the first parallel surface 141 of the first side surface 14a and the connection portion between the outer peripheral surface 12 and the first parallel surface 141 of the second side surface 14b. That is, the outer peripheral surface 12 of this example has two first orthogonal surfaces 12a, two first side end surfaces 12b, and one first central surface 12c. The outer peripheral surface 12 of this example has the first orthogonal surface 12a, the first side end surface 12b, the first central surface 12c, the first side end surface 12b, and the first orthogonal surface 12a, which are arranged in this order from the first parallel surface 141 of the first side surface 14a toward the first parallel surface 141 of the second side surface 14b. Each of the first orthogonal surfaces 12a is connected to each of the first parallel surfaces 141 so as to be perpendicular to the corresponding one of the first parallel surfaces 141. Each of the first side end surfaces 12b is connected to each of the first orthogonal surfaces 12a. The first central surface 12c is connected to both of the first side end surfaces 12b.

[0057] The width W11 of each first orthogonal surface 12a depends on the size of the core piece 1, but is, for example, 0.05 mm or more and 0.40 mm or less. The width W11 is the length along the first orthogonal surface 12a in FIG. 8 . If the width W11 is 0.05 mm or more, the width of the first orthogonal surface 54a at the first lower end surface 541e of the upper punch 54, described later with reference to FIG. 16 , is not too small. The first orthogonal surface 54a is the surface that forms the first orthogonal surface 12a. Because the width of the first orthogonal surface 54a is not too small, the stress acting locally on the first lower end surface 541e is not too high. This tends to extend the life of the upper punch 54, and therefore increases the number of core pieces 1 that can be produced with one mold 5. If the width W11 is 0.40 mm or less, the winding is less likely to come into excessive contact with the first corner 12d between the first parallel surface 141 and the first orthogonal surface 12a. Therefore, the insulating coating of the winding is less likely to be damaged. The width W11 may be 0.10 mm or more and 0.35 mm or less, or 0.15 mm or more and 0.30 mm or less.

[0058] Each first side end surface 12b has an arc portion 121 protruding outward from the outer peripheral surface 12. Each first side end surface 12b may be composed of a single arc portion 121 with a uniform radius of curvature, multiple arc portions 121 with different radii of curvature, or one or more arc portions 121 and one or more flat surfaces 122. Each first side end surface 12b in this example is composed of one arc portion 121 and one flat surface 122. Each first side end surface 12b in this example has one flat surface 122 and one arc portion 121 arranged in order from each first orthogonal surface 12a toward the first central surface 12c. The flat surface 122 is connected to the first orthogonal surface 12a. The arc portion 121 is connected to the flat surface 122 and the first central surface 12c.

[0059] The first central surface 12c has an arc portion 123 that protrudes outward from the outer peripheral surface 12. The first central surface 12c may be composed of a single arc portion 123 with a uniform radius of curvature, or may be composed of multiple arc portions 123 with different radii of curvature, or may be composed of one or more arc portions 123 and one or more flat surfaces 124. As shown in FIG. 9 , the first central surface 12c of this example is composed of two arc portions 123 and one flat surface 124. The first central surface 12c of this example has one arc portion 123, one flat surface 124, and one arc portion 123 arranged in order from one first orthogonal surface 12a to the other first orthogonal surface 12a.

[0060] The radius of curvature R11 of the arc portion 121 of each first side end face 12b is smaller than the radius of curvature R12 of the arc portion 123 of the first central face 12c. If the first side end face 12b has multiple arc portions 121 with different radii of curvature, the radius of curvature R11 is the largest radius of curvature. If the first central face 12c has multiple arc portions 123 with different radii of curvature, the radius of curvature R12 is the smallest radius of curvature. Because each radius of curvature R11 is smaller than the radius of curvature R12, the winding is less likely to come into excessive contact with the first corner portion 12d. As a result, the insulating coating of the winding is less likely to be damaged. If the first corner portion 12d is located on the extension plane E1 of the arc portion 123 of the first central surface 12c, the winding is less likely to come into excessive contact with the first corner portion 12d, and if the first corner portion 12d is located more inward than the extension plane E1, the winding is even less likely to come into excessive contact with the first corner portion 12d.

[0061] The angle θ1 formed between each first orthogonal surface 12a and a tangent to the first side end surface 12b passing through each connection point between each first orthogonal surface 12a and each first side end surface 12b is greater than 90° and less than 150°. When the angle θ1 is greater than 90°, the width of the portion of the upper punch 54 that forms the first orthogonal surface 12a does not become too thin, which tends to extend the life of the upper punch 54. When the angle θ1 is less than 150°, the winding is less likely to come into excessive contact with the first corner portion 12d. The angle θ1 may be greater than 95° and less than 140°, or greater than 100° and less than 135°.

[0062] The ratio P1 of the sum of the width W13 of the width W11 of the first orthogonal surface 12a and the width W12 of the first side end surface 12b to the width W10 of the outer peripheral surface 12 is, for example, 3% or more and 50% or less. The ratio P1 is (W13 / W10) × 100. The width W12 of the first side end surface 12b is the length along the first orthogonal surface 12a at the first side end surface 12b in FIG. 8. If the ratio P1 is 3% or more, the widths of the first orthogonal surface 54a and the first side end surface 54b at the first lower end surface 541e of the upper punch 54, which will be described later with reference to FIG. 16, are not too small. The first side end surface 54b is the surface that forms the first side end surface 12b. Because the widths of the first orthogonal surface 54a and the first side end surface 54b are not too small, the stress acting on the upper punch 54 is not too high. If the ratio P1 is 50% or less, the winding is less likely to come into excessive contact with the first corner portion 12d. The ratio P1 may be 5% to 20%, 7% to 18%, or 8% to 16%.

[0063] The ratio R12 / W10 of the radius of curvature R12 of the first central surface 12c to the width W10 of the outer peripheral surface 12 is, for example, 0.5 or greater. If the ratio R12 / W10 is 0.5 or greater, the depth of the first central surface 54e at the first lower end surface 541e of the upper punch 54, described later with reference to FIG. 16, is not too deep. The depth of the first central surface 54e is the length along a direction perpendicular to the first orthogonal surface 54a between the deepest portion of the first central surface 54e and the first orthogonal surface 54a. The first central surface 54e is the surface that forms the first central surface 12c. Because the depth of the first central surface 54e is not too deep, large stresses are unlikely to act locally on the first lower end surface 541e of the upper punch 54. This tends to extend the life of the upper punch 54. The ratio R12 / W10 is, for example, 3.0 or less. If the ratio R12 / W10 is 3.0 or less, the radius of curvature R12 is not too large, and therefore the winding is less likely to come into excessive contact with the first corner portion 12d. The ratio R12 / W10 may be 0.50 to 3.0, 0.55 to 2.5, or 0.60 to 2.0.

[0064] 2 and 3, the outer peripheral surface 12 has an outer peripheral inclined surface 12e that extends in the X1 direction toward the outer peripheral protruding portion 213 at a portion of the outer peripheral surface 12 that connects to the outer peripheral protruding portion 213 of the second member 20. As shown in Figures 2 and 4, the outer peripheral surface 12 has an outer peripheral inclined surface 12f that extends in the X1 direction toward the outer peripheral protruding portion 313 at a portion of the outer peripheral surface 12 that connects to the outer peripheral protruding portion 313 of the third member 30. A core piece 1 that has the outer peripheral inclined surfaces 12e, 12f is superior in productivity because it is easier to separate the core piece 1 from the lower end surface of the upper punch 54 compared to a core piece that does not have the outer peripheral inclined surfaces 12e, 12f.

[0065] As shown in FIGS. 3 and 4 , the widths of the outer peripheral inclined surfaces 12e and 12f decrease toward the outer peripheral protrusion 213 and the outer peripheral protrusion 313, respectively. The widths of the outer peripheral inclined surfaces 12e and 12f are lengths along a direction perpendicular to both the X1 and Z1 directions. If the widths of the outer peripheral inclined surfaces 12e and 12f are reduced as described above, the tension acting on the windings wound around the outer peripheral inclined surfaces 12e and 12f tends to be smaller than when the widths of the outer peripheral inclined surfaces 12e and 12f are uniform rather than reduced as described above. The minimum width of the outer peripheral inclined surfaces 12e and 12f is, for example, 95% or less of the maximum width of the outer peripheral inclined surfaces 12e and 12f. In this case, the tension acting on the windings wound around the outer peripheral inclined surfaces 12e and 12f tends to be smaller. The minimum width of the outer peripheral inclined surfaces 12e is the width of the portion of the outer peripheral inclined surfaces 12e that connects to the second end surface 27. The minimum width of the outer peripheral inclined surface 12f is the width of the outer peripheral inclined surface 12f at a point where it connects to the first end face 36. The maximum width of the outer peripheral inclined surface 12e is the width of the outer peripheral inclined surface 12e at a point farthest from the second end face 27. The maximum width of the outer peripheral inclined surface 12f is the width of the outer peripheral inclined surface 12f at a point farthest from the first end face 36. The minimum width of the outer peripheral inclined surfaces 12e, 12f is, for example, 20% or more of the maximum width of the outer peripheral inclined surfaces 12e, 12f. The minimum width of the outer peripheral inclined surfaces 12e, 12f is 20% or more and 95% or less, 25% or more and 90% or less, or 30% or more and 85% or less of the maximum width of the outer peripheral inclined surfaces 12e, 12f.

[0066] 10 and 11 , the inner circumferential surface 13 of this example has second orthogonal surfaces 13a, second side end surfaces 13b, and a second central surface 13c, which are arranged in this order from both ends of the inner circumferential surface 13 toward the center. The two ends of the inner circumferential surface 13 are the connection portion between the inner circumferential surface 13 and the second parallel surface 142 of the first side surface 14a, and the connection portion between the inner circumferential surface 13 and the second parallel surface 142 of the second side surface 14b. That is, the inner circumferential surface 13 of this example has two second orthogonal surfaces 13a, two second side end surfaces 13b, and one second central surface 13c. In this example, the inner peripheral surface 13 has second orthogonal surfaces 13a, second side end surfaces 13b, second central surfaces 13c, second side end surfaces 13b, and second orthogonal surfaces 13a, which are arranged in this order from the second parallel surfaces 142 of the first side surfaces 14a toward the second parallel surfaces 142 of the second side surfaces 14b. Each second orthogonal surface 13a is connected to each second parallel surface 142 so as to be perpendicular to the corresponding second parallel surfaces 142. Each second side end surface 13b is connected to each second orthogonal surface 13a. The second central surfaces 13c are connected to both second side end surfaces 13b.

[0067] The range of the width W21 of each second orthogonal surface 13a and the reasons for limiting it are the same as the range of the width W11 described above. The width W21 may be the same as or different from the width W11 within the range of the width W21.

[0068] Each second side end face 13b has an arc portion 131 protruding outward from the inner circumferential surface 13. Each second side end face 13b may be composed of a single arc portion 131 with a uniform radius of curvature, multiple arc portions 131 with different radii of curvature, or one or more arc portions 131 and one or more flat surfaces 132. Each second side end face 13b in this example is composed of one arc portion 131 and one flat surface 132. Each second side end face 13b in this example has one flat surface 132 and one arc portion 131 arranged in order from each second orthogonal surface 13a toward the second central surface 13c. The flat surface 132 is connected to the second orthogonal surface 13a. The arc portion 131 is connected to the flat surface 132 and the second central surface 13c.

[0069] The second central surface 13c has an arc portion 133 that protrudes outward from the inner circumferential surface 13. The second central surface 13c may be composed of one arc portion 133 with a uniform radius of curvature, or may be composed of multiple arc portions 133 with different radii of curvature, or may be composed of one or more arc portions 133 and one or more flat surfaces 134. As shown in FIG. 11 , the second central surface 13c of this example is composed of two arc portions 133 and one flat surface 134. The second central surface 13c of this example has one arc portion 133, one flat surface 134, and one arc portion 133 arranged in this order from one second orthogonal surface 13a to the other second orthogonal surface 13a.

[0070] The radius of curvature R21 of the arc portion 131 of each second side end face 13b is smaller than the radius of curvature R22 of the arc portion 133 of the second central face 13c. If the second side end face 13b has multiple arc portions 131 with different radii of curvature, the radius of curvature R21 is the largest radius of curvature. If the second central face 13c has multiple arc portions 133 with different radii of curvature, the radius of curvature R22 is the smallest radius of curvature. Because each radius of curvature R21 is smaller than the radius of curvature R22, the winding is less likely to come into excessive contact with the second corner 13d where the second parallel face 142 and the second orthogonal face 13a meet. This makes it less likely that the insulating coating of the winding will be damaged. If the second corner portion 13d is located on the extension surface E2 of the arc portion 133 of the second central surface 13c, the winding is less likely to come into excessive contact with the second corner portion 13d, and if the second corner portion 13d is located more inward than the extension surface E2, the winding is even less likely to come into excessive contact with the second corner portion 13d.

[0071] The numerical range and reasons for limiting the angle θ2 between each second orthogonal surface 13a and a tangent to the second side end surface 13b passing through each connection point between each second orthogonal surface 13a and each second side end surface 13b are the same as the numerical range and reasons for limiting the angle θ1. The angle θ2 may be the same as or different from the angle θ1 within the above numerical range.

[0072] The range and reasons for limiting the ratio P2 of the sum W23 of the width W21 of the second orthogonal surface 13a and the width W22 of the second side end surface 13b to the width W20 of the inner circumferential surface 13 is the same as the range and reasons for limiting the ratio P1. The ratio P2 is (W23 / W20) x 100. The ratio P2 may be the same as or different from the ratio P1 within the above range.

[0073] The numerical range and reasons for limiting the ratio R22 / W20 of the radius of curvature R22 of the second central surface 13c to the width W20 of the inner circumferential surface 13 are the same as those for the ratio R12 / W10. The ratio R22 / W20 may be the same as or different from the ratio R12 / W10 within the above numerical range.

[0074] 2 and 5, the inner circumferential surface 13 has an inner circumferential inclined surface 13e that extends in the X2 direction toward the inner circumferential protruding portion 214 at a location on the inner circumferential surface 13 that connects to the inner circumferential protruding portion 214 of the second member 20. As shown in Figures 2 and 6, the inner circumferential surface 13 has an inner circumferential inclined surface 13f that extends in the X2 direction toward the inner circumferential protruding portion 314 at a location on the inner circumferential surface 13 that connects to the inner circumferential protruding portion 314 of the third member 30. A core piece 1 that has the inner circumferential inclined surfaces 13e, 13f is easier to separate from the upper end surface of the lower punch 55 than a core piece that does not have the inner circumferential inclined surfaces 13e, 13f, and therefore has excellent productivity.

[0075] As shown in FIGS. 5 and 6 , the widths of the inner circumferential inclined surfaces 13e, 13f decrease toward the inner circumferential protrusion 214 and the inner circumferential protrusion 314, respectively. If the widths of the inner circumferential inclined surfaces 13e, 13f decrease as described above, the tension acting on the windings wound on the inner circumferential inclined surfaces 13e, 13f tends to be smaller than when the widths of the inner circumferential inclined surfaces 13e, 13f are uniform rather than decreasing as described above. The minimum width of the inner circumferential inclined surfaces 13e, 13f is, for example, 95% or less of the maximum width of the inner circumferential inclined surfaces 13e, 13f. In this case, the tension acting on the windings wound on the inner circumferential inclined surfaces 13e, 13f tends to be smaller. The definitions of the width, minimum width, and maximum width of the inner circumferential inclined surfaces 13e, 13f are the same as those of the width, minimum width, and maximum width of the outer circumferential inclined surfaces 12e, 12f described above. The minimum width of the inner peripheral inclined surfaces 13e, 13f is, for example, 20% or more of the maximum width of the inner peripheral inclined surfaces 13e, 13f, and is 20% to 95%, 25% to 90%, or 30% to 85% of the maximum width of the inner peripheral inclined surfaces 13e, 13f.

[0076] 1 to 6 , the second member 20 is a plate-shaped member provided at a first end in the Z1 direction of the first member 10. When the core laminations 1 form the stator core 7 included in the DS / SR type rotating electric machine 9, the second member 20 forms a yoke. When the core laminations 1 form the stator core 7 included in the SS / DR type rotating electric machine 9, the second member 20 forms a flange.

[0077] The cross-sectional shape of the second member 20 is, for example, a fan shape. The cross-section of the second member 20 is a cross section cut along a plane perpendicular to the Z1 direction.

[0078] The second member 20 has a protrusion 21 that protrudes outward from the peripheral surface 10a of the first member 10. In this example, the protrusion 21 is annular. As shown in FIGS. 2 to 4 , the protrusion 21 in this example has a first protrusion 211, a second protrusion 212, an outer peripheral protrusion 213, and an inner peripheral protrusion 214. The first protrusion 211 protrudes in the Y1 direction from the first side surface 14a of the first member 10. The second protrusion 212 protrudes in the Y2 direction from the second side surface 14b of the first member 10. The outer peripheral protrusion 213 protrudes in the X1 direction from the outer peripheral surface 12 of the first member 10. The inner peripheral protrusion 214 protrudes in the X2 direction from the inner peripheral surface 13 of the first member 10. Unlike this example, the second member 20 may have the first protruding portion 211 and the second protruding portion 212 without having the outer peripheral protruding portion 213 and the inner peripheral protruding portion 214 .

[0079] When the core laminations 1 form a stator core 7 included in a rotating electric machine 9 of DS / SR type, the protruding lengths of the first protruding portion 211 and the second protruding portion 212 of the second member 20 are longer than the protruding lengths of the first protruding portion 311 and the second protruding portion 312 of the third member 30 (described later). The protruding length of the first protruding portion 211 is the distance between the first side surface 14a and the first side surface 24a. The protruding length of the second protruding portion 212 is the distance between the second side surface 14b and the second side surface 24b.

[0080] The second member 20 has an outer peripheral surface 22, an inner peripheral surface 23, a first side surface 24a, a second side surface 24b, a first end surface 26, and a second end surface 27. As described above, 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 the same as the positional relationship between the respective surfaces of the first member 10. The first end surface 26 and the second end surface 27 are disposed in positions facing each other. The first end surface 26 is a surface facing the Z1 direction. The second end surface 27 is a surface facing the Z2 direction. The second end surface 27 is connected to the outer peripheral surface 10a of the first member 10 shown in FIG. 1.

[0081] The outer peripheral surface 22 is connected to the X1-direction edge of the first side surface 24a, the X1-direction edge of the second side surface 24b, the X1-direction edge of the first end surface 26, and the X1-direction edge of the second end surface 27. The inner peripheral surface 23 is connected to the X2-direction edge of the first side surface 24a, the X2-direction edge of the second side surface 24b, the X2-direction edge of the first end surface 26, and the X2-direction edge of the second end surface 27. 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 10a of the first member 10 shown in FIG. 1.

[0082] As shown in Fig. 12, the width of the outer peripheral surface 22 is longer than the width of the inner peripheral surface 23. The width of the outer peripheral surface 22 is the length between the first parallel surface 241 of the first side surface 24a and the first parallel surface 241 of the second side surface 24b. The width of the inner peripheral surface 23 is the length between the second parallel surface 242 of the first side surface 24a and the second parallel surface 242 of the second side surface 24b. The width of the outer peripheral surface 22 is longer than the width W10 of the outer peripheral surface 12 shown in Fig. 7. The width of the inner peripheral surface 23 is longer than the width W20 of the inner peripheral surface 13 shown in Fig. 7.

[0083] In this example, the outer peripheral surface 22 has an arc portion that is convex in the X1 direction. Unlike this example, the outer peripheral surface 22 may be configured as a flat surface. In this example, the inner peripheral surface 23 is configured as a flat surface that is perpendicular to the X2 direction. Unlike this example, the inner peripheral surface 23 may have an arc portion that is convex in the X2 direction or an arc portion that is concave in the X1 direction.

[0084] Each of the first side surface 24a and the second side surface 24b has a first parallel surface 241, a second parallel surface 242, and a first inclined surface 243. Each of the first parallel surfaces 241 and each of the second parallel surfaces 242 are parallel to the X1 direction and the X2 direction. The first parallel surfaces 241 are parallel to each other. The second parallel surfaces 242 are parallel to each other. Each of the first parallel surfaces 241 and each of the second parallel surfaces 242 are parallel to each other. Each of the first parallel surfaces 241 is connected to the outer peripheral surface 22. Each of the second parallel surfaces 242 is connected to the inner peripheral surface 23. Each of the first inclined surfaces 243 is connected to each of the first parallel surfaces 241 and each of the second parallel surfaces 242.

[0085] 12 , the numerical ranges and reasons for limiting the first inclination angle θ21, which is the angle between the first inclined surface 243 and an extension E21 of the first parallel surface 241 on the first side surface 24a, and the second inclination angle θ22, which is the angle between the first inclined surface 243 and an extension E22 of the first parallel surface 241 on the second side surface 24b, are the same as the numerical ranges and reasons for limiting the first inclination angle θ11 and the second inclination angle θ12. The first inclination angle θ21 and the second inclination angle θ22 may be the same as or different from the first inclination angle θ11 and the second inclination angle θ12.

[0086] <Third Member> As shown in Figs. 1 to 6 , the third member 30 is a plate-shaped member provided at the second end of the first member 10 in the Z2 direction. The third member 30 forms a flange portion regardless of whether the core laminations 1 form the stator core 7 provided in the rotating electric machine 9 of the DS / SR type or the stator core 7 provided in the rotating electric machine 9 of the SS / DR type. In this example, the cross-sectional shape of the third member 30 is a sector shape. The cross-section of the third member 30 is a cross section cut along a plane perpendicular to the Z2 direction.

[0087] The third member 30 has a protruding portion 31 that protrudes outward from the peripheral surface 10a of the first member 10. The protruding portion 31 in this example is annular. As shown in FIGS. 2 to 4 , the protruding portion 31 in this example has a first protruding portion 311, a second protruding portion 312, an outer peripheral protruding portion 313, and an inner peripheral protruding portion 314. The first protruding portion 311 protrudes in the Y1 direction from the first side surface 14a of the first member 10. The second protruding portion 312 protrudes in the Y2 direction from the second side surface 14b of the first member 10. The outer peripheral protruding portion 313 protrudes in the X1 direction from the outer peripheral surface 12 of the first member 10. The inner peripheral protruding portion 314 protrudes in the X2 direction from the inner peripheral surface 13 of the first member 10. The protrusion 31 may have at least one of a first protrusion 311 , a second protrusion 312 , an outer peripheral protrusion 313 , and an inner peripheral protrusion 314 .

[0088] As shown in FIGS. 2 to 6 , the third member 30 has an outer peripheral surface 32, an inner peripheral surface 33, a first side surface 34 a, a second side surface 34 b, a first end surface 36, and a second end surface 37. As described above, the positional relationship between the outer peripheral surface 32, the inner peripheral surface 33, the first side surface 34 a, and the second side surface 34 b is the same as the positional relationship between the respective surfaces of the first member 10. The first end surface 36 and the second end surface 37 are disposed in positions facing each other. The first end surface 36 is a surface facing the Z1 direction. The first end surface 36 is connected to the peripheral surface 10 a of the first member 10 shown in FIG. 1. The second end surface 37 is a surface facing the Z2 direction.

[0089] The outer peripheral surface 32 is connected to the X1-direction edge of the first side surface 34a, the X1-direction edge of the second side surface 34b, the X1-direction edge of the first end surface 36, and the X1-direction edge of the second end surface 37. The inner peripheral surface 33 is connected to the X2-direction edge of the first side surface 34a, the X2-direction edge of the second side surface 34b, the X2-direction edge of the first end surface 36, and the X2-direction edge of the second end surface 37. The first end surface 36 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 10a of the first member 10 shown in FIG. 1. The second end surface 37 is connected to the outer peripheral surface 32, the first side surface 34a, the second side surface 34b, and the inner peripheral surface 33.

[0090] As shown in FIG. 13 , the width of the outer peripheral surface 32 is longer than the width of the inner peripheral surface 33. The width of the outer peripheral surface 32 is the length between the first parallel surface 341 of the first side surface 34a and the first parallel surface 341 of the second side surface 34b. The width of the inner peripheral surface 33 is the length between the second parallel surface 342 of the first side surface 34a and the second parallel surface 342 of the second side surface 34b. The width of the outer peripheral surface 32 is longer than the width W10 of the outer peripheral surface 12 shown in FIG. 7 and shorter than the width of the outer peripheral surface 22 shown in FIG. 12. The width of the inner peripheral surface 33 is longer than the width W20 of the inner peripheral surface 13 shown in FIG. 7 and shorter than the width of the inner peripheral surface 23 shown in FIG. 12.

[0091] In this example, the outer peripheral surface 32 has an arc portion that is convex in the X1 direction. Unlike this example, the outer peripheral surface 32 may be configured as a flat surface. In this example, the inner peripheral surface 33 is configured as a flat surface that is perpendicular to the X2 direction. Unlike this example, the inner peripheral surface 33 may have an arc portion that is convex in the X2 direction or an arc portion that is concave in the X1 direction.

[0092] Each of the first side surface 34a and the second side surface 34b has a first parallel surface 341, a second parallel surface 342, and a first inclined surface 343. Each of the first parallel surfaces 341 and each of the second parallel surfaces 342 are parallel to the X1 direction and the X2 direction. The first parallel surfaces 341 are parallel to each other. The second parallel surfaces 342 are parallel to each other. Each of the first parallel surfaces 341 and each of the second parallel surfaces 342 are parallel to each other. Each of the first parallel surfaces 341 is connected to the outer peripheral surface 32. Each of the second parallel surfaces 342 is connected to the inner peripheral surface 33. Each of the first inclined surfaces 343 is connected to each of the first parallel surfaces 341 and each of the second parallel surfaces 342.

[0093] 13 , the numerical ranges and reasons for limiting the first inclination angle θ31, which is the angle between the extension E31 of the first parallel surface 341 on the first side surface 34a and the first inclined surface 343, and the second inclination angle θ32, which is the angle between the extension E32 of the first parallel surface 341 on the second side surface 34b and the first inclined surface 343, are the same as the numerical ranges and reasons for limiting the first inclination angle θ11 and the second inclination angle θ12. The first inclination angle θ31 and the second inclination angle θ32 may be the same as or different from the first inclination angle θ11 and the second inclination angle θ12. The first inclination angle θ31 and the second inclination angle θ32 may be the same as or different from the first inclination angle θ21 and the second inclination angle θ22.

[0094] <Materials> The powder compact contains 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 soft magnetic powder containing a plurality of soft magnetic particles. The soft magnetic particles contain a plurality of iron-based particles made of pure iron or an iron-based alloy. Pure iron refers to iron with a purity of 99% by mass or more. The iron-based alloy contains at least one of silicon (Si) and aluminum (Al), with the remainder consisting of Fe and inevitable impurities. The iron-based alloy is at least one selected from the group consisting of an Fe-Si alloy, an Fe-Al alloy, and an Fe-Si-Al alloy. An example of an Fe-Si alloy is silicon steel. An example of an Fe-Si-Al alloy is sendust. Because the above materials are relatively soft, the soft magnetic particles are easily deformed during molding of the powder compact. As a result, the core piece 1 has high density and excellent dimensional accuracy. The powder compact may be composed of an aggregate of a plurality of coated soft magnetic particles having a first insulating coating on the surface of the soft magnetic particles. That is, the powder compact may be a compact obtained by compression molding a coated soft magnetic powder having a plurality of coated soft magnetic particles. If a first insulating coating is formed, the first insulating coating easily provides electrical insulation between particles. Therefore, iron loss of the powder compact caused by eddy current loss can be reduced. The soft magnetic particles are as described above. The first insulating coating is, for example, a phosphate coating or a silica coating.

[0095] <<Relative Density>> The relative density of the powder compact is, for example, 85% or more. "Relative density" refers to the ratio (%) of the actual density of the powder compact to the true density of the soft magnetic particles that make up the powder compact. Powder compacts with a relative density of 85% or more are excellent in magnetic properties such as saturation magnetic flux density, and mechanical properties such as strength. The relative density of the powder compact may be 90% or more, or 93% or more. The relative density of the powder compact is less than 100%.

[0096] <Manufacturing Method> The core piece 1 according to the first embodiment can be manufactured by a core piece manufacturing method including steps A and B. In step A, raw material powder is filled into the cavity of the die 5. In step B, the raw material powder in the cavity is compression-molded. After explaining the die 5 with reference to Figs. 14 to 21, each step will be explained.

[0097] <<Mold>> The mold 5 includes a die 50, an upper punch 54, and a lower punch 55. The die 50 and the lower punch 55 form a cavity into which the raw material powder is filled.

[0098] [Die] The hole 50h of the die 50 is arranged so that the upper punch 54 and the lower punch 55 face each other. The inner peripheral shape of the hole 50h corresponds to the shape of the core piece 1. The upper punch 54 can be driven independently above and below the die 50. The lower punch 55 can be driven independently above and below the die 50.

[0099] As shown in Fig. 14, the hole 50h has a first hole 51, a second hole 52, and a third hole 53. Fig. 14 is a cross-sectional view showing the state in which the raw material powder filled in the cavity has been pressure-molded by an upper punch 54 and a lower punch 55. The cutting position in the cross-sectional view of Fig. 14 corresponds to a position that passes through the center of the stator core 7 and divides the core piece 1 into two equal parts around the central axis of the stator core 7.

[0100] The first hole portion 51 has an inner peripheral surface that forms the first side surface 14a and the second side surface 14b of the first member 10. The second hole portion 52 has an inner peripheral 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 member 20. The third hole portion 53 has an inner peripheral 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 member 30. The first hole portion 51, the second hole portion 52, and the third hole portion 53 are formed continuously in a direction perpendicular 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 a first end of the first hole portion 51 in the perpendicular direction. The third hole portion 53 is connected to a second end of the first hole portion 51 in the perpendicular direction.

[0101] As shown in FIG. 15 , the first hole portion 51 includes a first straight portion 511, a second straight portion 512, and a tapered portion 513. FIG. 15 is a cross-sectional view showing the state in which the raw material powder filled in the cavity is pressure-molded by the upper punch 54 and the lower punch 55. The cutting position of the cross-sectional view in FIG. 15 corresponds to the center of the length of the first member 10 in the Z1 direction. The first straight portion 511, the tapered portion 513, and the second straight portion 512 are formed continuously in this order from the upper punch 54 toward the lower punch 55. The first straight portion 511 forms the first parallel surfaces 141 of the first side surface 14 a and the second side surface 14 b of the first member 10. The second straight portion 512 forms the second parallel surfaces 142 of the first side surface 14 a and the second side surface 14 b of the first member 10. The tapered portion 513 forms the first inclined surface 143 of the first side surface 14 a and the second side surface 14 b of the first member 10 .

[0102] Similarly, although not shown, the second hole portion 52 includes a first straight portion, a second straight portion, and a tapered portion. The first straight portion, tapered portion, and second straight portion of the second hole portion 52 are formed continuously in this order from the upper punch 54 toward the lower punch 55. The first straight portion of the second hole portion 52 forms the first parallel surfaces 241 of the first side surface 24a and the second side surface 24b of the second member 20. The second straight portion of the second hole portion 52 forms the second parallel surfaces 242 of the first side surface 24a and the second side surface 24b of the second member 20. The tapered portion of the second hole portion 52 forms the first inclined surfaces 243 of the first side surface 24a and the second side surface 24b of the second member 20.

[0103] Similarly, although not shown, the third hole portion 53 includes a first straight portion, a second straight portion, and a tapered portion. The first straight portion, tapered portion, and second straight portion of the third hole portion 53 are formed continuously in this order from the upper punch 54 toward the lower punch 55. The first straight portion of the third hole portion 53 forms a first parallel surface 341 of the first side surface 34a and the second side surface 34b of the third member 30. The second straight portion of the third hole portion 53 forms a second parallel surface 342 of the first side surface 34a and the second side surface 34b of the third member 30. The tapered portion of the third hole portion 53 forms a first inclined surface 343 of the first side surface 34a and the second side surface 34b of the third member 30.

[0104] [Upper Punch] As shown in Figures 18 and 19, the upper punch 54 has a first upper punch portion 541, a second upper punch portion 542, and a third upper punch portion 543. 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 member 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 member 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 member 30. The first upper punch portion 541, the second upper punch portion 542, and the third upper punch portion 543 may be formed integrally and inseparably, or may be formed independently of each other so as to be able to move up and down independently. When the first upper punch portion 541, the second upper punch portion 542, and the third upper punch portion 543 are inseparably formed as a single unit, the first lower end surface 541e, the second lower end surface 542e, and the third lower end surface 543e are inseparably formed as a single unit. The shape of the first lower end surface 541e corresponds to the shape of the outer peripheral surface 12 of the first member 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.

[0105] As shown in FIG. 16 , the first lower end surface 541e has a first orthogonal surface 54a, a first side end surface 54b, and a first central surface 54e. The first orthogonal surface 54a forms the first orthogonal surface 12a. The first orthogonal surface 54a is connected to the side surface of the upper punch 54 so as to be perpendicular to the surface. The configuration of the first orthogonal surface 54a corresponds to the configuration of the first orthogonal surface 12a. The first side end surface 54b forms the first side end surface 12b. The first side end surface 54b is connected to the first orthogonal surface 54a. The configuration of the first side end surface 54b corresponds to the configuration of the first side end surface 12b. In this example, the first side end surface 54b has an arc portion 54c that forms the arc portion 121 and a flat surface 54d that forms the flat surface 122. The first central surface 54e forms the first central surface 12c. The first central surface 54e is connected to both first side end surfaces 54b. The configuration of the first central surface 54e corresponds to the configuration of the first central surface 12c. Although not shown in the figure, the first central surface 54e in this example has an arc portion that forms the arc portion 123 and a flat surface that forms the flat surface 124.

[0106] As shown in Figures 18 and 19, the first lower end surface 541e has inclined surfaces 54f and 54g. The inclined surfaces 54f and 54g form the outer peripheral inclined surfaces 12e and 12f. The configuration of the inclined surfaces 54f and 54g corresponds to the configuration of the outer peripheral inclined surfaces 12e and 12f. The inclined surface 54f is connected to the second lower end surface 542e. The inclined surface 54g is connected to the third lower end surface 543e.

[0107] [Lower Punch] As shown in Figures 20 and 21 , the lower punch 55 has a first lower punch portion 551, a second lower punch portion 552, and a third lower punch portion 553. The first lower punch portion 551 has a first upper end surface 551e. The first upper end surface 551e forms the inner circumferential surface 13 of the first member 10. The second lower punch portion 552 has a second upper end surface 552e. The second upper end surface 552e forms the inner circumferential surface 23 of the second member 20. The third lower punch portion 553 has a third upper end surface 553e. The third upper end surface 553e forms the inner circumferential surface 33 of the third member 30. The first lower punch portion 551, the second lower punch portion 552, and the third lower punch portion 553 may be formed integrally and inseparably, or may be formed independently of each other so as to be able to move up and down independently. When the first lower punch portion 551, the second lower punch portion 552, and the third lower punch portion 553 are inseparably formed as a single unit, the first upper end surface 551e, the second upper end surface 552e, and the third upper end surface 553e are inseparably formed as a single unit. The shape of the first upper end surface 551e corresponds to the shape of the inner circumferential surface 13 of the first member 10. The shape of the second upper end surface 552e corresponds to the shape of the inner circumferential surface 23 of the second member 20. The shape of the third upper end surface 553e corresponds to the shape of the inner circumferential surface 33 of the third member 30.

[0108] As shown in FIG. 17 , the first upper end surface 551e has a second orthogonal surface 55a, a second side end surface 55b, and a second central surface 55e. The second orthogonal surface 55a forms the second orthogonal surface 13a. The second orthogonal surface 55a is connected to the side surface of the lower punch 55 so as to be perpendicular to the second orthogonal surface 13a. The configuration of the second orthogonal surface 55a corresponds to the configuration of the second orthogonal surface 13a. The second side end surface 55b forms the second side end surface 13b. The second side end surface 55b is connected to the second orthogonal surface 55a. The configuration of the second side end surface 55b corresponds to the configuration of the second side end surface 13b. In this example, the second side end surface 55b has an arc portion 55c that forms the arc portion 131 and a flat surface 55d that forms the flat surface 132. The second central surface 55e forms the second central surface 13c. The second central surface 55e is connected to both second side end surfaces 55b. The configuration of the second central surface 55e corresponds to the configuration of the second central surface 13c. Although not shown in the figure, the second central surface 55e in this example has an arc portion that forms the arc portion 133 and a flat surface that forms the flat surface 134.

[0109] As shown in Figures 20 and 21, the first upper end surface 551e has inclined surfaces 55f and 55g. The inclined surfaces 55f and 55g form inner peripheral inclined surfaces 13e and 13f. The configuration of the inclined surfaces 55f and 55g corresponds to the configuration of the inner peripheral inclined surfaces 13e and 13f. The inclined surface 55f is connected to the second upper end surface 552e. The inclined surface 55g is connected to the third upper end surface 553e.

[0110] [Step A] Raw material powder is filled into the cavity formed by the die 50 and the lower punch 55. The raw material powder is the soft magnetic powder or coated soft magnetic powder described above. In addition to the soft magnetic powder or coated soft magnetic powder, the raw material powder may contain at least one of a binder and a lubricant. A lubricant may be applied to the inner surface of the hole 50h of the die 50.

[0111] [Step B] The raw material powder in the cavity is compression-molded by the upper punch 54 and the lower punch 55. The raw material powder is compressed in the X1 and X2 directions of the core piece 1. The higher the pressure during compression molding, the higher the relative density of the core piece 1 produced. The pressure may be, for example, 700 MPa or more, or 980 MPa or more.

[0112] [Other Steps] The powder compact obtained by performing step B may be subjected to heat treatment as needed. For example, the heat treatment may be used to remove distortion from the powder compact, thereby producing a low-loss core piece 1. For example, the heat treatment may be used to remove binders and lubricants. When the raw material powder contains the coated soft magnetic particles described above, the heat treatment temperature may be equal to or lower than the decomposition temperature of the insulating coating.

[0113] [Embodiment 2] <Core Laminate> A core laminate 1 of embodiment 2 will be described with reference to Figure 22. Figure 22 is a cross-sectional view of the core laminate 1 cut at a position that passes through the center of the stator core 7 and divides the core laminate 1 into two equal parts around the central axis of the stator core 7. The core laminate 1 of embodiment 2 differs from the core laminate 1 of embodiment 1 in that it includes a second insulating coating 40 that covers the peripheral surface 10a of the first member 10. The following description will focus on the differences from embodiment 1. Description of the same configuration and effects as embodiment 1 will be omitted.

[0114] <<Second Insulating Coating>> The second insulating coating 40 covers at least the circumferential surface 10a of the first member 10. The coil 80 is disposed on the circumferential surface 10a of the first member 10. Therefore, the second insulating coating 40 covering the circumferential surface 10a easily improves the electrical insulation between the core laminations 1 and the coil 80. The second insulating coating 40 may further cover at least one of the second end surface 27 of the second member 20 and the first end surface 36 of the third member 30. The second end surface 27 and the first end surface 36 have portions that contact the coil 80. Therefore, the second insulating coating 40 covering one or both of the second end surface 27 and the first end surface 36 easily further improves the electrical insulation between the core laminations 1 and the coil 80. The second insulating coating 40 may cover the entire areas of the first member 10, the second member 20, and the third member 30. In this example, the entire surface of the core laminations 1 is covered with the second insulating coating 40.

[0115] The average thickness of the second insulating coating 40 is, for example, 100 μm or less. A second insulating coating 40 with an average thickness of 100 μm or less makes it difficult for the core pieces 1 to become large. The average thickness of the second insulating coating 40 is, for example, 5 μm or more. A second insulating coating 40 with an average thickness of 5 μm or more is likely to improve the electrical insulation between the core pieces 1 and the coil 80. The average thickness of the second insulating coating 40 may be 5 μm or more and 100 μm or less, 7 μm or more and 80 μm or less, or 10 μm or more and 60 μm or less.

[0116] The average thickness of the second insulating coating 40 is determined using an electromagnetic induction type film thickness meter. The thickness of the second insulating coating 40 is measured by contacting the probe of the film thickness meter with the surface of the second insulating coating 40. The measurement location is the second insulating coating 40 provided on the flat surface of the core piece 1. The number of measurements is 100 or more. The average value is the average thickness of the second insulating coating 40.

[0117] The second insulating coating 40 is made of at least one resin selected from the group consisting of, for example, epoxy resin, acrylic resin, fluorine resin, and polyimide resin. These resins tend to improve the electrical insulation between the core piece 1 and the coil 80.

[0118] [Embodiment 3] <Axial Gap Type Rotating Electric Machine> A rotating electric machine 9 of embodiment 3 will be described with reference to Figures 23 and 24. Figure 23 is a cross-sectional view taken along a plane parallel to the shaft 91 of the rotating electric machine 9 and passing through the circumferential center of the core laminations 1. The rotating electric machine 9 of embodiment 3 is a DS / SR type rotating electric machine. The rotating electric machine 9 is arranged such that one rotor 90 is sandwiched between two stators 8 along the axis of the shaft 91. In the rotating electric machine 9, a gap is provided between the rotor 90 and one of the stators 8, and a gap is also provided between the rotor 90 and the other stator 8. The rotating electric machine 9 can be used as a motor or a generator.

[0119] <<Stator>> As shown in FIG. 24 , each stator 8 includes one stator core 7 and a plurality of coils 80 .

[0120] [Stator Core] Each stator core 7 has a plurality of core pieces 1 arranged in an annular shape. In this example, each core piece 1 is the core piece 1 of the second embodiment. Unlike this example, each core piece 1 may be the core piece 1 of the first embodiment.

[0121] [Coils] Each coil 80 has a cylindrical portion formed by winding a wire. In this example, the winding is a coated round wire. The coated round wire includes a round wire conductor and an insulating coating formed around the conductor. Note that FIGS. 23 and 24 show only the cylindrical portion of each coil 80 in a simplified manner, and both ends of the winding are omitted. The cylindrical portion of each coil 80 is disposed outside the circumferential surface 10a of the first member 10 of each core lamination 1, and between the second member 20 and the third member 30. The stator core 7 can be fabricated by winding a wire around the circumferential surface 10a of the first member 10 of each core lamination 1. The conductor is not limited to a round wire and may have other shapes, such as a rectangular wire.

[0122] <Rotor> The rotor 90 includes a magnet 95 and a support member 96. The magnet 95 is fixed to the support member 96. The support member 96 supports the magnet 95. The support member 96 is supported by a shaft 91 to be rotatable relative to a case 92.

[0123] The number of magnets 95 may be one or more. When there is one magnet 95, the shape of the magnet 95 is annular. The south pole and north pole of each magnet 95 are arranged alternately in the circumferential direction. The multiple magnets 95 are arranged at equal intervals in the circumferential direction of the support member 96. Each magnet 95 is, for example, flat. Each magnet 95 is magnetized in the axial direction of the rotation shaft of the rotor 90. The magnetization directions of adjacent magnets 95 in the circumferential direction of the support member 96 are opposite to each other. The rotating magnetic field generated by the stator 8 causes the magnet 95 to repeatedly attract and repel each tooth, causing the rotor 90 to rotate.

[0124] [Case] ​​The case 92 has a cylindrical internal space that houses the stator 8 and the rotor 90. The case 92 includes, for example, a cylindrical portion 921 and two plates 922. The cylindrical portion 921 surrounds the outer peripheries of the stator 8 and the rotor 90. A plate 922 is disposed on each end of the cylindrical portion 921. The two plates 922 are fixed to both end surfaces of the cylindrical portion 921 so as to sandwich the stator 8 and the rotor 90 from both sides in the axial direction. Both plates 922 have a through hole in their center. A bearing 93 is provided in the through hole. The shaft 91 is inserted into the through hole via this bearing 93. The shaft 91 passes through the case 92.

[0125] In the test example, core pieces having different shapes of the outer peripheral surface and the inner peripheral surface of the first member were manufactured. The stress acting on the lower punch when manufacturing the core pieces and the degree of damage to the insulating coating of the winding when the winding was wound around the circumferential surface of the first member were investigated.

[0126] <Sample No. 1> The core piece of Sample No. 1 is the core piece 1 described in Embodiment 1 with reference to Figures 1 to 13. The core piece of Sample No. 1 was manufactured by the core piece manufacturing method described above. That is, the core piece of Sample No. 1 was manufactured using the mold described with reference to Figures 14 to 21. In the core piece of Sample No. 1, the angles θ1 and θ2 of the outer peripheral surface 12 and the inner peripheral surface 13 of the first member 10 shown in Figures 8 and 10 were 120°.

[0127] 25 to 27 , the core piece of Sample No. 101 differs from Sample No. 1 in that the outer peripheral surface 12 and the inner peripheral surface 13 of the first member 10 are configured as a single arc portion with a uniform radius of curvature. In other words, the outer peripheral surface of the core piece of Sample No. 101 does not have a first orthogonal surface.

[0128] <Sample No. 102> As shown in Figures 28 to 30, the core piece of Sample No. 102 differs from the core piece of Sample No. 1 in that the angle θ1 and the angle θ2 of the outer circumferential surface 12 and the inner circumferential surface 13 of the first member 10 are 150°.

[0129] <Stress analysis> The stress distribution acting on the lower punch when manufacturing the core piece of each sample was analyzed by CAE (Computer Aided Engineering). From the CAE analysis results, the maximum stress value (MPa) generated in the lower punch was calculated. The results are shown in Table 1.

[0130] <Evaluation of the insulating coating of the winding> A winding was wound directly around the circumferential surface of the first member of the core piece of each sample, and the degree of damage to the insulating coating of the winding was examined. In this example, an MΩ tester was used to measure the electrical resistance between the core piece and the coil when the measurement voltage was DC 500 V. The results are shown in Table 1. In Table 1, "A" means that the electrical resistance was 10 MΩ or more, and "B" means that the electrical resistance was less than 10 MΩ.

[0131]

[0132] As shown in Table 1, Sample No. 1 had a smaller maximum stress value of the lower punch than Sample No. 101 and Sample No. 102, and was found to be less likely to damage the insulating coating of the winding wire than Sample No. 102. It was found that the core piece of Sample No. 1 was both less likely to damage the die during manufacturing and less likely to damage the insulating coating of the wound winding wire.

[0133] The present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. It should be understood that at least one configuration or feature described in each embodiment can be combined with another embodiment or modified in various ways. For example, an axial gap type rotating electric machine may have one rotor and one stator.

[0134] 1 Core piece 10 First member 10a Peripheral surface, 11 Connecting surface, 12 Outer peripheral surface, 12a First orthogonal surface 12b First side end face, 121 Arc portion, 122 Plane, 12c First central surface 123 Arc portion, 124 Plane, 12d First corner portion, 12e, 12f Outer peripheral inclined surface 13 Inner peripheral surface, 13a Second orthogonal surface, 13b Second side end face, 131 Arc portion 132 Plane, 13c Second central surface, 133 Arc portion, 134 Plane 13d Second corner portion, 13e, 13f Inner peripheral inclined surface 14a First side surface, 14b Second side surface 141 First parallel surface, 142 Second parallel surface, 143 First inclined surface 20 Second member 21 Protrusion, 211 First protrusion, 212 Second protrusion 213 Outer peripheral protrusion 214 Inner peripheral protrusion 22 Outer peripheral surface 23 Inner peripheral surface 24a First side surface 24b Second side surface 241 First parallel surface 242 Second parallel surface 243 First inclined surface 26 First end surface 27 Second end surface 30 Third member 31 Protrusion 311 First protrusion 312 Second protrusion 313 Outer peripheral protrusion 314 Inner peripheral protrusion 32 Outer peripheral surface 33 Inner peripheral surface 34a First side surface 34b Second side surface 341 First parallel surface 342 Second parallel surface 343 First inclined surface 36 First end surface 37 Second end surface 40 Second insulating coating 5 Mold 50 Die 50h Hole 51 First hole 511 First straight portion 512 Second straight portion 513 Tapered portion, 52 Second hole portion, 53 Third hole portion, 54 Upper punch, 541 First upper punch portion, 541e First lower end surface, 54a First orthogonal surface, 54b First side end surface, 54c Arc portion, 54d Flat surface, 54e First central surface, 54f, 54g Inclined surface, 542 Second upper punch portion, 542e Second lower end surface, 543 Third upper punch portion, 543e Third lower end surface, 55 Lower punch, 551 First lower punch portion, 551e First upper end surface, 55a Second orthogonal surface, 55b Second side end surface, 55c Arc portion, 55d Flat surface, 55e Second central surface, 55f, 55g Inclined surface, 552 Second lower punch portion, 552e Second upper end surface, 553 Third lower punch portion, 553e Third upper end surface, 7 stator core, 8 stator, 80 coil 9 axial gap type rotating electric machine (rotating electric machine) 90 rotor, 91 shaft, 92 case, 921 cylindrical portion, 922 plate93 Beaming, 95 Magnet, 96 Supporting components A1, A2, A3, A4, B1, B2 Area R11, R12, R21, R22 Radius of curvature W10, W11, W12, W13, W20, W21, W22, W23 Amplitude θ1, θ2 Angles E1, E2, E11, E12, E21, E22, E31, E32 Extension surface θ11, θ21, θ31 First tilt angle θ12, θ22, θ32 Second tilt angle

Claims

Core pieces arranged in an annular arrangement to form a stator core of an axial gap type rotating electric machine, a columnar first member extending in a direction along the central axis of the stator core; a plate-shaped second member provided at a first end of the first member in a direction along the central axis; a plate-shaped third member provided at a second end of the first member in a direction along the central axis, The peripheral surface of the first member is a first side surface disposed in a first direction around the central axis; a second side surface disposed in a second direction around the central axis; a connecting surface connecting the first side surface and the second side surface, each of the second member and the third member has a protruding portion that protrudes outward from the circumferential surface; the first member, the second member, and the third member are configured as an integrally molded powder compact, each of the first side surface and the second side surface has a parallel surface that is connected to the connecting surface and is parallel to a direction along the diameter of the stator core; The connecting surface is formed by, in order from both ends of the connecting surface toward the center, an orthogonal surface that is connected to each of the parallel surfaces of the first side surface and the second side surface so as to be orthogonal to each of the parallel surfaces; side end faces connected to each of the orthogonal faces; a central surface connected to each of the side end surfaces; Each of the side end surfaces and the central surface has an arcuate portion that protrudes outward from the connecting surface, the radius of curvature of the arc portion of each of the side end surfaces is smaller than the radius of curvature of the arc portion of the central surface; The angle between the tangent to the side end surface passing through the connection point between the orthogonal surface and the side end surface and the orthogonal surface is greater than 90° and less than or equal to 150°. Core piece. 　 The connecting surface is an outer peripheral surface disposed on the outer periphery of the stator core; an inner circumferential surface disposed on the inner periphery of the stator core; The parallel surfaces of the first side surface and the second side surface are a first parallel surface connected to the outer circumferential surface; a second parallel surface connected to the inner circumferential surface, The orthogonal plane is a first orthogonal surface connected to each of the first parallel surfaces; a second orthogonal surface connected to each of the second parallel surfaces; The side end surface is a first side end surface connected to each of the first orthogonal surfaces; a second side end surface connected to each of the second orthogonal surfaces; The central surface is a first central surface connected to each of the first side end surfaces; a second central surface connected to each of the second side end surfaces; a radius of curvature of the arcuate portion of each of the first side end surfaces is smaller than a radius of curvature of the arcuate portion of the first central surface; the radius of curvature of the arcuate portion of each of the second side end surfaces is smaller than the radius of curvature of the arcuate portion of the second central surface; an angle formed by a tangent to the first side end surface passing through a connection point between the first orthogonal surface and the first side end surface and the first orthogonal surface is greater than 90° and not greater than 150°; The core piece according to claim 1 , wherein an angle formed between a tangent to the second side end surface passing through a connection point between the second orthogonal surface and the second side end surface and the second orthogonal surface is greater than 90° and less than or equal to 150°. The core piece according to claim 2 , wherein the width of each of the first orthogonal surfaces and the width of each of the second orthogonal surfaces are 0.05 mm or more and 0.40 mm or less. 　 The core piece according to claim 2 or 3, wherein a ratio of the total width of the first orthogonal surface and the first side end surface to the width of the outer circumferential surface is 3% or more and 50% or less. 　 A core piece according to any one of claims 2 to 4, wherein the ratio of the total width of the second orthogonal surface and the second side end surface to the width of the inner peripheral surface is 3% or more and 50% or less. 　 The core piece according to claim 2 , wherein a ratio of the radius of curvature of the arcuate portion of the first central surface to a width of the outer circumferential surface is 0.5 or more. 　 The core piece according to claim 2 , wherein a ratio of a radius of curvature of the arcuate portion of the second central surface to a width of the inner circumferential surface is 0.5 or more. 　 the protruding portion of each of the second member and the third member has an outer peripheral protruding portion that protrudes outward from the outer peripheral surface, the outer peripheral surface has an outer peripheral inclined surface at a location connected to the outer peripheral protruding portion of each of the second member and the third member, the outer peripheral surface inclined so as to move away from the inner peripheral surface toward the outer peripheral protruding portion of each of the second member and the third member, The core piece according to claim 2 , wherein a width of the outer peripheral inclined surface decreases toward the outer peripheral protrusion of each of the second member and the third member. 　 the protruding portion of each of the second member and the third member has an inner peripheral protruding portion that protrudes outward from the inner peripheral surface, the inner circumferential surface has, at a location connected to the inner circumferential protruding portion of each of the second member and the third member, an inner circumferential inclined surface that is inclined so as to move away from the outer circumferential surface toward the inner circumferential protruding portion of each of the second member and the third member, The core piece according to claim 2 , wherein a width of the inner peripheral inclined surface decreases toward the inner peripheral protruding portion of each of the second member and the third member. 　 The core piece according to claim 2 , wherein the ratio of the width of the outer peripheral surface to the width of the inner peripheral surface is greater than 1 and is equal to or less than 4. 　 Further, an insulating coating is provided covering the surface of the peripheral surface, The core piece according to claim 1 , wherein the insulating coating has an average thickness of 100 μm or less. 　 the powder compact is composed of an aggregate of a plurality of soft magnetic particles, The soft magnetic particles are iron-based particles made of at least one metal selected from the group consisting of pure iron, Fe-Si alloys, Fe-Al alloys, and Fe-Si-Al alloys. A core piece according to any one of claims 1 to 11. 　 A rotor and a stator are provided, The stator includes: the stator core in which the core pieces according to any one of claims 1 to 12 are arranged in an annular manner; a coil disposed on each of the first members of the stator core, Axial gap type rotating electric machine.

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