Coil layer, armature, axial gap motor, and method for manufacturing coil layer

Abstract

A coil layer (54) is used in an armature (14) of an axial gap motor (10), and comprises: a plurality of first segment conductors (60A) arranged in an annular shape and disposed on one side of the coil layer in the axial direction; and a plurality of second segment conductors (60B) arranged in an annular shape and disposed on the other side of the coil layer in the axial direction. The first segment conductors have first terminal parts (64A, 65A), and the second segment conductors have second terminal parts (64B, 65B) that overlap the first terminal parts in the axial direction of the coil layer and are joined to the first terminal parts. Joint boundary parts (66, 67) between the first terminal parts and the second terminal parts are visible in the axial direction of the coil layer.

Description

Coil Layer, Armature, Axial Gap Motor, and Method for Manufacturing Coil Layer Cross-Reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2025-054571 filed on March 27, 2025, and claims the benefit of priority therefrom. The entire content of that patent application is incorporated herein by reference.

[0002] The technology of the present disclosure relates to a coil layer, an armature, an axial gap motor, and a method for manufacturing a coil layer.

[0003] A coil layer used for an armature of an axial gap motor includes a plurality of first segment conductors arranged annularly and disposed on one axial side of the coil layer, and a plurality of second segment conductors arranged annularly and disposed on the other axial side of the coil layer (see, for example, Japanese Unexamined Patent Application Publication No. 2009-183072). In this coil layer, the first segment conductor has a first terminal portion, and the second segment conductor has a second terminal portion. The second terminal portion overlaps the first terminal portion in the axial direction of the coil layer and is joined to the first terminal portion.

[0004] As a result of detailed studies by the inventor, the following problem has been found. That is, when a joining process is performed from the radial direction of the coil layer on the joining boundary between the first terminal portion and the second terminal portion using a joining tool, it is necessary to change the posture of the coil layer or the joining tool in the circumferential direction of the coil layer.

[0005] The technology of the present disclosure provides a coil layer, an armature, an axial gap motor, and a method for manufacturing a coil layer, which enable a joining process to be performed on the joining boundary between the first terminal portion and the second terminal portion using a joining tool without changing the posture of the coil layer or the joining tool in the circumferential direction of the coil layer.

[0006] A first aspect of the technology of the present disclosure is a coil layer used in the armature of an axial gap motor, comprising: a plurality of first segment conductors arranged in an annular shape and positioned on one axial side of the coil layer; and a plurality of second segment conductors arranged in an annular shape and positioned on the other axial side of the coil layer, wherein the first segment conductors have first terminal portions, and the second segment conductors have second terminal portions that overlap with the first terminal portions in the axial direction of the coil layer and are joined to the first terminal portions, and the joint boundary between the first terminal portions and the second terminal portions is visible in the axial direction of the coil layer.

[0007] A second aspect of the technology of this disclosure is an armature comprising a coil layer according to the first aspect and a core to which the coil layer is attached.

[0008] A third aspect of the technology of this disclosure is an axial gap motor comprising a stator as an armature according to the second aspect, and a rotor facing the stator in the axial direction of the stator.

[0009] A fourth aspect of the technology of the present disclosure is a method for manufacturing a coil layer used in the armature of an axial gap motor, comprising: an assembly step of assembling the coil layer by combining a plurality of first segment conductors and a plurality of second segment conductors arranged in an annular shape in the axial direction of the coil layer, and overlapping the first terminal portion of the first segment conductor with the second terminal portion of the second segment conductor in the axial direction of the coil layer; and a joining step of joining the first terminal portion and the second terminal portion by performing a joining process on the joint boundary portion between the first terminal portion and the second terminal portion, which is visible in the axial direction of the coil layer, from the axial direction of the coil layer using a joining device.

[0010] The present invention provides a coil layer, an armature, an axial gap motor, and a method for manufacturing a coil layer, which enable joining of the joint boundary between a first terminal and a second terminal using a joining device without changing the orientation of the coil layer or the joining device in the circumferential direction of the coil layer.

[0011] This is a perspective view showing a part of a motor according to one embodiment of the technology of this disclosure, cut off. This is a perspective view showing the motor in an exploded view. This is a schematic cross-sectional view showing a cross-section obtained by cutting the motor along the axial and radial directions. This is a perspective view of the coil layer. This is a perspective view showing the coil layer in an exploded view. This is a perspective view of the first segment conductor and the second segment conductor. This is a plan view of the first segment conductor. This is a plan view of the second segment conductor. This is a perspective view of the connection between the first outer end portion and the second outer end portion. This is a plan view of the connection between the first outer end portion and the second outer end portion. This is a plan view of the connection between the first inner end portion and the second inner end portion. This is a perspective view showing an example of joining the outer joint boundary using a soldering iron. This is a perspective view showing an example of joining the outer joint boundary using a laser welding gun. This is a perspective view showing an example of joining the outer joint boundary using an adhesive application nozzle. This is a schematic plan view showing a first modified example of the first outer end portion and the second outer end portion. This is a schematic plan view showing a second modified example of the first outer end portion and the second outer end portion. This is a schematic plan view showing a third modified example of the first and second outer terminal portions. This is a schematic plan view showing a fourth modified example of the first and second outer terminal portions. This is a schematic plan view showing a fifth modified example of the first and second outer terminal portions. This is a schematic plan view showing a sixth modified example of the first and second outer terminal portions.

[0012] First, with reference to Figures 1 to 3, the general configuration of a motor 10 according to one embodiment of the technology of this disclosure will be described. Note that the arrows Z, R, and C shown in Figures 1 to 3 indicate one axial side, one radially outward side, and one circumferential side of the motor 10, respectively. Furthermore, in the following description, the axial, radial, and circumferential directions of the motor 10 will be referred to as the axial, radial, and circumferential directions, respectively.

[0013] The motor 10 comprises a rotor 12, a stator 14, a first frame 21, and a second frame 23. The stator 14 is an example of an "armature" according to the technology of this disclosure. The rotor 12 and the stator 14 face each other in the axial direction. That is, the motor 10 is an axial gap type motor in which the rotor 12 and the stator 14 face each other in the axial direction via an axial gap. The motor 10 is also a brushless motor without brushes. Furthermore, as will be described later, the motor 10 is a double axial gap type motor in which the stator 14 is positioned between a first magnet 18 and a second magnet 19 that are spaced apart in the axial direction, thereby forming a first axial gap between the first magnet 18 and the stator 14, and a second axial gap between the second magnet 19 and the stator 14.

[0014] The stator 14 generates a rotating magnetic field relative to the rotor 12. The rotor 12 rotates due to the rotating magnetic field generated by the stator 14. The first frame 21 and the second frame 23 are spaced apart in the axial direction. The stator 14 is fixed to the first frame 21 and the second frame 23, and the rotor 12 is rotatably supported on both frames.

[0015] The rotor 12 comprises a rotating shaft 22, a first magnet 18, a second magnet 19, a first magnet support member 24, and a second magnet support member 25. The rotating shaft 22 extends in the axial direction. The first magnet 18 is fixed to the rotating shaft 22 via the first magnet support member 24. The second magnet 19 is fixed to the rotating shaft 22 via the second magnet support member 25.

[0016] The first magnet support member 24 and the second magnet support member 25 are formed from a non-magnetic material and are shaped like discs with the axial direction as the thickness direction. However, the first magnet support member 24 and the second magnet support member 25 may also be formed from a magnetic material. The first magnet support member 24 and the second magnet support member 25 are fixed to the rotation shaft 22, spaced apart from each other in the axial direction.

[0017] The first magnet 18 and the second magnet 19 are, for example, ring magnets formed in an annular shape along the circumferential direction. The first magnet 18 and the second magnet 19 may also be configured with multiple segment magnets arranged in an annular shape along the circumferential direction. The first magnet 18 is fixed to the other axial side of the first magnet support member 24. The second magnet 19 is fixed to the one axial side of the second magnet support member 25. As a result, the first magnet 18 and the second magnet 19 are positioned facing each other in the axial direction.

[0018] The magnetic pole center of the north pole of the first magnet 18 and the magnetic pole center of the south pole of the second magnet 19 are positioned opposite each other in the axial direction and at the same position in the circumferential direction.

[0019] The stator 14 comprises a core 26 and a coil section 32. The core 26 is positioned between the first magnet 18 and the second magnet 19. The coil section 32 is provided on the core 26.

[0020] The core 26 comprises a plurality of tooth portions 26A, an inner flange portion 26B, and an outer flange portion 26C. The plurality of tooth portions 26A are arranged at intervals in the circumferential direction. The plurality of tooth portions 26A form a magnetic flux path between the first magnet 18 and the second magnet 19. The inner flange portion 26B is located radially inward from the plurality of tooth portions 26A and connects the plurality of tooth portions 26A in the circumferential direction. The outer flange portion 26C is located radially outward from the plurality of tooth portions 26A and connects the plurality of tooth portions 26A in the circumferential direction.

[0021] Multiple (for example, 72) tooth portions 26A are set to have the same shape and dimensions. Multiple tooth portions 26A are arranged at equal intervals along the circumferential direction. Multiple tooth portions 26A are formed in a plate shape (in other words, a rectangular block shape) that extends axially with the circumferential direction as the thickness direction. The thickness dimension of the tooth portion 26A gradually increases towards the radially outward direction. Also, the axial dimension of the tooth portion 26A gradually decreases towards the radially outward direction. One axial side surface of the tooth portion 26A is formed as a first opposing surface 26D that is positioned axially opposite to the first magnet 18. The other axial side surface of the tooth portion 26A is formed as a second opposing surface 26E that is positioned axially opposite to the second magnet 19.

[0022] The inner flange portion 26B is formed in an annular shape, extending circumferentially with the axial direction as the thickness direction. The thickness dimension of the inner flange portion 26B is set to be smaller than the axial dimension of the multiple teeth portions 26A. The inner flange portion 26B connects the axial central portions of the radially inner ends of the multiple teeth portions 26A along the circumferential direction.

[0023] The outer flange portion 26C is formed in an annular shape, extending circumferentially with the axial direction as the thickness direction. The thickness dimension of the outer flange portion 26C is set to be smaller than the axial dimension of the multiple teeth portions 26A. The thickness dimension of the outer flange portion 26C is set to be the same as the thickness dimension of the inner flange portion 26B. Multiple notches 26F are formed on the outer circumference of the outer flange portion 26C. The multiple notches 26F have a shape that is cut out so that the radially outer side is open. For example, 16 notches 26F are formed on the outer circumference of the outer flange portion 26C. The 16 notches 26F are arranged at equal intervals along the circumferential direction. The 16 notches 26F have the function of preventing rotation of the first frame 21 and the second frame 23, which will be described later, and the function of allowing the bolt 50 to pass through in the axial direction.

[0024] The coil section 32 is formed by a plurality of coil layers 54. For example, the coil section 32 has four coil layers 54. Two of the four coil layers 54 are attached to one axial side of the core 26 in an axially overlapping state. The remaining two coil layers 54 are attached to the other axial side of the core 26 in an axially overlapping state.

[0025] Each coil layer 54 has a plurality of segment conductors 60, as will be described in detail later. When the four coil layers 54 are attached to the core 26, that is, when the coil section 32 is attached to the core 26, the segment conductors 60 of each coil layer 54 function as a coil wound around the teeth section 26A. The segment conductors 60 of each coil layer 54 are connected in a predetermined manner. The coil composed of the plurality of segment conductors 60 is in the form of a distributed winding wound across the plurality of teeth section 26A. However, the coil composed of the plurality of segment conductors 60 may be in the form of a concentrated winding wound around each tooth section 26A.

[0026] As an example, the first frame 21 is formed as a frame end, and the second frame 23 is formed as a heat sink. The first frame 21 comprises a disc portion 21A and a peripheral wall portion 21B. The disc portion 21A is formed in the shape of a disc with its thickness in the axial direction. The peripheral wall portion 21B is formed on the outer circumference of the disc portion 21A and extends from the outer circumference of the disc portion 21A toward the other side in the axial direction. The second frame 23 comprises a disc portion 23A and a peripheral wall portion 23B. The disc portion 23A is formed in the shape of a disc with its thickness in the axial direction. The peripheral wall portion 23B is formed on the outer circumference of the disc portion 23A and extends from the outer circumference of the disc portion 23A toward the one side in the axial direction. Through holes that penetrate in the axial direction are formed in the center of the disc portion 21A and the disc portion 23A, and bearings 20 are fixed to the inner circumference of each through hole. Furthermore, the rotating shaft 22 of the rotor 12 is rotatably supported by each bearing 20.

[0027] Multiple (e.g., eight) insertion holes 21C are formed in the peripheral wall portion 21B of the first frame 21, and multiple (e.g., eight) insertion holes 23C are formed in the peripheral wall portion 23B of the second frame 23. The multiple insertion holes 21C are arranged at equal intervals along the circumferential direction. Similarly, the multiple insertion holes 23C are arranged at equal intervals along the circumferential direction. Bolts 50 are inserted into each insertion hole 21C and insertion hole 23C from the other side in the axial direction.

[0028] Multiple protrusions 21D are formed on the axial end of the peripheral wall portion 21B of the first frame 21. The multiple protrusions 21D project toward the axial direction toward the other side. The multiple protrusions 21D are arranged at equal intervals along the circumferential direction. Each protrusion 21D is positioned in the center of a pair of circumferentially adjacent insertion holes 21C.

[0029] Multiple protrusions 23D are formed on one axial end of the peripheral wall portion 23B of the second frame 23. The multiple protrusions 23D project toward one axial direction. The multiple protrusions 23D are arranged at equal intervals along the circumferential direction. Each protrusion 23D is positioned in the center of a pair of circumferentially adjacent insertion holes 23C.

[0030] The multiple protrusions 23D are positioned at a 90° offset in the circumferential direction from the multiple protrusions 21D. The protrusions 21D of the first frame 21 and the protrusions 23D of the second frame 23 are fitted into the notches 26F of the core 26, thereby preventing the core 26 from rotating relative to the first frame 21 and the second frame 23.

[0031] A bolt 50 is inserted into the insertion hole 21C and the insertion hole 23C from the other axial side, and a nut 56 is screwed onto the bolt 50 from the one axial side. As a result, the core 26 is fixed to the first frame 21 and the second frame 23 with the outer flange portion 26C of the core 26 sandwiched between the peripheral wall portion 21B of the first frame 21 and the peripheral wall portion 23B of the second frame 23. In other words, the stator 14 is fixed to the first frame 21 and the second frame 23.

[0032] As shown in Figure 3, the first opposing surface 26D of the teeth portion 26A has a teeth portion-side inclined surface 26D1 that inclins radially outward towards the other axial side. Similarly, the second opposing surface 26E of the teeth portion 26A has a teeth portion-side inclined surface 26E1 that inclins radially outward towards one axial side. The radially inner end of the first opposing surface 26D is formed as a teeth portion-side vertical surface 26D2 that is perpendicular to the axial direction. Similarly, the radially inner end of the second opposing surface 26E is formed as a teeth portion-side vertical surface 26E2 that is perpendicular to the axial direction.

[0033] Furthermore, the other axial surface of the first magnet 18 has a magnet-side inclined surface 18A1 that is inclined in the same direction as the teeth-side inclined surface 26D1. Similarly, the one axial surface of the second magnet 19 has a magnet-side inclined surface 19A1 that is inclined in the same direction as the teeth-side inclined surface 26E1. The radially inner end of the other axial surface of the first magnet 18 is formed as a magnet-side vertical surface 18A2 that is perpendicular to the axial direction. Similarly, the radially inner end of the one axial surface of the second magnet 19 is formed as a magnet-side vertical surface 19A2 that is perpendicular to the axial direction.

[0034] The inclined surface 26D1 on the teeth side and the inclined surface 18A1 on the magnet side are opposite each other in the axial direction, and the inclined surface 26E1 on the teeth side and the inclined surface 19A1 on the magnet side are opposite each other in the axial direction. Also, the vertical surface 26D2 on the teeth side and the vertical surface 18A2 on the magnet side are opposite each other in the axial direction, and the vertical surface 26E2 on the teeth side and the vertical surface 19A2 on the magnet side are opposite each other in the axial direction.

[0035] Next, the configuration of the coil layer 54 will be described in detail.

[0036] The four coil layers 54 have the same configuration. The configuration of one of the four coil layers 54 will be described in detail below. As shown in Figures 4 and 5, the coil layer 54 has coil bodies 55 of multiple phases. As an example, the coil body 55 has a U-phase coil body 55U, a V-phase coil body 55V, and a W-phase coil body 55W. The U-phase coil body 55U, the V-phase coil body 55V, and the W-phase coil body 55W are combined with each other such that the segment conductors 60 of each phase are repeatedly arranged in the circumferential direction of the coil layer 54 in this order.

[0037] As an example, in the multiple segment conductors 60 that constitute the coil body 55 of each phase, the multiple segment conductors 60 are stacked in two stages in the axial direction. Specifically, the multiple segment conductors 60 that constitute the coil body 55 of each phase have a first segment conductor 60A arranged on one axial side of the coil layer 54 and a second segment conductor 60B arranged on the other axial side of the coil layer 54. The first segment conductor 60A and the second segment conductor 60B are formed to be the same shape as each other. That is, the same segment conductor 60 is used for both the first segment conductor 60A and the second segment conductor 60B.

[0038] As shown in Figure 6, the first segment conductor 60A and the second segment conductor 60B are arranged symmetrically around the radial direction of the coil layer 54. That is, the second segment conductor 60B is a representation of the first segment conductor 60A rotated 180 degrees around the radial direction of the coil layer 54 (an inverted representation).

[0039] The first segment conductor 60A has a first main body portion 61A extending radially to the coil layer 54, a first outer inclined portion 62A extending radially outward from the first main body portion 61A and inclining toward one side of the circumferential direction of the coil layer 54 as it moves radially outward, and a first inner inclined portion 63A extending radially inward from the first main body portion 61A and inclining toward the other side of the circumferential direction of the coil layer 54 as it moves radially inward.

[0040] The tip of the first outer inclined portion 62A is formed as the first outer terminal portion 64A, and the tip of the first inner inclined portion 63A is formed as the first inner terminal portion 65A. The first segment conductor 60A is a member in which an insulating coating is applied to a conductor, and the first outer terminal portion 64A and the first inner terminal portion 65A are formed by the conductor exposed from the insulating coating. The first outer terminal portion 64A is located on the outer periphery of the coil layer 54, and the first inner terminal portion 65A is located on the inner periphery of the coil layer 54. The first outer terminal portion 64A and the first inner terminal portion 65A are examples of the "first terminal portion" according to the technology of this disclosure.

[0041] The second segment conductor 60B includes a second main body portion 61B extending radially from the coil layer 54, a second outer inclined portion 62B extending radially outward from the second main body portion 61B and inclining toward the other circumferential side of the coil layer 54 as it moves radially outward from the coil layer 54, and a second inner inclined portion 63B extending radially inward from the second main body portion 61B and inclining toward one circumferential side of the coil layer 54 as it moves radially inward from the coil layer 54.

[0042] The tip of the second outer inclined portion 62B is formed as the second outer terminal portion 64B, and the tip of the second inner inclined portion 63B is formed as the second inner terminal portion 65B. The second segment conductor 60B is a member in which an insulating coating is applied to a conductor, and the second outer terminal portion 64B and the second inner terminal portion 65B are formed by the conductor exposed from the insulating coating. The second outer terminal portion 64B is located on the outer periphery of the coil layer 54, and the second inner terminal portion 65B is located on the inner periphery of the coil layer 54. The second outer terminal portion 64B and the second inner terminal portion 65B are examples of the "second terminal portion" according to the technology of this disclosure.

[0043] Hereinafter, the outer terminal portion of the segment conductor 60 used in the first segment conductor 60A and the second segment conductor 60B (i.e., the first outer terminal portion 64A or the second outer terminal portion 64B) will be referred to as the "outer terminal portion 64". Also, the inner terminal portion of the segment conductor 60 (i.e., the first inner terminal portion 65A or the second inner terminal portion 65B) will be referred to as the "inner terminal portion 65".

[0044] The first outer terminal portion 64A is overlapped on the second outer terminal portion 64B from one axial side of the coil layer 54 relative to the second outer terminal portion 64B. The first outer terminal portion 64A is joined to the second outer terminal portion 64B. Similarly, the first inner terminal portion 65A is overlapped on the second inner terminal portion 65B from one axial side of the coil layer 54 relative to the second inner terminal portion 65B. The first inner terminal portion 65A is joined to the second inner terminal portion 65B. The first segment conductors 60A adjacent to each other in the circumferential direction of the coil layer 54 and the second segment conductors 60B adjacent to each other in the circumferential direction of the coil layer 54 form a coil wound around one tooth portion 26A.

[0045] As shown in Fig. 7, when a line passing through the center of the width of the first outer terminal portion 64A and extending in the radial direction of the coil layer 54 in a plan view (viewed from the axial direction of the coil layer 54) is defined as the width-direction center line CL1 of the first outer terminal portion 64A, the first outer terminal portion 64A is formed asymmetrically with respect to the width-direction center line CL1. The width of the first outer terminal portion 64A is a width along a direction orthogonal to the radial direction of the coil layer 54 in the plan view.

[0046] Specifically, the first outer terminal portion 64A includes: a radially outer surface 64A1 facing outward in the radial direction of the coil layer 54, an inclined surface 64A2 adjacent to the other circumferential side of the coil layer 54 relative to the radially outer surface 64A1 and inclined with respect to the radially outer surface 64A1, a circumferential surface 64A3 facing one circumferential side of the coil layer 54, and a circumferential surface 64A4 facing the other circumferential side of the coil layer 54. The circumferential surface 64A3 and the circumferential surface 64A4 are an example of "the first circumferential surface" in the technology of the present disclosure. The radially outer surface 64A1 is an example of "the first radial surface" according to the technology of the present disclosure.

[0047] The radially outer side surface 64A1 is formed along a direction orthogonal to the width-direction center line CL1 in a plan view. The inclined surface 64A2 is formed along a direction inclined with respect to the width-direction center line CL1 in a plan view. The inclined surface 64A2 is inclined toward one circumferential side of the coil layer 54 as it goes toward the radially outer side of the coil layer 54. The length of the circumferential surface 64A3 along the radial direction of the coil layer 54 is set to a dimension longer than the length of the circumferential surface 64A4 along the radial direction of the coil layer 54. The circumferential surface 64A3 and the circumferential surface 64A4 are formed along the width-direction center line CL1.

[0048] Similarly, when a line passing through the center of the width of the first inner terminal portion 65A and extending in the radial direction of the coil layer 54 in a plan view (viewed from the axial direction of the coil layer 54) is defined as the width-direction center line CL2 of the first inner terminal portion 65A, the first inner terminal portion 65A is formed asymmetrically with respect to the width-direction center line CL2. The width of the first inner terminal portion 65A is a width along a direction orthogonal to the radial direction of the coil layer 54 in a plan view.

[0049] Specifically, the first inner terminal portion 65A includes a radially inner side surface 65A1 facing radially inward of the coil layer 54, an inclined surface 65A2 adjacent to one circumferential side of the coil layer 54 relative to the radially inner side surface 65A1 and inclined with respect to the radially inner side surface 65A1, a circumferential surface 65A3 facing one circumferential side of the coil layer 54, and a circumferential surface 65A4 facing the other circumferential side of the coil layer 54. The circumferential surface 65A3 and the circumferential surface 65A4 are an example of the "first circumferential surface" in the technology of the present disclosure. The radially inner side surface 65A1 is an example of the "first radial surface" according to the technology of the present disclosure.

[0050] The radially inner side surface 65A1 is formed along a direction orthogonal to the width-direction center line CL2 in a plan view. The inclined surface 65A2 is formed along a direction inclined with respect to the width-direction center line CL2 in a plan view. The inclined surface 65A2 is inclined toward the other circumferential side of the coil layer 54 as it goes toward the radially inner side of the coil layer 54. The length of the circumferential surface 65A3 along the radial direction of the coil layer 54 is set to a dimension longer than the length of the circumferential surface 65A4 along the radial direction of the coil layer 54. The circumferential surface 65A3 and the circumferential surface 64B4 are formed along the width-direction center line CL2.

[0051] As described above, the first segment conductor 60A and the second segment conductor 60B are formed to be the same shape as each other, and the second segment conductor 60B is a form obtained by rotating the first segment conductor 60A 180 degrees around the radial direction of the coil layer 54 (an inverted form). For this reason, as shown in Figure 8, with respect to the second segment conductor 60B, if the line passing through the center of the width of the second outer terminal portion 64B and extending in the radial direction of the coil layer 54 in a plan view (axial view of the coil layer 54) is defined as the widthwise center line CL1 of the second outer terminal portion 64B, then the second outer terminal portion 64B is formed asymmetrically with respect to the widthwise center line CL1.

[0052] Specifically, the second outer terminal portion 64B has a radial outer surface 64B1 facing radially outward of the coil layer 54, an inclined surface 64B2 adjacent to one circumferential side of the coil layer 54 with respect to the radial outer surface 64B1 and inclined with respect to the radial outer surface 64B1, a circumferential surface 64B3 facing the other circumferential side of the coil layer 54, and a circumferential surface 64B4 facing one circumferential side of the coil layer 54. The circumferential surfaces 64B3 and 64B4 are examples of the "second circumferential surface" in the technology of this disclosure. The radial outer surface 64B1 is an example of the "second radial surface" in the technology of this disclosure.

[0053] The radial outer surface 64B1 is formed along a direction perpendicular to the widthwise centerline CL1 in a plan view. The inclined surface 64B2 is formed along a direction inclined with respect to the widthwise centerline CL1 in a plan view. The inclined surface 64B2 is inclined toward the other side of the circumferential direction of the coil layer 54 as it moves toward the radial outer side of the coil layer 54. The length of the circumferential surface 64B3 along the radial direction of the coil layer 54 is set to be longer than the length of the circumferential surface 64B4 along the radial direction of the coil layer 54. The circumferential surfaces 64B3 and 64B4 are formed along the widthwise centerline CL1.

[0054] Similarly, if, in a plan view (axial view of the coil layer 54), the line passing through the center of the width of the second inner terminal portion 65B and extending radially across the coil layer 54 is defined as the widthwise center line CL2 of the second inner terminal portion 65B, then the second inner terminal portion 65B is formed asymmetrically with respect to the widthwise center line CL2.

[0055] Specifically, the second inner terminal portion 65B has a radial inner surface 65B1 facing radially inward of the coil layer 54, an inclined surface 65B2 adjacent to the other circumferential side of the coil layer 54 with respect to the radial inner surface 65B1 and inclined with respect to the radial inner surface 65B1, a circumferential surface 65B3 facing the other circumferential side of the coil layer 54, and a circumferential surface 65B4 facing one circumferential side of the coil layer 54. The circumferential surfaces 65B3 and 65B4 are examples of the "second circumferential surface" in the technology of this disclosure. The radial inner surface 65B1 is an example of the "second radial surface" in the technology of this disclosure.

[0056] The radial inner surface 65B1 is formed along a direction perpendicular to the widthwise centerline CL2 in a plan view. The inclined surface 65B2 is formed along a direction inclined with respect to the widthwise centerline CL2 in a plan view. The inclined surface 65B2 is inclined toward one side of the circumferential direction of the coil layer 54 as it moves toward the radial inner side of the coil layer 54. The length of the circumferential surface 65B3 along the radial direction of the coil layer 54 is set to be shorter than the length of the circumferential surface 65B4 along the radial direction of the coil layer 54. The circumferential surfaces 65B3 and 64B4 are formed along the widthwise centerline CL2.

[0057] Furthermore, as shown in Figure 9, the first outer terminal portion 64A has an axial surface 64A5 facing the other axial side of the coil layer 54 and an axial surface 64A6 facing the other axial side of the coil layer 54. The second outer terminal portion 64B has an axial surface 64B5 facing the other axial side of the coil layer 54 and an axial surface 64B6 facing one axial side of the coil layer 54.

[0058] As shown in Figures 9 and 10, when the first outer end portion 64A is superimposed on the second outer end portion 64B in the axial direction of the coil layer 54, the circumferential surface 64A3 of the first outer end portion 64A and the circumferential surface 64B4 of the second outer end portion 64B are positioned relative to each other so as to be flush, that is, so that the circumferential position of the coil layer 54 is the same. Similarly, the circumferential surface 64A4 of the first outer end portion 64A and the circumferential surface 64B3 of the second outer end portion 64B are positioned relative to each other so as to be flush, that is, so that the circumferential position of the coil layer 54 is the same. Note that the positioning of either the circumferential surface 64A3 and circumferential surface 64B4 or the positioning of the circumferential surface 64A4 and circumferential surface 64B3 may be omitted.

[0059] Furthermore, the radial outer surface 64A1 of the first outer terminal portion 64A and the radial outer surface 64B1 of the second outer terminal portion 64B are positioned relative to each other so as to be flush with each other, that is, so that the radial positions of the coil layer 54 are the same.

[0060] Similarly, when the first inner end portion 65A is superimposed on the second inner end portion 65B in the axial direction of the coil layer 54, the circumferential surface 65A3 of the first inner end portion 65A and the circumferential surface 65B4 of the second inner end portion 65B are positioned relative to each other so as to be flush, that is, so that the circumferential position of the coil layer 54 is the same. Also, the circumferential surface 64A4 of the first inner end portion 65A and the circumferential surface 65B3 of the second inner end portion 65B are positioned relative to each other so as to be flush, that is, so that the circumferential position of the coil layer 54 is the same. Note that the positioning of either the circumferential surface 65A3 and circumferential surface 65B4 or the positioning of the circumferential surface 65A4 and circumferential surface 65B3 may be omitted.

[0061] Furthermore, the radial inner surface 65A1 of the first inner terminal portion 65A and the radial inner surface 65B1 of the second inner terminal portion 65B are positioned relative to each other so as to be flush with each other, that is, so that the radial positions of the coil layer 54 are the same.

[0062] As described above, the first outer terminal portion 64A and the second outer terminal portion 64B are positioned in the circumferential and radial directions of the coil layer 54, and the first inner terminal portion 65A and the second inner terminal portion 65B are positioned in the circumferential and radial directions of the coil layer 54, thereby positioning the first segment conductor 60A and the second segment conductor 60B in the circumferential and radial directions of the coil layer 54.

[0063] When the first segment conductor 60A and the second segment conductor 60B are positioned, as shown in Figures 9 and 10, an outer joint boundary portion 66, which is a joint boundary portion, is formed between the first outer end portion 64A and the second outer end portion 64B. The outer joint boundary portion 66 is visible in the axial direction of the coil layer 54. Specifically, the boundary between the inclined surface 64A2 of the first outer end portion 64A and the axial surface 64B6 of the second outer end portion 64B is the outer joint boundary portion 66, and the outer joint boundary portion 66 is visible on one side in the axial direction of the coil layer 54. The outer joint boundary portion 66 is inclined with respect to the radial direction of the coil layer 54 in accordance with the inclination of the inclined surface 64A2 and is formed in a straight line. The outer joint boundary portion 66 is an example of a "joint boundary portion" according to the technology of this disclosure.

[0064] Here, "visible in the axial direction of the coil layer 54" refers to a configuration in which the coil layer 54 is visible when viewed from the axial direction of the coil layer 54, and is accessible by a joining device (see Figures 12 to 14) described later.

[0065] Similarly, as shown in Figure 11, when the first segment conductor 60A and the second segment conductor 60B are positioned, an inner joint boundary portion 67, which is a joint boundary portion, is formed between the first inner terminal portion 65A and the second inner terminal portion 65B. The inner joint boundary portion 67 is visible in the axial direction of the coil layer 54. Specifically, the boundary between the inclined surface 65A2 of the first inner terminal portion 65A and the axial surface 65B6 of the second inner terminal portion 65B is the inner joint boundary portion 67, and the inner joint boundary portion 67 is visible on one side in the axial direction of the coil layer 54. The inner joint boundary portion 67 is inclined with respect to the radial direction of the coil layer 54 in accordance with the inclination of the inclined surface 65A2 and is formed in a straight line. The inner joint boundary portion 67 is an example of a "joint boundary portion" according to the technology of this disclosure.

[0066] The first outer terminal portion 64A and the second outer terminal portion 64B are joined to each other by applying a joining process to the outer joining boundary portion 66 from one axial side of the coil layer 54 using a joining device.

[0067] For example, as shown in Figure 12, a soldering iron 70 (soldering gun) may be used as a joining tool, and soldering may be performed on the outer joining boundary 66 from one axial side of the coil layer 54 using the soldering iron 70. This joins the first outer end portion 64A and the second outer end portion 64B to each other. Specifically, the inclined surface 64A2 of the first outer end portion 64A and the axial surface 64B6 of the second outer end portion 64B are joined to each other by a solder portion 71 across the outer joining boundary 66. The solder portion 71 may be formed in a fillet shape.

[0068] Furthermore, as shown in Figure 13, for example, a laser welding gun 72 may be used as a joining device, and laser welding may be performed on the outer joining boundary 66 from one axial side of the coil layer 54 using the laser welding gun 72. This joins the first outer end portion 64A and the second outer end portion 64B to each other. Specifically, the inclined surface 64A2 of the first outer end portion 64A and the axial surface 64B6 of the second outer end portion 64B are joined to each other by the laser welding portion 73, straddling the outer joining boundary 66. The laser welding portion 73 may be formed in a straight line along the outer joining boundary 66.

[0069] Furthermore, as shown in Figure 14, for example, an adhesive application nozzle 74 for applying a conductive adhesive may be used as a joining device, and an adhesive treatment may be applied to the outer joining boundary 66 from one axial side of the coil layer 54 using the adhesive application nozzle 74. As a result, the first outer end portion 64A and the second outer end portion 64B are joined to each other. Specifically, the inclined surface 64A2 of the first outer end portion 64A and the axial surface 64B6 of the second outer end portion 64B are joined to each other by a conductive adhesive portion 75 across the outer joining boundary 66. The adhesive portion 75 may be formed in a fillet shape.

[0070] Similarly, the first inner terminal portion 65A and the second inner terminal portion 65B are joined to each other by applying a joining process to the inner joining boundary portion 67 from one axial side of the coil layer 54 using a joining device.

[0071] The joining process may be performed using a robot or by hand.

[0072] Next, a method for manufacturing the coil layer 54 according to this embodiment will be described.

[0073] The method for manufacturing the coil layer 54 according to this embodiment comprises an assembly step and a joining step. The assembly step is a step of assembling the coil layer 54 by combining a plurality of annularly arranged first segment conductors 60A and a plurality of annularly arranged second segment conductors 60B in the axial direction of the coil layer 54, overlapping the first outer end portion 64A of the first segment conductor 60A with the second outer end portion 64B of the second segment conductor 60B in the axial direction of the coil layer 54, and overlapping the first inner end portion 65A of the first segment conductor 60A with the second inner end portion 65B of the second segment conductor 60B in the axial direction of the coil layer 54. By assembling the coil layer 54, an outer joint boundary portion 66 between the first outer end portion 64A and the second outer end portion 64B, which is visible on one axial side of the coil layer 54, and an inner joint boundary portion 67 between the first inner end portion 65A and the second inner end portion 65B, which is visible on one axial side of the coil layer 54, are obtained.

[0074] The joining process involves joining the first outer end portion 64A and the second outer end portion 64B by applying a joining treatment using a joining device to the outer joining boundary portion 66, which is visible on one axial side of the coil layer 54, from one axial side of the coil layer 54, and joining the first inner end portion 65A and the second inner end portion 65B by applying a joining treatment using a joining device to the inner joining boundary portion 67, which is visible on one axial side of the coil layer 54, from one axial side of the coil layer 54.

[0075] In the joining process, the first segment conductor 60A and the second segment conductor 60B are positioned before the joining process is carried out. Specifically, the circumferential surface 64A3 of the first outer end portion 64A and the circumferential surface 64B4 of the second outer end portion 64B are positioned relative to each other so that they are flush, that is, so that the circumferential positions of the coil layer 54 are the same. Furthermore, the circumferential surface 64A4 of the first outer end portion 64A and the circumferential surface 64B3 of the second outer end portion 64B are positioned relative to each other so that they are flush, that is, so that the circumferential positions of the coil layer 54 are the same. Note that either the positioning of the circumferential surface 64A3 and the circumferential surface 64B4, or the positioning of the circumferential surface 64A4 and the circumferential surface 64B3, may be omitted.

[0076] Furthermore, the radial outer surface 64A1 of the first outer end portion 64A and the radial outer surface 64B1 of the second outer end portion 64B are positioned relative to each other so that they are flush with each other, that is, so that the radial positions of the coil layer 54 are the same.

[0077] Similarly, the circumferential surface 65A3 of the first inner end portion 65A and the circumferential surface 65B4 of the second inner end portion 65B are positioned relative to each other so that they form a flush surface, that is, so that the circumferential position of the coil layer 54 is the same. Furthermore, the circumferential surface 65A4 of the first inner end portion 65A and the circumferential surface 65B3 of the second inner end portion 65B are positioned relative to each other so that they form a flush surface, that is, so that the circumferential position of the coil layer 54 is the same. Note that either the positioning of the circumferential surface 65A3 and the circumferential surface 65B4, or the positioning of the circumferential surface 65A4 and the circumferential surface 65B3, may be omitted.

[0078] Furthermore, the radial inner surface 65A1 of the first inner end portion 65A and the radial inner surface 65B1 of the second inner end portion 65B are positioned relative to each other so that they are flush with each other, that is, so that the radial positions of the coil layer 54 are the same.

[0079] Next, a description of the motor manufacturing method according to this embodiment will be given.

[0080] The manufacturing method (assembly method) of the motor 10 according to this embodiment is performed by stacking the components constituting the motor 10 from one side in the axial direction. That is, the multiple components constituting the motor 10 are stacked from one side in the axial direction of the motor 10. Specifically, the second magnet support member 25, the second magnet 19, two coil layers 54, the core 26, two coil layers 54, the first magnet 18, the first magnet support member 24, and the first frame 21 are stacked on the second frame 23 from one side in the axial direction. Each coil layer 54 is stacked in such a way that both the outer joint boundary portion 66 and the inner joint boundary portion 67 are visible on one side in the axial direction of the motor 10.

[0081] The rotating shaft 22 is assembled at an appropriate timing. The second magnet support member 25 and the second magnet 19 may be assembled as a single unit. Similarly, the first magnet support member 24 and the first magnet 18 may be assembled as a single unit. In addition, some of the components constituting the motor 10 may be assembled as a single unit.

[0082] Furthermore, the joining step among the manufacturing methods for the coil layer 54 described above may be performed after the multiple first segment conductors 60A and second segment conductors 60B are stacked as components constituting the motor 10, or it may be performed before the multiple first segment conductors 60A and second segment conductors 60B are stacked as components constituting the motor 10.

[0083] Next, the effects of this embodiment will be described.

[0084] As described in detail above, in the coil layer 54 according to this embodiment, when the first outer end portion 64A of the first segment conductor 60A is superimposed on the second outer end portion 64B of the second segment conductor 60B in the axial direction of the coil layer 54, the outer joint boundary portion 66, which is the joint boundary portion between the first outer end portion 64A and the second outer end portion 64B, becomes visible on one side of the coil layer 54 in the axial direction. Similarly, when the first inner end portion 65A of the first segment conductor 60A is superimposed on the second inner end portion 65B of the second segment conductor 60B in the axial direction of the coil layer 54, the inner joint boundary portion 67, which is the joint boundary portion between the first inner end portion 65A and the second inner end portion 65B, becomes visible on one side of the coil layer 54 in the axial direction.

[0085] Here, if the outer joint boundary 66 is visible on the radially outer side of the coil layer 54, the joining process must be performed on the outer joint boundary 66 from the radially outer side of the coil layer 54. Similarly, if the inner joint boundary 67 is visible on the radially inner side of the coil layer 54, the joining process must be performed on the inner joint boundary 67 from the radially inner side of the coil layer 54. However, in these cases, the orientation of the coil layer 54 or the joining device must be changed in the circumferential direction of the coil layer 54, so if the orientation of the coil layer 54 or the joining device is changed using automated equipment, the automated equipment will become larger.

[0086] In contrast, in this embodiment, since the outer joining boundary 66 and the inner joining boundary 67 are visible on one side of the axial direction of the coil layer 54, the joining process can be performed on the outer joining boundary 66 and the inner joining boundary 67 from one side of the axial direction of the coil layer 54. Therefore, since the orientation of the coil layer 54 or the joining device does not need to be changed in the circumferential direction of the coil layer 54, it is possible to suppress the need for large automated equipment to change the orientation of the coil layer 54 or the joining device.

[0087] Furthermore, although the outer joint boundary 66 is located on the outer periphery of the coil layer 54 and the inner joint boundary 67 is located on the inner periphery of the coil layer 54, the outer joint boundary 66 and the inner joint boundary 67 are visible on one axial side of the coil layer 54, so the joining process can be performed on the outer joint boundary 66 and the inner joint boundary 67 from one axial side of the coil layer 54. As a result, the first outer end portion 64A and the second outer end portion 64B can be easily joined, and the first inner end portion 65A and the second inner end portion 65B can be easily joined, compared to the case where the outer joint boundary 66 and the inner joint boundary 67 are visible in the radial direction of the coil layer 54.

[0088] In particular, since the inner joint boundary 67 is located on the inner circumference of the coil layer 54, even if one attempts to bring a joining tool close to the inner joint boundary 67 from the radially inner side of the coil layer 54, the joining tool will interfere with the part of the inner circumference of the coil layer 54 opposite to the inner joint boundary 67 that is to be joined. Therefore, it is generally difficult to perform a joining process on the inner joint boundary 67. However, as in this embodiment, when the inner joint boundary 67 is visible on one axial side of the coil layer 54, the joining tool can be easily brought close to the inner joint boundary 67 from one axial side of the coil layer 54. This makes it possible to perform a joining process on the inner joint boundary 67 located on the inner circumference of the coil layer 54.

[0089] Furthermore, the first segment conductor 60A and the second segment conductor 60B are segment conductors formed to the same shape. This reduces the number of parts compared to the case where the first segment conductor 60A and the second segment conductor 60B are segment conductors formed to different shapes, thus reducing costs.

[0090] Furthermore, the outer end portions 64 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B (i.e., the first outer end portion 64A or the second outer end portion 64B) are formed asymmetrically with respect to the widthwise center line CL1. Therefore, when the first outer end portion 64A is superimposed on the second outer end portion 64B in the axial direction of the coil layer 54, a difference in area is created between the first outer end portion 64A and the second outer end portion 64B in a plan view, and this difference makes it possible to obtain an outer joint boundary portion 66 that is visible on one side in the axial direction. Thus, by a simple configuration in which the outer end portions 64 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B are formed asymmetrically with respect to the widthwise center line CL1, an outer joint boundary portion 66 that is visible on one side in the axial direction of the coil layer 54 can be realized.

[0091] Furthermore, the inner end portions 65 (i.e., the first inner end portion 65A or the second inner end portion 65B) of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B are also formed asymmetrically with respect to the widthwise center line CL2. Therefore, when the first inner end portion 65A is superimposed on the second inner end portion 65B in the axial direction of the coil layer 54, a difference in area is created between the first inner end portion 65A and the second inner end portion 65B in a plan view, and this difference makes it possible to obtain an inner joint boundary portion 67 that is visible on one side in the axial direction. Thus, an inner joint boundary portion 67 that is visible in the axial direction can be realized with a simple configuration in which the inner end portions 65 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B are formed asymmetrically with respect to the widthwise center line CL2.

[0092] Furthermore, the outer joint boundary portion 66 is inclined with respect to the radial direction of the coil layer 54 in a plan view. Therefore, compared to the case where the outer joint boundary portion 66 is perpendicular to the radial direction of the coil layer 54, the length of the outer joint boundary portion 66 and, consequently, the joining area between the first outer end portion 64A and the second outer end portion 64B can be secured. This ensures the joining strength between the first outer end portion 64A and the second outer end portion 64B.

[0093] Furthermore, since the outer joint boundary portion 66 is formed in a straight line, the configuration of the first outer terminal portion 64A and the second outer terminal portion 64B can be simplified compared to the case where the outer joint boundary portion 66 is formed in a shape other than a straight line (for example, a bent or curved shape).

[0094] Similarly, the inner joint boundary 67 is inclined with respect to the radial direction of the coil layer 54 in a plan view. Therefore, compared to the case where the inner joint boundary 67 is perpendicular to the radial direction of the coil layer 54, the length of the inner joint boundary 67 and, consequently, the joining area between the first inner end portion 65A and the second inner end portion 65B can be secured. This ensures the joining strength between the first inner end portion 65A and the second inner end portion 65B.

[0095] Furthermore, since the inner joint boundary portion 67 is formed in a straight line, the configuration of the first inner terminal portion 65A and the second inner terminal portion 65B can be simplified compared to the case where the inner joint boundary portion 67 is formed in a shape other than a straight line (for example, a bent or curved shape).

[0096] Furthermore, the first outer end portion 64A has a circumferential surface 64A3 facing one side in the circumferential direction of the coil layer 54, and the second outer end portion 64B has a circumferential surface 64B4 facing one side in the circumferential direction of the coil layer 54. Therefore, by positioning the circumferential surfaces 64A3 and 64B4 relative to each other so that they form a flush surface, that is, so that the circumferential positions of the coil layer 54 are the same, the first outer end portion 64A and the second outer end portion 64B can be positioned in the circumferential direction.

[0097] Furthermore, the first outer end portion 64A has a circumferential surface 64A4 facing the other side of the coil layer 54 in the circumferential direction, and the second outer end portion 64B also has a circumferential surface 64B3 facing the other side of the coil layer 54 in the circumferential direction. Therefore, by positioning the circumferential surfaces 64A4 and 64B3 relative to each other so that they form a flush surface, that is, so that the circumferential positions of the coil layer 54 are the same, the first outer end portion 64A and the second outer end portion 64B can be positioned in the circumferential direction.

[0098] Furthermore, the first outer end portion 64A has a radial outer surface 64A1 facing radially outward of the coil layer 54, and the second outer end portion 64B also has a radial outer surface 64B1 facing radially outward of the coil layer 54. Therefore, by positioning the radial outer surface 64A1 and the radial outer surface 64B1 relative to each other so that they are flush with each other, that is, so that the radial positions of the coil layer 54 are the same, the first outer end portion 64A and the second outer end portion 64B can be positioned radially.

[0099] Furthermore, the first inner end portion 65A has a circumferential surface 65A3 facing one side in the circumferential direction of the coil layer 54, and the second inner end portion 65B has a circumferential surface 65B4 facing the same side in the circumferential direction of the coil layer 54. Therefore, by positioning the circumferential surfaces 65A3 and 65B4 relative to each other so that they form a flush surface, that is, so that the circumferential positions of the coil layer 54 are the same, the first inner end portion 65A and the second inner end portion 65B can be positioned in the circumferential direction.

[0100] Furthermore, the first inner end portion 65A has a circumferential surface 65A4 facing the other side in the circumferential direction of the coil layer 54, and the second inner end portion 65B also has a circumferential surface 65B3 facing the other side in the circumferential direction of the coil layer 54. Therefore, by positioning the circumferential surfaces 65A4 and 65B3 relative to each other so that they form a flush surface, that is, so that the circumferential positions of the coil layer 54 are the same, the first inner end portion 65A and the second inner end portion 65B can be positioned in the circumferential direction.

[0101] Furthermore, the first inner end portion 65A has a radial inner surface 65A1 facing radially inward of the coil layer 54, and the second inner end portion 65B also has a radial inner surface 65B1 facing radially inward of the coil layer 54. Therefore, by positioning the radial inner surface 65A1 and the radial inner surface 65B1 relative to each other so that they form a flush surface, that is, so that the radial position of the coil layer 54 is the same, the first inner end portion 65A and the second inner end portion 65B can be positioned radially.

[0102] Furthermore, both the outer joint boundary 66 and the inner joint boundary 67 are visible on one axial side of the motor 10, and the side on which the multiple components constituting the motor 10 are stacked is the same as the side on which the outer joint boundary 66 and the inner joint boundary 67 are visible. Therefore, the joining step in the manufacturing method of the coil layer 54 described above can be performed immediately after stacking the multiple first segment conductors 60A and second segment conductors 60B as components constituting the motor 10. This makes it possible to achieve one-way assembly, in which the multiple components constituting the motor 10 are assembled from one direction.

[0103] Next, a modified example of this embodiment will be described.

[0104] In the above embodiment, the outer terminal portions 64 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B are formed asymmetrically with respect to the widthwise center line CL1 by forming an inclined surface (i.e., inclined surface 64A2 or inclined surface 64B2) that is inclined with respect to the radial direction of the coil layer 54 on a part of the surface facing radially outward of the coil layer 54 (see Figures 7 and 8). However, the first outer terminal portion 64A and the second outer terminal portion 64B may be configured as follows.

[0105] For example, in the example shown in Figure 15, the first outer end portion 64A and the second outer end portion 64B are formed asymmetrically with respect to the widthwise center line CL1, by forming the radially outward-facing surface of the coil layer 54 with an inclined surface 80. The outer joint boundary portion 66 obtained by overlapping the first outer end portion 64A and the second outer end portion 64B configured in this way in the axial direction of the coil layer 54 is formed in a straight line along the inclined surface 80 of the first outer end portion 64A.

[0106] Furthermore, for example, in the example shown in Figure 16, the first outer end portion 64A and the second outer end portion 64B are formed asymmetrically with respect to the widthwise center line CL1, by forming a part of the radially outward-facing surface of the coil layer 54 with a bent surface 81. The outer joint boundary portion 66 obtained by overlapping the first outer end portion 64A and the second outer end portion 64B configured in this way in the axial direction of the coil layer 54 is formed in a curved shape along the bent surface 81 of the first outer end portion 64A, as an example of a non-linear shape.

[0107] In the examples shown in Figures 15 and 16, the first segment conductor 60A and the second segment conductor 60B are segment conductors formed to the same shape. This reduces the number of parts compared to the case where the first segment conductor 60A and the second segment conductor 60B are segment conductors formed to different shapes, thus reducing costs.

[0108] Furthermore, by forming the outer terminal portions 64 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B asymmetrically with respect to the widthwise center line CL1, an outer bonding boundary portion 66 that is visible on one axial side of the coil layer 54 can be realized.

[0109] Furthermore, as shown in the example in Figure 16, when the outer joint boundary portion 66 is formed in a non-linear shape, the length of the outer joint boundary portion 66 and, consequently, the joining area between the first outer end portion 64A and the second outer end portion 64B can be secured compared to when the outer joint boundary portion 66 is formed in a linear shape. This ensures the joint strength between the first outer end portion 64A and the second outer end portion 64B.

[0110] In addition to the examples shown in Figures 15 and 16, the outer terminal portions 64 of the segment conductors 60 used as the first segment conductor 60A and the second segment conductor 60B may be formed in any shape, as long as they are formed asymmetrically with respect to the widthwise center line CL1.

[0111] Furthermore, in the above embodiment, the first segment conductor 60A and the second segment conductor 60B are segment conductors 60 formed in the same shape, but they may also be segment conductors formed in different shapes.

[0112] Furthermore, if the first segment conductor 60A and the second segment conductor 60B are segment conductors formed in different shapes, the first outer terminal portion 64A and the second outer terminal portion 64B may be configured as follows.

[0113] For example, in the example shown in Figure 17, a portion of the surface of the first outer end portion 64A facing radially outward of the coil layer 54 is formed by a bent surface 82, and the surface of the second outer end portion 64B facing radially outward of the coil layer 54 is formed by an orthogonal surface 83 perpendicular to the radial direction of the coil layer 54. The area of ​​the joint surface (axial surface 64B6) of the second outer end portion 64B with the first outer end portion 64A is set to be larger than the area of ​​the joint surface (axial surface 64A6) of the first outer end portion 64A with the second outer end portion 64B. The outer joint boundary portion 66 obtained by overlapping the first outer end portion 64A and the second outer end portion 64B configured in this way in the axial direction of the coil layer 54 is formed in a bent shape as an example of a non-linear shape.

[0114] Furthermore, for example, in the example shown in Figure 18, the surface of the first outer terminal portion 64A facing radially outward of the coil layer 54 is formed by an inclined surface 84 that is inclined with respect to the radial direction of the coil layer 54, and the surface of the second outer terminal portion 64B facing radially outward of the coil layer 54 is formed by an orthogonal surface 85 that is perpendicular to the radial direction of the coil layer 54. As a result, the area of ​​the joint surface between the second outer terminal portion 64B and the first outer terminal portion 64A is set to be larger than the area of ​​the joint surface between the first outer terminal portion 64A and the second outer terminal portion 64B. The outer joint boundary portion 66 obtained by overlapping the first outer terminal portion 64A and the second outer terminal portion 64B configured in this way in the axial direction of the coil layer 54 is formed in a shape that is inclined with respect to the radial direction of the coil layer 54 and extends in a straight line.

[0115] Furthermore, in the example shown in Figure 19, the external shape of the first outer end portion 64A and the external shape of the second outer end portion 64B are formed to be the same, but a through hole 86 is formed in the first outer end portion 64A that penetrates in the axial direction of the coil layer 54. As a result, the area of ​​the joint surface between the second outer end portion 64B and the first outer end portion 64A is set to be larger than the area of ​​the joint surface between the first outer end portion 64A and the second outer end portion 64B by the cross-sectional area of ​​the through hole 86. The outer joint boundary portion 66 obtained by overlapping the first outer end portion 64A and the second outer end portion 64B configured in this way in the axial direction of the coil layer 54 is formed in a circular shape along the inner circumference of the through hole 86, as an example of a non-linear shape.

[0116] Furthermore, for example, in the example shown in Figure 20, the outer shape of the second outer end portion 64B in plan view is rectangular, but the outer shape of the first outer end portion 64A in plan view is formed by cutting out a part of the outer shape of the second outer end portion 64B from the radially outer side of the coil layer 54 by an arc-shaped notch 87. As a result, the area of ​​the joint surface (axial surface) of the second outer end portion 64B with the first outer end portion 64A is set to be larger than the area of ​​the joint surface (axial surface) of the first outer end portion 64A with the second outer end portion 64B by the cross-sectional area of ​​the notch 87. The outer joint boundary portion 66 obtained by overlapping the first outer end portion 64A and the second outer end portion 64B configured in this way in the axial direction of the coil layer 54 is formed in an arc shape along the inner circumference of the notch 87 as an example of a non-linear shape. Note that the cross-sectional shape of the notch 87 may be other than an arc shape.

[0117] As shown in the examples from Figures 17 to 20 above, an outer bonding boundary portion 66 that is visible on one axial side of the coil layer 54 can also be obtained.

[0118] Furthermore, in the examples shown in Figures 16, 17, 19, and 20, the outer joint boundary portion 66 is formed in a non-linear shape, which allows for a larger joint area between the first outer end portion 64A and the second outer end portion 64B compared to the case where the outer joint boundary portion 66 is formed in a linear shape. This ensures sufficient joint strength between the first outer end portion 64A and the second outer end portion 64B.

[0119] Furthermore, the outer joint boundary portion 66 may be formed in various non-linear shapes other than those described above.

[0120] Furthermore, Figures 15 to 20 show modified examples of the outer joint boundary 66 obtained by overlapping the first outer terminal portion 64A and the second outer terminal portion 64B in the axial direction of the coil layer 54. However, the same modified examples as those shown in Figures 15 to 20 may be applied to the inner joint boundary 67 obtained by overlapping the first inner terminal portion 65A and the second inner terminal portion 65B in the axial direction of the coil layer 54.

[0121] Furthermore, in the above embodiment, the first outer terminal portion 64A and the second outer terminal portion 64B are overlapped in the axial direction of the coil layer 54 to obtain an outer joint boundary portion 66 that is visible on one side of the axial direction of the coil layer 54, and the joining process is performed on this outer joint boundary portion 66 from one side of the axial direction of the coil layer 54. However, the first outer terminal portion 64A and the second outer terminal portion 64B may be overlapped in the axial direction of the coil layer 54 to obtain an outer joint boundary portion 66 that is visible on the other side of the axial direction of the coil layer 54, and the joining process may be performed on this outer joint boundary portion 66 from the other side of the axial direction of the coil layer 54. Alternatively, the joining process may be performed on both the outer joint boundary portion 66 that is visible on one side of the axial direction of the coil layer 54 and the outer joint boundary portion 66 that is visible on the other side of the axial direction of the coil layer 54.

[0122] Similarly, in the above embodiment, the first inner terminal portion 65A and the second inner terminal portion 65B are overlapped in the axial direction of the coil layer 54 to obtain an inner joint boundary portion 67 that is visible on one side of the axial direction of the coil layer 54, and the joining process is performed on this inner joint boundary portion 67 from one side of the axial direction of the coil layer 54. Alternatively, the first inner terminal portion 65A and the second inner terminal portion 65B may be overlapped in the axial direction of the coil layer 54 to obtain an inner joint boundary portion 67 that is visible on the other side of the axial direction of the coil layer 54, and the joining process may be performed on this inner joint boundary portion 67 from the other side of the axial direction of the coil layer 54. Furthermore, the joining process may be performed on both the inner joint boundary portion 67 that is visible on one side of the axial direction of the coil layer 54 and the inner joint boundary portion 67 that is visible on the other side of the axial direction of the coil layer 54.

[0123] Furthermore, in the above embodiment, the first segment conductor 60A and the second segment conductor 60B may each be formed by a copper pattern on a printed circuit board.

[0124] Furthermore, although the motor 10 is configured as a double axial gap motor in the above embodiment, it may also be configured as a single axial gap motor, in which either the configuration on one axial side or the configuration on the other axial side is omitted.

[0125] Furthermore, the motor 10 may also be configured in which multiple sets of rotor 12 and stator 14 are arranged in the axial direction.

[0126] Furthermore, among the above-mentioned variations, any combination of compatible variations may be combined as appropriate.

[0127] Although one embodiment of the technology of this disclosure has been described above, the present invention is not limited to the above, and it is of course possible to implement it in various modified forms without departing from the spirit of the invention.

[0128] The following are additional notes regarding the technology of the present disclosure. (Note 1) A coil layer (54) used in the armature (14) of an axial gap motor (10), comprising: a plurality of first segment conductors (60A) arranged in a ring and located on one axial side of the coil layer; and a plurality of second segment conductors (60B) arranged in a ring and located on the other axial side of the coil layer, wherein the first segment conductors have first terminal portions (64A, 65A), and the second segment conductors have second terminal portions (64B, 65B) that are superimposed on the first terminal portions in the axial direction of the coil layer and joined to the first terminal portions, and the joining boundary portions (66, 67) between the first terminal portions and the second terminal portions are visible in the axial direction of the coil layer. (Note 2) The coil layer according to Note 1, wherein the first terminal portions and the second terminal portions are located on the outer or inner circumference of the coil layer. (Note 3) The coil layer according to Note 1 or Note 2, wherein the first segment conductor and the second segment conductor are segment conductors (60) formed in the same shape, and the terminal portions (64, 65) of the segment conductors are formed asymmetrically with respect to the widthwise center line of the terminal portions. (Note 4) The coil layer according to any one of Notes 1 to 3, wherein the joining boundary portion is inclined with respect to the radial direction of the coil layer and is formed in a straight line. (Note 5) The coil layer according to Note 1 or Note 2, wherein the first segment conductor and the second segment conductor are segment conductors formed in different shapes, and the area of ​​the joining surface (64B6) of the second terminal portion with the first terminal portion is set to be larger than the area of ​​the joining surface (64A6) of the first terminal portion with the second terminal portion. (Note 6) The joint boundary portion is formed in a non-linear shape, the coil layer according to any one of Notes 1 to 5.(Note 7) The coil layer according to any one of Notes 1 to 6, wherein the first terminal portion has a first circumferential surface (64A3, 64A4, 65A3, 65A4) facing the circumferential direction of the coil layer, and the second terminal portion has a second circumferential surface (64B3, 64B4, 65B3, 65B4) facing the same side as the first circumferential surface, and the first circumferential surface and the second circumferential surface are flush. (Note 8) The coil layer according to any one of Notes 1 to 7, wherein the first terminal portion has a first radial surface (64A1, 65A1) facing the radial direction of the coil layer, and the second terminal portion has a second radial surface (64B1, 65B1) facing the same side as the first radial surface, and the first radial surface and the second radial surface are flush. (Note 9) An armature comprising a coil layer as described in any one of Notes 1 to 8, and a core (26) to which the coil layer is attached. (Note 10) An axial gap motor comprising a stator (14) as an armature as described in Note 9, and a rotor (12) facing the stator in the axial direction of the stator. (Note 11) An axial gap motor as described in Note 10, wherein the plurality of members constituting the axial gap motor are stacked from one side in the axial direction of the axial gap motor, and the joint boundary is visible from one side in the axial direction of the axial gap motor. (Note 12) A method for manufacturing a coil layer used in the armature of an axial gap motor, comprising: an assembly step of assembling the coil layer by combining a plurality of first segment conductors and a plurality of second segment conductors arranged in a ring in the axial direction of the coil layer, and overlapping the first terminal portion of the first segment conductor with the second terminal portion of the second segment conductor in the axial direction of the coil layer; and a joining step of joining the first terminal portion and the second terminal portion by performing a joining process on the joint boundary portion between the first terminal portion and the second terminal portion, which is visible in the axial direction of the coil layer, from the axial direction of the coil layer using joining devices (70, 72, 74) to join the first terminal portion and the second terminal portion.

Claims

1. A coil layer (54) used in the armature (14) of an axial gap motor (10), comprising: a plurality of first segment conductors (60A) arranged in a ring and positioned on one axial side of the coil layer; and a plurality of second segment conductors (60B) arranged in a ring and positioned on the other axial side of the coil layer, wherein the first segment conductors have first terminal portions (64A, 65A), the second segment conductors have second terminal portions (64B, 65B) that overlap with the first terminal portions in the axial direction of the coil layer and are joined to the first terminal portions, and the joining boundary portions (66, 67) between the first terminal portions and the second terminal portions are visible in the axial direction of the coil layer.

2. The coil layer according to claim 1, wherein the first terminal portion and the second terminal portion are located on the outer or inner circumference of the coil layer.

3. The coil layer according to claim 1 or claim 2, wherein the first segment conductor and the second segment conductor are segment conductors (60) formed in the same shape, and the terminal portions (64, 65) of the segment conductors are formed asymmetrically with respect to the widthwise center line of the terminal portions.

4. The coil layer according to any one of claims 1 to 3, wherein the joint boundary portion is inclined with respect to the radial direction of the coil layer and is formed in a straight line.

5. The coil layer according to claim 1 or claim 2, wherein the first segment conductor and the second segment conductor are segment conductors formed in different shapes, and the area of ​​the joint surface (64B6) at the second terminal portion with the first terminal portion is set to be larger than the area of ​​the joint surface (64A6) at the first terminal portion with the second terminal portion.

6. The coil layer according to any one of claims 1 to 5, wherein the joint boundary portion is formed in a non-linear shape.

7. The coil layer according to any one of claims 1 to 6, wherein the first terminal portion has a first circumferential surface (64A3, 64A4, 65A3, 65A4) facing the circumferential direction of the coil layer, and the second terminal portion has a second circumferential surface (64B3, 64B4, 65B3, 65B4) facing the same side as the first circumferential surface, and the first circumferential surface and the second circumferential surface are flush.

8. The coil layer according to any one of claims 1 to 7, wherein the first terminal portion has a first radial surface (64A1, 65A1) facing the radial direction of the coil layer, and the second terminal portion has a second radial surface (64B1, 65B1) facing the same side as the first radial surface, and the first radial surface and the second radial surface are flush.

9. An armature comprising: a coil layer according to any one of claims 1 to 8; and a core (26) to which the coil layer is attached.

10. An axial gap motor comprising: a stator (14) as an armature as described in claim 9; and a rotor (12) facing the stator in the axial direction of the stator.

11. The axial gap motor according to claim 10, wherein the plurality of members constituting the axial gap motor are stacked from one axial side of the axial gap motor, and the joint boundary is visible from one axial side of the axial gap motor.

12. A method for manufacturing a coil layer used in the armature of an axial gap motor, comprising: an assembly step of assembling the coil layer by combining a plurality of first segment conductors and a plurality of second segment conductors arranged in an annular shape in the axial direction of the coil layer, and overlapping the first terminal portion of the first segment conductor with the second terminal portion of the second segment conductor in the axial direction of the coil layer; and a joining step of joining the first terminal portion and the second terminal portion by performing a joining process on the joint boundary portion between the first terminal portion and the second terminal portion, which is visible in the axial direction of the coil layer, from the axial direction of the coil layer using joining devices (70, 72, 74).

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