Method of manufacturing an armature

Abstract

Provided is an armature that has high insulation between adjacent coils in the same layer.　This armature is disposed so as to face a movable element via a gap. When a direction facing the movable element is defined as a first direction, a direction orthogonal to the first direction and in which the movable element moves relative to the armature is defined as a second direction, and a direction orthogonal to the first direction and the second direction is defined as a third direction, the armature comprises a coil the width of which varies along the third direction as viewed from the first direction. Coils (41, 42) are laminated in two or more layers via an insulator in the first direction, at least two or more coils (41, 43) are disposed in the second direction, and chamfered parts (40) are formed in the corner parts of the coils in a cross section in a direction orthogonal to the third direction.

Description

Technical Field

[0001] This disclosure relates to child a method for manufacturing an electric machine

Background Art

[0002] There is an axial-gap type rotating electric machine in which an annular rotor and a stator are arranged to face each other as a thin rotating electric machine. As a stator of an axial-gap type rotating electric machine, for example, a stator in which a plurality of coils manufactured by punching a copper plate are laminated with an insulating layer interposed therebetween is disclosed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional stator, since a plurality of coils manufactured by punching a copper plate are laminated with an insulating layer interposed therebetween, there is a problem that the insulation between adjacent coils in the same layer is low.

[0005] This disclosure has been made to solve the above problems, and an object thereof is to provide a stator having high insulation between adjacent coils in the same layer.

Means for Solving the Problems

[0006] The stator of this disclosure Manufacturing method is The process includes: a coil forming step of forming two or more coils by drilling slits through a metal plate; a chamfering step of forming chamfered portions on the corners of the two or more coils formed in the coil forming step; an insulating coating forming step of forming an insulating coating on the surface of the two or more coils on which the chamfered portions were formed in the chamfering step; and a coil joining step of joining the two or more coils on which the insulating coating was formed in the insulating coating forming step by overlapping them. .

Effects of the Invention

[0007] The stator of this disclosure Manufacturing method is The process comprises: a coil forming step of forming two or more coils by drilling slits through a metal plate; a chamfering step of forming chamfered portions on the corners of the two or more coils formed in the coil forming step; an insulating coating forming step of forming an insulating coating on the surface of the two or more coils on which the chamfered portions were formed in the chamfering step; and a coil joining step of overlapping and joining the two or more coils on which the insulating coating was formed in the insulating coating forming step. such that the insulation between adjacent coils in the same layer can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view of a rotating electric machine according to Embodiment 1. [Figure 2] This is a plan view of the rotor according to Embodiment 1. [Figure 3] This is a plan view of the armature according to Embodiment 1. [Figure 4] This is a side view of the armature according to Embodiment 1. [Figure 5] This is a plan view of the armature according to Embodiment 1. [Figure 6] This is a circuit diagram of the armature according to Embodiment 1. [Figure 7] This is a plan view of the armature of a reference example according to Embodiment 1. [Figure 8] This is an enlarged cross-sectional view of the armature coil according to Embodiment 1. [Figure 9] This is an enlarged cross-sectional view of the armature coil of a comparative example according to Embodiment 1. [Figure 10] This is an enlarged view of the armature coil according to Embodiment 1. [Figure 11] This is an enlarged view of the armature coil of a comparative example according to Embodiment 1. [Figure 12] This is a flowchart showing the method for manufacturing an armature according to Embodiment 1. [Figure 13] This figure shows a coil in the process of being manufactured according to Embodiment 1. [Figure 14] This is a diagram illustrating the manufacturing method of an armature according to Embodiment 1. [Figure 15] This is a diagram illustrating the manufacturing method of an armature according to Embodiment 1. [Figure 16] This figure illustrates the deformation of the coil when the armature according to Embodiment 1 is pressed by a mold. [Figure 17] This figure illustrates the deformation of the coil when the armature according to Embodiment 1 is pressed by a mold. [Figure 18] It is a diagram for explaining the deformation of a coil when pressed by a mold in the armature according to Embodiment 1. [Figure 19] It is a plan view of the armature according to Embodiment 1. [Figure 20] It is an enlarged cross-sectional view of the coil of the armature according to Embodiment 2. [Figure 21] It is an enlarged view of the coil of the armature according to Embodiment 2. [Figure 22] It is an enlarged cross-sectional view of the coil of the armature according to Embodiment 3. [Figure 23] It is an enlarged cross-sectional view of the coil of the armature of the comparative example according to Embodiment 3. [Figure 24] It is an enlarged view of the coil of the armature according to Embodiment 3. [Figure 25] It is an enlarged view of the coil of the armature of the comparative example according to Embodiment 3. [Figure 26] It is an enlarged cross-sectional view of the coil of the armature of the comparative example according to Embodiment 3. [Figure 27] It is an enlarged cross-sectional view of the coil of the armature according to Embodiment 4. [Figure 28] It is an enlarged cross-sectional view of the coil of the armature according to Embodiment 4. [Figure 29] It is an enlarged view of the coil of the armature according to Embodiment 4. [Figure 30] It is an enlarged view of the coil of the armature according to Embodiment 4. [Figure 31] It is an enlarged cross-sectional view of the coil of the armature according to Embodiment 5. [Figure 32] It is an enlarged view of the coil of the armature according to Embodiment 5.

Mode for Carrying Out the Invention

[0009] Hereinafter, the armature according to the embodiment for implementing the present disclosure will be described in detail with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts.

[0010] Embodiment 1. Figure 1 is a cross-sectional view of a rotating electric machine according to Embodiment 1. Figure 1 is a cross-sectional view showing the structure of the right half from the center of rotation, which will be described later, in order to explain the structure of the rotating electric machine according to this embodiment. The rotating electric machine 1 of this embodiment is an axial gap type rotating electric machine in which a ring-shaped rotor and an armature are arranged facing each other in the axial direction.

[0011] The rotating electric machine 1 of this embodiment consists of a stator 2 and a rotor 3. The stator 2 has an annular armature 21, a housing 22 that holds the armature 21, a bearing 23 and a bracket 24. The rotor 3 has a rotating shaft 31 that is rotatably supported relative to the stator 2 via the bearing 23, an annular rotor core 32 fastened to the rotating shaft 31 and magnets 33 arranged in the circumferential direction of the rotor core 32.

[0012] The rotating shaft 31 rotates around the rotation center C. Hereafter, the direction parallel to the rotation center C will be referred to as the axial direction, the direction perpendicular to the axial direction as the radial direction, and the circumferential direction of the annular armature 21 as the circumferential direction. Furthermore, the inner diameter side is the direction approaching the rotation center C in the radial direction, and the outer diameter side is the direction moving away from the rotation center C in the radial direction. The rotor core 32 is arranged on both sides of the armature 21 in the axial direction, and the magnets 33 are arranged opposite the armature 21 with a gap in the axial direction. Coils are formed on the armature 21, and current is applied to these coils from the power supply terminals 4. The armature 21 generates a rotating magnetic field due to the applied current. The rotor 3 rotates due to this rotating magnetic field. Therefore, the rotor 3 can also be described as a movable element that is arranged coaxially with respect to the armature 21 with a gap in between, and moves relative to the armature 21.

[0013] Figure 2 is a plan view of the rotor 3 of this embodiment as seen from the armature 21 side. As shown in Figure 2, in the rotor 3 of this embodiment, the magnets 33 are arranged in the circumferential direction of the annular rotor core 32. The magnets 33 are magnetized in a direction perpendicular to the plane of the paper in Figure 2, and the south poles and north poles are arranged alternately in the circumferential direction.

[0014] Figure 3 is a plan view of the armature 21 of this embodiment, and Figure 4 is a side view of the armature 21 of this embodiment. The armature 21 of this embodiment is composed of two layers of coils stacked in the axial direction. Therefore, Figure 3 shows the first layer of coil. Figure 5 is a plan view of the second layer of coil of the armature 21 of this embodiment. Each layer of coil is made of a conductive metal such as copper, and an insulating coating is formed on its surface.

[0015] As shown in Figures 3 and 5, in the armature 21 of this embodiment, a coil 26 is formed by dividing it into 72 sections in the circumferential direction by a slit 25. Each coil 26 consists of a slot section 26a in the central radial portion, an outer diameter turn section 26b on the outer diameter side of the slot section 26a, and an inner diameter turn section 26c on the inner diameter side of the slot section 26a. The first layer of coil 26 is joined to the second layer of coil 26 at an outer diameter joint section 27. The second layer of coil 26, joined at the outer diameter joint section 27, is joined to the first layer of coil 26 at an inner diameter joint section 28. The coils 26 thus joined are joined to coils 26 located 6 pitches apart in the circumferential direction by a busbar 29. The busbar 29 may be used for purposes other than electrically joining coils in the stacking direction. For example, it may be used at the neutral point connection in a Y connection. Furthermore, the busbar 29 is not limited to joining coils that are 6 slots apart, but may also join coils that are 5 slots apart or 7 slots apart.

[0016] The armature coils are formed by sequentially joining the first and second layer coils, which are located 6 pitches apart. The armature in this embodiment is a distributed winding with 2 windings per pole per phase, and as shown in Figure 3, the coils U1, U2, W1, W2, V1, and V2 are arranged in order. Also, as shown in Figure 4, power supply terminals 4 are connected to both ends of the coils U1, U2, W1, W2, V1, and V2, respectively.

[0017] Figure 6 is a circuit diagram of the armature according to this embodiment. The U-phase coil, in which coils U1 and U2 are connected in series, the W-phase coil, in which coils W1 and W2 are connected in series, and the V-phase coil, in which coils V1 and V2 are connected in series, are connected in a Y-connection, and a three-phase AC power supply 30 such as an inverter is connected to the ends of each phase coil. A rotating magnetic field is generated in the armature by applying a three-phase AC current from the three-phase AC power supply 30 to each phase coil.

[0018] In this embodiment, the armature is a fully-winding distributed winding with 2 windings per pole per phase. However, any winding method that generates a rotating magnetic field and in which coils set to different potentials are arranged adjacent to each other may be used for the armature, such as short-winding, a distributed winding with 1 winding per pole per phase, or salient-pole concentrated winding. Furthermore, the armature of this embodiment is not limited to three phases and can be applied to double-three-phase structures, five-phase, or seven-phase structures that generate a rotating magnetic field.

[0019] Figure 7 is a plan view of an armature wound with magnet wire of the same cross-sectional shape, as a reference example. Note that the busbars and power supply terminals are omitted in Figure 7. In this reference example, the width of the coil 26 must be determined by physical constraints such as space interference in the inner diameter and ensuring insulation distance. In this case, the space other than the coil becomes large on the outer diameter side. Therefore, the coil's packing factor cannot be increased, which causes a decrease in efficiency and output.

[0020] In contrast, in the armature of this embodiment, as shown in Figure 3, the width of the coil as viewed from the axial direction is varied, so that coils can be arranged at a high density even on the outer diameter side, resulting in improved efficiency and higher output. On the other hand, in order to obtain coil shapes with different cross-sectional areas, it is necessary to form the coils by punching, laser processing, etching, etc. For example, when a coil is formed by punching, the corners of the coil become nearly right angles.

[0021] Figure 8 is an enlarged cross-sectional view of the armature coil according to this embodiment. Figure 8 is a cross-sectional view of the location indicated by AA in Figure 3, that is, a cross-sectional view in a direction perpendicular to the radial direction, where the vertical direction of the paper is the axial direction and the horizontal direction is the circumferential direction. Figure 8 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 8, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. These coils 41 to 44 are covered with an insulating coating 45. The potential difference between coils 41 and 43 of different phases is greater than the potential difference between coils 41 and 42 of the same phase.

[0022] As shown in Figure 8, in the armature of this embodiment, the corners of the coil are chamfered in the radial cross-section. Here, chamfering means removing sharp corners after machining to create a flat or curved surface, and the chamfered shape means a shape that can mitigate electric field concentration by removing sharp corners. Specifically, in the armature of this embodiment, the corners of the coil are rounded. Hereafter, the chamfered shape will be referred to as the chamfered portion 40. It should be noted that the shape of the chamfered portion as defined in this embodiment is not limited to the machining method of removing sharp corners after machining, but may also be formed directly using a near-net shape with a 3D printer, die casting, etc.

[0023] Figure 9 is an enlarged cross-sectional view of an armature coil of a comparative example according to this embodiment. Figure 9 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 9 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 9, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. These coils 41 to 44 are covered with an insulating coating 45. The potential difference between coils 41 and 43 of different phases is greater than the potential difference between coils 41 and 42 of the same phase.

[0024] In the comparative example armature shown in Figure 9, the corners of the coil are not chamfered, so in the radial cross-section, the corners of the coil are nearly right angles. In this embodiment, when the corners of the coil are not chamfered in the radial cross-section, the corners of the coil become close to right angles.

[0025] Figure 10 is an enlarged view of the portion indicated by the dashed circle in Figure 8, and Figure 11 is an enlarged view of the portion indicated by the dashed circle in Figure 9. As shown in Figures 10 and 11, there are three locations where coil 41 may short-circuit with other coils, indicated by arrow a at both ends: between the corner of coil 41 and the corner of coil 42, indicated by arrow b at both ends: between the corner of coil 41 and the corner of coil 43, and indicated by arrow c at both ends: between the corner of coil 41 and the corner of coil 44. The lengths of arrow a and arrow b at both ends are the same between the armature of this embodiment and the armature of the comparative example. However, in the armature of this embodiment shown in Figure 10, the corners have the shape of chamfered portions 40, so electric field concentration is mitigated compared to the armature of the comparative example shown in Figure 11.

[0026] The length of the arrow c at both ends is longer in the armature of this embodiment shown in Figure 10 compared to the armature of the comparative example shown in Figure 11. Therefore, the insulation between the corners of coil 41 and coil 44 is higher in the armature of this embodiment than in the armature of the comparative example. Furthermore, in the armature of this embodiment, the corners have a chamfered shape, which reduces electric field concentration compared to the armature of the comparative example shown in Figure 11.

[0027] Thus, in the armature of this embodiment, the corners of the coils in the radial cross-section are chamfered 40, which improves the insulation between adjacent coils in the same layer. Furthermore, in the armature of this embodiment, the insulation between adjacent coils in the same layer is improved compared to the armature of the comparative example, so the thickness of the insulating coating 45 can be reduced. Reducing the thickness of the insulating coating 45 also improves the coil's packing factor. As a result, it is possible to achieve miniaturization, higher output, and higher efficiency of the armature.

[0028] In this embodiment, the chamfered portion of the armature has a rounded shape, but the chamfered portion may also be a shape called C-chamfer, in which the sharp corners after machining are cut to a 45-degree angle; a shape called thread chamfer, in which only the tip of the sharp corner is cut; or a shape in which the sharp corner is cut into a polygon.

[0029] Next, the method for manufacturing the armature of this embodiment will be described. Figure 12 is a flowchart showing the method for manufacturing an armature according to this embodiment. The method for manufacturing an armature in this embodiment consists of a coil formation step S1, a chamfering step S2, an insulating coating formation step S3, a coil joining step S4, and a coil cutting step S5.

[0030] First, in the coil formation process S1, a coil is formed by punching or laser cutting a slit through a plate-shaped metal sheet such as copper. Figure 13 shows the coil in the state after the slit has been cut through in the coil formation process S1. As shown in Figure 13, in the coil formation process S1, the metal sheet 34 is processed into an annular shape and a slit 25 is formed through the metal sheet 34. By forming the slit 25, a coil 26 is formed in the metal sheet 34, consisting of a slot portion 26a, an outer diameter turn portion 26b, and an inner diameter turn portion 26c.

[0031] In the coil formation process S1, the coil 26 is formed, and at the same time, the outer diameter joint portion 27 and the inner diameter joint portion 28 are formed. At this time, the outer diameter joint portion 27 is connected to the outer diameter connecting portion 36 via the outer diameter cutting portion 35. Similarly, the inner diameter joint portion 28 is connected to the inner diameter connecting portion 38 via the inner diameter cutting portion 37. Also in the coil formation process S1, a positioning hole 39 is formed in the outer diameter connecting portion 36.

[0032] By connecting the coil 26 to the outer diameter connecting portion 36 and the inner diameter connecting portion 38 in this manner, the coil can be easily transported, and the positioning hole 39 can be formed to facilitate positioning in subsequent processes.

[0033] Next, in the chamfering process S2, chamfers are formed on the corners of the coil in the radial cross-section. Figure 14 is a diagram illustrating the chamfering process S2. The coil 26 formed in the coil forming process S1 has corners that are almost right angles. As shown in Figure 14, this coil 26 is placed on the lower die 51. The upper die 52 is pressed from above onto the coil 26 placed on the lower die 51. Through this process, chamfers 40 are formed on the corners of the coil 26. Note that, as shown in Figure 15, multiple coils 26 arranged in the circumferential direction may be pressed simultaneously using the lower die 51 and the upper die 52. Alternatively, the entire coil 26 may be pressed simultaneously.

[0034] Figure 16 illustrates the deformation of a coil when a limited number of coils are pressed by a mold. In Figure 16, the arrows indicate the force applied from the coil 26 to the upper mold 52. A similar force is also applied to the lower mold 51, but it is not shown in the illustration. As shown in Figure 16, a force is applied perpendicular to the coil at the end of the upper mold 52, which can cause the mold to deform. In actual coils, a smaller circumferential gap is desirable to improve the coil's packing efficiency, so the thickness of the mold at the circumferential ends becomes smaller. If the circumferential gap of the coil is increased to suppress mold deformation, the output of the rotating electric machine will decrease.

[0035] Figure 17 illustrates the deformation of coils when a limited number of coils are pressed by a mold. As shown in Figure 17, one method is to form a chamfer on only one side of the coil adjacent to the mold end. In this case, the force imbalance on the mold is smaller compared to the method shown in Figure 16, but the coil adjacent to the mold end moves. If the coil shifts circumferentially, in the worst case, it will short-circuit with the adjacent coil. Even if a short circuit does not occur, the necessary insulation distance cannot be secured, and the reliability of the insulation cannot be ensured.

[0036] Figure 18 illustrates the deformation of a coil when the entire coil is pressed simultaneously by a die. As shown in Figure 18, when the entire coil is pressed simultaneously by a die, the circumferential ends of the die are eliminated, which has the effect of suppressing the deformation of the coil 26. By suppressing the deformation of the coil 26 and reducing variations in the circumferential gap of the coil, the reliability of the insulation is improved. In addition, when the entire coil 26 is pressed simultaneously, the force acting on the die is reduced because the ends are eliminated, which also has the effect of extending the life of the die. Furthermore, pressing the entire coil 26 simultaneously can also prevent the coil from warping.

[0037] Next, in the insulating coating formation step S3, an insulating coating is formed on the surface of the coil. Methods such as electrodeposition coating and powder coating can be used to form the insulating coating.

[0038] The coil formation process S1, the chamfering process S2, and the insulating film formation process S3 are performed on two metal plates to manufacture the first layer coil and the second layer coil.

[0039] Next, in the coil joining process S4, the insulating coating formed on the surface of the outer diameter joining portion 27 and the inner diameter joining portion 28 is first peeled off. Then, the first layer of coil and the second layer of coil are superimposed and joined at the positions of the outer diameter joining portion 27 and the inner diameter joining portion 28. As for the method of joining the coils, methods such as welding, crimping, and soldering can be used. Furthermore, in the coil joining process S4, the power supply terminal 4 and the busbar 29 are joined to the coil 26, respectively.

[0040] Finally, in the coil cutting process S5, the outer diameter cutting portion 35 and the inner diameter cutting portion 37 are cut to separate the outer diameter connecting portion 36 and the inner diameter connecting portion 38 from the coil 26. The armature of this embodiment is manufactured through these processes.

[0041] In this embodiment, the chamfering process S2 describes a method of forming a chamfer by pressing the corners of the coil using a mold. However, the chamfer may also be formed by cutting the corners of the coil using an abrasive. Methods using abrasives include sandblasting, shot blasting, and barrel polishing. Using an abrasive allows for the formation of a chamfer without the use of a mold, thus reducing costs. Furthermore, the abrasive increases the surface roughness of the coil, improving the adhesion between the coil and the insulating coating, which suppresses the occurrence of pinholes and peeling in the insulating coating. As a result, the reliability of the coil's insulation is improved.

[0042] Furthermore, in the armature manufacturing method of this embodiment, since the insulating coating is formed after chamfering the corners of the coil, the thickness of the insulating coating at the corners of the coil can be made more uniform compared to coils without chamfering. If the insulating coating is formed without forming chamfering, the thickness of the insulating coating will be uneven due to electric field concentration at the corners. Therefore, in order to ensure the insulating properties of the insulating coating, it is necessary to increase the average thickness of the insulating coating as a whole. As a result, in armatures without chamfering, the packing factor of the coil decreases. In the armature manufacturing method of this embodiment, since the insulating coating is formed after chamfering the corners of the coil, it is not necessary to increase the average thickness of the insulating coating more than necessary, thus also having the effect of improving the packing factor of the coil.

[0043] In this embodiment, the method for manufacturing the armature is shown in which the coil 26 is processed while connected to the outer diameter connecting portion 36 and the inner diameter connecting portion 38. However, the coil 26 may also be processed while separated. Even in this case, by providing the chamfering portion forming step S2 before the insulating coating forming step S3, the thickness of the insulating coating at the corners of the coil can be made uniform.

[0044] In this embodiment, the armature of an axial gap type rotating electric machine was described, but the same effect as in this embodiment can be obtained in the armature of a linear motor in which disc-shaped coils 26 are arranged in a straight line, as shown in Figure 19, by forming chamfered portions on the corners of the coils. Furthermore, the same effect as in this embodiment can be obtained in a radial gap type rotating electric machine in which the armature is constructed by processing linearly arranged coils into a cylindrical shape, by forming chamfered portions on the corners of the coils.

[0045] Furthermore, although this embodiment describes an armature composed of two layers of coils as an example, the same effect can be obtained in an armature composed of three or more layers of coils by forming chamfered edges on the corners of the coils. By making the coils multilayered, the axial thickness of the coils can be reduced, thereby reducing the skin effect and eddy current losses. In addition, although this embodiment describes an armature with Y-connected coils as an example, coils with parallel connections, delta connections, etc., may also be used.

[0046] Embodiment 2. The armature according to Embodiment 2 has two layers of coils arranged offset in the circumferential direction compared to the armature of Embodiment 1. The rotating electric machine having the armature of this embodiment is the same as the rotating electric machine shown in Figure 1 of Embodiment 1.

[0047] Figure 20 is an enlarged cross-sectional view of the armature coil according to this embodiment. Figure 20 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 20 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 20, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. These coils 41 to 44 are covered with an insulating coating 45.

[0048] As shown in Fig. 20, in the armature of the present embodiment, chamfered portions 40 are formed at the corners of the coils in the radial cross-section. Also, in the armature of the present embodiment, the second-layer coil is arranged with a circumferential shift relative to the first-layer coil. Fig. 21 is an enlarged view of the portion indicated by the broken-line circle in Fig. 20. As shown in Fig. 21, in the armature of the present embodiment, the corners of the axially adjacent coils do not face each other, and the corner of one coil faces the flat portion of the axially adjacent coil. Therefore, in the armature of the present embodiment, the insulation property is improved compared to the armature of Embodiment 1 in which the corners of the axially adjacent coils face each other.

[0049] Here, as shown in Fig. 21, let the circumferential shift amount between the axially adjacent coils be X, the distance between the circumferentially adjacent coils be Y, and the distance from the circumferential end of the coil to the start position of the chamfered portion 40 be R. In the armature of the present embodiment, it is preferable that X > R. By satisfying this condition, the corners of the axially adjacent coils do not face each other, and the corner of one coil always faces the flat portion of the axially adjacent coil.

[0050] Also, in the armature of the present embodiment, it is preferable that X < Y + 2R. If X ≥ Y + 2R, the distance between the coils 42 and 43 with different phases becomes small, and there is a possibility that the insulation property deteriorates. By satisfying X < Y + 2R, the distance between the coils with different phases can be increased, so that the deterioration of the insulation property can be prevented.

[0051] Embodiment 3. In the armature of Embodiment 1, the two layers of coils laminated in the axial direction ensure the insulation between the coils with an insulating film formed on the surface of the coils. In the armature according to Embodiment 3, an insulating sheet is arranged between the two layers of coils laminated in the axial direction to ensure the insulation between the coils. Note that the rotating electric machine having the armature of the present embodiment is the same as the rotating electric machine shown in Fig. 1 of Embodiment 1.

[0052] Figure 22 is an enlarged cross-sectional view of the armature coil according to this embodiment. Figure 22 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 22 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 22, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. Chamfered portions 40 are formed at the corners of these coils 41 to 44. Furthermore, no insulating coating is formed on the surfaces of these coils 41 to 44, and insulating sheets 46 are placed between axially adjacent coils.

[0053] The armature of this embodiment is manufactured in the armature manufacturing method shown in Figure 12 of Embodiment 1, except for the insulating film formation step S3, by placing an insulating sheet in the parts other than the outer diameter joint and the inner diameter joint when the first layer coil and the second layer coil are superimposed in the coil joining step S4.

[0054] Figure 23 is an enlarged cross-sectional view of the armature coil of a comparative example according to this embodiment. Figure 23 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 23 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 23, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. No chamfers are formed on the corners of these coils 41 to 44. In addition, no insulating coating is formed on the surfaces of these coils 41 to 44, and an insulating sheet 46 is placed between axially adjacent coils.

[0055] Figure 24 is an enlarged view of the portion indicated by the dashed circle in Figure 22, and Figure 25 is an enlarged view of the portion indicated by the dashed circle in Figure 23. In Figures 24 and 25, the creepage distance between adjacent coils in the circumferential direction is indicated by the arrows d at both ends. The length of the arrows d at both ends is longer for the armature of this embodiment shown in Figure 24 than for the armature of the comparative example shown in Figure 25. Therefore, the insulation between adjacent coils in the circumferential direction is higher for the armature of this embodiment, which has a chamfered portion 40, than for the armature of the comparative example.

[0056] Figure 26 is an enlarged cross-sectional view of the armature coil of another comparative example according to this embodiment. The armature of the other comparative example shown in Figure 26 employs punching in the coil formation process and does not form a chamfered portion.

[0057] As shown in Figure 26, when punching is used in the coil formation process, protrusions 47 called burrs are generated at the corners of the coil. In the armature of this comparative example, where chamfered edges are not formed, these protrusions 47 may damage the insulating sheet 46, potentially reducing the insulating properties of the insulating sheet 46. Even if the protrusions 47 do not damage the insulating sheet 46, a gap 48 may form between the insulating sheet 46 and the protrusions 47. This gap 48 reduces the coil's packing factor and increases the thermal resistance from the coil to the insulating sheet. As a result, a rotating electric machine equipped with the armature of this comparative example will experience a decrease in output.

[0058] In contrast, in the armature of this embodiment, as shown in Figure 24, the coil and the insulating sheet are in close contact, which improves the coil's fill factor and reduces the thermal resistance from the coil to the insulating sheet. As a result, a rotating electric machine equipped with the armature of this embodiment can achieve higher output.

[0059] Embodiment 4. In the armature of Embodiment 3, an insulating sheet is placed between two layers of coils stacked in the axial direction. The armature of Embodiment 4 is the armature of Embodiment 3, in which adjacent coils in the circumferential direction are fixed with a fixing member. The rotating electric machine having the armature of this embodiment is the same as the rotating electric machine shown in Figure 1 of Embodiment 1.

[0060] Figure 27 is an enlarged cross-sectional view of the armature coil according to this embodiment. Figure 27 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 27 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 27, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. Chamfered portions 40 are formed at the corners of these coils 41 to 44. Furthermore, no insulating coating is formed on the surfaces of these coils 41 to 44, and insulating sheets 46 are placed between axially adjacent coils. In addition, fixing members 49 are placed between circumferentially adjacent coils 41 and 43, and between circumferentially adjacent coils 42 and 44. The fixing members 49 fix the circumferentially adjacent coils together. As the fixing members 49, for example, a thermosetting resin or a room-temperature curing adhesive can be used.

[0061] The armature configured in this way has improved rigidity, thus having the effect of suppressing vibration and noise. Figure 28 is an enlarged cross-sectional view of a coil of another armature according to this embodiment. Figure 28 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. As shown in Figure 28, in the armature of this embodiment, it is preferable that the surface of the fixing member 49 is curved.

[0062] Figure 29 is an enlarged view of the portion indicated by the dashed circle in Figure 27, and Figure 30 is an enlarged view of the portion indicated by the dashed circle in Figure 28. In Figures 29 and 30, the creepage distance between adjacent coils in the circumferential direction is indicated by the arrows d at both ends. The length of the arrows d at both ends is longer for the armature shown in Figure 30 than for the armature shown in Figure 29. Therefore, the insulation between adjacent coils in the circumferential direction is higher for the armature shown in Figure 30 than for the armature shown in Figure 29. For this reason, in the armature of this embodiment, it is preferable that the surface of the fixing member 49 is curved.

[0063] Embodiment 5. The armature of Embodiment 5 is the same as that of Embodiment 1, but with a magnetic member placed between circumferentially adjacent coils. The rotating electric machine having the armature of this embodiment is the same as the rotating electric machine shown in Figure 1 of Embodiment 1.

[0064] Figure 31 is an enlarged cross-sectional view of the armature coil according to this embodiment. Figure 31 is a cross-sectional view in a direction perpendicular to the radial direction, with the vertical direction of the paper being the axial direction and the horizontal direction being the circumferential direction. Figure 31 shows an enlarged view of a slot portion where coils of different phases are adjacent in the circumferential direction. In Figure 31, for example, coils 41 and 42 stacked in two layers in the axial direction are U-phase coils, and coils 43 and 44 stacked in two layers in the axial direction are W-phase coils. Chamfered portions 40 are formed at the corners of these coils 41 to 44. Furthermore, these coils 41 to 44 are covered with an insulating coating 45. In addition, in the armature according to this embodiment, a magnetic member 50 is inserted between circumferentially adjacent coils. Figure 32 is an enlarged view of the portion indicated by the dashed circle in Figure 31. As the magnetic member 50, for example, a material made by solidifying magnetic metal particles such as iron-based or iron-silicon-based materials with resin can be used.

[0065] The magnetic member 50 only needs to be inserted into at least a portion of the coils that are adjacent in the circumferential direction. For example, in the coil 26 in Figure 5 of Embodiment 1, the magnetic member may be inserted only between the slot portions 26a. Since the magnetic member is normally conductive, it is necessary to ensure insulation between the coil and the magnetic member, but even in this case, the chamfered portion of the coil has the effect of improving insulation. Furthermore, in the portion where the magnetic material is not inserted, the coils are adjacent in the circumferential direction without the magnetic material in between, so the same effect as in Embodiment 1 can be expected.

[0066] In an armature configured in this way, the magnetic resistance of the armature as a magnetic circuit is reduced, so a larger torque can be obtained with the same current value. As a result, a rotating electric machine equipped with the armature of this embodiment can achieve higher output.

[0067] The various aspects of this disclosure are summarized below as an appendix. (Note 1) An armature positioned opposite a movable element with a gap in between, When the direction facing the movable element is defined as the first direction, the direction perpendicular to the first direction in which the movable element moves relative to the armature is defined as the second direction, and the direction perpendicular to both the first and second directions is defined as the third direction, the coil has a width that changes toward the third direction when viewed from the first direction, The armature is characterized in that the coils are stacked in two or more layers with an insulator in the first direction, at least two of the coils are arranged in the second direction, and chamfered portions are formed at the corners of the coils in a cross-section in a direction perpendicular to the third direction. (Note 2) The armature according to Appendix 1, characterized in that the coils adjacent to each other in the stacking direction are offset from each other in a direction perpendicular to the stacking direction. (Note 3) The armature according to Appendix 2, characterized in that, if X is the amount of displacement in a direction perpendicular to the stacking direction of coils adjacent to each other in the stacking direction, and R is the distance between the end of the coil and the starting position of the chamfered portion, then X > R. (Appendix 4) For the armature according to Appendix 3, if the distance between the adjacent coils in a direction orthogonal to the lamination direction is Y, then X < Y + 2R. (Appendix 5) The armature according to any one of Appendices 1 to 4, wherein an insulating film is formed on the surface of the coil. (Appendix 6) The armature according to any one of Appendices 1 to 4, wherein an insulating sheet is disposed between the coils adjacent to each other in the lamination direction. (Appendix 7) The armature according to Appendix 6, wherein a fixing member for fixing the coils to each other is disposed between the coils adjacent to each other in a direction orthogonal to the lamination direction. (Appendix 8) The armature according to any one of Appendices 1 to 4, wherein a magnetic member is disposed between the coils adjacent to each other in a direction orthogonal to the lamination direction. (Appendix 9) A rotating electric machine, comprising: an armature according to any one of Appendices 1 to 8; and a rotor coaxially opposed to the armature via a gap. (Appendix 10) A linear motor, comprising: an armature according to any one of Appendices 1 to 8; and a rotor linearly opposed to the armature via a gap. (Appendix 11) A coil forming step of forming two or more coils by passing a slit through a metal plate; A chamfering step of forming chamfers at the corners of the two or more coils formed in the coil forming step; An insulating film forming step of forming an insulating film on the surfaces of the two or more coils on which the chamfers are formed in the chamfering step; A method for manufacturing an armature, comprising: a coil joining step of overlapping and joining the two or more coils on which the insulating film is formed in the insulating film forming step. (Appendix 12) The method for manufacturing an armature according to Appendix 11, characterized in that the chamfering portion forming step involves pressing the corner of the coil using a mold to form the chamfered portion. (Note 13) The method for manufacturing an armature according to Appendix 11, characterized in that the chamfering portion forming step involves cutting the corners of the coil using an abrasive to form the chamfered portion.

[0068] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable to the embodiments individually or in various combinations. Accordingly, countless variations not illustrated are conceivable within the scope of the art disclosed in this specification. These include, for example, modifying, adding or omitting at least one component, or even extracting at least one component and combining it with components of other embodiments. [Explanation of Symbols]

[0069] 1 Rotating electric machine, 2 Stator, 3 Rotor, 4 Power supply terminal, 21 Armature, 22 Housing, 23 Bearing, 24 Bracket, 25 Slit, 26 Coil, 26a Slot section, 26b Outer diameter turn section, 26c Inner diameter turn section, 27 Outer diameter joint section, 28 Inner diameter joint section, 29 Busbar, 30 Three-phase AC power supply, 31 Rotating shaft, 32 Rotor core, 33 Magnet, 34 Metal plate, 35 Outer diameter cut section, 36 Outer diameter connecting section, 37 Inner diameter cut section, 38 Inner diameter connecting section, 39 Positioning hole, 40 Chamfered section, 41, 42, 43, 44 Coil, 45 Insulating coating, 46 Insulating sheet, 47 Protrusion, 48 Gap, 49 Fixing member, 50 Magnetic member, 51 Lower mold, 52 Upper mold.

Claims

1. A coil forming process involves forming two or more coils by passing slits through a metal plate, A chamfering portion forming step in which chamfered portions are formed on the corners of two or more coils formed in the coil forming step, An insulating coating forming step is to form an insulating coating on the surfaces of two or more coils on which the chamfered portion has been formed in the chamfered portion forming step, A method for manufacturing an armature, characterized by comprising: a coil joining step of overlapping and joining two or more coils on which the insulating coating has been formed in the insulating coating forming step.

2. The method for manufacturing an armature according to claim 1, characterized in that the chamfering portion forming step involves pressing the corner of the coil using a mold to form the chamfered portion.

3. The method for manufacturing an armature according to claim 1, characterized in that the chamfering portion forming step involves cutting the corners of the coil using an abrasive to form the chamfered portion.

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