Rotary electric machine and stator of rotary electric machine

Abstract

A stator core (1) has: a yoke part (11) disposed in the circumferential direction; and a plurality of teeth (12) protruding radially inward of the yoke part (11). A coil (7) is wound around the teeth (12). An upper winding frame (2) is disposed at the upper part in the axial direction of the stator core (1), and a first undercut part (112A) is provided by shaving the inner peripheral surface of the yoke part (11), which is a part that does not affect the magnetic characteristics. The upper winding frame (2) is provided with a second undercut part (2000) having a shape that is entirely recessed in a linear state on the surface on the yoke part (11) side, and at least a part of the coil (7) is disposed in the first undercut part (112A) and the second undercut part (2000).

Description

Rotating electric machine and stator for rotating electric machine

[0001] The present disclosure relates to a rotating electric machine and a stator for the rotating electric machine.

[0002] In rotating electrical machines such as electric motors and generators, it is important to improve efficiency. It is generally known that improving the space factor of conductors is an effective way to improve efficiency. For example, there are rotating electrical machines that use a film material instead of a resin molded material in an insulating bobbin provided on the teeth of a stator core to improve the space factor.

[0003] In order to improve the space factor, there is a stator core in which the roots of the teeth that do not affect the magnetic properties are recessed and the windings are arranged therein (see Patent Document 1).In addition, there is a stator core in which the inner diameter side of the back yoke is formed in an arc so as not to affect the magnetic properties, thereby expanding the winding area (see Patent Document 2).

[0004] JP 2013-208021 JP 11-299132

[0005] To reduce the cost of rotating electrical machines, aluminum wire is used for the coils. However, to achieve the same efficiency as copper wire, the number of turns must be increased to improve the space factor. Generally, when winding a coil on a stator core, the coil must be arranged in the desired position to improve the space factor. If winding irregularities occur in the lower layers, all subsequent windings will be wound in different positions from the target, resulting in a deterioration in the space factor.

[0006] The stator described in Patent Document 1 has a recess large enough for one coil, but because the inner diameter side shape of the back yoke is perpendicular to the tooth side, the winding area cannot be expanded beyond the size of one coil. In other words, the space factor cannot be significantly improved. Patent Document 1 also describes an example of a stator with cutout grooves large enough to accommodate several coils, but because the coils are arranged along an arc shape, the winding position of the first layer cannot be accurately positioned. Furthermore, when winding the coil on the back yoke side of the second layer, the coil coming out of the winding nozzle interferes with the stator core, making it impossible to accurately position the winding position.

[0007] Furthermore, in the stator described in Patent Document 2, the inner diameter side of the back yoke is configured as an arc shape, which allows for an expansion of the winding area and an improvement in the space factor. However, it is difficult to perfectly align the coil along the arc shape, and winding irregularities occur. When winding irregularities occur, the coils may slip out of the winding or become thicker, causing contact between the coil and the stator core, or contact between coils wound around the teeth of adjacent stators, which can cause short circuits and poor insulation. In other words, it is not possible to improve the space factor.

[0008] The present disclosure discloses a technique for solving the above-mentioned problems, and its purpose is to provide a stator in which the coil wires are perfectly aligned when the coils are formed and the space factor of the coil wires is improved, and a rotating electric machine using this stator.

[0009] The presently disclosed rotating electric machine stator includes a yoke portion arranged in the circumferential direction, a stator core having a plurality of teeth that protrude radially inward from the yoke portion and are formed at predetermined intervals in the circumferential direction, a coil wound around the teeth, and a top winding frame arranged axially above the stator core, wherein a first undercut portion is formed by cutting the inner peripheral surface of the yoke portion, which is a portion that does not affect magnetic characteristics, and the top winding frame is provided with a second undercut portion that is a linearly recessed overall shape on the surface facing the yoke portion, and at least a portion of the wound coil is disposed in the first undercut portion and the second undercut portion. The presently disclosed rotating electric machine also includes the stator of the rotating electric machine and a rotor arranged opposite the stator with a gap between them.

[0010] According to the rotating electric machine and the stator for the rotating electric machine of the present disclosure, the coils can be wound in an aligned manner and the number of turns of the coils can be increased.

[0011] 1 is a cross-sectional view showing a rotating electric machine having a stator according to embodiment 1. FIG. 2 is a plan cross-sectional view showing the cross section along line B-B in FIG. 1. FIG. 3 is a perspective view showing a stator of a rotating electric machine according to embodiment 1. FIG. 4 is a plan view showing teeth of one stator core according to embodiment 1, as viewed from above. FIG. 5 is a perspective view showing the configuration of one core plate that constitutes the stator core in the stator according to embodiment 1. FIG. 6 is a perspective view showing the configuration of a stator core formed by stacking core plates according to embodiment 1. FIG. 7 is a plan view showing one core plate. FIG. 8 is a cross-sectional view showing a connecting portion of the stator according to embodiment 1. FIG. 9 is a perspective view showing the configuration of an upper winding frame of an insulating member used in the stator according to embodiment 1. FIG. 10 is a perspective view showing the configuration of a lower winding frame of an insulating member used in the stator according to embodiment 1. FIG. 11 is a perspective view showing a state in which the upper winding frame and lower winding frame are attached to the core section according to embodiment 1. FIG. 12 is a plan view of the core section as viewed in the direction indicated by arrow D. FIG. 13 is a side view of the core section as viewed in the direction indicated by arrow E. FIG. 14 is a front view of the core section as viewed in the direction indicated by arrow F. FIG. 15 is a plan view showing a method for manufacturing the stator according to embodiment 1. FIG. 16 is a plan view showing a method for manufacturing the stator according to embodiment 1. Fig. 18A is an enlarged plan view showing a manufacturing method of a stator according to embodiment 1, and Fig. 18B is an enlarged plan view showing a manufacturing method of a stator according to embodiment 1. A flowchart showing a coil forming process according to embodiment 1. A flowchart showing a manufacturing process of a rotary electric machine according to embodiment 1. A perspective view showing a stator core of a stator of a rotary electric machine according to embodiment 2. An enlarged plan view showing a thin-walled connecting portion of the stator core according to embodiment 2. A perspective view showing a stator core of a stator of a rotary electric machine according to embodiment 3. A plan view showing a core according to embodiment 4. A plan view showing a manufacturing method of a stator according to embodiment 4.

[0012] Embodiment 1. This embodiment relates to a stator for a rotating electric machine, and to a stator structure for winding coils at high density. Fig. 1 is a cross-sectional view showing a rotating electric machine having a stator according to this embodiment. A rotating electric machine 1000 includes a stator 100 according to this embodiment, a rotor 102 provided on the inner periphery of the stator 100 via a predetermined air gap G, and a housing 101 that fixes the rotor 102 and the stator 100. The rotor 102 is rotatably held by fitting a shaft 1021 into an inner ring of a bearing 1011 provided in the housing 101.

[0013] 2 is a plan cross-sectional view showing the cross section along line B-B in FIG. 1. Permanent magnets 1022 are embedded in a V-shape in rotor core 1023 fixed to the outer periphery of shaft 1021. They may also be arranged in other shapes, such as linear. Furthermore, permanent magnets 1022 do not have to be embedded, but may be attached to the outer surface of rotor core 1023 and arranged to face stator 100.

[0014] Fig. 3 is a perspective view showing stator 100 of rotating electric machine 1000 according to embodiment 1. Fig. 4 is a plan view of the teeth of one stator core 1 as viewed from above, and is a plan view showing an arrangement of coils 7. In Figs. 3 and 4, stator 100 includes stator core 1, coil 7, yoke portion 11, upper and lower bobbins 2 and 3, and insulating film 8, which serve as insulating portions arranged to insulate stator core 1 from coil 7. Coil 7 is formed by winding insulatingly coated conductor wire 70 around teeth 12.

[0015] In the following description, the various directions in the stator 100 of the rotating electric machine 1000 are indicated as the circumferential direction Z, the axial direction Y, the radial direction X, the outer side X1 in the radial direction X, and the inner side X2 in the radial direction X, respectively, based on the state in which the yoke portions 11 of the stator 100 are arranged in an annular arrangement, as shown in Figure 3. Therefore, even if a plurality of yoke portions 11 of the stator core 1 of the stator 100 are connected and arranged in a linear shape, or even if the yoke portions 11 are arranged in a reversed cambered shape in which the protruding directions of the teeth 12 are reversed, the various directions will be illustrated and described in each drawing based on the directions in the state in which the yoke portions 11 of the stator 100 are arranged in an annular arrangement. Note that the directions will also be illustrated and described based on the same standards in other embodiments.

[0016] The stator core 1 of the stator 100 is formed by laminating two types of core plates 6, a first core plate 601 and a second core plate 602, which are bilaterally symmetrical and formed by punching thin magnetic steel plates as shown in Fig. 5, alternately in the axial direction Y as shown in Fig. 3. That is, as shown in Fig. 5, the first core plate 601 is made of a magnetic plate such as an electromagnetic steel plate, and has a convex end 601A (hereinafter referred to as the first end 601A) at one end in a first circumferential direction Z1 and a concave end 601B (hereinafter referred to as the second end 601B) at one end in a second circumferential direction Z2 opposite to the first circumferential direction. The stator core 1 has a yoke portion 11 having connecting portions 601 e and 601 f at the first end 601A, and teeth 12 protruding radially inward from the yoke portion 11. The first core plate 601 has a plurality of core pieces arranged by fitting together first end portion 601A and second end portion 601B that are adjacent in the circumferential direction.

[0017] 5 , the second core plate 602 is made of a magnetic plate such as an electromagnetic steel plate, and has a convex end 602A (hereinafter referred to as the first end 602A) at one end in the second circumferential direction Z2 and a concave end 602B (hereinafter referred to as the second end 602B) at one end in the first circumferential direction Z1, and also has a yoke portion 11 having connecting portions 602e, 602f at the first end 602A, and teeth 12 protruding radially inward from the yoke portion 11. The second core plate 602 is made up of a plurality of core pieces arranged by fitting the first ends 602A and second ends 602B of circumferentially adjacent core pieces together, and is arranged in the opposite circumferential direction to the first core plate 601. The two types of core plates 6, the first core plate 601 and the second core plate 602, are formed by stacking multiple sheets so that the convex end 601A and the concave end 602B overlap in the axial direction Y as shown in Figure 5.

[0018] The formed stator core 1 is shown in Fig. 6. The stator core 1 has a yoke portion 11 arranged in an annular shape in the circumferential direction Z (however, as previously shown, each drawing shows only one tooth cut out), and a plurality of teeth 12 that protrude inward X2 in the radial direction X from the yoke portion 11 and are formed at predetermined intervals in the circumferential direction Z.

[0019] Next, one core plate is shown in FIGS. 7 and 8 . The stator core 1 is formed by stacking these core plates 6, and each part of the core portion 60 will be described with reference to FIG. 7 . The surface of the yoke portion 11 extending along the axial direction Y on the outer side X1 in the radial direction X is called the outer peripheral surface 113. The outer peripheral surface 113 of the yoke portion 11 is formed with recesses 114 extending along the axial direction Y. The recesses 114 are used for positioning when the stator core 1 is attached to a winding machine that forms the coils 7. Furthermore, the teeth 12 have shoe portions 13 protruding in the circumferential direction Z at the tips of the inner sides X2 in the radial direction X. FIG. 8 also shows the shape of the core plate 6, but the shape of the yoke portion is different from that shown in FIG. 7 . As shown in FIG. 8 , the inner peripheral surface 112 of the yoke portion 11, which does not affect the magnetic characteristics of the rotating electric machine, is cut away to form an additional inner peripheral surface 112A, and an undercut portion (first undercut portion) is created to enlarge the slot 14, which is the area where the coil is arranged. The inner peripheral surface of the yoke portion 11 has an undercut portion 112A formed by a recess punched in an arc shape, similar to the outer peripheral surface of the yoke portion 11.

[0020] The surfaces of the teeth 12 at both ends in the circumferential direction Z that extend in the axial direction Y are referred to as first side surfaces 121, and the surfaces of the teeth 12 at the tips of the inner sides X2 in the radial direction X that extend in the axial direction Y are referred to as tip surfaces 122. The surfaces of the shoe portions 13 at the outer sides X1 in the radial direction X that extend in the axial direction Y are referred to as second side surfaces 131. The first side surfaces 121, second side surfaces 131, and tip surfaces 122 are the side surfaces of the teeth 12 that extend in the axial direction Y. The areas surrounded by the inner circumferential surfaces 112, the first side surfaces 121, and the second side surfaces 131 are the slots 14 around which the conductor wire 70 is wound to form the coils 7.

[0021] 9 , the first core plate 601 has a convex portion 1111A on one surface of the end of the yoke portion 11 in the first circumferential direction Z1 of each core piece, and a concave portion 1112A on the other surface. The second core plate 602 has a concave portion 1112B on one surface of the end of the yoke portion 11 in the second circumferential direction Z2, symmetrically to the first core plate 601 with respect to the circumferential direction Z, and a convex portion 1111B on the other surface. The yoke portions 11 of the stator core 1 and the adjacent stator core 1 are connected to each other by fitting the convex portion and the concave portion together to form a connecting portion 111. Here, the stator core 1 is composed of nine core portions 60 connected by the connecting portions 111. The first core plate 601 and the second core plate 602 are stacked by being crimped in the Y direction at crimping portions 1500. The yoke portion 11 of the stator core 1 can be freely bent at the connecting portion 111, which allows it to be made straight, and further allows it to be deformed into a reverse-curved shape that reverses the direction in which the teeth 12 protrude in the radial direction X.

[0022] The method of connecting the core portions 60 to the yoke portion 11 is not limited to the above-described structure, and other structures may be used as long as they allow for deformable connection. As shown in Fig. 6 , the core portions 60 arranged in the circumferential direction Z are, from the winding start side of the conductor wire 70, a first core portion 61, a second core portion 62, a third core portion 63, a fourth core portion 64, a fifth core portion 65, a sixth core portion 66, a seventh core portion 67, an eighth core portion 68, and a ninth core portion 69. Here, the power supply is constituted by three-phase AC having U, V, and W phases, and a wiring structure is adopted in which different phases are arranged for each of the core portions 60 adjacent in the circumferential direction Z. The first core portion 61 is the U phase (U1), the second core portion 62 is the V phase (V1), the third core portion 63 is the W phase (W1), the fourth core portion 64 is the U phase (U2), the fifth core portion 65 is the V phase (V2), the sixth core portion 66 is the W phase (W2), the seventh core portion 67 is the U phase (U3), the eighth core portion 68 is the V phase (V3), and the ninth core portion 69 is the W phase (W3).

[0023] When there is no need to explain the order, the cores will be collectively referred to as core portion 60. As shown in Figures 3 and 4, each of core portions 61 to 69 is similarly provided with a coil 7, an upper winding frame 2 and a lower winding frame 3 as insulating portions, and an insulating film 8. However, the same reference numerals will be used for each of core portions 61 to 69 regardless of whether or not the coil 7, the upper winding frame 2 and the lower winding frame 3 as insulating portions, and the insulating film 8 are provided in the core portion 61 to 69.

[0024] Next, the insulating portion of the upper and lower winding frames 2, 3, and insulating film 8 will be described for a stator having one tooth shown in FIG. 4 with reference to FIGS. 10 to 15. As shown in FIG. 10, the upper and lower winding frames 2 are formed with a first protrusion 21 and a first leg 22. As shown in FIG. 11, the lower winding frame 3 is formed with a second protrusion 31 and a second leg 32. FIG. 12 shows the upper and lower winding frames 2, 3, and insulating film 8 placed on a core 60, with the first protrusion 21 protruding from one side of the core 60 in the axial direction Y. The second protrusion 31 protruding from the other side of the core 60 in the axial direction Y. The insulating portion includes a film portion between the first and second protrusions 21 and 31, which is formed with insulating film 8 covering the side surfaces of the tooth 12.

[0025] Fig. 13 is a plan view of the core portion 60 as viewed from direction D in Fig. 12, Fig. 14 is a side view as viewed from direction E in Fig. 12, and Fig. 15 is a front view as viewed from direction F in Fig. 12. As shown in Fig. 13, an introduction groove 214 is formed in the height direction of the first protrusion 21 of the upper winding frame 2, i.e., at the apex in the axial direction Y, so as to communicate from the outer side X1 in the radial direction X of the first protrusion 21 to the inner side X2 in the radial direction X. Therefore, the introduction groove 214 is formed continuously from the outer peripheral surface 201 of the first protrusion 21 to the inner peripheral surface 202 on the inner side X2 in the radial direction X.

[0026] 13 , the insulating member has an undercut portion 2000 (second undercut portion) recessed from one end in the circumferential direction Z toward the radially outward direction X1 from a plane perpendicular to the circumferential side surface (first side surface 121) of the tooth 12. The undercut portion 2000 is provided on the surface of the upper bobbin 2 facing the yoke portion 11. The insulating member has a shape in which the entire region on the yoke portion 11 side is expanded linearly toward the yoke portion 11 by the radius of the conductor wire 70. This undercut portion 2000 has a generally recessed linear shape, and the coils 7 are aligned and arranged in the slots 14, which form the expanded region.

[0027] As shown in FIGS. 10 to 12 , the first leg 22 of the upper winding frame 2 and the second leg 32 of the lower winding frame 3 are configured to cover the inner circumferential surface 112, the first side surface 121, and the second side surface 131 of the core portion 60. Also, as shown in FIG. 7 , the stator core 1 has a yoke central groove 115 formed in the axial direction Y in the teeth 12. The yoke central groove 115 may be either a through groove or a non-through groove machined from the top or bottom to the required depth. The upper winding frame 2 and the lower winding frame 3 are installed by fitting the protrusions 215 and 315 into the yoke central groove 115 of the stator core 1. The first leg 22 of the upper winding frame 2 and the second leg 32 of the lower winding frame 3 are provided with claws 211, 212, 213, 311, 312, and 313 for securing the insulating film 8 that insulates the coil 7 from the stator core 1. That is, the first leg portion 22 and the second leg portion 32 are fitted into the slot 14 to insulate the coil 7 from the stator core 1 and also to fix the insulating film 8 .

[0028] The insulating film 8 is formed of a thin insulating film material, e.g., a film material with a thickness of 0.125 mm. The film material is creased. As shown in FIG. 12 , the creases define the insulating film 8 as follows: a first side surface 81 covering the inner circumferential surface 112 (see FIG. 7 ), which is the side surface along the axial direction Y on the inner side X2 of the radial direction X of the yoke portion 11; a second side surface 82 covering the first side surface 121 and the second side surface 131, which are the side surfaces along the axial direction Y of the teeth 12; and a third side surface 83 covering the tip surface 122, which is the side surface along the axial direction Y of the teeth 12. When attached to the stator core 1, the insulating film 8 is in continuous contact with the first protrusion 21 and the second protrusion 31 in the axial direction Y. The insulating film 8 is continuously formed to correspond to all of the core portions 61 to 69 of the stator core 1.

[0029] Specifically, the continuous contact of the insulating film 8 in the axial direction Y with the first protruding portion 21 of the upper winding frame 2 and the second protruding portion 31 of the lower winding frame 3 is achieved by forming the insulating film 8 at both ends in the axial direction Y to be longer than the length of the stator core 1 in the axial direction Y. The portions of the insulating film 8 that are longer than both ends in the axial direction Y of the stator core 1 are fixed by the claw portions 211, 212, 213 of the upper winding frame 2 and the claw portions 311, 312, 313 of the lower winding frame 3, respectively.

[0030] 13 , the top surface 21A of the first protrusion 21 of the upper bobbin 2, which connects to the introduction groove 214 of the first protrusion 21, is positioned radially outward from the inner circumferential surface 2111 by the radius of the wire conductor 70. The inner circumferential surface 2111 is provided with a guide 21B (first guide) whose radially inner end face is positioned radially inward from the inner circumferential surface 2111 by the radius of the wire conductor 70. The first turn of the wire conductor 70 introduced through the introduction groove 214 passes through the top surface 21A and is positioned on the radially inner end face of the guide 21B. In this embodiment, an introduction groove 214 for the coil 7 is provided on the axial upper surface of the first protrusion 21 provided on the upper winding frame 2, and a portion of the first turn of the coil 7 introduced from the introduction groove 214 passes through the first undercut portion 112A and the second undercut portion 2000, with the entire remaining first turn of the coil 7 existing in an area outside the first undercut portion 112A and the second undercut portion 2000.

[0031] Next, a manufacturing method for forming the coil 7 will be described with reference to FIG. 16 . The winding machine 400 has a hexagonal chuck mechanism 40. The chuck mechanism 40 has six chucks, 41, 42, 43, 44, 45, and 46. A winding nozzle 51 for winding the conductor wire 70 is installed in a position of the chuck mechanism 40 opposite chuck 42. Each winding nozzle 51 rotates around the rotation axis T1 to wind the conductor wire 70 around each tooth 12. First, the first core portion 61 of the stator core 1 is fixed to the chuck 41. Then, the first conductor wire 71 is introduced from the outer side X1 to the inner side X2 in the radial direction X using the introduction groove 214 of the first core portion 61.

[0032] FIG. 17 is a plan view showing the winding in progress, and FIGS. 18A and 18B are enlarged plan views showing the folded portion. A method for forming the coil 7 by rotating the winding nozzle 51 about the rotation axis T1 and winding the conductor wire 70 around each tooth 12 will be described with reference to FIGS. 17 and 18 . First, the conductor wire 70 is introduced from the outer side X1 to the inner side X2 in the radial direction X using the introduction groove 214 of the first core portion 61. The introduced conductor wire 70 is positioned from the upper bobbin 2 toward the lower bobbin 3, aligning with the second side surface 82 of the insulating film 8 covering the first side surface 121 of the stator core. At this time, the conductor wire 70 is positioned at position No. 1 on the left side surface of the tooth 12 in FIG. 17 . Next, the winding begins by rotating the winding nozzle 51 about the rotation axis T1 in a counterclockwise direction as viewed from the inner diameter side of the tooth 12. That is, the conductor wire 70 is wound from the left side surface of the tooth, via the lower bobbin, to the right side surface of the tooth in FIG. 17 .

[0033] The wire conductor 70 for the first turn is aligned along guides 311A ​​(second guides, see FIG. 11 ) extending radially inward in the X2 direction from the claws 311 of the lower bobbin 3, and the winding nozzle 51 is pitch-fed in the X2 direction by an amount equal to the diameter of the wire conductor 70, so that the wire conductor 70 is positioned at position No. 1 on the right side of the tooth. The wire conductor 70 is then pitch-fed in the X2 direction to position No. 11, and then pitch-fed in the X1 direction from position No. 12 to position No. 22.

[0034] Next, a method for winding wire around the undercut portion will be described. The undercut portion refers to the area of ​​the core portion indicated by 112A in Fig. 8, where the inner peripheral surface 112 has been cut away. The insulating member refers to the area indicated by 2000 in Fig. 13, where the surface of the inner peripheral surfaces 202, 302 of the upper and lower winding frames 2, 3 in the circumferential direction Z is defined as one end face, and the area is offset toward the back yoke by the radius of the conductor wire 70 from a plane perpendicular to the first side surface 121 of the tooth 12.

[0035] As shown in Figure 18, after winding the wire at position No. 22 on the second layer, the final turn of the second layer, indicated by No. 23 in the undercut portion, is placed from the target position (Figure 18A) to position No. 23 as shown in Figure 18B, using the previous No. 22 conductor as a guide, while aligning the wire conductor indicated by No. 23 along the wire conductor at position No. 22, as shown in Figure 18A. This is to prevent interference between the protrusions 200A at both ends of the back yoke and the wire conductor 70 emerging from the winding nozzle 51 if the wire conductor is placed directly at position No. 23 (Figure 18B), which could result in irregular winding of the coil and a deterioration in the insulation quality of the coil. Furthermore, the placed wire conductor No. 23 is positioned so that it contacts the surface of the overall linearly recessed portion of the undercut portion of the insulating member. This is necessary to align the wire conductor and suppress irregular winding. From then on, the winding of the undercut portions for the third and subsequent layers is performed in the same manner as for the conductor wire shown in No. 23, using the conductor wire 70 on the core back side as a guide, using the previous coil as a guide. Furthermore, the conductor wires arranged in the undercut portions for the third and subsequent layers are also positioned in contact with the generally linearly recessed surface of the undercut portion of the insulating material to achieve aligned winding, similar to No. 23. For example, in FIG. 4 , the last turns of the layers 2, 4, 6, etc. are positioned in contact with the generally linearly recessed surface of the undercut portion of the insulating material. In this embodiment, the last turns of the second and subsequent layers, which are wound circumferentially outward of the first layer including the first turn of the coil 7 introduced through the introduction groove 214, are in contact with the generally linearly recessed surface of the second undercut portion 2000. Furthermore, the last turns of the second and subsequent layers are in contact with the generally linearly recessed surface of the second undercut portion 2000.

[0036] After the first winding is completed, the winding nozzle 51 is moved back and forth and up and down, while the terminal wire is processed. Next, the chuck mechanism 40 rotates at 60° intervals. That is, the second core 62 moves at 60° intervals to the position of the chuck 41 where the first core 61 was fixed during the first winding. The other cores 60 also move simultaneously. In this manner, winding is performed sequentially, and winding is completed up to the ninth core 69. Because the cores 60 are ejected from the position of the chuck 46, they are not fixed at the position of the chuck 45. Then, the connections of the U-phase, V-phase, and W-phase wires, as well as the power wire and neutral point, are grouped together and processed as terminal wires. The grouping method may be a connection process such as crimping, brazing, or soldering of jumper wires.

[0037] The coil forming process, which is the wiring process for the stator 100, is shown in the flowchart of FIG. 19. In FIG. 19, first, the stator core is fed into a winding machine, and the conductor wire 70 is wound around the teeth 12 to form the coil 7 (step S191). Next, it is determined whether the conductor wire 70 has been wound around all of the teeth 12 (step S192). If any teeth 12 remain, the adjacent teeth are set to the winding position (step S193), and the process returns to step S191. Once the conductor wire 70 has been wound around all of the teeth 12, the winding machine is removed (step S194). Then, connection and wiring processes are performed (step S195), and the neutral point 700 is connected, completing the wiring process for the stator 100. Next, the stator core 1 is formed into a ring shape, and the ends of the stator core 1 are fixed together by welding or the like. The stator 100 is formed through these processes. Next, the entire rotating electric machine shown in FIG. 1 is assembled.

[0038] The manufacturing method of the rotating electric machine 1000 described above will be summarized using the flowchart in Figure 20. In Figure 20, two types of core piece groups are punched alternately from a magnetic steel sheet, and multiple groups of each type are stacked in the axial direction Y and connected at the connecting portions 111 of the yoke portions 11 to form the stator core 1 (step S201). Next, the upper and lower winding frames 2 and 3, which are formed by, for example, injection molding an insulating resin, are attached to the stator core 1. Furthermore, after the insulating film 8 is aligned with the stator core, the first leg 22 of the upper winding frame 2 and the second leg 32 of the lower winding frame 3 are inserted and fitted into the slots 14 from both ends of the stator core in the axial direction Y, fixing the insulating film 8, and the upper and lower winding frames 2 and 3 are attached to the stator core (step S202).

[0039] Next, wiring processing is performed on the stator 100. As a result, the coil 7 is formed in the core portion 60 of the stator 100, and wiring is completed (step S203), as shown in FIG. 1 . The stator core 1 of the stator 100 thus formed is deformed into an annular shape (step S204), and both ends of the connected stator core are welded to complete the stator 100 (step S205). Next, the stator 100 is fixed to the housing 101 of the rotating electrical machine 1000 (step S206), and the rotor 102 is disposed opposite the stator 100 (step S207), thereby completing the rotating electrical machine 1000.

[0040] In this embodiment, an example in which the stator 100 has nine core portions 60 has been described, but the number of core portions 60 may be any number, and a similar manufacturing method is possible by repeating the manufacturing method of the stator 100.

[0041] As described above, the stator of the rotating electric machine according to this embodiment is the stator 100 of the rotating electric machine 1000, which includes the coil 7 wound around the stator core 1 via an insulating portion. The yoke portion 11 of the stator core 1 has a shape in which the area that affects the magnetic characteristics of the inner and outer circumferential surfaces at both ends of the yoke portion 11 is left, while the area that does not affect the magnetic characteristics is punched out to expand the area where the coil is to be placed. The insulating member has a shape in which the entire area on the yoke portion 11 side is expanded toward the yoke portion 11 in a straight state by the radius of the conductor wire 70. According to this embodiment, the area that does not affect the magnetic characteristics of the stator core 1 is punched out to expand the winding area, and further, the yoke surface of the insulating member is expanded toward the yoke portion 11 while remaining straight. This makes it possible to wind the conductor wire 70 in an aligned manner and increase the number of turns, thereby improving the efficiency of the rotating electric machine.

[0042] Embodiment 2. A stator for a rotating electric machine according to embodiment 2 will be described below with reference to Figures 21 and 22. In the description of embodiment 2, differences from embodiment 1 will be mainly described, and common parts will not be described. A stator 100 according to this embodiment is similar to the stator 100 according to embodiment 1, except for the structure of the stator core 1 used in the stator. Figure 21 is a perspective view showing a thin-walled connecting core used in the stator according to embodiment 2. Figure 22 is an enlarged plan view showing the thin-walled connecting core used in the stator according to embodiment 2.

[0043] Like embodiment 1, stator 100 of the present embodiment also includes a stator core, an insulating member, and an insulating film. Furthermore, like embodiment 1, the thin-walled connecting core according to embodiment 2 also includes a yoke portion 11 arranged in an annular shape and a plurality of teeth 12 formed so as to protrude inward X2 in the radial direction X from the inner peripheral surface of yoke portion 11 at predetermined intervals in the circumferential direction Z. The thin-walled connecting core according to embodiment 2 is also formed by stacking a plurality of core plates formed by punching thin magnetic steel plates in the axial direction Y.

[0044] The present embodiment differs from the first embodiment in that the stator core 1 used in the first embodiment is formed by connecting portions 111 provided at the ends in the circumferential direction Z. In contrast, the thin-walled connecting core of the present embodiment is configured by thin-walled connecting portions 116 between yoke portions whose ends are adjacent to each other. At these thin-walled connecting portions 116, the yoke portions 11 of the thin-walled connecting core cannot be bent freely as in the stator core shown in the first embodiment, but are held in a straight state. After winding is completed, the thin-walled connecting portions 116 are plastically deformed and bent into an annular shape.

[0045] According to this embodiment, areas that do not affect the magnetic properties of the stator core are punched out to expand the winding area, allowing for an increased number of turns and improved efficiency. Furthermore, the shape of the connecting portions of the stator cores varies depending on the product. The rotary connecting core of embodiment 1 has a reverse bow as shown in FIG. 16, allowing for high-speed winding. In contrast, the thin-walled connecting core of embodiment 2 can be maintained in a straight state, facilitating the operation of the crossover wires for continuous winding between each stator core. Furthermore, loosening of the crossover wires can be prevented. The stator of this embodiment has the same configuration as the stator core of embodiment 1, except for the connecting portions of the stator cores, and similar effects can be obtained using a similar manufacturing method.

[0046] Embodiment 3. A stator for a rotating electric machine according to embodiment 3 will now be described with reference to FIG. 23. In the description of embodiment 3, differences from embodiment 1 will be mainly described, and common parts will not be described. A stator 100 of this embodiment is similar to the stator 100 of embodiment 1, except for the structure of the stator core used in the stator. FIG. 23 is a perspective view showing a split core used in the stator according to embodiment 3. Like embodiment 1, the stator of this embodiment also includes a stator core, insulating members, and insulating films.

[0047] Unlike the first and second embodiments, the split core used in this embodiment is formed by dividing it into individual teeth. Like the first embodiment, the split core also has a yoke portion 11 arranged in an annular shape and a plurality of teeth 12 formed to protrude inward in the radial direction X2 from the inner peripheral surface of the yoke portion 11 at predetermined intervals in the circumferential direction Z. The split core according to this embodiment is also formed by laminating a plurality of core plates formed by punching thin magnetic steel plates in the axial direction Y. The difference from the first embodiment is that there is no connecting portion and the core is divided into individual teeth. This configuration makes it easier to wind the conductor wire using a nozzle.

[0048] The winding work involves holding the split cores in a split core fixing jig and winding them continuously in the same manner as in embodiment 1. The nine split cores are then arranged in a circular ring shape and each core is fixed to form the stator. Fixing methods include welding or shrink fitting. Alternatively, the cores can be held in place by connecting insulating members without using a fixing jig. The stator of this embodiment has the same configuration as the stator of embodiment 1 except for the core connecting parts, and can achieve the same effects as those of embodiment 1 described above.

[0049] Fourth Embodiment A stator for a rotating electric machine according to a fourth embodiment will be described below with reference to Fig. 24. In the description of the fourth embodiment, differences from the first, second, and third embodiments will be mainly described, and common portions will not be described. The stator 100 of this embodiment is the same as the stator 100 of the first embodiment, except that the structures of the undercut portion (first undercut portion) of the stator core 1 used in the stator and the undercut portion 2100 (second undercut portion) of the insulating member are different.

[0050] As in the first, second, and third embodiments, the undercut portion refers to a portion where the inner circumferential surface 112 (see FIG. 8) has been cut away. In the insulating member, this is the region indicated by 2100 in FIG. 24 , which is an area offset toward the back yoke by the diameter of the conductor wire 70 from a plane perpendicular to the first side surface 121 of the tooth 12, with the surfaces of the inner circumferential surfaces 202, 302 of the upper winding frame 2 and the lower winding frame 3 along the circumferential direction Z as one end face.

[0051] 24 is a plan view showing the state in which the upper and lower bobbins and insulating film are installed on the core portion according to the fourth embodiment. As shown in FIG. 24 , the insulating member has an undercut portion 2100 (second undercut portion) of the insulating member that is recessed from one end in the circumferential direction Z to the radially outward direction X1 from a plane perpendicular to the circumferential side surface (first side surface 121) of the tooth 12. The undercut portion 2100 is provided on the surface of the upper bobbin 2 facing the yoke portion 11. The insulating member has a shape in which the entire region on the yoke portion 11 side is linearly expanded toward the yoke portion 11 by the diameter of the conductor wire 70. This undercut portion 2100 has a generally linearly recessed shape, and in the expanded region, the slot 14, the coil 7 is aligned and arranged as in the first, second, and third embodiments.

[0052] Next, a method of winding the wire around the undercut portion will be described with reference to Figures 11, 18, and 25. In stator 100 of this embodiment, as in the first, second, and third embodiments, the wire conductor 70 in the first turn is aligned along guide 311A ​​(second guide, see Figure 11) that extends radially inward in the X2 direction from claw portions 311 of lower bobbin 3, and winding nozzle 51 is pitch-fed in the X2 direction by an amount equal to the diameter of the wire conductor 70, so that the wire conductor 70 is positioned at position No. 1 on the right side of the tooth.

[0053] Then, after the first layer of conductor wire 70 is placed by pitch feed in the X2 direction to position No. 11, the conductor wire 70 is placed by pitch feed in the X1 direction from position No. 12 to position No. 22. After winding the second layer at position No. 22, the winding indicated by No. 23, which is included in the undercut portion of the radius in Figure 25, is placed from the target position (Figure 18A) to position No. 23 shown in Figure 18B, using the previous conductor wire No. 22 as a guide, while aligning the conductor wire indicated by No. 23 with the conductor wire at position No. 22, as shown in Figure 18A. This is because if the conductor wire were placed directly at position No. 23 (Figure 18B), there is a risk of interference between the protrusions 200A at both ends of the back yoke and the conductor wire 70 emerging from the winding nozzle 51, which could result in irregular winding of the coil and a deterioration in the insulation quality of the coil. The above is the same as in embodiment 1.

[0054] In the fourth embodiment, when placing the third-layer conductor 70, wire No. 24 is not placed on the yoke side, i.e., closer to the X1 side than wire No. 23, but is placed between wire No. 22 and wire No. 23, closer to the X2 side than wire No. 23, as shown in FIG. 25. This is to prevent interference between the protrusions 200A on both ends of the back yoke and the wire conductor 70 emerging from the winding nozzle 51, as was the case when placing wire No. 23. For the third-layer winding, wire conductor 70 is placed by pitching in the X2 direction to wire No. 34, leaving a space of one wire diameter on the yoke side, and then wire conductor 70 for the fourth layer is placed by pitching in the X1 direction from position No. 35 to position No. 45.

[0055] Next, the winding nozzle 51 is fed half a pitch in the X1 direction to position No. 48 (the limit of interference with the protrusion 200A). As with No. 23 for the second layer, using No. 24 and No. 45 as guides, the conductor wire 70 is placed at position No. 46, where it will fit within the undercut portion 2100 by the diameter of the coil 7. The conductor wire 70 is then wound around the tooth 12, and the next conductor wire 70 is placed at position No. 47, where it will fit within the undercut portion 2100 by the radius. This completes the placement of the third and fourth layers. From then on, for the fifth and subsequent layers, the winding around the undercut portion 2100 is performed using the conductor wire 70 on the core back side as a guide, just like the conductor wires 70 shown in No. 23, No. 46, and No. 47.

[0056] In this embodiment, an introduction groove 214 for the coil 7 is provided on the axial upper surface of the first protrusion 21 provided on the upper bobbin 2, and the top surface 21A of the first protrusion 21 connected to the introduction groove 214 is positioned radially outward from the inner circumferential surface 2111 by the diameter of the coil 7. The inner circumferential surface 2111 is provided with a first guide 21B whose radially inner end surface is positioned radially inward from the inner circumferential surface 2111 by the diameter of the coil 7, and the first turn of the coil 7 introduced from the introduction groove 214 passes through the top surface 21A and is positioned on the radially inner end surface of the first guide 21B. The last turn of the second or subsequent layers that contacts the generally linearly recessed surface of the second undercut portion 2100 is housed within the first undercut portion 112A and the second undercut portion 2100.

[0057] According to this embodiment, the area of ​​the stator core that does not affect the magnetic properties is punched out to expand the area of ​​the winding, and the number of turns can be increased to improve efficiency. The stator of this embodiment has the same configuration as the stator core of embodiment 1 except for the area of ​​the undercut portion, and is manufactured by the same manufacturing method, and the same effects can be obtained.

[0058] Although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0059] Various aspects of the present disclosure will be summarized below.

[0060] (Supplementary Note 1) A stator for a rotating electric machine comprising: a yoke portion arranged in the circumferential direction, a stator core having a plurality of teeth that protrude radially inward from the yoke portion and are formed at predetermined intervals in the circumferential direction, a coil wound around the teeth, and a top bobbin arranged axially above the stator core, wherein a first undercut portion is formed by cutting away an inner peripheral surface of the yoke portion that does not affect magnetic characteristics, and the top bobbin is provided with a second undercut portion that is an overall linearly recessed shape on its surface facing the yoke portion, and at least a portion of the wound coil is disposed in the first undercut portion and the second undercut portion. (Supplementary Note 2) A stator for a rotating electric machine according to Supplementary Note 1, wherein the first undercut portion is formed by a recess that is punched out in an arc shape into the inner peripheral surface of the yoke portion similar to the outer peripheral surface of the yoke portion. (Supplementary Note 3) The stator of a rotating electric machine according to Supplementary Note 1 or Supplementary Note 2, wherein the second undercut portion has a structure recessed radially outward from one circumferential end portion from a plane perpendicular to the circumferential side surface of the tooth. (Supplementary Note 4) The stator of a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper bobbin, and a part of a first turn of the coil introduced from the introduction groove passes through the first undercut portion and the second undercut portion, and the entire remaining first turn of the coil is present in an area outside the first undercut portion and the second undercut portion. (Supplementary Note 5) The stator of a rotating electric machine according to Supplementary Note 4, wherein a final turn of a second or subsequent layer wound circumferentially outward from a first layer including the first turn of the coil introduced from the introduction groove is in contact with a surface of the second undercut portion that is recessed in a linear shape overall. (Supplementary Note 6) The stator of the rotating electric machine according to Supplementary Note 5, wherein the final turn of the second and subsequent layers is in contact with a surface of the second undercut portion that is generally recessed in a linear state.(Supplementary Note 7) The stator of any one of Supplementary Notes 1 to 6, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper winding frame, and a top surface of the first protrusion connected to the introduction groove is positioned radially outward from the inner circumferential surface by a radius of the coil, and a first guide is provided on the inner circumferential surface, the first guide having a radially inner end surface positioned radially inward from the inner circumferential surface by a radius of the coil, and a first turn of the coil introduced from the introduction groove passes through the top surface and is positioned on the radially inner end surface of the first guide. (Supplementary Note 8) The stator of a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper bobbin, a top surface of the first protrusion connected to the introduction groove is shifted radially outward from the inner circumferential surface by a diameter of the coil, a first guide is provided on the inner circumferential surface, and an end surface of the first guide in the radial direction is shifted radially inward from the inner circumferential surface by a diameter of the coil, and a first turn of the coil introduced from the introduction groove passes through the top surface and is disposed on the radially inner end surface of the first guide. (Supplementary Note 9) The stator of a rotating electric machine according to Supplementary Note 5 or Supplementary Note 8, wherein a last turn of a second or subsequent layer that contacts a surface of the second undercut portion that is generally recessed in a linear state is housed within the first undercut portion and the second undercut portion. (Supplementary Note 10) The stator for a rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 9, wherein an insulating portion arranged to insulate the stator core from the coil is composed of the upper winding frame, a lower winding frame arranged axially below the stator core, and an insulating film covering side surfaces of the teeth between the upper winding frame and the lower winding frame. (Supplementary Note 11) The stator core is formed by stacking a plurality of first core plates and second core plates in the axial direction, wherein the first core plate has a convex portion on one surface of an end portion of the yoke portion in a first circumferential direction and a concave portion on the other surface, and the second core plate has a convex portion on one surface of an end portion of the yoke portion in a second circumferential direction and a concave portion on the other surface, and the yoke portions of adjacent stator cores are connected by a connecting portion when the convex portion and the concave portion are fitted together.(Supplementary Note 12) The stator of a rotating electric machine according to Supplementary Note 11, wherein the stator core is connected by the yoke portion in a reverse-warped shape facing outward. (Supplementary Note 13) The stator of a rotating electric machine according to any one of Supplementary Notes 1 to 10, wherein the stator cores are connected by a thin wall at the yoke portion. (Supplementary Note 14) The stator of a rotating electric machine according to Supplementary Note 11 or Supplementary Note 13, wherein a plurality of the stator cores can be connected linearly at the yoke portion. (Supplementary Note 15) The stator of a rotating electric machine according to any one of Supplementary Notes 1 to 10, wherein the stator core is configured by being divided into individual teeth. (Supplementary Note 16) A rotating electric machine comprising the stator of any one of Supplementary Notes 1 to 15, and a rotor disposed opposite the stator with a gap interposed therebetween.

[0061] REFERENCE SIGNS LIST 1 stator core, 2 upper winding frame, 3 lower winding frame, 7 coil, 8 insulating film, 11 yoke portion, 12 teeth, 21 first protrusion, 21A top surface, 21B guide, 70 conductor wire, 100 stator, 111 connecting portion, 112A, 2000, 2100 undercut portion, 116 thin-walled connecting portion, 214 introduction groove portion, 601 first core plate, 602 second core plate, 1000 rotating electric machine, 1111A, 1111B convex portion, 1112A, 1112B concave portion, 2111 inner circumferential surface.

Claims

1. A stator for a rotating electric machine comprising a yoke portion arranged in the circumferential direction, a stator core having a plurality of teeth that protrude radially inward from the yoke portion and are formed at a predetermined interval in the circumferential direction, a coil wound around the teeth, and an upper winding frame arranged in the axial upper part of the stator core, wherein a first undercut portion is provided by cutting the inner surface of the yoke portion, which is a part that does not affect the magnetic characteristics, and a second undercut portion that is generally recessed in a linear state is provided on the surface of the upper winding frame facing the yoke portion, and at least a part of the wound coil is arranged in the first undercut portion and the second undercut portion.

2. A stator for a rotating electric machine according to claim 1, wherein the first undercut portion is formed by punching out an arc-shaped recess in the inner peripheral surface of the yoke portion in the same manner as in the outer peripheral surface of the yoke portion.

3. A stator for a rotating electric machine according to claim 1 or 2, wherein the second undercut portion is structured so as to be recessed radially outward from one circumferential end of the tooth on a plane perpendicular to the circumferential side surface of the tooth.

4. A stator for a rotating electric machine as claimed in any one of claims 1 to 3, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper winding frame, and a portion of the first turn of the coil introduced from the introduction groove passes through the first undercut portion and the second undercut portion, and the entire remaining first turn of the coil is present in an area outside the first undercut portion and the second undercut portion.

5. A stator for a rotating electric machine as described in claim 4, wherein the final turn of a second or subsequent layer wound circumferentially outside the first layer, including the first turn of the coil introduced from the introduction groove portion, contacts the generally linearly recessed surface of the second undercut portion.

6. A stator for a rotating electric machine as set forth in claim 5, wherein the final turn of the second and subsequent layers is in contact with a surface of said second undercut portion that is generally recessed in a linear shape.

7. A stator for a rotating electric machine as claimed in any one of claims 1 to 6, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper winding form, a top surface of the first protrusion connected to the introduction groove is positioned radially outward from the inner circumferential surface by a radius of the coil, and a first guide is provided on the inner circumferential surface, the radially inner end surface of which is positioned radially inward from the inner circumferential surface by a radius of the coil, and a first turn of the coil introduced from the introduction groove passes through the top surface and is positioned on the radially inner end surface of the first guide.

8. A stator for a rotating electric machine as claimed in any one of claims 1 to 3, wherein an introduction groove for the coil is provided on an axial upper surface of a first protrusion provided on the upper winding frame, a top surface of the first protrusion connected to the introduction groove is positioned radially outwardly from the inner circumferential surface by a diameter of the coil, and a first guide is provided on the inner circumferential surface, the radially inner end surface of which is positioned radially inwardly from the inner circumferential surface by a diameter of the coil, and a first turn of the coil introduced from the introduction groove passes through the top surface and is positioned on the radially inner end surface of the first guide.

9. A stator for a rotating electric machine as described in claim 5 or claim 8, wherein the last turn of the second or subsequent layers that contacts the surface of the second undercut portion that is generally recessed in a linear state is contained within the first undercut portion and the second undercut portion.

10. A stator for a rotating electric machine as described in any one of claims 1 to 9, wherein the insulating portion arranged to insulate the stator core from the coil is composed of the upper winding frame, a lower winding frame arranged axially below the stator core, and an insulating film covering the side surfaces of the teeth between the upper winding frame and the lower winding frame.

11. A stator for a rotating electric machine as described in any one of claims 1 to 10, wherein the stator core is formed by stacking a first core plate and a second core plate in the axial direction in a plurality of layers, wherein the first core plate has a convex portion on one surface side of a first circumferential end of the yoke portion and a concave portion on the other surface side, and the second core plate has a convex portion on one surface side of a second circumferential end of the yoke portion and a concave portion on the other surface side, and the yoke portions of adjacent stator cores are connected by a connecting portion by fitting together the convex portion and the concave portion.

12. A stator for a rotating electric machine according to claim 11, wherein said stator core has said teeth connected at said yoke portion in a reversely curved shape facing outward.

13. A stator for a rotating electric machine according to any one of claims 1 to 10, wherein the stator core is connected at a thin wall at the yoke portion.

14. A stator for a rotating electric machine according to claim 11 or 13, wherein a plurality of said stator cores can be connected in a straight line at said yoke portions.

15. A stator for a rotating electric machine according to any one of claims 1 to 10, wherein the stator core is configured to be divided into individual teeth.

16. A rotating electric machine comprising a rotating electric machine stator according to any one of claims 1 to 15, and a rotor disposed opposite the stator with a gap therebetween.

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