Stator of a rotating electric machine

Abstract

The present application relates to a stator of a rotary electric machine. According to the embodiment, the stator is provided with a stator core (16) having a plurality of slots (20), and a multi-phase segmented coil having a plurality of coil segments each formed of a flat conductor and having a first linear portion and a second linear portion each disposed in a different slot, and a bridging portion. At least the coil segment (CS1) disposed on the innermost circumferential side is configured by joining a plurality of divided segments (DS1, DS2) to each other, the divided segments (DS1, DS2) being formed of a flat conductor having a smaller cross-sectional area than the other coil segments and each having a first linear portion (LA1, LB1) and a second linear portion (LA2, LB2), and a bridging portion (BA, BB). The bridging portions of the divided segments are disposed so as to cross each other in the radial direction. The first linear portions are arranged in the slots in a first direction along the radial direction, and the second linear portions are arranged in the slots in a direction opposite to the first direction.

Description

Technical Field

[0001] Embodiments of the present invention relate to a stator of a rotary electric machine. Background Technology

[0002] A rotating electric machine has an annular stator and a rotor rotatably disposed in the excitation region of the stator. The stator includes: an annular stator core with multiple slots; and multi-phase stator coils mounted in the stator core. These stator coils are composed of wire conductors arranged in multiple slots. In each slot, multiple wire conductors are arranged radially. The stator coils have coil ends projecting axially from both end faces of the stator core.

[0003] In recent years, especially in the stators of rotary motors used for driving mobile bodies where miniaturization is a high priority, segmented coils have been adopted. These coils consist of U-shaped coil segments (coil sections) made of flat wire inserted into slots in the stator core and formed by twisting and welding the ends. Compared to stator coils using thin round wire, segmented coils allow for improved space utilization within the slots and smaller coil ends. Furthermore, by using flat conductors with thicker wire diameters to construct the segmented coils, resistance is reduced, resulting in lower losses at low speeds.

[0004] On the other hand, when rotating at high speeds, the current flowing through the conductor and the magnetic flux passing through it become more frequent, thus inducing eddy currents within the conductor, raising concerns about increased losses. As a countermeasure, this is achieved by using multiple rows of flat wires with thinner diameters, which can mitigate the increase in losses. However, as the number of wires increases, the volume of the insulation increases, thereby reducing the space utilization within the slot. As a result, there are reversible problems in different speed ranges, such as the inability to achieve loss reduction at low speeds. Furthermore, when using multiple rows of wire conductors, to suppress the generation of eddy currents (return current) in the coil, the configuration is such that at least a portion of the divided multiple wire conductors is twisted, thereby misaligning the arrangement of the multiple wire conductors.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6491727

[0008] Patent Document 2: Japanese Patent No. 6330656

[0009] Patent Document 3: Japanese Patent No. 5854268

[0010] Patent Document 4: Japanese Patent Application Publication No. 2013-138594 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] In the stator of a rotating electric machine configured as described above, when at least a portion of the stator coils are multi-rowed, the wiring of the linear conductors becomes complicated, and the configuration of the coil ends becomes complicated due to the application of twisting.

[0013] The objective of embodiments of the present invention is to provide a stator for a rotary electric motor that enables miniaturization and simplification of the coil ends.

[0014] Methods for solving problems

[0015] According to an embodiment, the stator of the rotating electric machine includes: a stator core having an annular magnetic yoke having a central axis and a plurality of teeth extending from the inner periphery of the magnetic yoke, with slots formed between adjacent teeth; and multiphase segmented coils, each having a plurality of coil segments formed of flat conductors and having a first linear portion and a second linear portion respectively disposed in different slots, and a bridging portion located outside the stator core and connecting the first linear portion and the second linear portion to each other. With the direction of the central axis defined as axial, the direction orthogonal to the central axis defined as radial, and the direction around the central axis defined as circumferential, a plurality of first or second linear portions are arranged radially within the slot. The coil segment, located at least on the innermost circumference within the slot, is formed by joining multiple segmented segments together. Each segment is formed from a flat conductor with a cross-sectional area smaller than that of the flat conductor and has a first linear portion and a second linear portion, as well as a bridging portion located outside the stator core and connecting the first and second linear portions. The bridging portions of the multiple segmented segments are arranged intersecting each other radially. The first linear portions of the multiple segmented segments are arranged radially in a first direction within the slot, and the second linear portions are arranged radially in the opposite direction within the slot. Attached Figure Description

[0016] Figure 1 This is a longitudinal cross-sectional view of the rotary electric machine according to the first embodiment.

[0017] Figure 2 This is a cross-sectional view of the rotary electric motor according to the first embodiment.

[0018] Figure 3 This is a perspective view showing the first end face of the stator of the aforementioned rotary electric machine.

[0019] Figure 4 This is a schematic diagram showing a portion of the cross-section of the aforementioned stator and its segmented sections.

[0020] Figure 5 This is a perspective view showing an enlarged portion of the first end face of the stator described above.

[0021] Figure 6 This is a plan view showing a portion of the first end face of the stator described above.

[0022] Figure 7 This is a perspective view showing a portion of the first end face of the stator and the segmented coils of the multi-row inner circumferential side.

[0023] Figure 8 This is a perspective view showing a portion of the second end face of the stator described above.

[0024] Figure 9 This is a plan view showing a portion of the second end face of the stator described above.

[0025] Figure 10 It is a diagram that schematically represents the state of magnetic flux passage in a multi-column coil segment.

[0026] Figure 11 This is a perspective view showing a portion of the first end face of the stator in the second embodiment and the segmented coils of the multi-row inner circumferential side.

[0027] Figure 12 This is a plan view showing a portion of the first end face of the stator described above in the second embodiment.

[0028] Figure 13 This is a perspective view showing a portion of the first end face of the stator in the third embodiment and the segmented coils of the multi-row inner circumferential side.

[0029] Figure 14 This is a plan view showing a portion of the first end face of the stator described in the third embodiment.

[0030] Figure 15 This is a schematic diagram showing a portion of the cross-section of the stator in the first modified example and the segmented section.

[0031] Figure 16 This is a schematic diagram showing a portion of the cross-section of the stator in the second modified example and the segmented section.

[0032] Figure 17 This is a schematic diagram showing a portion of the cross-section of the stator in the third modified example and the segmented section. Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the disclosure is merely an example, and appropriate modifications that can be readily conceived by those skilled in the art while maintaining the spirit of the invention are of course included within the scope of the present invention. In addition, regarding the drawings, for the purpose of clearer explanation, the width, thickness, shape, etc., of various parts are sometimes schematically shown compared to the actual form, but this is only an example and does not limit the interpretation of the present invention. Furthermore, in this specification and in the various drawings, for elements that are the same as those stated with respect to previously presented figures, the same symbols are sometimes used, and detailed descriptions are appropriately omitted.

[0034] (First Embodiment)

[0035] First, an example of a rotary electric motor with a stator that has been implemented will be described.

[0036] Figure 1 This is a longitudinal cross-sectional view of the rotary electric machine according to the first embodiment, showing only one half with the central axis C1 as the center. Figure 2 This is a cross-sectional view of a rotary electric motor.

[0037] like Figure 1 As shown, the rotary motor 10 is configured, for example, as a permanent magnet type rotary motor. The rotary motor 10 includes: a ring-shaped or cylindrical stator 12; a rotor 14, which is rotatable about a central axis C1 and is supported coaxially with the stator 12 on the inner side of the stator 12; and a housing 30 that supports the stator 12 and the rotor 14.

[0038] In the following description, the direction of extension of the central axis C1 is called the axial direction, the direction of rotation around the central axis C1 is called the circumferential direction, and the direction orthogonal to the axial and circumferential directions is called the radial direction.

[0039] like Figure 1 as well as Figure 2 As shown, the stator 12 includes a cylindrical stator core 16 and a rotor winding (segmented coil) 18 mounted on the stator core 16. The stator core 16 is constructed by stacking multiple annular electromagnetic steel plates 17 made of magnetic materials such as silicon steel in a coaxial manner. The multiple electromagnetic steel plates 17 are connected in a stacked state by welding multiple portions of the outer peripheral surface of the stator core 16. The stator core 16 has a first end face 16a located at one end in the axial direction and a second end face 16b located at the other end in the axial direction. The first end face 16a and the second end face 16b extend orthogonally to the central axis C1.

[0040] A plurality of slots 20 (e.g., 72) are formed on the inner periphery of the stator core 16. In this embodiment, the plurality of slots 20 are arranged at equal intervals in the circumferential direction. However, the circumferential intervals of the plurality of slots 20 may also be non-equal. Each slot 20 opens on the inner circumferential surface of the stator core 16 and extends radially from the inner circumferential surface toward the outer circumferential surface of the stator core. Each slot 20 extends along the entire axial length of the stator core 16. One end of each slot 20 opens on a first end face 16a, and the other end opens on a second end face 16b. Alternatively, the slots 20 may not open on the inner circumferential surface of the stator core 16. That is, the slots 20 may also be formed as through holes extending axially in the stator core 16.

[0041] By forming multiple slots 20, the inner periphery of the stator core 16 comprises multiple (e.g., 72 in this embodiment) teeth 21 protruding toward the central axis C1. The teeth 21 are arranged at equal intervals along the circumferential direction. Thus, the stator core 16 integrally has an annular yoke portion and multiple teeth 21 protruding radially from the inner circumferential surface of the yoke portion toward the central axis C1. Slots 20 are formed between adjacent pairs of teeth 21 in the circumferential direction.

[0042] Coils 18 are embedded in multiple slots 20 and wound around teeth 21. The coils 18 are configured to have coil ends 18a, 18b extending axially outward from the first end face 16a and the second end face 16b of the stator core 16. By flowing an alternating current in the coils 18, a predetermined linked magnetic flux is formed in the stator 12 (teeth 21).

[0043] like Figure 1 As shown, core pressing parts 26 are provided at both ends of the stator core 16 along the axial direction.

[0044] The housing 30 has a generally cylindrical first bracket 32a and a bowl-shaped second bracket 32b. The first bracket 32a is connected to a core pressing member 26 located on the drive end side of the stator core 16. The second bracket 32b is connected to the core pressing member 26 located on the reverse drive end side. The first and second brackets 32a and 32b are formed, for example, from aluminum alloy. An annular bearing bracket 34 is coaxially fastened to the front end side of the first bracket 32a by bolts. A first bearing portion 36, for example, incorporating a roller bearing 35, is fastened to the central portion of the bearing bracket 34. A second bearing portion 38, for example, incorporating a ball bearing 37, is fastened to the central portion of the second bracket 32b.

[0045] On the other hand, the rotor 14 has: a cylindrical shaft (rotation shaft) 42, supported by first and second bearing portions 36 and 38, which allows it to rotate freely about the central axis C1; a cylindrical rotor core 44, fixed to approximately the central portion of the shaft 42 in the axial direction; and a plurality of permanent magnets 46 embedded in the rotor core 44. The rotor core 44 is configured as a laminated body formed by stacking multiple annular electromagnetic steel plates 47 of magnetic materials such as silicon steel in a concentric manner. The rotor core 44 has an inner hole 48 formed coaxially with the central axis C1. The shaft 42 is inserted through and fitted into the inner hole 48 and extends coaxially with the rotor core 44. Approximately circular end plates 54 and core pressing members 56 are provided at both axial ends of the rotor core 44.

[0046] like Figure 1 as well as Figure 2 As shown, the rotor core 44 is coaxially disposed inside the stator core 16 with a small gap (air gap). That is, the outer circumferential surface of the rotor core 44 is separated by a small gap and faces the inner circumferential surface (front end face of tooth 21) of the stator core 16.

[0047] The rotor core 44 has a plurality of magnet insertion holes extending along the axial direction. Permanent magnets 46 are filled and disposed in each magnet insertion hole and fixed to the rotor core 44, for example, by an adhesive. Each permanent magnet 46 extends along the entire length of the rotor core 44. Furthermore, the plurality of permanent magnets 46 are arranged at predetermined intervals in the circumferential direction of the rotor core 44.

[0048] like Figure 2 As shown, the rotor core 44 has a d-axis extending along the radial or radial direction of the rotor core 44, and a q-axis electrically separated from the d-axis by 90°. Here, the axis extending radially through the boundary between adjacent magnetic poles and the central axis C1 is defined as the q-axis, and the direction electrically perpendicular to the q-axis is defined as the d-axis. The d-axis and q-axis alternate in the circumferential direction of the rotor core 44 and are arranged in a predetermined phase.

[0049] Two permanent magnets 46 are arranged on both sides of each d-axis in the circumferential direction of the rotor core 44. In this embodiment, each permanent magnet 46 is formed as an elongated plate with a rectangular cross-section and has a length approximately equal to the axial length of the rotor core 44. When viewed in a cross-section of the rotor core 44 orthogonal to the central axis C1, the permanent magnets 46 are inclined relative to the d-axis. The two permanent magnets 46 are arranged in a generally V-shape, for example. Here, the inner circumferential ends of the permanent magnets 46 are adjacent to the d-axis and face each other with a small gap. The outer circumferential ends of the permanent magnets 46 are separated from the d-axis along the circumferential direction of the rotor core 44 and are located near the outer circumferential surface of the rotor core 44 and near the q-axis. Thus, the outer circumferential ends of the permanent magnets 46 are adjacent to and face each other across the q-axis. In this embodiment, the rotor core 44 constitutes 12 magnetic poles arranged in the circumferential direction, each magnetic pole including two permanent magnets 46.

[0050] Furthermore, the shape of the permanent magnet 46 is not limited to a long, thin plate with a rectangular cross-section; various shapes can be used.

[0051] Next, the structure of stator 12 will be described in detail.

[0052] Figure 3 This is a three-dimensional view showing the first end face of the stator. Figure 4 It is a schematic diagram showing a portion of the stator's cross-section and its segmented sections.

[0053] like Figure 3 As shown, the stator 12 is driven by a three-phase (U-phase, V-phase, and W-phase) AC power supply. For example, coils 18 corresponding to the U-phase and connected in parallel, coils 18 corresponding to the V-phase and connected in parallel, and coils 18 corresponding to the W-phase and connected in parallel are wound on the teeth 21 in a distributed configuration. That is, a total of six coils 18, each connected in parallel and corresponding to the U-phase, V-phase, and W-phase, are wound on the teeth 14. As will be described later, the coils 18 include three-phase (U, V, W) coils for each magnetic pole, and the coils of each phase are arranged in two of the six slots corresponding to one magnetic pole. In addition, the coils in each phase of the stator 12 are not limited to being connected in parallel; coils connected in series can also be used.

[0054] Each coil 18 is composed of a segmented coil formed by joining multiple coil segments made of flat conductors together. The flat conductor has a cross-section (transverse section) that is approximately rectangular with respect to its long side, or at least has two opposing long sides with respect to its long side. When the cross-section of the flat conductor is rectangular, the four corners do not need to be right angles; chamfering or rounding is also acceptable. Except for the conductive portion at the front end, the flat conductor is covered almost the entire circumference with an insulating layer such as enamel.

[0055] As described later, each coil segment integrally includes: a first wire portion and a second wire portion respectively inserted into different slots 20; and a bridging portion located opposite the second end face 16b on the outside of the stator core 16 and connecting the first wire portion and the second wire portion. Multiple bridging portions constitute coil ends 18b. The first wire portion and the second wire portion each have protruding ends extending from the first end face 16a of the stator core 16 toward the outside of the stator core 16. These protruding ends are bent circumferentially and constitute coil ends 18a of the coil 18.

[0056] like Figure 2 as well as Figure 4 As shown, each slot 20 has multiple, for example, four first or second linear portions arranged radially along the slot 20 with one side of each other facing each other in a rectangular configuration. An insulating sheet SP is wound around each of the four linear portions within the slot 20. At least one of the four coil segments CS is divided into multiple segments and arranged in multiple rows. In this embodiment, the coil segment CS1 located on the innermost periphery of the slot 20 is, for example, composed of two segmented segments DS1 and DS2. The segmented segments DS1 and DS2 are formed by a flat conductor having a cross-sectional area approximately half that of the other coil segments CS, i.e., a flat conductor thinner than the other coil segments CS.

[0057] like Figure 4 As shown, segment DS1 integrally includes a first linear portion LA1 and a second linear portion LA2, and a bridging portion BA located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LA1 and the second linear portion LA2. Similarly, segment DS2 integrally includes a first linear portion LB1 and a second linear portion LB2, and a bridging portion BB located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LB1 and the second linear portion LB2.

[0058] A pair of first linear portions LA1 and LB1 are disposed within slot 20 and are arranged adjacent to each other along a first radial direction. For example, the first linear portion LA1 is disposed adjacent to the innermost circumference of slot 20, and the first linear portion LB1 is disposed adjacent to the radially outer side of the first linear portion LA1. Second linear portions LA2 and LB2 are disposed within a fifth slot 20, for example, away from the first linear portions LA1 and LB1, and are adjacent to each other. Here, the bridging portions BA and BB are arranged to cross each other radially in the stator core 16. Thus, the arrangement relationship of the second linear portions LA2 and LB2 with the first linear portions LA1 and LB1 is replaced, becoming the opposite arrangement relationship. That is, the second linear portions LA2 and LB2 are arranged in a direction opposite to the first direction, the second linear portion LB2 is disposed adjacent to the innermost circumference of slot 20, and the second linear portion LA2 is disposed adjacent to the radially outer side of the second linear portion LB2.

[0059] In addition, the number of slots from which the second linear portions LA2 and LB2 exit the first linear portions LA1 and LB1 is not limited to 5, and various values ​​can be adopted according to the electrical design of the stator.

[0060] Figure 5 This is a magnified perspective view of a portion of the first end face of the stator described above. Figure 6 This is a plan view showing a portion of the first end face of the stator described above.

[0061] like Figure 5 as well as Figure 6 As shown, the segmented coil 18 of phase 1 includes: a first coil segment CS1, disposed on the innermost periphery of the slot 20; and a second coil segment CS2, disposed such that it sandwiches the first coil segment CS1 from both sides in the circumferential direction, and is also disposed on the innermost periphery of the slot 20. The first coil segment CS1 and the second coil segment CS2 are each multi-rowed and each consists of two segmented sections.

[0062] In one example, the first coil segment CS1 and the second coil segment CS2 of the U phase are arranged in two adjacent slots 20 in the circumferential direction, and the first coil segment CS1 and the second coil segment CS2 of the V phase are arranged in two slots 20 adjacent to these slots 20 in the circumferential direction. Furthermore, the first coil segment CS1 and the second coil segment CS2 of the W phase are arranged in two slots 20 adjacent to the two slots 20 where the first and second coil segments CS1 and CS2 of the V phase are arranged in the circumferential direction. Thus, on the innermost periphery of the slot 20, there are two U-phase coil segments, two V-phase coil segments, and two W-phase coil segments arranged sequentially in the circumferential direction.

[0063] Figure 7 This is a three-dimensional diagram showing the configuration of the first coil segment CS1 and the second coil segment CS2 of phase 1.

[0064] As shown in the figure, the first coil segment CS1 is composed of segmented segments (first segment and second segment) DS1 and DS2. Segmented segment DS1 integrally has a first linear portion LA1 and a second linear portion LA2, and a bridging portion BA located opposite the second end face 16b on the outside of the stator core 16, connecting the first linear portion LA1 and the second linear portion LA2. Similarly, segmented segment DS2 integrally has a first linear portion LB1 and a second linear portion LB2, and a bridging portion BB located opposite the second end face 16b on the outside of the stator core 16, connecting the first linear portion LB1 and the second linear portion LB2.

[0065] A pair of first linear portions LA1 and LB1 of the first coil segment CS1 are disposed within the slot 20 and are arranged radially adjacent to each other. For example, the first linear portion LA1 is disposed adjacent to the innermost circumferential side of the slot 20, and the first linear portion LB1 is disposed adjacent to the radially outer side of the first linear portion LA1. In the first linear portions LA1 and LB1, the protruding ends protruding from the second end face 16 of the stator core 16 are bent radially inward towards the stator core 16, and then bent axially. As a result, the protruding ends of the first linear portions LA1 and LB1 are located at a position offset radially inward from the inner circumferential side of the slot 20, that is, from the inner circumference of the stator core 16.

[0066] The bridging portion BA of the segment DS1 has: a first section SA1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LA1; a first curved arm CR1, extending approximately parallel to the second end face 16b from the end of the first section SA1 toward the radially outward direction; and a second section SA2, extending approximately parallel to the second end face 16b along the circumference from the end of the first curved arm CR1 to the protruding end of the second linear portion LA2. The first curved arm CR1 is located approximately midway between the first linear portion LA1 and the second linear portion LA2. The bridging portion BA is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LA2 is disposed in the fifth slot 20 exiting from the first linear portion LA1.

[0067] In addition, the bridging part BA of the segment DS1 is the part that connects the segment DS1 stored in slots 20 at different circumferential positions of the stator core 16. Therefore, the first section SA1 and the second section SA2 are not necessarily parallel (or approximately parallel) to the second end face 16b of the stator core 16, and can be in various shapes.

[0068] The bridging portion BA of the segment DS1 is positioned opposite the second end face 16b at a distance. The first section SA1 is located at a position offset inward from the inner periphery of the stator core 16. By providing the first curved arm portion CR1, the second section SA2 is positioned relative to the first section SA1 at a position offset radially outward by approximately three times the thickness of the segment DS1. Consequently, the second linear portion LA2 is configured within the slot 20 with a radially outward offset relative to the first linear portion LA1 by a thickness.

[0069] The bridging portion BB of the segment DS2 has: a first section SB1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LB1; a second curved arm CR2, extending approximately parallel to the second end face 16b from the end of the first section SB1 in a radially outward inclination; and a second section SB2, extending approximately parallel to the second end face 16b along the circumference from the end of the second curved arm CR2 to the protruding end of the second linear portion LB2. The second curved arm CR2 is located approximately midway between the first linear portion LB1 and the second linear portion LB2. The bridging portion BB is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LB2 is disposed in the fifth slot 20 exiting from the first linear portion LB1.

[0070] Furthermore, since the bridging portion BB of the segment DS2 is also the part that connects the segment DS2 stored in slots 20 at different circumferential positions of the stator core 16, the first interval SB1 and the second interval SB2 are not necessarily parallel (or approximately parallel) to the second end face 16b of the stator core 16, and can be in various shapes.

[0071] The first linear portion LB1 and the second linear portion LB2 extend axially from the stator core 16 by approximately twice the width of the flat conductor, exceeding the height of the first linear portion LA1 and the second linear portion LA2 of the segment DS1. Thus, the bridging portion BB is positioned approximately parallel to the second end face 16b, separated by a larger gap than the bridging portion BA. The first interval SB1 is located offset inward from the inner circumferential end of the slot 20 and is approximately above the inner circumferential edge of the stator core 16. Furthermore, the first interval SB1 is located radially outwardly offset by the thickness of the flat conductor relative to the first interval SA1 of the segment DS1, and axially upwardly offset by the width of the flat conductor. The second curved arm portion CR2 overlaps axially above the first curved arm portion CR1 and extends intersectingly with it. The extension length (radial height) (second length) of the second curved arm portion CR2 along the long side direction of the flat conductor is less than half the extension length (first length) of the first curved arm portion CR1. Therefore, the second section SB2 is located radially inwardly offset from the second section SA2 of the segment DS1 by the thickness of the flat conductor, and further axially upwardly offset from the width of the flat conductor (away from the second end face 16b). The second linear portion LB2 is located radially inwardly relative to the first linear portion LB1 and is positioned on the innermost circumferential side within the slot 20.

[0072] Thus, the bridging portion BA of segment DS1 and the bridging portion BB of segment DS2 extend radially intersecting each other, and the positional relationship of the first linear portions LA1 and LB1 is opposite to that of the second linear portions LA2 and LB2. That is, the first linear portion LA1 is located radially inside the first linear portion LB1, and the second linear portion LA2 is located radially outside the second linear portion LB2.

[0073] The second coil segment CS2, arranged to sandwich the first coil segment CS1 from both sides circumferentially, is composed of segmented segments (third segmented segment and fourth segmented segment) DS3 and DS4. Segmented segment DS3 integrally includes a first linear portion LC1 and a second linear portion LC2, and a bridging portion BC located opposite the second end face 16b on the outside of the stator core 16, connecting the first linear portion LC1 and the second linear portion LC2. Similarly, segmented segment DS4 integrally includes a first linear portion LD1 and a second linear portion LD2, and a bridging portion BD located opposite the second end face 16b on the outside of the stator core 16, connecting the first linear portion LD1 and the second linear portion LD2.

[0074] The pair of first linear portions LC1 and LD1 of the second coil segment CS2 are disposed in a slot 20 adjacent to (circumferentially outward) the slot 20 where the first linear portions LA1 and LB1 of the first coil segment CS1 are disposed, and are arranged adjacent to each other in a first radial direction. For example, the first linear portion LC1 is disposed adjacent to the innermost circumferential side of the slot 20, and the first linear portion LD1 is disposed adjacent to the radially outward side of the first linear portion LC1. In the first linear portions LC1 and LD1, the protruding ends protruding from the second end face 16 of the stator core 16 are bent radially inward towards the stator core 16, and then bent axially. Thus, in this embodiment, the protruding ends of the first linear portions LC1 and LD1 are located at a position offset radially inward from the inner circumferential side end of the slot 20, that is, from the inner circumference of the stator core 16.

[0075] The bridging portion BC of segment DS3 comprises: a first section SC1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LC1; a first curved arm (third curved arm) CR3, extending approximately parallel to the second end face 16b from the end of the first section SC1 in a radially outward inclination; and a second section SC2, extending approximately parallel to the second end face 16b along the circumference from the end of the first curved arm CR3 to the protruding end of the second linear portion LA2. The first curved arm CR3 is located approximately midway between the first linear portion LC1 and the second linear portion LC2. The bridging portion BC is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LC2 is disposed in the seventh slot 20 that exits from the first linear portion LC1, that is, in a slot 20 adjacent (circumferentially outward) to the slot 20 where the second linear portions LA2 and LB2, which are disposed of the first coil segment CS1. Furthermore, the number of slots from which the second linear portion LC2 exits from the first linear portion LC1 is not limited to seven, and various values ​​can be adopted depending on the electrical design of the stator.

[0076] The first linear portion LC1 and the second linear portion LC2 extend axially from the stator core 16 by approximately the width of the flat conductor, exceeding the first linear portion LA1 and the second linear portion LA2 of the segmented segment DS1. Consequently, the bridging portion BC is positioned approximately parallel to the second end face 16b, separated by a larger gap than the bridging portion BA.

[0077] In addition, the bridging part BC of the segment DS3 is also the part that connects the segment DS3 stored in the slots 20 at different circumferential positions of the stator core 16. Therefore, the first section SC1 and the second section SC2 are not necessarily parallel (or approximately parallel) to the second end face 16b of the stator core 16, and can be in various shapes.

[0078] The first section SC1 of the bridging section BC is located at a position offset inward from the inner periphery of the stator core 16. By providing the first curved arm CR3, the second section SC2 is positioned relative to the first section SC1 at a position approximately three times the thickness of the segment DS3, offset radially outward. Consequently, the second linear section LC2 is disposed within the slot 20 relative to the first linear section LC1, offset radially outward by a thickness. The first section SC1, the first curved arm CR3, and the second section SC2 of the bridging section BC are axially overlapped with the first section SA1, the first curved arm CR1, and the second section SA2 of the segment DS1, respectively.

[0079] The bridging portion BD of the segment DS4 has: a first section SD1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LD1; a second curved arm portion (fourth curved arm portion) CR4, extending approximately parallel to the second end face 16b from the end of the first section SD1 in a radially outward direction; and a second section SD2, extending approximately parallel to the second end face 16b along the circumference from the end of the second curved arm portion CR4 to the protruding end of the second linear portion LD2. The second curved arm portion CR is located approximately midway between the first linear portion LD1 and the second linear portion LD2. The bridging portion BD is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LD2 is disposed in the seventh slot 20 exiting from the first linear portion LD1.

[0080] Furthermore, the number of slots from which the second linear portion LD2 exits the first linear portion LD1 is not limited to seven, and various values ​​can be adopted depending on the electrical design of the stator. In addition, the bridging portion BD of the segment DS4 is also the part that connects the segment DS4 housed in slots 20 at different circumferential positions in the stator core 16, so the first interval SD1 and the second interval SD2 do not necessarily have to be parallel (or approximately parallel) to the second end face 16b of the stator core 16, and can be in various shapes.

[0081] The first linear portion LD1 and the second linear portion LD2 extend axially from the stator core 16 by approximately twice the width of the flat conductor, exceeding the height of the first linear portion LC1 and the second linear portion LC2 of the segmented segment DS3. Consequently, the bridging portion BD is positioned approximately parallel to the second end face 16b, separated by a larger gap than the bridging portion BC. The first interval SD1 is located offset inward from the inner circumferential end of the slot 20 and is approximately located above the inner circumferential edge of the stator core 16. Furthermore, the first interval SD1 is located radially outwardly offset by the thickness of the flat conductor relative to the first interval SC1 of the segmented segment DS3, and is located axially upwardly offset by twice the width of the flat conductor (away from the second end face 16b). The second curved arm portion CR4 overlaps axially above the first curved arm portion CR3 and extends intersectingly with it. The extension length (radial height) of the second curved arm portion CR4 along the long side direction of the flat conductor is less than half the extension length of the first curved arm portion CR3. Therefore, the second section SD2 is located radially inwardly offset from the second section SC2 of the segment DS3 by the thickness of the flat conductor, and further offset axially upward (away from the second end face 16b) by twice the width of the flat conductor. Consequently, the second linear portion LD2 is located radially inwardly relative to the first linear portion LC1 and is positioned on the innermost circumferential side within the slot 20. The first section SD1, the second curved arm portion CR4, and the second section SD2 of the bridging portion BD are axially overlapped with the first section SB1, the second curved arm portion CR2, and the second section SB2 of the segment DS2, respectively.

[0082] Thus, the bridging portion BC of segment DS3 and the bridging portion BD of segment DS4 extend radially intersecting each other, and the positional relationship of the first linear portions LC1 and LD1 is opposite to that of the second linear portions LD2 and LD2. That is, the first linear portion LC1 is located radially inward relative to the first linear portion LD1, and the second linear portion LC2 is located radially outward relative to the second linear portion LD2. The second linear portions LC2 and LD2 are arranged in a direction opposite to the first direction described above.

[0083] Figure 8 This is a three-dimensional view showing a portion of the first end face of the stator. Figure 9 It is a plan view showing a portion of the first end face of the stator.

[0084] As shown in the figure, on the first end face 16a side of the stator core 16, the first and second linear portions of the coil segment CS have protrusions extending from the first end face 16a toward the outside of the stator core 16. These protrusions are bent at a predetermined angle in the circumferential direction and extend obliquely relative to the axial direction. Similarly, the first and second linear portions of the segmented segments DS1 to DS4 each have protrusions extending from the first end face 16a toward the outside of the stator core 16. These protrusions are bent at a predetermined angle in the circumferential direction and extend obliquely relative to the axial direction. The protruding ends of each protrusion form an end face (joint surface) ds that is substantially parallel to the first end face 16a.

[0085] The protrusions of the four first or second linear portions inserted into each slot 20 are alternately bent in one direction and the opposite direction. That is, the protrusion of the first or second linear portion of the outermost coil segment CS is bent in one direction circumferentially toward the stator core 16, while the protrusion of the first or second linear portion of the innermost coil segment CS is bent in the opposite direction circumferentially. The linear portion of the first or second linear portion of the innermost coil segment CS is bent in the aforementioned direction. Furthermore, the protrusions of the first or second linear portions of the innermost segmented segments CS1 and CS2 are bent in the aforementioned opposite direction.

[0086] The end faces ds of four protrusions extending from different slots 20 are located in a generally coplanar row along the radial direction of the stator core 16. The innermost coil segments CS1 and CS2 of the four protrusions each include two end faces ds1 and ds2 of two segmented sections.

[0087] The end faces ds of the four protrusions in each column are welded together in pairs (two of each) and electrically connected. That is, the end faces ds of the two protrusions on the outer periphery are welded together to form a weld bead WB spanning the two end faces ds. The end faces ds of the two protrusions on the inner periphery are welded together to form a weld bead WB. At this time, the two end faces ds1 (or ds2) of the two segmented sections are joined together by welding, the segmented sections are electrically joined to each other, and then the two end faces ds1 (or ds2) are simultaneously joined with the end faces ds of the protrusions of the adjacent coil segment CS. Thus, a weld bead WB spanning three end faces ds, ds1, ds1 (or three end faces ds, ds2, ds2) is formed. Laser welding can be used, for example, in welding the end faces ds of the protrusions. Each welded or joined part of the coil segment is covered with an insulating material such as powder coating or varnish.

[0088] By connecting the protruding ends of the coil segments to each other as described above, a three-phase segmented coil 18 is formed. The protruding portions of these coil segments form coil ends 18a protruding from the first end face 16a. The three coils in the coil 18 are respectively connected to a U-phase connection terminal TU (not shown), a V-phase connection terminal TV, and a W-phase connection terminal TW. This embodiment illustrates the case where the number of coils in parallel on the stator 12 is set to 2, and connection terminals 8 corresponding to the number of coils in parallel are provided.

[0089] As described above, in this embodiment, a rotary motor with 3 phases, 12 magnetic poles, and 72 slots is configured such that the number of slots for the stator core 16, which is equivalent to 1 magnetic pole, is set to 6 slots, and the coils of each phase are arranged in 2 slots relative to 1 magnetic pole.

[0090] According to this embodiment of the rotary electric machine and its stator, by using segmented coils to construct the coil 18, the protrusion height of the coil ends 18a, 18b protruding from the first end face 16a and the second end face 16b of the stator core 16 can be significantly reduced, thereby achieving miniaturization of the stator 12. Furthermore, at least the innermost coil segments CS1, CS2 of the segmented coils with three or more turns arranged radially within the slot 20 are multi-rowed and constructed using multiple segmented segments DS1 to DS4 formed from flat conductors with a thinner wire diameter. By multiplying the innermost segmented coils, the decrease in slot space utilization associated with the increase in the number of conductors can be suppressed, maintaining a loss reduction effect at low speeds. Simultaneously, by dividing the coil segments radially, the cross-sectional area of ​​the conductor orthogonal to the magnetic flux traversing the slot 20 in the circumferential direction can be reduced, decreasing eddy currents generated within the conductor during high-speed rotation and the resulting losses.

[0091] In multi-coil segments, the ends of multiple segmented sections are welded together electrically, thus creating a closed circuit at the weld points in a single coil group. Without a misalignment at the coil ends, circulating current is induced within this closed circuit, becoming a new cause of increased losses. However, by configuring the coil as in this embodiment, where the bridging portions of the two segmented sections cross and the positional relationship between the first and second linear portions is misaligned, the generation of this circulating current can be suppressed. Therefore, no new cause of increased losses is generated, and low losses in the innermost coil of the multi-coil system can be achieved.

[0092] Figure 10 This is a schematic diagram illustrating the flow of magnetic flux through a multi-column coil segment. For example... Figure 10 As shown in (a), when the bridging portions of the two segmented segments DS1 and DS2 intersect and the weld points at both ends are misaligned, mutually opposing magnetic fluxes pass through the loop between each weld point and the intersection position. Therefore, as Figure 10As shown in (b), the circulating currents I1 and I2 generated in one loop and the other loop have opposite directions and act in a way that cancels each other out. Therefore, it is possible to suppress the generation of circulating currents and prevent the increase of losses.

[0093] By bending the segmented sections DS1 and DS2 without twisting in the thickness direction or in a direction orthogonal to the thickness direction to swap the wires of the first section SA1 and SB1 and the second section SA2 and SB2, a misaligned configuration in which the positional relationship of the two ends is reversed can be obtained. Therefore, compared with the twisted case, the manufacture and assembly of the segmented coils become easier.

[0094] Furthermore, according to this embodiment, in each of the multi-column first coil segment CS1 and second coil segment CS2, the first curved arm portions CR1, CR3 and the second curved arm portions CR2, CR4 of the bridging portion are located directly above a slot located between coil segments of another phase adjacent in the circumferential direction, allowing them to be arranged near the coil segment of another phase without interference. Therefore, miniaturization and simplification of the coil end portion 18b are possible.

[0095] Furthermore, in this embodiment, the first curved arm portions CR1 and CR3 with longer wire lengths are positioned below the second curved arm portions CR2 and CR3 with shorter wire lengths, i.e., on the side of the stator core 16, thereby enabling easy setting and assembly of the coil segments.

[0096] Based on the above description, this embodiment provides a stator for a rotary motor that can suppress the generation of eddy currents and achieve miniaturization and simplification of the coil ends.

[0097] Next, the stator of other embodiments will be described. In the other embodiments described below, the same reference numerals are used for the parts that are the same as those in the first embodiment described above, and their detailed descriptions are omitted or simplified. The description will focus on the parts that are different from those in the first embodiment.

[0098] (Second Implementation)

[0099] Figure 11 This is a perspective view showing the configuration of the first coil segment CS1 and the second coil segment CS2 of one phase of the stator in the second embodiment. Figure 12 This is a plan view showing a portion of the first end face of the stator described above.

[0100] As shown in the figure, according to the second embodiment, in the multi-column first coil segment CS1 and second coil segment CS2, the bridging portions BB and BD, which have shorter curved arm portions CR2 and CR4, are arranged overlapping in the axial direction of the stator core 16. Bridging portions BA and BC, which have longer curved arm portions CR1 and CR2, are arranged on top of these bridging portions. Furthermore, the bridging portions BA and BC are arranged overlapping in the radial direction of the stator core 16. This reduces the extension height of the coil ends, achieving further miniaturization.

[0101] In detail, the first coil segment CS1 is composed of segmented segments DS1 and DS2. A pair of first linear portions LA1 and LB1 of the first coil segment CS1 are disposed within the slot 20, arranged radially adjacent to each other. For example, the first linear portion LA1 is disposed adjacent to the innermost circumferential side of the slot 20, and the first linear portion LB1 is disposed adjacent to the radially outer side of the first linear portion LA1. In the first linear portions LA1 and LB1, the protruding ends protruding from the second end face 16 of the stator core 16 are bent radially inward towards the stator core 16, and further bent axially. Thus, the protruding ends of the first linear portions LA1 and LB1 are located radially inward from the inner circumferential side of the slot 20, i.e., the inner circumference of the stator core 16.

[0102] The bridging portion BA of the segment DS1 has: a first section SA1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LA1; a first curved arm CR1, extending approximately parallel to the second end face 16b from the end of the first section SA1 toward the radially outward direction; and a second section SA2, extending approximately parallel to the second end face 16b along the circumference from the end of the first curved arm CR1 to the protruding end of the second linear portion LA2. The first curved arm CR1 is located approximately midway between the first linear portion LA1 and the second linear portion LA2. The bridging portion BA is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LA2 is disposed in the fifth slot 20 exiting from the first linear portion LA1.

[0103] The bridging portion BA of the segment DS1 is spaced apart from the second end face 16b. In one example, the first section SA1 is located at a position offset inward from the inner periphery of the stator core 16. By providing the first curved arm portion CR1, the second section SA2 is located relative to the first section SA1 at a position offset radially outward by approximately three times the thickness of the segment DS1. Thus, the second linear portion LA2 is configured within the slot 20 with a radially outward offset relative to the first linear portion LA1 by a thickness.

[0104] The bridging portion BB of the segment DS2 has: a first section SB1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LB1; a second curved arm CR2, extending approximately parallel to the second end face 16b from the end of the first section SB1 in a radially outward inclination; and a second section SB2, extending approximately parallel to the second end face 16b along the circumference from the end of the second curved arm CR2 to the protruding end of the second linear portion LB2. The second curved arm CR2 is located approximately midway between the first linear portion LB1 and the second linear portion LB2. The bridging portion BB is formed by bending the flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. In one example, the second linear portion LB2 is disposed in the fifth slot 20 exiting from the first linear portion LB1.

[0105] The first linear portion LB1 and the second linear portion LB2 extend axially from the stator core 16 by approximately twice the width of the flat conductor, compared to the first linear portion LA1 and the second linear portion LA2 of the segment DS1. Thus, the bridging portion BB is positioned approximately parallel to the second end face 16b, separated by a smaller interval than the bridging portion BA. In one example, the first section SB1 is located offset inward from the inner circumferential end of the slot 20 and is approximately above the inner circumferential edge of the stator core 16. Furthermore, the first section SB1 is located radially outwardly offset by the thickness of the flat conductor relative to the first section SA1 of the segment DS1, and axially downwardly offset by the width of the flat conductor (approaching the second end face 16b). The second curved arm portion CR2 overlaps axially below the first curved arm portion CR1 and extends intersectingly with it. The extension length (radial height) of the second curved arm portion CR2 along the long side direction of the flat conductor is less than half the extension length of the first curved arm portion CR1. Therefore, the second section SB2 is located radially inwardly offset from the second section SA2 of the segment DS1 by the thickness of the flat conductor, and further axially downwardly offset (in the direction close to the second end face 16b) by the width of the flat conductor. The second linear portion LB2 is located radially inwardly relative to the second linear portion LB1 and is positioned on the innermost circumferential side within the slot 20.

[0106] Thus, the bridging portion BA of segment DS1 and the bridging portion BB of segment DS2 extend radially intersecting each other, and the positional relationship of the first linear portions LA1 and LB1 is opposite to that of the second linear portions LA2 and LB2. That is, the first linear portion LA1 is located radially inside the first linear portion LB1, and the second linear portion LA2 is located radially outside the second linear portion LB2.

[0107] The second coil segment CS2, arranged to sandwich the first coil segment CS1 from both sides circumferentially, is composed of segmented segments DS3 and DS4. A pair of first linear portions LC1 and LD1 of the second coil segment CS2 are arranged in a slot 20 adjacent to (circumferentially outward) the slot 20 where the first linear portions LA1 and LB1 of the first coil segment CS1 are located, and are radially arranged adjacent to each other. For example, the first linear portion LC1 is adjacent to the innermost circumferential side of the slot 20, and the first linear portion LD1 is adjacent to the radially outward side of the first linear portion LC1. In the first linear portions LC1 and LD1, the protruding ends protruding from the second end face 16 of the stator core 16 are bent radially inward towards the stator core 16, and further bent axially. Thus, the protruding ends of the first linear portions LC1 and LD1 are located at a position offset radially inward from the inner circumferential end of the slot 20, i.e., from the inner circumference of the stator core 16. In particular, the protruding end of the first linear portion LC1 is larger than that of the first linear portion LD1, for example, located at a position that is about three times the thickness of the first linear portion and is offset radially inward.

[0108] The bridging portion BC of the segmented segment DS3 includes: a first section SC1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LC1; a first curved arm portion CR3, extending approximately parallel to the second end face 16b from the end of the first section SC1 in a radially outward inclination; a second section SC2, extending approximately parallel to the second end face 16b along the circumference from the end of the first curved arm portion CR3 to the protruding end of the second linear portion LA2; and a fifth curved arm portion CR5, located in the middle of the second section SC2, extending approximately parallel to the second end face 16b in a radially outward inclination. The first curved arm portion CR3 is located approximately midway between the first linear portion LC1 and the second linear portion LC2. The protruding length (radial height) of the first curved arm portion CR3 is approximately three times the thickness of the flat conductor. On the other hand, the radial protruding length of the fifth curved arm portion CR5 is approximately equal to the thickness of the flat conductor.

[0109] The bridging portion BC is formed by bending a flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. The second linear portion LC2 is disposed in the seventh slot 20 that is away from the first linear portion LC1, that is, in the slot 20 adjacent to (circumferentially outward) the slot 20 where the second linear portions LA2 and LB2, which are disposed of the first coil segment CS1, are located.

[0110] The first linear portion LC1 and the second linear portion LC2 extend axially from the stator core 16 to a height approximately equal to that of the first linear portion LA1 and the second linear portion LA2 of the segment DS1. Thus, the bridging portion BC is positioned approximately parallel to the second end face 16b, separated by an interval equal to that of the bridging portion BA, and is located radially inside the bridging portion BA and radially opposite to it.

[0111] In one example, the first section SC1 of the bridging portion BC is located at a position offset inward from the inner periphery of the stator core 16. By providing the first curved arm CR3, the second section SC2 is positioned approximately three times the thickness of the segment DS3 relative to the first section SC1, offset radially outward. By providing the fifth curved arm CR5, the end portion of the second section SC2 is further offset radially outward by one thickness. Thus, the second linear portion LC2 is configured within the slot 20 with a radial offset of one thickness relative to the first linear portion LC1. The first section SC1, the first curved arm CR3, and the second section SC2 of the bridging portion BC are radially overlapped with the first section SA1, the first curved arm CR1, and the second section SA2 of the segment DS1, respectively.

[0112] The bridging portion BD of the segment DS4 has: a first section SD1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LD1; a second curved arm portion CR4, extending approximately parallel to the second end face 16b from the end of the first section SD1 in a radially outward inclination; and a second section SD2, extending approximately parallel to the second end face 16b along the circumference from the end of the second curved arm portion CR4 to the protruding end of the second linear portion LD2. The second curved arm portion CR4 is located approximately midway between the first linear portion LD1 and the second linear portion LD2. The bridging portion BD is formed by bending a flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. The second linear portion LD2 is disposed in the seventh slot 20, which is located away from the first linear portion LD1.

[0113] The first linear portion LD1 and the second linear portion LD2 extend axially from the stator core 16 by a width greater than the first linear portion LC1 and the second linear portion LC2 of the segment DS3. Thus, the bridging portion BD is positioned approximately parallel to the second end face 16b, separated by a smaller interval than the bridging portion BC. The first interval SD1 is located offset inward from the inner circumferential end of the slot 20 and is approximately above the inner circumferential edge of the stator core 16. Furthermore, the first interval SD1 is located radially outward at a position three times the thickness of the flat conductor relative to the first interval SC1 of the segment DS3, and is also located axially downward (in a direction close to the second end face 16b) by a width of the flat conductor. The second curved arm portion CR4 overlaps axially below the first curved arm portion CR3 and extends intersectingly with it. The extension length (radial height) of the second curved arm CR4 along the long side of the flat conductor is approximately one-third of the extension length of the first curved arm CR3. Therefore, the second section SD2 is located at the same radial position as the second section SC2 of the segment DS3, and further at a position offset axially downwards (approaching the second end face 16b) by the width of the flat conductor. That is, the second section SD2 is located between the second section SB2 of the segment DS2 and the second section SC2 of the segment DS3, and is arranged to overlap axially.

[0114] As a result, the second linear portion LD2 is located radially inward relative to the second linear portion LC1, and is disposed on the innermost circumferential side within the slot 20. The first section SD1, the second curved arm portion CR4, and the second section SD2 of the bridging portion BD are respectively disposed axially overlapping with the first section SB1, the second curved arm portion CR2, and the second section SB2 of the segmented segment DS2.

[0115] Thus, the bridging portion BC of segment DS3 and the bridging portion BD of segment DS4 extend radially intersecting each other, and the positional relationship of the first linear portions LC1 and LD1 is opposite to that of the second linear portions LD2 and LD2. That is, the first linear portion LC1 is located radially inside the first linear portion LD1, and the second linear portion LC2 is located radially outside the second linear portion LD2.

[0116] In the second embodiment, the other components of the stator are the same as those in the first embodiment described above.

[0117] Furthermore, in the second embodiment, the first and second sections of the bridging portion of the segment are not necessarily parallel (or approximately parallel) to the second end face 16b of the stator core 16, and can be in various shapes.

[0118] In the second embodiment configured as described above, by bending the segmented segments DS1, DS2, DS3, and DS4 without twisting in the thickness direction or a direction orthogonal to the thickness direction to swap the wires of the first section SA1, SB1, SC1, and SD1 with the second section SA2, SB2, SC2, and SD2, it is also possible to obtain a misaligned configuration in which the positional relationship of the two ends of the first coil segment CS1 and the second coil segment CS2 is reversed. Therefore, compared with the twisted case, the manufacture and assembly of the segmented coils become easier.

[0119] Furthermore, according to this embodiment, in each of the multi-column first coil segment CS1 and second coil segment CS2, the first curved arm portions CR1, CR3 and the second curved arm portions CR2, CR4 of the bridging portion are located directly above a slot located between coil segments of another phase adjacent in the circumferential direction, and can be arranged near the coil segment of another phase without interfering with it. Therefore, miniaturization and simplification of the coil end 18b can be achieved.

[0120] Furthermore, in this embodiment, in the multi-column first coil segment CS1 and the second coil segment CS2, the bridging portions BB and BD, which have shorter curved arm portions CR2 and CR4, are arranged overlapping in the axial direction of the stator core 16, and bridging portions BA and BC, which have longer curved arm portions CR1 and CR2, are arranged on top of these bridging portions. Moreover, the bridging portions BA and BC are arranged overlapping in the radial direction of the stator core 16. This reduces the extension height of the coil ends, achieving further miniaturization.

[0121] Based on the above description, according to the second embodiment, a stator for a rotary electric machine can be obtained, which can suppress the generation of eddy currents and achieve miniaturization and simplification of the coil ends.

[0122] (Third Implementation)

[0123] Figure 13 This is a perspective view showing the configuration of the first coil segment CS1 and the second coil segment CS2 of one phase of the stator in the third embodiment. Figure 14 This is a plan view showing a portion of the first end face of the stator described above.

[0124] In the second embodiment described above, the bridging portion BC of the segment DS3 of the second coil segment CS2 is arranged to overlap with the bridging portion BA of the segment DS1 of the first coil segment CS1 in the radial direction of the stator core 16. In contrast, according to the third embodiment, as shown in the figure, the bridging portion BC of the segment DS3 is arranged to overlap with the bridging portion BA of the segment DS1 in the radial direction of the stator core 16.

[0125] Specifically, in the second coil segment CS2, the first linear portion LC1 of the segmented segment DS3 is positioned on the innermost circumferential side of the slot 20. In the first linear portion LC1, the protruding end protruding from the second end face 16 of the stator core 16 is bent radially inward towards the stator core 16, and further bent axially. Thus, the protruding end of the first linear portion LC1 is, for example, located at a position radially inward offset from the inner circumferential end of the slot 20 by the thickness of the first linear portion.

[0126] The bridging portion BC of the segment DS3 comprises: a first section SC1, extending approximately parallel to the second end face 16b along the circumference of the stator core 16 from the protruding end of the first linear portion LC1; a first curved arm portion CR3, extending approximately parallel to the second end face 16b from the end of the first section SC1 in a radially outward inclination; and a second section SC2, extending approximately parallel to the second end face 16b along the circumference from the end of the first curved arm portion CR3 to the protruding end of the second linear portion LA2. The first curved arm portion CR3 is located approximately midway between the first linear portion LC1 and the second linear portion LC2. The protruding length (radial height) of the first curved arm portion CR3 is approximately three times the thickness of the flat conductor.

[0127] The bridging portion BC is formed by bending a flat conductor without twisting in the thickness direction or in a direction orthogonal to the thickness direction. The second linear portion LC2 is disposed in the seventh slot 20 that is away from the first linear portion LC1, that is, in the slot 20 adjacent to (circumferentially outward) the slot 20 where the second linear portions LA2 and LB2, which are disposed of the first coil segment CS1, are located.

[0128] The first linear portion LC1 extends axially from the stator core 16 by a greater amount than the width of the flat conductor than the first linear portion LA1 of the segmented segment DS1. Thus, the first section SC1, the first curved arm portion CR3, and the second section SC2 of the bridging portion BC are respectively arranged to overlap axially with the first section SA1, the first curved arm portion CR1, and the second section SA2 of the bridging portion BA of the segmented segment DS1.

[0129] In the third embodiment, the other configurations of the first coil segment CS1 and the second coil segment CS2 are the same as those in the second embodiment described above. In the third embodiment, the first and second sections of the bridging portion of the segment are not necessarily parallel (or substantially parallel) to the second end face 16b of the stator core 16, and can be of various shapes.

[0130] In the third embodiment configured as described above, by bending the segmented segments DS1, DS2, DS3, and DS4 without twisting in the thickness direction or a direction orthogonal to the thickness direction, the first section SA1, SB1, SC1, and SD1 are swapped with the second section SA2, SB2, SC2, and SD2. This also allows for a misaligned configuration where the positions of the two ends of the first coil segment CS1 and the second coil segment SC2 are reversed. Therefore, compared to the twisted case, the manufacture and assembly of the segmented coils become easier.

[0131] Furthermore, according to this embodiment, in each of the multi-column first coil segment CS1 and second coil segment CS2, the first curved arm portions CR1, CR3 and the second curved arm portions CR2, CR4 of the bridging portion are located directly above a slot located between coil segments of another phase adjacent in the circumferential direction, and can be arranged near the coil segment of another phase without interfering with it. Therefore, miniaturization and simplification of the coil end 18b can be achieved.

[0132] Based on the above description, in the third embodiment, a stator for a rotary electric machine can be obtained that can suppress the generation of eddy currents and achieve miniaturization and simplification of the coil ends.

[0133] In the above embodiment, a configuration is shown in which the coil segment located at the innermost periphery of the slot 20 is divided into two segments. However, the division is not limited to two segments and can also be divided into three or four segments.

[0134] (First variation)

[0135] Figure 15 A portion of the cross-section of the stator in the first modified example and the segment are schematically shown.

[0136] As shown in the figure, in the first variation, the coil segment CS1 disposed on the innermost periphery of the slot 20 is divided into three segments (first, second, and third segments) DS1, DS2, and DS3, thus increasing the number of segments. The segments DS1, DS2, and DS3 are formed by flat conductors with a cross-sectional area of ​​approximately one-third that of the other coil segments CS, i.e., flat conductors that are thinner than the other coil segments CS.

[0137] The segment DS1 integrally includes a first linear portion LA1 and a second linear portion LA2, and a bridging portion BA located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LA1 and the second linear portion LA2. Similarly, the segment DS2 integrally includes a first linear portion LB1 and a second linear portion LB2, and a bridging portion BB located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LB1 and the second linear portion LB2. Likewise, the segment DS3 integrally includes a first linear portion LC1 and a second linear portion LC2, and a bridging portion BC located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LC1 and the second linear portion LC2.

[0138] Three first linear portions LA1, LB1, and LC1 are disposed within slot 20 and are arranged radially adjacent to each other. For example, the first linear portion LA1 is disposed adjacent to the innermost circumference of slot 20, the first linear portion LB1 is disposed adjacent to the radially outer side of the first linear portion LA1, and the first linear portion LC1 is disposed adjacent to the radially outer side of the first linear portion LB1. In one example, the second linear portions LA2, LB2, and LC2 are disposed adjacent to each other in a fifth slot 20 that is separated from the first linear portions LA1, LB1, and LC1. The bridging portion BA is disposed radially opposite to the bridging portion BB in the stator core 16, with a portion of the bridging portion BA located radially outer of the bridging portion BB. The bridging portion BC is disposed radially opposite to the bridging portion BB in the stator core 16, with a portion of the bridging portion BC located radially inner of the bridging portion BB.

[0139] Therefore, the configuration relationship between the second linear portions LA2 and LC2 and the first linear portions LA1 and LC1 is replaced, becoming the opposite configuration relationship. That is, the second linear portion LC2 is disposed adjacent to the innermost circumference of the slot 20, and the second linear portion LA2 sandwiches the second linear portion LB2 while being disposed adjacent to the radial outer side of the second linear portion LC2.

[0140] In the construction of the bridging sections BA, BB, and BC, any of the configurations shown in the first, second, and third embodiments described above can also be applied.

[0141] As described above, by increasing the number of coil segment divisions, the cross-sectional area of ​​the conductor orthogonal to the magnetic flux traversing the slot 20 in the circumferential direction can be further reduced, thereby reducing eddy currents generated in the conductor during high-speed rotation and the resulting losses. By configuring the bridging portions of the three segments to intersect and misaligning the positional relationships of the first and second linear portions, the generation of circulating current can be suppressed. Therefore, low-loss innermost coils with multiple rows can be achieved without introducing new losses.

[0142] (Second variation)

[0143] Figure 16 The diagram schematically shows a portion of the cross-section of the stator in the second modified example, as well as the segmented section.

[0144] As shown in the figure, in the second variation, the coil segment CS1 located on the innermost periphery of the slot 20 is divided into four segments (segments 1, 2, 3, and 4) DS1, D2, D3, and D4, thus creating multiple rows. The segments DS1, DS2, and DS3 are formed from flat conductors having a cross-sectional area approximately one-quarter that of the other coil segments CS.

[0145] Similar to the segmented sections DS1, DS2, and DS3, the segmented section DS4 integrally has a first linear portion LD1 and a second linear portion LD2, and a bridging portion BD located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LD1 and the second linear portion LD2.

[0146] Four first linear portions LA1, LB1, LC1, and LD1 are disposed within the slot 20 and are arranged radially adjacent to each other. For example, the first linear portion LA1 is located on the innermost periphery of the slot 20, and the first linear portions LB1, LC1, and LD1 are arranged sequentially on its outer side. In one example, the second linear portions LA2, LB2, LC2, and LD2 are disposed adjacent to each other in a fifth slot 20 that is located away from the first linear portions LA1, LB1, and LC1.

[0147] The bridging portions BA and BB of the segmented sections DS1 and DS2 are arranged radially in the stator core 16 relative to the segmented snow surface and the bridging portions BC and BD of DS3 and DS4, with a portion of the bridging portions BA and BB located radially outside the bridging portions BC and BD.

[0148] Therefore, the arrangement of the second linear portions LA2, LB2 and LC2, LD2 with that of the first linear portions LA1, LB1 and LC1, LD1 is reversed. That is, the second linear portion LC2 is located on the innermost periphery of the slot 20, and the second linear portions LD2, LA2, LB2 are arranged sequentially on its outer side.

[0149] In the configuration of the bridging parts BA, BB, BC, and BD, any configuration shown in the first, second, and third embodiments described above can also be applied.

[0150] As described above, in the second variation, by increasing the number of coil segment divisions, the cross-sectional area of ​​the conductor orthogonal to the magnetic flux traversing the slot 20 in the circumferential direction can be further reduced, thereby reducing eddy currents generated in the conductor during high-speed rotation and the resulting losses. By configuring the bridging portions of the four segments to intersect and the positional relationship between the first and second linear portions to be misaligned, the generation of circulating current can be suppressed. Therefore, low loss of the innermost circumferential coil in a multi-row configuration can be achieved without generating new losses.

[0151] (3rd variation)

[0152] Figure 17 A portion of the cross-section of the stator in the third modified example and the segment are schematically shown.

[0153] As shown in the figure, in the third variation, in addition to the coil segment CS1 disposed on the innermost periphery of the slot 20, the coil segment CS4 disposed on the outermost periphery of the slot 20 is also divided into multiple segments, for example, two segments DS1 and DS2, and arranged in multiple rows. The segments DS1 and DS2 are formed by flat conductors having a cross-sectional area of ​​about 1 / 2 that of the other coil segments CS.

[0154] The segment DS1 of coil segment CS4 integrally includes a first linear portion LA1 and a second linear portion LA2, and a bridging portion BA located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LA1 and the second linear portion LA2. Similarly, the segment DS2 integrally includes a first linear portion LB1 and a second linear portion LB2, and a bridging portion BB located opposite the second end face 16b on the outside of the stator core 16 and connecting the first linear portion LB1 and the second linear portion LB2.

[0155] In coil segment CS4, two first linear portions LA1 and LB1 are disposed within slot 20 and are arranged radially adjacent to each other. For example, the first linear portion LB1 is disposed on the outermost periphery of slot 20, and the first linear portion LA1 is disposed adjacent to the radially inner side of the first linear portion LB1. In one example, the second linear portions LA2 and LB2 are disposed adjacent to each other in a fifth slot 20 that is away from the first linear portions LA1 and LB1. The bridging portion BA is arranged radially intersecting the bridging portion BB relative to the bridging portion BB, with a portion of the bridging portion BA located radially outside the bridging portion BB.

[0156] Therefore, the configuration relationship between the second linear portions LA2 and LB2 and the first linear portions LA1 and LB1 is replaced, becoming the opposite configuration relationship. That is, the second linear portion LA2 is disposed adjacent to the outermost periphery of the slot 20, and the second linear portion LB2 is disposed adjacent to the radial inner side of the second linear portion LA2.

[0157] In the configuration of the bridging sections BA and BB, any of the configurations shown in the first, second, and third embodiments described above can also be applied. Furthermore, the configuration of the coil segment CS1 can also be any of the configurations shown in the first, second, and third embodiments described above.

[0158] As described above, by multiplying the innermost coil segment CS1 and the outermost coil segment CS4 of the slot 20, the cross-sectional area of ​​the conductor orthogonal to the magnetic flux traversing the slot 20 laterally can be further reduced, thereby reducing eddy currents generated in the conductor during high-speed rotation and the resulting losses. In each coil segment CS1 and CS4, by configuring the bridging portions of the two segmented segments DS1 and DS2 to cross and the positional relationship between the first linear portion and the second linear portion to be misaligned, the generation of circulating current can be suppressed. Therefore, low-loss innermost coils with multiple rows can be achieved without introducing new losses.

[0159] In addition, in the third variation, the number of coil segments is not limited to two; it can also be achieved by using three or more segmented segments.

[0160] Several embodiments of the present invention have been described, but these embodiments are provided by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, and are included in the scope of the invention described in the claims and its equivalents.

[0161] For example, the number of turns of the coil and the number of coil segments are not limited to the above embodiment and can be increased or decreased appropriately. For example, it can also be configured as a linear section with 4 or 8 segments arranged in one slot. The size, material, shape, etc. of the rotor are not limited to the above embodiment and can be modified in various ways according to the design. The rotor and motor of this embodiment are not limited to permanent magnet motors and can also be applied to induction motors.

Claims

1. A stator for a rotary electric motor, comprising: The stator core comprises an annular magnetic yoke having a central axis and a plurality of teeth extending from the inner periphery of the magnetic yoke, with slots formed between adjacent teeth; and The multiphase segmented coil has multiple coil segments, each formed of a flat conductor, and includes a first linear portion and a second linear portion respectively disposed in different slots, as well as a bridging portion located outside the stator core and connecting the first and second linear portions to each other. When the direction of the aforementioned central axis is defined as axial, the direction orthogonal to the aforementioned central axis is defined as radial, and the direction around the aforementioned central axis is defined as circumferential, A plurality of first linear portions or second linear portions are arranged radially within the aforementioned slot. The coil segment disposed at least on the innermost circumference side within the aforementioned slot is formed by joining multiple segmented segments together. Each segment is formed of a flat conductor with a cross-sectional area smaller than that of the flat conductor, and each segment has a first linear portion and a second linear portion, as well as a bridging portion located outside the stator core that connects the first linear portion and the second linear portion to each other. The bridging portions of the aforementioned multiple segmented sections are arranged to intersect each other in the aforementioned radial direction. The first linear portions of the aforementioned plurality of segmented sections are arranged in the slot along the first radial direction, and the second linear portions are arranged in the slot along a direction opposite to the first direction. The coil segment configured on the innermost circumference includes: The first coil segment is composed of a first segment and a second segment; and the second coil segment is composed of a third segment and a fourth segment, and is arranged to sandwich the first coil segment from both sides in the aforementioned circumferential direction. The bridging portion of the first segment comprises: a first section extending circumferentially from the protruding end of the first linear portion; a first curved arm bending outwards radially by a first length from the first section; and a second section extending circumferentially from the first curved arm to the protruding end of the second linear portion, located radially outwards by the first length relative to the first section. The bridging portion of the second segment described above has: a first section extending circumferentially from the protruding end of the first linear portion; a second curved arm portion curving radially outward from the first section to a second length shorter than the first length; and a second section extending circumferentially from the second curved arm portion to the protruding end of the second linear portion, located radially outward by the second length relative to the first section. The first and second curved arm portions are arranged overlappingly in the axial direction, and the second curved arm portion extends intersectingly with the first curved arm portion.

2. The stator of the rotary electric motor according to claim 1, wherein, The bridging portion of the third segment described above has: a first section extending circumferentially from the protruding end of the first linear portion; a third curved arm bending outwards radially by a first length from the first section; and a second section extending circumferentially from the third curved arm to the protruding end of the second linear portion, located radially outwards by the first length relative to the first section. The bridging portion of the fourth segment described above has: a first section extending circumferentially from the protruding end of the first linear portion; a fourth curved arm portion curving radially outward from the first section to a second length shorter than the first length; and a second section extending circumferentially from the fourth curved arm portion to the protruding end of the second linear portion, located radially outward by the second length relative to the first section. The third and fourth curved arm portions are arranged overlappingly in the aforementioned axial direction, and the fourth curved arm portion extends intersectingly with the third curved arm portion.

3. The stator of the rotary electric motor according to claim 2, wherein, The third crank arm portion is disposed on top of the first crank arm portion in the aforementioned axial direction, the second crank arm portion is disposed on top of the third crank arm portion in the aforementioned axial direction, and the fourth crank arm portion is disposed on top of the second crank arm portion in the aforementioned axial direction.

4. The stator of the rotary electric motor according to claim 2, wherein, The fourth crank arm portion is disposed on top of the second crank arm portion in the axial direction, and the first and third crank arm portions are disposed on top of the fourth crank arm portion in the axial direction, and are disposed on top of each other in the radial and circumferential directions.

5. The stator of the rotary electric motor according to claim 2, wherein, The fourth curved arm portion is disposed on top of the second curved arm portion in the aforementioned axial direction, the first curved arm portion is disposed on top of the fourth curved arm portion in the aforementioned axial direction, and the third curved arm portion is disposed on top of the first curved arm portion in the aforementioned axial direction.

6. The stator of the rotary electric machine according to claim 1, wherein, The first coil segment also has a fifth segment. The first linear portions of the first, second, and fifth segments are arranged in the slot along the first radial direction. The second linear portions of the first, second, and fifth segments are arranged in another slot along a direction opposite to the first direction. The second coil segment also has a sixth segment. The first linear portions of the third, fourth, and sixth segments are arranged in the slot along the first radial direction. The second linear portions of the third, fourth, and sixth segments are arranged in another slot along a direction opposite to the first direction.

7. The stator of the rotary electric machine according to claim 1, wherein, The coil segment disposed on the outermost periphery within the aforementioned slot is constructed by joining multiple segmented segments together. Each segment is formed from a flat conductor with a cross-sectional area smaller than that of the flat conductor, and each segment has a first linear portion and a second linear portion, as well as a bridging portion located outside the stator core that connects the first linear portion and the second linear portion to each other. The bridging portions of the aforementioned multiple segmented sections are arranged to intersect each other in the aforementioned radial direction. The first linear portions of the aforementioned plurality of segmented segments are arranged in the aforementioned slot along the aforementioned first radial direction, and the second linear portions are arranged in another of the aforementioned slots along a direction opposite to the aforementioned first direction.

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