Stator for rotating electric machines

Abstract

This makes it easier to ensure the necessary insulation at the joints between connecting sections. [Solution] A stator for a rotating electric machine is disclosed, comprising a stator coil and a stator core, wherein the stator coil has a slot insertion portion and a connecting portion that is exposed from the axial end face of the stator core and extends circumferentially in a manner that connects a pair of slot insertion portions, and each of the connecting portions on one side in the axial direction is formed by joining two connecting portions together in a manner that the joint portion is located at an intermediate position in the circumferential direction, and the joint portion relating to the plurality of connecting portions includes a first joint portion located at the outermost radial position, a second joint portion located at the innermost radial position, and a third joint portion located at an intermediate position between the innermost radial position and the outermost radial position, and the first and second joint portions are offset circumferentially and radially with respect to the third joint portion.

Description

Technical Field

[0006] , , ,

[0001] The present disclosure relates to a stator for a rotating electrical machine.

Background Art

[0002] A stator coil has a slot insertion portion inserted into each slot of a stator core, and an extension portion that is exposed from an axial end surface of the stator core and extends in the circumferential direction in a manner connecting between a pair of slot insertion portions. Each of the extension portions on one side in the axial direction is formed by joining two extension forming portions. A technique is known.

Prior Art Documents

Patent Documents

[0007] In one respect, this disclosure makes it easier to ensure the necessary insulation at the joints between connecting portions. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view of the rotating electric machine (stator) according to this embodiment. [Figure 2] This is a circuit diagram of a Y-connected three-phase coil according to this embodiment. [Figure 3] This is a perspective view of the stator according to this embodiment. [Figure 4] This is a diagram illustrating the configuration of the coil pieces that form the stator coil. [Figure 5] This is a diagram (part 1) showing the configuration related to the U-phase coil. [Figure 6] This is a diagram (part 2) showing the configuration related to the U-phase coil. [Figure 7] This diagram (part 1) shows the configuration of the U-phase coil, with the U1 coil section and the U2 coil section separated into upper and lower parts. [Figure 8] This is a diagram (part 2) showing the configuration of the U-phase coil, with the U1 coil section and the U2 coil section separated into upper and lower parts. [Figure 9] It is a perspective view showing only all the coil pieces forming the U-phase coil. [Figure 10] It is a perspective view showing one of a plurality of types of coil pieces. [Figure 11] It is a perspective view showing another one of a plurality of types of coil pieces. [Figure 12] It is a perspective view showing yet another one of a plurality of types of coil pieces. [Figure 13] It is a perspective view showing yet another one of a plurality of types of coil pieces. [Figure 14] It is a perspective view showing two adjacent coil pieces in the circumferential direction and the radial direction, and is a perspective view showing the arrangement state of the coil piece shown in FIG. 10 and the coil piece shown in FIG. 13. [Figure 15] It is a perspective view showing the coil end on the Z1 side from the outside in the radial direction. [Figure 16] It is a perspective view showing the coil end on the Z1 side from the inside in the radial direction. [Figure 17] It is a plan view showing the coil end on the Z2 side in an axial direction view. [Figure 18] It is a perspective view showing the coil end on the Z1 side from the outside in the radial direction in a direction view close to the axial direction. [Figure 19] It is an explanatory view of the arrangement of the joints according to the comparative example, and is a view schematically showing the arrangement of the four joints in an axial direction view.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not limited thereto, and the shapes and the like in the drawings may be exaggerated partially for the convenience of explanation. Also, in the drawings, for the sake of clarity, only some of the parts having the same attribute and existing in plurality may be provided with reference numerals.

[0010] FIG. 1 is a plan view of a rotating electric machine (stator) according to the present embodiment.

[0011] In this specification, "axial direction" means the direction along the rotation axis (symbol O) of the stator core 10 (rotor 150) (Z direction: see Figure 1). One side of the axial direction is designated as the Z1 side, and the other side as the Z2 side. "Circumferential direction" means the circumferential direction (A direction) of the stator core 10. One side of the circumferential direction is designated as the A1 direction, and the other side as the A2 direction. "Radial direction" means the radial direction (B direction) with respect to the rotation axis of the stator core 10 (rotor 150). "Inner radial direction" and "inner diameter side" mean the direction toward the center of the stator core 10 (B1 direction). "Outer radial direction" and "outer diameter side" mean the direction toward the outside of the stator core 10 (B2 direction).

[0012] As shown in Figure 1, the rotating electric machine 200 comprises a stator 100 and a rotor 150. Each of the stator 100 and rotor 150 is formed in an annular shape. The stator 100 and rotor 150 face each other. The rotor 150 is positioned radially inward (towards the B1 direction) of the stator 100. The rotor 150 is provided with a plurality of permanent magnets (not shown). In other words, the rotating electric machine 200 of this embodiment is configured as an inner rotor type rotating electric machine.

[0013] The stator 100 includes a stator core 10. The stator core 10 is positioned radially opposite the rotor 150. The stator core 10 is also provided with a plurality of (for example, 48) slots 11. Teeth 12 are provided between adjacent slots 11. The stator core 10 is configured such that a plurality of electromagnetic steel sheets are stacked in the rotational axis direction (Z1 direction and Z2 direction), allowing magnetic flux to pass through. The stator core 10 may also be formed by compression molding of magnetic powder. The stator core 10 has end faces 10a on one side (Z1 side) and the other side (Z2 side) in the axial direction. The stator 100 also includes a stator coil 20.

[0014] Figure 2 is a circuit diagram of a Y-connected three-phase coil according to this embodiment.

[0015] As shown in Figure 2, the stator coil 20 is connected to an external power supply and is configured to receive power (for example, three-phase AC power). The stator coil 20 is configured to generate a magnetic field when power is supplied. The stator coil 20 includes a U-phase coil 30, a V-phase coil 40, and a W-phase coil 50, through which the three-phase (U-phase, V-phase, and W-phase) AC currents flow, respectively.

[0016] The U-phase coil 30 includes U1 coil section 31 and U2 coil section 32 connected in parallel to each other. The V-phase coil 40 also includes V1 coil section 41 and V2 coil section 42 connected in parallel to each other. The W-phase coil 50 also includes W1 coil section 51 and W2 coil section 52 connected in parallel to each other. The U-phase coil 30, V-phase coil 40, and W-phase coil 50 are connected in a Y-connection (star connection). In other words, a so-called "2Y" connection is realized. The AC power related to the U-phase, V-phase, and W-phase, respectively, is input to the U-phase coil 30, V-phase coil 40, and W-phase coil 50 from the power line terminal 61. The output sides of the U-phase coil 30, V-phase coil 40, and W-phase coil 50 are connected to each other via the neutral wire terminal 62.

[0017] While this example describes the application to a "2Y" connection, it can also be applied to other connection configurations such as "1Y" and "4Y" connections.

[0018] Figure 3 is a perspective view of the stator 100 according to this embodiment. Figure 4 is a diagram illustrating the configuration of the coil pieces 70 that form the stator coil 20.

[0019] As shown in Figure 3, the stator coil 20 is wound around the stator core 10. In this embodiment, the stator coil 20 consists of multiple coil pieces 70 (Figure 4) arranged in each of the multiple slots 11. Specifically, as shown in Figure 4, the stator coil 20 is formed by connecting multiple coil pieces 70. Each of the multiple coil pieces 70 may be a rectangular cross-section flat conductor covered with an insulating coating.

[0020] Each of the multiple coil pieces 70 may have an inverted U-shape when viewed with the Z1 side facing upwards. Each of the multiple coil pieces 70 may be formed by molding the Z2 side with a mold, and by bending the Z1 side after assembly (see arrow R4). Note that Figure 4 is an explanatory diagram and only shows a portion of the multiple coil pieces 70, but the bending method will differ depending on the type of coil piece 70 (described later).

[0021] Although there are multiple types of coil pieces 70, we will first describe their common characteristics.

[0022] Each of the multiple coil pieces 70 includes a slot insertion portion 21 and a connecting portion 22.

[0023] The slot insertion portion 21 extends in the axial direction (Z direction) and is housed in each of the multiple slots 11.

[0024] The connecting portion 22 connects multiple slot insertion portions 21 in pairs. That is, the connecting portion 22 connects slot insertion portions 21 housed in different slots 11. The connecting portion 22 is formed on both the Z2 side and the Z1 side. The connecting portion 22 forms the coil end portion.

[0025] As shown in Figure 4, after the coil pieces 70 are arranged so that the slot insertion portion 21 is accommodated in each of the slots 11, the connecting portion 22 on the Z1 side is bent in the circumferential direction and may be joined to the connecting portion 22 on the Z1 side of different coil pieces 70 by laser bonding or the like.

[0026] Thus, in this embodiment, the connecting portion 22 on the Z1 side is formed by joining the connecting portion 71 of the two coil pieces 70 together. On the other hand, the connecting portion 22 on the Z2 side is a continuous form without a joint and may be formed by a mold. The connecting portion 22 on the Z2 side has a form that is offset by one turn in the radial direction.

[0027] In the stator coil 20, the U-phase coil 30, V-phase coil 40, and W-phase coil 50 have substantially the same configuration. Therefore, the following description will mainly focus on the U-phase coil 30.

[0028] The U-phase coil 30 is arranged on the stator core 10 in a configuration where two sets, a U1 coil section 31 and a U2 coil section 32, form a parallel circuit. One end of each of the U1 coil section 31 and U2 coil section 32 is connected to a power line terminal 61. AC power is supplied from the power line terminal 61. The other end of each of the U1 coil section 31 and U2 coil section 32 is connected to a neutral wire terminal 62.

[0029] Figures 5 and 6 show the configuration of the U-phase coil 30. Figures 7 and 8 show the configuration of the U-phase coil 30, divided into upper and lower sections, showing the configuration of the U1 coil section 31 and the configuration of the U2 coil section 32, respectively.

[0030] In Figures 5 through 8, the number below the word "Turn" on the left indicates the turn position (which turn it is), and the number below the word "#" indicates the slot position. For example, out of 48 slots 11, the first slot position is indicated by "#1". The symbols "U", "V", or "W" below the numbers indicating the slot positions represent the phase.

[0031] In Figures 5 to 8, the connecting section 22 on the Z1 side is shown with a solid line, and the connecting section 22 on the Z2 side is shown with a dotted line.

[0032] As shown in Figures 5 to 8, the U-phase coil 30 has a 4-turn configuration and is placed in slots #1, #2, #7, #8, #13, #14, #19, #20, #25, #26, #31, #32, #37, #38, #43, and #44 of the 48 slots 11. Here, slots #1 and #2, slots #7 and #8, slots #13 and #14, slots #19 and #20, slots #25 and #26, slots #31 and #32, slots #37 and #38, and slots #43 and #44 are each two adjacent slots 11 in the circumferential direction (direction A). Figures 5 to 8 show the annular stator core 10 in an unfolded state, with the vertical direction being the radial direction (direction B) of the stator core 10 and the horizontal direction being the circumferential direction (direction A) of the stator core 10. In other words, in Figures 5 to 8, the left and right ends of the figures are connected to each other. Although not shown in the illustrations, the V-phase coil 40 and the W-phase coil 50 are positioned in the stator core 10 with two and four slots 11 offset from the U-phase coil 30, respectively.

[0033] Multiple slot insertion sections 21 are housed in each of the multiple slots 11, arranged along the radial direction (B direction) of the stator core 10. Specifically, in this embodiment, four slot insertion sections 21 are arranged in a single row radially within one slot 11. For example, in one slot 11, the slot insertion section 21 located on the outermost side (outer diameter side: B2 direction side) is designated as the 1st turn (1st layer), and the slot insertion section 21 located on the innermost side (inner diameter side: B1 side) is designated as the 4th turn (4th layer).

[0034] In this embodiment, the connecting portion 22 on the Z1 side is joined at an intermediate position in the circumferential direction. In Figures 5 to 8, each joint 90 related to the connecting portion 22 on the Z1 side is schematically shown by a circle (the reference numeral 90 is assigned to only some of them). For example, the connecting portion 22 on the Z1 side between slot 11 #7 and slot 11 #13 has a joint 90 at a circumferential position corresponding to slot 11 #10. Also, the connecting portion 22 on the Z1 side between slot 11 #13 and slot 11 #19 has a joint 90 at a circumferential position corresponding to slot 11 #16.

[0035] In this embodiment, the connecting portion 22 on the Z2 side has two forms. Specifically, the connecting portion 22 on the Z2 side consists of two types: a radially inward connecting portion 221 and a radially outward connecting portion 222. This makes it possible to minimize the number of molds required to form the connecting portion 22 on the Z2 side.

[0036] In other words, if the number of types of connecting sections required on the other axial side (non-welded side) increases, depending on the equipment configuration, there is a problem that the machine cycle time and equipment costs will increase. However, according to this embodiment, such problems can be minimized.

[0037] Next, the stator coil 20 will be further explained with reference to Figure 9 and subsequent figures.

[0038] Figure 9 is a perspective view showing only all the coil pieces 70 that make up the U-phase coil 30, Figures 10 to 13 are perspective views showing some of the various types of coil pieces 70, Figure 14 is a perspective view showing two adjacent coil pieces 70 in the circumferential and radial directions, and is a perspective view showing the arrangement of the coil pieces 70 shown in Figure 10 and the coil pieces 70 shown in Figure 13.

[0039] As shown in Figure 9, the U-phase coil 30 is formed by arranging multiple types of coil pieces 70 and joining the connecting portions 71 on the Z1 side at the joint portion 90, aligning them radially.

[0040] The multiple types of coil pieces 70 include a coil piece 70 positioned on the outermost radial side (also referred to as "coil piece 70A" for distinction), a coil piece 70 positioned on the innermost radial side (also referred to as "coil piece 70B" for distinction), and a coil piece 70 positioned radially between coil piece 70A and coil piece 70B (also referred to as "coil pieces 70C, D" for distinction).

[0041] Each coil piece 70A has a pair of slot insertion portions 21 (hereinafter referred to as "slot insertion portions 210A and 211A" when distinguishing them). The slot insertion portions 210A and 211A are inserted into two slots 11 that are separated by 7 slots in the circumferential direction.

[0042] As shown in Figure 10, the coil piece 70A has two connecting portions 71 (also referred to as "connecting portions 710A and 711A" for distinction) that are continuous with the pair of slot insertion portions 210A and 211A, respectively. The connecting portions 710A and 711A are bent and formed in the circumferential direction so that they extend in the same direction relative to each other in the circumferential direction.

[0043] Of the connecting sections 710A and 711A, connecting section 710A is not offset radially with respect to the continuous slot insertion section 21, whereas connecting section 711A is offset radially outward with respect to the continuous slot insertion section 21. In other words, connecting section 710A is located at the position of the second turn in the radial direction, while connecting section 711A is bent and formed to be offset radially outward by one turn relative to the position of the first turn in the radial direction. Figure 10 shows the coil piece 70A from the radially outward side.

[0044] Each coil piece 70B has a pair of slot insertion portions 21 (hereinafter, when distinguishing them, also referred to as "slot insertion portions 210B and 211B"). The slot insertion portions 210B and 211B are inserted into two slots 11 that are separated by 5 slots in the circumferential direction.

[0045] As shown in Figure 11, the coil piece 70B has two connecting portions 71 (also referred to as "connecting portions 710B and 711B" for distinction) that are continuous with the pair of slot insertion portions 210B and 211B, respectively. The connecting portions 710B and 711B are bent and formed in the circumferential direction so that they extend in the same direction relative to each other in the circumferential direction.

[0046] Of the connecting sections 710B and 711B, connecting section 710B is not offset radially with respect to the continuous slot insertion section 21, whereas connecting section 711B is offset radially outward with respect to the continuous slot insertion section 21. In other words, connecting section 710B is located at the 3rd turn position in the radial direction, while connecting section 711B is bent and formed to be offset radially inward by 1 turn relative to the 4th turn position in the radial direction. Figure 11 shows the coil piece 70B from the radially inward side.

[0047] Each coil piece 70C has a pair of slot insertion portions 21 (hereinafter referred to as "slot insertion portions 210C, 211C" when distinguishing them). The slot insertion portions 210C, 211C are inserted into two slots 11 that are separated by 6 slots in the circumferential direction.

[0048] As shown in Figure 12, the coil piece 70C has two connecting sections 71 (also referred to as "connecting sections 710C and 711C" for distinction) that are continuous with the pair of slot insertion sections 210C and 211C, respectively. The connecting sections 710C and 711C are bent in the circumferential direction so that they extend in opposite directions relative to each other. The connecting sections 710C and 711C are not offset radially with respect to the continuous slot insertion section 21. That is, the connecting sections 710C and 711C are offset by one turn each as a result of being located at the same radial position as the continuous slot insertion section 21 (radial positions that are one turn apart from each other).

[0049] The coil piece 70D has a pair of slot insertion portions 21 (hereinafter referred to as "slot insertion portions 210D, 211D" when distinguishing them). The slot insertion portions 210D, 211D are inserted into two slots 11 that are separated by 6 slots in the circumferential direction.

[0050] As shown in Figure 13, the coil piece 70D has two connecting sections 71 (also referred to as "connecting sections 710D and 711D" for distinction) that are continuous with the pair of slot insertion sections 210D and 211D, respectively. The connecting sections 710D and 711D are bent in the circumferential direction so that they extend in opposite directions relative to each other. The connecting sections 710D and 711D are not offset radially with respect to the continuous slot insertion section 21. That is, the connecting sections 710D and 711D are offset by one turn each as a result of being located at the same radial position as the continuous slot insertion section 21 (radial positions that are one turn apart from each other).

[0051] With this configuration, for example, as shown in Figure 14, the first and second turns of the U-phase coil 30 can be formed by offsetting the coil piece 70A shown in Figure 10 and the coil piece 70D shown in Figure 13 by one slot in the circumferential direction. Similarly, although not shown in the diagram corresponding to Figure 14, the second and third turns of the U-phase coil 30 can be formed by offsetting the coil piece 70D shown in Figure 13 and the coil piece 70C shown in Figure 12 by one slot in the circumferential direction. Similarly, although not shown in the diagram corresponding to Figure 14, the third and fourth turns of the U-phase coil 30 can be formed by offsetting the coil piece 70C shown in Figure 12 and the coil piece 70B shown in Figure 11 by one slot in the circumferential direction.

[0052] Figures 15 to 18 show characteristic configurations of the coil ends. Figure 15 is a perspective view showing the coil end on the Z1 side from the radially outer side, and Figure 16 is a perspective view showing the coil end on the Z1 side from the radially inner side. Figure 17 is a plan view showing the coil end on the Z2 side in an axial view.

[0053] The Q1 section shown in Figure 15 corresponds to the Q1 section shown in Figure 14. In this embodiment, as shown in the Q1 section, the connecting sections 71 that are continuous from a pair of slot insertion sections 21 located at the outermost radial positions of adjacent slots 11 extend in opposite directions in the circumferential direction, and intersect radially with respect to the other, with one being radially offset. Specifically, as shown in Figures 14 and 15, the connecting section 711A and the connecting section 711D are continuous from a pair of slot insertion sections 21 located at the outermost radial positions of adjacent slots 11. The connecting section 711A and the connecting section 711D extend in opposite directions in the circumferential direction, and the connecting section 711A intersects radially with respect to the connecting section 711D, with the connecting section 711A being radially offset outward.

[0054] With this distinctive configuration (hereinafter also referred to as the "first distinctive configuration"), as shown in Figure 15, there are only two overlapping connecting sections 71 in the radial position of the first turn when viewed in the axial direction, thus reducing the axial size on the radially outer side of the coil end. The overlapping connecting sections 71 in the radial position of the first turn when viewed in the axial direction are a pair of connecting sections 71 that are continuous from two slot insertion sections 21 that are separated by one turn in the circumferential direction, as shown in Figure 15. The pair of connecting sections 71 are bent in the same direction in the circumferential direction, forming connecting sections 22 that relate to different phases.

[0055] Furthermore, this first characteristic configuration, when combined with other characteristic configurations described later (the second characteristic configuration described later), allows for the realization of the characteristic configuration of the coil end on the Z2 side (the third characteristic configuration described later), as shown in Figure 17.

[0056] In this embodiment, the connecting portion 71, which is continuous with a pair of slot insertion portions 21 located at the radial intermediate position of adjacent slots 11 (a position that is neither the radially innermost nor the radially outermost), extends toward the same side in the circumferential direction, and one portion overlaps the other in the axial direction while being offset in the axial direction.

[0057] The Q2 section shown in Figure 16 has the same configuration as the Q1 section shown in Figure 15. That is, in this embodiment, as shown in the Q2 section, the connecting sections 71 that are continuous from a pair of slot insertion sections 21 located at the innermost radial position of adjacent slots 11 extend toward opposite sides in the circumferential direction, and intersect radially with respect to the other, with one being radially offset. Specifically, as shown in Figure 16, the connecting section 711B of one phase (e.g., U phase) and the connecting section 711C of the other phase (e.g., V phase) are continuous from a pair of slot insertion sections 21 located at the outermost radial position of adjacent slots 11. The connecting section 711B and the connecting section 711C extend toward opposite sides in the circumferential direction, and the connecting section 711B intersects radially with respect to the connecting section 711C, with the connecting section 711B being radially offset inward.

[0058] With this distinctive configuration (hereinafter also referred to as the "second distinctive configuration"), as shown in Figure 16, at the radial position of the fourth turn, there are only two overlapping connecting sections 71 when viewed in the axial direction, thus reducing the axial size on the radially inner side of the coil end. The overlapping connecting sections 71 when viewed in the axial direction at the radial position of the fourth turn are, as shown in Figure 16, a pair of connecting sections 71 that are continuous from two slot insertion sections 21 that are separated by one turn in the circumferential direction. The pair of connecting sections 71 are bent in the same direction in the circumferential direction, forming connecting sections 22 that relate to different phases.

[0059] Furthermore, this second characteristic configuration, when combined with the first characteristic configuration described above, makes it possible to reduce the radial size of the coil end on the Z2 side.

[0060] Specifically, according to the first and second characteristic configurations described above, as a third characteristic configuration, the connecting portion 22 on the Z2 side can have a form that is offset by one turn in the radial direction, as shown in Figure 17 (see also Figures 9 to 14). In this case, the connecting portion 22 on the Z2 side that is continuous from the slot insertion portion 21 of the first turn is offset radially inward and continues to the slot insertion portion 21 of the second turn. Similarly, the connecting portion 22 on the Z2 side that is continuous from the slot insertion portion 21 of the fourth turn is offset radially outward and continues to the slot insertion portion 21 of the third turn. As a result, the radial size of the coil end on the Z2 side is reduced to only four turns, thereby reducing the radial size of the coil end on the Z2 side.

[0061] Figure 18 is a perspective view showing the coil end on the Z1 side from the radially outer side, viewed in a direction close to the axial direction.

[0062] In this embodiment, by having the first and second characteristic configurations described above, a fourth characteristic configuration is possible, in which the joint portions 90 can be arranged in a staggered pattern on the Z1 side.

[0063] Specifically, the multiple joints 90 arranged in a staggered pattern consist of the joint 90 located furthest radially outward (hereinafter referred to as the "first joint 91" for distinction), the joint 90 located furthest radially inward (hereinafter referred to as the "second joint 92" for distinction), and two joints 90 located in the radially intermediate position (hereinafter referred to as the "third joint 93" for distinction). The radially intermediate position refers to a position that is neither the radially inward nor the radially outward, and specifically refers to a position radially inward from the first joint 91 and radially outward from the second joint 92.

[0064] The first joint 91 is formed by joining connecting forming portions 71 that are continuous with the slot insertion portions 21 located at the outermost radial position (i.e., the first turn) within the pair of slots 11. In this case, the pair of slots 11 are two slots 11 that are separated by 7 slots, as described above.

[0065] The second joint 92 is formed by joining connecting forming portions 71 that are continuous with the slot insertion portions 21 located at the innermost radial position (i.e., the 4th turn) within the pair of slots 11. In this case, the pair of slots 11 are two slots 11 that are separated by 5 slots, as described above.

[0066] The third joint 93 is formed by joining two connecting forming portions 71 that are continuous with the slot insertion portions 21 located at radial intermediate positions within the pair of slots 11, and radially offset from each other by one turn. In this case, the pair of slots 11 are two slots 11 that are separated by six slots, as described above.

[0067] In this case, the first joint 91 and the second joint 92 are offset circumferentially and radially with respect to the third joint 93. In this case, the first joint 91 and the second joint 92 are offset circumferentially by half a slot pitch and radially by two turns with respect to the third joint 93. Here, one slot pitch corresponds to the distance between the circumferential center positions of adjacent slots 11 (distance along the circumferential direction). The first joint 91 and the second joint 92 are located at the same circumferential position relative to each other and are offset radially by four turns.

[0068] The first joint 91 and the second joint 92 are located at the same circumferential position, midway between adjacent slots 11 in the circumferential direction (the circumferential center position of the teeth 12). Furthermore, the first joint 91 and the second joint 92 are regularly positioned in the circumferential direction at a 2-slot pitch. The radial center of the first joint 91 corresponds to the radially outer position of the first turn, and the radial center of the second joint 92 corresponds to the radially inner position of the fourth turn. On the other hand, the third joint 93 is located at the same circumferential position as the slots 11. The third joint 93 is regularly positioned in the circumferential direction at a 1-slot pitch.

[0069] Figure 19 is an explanatory diagram of the arrangement of the joint portion 90' according to the comparative example, and is a schematic diagram showing the arrangement of the four joint portions 90' in an axial view.

[0070] The comparative example has a 4-turn configuration similar to this embodiment, but lacks the first and second characteristic configurations described above. Therefore, the joints 90' are arranged within a radial range of 4 turns, and two of them are adjacent radially. In this case, the gap Δ (radial gap) between radially adjacent joints 90' must be set relatively wide due to the required insulation distance and the requirements of the jig (welding jig). Consequently, in the comparative example, in order to secure the insulation distance, it is necessary to bend the connecting portion continuous with the slot insertion portion of the second or third turn radially, or to form a gap between the slot insertion portion of the second and third turns. This presents problems such as complicating the molding process and reducing the space utilization rate within the slot. Alternatively, if the circumferential position of the joints 90' is to be shifted, it becomes necessary to lengthen the circumference of one of the pair of connecting portions to be welded, which presents problems such as increasing the axial size of the coil end.

[0071] In contrast, according to the characteristic arrangement of the joints 90 in this embodiment (i.e., staggered arrangement), the first joint 91 and the second joint 92 are offset circumferentially and radially with respect to the third joint 93, so that the insulation distance between each joint 90 can be efficiently secured. Therefore, for example, it is possible to apply an insulating coating (not shown) only to the second joint 92, and not to the first joint 91 and the second joint 92. Alternatively, the insulating properties of the insulating coating applied to the first joint 91 and the second joint 92 may be significantly lower than the insulating properties of the insulating coating applied to the third joint 93. Conversely, it is also possible to apply an insulating coating only to the first joint 91 and the second joint 92, and not to the third joint 93. Alternatively, the insulating properties of the insulating coating applied to the third joint 93 may be significantly lower than the insulating properties of the insulating coating applied to the first joint 91 and the second joint 92. In all cases, the method for forming the insulating coating is arbitrary, and methods such as immersion in a tank of insulating material, coating, or electrodeposition coating may be used. Furthermore, the insulating properties of the insulating coating may be adjusted by the thickness or material of the insulating coating (e.g., filler).

[0072] Furthermore, according to this embodiment, since each joint 90 is formed at an intermediate position in the circumferential direction of the connecting portion 22 on the Z1 side, as described above, the axial size of the coil end on the Z1 side can be minimized. In other words, since each joint 90 is formed at an intermediate position in the circumferential direction of the connecting portion 22 on the Z1 side, the necessary insulation distance between each joint 90 can be secured, thereby minimizing the axial size of the coil end on the Z1 side.

[0073] Although each embodiment has been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope described in the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above.

[0074] For example, in the embodiment described above, the slot insertion portion 21 continuous with the two connecting portions 71 forming the first joint 91 is inserted into two slots 11 separated by 7 slots, the slot insertion portion 21 continuous with the two connecting portions 71 forming the second joint 92 is inserted into two slots 11 separated by 5 slots, and the slot insertion portion 21 continuous with the two connecting portions 71 forming the third joint 93 is inserted into two slots 11 separated by 6 slots. However, the spacing between pairs of slots where the slot insertion portion 21 continuous with the two connecting portions 71 forming each joint 90 is located is not limited to these. That is, the spacing for the first joint 91 is 7 slots (an example of the first number of slots), the spacing for the second joint 92 is 5 slots (an example of the second number of slots), and the spacing for the third joint 93 is 6 slots (an example of the third number of slots), but is not limited to these. For example, the spacing for the first joint 91 may be N1 slots, the spacing for the second joint 92 may be N2 slots, and the spacing for the third joint 93 may be N3 slots. In this case, N1 (an example of the number of first slots) and N3 (an example of the number of third slots) may both be even numbers, and N2 (an example of the number of second slots) may be odd numbers, and N1 > N3 > N2. Alternatively, N1 and N3 may both be odd numbers, and N2 may be even numbers, and N1 > N3 > N2. In this case, N1=7, N2=5, and N3=6 correspond to the embodiment described above.

[0075] Furthermore, in the embodiment described above, both the first characteristic configuration and the second characteristic configuration are realized as described above, but either one or the other may be realized.

[0076] The following additional information is disclosed regarding the above embodiments.

[0077] [Note 1] Stator coil and, It comprises a stator core having multiple slots around which the stator coil is wound, The stator coil is, A slot insertion portion inserted into each corresponding slot among the plurality of slots, The stator core has a connecting portion that is exposed from the axial end face and extends circumferentially in a manner that connects the pair of slot insertion portions, Each of the aforementioned connecting portions on one side in the axial direction is formed by joining two connecting portions together such that the joint is located at an intermediate position in the circumferential direction. The joint portion relating to the multiple connecting portions includes a first joint portion located furthest radially outward, a second joint portion located furthest radially inward, and a third joint portion located at an intermediate position between the furthest radially inward position and the furthest radially outward position. A stator for a rotating electric machine, wherein the first joint and the second joint are offset circumferentially and radially with respect to the third joint.

[0078] [Note 2] The two connecting portions that form the first joint connect the pairs of slot insertion portions that are separated circumferentially by the number of first slots, The two connecting portions that form the second joint connect the pairs of slot insertion portions that are separated circumferentially by the number of second slots, The two connecting portions forming the second joint connect the pairs of slot insertion portions that are separated circumferentially by the number of third slots, The stator for a rotating electric machine as described in Appendix 1, wherein the number of the first slots and the number of the second slots are the same with respect to odd or even numbers, and the number of the third slots is different with respect to odd or even numbers.

[0079] [Note 3] The plurality of slots are formed at a predetermined pitch in the circumferential direction, The first joint and the second joint are located at the same circumferential position. The stator for a rotating electric machine as described in Appendix 1, wherein the first joint and the second joint are offset circumferentially by half of the predetermined pitch with respect to the third joint.

[0080] [Note 4] The first joint is formed by joining the connecting forming portions that are continuous with the slot insertion portions located at the radially outermost positions within the pair of slots, The second joint is formed by joining the connecting forming portions that are continuous with the slot insertion portions located at the innermost radial position within the pair of slots, The stator for a rotating electric machine according to any one of the appendices 1 to 3, wherein the third joint is formed by joining the connecting forming portions that are continuous with the slot insertion portion located at an intermediate position between the innermost radial position and the outermost radial position within a pair of slots, and at radial positions offset by one turn from each other in the radial direction.

[0081] [Note 5] Either the first joint or the third joint has an insulating coating, and the other does not have an insulating coating, or has an insulating coating of lower quality than the other. The second joint has the same insulating properties as the first joint, and is a stator for a rotating electric machine as described in any one of the appendices 1 to 4. [Explanation of Symbols]

[0082] 100 Stator, 10 Stator core, 11 Slot, 20 Stator coil, 21 Slot insertion section, 22 Connecting section, 71 Connecting section

Claims

1. Stator coil and It comprises a stator core having multiple slots around which the stator coil is wound, The stator coil is, A slot insertion portion inserted into each corresponding slot among the aforementioned plurality of slots, The stator core has a connecting portion that is exposed from the axial end face and extends circumferentially in a manner that connects the pair of slot insertion portions, Each of the aforementioned connecting portions on one side in the axial direction is formed by joining two connecting portions together such that the joint is located at an intermediate position in the circumferential direction. The joint portion relating to the multiple connecting portions includes a first joint portion located furthest radially outward, a second joint portion located furthest radially inward, and a third joint portion located at an intermediate position between the furthest radially inward position and the furthest radially outward position. A stator for a rotating electric machine, wherein the first joint and the second joint are offset circumferentially and radially with respect to the third joint.

2. The two connecting portions that form the first joint connect the pairs of slot insertion portions that are separated in the circumferential direction by the number of first slots, The two connecting portions that form the second joint connect the pairs of slot insertion portions that are separated circumferentially by the number of second slots, The two connecting portions that form the second joint connect the pairs of slot insertion portions that are separated circumferentially by the number of third slots, The stator for a rotating electric machine according to claim 1, wherein the number of first slots and the number of second slots are the same with respect to odd or even numbers, and differ with respect to odd or even numbers with respect to the number of third slots.

3. The plurality of slots are formed at a predetermined pitch in the circumferential direction, The first joint and the second joint are located at the same circumferential position, The stator for a rotating electric machine according to claim 1, wherein the first joint and the second joint are offset circumferentially from the third joint by half of the predetermined pitch.

4. The first joint is formed by joining the connecting forming portions that are continuous with the slot insertion portions located at the radially outermost positions within the pair of slots, The second joint is formed by joining the connecting forming portions that are continuous with the slot insertion portions located at the innermost radial position within the pair of slots. The stator for a rotating electric machine according to any one of claims 1 to 3, wherein the third joint is formed by joining the connecting forming portions that are continuous with the slot insertion portion located at an intermediate position between the innermost radial position and the outermost radial position within a pair of slots, and at radial positions offset by one turn from each other in the radial direction.

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