Stator, rotating electric machine, and method for manufacturing a stator

Abstract

To provide a stator that allows coolant to flow between the conductor and the slot and has an insulator that can be easily and economically manufactured. [Solution] A stator comprising a conductor and an insulator disposed between the slot and the conductor in a slot formed in the stator core, and having a coolant flow path for circulating coolant between the slot and the conductor, wherein the insulator has a foamed layer that foams when heated in the slot, and the foamed layer has a foamed function portion that fills the gap between the slot and the conductor by a heat foaming function, and a foamed function reduced portion that is thinner than the foamed function portion because the heat foaming function of the foamed layer is reduced compared to the foamed function portion, and forms a gap between the slot and the conductor through which coolant can flow.

Description

Technical Field

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

Background Art

[0002] Conventionally, a stator is known in which conductors are arranged and inserted into slots of a stator of a rotating electric machine via an insulator, and the insulator is formed with a coolant flow path for cooling the conductors between the conductors. On the surface of the insulator facing the conductors, a plurality of rows of foamed resin layers are formed by heating and foaming a foaming adhesive formed in a plurality of rows in a strip shape. The coolant flow path is formed by a gap between adjacent foamed resin layers (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology, since it is necessary to apply and form a foaming adhesive in a row shape on the base material of the insulator, the manufacture of the insulator is complicated. Moreover, since the arrangement of the coolant flow path varies depending on the type of the stator (the thickness of the stator core, the cross-sectional shape of the conductor, the number of rows of the conductors, the size of the slot with respect to the conductor), when the type of the stator is different, it is necessary to apply and form the foaming adhesive while changing the arrangement for each type, and the cost of the insulator becomes high, increasing the manufacturing cost of the stator. <00000​​​​​​​

[0006] (1) A stator (e.g., stator 3 described later) comprising a conductor (e.g., conductors 8, 81, 82 described later) in a slot (e.g., slot 7 described later) formed in a stator core (e.g., stator core 6 described later), an insulator (e.g., insulator 11 described later) disposed between the slot and the conductor, and having a coolant flow path (e.g., a second coolant flow path 21b described later) for circulating coolant (e.g., coolant CL described later) between the slot and the conductor, wherein the insulator is heated within the slot The stator has a foamed layer (for example, the foamed layer 112 described later) that foams when heated, and the foamed layer has a foaming function portion (for example, the foaming function portion Fa described later) that fills the gap between the slot and the conductor by a heat foaming function, and a foaming function reduction portion (for example, the foaming function reduction portion Fb described later) which is thinner than the foaming function portion because the heat foaming function of the foamed layer is reduced compared to the foaming function portion, and forms a gap between the slot and the conductor through which the coolant can flow.

[0007] According to (1) above, a stator having an insulator through which coolant can flow can be easily and economically manufactured by simply forming a foamed functional part that fills the gap between the slot and the conductor, and a foamed functional reduction part that is thinner than the foamed functional part and forms a gap between the slot and the conductor through which coolant can flow, on the foamed layer formed on the insulator.

[0008] (2) In the stator described in (1) above, the conductor has a normal shape portion (for example, normal shape portions 8N, 81N, 82N described later) and a specific shape portion (for example, specific shape portions 8S, 81S, 82S described later) in the portion inserted into the slot, the conductor width along the circumferential direction of the stator core is partially thinner than the conductor width of the normal shape portion, and the coolant can flow in the radial direction of the stator core, and the foaming function reducing portion of the insulator is arranged in the portion of the conductor corresponding to the specific shape portion.

[0009] According to (2) above, the cooling liquid can be smoothly circulated along the compressed portion of the conductor within the slot, thereby improving the cooling performance of the conductor.

[0010] (3) In the stator described in (1) or (2) above, the slot has a slit (for example, a slit 71 described later) that opens toward the central axis hole (for example, a central axis hole 61 described later) of the stator core, and the foamed functional portion of the insulator is arranged to block the slit.

[0011] According to (3) above, the coolant that flows into the slot can effectively prevent it from leaking out of the slit.

[0012] (4) A rotating electric machine (e.g., rotating electric machine 1 described below) comprising a stator as described in any one of items (1) to (3) above (e.g., stator 3 described below).

[0013] According to (4) above, a stator having an insulator through which coolant can flow can be easily and economically manufactured by simply forming a foamed functional portion that fills the gap between the slot and the conductor, and a foamed functional reduction portion that is thinner than the foamed functional portion and forms a gap between the slot and the conductor through which coolant can flow, on the foamed layer formed on the entire surface of the insulator.

[0014] (5) A method for manufacturing a stator (e.g., a stator 3 described later) comprising a conductor (e.g., conductors 8, 81, 82 described later) and an insulator (e.g., an insulator 11 described later) disposed between the slot and the conductor, wherein the stator (e.g., a stator core 6 described later) has a slot (e.g., a slot 7 described later) formed in the stator core, and the stator has a coolant flow path (e.g., a second coolant flow path 21b described later) for circulating a coolant (e.g., a coolant CL described later) between the slot and the conductor, wherein the insulator has a foamed layer (e.g., a foamed layer 112 described later) that foams when heated in the slot, and before inserting the insulator into the slot A method for manufacturing a stator, comprising: locally heating the foamed layer in areas where a gap is required between it and at least the conductor through which the coolant can flow, causing the foamed layer to foam; then pressurizing the foamed areas to reduce the foaming function, thereby forming a foaming function reduction portion (for example, a foaming function reduction portion Fb described later) in the foamed layer; inserting the insulator on which the foaming function reduction portion is formed into the slot; and heating the entire insulator to heat and foam the foamed layer other than the foaming function reduction portion, thereby forming a foaming function portion (for example, a foaming function portion Fa described later); and using the foaming function portion to fill the gap between the slot and the conductor.

[0015] According to (5) above, by locally heating and foaming the foamed layer formed on the insulator and then pressurizing it, a foamed function reduction portion can be formed in the foamed layer, and by heating the entire insulator, a foamed function portion that fills the gap between the slot and the conductor can be formed. Thus, a stator equipped with an insulator that has a locally located area through which a coolant can flow can be easily and economically manufactured.

[0016] (6) In the method for manufacturing a stator as described in (5) above, a normal-shaped portion (for example, normal-shaped portions 8N, 81N, 82N described later) and a specific-shaped portion (for example, specific-shaped portions 8S, 81S, 82S described later) are formed in the portion of the conductor that is inserted into the slot, and the conductor width along the circumferential direction of the stator core is partially thinner than the conductor width of the normal-shaped portion, and the cooling liquid is made to flow in the radial direction of the stator core. The foaming function reducing portion of the insulator is formed to be located in the portion of the conductor corresponding to the specific-shaped portion.

[0017] According to (6) above, the coolant can be smoothly circulated along the crushed portion of the conductor in the slot, improving the cooling performance of the conductor and enabling the stator to be manufactured easily and economically.

[0018] (7) In the method for manufacturing a stator as described in (5) or (6) above, the slot has a slit (for example, a slit 71 described later) that opens toward the central axis hole (for example, a central axis hole 61 described later) of the stator core, and the foamed functional portion of the insulator is formed to be placed in the slit.

[0019] According to (7) above, a stator that can effectively prevent the coolant flowing into the slot from leaking out of the slit can be manufactured easily and economically. [Effects of the Invention]

[0020] According to this disclosure, it is possible to provide a stator having an insulator that allows a coolant to flow between a conductor and a slot and can be manufactured easily and economically, a rotating electric machine equipped with the same, and a method for manufacturing the stator. [Brief explanation of the drawing]

[0021] [Figure 1] This is a conceptual diagram of a coolant circulation mechanism in a rotating electric machine, which is an example of the disclosure. [Figure 2] Figure 1 is a schematic diagram showing an example of a coolant flow path from the stator core to the conductor in a rotating electric machine. [Figure 3] It is a schematic diagram showing another example of a coolant flow path from a stator core to a conductor in the rotating electric machine of FIG. 1. [Figure 4A] It is a diagram showing one step in an example of a method for manufacturing a conductor applied to the rotating electric machine of FIG. 1. [Figure 4B] It is a diagram showing the next step in an example of a method for manufacturing a conductor applied to the rotating electric machine of FIG. 1. [Figure 4C] It is a diagram showing a further next step in an example of a method for manufacturing a conductor applied to the rotating electric machine of FIG. 1. [Figure 5] It is a schematic diagram showing a coolant flow path within a rectangular region IS in FIGS. 2 and 3. [Figure 6] It is a schematic diagram showing the coolant flow path of FIG. 5 in a cross-section taken along line A-A. [Figure 7] It is a schematic diagram showing the coolant flow path of FIG. 5 in a cross-section taken along line B-B. [Figure 8] It is a perspective view showing a stator of a rotating electric machine which is another example of the present disclosure. [Figure 9] It is a schematic diagram showing an example of a coolant flow path within a slot in the stator of FIG. 8. [Figure 10] It is a schematic diagram showing a coolant flow path within a rectangular region IS in FIG. 9. [Figure 11] It is a schematic diagram showing the coolant flow path of FIG. 10 in a cross-section taken along line A-A. [Figure 12] It is a schematic diagram showing the coolant flow path of FIG. 10 in a cross-section taken along line B-B. [Figure 13] It is a diagram showing another example of conductors arranged within slots of the rotating electric machines of FIGS. 1 and 8. [Figure 14] It is a diagram showing yet another example of conductors arranged within slots of the rotating electric machines of FIGS. 1 and 8. [Figure 15A] It is a diagram showing one step in another example of a method for manufacturing a conductor applied to the rotating electric machines of FIGS. 1 and 8. [Figure 15B] It is a diagram showing the next step in another example of a method for manufacturing a conductor applied to the rotating electric machines of FIGS. 1 and 8. [Figure 15C]Figures 1 and 8 show further steps in another example of a method for manufacturing a conductor applied to a rotating electric machine. [Figure 16] Figures 5 to 7 are perspective views showing an example of the configuration around the coolant flow path. [Figure 17] This is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 16. [Figure 18] Figures 5 to 7 are perspective views showing other examples of configurations around the coolant flow path. [Figure 19] This is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 18. [Figure 20] Figures 5 to 7 are perspective views showing yet another example of the configuration around the coolant flow path. [Figure 21] This is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 20. [Figure 22] This is a cross-sectional view of an insulator used in the rotating electric machine shown in this embodiment. [Figure 23] This is a front view showing the insulator used in the rotating electric machine shown in this embodiment, in an unfolded state. [Figure 24] Figure 23 is a schematic cross-sectional view showing the stator slots containing the insulator and conductor. [Figure 25] Figure 24 is a schematic diagram showing the slot in cross-section along the CC line. [Figure 26] This is a schematic diagram showing an enlarged view of the relationship between the insulator and the crushed portion of the conductor in the slot shown in Figure 24. [Figure 27] Figure 23 illustrates the manufacturing process of the insulator shown. [Modes for carrying out the invention]

[0022] The rotating electric machine of this disclosure will be described below with reference to the drawings. In the following figures, corresponding parts are denoted by the same reference numerals. In figures with direction indications, AD represents the axial direction of the rotating electric machine and stator, CD represents the circumferential direction of the rotating electric machine and stator, and RD represents the radial direction of the rotating electric machine and stator.

[0023] Figure 1 is a conceptual diagram of a coolant circulation mechanism in a rotating electric machine 1, which is an example of the present disclosure. In Figure 1, the rotating electric machine 1 is composed of a rotor 2 and a stator 3. The rotor 2 is formed in a cylindrical shape. The stator 3 is arranged around the rotor 2 with a predetermined gap. The stator 3 has a stator core 6 with an annular cross-section. The stator core 6 has a central shaft hole 61 that penetrates axially through its center.

[0024] A casing 4, which forms the outer shell of the rotating electric machine 1, is provided in contact with the outer circumference of the stator 3. A rotating shaft 5 passes through the rotor 2 at its center of rotation. The rotating shaft 5 is supported at both axial ends of the casing 4 by bearings (not shown).

[0025] In the stator core 6 of the stator 3, multiple slots 7 are arranged circumferentially at equal intervals. Each slot 7 has a slit 71 that opens toward the central axial hole 61 of the stator core 6. The slits 71 are formed along the axial direction of the stator core 6. Multiple conductors 8 are arranged in each of the multiple slots 7 of the stator core 6. The conductors 8 are rectangular conductors (square conductors) with a rectangular cross-section. The multiple conductors 8 are electrically connected to form a coil 9 arranged in the stator core 6.

[0026] An insulator 11 is placed along the inner wall surface 10 in each of the multiple slots 7. As shown in Figure 22, the insulator 11 has a foamed layer 112 covering the entire surface on one side of a sheet-like base material 111, and a non-foamed adhesive layer 113 on the other side. The adhesive layer may be formed only in the relevant areas.

[0027] The rotating electric machine 1 generates heat due to copper and iron losses, but the stator core 6 and coil 9 are cooled by coolant circulating in a coolant flow path 12 formed in the stator 3 (described later). For example, ATF (automatic transmission fluid) can be used as the coolant. Coolant from the coolant reservoir 13 provided in the casing 4 is supplied to the suction side of the pump 15 through a filter 14. This coolant is cooled by heat exchange with the coolant flowing in the external coolant flow path 17 in a heat exchanger 16 provided on the delivery side of the pump 15, and is supplied to the coolant supply port 19 of the stator core 6 through a coolant supply passage 18. The coolant supplied to the stator core 6 flows through a path described later, cooling the conductors 8 in the stator core 6 and slots 7, and is recovered in the coolant reservoir 13, where it is recirculated repeatedly.

[0028] Figure 2 is a schematic diagram showing an example of a coolant flow path 12 from the stator core 6 to the coil 9 in the slot 7 in the rotating electric machine 1 of Figure 1. Figure 3 is a schematic diagram showing another example of a coolant flow path 12 from the stator core 6 to the coil 9 in the rotating electric machine 1 of Figure 1. Referring to Figure 2, the coolant flow path 12 is configured to reach the coil 9 in the slot 7, passing from the casing 4 side of the stator 3 through the stator core coolant flow path 20 provided in the stator core 6. Note that in the following figures, the insulator 11 in the slot 7 may be omitted to facilitate understanding of the coolant flow path 12.

[0029] In Figure 2, the coolant flow path 12 is configured such that the coolant supply port 19 of the casing 4 and the outer peripheral end of the slot 7 communicate with each other via a stator core internal coolant flow path 20 provided within the stator core 6. In the coolant flow path 12 of Figure 2, the stator core internal coolant flow path 20 extends straight radially inward from the coolant supply port 19 of the casing 4 to the outer peripheral end of the slot 7 and communicates with a first coolant flow path 21a, which will be described later. The first coolant flow path 21a communicates with a second coolant flow path 21b that runs along the longitudinal direction of the straight section of the conductor 8.

[0030] On the other hand, the stator core coolant flow path 20 in the coolant flow path 12 of Figure 3 extends axially from the coolant supply port 19 provided at the side end near the outer circumference of the stator core 6, changes direction radially inward at an intermediate position in the thickness dimension of the stator core 6, reaches the outer circumference end of the slot 7, and communicates with the first coolant flow path 21a, which will be described later. The first coolant flow path 21a communicates with the second coolant flow path 21b which runs along the longitudinal direction of the straight section of the conductor 8. Note that the stator core coolant flow path 20 in Figure 3 communicates with the coolant circumferential passage 21 formed in the circumferential direction (the direction intersecting the plane of the paper in Figure 3) at a position along the way to the radially inward direction.

[0031] Here, the conductor 8 that constitutes the coil 9 will be explained with reference to Figures 4A, 4B, and 4C. Figure 4A shows one step in an example of a method for manufacturing the conductor 8 applied to the rotating electric machine 1. Figure 4B shows the next step in an example of a method for manufacturing the conductor 8. Figure 4C shows a further subsequent step in an example of a method for manufacturing the conductor 8.

[0032] First, prepare the conductor 8 shown in Figure 4A. This conductor 8 has a constant rectangular cross-sectional shape along its entire length, and its cross-sectional dimensions are also constant. Like other common rectangular conductors of this type, the conductor 8 is covered with an insulating coating.

[0033] Next, the intermediate portion of the straight section of the conductor 8 that is placed in the slot 7 is partially pressed with a press machine. The direction in which pressure is applied to the conductor 8 is the direction along the circumferential direction of the stator core 6 when the conductor 8 is inserted into the slot 7. Due to this pressure, as shown in Figure 4B, the intermediate portion of the conductor 8 is partially crushed and deformed, forming a specific shaped section 8S in which the conductor width along the circumferential direction of the stator core 6 is partially thinner. In the specific shaped section 8S, the thickness dimension in the direction perpendicular to the longitudinal direction of the conductor 8 is relatively thin in one direction (dimension CW in Figure 4B) and relatively thick in the other direction (dimension EW in Figure 4B). In this case, the normal shaped section 8N of the conductor 8 that is not the specific shaped section 8S is not crushed by the press machine and maintains its original form, as shown in Figure 4A, that is, the cross-sectional shape is a constant rectangle along its entire length, and the dimensions of its cross-section are also constant as before. Therefore, the conductor width of the normal-shaped portion 8N along the circumferential direction of the stator core 6 is thicker than the conductor width of the specific-shaped portion 8S along the circumferential direction of the stator core 6. The inventors have also verified that even if the conductor 8 is partially deformed by applying pressure with a press machine as shown in Figure 4B, no damage occurs to the insulating coating.

[0034] In the next step, multiple conductors 8, formed as shown in Figure 4B, are arranged in the slots 7 so that the positions of the specific shaped portions 8S align with each other, as shown in Figure 4C. The ends of the conductors 8 (normally shaped portions 8N) arranged in this manner are made to obtain a predetermined electrical connection relationship and function as a coil 9. Since the conductors 8 do not have special grooves along their longitudinal direction, they are easy to manufacture. Alternatively, at the stage shown in Figure 4A, a conductor 8 without an insulating coating may be prepared, and after partially pressing and deforming it with a press machine as shown in Figure 4B, an insulating coating may be applied (painted) to the parts other than the welding area.

[0035] As described above, by using a conductor 8 in which a specific shape portion 8S is formed between the normally shaped portions 8N, which are crushed portions obtained by partially crushing and deforming the conductor 8, a coolant flow path is formed around the coil 9. Next, the coolant flow path around the coil 9 will be described with reference to Figures 5, 6 and 7.

[0036] Figure 5 is a schematic diagram showing the coolant flow path within the rectangular region IS in Figures 2 and 3. Figure 6 is a schematic diagram showing the coolant flow path of Figure 5 in a cross-section along line AA. Figure 7 is a schematic diagram showing the coolant flow path of Figure 5 in a cross-section along line BB. In the portion shown in Figure 6, specific shaped portions 8S of the conductor 8 are arranged in the radial direction (radial direction of the stator core 6) within the slot 7, overlapping each other without any gaps.

[0037] In Figure 6, the relatively thicker dimension EW portion of the specific shaped portion 8S shown in Figure 4B overlaps radially within the slot 7, while the relatively thinner dimension CW portion faces the stator core 6 in the circumferential direction (left-right direction in Figure 6) within the slot 7. In this state, the gaps created between both sides of the specific shaped portion 8S of each conductor 8 (both sides of the relatively thin dimension CW portion) and the inner wall of the slot 7 constitute the second coolant flow path 21b. As schematically shown on the right side of Figure 6, the coolant CL flows through the second coolant flow path 21b from the radial outside to the inside. An opening 114 is formed in the insulator 11 within the slot 7 at a position corresponding to the bottom wall surface 10a inside the slot 7 opposite the slit 71, allowing the coolant CL flowing from the stator core coolant flow path 20 into the slot 7 to flow between the conductor 8 and the insulator 11.

[0038] On the other hand, in the part shown in Figure 7, the normal-shaped portions 8N of the conductor 8 are arranged radially within the slot 7, overlapping with gaps between them. In Figure 7, the relatively thicker portion EW of the specific-shaped portion 8S overlaps with the CW portion EW of Figure 4B, as shown in Figure 6, resulting in gaps between the normal-shaped portions 8N of the conductor 8 that are not the specific-shaped portion 8S. These gaps constitute the first coolant flow path 21a. The area schematically enclosed by dashed lines on the right side of Figure 7 is the first coolant flow path 21a. The coolant CL flows through the multiple first coolant flow paths 21a in the axial direction of the stator 3.

[0039] Next, a rotating electric machine 1, which is another example of the present disclosure, will be described with reference to Figure 8. Figure 8 is a perspective view showing the stator 3 of the rotating electric machine 1, which is another example of the present disclosure. In the rotating electric machine 1, a stator core 6 with an annular cross-section has a plurality of slots 7 arranged circumferentially at equal intervals. A plurality of conductors 8 are arranged in each of the plurality of slots 7. The conductors 8 are rectangular conductors (square conductors) with a rectangular cross-section, and the plurality of conductors 8 are electrically connected at their ends to form a coil 9.

[0040] Conductor 8 is the same as that described with reference to Figures 4B and 4C. Annular front cover member 22 and rear cover member 23 are attached to the axial front end (front side in Figure 8) and axial rear end (back side in Figure 8) of the stator core 6, respectively, to cover the front and rear ends of the coil 9. The front cover member 22 and rear cover member 23 house the connecting conductor portions of the front and rear ends of the coil 9 inside, and also constitute a part of the coolant flow path CL. That is, the coolant CL introduced into the front cover member 22 circulates annularly inside the front cover member 22, and also passes through the first coolant flow path 21a (partially the second coolant flow path 21b) formed between the conductors 8 in the slot 7 to the rear cover member 23, forming a coolant flow path 12 that circulates through a coolant circulation path (not shown).

[0041] Figure 9 is a schematic diagram showing an example of a coolant flow path 12 in the slot 7 of the rotating electric machine 1 in Figure 8. Figure 10 is a schematic diagram showing the coolant flow path in the rectangular region IS of Figure 9. Figure 11 is a schematic diagram showing the coolant flow path of Figure 10 in a cross-section along line AA. Figure 12 is a schematic diagram showing the coolant flow path of Figure 10 in a cross-section along line BB. In the coolant flow path 12 of Figure 9, the coolant CL introduced into the front cover member 22 passes through a first coolant flow path 21a (partially a second coolant flow path 21b between both sides of the conductor 8 and the inner wall of the slot 7) which is formed by gaps between the conductors 8 (normal shape portion 8N of the conductor 8) to the rear cover member 23 and is returned to a circulation path not shown.

[0042] In Figures 10, 11, and 12, the formation of the first coolant flow path 21a and the second coolant flow path 21b, and the flow mode of the coolant CL in these first and second coolant flow paths 21a and 21b are substantially the same as those described with reference to Figures 5, 6, and 7. Therefore, the same explanations in Figures 5, 6, and 7 will be used to describe the formation of the first and second coolant flow paths 21a and 21b in Figures 10, 11, and 12, and the flow mode of the coolant CL in these first and second coolant flow paths 21a and 21b.

[0043] Figure 13 shows another example of a conductor arranged in the slots of the rotating electric machine shown in Figures 1 and 8. In the example in Figure 13, the conductor 81 is a rectangular conductor (square conductor) with a rectangular cross-section, and has two flattened specific shape portions 81S in the straight section arranged in the slot 7 of the rotating electric machine 1. Normal shape portions 81N are connected between these two specific shape portions 81S and at both ends of the straight section. The specific shape portions 81S themselves are the same as the specific shape portion 8S described above. Similarly, the normal shape portions 81N themselves are the same as the normal shape portion 8N described above. By making the conductor 81 such that it has two specific shape portions 81S in its straight section, it becomes possible to form two second coolant flow channels 21b radially in one slot 7. This reduces the overall flow resistance of the coolant CL and improves the energy efficiency of the rotating electric machine 1.

[0044] Figure 14 shows yet another example of a conductor arranged in the slots of the rotating electric machine shown in Figures 1 and 8. In the example in Figure 14, the conductor 82 is a rectangular conductor (square conductor) with a rectangular cross-section, and has three flattened specific shape sections 82S in the straight section arranged in the slot 7 of the rotating electric machine 1. Normal shape sections 82N are connected between these three specific shape sections 82S and at both ends of the straight section. The specific shape sections 82S themselves are the same as the specific shape sections 8S described above. Similarly, the normal shape sections 82N themselves are the same as the normal shape sections 8N described above. By making the conductor 82 such that it has three specific shape sections 82S in its straight section, it becomes possible to form three radial second coolant flow channels 21b in one slot 7. This reduces the overall flow resistance of the coolant CL and improves the energy efficiency of the rotating electric machine 1.

[0045] Here, other examples of methods for manufacturing conductors will be described with reference to Figures 15A, 15B, and 15C. Figure 15A shows one step in another example of a method for manufacturing conductor 8 applied to the rotating electric machine 1 in Figures 1 and 8. Figure 15B shows the next step in another example of a method for manufacturing conductor 8 applied to the rotating electric machine 1. Figure 15C shows yet another step in another example of a method for manufacturing conductor 8 applied to the rotating electric machine 1 in Figures 1 and 8.

[0046] In the manufacturing method shown in Figures 15A, 15B, and 15C, first, a conductor 8 is prepared, as shown in Figure 15A, which has a constant rectangular cross-sectional shape along its entire length and constant dimensions. In this case, the conductor 8 is selected such that the ratio of the long side to the short side in the rectangular cross-section is the same as the ratio of EW to CW in the specific shaped section 8S in Figure 4B.

[0047] Next, the conductor 8 is pressed with a press machine at both ends, excluding the middle section (center position) of the straight section placed in the slot 7. The direction of pressure applied to the conductor 8 is along the radial direction of the stator core 6 when the conductor 8 is inserted into the slot 7. In Figure 15B, this pressed area is shown as a dashed elliptical region PP. Due to this pressure, as shown in Figure 15B, the portions at both ends are crushed and deformed, becoming rectangular in cross-sections corresponding to the normal shape portion 8N in Figure 4A.

[0048] The specific shaped portion 8S of the conductor 8, which is not the normal shaped portion 8N, is not crushed by the press and retains its original form as shown in Figure 15A, that is, the cross-sectional shape is a constant rectangle along its entire length, and the ratio of the short side to the long side of that rectangle maintains the CW to EW ratio defined for the specific shaped portion 8S in Figure 4B. As a result, the conductor width of the specific shaped portion 8S along the circumferential direction of the stator core 6 is thinner than the conductor width of the normal shaped portion 8N along the circumferential direction of the stator core 6.

[0049] In the next step, multiple conductors 8, formed as shown in Figure 15B, are arranged in the slot 7 so that the positions of the specific shaped portions 8S align with each other, as shown in Figure 15C. After this, the ends of the arranged conductors 8 (normal shaped portions 8N) are connected by welding or other means to obtain a predetermined electrical connection, so that they function as a coil 9. As described above, by using conductors 8 in which specific shaped portions 8S are formed between the normal shaped portions 8N, a coolant flow path is formed around the coil 9. Since the conductors 8 do not have special grooves along the longitudinal direction, they are easy to manufacture.

[0050] Next, with reference to Figures 16 and 17, we will give an overall overview of one configuration of the coolant flow path CL in one slot 7 of the rotating electric machine 1 of this disclosure. Figure 16 is a perspective view showing an example of the configuration around the coolant flow path shown in Figures 5 to 7. Figure 17 is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 16. As outlined with reference to Figure 1, the coolant CL is supplied from the outside to an axial intermediate position in the stator core 6 of the rotating electric machine 1.

[0051] The supplied coolant CL flows radially inward through second coolant passages 21b formed at three intermediate positions within the slot 7, which are gaps between specific shaped portions 8S of each conductor 8 stacked and aligned radially within the slot 7 and the inner wall of the slot 7. In the examples of Figures 16 and 17, the second coolant passages 21b are provided at three locations: the central position in the axial direction of the slot 7, and two positions spaced apart from this central position on one axial end and the other end. More specifically, the second coolant passages 21b are formed as gaps between insulating paper, which acts as an insulator 11 in close contact with the inner wall of the slot 7, and the outer surface of the conductor 8.

[0052] The coolant CL flowing through the second coolant passage 21b also flows through the first coolant passage 21a, which is connected to the second coolant passage 21b. The first coolant passage 21a is formed along the longitudinal direction of the conductor 8 as a gap between the normally shaped portions 8N of the conductor 8. The coolant CL that has flowed from the second coolant passage 21b into the first coolant passage 21a flows through the first coolant passage 21a in the axial direction of the rotating electric machine 1.

[0053] The coolant CL flows from the second coolant flow path 21b, located in the axial center, to one and the other axial end of the first coolant flow path 21a. The coolant CL flowing through the second coolant flow path 21b and the first coolant flow path 21a flows through the slot 7 to one and the other axial end while exchanging heat with the conductor 8 and cooling the heat generated by copper loss. It is then discharged and dripped from both axial ends of the slot 7 and flows into the coolant storage section 13 (see Figure 1) where it is recovered as described above.

[0054] Next, with reference to Figures 18 and 19, we will give an overall overview of other configurations of the coolant flow path CL in one slot 7 of the rotating electric machine 1 of this disclosure. Figure 18 is a perspective view showing another example of the configuration around the coolant flow path shown in Figures 5 to 7. Figure 19 is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 18. As outlined with reference to Figure 1, the coolant CL is supplied from the outside to an axial intermediate position in the stator core 6 of the rotating electric machine 1.

[0055] The supplied coolant CL flows radially inward through second coolant passages 21b, which are formed at three intermediate positions within the slot 7 as gaps between specific shaped portions 8S of each conductor 8, which are stacked and aligned radially within the slot 7, and the inner wall of the slot 7. More specifically, the second coolant passages 21b are formed as gaps between insulating paper, which acts as an insulator 11 in close contact with the inner wall of the slot 7, and the outer surface of the conductor 8.

[0056] In the examples shown in Figures 18 and 19, the axial phase position of the specific shaped portion 8S of each conductor 8 is sequentially shifted axially as the radial direction moves inward from the outermost conductor 8 to the innermost conductor 8. Therefore, the second coolant flow path 21b formed within the slot 7, extending from the outer circumference to the inner circumference, is inclined radially in accordance with the axial phase shift of the specific shaped portion 8S described above. This second coolant flow path 21b is provided so as to be inclined toward the inner circumference from three locations: the central position in the axial direction at the outermost circumference of the slot 7, and two positions spaced apart from this central position on one axial end and the other end.

[0057] The coolant CL flowing through the second coolant passage 21b also flows through the first coolant passage 21a, which is connected to the second coolant passage 21b. The first coolant passage 21a is formed along the longitudinal direction of the conductor 8 as a gap between the normally shaped portions 8N of the conductor 8. The coolant CL that has flowed from the second coolant passage 21b into the first coolant passage 21a flows through the first coolant passage 21a in the axial direction of the rotating electric machine 1.

[0058] The coolant CL flows from the second coolant flow path 21b, located in the axial center, to one and the other axial end of the first coolant flow path 21a. The coolant CL flowing through the second coolant flow path 21b and the first coolant flow path 21a flows through the slot 7 to one and the other axial end while exchanging heat with the conductor 8 and cooling the heat generated by copper loss. It is then discharged and dripped from both axial ends of the slot 7 and flows into the coolant storage section 13 (see Figure 1) where it is recovered as described above.

[0059] Next, with reference to Figures 20 and 21, we will provide an overview of yet another aspect of the coolant flow path in one slot 7 of the rotating electric machine 1 of this disclosure. Figure 20 is a perspective view showing yet another example of the configuration around the coolant flow path shown in Figures 5 to 7. Figure 21 is a conceptual diagram showing an extracted portion of the coolant flow path in Figure 20. As outlined with reference to Figure 1, the coolant CL is supplied from the outside to an axial intermediate position in the stator core 6 of the rotating electric machine 1.

[0060] The supplied coolant CL flows radially inward through second coolant passages 21b, which are formed at three intermediate positions within the slot 7 as gaps between specific shaped portions 8S of each conductor 8, which are stacked and aligned radially within the slot 7, and the inner wall of the slot 7. More specifically, the second coolant passages 21b are formed as gaps between insulating paper, which acts as an insulator 11 in close contact with the inner wall of the slot 7, and the outer surface of the conductor 8.

[0061] In the examples shown in Figures 20 and 21, the axial phase position of the specific shaped portion 8S of each conductor 8 changes in a zigzag pattern, shifting in one direction and then returning to its original position as the radial inward direction moves from the outermost conductor 8 to the innermost conductor 8. Therefore, the second coolant flow path 21b formed within the slot 7, extending from the outer circumference to the inner circumference, becomes zigzag in accordance with the axial phase shift of the specific shaped portion 8S described above. Such a second coolant flow path 21b is provided in a zigzag pattern as it extends inward from three locations: the central position in the axial direction at the outermost circumference of the slot 7, and two positions spaced apart from this central position on one axial end and the other end.

[0062] The coolant CL flowing through the second coolant passage 21b also flows through the first coolant passage 21a, which is connected to the second coolant passage 21b. The first coolant passage 21a is formed along the longitudinal direction of the conductor 8 as a gap between the normally shaped portions 8N of the conductor 8. The coolant CL that has flowed from the second coolant passage 21b into the first coolant passage 21a flows through the first coolant passage 21a in the axial direction of the rotating electric machine 1.

[0063] The coolant CL flows from the second coolant flow path 21b, located in the axial center, to one and the other axial end of the first coolant flow path 21a. The coolant CL flowing through the second coolant flow path 21b and the first coolant flow path 21a flows through the slot 7 to one and the other axial end while exchanging heat with the conductor 8 and cooling the heat generated by copper loss. It is then discharged and dripped from both axial ends of the slot 7 and flows into the coolant storage section 13 (see Figure 1) where it is recovered as described above.

[0064] Next, the insulator 11 used in the stator 3, in which the conductors 8, 81, and 82 described above are inserted into the slots 7, will be described with reference to Figures 22 to 26. As shown in Figure 22, the insulator 11 has a foamed layer 112 covering the entire surface on one side of a sheet-like base material 111, and a non-foamed adhesive layer 113 on the other side. The insulator 11 is inserted into each slot 7 together with the conductors 8, 81, and 82, and is positioned between the inner wall surface 10 of the slot 7 and the conductors 8, 81, and 82.

[0065] Figure 23 shows one insulator 11 laid flat. The insulator 11 is composed of a slit shielding portion 11a, radial housing portions 11b, 11b, and folded portions 11c, 11d.

[0066] The slit shielding portion 11a is positioned in the center of the width direction of the unfolded insulator 11 and extends along the entire length of the insulator 11 in the height direction. The width direction of the unfolded insulator 11 is along the circumferential direction of the stator core 6 within the slot 7. The height direction of the insulator 11 is along the axial direction of the stator core 6 within the slot 7. The slit shielding portion 11a is positioned to block the entire slit 71 from inside the slot 7 when the insulator 11 is housed in the slot 7.

[0067] The radial housing portions 11b, 11b are formed continuously on both sides of the slit shielding portion 11a. The radial housing portions 11b, 11b are arranged to cover the entire radial surface 10 of the inner wall surface 10 inside the slot 7 when the insulator 11 is housed inside the slot 7.

[0068] The folded portions 11c and 11d are formed continuously on both sides of the radial housing portions 11b and 11b, respectively. When the insulator 11 is housed in the slot 7, the folded portions 11c and 11d are positioned along the bottom wall surface 10a inside the slot 7. One of the folded portions 11c has a rectangular opening 11c1 formed approximately in the center of the insulator 11 in the height direction. The other folded portion 11d has a notch 11d1 formed approximately in the center of the insulator 11 in the height direction, with the edge of the folded portion 11d cut out in a rectangular shape.

[0069] As shown by the dashed lines in Figure 23, the insulator 11 has mountain fold lines 11e running along the height direction of the insulator 11 between the slit shielding portion 11a and the radial housing portions 11b, 11b, and between the radial housing portions 11b, 11b and the folded portions 11c, 11d. The mountain fold lines 11e are hypothetical lines set on the insulator 11. By folding the insulator 11 along these mountain fold lines 11e, it is formed into a substantially rectangular shape that conforms to the inner surface shape of the slot 7 and allows multiple conductors 8, 81, 82 to be arranged on the inside along the radial direction of the stator core 6. The folded portions 11c, 11d of the insulator 11 after folding overlap each other, and the opening hole 11c1 and the notch 11d1 overlap to form an opening 114 that allows the coolant CL to flow into the inside of the insulator 11.

[0070] After the insulator 11 is placed in the slot 7 together with the conductors 8, 81, and 82, the stator core 6 is heated. This causes the foamed layer 112 of the insulator 11 to foam due to the heating foaming function, filling the gap between the conductors 8, 81, and 82 and the inner wall surface 10 of the slot 7. When the adhesive layer 113 of the insulator 11 is placed facing the conductors 8, 81, and 82, it adheres to the conductors 8, 81, and 82 by heating, and when the adhesive layer 113 is placed facing the inner wall surface 10 of the slot 7, it adheres to the inner wall surface 10 by heating. In either case, the insulator 11 fixes the conductors 8, 81, and 82 in the slot 7, thereby fixing the coil 9 to the stator core 6.

[0071] Here, the insulator 11 has a foaming function section Fa that exhibits a normal heating foaming function when heated in the slot 7, as well as a foaming function reduction section Fb that, when heated in the slot 7, exhibits a reduced heating foaming function compared to the foaming function section Fa, or does not exhibit a heating foaming function at all, or exhibits a reduced heating foaming function compared to the foaming function section Fa, so as not to obstruct the flow of coolant CL in the second coolant flow path 21b formed between the insulator 11 and the specific shaped sections 8S, 81S, 82S of the conductors 8, 81, 82.

[0072] The insulator 11 shown in Figure 23 exemplifies an example that applies when a conductor 82 having three specific shaped portions 82S within the slot 7 is inserted into the slot 7. In Figure 23, the area of ​​the foaming function reduction portion Fb is indicated by hatching. All parts of the insulator 11 that are not hatched are areas of the foaming function portion Fa. For other conductors 8, 81, the configuration of the insulator 11 shown in Figure 23 applies similarly, except that the position and number of foaming function reduction portions Fb differ depending on the position and number of specific shaped portions 81S, 82S of the conductors 8, 81.

[0073] The foamed functional sections Fa in the insulator 11 are formed in four locations each in the entire slit shielding section 11a, and in the radial housing sections 11b, 11b and the folded sections 11c, 11d. The four foamed functional sections Fa in the radial housing sections 11b, 11b and the folded sections 11c, 11d are each composed of foamed functional sections Fa, Fa at both ends in the height direction of the insulator 11 and two foamed functional sections Fa, Fa positioned between them. The foamed functional sections Fa formed in the radial housing sections 11b, 11b and the folded sections 11c, 11d are continuous in the width direction of the unfolded insulator 11 via the foamed functional section Fa in the slit shielding section 11a.

[0074] The foaming function reducing sections Fb in the insulator 11 are formed in three locations each in the radial housing sections 11b, 11b and the folded sections 11c, 11d. The three foaming function reducing sections Fb in the radial housing sections 11b, 11b and the folded sections 11c, 11d are positioned between adjacent foaming function sections Fa, Fa in the height direction of the insulator 11. Since the foaming function reducing sections Fb are not formed in the slit shielding section 11a, they are not continuous in the width direction of the unfolded insulator 11; therefore, the six foaming function reducing sections Fb are independently positioned in the insulator 11. The openings 11c1 and notches 11d1 of the folded sections 11c, 11d are located within the regions of the two foaming function reducing sections Fb, Fb positioned in the center of the height direction of the insulator 11.

[0075] The foaming function portion Fa in the insulator 11 is the area where, after the stator core 6 is heated following the insertion of the conductor 82 and the insulator 11 into the slot 7, the foamed layer 112 exhibits its normal heat-foaming function and foams, filling the gap between the conductor 82 and the inner wall surface 10 of the slot 7. On the other hand, the foaming function reduction portion Fb in the insulator 11 is the area where the heat-foaming function of the foamed layer 112 is reduced compared to the foaming function portion Fa. The foaming function reduction portion Fb is the area where, when the stator core 6 is heated, the heat-foaming function of the foamed layer 112 does not manifest at all, or the heat-foaming function is less likely to manifest compared to the foaming function portion Fa. Therefore, the thickness of the foaming function reduction portion Fb in the insulator 11 after heating of the stator core 6 is formed to be thinner than that of the foaming function portion Fa.

[0076] Figures 24 and 25 show the case where four conductors 82 and an insulator 11 are inserted into the slot 7. In Figure 24, only the area of ​​the foaming function reduction section Fb is shown by a dashed rectangular area. The opening 114 formed in the insulator 11 is positioned to communicate with the stator core internal coolant flow path 20 formed in the stator core 6.

[0077] As shown in Figures 24 and 26, the foaming function portion Fa of the insulator 11 is positioned corresponding to the area where the normal-shaped portion 82N of the conductor 82 is arranged, and the foaming function reduction portion Fb of the insulator 11 is positioned corresponding to the area where the specific-shaped portion 82S of the conductor 82 is arranged. When the stator core 6 is heated, the foaming function portion Fa of the insulator 11 exhibits its heating foaming function as usual and foams, filling the gap between the normal-shaped portion 82N of the conductor 82 and the inner wall surface 10 of the slot 7.

[0078] In contrast, as shown in Figures 25 and 26, the foaming function reducing portion Fb of the insulator 11 does not exhibit a heat-induced foaming function when the stator core 6 is heated, or exhibits a less pronounced heat-induced foaming function than the foaming function portion Fa. Therefore, it does not fill the gap between the specific shaped portion 82S of the conductor 82 and the inner wall surface 10 of the slot 7, as the foaming function portion Fa does. Consequently, the second coolant flow path 21b formed between the specific shaped portion 82S of the conductor 82 and the inner wall surface 10 of the slot 7 is not blocked by the foam layer 112, and the flow of coolant CL in the second coolant flow path 21b is ensured.

[0079] As shown in Figure 26, the insulator 11 is positioned in the slot 7 with the foam layer 112 facing the inner wall surface 10 of the slot 7 and the adhesive layer 113 facing the conductor 82. However, since a foam function reduction portion Fb is formed on the portion of the foam layer 112 corresponding to the specific shaped portion 82S of the conductor 82, the foam function reduction portion Fb does not press the base material 111 and adhesive layer 113 of the insulator 11 toward the conductor 82, and thus the second coolant flow path 21b is properly secured in the specific shaped portion 82S of the conductor 82. However, the insulator 11 may also be positioned in the slot 7 with the foam layer 112 facing the conductor 82 and the adhesive layer 113 facing the inner wall surface 10 of the slot 7.

[0080] As shown in Figure 25, the slit shielding portion 11a of the insulator 11 is positioned on the slit 71 side within the slot 7, thereby shielding the slit 71 from the inside of the slot 7. As shown in Figure 23, the entire slit shielding portion 11a has a foaming function portion Fa, so the insulator 11 is heated within the slot 7, substantially blocking the slit 71. Therefore, there is no risk of the coolant CL flowing through the second coolant passage 21b leaking out from the slit 71.

[0081] Next, a method for manufacturing a stator 3 having insulators 11 in the slots 7 of the stator core 6 will be described with reference to Figure 27. Figure 27 shows the molding process of the insulators 11 before they are placed in the slots 7 of the stator core 6, and the molding process (ASSY) of the insulators 11 after they are placed in the slots 7 of the stator core 6.

[0082] First, an insulator 11 is formed before heating, having a foamed layer 112 covering the entire surface of one side of a sheet-like base material 111, and an adhesive layer 113 on the other side (insulator forming process). As such an insulator 11, a general insulator with a foamed layer 112 formed on the entire surface of one side can be used.

[0083] Next, in the foamed layer 112 of the insulator 11, localized heating is performed in areas where a gap is required for the coolant CL to flow between at least the specific shaped portions 8S, 81S, 82S of the conductors 8, 81, 82, i.e., in areas where foam function reduction portions Fb should be formed (localized heating step). This localized heating causes the foamed layer 112 to exhibit a localized heat foaming function, forming localized foamed portions 112a in the heated areas.

[0084] There are no specific limitations on the method for localized heating. For example, one method is to heat the insulator 11 while masking the area where the foamed functional portion Fa should be formed, i.e., the area that fills the gap between the normally shaped portions 8N, 81N, 82N of the conductors 8, 81, 82 and the inner wall surface 10 of the slot 7, with a heat-insulating mask member. Another method is to use a selectively heatable heating element and bring this heating element into contact with the area in the foamed layer 112 of the insulator 11 where the foamed functional reduction portion Fb should be formed, thereby selectively heating only the contact area. The heating temperature at this time is such that the heated portion of the foamed layer 112 exhibits the heat-foaming function and begins to foam, but the adhesive layer 113 has not yet exhibited adhesive strength.

[0085] Next, the foamed portion 112a, which has been foamed by locally heating the foamed layer 112, is forcibly crushed by applying pressure (local pressure step). When the foamed portion 112a is forcibly crushed, it will not foam again, or will foam less easily, even if the foamed portion 112a is heated again. As a result, a foaming function reduction portion Fb is formed in the foamed layer 112, and a foaming function portion Fa is formed in the foamed layer 112 by the unfoamed portion 112b other than this foaming function reduction portion Fb.

[0086] Next, the insulator 11, in which the foam function reduction portion Fb is formed by forcibly crushing the foam portion 112a, is inserted into the slot 7 of the stator core 6 together with the conductors 8, 81, and 82. Then, the insulator 11 is heated by heating the stator core 6, causing the foam layer 112 to foam (heat foaming process). The heating temperature at this time is such that the foam layer 112 exhibits its normal heat foaming function and begins to foam, and the adhesive layer 113 exhibits adhesive strength.

[0087] At this time, the foaming function section Fa, which is the portion of the foamed layer 112 that was not heated in the local heating process other than the foaming function reduction section Fb, exhibits its heating and foaming function as usual and foams, filling the gap between the conductors 8, 81, 82 and the inner wall surface 10 of the slot 7, and fixing the conductors 8, 81, 82 inside the slot 7. On the other hand, the foaming function reduction section Fb formed in the local pressurization process does not foam at all or foams very little, so it is thinner than the foaming function reduction section Fb, and an appropriate gap is formed between it and the specific shaped portions 8S, 81S, 82S of the conductors 8, 81, 82 in the second coolant flow path 21b, allowing the coolant CL to flow.

[0088] The resulting stator 3 allows for smooth flow of coolant CL between the conductors 8, 81, and 82 and the slots 7, enabling the construction of a high-performance rotating electric machine 1 with excellent cooling performance. The insulator 11 can be made using a general insulator with a foamed layer 112 formed on the entire surface of one side, making it easy and economical to manufacture. Therefore, the stator 3 and the rotating electric machine 1 can be manufactured at low cost and are economically efficient. [Explanation of Symbols]

[0089] 1 Rotating electric machine, 21b Second coolant flow path, 3 Stator, 6 Stator core, 61 Central shaft hole, 7 Slot, 71 Slit, 8,81,82 Conductors, 8N,81N,82N Normal shape parts, 8S,81S,82S Specific shape parts, 11 Insulator, 112 Foam layer, CL Coolant, Fa Foam function part, Fb Foam function reduction part

Claims

1. A stator comprising a conductor in a slot formed in the stator core, an insulator disposed between the slot and the conductor, and having a coolant flow path for circulating coolant between the slot and the conductor, The insulator has a foamed layer that foams when heated within the slot, The aforementioned foam layer is A foaming function section that fills the gap between the slot and the conductor by a heating and foaming function, A stator having a foaming function reduction section which is thinner than the foaming function section because the heating foaming function of the foam layer is reduced compared to the foaming function section, and which forms a gap between the slot and the conductor through which the coolant can flow.

2. The conductor has, in the portion inserted into the slot, a normally shaped portion and a specific shaped portion in which the conductor width along the circumferential direction of the stator core is partially thinner than the conductor width of the normally shaped portion, and the coolant can flow in the radial direction of the stator core. The stator according to claim 1, wherein the foaming function reducing portion of the insulator is arranged in a portion corresponding to the specific shape portion of the conductor.

3. The slot has a slit that opens toward the central axis hole of the stator core, The stator according to claim 1 or 2, wherein the foamed functional portion of the insulator is arranged to block the slit.

4. A rotating electric machine comprising a stator according to claim 1 or 2.

5. A method for manufacturing a stator comprising a conductor in a slot formed in the stator core, an insulator disposed between the slot and the conductor, and a coolant flow path for circulating coolant between the slot and the conductor, The insulator has a foamed layer that foams when heated within the slot, Before inserting the insulator into the slot, the foamed layer is locally heated in areas where a gap is required between it and the conductor for the coolant to flow, causing the foamed layer to foam. Then, the foamed areas are pressurized to reduce the heat-induced foaming function, thereby forming a foaming function reduction portion in the foamed layer. A method for manufacturing a stator, comprising: inserting the insulator on which the foaming function reduction portion is formed into the slot; heating the entire insulator to heat and foam the foam layer other than the foaming function reduction portion to form a foaming function portion; and filling the gap between the slot and the conductor with the foaming function portion.

6. The portion of the conductor inserted into the slot is formed with a normal shape and a specific shape where the conductor width along the circumferential direction of the stator core is partially thinner than the conductor width of the normal shape, and the coolant can flow in the radial direction of the stator core. The method for manufacturing a stator according to claim 5, wherein the foaming function reducing portion of the insulator is formed to be located in a portion corresponding to the specific shape portion of the conductor.

7. The slot has a slit that opens toward the central axis hole of the stator core, The method for manufacturing a stator according to claim 5 or 6, wherein the foamed functional portion of the insulator is formed to be arranged in the slit.

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