stata

Abstract

The present invention provides a stator that can increase the likelihood of reducing the peeling of the foam layer from the insulating material. [Solution] The stator comprises an annular stator core, coils arranged in slots of the stator core, and insulating members provided within the slots so as to surround the coils and including a sheet-like base material. An axial flow path, which is a coolant flow path, is formed within the slots, penetrating between both ends of the slots in the axial direction of the stator core. At least a portion of the insulating member that does not come into contact with the axial flow path is configured as a double-sided foamed portion, with foamed layers provided on both surfaces of the base material. At least the surface of the base material on the axial flow path side in the portion of the insulating member that comes into contact with the axial flow path does not have a foamed layer over the entire area of ​​the base material in the axial direction.

Description

Technical Field

[0001] The present invention relates to a stator.

Background Art

[0002] Conventionally, a stator including a stator coil, an insulating member that houses the stator coil, and an annular stator core in which a plurality of slots into which the stator coil housed in the insulating member is inserted is known (see, for example, Patent Document 1). In Patent Document 1, it is disclosed that a foam layer is provided on the surface of the insulating member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a configuration having a foam layer on the surface of the insulating member, the foam layer may be peeled off from the insulating member by the refrigerant flowing through the flow path in the slot, and the flow path may be clogged by the peeled-off foam layer.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a stator that can enhance the possibility of reducing the peeling of the foam layer from the insulating member.

Means for Solving the Problems

[0006] A stator according to one embodiment comprises an annular stator core having a plurality of teeth arranged circumferentially and protruding radially, and a plurality of slots formed between the teeth in the circumferential direction, a coil disposed in the slots, and an insulating member provided within the slots so as to surround the coil and including a sheet-like base material, wherein an axial flow path, which is a coolant flow path, is formed in the slots and penetrates between both ends of the slots in the axial direction of the stator core, and at least a portion of the insulating member that does not contact the axial flow path is configured as a double-sided foamed portion in which a foamed layer is provided on both surfaces of the base material to fill the gap between the surface and the coil and the wall surface of the slot, and the foamed layer is not provided over the entire area of ​​the base material in the axial direction in the portion of the insulating member that contacts the axial flow path.

[0007] According to this, since the foam layer is not provided over the entire area of ​​the substrate in the axial direction on at least the surface of the substrate on the axial flow path side in the portion of the insulating member that is in contact with the axial flow path, it is possible to increase the likelihood of reducing the peeling of the foam layer from the insulating member. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view of the stator. [Figure 2] This is an enlarged view of section A in Figure 1, and is a plan view showing the slot, insulating member, etc., of the first embodiment. [Figure 3] This is a plan view of the central part of the slot in the first embodiment. [Figure 4] This diagram shows a cross-section of an insulating material, and includes a double-sided foamed section (Figure 4A) where foamed layers are provided on both surfaces of the base material, a foamed layer-free section (Figure 4B) where foamed layers are not provided on both surfaces of the base material, and a single-sided foamed section (Figure 4C) where a foamed layer is provided on the outer surface of the base material but not on the inner surface. [Figure 5] Figure 2 is a cross-sectional view along the VV line. [Figure 6]This is a plan view showing the slots, insulating members, etc., of the second embodiment. [Figure 7] This is a cross-sectional view along line VII-VII in Figure 6. [Figure 8] This is a plan view showing the slots, insulating members, etc., of the third embodiment. [Figure 9] Figure 8 shows a cross-sectional view along the IX-IX line. [Figure 10] This is a plan view showing the slots, insulating members, etc., of the fourth embodiment. [Figure 11] Figure 10 shows a cross-sectional view along the line XI-XI. [Figure 12] This is a plan view showing the slots, insulating members, etc., of the fifth embodiment. [Figure 13] Figure 12 shows a cross-sectional view along line XIII-XIII. [Figure 14] This is a plan view showing the slots, insulating members, etc., of the sixth embodiment. [Figure 15] Figure 14 is a cross-sectional view taken along the line XV-XV. [Modes for carrying out the invention]

[0009] Herein, embodiments of this disclosure will be described in the following order. (1) First embodiment: (2) Second embodiment: (3) Third embodiment: (4) Fourth embodiment: (5) Fifth embodiment: (6) Sixth embodiment: (7) Other embodiments:

[0010] (1) First embodiment: FIG. 1 is a plan view of the stator 1 according to the present embodiment. FIG. 2 is an enlarged view of part A in FIG. 1. Hereinafter, a direction parallel to the central axis, which is a straight line perpendicular to the plane of FIG. 1 and passes through the center O of the stator core 2 described later, is referred to as the axial direction. Further, a direction along the circumference of a circle centered on the central axis is referred to as the circumferential direction, and a direction parallel to the radius of the circle is referred to as the radial direction. Furthermore, in the radial direction, a direction approaching the central axis is referred to as the inner radial side, and a direction moving away from the central axis is referred to as the outer radial side. In FIG. 1, the state of the stator 1 viewed from the axial direction is shown, and a part of the coil 3 that is not accommodated in the stator core 2, that is, the coil end portion, is shown in a state where it is cut in a direction perpendicular to the axial direction.

[0011] The stator 1 is a stator of a rotating electrical machine. The rotating electrical machine to which the stator 1 is applied is, for example, a synchronous motor. The rotating electrical machine to which the stator 1 is applied is of an inner rotor type. That is, the rotating electrical machine includes the stator 1 and a rotor (not shown) provided inside the stator 1. The stator 1 is a member for forming magnetic poles on the teeth 22 described later and for forming a rotating magnetic field whose magnetic pole polarities (N pole, S pole) change with time. The rotor is provided rotatably around the central axis. The rotor forms magnetic poles on its outer circumference. Due to the interaction between the magnetic poles of the rotor and the magnetic poles of the stator 1, the rotor rotates. The stator 1 and the rotor are accommodated in a case (not shown).

[0012] The stator 1 includes a stator core 2, a coil 3, an inner peripheral cover 4, and an insulating member 5. The stator core 2 is an annular member. The stator core 2 is a laminate formed by laminating a plurality of electromagnetic steel sheets (for example, silicon steel sheets) formed into a substantially annular shape by, for example, press working, in the axial direction. Alternatively, the stator core 2 may be a dust core formed by press molding magnetic particles. The stator core 2 has an annular core body 21, a plurality of teeth 22 arranged in the circumferential direction and protruding radially inward from the inner peripheral surface of the core body 21, and a plurality of slots 23 formed between the teeth 22 in the circumferential direction.

[0013] The teeth 22 are formed at regular intervals in the circumferential direction over the entire circumference of the inner circumferential surface of the core body 21. The number of teeth 22 may be various numbers. In the present embodiment, the cross-sectional shape of the teeth 22 in a direction perpendicular to the axial direction is the same at any position in the axial direction. Therefore, the teeth 22 are portions that protrude toward the radially inner side and extend in the axial direction with the same cross-sectional shape in a direction perpendicular to the axial direction. Also, each of the teeth 22 has the same shape as each other.

[0014] The slot 23 is a space for accommodating the coil 3 formed between the teeth 22 in the circumferential direction. The slot 23 penetrates the stator core 2 in the axial direction. The slot 23 forms an opening on the radially inner side. The cross-sectional shape of the slot 23 in a direction perpendicular to the axial direction is the same at any position in the axial direction except for the shape at the central position in the axial direction of the slot 23 (see FIG. 3). Note that the above central position means a position that bisects the slot 23 in the axial direction. FIG. 2 is a view of the slot 23 etc. at an axial position other than the central position as viewed from the axial direction. Each of the slots 23 has the same shape as each other.

[0015] As shown in FIG. 2, the slot 23 has a bottom surface 231 that constitutes a part of the inner circumferential surface of the core body 21 as viewed from the axial direction, two side surfaces 232 that extend radially from the end of the bottom surface 231, and two extension surfaces 233 that extend radially inward from the side surfaces 232. The bottom surface 231 is a surface located on the radially outer side among the wall surfaces of the slot 23. The bottom surface 231 is a surface that draws a straight line perpendicular to the radial direction as viewed from the axial direction. The side surface 232 is a surface that draws a straight line extending parallel to the radial direction as viewed from the axial direction. The side surface 232 constitutes a part of the side surface of the tooth 22. The two side surfaces 232 are provided parallel to each other. The space surrounded by the bottom surface 231 and the two side surfaces 232 is the accommodation space for the coil 3.

[0016] The extension surface 233 is located radially inward from the coil 3 housed within the slot 23. The extension surface 233 constitutes the tip portion of the side surface of the tooth 22. The extension surface 233 includes a surface that is not parallel to the radial direction. Also, the width between the two extension surfaces 233 is smaller than the width between the two side surfaces 232, i.e., the width of the space where the coil 3 is housed. This prevents the coil 3 from coming out of the slot 23. The extension surface 233 is the surface of the refrigerant flow path. That is, the space 24 sandwiched between the two extension surfaces 233 is the refrigerant flow path. The flow path 24 penetrates the stator core 2 in the axial direction. In other words, the flow path 24 is an axial flow path that penetrates between the ends of the slot 23 in the axial direction. The axial flow path 24 is located radially inward from the coil 3.

[0017] Figure 3 shows a cross-section perpendicular to the axial direction of a portion 230 of the slot 23 at its axial center. Hereinafter, portion 230 may be referred to as the slot center. The slot center 230 is formed in a larger shape than the portions of the slot 23 other than the central portion. Specifically, the slot center 230 has a bottom surface 231a that constitutes part of the inner circumferential surface of the core body 21, two side surfaces 232a extending radially from the end of the bottom surface 231a, and two extended surfaces 233a extending radially inward from the side surfaces 232a. These surfaces 231a, 232a, and 233a form a gap 26 between themselves and the insulating member 5, which will be described later, allowing the coolant to flow in a direction perpendicular to the axial direction. The gap 26 includes a gap 26a formed between the bottom surface 231a and a portion 51 of the insulating member 5 facing it, a gap 26b formed between the side surface 232a and a portion 52 of the insulating member 5 facing it, and a gap 26c connecting the axial flow path 24 and the gap 26b.

[0018] The bottom surface 231a is located radially outward from the bottom surface 231 at axial positions other than the central position (see Figure 2) by the radial width of the gap 26a. An opening 25c is also formed in the bottom surface 231a, which serves as an inlet for the refrigerant into the central part 230 of the slot. The width between the two side surfaces 232a is greater than the width between the two side surfaces 232 in Figure 2. Hereafter, the gap 26 may be referred to as the central flow path.

[0019] The core body 21 has a flow path 25 for supplying refrigerant to the central flow path 26. The flow path 25 includes, for example, a circumferential flow path 25a extending in the circumferential direction and a radial flow path 25b extending radially from the circumferential flow path 25a. The circumferential flow path 25a may be formed over the entire circumference in the circumferential direction at the axial central position of the core body 21. Alternatively, the circumferential flow path 25a may be divided into multiple sections in the circumferential direction. Multiple radial flow paths 25b may extend from the circumferential flow path 25a toward the slot center 230 of each slot 23. The radially inner end of the radial flow path 25b is an opening 25c formed in the bottom surface 231a.

[0020] Multiple coils 3 are arranged radially in the space enclosed by the bottom surfaces 231, 231a and the sides 232, 232a within the slot 23. The number of coils 3 arranged radially is not limited, but in this embodiment there are six. Each coil 3 includes a housing portion that is placed within the slot 23 and a coil end portion that protrudes axially from the end face of the stator core 2. The housing portion of the coil 3 extends linearly in the axial direction. In this embodiment, the coil 3 has a rectangular cross-section, but it may also be a round wire with a circular cross-section. Each coil 3 is connected to, for example, one of the phases of a three-phase alternating current. As a result, each coil 3 generates a magnetic pole on each tooth 22 whose polarity changes over time.

[0021] The inner circumferential cover 4 is a cylindrical member, and its axial length is approximately the same as the axial length of the stator core 2. The diameter of the radially outer outer surface of the inner circumferential cover 4 is approximately the same as the diameter of the radially inner inner surface of the stator core 2. The inner circumferential cover 4 is fitted into the radially inner side of the stator core 2. The inner circumferential cover 4 is a plate-like member and is present around the entire inner circumference of the stator core 2, thus blocking the opening of the slot 23 on the radially inner side. As a result, it is possible to prevent the refrigerant flowing through the axial flow path 24 from leaking radially inward.

[0022] The insulating members 5 shown in Figures 2 and 3 are provided for each slot 23 and are positioned to surround the portion of the coil 3 that is housed within the slot 23. The insulating members 5 are positioned between the bottom surface 231, 231a and side surfaces 232, 232a of the slot 23 and the outer surface of the coil 3. The insulating members 5 are also positioned to surround all the coils 3 that are housed within a single slot 23. The insulating members 5 are in the form of a sheet folded to conform to the shape of the slot 23 and the outer shape of the coil 3. The insulating members 5 have a length, for example, that is equal to the total length of the slot 23 in the axial direction, but may be formed to be longer than the total length of the slot 23.

[0023] The insulating member 5 includes an outer periphery 51, two side portions 52, two corner portions 53, and two non-contact portions 54. The outer periphery 51 is the portion located radially outward from the coil 3. The outer periphery 51 is also the portion facing the bottom surface 231, 231a of the slot 23 and the radially outward surface of the coil 3. In the central portion 230 of the slot, the outer periphery 51 faces the opening 25c formed in the bottom surface 231a. When viewed from the axial direction, the outer periphery 51 extends linearly in a direction perpendicular to the radial direction. The side portions 52 are the portions facing the side surfaces 232, 232a of the slot 23 and the side surfaces of the coil 3. When viewed from the axial direction, the side portions 52 extend linearly radially inward from the end of the outer periphery 51. One of the two side portions 52 extends radially inward from one end of the outer periphery 51 and faces one of the side surfaces 232, 232a. The other side portion 52 extends radially inward from the other end of the outer peripheral portion 51 and faces the other side surfaces 232, 232a.

[0024] The corner portion 53 is connected to the radially inward end of the side portion 52 and is a portion that is bent relative to the side portion 52, following the shape of the coil 3 and the slot 23. The corner portion 53 is the portion between the side portion 52 and the non-contact portion 54. That is, the corner portion 53 is a bent portion of the insulating member 5 located at the boundary between the portion 54 that contacts the axial flow path 24 and the portion 52 that does not contact the axial flow path 24. One corner portion 53 is connected to one side portion 52. The other corner portion 53 is connected to the other side portion 52. The outer peripheral portion 51, the side portion 52 and the corner portion 53 are in contact with the outer peripheral surface of the coil 3.

[0025] The non-contact portion 54 is a part of the insulating member 5 from the end when viewed from the axial direction, and is not in contact with the coil 3. In other words, the non-contact portion 54 is the part that extends radially inward from the radially inward surface of the coil 3. The non-contact portion 54 is located radially inward from the coil 3. One of the two non-contact portions 54 constitutes a part of one end of the insulating member 5 when viewed from the axial direction. The other non-contact portion 54 constitutes a part of the other end of the insulating member 5 when viewed from the axial direction. Each non-contact portion 54 is displaced radially inward from each corner 53 as it approaches the center line L of the slot 23 (see Figure 2). The center line L is a radially extending straight line that passes between the two sides 232. A gap is provided between the end of one non-contact portion 54 opposite to the side to which the corner 53 is connected and the end of the other non-contact portion 54. That is, the pair of non-contact portions 54 do not overlap each other. Furthermore, the non-contact portion 54 is in contact with the axial flow path 24. In other words, the non-contact portion 54 is located within the axial flow path 24.

[0026] As shown in Figures 4A and 4B, the insulating member 5 includes a sheet-like base material 5a. The base material 5a is a resin sheet formed from an insulating resin material such as polyphenylene sulfide or polyethylene naphthalate. The base material 5a may have a configuration in which multiple layers are laminated, for example, a configuration in which a fiber layer formed from aramid fibers and the resin sheet are laminated. The insulating member 5 is composed of a double-sided foamed portion 501 (see Figure 4A) which includes the base material 5a and foamed layers 5b and 5c provided on both surfaces, and a foamed layer-free portion 502 (see Figure 4B) in which foamed layers are not provided on both surfaces of the base material 5a. The foamed layer-free portion 502 is the part in which the base material 5a is exposed. The foamed layer-free portion 502 is thinner than the double-sided foamed portion 501 because it does not have a foamed layer. The configuration of Figure 4C will be described in (7) Other Embodiments.

[0027] The double-sided foamed section 501 includes a foamed layer 5b provided on the outer surface of the base material 5a, which is the surface facing the wall of the slot 23, and a foamed layer 5c provided on the inner surface of the base material 5a, which is the surface facing the coil 3. The foamed layers 5b and 5c are formed, for example, by a foaming agent that foams and expands when heated and is also tacky. The foaming agent that forms the foamed layers 5b and 5c is composed of a base material made of epoxy resin material, for example, in which acrylic capsules containing liquid isopentane are dispersed. As a result, when the foaming agent is heated, the liquid isopentane inside the capsules vaporizes and expands, causing the base material to foam.

[0028] In this embodiment, the outer periphery 51 and the two side portions 52 in Figure 2, which are positioned in axial positions other than the central portion 230 of the slot in Figure 3, are configured as double-sided foam portions 501. That is, the outer periphery 51 and side portions 52 in Figure 2 include a base material 5a, a foam layer 5b provided on the outer surface of the base material 5a, and a foam layer 5c provided on the inner surface of the base material 5a. The foam layer 5b fills the space between the outer surface of the base material 5a and the bottom surface 231 and the two side portions 232 of the slot 23. The foam layer 5c fills the space between the inner surface of the base material 5a and the outer periphery of the coil 3. In this way, the outer periphery 51 is in close contact and bonded to the bottom surface 231 and the coil 3 by the foam layers 5b and 5c. The side portions 52 are in close contact and bonded to the side portions 232 and the coil 3 by the foam layers 5b and 5c.

[0029] More specifically, in positions along the axial direction where there are no refrigerant flow paths other than the axial flow path 24 within the slot 23, i.e., positions other than the axial center, the outer periphery 51 and side portions 52 in Figure 2 are configured as double-sided foamed portions 501 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction, except for the corner portion 53. Furthermore, except for the portion of the coil 3 in contact with the corner portion 53, the side surfaces and radially outer surfaces of the coil 3 and the walls 231 and 232 of the slot 23 facing them are fixed by the foamed layers 5b and 5c of the outer periphery 51 and side portions 52 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction. Note that in Figure 2, to make the positional relationship between the members easier to understand, gaps are shown between the outer periphery 51 and side portions 52 and the coil 3, or between the outer periphery 51 and side portions 52 and the walls 231 and 232, but in reality, these gaps are filled with the foamed layers 5b and 5c. Furthermore, in this embodiment, the outer peripheral portion 51 and the side portion 52 are configured as double-sided foamed portions 501 over the entire axial range except for the central position in the axial direction.

[0030] On the other hand, the two non-contact portions 54 in Figure 2 and the portions 51-54 of the insulating member 5 in the central portion 230 of the slot in Figure 3 are configured as foam layer-free portions 502. The non-contact portion 54 is configured as a foam layer-free portion 502 over its entire axial range. In addition, the two corner portions 53 in Figure 2 may be configured as double-sided foam portions 501 or as foam layer-free portions 502.

[0031] Next, the flow of the refrigerant in this embodiment will be described with reference to Figures 3 and 5. Note that Figure 5 is a cross-sectional view taken along the VV line in Figure 2. In Figures 3 and 5, the flow of the refrigerant is indicated by arrows E1 to E4. Flow E1 shows the flow of the refrigerant in the flow path 25 of the core body 21. Flow E2 shows the flow of the refrigerant in the central flow path 26 formed in the central part 230 of the slot. Flows E3 and E4 show the flow of the refrigerant in the axial flow path 24. Note that the refrigerant is an oil such as lubricating oil or hydraulic oil, but it may be another liquid or gas. The refrigerant sent out by a pump (not shown) is cooled by a heat exchanger (not shown) and then supplied to the flow path 25 of the core body 21. The refrigerant supplied to the flow path 25 flows into the central flow path 26 of the central part 230 of each slot. The refrigerant that flows into the central flow path 26 first flows through the gap 26a between the bottom surface 231a and the coil 3, and then flows radially inward through the gap 26b between the side surface 232a and the coil 3. Subsequently, the refrigerant passes through the gap 26c and flows into the axial flow path 24. The refrigerant that flows into the axial flow path 24 splits into a flow E3 in one axial direction and a flow E4 in the other axial direction, and flows axially within the axial flow path 24. Subsequently, the refrigerant flows out of the stator core 2 through the openings at both ends of the axial flow path 24 in the axial direction. The discharged refrigerant flows through an external flow path (not shown) and is then returned to the pump.

[0032] The effects of this embodiment will now be explained. According to this embodiment, an axial flow path 24 is provided in each slot 23, extending over the entire axial range of the slot 23, and a coolant flows through this axial flow path 24. This allows the coils 3 and stator core 2 provided in the slot 23 to be cooled over a wide axial range, and consequently, the stator 1 to be cooled efficiently. Of the multiple coils 3 arranged in the slot 23, the coil 3 located radially inward is the most prone to generating heat. In this embodiment, since the axial flow path 24 is located radially inward of the coils 3, the coils 3 located radially inward can be cooled efficiently. Furthermore, since there is no axial flow path between the side surface 232 of the slot 23 and the coils 3, the circumferential width of the slot 23 can be reduced.

[0033] Since the coil 3 is surrounded by the insulating member 5 within the slot 23, the coil 3 and the stator core 2 can be insulated. The non-contact portion 54 of the insulating member 5 that does not come into contact with the coil 3 is in contact with the axial flow path 24. Since the non-contact portion 54 is a foam-free portion 502 where the foam layer is not present on both surfaces of the base material 5a, it is possible to reduce the peeling of the foam layer from the insulating member 5 by the refrigerant flowing through the axial flow path 24, and to reduce the clogging of the axial flow path 24 by the foam layer. In addition, since the foam-free portion 502 is thinner than the double-sided foam portion 501, it is possible to reduce the narrowing of the axial flow path 24. This allows for efficient cooling of the coil 3 and the stator core 2. Furthermore, since the foam layer is not provided over the entire axial range of the non-contact portion 54, the peeling of the foam layer from the insulating member 5 can be further reduced, and the axial flow path 24 can be widened over a wide range in the axial direction. In addition, a gap is formed between the tips of the two non-contact portions 54, allowing the refrigerant to come into direct contact with the coil through this gap. This allows for more efficient cooling of coil 3.

[0034] At positions other than the axial center, the outer periphery 51 and side portions 52 of the insulating member 5 are double-sided foamed portions 501 having foamed layers 5b and 5c on both surfaces of the base material 5a over the entire range along the outer circumference of the coil 3 when viewed from the axial direction. Therefore, the coil 3 can be effectively fixed to the slot 23 via the double-sided foamed portions 501. That is, both sides of the coil 3 facing the side surface 232 of the slot 23, and the radially outer surface of the coil 3 facing the bottom surface 231, can be fixed to the walls 232 and 231 of the slot 23 by the foamed layers 5b and 5c over the entire range along the outer circumference of the coil 3 when viewed from the axial direction. This reduces the movement of the coil 3 within the slot 23 even if the foamed layers 5b and 5c are not provided over the entire range in the axial direction, and makes it easy to secure the axial flow path 24 within the slot 23. In addition, the presence of the insulating member 5 allows for more effective insulation between the coil 3 and the stator core 2 compared to when the insulating member 5 is not provided. Furthermore, since the outer periphery 51 and side portions 52 are configured as double-sided foamed portions 501 over the entire axial range except for the axial center position, the coil 3 can be more effectively fixed within the slot 23.

[0035] Furthermore, portions 51 to 53 of the insulating member 5 that are in contact with the central channel 26 (see Figure 3) are configured as foam-free portions 502. Therefore, the peeling of the foam layer of the insulating member 5 by the refrigerant flowing through the central channel 26 can be reduced, and the narrowing of the central channel 26 due to the foam layer can be reduced. As a result, the coil 3 and stator core 2 can be cooled efficiently.

[0036] (2) Second embodiment: Next, a second embodiment of this disclosure will be described, focusing on the differences from the first embodiment. Figure 6 is a view of the slot 23A, insulating member 5A, etc., of this embodiment from the axial direction. Figure 6 shows the shape of the slot 23A at a position other than the central position in the axial direction. Figure 7 is a cross-sectional view taken along the line VII-VII in Figure 6. In Figures 6 and 7, components similar to those in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0037] Slot 23A has an axial flow path 27 between its bottom surface 231 and the outer peripheral portion 51 of the insulating member 5, which penetrates from both ends of the slot 23A in the axial direction. That is, the axial flow path 27 penetrates the stator core 2A (see Figure 7) in the axial direction. The axial flow path 27 is located radially outward from the coil 3. Slot 23A differs from slot 23 of the first embodiment in that it has an axial flow path 27, but is otherwise the same as slot 23, so its description is omitted. Also, stator core 2A differs from stator core 2 of the first embodiment in that it has a slot 23A with an axial flow path 27, but is otherwise the same as stator core 2.

[0038] The coil 3 and inner cover 4 are the same as the coil 3 in the first embodiment. The outer periphery 51 of the insulating member 5A is in contact with the axial flow path 27 over the entire axial range. The outer periphery 51 (excluding the corners 51a) is configured as a foam layer-free portion 502 as shown in Figure 4B. The corners 51a of the outer periphery 51 may be configured as a foam layer-free portion 502 or as a double-sided foam portion 501. The side portion 52 is configured as a double-sided foam portion 501 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction, except for the corners 51a and 53. Furthermore, the side surface of the coil 3 and the wall surface 232 of the slot 23 opposite it are fixed by the foam layers 5b and 5c of the side portion 52 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction, except for the portion of the coil 3 that is in contact with the corners 51a and 53. In addition, the side portion 52 is configured as a double-sided foam portion 501 over the entire range in the axial direction, except for the central position in the axial direction. The insulating member 5A is the same as the insulating member 5 of the first embodiment, except as described above.

[0039] Next, the refrigerant flow in this embodiment will be described with reference to Figure 7. In Figure 7, the refrigerant flow is indicated by arrows E1 to E6. Flows E1 to E4 are the same as the flows E1 to E4 in the first embodiment (see Figures 3 and 5). Flows E5 and E6 indicate the refrigerant flow in the axial flow path 27. The refrigerant sent out by a pump (not shown) is cooled by a heat exchanger (not shown) and then supplied to the flow path 25 of the stator core 2A. The refrigerant supplied to the flow path 25 flows into the center of the slot. The refrigerant that has flowed into the center of the slot flows axially within the axial flow path 27, in addition to the flows E1 to E4 similar to those in the first embodiment. That is, from the axial center, the refrigerant splits into a flow E5 in one axial direction and a flow E6 in the other axial direction, and flows axially within the axial flow path 27. After that, the refrigerant flows out to the outside of the stator core 2A from the openings at both ends of the axial flow path 27 in the axial direction. The outflowing refrigerant flows through an external flow path (not shown) and is then returned to the pump.

[0040] According to this embodiment, since the refrigerant flows axially through the axial flow path 27, in addition to the effects of the first embodiment, the coil 3 and stator core 2A can be cooled even more efficiently. The outer periphery 51 of the insulating member 5 in contact with the axial flow path 27 is configured as a foam layer-free portion 502 over the entire axial range, so that the foam layer of the insulating member 5 peels off and clogs the axial flow path 27, which can be reduced. Furthermore, the narrowing of the axial flow path 27 by the foam layer can be reduced.

[0041] (3) Third embodiment: Next, a third embodiment of this disclosure will be described, focusing on the differences from the above embodiments. Figure 8 is a view of the slot 23, insulating member 5B, etc. of this embodiment from the axial direction. Figure 8 shows the shape of the slot 23 at a position other than the central position in the axial direction. Figure 9 is a cross-sectional view taken along the line IX-IX in Figure 8. In Figures 8 and 9, the same reference numerals are used for components that are the same as those in the above embodiments, and their descriptions are omitted as appropriate. In this embodiment, the shape of the insulating member 5B differs from that of the insulating member 5 of the first embodiment. Components other than the insulating member 5B, specifically the stator core 2, slot 23, coil 3, and inner circumference cover 4, are the same as those of the first embodiment.

[0042] The insulating member 5B includes an outer periphery 55, a side portion 56, and an inner periphery 57. The outer periphery 55 is located radially outward from the coil 3 and is the portion facing the bottom surface 231 of the slot 23. The outer periphery 55 includes a first outer periphery 55a that constitutes a portion from one end of the insulating member 5B when viewed from the axial direction, and a second outer periphery 55b that constitutes a portion from the other end of the insulating member 5B. These pair of outer periphery portions 55a and 55b are arranged to overlap. That is, at least a portion of the first outer periphery 55a is provided radially inward from the second outer periphery 55b. The radially outward surface of the first outer periphery 55a and the radially inward surface of the second outer periphery 55b are in contact. The outer periphery 55 is in contact with the radially outward surface of the coil 3. Specifically, at least the first outer periphery 55a is in contact with the coil 3. The outer periphery 55 is in contact with the bottom surface 231. Specifically, at least the second outer periphery 55b contacts the bottom surface 231.

[0043] The portions of the first outer periphery 55a and the second outer periphery 55b, other than the axial center, are configured as double-sided foamed portions 501 as shown in Figure 4A. The foamed layer 5c provided on the inner surface of the base material 5a of the first outer periphery 55a fills the gap between the base material 5a and the coil 3. Similarly, the foamed layer 5b provided on the outer surface of the base material 5a of the second outer periphery 55b fills the gap between the base material 5a and the bottom surface 231. In this way, the outer periphery 55 is in close contact and bonded to the bottom surface 231 and the coil 3 by the foamed layers 5b and 5c at positions other than the axial center. Furthermore, the portions of the first outer periphery 55a and the second outer periphery 55b at the axial center are configured as foamed layer-free portions 502 because they face the flow path 25 of the stator core 2 (see Figure 9).

[0044] The side portion 56 is the same as the side portion 52 in the first embodiment. The inner circumference portion 57 is the portion located radially inward from the coil 3. When viewed from the axial direction, the inner circumference portion 57 extends linearly in a direction perpendicular to the radial direction, along the radially inward surface of the coil 3. The inner circumference portion 57 is also in contact with the axial flow path 24. Except for its corner portion 57a, the inner circumference portion 57 is configured as a foam layer-free portion 502 in the entire axial range as shown in Figure 4B. The corner portion 57a ​​of the inner circumference portion 57 may be configured as a foam layer-free portion 502 or as a double-sided foam portion 501.

[0045] Thus, at positions other than the axial center, the outer peripheral portion 55 and the side portion 56 are configured as double-sided foamed portions 501 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction, except for the corner portion 57a ​​located at the boundary between the side portion 56 and the inner peripheral portion 57. Furthermore, the side surfaces and radially outer surfaces of the coil 3 and the walls 231 and 232 of the opposing slot 23 are fixed by the foamed layers 5b and 5c of the outer peripheral portion 55 and the side portion 56 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction, except for the portion in contact with the corner portion 57a.

[0046] In Figure 9, the flow of the refrigerant is indicated by arrows E1 to E4. The flows E1 to E4 are the same as those in the first embodiment (see Figures 3 and 5).

[0047] According to this embodiment, the same effects as in the first embodiment can be obtained. Specifically, since the inner circumference 57 in contact with the axial flow path 24 is configured as a foam layer-free portion 502 over the entire axial range, it is possible to reduce the likelihood of the foam layer of the insulating member 5 peeling off and clogging the axial flow path 24. It is also possible to reduce the narrowing of the axial flow path 24 by the foam layer. Furthermore, since the portion of the outer circumference 55 at the axial center is configured as a foam layer-free portion 502, it is possible to reduce the likelihood of the foam layer of the insulating member 5 clogging the flow path 25 of the stator core 2 or the flow path in the center of the slot. In addition, since the inner circumference 57 is provided so as to cover the radially inner surface of the coil 3, the coil 3 and the stator core 2 can be insulated more effectively.

[0048] (4) Fourth Embodiment Next, a fourth embodiment of this disclosure will be described, focusing on the differences from the above embodiments. Figure 10 is a view of the slot 23A, insulating member 5C, etc. of this embodiment from the axial direction. Figure 10 shows the shape of the slot 23A at a position other than the central position in the axial direction. Figure 11 is a cross-sectional view taken along the line XI-XI in Figure 10. In Figures 10 and 11, components similar to those in the above embodiments are denoted by the same reference numerals, and their descriptions are omitted as appropriate. In this embodiment, the stator core 2A and slot 23A are configured in the same way as those in the second embodiment.

[0049] The insulating member 5C has an outer periphery 55 that is configured as a foam layer-free portion 502 over the entire axial range. The corners 55c of the outer periphery 55 may be configured as foam layer-free portions 502 or as double-sided foam portions 501. The side portion 56, except for the corners 55c and 57a, is configured as a double-sided foam portion 501 over the entire range along the outer periphery of the coil 3 when viewed from the axial direction. Furthermore, except for the portions of the coil 3 that are in contact with the corners 55c and 57a, the side surface of the coil 3 and the wall surface 232 of the slot 23A facing it are fixed by the foam layers 5b and 5c of the side portion 56 over the entire range along the outer periphery of the coil 3 when viewed from the axial direction. In addition, the side portion 56 is configured as a double-sided foam portion 501 over the entire range in the axial direction, except for the central position in the axial direction. The insulating member 5C is the same as the insulating member 5B of the third embodiment except as described above.

[0050] The coil 3 and inner cover 4 are the same as those in the above embodiment. The refrigerant flow E1 to E6 are the same as those in the second embodiment (see Figure 7). In this embodiment, the refrigerant flows axially through the axial flow path 27, and the outer circumference 55 is configured as a foam layer-free portion 502, so the same effects as in the second embodiment can be obtained.

[0051] (5) Fifth embodiment Next, a fifth embodiment of this disclosure will be described, focusing on the differences from the above embodiments. Figure 12 is a view of the slot 23, insulating member 5D, etc. of this embodiment from the axial direction. Figure 12 shows the shape of the slot 23 at a position other than the central position in the axial direction. Figure 13 is a cross-sectional view taken along the line XIII-XIII in Figure 12. In Figures 12 and 13, the same reference numerals are used for components that are the same as those in the above embodiments, and their descriptions are omitted as appropriate. In this embodiment, the shape of the insulating member 5D differs from that of the insulating member 5 in the first embodiment. Components other than the insulating member 5D, specifically the stator core 2, slot 23, coil 3, and inner circumference cover 4, are the same as those in the first embodiment.

[0052] The insulating member 5D includes an outer periphery 58, a side portion 59, and an inner periphery 60. The outer periphery 58 and side portion 59 are the same as the outer periphery 51 and side portion 52 of the first embodiment. That is, at positions other than the axial center, except for the corner portion 60c located at the boundary between the side portion 59 and the inner periphery 60, the outer periphery 58 and side portion 59 are configured as double-sided foam portions 501 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction. Furthermore, except for the portion of the coil 3 in contact with the corner portion 60c, the side surfaces and radially outer surfaces of the coil 3 and the wall surfaces 231 and 232 of the slot 23 facing them are fixed by the foam layers 5b and 5c of the outer periphery 58 and side portion 59 over the entire range along the outer circumference of the coil 3 when viewed from the axial direction. In addition, the outer periphery 58 and side portion 59 are configured as double-sided foam portions 501 over the entire range in the axial direction except for the axial center.

[0053] The inner circumference portion 60 includes a first inner circumference portion 60a that forms part of one end of the insulating member 5D when viewed from the axial direction, and a second inner circumference portion 60b that forms part of the other end of the insulating member 5D. These pair of inner circumference portions 60a and 60b are arranged to overlap. That is, at least a part of the first inner circumference portion 60a is provided radially outward than the second inner circumference portion 60b. The radially inner surface of the first inner circumference portion 60a and the radially outer surface of the second inner circumference portion 60b are in contact. The radially inner surface of the coil 3 is covered by the inner circumference portion 60. The inner circumference portion 60 is in contact with the radially inner surface of the coil 3. Specifically, at least the first inner circumference portion 60a is in contact with the coil 3. The inner circumference portion 60 is also in contact with the axial flow path 24. The first inner circumference 60a and the second inner circumference 60b are configured as foam layer-free areas 502 in Figure 4B over the entire axial range. The corners 60c of the inner circumference 60 may be configured as foam layer-free areas 502 or as double-sided foamed areas 501.

[0054] The refrigerant flow E1 to E4 is the same as that of the first embodiment (see Figure 5). In this embodiment, the refrigerant flows axially within the axial flow path 24, and the inner circumference 60 is configured as a foam layer-free portion 502, so the same effects as in the first embodiment can be obtained. In addition, since the inner circumference 60 is provided so as to cover the radially inner surface of the coil 3, the coil 3 and the stator core 2 can be insulated more effectively.

[0055] (6) Sixth Embodiment Next, a sixth embodiment of this disclosure will be described, focusing on the differences from the above embodiments. Figure 14 is a view of the slot 23A, insulating member 5E, etc. of this embodiment from the axial direction. Figure 14 shows the shape of the slot 23A at a position other than the central position in the axial direction. Figure 15 is a cross-sectional view taken along the line XV-XV in Figure 14. In Figures 14 and 15, the same reference numerals are used for components that are the same as those in the above embodiments, and their descriptions are omitted as appropriate. In this embodiment, the stator core 2A and the slot 23A are configured in the same way as those in the second embodiment. The insulating member 5E differs from the insulating member 5D of the fifth embodiment in that its outer periphery 58 (excluding the corners 58a) is configured as a foam layer-free portion 502 over the entire axial range. The corners 58a of the outer periphery 58 may be configured as a foam layer-free portion 502, or as a double-sided foam portion 501.

[0056] The side portion 59 of the insulating member 5E is configured as a double-sided foamed portion 501 over the entire area along the outer circumference of the coil 3 when viewed from the axial direction, except for the corner portions 58a and 60c. Furthermore, the side of the coil 3 and the wall surface 232 of the slot 23A facing it are fixed by the foamed layers 5b and 5c of the side portion 59 over the entire area along the outer circumference of the coil 3 when viewed from the axial direction, except for the portion in contact with the corner portions 58a and 60c. In addition, the side portion 59 is configured as a double-sided foamed portion 501 over the entire area in the axial direction, except for the central position in the axial direction. The insulating member 5E is the same as the insulating member 5D except as described above. The coil 3 and inner circumference cover 4 are the same as those in the above embodiment. The refrigerant flow E1 to E6 are the same as those in the second embodiment (see Figure 7).

[0057] In this embodiment, the refrigerant flows axially through the axial passages 24 and 27, allowing for more efficient cooling of the coil 3 and stator core 2A. Furthermore, since the inner circumferential portion 60 and outer circumferential portion 58 in contact with the axial passages 24 and 27 are configured as foam layer-free portions 502 over the entire axial range, the risk of the foam layer of the insulating member 5E peeling off and clogging the axial passages 24 and 27 is reduced. This also reduces the narrowing of the axial passages 24 and 27 by the foam layer. Additionally, since the inner circumferential portion 60 is provided to cover the radially inner surface of the coil 3, the coil 3 and the stator core 2 can be insulated more effectively.

[0058] (7) Other embodiments In the embodiments described above, examples were shown in which the portion of the insulating member in contact with the axial flow path is configured as a portion without a foam layer. However, the invention is not limited to this, and a foam layer may not be provided on the outer surface of the substrate of the insulating member, which is the surface on the axial flow path side, while a foam layer may be provided on the inner surface, which is the surface opposite the outer surface of the substrate. Specifically, the outer periphery 51 in Figure 6, the inner periphery 57 in Figure 8, the outer periphery 55 in Figure 10, the inner periphery 57 in Figure 10, the inner periphery 60 in Figure 12, the outer periphery 58 in Figure 14, and the inner periphery 60 in Figure 14 may be configured as a single-sided foamed portion 503 in which a foam layer is not provided on the outer surface of the substrate 5a, and a foam layer 5c is provided on the inner surface of the substrate 5a, as shown in Figure 4C. Furthermore, the outer periphery 51 in Figure 6, the inner periphery 57 in Figure 8, the outer periphery 55 in Figure 10, the inner periphery 57 in Figure 10, the inner periphery 60 in Figure 12, the outer periphery 58 in Figure 14, and the inner periphery 60 in Figure 14 are parts that are in contact with the axial flow path 27 or axial flow path 24 and cover the radially outer or radially inner surface of the coil 3. In addition, the non-contact part 54 in Figures 2 and 6 may be configured as a single-sided foamed part 503. Even if the parts 51, 54, 55, 57, 58, and 60 of the insulating members 5, 5A to 5E that are in contact with the axial flow paths 24 and 25 are configured as single-sided foamed parts 503, the flow of the foamed layer into the axial flow paths 24 and 25 can be reduced. In addition, the coil 3 can be fixed more effectively within the slots 23 and 23A.

[0059] Furthermore, in the above embodiment, in the central part 230 of the slot in Figure 3, an example was shown in which the outer periphery 51, side portions 52, and corner portions 53 of the insulating member 5, in addition to the non-contact portion 54, are also configured as foam layer-free portions 502. However, the embodiment is not limited to this, and each portion 51 to 53 in Figure 3 only needs to have a foam layer provided on its outer surface, which is the surface facing the gap 26. That is, each portion 51 to 53 in Figure 3 may be configured as a single-sided foam portion 503 in Figure 4C. The non-contact portion 54 in the central part 230 of the slot may also be configured as a single-sided foam portion 503. This reduces the amount of foam layer flowing into the central flow path 26 and the flow path 25 of the stator core 2, and allows the coil 3 to be fixed more effectively within the slot 23.

[0060] In the above embodiment, an example was shown in which the refrigerant is supplied to the axial flow path from a central position that divides the axial flow path into two equal parts in the axial direction, among the intermediate positions between one end and the other end of the axial flow path. However, the embodiment is not limited to this, and the refrigerant may be supplied to the axial flow path from a position other than the central position in the axial direction. Specifically, the refrigerant may be supplied from one end of the axial flow path in the axial direction and discharged from the other end. Alternatively, the refrigerant may be supplied to the axial flow path from an intermediate position that does not divide the axial flow path into two equal parts in the axial direction, and discharged from both ends of the axial flow path.

[0061] Furthermore, in the above embodiment, an example was shown in which the non-contact portion of the insulating member that does not contact the coil is in contact with an axial flow path that penetrates the stator core in the axial direction. However, the invention is not limited to this, and the non-contact portion may be in contact with a flow path other than the axial flow path that penetrates the stator core in the axial direction. Even in this case, the non-contact portion may be configured as a foam layer-free portion or a single-sided foam portion in which a foam layer is not provided on at least the surface on the flow path side. That is, the stator of this disclosure may be configured as follows. An annular stator core having a plurality of teeth arranged circumferentially and projecting radially, and a plurality of slots formed between the teeth in the circumferential direction, A coil arranged in the aforementioned slot, The slot is provided so as to surround the coil and comprises an insulating member including a sheet-like base material, A refrigerant flow path is formed within the aforementioned slot. At least a portion of the insulating member that does not come into contact with the flow path is configured as a double-sided foamed portion, in which a foamed layer is provided on both surfaces of the substrate to fill the gap between the surface and the walls of the coil and the slot. When viewed from the axial direction, a portion from one end of the insulating member and a portion from the other end are not in contact with the coil. The portion of the insulating member that is not in contact with the coil is in contact with the flow path, and neither of its surfaces has the foam layer. stata.

[0062] According to this, at least a portion of the insulating member that does not come into contact with the flow path is configured as a double-sided foamed portion, in which foam layers are provided on both surfaces of the substrate of the insulating member. This increases the likelihood of effectively fixing the coil within the slot compared to a configuration in which the foam layer is provided on only one side of the substrate. Since the double-sided foamed portion is provided in a portion that does not come into contact with the flow path, it increases the likelihood of reducing the likelihood of the foam layer of the double-sided foamed portion peeling off due to the refrigerant. Furthermore, the insulating member has a pair of non-contact portions, where a portion from one end of the insulating member and a portion from the other end do not come into contact with the coil when viewed from the axial direction. The pair of non-contact portions come into contact with the flow path in the slot, but since they do not have foam layers on both surfaces, it increases the likelihood of reducing the likelihood of the foam layer peeling off from the insulating member.

[0063] In the above embodiment, in positions along the axial direction where no refrigerant flow paths other than the axial flow path exist within the slot, the portion of the insulating member not in contact with the axial flow path, excluding the corner of the insulating member located at the boundary between the portion in contact with the axial flow path and the portion not in contact with the axial flow path, is shown as a double-sided foamed portion over the entire range along the outer circumference of the coil when viewed from the axial direction. However, the embodiment is not limited to this, and the portion of the insulating member not in contact with the axial flow path may be configured as a double-sided foamed portion in a portion along the outer circumference of the coil when viewed from the axial direction, and in the remaining portion, as a foamed layer-free portion where foam layers are not provided on both sides of the base material, or as a single-sided foamed portion where foam layers are provided only on one side (outer or inner surface) of the base material. For example, the outer circumference 51 and side portion 52 in Figure 2 may be configured as a double-sided foamed portion 501 in a portion along the outer circumference of the coil when viewed from the axial direction, and as a foamed layer-free portion 502 or a single-sided foamed portion 503 in the remaining portion.

[0064] Furthermore, in the above embodiment, the portion of the insulating member that does not contact the axial flow path is shown as a double-sided foamed portion over the entire axial range except for the central position, which is an axial position where a refrigerant flow path other than the axial flow path is provided. However, it is not limited to this, and the portion of the insulating member that does not contact the axial flow path may be configured as a double-sided foamed portion in a portion of the axial direction excluding the central position, and in the remaining portion, it may be configured as a foamed layer-free portion where foam layers are not provided on both sides of the base material, or as a single-sided foamed portion where foam layers are provided only on one side (outer or inner surface) of the base material. For example, the outer periphery 51 and side portion 52 in Figure 2 may be configured as a double-sided foamed portion 501 in a portion of the axial direction excluding the central position, and in the remaining portion, it may be configured as a foamed layer-free portion 502 or a single-sided foamed portion 503.

[0065] Alternatively, instead of the inner circumferential cover 4, a member may be provided at each slot 23, 23A to close the radially inner opening of slots 23, 23A. The axial flow path may be provided at a position other than radially inward or outward from the coil, that is, at a position adjacent to the coil and insulating member in the circumferential direction of the stator core. In this case, the foam layer may not be provided over the entire axial range of the substrate on at least the surface of the substrate on the axial flow path side of the side of the insulating member that is in contact with the axial flow path.

[0066] The stator core can be an annular member having multiple teeth arranged in the circumferential direction and multiple slots formed between the teeth in the circumferential direction. That is, the stator core can have multiple slots formed by the multiple teeth, with coils placed in each slot. Furthermore, it should be configured so that the rotor rotates relative to the stator through the interaction between the magnetic field formed by the coils and the magnetic field formed by the rotor. The number of magnetic poles, the number of slots, the material, etc., of the stator core can be of various configurations.

[0067] The stator core may be annular in its overall form. The shapes of the radially inner and radially outer surfaces of the ring formed by the stator core are not limited. For example, the radially outer surface may be circular when viewed from the axial direction, or it may have a polygonal shape. Teeth are formed on the radially inner surface, and slots are formed between the teeth. In the stator core, the general shape including the teeth can be considered annular, or the portion excluding the teeth can be considered annular. Furthermore, the stator of this disclosure may be applied to a generator, which is a type of rotating electric machine.

[0068] The coil only needs to be positioned within the slot. The shape of the coil and the method of positioning it are not limited. Therefore, the coil may be wound around teeth, or segment coils may be inserted axially and joined at the axial ends. The coil includes at least a housing portion that is housed in the slot and a coil end portion that protrudes axially from the end face of the stator core. The housing portion is the part housed in the slot, and is usually the portion within the slot that is sandwiched between the two end faces of the stator core in the axial direction. The coil end portion is the portion that protrudes axially from the end face of the stator core; that is, the coil that is on the side of the slot opposite to the end face of the stator core is the coil end portion. [Explanation of Symbols]

[0069] 1...Stator, 2...Stator core, 21...Core body, 22...Teeth, 23...Slot, 23A...Slot, 230...Slot center, 24...Axial flow path, 25...Core body flow path, 26...Central flow path, 27...Axial flow path, 3...Coil, 4...Inner cover, 5...Insulating member, 5A...Insulating member, 5B...Insulating member, 5C...Insulating member, 5D...Insulating member, 5E...Insulating member, 51...Outer periphery of insulating member, 52...Side of insulating member, 54...Non-contact portion of insulating member, 55...Outer periphery of insulating member, 56...Side of insulating member, 57...Inner periphery of insulating member, 58...Outer periphery of insulating member, 59...Side of insulating member, 60...Inner periphery of insulating member

Claims

1. An annular stator core having a plurality of teeth arranged circumferentially and projecting radially, and a plurality of slots formed between the teeth in the circumferential direction, A coil arranged in the aforementioned slot, The slot is provided so as to surround the coil and comprises an insulating member including a sheet-like base material, Within the slot, an axial flow path is formed, which is a coolant flow path that penetrates between the ends of the slot in the axial direction of the stator core. At least a portion of the insulating member that does not come into contact with the axial flow path is configured as a double-sided foamed portion, in which a foamed layer is provided on both surfaces of the substrate to fill the gap between the surface and the walls of the coil and the slot. The foam layer is not provided over the entire area of ​​the substrate in the axial direction in the portion of the insulating member that is in contact with the axial flow path. stata.

2. The axial flow path is provided radially inward or radially outward from the coil. The portion of the insulating member in which the foam layer is not provided is a portion radially inward or radially outward from the coil where the axial flow path is located. The stator according to claim 1.

3. When the bent portion of the insulating member located at the boundary between the portion in contact with the axial flow path and the portion not in contact with the axial flow path is defined as a corner, The portion of the insulating member that does not come into contact with the axial flow path, excluding the corners, is configured as the double-sided foamed portion over the entire area along the outer circumference of the coil when viewed from the axial direction. The stator according to claim 1.

4. When viewed from the axial direction, a portion from one end of the insulating member and a portion from the other end are not in contact with the coil. The portion of the insulating member that is not in contact with the coil is in contact with the axial flow path, and does not have the foam layer on either surface. The stator according to claim 1.

5. The stator core has a flow path formed in the intermediate position of the slot in the axial direction for supplying refrigerant. A gap is formed between the wall surface of the slot and the insulating member at the intermediate position of the slot, and this gap is connected to the axial flow path. At the intermediate position, the portion of the insulating member that is in contact with the gap does not have the foam layer on at least the surface facing the gap. The stator according to claim 1.

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