Stator for rotary electric machines

Abstract

To efficiently cool an entire coil of a stator for rotary electric machines.SOLUTION: A stator 2 for rotary electric machines comprises: a stator core 20 in which a plurality of circumferential slots 22 is provided while extending in an axial direction; a coil 21 disposed on the slot 22; and an insulation member 40 which is disposed in the slot 22 so as to enclose the coil 21. The stator core 20 includes a pair of side faces 222a and 222b opposed to each other of the slot 22. The side face 222a includes a projection 25 which protrudes toward the side face 222b and to which one circumferential end of the coil 21 is abutted via the insulation member 40. The stator 2 for rotary electric machines further comprises a foam 45 which is filled via the insulation member 40 between the other circumferential end of the coil 21 and the side face 222b.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a stator for a rotating electric machine. [Background technology]

[0002] As a technology for cooling coils included in a stator for a rotating electric machine, a stator is known in which a cooling pipe extending in the axial direction is arranged above the coil end and a cooling medium is dripped from above the coil end through the cooling pipe (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-34873 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the configuration in which the cooling medium is dripped toward the coil ends as described in Patent Document 1 above, it is difficult to sufficiently cool the entire coil, including the portions within the slots. [Means for solving the problem]

[0005] A stator for a rotating electric machine according to one aspect of the present invention includes a stator core having a plurality of circumferential slots extending in the axial direction, a coil arranged in the slots, and an insulating member arranged in the slots so as to surround the coil. The stator core is provided with a flow path for guiding a cooling medium into the inside of the slot. The stator core has a first inner surface and a second inner surface constituting a pair of inner side surfaces facing each other of the slots, the first inner surface having a protrusion protruding toward the second inner surface and against which one circumferential end of the coil abuts via the insulating member, and the stator for a rotating electric machine further includes a foam filled between the other circumferential end of the coil and the second inner surface via the insulating member. Effect of the Invention

[0006] According to the present invention, the entire coil of the stator can be sufficiently cooled. [Brief description of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view showing a configuration of a main part of a rotating electric machine including a stator for a rotating electric machine according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged view of a main part of FIG. 1 showing the configuration of a slot. [Figure 3A] FIG. 4 is a perspective view showing the configuration of a sheet-like substrate constituting an insulating member disposed in a slot. [Figure 3B] FIG. 4 is a perspective view showing a configuration of an insulating member disposed in a slot. [Figure 4] 4 is a perspective view illustrating a manufacturing process of the stator for a rotating electric machine according to the embodiment of the present invention; FIG. [Diagram 5] 5A and 5B are diagrams illustrating the configuration of a side wall of an insulating member before and after heating. [Figure 6] 6 is a cross-sectional view of the stator core taken along line VI-VI in FIG. 4. [Figure 7] FIG. 2 is a cross-sectional view of a main portion of a stator for a rotating electric machine according to an embodiment of the present invention, illustrating a flow of cooling oil. [Figure 8] FIG. 8 is a view taken along line VIII of FIG. [Figure 9] FIG. 3 is a diagram showing a reference example of FIG. 2. [Figure 10] FIG. 9 is a diagram showing a modification of FIG. 8 . [Figure 11A] 11 is a cross-sectional view taken along line AA in FIG. 10. [Figure 11B] FIG. 11 is a cross-sectional view taken along line BB in FIG. [Figure 12] FIG. 9 is a diagram showing another modified example of FIG. 8. [Figure 13A] 13 is a cross-sectional view taken along line AA in FIG. 12. [Figure 13B] FIG. 13 is a cross-sectional view taken along line BB in FIG. 12 . [Figure 14] FIG. 7 is a diagram showing a configuration of flow paths leading to slots, different from that shown in FIG. 6. [Figure 15]15 is a perspective view of an insulating member received in the slot of FIG. 14. [Figure 16] FIG. 14, viewed from the arrow XVI side. [Figure 17] 13 is a perspective view showing a modified example of an insulating member accommodated in a slot. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 17. Fig. 1 is a cross-sectional view showing a configuration of a main part of a rotating electric machine 100 including a stator for a rotating electric machine according to an embodiment of the present invention. The rotating electric machine 100 is mounted on a hybrid vehicle or an electric vehicle and can be used as an electric motor for driving the vehicle, and can also be used as a generator. Note that the rotating electric machine 100 can also be mounted on something other than a vehicle and used for various purposes.

[0009] Fig. 1 is a cross-sectional view perpendicular to an axis line CL0 showing a configuration of a main part of a rotating electric machine 100. As shown in Fig. 1, the rotating electric machine 100 includes a rotor 1 that rotates around an axis line CL0, and a stator 2 that is provided outside the rotor 1 so as to surround an outer circumferential surface 1a of the rotor 1. A case 3 is disposed around the stator 2. In the following, the direction in which the axis line CL0 extends is defined as the axial direction, the direction extending radially from the axis line CL0 as the radial direction, and the direction along the circumference of a circle centered on the axis line CL0 as the circumferential direction.

[0010] The rotating electric machine 100 is configured as, for example, an embedded magnet type synchronous motor. Therefore, the rotor 1 has a rotor core 10 having a substantially annular shape centered on an axis CL0, and a plurality of magnetic pole portions (not shown) formed in the rotor core 10 in the circumferential direction. Permanent magnets are embedded in the magnetic pole portions. For example, a rotor shaft (not shown) constituting the output shaft of the rotating electric machine 100 is fitted into an inner peripheral surface 10a of the rotor core 10, and the rotor 1 rotates integrally with the rotor shaft. The outer peripheral surface 1a of the rotor 1 corresponds to the outer peripheral surface of the rotor core 10. The rotor core 10 is formed by stacking a plurality of (for example, several tens of) magnetic steel sheets made of metal, which is a magnetic body, in the axial direction. The thickness of each magnetic steel sheet is 1 mm or less (for example, about 0.2 mm to 0.3 mm).

[0011] The stator 2 has a substantially annular stator core 20 centered on an axis CL0 and having an inner circumferential surface 20a disposed at a predetermined distance in the radial direction from the outer circumferential surface 1a of the rotor 1, and a coil 21 attached to the stator core 20. The stator core 20 is formed by stacking multiple electromagnetic steel plates made of a magnetic metal in the axial direction.

[0012] The stator core 20 has a plurality of circumferential teeth 23 that protrude radially inward from a substantially cylindrical yoke 24 at equal intervals in the circumferential direction. A plurality of circumferential slots 22 are provided between adjacent teeth 23 in the circumferential direction from the inner peripheral surface 20a to the radially outward direction, and a coil 21 is attached to each slot 22. The slots 22 are provided all around the inner peripheral surface 20a, but for convenience, only a portion of the slots 22 in the circumferential direction is shown in FIG. 1. The total number of slots 22 is, for example, 48. The total number of slots 22 may be more or less than 48. The outer peripheral surface 20b of the stator core 20 is fitted liquid-tightly to the inner peripheral surface 31 of the case 3.

[0013] The coil 21 is a conductor having a substantially rectangular cross section. The coil 21 may be a conductor having a circular cross section. The coil 21 includes a U-phase coil, a V-phase coil, and a W-phase coil, and is configured as a three-phase coil. The U-phase coil, the V-phase coil, and the W-phase coil are electrically connected to a power conversion device (not shown) via a U-phase lead wire, a V-phase lead wire, and a W-phase lead wire, respectively. When the rotating electric machine 100 is used as an electric motor, three-phase AC power is supplied from the power conversion device to each coil 21. This generates a magnetic field in the stator 2, and the rotor 1 rotates due to the interaction between this magnetic field and a magnetic field generated by a permanent magnet of the magnetic pole portion of the rotor 1. As a result, a running driving force is generated, and the vehicle runs. When the rotating electric machine 100 is used as a generator, the three-phase AC power generated by driving the rotating electric machine 100 is supplied to a power conversion device (not shown) or the like.

[0014] FIG. 2 is an enlarged view of a main part of the stator 2. FIG. 2 mainly shows the configuration of a single slot 22 and its surroundings. As shown in FIG. 2, the slot 22 has an opening 221 provided in the inner peripheral surface 20a of the stator core 20 and an accommodation portion 222 provided radially outward of the opening 221. The accommodation portion 222 has a pair of side surfaces 222a, 222b extending in the radial direction and facing each other, and a bottom surface 222c extending in the circumferential direction and connecting the ends of the pair of side surfaces 222a, 222b on the outer diameter side. The width of the accommodation portion 222, i.e., the distance (circumferential length) between the pair of side surfaces 222a, 222b, is constant in the radial direction, and the accommodation portion 222 is formed in a substantially rectangular shape elongated in the radial direction. The teeth 23 have protruding portions 231 protruding on both circumferential sides at the radially inner tip portion, and the opening 221 is provided between the pair of protruding portions 231 (teeth tip portion). The width of the accommodation portion 222 is greater than the width of the opening 221 .

[0015] An insulating member 40 having a generally rectangular frame-like cross section is disposed in the slot 22. The insulating member 40 forms a generally rectangular parallelepiped accommodation space inside, and six conductor segments 210 forming the coil 21 are disposed in a row in the radial direction in the accommodation space. The number of conductor segments 210 in the slot may be more or less than six. The conductor segments 210 are covered with an insulating coating.

[0016] A plurality of (six) radial protrusions 25 are provided on one side surface 222a of the slot 22 of the stator core 20 in correspondence with the positions of the coil 21 (conductor segment 210), and the side surface 222a is formed in an uneven shape. The protrusions 25 extend over a predetermined length in the axial direction (see FIG. 8). Note that, for convenience, FIG. 2 shows all the protrusions 25 arranged in the radial direction, but the actual arrangement of the protrusions 25 will be described later.

[0017] The tip of the protrusion 25 is formed in a substantially arc shape (e.g., semicircular shape). In this case, the diameter of the protrusion 25 is preferably, for example, about 0.5 mm. The other side surface 222b of the slot 22 is a flat surface. The slot 22 is formed, for example, by punching an electromagnetic steel sheet, and the protrusion 25 can be formed at the same time.

[0018] The insulating member 40 is formed by folding a sheet-like base material. FIG. 3A is a perspective view showing the overall configuration of the sheet-like base material 400 before folding, and FIG. 3B is a perspective view showing the overall configuration of the insulating member 40 formed by folding the sheet-like base material 400. The X direction in FIG. 3A and FIG. 3B corresponds to the axial direction, and the Y direction and Z direction in FIG. 3B correspond to the circumferential direction and the radial direction, respectively. As shown in FIG. 3A, the sheet-like base material 400 has a three-layer structure of an adhesive layer 41, an insulating layer 42, and a foam layer 43.

[0019] The insulating layer 42 is made of a resin material having electrical insulation properties, and has a generally rectangular shape as a whole. An adhesive layer 41 is formed over the entire surface of one surface of the insulating layer 42. An adhesive is applied to the adhesive layer 41 in advance. A foam layer 43 is formed in a partial area of ​​the other surface of the insulating layer 42. The foam layer 43 is made of a thermosetting foamable resin material, such as an epoxy-based foamable resin material. The foam layer 43 may be made of a thermoplastic resin material. The foam layer 43 foams and expands when heated to a predetermined temperature, becoming a foam.

[0020] The sheet-like substrate 400 is folded so that the adhesive layer 41 is disposed inside the insulating member 40 and the foam layer 43 is disposed outside the insulating member 40. Specifically, the sheet-like substrate 400 is folded along dashed dotted lines L1 to L3 extending in the X direction in Fig. 3A. As a result, the insulating member 40 having a substantially rectangular frame shape is formed as shown in Fig. 3B.

[0021] The insulating member 40 has a pair of side walls 401, 402 extending in the radial direction (Z direction) and a pair of peripheral walls 403, 404 extending in the circumferential direction (Y direction). One axial end 40a and the other axial end 40b of the insulating member 40 are each opened, and the coil 21 (FIG. 2) protrudes in the axial direction from the insulating member 40 through these openings to form coil ends. A foam layer 43 is provided over the entire outer surface of one side wall 402. A concave fold 46 (only a part of which is shown in FIG. 3A) is provided on the outer surface of the other side wall 401 at a position where the convex portion 25 (FIG. 2) of the stator core 20 abuts.

[0022] One end 400A and the other end 400B of the sheet-like substrate 400 shown in FIG. 3A are abutted against each other at the end of the peripheral wall 403 on the radially outer side. Alternatively, the one end 400A and the other end 400B of the sheet-like substrate 400 may be overlapped with each other. For example, the one end 400A and the other end 400B may be overlapped at the outer diameter side end to form the peripheral wall 403. A substantially rectangular opening 400c penetrating the peripheral wall 403 is provided at the center in the axial direction (X direction) of the peripheral wall 403. The space inside the insulating member 40 communicates with the space on the radially outer side through the opening 400c.

[0023] 4 is a perspective view showing a process of inserting the insulating member 40 into the stator core 20. As shown in FIG. 4, the insulating member 40 is inserted into the slot 22 of the stator core 20 along the axial direction (arrow X1) from one end face 200a to the other end face 200b of the stator core 20. The axial length of the insulating member 40 is the same as the axial length of the stator core 20, and the insulating member 40 is disposed inside the stator core 20 without protruding from the axial end face of the stator core 20. The axial length of the insulating member 40 may be longer or shorter than the axial length of the stator core 20.

[0024] After the insulating member 40 is inserted, a plurality of conductor segments 210 (only two are shown in FIG. 4 ) are inserted along the axial direction inside the insulating member 40. For example, a pair of legs of a substantially U-shaped conductor segment 210 are inserted into insulating members 40 arranged in different slots 22. Note that the configuration of the conductor segments 210 is not limited to a substantially U-shape.

[0025] After the conductor segment 210 is inserted, the insulating member 40 is heated. Fig. 5 is a diagram showing a schematic configuration of the side wall 402 of the insulating member 40 before and after heating. As shown in Fig. 5, before the insulating member 40 is heated, the foam layer 43 is not foamed, and the plate thickness of the side wall 402 remains the plate thickness of the sheet-like substrate 400 (Fig. 3A). Therefore, inside the insulating member 40, a relatively large space SP1 is formed between the side wall 402 and the coil 21, and the conductor segment 210 can be easily inserted into the space SP1 along the axial direction.

[0026] When the insulating member 40 is heated to a predetermined temperature, the foam layer 43 expands to become a foam 45. Although the foam 45 is a part of the insulating member 40, in the following, the foam 45 and the insulating member 40 are treated as separate members for convenience. In other words, the foam 45, which does not have an insulating function, is treated as a member different from the insulating member 40. Note that the foam 45 may be treated as a part of the insulating member 40, and the insulating member 40 may include the foam 45.

[0027] When the foam layer 43 expands to become foam 45, one end face (foam layer 43 side) of the side wall 402 remains in contact with the side surface 222b of the slot 22, while the other end face (adhesive layer 41 side) moves toward the conductor segment 210. As a result, the side wall 402 (adhesive layer 41) comes into contact with the end face of the conductor segment 210 (coil 21), and a pressing force F as indicated by an arrow is applied to the coil 21. As a result, as shown in FIG. 2, the end face of the coil 21 comes into contact with the protrusion 25 via the side wall 401 of the insulating member 40, and the coil 21 is restrained. Note that in order to avoid complication of the figure, the adhesive layer 41 is omitted from FIG. 2.

[0028] Side wall 401 is provided with folds 46 ( FIG. 3A ) in advance corresponding to the positions of protrusions 25. Therefore, as shown in FIG. 2, side wall 401 has a radially uneven shape along side surface 222a of slot 22, and gaps SP2 are provided between side wall 401 and coil 21. Note that instead of folds 46, a plurality of recesses may be provided in advance on the outer surface of side wall 401 corresponding to the positions of protrusions 25, and the recesses may engage with protrusions 25. Cooling oil is supplied into the slot from the outside of stator core 20 through openings 400c in peripheral wall 403 of insulating member 40.

[0029] As shown in FIG. 4, a groove 200 having a predetermined depth is provided on the outer peripheral surface 20b of the stator core 20 in the axial center of the stator core 20 over the entire circumference. As shown in FIG. 1, the outer peripheral surface 20b of the stator core 20 is liquid-tightly covered by the inner peripheral surface 31 of the case 3. As a result, an annular flow path PA0 centered on the axis line CL0 is formed between the groove 200 (dotted line in FIG. 1) and the inner peripheral surface 31 of the case 3. A flange portion 32 for supplying cooling oil is provided on the outer peripheral surface of the case 3. The flange portion 32 is provided, for example, at the uppermost part in the gravity direction of the outer peripheral surface of the case 3. A through hole 32a is drilled in the flange portion 32, penetrating the case 3 in the radial direction, and the external space of the case 3 and the flow path PA0 are communicated via the through hole 32a. The flange portion 32 may be provided on the axial end surface of the case 3, and a flow path extending in the axial direction and communicating with the flow path PA0 may be formed in the case 3.

[0030] Fig. 6 is a cross-sectional view of the stator core 20 taken along line VI-VI in Fig. 4. Note that Fig. 6 shows only a portion (three slots) of the stator core 20 in the circumferential direction. As shown in Fig. 6, a bottom surface 200c of the groove 200 of the stator core 20 is provided with a plurality of through holes 202 that extend toward bottom surfaces 222c of a plurality of slots 22 in the circumferential direction and penetrate the stator core 20 in the radial direction. In other words, the stator core 20 is provided with the through holes 202 extending in the radial direction in the yoke 24 on the radial outside of the slots 22. The through holes 202 form an oil passage for supplying cooling oil.

[0031] The through hole 202 is composed of a notch 202a extending radially inward from a bottom surface 200c of the groove 200 and a notch 202b extending radially outward from a bottom surface 222c of the slot 22. That is, the notch 202a and the notch 202b are formed in electromagnetic steel sheets adjacent to each other in the axial direction (see FIG. 8), and the bottom (inner diameter side end) of the notch 202a and the bottom (outer diameter side end) of the notch 202b communicate with each other in the axial direction to form the through hole 202 that extends from the bottom surface 200c of the groove 200 to the bottom surface 222c of the slot 22.

[0032] 7 is a cross-sectional view of a main part of the stator 2 for a rotating electric machine according to an embodiment of the invention, showing the flow of cooling oil. As shown by the arrows in FIG. 7, cooling oil supplied from the outside of the case 3 flows into an annular flow path PA0 provided on the outer circumferential surface of the stator core 20 via the through hole 32a of the case 3. The cooling oil that has flowed into the flow path PA0 flows in the circumferential direction along the flow path PA0, and flows into the inside of the insulating member 40 via the multiple through holes 202 in the circumferential direction of the stator core 20 and the opening 400c of the insulating member 40.

[0033] The protrusions 25 on the side surface 222a of the slot 22 are not provided over the entire axial length of the side surface 222a, but are provided intermittently in the axial direction so that cooling oil flows radially within the slot, as shown by the arrows in Fig. 7. Fig. 8 is a view taken along the arrow VIII in Fig. 7, showing the arrangement of the protrusions 25 within the slot. In Fig. 8, the insulating member 40 and the foam 45 are omitted, and the coil 21 is indicated by a two-dot chain line for the sake of convenience.

[0034] In the figure, the multiple coils 21 are referred to as the first to sixth coils in order from the inner diameter side for convenience, and are represented by C1 to C6, respectively. The stator core 20 is formed by stacking multiple (e.g., six) electromagnetic steel sheet groups in the axial direction, each group having n (e.g., 20) laminated electromagnetic steel sheets. The multiple electromagnetic steel sheet groups are referred to as the first to sixth electromagnetic steel sheet groups in order from one end surface 200a of the stator core 20 for convenience, and are represented by S1 to S6, respectively.

[0035] As shown in Fig. 8, the stator core 20 is provided with through holes 202 (Fig. 6) on the radial outside of the slots 22 of the electromagnetic steel sheet group S3. The odd-numbered electromagnetic steel sheet groups S1, S3, S5 are provided with protruding portions 25 over the entire axial length of each of the electromagnetic steel sheet groups S1, S3, S5, facing the second-stage coil C2, the fourth-stage coil C4, and the sixth-stage coil C6. The even-numbered electromagnetic steel sheet groups S2, S4, S6 are provided with protruding portions 25 over the entire axial length of each of the electromagnetic steel sheet groups S2, S4, S6, facing the first-stage coil C1, the third-stage coil C3, and the fifth-stage coil C5. In this way, on the side surface 222a of the slot 22, a plurality of protruding portions 25 extending over a predetermined axial length are arranged alternately in the radial and axial directions, i.e., in a staggered pattern.

[0036] As a result, as shown by the arrows in Fig. 8, the cooling oil that flows into the slots through the through holes 202 flows radially inward and axially outward. Therefore, the cooling oil flows along the coil 21, and the coil 21 in the slot can be efficiently cooled. The cooling oil that flows in the axial direction flows out from one axial end 40a and the other axial end 40b of the insulating member 40 shown in Fig. 3B. Therefore, the cooling oil flows along the coil ends, and the coil ends can also be efficiently cooled.

[0037] FIG. 9 is a diagram showing a reference example of FIG. 2. In the example of FIG. 9, foams 45 are provided facing both side surfaces 222a, 222b of the slot 22. Therefore, a sufficient gap for the cooling oil to flow is not provided between the coil 21 and the insulating member 40A, and it is difficult to flow the cooling oil uniformly in the axial direction along the coil 21. In contrast, in this embodiment, a convex portion 25 is provided on one side surface 222a of the slot 22, so that a uniform gap SP2 (FIG. 2) is provided between the end face of the coil 21 and the side wall 401 of the insulating member 40 in the axial direction. Therefore, the cooling oil flows smoothly in the axial direction inside the slot, and the coil 21 can be uniformly cooled.

[0038] The arrangement of the protrusions 25 on the side surface 222a of the slot 22 is not limited to that shown in FIG. 8. FIG. 10 is a diagram showing a modified example of FIG. 8, and FIGS. 11A and 11B are cross-sectional views taken along lines AA and BB in FIG. 10, respectively. Note that in FIG. 10, the yoke 24 on the radially outer side of the slot 22 is omitted. As shown in FIG. 10, the odd-numbered electromagnetic steel sheet groups S1, S3, and S5 are provided with protrusions 25 over the entire axial length of each of the electromagnetic steel sheet groups S1, S3, and S5, facing the second-stage coil C2, the fourth-stage coil C4, and the sixth-stage coil C6. The even-numbered electromagnetic steel sheet groups S2, S4, and S6 are provided with protrusions 25 over the entire axial length of each of the electromagnetic steel sheet groups S2, S4, and S6, facing the first-stage coil C1, the third-stage coil C3, and the fifth-stage coil C5.

[0039] Further, in the example of FIG. 10, a protrusion 25 is provided over the entire axial length of all the electromagnetic steel sheet groups S1 to S6, facing the inner diameter side corner 211 of the first stage coil C1. The innermost diameter side protrusions 25 are located at the same radial position. Therefore, the protrusion 25 extends in a straight line from one end face 200a to the other end face 200b of the stator core 20, and becomes a long protrusion 25 as a whole (for convenience, referred to as an inner diameter side protrusion 251). As shown in FIG. 11A and FIG. 11B, the tip end of the inner diameter side protrusion 251 is located slightly on the inner diameter side of the radially inner end face 212 of the first stage coil C1, strictly speaking. Therefore, the inner diameter side corner 211 of the first stage coil C1 abuts against the inclined surface of the inner diameter side protrusion 251, thereby preventing the coil 21 from moving radially inward.

[0040] Fig. 12 is a diagram showing a further modified example of Fig. 8, and Figs. 13A and 13B are cross-sectional views taken along lines AA and BB in Fig. 12, respectively. As shown in Fig. 12, in the electromagnetic steel sheet groups S1 and S5, convex portions 25 are provided over the entire axial length of each of the electromagnetic steel sheet groups S1 and S5, facing the second-stage coil C2, the fourth-stage coil C4 and the sixth-stage coil C6. In the electromagnetic steel sheet groups S2 and S6, convex portions 25 are provided over the entire axial length of each of the electromagnetic steel sheet groups S2 and S6, facing the first-stage coil C1, the third-stage coil C3 and the fifth-stage coil C5.

[0041] Further, in the example of FIG. 12, the electromagnetic steel sheet groups S3, S4 at the axial center are provided with protrusions 25 (for convenience, referred to as boundary protrusions 252) over the entire axial length of the electromagnetic steel sheet groups S3, S4, facing the boundary portions 213 of the radially adjacent coils 21, such as the boundary portion between the first-stage coil C1 and the second-stage coil C2, and the boundary portion between the second-stage coil C2 and the third-stage coil C3. As shown in FIG. 13B, the boundary protrusions 252 abut against the boundary portions 213 of the coils 21. This makes it possible to prevent the radial movement of each coil 21. In this case, as shown in FIG. 13A, the protrusions 25 abut against the end faces of the coils 21 via the insulating member 40 at a portion other than the axial center portion of the stator core 20, so that a sufficient gap SP2 can be secured between the coils 21 and the insulating member 40, and the cooling oil can flow smoothly.

[0042] In the above, a flow path (through hole 202) is provided in the yoke 24 on the radial outside of the slot 22, and the cooling oil is guided from the radial outside of the slot 22 into the slot through the bottom surface 222c on the radial outside of the slot 22, but the configuration of the flow path is not limited to this. For example, the cooling oil may be guided into the slot from one side surface 222a of the slot 22. FIG. 14 is a cross-sectional view of the slot 22 showing an example, and FIG. 15 is a perspective view of the insulating member 40 accommodated in the slot 22 of FIG. 14. As shown in FIG. 15, the insulating member 40 is provided with a substantially rectangular opening 400c in the axial center of the side wall 401 on the protruding portion 25 side of the slot 22.

[0043] As shown in FIG. 14, the stator core 20 is provided with a through hole 202 that extends radially inward from the bottom surface of the groove 200 on the outer circumferential surface and reaches an opening 222d of a side surface 222a of the slot 22. As in FIG. 6, the through hole 202 is also formed of a notch (dotted line) that extends radially inward from the bottom surface 200c of the groove 200 and a notch (solid line) that extends radially outward from the opening 222d. FIG. 16 is a view taken along the arrow XVI in FIG. 14 showing the arrangement of the protrusion 25. As shown in FIG. 16, the opening 222d of the slot 22 is provided facing the boundary portion 213 between the fifth-stage coil C5 and the sixth-stage coil C6 of the electromagnetic steel plate group S3. The position of the opening 222d coincides with the position of the opening 400c of the insulating member 40 inserted into the slot 22, and thus the cooling oil can be guided to the inside of the insulating member 40 through the through hole 202.

[0044] As shown in Fig. 16, unlike Fig. 8, there is no protruding portion 25 (dotted line) at a position facing the fifth-stage coil C5 of the electromagnetic steel sheet group S3, and instead, protruding portions 25 are provided at positions facing the fifth-stage coil C5 of the electromagnetic steel sheet groups S2 and S4 on both sides of the group. That is, in Fig. 16, an opening 222d is provided in the side surface 222a of the slot 22, so that the distance from the opening 222d to the protruding portion 25 (dotted line) is less than a predetermined distance. Therefore, the protruding portion 25 (dotted line) is shifted in the axial direction so that the distance from the opening 222d to the protruding portion 25 is equal to or greater than the predetermined distance. This makes it possible to ensure a sufficient insulation distance (insulation distance equal to or greater than a predetermined distance) between the coil 21 and the protruding portion 25 via the opening 400c of the insulating member 40. In order to ensure a sufficient insulation distance, the protrusions 25 of the electromagnetic steel sheet groups S2 and S4 facing the fifth-stage coil C5 may be shifted radially inward, and the protrusions 25 facing the sixth-stage coil C6 may be shifted radially outward. The protrusions 25 (dotted lines) of the electromagnetic steel sheet group S3 may be shifted radially inward to ensure the insulation distance.

[0045] According to this embodiment, the following advantageous effects can be obtained. (1) A stator 2 for a rotating electric machine includes a stator core 20 having a plurality of circumferential slots 22 extending in the axial direction, a coil 21 arranged in the slot 22, and an insulating member 40 arranged in the slot 22 so as to surround the coil 21 (FIGS. 1 and 2). The stator core 20 is provided with an oil passage (through hole 202) for guiding cooling oil into the inside of the slot 22 (FIG. 6). The stator core 20 has a pair of opposing side surfaces 222a, 222b of the slot 22, and the side surface 222a has a protrusion 25 that protrudes toward the side surface 222b and against which one circumferential end of the coil 21 abuts via the insulating member 40 (FIG. 2). The stator 2 further includes a foam 45 filled between the other circumferential end of the coil 21 and the side surface 222b via the insulating member 40 (FIG. 2).

[0046] By providing protrusion 25 on side surface 222a of slot 22 in this manner, a gap SP2 can be provided between side surface 222a and coil 21 pressed against the protrusion by foam 45. This allows the cooling oil introduced into the slot via the oil passage (through hole 202) to flow smoothly in the axial direction, allowing the entire coil to be sufficiently cooled.

[0047] (2) The insulating member 40 has a side wall 401 facing the side surface 222a of the slot 22 and a side wall 402 facing the side surface 222b (FIG. 2). The foam 45 is formed by a foam layer 43 that is provided in advance only on the side wall 402 of the pair of side walls 401, 402 (FIG. 3B). With this configuration, a gap is provided in the space inside the insulating member 40 before the foam layer 43 is foamed. This makes it easy to insert the coil 21 inside the insulating member 40. In addition, after the foam layer 43 is foamed, the coil 21 is pressed by the foam 45, and the position of the coil 21 can be restrained.

[0048] (3) The protrusions 25 are provided at multiple locations in the radial direction, and the multiple protrusions 25 extend in the axial direction (FIGS. 8, 10, and 12). This allows the cooling oil to flow smoothly in the axial direction within the slot, and the coil 21 can be cooled efficiently.

[0049] (4) The stator core 20 has electromagnetic steel sheet groups (e.g., electromagnetic steel sheet groups S1, S2) adjacent to each other in the axial direction (FIG. 8). The multiple protrusions 25 include a protrusion 25 provided in the electromagnetic steel sheet group S1 and a protrusion 25 provided in the electromagnetic steel sheet group S2 (FIG. 8). The protrusions 25 of these electromagnetic steel sheet groups S1, S2 are provided at different positions in the radial direction (FIG. 8). More specifically, the multiple protrusions 25 are arranged in a staggered pattern (FIG. 8). This allows the cooling oil to spread throughout the entire area in the slot in the radial and axial directions, and allows the coils 21 to be uniformly cooled.

[0050] (5) The coils 21 include a first-stage coil C1 (innermost coil portion) disposed on the innermost side of the slot 22 and extend in the axial direction (FIGS. 2 and 10). The protrusions 25, particularly the protrusion 25 on the innermost side (inner-diameter side protrusion 251) extend in the axial direction of the stator core 20 along the inner-diameter side end portion (inner-diameter side corner portion 211) of the first-stage coil C1 (FIG. 10). This allows the position of the inner-diameter side end portion of the coils 21 to be regulated by the protrusions 25.

[0051] (6) The coil 21 includes a plurality of coils 21 (e.g., a first-stage coil C1 and a second-stage coil C2) that are adjacent to each other in the radial direction and extend in the axial direction (FIG. 12). The protrusion 25, particularly the boundary protrusion 252, extends in the axial direction along the boundary 213 between the first-stage coil C1 and the second-stage coil C2 (FIG. 12). This makes it possible to regulate the radial position of the coils 21 in each stage.

[0052] (7) The insulating member 40 is provided with an opening 400c that penetrates the side wall 401 and communicates with the oil passage (through hole 202) (FIG. 15). The protrusion 25 is provided at a position shifted in the radial and axial directions from the opening 400c so that the distance from the opening 400c to the protrusion 25 is equal to or greater than a predetermined distance (FIG. 16). This ensures a sufficient insulation distance from the coil 21 to the protrusion 25 via the opening 400c.

[0053] This embodiment can be modified in various ways. Some modified examples will be described below. FIG. 17 is a perspective view showing a modified example of the insulating member 40. In FIG. 17, one end 400A side and the other end 400B side of the sheet-like base material 400 (FIG. 3A) are folded toward the side wall 401 at the radial center of the side wall 402, and the inside of the insulating member 40 is divided into two spaces SP11 and SP12 in the radial direction. The side wall 402 is divided into two (side wall portions 402a and 402b) in the radial direction, and foam layers 43 are provided on the surfaces of the side wall portions 402a and 402b, respectively. Three coils 21 are inserted in the radial direction into the spaces SP12 and SP12, respectively.

[0054] An opening 400c is provided in the axial center of the side wall 401 and the peripheral wall 403, from near the radially inner end of the side wall 401 to the circumferential center of the peripheral wall 403 or toward the side wall 402 side from the circumferential center. The opening 400c is connected to the through hole 202 (FIG. 6) on the radial outside of the slot 22. This allows cooling oil to be guided to the spaces SP11 and SP12 in the slot via the through holes. As a result, the cooling oil flows in the axial direction through the spaces SP11 and SP12 inside the insulating member 40, and the coil 21 can be cooled.

[0055] In the above embodiment (FIG. 3A), the sheet-like base material 400 constituting the insulating member 40 has a three-layer structure of the adhesive layer 41, the insulating layer 42, and the foam layer 43, but the adhesive layer 41 may be omitted and the sheet-like base material 400 may have a two-layer structure. In the above embodiment, the adhesive layer 41 is provided between the coil 21 and the insulating layer 42, but the adhesive layer 41 may be provided between the insulating layer 42 and the protruding portion 25. In the above embodiment, the foam layer 43 is provided on the outer surface of the side wall 402 of the pair of side walls 401, 402 of the insulating member 40, that is, the side wall 401 (first opposing portion) opposing one side surface 222a (first inner surface) of the slot 22 and the side wall 402 (second opposing portion) opposing the other side surface 222b (second inner surface), and the foam layer 43 is foamed to form the foam 45, but the configuration of the foam is not limited thereto.

[0056] In the above embodiment (FIG. 8), focusing on two axially adjacent ones of the electromagnetic steel sheet groups S1 to S6 constituting the stator core 20, for example, the electromagnetic steel sheet group S1 (first stator core portion) and the electromagnetic steel sheet group S2 (second stator core portion), the radial positions of the protrusions 25 (first protrusions) provided on the electromagnetic steel sheet group S1 and the protrusions 25 (second protrusions) provided on the electromagnetic steel sheet group S2 are made different from each other, but protrusions 25 having the same radial position may be included, such as the protrusions 251 and 252 in FIGS. 10 and 12. In the above embodiment, the protrusions 25 extend over a predetermined length in the axial direction, but the shape of the protrusions is not limited to that described above.

[0057] In the above embodiment (FIG. 12), when focusing on the coils 21 that are adjacent to each other in the radial direction and extend in the axial direction, for example, the first-stage coil S1 (first coil portion) and the second-stage coil S2 (second coil portion), the convex portion 25 (boundary convex portion 252) of the electromagnetic steel plate groups S3 and S4 is configured to extend in the axial direction along the boundary portion 213 between the first-stage coil S1 and the second-stage coil S2, but the boundary convex portion may be disposed at another axial position (for example, the axial end portion of the stator core 20). In the above embodiment, the gap SP2 through which the cooling oil flows is provided between the side wall 402 of the insulating member 40 and the coil 21, but a gap through which another cooling medium flows may be provided, and the cooling medium is not limited to the cooling oil. In the above embodiment (FIG. 1), the cooling oil is supplied into the slot from one point on the radial outside of the stator 2, but the supply path of the cooling medium is not limited to the above. For example, the cooling medium may be supplied into the slots from a plurality of locations on the radial outside of the stator, or the cooling medium may be supplied into the slots from the axial outside of the stator.

[0058] The above description is merely an example, and the present invention is not limited to the above-mentioned embodiment and modifications, as long as the features of the present invention are not impaired. The above-mentioned embodiment and one or more modifications can be arbitrarily combined, and modifications can be combined with each other. [Explanation of symbols]

[0059] 2 stator, 20 stator core, 21 coil, 22 slot, 25 convex portion, 40 insulating member, 42 insulating layer, 43 foam layer, 45 foam, 202 through hole, 222a, 222b side surface, 251 inner diameter side convex portion, 252 boundary convex portion, 400c opening, 401, 402 side wall, S1 to S6 electromagnetic steel plate group, C1 to C6 1st stage coil to 6th stage coil

Claims

1. A stator core having a plurality of circumferential slots extending in an axial direction; A coil disposed in the slot; an insulating member disposed in the slot so as to surround the coil, The stator core is provided with a flow passage for guiding a cooling medium into the slot, the stator core has a first inner side surface and a second inner side surface that constitute a pair of inner side surfaces facing each other of the slot, the first inner surface has a protrusion that protrudes toward the second inner surface and abuts against one circumferential end of the coil via the insulating member, The stator for a rotating electric machine further comprises a foam filled between the other circumferential end of the coil and the second inner surface with the insulating member interposed therebetween.

2. 2. The stator for a rotating electric machine according to claim 1, the insulating member has a first opposing portion opposing the first inner side surface and a second opposing portion opposing the second inner side surface, a foam layer provided in advance only on the second opposing portion out of the first opposing portion and the second opposing portion,

3. 3. The stator for a rotating electric machine according to claim 1, The stator for a rotating electric machine, wherein the protrusions are provided at a plurality of locations in a radial direction, and the plurality of protrusions extend in an axial direction.

4. 4. The stator for a rotating electric machine according to claim 3, The stator core has a first stator core portion and a second stator core portion adjacent to each other in the axial direction, the plurality of protruding portions include a first protruding portion provided on the first stator core portion and a second protruding portion provided on the second stator core portion, The stator for a rotating electric machine, wherein the first protrusion and the second protrusion are provided at different positions in a radial direction.

5. 4. The stator for a rotating electric machine according to claim 3, The coil has a plurality of coil portions extending in an axial direction, including an innermost coil portion disposed on the innermost side of the slot, a protruding portion extending in an axial direction of the stator core along an inner diameter side end portion of the innermost coil portion;

6. 4. The stator for a rotating electric machine according to claim 3, The coil has a first coil portion and a second coil portion that are adjacent to each other in a radial direction and each extend in an axial direction, The stator for a rotating electric machine, wherein the protruding portion extends in the axial direction along a boundary between the first coil portion and the second coil portion.

7. 3. The stator for a rotating electric machine according to claim 2, The insulating member has an opening penetrating the first opposing portion and communicating with the flow path. a projection disposed at a position shifted in a radial direction and an axial direction from the opening such that a distance from the opening to the projection is equal to or greater than a predetermined distance;

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