Stator of rotary electric machine

Abstract

To secure a press-fit surface pressure due to a fastening margin as designed.SOLUTION: A stator coil includes: a first segment coil which is inserted into a slot from one axial end side of a stator core; a second segment coil which is inserted into the slot from the other axial end side of the stator core; a hollow copper pipe which is provided in the slot and bonds the first segment coil and the second segment by press-fitting a press-fitting part of the first segment coil and a press-fitting part of the second segment coil; and a projection part which is provided in a first flat surface part included in an outer peripheral surface of the press-fitting part or a second flat surface part included in an inner peripheral surface of the hollow copper pipe, and is contacted with its facing surface. The projection part is provided in a portion other than a center part in a direction orthogonal to the axial direction in the first flat surface part or the second flat surface part. The projection part is provided in one of the two first flat surface parts parallel with each other or the two second flat surface parts parallel with each other, and the projection part is not provided in the other one.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Patent Document 1 listed below discloses a technique for connecting two segment coils of a stator coil by press-fitting the two segment coils into a conductive cylindrical connecting member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-132457 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the technology disclosed in Patent Document 1, if the segment coil is pressed into the hollow copper tube in an inclined state, the hollow copper tube will be significantly deformed, which may make it difficult to ensure the designed press-fitting surface pressure due to the tightening margin. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, a stator of a rotating electric machine according to one embodiment is a stator of a rotating electric machine including a stator core having slots and a stator coil wound around the stator core through the slots, the stator coil including a first segment coil inserted into the slot from one axial end side of the stator core, a second segment coil inserted into the slot from the other axial end side of the stator core, a hollow copper tube provided in the slot and joining the first segment coil and the second segment coil by pressing the press-fit portion of the first segment coil into the press-fit portion of the second segment coil, and a protrusion provided on a first flat portion on the outer peripheral surface of the press-fit portion or a second flat portion on the inner peripheral surface of the hollow copper tube and in contact with the opposing surface, the protrusion being provided on the first flat portion or the second flat portion in a portion other than the center in a direction perpendicular to the axial direction, and the protrusion being provided on one of the two first flat portions or the two second flat portions that are parallel to each other, and the protrusion not being provided on the other. Effect of the Invention

[0006] According to the stator for a rotating electrical machine according to one embodiment, it is possible to ensure the press-fit surface pressure due to the interference as designed. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a first example of a connection structure provided in a stator of a rotating electric machine according to an embodiment; [Diagram 2] FIG. 13 is a diagram illustrating a second example of a coupling structure provided in a stator of a rotating electric machine according to an embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] (First example of a connected structure) Fig. 1 is a diagram showing a first example of a connecting structure provided in a stator of a rotating electric machine according to one embodiment, Fig. 1(a) is a cross-sectional view of a connecting structure 20 according to one embodiment as viewed from the side, and Fig. 1(b) is a cross-sectional view of the connecting structure 20 according to one embodiment taken along line AA.

[0010] The connecting structure 20 shown in Fig. 1 is provided on a segment coil provided in a stator of a rotating electrical machine in order to connect a first segment coil 21 and a second segment coil with a hollow copper tube 24. Note that Fig. 1 shows an enlarged view of the connecting structure 20, in which the first segment coil 21 is pressed into the hollow copper tube 24.

[0011] Here, we will explain the segment coil. The segment coil constitutes the stator coil provided in the stator of the rotating electric machine. The stator coil is composed of multiple segment coils, which are wound around the stator core through slots in the stator core. The segment coil has a first segment coil 21, a second segment coil, and a hollow copper tube 24.

[0012] The first segment coil 21 is inserted into a slot of the stator core from one end in the axial direction (Z-axis direction) of the stator core. A press-fit portion 21A that is press-fitted into the hollow copper tube 24 is provided at the tip of the first segment coil 21.

[0013] The second segment coil is inserted into a slot of the stator core from the other end in the axial direction (Z-axis direction) of the stator core. A press-fit portion that is press-fitted into the hollow copper tube 24 is provided at the tip of the second segment coil.

[0014] The hollow copper tube 24 is a cylindrical member provided in a slot of the stator core. The press-fit portion 21A of the first segment coil 21 is press-fitted into the hollow copper tube 24 from one end side, and the press-fit portion of the second segment coil is press-fitted into the hollow copper tube 24 from the other end side, thereby joining the first segment coil 21 and the second segment coil.

[0015] Both the first segment coil 21 and the second segment coil have a conductor and a coil coating that covers the outer peripheral surface of the conductor. The conductor is made of a conductive material such as copper. The coil coating is made of an insulator such as enamel. However, the press-fit portion 21A of the first segment coil 21 and the press-fit portion of the second segment coil are not provided with a coil coating.

[0016] The hollow copper tube 24 has a cylindrical body and an insulating coating that covers the outer circumferential surface of the cylindrical body. The cylindrical body is made of copper, which is a conductive material. The insulating coating is made of an insulator such as enamel.

[0017] Additionally, both the first segment coil 21 and the second segment coil have a rectangular cross-sectional shape, and accordingly, the hollow copper tube 24 has a square tubular shape.

[0018] 1, the inner peripheral surface of the hollow copper tube 24 has two second flat portions 24A1 and 24A2 that are parallel to each other. Meanwhile, the outer peripheral surface of the press-fit portion 21A of the first segment coil 21 has two first flat portions 21B1 and 21B2 that are parallel to each other. The second flat portion 24A1 faces the first flat portion 21B1. The second flat portion 24A2 faces the first flat portion 21B2.

[0019] Of the two first flat portions 21B1 and 21B2, the first flat portion 21B1 has two protrusions 25-1 and 25-2, and the other first flat portion 21B2 has no protrusions 25. The two protrusions 25-1 and 25-2 protrude from the first flat portion 21B1 toward the outside (i.e., toward the second flat portion 24A1 of the hollow copper tube 24) and are pressed by the second flat portion 24A1 of the hollow copper tube 24 when the press-fit portion 21A of the first segment coil 21 is press-fitted into the hollow copper tube 24. In the example shown in FIG. 1, the two protrusions 25-1 and 25-2 have a hemispherical shape.

[0020] As a result, in the connecting structure 20 of one embodiment, when the press-fit portion 21A of the first segment coil 21 is pressed into the hollow copper tube 24, the two protrusions 25-1, 25-2 are pressed by one of the second flat portions 24A1 of the hollow copper tube 24, generating a high surface pressure, and this high surface pressure can press the other first flat portion 21B2 of the press-fit portion 21A of the first segment coil 21 against the other second flat portion 24A2 of the hollow copper tube 24 over its entire surface.

[0021] In addition, in one embodiment of the connecting structure 20, the two protrusions 25-1, 25-2 penetrate into the second flat portion 24A1 of the hollow copper tube 24 with high surface pressure and adhere to it, thereby increasing the friction coefficient and making it difficult for the first segment coil 21 to fall out of the hollow copper tube 24.

[0022] Here, when the press-fit portion 21A of the first segment coil 21 is press-fitted into the hollow copper tube 24, the two protrusions 25-1, 25-2 continuously contact (i.e., slide) with one of the second flat portions 24A1 along the axial direction (Z-axis direction), thereby generating a high surface pressure. As a result, in the connection structure 20 according to one embodiment, even if an axially misaligned load is applied in a direction that tilts the first segment coil 21 when the press-fit portion 21A of the first segment coil 21 is press-fitted into the hollow copper tube 24, the other first flat portion 21B2 of the press-fit portion 21A of the first segment coil 21 is pressed against and tightly attached to the other second flat portion 24A2 of the hollow copper tube 24, thereby suppressing the tilt of the first segment coil 21 and suppressing the deformation of the hollow copper tube 24, and therefore the press-fit surface pressure due to the tightening margin as designed can be secured.

[0023] In particular, as shown in Fig. 1(b), when the first flat surface portion 21B1 is divided into three equal parts in a direction (Y-axis direction) perpendicular to the axial direction (Z-axis direction), one protrusion portion 25-1 is provided in a region closer to one end portion (positive side of the Y-axis) than the center portion. The other protrusion portion 25-2 is provided in a region closer to the other end portion (negative side of the Y-axis) than the center portion. In other words, both of the two protrusion portions 25-1 and 25-2 are provided in a portion of one first flat surface portion 21B1 other than the center portion in a direction (Y-axis direction) perpendicular to the axial direction (Z-axis direction).

[0024] In this way, in the connecting structure 20 of one embodiment, the two protrusions 25-1, 25-2 are provided in the vicinity of the two corners 24C1, 24C2 of the hollow copper tube 24, which have relatively high rigidity, so that deformation of the hollow copper tube 24 can be further suppressed, and therefore, high surface pressure can be generated as designed.

[0025] In the connecting structure 20 according to the embodiment, the height dimensions (dimension in the X-axis direction) of the two protrusions 25-1, 25-2 are equal to each other. In addition, in the connecting structure 20 according to the embodiment, the height positions in the axial direction (Z-axis direction) of the two protrusions 25-1, 25-2 are equal to each other. Therefore, in the connecting structure 20 according to the embodiment, the two protrusions 25-1, 25-2 can generate uniform high surface pressure at both ends of the first flat portion 21B1 in a direction (Y-axis direction) perpendicular to the axial direction (Z-axis direction).

[0026] In the connection structure 20 according to one embodiment, the configuration of the press-fit portion of the second segment coil into the hollow copper tube 24 is similar to the configuration of the press-fit portion of the first segment coil 21 into the hollow copper tube 24 shown in Fig. 1. Therefore, the connection structure 20 according to one embodiment can achieve the same effect in the press-fit portion of the second segment coil as in the press-fit portion of the first segment coil 21.

[0027] In addition, in the connecting structure 20 of one embodiment, a similar protrusion portion 25 may be further provided on either one of the other two planar portions (i.e., two planar portions perpendicular to the two first planar portions 21B1, 21B2) that are provided on the outer peripheral surface of the press-fit portion 21A of the first segment coil 21.

[0028] Furthermore, in the connection structure 20 according to one embodiment, three or more protrusions 25 may be provided on the first flat portion 21B1 of the press-fit portion 21A of the first segment coil 21. In this case, it is preferable to provide at least two protrusions 25 at the same height position in the axial direction (Z-axis direction); that is, it is not necessary to provide all of the protrusions 25 (Z-axis direction) at the same height position in the axial direction.

[0029] (Second example of connected structure) 2A and 2B are diagrams illustrating a second example of a coupling structure included in a stator of a rotating electric machine according to an embodiment of the present invention, in which Fig. 2A is a cross-sectional view of a coupling structure 20-2 according to an embodiment of the present invention as viewed from the side, and Fig. 2B is a cross-sectional view of the coupling structure 20-2 according to an embodiment of the present invention, taken along line BB.

[0030] A connection structure 20-2 shown in FIG. 2 differs from the connection structure 20 shown in FIG. 1 in that two protrusions 25-1 and 25-2 are provided on a second flat portion 24A1 of the hollow copper tube 24.

[0031] As a result, in the connecting structure 20-2 shown in Figure 2, similar to the connecting structure 20 shown in Figure 1, the two protrusions 25-1, 25-2 are pressed by the first flat portion 21B1 of the press-fit portion 21A of the first segment coil 21 to generate high surface pressure, and this high surface pressure can press the other first flat portion 21B2 of the press-fit portion 21A of the first segment coil 21 against the other second flat portion 24A2 of the hollow copper tube 24 over its entire surface.

[0032] In addition, in the connecting structure 20-2 shown in Figure 2, the two protrusions 25-1, 25-2 are adhered to the first flat portion 21B1 of the press-fit portion 21A of the first segment coil 21 by biting into it with high surface pressure, thereby increasing the friction coefficient and making it difficult for the first segment coil 21 to fall out of the hollow copper tube 24.

[0033] Furthermore, in the connecting structure 20-2 shown in Figure 2, even if an axially offset load is applied in a direction that tilts the first segment coil 21 when the press-fit portion 21A of the first segment coil 21 is pressed into the hollow copper tube 24, the other first flat portion 21B2 of the press-fit portion 21A of the first segment coil 21 is pressed against and tightly attached to the other second flat portion 24A2 of the hollow copper tube 24, thereby suppressing the tilt of the first segment coil 21 and suppressing deformation of the hollow copper tube 24, and therefore the press-fit surface pressure due to the tightening margin as designed can be secured.

[0034] In addition, the connecting structure 20-2 shown in Figure 2 has two protrusions 25-1, 25-2 located near two corners 24C1, 24C2 of the hollow copper tube 24, which have relatively high rigidity, and therefore can further suppress deformation of the hollow copper tube 24, and therefore can generate high surface pressure as designed.

[0035] 2, the height dimensions (dimension in the X-axis direction) of the two protrusions 25-1, 25-2 are equal to each other. Also, in the connecting structure 20-2 shown in Fig. 2, the height positions in the axial direction (Z-axis direction) of the two protrusions 25-1, 25-2 are equal to each other. Therefore, in the connecting structure 20-2 shown in Fig. 2, the two protrusions 25-1, 25-2 can generate uniform high surface pressure at both ends of the first flat portion 21B1 in the direction (Y-axis direction) perpendicular to the axial direction (Z-axis direction).

[0036] In the connection structure 20-2 shown in Fig. 2, the configuration of the press-fit portion of the second segment coil into the hollow copper tube 24 is similar to the configuration of the press-fit portion of the first segment coil 21 into the hollow copper tube 24 shown in Fig. 2. Therefore, the connection structure 20-2 shown in Fig. 2 can achieve the same effect in the press-fit portion of the second segment coil as in the press-fit portion of the first segment coil 21.

[0037] In addition, in the connection structure 20-2 shown in Figure 2, a similar protrusion portion 25 may be further provided on either one of the other two flat portions (i.e., two flat portions perpendicular to the two second flat portions 24A1, 24A2) that the inner surface of the hollow copper tube 24 has.

[0038] 2, three or more protrusions 25 may be provided on the second flat portion 24A1 of the hollow copper tube 24. In this case, it is preferable to provide at least two protrusions 25 at the same height in the axial direction (Z-axis direction); that is, it is not necessary to provide all of the protrusions 25 (Z-axis direction) at the same height in the axial direction.

[0039] (Modification of the connection structure) Modifications of the above-mentioned connecting structures 20 and 20-2 will now be described.

[0040] For example, in the above-mentioned connection structures 20 and 20-2, the cross-sectional shape of each segment coil and hollow copper tube 24 may be rectangular. In this case, a protrusion 25 may be provided on one of the two flat surfaces constituting the short side of each segment coil or hollow copper tube 24.

[0041] In this case, since the connecting structures 20, 20-2 have the protrusions 25 provided in relatively rigid parts of each segment coil or hollow copper tube 24, deformation of the hollow copper tube 24 can be further suppressed, and therefore high surface pressure can be generated as designed.

[0042] Furthermore, for example, in the above-described connecting structures 20 and 20-2, the protrusions 25 may be provided at a plurality of different positions in the axial direction (Z-axis direction) on the first flat surface portion 21B1 or the second flat surface portion 24A1.

[0043] In this case, the connecting structures 20, 20-2 can generate high surface pressure by the protrusions 25 over a wide range in the axial direction (Z-axis direction). In this case, the height of each of the multiple protrusions 25 may be set so that the height of the protrusions 25 gradually increases toward the opening of the hollow copper tube 24. In this case, even if the diameter of the hollow copper tube 24 near the opening expands due to the press-in of each segment coil, high surface pressure can be generated by the taller protrusions 25 near the opening.

[0044] Also, for example, in the above-described connecting structures 20 and 20-2, a longitudinal protrusion 25 extending in the axial direction (Z-axis direction) may be provided on the first planar portion 21B1 or the second planar portion 24A1.

[0045] In this case, the connecting structures 20, 20-2 can generate high surface pressure by the protrusions 25 over a wide range in the axial direction (Z-axis direction). In this case, the height of the protrusions 25 may be set so that the height of the protrusions 25 gradually increases toward the opening of the hollow copper tube 24. In this case, even if the diameter of the hollow copper tube 24 near the opening expands due to the press-in of each segment coil, high surface pressure can be generated by the higher protrusions 25 near the opening.

[0046] Also, for example, in the above-mentioned connection structures 20, 20-2, the protrusions 25 may be formed by applying pressure to the outer peripheral surface of the segment coil or the inner peripheral surface of the hollow copper tube 24 around the protrusions 25 to cause a recess.

[0047] Furthermore, for example, in the above-mentioned connection structures 20, 20-2, instead of providing a protrusion 25 on the flat portion of the outer peripheral surface of the segment coil or the flat portion of the inner peripheral surface of the hollow copper tube 24, a protrusion 25 (i.e., a rib) protruding toward the center of the hollow copper tube 24 and extending linearly in the axial direction (Z-axis direction) may be provided on at least one of the four inner corners of the hollow copper tube 24.

[0048] In this case, the connecting structure 20, 20-2 generates high surface pressure by pressing the protrusion 25 against at least one of the four outer corners of the segment coil, and the high surface pressure can press the outer surface of the segment coil against the inner surface of the hollow copper tube 24. In addition, the connecting structure 20, 20-2 can generate high surface pressure at the inner corners of the hollow copper tube 24, which has a relatively high rigidity, so deformation of the hollow copper tube 24 can be suppressed.

[0049] In this case, each of the four outer corners of the segment coil may be cut obliquely to provide a flat portion at each of the four outer corners, and the protrusions 25 may be abutted against the flat portions.

[0050] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0051] 20,20-2 Connection structure 21 First segment coil 21A Press-fit part 21B1,21B2 1st plane part 24 Hollow copper tube 24A1,24A2 2nd plane part 24C1,24C2 Corner 25-1,25-2 Protrusion

Claims

[Claim 1] a stator core having slots; a stator coil wound around the stator core through the slot; A stator for a rotating electric machine comprising: The stator coil is A first segment coil is inserted into the slot from one axial end side of the stator core; A second segment coil is inserted into the slot from the other axial end side of the stator core; A hollow copper tube provided in the slot, the press-fit portion of the first segment coil and the press-fit portion of the second segment coil being pressed into each other to join the first segment coil and the second segment coil; a protrusion provided on a first flat portion of the outer circumferential surface of the press-fit portion or a second flat portion of the inner circumferential surface of the hollow copper tube, the protrusion being in contact with the opposing surface; having The protrusion is the first flat surface portion or the second flat surface portion is provided in a portion other than a central portion in a direction perpendicular to the axial direction, The protrusion is provided on one of the two first planar portions parallel to each other or the two second planar portions parallel to each other, and the protrusion is not provided on the other of the two first planar portions parallel to each other. A stator for a rotating electric machine comprising:

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