Rotating electrical machine and stator of rotating electrical machine

Abstract

This rotating electrical machine includes a stator having a core in which a plurality of slots are formed, a plurality of coils inserted into the plurality of slots, and bobbins disposed between the slots and the coils, wherein: the bobbins have projections formed thereon, said projections being disposed between the plurality of coils on the inner surface in the circumferential direction of the rotating electrical machine; an adhesive is disposed between the inner surface of the bobbins in the circumferential direction and the coils, and between the outer surface of the bobbins and the slots; and a flow path through which a refrigerant for cooling the coil flows is formed between the plurality of coils.

Description

Rotating electric machines, stators for rotating electric machines

[0001] The present invention relates to a rotating electric machine and a stator for the rotating electric machine.

[0002] The following Patent Document 1 discloses a configuration in which insulation performance is ensured by positioning coils using protrusions provided on the teeth of the stator of a rotating electric machine, and insulation performance is improved by reliably filling foam adhesive between the coils.

[0003] International Publication No. 2017-047247

[0004] As one method for cooling the coils in the slots, which are heat-generating parts of the stator of a rotating electrical machine, slot oil cooling, which allows cooling oil to come into direct contact with the coils, is expected to have high cooling performance.However, in the configuration described in Patent Document 1, a configuration using insulating paper and varnish is applied to the slots, so in order to both form flow channels in the slots and fix the coils, it is necessary to control the flow of the varnish before it hardens, which makes it difficult to form flow channels.

[0005] A rotating electric motor having a stator having a core in which a plurality of slots are formed, a plurality of coils inserted into the plurality of slots, and a bobbin arranged between the slots and the coils, wherein the bobbin has protrusions formed on its circumferential inner surface that are arranged between the plurality of coils, adhesive is arranged between the circumferential inner surface of the bobbin and the coils and between the outer surface of the bobbin and the slots, and flow paths are formed between the plurality of coils through which a refrigerant flows to cool the coils.

[0006] It is possible to provide a rotating electric machine and a stator for the rotating electric machine that realize improved cooling performance, miniaturization, and improved reliability.

[0007] 1 is a perspective view and an exploded view of a stator for a rotating electric machine according to one embodiment of the present invention; 2 is a cross-sectional view of a stator for a rotating electric machine according to one embodiment of the present invention; 3 is a cross-sectional view of a stator for a rotating electric machine according to one embodiment of the present invention; 4 is a diagram illustrating the configuration of a bobbin and a coil according to one embodiment of the present invention; and 5 is a diagram illustrating an adhesive application device according to one embodiment of the present

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (Figs. 1 and 2) Fig. 1(a) is an overall perspective view of a stator of a rotating electric machine, and Fig. 1(b) is an exploded perspective view of Fig. 1(a). The stator 1 of the rotating electric machine has a stator core 21, a coil end cover 23, and a wire connection plate 30. The stator core 21 is formed by laminating electromagnetic steel sheets. The stator core 21 has a plurality of slots 22 formed in its inner diameter portion. A plurality of coils 9 are inserted radially into the slots 22.

[0011] The bobbin 10 is made of resin and formed into a straw shape, and is placed in the slot 22. By being placed between the slot 22 and the coil 9, the bobbin 10 insulates the coil 9 inserted in the slot 22 from the stator core 21, and also forms a cooling flow path between the coils 9 in the slot 22.

[0012] The connection plate 30 is connected to the coil 9 to supply power to the coil 9. The coil end cover 23 is adhesively fixed to the cuff 11.

[0013] The cuffs 11 are provided at the joints between the coil end covers 23 and the bobbins 10. Cooling oil 5 flows through the coil end covers 23. The cuffs 11 are adhesively fixed to the end faces of the stator cores 21 so as to fit over the bobbins 10. This configuration prevents the coolant from flowing between the bobbins 10 and the stator cores 21, forms a flow path that continues in the circumferential direction of the stator cores 21, and enables the coolant to be guided to the cooling flow paths 6 ( FIG. 4 ) formed by the bobbins 10.

[0014] (Fig. 3) The stator 1 of the rotating electrical machine has an outer housing 2 and an inner housing 3. The outer housing 2 has oil passages 4 through which cooling oil 5 flows. End brackets 13 are arranged on the axial end faces of the outer housing 2, and cover the inside of the stator 1. The inner housing 3 has water passages 18 through which cooling water flows in the slots 22, and oil passages 4. The oil passages 4 of the inner housing 3 are connected to the oil passages 4 of the outer housing, and the cooling oil 5 that flows in is circulated through the coils 9 inserted in the stator 1, thereby cooling the coils 9.

[0015] The inner housing 3 has an O-ring 8 and a cover member 7 arranged to cover the location where the O-ring 8 is installed. The cover member 7 is fitted at a fitting portion 12 on the axial surface of the inner housing 3. This seals the oil passage 4 in the stator 1 of the rotating electrical machine, allowing the cooling oil 5 to reliably flow to the coils 9 inserted in the stator 1 of the rotating electrical machine.

[0016] (FIG. 4) FIG. 4(a) shows an example of the shape of the bobbin 10, and FIG. 4(b) shows the bobbin 10 and coil 9 of FIG. 4(a) provided in a slot 22.

[0017] The bobbin 10 has protrusions 10c arranged between the multiple coils 9 on an inner surface 10b in the circumferential direction of the rotating electric machine. The bobbin 10 also has adhesive 15 applied between the inner surface 10b in the circumferential direction and the coils 9, and between the outer surface 10a in the circumferential direction and the slots 22. The adhesive 15 is applied to at least a portion of the inner surface 10b in the circumferential direction of the bobbin 10. The adhesive 15 is not applied to the radial surface 9b of the coils 9. The adhesive 15 is, for example, a foam adhesive.

[0018] The protrusions 10c are either not coated with adhesive 15 or have a smaller amount of adhesive 15 coated thereon than the portions of the bobbin 10 other than the protrusions 10c. In this way, as long as the adhesive 15 remains in a thin adhesive layer on the protrusions 10c of the bobbin 10, flow paths are reliably formed between the coils 9 in the radial direction, improving cooling performance. If the adhesive 15 is not coated on the protrusions 10c, the cross-sectional area of ​​the cooling flow path 6 can be maximized.

[0019] The bobbin 10, with the adhesive 15 applied thereto, is inserted into the slot 22 of the stator core 21. As a result, the coil 9 is inserted into the inner circumferential side of the bobbin 10, and the adhesive 15 applied to at least one surface of the coil 9 bonds the bobbin 10 and the coil 9 together, thereby fixing the coil 9 in place.

[0020] A plurality of protrusions 10c are provided on the inner surface 10b of the bobbin 10, and form gaps between the plurality of coils 9 inserted into the inner periphery of the bobbin 10 in the radial direction, and maintain the spacing of the gaps. These gaps are used as cooling flow paths 6 through which a refrigerant for cooling the coils 9 flows. In other words, flow paths 6 through which a refrigerant for cooling the coils 9 flows are formed between the plurality of coils 9. The protrusions 10c are, for example, rounded.

[0021] The coil 9 is inserted into the bobbin 10, and the adhesive 15 is cured to bond and fix the stator core 21 and the bobbin 10, and the bobbin 10 and the coil 9 together. At this time, at least one side of the coil 9 is in contact with the protrusion 10c. This makes it easy to position the coil 9, and ensures that the minimum clearance required to form the flow path 6 between the coils 9 is ensured.

[0022] As a result, there is a gap between the radial surfaces 9b of the coils 9 because there is no adhesive 15. This gap is the cooling flow path 6 through which the cooling oil 5 flows. As a result, the coils 9 are not bonded together and are directly cooled by the cooling oil 5, improving the cooling performance of the stator 1 of the rotating electrical machine. Furthermore, providing such a gap improves insulation reliability and contributes to miniaturization.

[0023] A gap of at least 50 μm is ensured between the bobbin 10 and the coil 9, and between the bobbin 10 and the stator core 21. This prevents assembly defects due to manufacturing variations, improving assembly efficiency. Furthermore, the adhesive strength of the adhesive 15 is increased, improving reliability.

[0024] The flow paths 6 formed by the gaps between the coils 9 have a radial spacing of 0.1 mm or more. The formation of the protrusions 10c on the bobbin 10 also ensures cooling performance equal to or better than that of conventional indirect water cooling.

[0025] (FIG. 5) The adhesive applicator 16 will be described. The adhesive applicator 16 has an outer jig 16a and an inner jig 16b, and is a device that accurately controls the thickness of the adhesive 15 applied to the bobbin 10 to achieve both the adhesive strength of the adhesive 15 applied to the bobbin 10 and the formation of the cooling flow passage 6 described above. The outer jig 16a applies the adhesive 15 to the outer surface 10a of the bobbin 10, and the inner jig 16b applies the adhesive 15 to the inner surface 10b of the bobbin 10. The adhesive applicator 16 ensures that the adhesive 15 applied to the bobbin 10 has a predetermined thickness, thereby ensuring adhesion reliability.

[0026] The adhesive 15 is applied only to the side surfaces of the bobbin 10 using the adhesive applicator 16, and is not applied in the radial direction, particularly between the coils 9. In this way, by applying only the necessary amount of adhesive 15 to the necessary parts of the adhesive applicator 16, it is possible to secure the fixing force of the coil 9 and form a flow path at the same time.

[0027] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0028] (1) A rotating electric machine including a stator 1 having a core 21 in which a plurality of slots 22 are formed, a plurality of coils 9 inserted into the plurality of slots 22, and a bobbin 10 arranged between the slots 22 and the coils 9, wherein the bobbin 10 has protrusions 10c formed on its circumferential inner surface that are arranged between the plurality of coils 9, adhesive 15 is arranged between the circumferential inner surface 10b of the bobbin 10 and the coils 9 and between the outer surface 10a of the bobbin 10 and the slots 22, and flow paths 6 are formed between the plurality of coils 9 through which a refrigerant 5 flows to cool the coils 9. In this way, a rotating electric machine can be provided that has improved cooling performance, is more compact, and is more reliable.

[0029] (2) At least one side of the coil 9 contacts the protrusion 10c. This not only positions the coil 9 on the inner surface of the bobbin 10 but also ensures the clearance required to form the cooling flow passage 6 between the coils 9.

[0030] (3) A gap of at least 50 μm is provided between the bobbin 10 and the coil 9, and between the bobbin 10 and the core 21. This improves the adhesive strength of the adhesive 15.

[0031] (4) The flow paths 6 are spaced apart from each other by 0.1 mm or more in the radial direction, ensuring sufficient cooling performance between the coils 9.

[0032] (5) The adhesive 15 is not applied to the radial surface of the coil 9. This ensures the cooling flow path 6.

[0033] (6) The adhesive 15 is applied to at least a portion of the inner circumferential surface of the bobbin 10. This allows the coil 9 to be fixed to the bobbin 10.

[0034] (7) The adhesive 15 is applied to at least one surface of the coil 9. This allows the coil 9 to be fixed to the bobbin 10.

[0035] (8) The protrusions 10c are not coated with adhesive 15, or the amount of adhesive 15 coated on the protrusions 10c is less than that on the other portions of the bobbin 10. This allows the cross-sectional area of ​​the cooling flow path 6 to be increased.

[0036] (9) The adhesive 15 is applied to a predetermined thickness on the bobbin 10. This ensures both the fixing force of the coil 9 on the bobbin 10 and the formation of the cooling flow path 6.

[0037] (10) A stator 1 for a rotating electric machine includes a stator 1 having a core 21 in which a plurality of slots 22 are formed, a plurality of coils 9 inserted into the plurality of slots 22, and a bobbin 10 arranged between the slots 22 and the coils 9, wherein the bobbin 10 has protrusions 10c formed on its circumferential inner surface in the rotating electric machine and arranged between the plurality of coils 9, and adhesive 15 is arranged between the circumferential inner surface 10b of the bobbin 10 and the coils 9 and between the outer surface 10a of the bobbin 10 and the slots 22, and flow paths 6 are formed between the plurality of coils 9 through which a refrigerant 5 for cooling the coils 9 flows. In this way, a stator 1 for a rotating electric machine can be provided that achieves improved cooling performance, miniaturization, and improved reliability.

[0038] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0039] REFERENCE SIGNS LIST 1 stator 2 outer housing 3 inner housing 4 oil passage 5 cooling oil 6 cooling flow passage 7 cover member 8 O-ring 9 coil 9a coil circumferential surface 9b coil radial surface 10 bobbin 10a outer surface 10b inner surface 10c protrusion 11 cuff 12 fitting portion 13 end bracket 15 foam adhesive 16 adhesive application device 16a outer jig 16b inner jig 18 water passage 21 stator core 22 slot 23 coil end cover 24 insulating member 25 bending load receiver R 30 connection plate

Claims

1. A rotating electric machine comprising a stator having a core in which a plurality of slots are formed, a plurality of coils inserted into the plurality of slots, and a bobbin arranged between the slots and the coils, wherein the bobbin has protrusions formed on its circumferential inner surface that are arranged between the plurality of coils, an adhesive is arranged between the circumferential inner surface of the bobbin and the coils and between the outer surface of the bobbin and the slots, and a flow path is formed between the plurality of coils through which a refrigerant flows to cool the coils.

2. A rotating electric machine according to claim 1, wherein at least one side of the coil is in contact with the protrusion.

3. A rotating electric machine according to claim 1, wherein a gap of at least 50 μm is provided between the bobbin and the coil, and between the bobbin and the core.

4. A rotating electric machine according to claim 1, wherein the flow passages are spaced apart from each other at intervals of 0.1 mm or more in the radial direction.

5. A rotating electric machine according to claim 1, wherein the adhesive is not applied to radial surfaces of the coil.

6. A rotating electric machine according to claim 1, wherein the adhesive is applied to at least a portion of the inner circumferential surface of the bobbin.

7. A rotating electric machine according to claim 1, wherein the adhesive is applied to at least one surface of the coil.

8. A rotating electric machine according to claim 1, wherein the adhesive is not applied to the protrusions or the amount of adhesive applied to the protrusions is less than that of the portions of the bobbin other than the protrusions.

9. A rotating electric machine according to claim 1, wherein the adhesive is applied to the bobbin to a predetermined thickness.

10. A stator for a rotating electric machine having a core in which a plurality of slots are formed, a plurality of coils inserted into the plurality of slots, and a bobbin arranged between the slots and the coils, wherein the bobbin has protrusions formed on its circumferential inner surface in the rotating electric machine that are arranged between the plurality of coils, adhesive is arranged between the circumferential inner surface of the bobbin and the coils and between the outer surface of the bobbin and the slots, and flow paths are formed between the plurality of coils through which a refrigerant flows to cool the coils.

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