Stator and motor equipped therewith

Abstract

The present invention provides a stator capable of reliably supplying refrigerant to the coil ends, and a motor equipped therewith. [Solution] A stator 12 having a stator core 13, coils 2 inserted into a plurality of slots 16 such that coil ends 20 protrude axially δ from the stator core 13, and a plurality of insulating papers 4 inserted into each slot 16, wherein the stator core 13 is provided with an internal core flow path 17 for circulating refrigerant, and an outlet 18 located radially outward from each slot 16 for the refrigerant that has passed through the internal core flow path 17 to flow out axially δ, and a guide path 5A is formed in the protruding portion 40A of the upper insulating paper 4A located at the top of the stator core 13 by cutting a slit-shaped notch in the upper insulating paper 4A along axial δ to guide the refrigerant that has flowed down from the outlet 18 to the tip portion 24 of the coil end 20 along axial δ.

Description

Technical Field

[0001] The present invention relates to a stator and a motor provided with the same.

Background Art

[0002] Conventionally, as a stator, there is known a stator in which a flow path for circulating a coolant is provided inside a stator core, and the coolant that has passed through the flow path is caused to flow outward in the axial direction from an outlet arranged radially outward of the slots of the stator core (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in general, insulating paper is inserted into the slots of the stator core so as to be interposed between the inner wall surface of the slot and the coil (see, for example, Patent Document 2). The insulating paper has a protruding portion that protrudes in the axial direction from the slot, from the viewpoint of ensuring insulation between the stator and the coil and from the viewpoint of absorbing axial variations caused by assembly.

[0005] Focusing on the upper part of the stator core, if the refrigerant that has passed through the flow path inside the stator core is discharged axially outward from an outlet located radially outside the slot, as described in Patent Document 1 above, the refrigerant first flows down to the protruding part of the insulating paper. From there, it is expected that the refrigerant that has flowed down onto the protruding part will drip laterally from the protruding part of the insulating paper before reaching the tip of the coil end, resulting in a situation where it does not apply to the coil end as desired. For this reason, a technology to reliably apply the refrigerant to the coil end has been desired.

[0006] The present invention has been made in view of the above, and aims to provide a stator capable of reliably applying refrigerant to the coil ends and a motor equipped therewith. [Means for solving the problem]

[0007] To achieve the above objective, the stator according to the present invention is configured as follows. The stator according to the present invention is a stator having a stator core on which a plurality of slots are arranged in the circumferential direction on its inner circumference, coils inserted into the plurality of slots such that the coil ends protrude axially from the stator core, and a plurality of insulating papers inserted into each of the plurality of slots so as to be interposed between the inner wall surface of each slot and the coil. The stator core is provided with an internal flow path for circulating refrigerant, and an outlet located radially outward from each of the slots, which causes the refrigerant that has passed through the internal flow path to flow outward in the axial direction. Each of the plurality of insulating papers has a protruding portion that protrudes axially from the slot so as to overlap the outermost radial part of the coil end. Of the plurality of insulating papers, the upper insulating paper located above the stator core has a guide path portion in the protruding portion that guides the refrigerant flowing down from the outlet to the tip of the coil end along the axial direction, which is formed by cutting a slit-shaped notch in the upper insulating paper along the axial direction, or by folding the upper insulating paper along a plurality of fold lines extending in the axial direction before insertion into the slot.

[0008] According to the above configuration, first, the refrigerant that has passed through the internal flow path of the stator core can be discharged outward in the axial direction from outlets located radially outside each slot. Furthermore, since each of the multiple insulating papers has a protrusion that extends axially from the slot so as to overlap the radially outermost part at the coil end, the refrigerant can be discharged from the outlets to the protrusions of the insulating papers at the top of the stator core.

[0009] Furthermore, among the multiple insulating papers, the upper insulating paper located above the stator core has a protruding portion that guides the refrigerant flowing down from the outlet to the tip of the coil end along the axial direction. This guide passage is formed by cutting a slit-shaped notch in the upper insulating paper along the axial direction, or by folding the upper insulating paper along multiple fold lines extending in the axial direction before insertion into the slot. With this configuration, the guide passage that guides the refrigerant to the tip of the coil end along the axial direction can be easily formed by cutting or folding the upper insulating paper itself, and the refrigerant can be reliably applied to the coil end by this guide passage.

[0010] In the stator described above, the guide path may be formed continuously from the protruding portion of the upper insulating paper to the portion interposed between the inner wall surface of the slot in the upper insulating paper and the coil. This ensures that even if the landing point of the refrigerant flowing down from the outlet is shifted inward in the axial direction, the refrigerant can be reliably guided to the tip of the coil end.

[0011] In this case, if the guide path is formed by cutting out the upper insulating paper, the portion of the guide path formed in the intervening part (intervening part) between the inner wall surface of the slot and the coil in the upper insulating paper will fit within the space normally occupied by the insulating paper in the slot. On the other hand, even if the guide path is formed by folding the upper insulating paper, the portion of the guide path formed in the intervening part of the upper insulating paper will be compressed and will generally fit within the space normally occupied by the insulating paper in the slot.

[0012] Thus, regardless of the method of forming the guide path, the guide path formed in the upper insulating paper interposition does virtually no decrease in the space occupied by the coil within the slot. Therefore, the guide path can be formed in the upper insulating paper interposition without significantly reducing the coil's cross-sectional area (cross-sectional area cut by a plane perpendicular to the axial direction), and furthermore, without significantly increasing the Joule heat associated with the reduction in the coil's cross-sectional area.

[0013] In the stator described above, the plurality of fold lines consist of three first mountain folds, four valley folds, and three second mountain folds, arranged in a direction perpendicular to the axial direction with spacing between them. The guide path may have a first rising portion formed by folding the three first mountain folds, a second rising portion formed by folding the three second mountain folds, and a groove formed between the first and second rising portions by folding the four valley folds. With this configuration, a groove is formed between the first and second rising portions, both of which are rectangular tubes, making it easy to realize a groove with a stable groove width.

[0014] In the stator described above, the plurality of fold lines may be formed over the entire axial area of ​​the upper insulating paper. With this configuration, in the manufacturing process of the stator, the fold lines can be uniformly formed in advance along the pulling direction on the insulating paper pulled from the roll. Therefore, by cutting this folded insulating paper and inserting it into the slot, the guide path can be formed even more easily.

[0015] The motor according to the present invention is equipped with the stator described above. With this configuration, the refrigerant can be reliably applied to the coil ends, as described above. [Effects of the Invention]

[0016] As described above, according to the present invention, the refrigerant can be reliably applied to the coil end. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] [Figure 1] This is a schematic diagram showing the motor unit according to Embodiment 1 of the present invention. [Figure 2] This is a schematic diagram of a part of the stator according to Embodiment 1 of the present invention as viewed from the axially outer side. [Figure 3] This is a schematic perspective view showing an example of conventional insulating paper. [Figure 4] This is a schematic perspective view showing the protruding portion of the upper insulating paper according to Embodiment 1 of the present invention. [Figure 5] This is a schematic plan view showing the upper insulating paper of Fig. 4 before insertion into the slot. [Figure 6] This is a schematic perspective view showing the protruding portion of the upper insulating paper according to Embodiment 2 of the present invention. [Figure 7] This is a schematic plan view showing the upper insulating paper of Fig. 6 before insertion into the slot. [Figure 8] This is a schematic perspective view showing the protruding portion of the upper insulating paper according to a modification of Embodiment 2. [Figure 9] This is a schematic plan view showing the upper insulating paper of Fig. 8 before insertion into the slot. DESCRIPTION OF EMBODIMENTS FOR IMPLEMENTING THE INVENTION

[0018] Hereinafter, the modes for implementing the present invention will be described with reference to the drawings. (Embodiment 1) <Motor Unit> Fig. 1 is a schematic diagram showing a motor unit A according to Embodiment 1 of the present invention. As shown in Fig. 1, the motor unit A in the present embodiment includes a motor 1 used as a drive source for vehicles such as electric vehicles and hybrid vehicles. The motor 1 is, for example, an interior permanent magnet embedded motor (IPM motor: Interior Permanent Magnet Motor).

[0019] As shown in Figure 1, the motor 1 is a so-called radial gap type motor, comprising a cylindrical rotor 11 with a shaft 10 fixed in a central hole, and a stator 12 arranged to surround the outer surface of the rotor 11.

[0020] The rotor 11 is made up of multiple layers of electromagnetic steel sheets (for example, silicon steel sheets). Permanent magnets (not shown) are embedded in the rotor 11.

[0021] Figure 2 is a schematic diagram of a part of a stator 12 according to Embodiment 1 of the present invention, viewed from the outside in the axial direction δ. As shown in Figure 2, the stator 12 has a cylindrical stator core 13, a coil 2, and a plurality of insulating papers 4. In Figure 2, the thickness of the insulating paper 4 is exaggerated for clarity, and the same applies to the following figures. The stator core 13 includes a cylindrical yoke 14 and a plurality of teeth 15 that protrude radially inward from the inner circumferential surface of the yoke 14, arranged at equal intervals in the circumferential direction. Between adjacent teeth 15, slots 16 are formed that penetrate the stator core 13 in the axial direction δ. Thus, the inner circumferential portion of the stator core 13 is provided with a plurality of slots 16 arranged at equal intervals in the circumferential direction, similar to the plurality of teeth 15.

[0022] Returning to Figure 1, the stator core 13 is provided with an internal flow path 17 for circulating a coolant (e.g., oil) and an outlet 18 for draining the oil that has passed through the internal flow path 17 outward in the axial direction δ. The internal flow path 17 extends from one end to the other in the axial direction δ of the stator core 13. As shown in Figure 2, the outlet 18 is located radially outward relative to each slot 16 in the stator core 13.

[0023] Coil 2 is a so-called SC (segment conductor) winding consisting of multiple interconnected segment coils. As shown in Figure 1, coil 2 is inserted into slot 16 such that the coil end 20 protrudes axially δ from the stator core 13. Coil 2 is the main heat source of the stator 12.

[0024] Multiple insulating papers 4 are inserted into each slot 16 so as to be interposed between the inner wall surface of each slot 16 and the coil 2. Each of the multiple insulating papers 4 has a projection 40 that protrudes axially δ from the slot 16. In this embodiment, the projection 40 overlaps the radial outermost part 21 and both sides 22, 23 of the coil end 20, but does not cover the tip 24 of the coil end 20. The details of the insulating papers 4 will be described in detail later.

[0025] Returning to Figure 1, the motor unit A includes a motor 1 and a housing 3. The housing 3 is box-shaped with a bottom 30 and houses the rotor 11 and stator 12 inside. Bearings 31 and 32 are attached to both ends of the housing 3 in the axial direction δ, which rotatably support the shaft 10. The housing 3 is made of a non-magnetic material (e.g., aluminum).

[0026] The motor unit A described above is connected to a circulation path CR through which oil circulates. The circulation path CR is connected in the following order: the motor unit A, an oil pump P (supply unit) that circulates the oil, and an oil cooler C that cools the oil. When the oil pump P is driven, the oil accumulated at the bottom 30 of the housing 3 is sent to the oil cooler C, and the oil cooled by the oil cooler C is supplied to the flow path including the internal flow path 17 of the stator core 13 of the motor unit A. The oil supplied to the motor unit A cools the motor 1 by removing heat from it, and then returns to the bottom 30 of the housing 3.

[0027] Figure 3 is a schematic perspective view showing an example of conventional insulating paper. Figure 4 is a schematic perspective view showing the protruding portion 40A of the upper insulating paper 4A according to Embodiment 1 of the present invention. Figure 5 is a schematic plan view showing the upper insulating paper 4A before insertion into the slot 16. In Figures 3 and 4, the flow of oil is indicated by thick arrows, and the same applies to the following figures. In Figure 5, the boundary line of the protruding portion 40A is indicated by a dashed line, and the same applies to the following figures. Focusing on the upper part of the stator core 13 (the part within a range of approximately ±45 degrees from the vertical center line of the stator core 13, including the part shown in Figure 2), the oil that has passed through the internal core flow path 17 first flows down from the outlet 18 to the protruding portion 90 of the insulating paper 9 (specifically, the part that overlaps with the radially outermost 21 of the coil end 20), as conceptually shown by the thick dashed arrow in Figure 3. From this point, the oil that flows onto the protruding portion 90 is expected to drip laterally from the protruding portion 90 of the insulating paper 9 before reaching the tip portion 24 of the coil end 20, as conceptually shown by the thick solid arrow in Figure 3, and therefore will not reach the coil end 20 as desired.

[0028] In this regard, as shown in Figure 4, in this embodiment, among the multiple insulating papers 4, the protruding portion 40A of the upper insulating paper 4A located above the stator core 13 has a guide path portion 5A that guides the oil flowing down from the outlet 18 along the axial direction δ to the tip portion 24 of the coil end 20. This guide path portion 5A is formed by cutting a slit-shaped notch in the upper insulating paper 4A along the axial direction δ. Specifically, as shown in Figures 4 and 5, the guide path portion 5A extends inward from the edge 41 of the upper insulating paper 4A along the axial direction δ, and has a slit-groove shape with a groove depth equal to the thickness of the upper insulating paper 4A.

[0029] With the upper insulating paper 4A described above, a guide path 5A that guides the oil along the axial direction δ to the tip 24 of the coil end 20 can be easily formed by cutting out a section of the upper insulating paper 4A itself, and this guide path 5A ensures that the oil is reliably applied to the coil end 20. When the guide path 5A is formed by cutting out a slit-shaped section of the upper insulating paper 4A in this manner, the oil comes into contact with the coil end 20 earlier, before it reaches the tip 24 of the coil end 20, thus allowing the coil end 20 to be cooled more efficiently. Furthermore, the process of cutting out a slit-shaped section of the upper insulating paper 4A to form the guide path 5A may be performed either before or after insertion into the slot 16.

[0030] As shown in Figure 4, the guide path 5A in this embodiment is formed continuously from the protruding portion 40A of the upper insulating paper 4A to the portion (intervening portion 42) interposed between the inner wall surface of the slot 16 in the upper insulating paper 4A and the coil 2. As a result, even if the landing point of the oil flowing down from the outlet 18 is shifted inward in the axial direction δ, the oil can be reliably guided to the tip portion 24 of the coil end 20.

[0031] Here, if the guide path 5A is formed by cutting out the upper insulating paper 4A as described above, the portion 50A of the guide path 5A formed in the intervening portion 42 of the upper insulating paper 4A fits directly into the space normally occupied by the insulating paper 4 within the slot 16. Therefore, since the guide path 5A formed in the intervening portion 42 of the upper insulating paper 4A does virtually no reduction in the space occupied by the coil 2 within the slot 16, the guide path 5A can be formed in the intervening portion 42 of the upper insulating paper 4A without significantly reducing the cross-sectional area of ​​the coil 2 (cross-sectional area cut by a plane perpendicular to the axial direction δ), and furthermore, without significantly increasing the Joule heat associated with the reduction in the cross-sectional area of ​​the coil 2.

[0032] (Embodiment 2) Figure 6 is a schematic perspective view showing the protruding portion 40B of the upper insulating paper 4B according to Embodiment 2 of the present invention. Figure 7 is a schematic plan view showing the upper insulating paper 4B before insertion into the slot 16. Embodiment 2 differs from Embodiment 1 in that the guide path portion 5B is formed by folding the upper insulating paper 4B along a plurality of fold lines 7B extending in the axial direction δ before insertion into the slot 16. As shown in Figure 6, the guide path portion 5B has a first rising portion 60, a second rising portion 61, and a groove portion 62 located between the first rising portion 60 and the second rising portion 61, which are formed three-dimensionally by folding. The groove portion 62 opens upward. As shown in Figure 7, the fold lines 7B in this embodiment consist of three first mountain fold portions 70-72, four valley fold portions 80-83, and three second mountain fold portions 73-75, which are arranged in this order with spacing between them in a direction perpendicular to the axial direction δ.

[0033] By sequentially folding the three first mountain folds 70-72, the four valley folds 80-83, and the three second mountain folds 73-75 described above, a first rising portion 60, a second rising portion 61, and a groove portion 62 are formed on the upper insulating paper 4B. Specifically, by mountain folding the first mountain folds 70-72 on the upper insulating paper 4B, a rectangular cylindrical first rising portion 60 is formed; similarly, by mountain folding the second mountain folds 73-75, a rectangular cylindrical second rising portion 61 is formed; and by valley folding the valley folds 80-83, a groove portion 62 is formed. According to this folding line 7B, a groove portion 62 is formed between the first rising portion 60 and the second rising portion 61, both of which are rectangular cylindrical, making it easy to realize a groove portion 62 with a stable groove width.

[0034] With the upper insulating paper 4B described above, a guide path 5B that guides the oil along the axial direction δ to the tip 24 of the coil end 20 can be easily formed by folding the upper insulating paper 4B itself, and the oil can be reliably applied to the coil end 20 by this guide path 5B.

[0035] As shown in Figure 6, the guide path portion 5B in this embodiment is formed continuously from the protruding portion 40B of the upper insulating paper 4B to the portion (intervening portion 43) interposed between the inner wall surface of the slot 16 and the coil 2, similar to the first embodiment described above. This ensures that even if the landing point of the oil flowing down from the outlet 18 shifts inward in the axial direction δ, the oil can be reliably guided to the tip portion 24 of the coil end 20. Here, when the guide path portion 5B is formed by folding the upper insulating paper 4B as described above, the portion 50B of the guide path portion 5B formed in the intervening portion 43 of the upper insulating paper 4B collapses and generally fits within the space normally occupied by the insulating paper 4 in the slot 16. Therefore, similar to the first embodiment described above, the guide path portion 5B can be formed in the intervening portion 43 of the upper insulating paper 4B without significantly reducing the cross-sectional area of ​​the coil 2, and without significantly increasing the Joule heat associated with the reduction in the cross-sectional area of ​​the coil 2.

[0036] In this embodiment, the fold lines 7B are formed over the entire axial area δ of the upper insulating paper 4B. With these fold lines 7B configured, the fold lines 7B can be uniformly formed in advance along the pulling direction on the insulating paper pulled from the roll during the manufacturing process of the stator 12. Therefore, by cutting this folded insulating paper and inserting it into the slot 16, the guide path 5B can be formed even more easily.

[0037] Figure 8 is a schematic perspective view showing the protruding portion 40C of the upper insulating paper 4C according to one modification of Embodiment 2. Figure 9 is a schematic plan view showing the upper insulating paper 4C before insertion into the slot 16. However, the above is not limited to the above, and for example, as shown in Figure 8, the first rising portion 63 and the second rising portion 64 may both be formed in an inverted triangular tubular shape. In this case, the fold line 7C consists of two first mountain folds 76, 77, two valley folds 84, 85, and two second mountain folds 78, 79, which are arranged in this order with spacing between them in a direction perpendicular to the axial direction δ, for example as shown in Figure 9. The first rising portion 63 is formed in an inverted triangular tubular shape by mountain folding the two first mountain folds 76, 77 in the upper insulating paper 4C, and similarly, the second rising portion 64 is formed in an inverted triangular tubular shape by mountain folding the two second mountain folds 78, 79, and the groove portion 65 is formed by valley folding the two valley folds 84, 85. This upper insulating paper 4C allows the guide channel 5C to be formed with fewer folding steps.

[0038] In this modified example, as in the second embodiment described above, the portion 50C of the guide path 5C formed in the intervening portion 44 of the upper insulating paper 4C is compressed and generally fits within the space normally occupied by the insulating paper 4 in the slot 16. Therefore, the guide path 5C can be formed in the intervening portion 44 of the upper insulating paper 4C without significantly reducing the cross-sectional area of ​​the coil 2, and furthermore, without significantly increasing the Joule heat associated with the reduction in the cross-sectional area of ​​the coil 2.

[0039] The embodiments described above are illustrative in all respects and are not intended to be limited in their interpretation. Therefore, the technical scope of the present invention is not construed solely by the embodiments and examples described above, but is defined based on the claims. Furthermore, any modifications or changes falling within the equivalent scope of the claims are all within the scope of the present invention. [Explanation of Symbols]

[0040] 1 motor 12 staters 13 Stator Core 16 slots 17. Channels within the core 18 Outlet 2 coils 20 coil ends 21 Outermost 24 Tip 4.9 Insulating paper 4A, 4B, 4C Upper insulating paper 40,40A,40B,90 Protrusion 5A,5B,5C Guideway section 60, 63 First rising section 61, 64 Second rising section 62, 65 grooves 7B, 7C Folding lines 70-72, 76, 77 First mountain fold section 73-75, 78, 79 Second mountain fold section 80-85 Valley fold section δ axis direction

Claims

1. A stator core having multiple slots arranged in the circumferential direction on its inner circumference, A coil inserted into the plurality of slots such that the coil ends protrude axially from the stator core, A stator having a plurality of insulating papers inserted into each slot so as to be interposed between the inner wall surface of each of the plurality of slots and the coil, The stator core is provided with an internal flow path for circulating the refrigerant, and an outlet located radially outside each slot, which causes the refrigerant that has passed through the internal flow path to flow outward in the axial direction. Each of the plurality of insulating papers has a protruding portion that extends axially from the slot so as to overlap the outermost radial portion at the coil end, A stator in which, among the plurality of insulating papers, the upper insulating paper located above the stator core has a guide path portion in the protruding portion that guides the refrigerant flowing down from the outlet to the tip of the coil end along the axial direction, formed by cutting a slit-shaped notch in the upper insulating paper along the axial direction, or by folding the upper insulating paper along a plurality of fold lines extending in the axial direction before insertion into the slot.

2. In the stator according to claim 1, The guide path portion is formed continuously from the protruding portion of the upper insulating paper to the portion of the upper insulating paper interposed between the inner wall surface of the slot and the coil, in a stator.

3. In the stator according to claim 1, The aforementioned plurality of fold lines consist of three first mountain folds, four valley folds, and three second mountain folds, which are arranged in this order with spacing between them in a direction perpendicular to the axial direction. The guide path portion is a stator having a first rising portion formed by folding the three first mountain folds, a second rising portion formed by folding the three second mountain folds, and a groove portion formed between the first rising portion and the second rising portion by folding the four valley folds.

4. In the stator according to claim 1, The plurality of fold lines are formed over the entire axial area of ​​the upper insulating paper, forming a stator.

5. A motor comprising the stator described in claim 1.

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