JP2004343961A - Cooling structure of rotating electric machine - Google Patents

Abstract

To cool a stator core and a coil as uniformly and efficiently as possible.
An insulating material is arranged around a teeth portion protruding from a yoke portion of a stator core to an inner peripheral surface side, and a coil wound from the outside is accommodated in a slot between the teeth portions. Then, the opening of the slot 13 on the inner peripheral surface side of the stator core is closed to form a cooling passage through which the coolant can flow in the slot. Furthermore, the stator core 5 is formed by laminating a number of magnetic steel plates in the axial direction, and the distribution of the height of the yoke portion 11 and the teeth portion 12 is different between the axial end portions and the central portion therebetween. And a gap 21 is formed at the center between the upper surface of the coil 16 wound around the teeth portion 11 and the lower surface of the yoke portion and communicates with the cooling passage 6.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cooling structure for a rotating electric machine that cools a stator and a coil by flowing a coolant inside a stator.
[0002]
[Prior art]
In order to cool the stator and coil that generate heat in the rotating electric machine, insert an underplate into the slot opening where the coil of the stator is housed and close it, cover the coil end with an oil jacket, and coolant inside the slot. Patent Document 1 proposes a configuration in which a heat-generating portion is directly cooled by a refrigerant by using a cooling passage that circulates.
[0003]
[Patent Document 1]
JP 2001-145302 A
[Problems to be solved by the invention]
However, an insulating material is arranged around the teeth portion of the stator core around which the coil is wound, and the coil is wound therefrom. Since these coils have a large thermal resistance, a portion close to the stator core of the coil or a coil may be used. There is a problem that cooling is not always sufficient for the adjacent stator portion, there is a local temperature rise, and the temperature distribution varies.
[0005]
An object of the present invention is to cool a stator core and a coil as uniformly and efficiently as possible.
[0006]
[Means for Solving the Problems]
In the rotating electric machine of the present invention, an insulating material is arranged around teeth protruding from the yoke portion of the stator core to the inner peripheral surface side, and a coil wound from the outside is accommodated in a slot between the teeth portions, The opening of the slot on the inner peripheral surface side of the stator core is closed to form a cooling passage through which the coolant can flow inside the slot. Further, in the rotating electric machine, the stator core is formed by laminating a large number of magnetic steel plates in the axial direction, and the distribution of the height of the yoke portion and the teeth portion is different between the both end portions in the axial direction and the central portion therebetween. A stator core is arranged, and a gap is formed at the central portion between the upper surface of the coil wound around the teeth portion and the lower surface of the yoke portion and communicates with the cooling passage.
[0007]
[Action / Effect]
Therefore, a gap is formed between the upper surface of the coil wound around the tooth portion and the lower surface of the tooth portion and communicates with the cooling passage. By guiding the cooling water there, not only the coil but also the yoke portion is formed. The bottom surface can be cooled directly or the coolant can be cooled directly to the corners of the yoke and teeth where heat is difficult to escape, enabling uniform and effective cooling with less variation in stator core temperature. Become.
[0008]
Embodiment
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0009]
1 and 2 show the entire structure of the rotating electric machine, FIG. 1 shows a cross section including the rotating shaft of the rotating electric machine, and FIG. 2 shows a cross section orthogonal to the rotating shaft. The rotating electric machine is an electric motor or a generator. In this embodiment, a case where the present invention is applied to a permanent magnet type electric motor will be described.
[0010]
In FIG. 1, a case 1 of a rotating electrical machine includes a cylindrical portion 1A and side plates 1B and 1C that close openings at both axial ends of the cylindrical portion 1A. The rotor 2 attached to the rotating shaft 2A is housed in the case 1A. The rotor 2 rotates integrally with a rotating shaft 2A supported by bearings 3 on the side plates 1B and 1C of the case 1. As shown in FIG. 2, the rotor 2 includes a plurality of permanent magnets 4 arranged at equal intervals around the rotation axis, and the adjacent permanent magnets 4 are set to have different magnetic poles.
[0011]
A cylindrical stator core 5 is arranged on the inner periphery of the cylindrical portion 1A of the case 1 so as to surround the periphery of the rotor 2, and at this time, a predetermined gap is formed between the stator core 5 and the outer periphery of the rotor 2.
[0012]
As shown in FIG. 2, the stator core 5 is configured by connecting a plurality of (in this embodiment, 12) divided cores 10 in an annular shape. Each split core 10 is formed in a substantially T shape including a yoke portion 11 and a tooth portion 12. The teeth portion 12 is formed so as to protrude from the center of the yoke portion 11 to the inner peripheral side of the stator core 5.
[0013]
Each of the split cores 10 is formed by laminating a large number of substantially T-shaped magnetic steel plates having a predetermined thickness in the axial direction of the rotating shaft 2A so that the stator core 5 has a predetermined length.
[0014]
When the divided cores 10 are arranged in an annular shape, slots (grooves) 13 are formed between the teeth 12. After arranging an insulating material 15 around each tooth portion 12, a coil 16 is wound from the outside thereof. The coil 16 is accommodated in the slot 13 between the teeth 12, and the winding layers of the coil 16 are set to a plurality of layers as necessary.
[0015]
A plate 17 for closing the opening of the slot 13 is disposed between the tips of the teeth 12, and the plate 17 and the teeth 12 are integrally molded by a resin seal 18 to completely seal the opening. . Thus, the cooling passage 6 through which the coolant can flow is formed inside the slot 13.
[0016]
As shown in FIG. 1, a part of the seal portion 18 forms a cylindrical portion 18A extending from both ends of the stator core 5, and the distal end of the cylindrical portion 18A is fitted to the inner surfaces of the cases 1B and 1C in a liquid-tight manner. Accordingly, annular cooling jackets 7A and 7B are formed inside the case 1 at both ends of the stator core 5. The cooling jackets 7A and 7B accommodate the end portions of the coils 16 and communicate with both ends of the cooling passage 6 extending axially in each slot 13. The cooling jacket 7A is connected to a refrigerant inlet 8A provided through the cylindrical portion 1A, and the cooling jacket 7B is connected to a refrigerant outlet 8B provided through the cylindrical portion 1A. Flows through each cooling passage 6 in the direction of the rotation axis of the rotor, during which the stator core 5 and the coil 16 are cooled and circulated from the cooling jacket 7B on the opposite side to the outside.
[0017]
In order to perform the cooling of the stator core 5 and the coil 16 by the refrigerant as evenly and efficiently as possible, in the first embodiment, as shown in FIGS. A gap 21 is provided between the first and second yoke portions 11 so as to guide the refrigerant into the gap 21.
[0018]
FIG. 3 is a side view of the split core 10 along the slot 13, and FIG. 4 shows an end face of the split core 10 viewed from a direction orthogonal to the slot 13 and a different cross section.
[0019]
A large number of the divided cores 10 are stacked in the direction of the rotor rotation axis to form the stator core 5, and the shape of the divided core 10 is different between both end portions in the axial direction and a central portion sandwiched between these portions. As shown in FIG. 4, the split core 10B at the central portion with respect to 10A has a higher height of the teeth portion 12B toward the inner peripheral side of the stator core and a shorter height of the yoke portion 11B.
[0020]
That is, the split cores 10A and 10B have the same height from the outer circumferential surface to the inner circumferential surface of the stator core, that is, the total length in the radial direction, but the ratio of the height in the radial direction of the yoke portion 11A and the teeth portion 12A is equal to the yoke portion. It differs from the ratio of the height in the radial direction between the portion 11B and the teeth portion 12B.
[0021]
The coils 16 are concentratedly wound around the teeth 12A and 12B of the split cores 10A and 10B with the insulating material 15 interposed therebetween. The insulating material 15 is a plate-shaped member having a predetermined thickness. In the axial direction of the stator core 5, each of the teeth portions has a side portion 19 </ b> A along both side surfaces of the teeth portions 12 </ b> A and 12 </ b> B and an upper surface portion 19 </ b> B along the lower surfaces of the yoke portions 11 </ b> A and 11 </ b> B. A pair formed in a character shape is configured as one set.
[0022]
Note that the end surface of the tooth portion 12 is covered with a member 19C connecting the left and right insulating members 15 at the coil end portion.
[0023]
The insulating material 15 is arranged on both sides of the teeth portion 12 of the split core 10 as a pair of left and right, but the upper surface portion 19B of the insulating material 15 is brought into close contact with the lower surface of the yoke portion 11A of the split core 10A at both end portions. By winding the coil 16 from the outside, a gap 21 is formed between the lower surface of the yoke portion 11B and the upper surface portion 19B of the insulating material 15 in the center core divided core 10B.
[0024]
The gap 21 opens to face the slot 13. Therefore, when the coolant flows through the cooling passage 6 in the slot, the coolant also enters the gap 21.
[0025]
With this configuration, when the refrigerant flows through the cooling passage 6 in the slot extending in the axial direction of the stator core 5, the refrigerant directly cools the coil 16 facing the cooling passage 6, and the refrigerant flows in the axial direction of the stator core 5. The coolant also flows into the gap 21 formed between the yoke portion 11B of the divided core 10B at the central portion and the upper surface portion 19B of the insulating material 15, which occupies the majority, and therefore, the coolant flows into the gap 21. The lower surface and the upper surface of the coil 16 are directly subjected to the cooling action by the refrigerant. In particular, the corner where the lower surface of the yoke portion 11B and the teeth portion 12B are connected is covered with the coil 16 wound in a plurality of layers, and is a portion where heat is hardly escaping. When the refrigerant enters the reaching gap 21, it is possible to effectively cool the portion where the temperature is easily increased locally.
[0026]
Therefore, according to the present embodiment, in the axial direction of the stator core 5, the ratio of the height (height) of the yoke portions 11A and 11B of the divided cores 10A and 10B at the both end portions and the central portion and the teeth portions 12A and 12B is set. Is set differently, and a gap 21 is formed between the uppermost layer of the coil 16 wound around the both end portions and the lower surface of the yoke portion 11B so that the refrigerant enters there. In addition, it is possible to directly cool the corners of the yoke portion 11B and the teeth portion 12B, which are difficult to release heat, with the refrigerant, and it is possible to perform effective cooling while suppressing temperature variations.
[0027]
Also, the height of the teeth portion 12A of the divided core 10A at both end portions is set low and the coil 16 is wound based on this, so that the gap 21 is automatically formed on the lower surface of the yoke portion 11B of the divided core 10B at the central portion. Can be formed, and the coil 16 can be securely wound without lowering the working efficiency of the winding operation of the coil 16.
[0028]
Further, since the coil 16 is in close contact with the side surface portion 19A and the upper surface portion 19B of the insulating material 15, the coil 16 does not collapse and can be wound stably.
[0029]
Since the insulating material 15 has the same shape, the number of parts is small and the productivity is improved.
[0030]
Next, a second embodiment shown in FIGS. 5 and 6 will be described.
[0031]
Mainly describing the differences from the first embodiment, in this embodiment, the split core 10A at both ends and the split core 10B at the center are configured in the same manner as in the first embodiment, that is, at the center. The split core 10B has the same configuration in which the length of the teeth portion 12B is longer and the length of the yoke portion 11B is shorter in the radial direction, but the insulating material 15 corresponds to the split cores 10A and 10B. Thus, the stator core 5 is formed in a different shape in the axial direction.
[0032]
That is, the insulating material 15 includes an insulating material 15A corresponding to both end portions and an insulating material 15B corresponding to the central portion. The insulating material 15B corresponds to the length of the side portion 19A corresponding to the length of the teeth portion 12B. Is set longer than the insulating material 15A.
[0033]
The coil 16 is wound on the basis of the divided cores 10A at both end portions. Therefore, even if the uppermost layer of the coil 16 is brought into close contact with the upper surface portion 19A of the insulating material 15A, the divided core 10B at the central portion is not wound. The uppermost layer does not reach the upper surface portion 19B of the insulating material 15B, and a gap 21A is formed therebetween.
[0034]
The coil 16 is wound around the axial end of the stator core 5 and the slot 13 by a winding machine or the like, and the winding layer of the coil 16 is regulated according to the shape of both ends. At the central portion in the slot axis direction, it is not possible to adhere to the upper surface portion 19B of the insulating material 15B, and a gap 21A is formed.
[0035]
As described above, according to the present embodiment, the upper surface portion 19B of the insulating material 15B contacts the lower surface of the yoke portion 11B of the split core 10B at the central portion. Since the gap 21A is formed between the gaps, the refrigerant also enters the gap 21A, thereby directly cooling the lower surface of the yoke portion 11B and the uppermost layer of the coil 16, so that the portion where heat is hardly released can be effectively used. Cooling can be performed locally, and a local excessive rise in temperature can be suppressed.
[0036]
Next, a third embodiment shown in FIGS. 7 and 8 will be described.
[0037]
In this embodiment, the position of the insulating material 15B is intermediate between the first embodiment and the second embodiment, whereby the insulating material 15B is located between the upper surface portion 19B and the yoke portion 11B and between the upper surface portion 19B and the upper surface portion 19B. Gaps 21A and 21B are formed between the coil 16 and the uppermost layer.
[0038]
As in the second embodiment, the divided core 10A at the both end portions and the divided core 10B at the central portion have the teeth portion 12B longer in the radial direction at the central portion 11B is configured to have a short length, and the insulating material 15 has a different shape in the axial direction of the stator core 5 corresponding to the divided cores 10A and 10B, that is, an insulating material 15A corresponding to both end portions, respectively. And an insulating material 15B corresponding to the central portion.
[0039]
However, as for the insulating material 15B at the central portion, the upper surface portion 19B is arranged so that the upper surface portion 19B does not adhere to the lower surface of the yoke portion 11B of the split core 10B and does not adhere to the uppermost layer of the coil 16, so that both ends are provided. The gaps 21A and 21B are formed when the coil 16 is wound on the basis of the divided core 10A.
[0040]
In this way, in the present embodiment, the gaps 21A and 21B are formed between the upper surface portion 19B of the insulating material 15B, the lower surface of the yoke portion 11B, and the uppermost layer of the coil 16, so that the upper surface of the coil 16 In addition, the lower surface of the yoke portion 11B can be directly cooled by the refrigerant, and the portion where heat is difficult to escape can be effectively cooled, and a local rise in temperature can be suppressed.
[0041]
It is apparent that the present invention is not limited to the above-described embodiments, but includes various changes and improvements that can be made by those skilled in the art within the scope of the technical idea described in the claims.
[Brief description of the drawings]
FIG. 1 shows a first embodiment of the present invention, and is a cross-sectional view along an axial direction of a rotating electric machine.
FIG. 2 is a sectional view of a stator and a rotor which are also orthogonal to the axis of the rotating electric machine.
FIG. 3 is a side view of the stator core along a slot direction.
4A and 4B show a plane orthogonal to the slots of the stator core, wherein FIG. 4A is a view shown by an arrow AA, FIG. 4B is a view shown by an arrow BB, and FIG.
FIG. 5 is a side view showing a second embodiment, taken along a slot direction of a stator core.
6A and 6B show planes orthogonal to the slots of the stator core, wherein FIG. 6A is a diagram shown by an arrow AA, FIG. 6B is a diagram shown by an arrow BB, and FIG.
FIG. 7 shows a third embodiment, and is a side view along a slot direction of a stator core.
8A and 8B show planes orthogonal to the slots of the stator core, wherein FIG. 8A is a diagram shown by an arrow AA, FIG. 8B is a diagram shown by an arrow BB, and FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case 2 Rotor 5 Stator core 6 Cooling passage 10, 10A, 10B Split core 11, 11A, 11B Yoke part 12, 12A, 12B Teeth part 13 Slot 15, 15A, 15B Insulating material 16 Coil 19A Side part 19B Top part 21, 21A , 21B gap

Claims (10)

An insulating material is arranged around the teeth protruding from the yoke of the stator core to the inner peripheral surface side, and a coil wound from the outside is accommodated in a slot between the teeth, and the stator core inner peripheral side of the slot is disposed. In the cooling structure of the rotating electric machine, the opening of which is closed and a cooling passage through which the refrigerant can flow in the slot,
The stator core is formed by laminating a large number of magnetic steel plates in the axial direction, and at both end portions in the axial direction and a central portion therebetween, a stator core in which the distribution of the height of the yoke portion and the tooth portion is different is arranged, A cooling structure for a rotating electric machine, wherein a gap is formed in the central portion between an upper surface of a coil wound around a teeth portion and a lower surface of a yoke portion and communicates with the cooling passage. The cooling structure for a rotating electric machine according to claim 1, wherein the gap is formed so as to reach a side surface of the teeth portion. The cooling structure for a rotating electric machine according to claim 1, wherein a height of the teeth portion is formed lower at the both end portions than at the central portion. The cooling structure for a rotating electric machine according to any one of claims 1 to 3, wherein the gap is formed between an upper surface of the insulating material that contacts an uppermost layer of the coil and a lower surface of the yoke portion. The cooling structure for a rotating electric machine according to any one of claims 1 to 3, wherein the gap is formed between a lower surface of the insulating material that contacts a lower surface of the yoke portion and an uppermost layer of the coil. The gap according to any one of claims 1 to 3, wherein the gap is formed between a lower surface of the yoke portion and an upper surface of the insulating material, and between a lower surface of the insulating material and an uppermost layer of the coil. The cooling structure of the rotating electric machine according to the above description. The said insulating material is an L-shaped member which is arrange | positioned on both sides of the said teeth part and consists of a side surface part along the said teeth part and an upper surface part along the lower surface of the yoke part. 7. The cooling structure for a rotating electric machine according to any one of 6. 8. The cooling structure for a rotating electric machine according to claim 7, wherein the insulating material is formed to have a different length of a side portion corresponding to the both end portions and the center portion of the stator core. 9. The cooling structure for a rotating electric machine according to claim 8, wherein the height of the side portion of the insulating material located at the both end portions is lower than the height of the side portion of the insulating material located at the central portion. The cooling structure for a rotating electric machine according to claim 9, wherein the coil is wound in multiple layers such that an uppermost coil thereof is in contact with an upper surface portion with reference to the insulating material located at the both end portions.

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