JP7709115B2 - Guide parts and rotating electrical machines - Google Patents

Description

The present invention relates to a guide part and a rotating electric machine, and more specifically to a guide part that is attached to the core end face of a stator core having a structure in which coils housed in slots are solidified with resin, and a rotating electric machine equipped with the same.

Factors that limit the continuous output of general motors, including motors used to drive automobiles, include the upper coil temperature limit required to ensure the insulation of the coil coating, and the upper magnet temperature limit required to prevent demagnetization of the magnet. Therefore, the motor's cooling structure is important for continuous output.

When a drive motor in an electric vehicle is in operation, current flows through the stator coil, causing the coil to heat up due to Joule heat in the conductor that makes up the coil. In the cooling mechanism of such a drive motor, the heat generated in the coil is transmitted from the coil to the stator core, and then from the stator core to a refrigerant such as cooling water.

In a typical stator structure, the coil is fixed to the stator core by filling the space between the coil housed in the slot and the stator core with a resin such as varnish and then solidifying it. This solidified resin becomes a transmission path for heat generated in the coil. For this reason, the heat dissipation function of the solidified resin is becoming increasingly important.

Conventionally, a rotating electric machine that combines productivity and insulation has been proposed (see Patent Document 1). This rotating electric machine has a coil guide arranged at at least one opening of the slot of the stator core, typically at the end face of the stator core. This coil guide has a slot insertion portion located between the slot and the segment conductor, and at least one partition portion located between the segment conductors, and the slot insertion portion and the partition portion are arranged in the slot together with the segment conductor.

Patent No. 6122148

However, when the inventors attempted to inject molten resin from the end face side of the stator core into a slot equipped with a coil guide as described in Patent Document 1, they discovered a new technical problem: because the coil guide has a partition, it is difficult to fill the molten resin homogeneously.

The present invention was made based on these new technical challenges, and aims to provide a guide part that can uniformly fill molten resin into the slots of a stator core, and a rotating electric machine equipped with the same.

After extensive research into how to achieve the above objective, the inventors discovered that the above objective could be achieved by forming a gap for resin filling between the end face of the stator core and the retaining portion, which led to the completion of the present invention.

That is, the guide part of the present invention is a guide part to be attached to an end surface of a stator core having a structure in which coils accommodated in slots are solidified with resin,
a frame-shaped holding portion having an opening through which the coil passes, the holding portion having a fixing portion that fits into the slot on a surface facing the core end face, and a protrusion that abuts against the core end face when the fixing portion is fitted into the slot,
The retaining portion is a rectangular frame having short and long sides, the fixing portion is arranged on the short side, and the retaining portion has a comb-tooth-shaped protrusion portion consisting of a plurality of protrusions arranged at regular intervals on the long side and arranged at a distance from the core end face, the side of the protrusion on the inner wall surface of the retaining portion is flush with the inner wall surface of the retaining portion, and when attached to the core end face , the convex portion forms a gap for filling with resin between the long side and the core end face .

The rotating electric machine of the present invention is further provided with a stator core having a structure in which coils housed in slots are solidified with resin, and a guide part attached to the end face of the core. The guide part is characterized in that it is the above-mentioned guide part.

According to the present invention, a gap for resin filling is formed between the end face of the stator core and the retaining portion, so that it is possible to provide a guide part that can uniformly fill the molten resin into the slots of the stator core, and a rotating electric machine equipped with the guide part.

1 is a perspective view showing an embodiment of a rotating electric machine according to the present invention; 2(A) is a top view of the slot portion of the stator shown in FIG. 1 surrounded by line II, FIG. 2(B) is a cross-sectional view of the slot portion cut along the radial direction of the stator, and FIG. 2(C) is a cross-sectional view of the slot portion cut along the circumferential direction of the stator. FIG. 3(A) is an embodiment of a guide part of the present invention, and is a perspective view of the guide part shown in FIG. 1, FIG. 3(B) is a front view of the guide part, FIG. 3(C) is a plan view of the guide part, FIG. 3(D) is a bottom view of the guide part, FIG. 3(E) is a left side view of the guide part, and FIG. 3(F) is a right side view of the guide part. 2 is a perspective view showing a state in which the guide part shown in FIG. 1 is attached to a stator core. FIG. 5A is a perspective view showing a state in which the guide part shown in FIG. 1 is attached to a stator core, and FIG. 5B is a front view showing a state in which the guide part shown in FIG. 1 is attached to a stator core. Figure 6(A) is an oblique view showing another example of a guide part, Figure 6(B) is a front view showing another example of a guide part, Figure 6(C) is a plan view showing another example of a guide part, Figure 6(D) is a bottom view showing another example of a guide part, Figure 6(E) is a left side view showing another example of a guide part, Figure 6(F) is a right side view showing another example of a guide part, and Figure 6(G) is a cross-sectional view of the guide part shown in Figure 6(B) taken along line G-G'. FIG. 13 is a perspective view showing still another example of a guide component. FIG. 13 is a perspective view showing still another example of a guide component. 9 is a perspective view showing a state in which the guide part shown in FIG. 8 is attached to a stator core. 9 is a perspective view showing a state in which the guide part shown in FIG. 8 is attached to a stator core.

The guide component and rotating electric machine of the present invention will be described in detail below with reference to the drawings. Note that the dimensional ratios of the drawings cited below have been exaggerated for the convenience of explanation and may differ from the actual ratios.

(Embodiment 1)
Fig. 1 is a perspective view showing a main part of an embodiment of a rotating electric machine of the present invention. As shown in Fig. 1, the rotating electric machine 1 of this embodiment includes a stator 10 and a rotor 30, and a guide component 20 of the present invention is attached to the stator 10. The stator 10 includes an annular stator core 11 having a plurality of slots 11A for accommodating coils (not shown). The guide component 20 is attached to an end face 11B of the stator core, more specifically, in the vicinity of the openings of the slots 11A in the core end face 11B.

Figures 2 (A) to (C) show the installation state of the guide part. As shown in these figures, the guide part 20 is attached to the core end surface 11B of the stator core 11, which has a structure in which coils 13 with insulating coating are housed in slots 11A and solidified with resin 15. Here, the arrow Z in Figure 2 (C) indicates the flow direction of the molten resin when it is injected. Note that the stator core is actually wound with multiple coils, but this is omitted for the sake of explanation. Also, the rotor is actually assembled with a rotor shaft, multiple magnets, etc., but this is omitted for the sake of explanation.

(Embodiment 2)
3A to 3F show an embodiment of the guide part of the present invention, and in these figures, the guide part 20 has a frame-shaped holding part 21 having an opening 21A through which a coil (not shown) passes. The holding part 21 has a fixing part 23 and a protruding part 25 on a surface 21C facing the core end face (core end face 11B: see FIG. 1). When the guide part 20 is attached, the fixing part 23 fits into the slot 11A (see FIG. 1), and during this fitting, the protruding part 25 abuts against the core end face 11B, forming a gap 20A between the holding part 21 and the core end face 11B for filling with a solidifying resin (see FIGS. 3B and 2C).

In the guide part 20 of this embodiment, the holding portion 21 has a rectangular frame shape having a short side portion 211 and a long side portion 213. By arranging the long side portion 213 along the radial direction of the stator core 11 as shown in FIG. 1, the fixing portion 23 is arranged on the short side portion 211, and a gap 20A is formed between the long side portion 213 and the core end face 11B.

As shown in FIG. 4, by inserting the guide part 20 of this embodiment into the slot 11A as indicated by the arrow Y, the fixing part 23 fits into the slot 11A and the protruding part 25 abuts the core end face. Then, as shown in FIG. 5, the guide part 20 is attached to the core end face 11B, forming a gap 20A for resin filling between the holding part 21 and the core end face 11B. At this time, the protruding part 25 functions as a stopper for the fixing part 23, so that the gap 20A can be easily and reliably formed and its height can be made uniform.

As described above, according to the guide part of this embodiment, a gap 20A for resin filling is formed between the core end face 11B and the retaining portion 21, so that the resin flow is less likely to branch or merge, compared to, for example, when molten resin is injected between the coils. In this way, because the gap 20A is formed between the core end face and the retaining portion, the filling pressure is less likely to increase during resin injection, and the flow of molten resin is less likely to be disturbed. Therefore, the inclusion of air bubbles and the generation of resin interfaces during resin filling are less likely to occur, and as a result, the molten resin can be filled uniformly into the slots of the stator core.

As described above, the resin is filled homogeneously and solidifies, so the solidified resin is homogeneous and has few defects, improving the resin strength, coil heat dissipation performance, and coil insulation performance of the rotating electric machine. Furthermore, because the guide component of this embodiment does not have a coil partition, the coil space factor in the slot can be increased. Furthermore, by using this guide component, it is possible to eliminate insulating paper while ensuring insulation, improving coil heat dissipation performance.

If the guide part of this embodiment is attached in advance, when inserting the coil into the slot 11A, contact between the coil and the edge or inner surface of the slot can be suppressed, making the insertion smoother. This suppresses the occurrence of scratches on the coil surface. In this way, this guide part also functions as a coil guide, narrowing the gap between the coil and the inner surface of the slot, improving the coil's heat dissipation performance.

Furthermore, in the guide part of this embodiment, the retaining portion 21 is a rectangular frame having a short side portion 211 and a long side portion 213, the fixing portion 23 is disposed on the short side portion 211 side, and the gap 20A is formed on the long side portion 213 side (Fig. 3). This allows the size of the gap 20A to be increased, making it easier to fill a sufficient amount of molten resin into the slots of the stator core 11, and allowing the molten resin to be filled more uniformly into the slots 11A when the molten resin is injected from the stator core end face 11B side.

(Embodiment 3)
6A to 6G show another embodiment of the guide part of the present invention. In these figures, the guide member 22 has the same configuration as the guide part shown in FIG. 1, except that the holding part 21 has a comb-teeth-shaped protrusion 215. Here, the comb-teeth-shaped protrusion 215 is composed of a plurality of protrusions 217 arranged at regular intervals on the long side part 213. The comb-teeth-shaped protrusion 215 is also arranged spaced apart from the core end face 11B. Furthermore, the side surface 217A of the protrusion 217 on the inner wall surface 21B side of the holding part 21 is formed flush with the inner wall surface 21B of the holding part 21 (FIGS. 6D and 6G).

The guide part of this embodiment has the above-mentioned comb-tooth-shaped protrusions 215, and in addition to the advantages of the guide part of embodiment 2, when inserting the coil into the slot 11A, it can further reduce contact between the coil and the edge or inner surface of the slot. This further reduces the occurrence of scratches on the coil surface, and as a result, the guide part of this embodiment can further narrow the gap between the coil and the inner surface of the slot, further improving the heat dissipation performance of the coil.

(Embodiment 4)
7 shows yet another embodiment of the guide part of the present invention, in which a plurality of guide parts 20 are integrated to form an arc-shaped guide part 24. In the illustrated example, a plurality of guide parts 20 are integrated to form a guide part 24 having an arc shape of 120°, but this is not limited thereto, and a guide part having an arc shape of 180° or 90° may also be used.

(Embodiment 5)
Fig. 8 shows yet another embodiment of the guide part of the present invention, in which a plurality of guide parts 20 are integrated to form a guide part 26 having a circular ring shape. As shown in Fig. 9, the above-mentioned guide part 26 can be fitted and attached to the slot 11A and the stator core 11 as shown by the arrow X, and is attached to the core end face 11B in the same manner as the guide part 20 (see Figs. 4 and 5). At this time, as shown in Fig. 10, in the guide part 26 of this embodiment, a gap 20A for resin filling is formed between the holding part 21 and the core end face 11B, specifically between the long side part 213 and the core end face 11B. The circular arc-shaped guide part 24 of the fourth embodiment is also attached to the stator core in the same manner, and a gap 20A is formed, although the number of steps is three.

The above-mentioned guide parts 24 and 26 have a structure in which multiple guide parts 20 are integrated, so they have some flexibility overall, and the degree of installation is improved compared to attaching the guide parts 20 individually to each slot, and the labor required for installation on the stator core 11 can be reduced. In addition, since these guide parts have an arc shape or annular shape, they have excellent mechanical strength. Furthermore, since these guide parts have an arc shape or annular shape, they are less susceptible to the influence of shape errors in the slots that occur during the forming process, and the accuracy of the coil insertion position can be improved.

In the guide parts of each of the above-mentioned embodiments, the coil may be pre-assembled to the holding portion 21. Such a guide part with a coil can make a portion of the guide part thinner, and can increase the space factor of the coil in the slot. It also has the advantage of reducing the amount of material used in the guide part. Furthermore, since the positioning of the stator core and the coil can be performed by the guide part with a coil, there is no need for adjustments such as coil positioning during the assembly process of the rotating electric machine, and the assembly process can be simplified.

The material for forming the guide parts in each of the above-mentioned embodiments is not particularly limited as long as it is an electrically insulating material. Examples of such materials include organic materials such as insulating resins, inorganic materials such as insulating ceramics and glass, and metal materials with insulating surfaces. When the guide parts are formed from a resin material, the guide parts can be manufactured by, for example, injection molding. In addition, since the coil may slide on the inner wall surface of the holding part when it is inserted, it is preferable that the inner wall surfaces of the holding part and the fixing part of the guide parts are smoothly finished so as not to scratch the coil.

Although the present invention has been described above using a few embodiments, the present invention is not limited to these, and various modifications are possible within the scope of the gist of the present invention. For example, the components described above are not limited to the configurations shown in each embodiment, and it is possible to change the details of the specifications of the holding portion, fixing portion, and protrusion, or to apply the components of each embodiment to other embodiments. Also, in the guide parts of each embodiment, the holding portion has been described as a rectangular frame shape having short and long sides, but is not limited to this as long as it has a shape that fits into the slot. For example, if the opening of the slot is shaped like a fan frame, the holding portion can be shaped like a fan frame.

Reference Signs List 1 Rotating electric machine 10 Stator 11 Stator core 11A Slot 11B Core end surface 13 Coil 15 Resin 20, 22, 24, 26 Guide part 20A Gap 21 Holding portion 21A Opening 21B Inner wall surface 21C Opposing surface 211 Short side portion 213 Long side portion 215 Comb-tooth-shaped protrusion portion 217 Protrusion 217A Side surface 23 Fixing portion 25 Convex portion 30 Rotor

Claims (4)

A guide part is attached to the end surface of a stator core having a structure in which coils housed in slots are hardened with resin,
A frame-shaped holding portion having an opening through which the coil passes,
the holding portion has, on a surface facing the core end face, a fixing portion that fits into the slot, and a protrusion that abuts against the core end face in a state where the fixing portion is fitted into the slot,
The holding portion is a rectangular frame having short sides and long sides,
The fixing portion is disposed on the short side portion,
a comb-shaped projection portion that is made up of a plurality of projections that are arranged at regular intervals on the long side portion and that is arranged apart from the core end surface,
a side surface of the protrusion on the inner wall surface side of the holding portion is flush with the inner wall surface of the holding portion,
A guide component, characterized in that, when attached to the core end surface , the convex portion forms a gap for filling with resin between the long side portion and the core end surface . The guide component according to claim 1 , wherein the coil is attached to the holding portion. 3. The guide part according to claim 1 , wherein a plurality of guide parts attached to the core end surface are integrated into one body having an arc shape or an annular shape. A rotating electric machine including a stator core having a structure in which coils housed in slots are hardened with resin, and a guide part attached to an end face of the core,
A rotating electric machine, wherein the guide part is the guide part according to any one of claims 1 to 3 .