JP2019088139A - Stator and rotating electric machine - Google Patents

Abstract

To provide a stator and a dynamo-electric machine capable of improving the partial discharge characteristics and the space factor compared with the prior art.SOLUTION: A stator includes a coil attached to a stator core 11, and composed of multiple segment conductors 31 where a core wire 50 is coated with an insulating coating, where the multiple segment conductors 31 each have a pair of insertion parts 40 placed in a slot 23, and a coil end 41 placed on the outside of the slot 23, the coil end 41 has a connection part 41a placed between the pair of insertion parts 40, and a bend 41b bent in the radial direction of the stator core 11, a coating thickness of an insertion part coating 51a covering the insertion part 40 is thinner than a coating thickness of a connection part coating 51b covering the connection part 41a of the coil end 41, and the insertion parts 40 of one segment conductor 31 and the insertion part 40 of the other segment conductor 31 are in contact with each other in the slot 23.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a stator and a rotating electrical machine.

  BACKGROUND ART Conventionally, a rotating electrical machine is used as a power source of a hybrid vehicle or an electric vehicle. The rotating electrical machine has a stator core having a slot, and a coil partially disposed in the slot and mounted on the stator core. The coil is formed of a plurality of conductors whose core is covered with an insulating film (see, for example, Patent Document 1).

  In the conductor described in Patent Document 1, a core wire is covered with a three-layer film. According to the technique described in Patent Document 1, it is said that the partial discharge characteristics can be improved without reducing the conductor adhesion and the flexibility.

JP, 2014-203585, A

  However, in the conductor described in Patent Document 1 described above, since the core wire is covered with a three-layer film, the film is thicker than a general conductor in which the core wire is covered with a single layer film. . For this reason, the space factor (hereinafter simply referred to as space factor) of core wires in the slots of the stator core is reduced. Therefore, in the prior art, there is a problem in that the partial discharge characteristics and the space factor are improved.

  Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a stator and a rotary electric machine capable of improving partial discharge characteristics and space factor as compared with the prior art.

  In order to solve the above-mentioned subject, a stator (stator 3 of an embodiment mentioned below) concerning the invention according to claim 1 is a stator core (slot of an embodiment mentioned later) provided with a slot (an embodiment mentioned later). A plurality of segment conductors (segments of an embodiment described later) including a flat wire attached to the stator core 11) and having a core wire (a core wire 50 of an embodiment described later covered with an insulating film (film 51 of an embodiment described later) A coil (a coil 12 of an embodiment to be described later) configured by the conductor 31), and the plurality of segment conductors are a pair of insertion portions (an insertion portion 40 of an embodiment to be described later) disposed in the slot; A coil end (a coil end 41 in an embodiment described later) disposed outside the slot and connecting the pair of insertion portions, the coil end includes the pair A curved portion (a connecting portion (a connecting portion 41a in an embodiment described later) disposed between the inserting portions and the connecting portion and the inserting portion and bent in the radial direction of the stator core The film thickness of the insertion portion is thinner than the film thickness of at least the connection portion of the coil end, and The insertion portion and the insertion portions of the other segment conductors are characterized in that they are disposed in contact with each other in the slot.

  In the stator according to the second aspect of the present invention, a gap (a gap G in an embodiment described later) is formed between the curved portion of one of the segment conductors and the curved portion of the other segment conductor. Are provided.

  In the stator according to the third aspect of the present invention, the main surface (the main surface S of the embodiment described later) of the connection portion of one of the segment conductors and the connection portion of the other segment conductor is The film thickness of the first region (first region D1 of the embodiment to be described later) disposed to face the main surface corresponds to the second region (second region of the embodiment to be described later) other than the first region It is characterized in that it is thicker than the film thickness of D2).

  The stator according to the invention described in claim 4 is characterized in that the curved portion is bent outward in the radial direction of the stator core.

  A rotary electric machine (motor 1 of an embodiment described later) according to the invention described in claim 5 is characterized by having the above-mentioned stator.

According to the stator according to the first aspect of the present invention, the coil end includes the curved portion bent in the radial direction of the stator core, so the stator can be axially oriented as compared to the case without the curved portion. Can be made thinner.
Further, since the film thickness of the pair of insertion portions disposed in the slot is thinner than at least the film thickness of the connection portion of the coil end, the film thickness of the insertion portion and the film of at least the connection portion of the coil end The space factor in the slot can be improved as compared to the case where the thickness is the same. Moreover, since the film thickness of the connection part of the coil end which partial discharge tends to produce is thicker than the film thickness of an insertion part, generation | occurrence | production of a partial discharge can be prevented. Therefore, according to the stator of the present invention, partial discharge characteristics and space factor can be improved as compared with the prior art. As a result, since the stator of the present invention can reduce copper loss and increase the partial discharge inception voltage, it can improve the output as compared with the prior art, or maintain the physique while maintaining the output equal to the prior art. It can be reduced.

  According to the stator of claim 2 of the present invention, since the gap is provided between the curved portion of one segment conductor constituting the coil and the curved portion of the other segment conductor, the film of the coil end The insertion portion of one segment conductor disposed in the slot and the insertion portion of the other segment conductor can be reliably brought into close contact with each other while absorbing the film thickness difference between the thickness and the film thickness of the insertion portion. Therefore, according to the stator of the present invention, the space factor can be further improved as compared with the prior art.

  In the stator according to the third aspect of the present invention, the connection portion of one segment conductor and the connection portion of the other segment conductor are disposed such that the main surfaces thereof face each other, and the first portion corresponding to the main surfaces Since the film thickness of the region is thicker than the film thickness of the second region other than the first region, it is possible to increase the partial discharge inception voltage of the connection at the coil end where partial discharge is likely to occur. Therefore, according to the stator of the present invention, partial discharge characteristics can be further improved as compared with the prior art.

  According to the stator according to the fourth aspect of the present invention, the curved portion is bent outward in the radial direction of the stator core, so that interference with the rotor disposed in the radial direction of the stator core can be ensured. It is possible to construct a compact stator that effectively utilizes dead space while avoiding it.

  According to the rotating electrical machine of the fifth aspect of the present invention, the partial discharge characteristics and the space factor can be improved by providing the above-described stator. As a result, the rotating electrical machine of the present invention can reduce copper loss and increase the partial discharge inception voltage. Therefore, compared with the prior art, the stator improves the output or maintains the output equal to the prior art. Can reduce the physique of Therefore, according to the present invention, a high performance rotating electric machine can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the whole structure of the electric motor provided with the stator of embodiment. It is a sectional view showing a part of stator. It is a perspective view showing one segment coil contained in winding. It is a perspective view showing one segment conductor. It is an enlarged view of the bending part of a coil end. It is explanatory drawing of the stator which concerns on the modification of embodiment, and is a figure when a segment coil is seen from inner side of radial direction. It is sectional drawing which follows the VII-VII line in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a cross-sectional view showing an entire configuration of a motor including the stator of the embodiment.
A motor 1 (corresponding to “a rotating electric machine” in the claims) according to the embodiment includes a case 2, a stator 3, a rotor 4, and an output shaft 5.
The electric motor 1 of the present embodiment is, for example, a driving motor mounted on a vehicle such as a hybrid vehicle or an electric vehicle. However, the configuration of the present embodiment is not limited to the above example, and can be applied to motors for other uses such as a motor for power generation mounted on a vehicle. Further, the configuration of the present embodiment is a rotating electrical machine other than that mounted on a vehicle, and is applicable to so-called rotating electrical machines in general including a generator.

The case 2 is formed in, for example, a cylindrical shape that accommodates the stator 3 and the rotor 4.
The stator 3 is formed in an annular shape and attached to, for example, the inner circumferential surface of the case 2. The stator 3 has a stator core 11 and a coil 12 attached to the stator core 11, and applies a rotating magnetic field to the rotor 4.
The rotor 4 has, for example, a rotor core and a magnet attached to the rotor core, and is rotationally driven inside the stator 3.
The output shaft 5 is connected to the rotor 4 and outputs the rotation of the rotor 4 as a driving force.
In the following description, the direction along the axis C of the output shaft 5 is simply referred to as the axial direction, the direction orthogonal to the axis C may be referred to as the radial direction, and the direction around the axis C may be referred to as the circumferential direction.

FIG. 2 is a cross-sectional view showing a part of the stator.
As shown in FIG. 2, the stator 3 includes a stator core 11 and a coil 12. Although the stator 3 may be further provided with a resin layer and a filled and fixed material such as a varnish in the slot 23, for example, the illustration and the description thereof will be omitted for convenience of description in the present application.

  The stator core 11 is formed in an annular shape surrounding the rotor 4. The stator core 11 may be, for example, a divided stator core formed by connecting a plurality of pieces divided in the circumferential direction to one another, or a laminated stator core formed by laminating a plurality of electromagnetic steel plates in the axial direction. May be.

The stator core 11 has an annular yoke portion 21, a plurality of teeth portions 22, and a plurality of slots 23. The plurality of teeth 22 project from the yoke 21 toward the inner side in the radial direction of the stator core 11. Each slot 23 is formed between two teeth 22 adjacent to each other in the circumferential direction of the stator core 11. Each slot 23 penetrates the stator core 11 in the axial direction of the stator core 11.
Each slot 23 has an inner surface 23 i facing the coil 12. In the present application, “facing” is not limited to directly facing, but also includes facing when interposing another member (for example, a filling and adhering substance such as a resin layer or a varnish).

  As shown in FIG. 2, the inner surface 23i of each slot 23 has a pair of side surfaces 23a and 23b, a bottom surface 23c, and a pair of tip end surfaces 23d and 23e. The pair of side surfaces 23 a and 23 b are formed by teeth portions 22 different from each other, and are separated from each other in the circumferential direction of the stator core 11. The pair of side surfaces 23a and 23b are substantially parallel to each other. The bottom surface 23c connects the radially outer end portions of the pair of side surfaces 23a and 23b. The pair of tip end surfaces 23 d and 23 e extend from the radially inner end of the pair of side surfaces 23 a and 23 b so as to approach each other.

  The slot 23 of this embodiment is an open slot in which the inner side in the radial direction is opened, and has a slit 24 formed between the tips of the pair of teeth 22. The slits 24 communicate with the slots 23 in the radial direction of the stator core 11. The circumferential width of the slit 24 is narrower than the circumferential width of the slot 23 (that is, the distance between the pair of side surfaces 23 a and 23 b).

  The coil 12 is accommodated in the slot 23 of the stator core 11 and attached to the stator core 11. The coil 12 is a three-phase coil composed of a U phase, a V phase and a W phase. The coil 12 of the present embodiment is formed by a plurality of segment coils 30 used in connection with each other.

FIG. 3 is a perspective view showing one segment coil included in the winding.
As shown in FIG. 3, one segment coil 30 has a plurality of (for example, four) segment conductors 31. The core wire 50 of the segment conductor 31 is, for example, a flat wire. The sectional shape of the segment conductor 31 is formed in a rectangular shape. The “cross-section” or “cross-sectional shape” in the present application regarding the coil 12 means a cross-section or cross-sectional shape along a plane substantially orthogonal to the axial direction of the stator core 11.
Although details will be described later, each segment conductor 31 of the segment coil 30 is coated with an insulating film 51 on the outer surface of the core wire 50.

  Each segment conductor 31 has a pair of insertion portions 40, a coil end 41, and a pair of connection portions 42A and 42B. The pair of insertion parts 40 are divided into different slots 23 and accommodated, for example, in a state covered with insulating paper (not shown). The plurality of segment coils 30 divided and accommodated in the plurality of slots 23 are U phase, U phase, V phase, V phase, W phase, W phase, U phase, U phase ... in the circumferential direction of the stator core 11. It is arranged in order of.

The coil end 41 is disposed outside the slot 23 and connects the pair of insertion portions 40, and has a connection portion 41a and a bending portion 41b.
The connection portion 41 a is disposed between the pair of insertion portions 40. The connection portion 41 a is formed to bulge outward in the radial direction when viewed from the axial direction.
The curved portion 41 b is disposed between the connection portion 41 a and the pair of insertion portions 40. The respective curved portions 41 b are bent toward the outer side in the radial direction of the stator core 11 so as to approach each other.

  The coupling portions 42A and 42B are located on the opposite side of the insertion portion 40 from the coil end 41 and are disposed outside the slot 23. One connecting portion 42A is joined to the connecting portion 42B of another segment coil 30 by TIG welding, laser welding or the like. The other connecting portion 42B is joined to another connecting portion 42A of the segment coil 30 by TIG welding, laser welding or the like. Thereby, the plurality of segment coils 30 are sequentially coupled. In addition, the coating by powder insulation is given to each joined connection part 42A, 42B, for example. Thereby, the insulation of connection part 42A, 42B is ensured.

  The segment coils 30 are inserted into the slots 23 from the outside of the stator core 11 along the axial direction of the stator core 11. Specifically, the segment coil 30 is inserted into the slot 23 with the connecting portions 42A and 42B in a straight line along the insertion portion 40. The segment coil 30 can be connected to another segment coil 30 by bending the connecting portions 42A and 42B with respect to the insertion portion 40 after the insertion portion 40 is inserted into the slot 23.

  FIG. 4 is a perspective view showing one segment conductor. In addition, in FIG. 4, in order to make description intelligible, one segment conductor 31 is shown in figure among the several segment conductors which comprise the segment coil 30, and illustration of the other segment conductor is abbreviate | omitted. . Further, the film thickness difference of the film 51 of the segment conductor 31 described later is exaggeratedly shown. In addition, in FIG. 4, the basic configuration is the same as the other segment conductors (not shown) and the one segment conductor 31 shown.

As shown in FIG. 4, in the segment conductor 31, the core wire 50 is covered with an insulating film 51. The film 51 is, for example, an enamel layer.
The film 51 has an insertion portion film 51 a covering the insertion portion 40, a connection portion film 51 b covering the connection portion 41 a of the coil end 41, and a curved portion film 51 c covering the curved portion 41 b of the coil end 41.

The insertion portion film 51 a covering the insertion portion 40 has a substantially uniform film thickness throughout the insertion portion 40.
The connection portion film 51b covering the connection portion 41a has a substantially uniform film thickness over the entire connection portion 41a.
The curved portion film 51c covering the curved portion 41b has a substantially uniform film thickness over the entire curved portion 41b.

Here, when the film thickness of the insertion portion film 51a covering the insertion portion 40 is d1, and the film thickness of the connection portion film 51b covering the connection portion 41a of the coil end 41 is d2,
d1 <d2 (1)
It is set to satisfy you. That is, the film thickness d1 of the insertion portion film 51a covering the insertion portion 40 is set to be smaller than the film thickness d2 of the connection portion film 51b covering the connection portion 41a of the coil end 41.
In the present embodiment, the film thickness of the curved portion film 51 c covering the curved portion 41 b of the coil end 41 is substantially the same as the film thickness of the insertion portion film 51 a covering the insertion portion 40.

  FIG. 5 is an enlarged view of a curved portion of the coil end. In FIG. 5, the stator core 11 is illustrated by a two-dot chain line. Further, the front and back of the drawing in FIG. 5 is the radial direction, and the direction in which the curved portion 41 b is bent (left side in FIG. 5) is the outer side in the radial direction of the stator core.

  As shown in FIG. 5, a plurality of the segment conductors 31 described above are arranged side by side in the slot 23 to configure the coil 12. At this time, the bending R of the curved portion 41b of the plurality of segment conductors 31 arranged side by side is formed to increase from the outer side in the radial direction toward the inner side in the radial direction (from the left side to the right side in FIG. 5) . That is, the bending R of the curved portion 41b of the plurality of segment conductors 31 arranged side by side is the smallest in the radially outermost segment conductor 31 and the largest in the radial innermost segment conductor 31. It is formed as.

  Here, the film thickness of the curved portion film 51c is substantially the same as the film thickness of the insertion portion film 51a, and is thinner than the connection portion film 51b. Therefore, in the coil 12 formed by arranging the plurality of segment conductors 31 side by side, between the curved portion 41 b of the adjacent segment conductor 31 and the curved portion 41 b of the other segment conductor 31, A gap G is provided.

  By providing a gap G between the curved portion 41 b of one segment conductor 31 constituting the coil 12 and the curved portion 41 b of the other segment conductor 31, the film thickness of the connection portion film 51 b and the insertion portion at the coil end 41 While absorbing the film thickness difference with the film thickness of the film 51a, the insertion portion 40 of one segment conductor 31 disposed in the slot 23 and the insertion portion 40 of the other segment conductor 31 securely adhere. Thereby, the space factor of the one segment conductor 31 disposed in the slot 23 is further improved as compared with the prior art.

According to the stator 3 of the above-described embodiment, since the coil end 41 includes the curved portion 41b bent in the radial direction of the stator core 11, the stator 3 can be compared with the case where the coiled portion 41b is not provided. It can be thinned in the axial direction.
Further, the film thickness d1 of the insertion portion film 51a covering the pair of insertion portions 40 disposed in the slot 23 is thinner than the film thickness d2 of the connection portion film 51b covering the connection portion 41a of the coil end 41. The space factor in the slot 23 can be improved as compared with the case where the film thickness d1 of the insertion portion film 51a and the film thickness d2 of the connection portion film 51b are the same. Further, since the film thickness d2 of the connection portion film 51b covering the connection portion 41a of the coil end 41 in which partial discharge easily occurs is thicker than the film thickness d1 of the insertion portion film 51a, generation of partial discharge can be prevented. Therefore, according to the stator 3 of the present embodiment, partial discharge characteristics and space factor can be improved as compared with the prior art. As a result, since the stator 3 of the present embodiment can reduce copper loss and increase the partial discharge inception voltage, it can improve the output as compared with the prior art, or maintain the output equal to the prior art. It can reduce the physique.

  Further, according to the stator 3 of the present embodiment, since the gap G is provided between the curved portion 41 b of one segment conductor 31 constituting the coil 12 and the curved portion 41 b of the other segment conductor 31, The insertion portion 40 of one segment conductor 31 disposed in the slot 23 and the other while absorbing the difference in film thickness between the film thickness d2 of the connection portion film 51b and the film thickness d1 of the insertion portion film 51a in the coil end 41 The insertion portion 40 of the segment conductor 31 can be reliably in close contact. Therefore, according to the stator 3 of the present embodiment, the space factor can be further improved as compared with the prior art.

  Further, according to the stator 3 of the present embodiment, since the curved portion 41b is bent outward in the radial direction of the stator core 11, interference with the rotor 4 disposed in the radial direction of the stator core 11 can be avoided. It is possible to configure a compact stator 3 that effectively utilizes the dead space while reliably avoiding it.

  Moreover, according to the motor 1 of the present embodiment, the partial discharge characteristics and the space factor can be improved by providing the above-described stator 3. As a result, since the motor 1 of the present embodiment can reduce copper loss and increase the partial discharge inception voltage, the output can be improved compared to the prior art, or the output can be maintained equivalent to the prior art. The size of the stator 3 can be reduced. Therefore, according to the present embodiment, the high-performance motor 1 can be obtained.

(Modification of the embodiment)
FIG. 6 is an explanatory view of a stator according to a modification of the embodiment, as viewed from the inner side in the radial direction of the segment coil. In FIG. 6, two segment conductors 31 are illustrated for the sake of clarity, and the remaining segment conductors 31 are not illustrated.
7 is a cross-sectional view taken along the line VII-VII in FIG.
In the stator 3 of the above-described embodiment, the connection portion film 51b covering the connection portion 41a has a substantially uniform film thickness over the entire connection portion 41a.
On the other hand, as in the stator of the modification of the embodiment shown in FIGS. 6 and 7, the connection portion film 51b covering the connection portion 41a is thicker than the other second regions D2 in the predetermined first region D1. It may be configured to be Details will be described below.

As shown in FIGS. 6 and 7, in the segment coil 30 of the stator according to the modification of the embodiment, the connection portion 41 a of one segment conductor 31 and the connection portion 41 a of the other segment conductor 31 have their main surfaces mutually S are arranged to face each other.
Here, as shown in FIG. 7, when the film thickness of the first region D1 corresponding to the main surface S is t1, and the film thickness of the second region D2 other than the first region D1 is t2,
t1> t2 (2)
It is set to satisfy you. That is, the film thickness t1 of the first region D1 corresponding to the main surface S is larger than the film thickness t2 of the second region D2 other than the first region D1.

  According to the modification of the embodiment, the connection portion 41 a of one segment conductor 31 and the connection portion 41 a of the other segment conductor 31 are disposed such that the main surfaces S face each other, and Since the film thickness t1 of the one region D1 is larger than the film thickness t2 of the second region D2 other than the first region D1, the partial discharge inception voltage of the connection portion 41a at the coil end 41 where partial discharge tends to occur is increased It can be done. Therefore, according to the modification of the embodiment, the partial discharge characteristics can be further improved as compared with the prior art.

  The present invention is not limited to the above-described embodiment described above with reference to the drawings and modifications of the embodiment, and various modifications may be considered within the technical scope thereof.

  Although the eight segment conductors 31 are disposed in one slot 23 in the above-described embodiment and the variation of the embodiment, the number of segment conductors 31 disposed in one slot 23 is not limited.

  In the above-described embodiment and the modification of the embodiment, the film thickness of the curved portion film 51c covering the curved portion 41b of the coil end 41 and the film thickness of the insertion portion film 51a covering the insertion portion 40 are substantially the same. There was a step in the connection portion between the connection portion film 51b and the curved portion film 51c (see FIG. 5). On the other hand, for example, by gradually increasing the film thickness of the curved portion film 51c from the insertion portion 40 toward the connecting portion 41a, the curved portion film 51c and the connecting portion film 51b may be connected smoothly. .

  In addition, without departing from the spirit of the present invention, it is possible to replace components in the above-described embodiment with known components as appropriate.

1 Motor (rotary machine)
Reference Signs List 3 stator 11 stator core 12 coil 23 slot 31 segment conductor 40 insertion portion 41 coil end 41 a connection portion 41 b curved portion 50 core wire 51 film d1 film thickness of the insertion portion d2 film thickness of the connection portion D1 first region D2 second region t1 first Film thickness t2 of the region film thickness G of the second region gap S main surface

Claims (5)

A coil mounted on a slotted stator core, the core wire being constituted by a plurality of segment conductors including a flat wire covered with an insulating film;
The plurality of segment conductors are
A pair of inserts disposed in the slot;
A coil end disposed outside the slot and connecting the pair of insertion parts;
Have
The coil end includes a connection portion disposed between the pair of insertion portions, and a bending portion disposed between the connection portion and the insertion portion and bent in the radial direction of the stator core. Have
The film thickness of the insertion portion is thinner than the film thickness of at least the connection portion of the coil end,
The stator, wherein the insertion portion of one segment conductor and the insertion portion of another segment conductor are disposed in contact with each other in the slot.   The stator according to claim 1, wherein a gap is provided between the curved portion of one of the segment conductors and the curved portion of the other segment conductor. The connection portion of one of the segment conductors and the connection portion of the other segment conductor are disposed such that their main surfaces face each other,
The film thickness of the 1st field corresponding to the principal surface is thicker than the film thickness of the 2nd field other than the 1st field, The stator according to claim 1 or 2 characterized by things.   The stator according to any one of claims 1 to 3, wherein the curved portion is bent outward in the radial direction of the stator core.   A rotating electrical machine comprising the stator according to any one of claims 1 to 4.

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