JP6919586B2 - Rotating machine stator coil - Google Patents

Description

The present invention relates to a stator coil of a rotary electric machine, particularly a structure of a joint portion of a plurality of conductor segments constituting the stator coil.

Conventionally, a rotating electric machine that is mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle and functions as an electric motor or a generator is known. The rotary electric machine includes a stator and a rotor. The stator has an annular yoke, a plurality of teeth protruding radially inward from the inner peripheral surface of the yoke, a stator core having a slot formed between the teeth, and a stator core inserted into the slot of the stator core. It includes a wound stator coil.

In the stator coil, a plurality of U-shaped conductor segments in which a conductor is coated with an insulating layer are inserted into slots of the stator core, and the end of the lead portion of the conductor segment protruding from the end face of the stator core and the lead of another conductor segment are inserted. Some are formed by joining the ends of the portions. The insulating layer at the end of the lead portion of the conductor segment (hereinafter, also referred to as a coil joint portion) is peeled off and electrically joined by welding or the like (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-201966

In the stator coil formed by a plurality of conductor segments, the lead portions of the conductor segments of each row arranged in the circumferential direction of the stator core are tilted in a certain clockwise or counterclockwise direction, and the conductor segments adjacent in the radial direction Some of the lead portions have a structure in which the end portions of the lead portions of the conductor segments that are in contact with each other in the radial direction are joined to each other by being tilted in opposite directions.

In the stator coil having this structure, in addition to the conductor segment that is the joining partner, the conductor segment that is not the joining partner is also adjacent in the radial direction. The insulating layer on the joint surface (joint surface of the coil joint) where the end of the lead portion of the conductor segment is in contact with the end of the lead portion of another conductor segment to which the conductor segment is joined is peeled off to expose the internal conductor. It is desired to increase the insulation distance between this peeled region and a conductor segment that is adjacent in the radial direction and is not a bonding partner.

An object of the present invention is to provide a stator coil of a rotary electric machine capable of increasing the insulation distance between the peeled region of the insulating layer on the joint surface of the coil joint portion and a conductor segment that is adjacent to the stator core in the radial direction and is not a joint partner. There is.

The stator coil of the rotary electric machine of the present invention is wound around a stator core having an annular yoke, a plurality of teeth protruding radially inward from the inner peripheral surface of the yoke, and a slot formed between the teeth. It is a rotated stator coil, and a plurality of conductor segments in which an insulating layer is coated on a conductor are inserted into the slot, and the end portion of the lead portion of the conductor segment protruding from the end face of the stator core and the lead portion of another conductor segment are inserted. It is a stator coil of a rotating electric machine formed by joining the ends of the conductors, and the lead portions of the conductor segments of each row arranged in the circumferential direction of the stator core are tilted in a certain direction in the clockwise direction or the counterclockwise direction. , The lead portions of the conductor segments adjacent to each other in the radial direction are tilted in opposite directions, and the ends of the lead portions of the conductor segments that are in contact with each other in the radial direction are joined to each other. The insulating layer on the joint surface in contact with the end of the lead portion of the other conductor segment is peeled off according to the shape of the joint surface of the joint partner, and the length of the lower side of the peeled region of the insulating layer on the joint surface. Is characterized in that it is shorter than the length of its upper side.

According to the present invention, the insulating layer of the joint surface (joint surface of the coil joint portion) in which the end portion of the lead portion of the conductor segment is in contact with the end portion of the lead portion of another conductor segment matches the shape of the joint surface of the joint partner. The length of the lower side of this peeled area is shorter than the length of the upper side. Therefore, it is possible to increase the insulation distance between this peeling region and the conductor segment that is adjacent to the stator core in the radial direction and is located below the peeling region and is not a bonding partner.

It is a flowchart which shows the process procedure of forming a stator coil. It is a side view of the conductor segment before the peeling process. It is a side view of the end part of the lead part of a conductor segment after a peeling process. It is a figure which shows the state of inserting a conductor segment bent in a U shape into a slot of a stator core. It is sectional drawing of the stator core. It is a side view of the stator core after a fold-down process. It is a perspective view of the lead side coil end after a folding process. It is a side view which shows the end of the lead part of two conductor segments to be joined. It is a figure for demonstrating the insulation distance between the peeling region of the joint surface of a coil joint part, and the conductor segment which is adjacent in the radial direction of a stator core and is not a joint partner. It is a side view of the end portion of the lead portion of the conductor segment after the peeling step in the second embodiment. It is a side view which shows the end part of the lead part of the two conductor segments to be joined in Embodiment 2. FIG. It is a figure for demonstrating the insulation distance between the peeling area of the joint surface of the coil joint part in Embodiment 2 and the conductor segment which is adjacent in the radial direction of a stator core and is not a joint partner.

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

<Embodiment 1>
The rotary electric machine includes a stator having a stator core around which a stator coil is wound, and a rotor provided on the inner peripheral side of the stator. The rotary electric machine is mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle and used as an electric motor and a generator.

The stator coil of the rotary electric machine according to the present embodiment is formed by inserting a large number of U-shaped conductor segments into slots of the stator core and sequentially joining the ends of the lead portions thereof. The conductor segment is a flat conductor, and is configured by coating an insulating layer around a metal (conductor) such as copper having high conductivity. As the insulating layer, a resin such as enamel having high insulating properties is used.

Here, a method of forming a stator coil of a rotary electric machine according to the present embodiment will be described. FIG. 1 is a flowchart showing a flow of a process of forming a stator coil. S100 and S102 are the steps of the step of forming the conductor segment, and S104 to S108 are the steps of the step of forming the stator coil using a plurality of the conductor segments.

First, in S100 of FIG. 1, the insulating layer at the end of the lead portion of the conductor segment is peeled off (peeling step). FIG. 2 is a side view showing the conductor segment 10 before the peeling step. As shown in FIG. 2, at both ends of the conductor segment 10, there are lead portions 16 which are portions protruding from the end face of the stator core when the conductor segment 10 is formed into a U shape and inserted into the slot of the stator core. Further, as shown by being surrounded by the alternate long and short dash line in FIG. 2, there is an end portion 20 of a lead portion which is a tip portion of each lead portion 16. In order to form a stator coil by electrically joining the end 20 of the lead portion of the conductor segment 10 and the end 20 of the lead portion of the other conductor segment 10, in the peeling step, the lead portion of the conductor segment 10 is subjected to. The insulating layer at the end 20 is peeled off with a laser or the like.

FIG. 3 is a side view of the end portion 20 of the lead portion of the conductor segment after the peeling step (the end portion 20 of the lead portion on the left side of FIG. 2). In FIG. 3, a portion where the insulating layer 24 is peeled off and the internal conductor 22 is exposed is shown by an oblique line, and the same applies to the drawings described below. As shown in FIG. 3, in the present embodiment, in addition to the joint surface 26 in which the end portion 20 of the lead portion of the conductor segment is in contact with the end portion 20 of the lead portion of another conductor segment, the upper surface, the lower surface, and the end surface (lead portion). The insulating layer 24 on the front end side surface of the end portion 20 and the back surface side of the joint surface 26 is peeled off. Further, the insulating layer 24 of the joint surface 26 is peeled off according to the shape of the joint surface 26 at the end of the lead portion of the other conductor segment to be joined, and the peeled region 25 (conductor 22) of the insulating layer of the joint surface 26 is peeled off. The length B of the lower side of the exposed portion) is peeled off so as to be shorter than the length A of the upper side thereof. Hereinafter, the term “peeling region 25” simply refers to a region (exposed portion of the conductor 22) from which the insulating layer has been peeled off on the joint surface 26. In the present embodiment, as shown in FIG. 3, the insulating layer is peeled so that the boundary (peeling boundary) between the peeled region 25 and the insulating layer 24 becomes two straight lines. Although the peeling of the insulating layer at the end 20 of the left lead portion in FIG. 2 has been described here, the insulating layer is similarly peeled symmetrically at the end 20 of the lead portion on the right side.

Next, in S102 of FIG. 1, the conductor segment is bent (bending step) into a U shape. FIG. 4 shows a conductor segment 10 bent in a U shape. The process up to this point is the process of forming the conductor segment.

Next, the steps (S104 to S108) of forming the stator coil by using a plurality of conductor segments formed in the above steps will be described.

In S104, the two legs of each of the plurality of U-shaped conductor segments 10 are inserted into the slots of the stator core (insertion step). FIG. 4 is a diagram showing how the U-shaped conductor segment 10 is inserted into the slot of the stator core 28. FIG. 5 is a cross-sectional view of the stator core 28. As shown in FIG. 5, the stator core 28 includes an annular yoke 34, a plurality of teeth 36 protruding inward in the radial direction from the inner peripheral surface of the yoke 34, and arranged at intervals in the circumferential direction, and each of the teeth 36. It has a slot 38 formed between them. The stator core 28 is formed by laminating electromagnetic steel sheets. The two legs 14 (see FIG. 4) of the conductor segment 10 are inserted into the two predetermined slots 38 of the stator core 28 from the lower side in the axial direction of the stator core 28 as shown in FIG. This is done for a large number of conductor segments 10.

Next, in S106 of FIG. 1, by inserting the conductor segment 10 into the slot, the lead portion, which is a portion protruding from the end surface of the stator core 28, is tilted in the circumferential direction of the stator core 28 (folding step). FIG. 6 is a side view of the stator core 28 after the folding step, showing a state in which the lead portion 16 is tilted in the circumferential direction. The leg portion (lead portion 16) of the conductor segment protruding from the upper end surface of the stator core 28 constitutes the lead side coil end. FIG. 7 is a perspective view of the lead side coil end after the folding step, and the end portion of the lead portion 16 is simplified and drawn in a curved shape. As shown in FIG. 7, in the folding step, the lead portion 16 of the conductor segment on the outermost periphery is tilted in the circumferential direction and the counterclockwise direction, and the lead portion 16 of the conductor segment adjacent inward in the radial direction thereof is rotated. The lead portions 16 of the conductor segments adjacent to each other in the radial direction are tilted in the direction and the clockwise direction, and the lead portions 16 of the conductor segments are tilted in the circumferential direction and the counterclockwise direction. In other words, the lead portions 16 of the conductor segments of each row arranged in the circumferential direction of the stator core are tilted in a certain direction in the clockwise or counterclockwise direction, and the lead portions 16 of the conductor segments adjacent in the radial direction are tilted in opposite directions. Defeat. As a result, as shown in FIG. 7, the ends of the lead portions 16 of the two conductor segments to be joined are arranged in contact with each other in the radial direction, and as will be described later, the stator coil 40 is formed by joining them. NS. Further, as shown in FIG. 7, in the radial direction of the lead portion 16b of the conductor segment, in addition to the lead portion 16a of the conductor segment which is the joining partner, the lead portion 16c of the conductor segment which is not the joining partner is also adjacent.

FIG. 8 is a side view of the lead portions 16a and 16b of the two conductor segments shown in FIG. 7. As described above, the shape of the peeling region 25 of the end portion 20 of the lead portion of the conductor segment matches the shape of the joining surface 26 of the joining partner. Therefore, as shown in FIG. 8, when the lead portions 16a and 16b of the two conductor segments to be joined are collapsed in the folding step, the joint surface 26 of the end portion 20 of the lead portion of one conductor segment is collapsed. A part (two sides) of the shape of the joint surface 26 of the end portion 20 of the lead portion of the other conductor segment is located along the peeling boundary (two straight lines) of the peeling region 25.

Next, in S108 of FIG. 1, the ends 20 of the lead portions of the corresponding conductor segments arranged in contact with each other in the radial direction of the stator core are joined to each other (joining step). This is done, for example, by laser welding. Specifically, welding is performed by irradiating a laser from above between the end portions 20 of the lead portions of the conductor segment to be joined, and the end portions 20 of the lead portions are joined to each other.

The stator coil is formed by the method described above. Next, the operation and effect of the stator coil of the rotary electric machine of the present embodiment will be described.

FIG. 9 is a side view of the lead portions 16b, 16c, 16d of the three conductor segments shown in FIG. 7. As shown in FIG. 9, the lead portion 16c of the conductor segment, which is not the joining partner of the conductor segment, is adjacent in the radial direction of the lead portion 16b of the conductor segment. Then, it is located below the peeling region 25 (exposed portion of the conductor) of the end portion 20b (coil joint portion) of the lead portion of the conductor segment. According to the stator coil of the rotary electric machine of the present embodiment, the peeling region 25 of the coil joint portion has a shape that matches the shape of the joint surface 26 of the joint partner, and the length B of the lower side becomes the length A of the upper side. Compared to short. Therefore, the insulation distance α between the peeling region 25 of the coil joining portion and the lead portion 16c of the conductor segment that is adjacent in the radial direction and is located below the peeling region 25 and is not the joining partner can be increased.

<Embodiment 2>
Next, the stator coil of the rotary electric machine in another embodiment will be described. Hereinafter, the above-described embodiment will be referred to as "Embodiment 1", and this other embodiment will be referred to as "Embodiment 2". The stator coil of the rotary electric machine according to the second embodiment is obtained by changing the shape of the end portion of the lead portion of the conductor segment in the stator coil of the rotary electric machine of the first embodiment and the shape of the peeled region of the insulating layer. It is the same as the first embodiment.

FIG. 10 is a view corresponding to FIG. 3 of the first embodiment, and is a side view of the end portion 20 of the lead portion of the conductor segment after the peeling step in the second embodiment. In FIG. 10, the same members as those of the conductor segment of the first embodiment are designated by the same reference numerals, and FIGS. 11 and 12 described below are also the same. As shown in FIG. 10, the shape of the end portion 20 of the lead portion of the conductor segment of the second embodiment is a curved shape with the upper side fan-shaped. Before the peeling step, the end portion 20 of the lead portion of the conductor segment is processed to form the shape. The surface of the lead portion 20 of the conductor segment from which the insulating layer is peeled off is the same as in the first embodiment, and the end portion 20 of the lead portion of the conductor segment comes into contact with the end portion 20 of the lead portion of another conductor segment. In addition to the joint surface 26, there are an upper surface, a lower surface, an end surface (a surface on the tip end side of the end portion 20 of the lead portion), and a surface on the back side of the joint surface 26. Further, as in the first embodiment, the insulating layer 24 of the joint surface 26 is peeled off according to the shape of the joint surface 26 at the end of the lead portion of the other conductor segment to be joined, and the insulating layer of the joint surface 26 is peeled off. The length B of the lower side of the peeled region 25 (exposed portion of the conductor 22) is peeled so as to be shorter than the length A of the upper side thereof. In the second embodiment, the shape of the peeling region 25 is a curved shape with the upper side fan-shaped according to the shape of the end portion 20 of the lead portion of the conductor segment, and the boundary (peeling boundary) between the peeling region 25 and the insulating layer 24 is formed. It becomes an inverted curve.

FIG. 11 is a view corresponding to FIG. 8 of the first embodiment, and is a side view of the lead portions 16a and 16b of the two conductor segments to be joined after the folding step in the second embodiment. Similar to the first embodiment, the shape of the peeling region 25 of the end portion 20 of the lead portion of the conductor segment matches the shape of the joining surface 26 of the joining partner. Therefore, as shown in FIG. 11, when the lead portions 16a and 16b of the two conductor segments to be joined are collapsed in the folding step, the joint surface 26 of the end portion 20 of the lead portion of one conductor segment is collapsed. A part of the shape of the joint surface 26 of the end portion 20 of the lead portion of the other conductor segment (inverted curve) is located along the peel boundary (inverted curve) of the peel region 25. become. Further, the curved shape on the fan side of the upper side of the peeling region 25 is arranged so as to match the upper side of the joint surface 26 of the end portion 20 of the lead portion of the other conductor segment having the same shape.

FIG. 12 is a view corresponding to FIG. 9 of the first embodiment, and is a side view of the lead portions 16b, 16c, 16d of the three conductor segments after the joining step in the second embodiment. As shown in FIG. 12, as in the first embodiment, in the radial direction of the lead portion 16b of the conductor segment, the lead portion 16c of the conductor segment which is not the joining partner of the conductor segment is adjacent to the lead portion 16c of the conductor segment. It is located below the peeling region 25 (exposed portion of the conductor) of the end portion 20b (coil joint portion) of the portion. Further, also in the stator coil of the rotary electric machine of the second embodiment, the peeling region 25 of the coil joint portion has a shape that matches the shape of the joint surface 26 of the joint partner, and the length B of the lower side is the length A of the upper side. Since it is shorter than that of the coil joint, the insulation distance α between the peeled region 25 of the coil joint and the lead portion 16c of the conductor segment that is adjacent in the radial direction and is located below the peeled region 25 and is not a bonding partner can be increased. ..

Further, according to the stator coil of the rotary electric machine of the second embodiment, most of the peeling area 25 of the end portion 20 of the lead portion of the conductor segment is covered with the joining surface of the joining partner and joined. Since the length A of the upper side of the peeling region 25 is large, the joint area can be made very large.

10 Conductor segment, 14 legs, 16, 16a, 16b, 16c, 16d Lead part, 20, 20b Lead end, 22 Conductor, 24 Insulation layer, 25 Peeling area, 26 Joint surface, 28 stator core, 34 yoke, 36 Teeth, 38 slots, 40 stator coils.

Claims (1)

A stator coil wound around a stator core having an annular yoke, a plurality of teeth protruding radially inward from the inner peripheral surface of the yoke, and a slot formed between the teeth.
A plurality of conductor segments coated with an insulating layer on a conductor are inserted into the slot, and the end of the lead portion of the conductor segment protruding from the end face of the stator core is joined to the end of the lead portion of another conductor segment. It is a stator coil of a rotary electric machine formed by
The lead portions of the conductor segments of each row arranged in the circumferential direction of the stator core are tilted in a certain direction in the clockwise or counterclockwise direction, and the lead portions of the conductor segments adjacent in the radial direction are tilted in opposite directions. , The ends of the lead portions of the conductor segments that are in contact with each other in the radial direction are joined to each other.
The insulating layer on the joint surface where the end of the lead portion of the conductor segment is in contact with the end portion of the lead portion of another conductor segment is peeled off according to the shape of the joint surface of the joint partner.
The length of the lower side of the peeled region of the insulating layer on the joint surface is shorter than the length of the upper side thereof.
A stator coil of a rotary electric machine characterized by this.

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