JP2013198328A - Rotary electric machine and method of manufacturing segment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that uses an inexpensive round wire and enhances cooling effects of a coil end portion.SOLUTION: A rotary electric machine uses, as a conductor forming a coil end portion, a deformed conductor which is formed by flattening a round wire, and has a sectional shape enclosed with two opposite parallel side surfaces 15 and two opposite arcuate surfaces 17. Consequently, the coil end portion is formed of the conductor having the parallel side surfaces 15 extending in a wire direction, so cooling effects can be enhanced like using a flat type wire. Further, the round wire has the parallel side surfaces 15 formed, so the cost is lower than when the flat type wire is used. Namely, the round wire is used and cooling effects of the coil end portion can be enhanced.

Description

  The present invention relates to a rotating electrical machine mounted on an automobile, a truck, or the like. Further, it can be applied to industrial equipment, home appliances and the like.

  Conventionally, in a stator of a rotating electrical machine as described in Patent Document 1, there is a technique that allows cooling air from a fan to pass through a coil end portion.

Japanese Patent No. 3456140

However, in Patent Document 1, a round wire or a flat wire is used for the conductor. In the case of a flat wire, although the cooling effect by a cooling air hit is high, there exists a problem that it is expensive. In the case of a round wire, there is a problem that the cooling effect is low although it is inexpensive.
Therefore, an object of the present invention is to use a round wire and enhance the cooling effect of the coil end portion.

A rotating electrical machine according to the present invention includes a stator core having a plurality of slots in the circumferential direction, a plurality of slot conductor portions accommodated in the slots, and a plurality of slot conductor portions connected to each other and projecting from an end portion in the axial direction of the stator core. A stator having a stator coil having a coil end portion and a rotor having a peripheral surface facing the peripheral surface of the stator core.
Then, at least a part of the conductor constituting the coil end portion has a deformed lead wire formed by flattening a round wire and having a cross-sectional shape surrounded by two opposing parallel side surfaces and two opposing arc surfaces. It is used.

  According to this, since the coil end portion is constituted by the conductive wires having parallel side surfaces on the outer periphery, the cooling effect of the coil end portion can be enhanced as in the case of using a flat wire. In addition, since the parallel side surfaces are formed by processing an inexpensive round wire, the cost is lower than when a flat wire is used. That is, a round wire can be used and the cooling effect of the coil end portion can be enhanced.

  Further, when the stator coil is formed of a rectangular wire, if the rectangular wire is bent, the corner portion bulges in the direction perpendicular to the bending direction inside the bending. For example, since the flat wire is bent along the circumferential direction of the stator core at the boundary portion between the slot conductor portion and the coil end portion, the corner portion bulges in the radial direction. As a result, the radial dimension of the stator is increased. On the other hand, in the case of a deformed conductive wire, the corners are less likely to bulge, which can contribute to the miniaturization of the stator.

  In addition, the space factor can be increased by using a deformed conductive wire for the conductor constituting the slot conductor portion as compared with the case of using a round wire.

(Example 1) which is a schematic sectional drawing of a rotary electric machine. (A) is explanatory drawing of a segment, (b) is sectional drawing of the conducting wire which forms a segment (Example 1). It is explanatory drawing explaining the manufacturing method of a deformation | transformation conducting wire (Example 1). It is a figure which shows the conductor insertion state of a slot (Example 1). (Example 1) which is a perspective view of the axial direction one end side of a stator. (Example 1) which is a perspective view of the other axial end side of a stator. (Example 1) which is a schematic plan view of the axial direction one end side of a stator. (A) is a top view of a shaping | molding jig, (b) and (c) are figures which show the twisting process of the segment of Example 1, (d) and (e) are the segments of a comparative example. It is a figure which shows a twist process. It is explanatory drawing explaining the effect of the Example compared with the flat wire (Example 1). It is a figure which shows the cross-sectional shape of conducting wire, and the direction of a junction part (Example 1, comparative example). (Example 2) which is a figure which shows the arrangement | positioning state in the slot of conducting wire. It is sectional drawing of conducting wire (Example 3). It is explanatory drawing explaining the manufacturing method of a deformation | transformation conducting wire (Example 3).

  The mode for carrying out the present invention will be described in detail with reference to the following examples.

[Configuration of Example 1]
A rotating electrical machine 1 according to a first embodiment will be described with reference to FIGS.
The rotating electrical machine 1 according to the first embodiment is an AC generator, and includes a stator 2, a rotor 3 disposed on the inner periphery of the stator 2, a fan 4 fixed to an axial end of the rotor 3, and the like. It has a configuration.
The rotor 3 has a Landel-type pole core 3a and a field coil 3b attached to the pole core 3a. The pole core 3a has a known structure in which a pair of claw magnetic poles are engaged in the axial direction. And the fan 4 is being fixed to the axial direction both ends of the pole core 3a, respectively.

The stator 2 is formed by winding a stator coil 8 around a stator core 7 formed by laminating a plurality of annular electromagnetic steel plates.
The stator core 7 has a tooth 9 whose tip is opposed to the outer peripheral surface of the rotor 3, and a magnetic flux path yoke 10 that magnetically connects the teeth 9 on the opposite rotor side (outer peripheral side) (FIGS. 4 and 4). 7).
A slot 11 in which the stator coil 8 is arranged is provided between the adjacent teeth 9.

The stator coil 8 includes a plurality of U-shaped segments 14 (see FIG. 2).
The segment 14 is formed by bending a conducting wire into a U shape. This conducting wire is formed by pressing and rounding a round wire having a round cross section.
That is, as shown in FIG. 3, the round wire is flattened through a step (first molding) of rolling the round wire with a pair of rollers R <b> 1 arranged so as to face the radial direction of the round wire. .

As a result, the round wire is flattened to become a conductive wire surrounded by two opposing parallel side surfaces 15 and two opposing circular arc surfaces 17 (hereinafter referred to as a deformed conductive wire).
In the cross-sectional shape cut perpendicular to the extending direction, the length L in the direction perpendicular to the direction in which the two parallel side surfaces 15 face each other is the length D in the direction in which the two parallel side surfaces 15 face each other (the parallel side surface 15 Longer than the width between).

  As shown in FIG. 2A, the segment 14 is formed by bending the deformed conductive wire so that the parallel side surface 15 is along the surface direction and the one arc surface 17 is inside, and then twisted. Has been. That is, the segment 14 is inserted into the slot 11 in the U-shaped portion 21 that connects the pair of parallel legs 20 to the U-shape by twisting from the state where the deformed conductive wire is simply bent into the U-shape. As a result, a skewed portion 22 extending in the circumferential direction from the leg portion 20 and a top portion 23 between the skewed portions 22 are formed. This twisting process will be described in detail later.

The stator coil 8 is configured by inserting the leg portions 20 of the segments 14 into the respective slots 11 and joining the leg portions 20 of the adjacent segments 14 together.
That is, as shown in FIG. 5 and FIG. 6, the leg portion 20 is inserted from one end side in the axial direction of the slot 11 and extended to the other end side in the axial direction, and the leg portion 20 is gripped by a jig on the other end side in the axial direction. The stator coil 8 is configured by bending so as to pass between the slots 11 and joining the adjacent leg portions 20 by welding.
Of the stator coil 8, the portion accommodated in the slot 11 is the slot conductor portion 25, and the portion protruding from the axial end portion of the stator 2 is the coil end portion 26.

Next, the slot conductor portion 25 will be described.
As shown in FIG. 4, the plurality of slot conductor portions 25 are stacked in the radial direction in the slot 11. Further, the parallel side surface 15 is arranged along the radial direction of the slot 11 when the stator core 7 is viewed in the axial direction. That is, the parallel side surfaces 15 are arranged so as to be sandwiched between the circumferential wall surfaces 11 a of the slots 11. An insulating member 28 is disposed between the wall surface of the slot 11 and the slot conductor portion 25.

  Here, the deformed conducting wire has a cross-sectional shape in which the maximum distance S between two opposing parallel side surfaces 15 is larger than the circumferential length W (slot width) of the slot 11. The maximum distance S between the two parallel side surfaces 15 facing each other is a distance connecting one end of one parallel side surface 15 and the other end of the other parallel side surface 15 in the cross-sectional shape.

Next, the coil end part 26 will be described.
A passage through which the cooling air from the fan 4 passes is formed between the plurality of coil end portions 26.
Cooling air from the fan 4 flows from the inner peripheral side of the stator core 7 toward the outer peripheral side. Therefore, a stator blade shape is formed by the coil end portions 26 so that the cooling air passes between the coil end portions 26 so that the cooling air can pass between the adjacent coil end portions 26.

Specifically, as shown in FIGS. 5 and 7, the segment 14 is attached to the stator core 7 so that the longitudinal direction of the top portion 23 is along the radial direction of the stator core 7, so that the adjacent top portions 23 are adjacent to each other. Gaps are formed radially. Further, on the other axial end side (joining side), as shown in FIG. 6, a stationary blade shape is formed by the end 20 a of the leg 20.
Here, at the top portion 23 and the end portion 20 a, the parallel side surface 15 faces the circumferential direction, and the cooling air flows along the parallel side surface 15.
In addition, as shown in FIG. 6, the joining part 20b by which the film | membrane peeling process was carried out at the edge part 20a of the leg part 20, and was made into the cross-sectional rectangular shape for welding. The joint portion 20 b is formed by peeling off the film so as to be along the parallel side surface 15, and a pair of opposite sides of the rectangular shape is shaped along the parallel side surface 15.

[About twisting process]
The twisting process will be described with reference to FIG.
The twisting process includes a first ring 31 that holds one of the two leg portions 20 and a second ring 32 that is provided concentrically on the inner peripheral side of the first ring 31 and holds the other leg portion 20. It is performed using a molding jig 33 having

Each of the first ring 31 and the second ring 32 has a holding slot 35 for holding the leg portion 20.
As shown in FIG. 8 (a), the first ring 31 and the first ring 31 are arranged in the radial direction so that the holding slot 35 of the first ring 31 and the holding slot 35 of the second ring 32 have the same circumferential position. The two ring 32 is positioned. Then, as shown in FIG. 8B, one leg 20 of one segment 14 before the twisting process is held in the holding slot 35 of the first ring 31, and the other leg 20 is held in the holding slot of the second ring 32. 35. Then, as shown in FIG. 8C, the segments 14 are twisted by shifting the circumferential positions of the first ring 31 and the second ring 32. Japanese Patent Laid-Open No. 2001-197709 discloses a similar twisting process.

  In this embodiment, a deformed lead wire is used for the segment 14, and the leg portion 20 is held such that the wall surface 35 a partitioning the circumferential direction of the holding slot 35 and the parallel side surface 15 abut against each other, and the torsion is Even if the process is performed, the leg portion 20 does not rotate in the holding slot 35.

[Effects of Example 1]
In the present embodiment, a deformed conductor formed by processing a round wire is used for the conductor constituting the coil end portion 26. A passage for passing cooling air from the fan 4 is formed between the coil end portions 26.
According to this, the cooling effect of the coil end portion 26 is enhanced because the cooling air hits the parallel side surface 15 of the deformed conductor when passing. Moreover, since a deformation | transformation conducting wire can be formed by the easy process with respect to a round wire, it is cheaply available.

Further, as shown in FIGS. 9A and 9B, when the stator coil 8 is formed of a flat wire, when the flat wire is bent, the corner c in a direction perpendicular to the bending direction is inside the bend. Swelling occurs.
For example, at the boundary portion between the slot conductor portion 25 and the coil end portion 26 (the portion surrounded by the two-dot chain line in FIGS. 5 and 6), the conducting wire is bent along the circumferential direction of the stator core 7. The corner portion c bulges in the radial direction. As a result, the radial dimension of the stator 2 is increased.
On the other hand, as shown in FIGS. 9C and 9D, in the case of a deformed conductor, if the boundary between the arc surface 17 and the parallel side surface 15 is a corner portion c, the corner portion on the inner side of the bend It is difficult for c to bulge out and can contribute to downsizing of the stator 2.

Further, in this embodiment, a deformed conductor is also used for the slot conductor portion 25, and the deformed conductor is arranged so that the parallel side surface 15 is sandwiched between the circumferential wall surfaces 11 a of the slot 11 from both sides.
According to this, a space factor can be improved rather than the case where a round wire is used.

Further, in the cross-sectional shape of the deformed conducting wire cut perpendicular to the extending direction, the length L in the direction perpendicular to the direction in which the two parallel side surfaces 15 face each other is the length D in the direction in which the two parallel side surfaces 15 face each other. Longer than.
According to this, when the cooling air passage is formed in the coil end portion 26, it is easy to secure a wide passage for the cooling air, and it is easy to form a stationary blade shape by the top portion 23.

And in the cross-sectional shape cut | disconnected perpendicularly | vertically to the extending direction, the maximum distance S between the two parallel side surfaces 15 which oppose is made larger than the circumferential direction length W (slot width) of the slot 11. FIG.
According to this, it is possible to prevent the slot conductor portion 25 from rotating in the slot 11.

Further, in the twisting process of the present embodiment, when the leg portion 20 is held, the wall surface 35 a partitioning the circumferential direction of the holding slot 35 and the parallel side surface 15 are held in contact with each other.
According to this, even if the twisting process is performed, the leg portion 20 does not rotate in the holding slot 35. Therefore, even when the twisting process is performed by forming the joint portion 20b in advance, the joining is performed before and after the twisting process. The direction of the part 20b is the same.

As a comparative example, a twisting process of a segment 14h formed by a round line will be described with reference to FIGS. 8 (d) and 8 (e). In the case of a round wire, even if the holding slot 35 and the surface of the round wire are held in contact with each other, the holding depends on the frictional force. The leg 20h rotates.
For this reason, if the joining part 20bh is formed in advance and the twisting process is performed, the direction of the joining part 20bh changes before and after the twisting process.

In this embodiment, since the direction of the joint portion 20b does not change before and after the twisting process, when the segment 14 after the twisting process is inserted into the slot 11 of the stator core 7 from one end side in the axial direction, it protrudes to the other end side in the axial direction. The plane of the joint portion 20b is along the parallel side surface 15 and faces the circumferential direction (see FIG. 10). For this reason, when performing a joining process, it becomes easy to hold | grip the junction part 20b from the circumferential direction both ends.
On the other hand, in the comparative example, since the joint portion 20bh rotates, it is difficult to turn the plane of the joint portion 20bh in the circumferential direction, and it is difficult to grip the joint portion 20bh from both ends in the circumferential direction.

[Example 2]
The rotating electrical machine 1 of the present embodiment will be described with reference to FIG. 11 with a focus on differences from the first embodiment. In addition, the same code | symbol as Example 1 shows the same structure, Comprising: The previous description is referred.
In the present embodiment, in the cross section perpendicular to the axial direction of the stator 2, the parallel side surface 15 in the slot 11 is inclined with respect to the center line X passing through the circumferential center of the slot 11.
For example, as shown in FIG. 11, the slot conductor portions 25 of the nth slot 11n are designated as slot conductor portions 25n1, 25n2, 25n3, and 25n4 in order from the inner diameter side. The slot conductor portions 25 of the m (m = n + 1) -th slot 25m are referred to as slot conductor portions 25m1, 25m2, 25m3, and 25m4 in order from the inner diameter side.
In each slot conductor portion 25, the angle formed by the parallel side surface 15 and the center line X extending in the radial direction through the circumferential center of each slot 11 is θn1, θn2, θn3, θn4, θm1, θm2, θm3, θm4. And
Θn1 to θn4 and θm1 to θm4 are all equal angles.

That is, in the present embodiment, in the cross section perpendicular to the axial direction of the stator 2, the parallel side surface 15 is inclined with respect to the center line X, and the angle between the parallel side surface 15 and the center line X is the radial direction in different slots 11. The positions are equal between the same slot conductor portions 25, and are equal between the slot conductor portions 25 at different radial positions in the same slot 11.
According to this, it becomes easy to align the direction in which the parallel side surface 15 faces in the coil end part 26.
Note that θn1 to θn4 may all be the same angle θx, and θm1 to θm4 may be an angle θy different from the angle θx. That is, the inclination angles may be merely equal between the slot conductor portions 25 at different radial positions in the same slot 11.

  Further, only θn1 = θm1, θn2 = θm2, θn3 = θm3, and θn4 = θm4 may be established. That is, it is only necessary that the inclination angles are equal between the slot conductor portions 25 having the same radial position in different slots 11.

Example 3
The rotating electrical machine 1 according to the present embodiment will be described with reference to FIGS. 12 and 13 with a focus on differences from the first embodiment. In addition, the same code | symbol as Example 1 shows the same structure, Comprising: The previous description is referred.
According to the present embodiment, in the deformed conductive wire, the second parallel side surface 37 perpendicular to the parallel side surface 15 is formed on the two arcuate surfaces 17 facing each other.
That is, the deformed conductive wire is rolled by a pair of rollers R2 facing in a direction perpendicular to the direction in which the pair of rollers R1 face after the first forming described in the first embodiment is performed on the round wire. It is formed by applying (second molding) (see FIG. 13).
According to this, it is possible to make it more approximate to a rectangular wire by processing the round wire, and the cooling effect can be enhanced. In addition, since the distance between the joint portions 20b can be reduced, the joint strength can be increased.

[Modification]
The present invention is not limited to the embodiments, and various modifications can be considered.
For example, in the embodiment, both the coil end portion 26 and the slot conductor portion 25 are configured by the deformed conductive wires. However, the parallel side surface 15 may be formed only on the conductive wires constituting the coil end portion 26. Moreover, the aspect which forms the parallel side surface 15 in a part of conducting wire which comprises the coil end part 26 may be sufficient.
In the embodiment, the coil end portion 26 is cooled by the cooling air generated by the fan 4, but may be oil-cooled.

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Stator 3 Rotor 4 Fan 7 Stator core 8 Stator coil 11 Slot 15 Parallel side surface 25 Slot conductor part 26 Coil end part

Claims (10)

A stator core (7) having a plurality of slots (11) in the circumferential direction, and a plurality of slot conductor portions (25) accommodated in the slots (11) and the slot conductor portions (25) are connected and the stator core A stator (2) comprising a stator coil (8) having a plurality of coil end portions (26) projecting at an axial end of (7);
A rotating electrical machine (1) comprising a rotor (3) having a circumferential surface facing the circumferential surface of the stator core (7),
At least a part of the conductor constituting the coil end portion (26) is formed by flattening a round wire, and is surrounded by two parallel side surfaces (15) facing each other and two arc surfaces (17) facing each other. A rotating electrical machine using a deformed lead wire having a cross-sectional shape. In the rotating electrical machine according to claim 1,
The deformation conducting wire is used as a conductor constituting the slot conductor portion (25),
The rotating electrical machine is characterized in that the deformed conductive wire is disposed so that the parallel side surface (15) is sandwiched from both sides by a circumferential wall (11a) of the slot (11). The rotating electrical machine according to claim 2,
The plurality of slot conductor portions (25) are aligned in the radial direction in each of the slots (11),
In a cross section perpendicular to the axial direction of the stator (2), the parallel side surface (15) is inclined with respect to a center line extending radially through the circumferential center of each slot (11),
An angle between the parallel side surface (15) and the center line is equal between the slot conductor portions (25) having the same radial position in the different slots (11). The rotating electrical machine according to any one of claims 2 and 3,
The plurality of slot conductor portions (25) are arranged in the radial direction of the slot (11),
In a cross section perpendicular to the axial direction of the stator (2), the parallel side surface (15) is inclined with respect to a center line extending radially through the circumferential center of the slot (11),
The rotating electrical machine characterized in that an angle formed between the parallel side surface (15) and the center line is the same between the slot conductor portions (25) at different radial positions in the same slot (11). In the rotating electrical machine according to any one of claims 1 to 4,
In the cross-sectional shape of the deformed conductive wire, a length in a direction perpendicular to a direction in which the two parallel side surfaces (15) face each other is longer than a length in a direction in which the two parallel side surfaces (15) face each other. Rotating electric machine. In the rotating electrical machine according to any one of claims 1 to 5,
The rotating electrical machine characterized in that, in the cross-sectional shape, the deformed conducting wire has a maximum distance between the two parallel side surfaces (15) larger than a circumferential length of the slot (11). In the rotating electrical machine according to any one of claims 1 to 6,
The rotating electrical machine, wherein the deformed conductive wire has a cross-sectional shape in which a second parallel side surface (37) perpendicular to the parallel side surface (15) is formed on the two arcuate surfaces (17). In the rotating electrical machine according to any one of claims 1 to 7,
A fan (4) fixed to an axial end of the rotor (3);
A rotating electric machine characterized in that a passage for passing cooling air from the fan (4) is formed between the plurality of coil end portions (26). In the rotating electrical machine according to any one of claims 1 to 8,
The stator coil (8) is composed of a plurality of segments (14) having two leg parts (20) and a U-shaped part (21) connecting the leg parts (20) in a U-shape, It is constituted by putting the legs (20) of the segments (14) into different slots (11) and joining the legs (20) of the adjacent segments (14) together,
The rotating electrical machine characterized in that the segment (14) is formed by the deformed conductive wire. The method of manufacturing a segment (14) according to claim 9,
A first ring (31) having a holding slot (35) for holding one of the two legs (20), and the other leg provided concentrically with the first ring (31) The two legs (20) on the molding jig (33) using a molding jig (33) having a second ring (32) having a holding slot (35) for holding (20). A twisting step of twisting the segment (14) by shifting the circumferential position of the first ring (31) and the second ring (32) from the same circumferential position.
The leg (20) is held by the holding slot (35) so that the wall surface (35a) partitioning the circumferential direction of the holding slot (35) and the parallel side surface (15) face each other. The manufacturing method of the segment (14).

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