JP7769679B2 - Continuous wire coil and stator - Google Patents

Description

The present invention relates to continuous wire coils and stators.

The stator of a rotating electrical machine such as an electric motor or generator consists of a stator core and coils that are fitted into the slots of the stator core. Commonly known coil types are segment coils and continuous wire coils. Segment coils are fitted to the stator core by inserting U-shaped segment conductors into two slots and then welding both ends. Continuous wire coils are fitted to the stator core without welding by forming a sheet-like coil with multiple linear slot fitting portions using multiple conductors and fitting each slot fitting portion into its respective slot.

Continuous wire coils are manufactured into long sheets by repeatedly bending the straight sections of multiple parallel conductors at an angle, and then folding back the bent sections at the center to form mountain-shaped coil ends (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2021-58076

Continuous wire coils come in two patterns: one in which a single sheet-shaped coil is formed in one layer (one turn) corresponding to one circumference of the stator (sometimes called flat winding), and one in which a single sheet-shaped coil is formed in two layers (two turns) corresponding to two circumferences of the stator (sometimes called sword winding).

Since flat-wound continuous wire coils form one turn per sheet, they can be used with the desired number of turns and stacked in the slots of the stator core to accommodate both odd and even numbers of turns. However, the coil end portion of a continuous wire coil, which is formed by folding back the conductor, has a thickness equivalent to two turns, so the thickness of the coil end portion is twice the number of turns. Therefore, when flat-wound continuous wire coils are used, the coil end portion cannot be made smaller, making it difficult to create a compact stator.

On the other hand, with a sword-winding continuous wire coil, the coil end has a thickness roughly equal to the number of turns, making it possible to make the coil end smaller. However, because a sword-winding continuous wire coil has a two-layer structure, the number of turns that can be accommodated is limited to an even number.

The objective of the present invention is to provide a continuous wire coil that can easily accommodate both odd and even numbers of turns and that allows for the miniaturization of the coil end portion, as well as a stator that uses this continuous wire coil.

(1) The continuous wire coil of the present invention has a plurality of slot fitting portions (e.g., slot fitting portion 21 described below) that fit into a plurality of slots (e.g., slot 34 described below) of a stator core (e.g., stator core 31 described below), and a plurality of coil end portions (e.g., coil end portion 22 described below) that are respectively arranged at both ends of the plurality of slot fitting portions in the extension direction and connect adjacent slot fitting portions, and the coil end portions are formed by folding back a conductor (e.g., conductor 2 described below) in the thickness direction, and the continuous wire coil is provided with: a two-layer coil portion (e.g., two-layer coil portion 11 described below) having a number of the plurality of slot fitting portions that corresponds to a circuit length of at least one circumference of the stator core; and a single-layer coil portion (e.g., single-layer coil portion 12 described below) that is provided contiguous to the two-layer coil portion and has a number of the plurality of slot fitting portions that corresponds to a circuit length of one circumference of the stator core.

(2) In the continuous wire coil described in (1) above, the two-layer coil portion is composed of a first layer (e.g., first layer 111 described below) and a second layer (e.g., second layer 112 described below) folded back at a folding portion (e.g., folding portion F described below).

(3) In the continuous wire coil described in (2) above, the coil end portion of the first layer (e.g., coil end portion 22A described below) and the coil end portion of the second layer (e.g., coil end portion 22B described below) are arranged alternately in the longitudinal direction of the two-layer coil portion.

(4) In the continuous wire coil described in (2) or (3) above, the one-layer coil portion is continuous with either the first layer or the second layer (e.g., the second layer 112 described below).

(5) A stator according to the present invention includes a stator core (e.g., stator core 31 described below) having a plurality of slots (e.g., slot 34 described below), and a sheet-shaped continuous wire coil (e.g., continuous wire coil 1 described below) mounted in the plurality of slots. The continuous wire coil includes a plurality of slot fitting portions (e.g., slot fitting portion 21 described below) that fit into the plurality of slots, and a plurality of coil end portions (e.g., coil end portion 2 described below) that are disposed at both ends of the plurality of slot fitting portions in the extension direction and connect adjacent slot fitting portions. 2), and in a stator (e.g., Stator 3 described below) in which the coil end portion is formed by folding back a conductor (e.g., Conductor 2 described below) in the thickness direction, the continuous wire coil comprises a two-layer coil portion (e.g., two-layer coil portion 11 described below) having a number of the slot fitting portions that corresponds to a circumference length of at least one circumference of the stator core, and a single-layer coil portion (e.g., single-layer coil portion 12 described below) that is continuous with the two-layer coil portion and has a number of the slot fitting portions that corresponds to a circumference length of one circumference of the stator core.

(6) In the stator described in (5) above, the two-layer coil portion is composed of a first layer (e.g., first layer 111 described below) and a second layer (e.g., second layer 112 described below) folded back at a folding portion (e.g., folding portion F described below).

(7) In the stator described in (6) above, the coil end portions of the first layer (e.g., coil end portion 22A described below) and the coil end portions of the second layer (e.g., coil end portion 22B described below) are arranged alternately in the longitudinal direction of the two-layer coil portion.

(8) In the stator described in (6) or (7) above, the single-layer coil portion is continuous with either the first layer or the second layer (e.g., the second layer 112 described below).

The continuous wire coil described in (1) above can be easily adapted to both odd and even numbers of turns by appropriately setting the length of the two-layer coil portion, and the coil end portion can be made smaller.

The continuous wire coil described in (2) above makes it easy to form a two-layer coil section.

The continuous wire coil described in (3) above allows the thickness of the two-layer coil portion to be minimized.

The continuous wire coil described in (4) above allows the two-layer coil section and the single-layer coil section to be easily attached to the stator core.

The stator described in (5) above allows for the appropriate length of the two-layer coil portion of the continuous wire coil to be appropriately set, making it possible to easily form stators with either an odd or even number of turns, and to construct a compact stator with smaller coil end portions.

The stator described in (6) above makes it easy to form a two-layer coil portion of a continuous wire coil.

The stator described in (7) above allows the thickness of the two-layer coil portion of the continuous wire coil to be minimized.

The stator described in (8) above allows a continuous wire coil having a two-layer coil portion and a single-layer coil portion to be easily attached to the stator core.

FIG. 2 is a front view of a continuous wire coil according to one embodiment. FIG. 2 is a plan view schematically illustrating a continuous wire coil according to an embodiment. FIG. 2 is a plan view showing a stator equipped with a continuous wire coil according to an embodiment. FIG. 2 is a plan view of a coil end portion of part A in FIG. 1 . 2 is a schematic plan view of a coil end portion of a portion B in FIG. 1 ; FIG. FIG. 1 is a diagram showing a schematic diagram of a seven-turn continuous wire coil.

Embodiments of the present invention will be described in detail below with reference to the drawings. As shown in Figures 1 and 2, the continuous wire coil 1 is formed into a long sheet extending along the X direction. As shown in Figure 3, the sheet-shaped continuous wire coil 1 is fitted into slots 34 of a stator core 31 to form the stator 3.

The stator core 31 has multiple teeth 33 that protrude toward the central axial hole 32. Radially arranged slots 34 that open toward the axial hole 32 are formed between adjacent teeth 33. In Figure 3, the continuous wire coil 1 is schematically indicated by arrows consisting of solid and dashed lines.

The directions of the continuous wire coil 1 shown in the figure are defined as follows: The X direction indicates the length direction of the continuous wire coil 1. The X direction corresponds to the circumferential direction D1 of the stator core 31 shown in Figure 3. The Y direction indicates the width direction of the continuous wire coil 1. The Y direction corresponds to the axial direction of the stator core 31. The axial direction of the stator core 31 is perpendicular to the plane of the paper in Figure 3. The Z direction indicates the thickness direction of the continuous wire coil 1. The Z direction corresponds to the radial direction D2 of the stator core 31 shown in Figure 3.

The continuous wire coil 1 will now be described in more detail. The continuous wire coil 1 is composed of multiple conductors 2, each of which has been bent and formed. The conductors 2 are, for example, metal wires such as copper wires. In this embodiment, the continuous wire coil 1 is composed of six conductors 2. The conductors 2 are formed by bending them so that they each have multiple slot fitting portions 21 and multiple coil end portions 22. The slot fitting portions 21 are portions that fit into the slots 34 of the stator core 31 and are formed linearly. The coil end portions 22 are portions that are exposed axially outward from the slots 34 of the stator core 31 and are formed into a mountain shape by folding the conductors 2 back in the thickness direction of the continuous wire coil 1.

In a single conductor 2 in which the slot fitting portions 21 and coil end portions 22 are bent and formed, the multiple slot fitting portions 21 are arranged in parallel, at intervals corresponding to the spacing between every six slots in the stator core 31. The coil end portions 22 alternately connect the ends of two slot fitting portions 21 arranged every six slots in the stator core 31, one to the other, in the extension direction, along the length of the continuous wire coil 1.

After bending, the six conductors 2 are stacked and staggered along the length of the continuous wire coil 1 so that the slot fitting portions 21 are spaced at a pitch approximately equal to the arrangement pitch of the slots 34 in the stator core 31. As a result, all of the slot fitting portions 21 of the continuous wire coil 1 are arranged in parallel along the length of the continuous wire coil 1 at a pitch approximately equal to the arrangement pitch of the slots 34 in the stator core 31.

As shown in Figures 1 and 2, the continuous wire coil 1 is composed of a two-layer coil section 11 and a single-layer coil section 12. The two-layer coil section 11 and the single-layer coil section 12 are continuous in the longitudinal direction of the continuous wire coil 1. In other words, the six conductors 2 are continuous and uninterrupted across the two-layer coil section 11 and the single-layer coil section 12.

As shown in Figure 3, the two-layer coil section 11 has a two-layer structure consisting of a first layer 111 and a second layer 112. The first layer 111 and the second layer 112 are stacked in the thickness direction of the continuous wire coil 1. The six conductors 2 in the two-layer coil section 11 are folded back in the length direction of the continuous wire coil 1 at the fold back portion F while maintaining the arrangement pitch of the slot fitting portions 21, thereby forming the first layer 111 and the second layer 112.

In more detail, the six conductors 2 in the two-layer coil section 11 alternately form slot fitting portions 21 and coil end portions 22 along the X1 direction from one end E1 of the continuous wire coil 1 to form the first layer 111, and then are inverted at the turn-back portion F. The six inverted conductors 2 alternately form slot fitting portions 21 and coil end portions 22 along the X2 direction to form the second layer 112. The multiple slot fitting portions 21 in each of the first layer 111 and the second layer 112 are stacked in the thickness direction of the continuous wire coil 1 while maintaining the same arrangement pitch. The slot fitting portions 21, 21 of the stacked two-layer coil section 11 are stacked and installed in the same slot 34 of the stator core 31.

The length L1 of the two-layer coil section 11 shown in FIG. 1 is a circumference length of at least one circumference of the stator core 31. Therefore, the two-layer coil section 11 has a number of slot engagement portions 21 that corresponds to a circumference length of at least one circumference of the stator core 31. Specifically, the stator core 31 of this embodiment shown in FIG. 3 has 72 slots 34. Therefore, the two-layer coil section 11 of this embodiment has 72 or more slot engagement portions 21 when viewed along the length direction of the continuous wire coil 1. Because the two-layer coil section 11 has a laminated structure in which the first layer 111 and the second layer 112 are laminated, the 72 or more slot engagement portions 21 are laminated in pairs along the thickness direction of the continuous wire coil 1.

As shown in Figures 1 and 2, the first-layer coil section 12 has a single-layer structure consisting of six conductors 2. Each first-layer coil section 12 has multiple slot engagement sections 21 arranged at a pitch approximately equal to the arrangement pitch of the slots 34 in the stator core 31.

The length L2 of the first-layer coil portion 12 shown in FIG. 1 is the circumference of one periphery of the stator core 31. Therefore, the first-layer coil portion 12 has a number of slot engagement portions 21 that corresponds to the circumference of one periphery of the stator core 31. Specifically, the first-layer coil portion 12 of this embodiment has 72 slot engagement portions 21.

Figure 4 is a plan view of the first-layer coil portion 12 of the continuous wire coil 1 in Figure 1, viewed in the direction of the arrow at part A. When observing one set of six coil end portions 22 in the first-layer coil portion 12, the conductors 2 are each folded back at their vertices 22a in the thickness direction of the continuous wire coil 1, so that each coil end portion 22 has a thickness T2 that is twice the thickness T1 of one layer of conductor 2. The six conductors 2 are stacked with a pitch that is approximately equal to the arrangement pitch of the slots 34 in the stator core 31, so the vertices 22a of the six coil end portions 22 do not overlap in the thickness direction of the continuous wire coil 1.

In contrast, Figure 5 shows a schematic plan view of the two-layer coil portion 11 of the continuous wire coil 1 in Figure 1, viewed in the direction of the arrow at part B. The hatched areas in Figure 5 indicate sets of six coil end portions 22A in the first layer 111, and the white areas indicate sets of six coil end portions 22B in the second layer 112. The coil end portions 22A and 22B in each set have the same structure as in Figure 4.

In the two-layer coil section 11, the pair of coil end sections 22A of the first layer 111 and the pair of coil end sections 22B of the second layer 112 are arranged alternately in the longitudinal direction of the continuous wire coil 1 without overlapping in the thickness direction of the continuous wire coil 1, as shown in FIG. 5 . The first layer 111 and the second layer 112 are not simply stacked on top of each other, but are stacked by interweaving the six conductors 2 that make up each of the first layer 111 and the second layer 112. Therefore, while the two-layer coil section 11 has a two-layer structure consisting of the first layer 111 and the second layer 112, the thickness of the coil end sections 22 (22A, 22B) is twice the thickness T1 of the conductors 2 for one layer, T2, just like the coil end sections 22 of the single-layer coil section 12.

As shown in FIG. 3, the continuous wire coil 1 is mounted around the stator core 31 by sequentially fitting each slot fitting portion 21 into the slot 34 of the stator core 31. In FIG. 3, solid lines indicate the two-layer coil portion 11, and dashed lines indicate the single-layer coil portion 12. In this continuous wire coil 1, the two-layer coil portion 11 has a circumference length equivalent to one turn around the stator core 31. Because the two-layer coil portion 11 has a two-layer structure, it forms two turns around the stator core 31. Because the single-layer coil portion 12 has a single-layer structure, it forms one turn around the stator core 31. Therefore, the continuous wire coil 1 shown in FIG. 3 forms an odd-numbered coil within the stator core 31: (two turns for the two-layer coil portion 11) + (one turn for the single-layer coil portion) = three turns.

Compared to a conventional flat-winding continuous wire coil, the thickness of the coil end portion of a one-turn continuous wire coil is twice the thickness of the conductor because the conductor is folded back in the thickness direction. Therefore, in the case of a conventional flat-winding three-turn continuous wire coil, the total is 3 turns x 2 = 6, and the coil end portion has a thickness equivalent to six conductors.

In contrast, in the case of the continuous wire coil 1 of this embodiment, the coil end portions 22 of the one-turn two-layer coil portion 11 and the one-layer coil portion 12 each have a thickness T2 that is twice that of the conductor 2, as shown in Figures 4 and 5. Therefore, the thickness of the coil end portions 22 of the three-turn continuous wire coil 1 attached to the stator core 31 is (two-layer coil portion 11: T2 x 1) + (one-layer coil portion: T2 x 1) = T2 x 2, which is reduced to the thickness of four conductors 2. This results in a compact stator 3 with smaller coil end portions 22.

The number of turns in the continuous wire coil 1 can be further increased by appropriately setting the length of the two-layer coil section 11. Figure 6 shows a schematic diagram of a continuous wire coil 1 having a two-layer coil section 11 set to a length equivalent to three turns around the stator core 31. In this case, the continuous wire coil 1 comprises seven turns, but the thickness of the coil end section 22 of the continuous wire coil 1 is (two-layer coil section 11: T2 x 3) + (single-layer coil section: T2 x 1) = T2 x 4, which is kept to the thickness of eight conductors 2.

Furthermore, for example, by setting the two-layer coil section 11 to a length equivalent to 2.5 turns around the stator core 31, a coil with an even number of turns (6) can be formed around the stator core 31. Therefore, the continuous wire coil 1 can accommodate both odd and even numbers of turns. As shown in the table below, the continuous wire coil 1 according to the present invention can reduce the thickness of the coil end portion 22 compared to the flat-winding continuous wire coil according to the prior art, regardless of whether the number of turns in the stator core 31 is increased to an odd or even number. Note that in the table below, the thickness of the coil end portion is indicated by the number of conductors.

In the stator 3 shown in Figure 3, the first-layer coil portion 12 of the continuous wire coil 1 is arranged in the innermost layer of the stator core 31, but this is not limited to this. The first-layer coil portion 12 of the continuous wire coil 1 may also be arranged in the outermost layer of the stator core 31.

REFERENCE SIGNS LIST 1 Continuous wire coil 11 Two-layer coil portion 111 First layer 112 Second layer 12 One-layer coil portion 2 Conductor 21 Slot fitting portion 22, 22A, 22B Coil end portion 3 Stator 31 Stator core 34 Slot F Turn-back portion

Claims (8)

A sheet-shaped continuous wire coil having a plurality of slot fitting portions that fit into a plurality of slots of a stator core, and a plurality of coil end portions that are respectively disposed at both ends in an extension direction of the plurality of slot fitting portions and connect adjacent slot fitting portions, wherein the coil end portions are formed by folding back a conductor in a thickness direction,
a two-layer coil portion having a two-layer structure, the two-layer coil portion including the plurality of slot fitting portions, the number of which corresponds to a circumference length of at least one circumference of the stator core;
a single-layer coil portion having a single-layer structure, the single-layer coil portion being provided continuously with the two-layer coil portion in the longitudinal direction of the continuous wire coil, the multiple slot fitting portions being the number of which corresponds to one circumference of the stator core. The continuous wire coil according to claim 1, characterized in that the two-layer coil portion is composed of a first layer and a second layer folded back at a folding portion. The continuous wire coil according to claim 2, wherein the coil end portions of the first layer and the coil end portions of the second layer are arranged alternately offset in the longitudinal direction of the two-layer coil portion. A continuous wire coil as described in claim 2 or 3, characterized in that the one-layer coil portion is continuous with either the first layer or the second layer. a stator core having a plurality of slots; and a sheet-shaped continuous wire coil fitted in the plurality of slots,
The continuous wire coil has a plurality of slot fitting portions that fit into the plurality of slots, and a plurality of coil end portions that are respectively disposed at both ends in an extension direction of the plurality of slot fitting portions and connect adjacent slot fitting portions, and the coil end portions are formed by folding back a conductor in a thickness direction. In this stator,
The continuous wire coil is
a two-layer coil portion having a two-layer structure, the two-layer coil portion including the plurality of slot fitting portions, the number of which corresponds to a circumference length of at least one circumference of the stator core;
a single-layer coil portion having a single-layer structure, the single-layer coil portion being provided continuously with the two-layer coil portion in the longitudinal direction of the continuous wire coil, the multiple slot fitting portions being the number of which corresponds to one circumference of the stator core. A stator as described in claim 5, characterized in that the two-layer coil portion is composed of a first layer and a second layer folded back at a folding portion. A stator as described in claim 6, wherein the coil end portions of the first layer and the coil end portions of the second layer are arranged alternately offset in the longitudinal direction of the two-layer coil portion. A stator as described in claim 6 or 7, characterized in that the first layer coil portion is continuous with either the first layer or the second layer.