Coil body

One U-phase coil portion and the next U-phase coil portion in a circumferential direction, one V-phase coil portion and the next V-phase coil portion in the circumferential direction, and one W-phase coil portion and the next W-phase coil portion in the circumferential direction are electrically connected by conductive junctions, respectively.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Japanese Patent Application No. 2018-234093 filed Dec. 14, 2018, the disclosure of which is hereby incorporated in its entirety by reference.

Field of the Invention

The present invention relates to a coil body used in a coreless rotating electrical machine.

Background of the Invention

In the technical field of rotating electrical machines, coreless rotating electrical machines have been known. In the related art, various proposals have been made as a coil body used in a coreless rotating electrical machine.

For example, JP 3704044 B2 has proposed a coil body formed in a manner that two thin metal plates each having a conductive band pattern formed by etching a conductive plate (for example, a copper plate) are used as cylindrical bodies, and the two cylindrical bodies are concentrically disposed as an inner cylindrical body and an outer cylindrical body. The cylindrical bodies have conductive bands of complementary patterns that constitute an electric circuit by the end portions being connected to each other. A layer of non-conductive fiber stranded wire is formed between the cylindrical bodies, and the conductive band of the inner cylindrical body and the conductive band of the outer cylindrical body are insulated by this layer. The coil body is encapsulated with a material that fills the conductive band portion and the non-conductive fiber stranded wire, specifically, polyimide.

JP 2017-70140 A has proposed a coil body formed by bending a conductive sheet having a plurality of conductive bands and forming the bent conductive sheet into a cylindrical shape.

SUMMARY

An object of the invention is to propose a coil body which is space-saving and miniaturized and causes a large current to pass, the coil body being for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having a U-phase coil portion constituting a U-phase, a V-phase coil portion constituting a V-phase, and a W-phase coil portion constituting a W-phase are sequentially arranged in a circumferential direction to form an annular cylindrical body in plan view.

A cylindrical coil body for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having a U-phase coil portion constituting a U-phase, a V-phase coil portion constituting a V-phase, and a W-phase coil portion constituting a W-phase are sequentially arranged in a circumferential direction to form an annular cylindrical body in plan view,

wherein one of the U-phase coil portions and the next U-phase coil portion in the circumferential direction, one of the V-phase coil portions and the next V-phase coil portion in the circumferential direction, and one of the W-phase coil portions and the next W-phase coil portion in the circumferential direction are electrically connected by conductive junctions, respectively.

The cylindrical coil body according to [1],

wherein the junction is disposed on a circumferential surface of the cylindrical coil body, and extends in the circumferential direction to form an arc shape in plan view,

in the junction, a small-diameter arc portion having a small radius of curvature and a large-diameter arc portion having a large radius of curvature are continuous to each other via a step portion which is formed in an intermediate portion in the circumferential direction and has a stair shape in plan view,

in the junction, a radially inner surface and a radially outer surface have electrical insulation, and

in the junction, concave portions where electrical connection is performed by a terminal portion of the U-phase coil portion, a terminal portion of the V-phase coil portion, or a terminal portion of the W-phase coil portion being bent to be inserted to the concave portion are provided on an upper side of both ends extending in the arc shape when being disposed on the circumferential surface of the cylindrical coil body.

According to the invention, it is possible to provide a coil body which is space-saving and miniaturized and causes a large current to pass, the coil body being for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having a U-phase coil portion constituting a U-phase, a V-phase coil portion constituting a V-phase, and a W-phase coil portion constituting a W-phase are sequentially arranged in a circumferential direction to form an annular cylindrical body in plan view.

DETAILED DESCRIPTION

A coil body of this embodiment is a coil body for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having a U-phase coil portion constituting the U-phase, a V-phase coil portion constituting the V-phase, and a W-phase coil portion constituting the W-phase are sequentially arranged in a circumferential direction so as to form an annular cylindrical body in plan view.

The U-phase coil portion constituting the U-phase includes a U-phase outer coil portion and a U-phase inner coil portion. The U-phase outer coil portion extends in a form including a portion extending from a U-phase outer terminal portion on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in an axial direction of the cylindrical shape. The U-phase inner coil portion is positioned inward of the U-phase outer coil portion in the radial direction in the cylindrical shape, extends in a form including a portion of which the lower end side is electrically connected to the lower end side of the U-phase outer coil portion and which extends toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a U-phase inner terminal portion positioned inward of the U-phase outer terminal portion in the radial direction on the upper end side of the cylindrical body. The U-phase coil portion is a coil body having a structure in which the U-phase outer coil portion and the U-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase.

The V-phase coil portion constituting the V-phase includes a V-phase outer coil portion and a V-phase inner coil portion. The V-phase outer coil portion extends in a form including a portion extending from a V-phase outer terminal portion on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in an axial direction of the cylindrical shape. The V-phase inner coil portion is positioned inward of the V-phase outer coil portion in the radial direction in the cylindrical shape, extends in a form including a portion of which the lower end side is electrically connected to the lower end side of the V-phase outer coil portion and which extends toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a V-phase inner terminal portion positioned inward of the V-phase outer terminal portion in the radial direction on the upper end side of the cylindrical body. The V-phase coil portion is a coil body having a structure in which the V-phase outer coil portion and the V-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase.

The W-phase coil portion constituting the W-phase includes a W-phase outer coil portion and a W-phase inner coil portion. The W-phase outer coil portion extends in a form including a portion extending from a W-phase outer terminal portion on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in an axial direction of the cylindrical shape. The W-phase inner coil portion is positioned inward of the W-phase outer coil portion in the radial direction in the cylindrical shape, has a lower end side electrically connected to the lower end side of the W-phase outer coil portion, extends in a form including a portion extending toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a W-phase inner terminal portion positioned inward of the W-phase outer terminal portion in the radial direction on the upper end side of the cylindrical body. The W-phase coil portion is a coil body having a structure in which the W-phase outer coil portion and the W-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase.

The U-phase inner terminal portion on the upper end side of one U-phase coil portion and the U-phase inner terminal portion on the upper end side of the next U-phase coil portion in the circumferential direction are electrically connected to each other by a conductive inner junction.

The V-phase inner terminal portion on the upper end side of one V-phase coil portion and the V-phase inner terminal portion on the upper end side of the next V-phase coil portion in the circumferential direction are electrically connected to each other by a conductive inner junction.

The W-phase inner terminal portion on the upper end side of one W-phase coil portion and the W-phase inner terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction are electrically connected to each other by a conductive inner junction.

The U-phase outer terminal portion on the upper end side of one U-phase coil portion and the U-phase outer terminal portion on the upper end side of the next U-phase coil portion in the circumferential direction are electrically connected to each other by a conductive outer junction.

The V-phase outer terminal portion on the upper end side of one V-phase coil portion and the V-phase outer terminal portion on the upper end side of the next V-phase coil portion in the circumferential direction are electrically connected to each other by a conductive outer junction.

The W-phase outer terminal portion on the upper end side of one W-phase coil portion and the W-phase outer terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction are electrically connected to each other by a conductive outer junction.

With the above configuration, the one U-phase coil portion and the next U-phase coil portion in the circumferential direction, the one V-phase coil portion and the next V-phase coil portion in the circumferential direction, and the one W-phase coil portion and the next W-phase coil portion in the circumferential direction are electrically connected by conductive junctions, respectively.

In the above, the inner junction is arranged on the inner circumferential side of the cylindrical coil body and extends in the circumferential direction to form an arc shape in plan view. In the inner junction, a small-diameter arc portion having a small radius of curvature and a large-diameter arc portion having a large radius of curvature are continuous to each other via a step portion which is formed in an intermediate portion in the circumferential direction and has a stair shape in plan view. The radially inner surface and the radially outer surface have electrical insulation. Concave portions are provided on the upper side of both ends extending in the arc shape when being disposed on the inner circumferential side of the cylindrical coil body. In the concave portion, electrical connection is performed by the U-phase inner terminal portion on the upper end side, the V-phase inner terminal portion on the upper end side, or the W-phase inner terminal portion on the upper end side being bent to be inserted thereto.

Moreover, in the above, the outer junction is arranged on the outer circumferential side of the cylindrical coil body and extends in the circumferential direction to form an arc shape in plan view. In the outer junction, a small-diameter arc portion having a small radius of curvature and a large-diameter arc portion having a large radius of curvature are continuous to each other via a step portion which is formed in an intermediate portion in the circumferential direction and has a stair shape in plan view. The radially inner surface and the radially outer surface have electrical insulation. Concave portions are provided on the upper side of both ends extending in the arc shape when being disposed on the outer circumferential side of the cylindrical coil body. In the concave portion, electrical connection is performed by the U-phase outer terminal portion on the upper end side, the V-phase outer terminal portion on the upper end side, or the W-phase outer terminal portion on the upper end side being bent to be inserted thereto.

EXAMPLE

A coil body1of this example is a coil body for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having a U-phase coil portion constituting the U-phase, a V-phase coil portion constituting the V-phase, and a W-phase coil portion constituting the W-phase are sequentially arranged in a circumferential direction so as to form an annular cylindrical body in plan view.

An example of the structure of a U-phase coil portion U1, a V-phase coil portion V1, and a W-phase coil portion W1of the coil body1used in such a three-phase rotating electrical machine will be described with reference toFIG. 9.

The U-phase coil portion U1(FIG. 9) is a coil body having a structure in which the U-phase outer coil portion and the U-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase. InFIG. 9, the front side of the drawing is the U-phase outer coil portion, and the rear side of the drawing is the U-phase inner coil portion.

The U-phase coil portion U1is formed such that the U-phase outer coil portion of the cylindrical shape and the U-phase inner coil portion of the cylindrical shape, which are electrically connected to each other at a lower end side U105, are insulated from each other in the radial direction.

Specifically, the U-phase outer coil portion of the U-phase coil portion U1extends in a form including a portion U103extending from a U-phase outer terminal portion U101on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in the axial direction of the cylindrical shape. The U-phase inner coil portion of the U-phase coil portion U1is positioned inward of the U-phase outer coil portion in the radial direction, has a lower end side electrically connected to the lower end side of the U-phase outer coil portion, extends in a form including a portion U104extending toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a U-phase inner terminal portion U102positioned inward of the U-phase outer terminal portion U101in the radial direction on the upper end side of the cylindrical body.

In the U-phase coil portion U1, the U-phase inner terminal portion U102is electrically connected to a U-phase inner terminal portion U202of the next U-phase coil portion U2in the circumferential direction ofFIG. 1. Further, the U-phase outer terminal portion U101is electrically connected to a U-phase outer terminal portion U201of the next U-phase coil portion U2in the circumferential direction ofFIG. 1.

In this example, it is the coil body1used in the three-phase rotating electrical machine. The U-phase coil portion U1has 5 windings per phase.

The V-phase coil portion V1(FIG. 9) is a coil body having a structure in which the V-phase outer coil portion and the V-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase. InFIG. 9, the front side of the drawing is the V-phase outer coil portion, and the rear side of the drawing is the V-phase inner coil portion.

The V-phase coil portion V1is formed such that the V-phase outer coil portion of the cylindrical shape and the V-phase inner coil portion of the cylindrical shape, which are electrically connected to each other at a lower end side V105, are insulated from each other in the radial direction.

Specifically, the V-phase outer coil portion of the V-phase coil portion V1extends in a form including a portion V103extending from a V-phase outer terminal portion V101on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in the axial direction of the cylindrical shape. The V-phase inner coil portion of the V-phase coil portion V1is positioned inward of the V-phase outer coil portion in the radial direction, has a lower end side electrically connected to the lower end side of the V-phase outer coil portion, extends in a form including a portion extending toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a V-phase inner terminal portion V102positioned inward of the V-phase outer terminal portion V101in the radial direction on the upper end side of the cylindrical body.

In the V-phase coil portion V1, the V-phase inner terminal portion V102is electrically connected to a V-phase inner terminal portion V202of the next V-phase coil portion V2in the circumferential direction ofFIG. 1. Further, the V-phase outer terminal portion V101is electrically connected to a V-phase outer terminal portion V201of the next V-phase coil portion V2in the circumferential direction ofFIG. 1.

In this example, it is the coil body1used in the three-phase rotating electrical machine. The V-phase coil portion V1has 5 windings per phase.

The W-phase coil portion W1(FIG. 9) is a coil body having a structure in which the W-phase outer coil portion and the W-phase inner coil portion in the radial direction of the cylindrical shape are insulated from each other and having a plurality of windings per phase. InFIG. 9, the front side of the drawing is the W-phase outer coil portion, and the rear side of the drawing is the W-phase inner coil portion.

The W-phase coil portion W1is formed such that the W-phase outer coil portion of the cylindrical shape and the W-phase inner coil portion of the cylindrical shape, which are electrically connected to each other at a lower end side W105, are insulated from each other in the radial direction.

Specifically, the W-phase outer coil portion of the W-phase coil portion W1extends in a form including a portion W103extending from a W-phase outer terminal portion W101on the upper end side of the cylindrical shape toward a lower end of the cylindrical shape in the axial direction of the cylindrical shape. The W-phase inner coil portion of the W-phase coil portion W1is positioned inward of the W-phase outer coil portion in the radial direction, has a lower end side electrically connected to the lower end side of the W-phase outer coil portion, extends in a form including a portion extending toward the upper end of the cylindrical shape in the axial direction of the cylindrical shape, and terminates at a W-phase inner terminal portion W102positioned inward of the W-phase outer terminal portion W101in the radial direction on the upper end side of the cylindrical body.

In the W-phase coil portion W1, the W-phase inner terminal portion W102is electrically connected to a W-phase inner terminal portion W202of the next W-phase coil portion W2in the circumferential direction ofFIG. 1. Further, the W-phase outer terminal portion W101is electrically connected to a W-phase outer terminal portion W201of the next W-phase coil portion W2in the circumferential direction ofFIG. 1.

In this example, it is the coil body1used in the three-phase rotating electrical machine. The W-phase coil portion W1has 5 windings per phase.

In the coil body of this example, the U-phase inner terminal portion U102on the upper end side of one U-phase coil portion U1and the U-phase inner terminal portion U202on the upper end side of the next U-phase coil portion U2in the circumferential direction are electrically connected to each other by a conductive inner junction501.

Similarly, the V-phase inner terminal portion V102on the upper end side of one V-phase coil portion V1and the V-phase inner terminal portion V202on the upper end side of the next V-phase coil portion V2in the circumferential direction are electrically connected to each other by a conductive inner junction601.

In addition, the W-phase inner terminal portion W102on the upper end side of one W-phase coil portion W1and the W-phase inner terminal portion W202on the upper end side of the next W-phase coil portion W2in the circumferential direction are electrically connected to each other by a conductive inner junction.

Further, the U-phase outer terminal portion U101on the upper end side of one U-phase coil portion U1and the U-phase outer terminal portion U201on the upper end side of the next U-phase coil portion U2in the circumferential direction are electrically connected to each other by a conductive outer junction500.

Similarly, the V-phase outer terminal portion V101on the upper end side of one V-phase coil portion V1and the V-phase outer terminal portion V201on the upper end side of the next V-phase coil portion V2in the circumferential direction are electrically connected to each other by a conductive outer junction600.

In addition, the W-phase outer terminal portion W101on the upper end side of one W-phase coil portion W1and the W-phase outer terminal portion W201on the upper end side of the next W-phase coil portion W2in the circumferential direction are electrically connected to each other by a conductive outer junction.

In this manner, the one U-phase coil portion and the next U-phase coil portion in the circumferential direction, the one V-phase coil portion and the next V-phase coil portion in the circumferential direction, and the one W-phase coil portion and the next W-phase coil portion in the circumferential direction are electrically connected by conductive junctions, respectively.

Inner junctions401,501, and601all have the same structure and are made of a conductive metal, for example, copper. Outer junctions400,500, and600all have the same structure, and are made of a conductive metal, for example, copper.

Referring toFIGS. 4A to 7, the outer junctions400,500, and600are arranged on the outer circumferential side of the cylindrical coil body1, and extend in the circumferential direction to form an arc shape in plan view as shown inFIGS. 4A to 4C and 5. Further, small-diameter arc portions402,502, and602having a small radius of curvature and large-diameter arc portions403,503, and603having a large radius of curvature are continuous via step portions410,510, and610which are formed in the intermediate portions in the circumferential direction and have a stair shape in plan view. Furthermore, concave portions406,407,506,507,606, and607are provided on the upper side of both ends extending in an arc shape when being disposed on the outer circumferential side of the cylindrical coil body1.

The U-phase outer terminal portions, the V-phase outer terminal portions, and the W-phase outer terminal portions which are sequentially arranged in the circumferential direction, are electrically connected to each other, respectively, by the U-phase outer terminal portions on the upper end side, the V-phase outer terminal portions on the upper end side, or the W-phase outer terminal portions on the upper end side of the cylindrical coil body1being bent to be inserted to the concave portions406,407,506,507,606, and607.

The radially inner surface and the radially outer surface of each of the outer junctions400,500, and600have electrical insulation. For example, an insulating coating film is formed on the radially inner surface and the radially outer surface of each of the copper outer junctions400,500, and600.

The inner junctions401,501, and601are arranged on the inner circumferential side of the cylindrical coil body1, and extend in the circumferential direction to form an arc shape in plan view as shown inFIGS. 4A to 4C and 6. Further, small-diameter arc portions404,504, and604having a small radius of curvature and large-diameter arc portions405,505, and605having a large radius of curvature are continuous via step portions410,510, and610which are formed in the intermediate portions in the circumferential direction and have a stair shape in plan view. Furthermore, concave portions408,409,508,509,608, and609are provided on the upper side of both ends extending in an arc shape when being disposed on the outer circumferential side of the cylindrical coil body1.

The U-phase inner terminal portions, the V-phase inner terminal portions, and the W-phase inner terminal portions which are sequentially arranged in the circumferential direction, are electrically connected to each other, respectively, by the U-phase inner terminal portions on the upper end side, the V-phase inner terminal portions on the upper end side, or the W-phase inner terminal portions on the upper end side of the cylindrical coil body1being bent to be inserted to the concave portions408,409,508,509,608, and609.

The radially inner surface and the radially outer surface of each of the inner junctions401,501, and601have electrical insulation. For example, an insulating coating film is formed on the radially inner surface and the radially outer surface of each of the copper inner junctions401,501, and601.

InFIG. 7, the outer junctions400,500, and600are arranged on the radially outer side, and the inner junctions401,501, and601are arranged on the radially inner side. Although not shown inFIG. 7, the coil body is sandwiched between the outer junctions and the inner junctions. That is, the U-phase inner terminal portion and the U-phase outer terminal portion on the upper end side of the U-phase coil portion consisting of the U-phase inner coil portion and the U-phase outer coil portion, the V-phase inner terminal portion and the V-phase outer terminal portion on the upper end side of the V-phase coil portion consisting of the V-phase inner coil portion and the V-phase outer coil portion, the W-phase inner terminal portion and the W-phase outer terminal portion on the upper end side of the W-phase coil portion consisting of the W-phase inner coil portion and the W-phase outer coil portion are sandwiched between the outer junctions and the inner junctions.

Therefore, when arranged in the circumferential direction of the cylindrical coil body1as shown inFIG. 1, the diameter of a circle formed by the large-diameter arc portions403,503,603, and the like of the outer junctions400,500,600, and the like is larger than the diameter of a circle formed by the large-diameter arc portions405,505,605, and the like of the inner junctions401,501,601, and the like.

Similarly, when arranged in the circumferential direction of the cylindrical coil body1as shown inFIG. 1, the diameter of a circle formed by the small-diameter arc portions402,502,602, and the like of the outer junctions400,500,600, and the like is larger than the diameter of a circle formed by the small-diameter arc portions404,504,604, and the like of the inner junctions401,501,601, and the like.

Since each of the outer junctions400,500, and600has the above-described structure, the outer junctions400,500, and600can be arranged on the outer circumference of the cylindrical coil body1so as to be shifted from each other in the circumferential direction of the coil body1as shown inFIG. 5. That is, the radially inner side of the large-diameter arc portion403of the outer junction400, which is at the leading position of the outer junction500in the circumferential direction, abuts on the radially outer side of the small-diameter arc portion502of the outer junction500. The radially outer side of the small-diameter arc portion602of the outer junction600, which is at the following position of the outer junction500in the circumferential direction, abuts on the radially inner side of the large-diameter arc portion503of the outer junction500.

Since each of the outer junctions400,500, and600has the above-described structure, it is possible to suppress an increase in thickness of the coil body1in the radial direction when the outer junctions400,500, and600are arranged on the outer circumference of the cylindrical coil body1as shown inFIG. 5.

When the outer junctions400,500, and600are mounted on the outer circumference of the coil body1as shown inFIGS. 5 and 1, the outer junctions400,500, and600can be mounted on the outer circumference of the coil body1by using a junction support portion (outer support portion)3made of synthetic resin as shown inFIG. 8B.

The U-phase outer terminal portion U101on the upper end side of one U-phase coil portion U1is bent to be connected to the concave portion506of the outer junction500. On the other hand, the U-phase outer terminal portion U201on the upper end side of the U-phase coil portion U2, which is at the following position in the circumferential direction, is bent to be connected to the concave portion507of the outer junction500. In this manner, the U-phase outer terminal portion U101on the upper end side of one U-phase coil portion U1and the U-phase outer terminal portion U201on the upper end side of the next U-phase coil portion U2in the circumferential direction are electrically connected to each other by the conductive outer junction500.

The V-phase outer terminal portion V101on the upper end side of one V-phase coil portion V1is bent to be connected to the concave portion606of the outer junction600. On the other hand, the V-phase outer terminal portion V201on the upper end side of the V-phase coil portion V2, which is at the following position in the circumferential direction, is bent to be connected to the concave portion607of the outer junction600. In this manner, the V-phase outer terminal portion V101on the upper end side of one V-phase coil portion V1and the V-phase outer terminal portion V201on the upper end side of the next V-phase coil portion V2in the circumferential direction are electrically connected to each other by the conductive outer junction600.

The W-phase outer terminal portion on the upper end side of one W-phase coil portion is bent to be connected to the concave portion407of the outer junction400. On the other hand, the W-phase outer terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction is bent to be connected to the concave portion406of the outer junction400. In this manner, the W-phase outer terminal portion on the upper end side of one W-phase coil portion and the W-phase outer terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction are electrically connected to each other by the conductive outer junction400.

Since each of the inner junctions401,501, and601has the above-described structure, the inner junctions401,501, and601can be arranged on the inner circumference of the cylindrical coil body1so as to be shifted from each other in the circumferential direction of the coil body1as shown inFIG. 6. That is, the radially inner side of the large-diameter arc portion405of the inner junction401, which is at the leading position of the inner junction501in the circumferential direction, abuts on the radially outer side of the small-diameter arc portion504of the inner junction501. The radially outer side of the small-diameter arc portion604of the inner junction601, which is at the following position of the outer junction500in the circumferential direction, abuts on the radially inner side of the large-diameter arc portion505of the inner junction501.

Since each of the inner junctions401,501, and601has the above-described structure, it is possible to suppress an increase in thickness of the coil body1in the radial direction when the inner junctions401,501, and601are arranged as shown inFIG. 6.

When the inner junctions401,501, and601are mounted on the inner circumference of the coil body1as shown inFIGS. 6 and 1, the inner junctions401,501, and601can be mounted on the inner circumference of the coil body1by using a junction support portion (inner support portion)2made of synthetic resin as shown inFIG. 8A.

The U-phase inner terminal portion U102on the upper end side of one U-phase coil portion U1is bent to be connected to the concave portion508of the inner junction501. The U-phase inner terminal portion U202on the upper end side of the next U-phase coil portion U2is bent to be connected to the concave portion509of the inner junction501. In this manner, the U-phase inner terminal portion U102on the upper end side of one U-phase coil portion U1and the U-phase inner terminal portion U202on the upper end side of the next U-phase coil portion U2in the circumferential direction are electrically connected to each other by the conductive inner junction501.

The V-phase inner terminal portion V102on the upper end side of one V-phase coil portion V1is bent to be connected to the concave portion608of the inner junction601. The V-phase inner terminal portion V202on the upper end side of the next V-phase coil portion V2is bent to be connected to the concave portion609of the inner junction601. In this manner, the V-phase inner terminal portion V102on the upper end side of one V-phase coil portion V1and the V-phase inner terminal portion V202on the upper end side of the next V-phase coil portion V2in the circumferential direction are electrically connected to each other by the conductive inner junction601.

The W-phase inner terminal portion on the upper end side of one W-phase coil portion is bent to be connected to the concave portion409of the inner junction401. On the other hand, the W-phase inner terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction is bent to be connected to the concave portion408of the inner junction401. In this manner, the W-phase inner terminal portion on the upper end side of one W-phase coil portion and the W-phase inner terminal portion on the upper end side of the next W-phase coil portion in the circumferential direction are electrically connected to each other by the conductive inner junction401.

With the coil body of this embodiment for a coreless rotating electrical machine having a cylindrical shape in which a plurality of sets each having the U-phase coil portion constituting the U-phase, the V-phase coil portion constituting the V-phase, and the W-phase coil portion constituting the W-phase are sequentially arranged in the circumferential direction so as to form an annular cylindrical body in plan view, the one U-phase coil portion and the next U-phase coil portion in the circumferential direction, the one V-phase coil portion and the next V-phase coil portion in the circumferential direction, and the one W-phase coil portion and the next W-phase coil portion in the circumferential direction are electrically connected by conductive junctions, respectively.

By using a highly conductive member such as copper as the conductive junction, it is possible to cause a large current to pass.

Further, by adopting the inner junction401and the like and the outer junction400and the like having the above-described structure, it is possible to suppress an increase in size in the radial direction, and to provide a coil body that is space-saving and miniaturized.

Although the embodiments and examples of the invention have been described above, the invention is not limited to the above-described embodiments and examples, and can be variously modified within the technical scope grasped from the description of the claims.