CN112953042A

CN112953042A - Stator of rotating electric machine

Info

Publication number: CN112953042A
Application number: CN202011413310.8A
Authority: CN
Inventors: 宫崎将吾; 井上雅志
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2019-12-10
Filing date: 2020-12-03
Publication date: 2021-06-11
Anticipated expiration: 2040-12-03
Also published as: JP2021093839A; CN112953042B

Abstract

Provided is a stator for a rotating electrical machine, which can reduce the manufacturing cost and can increase the partial discharge starting voltage of a coil. Leg portions (41) of eight segment conductors (40) aligned in a row in the radial direction are inserted into each of a plurality of slots (22) of a stator (10) of a rotating electrical machine. The coil has: a first joint portion in which four distal end portions, that is, a distal end portion of the first leg portion and a distal end portion of the second leg portion, and a distal end portion of the third leg portion and a distal end portion of the fourth leg portion inserted into slots offset by a predetermined number of slots in the first direction or the second direction in the circumferential direction, are integrally joined and conducted; and a second joint portion in which four distal end portions, that is, a distal end portion of the fifth leg portion and a distal end portion of the sixth leg portion, and a distal end portion of the seventh leg portion and a distal end portion of the eighth leg portion inserted into the slots that are offset by a predetermined number in the first direction or the second direction in the circumferential direction, are integrally joined and conducted.

Description

Stator of rotating electric machine

Technical Field

The present invention relates to a stator of a rotating electric machine, and more particularly, to a stator of a rotating electric machine including a coil in which a plurality of segment conductors are inserted into slots.

Background

Conventionally, there is known a stator of a rotating electric machine, which includes: a stator core; and coils of the respective phases of U-phase, V-phase, and W-phase, the coils being formed of a plurality of segment conductors inserted in a row in a radial direction into each of a plurality of slots formed in a circumferential direction of the stator core.

For example, patent document 1 discloses a stator of a four-layer two-parallel rotating electrical machine, in which segment conductors are inserted into slots in a radial direction in a row of four layers, and coils of U-phase, V-phase, and W-phase are connected in parallel with two windings, respectively.

For example, patent document 2 discloses an eight-layer two-parallel stator of a rotating electric machine in which segment conductors are inserted into slots in a radial direction in a row of eight layers, and coils of U-phase, V-phase, and W-phase are connected in parallel with two windings.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2012-029370

Patent document 2: japanese patent laid-open publication No. 2015-023670

Disclosure of Invention

Problems to be solved by the invention

In the stator of the four-layer two-parallel rotating electric machine of patent document 1, since the number of segment conductors inserted into the slots is small, the aspect ratio represented by the radial thickness of the conductor part of the segment conductor/the circumferential width of the conductor part can be easily increased. When the aspect ratio is increased, a large current can be caused to flow through the segment conductor, and the eddy current loss generated in the segment conductor is increased, which leads to a problem of an increase in the loss in the coil.

The stator of the eight-layer two-parallel rotating electric machine of patent document 2 has a smaller eddy current loss generated in the segment conductors than the stator of the four-layer two-parallel rotating electric machine of patent document 1. However, since the oblique portion formed in the portion protruding from the end surface of the stator core and obliquely running in the circumferential direction is formed at one end portion in the axial direction of the leg portion of the segment conductor, and the oblique portion of the segment conductor inserted into each slot obliquely runs in the opposite direction to the adjacent segment conductor, eight driving sources are required to form the oblique portion, and there is a problem in that the manufacturing cost becomes high.

Further, in the stator of the eight-layer two-parallel rotating electric machine of patent document 2, the segment conductors inserted into the respective slots are joined together every two layers, so that four joint portions are formed for the eight segment conductors inserted into the respective slots. Therefore, it is difficult to increase the radial distance between the joining portions and to increase the partial discharge start voltage of the coil.

The invention provides a stator of a rotating electric machine, which can reduce the manufacturing cost and can improve the partial discharge starting voltage of a coil.

Means for solving the problems

The present invention provides a stator of a rotating electric machine, comprising:

a stator core having a substantially annular shape and including a plurality of teeth protruding radially inward at predetermined intervals in a circumferential direction and a plurality of slots serving as spaces between the teeth adjacent to each other in the circumferential direction; and

a coil having a plurality of segment conductors respectively inserted into the plurality of slots,

each of the segment conductors has a leg portion arranged inside the slot and extending substantially linearly in the axial direction,

one axial end of the leg protrudes outward from one axial end of the stator core, and is formed with a diagonal portion extending diagonally in a circumferential direction in a first direction or a second direction and a tip portion extending axially outward from a tip of the diagonal portion,

the leg portions of eight segment conductors arranged in a row in the radial direction are inserted into the plurality of slots, respectively, wherein,

when viewed from the one end surface side in the axial direction of the stator core,

the leg portions of the eight segment conductors inserted into the slots in a row in the radial direction have, as counted from the radially inner side, a first leg portion disposed on the first layer, a second leg portion disposed on the second layer, a third leg portion disposed on the third layer, a fourth leg portion disposed on the fourth layer, a fifth leg portion disposed on the fifth layer, a sixth leg portion disposed on the sixth layer, a seventh leg portion disposed on the seventh layer, and an eighth leg portion disposed on the eighth layer,

the diagonal portion of the first leg portion and the diagonal portion of the second leg portion are diagonal in the same direction in the circumferential direction in either one of the first direction and the second direction,

the diagonal portion of the third leg portion and the diagonal portion of the fourth leg portion are diagonal in a circumferential direction in a direction opposite to a diagonal direction of the diagonal portion of the first leg portion and the diagonal portion of the second leg portion out of the first direction and the second direction,

the diagonal portion of the fifth leg portion and the diagonal portion of the sixth leg portion are diagonal in the same direction in the circumferential direction in either one of the first direction and the second direction,

the diagonal portion of the seventh leg portion and the diagonal portion of the eighth leg portion are diagonal in the circumferential direction to the opposite side of the diagonal direction of the diagonal portion of the fifth leg portion and the diagonal portion of the sixth leg portion,

the coil has:

a first joint portion in which four distal end portions of the distal end portion of the first leg portion and the distal end portion of the second leg portion, and the distal end portion of the third leg portion and the distal end portion of the fourth leg portion inserted into the insertion grooves that are offset by a predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction, are integrally joined and conducted, and

and a second joint portion in which four distal end portions, that is, the distal end portion of the fifth leg portion and the distal end portion of the sixth leg portion, and the distal end portion of the seventh leg portion and the distal end portion of the eighth leg portion inserted into the insertion grooves that are offset from the predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction, are integrally joined and conducted.

Effects of the invention

According to the present invention, since the diagonal portions of the first to eighth legs are identical in diagonal direction in the circumferential direction for each two layers, the diagonal portions of the first to eighth legs can be formed by one driving source for each two layers. Accordingly, the oblique portions of the first to eighth legs can be formed with a small number of driving sources, and therefore, the manufacturing apparatus for forming the oblique portions of the first to eighth legs can be simplified, and the manufacturing cost of the stator can be reduced.

Further, since the coil has the first joint portion where the front end portion of the first leg portion to the front end portion of the fourth leg portion are integrally joined and conducted and the second joint portion where the front end portion of the fifth leg portion to the front end portion of the eighth leg portion are integrally joined and conducted, two joint portions can be provided for the eight segment conductors inserted into the respective slots. This can increase the radial distance between the joining portions and increase the partial discharge start voltage of the coil.

Drawings

Fig. 1 is a view of a stator of a rotating electric machine according to an embodiment of the present invention, as viewed from the radially outer side.

Fig. 2 is a sectional view of a stator of the rotating electric machine of fig. 1 as viewed from an axial direction.

Fig. 3 is a perspective view of a segment conductor of a stator of the rotating electric machine of fig. 1.

Fig. 4 is an enlarged view of the periphery of the socket of fig. 2.

Fig. 5 is a perspective view of the stator of the rotating electric machine of fig. 1 as viewed from the first end surface side of the stator core.

Fig. 6 is a view of the segment conductor, the first holder, and the second holder when the first joint and the second joint of the stator of the rotating electrical machine of fig. 1 are formed, as viewed from the axial direction.

Fig. 7 is an enlarged perspective view of the periphery of the first joint and the second joint of the stator of the rotating electric machine of fig. 1.

Fig. 8 is a view of the stator of the rotating electric machine of fig. 1 as viewed in the axial direction from the first end surface side of the stator core.

Fig. 9 is a schematic diagram showing a coil structure of a stator of the rotating electric machine of fig. 1.

Fig. 10 is a developed view showing a structure of a V-phase coil of a stator of the rotating electric machine of fig. 1.

Fig. 11 is a developed view showing the structure of the coils of the U-phase, V-phase, and W-phase of the stator of the rotating electric machine of fig. 1.

Fig. 12 is a diagram showing a relationship between an aspect ratio of a segment conductor and a coil loss of a stator of the rotating electric machine of fig. 1.

Description of reference numerals:

10 stator

20 stator core

201 first end face (one end face)

21 tooth

22 slot

30 coil

40 segmented conductor

41 leg part

41a first end (one end)

411 first leg portion

412 second leg

413 third leg

414 fourth leg

415 fifth leg

416 sixth leg

417 the seventh leg

418 eighth leg

43 diagonal part

44 front end part

451 first engaging part

452 second joint part

Angle of inclination theta 2 to theta 7

Detailed Description

Hereinafter, one embodiment of a stator of a rotating electric machine according to the present invention will be described with reference to the drawings.

As shown in fig. 1 and 2, a stator 10 of a rotating electric machine according to the present embodiment includes a substantially annular stator core 20 and a coil 30 assembled to the stator core 20.

In the present specification and the like, for the sake of simplicity and clarity, the axial direction, the radial direction, and the circumferential direction refer to directions based on the center axes CL of the stator 10 and the stator core 20. The axially inner side refers to the center side of the stator 10 in the axial direction, and the axially outer side refers to the side away from the center of the stator 10 in the axial direction.

The stator core 20 has a substantially annular shape, and includes: a plurality of teeth 21 protruding radially inward at predetermined intervals in the circumferential direction; and a plurality of slots 22 as spaces between the teeth 21 adjacent in the circumferential direction. In the present embodiment, the stator core 20 has 48 teeth 21, and 48 slots 22 are formed. The stator core 20 is formed as a laminated core in which a plurality of electromagnetic steel sheets having a predetermined thickness are laminated in the axial direction. The stator core 20 has a first end face 201 and a second end face 202 in the axial direction.

The coil 30 is assembled to the stator core 20, and is formed with a first coil end 31 protruding axially outward from a first end face 201 of the stator core 20 and a second coil end 32 protruding axially outward from a second end face 202 of the stator core 20.

The coil 30 has a plurality of segment conductors 40 inserted into the 48 slots 22, respectively.

As shown in fig. 3, the segment conductor 40 is provided with an insulating coating portion 402 on a conductor portion 401 having a substantially rectangular cross section. The segment conductor 40 is provided with a pair of leg portions 41 extending parallel to each other and having a first end portion 41a and a second end portion 41b, and a bent portion 42 connecting the second end portions 41b of the pair of leg portions 41 to each other, and is formed in a substantially U shape. The segment conductor 40 is arranged such that the pair of leg portions 41 are inserted into the different slots 22 of the stator core 20, the bent portion 42 protrudes axially outward from the second end surface 202 of the stator core 20, and the first end portions 41a of the pair of leg portions 41 protrude axially outward from the first end surface 201 of the stator core 20.

The protruding portions of the pair of leg portions 41 protruding axially outward from the first end surface 201 of the stator core 20 are bent in the circumferential direction of the stator core 20 by relatively rotating in the circumferential direction while approaching the stator core 20 in the axial direction while holding the tip portion of the first end portion 41a with a jig not shown. Thus, the protruding portions of the first end portions 41a of the pair of leg portions 41 form the diagonal portion 43 extending by bending in the direction approaching each other or in the direction separating from each other in the circumferential direction of the stator core 20, and the tip portion of the first end portion 41a held by the jig, that is, the tip portion 44 extending from the tip of the diagonal portion 43 to the outside in the axial direction of the stator core 20.

The segment conductor 40 thus formed has: a wound segment conductor 40A in which the diagonal portions 43 extend in a direction in which they approach each other in the circumferential direction of the stator core 20; and the wave-wound segment conductor 40B in which the diagonal portions 43 extend while being bent in a direction in which the stator cores 20 are separated from each other.

As shown in fig. 4 and 5, the leg portions 41 of the segment conductors 40 are inserted into the slots 22 of the stator core 20 in a manner such that eight layers are arranged in a row in the radial direction. That is, the first leg 411 disposed in the first layer, the second leg 412 disposed in the second layer, the third leg 413 disposed in the third layer, the fourth leg 414 disposed in the fourth layer, the fifth leg 415 disposed in the fifth layer, the sixth leg 416 disposed in the sixth layer, the seventh leg 417 disposed in the seventh layer, and the eighth leg 418 disposed in the eighth layer are inserted into each slot 22 of the stator core 20 from the radially inner side.

The diagonal portions 43 of the first leg portion 411 and the second leg portion 412, which are inserted into the eight-layer leg portions 41 of the respective slots 22 of the stator core 20, are diagonally oriented counterclockwise in the circumferential direction when viewed from the first end surface 201 side of the stator core 20. The diagonal portions 43 of the third leg portion 413 and the fourth leg portion 414 are diagonally clockwise in the circumferential direction. The diagonal portions 43 of the fifth leg portion 415 and the sixth leg portion 416 are diagonally clockwise in the circumferential direction. The diagonal portions 43 of the seventh leg portion 417 and the eighth leg portion 418 are diagonally inclined counterclockwise in the circumferential direction.

In this way, the diagonal portions 43 of the first to eighth leg portions 411 to 418 are identical in diagonal direction in the circumferential direction for each two layers. Therefore, the first jig holding the distal end portion of the first end portion 41a of the first leg portion 411 and the second jig holding the distal end portion of the first end portion 41a of the second leg portion 412 can be relatively rotated counterclockwise in the circumferential direction while approaching the stator core 20 in the axial direction by one drive source. Similarly, the third jig holding the distal end portion of the first end portion 41a of the third leg portion 413 and the fourth jig holding the distal end portion of the first end portion 41a of the fourth leg portion 414 can be rotated relative to each other clockwise in the circumferential direction while approaching the stator core 20 in the axial direction by one drive source. The fifth jig holding the front end portion of the first end portion 41a of the fifth leg portion 415 and the sixth jig holding the front end portion of the first end portion 41a of the sixth leg portion 416 can be relatively rotated clockwise in the circumferential direction while approaching the stator core 20 in the axial direction by one drive source. The seventh jig holding the distal end portion of the first end portion 41a of the seventh leg portion 417 and the eighth jig holding the distal end portion of the first end portion 41a of the eighth leg portion 418 can be relatively rotated counterclockwise in the circumferential direction while approaching the stator core 20 in the axial direction by one drive source.

Since the diagonal portions 43 of the first to eighth leg portions 411 to 418 can be formed by the driving sources of half the number (4 in the present embodiment) of the leg portions 41 (8 in the present embodiment) of the segment conductors 40 inserted into the respective slots 22, the manufacturing apparatus of the diagonal portions 43 forming the first to eighth leg portions 411 to 418 can be simplified, and the manufacturing cost of the stator 10 can be reduced. In the present embodiment, since the third jig and the fourth jig and the fifth jig and the sixth jig are both rotated relative to the stator core 20 in the clockwise direction in the circumferential direction, the third jig to the sixth jig may be driven by one drive source. In this case, since the diagonal portion 43 of the first to eighth leg portions 411 to 418 can be formed by three driving sources, the manufacturing cost of the stator 10 can be further reduced.

When viewed from the first end surface 201 side of the stator core 20, the tip portion 44 extending axially outward from the tips of the diagonal portions 43 of the first leg portion 411 and the second leg portion 412 inserted into the slot 22, the tip portion 44 extending axially outward from the tips of the diagonal portions 43 of the seventh leg portion 417 and the eighth leg portion 418, the tip portion 44 extending axially outward from the tips of the diagonal portions 43 of the third leg portion 413 and the fourth leg portion 414 inserted into the counterclockwise sixth slot 22, and the tip portion 44 extending axially outward from the tips of the diagonal portions 43 of the fifth leg portion 415 and the sixth leg portion 416 press the tip portion 44 of the first leg portion 411, the tip portion 44 of the second leg portion 412, the tip portion 44 of the third leg portion 413, the tip portion 44 of the fourth leg portion 414, the tip portion 44 of the fifth leg portion 415, the tip portion 44 of the sixth leg portion 416, and the tip portion 44 of the seventh leg portion 417 from the radially inward, And the leading end 44 of the eighth leg 418 are radially aligned.

Next, as shown in fig. 6, the tip end portions 44 of the first to eighth leg portions 411 to 418 arranged in a row in the radial direction are sandwiched by the first clamper 91 arranged counterclockwise in the circumferential direction and the second clamper 92 arranged clockwise in the circumferential direction when viewed from the first end surface 201 side of the stator core 20.

The first clamper 91 has, when viewed from the first end surface 201 side of the stator core 20: a first side 911 extending in a radial direction; a second side 912 located radially outward of the first side 911 and extending radially substantially collinear with the first side 911; a third side surface 913 extending in the circumferential direction so as to face a radially inner side surface of the distal end portion 44 of the first leg portion 411; a fourth side surface 914 extending in the circumferential direction so as to face a radially outer side surface of the distal end portion 44 of the eighth leg portion 418; and a wedge portion 915 formed between a radially outer end 911a of the first side surface 911 and a radially inner end 912b of the second side surface 912.

The wedge 915 protrudes clockwise from the first side surface 911 and the second side surface 912 in the circumferential direction. The wedge 915 includes: a first inclined surface 915a inclined radially outward from a radially outer end 911a of the first side surface 911 and extending clockwise in the circumferential direction; and a second inclined surface 915b inclined radially inward from the radially inner end 912b of the second side surface 912 and extending clockwise in the circumferential direction.

The second clamper 92 includes, when viewed from the first end surface 201 side of the stator core 20: a first side 921 extending in a radial direction; a second side surface 922 located radially outward of the first side surface 921 and extending radially substantially in line with the first side surface 921; a third side surface 923 extending in the circumferential direction so as to face a radially inner side surface of the distal end portion 44 of the first leg portion 411; a fourth side surface 924 extending in the circumferential direction so as to face a radially outer side surface of the distal end portion 44 of the eighth leg portion 418; and a wedge portion 925 formed between a radially outer end 921a of the first side surface 921 and a radially inner end 922b of the second side surface 922.

The wedge portion 925 protrudes counterclockwise from the first and second side surfaces 921 and 922 in the circumferential direction. The wedge portion 925 includes: a first inclined surface 925a that is inclined radially outward from the radially outer end 921a of the first side surface 921 and extends clockwise in the circumferential direction; and a second inclined surface 925b inclined radially inward from the radially inner end 922b of the second side surface 922 and extending clockwise in the circumferential direction.

The first holder 91 and the second holder 92 have a shape that is symmetrical in the circumferential direction, i.e., line-symmetrical about the radial direction as an axis, when viewed from the first end surface 201 side of the stator core 20.

The first holder 91 and the second holder 92 are held between the front end portions 44 of the first leg 411 to the eighth leg 418 aligned in the radial direction.

At this time, when viewed from the first end surface 201 side of the stator core 20, the first side surface 911 of the first clamper 91 is opposed to the side surface on the counterclockwise side in the circumferential direction of the distal end portion 44 of the first to fourth leg portions 411 to 414 aligned in a radial direction, and the first side surface 921 of the second clamper 92 is opposed to the side surface on the clockwise side in the circumferential direction of the distal end portion 44 of the first to fourth leg portions 411 to 414 aligned in a radial direction. The second side face 912 of the first holder 91 is opposed to the side face on the counterclockwise side in the circumferential direction of the leading end portions 44 of the fifth to eighth legs 415 to 418 aligned in the radial direction, and the second side face 922 of the second holder 92 is opposed to the side face on the clockwise side in the circumferential direction of the leading end portions 44 of the fifth to eighth legs 415 to 418 aligned in the radial direction. The wedge portion 915 of the first holder 91 and the wedge portion 925 of the second holder 92 are located radially between the front end portion 44 of the fourth leg 414 and the front end portion 44 of the fifth leg 415, and are circumferentially opposite to each other. The third side surface 913 of the first holder 91 and the third side surface 923 of the second holder 92 extend in the circumferential direction substantially on the same straight line, and abut against or approach the radially inner side surface of the distal end portion 44 of the first leg 411. The fourth side surface 914 of the first holder 91 and the fourth side surface 924 of the second holder 92 extend substantially on the same line in the circumferential direction and abut against or approach the radially outer side surface of the distal end portion 44 of the eighth leg portion 418.

Then, the first gripper 91 and the second gripper 92 are moved so as to approach each other in the circumferential direction.

Then, the tip end portion 44 of the fourth leg portion 414 abuts against the first inclined surface 915a of the wedge portion 915 of the first holder 91 and the first inclined surface 925a of the wedge portion 925 of the second holder 92. Further, the tip end portion 44 of the fifth leg 415 abuts against the second inclined surface 915b of the wedge portion 915 of the first holder 91 and the second inclined surface 925b of the wedge portion 925 of the second holder 92.

Then, the first clamper 91 and the second clamper 92 are moved closer to each other in the circumferential direction.

Then, the first inclined surface 915a of the wedge portion 915 of the first clamp 91 and the first inclined surface 925a of the wedge portion 925 of the second clamp 92 press the distal end portion 44 of the fourth leg portion 414 radially inward. Thus, as the first holder 91 and the second holder 92 approach each other, the distal end portion 44 of the fourth leg portion 414 is bent and deformed so as to be inclined radially inward along the first inclined surface 915a of the wedge portion 915 of the first holder 91 and the first inclined surface 925a of the wedge portion 925 of the second holder 92. Further, the distal end portion 44 of the fourth leg portion 414 presses the distal end portion 44 of the third leg portion 413 radially inward as it is bent and deformed so as to be inclined radially inward, and the distal end portion 44 of the third leg portion 413 is bent and deformed so as to be inclined radially inward. Further, the distal end portion 44 of the third leg portion 413 presses the distal end portion 44 of the second leg portion 412 radially inward as it is bent and deformed so as to be inclined radially inward, and the distal end portion 44 of the second leg portion 412 is bent and deformed so as to be inclined radially inward. Since the distal end portion 44 of the first leg portion 411 abuts against or approaches the third side surface 913 of the first holder 91 and the third side surface 923 of the second holder 92, even if the distal end portion 44 of the second leg portion 412 is bent and deformed so as to be inclined radially inward and presses the distal end portion 44 of the first leg portion 411, the distal end portion 44 of the first leg portion 411 extends substantially parallel to the axial direction without being bent and deformed (see fig. 7). The distal end portions 44 of the first to fourth leg portions 411 to 414 are held by the first holder 91 and the second holder 92 in a state where the adjacent distal end portions 44 abut against each other.

At the same time, the second inclined surface 915b of the wedge portion 915 of the first holder 91 and the second inclined surface 925b of the wedge portion 925 of the second holder 92 press the distal end portion 44 of the fifth leg portion 415 radially outward. Thus, as the first holder 91 and the second holder 92 approach each other, the distal end portion 44 of the fifth leg 415 is bent and deformed so as to be inclined radially outward along the second inclined surface 915b of the wedge portion 915 of the first holder 91 and the second inclined surface 925b of the wedge portion 925 of the second holder 92. Further, the distal end portion 44 of the fifth leg portion 415 presses the distal end portion 44 of the sixth leg portion 416 radially outward as it is bent and deformed so as to be inclined radially outward, so that the distal end portion 44 of the sixth leg portion 416 is bent and deformed so as to be inclined radially outward. Further, the distal end portion 44 of the sixth leg portion 416 presses the distal end portion 44 of the seventh leg portion 417 radially outward as it is bent and deformed so as to be inclined radially outward, so that the distal end portion 44 of the seventh leg portion 417 is bent and deformed so as to be inclined radially outward. Since the distal end portion 44 of the eighth leg portion 418 abuts against or approaches the fourth side surface 914 of the first holder 91 and the fourth side surface 924 of the second holder 92, even if the distal end portion 44 of the seventh leg portion 417 is bent and deformed so as to be inclined radially outward and presses the distal end portion 44 of the eighth leg portion 418, the distal end portion 44 of the eighth leg portion 418 extends substantially in parallel with the axial direction without being bent and deformed (see fig. 7). The tip portions 44 of the fifth to eighth leg portions 415 to 418 are held by the first and

second grippers

91 and 92 in a state where the adjacent tip portions 44 abut against each other.

Then, in a state where the adjacent tip portions 44 of the first to fourth leg portions 411 to 414 abut each other and the adjacent tip portions 44 of the fifth to eighth leg portions 415 to 418 abut each other by the first holder 91 and the second holder 92, the tip portions 44 of the first and second leg portions 411 to 412, the tip portions 44 of the second and third leg portions 412 to 413 to 44 of the third and fourth leg portions 413 to 414 are joined by, for example, laser welding, and the tip portions 44 of the fifth and sixth leg portions 415 to 416, the tip portions 44 of the sixth and seventh leg portions 416 to 417 to 44 of the seventh and seventh leg portions 417 to 44 of the eighth leg portions 418 to 44. Thereby, the first joint portion 451 in which the four tip end portions 44 forming the first to fourth leg portions 411 to 414 are integrally joined and conducted, and the second joint portion 452 in which the four tip end portions 44 forming the fifth to eighth leg portions 415 to 418 are integrally joined and conducted are formed.

In this way, when viewed from the first end surface 201 side of the stator core 20, the tip portions 44 of the first leg portion 411 and the second leg portion 412 inserted into the slot 22 and the tip portions 44 of the third leg portion 413 and the fourth leg portion 414 inserted into the counterclockwise sixth slot 22 are aligned in a radial direction, and the tip portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the slot 22 and the tip portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the counterclockwise sixth slot 22 are aligned in a radial direction, and therefore, the tip portions 44 of the first leg portion 411 and the second leg portion 412 inserted into the slot 22 and the tip portions 44 of the third leg portion 413 and the fourth leg portion 414 inserted into the counterclockwise sixth slot 22 can be easily joined to each other using the first clip 91 and the second clip 92 having a simple shape, and the tip portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the slot 22 and the tip portions 44 of the fourth leg portion 415 and the counterclockwise leg portion 414 inserted into the counterclockwise sixth slot 22 can be easily joined to each other The front end 44 of the sixth leg 416. This makes it possible to easily form the first joint portion 451 and the second joint portion 452.

The distal ends 44 of the first leg 411 and the second leg 412 inserted into a part of the insertion groove 22 are joined to each other, but are not joined to the distal ends 44 of the third leg 413 and the fourth leg 414 inserted into a different insertion groove 22. Similarly, the distal ends 44 of the third leg 413 and the fourth leg 414 inserted into a part of the insertion groove 22 are joined to each other, but are not joined to the distal ends 44 of the first leg 411 and the second leg 412 inserted into a different insertion groove 22. The distal ends 44 of the fifth leg 415 and the sixth leg 416 inserted into a part of the insertion groove 22 are joined to each other, but are not joined to the distal ends 44 of the seventh leg 417 and the eighth leg 418 inserted into a different insertion groove 22. Similarly, the distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into a part of the insertion groove 22 are joined to each other, but are not joined to the distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into a different insertion groove 22. Details will be described later.

In this way, the coil 30 is constituted by the plurality of segment conductors 40 inserted into the 48 slots 22, respectively. The tapered portion 43 and the tip portion 44 of each segment conductor 40 form the first coil end 31 of the coil 30, and the bent portion 42 of each segment conductor 40 forms the second coil end 32 of the coil 30.

Therefore, the stator 10 of the present embodiment includes: a first joining portion 451 joining the distal end portions 44 of the first leg portion 411 and the second leg portion 412 inserted into the slot 22 and the distal end portions 44 of the third leg portion 413 and the fourth leg portion 414 inserted into different slots 22; and a second joint portion 452 that joins the distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the insertion slot 22 and the distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into different insertion slots 22. That is, in the stator 10 of the present embodiment, the tip end portions 44 of the leg portions 41 inserted into the respective slots 22 of the stator core 20 in a row of eight layers are joined together every four, so that two joint portions (the first joint portion 451, the second joint portion 452) are provided for the eight leg portions 41 inserted into one slot 22.

In a conventional stator, when legs of eight-layer segment conductors are inserted into slots of a stator core in a row in a radial direction to form a coil, the stator includes a first joint portion that joins a tip of a first leg to a tip of a second leg inserted into a different slot, a second joint portion that joins a tip of a third leg to a tip of a fourth leg inserted into a different slot, a third joint portion that joins a tip of a fifth leg to a tip of a sixth leg inserted into a different slot, and a fourth joint portion that joins a tip of a seventh leg to a tip of an eighth leg inserted into a different slot. Therefore, in the conventional stator, the tip end portions of the leg portions inserted into the slots of the stator core in a row of eight layers are joined together two by two, and four joint portions are provided for the eight leg portions inserted into one slot.

Therefore, since the conventional stator has four joining portions arranged in the radial direction, it is difficult to increase the radial intervals between the four joining portions and to increase the partial discharge start voltage of the coil.

In contrast, in the present embodiment, since the first joint portion 451 and the second joint portion 452, which are two joint portions, are arranged in the radial direction, the radial interval between the joint portions can be increased, and the partial discharge start voltage of the coil 30 can be increased.

In order to manufacture the conventional stator, it is necessary to provide wedge portions between the tip end portion of the second leg portion and the tip end portion of the third leg portion, between the tip end portion of the fourth leg portion and the tip end portion of the fifth leg portion, and between the tip end portion of the sixth leg portion and the tip end portion of the seventh leg portion in the radial direction in the first holder 91 and the second holder 92, and therefore, three wedge portions, which are six in total, need to be provided in the first holder 91 and the second holder 92, respectively. Further, in order to provide three wedge portions on the first clamp 91 and the second clamp 92, respectively, it is necessary to reduce the size of one wedge portion.

In contrast, in the present embodiment, since the four tip portions 44 of the first leg portion 411 to the fourth leg portion 414 are integrally joined and the four tip portions 44 of the fifth leg portion 415 to the eighth leg portion 418 are integrally joined, the first clamp 91 and the second clamp 92 may be provided with the

wedge portions

915 and 925 between the tip portion of the fourth leg portion and the tip portion of the fifth leg portion in the radial direction, that is, the first clamp 91 and the second clamp 92 may be provided with one wedge portion, and the total of the two

wedge portions

915 and 925 may be provided. This can simplify the shape of the first holder 91 and the second holder 92, and thus can reduce the manufacturing cost of the stator 10. Further, since only one

wedge portion

915, 925 is required to be formed in each of the first clamp 91 and the second clamp 92, the

wedge portions

915, 925 can be increased in size. This can increase the rigidity of the first holder 91 and the second holder 92, and thus can reduce the manufacturing cost of the stator 10.

As shown in fig. 7, the distal end portions 44 of the second to fourth leg portions 412 to 414 are bent so as to be inclined radially inward, and the distal end portions 44 of the fifth to seventh leg portions 415 to 417 are bent so as to be inclined radially outward, so that the radial distance between the distal end portion 44 of the fourth leg portion 414 and the distal end portion 44 of the fifth leg portion 415 is increased. This increases the partial discharge start voltage of the coil 30, and suppresses the generation of partial discharge in the coil 30, so that the coil 30 can be driven with a larger electric power, and the output performance of the rotating electrical machine can be improved.

When the tip end portions 44 of the second to fourth leg portions 412 to 414 are bent and deformed radially inward by the first and

second clampers

91 and 92, the inclination angle θ 3 of the tip end portion 44 of the third leg portion 413 radially inward with respect to the axial direction is larger than the inclination angle θ 2 of the tip end portion 44 of the second leg portion 412 radially inward with respect to the axial direction, and the inclination angle θ 4 of the tip end portion 44 of the fourth leg portion 414 radially inward is larger than the inclination angle θ 3. When the tip end portions 44 of the fifth to seventh leg portions 415 to 417 are bent and deformed radially outward by the first holder 91 and the second holder 92 in this manner, the inclination angle θ 6 of the tip end portion 44 of the sixth leg portion 416 radially outward in the axial direction is larger than the inclination angle θ 7 of the tip end portion 44 of the seventh leg portion 417 radially outward in the axial direction, and the inclination angle θ 5 of the tip end portion 44 of the fifth leg portion 415 radially outward is larger than the inclination angle θ 6.

Thus, the distal end portion 44 of the fourth leg portion 414 among the distal end portions 44 of the second to fourth leg portions 412 to 414 is bent so as to be inclined radially inward the most, and the distal end portion 44 of the fifth leg portion 415 among the distal end portions 44 of the fifth to seventh leg portions 415 to 417 is bent so as to be inclined radially outward the most, so that the radial interval between the distal end portion of the fourth segment conductor and the distal end portion of the fifth segment conductor, that is, the radial interval between the first joint portion 451 and the second joint portion 452 can be increased, and the partial discharge start voltage of the coil 30 can be further increased.

Further, since the distal end portion 44 of the first leg portion 411 and the distal end portion 44 of the eighth leg portion 418 do not bend radially inward and radially outward but extend parallel to the axial direction, the radial distance between the distal end portion of the fourth segment conductor and the distal end portion of the fifth segment conductor can be increased without increasing the radial length of the first coil end portion 31.

< construction of coil based on segmented conductor >

Next, a configuration of the coil 30 based on the segment conductors 40 (the lap-wound segment conductor 40A and the wave-wound segment conductor 40B) inserted into the slots 22 of the stator core 20 will be described.

As shown in fig. 8, U-phase lead line 50U, V, phase lead line 50V, and W-phase lead line 50W are connected to coil 30. And is electrically connected to a power conversion device not shown. When the rotating electric machine is driven as a motor, U-phase lead line 50U, V and W-phase lead line 50W supply U-phase ac power, V-phase ac power, and W-phase ac power, respectively, of three-phase ac power supplied from a power conversion device or the like, not shown, to coil 30. When the rotating electric machine is driven as a generator, U-phase lead line 50U, V and W-phase lead line 50V and W-phase lead line 50W supply U-phase ac power, V-phase ac power, and W-phase ac power, respectively, of three-phase ac power generated by the rotating electric machine to a power conversion device and the like, not shown.

In the present embodiment, U-phase lead line 50U has two lead lines, i.e., first U-phase lead line 51U and second U-phase lead line 52U. V-phase lead-out line 50V has two lead-out lines, i.e., first V-phase lead-out line 51V and second V-phase lead-out line 52V. W-phase lead line 50W has two lead lines, i.e., first W-phase lead line 51W and second W-phase lead line 52W. The first U-phase lead-out line 51U and the second U-phase lead-out line 52U, the first V-phase lead-out line 51V and the second V-phase lead-out line 52V, and the first W-phase lead-out line 51W and the second W-phase lead-out line 52W are electrically connected to the front end portion 44 of the prescribed segment conductor 40, respectively. Details of which of the front end portions 44 of the segment conductors 40 the first U-phase lead-out line 51U and the second U-phase lead-out line 52U, the first V-phase lead-out line 51V and the second V-phase lead-out line 52V, and the first W-phase lead-out line 51W and the second W-phase lead-out line 52W are electrically connected to will be described later.

The coil 30 is connected to the first U-phase bridge 61U and the second U-phase bridge 62U, the first V-phase bridge 61V and the second V-phase bridge 62V, and the first W-phase bridge 61W and the second W-phase bridge 62W. The first U-phase bridge 61U and the second U-phase bridge 62U, the first V-phase bridge 61V and the second V-phase bridge 62V, and the first W-phase bridge 61W and the second W-phase bridge 62W are conductors, and may be insulated or not. The first U-phase bridge 61U and the second U-phase bridge 62U, the first V-phase bridge 61V and the second V-phase bridge 62V, and the first W-phase bridge 61W and the second W-phase bridge 62W all extend in the circumferential direction on the axially outer side of the coil 30, and both end portions are electrically connected to the front end portions 44 of the different segment conductors 40, respectively. The details of which of the front end portions 44 of the segment conductors 40 the first U-phase bridge 61U and the second U-phase bridge 62U, the first V-phase bridge 61V and the second V-phase bridge 62V, and the first W-phase bridge 61W and the second W-phase bridge 62W are electrically connected to will be described later.

A neutral point 70 is connected to the coil 30. The neutral point 70 is a conductor, and may or may not be covered with an insulator. In the present embodiment, the neutral point 70 extends in the circumferential direction on the radially outer side of the coil 30, and is electrically connected to the tip end portions 44 of the plurality of segment conductors 40. Details of which of the front end portions 44 of the segment conductors 40 the neutral point 70 is electrically connected to will be described later.

As shown in fig. 9, coil 30 is composed of three-phase coils, i.e., U-phase coil 30U, V-phase coil 30V and W-phase coil 30W. U-phase coil 30U is electrically connected to U-phase lead line 50U. The V-phase coil 30V is electrically connected to the V-phase lead line 50V. W-phase coil 30W is electrically connected to W-phase lead line 50W.

The U-phase coil 30U is formed by connecting four windings U1, U2, U3, and U4 in parallel. Each of the windings U1, U2, U3, and U4 includes clockwise-wound windings U1-1, U2-1, U3-1, and U4-1, and counterclockwise-wound windings U1-2, U2-2, U3-2, and U4-2, respectively, when viewed radially outward from the center axis CL of the stator core 20. One end of each of the windings U1-1 and U2-1 is electrically connected to the first U-phase lead line 51U. One end of each of windings U3-1 and U4-1 is electrically connected to second U-phase outgoing line 52U. The other end portions of the windings U1-1, U2-1 and one end portions of the windings U1-2, U2-2 are electrically connected via a first U-phase bridge 61U. The other end portions of the windings U3-1, U4-1 and one end portions of the windings U3-2, U4-2 are electrically connected via a second U-phase bridge 62U. The other ends of the windings U1-2, U2-2 and the other ends of the windings U3-2, U4-2 are electrically connected to the neutral point 70.

The V-phase coil 30V is formed by connecting four windings V1, V2, V3, and V4 in parallel. The windings V1, V2, V3, and V4 include clockwise windings V1-1, V2-1, V3-1, and V4-1, and counterclockwise windings V1-2, V2-2, V3-2, and V4-2, respectively, when viewed radially outward from the center axis CL of the stator core 20. One end of each of windings V1-1 and V2-1 is electrically connected to first V-phase lead line 51V. One end of each of windings V3-1 and V4-1 is electrically connected to second V-phase outgoing line 52V. The other end portions of the windings V1-1, V2-1 and one end portions of the windings V1-2, V2-2 are electrically connected via a first V-phase bridge 61V. The other end portions of the windings V3-1, V4-1 and one end portions of the windings V3-2, V4-2 are electrically connected via a second V-phase bridge 62V. The other end portions of the windings V1-2, V2-2 and the other end portions of the windings V3-2, V4-2 are electrically connected to the neutral point 70.

The W-phase coil 30W is formed by connecting four windings W1, W2, W3, and W4 in parallel. The windings W1, W2, W3, and W4 include clockwise-wound windings W1-1, W2-1, W3-1, and W4-1, and counterclockwise-wound windings W1-2, W2-2, W3-2, and W4-2, respectively, when viewed radially outward from the center axis CL of the stator core 20. One end of each of windings W1-1 and W2-1 is electrically connected to first W-phase lead line 51W. One end of each of windings W3-1 and W4-1 is electrically connected to second W-phase lead line 52W. The other end portions of the windings W1-1, W2-1 and one end portions of the windings W1-2, W2-2 are electrically connected via a first W-phase bridge 61W. The other end portions of the windings W3-1, W4-1 and one end portions of the windings W3-2, W4-2 are electrically connected via a second W-phase bridge 62W. The other end portions of the windings W1-2, W2-2 and the other end portions of the windings W3-2, W4-2 are electrically connected to the neutral point 70.

For simplicity and clarity of description, as shown in fig. 2, the 48 slots 22 of the stator core 20 are referred to as first slots 2201 to 48 th slots 2248 in the clockwise direction when viewed from the first end surface 201 side of the stator core 20.

Here, with reference to fig. 10, a configuration of V-phase coil 30V among three-phase coils of U-phase coil 30U, V-phase coil 30V, W-phase coil 30W constituting coil 30 will be described. In fig. 10, the leg portions 41 constituting the windings V1, V2 are indicated by a dark color (shading of fine dots), and the leg portions 41 constituting the windings V3, V4 are indicated by a light color (shading of coarse dots).

As shown in fig. 10, when viewed from the first end surface 201 side of the stator core 20, the second end 41b of the first leg 411 and the second end 41b of the fifth leg 415 inserted into the counterclockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of legs 41 that overlap the segment conductor 40A. The second end portion 41b of the second leg portion 412 and the second end portion 41b of the sixth leg portion 416 inserted into the counterclockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 that lap the segment conductor 40A. The second end portion 41B of the third leg portion 413 and the second end portion 41B of the seventh leg portion 417 inserted into the counterclockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 of the corrugated segment conductor 40B. The second end portion 41B of the fourth leg portion 414 and the second end portion 41B of the eighth leg portion 418 inserted into the counterclockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 of the corrugated segment conductor 40B.

Therefore, when viewed from the first end surface 201 side of the stator core 20, the second end portion 41b of the fifth leg portion 415 and the second end portion 41b of the first leg portion 411 inserted into the clockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 that lap the segment conductor 40A. The second end portion 41b of the sixth leg portion 416 and the second end portion 41b of the second leg portion 412 inserted into the fifth slot 22 in the clockwise direction in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 that lap the segment conductor 40A. The second end portion 41B of the seventh leg portion 417 and the second end portion 41B of the third leg portion 413 inserted into the clockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 of the corrugated segment conductor 40B. The second end portion 41B of the eighth leg portion 418 and the second end portion 41B of the fourth leg portion 414 inserted into the clockwise fifth slot 22 in the circumferential direction are connected by the bent portion 42, and become a pair of leg portions 41 of the corrugated segment conductor 40B.

In addition, the front end portion 44 of the seventh leg portion 417 inserted into the 28 th slot 2228 and the front end portion 44 of the eighth leg portion 418 are joined and conducted by, for example, laser welding. In addition, the front end portion 44 of the fifth leg portion 415 inserted into the 22 nd slot 2222 and the front end portion 44 of the sixth leg portion 416 are joined and conducted by, for example, laser welding. On the other hand, the joined distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 28 th slot 2228 and the joined distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 22 nd slot 2222 are arranged side by side in a substantially straight line in the radial direction, but are not joined and are not conducted.

Likewise, the front end portion 44 of the seventh leg portion 417 inserted into the 27 th slot 2227 and the front end portion 44 of the eighth leg portion 418 are joined and conducted by, for example, laser welding. In addition, the front end portion 44 of the fifth leg portion 415 inserted into the 21 st slot 2221 and the front end portion 44 of the sixth leg portion 416 are joined and conducted by, for example, laser welding. On the other hand, the joined distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 27 th slot 2227 and the joined distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 21 st slot 2221 are arranged in parallel in a substantially straight line shape in the radial direction, but are not joined and are not conducted.

Further, the front end portion 44 of the seventh leg portion 417 inserted into the 21 st slot 2221 and the front end portion 44 of the eighth leg portion 418 are joined by, for example, laser welding and are electrically conducted. In addition, the front end portion 44 of the fifth leg portion 415 inserted into the 15 th insertion groove 2215 and the front end portion 44 of the sixth leg portion 416 are joined and conducted by, for example, laser welding. On the other hand, the joined distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 21 st slot 2221 and the joined distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 15 th slot 2215 are arranged in parallel in a substantially straight line in the radial direction, but are not joined and are not conductive.

Likewise, the front end portion 44 of the seventh leg portion 417 inserted into the 22 nd slot 2222 and the front end portion 44 of the eighth leg portion 418 are joined and conducted by, for example, laser welding. In addition, the front end portion 44 of the fifth leg portion 415 inserted into the 16 th insertion groove 2216 and the front end portion 44 of the sixth leg portion 416 are joined and conducted by, for example, laser welding. On the other hand, the joined distal end portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 22 nd slot 2222 and the joined distal end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 16 th slot 2216 are arranged in parallel in a substantially straight line in the radial direction, but are not joined and are not conductive.

Further, the tip of first V-phase lead line 51V of V-phase lead line 50V is joined to and conducted by, for example, laser welding with joined tip 44 of seventh leg portion 417 and eighth leg portion 418 inserted into 28 th slot 2228. The distal end 44 of the eighth leg portion 418 inserted into the 28 th slot 2228 serves as a starting point of the winding V1-1, and the distal end 44 of the seventh leg portion 417 inserted into the 28 th slot 2228 serves as a starting point of the winding V2-1.

The tip of second V-phase lead line 52V of V-phase lead line 50V is joined to and conducted by, for example, laser welding with joined tip 44 of seventh leg 417 and eighth leg 418 inserted into 27 th slot 2227. The distal end 44 of the eighth leg portion 418 inserted into the 27 th slot 2227 serves as a starting point of the winding V3-1, and the distal end 44 of the seventh leg portion 417 inserted into the 27 th slot 2227 serves as a starting point of the winding V4-1.

Conventionally, when four windings V1, V2, V3, and V4 are connected in parallel to form a V-phase coil 30V, the V-phase lead wire 50V needs four lead wires having the same number as the parallel connection. In the present embodiment, the tip of first V-phase lead line 51V of V-phase lead line 50V is joined to joined tip 44 of seventh leg 417 and eighth leg 418 inserted into 28 th slot 2228, and the tip of second V-phase lead line 52V is joined to joined tip 44 of seventh leg 417 and eighth leg 418 inserted into 27 th slot 2227. Accordingly, the V-phase lead line 50V can be electrically connected to the windings V1, V2, V3, and V4 by two lead lines, and thus the number of windings connected in parallel for each phase can be increased from two to four without increasing the number of lead lines for each phase.

Next, the winding V1(V1-1, V1-2) and the winding V2(V2-1, V2-2) will be explained.

The winding V1-1 is formed such that, starting from the front end 44 of the eighth leg 418 inserted into the 28 th slot 2228, the eighth leg 418 inserted into the 28 th slot 2228 is connected to the fourth leg 414 inserted into the 33 rd slot 2233 by the bent portion 42, the fourth leg 414 inserted into the 33 th slot 2233 is connected to the second leg 412 inserted into the 39 th slot 2239 by the first joint 451, the second leg 412 inserted into the 39 th slot 2239 is connected to the sixth leg 416 inserted into the 34 th slot 2234 by the bent portion 42, the sixth leg 416 inserted into the 34 th slot 2234 is connected to the eighth leg 418 inserted into the 40 th slot 2240 by the second joint 452, the eighth leg 418 inserted into the 40 th slot 2240 is connected to the fourth leg 414 inserted into the 45 th slot 2245 by the bent portion 42, the fourth leg 414 inserted into the 45 th slot 2245 is connected to the second leg 2203 by the first joint 451, the second leg portion 412 inserted into the third slot 2203 is connected to the sixth leg portion 416 inserted into the 46 th slot 2246 by the bent portion 42, the sixth leg portion 416 inserted into the 46 th slot 2246 is connected to the eighth leg portion 418 inserted into the fourth slot 2204 by the second joint portion 452, the eighth leg portion 418 inserted into the fourth slot 2204 is connected to the fourth leg portion 414 inserted into the ninth slot 2209 by the bent portion 42, the fourth leg portion 414 inserted into the ninth slot 2209 is connected to the second leg portion 412 inserted into the 15 th slot 2215 by the first joint portion 451, the second leg portion 412 inserted into the 15 th slot 2215 is connected to the sixth leg portion 416 inserted into the 10 th slot 2210 by the bent portion 42, the sixth leg portion 416 inserted into the 10 th slot 2210 is connected to the eighth leg portion 418 inserted into the 16 th slot 2216 by the second joint portion 452, the eighth leg portion 418 inserted into the 16 th slot 2216 is connected to the fourth leg portion 22221 by the bent portion 42, the fourth leg portion 414 inserted into the 21 st slot 2221 is connected to the second leg portion 412 inserted into the 27 th slot by the first joint portion 451, the second leg portion 412 inserted into the 27 th slot is connected to the sixth leg portion 416 inserted into the 22 nd slot 2222 by the bent portion 42, and the front end portion 44 of the sixth leg portion 416 inserted into the 22 nd slot 2222 is a terminal point. Thus, the winding V1-1 is wound clockwise around the entire circumference from the distal end 44 of the eighth leg 418 inserted into the 28 th slot 2228 as the starting point to the distal end 44 of the sixth leg 416 inserted into the 22 th slot 2222 as the ending point, as viewed radially outward from the center axis CL of the stator core 20.

The winding V2-1 is formed such that, starting from the front end 44 of the seventh leg 417 inserted into the 28 th slot 2228, the seventh leg 417 inserted into the 28 th slot 2228 is connected to the third leg 413 inserted into the 33 rd slot 2233 by the bent portion 42, the third leg 413 inserted into the 33 th slot 2233 is connected to the first leg 411 inserted into the 39 th slot 2239 by the first joint 451, the first leg 411 inserted into the 39 th slot 2239 is connected to the fifth leg 415 inserted into the 34 th slot 2234 by the bent portion 42, the fifth leg 415 inserted into the 34 th slot 2234 is connected to the seventh leg 417 inserted into the 40 th slot 2240 by the second joint 452, the seventh leg 417 inserted into the 40 th slot 2240 is connected to the third leg 413 inserted into the 45 th slot 2245 by the bent portion 42, the third leg 413 inserted into the 45 th slot 2245 is connected to the first leg 220411 inserted into the first slot 451 by the first joint 451, the first leg 411 inserted into the third slot 2203 is connected to the fifth leg 415 inserted into the 46 th slot 2246 by the bent portion 42, the fifth leg 415 inserted into the 46 th slot 2246 is connected to the seventh leg 417 inserted into the fourth slot 2204 by the second joint 452, the seventh leg 417 inserted into the fourth slot 2204 is connected to the third leg 413 inserted into the ninth slot 2209 by the bent portion 42, the third leg 413 inserted into the ninth slot 2209 is connected to the first leg 411 inserted into the 15 th slot 2215 by the first joint 451, the first leg 411 inserted into the 15 th slot 2215 is connected to the fifth leg 415 inserted into the 10 th slot 2210 by the bent portion 42, the fifth leg 415 inserted into the 10 th slot 2210 is connected to the seventh leg 417 inserted into the 16 th slot 2216 by the second joint 452, the seventh leg 417 inserted into the 16 th slot 2216 is connected to the third leg 22121 by the bent portion 42, the third leg portion 413 inserted into the 21 st slot 2221 is connected to the first leg portion 411 inserted into the 27 th slot by the first joint portion 451, the first leg portion 411 inserted into the 27 th slot is connected to the fifth leg portion 415 inserted into the 22 nd slot 2222 by the bent portion 42, and a front end portion 44 of the fifth leg portion 415 inserted into the 22 nd slot 2222 is a terminal point. Thus, the winding V2-1 is wound clockwise around the circumference from the tip 44 of the seventh leg 417 inserted into the 28 th slot 2228 and joined to the first V-phase lead line 51V as a starting point to the tip 44 of the fifth leg 415 inserted into the 22 th slot 2222 as an ending point, when viewed radially outward from the center axis CL of the stator core 20.

One end of the first V-phase bridge 61V is engaged with and conducted to the engaged tip portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 22 nd slot 2222, and the other end thereof is engaged with and conducted to the engaged tip portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 15 th slot 2215. Therefore, the joined front end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 22 nd slot 2222 and the joined front end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 15 th slot 2215 are electrically connected through the first V-phase bridge 61V.

Further, the front end portion 44 of the sixth leg portion 416 inserted into the 15 th slot 2215 joined to the other end portion of the first V-phase bridge 61V becomes the starting point of the winding V1-2, and the front end portion 44 of the fifth leg portion 415 inserted into the 15 th slot 2215 joined to the other end portion of the first V-phase bridge 61V becomes the starting point of the winding V2-2.

The winding V1-2 is formed such that, starting from the front end portion 44 of the sixth leg portion 416 inserted into the 15 th slot 2215, the sixth leg portion 416 inserted into the 15 th slot 2215 is connected to the second leg portion 412 inserted into the 20 th slot 2220 through the bent portion 42, the second leg portion 412 inserted into the 20 th slot 2220 is connected to the fourth leg portion 414 inserted into the 14 th slot 2214 through the first joint portion 451, the fourth leg portion 414 inserted into the 14 th slot 2214 is connected to the eighth leg portion 418 inserted into the ninth slot 2209 through the bent portion 42, the eighth leg portion 418 inserted into the ninth slot 2209 is connected to the sixth leg portion 416 inserted into the third slot 2203 through the second joint portion 452, the sixth leg portion 416 inserted into the third slot 2203 is connected to the second leg portion 412 inserted into the eighth slot 2208 through the bent portion 42, the second leg portion 412 inserted into the eighth slot 2208 is connected to the fourth leg portion 414 inserted into the second slot 451 through the first joint portion 451, the fourth leg portion 414 inserted into the second slot 2202 is connected to the eighth leg portion 418 inserted into the 45 th slot 2245 through the bent portion 42, the eighth leg portion 418 inserted into the 45 th slot 2245 is connected to the sixth leg portion 416 inserted into the 39 th slot 2239 through the second joint portion 452, the sixth leg portion 416 inserted into the 39 th slot 2239 is connected to the second leg portion 412 inserted into the 44 th slot 2244 through the bent portion 42, the second leg portion 412 inserted into the 44 th slot 2244 is connected to the fourth leg portion 414 inserted into the 38 th slot 2238 through the first joint portion 451, the fourth leg portion 414 inserted into the 38 th slot 2238 is connected to the eighth leg portion 418 inserted into the 33 th slot 2233 through the bent portion 42, the eighth leg portion 418 inserted into the 33 th slot 2233 is connected to the sixth leg portion 416 inserted into the 27 th slot 2227 through the second joint portion 452, the sixth leg portion 416 inserted into the 27 th slot 2227 is connected to the second leg portion 412 inserted into the second slot 2232 through the bent portion 42, the second leg portion 412 inserted into the 32 th slot 2232 is connected to the fourth leg portion 414 inserted into the 26 th slot by the first joint portion 451, the fourth leg portion 414 inserted into the 26 th slot is connected to the eighth leg portion 418 inserted into the 21 st slot 2221 by the bent portion 42, and the front end portion 44 of the eighth leg portion 418 inserted into the 21 st slot 2221 is a terminal point. Thus, the winding V1-2 is wound counterclockwise around the tip 44 of the sixth leg portion 416 inserted into the 15 th slot 2215 and joined to the second V-phase bridge 62V to the tip 44 of the eighth leg portion 418 of the 21 st slot 2221, when viewed radially outward from the center axis CL of the stator core 20.

The winding V2-2 is formed such that, starting from the front end portion 44 of the fifth leg portion 415 inserted into the 15 th slot 2215, the fifth leg portion 415 inserted into the 15 th slot 2215 is connected to the first leg portion 411 inserted into the 20 th slot 2220 through a bent portion 42, the first leg portion 411 inserted into the 20 th slot 2220 is connected to the third leg portion 413 inserted into the 14 th slot 2214 through a first joint portion 451, the third leg portion 413 inserted into the 14 th slot 2214 is connected to the seventh leg portion 417 inserted into the ninth slot 2209 through a bent portion 42, the seventh leg portion 417 inserted into the ninth slot 2209 is connected to the fifth leg portion 415 inserted into the third slot 2203 through a second joint portion 452, the fifth leg portion 415 inserted into the third slot 2203 is connected to the first leg portion 411 inserted into the eighth slot 2208 through a bent portion 42, the first leg portion 411 inserted into the eighth slot 2208 is connected to the third leg portion 2202 inserted into the second slot 451 through a first joint portion 451, the third leg portion 413 inserted into the second slot 2202 is connected to the seventh leg portion 417 inserted into the 45 th slot 2245 through the bent portion 42, the seventh leg portion 417 inserted into the 45 th slot 2245 is connected to the fifth leg portion 415 inserted into the 39 th slot 2239 through the second joint portion 452, the fifth leg portion 415 inserted into the 39 th slot 2239 is connected to the first leg portion 411 inserted into the 44 th slot 2244 through the bent portion 42, the first leg portion 411 inserted into the 44 th slot 2244 is connected to the third leg portion 413 inserted into the 38 th slot 2238 through the first joint portion 451, the third leg portion 413 inserted into the 38 th slot 2238 is connected to the seventh leg portion 417 inserted into the 33 th slot 2233 through the bent portion 42, the seventh leg portion 417 inserted into the 33 th slot 2233 is connected to the fifth leg portion 415 inserted into the 27 th slot 2227 through the second joint portion 452, the fifth leg portion 415 inserted into the 27 th slot 2227 is connected to the first leg portion 2232 through the bent portion 42, the first leg portion 411 inserted into the 32 th slot 2232 is connected to the third leg portion 413 inserted into the 26 th slot by the first engaging portion 451, the third leg portion 413 inserted into the 26 th slot is connected to the seventh leg portion 417 inserted into the 21 st slot 2221 by the bent portion 42, and the front end portion 44 of the seventh leg portion 417 inserted into the 21 st slot 2221 is a terminal. Thus, the winding V2-2 is wound counterclockwise around the circumference from the distal end portion 44 of the fifth leg portion 415 inserted into the 15 th slot 2215 and joined to the second V-phase bridge 62V as a starting point to the distal end portion 44 of the seventh leg portion 417 of the 21 st slot 2221 as an ending point, as viewed radially outward from the center axis CL of the stator core 20.

The engaged tip portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 21 st slot 2221 are engaged with the neutral point 70 and are electrically connected.

Next, the winding V3(V3-1, V3-2) and the winding V4(V4-1, V4-2) will be explained.

The winding V3-1 is formed so as to be wound in the same manner as the winding V1-1 at a position shifted counterclockwise by one slot 22 with respect to the winding V1-1 when viewed from the first end face 201 side of the stator core 20. Accordingly, the winding V3-1 starts at the leading end 44 of the eighth leg 418 inserted into the 27 th slot 2227 and ends at the leading end 44 of the sixth leg 416 inserted into the 21 st slot 2221. The winding V3-1 is wound clockwise around the entire circumference from the distal end 44 of the eighth leg 418 inserted into the 27 th slot 2227 as a starting point to the distal end 44 of the sixth leg 416 inserted into the 21 st slot 2221 as an ending point when viewed radially outward from the center axis CL of the stator core 20.

The winding V4-1 is formed so as to be wound in the same manner as the winding V2-1 at a position shifted counterclockwise by one slot 22 with respect to the winding V2-1 when viewed from the first end surface 201 side of the stator core 20. Therefore, the winding V4-1 starts at the front end 44 of the seventh leg 417 inserted into the 27 th slot 2227 and ends at the front end 44 of the fifth leg 415 inserted into the 21 st slot 2221. The winding V4-1 is wound clockwise around the circumference from the distal end portion 44 of the seventh leg portion 417 inserted into the 27 th slot 2227 as a starting point to the distal end portion 44 of the fifth leg portion 415 inserted into the 21 st slot 2221 as an ending point when viewed radially outward from the center axis CL of the stator core 20.

One end of the second V-phase bridge 62V is engaged with and conducted to the engaged tip portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 21 st slot 2221, and the other end thereof is engaged with and conducted to the engaged tip portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 16 th slot 2216. Therefore, the joined front end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 21 st slot 2221 and the joined front end portions 44 of the fifth leg portion 415 and the sixth leg portion 416 inserted into the 16 th slot 2216 are electrically connected via the second V-phase bridge 62V.

Further, the front end portion 44 of the sixth leg portion 416 inserted into the 16 th slot 2216 joined to the other end portion of the second V-phase bridge 62V becomes the starting point of the winding V3-2, and the front end portion 44 of the fifth leg portion 415 inserted into the 16 th slot 2216 joined to the other end portion of the second V-phase bridge 62V becomes the starting point of the winding V4-2.

The winding V3-2 is formed so as to be wound in the same manner as the winding V1-2 at a position shifted by one slot 22 clockwise with respect to the winding V1-2 when viewed from the first end surface 201 side of the stator core 20. Thus, the winding V3-2 starts at the front end 44 of the sixth leg 416 inserted into the 16 th slot 2216 and ends at the front end 44 of the eighth leg 418 inserted into the 22 th slot 2222. The winding V3-2 is wound counterclockwise around the circumference from the distal end portion 44 of the sixth leg portion 416 inserted into the 16 th slot 2216 as a starting point to the distal end portion 44 of the eighth leg portion 418 inserted into the 22 th slot 2222 as an end point when viewed radially outward from the center axis CL of the stator core 20.

The winding V4-2 is formed so as to be wound in the same manner as the winding V2-2 at a position shifted by one slot 22 clockwise with respect to the winding V2-2 when viewed from the first end surface 201 side of the stator core 20. Therefore, the winding V4-2 starts at the tip portion 44 of the fifth leg portion 415 inserted into the 16 th slot 2216 and ends at the tip portion 44 of the seventh leg portion 417 inserted into the 22 th slot 2222. The winding V4-2 is wound around the circumference counterclockwise from the distal end portion 44 of the fifth leg portion 415 inserted into the 16 th slot 2216 as a starting point to the distal end portion 44 of the seventh leg portion 417 inserted into the 22 th slot 2222 as an end point when viewed radially outward from the center axis CL of the stator core 20.

The engaged tip portions 44 of the seventh leg portion 417 and the eighth leg portion 418 inserted into the 22 nd slot 2222 are engaged with the neutral point 70 and are electrically connected.

In this way, the slant portions 43 of the first leg portion 411 and the second leg portion 412 are slanted in the counterclockwise direction in the circumferential direction, the slant portions 43 of the third leg portion 413 and the fourth leg portion 414 are slanted in the clockwise direction in the circumferential direction, the slant portions 43 of the fifth leg portion 415 and the sixth leg portion 416 are slanted in the clockwise direction in the circumferential direction, and the slant portions 43 of the seventh leg portion 417 and the eighth leg portion 418 are slanted in the counterclockwise direction in the circumferential direction, whereby the windings V1 and the windings V2 connected in parallel can be easily configured by the first leg portion 411 and the second leg portion 412, the third leg portion 413 and the fourth leg portion 414, the fifth leg portion 415 and the sixth leg portion 416, and the seventh leg portion 417 and the eighth leg portion 418. Accordingly, an eight-layer four-parallel rotating electrical machine in which the leg portions 41 of the segment conductors 40 are inserted into the slots 22 in a row of eight layers in the radial direction and the four windings V1, V2, V3, and V4 are connected in parallel can be easily configured, and therefore a larger current can be caused to flow through the V-phase coil 30V, and high output and high torque can be achieved.

In addition, in the conventional case where four windings V1, V2, V3, and V4 are connected in parallel to form a V-phase coil 30V, four bridges having the same number as the parallel connection are required. In the present embodiment, the four windings V1, V2, V3, and V4 can be connected in parallel by the first V-phase bridge 61V and the second V-phase bridge 62V, which are two bridges. In this way, since four windings can be connected in parallel by two bridges, the number of parallel connections of the windings of each phase can be increased from two to four without increasing the number of bridges of each phase.

Although the detailed description of the configurations of the U-phase coil 30U and the W-phase coil 30W is omitted, the U-phase coil 30U has the same configuration as the V-phase coil 30V except that it is shifted by four slots 22 counterclockwise with respect to the V-phase coil 30V when viewed from the first end surface 201 side of the stator core 20 as shown in fig. 11. The W-phase coil 30W has the same configuration as the V-phase coil 30V except that it is offset clockwise by four slots 22 with respect to the V-phase coil 30V when viewed from the first end surface 201 side of the stator core 20.

In fig. 11, U, V, W in reference numerals (18U, 25V, 31W, etc.) assigned to the first leg 411 to the eighth leg 418 inserted into the first slot 2201 to the 48 th slot 2248, respectively, indicate which phase of the windings constitutes U phase, V phase, W phase, and the numerical portion indicates the leg 41 connected several times from the U-phase lead line 50U, V phase lead line 50V and the W-phase lead line 50W, that is, indicates the connection order of the legs 41.

Thus, the windings U1 to U4, V1 to V4, and W1 to W4 are formed by the segment conductors 40 inserted into the slots 22 of the stator core 20, and thereby an eight-layer four-parallel rotary electric machine in which eight layers of the legs 41 are inserted into the slots 22 in a row in the radial direction and four windings of each phase are connected in parallel can be configured.

< loss in coil >

In general, when a current flows through a coil of a rotating electric machine, a copper loss Wc represented by the following formula (1) occurs due to a winding resistance of a winding that forms the coil.

Wc＝R×i²…(1)

Wc: copper loss [ W ]

R: winding resistance [ omega ]

i: current flowing through the winding [ A ]

Therefore, the larger the cross-sectional area of the winding constituting the coil, the smaller the winding resistance, and the copper loss Wc decreases in proportion to the winding resistance. In addition, the smaller the current flowing through the winding, the copper loss Wc decreases in proportion to the current flowing through the winding.

In the case of realizing high output and high torque of the rotating electric machine, one of the methods is to increase the current flowing through the coil. In this case, if the number of parallel windings of the coil is increased, the current flowing through the windings can be equally divided, and therefore, even if the current flowing through the coil is increased, the current flowing through the windings does not increase.

In the rotating electric machine, when the rotor rotates, leakage magnetic flux in the circumferential direction flows from the rotor side to the stator core side. When the leakage magnetic flux flows through the conductor portion of the winding that constitutes the coil, an eddy current is generated in the conductor portion of the winding, and an eddy current loss We represented by the following expression (2) is generated.

We∝f²Bm²t²…(2)

We: eddy current loss [ W ]

f: frequency [ Hz ]

Bm: magnetic flux density [ T ]

t: radial thickness of conductor part of winding [ m ]

Therefore, the smaller the radial thickness of the conductor portion of the winding, the smaller the eddy current loss We decreases in proportion to the square of the radial thickness of the conductor portion of the winding.

A four-layer two-parallel rotating electrical machine in which the same stator core 20 is used, and the leg portions of the segment conductors having the radial thickness of about twice the radial thickness of the present embodiment are inserted into the slots 22 in a row in the radial direction, and two windings of each phase are connected in parallel is compared with the copper loss Wc and the eddy current loss We of the eight-layer four-parallel rotating electrical machine of the present embodiment.

In the case of the four-layer two-parallel rotating electric machine, the leg 41 of the eight-layer four-parallel rotating electric machine according to the present embodiment has a radial thickness half of the radial thickness thereof, and therefore the winding resistance R is doubled, but the number of parallel windings is doubled, and therefore the current i flowing through the windings is halved. Therefore, according to the equation (1), the copper loss Wc of the eight-layer four-parallel rotating electric machine of the present embodiment is theoretically about 1/2 of the four-layer two-parallel rotating electric machine.

On the other hand, in the case of the four-layer two-parallel rotating electric machine, the radial thickness of the leg portion 41 of the eight-layer four-parallel rotating electric machine of the present embodiment is half of the radial thickness thereof, and therefore, according to equation (2), the eddy current loss We of the eight-layer four-parallel rotating electric machine of the present embodiment is theoretically about 1/4 of the four-layer two-parallel rotating electric machine.

Further, the eddy current loss We becomes larger in proportion to the square of the frequency. Therefore, the higher the speed of the rotating electrical machine, the higher the frequency, and the eddy current loss We becomes larger in proportion to the square of the frequency. Therefore, when the loss generated in the four-layer two-parallel rotating electric machine in which the leg portions of the segment conductors having the four layers and the radial thickness of which is approximately twice as thick as the present embodiment are inserted in the slots 22 in a row in the radial direction and the two windings of each phase are connected in parallel is compared with the loss generated in the eight-layer four-parallel rotating electric machine of the present embodiment, the loss generated in the eight-layer four-parallel rotating electric machine of the present embodiment can be greatly reduced as compared with the four-layer two-parallel rotating electric machine, in particular, when the rotating electric machine is driven to rotate at a higher speed.

Further, since the amount of heat generated by each winding increases in proportion to the current density of the current flowing therethrough, it is desirable that the current flowing through each winding be equal to or less than the upper limit value of the current having the current density of a predetermined value or less, from the viewpoint of heat generation and cooling of the rotating electrical machine. Since the radial thickness of the winding of the coil constituting the four-layer two-parallel rotating electric machine is about twice as thick as that of the present embodiment, the upper limit value of the current having the current density of one winding of the coil constituting the eight-layer four-parallel rotating electric machine of the present embodiment equal to or lower than the predetermined value is 1/2 of the upper limit value of the current having the current density of one winding of the coil constituting the four-layer two-parallel rotating electric machine equal to or lower than the predetermined value. On the other hand, the four-layer two-parallel rotating electric machines are connected in parallel in two, and therefore, the current can be equally divided into two windings, whereas the eight-layer four-parallel rotating electric machines of the present embodiment are connected in parallel in four, and therefore, the current can be equally divided into four windings. That is, in the eight-layer four-parallel rotating electrical machine according to the present embodiment, the upper limit value of the current having the current density of one winding equal to or less than the predetermined value is halved as compared with the four-layer two-parallel rotating electrical machine, but the number of windings through which the current can flow in parallel is doubled. Therefore, the current flowing through the coils of the eight-layer four-parallel rotating electric machines of the present embodiment can be made substantially equal to the upper limit value of the current that can flow through the coils of the four-layer two-parallel rotating electric machines.

Next, an eight-layer two-parallel rotating electrical machine in which eight layers of leg portions of segment conductors having the same cross section as that of the present embodiment are inserted in each slot 22 in a row in the radial direction and two windings of each phase are connected in parallel is compared with an eight-layer four-parallel rotating electrical machine of the present embodiment.

In the eight-layer two-parallel rotating electrical machine and the eight-layer four-parallel rotating electrical machine according to the present embodiment, the leg portions of the eight-layer same segment conductors are inserted into the slots 22 in a row in the radial direction, and therefore the eddy current loss We is theoretically substantially the same.

However, when the same current is caused to flow through the coils of the eight-layer two-parallel rotating electric machine and the coils of the eight-layer four-parallel rotating electric machine of the present embodiment, approximately twice the current that flows through the coils of the eight-layer two-parallel rotating electric machine of the present embodiment flows through the windings that constitute the coils of the eight-layer four-parallel rotating electric machine of the present embodiment. That is, since the current flowing through the windings of the coils constituting the eight-layer four-parallel rotating electric machine of the present embodiment is about 1/2 of the current flowing through the windings of the coils constituting the eight-layer two-parallel rotating electric machine, the copper loss Wc generated in the eight-layer four-parallel rotating electric machine of the present embodiment is about 1/2 of the copper loss Wc of the eight-layer two-parallel rotating electric machine.

Further, since the amount of heat generated by each winding increases in proportion to the current density of the current flowing, it is desirable from the viewpoint of heat generation and cooling of the rotating electrical machine that the current flowing through each winding is equal to or less than the upper limit value of the current whose current density is equal to or less than the predetermined value, but since the eight-layer two-parallel rotating electrical machine and the eight-layer four-parallel rotating electrical machine of the present embodiment have segment conductors having the same cross section, the upper limit value of the current whose current density is equal to or less than the predetermined value is the same for one winding. On the other hand, since the eight-layer two-parallel rotating electric machine is connected in parallel, the current can be divided into two and flows through the two windings, and therefore the upper limit of the current that can flow through the coil so that the current density becomes equal to or lower than the predetermined value is approximately twice the upper limit of the current that can flow through one winding so that the current density becomes equal to or lower than the predetermined value. In contrast, since the eight-layer four-parallel rotating electric machine according to the present embodiment is four-parallel connected, the current can be equally divided into four windings, and therefore the upper limit of the current that can be passed through the coil so that the current density becomes equal to or lower than the predetermined value is approximately four times the upper limit of the current that can be passed through one winding so that the current density becomes equal to or lower than the predetermined value. Therefore, the upper limit of the current that can flow through the coils of the eight-layer four-parallel rotating electric machine of the present embodiment so that the current density becomes equal to or less than the predetermined value is approximately twice the upper limit of the current that can flow through the coils of the eight-layer two-parallel rotating electric machine so that the current density becomes equal to or less than the predetermined value. In this way, the eight-layer four-parallel rotating electrical machine of the present embodiment can pass a larger current through the coil than the eight-layer two-parallel rotating electrical machine, and therefore can achieve a high output and a high torque.

In this way, the stator 10 of the eight-layer four-parallel rotating electrical machine of the present embodiment can achieve high output and high torque of the rotating electrical machine, and can reduce the loss generated by the rotating electrical machine.

< relationship between aspect ratio and coil loss >

The segment conductor 40 is provided with an insulating coating portion 402 on a conductor portion 401 having a substantially rectangular cross section. In the radial thickness Lt of the conductor portion 401 and the circumferential width Lw of the conductor portion 401, the aspect ratio is represented by the radial thickness Lt/the circumferential width Lw. The relationship between the aspect ratio and the coil loss in the present embodiment will be described with reference to fig. 12.

As shown in fig. 12, the copper loss Wc increases as the aspect ratio decreases. On the other hand, the eddy current loss We increases with an increase in the aspect ratio. When the aspect ratio is in the range of 0.5 or more and 0.7 or less, the sum of the copper loss Wc and the eddy current loss We becomes small. In particular, the sum of the copper loss Wc and the eddy current loss We becomes smaller in the range of 0.55 or more and 0.65 or less in the aspect ratio, and the sum of the copper loss Wc and the eddy current loss We becomes minimum in the range of about 0.6 in the aspect ratio.

The aspect ratio represented by the radial thickness Lt/circumferential width Lw of the conductor portion 401 of the segment conductor 40 of the present embodiment is 0.5 or more and 0.7 or less. Preferably, the aspect ratio represented by the radial thickness Lt/circumferential width Lw of the conductor portion 401 of the segment conductor 40 is 0.55 or more and 0.65 or less. More preferably, the aspect ratio represented by the radial thickness Lt/circumferential width Lw of the conductor portion 401 of the segment conductor 40 is 0.6. This can further reduce the loss in the coil 30.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and modifications, improvements, and the like can be appropriately made.

For example, in the present embodiment, the segment conductor 40 is formed in a substantially U shape including a pair of leg portions 41 extending parallel to each other and having a first end portion 41a and a second end portion 41b, and a bent portion 42 connecting the second end portions 41b of the pair of leg portions 41 to each other, but the segment conductor 40 may be joined by welding or the like without connecting the second end portions 41b of the leg portions 41 by the bent portion 42.

In the present specification, at least the following matters are described. Note that, although the corresponding components and the like in the above-described embodiments are shown in parentheses, the present invention is not limited to these.

(1) A stator (stator 10) of a rotating electric machine is provided with:

a substantially annular stator core (stator core 20) having a plurality of teeth (teeth 21) protruding radially inward at predetermined intervals in a circumferential direction and a plurality of slots (slots 22) which are spaces between the circumferentially adjacent teeth; and

a coil (coil 30) having a plurality of segment conductors (segment conductors 40) inserted into the plurality of slots, respectively,

each of the segment conductors has a leg portion (leg portion 41) arranged inside the slot and extending substantially linearly in the axial direction,

one end (first end 41a) of the leg in the axial direction protrudes outward from one end surface (first end surface 201) of the stator core in the axial direction, and is formed with a diagonal portion (diagonal portion 43) extending diagonally in a first direction (clockwise direction) or a second direction (counterclockwise direction) in the circumferential direction and a tip portion (tip portion 44) extending outward in the axial direction from a tip of the diagonal portion,

the eight segment conductors inserted into the slots in a row in the radial direction have, as counted from the radially inner side, a first leg (first leg 411) disposed in the first layer, a second leg (second leg 412) disposed in the second layer, a third leg (third leg 413) disposed in the third layer, a fourth leg (fourth leg 414) disposed in the fourth layer, a fifth leg (fifth leg 415) disposed in the fifth layer, a sixth leg (sixth leg 416) disposed in the sixth layer, a seventh leg (seventh leg 417) disposed in the seventh layer, and an eighth leg (eighth leg 418) disposed in the eighth layer,

the coil has:

a first joint portion (first joint portion 451) at which four tip portions, that is, the tip portions of the first leg portion and the second leg portion, and the tip portions of the third leg portion and the fourth leg portion inserted into the insertion grooves that are offset by a predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction, are integrally joined and conducted, and

and a second joint portion (second joint portion 452) in which four distal end portions, that is, the distal end portion of the fifth leg portion and the distal end portion of the sixth leg portion, and the distal end portion of the seventh leg portion and the distal end portion of the eighth leg portion inserted into the insertion grooves that are offset from the predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction, are integrally joined and conducted.

According to (1), since the diagonal portions of the first leg portion to the eighth leg portion are identical in diagonal direction in the circumferential direction for each two layers, the diagonal portions of the first leg portion to the eighth leg portion can be formed by one driving source for each two layers. Accordingly, the oblique portions of the first to eighth legs can be formed with a small number of driving sources, and therefore, the manufacturing apparatus for forming the oblique portions of the first to eighth legs can be simplified, and the manufacturing cost of the stator can be reduced.

(2) The stator of a rotating electric machine according to (1), wherein,

the distal end portion of the second leg portion, the distal end portion of the third leg portion, and the distal end portion of the fourth leg portion are bent so as to be inclined radially inward,

the distal end portion of the fifth leg portion, the distal end portion of the sixth leg portion, and the distal end portion of the seventh leg portion are bent so as to be inclined radially outward.

According to (2), since the distal end portion of the second leg portion, the distal end portion of the third leg portion, and the distal end portion of the fourth leg portion are bent so as to be inclined radially inward, and the distal end portion of the fifth leg portion, the distal end portion of the sixth leg portion, and the distal end portion of the seventh leg portion are bent so as to be inclined radially outward, the radial interval between the distal end portion of the fourth leg portion and the distal end portion of the fifth leg portion, that is, the radial interval between the first joint portion and the second joint portion increases. This can further increase the partial discharge start voltage of the coil.

(3) The stator of a rotating electric machine according to (2), wherein,

the front end portion of the first leg portion extends substantially parallel to the axial direction.

According to (3), since the tip end portion of the first leg portion extends parallel to the axial direction, the radial distance between the tip end portion of the fourth leg portion and the tip end portion of the fifth leg portion can be increased without increasing the radial length of the coil end portion that protrudes outward from the one end surface in the axial direction of the stator core.

(4) The stator of a rotating electric machine according to (2) or (3), wherein,

an inclination angle (inclination angle theta 3) of the distal end portion of the third leg portion with respect to the axial direction radially inward side is larger than an inclination angle (inclination angle theta 2) of the distal end portion of the second leg portion with respect to the axial direction radially inward side,

an inclination angle (inclination angle θ 4) of the distal end portion of the fourth leg portion to the radially inner side in the axial direction is larger than an inclination angle (inclination angle θ 3) of the distal end portion of the third leg portion to the radially inner side in the axial direction.

According to (4), since the distal end portion of the fourth leg portion is bent so as to be inclined most inward in the radial direction, the radial distance between the distal end portion of the fourth leg portion and the distal end portion of the fifth leg portion can be increased.

(5) The stator of a rotating electric machine according to any one of (1) to (4),

the distal end portion of the first leg and the distal end portion of the second leg, which form the first joint portion, and the distal end portion of the third leg and the distal end portion of the fourth leg, which are inserted into the insertion grooves that are offset from the predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction, are joined in a row in the radial direction in order from the radially inner side in the order of the distal end portion of the first leg, the distal end portion of the second leg, the distal end portion of the third leg, and the distal end portion of the fourth leg.

According to (5), the distal end portion of the first leg portion and the distal end portion of the second leg portion, and the distal end portion of the third leg portion and the distal end portion of the fourth leg portion inserted into the insertion grooves offset by the predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction are joined in a row in the radial direction in the order of the distal end portion of the first leg portion, the distal end portion of the second leg portion, the distal end portion of the third leg portion, and the distal end portion of the fourth leg portion from the radially inner side, so that the first joint portion can be easily formed.

(6) The stator of a rotating electric machine according to any one of (2) to (5),

the front end portion of the eighth leg portion extends substantially parallel to the axial direction.

According to (6), since the tip end portion of the eighth leg portion extends parallel to the axial direction, the radial distance between the tip end portion of the fourth leg portion and the tip end portion of the fifth leg portion can be increased without increasing the radial length of the coil end portion that protrudes outward from the one end surface in the axial direction of the stator core.

(7) The stator of a rotating electric machine according to any one of (2) to (6),

an inclination angle (inclination angle θ 6) of the distal end portion of the sixth leg portion with respect to the axial direction and the radial direction is larger than an inclination angle (inclination angle θ 7) of the distal end portion of the seventh leg portion with respect to the axial direction and the radial direction,

an inclination angle (inclination angle θ 5) of the tip portion of the fifth leg portion with respect to the axial direction radially outward is larger than an inclination angle (inclination angle θ 6) of the tip portion of the sixth leg portion with respect to the axial direction radially outward.

According to (7), since the distal end portion of the fifth leg portion is bent so as to be inclined most outward in the radial direction, the radial distance between the distal end portion of the fourth leg portion and the distal end portion of the fifth leg portion can be increased.

(8) The stator of a rotating electric machine according to any one of (1) to (7),

the tip end portions of the fifth leg and the sixth leg, and the tip end portions of the seventh leg and the eighth leg inserted into the slots offset from the predetermined number of slots in the first direction or the second direction in the circumferential direction, which form the second joint portion, are joined in a row in the radial direction in the order of the tip end portion of the fifth leg, the tip end portion of the sixth leg, the tip end portion of the seventh leg, and the tip end portion of the eighth leg from the radially inner side.

According to (8), the tip end portion of the fifth leg and the tip end portion of the sixth leg, and the tip end portion of the seventh leg and the tip end portion of the eighth leg inserted into the insertion groove offset by the predetermined number of insertion grooves in the first direction or the second direction in the circumferential direction are joined in a row in the radial direction from the radially inner side in the order of the tip end portion of the fifth leg, the tip end portion of the sixth leg, the tip end portion of the seventh leg, and the tip end portion of the eighth leg, so the second joint portion can be easily formed.

Claims

1. A stator of a rotating electric machine is provided with:

the coil has:

2. The stator of the rotating electric machine according to claim 1,

3. The stator of the rotating electric machine according to claim 2,

4. The stator of the rotating electric machine according to claim 2 or 3,

the angle of inclination of the front end portion of the third leg portion with respect to the axial direction is larger than the angle of inclination of the front end portion of the second leg portion with respect to the axial direction,

an inclination angle of the tip portion of the fourth leg portion with respect to the axial direction is larger than an inclination angle of the tip portion of the third leg portion with respect to the axial direction.

5. The stator of the rotating electric machine according to any one of claims 1 to 4,

6. The stator of the rotating electric machine according to any one of claims 2 to 5,

7. The stator of the rotating electric machine according to any one of claims 2 to 6,

an inclination angle of the front end portion of the sixth leg portion with respect to the axial direction is larger than an inclination angle of the front end portion of the seventh leg portion with respect to the axial direction,

an inclination angle of the front end portion of the fifth leg with respect to the axial direction is larger than an inclination angle of the front end portion of the sixth leg with respect to the axial direction.

8. The stator of the rotating electric machine according to any one of claims 1 to 7,