GB2553242A

GB2553242A - Rotating electrical machine stator, rotating electrical machine, rotating electrical machine stator production method

Info

Publication number: GB2553242A
Application number: GB1716302.3A
Authority: GB
Inventors: Hakoda Satoshi
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2015-06-24
Filing date: 2016-06-22
Publication date: 2018-02-28
Also published as: WO2016208629A1; JPWO2016208629A1; JP6334823B2; GB201716302D0; AU2016284404B2; AU2016284404A1; TWI599142B; TW201711344A

Abstract

A rotating electrical machine is provided with: a divided laminated yoke section (31a); and two laminated teeth sections (31b, 31c) on both ends of the divided laminated yoke section (31a). In the two laminated teeth sections (31b, 31c) and the divided yoke section (31a), the longitudinal direction of each laminated teeth sections (31b, 31c) and the longitudinal direction of the divided laminated yoke section (31a) are the same direction, and from a state in which each of the laminated teeth sections (31b, 31c) are lined up straight on both ends of the divided laminated yoke section (31a) in the longitudinal direction, the two laminated teeth sections (31b, 31c) are bendably or rotatably coupled to the divided laminated yoke section (31a) so as to be in a state facing the inner side of the stator (3).

Description

(56) Documents Cited:

JP 2003284268 A JP 2000232740 A JP3193357

H02K1/12 (2006.01) H02K 15/095 (2006.01)

JP 2003134701 A US 20130093374 A1 (86) International Application Data:

PCT/JP2016/068529 Ja 22.06.2016 (58) Field of Search: INT CL H02K (87) International Publication Data:

WO2016/208629 Ja 29.12.2016 (71) Applicant(s):

Mitsubishi Electric Corporation (Incorporated in Japan)

7-3 Marunouchi 2-chome, Chiyoda-ku, Tokyo 100-8310, Japan (72) Inventor(s):

Satoshi Hakoda (74) Agent and/or Address for Service:

Mewburn Ellis LLP

City Tower, 40 Basinghall Street, LONDON, Greater London, EC2V 5DE, United Kingdom (54) Title of the Invention: Rotating electrical machine stator, rotating electrical machine, rotating electrical machine stator production method

Abstract Title: Rotating electrical machine stator, rotating electrical machine, rotating electrical machine stator production method (57) A rotating electrical machine is provided with: a divided laminated yoke section (31a); and two laminated teeth sections (31b, 31c) on both ends of the divided laminated yoke section (31a). In the two laminated teeth sections (31b, 31c) and the divided yoke section (31a), the longitudinal direction of each laminated teeth sections (31b, 31c) and the longitudinal direction of the divided laminated yoke section (31a) are the same direction, and from a state in which each of the laminated teeth sections (31b, 31c) are lined up straight on both ends of the divided laminated yoke section (31a) in the longitudinal direction, the two laminated teeth sections (31b, 31c) are bendably or rotatably coupled to the divided laminated yoke section (31a) so as to be in a state facing the inner side of the stator (3).

MU

19°

31czr

1/14

Csll col

o CM ^l·
	O
	CM
	CO

FIG. 1

32czr i

2/14

FIG. 2

COUPLING STEP

3/14

FIG. 3

4/14

FIG. 4

OQ

5/14

FIG.5

6/14

FIG. 6

OQ

7/14

FIG. 7

8/14

9/14

CM

OO

10/14

FIG. 10

▼

11/14

FIG. 11

31czr 32czr

12/14

FIG. 12 :

Ψ

13/14

FIG. 13

331b

I__I

14/14

FIG. 14

DESCRIPTION

ROTATING ELECTRICAL MACHINE STATOR, ROTATING ELECTRICAL

MACHINE, ROTATING ELECTRICAL MACHINE STATOR PRODUCTION METHOD

TECHNICAL FIELD [0001] The present invention relates to a stator for a rotating electrical machine, a rotating electrical machine, and a method for producing the stator for the rotating electrical machine.

BACKGROUND ART [0002] Conventionally, the stator of a brushless motor having a permanent magnet-type rotor includes a circular yoke and a plurality of pole arms that project radially inward from the yoke (see, for example, Patent Document 1).

Regarding the stator proposed in Patent Document 1, the outer peripheral shape of a cross-section perpendicular to an axial direction is changed from a circle to a rectangle, and the stator has a configuration in which two cores each of which includes a linear yoke and two pole arms extending from both end portions of the yoke in a direction perpendicular to the yoke and in each of which the outer peripheral shape of a cross-section perpendicular to an axial direction is a C shape, are arranged such that the pole arms thereof oppose each other.

[0003] By changing the outer peripheral shape of the stator from a circle to a rectangle, the filling factor of the stator (the proportion of the stator components relative to the outer shape of the stator) can be increased, resulting in a small-size and high-efficiency rotating electrical machine. In addition, regarding a stator having a circular outer peripheral shape, the operating range of a winding machine is limited in order to avoid interference between each of the pole arms adjacent to each other and the winding 10 machine during winding of a coil. Meanwhile, regarding each pole arm in an outer peripheral shape that is a C shape, the operating range of the winding machine is not limited at a side at which the pole arms are not adjacent to each other. Accordingly, it becomes easier to wind a coil in a regularly aligned manner with respect to the pole arms, so that the density of the coil is increased.

CITATION LIST

PATENT DOCUMENT [0004] Patent Document 1: Japanese Utility Model

Registration No. 3193357, paragraphs 0002 to 0005

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION [0005] Regarding the stator of the rotating electrical machine disclosed in Patent Document 1, during winding of a coil, the operating range of a winding machine is not limited at the side at which the respective pole arms are not adjacent to each other. However, in slot spaces at the side at which the respective pole arms are adjacent to each other, a gap into which a nozzle of the winding machine is to be inserted is required between two tooth portions, and a space having a size corresponding to the width of the nozzle finally remains between a coil and a coil, so that there is a problem that the coil space factor cannot be improved.

[0006] The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a stator for a rotating electrical machine having a high coil space factor, a rotating electrical machine, and a method for producing the stator for the rotating electrical machine.

SOLUTION TO THE PROBLEMS [0007] A stator for a rotating electrical machine according to the present invention includes:

a plurality of substantially U-shaped divided stacked cores each formed by stacking core pieces; and a coil wound on each stacked tooth portion of each divided stacked core, wherein each divided stacked core includes a divided stacked yoke portion, and the two stacked tooth portions at both ends of the divided stacked yoke portion, and the two stacked tooth portions and the divided stacked yoke portion are connected to each other such that the two stacked tooth portions are rotatable or bendable relative to the divided stacked yoke portion from a state where a longitudinal direction of each stacked tooth portion and a longitudinal direction of the divided stacked yoke portion coincide with each other and the stacked tooth portions are aligned straight at both ends in the longitudinal direction of the divided stacked yoke portion, to a state where the two stacked tooth portions face an inner side of the stator.

[0008] A rotating electrical machine according to the present invention includes the stator and a rotor rotatably inserted into the inner side of the stator.

[0009] A method for producing a stator for a rotating electrical machine according to the present invention includes :

a core piece production step of cutting out, from an electromagnetic steel plate, a core piece in which a divided yoke portion and tooth portions at both ends of the divided yoke portion are arranged straight in a band shape such that a longitudinal direction of the divided yoke portion and a longitudinal direction of each tooth portion coincide with each other;

a stacking step of stacking a plurality of the core pieces to form a divided stacked core intermediate, in which a stacked divided yoke portion in which the divided yoke portions are stacked and two stacked tooth portions in which the two tooth portions are stacked, are stacked so as to be bendable or rotatable by connection portions;

a positioning/fixing step of positioning and fixing the divided stacked core intermediate to a winding machine such that an axial direction of a rotation shaft of a flyer of the winding machine coincides with a longitudinal direction of the divided stacked core intermediate;

a first winding step of winding a coil on one of the stacked tooth portions;

a second winding step of winding the coil on the other of the stacked tooth portions;

a bending step of bending the two stacked tooth portions of the divided stacked core intermediate on which the coil has been wound, at the connection portions in the same direction to form a substantially U-shaped divided stacked core; and a coupling step of fixing free end portions of the stacked tooth portions of a plurality of the divided stacked cores adjacent to each other, to each other.

EFFECT OF THE INVENTION [0010] In the stator for the rotating electrical machine, the rotating electrical machine, and the method for producing the stator for the rotating electrical machine according to the present invention, since the divided stacked yoke portion and the stacked tooth portions of the divided stacked core intermediate are arranged straight in a band shape in winding the coil, when the coil is wound on one of the stacked tooth portions, a rotation plane on which an end of the flyer rotates and the stacked tooth portion at the opposite side, do not interfere with each other. Accordingly, since the operating range of the flyer is not limited, the coil can easily be wound on the stacked tooth portions in a regularly aligned manner, a gap does not occur between two coils housed in one slot, the coil space factor can be improved, and the filling factor of the stator can be increased. In addition, since no obstacle is present around the flyer in winding the coil, the coil can be wound at a high speed. Moreover, an operation for connecting coil end portions can be eliminated, so that an inexpensive stator for a rotating electrical machine can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS [0011] [FIG. 1] FIG. 1 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine according to Embodiment 1 of the present invention.

[FIG. 2] FIG. 2 is a flowchart showing a method for producing a stator of the rotating electrical machine according to Embodiment 1 of the present invention.

[FIG. 3] FIG. 3 is a blanking arrangement diagram of core pieces according to Embodiment 1 of the present invention.

[FIG. 4] FIG. 4 is a schematic diagram of a divided stacked core intermediate and a winding machine carrying out a first winding step according to Embodiment 1 of the present invention.

[FIG. 5] FIG. 5 is a cross-sectional view taken along the line X-X' in FIG. 4.

[FIG. 6] FIG. 6 is a schematic diagram of the divided stacked core intermediate and the winding machine carrying out a second winding step according to Embodiment 1 of the present invention.

[FIG. 7] FIG. 7 is a cross-sectional view of a divided stacked core, having a coil wound thereon, according to Embodiment 1 of the present invention.

[FIG. 8] FIG. 8 is a blanking arrangement diagram of core pieces of a comparative example.

[FIG. 9] FIG. 9 is a schematic diagram of a divided stacked core intermediate and a winding machine carrying out a winding step according to Embodiment 2 of the present invention.

[FIG. 10] FIG. 10 is a flowchart showing a coil winding step for a rotating electrical machine according to

Embodiment 2 of the present invention.

[FIG. 11] FIG. 11 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine according to Embodiment 3 of the present invention.

[FIG. 12] FIG. 12 is a flowchart showing a coil winding step for the rotating electrical machine according to

Embodiment 3 of the present invention.

[FIG. 13] FIG. 13 is a cross-sectional schematic diagram showing the configuration of a divided stacked core, having a coil wound thereon, of a rotating electrical machine according to Embodiment 4 of the present invention.

[FIG. 14] FIG. 14 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine according to Embodiment 5 of the present invention.

DESCRIPTION OF EMBODIMENTS [0012] Embodiment 1

Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

In the present specification, unless otherwise specified, the terms axial direction, circumferential direction, radial direction, inner peripheral side, outer peripheral side, inner peripheral surface, outer peripheral surface, inner side, and outer side refer to the axial direction, the circumferential direction, the radial direction, the inner peripheral side, the outer peripheral side, the inner peripheral surface, the outer peripheral surface, the inner side, and the outer side of a stator, respectively. In addition, when an up-down relationship such as upper and lower is mentioned, the side away from the center of the stator is defined as an upper side, and the side close to the center of the stator is defined as a lower side.

[0013] FIG. 1 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine

100 according to Embodiment 1 of the present invention.

The rotating electrical machine 100 includes a rotor 2 and a stator 3. The rotor 2 includes a rotation shaft 21 and a permanent magnet 22 disposed on the outer circumference of the rotation shaft 21.

[0014] The stator 3 includes divided stacked cores 31 and each having a substantially U shape. The divided stacked core 31 includes a divided stacked yoke portion 31a and two stacked tooth portions 31b and 31c that bend at a right angle and project in the same direction from both ends of the divided stacked yoke portion 31a in the longitudinal direction thereof. Similarly, the divided stacked core 32 includes a divided stacked yoke portion 32a and two stacked tooth portions 32b and 32c that bend at a right angle and project in the same direction from both ends of the divided stacked yoke portion 32a. The divided stacked core 31 and the divided stacked core 32 have the same configuration, but will be described with different reference characters in the present specification, for the convenience of the following description.

[0015] A slot Si in which a coil 41b wound on the stacked tooth portion 31b and a coil 41c wound on the stacked tooth portion 31c are housed is formed between the stacked tooth portion 31b and the stacked tooth portion 31c. Similarly, a slot S2 in which a coil 42b wound on the stacked tooth portion 32b and a coil 42c wound on the stacked tooth portion

32c are housed is formed between the stacked tooth portion

32b and the stacked tooth portion 32c. The coils 41b, 41c,

42b, and 42c are wound on the stacked tooth portions 31b,

31c, 32b, and 32c with insulators 5 interposed therebetween.

[0016] The divided stacked core 31 and the divided stacked core 32 are arranged, with the rotor 2 interposed therebetween, such that the stacked tooth portion 31b and the stacked tooth portion 32b are linearly aligned and oppose each other and the stacked tooth portion 31c and the stacked tooth portion 32c are linearly aligned and oppose each other.

Magnetic attraction portions 31bz, 31cz, 32bz, and 32cz which are free end portions at the rotor 2 side of the stacked tooth portions 31b, 31c, 32b, and 32c extend along the outer peripheral surface of the rotor 2 and oppose the outer peripheral surface of the rotor 2.

[0017] The outer peripheral surfaces of the magnetic attraction portions 31bz, 31cz, 32bz, and 32cz have dovetail groove-like recesses 31bzr, 31czr, 32bzr, and 32czr (resin member joining portions) extending in the axial direction.

Both end portions of a fixing member 7b (resin member) made of a resin are fitted to the recess 31bzr and the recess

32bzr in the axial direction to fix the stacked tooth portion

31b and the stacked tooth portion 32b to each other.

Similarly, both end portions of a fixing member 7c made of a resin are fitted to the recess 31czr and the recess 32czr in the axial direction to fix the stacked tooth portion 31c and the stacked tooth portion 32c, which are adjacent to each other in the circumferential direction, to each other. It is noted that projections may be formed instead of the recesses

31bzr, 31czr, 32bzr, and 32czr, and recesses may be provided at the fixing member side.

[0018] Next, a method for producing the stator 3 of the rotating electrical machine 100 will be described with reference to the drawings.

FIG. 2 is a flowchart showing the method for producing the stator 3 of the rotating electrical machine

100.

FIG. 3 is a diagram showing an arrangement when a plurality of core pieces 6 are cut out from a single continuous electromagnetic steel plate P.

FIG. 4 is a schematic diagram of a divided stacked core intermediate 30 and a winding machine 8 carrying out a first winding step.

FIG. 5 is a cross-sectional view taken along the line X-X' in FIG. 4.

[0019] First, a step of producing the divided stacked core intermediate 30 from which the divided stacked cores 31 and are to be formed.

The core pieces 6 shown in FIG. 3 are plate-like members forming respective layers of the divided stacked cores 31 and 32. At the time at which the core pieces 6 are cut out from the electromagnetic steel plate P, the core pieces 6 are a single band-like member.

[0020] A required number of the core pieces 6 are cut out from the electromagnetic steel plate P in the arrangement shown in FIG. 3 (a core piece production step: S001). Each core piece 6 includes a divided yoke portion 6a at a center in the longitudinal direction thereof, and includes tooth portions 6b and 6c connected to both ends of the divided yoke portion 6a in the longitudinal direction by thin portions 6s.

V-shaped cuts 6v are provided between the divided yoke portion 6a and the tooth portions 6b and 6c of the core piece 6, and portions at which the divided yoke portion 6a and the tooth portions 6b and 6c are connected to each other are the thin portions 6s.

[0021] All the longitudinal directions of the divided yoke portion 6a and the two tooth portions 6b and 6c of each core piece 6 coincide with a feed direction in which the electromagnetic steel plate P is fed (the longitudinal directions = a rolling direction D in which the electromagnetic steel plate P is rolled).

[0022] Two core pieces 6 are arranged in parallel in a direction perpendicular to the rolling direction D of the electromagnetic steel plate P in the present embodiment.

However, the number of core pieces 6 arranged in parallel may be greater than 2 as long as the longitudinal direction of each core piece 6 and the rolling direction D of the electromagnetic steel plate P coincide with each other.

[0023] Next, the cut-out band-like core pieces 6 are stacked in the axial direction, and recesses and projections provided at the upper and lower sides of stacked surfaces that are not shown are swaged to join the respective core pieces 6 together, thereby producing a divided stacked core intermediate 30 (a stacking step: S002). A portion in which the divided yoke portions 6a of the core pieces 6 are stacked becomes a divided stacked yoke portion 30a of the divided stacked core intermediate 30 shown in FIG. 4, and the divided stacked yoke portion 30a becomes the divided stacked yoke portion 31a or 32a of the divided stacked core 31 or 32 shown in FIG. 1. Similarly, portions in which the tooth portions

6b and 6c of the core pieces 6 are stacked become stacked tooth portions 30b and 30c of the divided stacked core intermediate 30, and the stacked tooth portions 30b and 30c become the stacked tooth portions 31b and 31c or 32b and 32c of the divided stacked core 31 or 32.

[0024] Next, an insulator molding step (S003) is carried out. In the insulator molding step, the insulators 5 which electrically insulate a coil 40 (the coils 41b, 41c, 42b, and

42c) and the divided stacked core intermediate 30 (the divided stacked cores 31 and 32) from each other are integrally molded on the outer peripheries of the stacked tooth portions 30b and 30c.

[0025] Next, the configuration of the winding machine 8 which winds the coil 40 on the divided stacked core intermediate 30 will be described.

The winding machine 8 shown in FIG. 4 includes: a rotary positioning mechanism 80 for fixing the divided stacked core intermediate 30; and a flyer 88 from which a wire 41 that is to be the coil 40 is fed. The rotary positioning mechanism 80 includes a disk-shaped base portion

81, a dogleg-shaped block 82, and a top plate 83 and two screws 84 for fixing the divided stacked yoke portion 30a such that the divided stacked yoke portion 30a is interposed between the base portion 81 and the top plate 83.

[0026] The base portion 81 of the rotary positioning mechanism 80 is rotatable about a rotation axis A in the direction of an arrow Al in FIG. 4. The dogleg-shaped block is used for positioning the divided stacked yoke portion

30a of the divided stacked core intermediate 30 at a predetermined position on a board surface of the base portion

81. Knock pins 85 are used for guiding a jumper wire connecting two coils 40 in continuously winding the coils 40 on the two stacked tooth portions 30b and 30c. Two knock pins 85 are provided to the base portion 81. The knock pins are provided at the outer peripheral side of stacked thin connection portions 3s by which the divided stacked yoke portion 30a and the stacked tooth portions 30b and 30c of the divided stacked core intermediate 30 are bendably connected to each other. A rotation shaft B of the flyer 88 is located so as to be orthogonal to the rotation axis A of the rotary positioning mechanism 80, and the flyer 88 is movable forward and backward in an axial direction c of the rotation shaft B.

[0027] Next, a coil winding step will be described.

The coil winding step includes a positioning/fixing step (S100), the first winding step (S101), a core rotating step (S102), a second winding step (S103), and a removing step (S104). First, the screws 84 are inserted through two screw holes of the top plate 83 and through screw holes of the dogleg-shaped block 82 to fix the divided stacked yoke portion 30a to the base portion 81 with the divided stacked yoke portion 30a interposed between the base portion 81 and the top plate 83 in the axial direction (stacking direction) (the positioning/fixing step: S100).

[0028] At this time, the divided stacked core intermediate is positioned on the base portion 81 such that a corner portion, at the inner peripheral side, of the divided stacked yoke portion 30a is located so as to be in contact with a corner portion of a side surface, at the rotation axis A side, of the dogleg-shaped block 82. In addition, at this time, the divided stacked core intermediate 30 is arranged such that the free end portion side of the one stacked tooth portion 30b on which the coil 40 is to be wound earlier opposes the rotation shaft B of the flyer 88, and the other stacked tooth portion 30c faces at the opposite side. That is, the longitudinal direction of the divided stacked core intermediate 30 coincides with the axial direction of the rotation shaft B of the flyer 88.

[0029] Next, the first winding step (S101) is carried out on the stacked tooth portion 30b.

The coil 40 is wound by rotating the flyer 88 of the winding machine 8 around the stacked tooth portion 30b while moving the flyer 88 in the axial direction c of the rotation shaft B. At this time, a rotation plane Q on which an end of the flyer 88 rotates and the stacked tooth portion

30c at the opposite side, do not interfere with each other.

[0030] FIG. 6 is a schematic diagram of the divided stacked core intermediate 30 and the winding machine 8 carrying out the second winding step. After the winding of the coil 40 on the stacked tooth portion 30b ends, the rotary positioning mechanism 80 is rotated 180 degrees in the direction of the arrow Al in FIG. 4 without cutting a winding end portion of the coil 40 where the winding ends (the core rotating step: S102). Accordingly, a jumper wire 42 shown in

FIG. 6 is extended along the outer side of the two knock pins which are provided to the base portion 81 of the rotary positioning mechanism 80.

[0031] Subsequently, the second winding step (S103) is carried out on the stacked tooth portion 30c.

The coil 40 is wound by rotating the flyer 88 of the winding machine 8 around the stacked tooth portion 30c while moving the flyer 88 in the right-left direction of the sheet surface of FIG. 6. The direction in which the flyer 88 is rotated is set to be the same as the direction of the above winding on the stacked tooth portion 30b. Similarly to the first winding step, the rotation plane Q on which the end of the flyer 88 rotates and the stacked tooth portion 30c at the opposite side, do not interfere with each other.

[0032] After the coil 40 is wound on the two stacked tooth portions 30b and 30c of the divided stacked core intermediate as described above, the divided stacked core intermediate is removed from the rotary positioning mechanism 80 (the removing step: S104).

[0033] FIG. 7 is a cross-sectional view of the divided stacked core 31 having the coil wound thereon.

Next, the stacked tooth portion 30b and the stacked tooth portion 30c of the divided stacked core intermediate 30 on which the winding has been performed and which has been removed from the rotary positioning mechanism 80 are bent at the stacked thin connection portions 3s in directions in which the cuts 6v of the core pieces 6 are closed, such that a substantially U shape is formed (a bending step: S004), thereby obtaining the divided stacked core 31. Then, the same step is repeated, thereby obtaining the divided stacked core 32 having the coil wound thereon.

[0034] Next, the divided stacked core 31 and the divided stacked core 32 are arranged such that the stacked tooth portion sides thereof oppose each other, and the fixing member 7b is fitted and fixed to the recess 31bzr and the recess 32bzr. An adhesive may be used for firmly fixing the fixing member 7b. Similarly, the fixing member 7c is fitted and fixed to the recess 31czr and the recess 32czr at the opposite side. In this manner, the stator 3 is obtained in which the two divided stacked cores 31 and 32 are coupled to each other via the fixing members 7b and 7c with a certain interval maintained therebetween (a coupling step: S005).

The rotor 2 is inserted into the inner peripheral side of the stator 3, and the rotor 2 and the stator 3 are housed in a frame that is not shown, thereby obtaining the rotating electrical machine 100.

[0035] Next, advantageous effects regarding the shapes of the core pieces 6 used in the present embodiment will be described.

FIG. 8 is a diagram showing an arrangement when conventional integrated core pieces 60b are blanked out from an electromagnetic steel plate P2, as a comparative example.

The shape of each core piece 60b is the same as a shape obtained by bending the core piece 6 according to Embodiment 1 at the thin connection portions 61.

[0036] When the core pieces 6 are blanked out from the electromagnetic steel plate P in FIG. 3 in the arrangement shown in the drawing, where the area of the single core piece is denoted by A0, the length of the electromagnetic steel plate P in the longitudinal direction is denoted by Ll, and the length of the electromagnetic steel plate P in a direction perpendicular to the longitudinal direction is denoted by L2, a material effective use rate (2AO/L1’L2) is

59%.

[0037] On the other hand, when the core pieces 60b are blanked out in the arrangement shown in FIG. 8, the area of the single core piece 60b is A0 which is equal to that of the core piece 6. In this case, where the length of the electromagnetic steel plate P2 in the longitudinal direction is denoted by L3, and the length of the electromagnetic steel plate P2 in a direction perpendicular to the longitudinal direction is denoted by L4, a material effective use rate (2A0/L3L4) is 52%. As described above, a higher material use rate is achieved when blanking-out is performed in the arrangement shown in FIG. 3.

[0038] In the core piece 6 according to the present embodiment, at both the tooth portions 6b and 6c and the divided yoke portion 6a, directions J1 to J3 in which a magnetic flux flows therethrough coincide with the rolling direction D of the electromagnetic steel plate P. Generally, a magnet resistance is lower in a rolling direction than in a direction orthogonal to the rolling direction, so that iron loss occurring in a core can be reduced in the rolling direction. Therefore, as compared to the core piece 60b of the comparative example in which only either the tooth portions or the yoke portion can be caused to coincide with the rolling direction D, flow of a magnetic flux through the divided stacked cores 31 and 32 is made smooth by arranging the core piece 6 such that the rolling direction D of the electromagnetic steel plate P and the longitudinal direction of the core piece 6 coincide with each other, so that favorable magnetic characteristics are achieved.

[0039] In the stator of the rotating electrical machine, the rotating electrical machine, and the method for producing the stator of the rotating electrical machine according to

Embodiment 1 of the present invention, since the divided stacked yoke portion 30a and the stacked tooth portions 30b and 30c of the divided stacked core intermediate 30 are arranged straight in a band shape in winding the coil 40, when the coil 40 is wound on one of the stacked tooth portions, the rotation plane Q on which the end of the flyer rotates and the stacked tooth portion 30c at the opposite side, do not interfere with each other. Accordingly, since the operating range of the flyer 88 is not limited, the coil can easily be wound on the stacked tooth portions 30b and 30c in a regularly aligned manner, a gap does not occur between two coils housed in one slot, the coil space factor can be improved, and the filling factor of the stator 3 (the proportion of the stator components with respect to the outer shape of the stator 3) can be increased. In addition, since no obstacle is present around the flyer 88 in winding the coil 40, the coil can be wound at a high speed. Moreover, an operation for connecting coil end portions can be eliminated, so that the inexpensive stator 3 of the rotating electrical machine 100 can be obtained.

[0040] By fixing the magnetic attraction portion 31bz and

32bz and the magnetic attraction portions 31cz and 32cz of the divided stacked cores 31 and 32 to each other by means of the fixing members 7b and 7c, the accuracy of the positions of the magnetic attraction portions can be improved.

[0041] Since the coil 40 can be continuously extended without cutting the jumper wire 42 between the coils 40 which are wound on the two stacked tooth portions 30b and 30c, respectively, the productivity of the stator 3 and the rotating electrical machine 100 can be improved.

[0042] Embodiment 2

Hereinafter, Embodiment 2 of the present invention will be described mainly regarding differences from

Embodiment 1 with reference to the drawings.

FIG. 9 is a schematic diagram of the divided stacked core intermediate 30 and a winding machine carrying out a winding step.

FIG. 10 is a flowchart showing a coil winding step for a rotating electrical machine according to the present embodiment.

In FIG. 10, only a flowchart for a simultaneous winding step which is a difference from Embodiment 1 is shown.

In the coil winding step of Embodiment 1, the first winding step and the second winding step are sequentially performed by the one flyer 88 on the two stacked tooth portions 30b and 30c of the divided stacked core intermediate

30. However, in the present embodiment, as shown in FIG. 9, operations for winding the coils 40 are simultaneously performed by two flyers 88a and 88b on the two stacked tooth portions 30b and 30c (the simultaneous winding step: S201) .

[0043] Rotation shafts BI and B2 of the flyers 88a and 88b are located so as to oppose each other with the rotary positioning mechanism 80 interposed therebetween and so as to be orthogonal to the rotation axis A of the rotary positioning mechanism 80, and the flyers 88a and 88b are movable forward and backward in axial directions cl and c2 of the rotation shafts BI and B2, respectively.

[0044] Fixing the divided stacked core intermediate 30 to the rotary positioning mechanism 80 is the same as in

Embodiment 1. In winding the coils 40, the free end portions of the two stacked tooth portions 30b and 30c oppose the rotation shafts BI and B2 of the flyers 88a and 88b, respectively, and the operations for winding the coils 40 are simultaneously performed by the two flyers 88a and 88b.

After the coils 40 are simultaneously wound, the coils 40 wound on the two stacked tooth portions 30b and 30c are connected to each other by connecting winding end portions or winding start portions of the two stacked tooth portions where the winding ends or starts.

[0045] In the stator of the rotating electrical machine, the rotating electrical machine, and the method for producing the stator of the rotating electrical machine according to

Embodiment 2 of the present invention, the coils 40 can be simultaneously wound by the two flyers 88a and 88b on the two stacked tooth portions 30b and 30c, and thus the time for the operations for winding the coils 40 can be reduced by half or more of that in Embodiment 1.

[0046] Embodiment 3

Hereinafter, Embodiment 3 of the present invention will be described mainly regarding differences from

Embodiment 1 with reference to the drawings.

FIG. 11 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine

300 according to Embodiment 3 of the present invention.

FIG. 12 is a flowchart showing a coil winding step for the rotating electrical machine according to the present embodiment.

In FIG. 12, only a flowchart for a molding step which is a difference from Embodiment 1 is shown.

In the stator 3 of Embodiment 1, the two divided stacked cores 31 and 32 are coupled to each other by the fixing members 7b and 7c. In the present embodiment, as shown in FIG. 11, the outer periphery of the rotating electrical machine 300 is molded by a mold member 307 made of a resin (the molding step: S305).

[0047] The mold member 307 may cover the entirety of a stator 303 as shown in FIG. 11, or may be molded so as to cover the peripheries of the coils 41b, 41c, 42b, and 42c, at least the free end portions of the stacked tooth portions 31b and 32b of the divided stacked cores 31 and 32, and the free end portions of the stacked tooth portions 31c and 32c.

[0048] In the stator of the rotating electrical machine, the rotating electrical machine, and the method for producing the stator of the rotating electrical machine according to

Embodiment 3 of the present invention, the mold member 307 is integrally molded with the divided stacked cores 31 and 32.

Thus, as compared to the rotating electrical machine 100 of

Embodiment 1 in which the divided stacked cores 31 and 32 are fixed and assembled by using the fixing members 7b and 7c, assembling is easy, and the productivity of the stator 303 and the rotating electrical machine 300 is good. In addition, high-accuracy positioning can be performed by using a mold.

[0049] When a resin is filled into the dovetail groovelike recesses 31bzr, 31czr, 32bzr, and 32czr to which the fixing members 7b and 7c are fitted in Embodiment 1, and integral molding is performed, the rigidity and the accuracy of the stator 303 can be further increased.

[0050] Embodiment 4

Hereinafter, Embodiment 4 of the present invention will be described mainly regarding differences from

Embodiment 1 with reference to the drawings.

FIG. 13(a) is a cross-sectional schematic diagram showing the configuration of a divided stacked core 331, having a coil wound thereon, of a rotating electrical machine according to Embodiment 4 of the present invention.

FIG. 13(b) is an enlarged cross-sectional view taken along the line Y-Y' in FIG. 13 (a) .

[0051] In the divided stacked core 31 of Embodiment 1, the divided stacked yoke portion 31a and the stacked tooth portions 31b and 31c are bendably connected to each other by the stacked thin connection portions 3s. However, in the present embodiment, as shown in FIGS. 13(a) and 13(b), a divided stacked yoke portion 331a and stacked tooth portions 331b and 331c are rotatably connected to each other by swaging recesses and projections provided to each of thin plate-like core pieces 306a forming respective layers of the divided stacked core 331 and core pieces 306b and 306c (actually, there are two types for each) forming respective layers of the stacked tooth portions 331b and 331c.

[0052] Specifically, as shown in FIG. 13(b), projections

306cp are provided on the lower surfaces of the core pieces

306c of the stacked tooth portion 331c, and a rotatable connection portion R is formed by swaging the projections

306cp to recesses 306ar on the upper surfaces of the core pieces 306a of the divided stacked yoke portion 331a which are alternately stacked. In winding the coil 40 (41b, 41c) on the stacked tooth portions 331b and 331c, similarly to

Embodiment 1, the connection portion R may be rotated to be opened such that the divided stacked yoke portion 331a and the stacked tooth portions 331b and 331c are straight in a band shape.

[0053] In the stator of the rotating electrical machine, the rotating electrical machine, and the method for producing the stator of the rotating electrical machine according to

Embodiment 4 of the present invention, handling in returning the respective stacked tooth portions 331b and 331c into a substantially U-shaped state after the coil 40 is wound is easy as compared to bending at the thin portions in Embodiment 1, so that the productivity of the stator of the rotating electrical machine and the rotating electrical machine can be further improved.

[0054] Embodiment 5

Hereinafter, Embodiment 5 of the present invention will be described mainly regarding differences from

Embodiment 1 with reference to the drawing.

FIG. 14 is a cross-sectional schematic diagram showing the configuration of a rotating electrical machine 500 according to Embodiment 5 of the present invention.

The stator 3 of Embodiment 1 includes the two divided stacked cores 31 and 32. However, in the present embodiment, as shown in FIG. 14, a stator 503 includes three divided stacked cores 331, 332, and 333 each having a substantially U shape. The other configuration is the same as in Embodiment 1.

[0055] In the stator 503 of the rotating electrical machine 500, the rotating electrical machine 500, and the method for producing the stator 503 of the rotating electrical machine 500 according to Embodiment 5 of the present invention, torque ripples occurring in the rotating electrical machine 500 can be reduced by increasing the number of the stacked tooth portion as compared to that in

Embodiment 1 to increase the number of poles.

[0056] It is noted that, within the scope of the present invention, the respective embodiments may be freely combined with each other, or each of the respective embodiments may be modified or abbreviated as appropriate.

Claims

CLAIMS [1] A stator for a rotating electrical machine, comprising:

a plurality of substantially U-shaped divided stacked cores each formed by stacking core pieces; and a coil wound on each stacked tooth portion of each divided stacked core, wherein each divided stacked core includes a divided stacked yoke portion, and the two stacked tooth portions at both ends of the divided stacked yoke portion, and the two stacked tooth portions and the divided stacked yoke portion are connected to each other such that the two stacked tooth portions are rotatable or bendable relative to the divided stacked yoke portion from a state where a longitudinal direction of each stacked tooth portion and a longitudinal direction of the divided stacked yoke portion coincide with each other and the stacked tooth portions are aligned straight at both ends in the longitudinal direction of the divided stacked yoke portion, to a state where the two stacked tooth portions face an inner side of the stator.
[2] The stator for the rotating electrical machine according to claim 1, wherein the two stacked tooth portions respectively have resin member joining portions extending in an axial direction, on outer peripheral surfaces of magnetic attraction portions which are free end portions of the respective stacked tooth portions and oppose a rotor inserted into the inner side of the stator, and the stacked tooth portions, adjacent to each other in a circumferential direction, of the two divided stacked cores adjacent to each other in the circumferential direction are fixed to each other by a resin member fixed to the resin member joining portions.
[3] The stator for the rotating electrical machine according to claim 2, wherein the resin member is a mold member.
[4] The stator for the rotating electrical machine according to any one of claims 1 to 3, wherein the divided stacked yoke portion and each stacked tooth portion are bendably connected to each other by a stacked thin connection portion.
[5] The stator for the rotating electrical machine according to any one of claims 1 to 4, wherein the divided stacked yoke portion and each stacked tooth portion are rotatably connected to each other by a connection portion in which recesses and projections provided on stacked surfaces of the core pieces forming the divided stacked yoke portion and the stacked tooth portion are fitted to each other.
[6] A rotating electrical machine comprising:

the stator for the rotating electrical machine according to any one of claims 1 to 5; and a rotor rotatably inserted into the inner side of the stator.
[7] A method for producing a stator for a rotating electrical machine, the method comprising:

a core piece production step of cutting out, from an electromagnetic steel plate, a core piece in which a divided yoke portion and tooth portions at both ends of the divided yoke portion are arranged straight in a band shape such that a longitudinal direction of the divided yoke portion and a longitudinal direction of each tooth portion coincide with each other;

a stacking step of stacking a plurality of the core pieces to form a divided stacked core intermediate in which a stacked divided yoke portion in which the divided yoke portions are stacked and two stacked tooth portions in which the two tooth portions are stacked are stacked so as to be bendable or rotatable by connection portions;

a positioning/fixing step of positioning and fixing the divided stacked core intermediate to a winding machine such that an axial direction of a rotation shaft of a flyer of the winding machine coincides with a longitudinal direction of the divided stacked core intermediate;

a first winding step of winding a coil on one of the stacked tooth portions;

a second winding step of winding the coil on the other of the stacked tooth portions;

a bending step of bending the two stacked tooth portions of the divided stacked core intermediate on which the coil has been wound, at the connection portions in the same direction to form a substantially U-shaped divided stacked core; and a coupling step of fixing free end portions of the stacked tooth portions of a plurality of the divided stacked cores adjacent to each other, to each other.
[8] The method for producing the stator for the rotating electrical machine according to claim 7, further comprising, between the first winding step and the second winding step, a core rotating step of rotating the divided stacked core intermediate 180 degrees.
[9] The method for producing the stator for the rotating electrical machine according to claim 7, further comprising a simultaneous winding step of simultaneously executing the first winding step and the second winding step

5 by the two flyers.
[10] The method for producing the stator for the rotating electrical machine according to any one of claims 7 to 9, wherein a longitudinal direction of the core pieces

10 coincides with a rolling direction in which the electromagnetic steel plate is rolled.