Stator of rotating electric machine, rotating electric machine using same, and manufacturing method for stator for rotating electric machine
TECHNICAL FIELD
[0001] The present invention relates to a stator for a rotating electric machine, a rotating electric machine using the stator, and a manufacturing method for a stator for a rotating electric machine.
BACKGROUND ART
[0002] In a stator for a rotating electric machine, a stacked iron core having a structure in which a plurality of thin silicon steel plates obtained by stamping with a press or the like are stacked and integrated by means of swaging, welding, or the like, is used. By providing a winding on the stator with high density, an increase in efficiency, an increase in capacity, and further a reduction in size of a rotating electric machine can be achieved. In order to improve workability, divided cores obtained by dividing a stator core into a plurality of sections are used. For example, a stator is disclosed in which back yoke portions are bendably connected to each other, a winding is continuously provided with two unit cores as one set, and

three sets thereof are arranged in an annular shape (see, for example, Patent Document 1).
In this stator, since the back yoke portions are bendably connected to each other, a coil can be continuously wound on each magnetic pole piece without being cut, whereby the number of times a winding end portion is connected can be reduced, resulting in a reduction in production cost.
CITATION LIST
PATENT DOCUMENT
[0003] Patent Document 1: Japanese Laid-Open Patent
Publication No. 2010-246352 (paragraphs [0011] and [0012] and
FIGS. 1 and 2)
SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0004] However, in the case where the invention disclosed in Patent Document 1 is applied to, for example, a four-tooth stator and the respective magnetic pole pieces are arranged in an annular shape, each back yoke portion has an arc shape, and the operating range of a winding machine is limited by the back yoke portion when performing winding on each tooth portion. Thus, for a rotating electric machine required to have a higher space factor, winding work needs to be modified.
[0005] The present invention has been made to solve the

above problem, and an object of the present invention is to provide: a stator for a rotating electric machine which stator can have a wide space between tooth portions; a rotating electric machine using the stator; and a manufacturing method for a stator for a rotating electric machine.
SOLUTION TO THE PROBLEMS
[0006] A stator for a rotating electric machine according to the present invention includes a plurality of magnetic pole pieces and a plurality of yoke pieces arranged in an annular shape, each of the magnetic pole pieces includes a back yoke portion disposed along an outer peripheral portion of the annular shape and a tooth portion extending from the back yoke portion in a direction toward a center of the annular shape, each of the yoke pieces includes only a back yoke portion disposed along the outer peripheral portion of the annular shape, at least one of the yoke pieces is present between at least a pair of the magnetic pole pieces adjacent to each other, and the pair of the magnetic pole pieces and the yoke piece between the pair of the magnetic pole pieces are bendably connected to each other.
[0007] A rotating electric machine according to the present invention includes the above stator for a rotating electric machine and a rotor rotatably provided within the

stator for a rotating electric machine.
[0008] A manufacturing method for a stator for a rotating electric machine according to the present invention is a manufacturing method for a stator for a rotating electric machine, the stator including a plurality of magnetic pole pieces and a plurality of yoke pieces arranged in an annular shape, each of the magnetic pole pieces including a back yoke portion disposed along an outer peripheral portion of the annular shape and a tooth portion extending from the back yoke portion in a direction toward a center of the annular shape, each of the yoke pieces including only a back yoke portion disposed along the outer peripheral portion of the annular shape, the magnetic pole pieces and the yoke pieces being alternately arranged in an annular shape, the manufacturing method including: a stamping step of performing stamping such that the magnetic pole pieces and the yoke pieces are bendably connected to each other and a longitudinal direction of each of the back yoke portions of the magnetic pole pieces and a longitudinal direction of each of the back yoke portions of the yoke pieces coincide with a rolling direction in which an electromagnetic steel plate is rolled, and stacking and fixing the stamped pieces in an axial direction; a winding step of winding a coil on the tooth portions; and a core closing step of bending the yoke pieces and the magnetic pole pieces having the coil wound on

the tooth portions thereof into an annular shape, and connecting and integrating butted end surfaces.
EFFECT OF THE INVENTION
[0009] Since the stator for a rotating electric machine according to the present invention includes magnetic pole pieces each including a back yoke portion and a tooth portion and yoke pieces each including only a back yoke portion, a wide space can be taken between the tooth portions. [0010] In the rotating electric machine according to the present invention, the stator for a rotating electric machine includes: magnetic pole pieces each including a back yoke portion and a tooth portion; and yoke pieces each including only a back yoke portion is used, and thus a wide space can be taken between the tooth portions.
[0011] In the manufacturing method for the stator for a rotating electric machine according to the present invention, the stator for a rotating electric machine includes: magnetic pole pieces each including a back yoke portion and a tooth portion; and yoke pieces each including only a back yoke portion is used, and thus a wide space can be taken between the tooth portions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [FIG. 1] FIG. 1 is a cross-sectional view showing

the configuration of a stator for a rotating electric machine, which is an electric motor, according to Embodiment 1 of the present invention.
[FIG. 2] FIG. 2 is a cutting layout diagram of magnetic pole pieces and yoke pieces of the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 3] FIG. 3 illustrates winding work for the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 4] FIG. 4 illustrates fitting at the time of connection for the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 5] FIG. 5 is a cross-sectional view showing a configuration of a comparative example according to the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 6] FIG. 6 is a cutting layout diagram of magnetic pole pieces of the comparative example according to the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 7] FIG. 7 illustrates winding work of the comparative example according to the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 8] FIG. 8 illustrates a relationship between

the magnetic pole pieces and the yoke pieces of the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 9] FIG. 9 illustrates a relationship between the magnetic pole pieces and the yoke pieces of the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 10] FIG. 10 is a flowchart according to a manufacturing method for the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 11] FIG. 11 is a cross-sectional view showing another configuration example of the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 12] FIG. 12 is a cross-sectional view showing another configuration example of the stator for a rotating electric machine of Embodiment 1 of the present invention.
[FIG. 13] FIG. 13 illustrates winding work for a stator for a rotating electric machine of Embodiment 2 of the present invention.
[FIG. 14] FIG. 14 illustrates winding work of a comparative example according to the stator for a rotating electric machine of Embodiment 2 of the present invention.
[FIG. 15] FIG. 15 illustrates a connection means

of a stator for a rotating electric machine of Embodiment 3 of the present invention.
[FIG. 16] FIG. 16 is a cross-sectional view showing a configuration of a stator for a rotating electric machine of Embodiment 4 of the present invention.
[FIG. 17] FIG. 17 is a cross-sectional view showing the configuration of a rotating electric machine of Embodiment 5 of the present invention.
DESCRIPTION OF EMBODIMENTS
[0013] Embodiment 1
Embodiment 1 relates to a stator for a rotating electric machine that includes magnetic pole pieces and yoke pieces, and a manufacturing method for the stator for a rotating electric machine that includes a stamping step, a winding step, and a core closing step.
[0014] Hereinafter, the configuration of the stator for a rotating electric machine and the manufacturing method for the stator for a rotating electric machine according to Embodiment 1 of the invention of the present application will be described with reference to FIG. 1 which is a cross-sectional view showing the configuration of the stator for a rotating electric machine, FIG. 2 which is a cutting layout diagram of the magnetic pole pieces and the yoke pieces, FIG. 3 which illustrates winding work, FIG. 4 which illustrates

fitting at the time of connection, FIG. 5 which is a cross-sectional view showing a configuration of a comparative example, FIG. 6 which is a cutting layout diagram of magnetic pole pieces of the comparative example, FIG. 7 which illustrates winding work of the comparative example, FIGS. 8 and 9 each of which illustrates a relationship between the magnetic pole pieces and the yoke pieces, FIG. 10 which is a flowchart according to the manufacturing method for the stator for a rotating electric machine, and FIGS. 11 and 12 each of which is a cross-sectional view of another configuration example of the stator for a rotating electric machine.
[0015] First, the configuration of the stator for a rotating electric machine of Embodiment 1 will be described with reference to FIG. 1. FIG. 1 is a cross-sectional view showing the configuration of a stator 1 for a rotating electric machine.
Embodiment 1 will be described with, as an example, the stator 1 for a rotating electric machine that includes four magnetic pole pieces 2 and four yoke pieces 3.
Each magnetic pole piece 2 has a structure in which a plurality of thin electromagnetic steel plates are stacked along an axial direction. The magnetic pole piece 2 includes: a back yoke portion 4A extending in a direction perpendicular to the stacking direction; and a tooth portion

5 projecting from the back yoke portion 4A toward the stator radially inner side.
Each yoke piece 3 has a structure in which a plurality of thin electromagnetic steel plates are stacked along the axial direction. The yoke piece 3 includes only a back yoke portion 4B extending in a direction perpendicular to the stacking direction.
The back yoke portion of each magnetic pole piece 2 and the back yoke portion of each yoke piece 3 are distinguished from each other by being denoted by 4A and 4B, respectively. However, when these back yoke portions do not need to be distinguished from each other, these back yoke portions are referred to as back yoke portions 4 as appropriate.
[0016] The magnetic pole pieces 2 and the yoke pieces 3 are alternately arranged in an annular shape and are bendably connected to each other by thin portions 6 at the outer peripheries of the back yoke portions 4A and 4B adjacent to each other. However, of the back yoke portions 4A and 4B adjacent to each other, the back yoke portions 4A and 4B at one location are not connected to each other; a connection projection 7 is provided at one of the back yoke portions 4A and 4B, a connection recess 8 is provided at the other of the back yoke portions 4A and 4B, and the connection projection 7 and the connection recess 8 are butted against each other.

In other words, the stator 1 for a rotating electric machine includes a plurality of magnetic pole pieces 2 and a plurality of yoke pieces 3 arranged in an annular shape, and each magnetic pole piece 2 includes a back yoke portion 4A disposed along an outer peripheral portion of the annular shape and a tooth portion 5 extending from the back yoke portion 4A in a direction toward the center of the annular shape. Each yoke piece 3 includes only a back yoke portion 4B disposed along the annular outer peripheral portion.
An insulator 9 covers the periphery of the tooth portion 5 of each magnetic pole piece 2, and a coil 10 is wound around the insulator 9.
Here, the annular shape is represented. However, as is also obvious from the cross-sectional view of FIG. 1, the annular shape is not limited to an annular shape, a cross section of which has a perfect circle shape. For example, the concept of the annular shape includes a wide range of annular shapes such as a substantially quadrangular shape, a substantially hexagonal shape, a substantially octagonal shape, and other polygonal shapes.
In FIG. 1, each arrow H indicates the direction in which, a magnetic flux flows. Also in the other drawings, each arrow H similarly indicates the direction in which a magnetic flux flows.

[0017] Next, cutting layout and stamping for producing, from an electromagnetic steel plate 31, the magnetic pole pieces 2 and the yoke pieces 3 of the stator 1 for a rotating electric machine will be described.
5 FIG. 2 is a cutting layout diagram in the case of
creating a cutting layout of steel plate pieces 32 from the band-shaped electromagnetic steel plate 31 for the stator 1 for a rotating electric machine.
In FIG. 2, an arrow J indicates the feed direction
0 in which the electromagnetic steel plate 31 is fed. Also in another drawing, an arrow J similarly indicates the feed direction in which the electromagnetic steel plate 31 is fed. The feed direction J of the electromagnetic steel plate 31 coincides with a rolling direction J in which the
5 electromagnetic steel plate 31 is rolled.
Each steel plate piece 32 includes the magnetic pole pieces 2 and the yoke pieces 3, and the longitudinal direction of the back yoke portion 4A of each magnetic pole piece 2 coincides with the longitudinal direction of the back
0 yoke portion 4B of each yoke piece 3. The longitudinal direction of the steel plate piece 32, that is, the longitudinal direction of the back yoke portions 4A and 4B of the magnetic pole pieces 2 and the yoke pieces 3, coincides with the feed direction J of the electromagnetic steel plate
5 31. The two steel plate pieces 32 are aligned in a direction

perpendicular to the feed direction J of the electromagnetic steel plate 31.
In this case, the two steel plate pieces 32 are arranged such that the tooth portions 5 of both steel plate pieces 32 oppose each other, and are also aligned such that, between the tooth portions 5 of one of the steel plate pieces 32, each tooth portion 5 of the other steel plate piece 32 is located.
[0018] As shown in FIG. 2, the two steel plate pieces 32 arranged on the electromagnetic steel plate 31 are stamped. A predetermined number of the steel plate pieces 32 stamped from the band-shaped electromagnetic steel plate 31 are automatically stacked and fixed by means of swaging, whereby the magnetic pole pieces 2 and the yoke pieces 3 of the stator 1 for a rotating electric machine are formed.
Thereafter, the insulator 9 that is formed from an insulating material is integrally molded at the outer periphery of the tooth portion 5 of each magnetic pole piece 2.
In FIG. 2, A0 indicates the areas of hatched portions, that is, the area of one steel plate piece 32. [0019] Next, the winding work for the stator 1 for a rotating electric machine will be described.
FIG. 3 illustrates winding work performed using an automatic winding machine 21 in the case of forming the

stator 1 for a rotating electric machine. FIG. 3(a) is a top view of the magnetic pole pieces 2, the yoke pieces 3, and the automatic winding machine 21 during the winding work. FIG. 3(b) is an X-X' cross-sectional view of FIG. 3(a).
For easy understanding of a winding state, a state where the coil 10 is wound on the tooth portions 5 of the four magnetic pole pieces 2 is shown, and the tooth portions 5 on which the winding has been performed are shown in cross-section.
For easy understanding of the following description, in FIG. 3(a), the magnetic pole piece 2 at the left end is referred to as first magnetic pole piece 2, the subsequent magnetic pole pieces 2 are sequentially referred to as second magnetic pole piece 2 and third magnetic pole piece 2, and the magnetic pole piece 2 at the right end is referred to as fourth magnetic pole piece 2.
[0020] The automatic winding machine 21 includes: a fixing jig 22 for fixing the magnetic pole pieces 2 and the yoke pieces 3 before winding; and a flyer 23 for coil feed/winding. The fixing jig 22 includes a base portion 24, presser plates 25, screws 26, and guide pins 27.
The magnetic pole pieces 2 and the yoke pieces 3 are set on an axial end surface of the base portion 24 such that the longitudinal direction of the back yoke portion 4A of each magnetic pole piece 2 coincides with the longitudinal

direction of the back yoke portion 4B of each yoke piece 3. As shown in FIG. 3(b), the magnetic pole pieces 2 and the yoke pieces 3 are positioned in place by bringing radially outer end surfaces of the yoke pieces 3 into surface contact with the base portion 24. The presser plates 25 serve to fix the yoke pieces 3 by holding the back yoke portions 4B of the yoke pieces 3 between the presser plates 25 and the base portion 24 in the axial direction. The back yoke portions 4B of the yoke pieces 3 are held between the presser plates 25 and the base portion 24, and the yoke pieces 3 are fixed by means of the screws 26.
[0021] The guide pins 27 serve to guide jumper wires 20 that connect the coils 10 wound on the tooth portions 5 of the respective magnetic pole pieces 2, during winding. The guide pins 27 are provided on the base portion 24 so as to be located near the rotation centers of bend portions connecting the magnetic pole pieces 2 and the yoke pieces 3. The flyer 23 is disposed such that a rotation axis B thereof coincides with the longitudinal direction of the tooth portion 5 of the magnetic pole piece 2. The flyer 23 makes sliding movements in a direction C that coincides with the longitudinal direction of the tooth portion 5 of the magnetic pole piece 2, and also makes sliding movements in a direction D that coincides with the longitudinal direction of the back yoke portion 4A of the magnetic pole piece 2.

[0022] After the end of the winding work on the tooth portion 5 of the first magnetic pole piece 2, the flyer 23 is moved in a sliding manner in the direction D to a position at which the rotation axis B of the flyer 23 opposes the tooth portion 5 of the adjacent second magnetic pole piece 2 on which winding has not been performed. At this time, a winding finish portion of the coil 10 wound on the tooth portion of the first magnetic pole piece 2 is not cut and is caused to extend as the jumper wire 20 along the outer side of the guide pins 27 of the fixing jig 22. Subsequently, the coil 10 is wound on the tooth portion 5 of the second magnetic pole piece 2 in a direction opposite to the direction in which the coil 10 is wound on the first tooth portion 5. In the manner described above, the winding work is sequentially performed from the tooth portion 5 of the first magnetic pole piece 2 to the tooth portion 5 of the fourth magnetic pole piece 2.
[0023] Next, work will be described in which, after the end of the winding work on the tooth portions of the magnetic pole pieces 2, a core is closed to be integrated to complete the stator 1 for a rotating electric machine.
FIG. 4 is a diagram showing the time when the four magnetic pole pieces 2 and the four yoke pieces 3 are transformed by bending from a linear shape during the winding work to an annular shape after the end of the winding work.

The magnetic pole pieces 2 and the yoke pieces 3 are bent from the linear shape during winding to the annular shape by sequentially pressing distal end portions, at a free end side, of the tooth portions of the respective magnetic pole pieces 2 against a core metal 30.
The connection projection 7 and the connection recess 8 are formed on the end surfaces of the magnetic pole piece 2 and the yoke piece 3 that are butted against each other when being closed into the annular shape. Both end surfaces are fitted to each other by insertion of the connection projection 7 into the connection recess 8 in the circumferential direction. After the fitting, the butted end surfaces are connected and integrated by welding means such as TIG (tungsten inert gas) welding at the outer peripheral side of the fitted portion of the connection projection 7 and the connection recess 8. This is the end of the core closing work, and the stator 1 for a rotating electric machine is completed.
Since the connection projection 7 and the connection recess 8 are provided on the surfaces to be butted against each other, a backlash in the radial direction can be inhibited when the surfaces are butted against each other, so that inner diameter roundness can be improved. [0024] Next, a comparison with a comparative example is made in order to clarify the feature of the stator 1 for a •

rotating electric machine that includes the magnetic pole pieces 2 and the yoke pieces 3.
FIG. 5 is a cross-sectional view showing the configuration of a stator 101 for a rotating electric machine of the comparative example. The stator 101 for a rotating electric machine includes only four magnetic pole pieces 102. Each magnetic pole piece 102 has a structure in which a plurality of thin electromagnetic steel plates are stacked along an axial direction, and includes: a back yoke portion 104 extending in a direction perpendicular to the stacking direction; and a tooth portion 105 extending from the back yoke portion 104 in a direction toward the center of an annular shape. A coil 110 is wound around an insulator covering each tooth portion 105. The magnetic pole pieces 102 are bendably connected to each other by thin portions 106 at the outer peripheries of the back yoke portions 104 adjacent to each other.
In FIG. 5, each arrow H indicates the direction in which a magnetic flux flows.
[0025] FIG. 6 is a cutting layout diagram in the case of creating a cutting layout of steel plate pieces 132 from a band-shaped electromagnetic steel plate 31 for the stator 101 for a rotating electric machine. Each steel plate piece 132 has a shape in which the longitudinal directions of the back yoke portions 104 of the respective magnetic pole pieces 102

coincide with each other. The longitudinal direction of the back yoke portion 104 of each magnetic pole piece 102 of the steel plate piece 132 coincides with a feed direction J in which the electromagnetic steel plate 31 is fed, and the two steel plate pieces 132 are aligned in a direction perpendicular to the feed direction J of the electromagnetic steel plate 31.
Similar to the stator 1 for a rotating electric machine described with reference to FIG. 2, the two steel plate pieces 132 are arranged such that the tooth portions 105 of both steel plate pieces 132 oppose each other. In addition, the two steel plate pieces 132 are aligned such that, between the tooth portions 105 of one of the steel plate pieces 132, each tooth portion 105 of the other steel plate piece 132 is located, and the two steel plate pieces 132 are stamped.
In FIG. 6, B0 indicates the areas of hatched portions, that is, the area of one steel plate piece 132. [0026] Here, the difference between the magnetic material utilization factors of the stator 1 for a rotating electric machine of Embodiment 1 and the stator 101 for a rotating electric machine of the comparative example will be described with reference to FIGS. 2 and 6.
In the cutting layout for the stator 1 for a rotating electric machine of Embodiment 1 shown in FIG. 2,

where the area of the steel plate piece 32 is AO, the material utilization factor (2A0/(LlxL2)) is 37.8%.
Meanwhile, in the cutting layout for the stator 101 for a rotating electric machine of the comparative example shown in FIG. 6, where the area of the steel plate piece 132 is BO, the material utilization factor (2B0/(L3>E2 is satisfied. Thus, while winding is being performed on the tooth portion 5 of the magnetic pole piece 2, interference of the tooth portion 5 of the adjacent magnetic pole piece 2 with the flyer 23 is easily avoided. [0030] Next, the relationship between the magnetic pole

pieces 2 and the yoke pieces 3 of the stator 1 for a rotating electric machine of Embodiment 1 will be described with reference to FIGS. 8 and 9. In FIGS. 8 and 9, a portion corresponding to each thin portion 6 is referred to as joint 11.
FIG. 8 shows the case where the lengths, in the circumferential direction, of the back yoke portions 4A of the magnetic pole pieces 2 and the back yoke portions 4B of the yoke pieces 3, which form the stator 1 for a rotating electric machine, that is, the intervals between the joints 11, are different. Here, FIG. 8(a) shows a cross section showing the configuration of the stator 1 for a rotating electric machine, and FIG. 8(b) shows an arrangement shape during winding.
In FIG. 8 (a), the angle formed by a central axis and the joints 11 at both ends of the magnetic pole piece 2 is 91, and the angle formed by the central axis and the joints 11 at both ends of the yoke piece 3 is 92. Here, the magnetic pole pieces 2 and the yoke pieces 3 are arranged such that 91>92 is satisfied.
Thus, as shown in FIG. 8(b), the back yoke portion 4A of the magnetic pole piece 2 is present at the back surface side of each insulator 9 at the back yoke side. Therefore, when the magnetic pole pieces 2 and the yoke pieces 3 are arranged such that the longitudinal direction of

the back yoke portion 4A of each magnetic pole piece 2 coincides with the longitudinal direction of the back yoke portion 4B of each yoke piece 3, and the coil is wound on the tooth portion 5 of the magnetic pole piece 2, the insulator 9 can be inhibited from being bent toward the back yoke side. [0031] Meanwhile, FIG. 9 shows the case where the lengths, in the circumferential direction, of the back yoke portions 4A of the magnetic pole pieces 2 and the back yoke portions 4B of the yoke pieces 3, which form the stator 1 for a rotating electric machine, that is, the intervals between the joints 11, are equal to each other. Here, FIG. 9(a) shows a cross section showing the configuration of the stator 1 for a rotating electric machine, and FIG. 9(b) shows an arrangement shape during winding.
In FIG. 9(a), the angle formed by the central axis and the joints 11 at both ends of the magnetic pole piece 2 is 93, and the angle formed by the central axis and the joints 11 at both ends of the yoke piece 3 is 94. Here, the magnetic pole pieces 2 and the yoke pieces 3 are arranged such that 93=94 is satisfied.
Thus, as shown in FIG. 9(b), no back yoke portion 4A of the magnetic pole piece 2 is present on a part of the back surface of each insulator 9 at the back yoke side. Therefore, when the magnetic pole pieces 2 and the yoke pieces 3 are arranged such that the longitudinal direction of

the back yoke portion 4A of each magnetic pole piece 2 coincides with the longitudinal direction of the back yoke portion 4B of each yoke piece 3, and the coil is wound on the tooth portion 5 of the magnetic pole piece 2, bending of the insulator 9 to the back yoke side occurs at the part of the back surface where no back yoke portion 4A is present. [0032] Accordingly, in the stator 1 for a rotating electric machine of Embodiment 1, the magnetic pole pieces 2 and the yoke pieces 3 are arranged such that 91>02 is
i satisfied, and the lengths, in the circumferential direction, of the back yoke portions 4A of the magnetic pole pieces 2 are made larger than the lengths, in the circumferential direction, of the back yoke portions 4B of the yoke pieces 3 as in the configuration in FIG. 8.
i [0033] Next, the manufacturing method for the stator for a rotating electric machine of Embodiment 1 described above will be described with reference to the flowchart of FIG. 10.
The manufacturing method for the stator for a rotating electric machine of Embodiment 1 is a manufacturing
i method for the stator 1 for a rotating electric machine that includes the magnetic pole pieces 2 and the yoke pieces 3, the manufacturing method including the following step 1 (S01) to step 3 (S03). [0034] In a stamping step that is step 1 (S01), thin
i plates are stamped such that: the magnetic pole pieces 2 and

the yoke pieces 3 are arranged in such a manner that the longitudinal direction of the back yoke portion 4A of each magnetic pole piece 2 and the longitudinal direction of the back yoke portion 4B of each yoke piece 3 coincide with the rolling direction J of the electromagnetic steel plate 31; and the magnetic pole pieces 2 and the yoke pieces 3 are bendably connected to each other, and a predetermined number of the thin plates are stacked in the axial direction and fixed by means of swaging, whereby the magnetic pole pieces 2 and the yoke pieces 3 are formed.
[0035] In a winding step that is step 2 (S02), the coil 10 is wound onto the tooth portion 5 of each magnetic pole piece 2 using an automatic winding machine.
[0036] In a core closing step that is step 3 (S03), the linear-shaped magnetic pole pieces 2 and yoke pieces 3 in which the coil 10 has been wound on the tooth portion 5 of each magnetic pole piece 2 are bent into an annular shape, the connection projection 7 and the connection recess 8 on the end surfaces of the magnetic pole piece 2 and the yoke piece 3 are fitted to each other, and the end surfaces are connected and integrated with each other by means of welding.
[0037] As presented above, Embodiment 1 has been described with, as an example, the stator for a rotating electric machine that includes four magnetic pole pieces and four yoke pieces. However, each of the number of magnetic pole pieces

2 and the number of yoke pieces 3 is not limited to four, and may be six, may be eight, or may be greater than eight.
The above description has been given on the assumption that each of the magnetic pole pieces 2 and the yoke pieces 3 has a structure in which a plurality of thin electromagnetic steel plates are stacked along the axial direction. However, each of the magnetic pole pieces 2 and the yoke pieces 3 may be composed of a block. [0038] Next, other configuration examples will be described with reference to FIGS. 11 and 12. For distinguishing therebetween, a stator 71 for a rotating electric machine, magnetic pole pieces 72, yoke pieces 73, back yoke portions 74A of the magnetic pole pieces 72, back yoke portions 74B of the yoke pieces 73, and tooth portions 75 of the magnetic pole pieces 72 are illustrated in FIG. 11, and a stator 81 for a rotating electric machine, magnetic pole pieces 82, yoke pieces 83, back yoke portions 84A of the magnetic pole pieces 82, back yoke portions 84B of the yoke pieces 83, and tooth portions 85 of the magnetic pole pieces 82 are illustrated in FIG. 12.
The case where the number of the magnetic pole pieces and the number of the yoke pieces are equal to each other, that is, the case where the magnetic pole pieces and the yoke pieces are alternately arranged in an annular shape, has been described above. However, interference of each back

yoke portion with the flyer of the winding machine can be avoided even in the case where a plurality of the yoke pieces 73 are present between the magnetic pole pieces 72 as shown in FIG. 11, that is, in the case where the number of the yoke pieces is greater than that of the magnetic pole pieces. [0039] FIG. 12 shows the case where no yoke piece 83 is present between the magnetic pole pieces 82 at a location. That is, interference of each back yoke portion with the flyer of the winding machine can be avoided even in the case where the number of the yoke pieces is less than that of the magnetic pole pieces.
Due to the above description, with the configuration having at least one yoke piece between at least one pair of the adjacent magnetic pole pieces, the portion having the yoke piece between the one pair of the adjacent magnetic pole pieces can be away from the revolution plane of the flyer during winding, and thus interference of each back yoke portion with the flyer of the winding machine can be avoided.
[0040] As described above, Embodiment 1 relates to a stator for a rotating electric machine that includes magnetic pole pieces and yoke pieces, and a manufacturing method for the stator for a rotating electric machine that includes a stamping step, a winding step, and a core closing step.
Thus, in the stator for a rotating electric machine

and the manufacturing method therefor of Embodiment 1, a wide space can be taken between the tooth portions, and interference of each back yoke portion with the flyer of the winding machine can be avoided.
[0041] Embodiment 2
In a stator for a rotating electric machine and a manufacturing method therefor of Embodiment 2, winding work is performed simultaneously on tooth portions of two magnetic pole pieces using two automatic winding machines.
[0042] Hereinafter, the stator for a rotating electric machine and the manufacturing method therefor of Embodiment 2 will be described mainly with the difference from Embodiment 1 with reference to FIG. 13 which illustrates the winding work, and FIG. 14 which illustrates winding work of a comparative example. In FIGS. 13 and 14, components that are the same as or correspond to those in FIGS. 3 and 7 in Embodiment 1 are denoted by the same reference characters. In FIG. 14, the fixing jig is omitted.
[0043] Regarding the winding work for the stator for a rotating electric machine of Embodiment 1, the winding work is sequentially performed on the tooth portions 5 of the plurality of magnetic pole pieces 2 using one automatic winding machine 21. Regarding the winding work for the stator for a rotating electric machine of Embodiment 2, the winding work is performed simultaneously on the tooth

portions 5 of two magnetic pole pieces 2 using two automatic winding machines 21.
Also in FIG. 13, for easy understanding of the description, the magnetic pole piece 2 at the left end is referred to as first magnetic pole piece 2, the subsequent magnetic pole pieces 2 are sequentially referred to as second magnetic pole piece 2 and third magnetic pole piece 2, and the magnetic pole piece 2 at the right end is referred to as fourth magnetic pole piece 2.
[0044] As shown in FIG. 13, the winding work is performed simultaneously on the tooth portions 5 of the two magnetic pole pieces 2 using the flyers 23 of the two automatic winding machines 21. The two automatic winding machines 21
(flyers 23) are aligned such that the rotation axes B thereof coincide with the longitudinal directions of the tooth portions 5 of the magnetic pole pieces 2. After the end of the winding work on the tooth portions 5 of the first and third magnetic pole pieces 2, the two automatic winding machines 21 are simultaneously moved in a sliding manner in the direction D to positions at which the rotation axes B of the automatic winding machines 21 oppose the tooth portions 5 of the adjacent second and fourth magnetic pole pieces 2 on which winding has not been performed.
[0045] At this time, winding finish portions of the coils 10 wound on the tooth portions 5 of the first and third

magnetic pole pieces 2 are not cut and are caused to extend as the jumper wires 20 along the outer side of the guide pins 27 of the fixing jig 22. Subsequently, winding is performed on the tooth portions 5 of the second and fourth magnetic pole pieces 2 in a direction opposite to the direction in which winding is performed on the tooth portions 5 of the first and third magnetic pole pieces 2. In this manner, the winding work is sequentially performed on the tooth portions 5 of the magnetic pole pieces 2 on which winding has not been performed.
The time of the winding work is significantly shortened by using the two automatic winding machines 21, as compared to that in Embodiment 1.
[0046] It is possible to use the two automatic winding machines 21 for the stator 101 for a rotating electric machine described as the comparative example in Embodiment 1, as the comparative example. However, as shown in FIG. 14, in the stator 101 for a rotating electric machine of the comparative example, a pitch E2 between the tooth portions 105 of the magnetic pole pieces 102 is smaller than a pitch El between the tooth portions 5 of the magnetic pole pieces 2 of the stator 1 for a rotating electric machine shown in FIG. 13. Thus, interference between the flyers 23 of the two automatic winding machines 21 easily occurs, and it is more difficult to apply simultaneous winding to the stator 101 for

a rotating electric machine than to the stator 1 for a rotating electric machine.
[0047] In Embodiment 2, since the stator 1 for a rotating electric machine includes the four magnetic pole pieces 2 with tooth portions 5, the two automatic winding machines 21 are used. For a stator for a rotating electric machine that includes more magnetic pole pieces 2 with tooth portions 5, the number of automatic winding machines 21 is not limited to two, and three or more automatic winding machines 21 can be simultaneously used.
[0048] As described above, in the stator for a rotating electric machine and the manufacturing method therefor of Embodiment 2, the winding work is performed simultaneously on the tooth portions of the two magnetic pole pieces using the two automatic winding machines. Thus, in the stator for a rotating electric machine and the manufacturing method therefor of Embodiment 2, a wide space can be taken between the tooth portions, and interference of each back yoke portion with the flyer of the winding machine can be avoided. Moreover, the time of the winding work can be significantly shortened. [004 9] Embodiment 3
Embodiment 3 relates to a stator for a rotating electric machine that has a structure in which projections and recesses provided on magnetic pole pieces and yoke pieces

are used as a connection means in place of the thin portions at the outer peripheries of the back yoke portions of the stator for a rotating electric machine of Embodiment 1. [0050] Hereinafter, the configuration of the stator for a rotating electric machine of Embodiment 3 will be described mainly with the difference from Embodiment 1 with reference to FIG. 15 which illustrates the connection means of the stator for a rotating electric machine.
FIG. 15(a) is a cross-sectional view showing the configuration of the stator for a rotating electric machine of Embodiment 3, and FIG. 15(b) is a Y-Y' cross-sectional view of FIG. 15(a).
In FIG. 15, components that are the same as or correspond to those in FIG. 1 in Embodiment 1 are denoted by the same reference characters.
To be distinguished from the stator 1 for a rotating electric machine of Embodiment 1, a stator 51 for a rotating electric machine, magnetic pole pieces 52, yoke pieces 53, back yoke portions 54A and 54B, and tooth portions 55 are illustrated.
[0051] In the stator 1 for a rotating electric machine of Embodiment 1, the magnetic pole pieces 2 and the yoke pieces 3 are bendably connected to each other by the thin portions 6.
In the stator 51 for a rotating electric machine of Embodiment 3, as shown in FIG. 15(b), each magnetic pole

piece 52 and each yoke piece 53 are provided with projections 57 and recesses 58 at end portions thereof adjacent to each other in the circumferential direction. The projections 57 and the recesses 58 are swaged together in a stacking direction to form the connection means for bendable connection.
[0052] The stator 51 for a rotating electric machine of Embodiment 3 is easily handled when the magnetic pole pieces 52 and the yoke pieces 53 are bent into an annular shape after the coil 10 is wound, as compared to the stator 1 for a rotating electric machine of Embodiment 1 that includes the thin portions 6 as the connection means. Thus, further improvement of the productivity can be achieved. In addition, mechanical accuracy can be improved. Moreover, occurrence of a problem such as cracking, resulting in an increase in magnetic resistance and deterioration of magnetic characteristics, can be avoided even when bending is performed a plurality of times.
[0053] As described above, Embodiment 3 relates to a stator for a rotating electric machine that has a structure in which projections and recesses provided on magnetic pole pieces and yoke pieces are used as a connection means of the stator for a rotating electric machine.
Therefore, in the stator for a rotating electric machine of Embodiment 3, a wide space can be taken between

the tooth portions, and interference of each back yoke portion with the flyer of the winding machine can be avoided. Moreover, the productivity and mechanical accuracy of the stator for a rotating electric machine can be improved.
[0054] Embodiment 4
Embodiment 4 relates to a stator for a rotating electric machine that has a structure in which the number of magnetic pole pieces and the number of yoke pieces are increased from those in the stator for a rotating electric machine of Embodiment 1 to achieve multipolarization.
[0055] Hereinafter, the configuration of the stator for a rotating electric machine of Embodiment 4 will be described mainly with the difference from Embodiment 1 with reference to FIG. 16 which is a cross-sectional view showing the configuration of the stator for a rotating electric machine.
In FIG. 16, components that are the same as or correspond to those in FIG. 1 in Embodiment 1 are denoted by the same reference characters.
To be distinguished from the stator 1 for a rotating electric machine of Embodiment 1, a stator 61 for a rotating electric machine, magnetic pole pieces 62, yoke pieces 63, back yoke portions 64A and 64B, and tooth portions 65 are illustrated.
[0056] The stator 61 for a rotating electric machine in FIG. 16 is configured to include six magnetic pole pieces 62

and six yoke pieces 63 by increasing the number of magnetic pole pieces 2 and tooth portions 5 from those in the stator 1 for a rotating electric machine of Embodiment 1.
Since the number of magnetic pole pieces 2 and tooth portions 5 is increased to achieve multipolarization, torque ripple occurring in a rotating electric machine can be reduced.
[0057] In Embodiment 4, as an example of multipolarization, the stator 61 for a rotating electric machine that includes the six magnetic pole pieces 62 and the six yoke pieces 63 has been described. Each of the number of the magnetic pole pieces 62 and the number of the yoke pieces 63 is not limited to six, and a stator for a rotating electric machine that includes more magnetic pole pieces 62 and more yoke pieces 63 can be formed.
[0058] As described above, Embodiment 4 relates to a stator for a rotating electric machine that has a structure in which the number of magnetic pole pieces and the number of yoke pieces are increased from those in the stator for a rotating electric machine of Embodiment 1 to achieve multipolarization. Therefore, in the stator for a rotating electric machine of Embodiment 3, a wide space can be taken between the tooth portions, and interference of each back yoke portion with the flyer of the winding machine can be avoided. Moreover, torque ripple occurring in a rotating

electric machine can be reduced. [0059] Embodiment 5
Embodiment 5 relates to a rotating electric machine in which the stator for a rotating electric machine of Embodiment 1 is used.
[0060] Hereinafter, the configuration of the rotating electric machine of Embodiment 5 will be described with reference to FIG. 17 which is a cross-sectional view showing the configuration of the rotating electric machine.
In FIG. 17, components that are the same as or correspond to those in FIG. 1 in Embodiment 1 are denoted by the same reference characters.
[0061] A description will be given with, as an example, the case where the stator 1 for a rotating electric machine that includes the four magnetic pole pieces 2 and the four yoke pieces 3, is used in FIG. 17. In FIG. 17, portions denoted by the same reference characters as those in FIG. 1 in Embodiment 1 indicate the same components as the portions described above in Embodiment 1, and thus the description thereof is omitted here.
[0062] The rotating electric machine 201 includes the stator 1 and a rotor 202 rotatably provided within the stator 1. The rotor 202 includes a shaft 203 and a magnet 204.
The rotating electric machine 201 has a structure in which required rotational force is obtained by applying a

current to the coil 10, which is provided in the stator 1, to generate a magnetic field, thereby rotating the rotor 202. In the rotating electric machine 201 configured as described above, a wide space can be taken between the tooth portions 5 of the stator 1, and interference of the back yoke portion 4A or 4B with the flyer of the winding machine can be avoided. Therefore, it is possible to efficiently wind the coil 10 on the stator 1, and thus the productivity of the rotating electric machine 201 can be increased.
[0063] Here, the description has been given with, as an example, the stator for a rotating electric machine of Embodiment 1 that includes four magnetic pole pieces and four yoke pieces. Each of the number of magnetic pole pieces and the number of yoke pieces is not limited to four, and may be six, may be eight, or may be greater than eight.
The case where the number of the magnetic pole pieces and the number of the yoke pieces are equal to each other has been described here. However, the number of the yoke pieces may be greater than that of the magnetic pole pieces as shown in FIG. 11 in Embodiment 1, or the number of the yoke pieces may be less than that of the magnetic pole pieces as shown in FIG. 12.
Moreover, the stator for a rotating electric machine described in Embodiments 3 or 4 can also be used.
[0064] It is noted that, within the scope of the present

invention, the above embodiments may be freely combined with each other, or each of the above embodiments may be modified or simplified as appropriate.
INDUSTRIAL APPLICABILITY
[0065] The present invention includes: magnetic pole pieces each including a back yoke portion and a tooth portion; and yoke pieces each including only a back yoke portion, and a wide space can be taken between the tooth portions, and thus the present invention is applicable to a wide range of stators for rotating electric machines.

We Claim:
[ 1] A stator for a rotating electric machine, the stator comprising:
a plurality of magnetic pole pieces and a plurality of yoke pieces arranged in an annular shape, wherein
each of the magnetic pole pieces includes a back yoke portion disposed along an outer peripheral portion of the annular shape and a tooth portion extending from the back yoke portion in a direction toward a center of the annular shape,
each of the yoke pieces includes only a back yoke portion disposed along the outer peripheral portion of the annular shape, and
at least one of the yoke pieces is present between at least a pair of the magnetic pole pieces adjacent to each other, and the pair of the magnetic pole pieces and the yoke piece between the pair of the magnetic pole pieces are bendably connected to each other.
[2] The stator for a rotating electric machine according to claim 1, wherein an angle formed by both end surfaces in a longitudinal direction of the back yoke portion of each magnetic pole piece relative to a central axis is larger than an angle formed by both end surfaces in a longitudinal direction of the back yoke portion of each yoke

piece relative to the central axis.
[3] The stator for a rotating electric machine according to claim 1 or 2, wherein a connection recess is provided on an end surface of one of the magnetic pole piece and the yoke piece for connection in the annular shape, and a connection projection is provided on an end surface of the other of the magnetic pole piece and the yoke piece.
[4] The stator for a rotating electric machine according to any one of claims 1 to 3, wherein thin portions are provided at outer peripheries of. the back yoke portions of the magnetic pole pieces and the back yoke portions of the yoke pieces in order to bendably connect the magnetic pole pieces and the yoke pieces.
[5] The stator for a rotating electric machine according to any one of claims 1 to 3, wherein the magnetic pole pieces and the yoke pieces are formed by stacking thin plates in an axial direction, and projections and recesses fitted to each other in the axial direction are provided at end portions, in a circumferential direction, of the magnetic pole pieces and the yoke pieces in order to bendably connect the magnetic pole pieces and the yoke pieces.

[6] A manufacturing method for a stator for a rotating electric machine, the stator including a plurality of magnetic pole pieces and a plurality of yoke pieces arranged in an annular shape, each of the magnetic pole pieces including a back yoke portion disposed along an outer peripheral portion of the annular shape and a tooth portion extending from the back yoke portion in a direction toward a center of the annular shape, each of the yoke pieces including only a back yoke portion disposed along the outer peripheral portion of the annular shape, the magnetic pole pieces and the yoke pieces being alternately arranged in an annular shape, the manufacturing method comprising:
a stamping step of performing stamping such that the magnetic pole pieces and the yoke pieces are bendably connected to each other and a longitudinal direction of each of the back yoke portions of the magnetic pole pieces and a longitudinal direction of each of the back yoke portions of the yoke pieces coincide with a rolling direction in which an electromagnetic steel plate is rolled, and stacking and fixing stamped pieces in an axial direction;
a winding step of winding a coil on the tooth portions; and
a core closing step of bending the yoke pieces and the magnetic pole pieces having the coil wound on the tooth portions thereof into an annular shape, and connecting and

integrating butted end surfaces.
[7] The manufacturing method for the stator for a rotating electric machine according to claim 6, wherein the coil is wound simultaneously on a plurality of the tooth portions using a plurality of automatic winding machines in the winding step.
[8] A rotating electric machine comprising:
the stator for a rotating electric machine
according to any one of claims 1 to 5; and
a rotor rotatably provided within the stator for a
rotating electric machine.