JP7537347B2 - Rotating electric machine stator and manufacturing method thereof - Google Patents

Description

The present invention relates to a stator for a rotating electric machine.

Some stators for rotating electrical machines such as brushless motors have a stator core and a three-phase coil. The stator core has a cylindrical back yoke, and multiple teeth that protrude radially inward from the back yoke are arranged side by side at intervals in the circumferential direction. A three-phase coil is wound around these teeth. The stator core has a core sheet laminate in which multiple core sheets are stacked in the axial direction perpendicular to the radial direction, and end face sheets attached to both end faces in the axial direction of the core sheet laminate.

Each core sheet and each end sheet has a back yoke portion that constitutes a back yoke, and a teeth portion that protrudes radially inward from the back yoke portion to constitute a tooth. Each end sheet is attached to the end face of the core sheet laminate by having its own back yoke portion attached to the back yoke portion of the core sheet adjacent to it.

JP 2014-147176 A

Among such stators, for example, as in Patent Document 1 above, there are some in which each end sheet has a magnetic protrusion that protrudes from the tip of each tooth portion on the side opposite the core sheet laminate in the axial direction. In such cases, the inventors have noticed that the following problems can occur.

That is, depending on the dimensional accuracy, for example, ripples may form in the end sheet or the adjacent core sheet that shift axially as they progress in the circumferential direction. In this state, when the back yoke portion of the end sheet is attached to the back yoke portion of the adjacent core sheet, gaps are created between some of the teeth in the end sheet and the teeth of the adjacent core sheet. When the rotor of a rotating electric machine rotates in this state, the field magnetic flux of the rotor may intermittently generate large forces in a direction that eliminates the gap.

Specifically, for example, when the rotor rotates, magnetic attraction and magnetic repulsion occur alternately between the rotor and the teeth. When magnetic attraction occurs, the magnetic flux flowing through the protrusion applies a large force to the teeth of the end sheet in a direction that eliminates the gap. This force causes the teeth of the end sheet to collide with the teeth of the adjacent core sheet, generating abnormal noise. When magnetic repulsion occurs after that, the force in the direction that eliminates the gap becomes smaller, causing the gap to reoccur. When magnetic attraction occurs again after that, the teeth of the end sheet collide with the teeth of the adjacent core sheet again. This repetition causes the abnormal noise to continue.

Note that the above has been described using the example of an inner rotor stator in which the teeth protrude radially inward from a cylindrical back yoke, but similar issues can occur in the case of an outer rotor stator in which the teeth protrude radially outward from a cylindrical or columnar back yoke.

The present invention was made in consideration of the above circumstances, and its main objective is to suppress the generation of abnormal noise caused by collisions between the teeth of the end face sheet and the teeth of the adjacent core sheet.

The stator of the rotating electric machine of the present invention has a stator core and a coil. The stator core has a cylindrical or columnar back yoke, and a plurality of teeth protruding radially from the back yoke are arranged side by side at intervals in the circumferential direction of the back yoke. The coil is wound around the teeth. The stator core has a core sheet laminate in which a plurality of magnetic core sheets are laminated in an axial direction perpendicular to the radial direction, and a magnetic end face sheet attached to an end face in the axial direction of the core sheet laminate.

Each of the core sheets and the end face sheets has a back yoke portion that constitutes the back yoke, and a teeth portion that protrudes from the back yoke portion in the radial direction and constitutes the teeth. The end face sheets are attached to the end faces of the core sheet laminate by having their own back yoke portions attached to the back yoke portions of the core sheets adjacent to them.

In the stator of the rotating electric machine described above, the end face sheet has a protruding portion made of a magnetic material that protrudes from the tip of each of the teeth portions to the side opposite the core sheet laminate in the axial direction. A non-magnetic annular connecting ring is provided to connect the protruding portions together in the circumferential direction.

According to the present invention, even if a gap occurs between some of the teeth on the end face sheet and the teeth on the adjacent core sheet due to the aforementioned waviness or the like, the connecting ring connects each protrusion of the teeth where the gap occurs to each protrusion of the teeth where no gap occurs. This restricts the axial movement of each of the teeth on the end face sheet where the gap occurs, and inhibits collision with the teeth on the adjacent core sheet. This inhibits the generation of abnormal noise.

Moreover, because the connecting ring is non-magnetic, there is no need to worry about adversely affecting the flow of magnetic flux in the stator core. Therefore, according to the present invention, it is possible to suppress collisions between the teeth of the end face sheet and the teeth of the adjacent core sheet without adversely affecting the flow of magnetic flux in the stator core, thereby suppressing the generation of abnormal noise.

FIG. 1 is a cross-sectional view showing a rotating electric machine according to a first embodiment; FIG. 2 is a cross-sectional view taken along line II-II of FIG. FIG. 2 is a perspective view showing one end sheet in the axial direction and a core sheet adjacent thereto. FIG. 4 is a perspective view showing a state where a connecting ring is provided on the end face sheet of FIG. 1A to 1C are cross-sectional views showing steps in the manufacture of a connecting ring. FIG. 2 is an enlarged view of a right-hand portion of FIG. 1 . FIG. 13 is a cross-sectional view showing a stator of a comparative example in which a connecting ring is not provided. FIG. 1 is a cross-sectional view showing a stator according to an embodiment of the present invention having a connecting ring; FIG. 11 is a cross-sectional view showing a stator core according to another embodiment of the present invention; FIG. 11 is a cross-sectional view showing a stator core according to still another embodiment.

The following describes an embodiment of the present invention with reference to the drawings. However, the present invention is not limited to the following embodiment, and can be modified as appropriate without departing from the spirit of the invention.

Figure 1 is a cross-sectional view of a rotating electric machine 91 of this embodiment, and more specifically, a cross-section taken along line I-I in Figure 2, which will be referred to next. The rotating electric machine 91 may perform powering to rotate a connected object, may generate electricity using the rotational force of a connected object, or may perform both powering and electricity generation as appropriate. The rotating electric machine 91 has a rotor 70, a stator 30, and a housing 10.

Hereinafter, the center line of the rotor 70 is referred to as "axis A", the direction perpendicular to the length direction of axis A and toward axis A is referred to as "radial inward Ri", the opposite direction is referred to as "radial outward Ro", and radial inward Ri and radial outward Ro are collectively referred to as "radial direction R". For convenience, the length direction of axis A is referred to as "upper and lower Z" in accordance with the drawings, one of the upper and lower Z directions is referred to as "upper Z+" and the opposite direction is referred to as "lower Z-". However, the rotating electric machine 91 can be installed with the "upper and lower Z" referred to below in any direction, such as horizontal or oblique, not just vertical. In addition, the plan view seen from the upper and lower Z directions referred to below is referred to simply as "plan view", and the circumferential direction with axis A as the center line is referred to simply as "circumferential direction".

The rotor 70 has a rotating shaft 78, a rotor core 75, and a number of field magnets 71. The rotating shaft 78 is a shaft member that extends up and down Z and is installed on the axis A. The rotor core 75 is a cylindrical member that is fitted onto the rotating shaft 78 so that it cannot rotate relative to the rotating shaft 78. Each of the multiple field magnets 71 is a permanent magnet that is attached to the outer periphery of the rotor core 75 at intervals in the circumferential direction. Therefore, the rotating shaft 78, the rotor core 75, and the multiple field magnets 71 rotate together.

The stator 30 has a stator core 30a and a three-phase coil 30b. The stator core 30a is a cylindrical member, and is fitted onto the rotor 70 with a gap between its inner peripheral surface and the outer peripheral surface of the rotor 70. The stator core 30a has a plurality of core sheets 40 and two end sheets 50, one above the other. Each core sheet 40 has a disk shape, and a core sheet laminate 40L is formed by stacking a plurality of core sheets 40 vertically Z. Disk-shaped end sheets 50 are attached to the upper and lower end surfaces of the core sheet laminate 40L. A connection ring 60 is attached to each of the upper and lower end sheets 50. The three-phase coil 30b is attached to the stator core 30a.

The housing 10 has an upper portion 11 that constitutes the portion of the housing 10 closer to the upper Z+ side, and a lower portion 12 that constitutes the portion of the housing 10 closer to the lower Z- side. The upper portion 11 has a cylindrical shape with a bottom that opens to the lower Z- side, and the lower portion 12 has a cylindrical shape with a bottom that opens to the upper Z+ side. The upper portion 11 and the lower portion 12 are joined by multiple bolts 20 that are arranged in parallel in the circumferential direction and extend up and down Z, with the outer periphery of the stator core 30a sandwiched between them. This attaches the outer periphery of the stator core 30a to the housing 10.

A rotating shaft 78 is attached to the housing 10 via a bearing 17. The upper end of the rotating shaft 78 protrudes outward from the housing 10, and the connection target for the rotating electric machine 91 is connected to the outwardly protruding part.

Figure 2 is a cross-sectional view taken along line II-II in Figure 1. In Figure 2, the three-phase coil 30b is omitted from the illustration. The multiple field magnets 71 are arranged in a circumferential arrangement with alternating N poles Ri radially inward and S poles Ro radially outward, and N poles Ro radially outward and S poles Ri radially inward.

The stator core 30a has a cylindrical back yoke 31, and multiple teeth 34 protruding radially inward Ri from the back yoke 31 are arranged side by side at intervals in the circumferential direction. A slot S is formed between each pair of teeth 34 adjacent to each other in the circumferential direction.

Each tooth 34 has a tooth extension 35 and a tooth tip 36. The tooth tip 36 is the end of the tooth 34 on the rotor 70 side, i.e., the end on the radially inward Ri. On the other hand, the tooth extension 35 is the portion of the tooth 34 on the back yoke 31 side of the tooth tip 36, i.e., the portion on the radially outward Ro of the tooth tip 36. In each tooth 34, the tooth tip 36 is wider in the circumferential direction than the tooth extension 35. An annular connecting ring 60 is installed at the upper and lower ends of the tooth tip 36, i.e., the portion of the tooth tip 36 formed by the end face sheet 50.

The three-phase coils 30b, which are not shown in FIG. 2, are wound around the teeth 34 so that the coils of the three phases are offset from each other by 120° in electrical angle. Specifically, the coils of the three phases are distributed around the teeth 34 so that they are offset from each other by 30° in the circumferential direction when viewed from above. When the rotating electric machine 91 performs power running, the magnetic flux caused by the current flowing through the three-phase coils 30b acts on the field magnet 71, causing the rotor 70 to rotate. When the rotating electric machine 91 generates power, the magnetic flux of the field magnet 71 acts on the three-phase coils 30b, causing power to be generated.

Figure 3 is a perspective view showing the upper Z+ side end sheet 50 and the adjacent uppermost Z+ side core sheet 40.

The end face sheet 50 on the upper Z+ side has a back yoke portion 51 that constitutes the back yoke 31, teeth portions 54 that constitute the teeth 34, and protrusions 57 that protrude from the tips of the teeth portions 54 to the upper Z+. The back yoke portion 51 has a disk-like shape. The multiple teeth portions 54 are arranged side by side at intervals in the circumferential direction, each protruding radially inward Ri from the back yoke portion 51.

The teeth portion 54 has teeth extension portions 55 that constitute the teeth extension portion 35, and teeth tip portions 56 that constitute the teeth tip portion 36. The teeth tip portions 56 are wider in the circumferential direction than the teeth extension portions 55. The protrusions 57 protrude upward in the Z+ direction from the tips of the teeth tip portions 56.

The above explanation of the upper Z+ side end sheet 50 is the same for the lower Z- side end sheet 50, but with "upper Z+" replaced with "lower Z-".

The above description of the upper Z+ side end sheet 50 is also the same for each core sheet 40, except that "upper Z+ side end sheet 50," "back yoke portion 51," "teeth portion 54," "teeth portion extension portion 55," and "teeth portion tip portion 56" are replaced with "core sheet 40," "back yoke portion 41," "teeth portion 44," "teeth portion extension portion 45," and "teeth portion tip portion 46," respectively, and the description of the protrusion portion 57 is omitted. In other words, the configuration of each core sheet 40 is substantially the same as that of the end sheet 50, but differs from the end sheet 50 in that it does not have the protrusion portion 57.

On the upper surface of the back yoke portion 51, 41 of each sheet 50, 40 of each end sheet 50 and each core sheet 40, a plurality of crimping protrusions 52 protruding upward Z+ are arranged side by side at intervals in the circumferential direction. And on the back side, i.e., the underside, of each of the protrusions 52, 42 on the back yoke portion 51, 41 of each sheet 50, 40, a crimping recess 53, 43 (not shown in FIG. 3) is formed.

The upper Z+ side end sheet 50 is formed by punching out a magnetic plate such as a steel plate by press working and bending it. Specifically, the press working forms a back yoke portion 51, a number of teeth portions 54 protruding radially inward Ri from the back yoke portion 51, and protrusions 57 protruding further radially inward Ri from the tips of the teeth portions 54, while forming convex portions 52 and concave portions 53 in the back yoke portion 51. From this state, the protrusions 57 are bent at right angles to the upper Z+ side relative to the teeth portions 54 to form the upper Z+ side end sheet 50.

The above explanation of the manufacturing method for the upper Z+ side end sheet 50 is the same for the lower Z- side end sheet 50, but with "upper Z+" replaced with "lower Z-".

Each core sheet 40 is formed by punching out a magnetic plate such as a steel plate by press working. Specifically, the back yoke portion 41 and a plurality of teeth portions 44 are formed by press working, and the back yoke portion 41 is formed with a protrusion 42 and a recess 43.

Figure 4 is a perspective view showing a state in which a connection ring 60 is provided on the tooth tip 56 of the end face sheet 50 on the upper Z+ side. The entire connection ring 60 is made of a non-magnetic material such as resin, and connects the protrusions 57 together in the circumferential direction.

Figure 5 is a cross-sectional view showing each step in the manufacture of the connection ring 60. First, in the first step shown in Figure 5 (a), a mold 100 is placed so as to cover all of the protrusions 57 on the end face sheet 50 and the portions of all of the teeth tip portions 56 near the tips. The mold 100 has an upper mold 101 and a lower mold 102.

Next, in the second step shown in FIG. 5(b), the connection ring material P, such as resin, which is the material of the connection ring 60, is heated or otherwise rendered fluid and then injected into the inside of the mold 100. Next, in the third step shown in FIG. 5(c), the connection ring material P is hardened by cooling or otherwise to form the connection ring 60, and then the mold 100 is opened to release the connection ring 60 from the mold 100.

As described above, the connection ring 60 is provided on the end sheet 50. Therefore, the connection ring 60 covers the entirety of all the protrusions 57 on the end sheet 50 corresponding to it, and the portions near the tips of all the teeth tips 56 on the end sheet 50. On the other hand, the connection ring 60 does not abut against any of the teeth extensions 55 and back yoke parts 51 on the end sheet 50 corresponding to it.

Figure 6 is an enlarged view of a portion of the stator 30 shown in Figure 1 on the right side. Each core sheet 40 is attached to the upper surface of the core sheet 40 one layer below it on the Z-side by pressing the protrusion 42 on the upper surface of the core sheet 40 one layer below it into the recess 43 on its lower surface and crimping it. This integrates multiple core sheets 40 to form a core sheet laminate 40L.

The upper Z+ side end sheet 50 is attached to the upper end surface of the core sheet laminate 40L by pressing the convex portion 42 on the upper surface of the uppermost Z+ core sheet 40 into the concave portion 53 on its underside and crimping it. On the other hand, the lower Z- side end sheet 50 is attached to the lower end surface of the core sheet laminate 40L by pressing the convex portion 52 on its upper surface into the concave portion 43 on the underside of the lowermost Z- core sheet 40 and crimping it.

In this way, each sheet 50, 40 has its own recess 53, 43 pressed into the protrusion 42, 52 of the sheet 40, 50 one position below it on the Z-side, and is tightened, so that its own back yoke portion 51, 41 is attached to the back yoke portion 41, 51 of the sheet 40, 50 one position below it on the Z-side. On the other hand, the teeth portions 54, 44 of each sheet 50, 40 are not joined to each other.

Each field magnet 71 faces the inner circumferential surface of the core sheet laminate 40L and the inner circumferential surface of the connecting ring 60.

Figure 7 is a cross-sectional view showing a comparative example in which the end sheet 50 does not have a connection ring 60. Below, the effects of this embodiment will be explained with reference to this comparative example.

Depending on the dimensional accuracy, for example, undulations that shift up and down Z as they progress in the circumferential direction may be formed in the upper Z+ end sheet 50 or the uppermost Z+ core sheet 40. In this state, when the back yoke portion 51 of the upper Z+ end sheet 50 is attached to the back yoke portion 41 of the uppermost Z+ core sheet 40, a gap G is generated between some of the teeth tips 56 of the upper Z+ end sheet 50 and the teeth tips 46 of the uppermost Z+ core sheet 40. When the rotor 70 of the rotating electric machine 91 rotates in this state, the magnetic flux of the field magnet 71 of the rotor 70 may intermittently generate a large force in a direction that eliminates the gap G.

Specifically, for example, when the rotor 70 rotates, magnetic attraction and magnetic repulsion are generated alternately between the rotor 70 and the teeth tip 36. When the magnetic attraction is generated, the magnetic flux flowing through the protrusion 57 applies a large force in the direction of eliminating the gap G to the teeth tip 56 of the end face sheet 50 on the upper Z+ side. This force causes the teeth tip 56 of the end face sheet 50 on the upper Z+ side to descend and collide with the teeth tip 46 of the core sheet 40 on the upper Z+ side, generating an abnormal noise. When the magnetic repulsion is generated after that, the force in the direction of eliminating the gap G becomes smaller, so that the teeth tip 56 rises and the gap G is generated again. When the magnetic attraction is generated again after that, the teeth tip 56 of the end face sheet 50 on the upper Z+ side descends again and collide with the teeth tip 46 of the core sheet 40 on the upper Z+ side again. This repeated action causes the abnormal noise to continue.

In this regard, in this embodiment, as shown in FIG. 8, a connecting ring 60 is provided. The connecting ring 60 connects each protrusion 57 of the teeth tip 56 where the gap G is formed to each protrusion 57 of the teeth tip 56 where the gap G is not formed. As a result, the movement of each teeth tip 56 where the gap G is formed on the upper Z+ side end face sheet 50 in the up-down Z direction is suppressed, and collision with the teeth tip 46 of the uppermost Z+ side core sheet 40 is suppressed. Therefore, the generation of abnormal noise is suppressed.

The above explanation of the upper Z+ side end sheet 50 is the same for the lower Z- side end sheet 50, except that "upper Z+ side" is read as "lower Z- side", "downward" and "upward" are read as the other, and the phrase "as shown in FIG. 8" is omitted.

As a result, collisions between the tooth tip 56 of each of the upper and lower end sheets 50 and the tooth tip 46 of the adjacent core sheet 40 can be suppressed, thereby suppressing the generation of abnormal noise.

In addition, because the upper and lower connecting rings 60 are non-magnetic, there is no need to worry about adversely affecting the flow of magnetic flux in the stator core 30a. Therefore, according to this embodiment, the generation of abnormal noise can be suppressed without adversely affecting the flow of magnetic flux in the stator core 30a.

In addition, each of the upper and lower connecting rings 60 covers the entirety of all of the protrusions 57 on the end face sheet 50 corresponding to it. This allows the protrusions 57 of the end face sheets 50 corresponding to it to be firmly connected to each other. At the same time, each of the upper and lower connecting rings 60 does not abut against either the teeth portion extensions 55 or the back yoke portions 51 on the end face sheets 50 corresponding to it. This allows the connecting rings 60 to be provided as compactly as possible with as little waste as possible.

In addition, in this embodiment, as shown in FIG. 5, a mold 100 is placed so as to cover all of the protrusions 57 on the end sheet 50, and then the connection ring material P is injected inside the mold 100 and hardened to form the connection ring 60. This makes it easy to form the connection ring 60 on the end sheet 50.

[Other embodiments]
Each of the above-described embodiments can be modified as follows, for example.

In the first embodiment, as shown in FIG. 8, the connecting ring 60 does not cover the teeth extensions 55 or the back yoke portion 51 of the end face sheet 50 that corresponds to it. Alternatively, as shown in FIG. 9, for example, the connecting ring 60 may cover the entire end face sheet 50 that corresponds to it from the periphery. However, even in this case, the teeth extensions 55 are not connected to each other in the circumferential direction so that the slots S are not filled.

In the first embodiment, as shown in FIG. 5, a mold 100 is placed so as to cover all the protrusions 57 on the end sheet 50, and then the connection ring material P is injected inside the mold 100 and hardened to form the connection ring 60. Alternatively, the connection ring 60 may be provided by molding or the like separately from the end sheet 50 in a state where it is separated from the end sheet 50. Then, as shown in FIG. 10, the end sheet 50 provided separately may be attached to each protrusion 57 of the end sheet 50 by engagement or the like.

In the first embodiment, as shown in FIG. 5, the mold 100 and the connection ring 60 molded thereby cover the entire protrusion 57. Alternatively, the mold 100 and the connection ring 60 may cover a portion of each of the protrusions 57.

In the first embodiment, as shown in FIG. 5, the mold 100 and the connection ring 60 molded thereby cover only the portion of the teeth tip 56 near the tip. Alternatively, the mold 100 and the connection ring 60 may cover the entire teeth tip 56.

In the first embodiment, as shown in FIG. 6, each sheet 50, 40 is attached to the sheet 40, 50 one level below itself on the Z-side by pressing the protrusions 42, 52 of the sheet 40, 50 one level below itself on the Z-side into the recesses 53, 43 of the sheet 50, 40 and tightening the sheet. Alternatively, each sheet 50, 40 may be provided with a through hole penetrating vertically Z, and the sheets 50, 40 may be integrated by pressing a shaft member extending vertically Z into the through hole and tightening the through hole.

In the first embodiment, as shown in FIG. 2, the teeth tip portions 46, 56 are larger in the circumferential direction than the teeth extension portions 45, 55. Alternatively, the circumferential size of the teeth extension portions 45, 55 and the circumferential size of the teeth tip portions 46, 56 may be the same.

In the first embodiment, as shown in FIG. 1, the rotating electric machine 91 is an inner rotor type in which the rotor 70 is installed radially inward Ri of the cylindrical stator 30, but instead, it may be an outer rotor type in which a cylindrical rotor is installed radially outward of a cylindrical or columnar stator. In this case, the teeth 54, 44 of each seat 50, 40 protrude radially outward Ro instead of radially inward Ri.

In the first embodiment, the end sheets 50 are attached to both the upper and lower end faces of the core sheet laminate 40L, but instead, the end sheets 50 may be attached to only one of the upper and lower end faces of the core sheet laminate 40L.

In the first embodiment, a three-phase coil 30b is wound around the teeth 34, but a two-phase coil or a four or more phase coil may be wound instead.

30... stator, 30a... stator core, 30b... three-phase coil, 31... back yoke, 34... teeth, 40L... core sheet laminate, 40... core sheet, 41... back yoke portion, 44... teeth portion, 50... end face sheet, 51... back yoke portion, 54... teeth portion, 57... protrusion, 60... connection ring, 91... rotating electric machine, R... radial direction, Z... up and down.

Claims (5)

The stator core (30a) includes a cylindrical or columnar back yoke (31), and a plurality of teeth (34) protruding from the back yoke in a radial direction (R) are arranged in parallel at intervals in the circumferential direction of the back yoke, and a coil (30b) is wound around the teeth,
The stator core includes a core sheet laminate (40L) in which a plurality of magnetic core sheets (40) are laminated in an axial direction (Z) perpendicular to the radial direction, and an end face sheet (50) of magnetic material attached to an end face in the axial direction of the core sheet laminate,
Each of the core sheets and each of the end face sheets (40, 50) respectively has a back yoke portion (41, 51) constituting the back yoke, and a teeth portion (44, 54) protruding in the radial direction from the back yoke portion to constitute the teeth,
In a stator (30) of a rotating electric machine (91), the end face sheet is attached to the end face of the core sheet laminate by attaching the back yoke portion of the end face sheet to the back yoke portion of the core sheet adjacent to the end face sheet,
The end face sheet has a protruding portion (57) of a magnetic material protruding from a tip of each of the teeth portions to a side opposite to the core sheet laminate side in the axial direction,
a non-magnetic annular connecting ring (60) is provided to connect the protruding portions to each other in the circumferential direction;
The end face sheet has a tooth tip portion (56) that is a tip portion of the tooth portion, which is larger in the circumferential direction than a tooth extension portion (55) that is a portion of the tooth portion closer to the back yoke than the tooth tip portion,
The connection ring does not abut against either the teeth portion extension portion or the back yoke portion of the end face sheet. 2 . The stator of claim 1 , wherein the connecting ring covers the entirety of all of the protrusions on the end face sheet and at least a portion of each of the tip ends of all of the teeth on the end face sheet. 2. The stator of claim 1 , wherein the connection ring is provided separately from the end face sheet and attached to the end face sheet. The stator core (30a) includes a cylindrical or columnar back yoke (31), and a plurality of teeth (34) protruding from the back yoke in a radial direction (R) are arranged in parallel at intervals in the circumferential direction of the back yoke, and a coil (30b) is wound around the teeth,
The stator core includes a core sheet laminate (40L) in which a plurality of magnetic core sheets (40) are laminated in an axial direction (Z) perpendicular to the radial direction, and an end face sheet (50) of magnetic material attached to an end face in the axial direction of the core sheet laminate,
Each of the core sheets and each of the end face sheets (40, 50) respectively has a back yoke portion (41, 51) constituting the back yoke, and a teeth portion (44, 54) protruding in the radial direction from the back yoke portion to constitute the teeth,
In a stator (30) of a rotating electric machine (91), the end face sheet is attached to the end face of the core sheet laminate by attaching the back yoke portion of the end face sheet to the back yoke portion of the core sheet adjacent to the end face sheet,
The end face sheet has a protruding portion (57) of a magnetic material protruding from a tip of each of the teeth portions to a side opposite to the core sheet laminate side in the axial direction,
a non-magnetic annular connecting ring (60) is provided to connect the protruding portions to each other in the circumferential direction;
A stator for a rotating electric machine, wherein the connecting ring covers the entire end face sheet from the periphery. The stator core (30a) includes a cylindrical or columnar back yoke (31), and a plurality of teeth (34) protruding from the back yoke in a radial direction (R) are arranged in parallel at intervals in the circumferential direction of the back yoke, and a coil (30b) is wound around the teeth,
The stator core includes a core sheet laminate (40L) in which a plurality of magnetic core sheets (40) are laminated in an axial direction (Z) perpendicular to the radial direction, and an end face sheet (50) of magnetic material attached to an end face in the axial direction of the core sheet laminate,
Each of the core sheets and each of the end face sheets (40, 50) respectively has a back yoke portion (41, 51) constituting the back yoke, and a teeth portion (44, 54) protruding in the radial direction from the back yoke portion to constitute the teeth,
In a stator (30) of a rotating electric machine (91), the end face sheet is attached to the end face of the core sheet laminate by attaching the back yoke portion of the end face sheet to the back yoke portion of the core sheet adjacent to the end face sheet,
The end face sheet has a protruding portion (57) of a magnetic material protruding from a tip of each of the teeth portions to a side opposite to the core sheet laminate side in the axial direction,
A method for manufacturing a stator for a rotating electric machine, comprising the steps of: providing an annular non-magnetic connecting ring (60) that connects the protruding portions to each other in the circumferential direction, the method comprising the steps of:
A first step of placing a mold (100) so as to cover at least a portion of all of the protrusions on the end sheet;
A second step of injecting a fluid connecting ring material (P) into the mold;
a third step of hardening the connection ring material to form the connection ring and then releasing the connection ring from the mold;
A method for manufacturing a stator for a rotating electric machine comprising the steps of:

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