Stator core for rotary electric machine

Abstract

To suppress formation of an unintended gap between core sheets in a stacked state.SOLUTION: A stator core 11 includes: an annular back yoke 21; and a plurality of teeth 22 projecting in a radial direction from the back yoke 21, the stator core 11 being structured by stacking of a plurality of core sheets 30 in multiple layers. Each core sheet 30 includes: convex parts 34 which are provided in a circumferential direction at a predetermined interval, and which form a folded configuration being convex in the stacking direction, and which extend in the radial direction, the convex part 34 being stacked on top of each other in the stacking direction. Each convex part 34 and a flat part 35 lying between the convex parts 34 neighboring in the circumferential direction are different in thickness dimension, and the thickness dimension of the convex part 34 is smaller than that of the flat part 35.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a stator core of a rotating electrical machine.

Background Art

[0002] As a stator core of a rotating electrical machine, a configuration in which core sheets made of steel plates are laminated in multiple layers is known. Further, at the time of manufacturing the stator core, a technique is known in which bent portions having a triangular mountain shape or the like are formed at predetermined intervals in the circumferential direction on a strip-shaped core sheet, and the core sheet is bent by the bent portions (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a configuration in which a bent portion having a triangular mountain shape is formed on the core sheet and the bent portions are overlapped with each other, since the steel plate is inclined with respect to the lamination direction (that is, the stator axis direction) at the bent portion, in the stator core, the thickness in the lamination direction becomes locally thick. Therefore, in the stator core, gaps are unintentionally generated at locations other than the bent portions. In this case, there is a concern that the strength of the stator core may be insufficient in a configuration in which the core sheets are fixed by caulking, welding, or the like, or the performance of the rotating electrical machine may be deteriorated.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a stator core of a rotating electrical machine capable of suppressing the formation of unintentional gaps between core sheets in a laminated state.

Means for Solving the Problems

[0006] Hereinafter, means for solving the above problems and their effects will be described.

[0007] Means 1 is a stator core having an annular back yoke and a plurality of teeth protruding radially from the back yoke, and configured by laminating core sheets in multiple layers, wherein the core sheets are provided at predetermined intervals in the circumferential direction, have a bent shape that is convex in the stacking direction and have convex portions extending in the radial direction, and the convex portions are stacked in a state of overlapping each other in the stacking direction, the plate thickness dimensions are different between the convex portions and the flat portions between the convex portions adjacent to each other in the circumferential direction, and the plate thickness dimension of the convex portions is smaller than the plate thickness dimension of the flat portions.

[0008] In a stator core formed by laminating core sheets in multiple layers, the core sheets are provided with convex portions having a bent shape that is convex in the stacking direction and extending in the radial direction at predetermined intervals in the circumferential direction, and the core sheets are stacked in a state where the convex portions overlap each other in the stacking direction. In this case, the core sheets are curved in an arc shape by the convex portions, so that an annular back yoke is preferably formed. Further, in the core sheets, the plate thickness dimensions are made different between the convex portions and the flat portions between the convex portions adjacent to each other in the circumferential direction, and the plate thickness dimension of the convex portions is made smaller than the plate thickness dimension of the flat portions. As a result, even if the steel plate material is inclined in the stacking direction (i.e., the stator axis direction) at the convex portions, the difference in the thickness of the steel plate material between the convex portions and the flat portions in the stacking direction becomes small. As a result, it is possible to suppress the formation of unintentional gaps between the laminated core sheets in the stator core, and thus solve problems such as insufficient strength of the stator core.

[0009] In Means 2, the core sheet has different thicknesses of the steel plate material constituting the core sheet between the convex portion and the flat portion, and the convex portion has a large protruding height on the radially inner side and a small protruding height on the radially outer side in the back yoke, and is formed so as to protrude from the flat portion also at the radially outermost portion of the back yoke.

[0010] In the core sheet, when the protruding height of the convex portion becomes zero at the outermost diameter direction of the back yoke, the convex portion protrudes axially from the zero protruding height in the diameter direction which is the extending direction of the convex portion. In this case, at the starting portion of the convex portion, it becomes difficult to form the convex portion by bending and thinning the steel plate material. In view of this point, the convex portion is formed so as to protrude from the flat portion also at the portion that becomes the outermost diameter direction of the back yoke, that is, at the portion where the protruding height of the convex portion is minimized. In this case, in the core sheet, compared with the configuration where the protruding height of the convex portion becomes zero at the outermost diameter direction of the back yoke, it becomes easier to form the convex portion by bending and thinning the steel plate material, and the forming of the convex portion due to the thinning of the steel plate material can be properly performed.

[0011] In means 3, the concave side in the convex portion is the inner concave portion, and at the outermost diameter direction portion of the convex portion, the depth dimension of the inner concave portion is the same as or larger than the plate thickness dimension of the flat portion.

[0012] At the outermost diameter direction portion of the convex portion, the depth dimension of the inner concave portion is made the same as or larger than the plate thickness dimension of the flat portion. Thereby, appropriate thinning can be performed over the entire diameter range in the convex portion.

[0013] In means 4, in the core sheet, the convex portion has a triangular mountain shape, and the angle of the triangular top of the convex portion is different between the inner diameter direction and the outer diameter direction of the back yoke. In the convex portion, on the outer diameter side of the back yoke, the angle of the triangular top is larger and the plate thickness dimension is larger than that on the inner diameter side.

[0014] In the convex portion of the core sheet, by making the angles of the triangle tops different inside and outside the radial direction of the back yoke, the circumferential lengths on the inner peripheral side and the outer peripheral side of the back yoke can be made different, enabling the bending formation of the back yoke. Further, in the convex portion, on the outer side in the radial direction of the back yoke, the angle of the triangle top is made larger than that on the inner side in the radial direction, and the plate thickness dimension is increased. As a result, on the outer side in the radial direction where the protruding height of the convex portion is small, the angle of inclination with respect to the flat portion becomes small, and the increase in the thickness in the stator axial direction due to the inclination becomes small. Therefore, on the outer side in the radial direction where the size of the bend becomes small, the degree of thinning of the steel plate material can be reduced, and the thinning of the steel plate material can be appropriately performed.

[0015] In means 5, the core sheet is composed of a first sheet having the convex portion and continuous in the circumferential direction, and a second sheet composed of a portion of the first sheet excluding the convex portion, and these first sheet and second sheet are configured by being overlapped with each other in the lamination direction. In the core sheet, in a state where the second sheet is overlapped on the first sheet, the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion.

[0016] When the core sheet is configured by overlapping a first sheet having the convex portion and continuous in the circumferential direction and a second sheet composed of a portion of the first sheet excluding the convex portion, by overlapping the first sheet and the second sheet, the plate thickness dimension of the flat portion can be relatively increased without thinning the plate thickness of the convex portion. Therefore, a configuration in which the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion can be easily realized.

[0017] In means 6, the plate thickness dimension of the convex portion of the first sheet is the same as the plate thickness dimension of the portion other than the convex portion, and in the core sheet, in a state where the second sheet is overlapped on the first sheet, the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion.

[0018] In this case, even if the plate thickness dimensions are the same between the convex portions and the portions other than the convex portions in the first sheet, in other words, even if the steel plate material is not thinned, in the core sheet, a configuration in which the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion can be easily realized.

[0019] In means 7, in the first sheet, the convex portion is formed in a range from the innermost position in the radial direction to the intermediate position in the radial direction in the back yoke, and in the second sheet, in a state where the second sheet is stacked on the first sheet, portions on both circumferential sides of the convex portion are continuous at the outermost position in the radial direction.

[0020] In the first sheet, by setting the range of the convex portion in the radial direction to be from the innermost position in the radial direction to the intermediate position in the radial direction of the back yoke, the second sheet is configured such that portions on both circumferential sides of the convex portion in the back yoke are continuous at the outermost position in the radial direction. Thereby, both the first sheet and the second sheet become continuous in the longitudinal direction, and the operation of overlapping these sheets with each other can be suitably performed.

[0021] Means 8 is a stator core in which the teeth protrude in a direction extending radially inward from the back yoke, and the convex portion has a flat top surface in a predetermined range in the radial direction including the innermost position in the radial direction.

[0022] The convex portion of the core sheet is formed such that the top surface is flat in a predetermined range in the radial direction including the innermost position in the radial direction. Thereby, even in a configuration where the stator winding wound around each slot is bent radially outward at the coil end, interference between the stator winding and the convex portion can be suppressed.

[0023] In means 9, in one or a plurality of layers of the core sheets that are the axial end portions, a portion including at least the top of the convex portion is cut away.

[0024] In the core sheet that forms the axial end of the stator core, the top of the convex portion is cut off. In this case, since the axial length of the stator core is shortened by partially cutting off the convex portion, the core mass can be increased without increasing the axial length of the stator core. As a result, the magnetic path width is expanded and the torque output is improved.

[0025] In means 10, the core sheet has a yoke forming portion as a portion that forms the back yoke, and a tooth forming portion as a portion that forms the teeth. A rolling portion is provided at a radial edge portion on the side opposite to the tooth forming portion in the yoke forming portion, and by this rolling portion, a portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view.

[0026] When the core sheet is curved and formed by convex portions provided at predetermined intervals in the circumferential direction, the yoke forming portion becomes polygonal, and the back yoke is formed in a polygonal cylindrical shape by the polygonal yoke forming portion. In this case, in a rotating electric machine configured such that the stator core is assembled to a cylindrical housing, there is a concern that a decrease in the fixing force and a decrease in the motor efficiency may occur due to multiple point contact between the back yoke and the housing. In view of this point, a rolling portion is provided at a radial edge portion on the side opposite to the tooth forming portion in the yoke forming portion of the core sheet, and by this rolling portion, a portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view. In this case, while realizing the annular forming of the stator core by providing convex portions on the core sheet, it is possible to suppress the outer peripheral surface of the stator core from becoming polygonal by partially rolling the outer edge portion of the yoke forming portion.

[0027] In means 11, the core sheet has a yoke forming portion as a portion that forms the back yoke, and a tooth forming portion as a portion that forms the teeth. A rolling portion is provided at a radial edge portion on the side opposite to the tooth forming portion in the yoke forming portion and at a portion excluding the convex portion, and by this rolling portion, a portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view.

[0028] When the core sheet is curved and formed by convex portions provided at predetermined intervals in the circumferential direction, in the rotating electric machine in which the stator core is assembled to the cylindrical housing as described above, there is a concern that a decrease in the fixing force and a decrease in the motor efficiency may occur due to the multi-point contact between the back yoke and the housing. In view of this point, in the yoke forming portion of the core sheet, a rolling portion is provided at a radial edge portion on the side opposite to the tooth forming portion and excluding the convex portion, and by this rolling portion, a portion between the convex portions in the circumferential direction is formed in an arc shape in plan view. Thereby, while realizing the annular forming of the stator core by providing the convex portions on the core sheet, it is possible to suppress the outer peripheral surface of the stator core from becoming polygonal by partial rolling of the outer edge portion of the yoke forming portion. Further, since the rolling portions are intermittently provided in the yoke forming portion while avoiding the convex portions, it is possible to suppress the deformation of the outer edge portion of the yoke forming portion caused by the convex portions becoming flat.

Brief Description of the Drawings

[0029]

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Mode for Carrying Out the Invention

[0030] (First Embodiment) Hereinafter, an embodiment embodied in a stator of a rotating electrical machine mounted on a vehicle (for example, a hybrid vehicle or an electric vehicle) will be described with reference to the drawings. In the following embodiments and modifications, parts that are identical or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the parts with the same reference numerals is incorporated herein. The rotating electrical machine is, for example, an electric motor, a generator, or an MG (Motor Generator).

[0031] The rotating electrical machine of the present embodiment can be applied to a permanent magnet synchronous motor, a wound field type, or an induction machine, and is a rotating electrical machine having a three-phase winding. The rotating electrical machine includes a cylindrical stator 10 (stator) shown in FIG. 1 and a rotor (not shown) disposed radially inside the stator 10. The rotor is rotatably disposed with respect to the stator 10 about a rotation axis. Hereinafter, the axial direction refers to the axial direction of the stator 10, that is, the axial direction of the rotation axis of the rotor, the radial direction refers to the radial direction of the stator 10, that is, the direction passing through the center of the rotation axis of the rotor and perpendicular to the rotation axis, and the circumferential direction refers to the circumferential direction of the stator 10, that is, the circumferential direction centered on the rotation axis of the rotor.

[0032] As shown in FIGS. 1 and 2, the stator 10 includes an annular stator core 11 and a polyphase stator winding 12 wound around the stator core 11. The rotating electrical machine of this embodiment is an inner rotor type rotating electrical machine, and a rotor is arranged to be rotatable on the radially inner side of the stator 10. The stator winding 12 is a three-phase winding having a U-phase winding, a V-phase winding, and a W-phase winding as phase windings for each phase. A power line bus bar 13 is connected to one end of the phase winding of each phase, and a neutral line bus bar 14 is connected to the other end. In the stator winding 12, the range overlapping the stator core 11 in the axial direction is the coil side CS, and the portions on both axial sides and axially outside the stator core 11 are the coil ends CE.

[0033] FIG. 3 is a plan view of the stator core 11. The stator core 11 is formed by laminating core sheets 30 made of steel plates (electromagnetic steel plates) in multiple layers in the axial direction and fixing them by caulking, welding, adhesion, etc. In this embodiment, the stator core 11 has a helical stator core structure formed by laminating strip-shaped core sheets 30 in a spiral shape. By adopting the helical stator core structure for the stator core 11, it is possible to improve the material yield, save materials, and reduce costs.

[0034] The stator core 11 has an annular back yoke 21 and a plurality of teeth 22 protruding radially inward from the back yoke 21 and arranged at a predetermined distance in the circumferential direction. Slots 23 are formed between adjacent teeth 22. The slots 23 have an opening shape extending in the radial direction as the longitudinal direction, and are provided at equal intervals in the circumferential direction in the stator core 11. The slots 23 open to the inner circumferential side of the stator core 11.

[0035] As shown in Fig. 1, the stator winding 12 is wound around each slot 23 at a predetermined slot pitch. The stator winding 12 is configured by using, for example, an insulated coated wire in which a conductor is coated with an insulating layer, and the conductors are accommodated in a plurality of layers in the radial direction within each slot 23. In the present embodiment, the stator winding 12 has a segment structure, and the stator winding 12 is configured by joining a plurality of conductor segments 15 formed in a substantially U shape to each other. In the stator winding 12, a coil end CE on one side in the axial direction is formed by a turn portion of each conductor segment 15, and a coil end CE on the other side in the axial direction is formed by connecting the ends (linear portions) of different conductor segments 15 to each other. The stator winding 12 generates magnetic flux when power is supplied to each phase via an inverter (not shown).

[0036] In the present embodiment, the core sheet 30 is configured to be curved in an arc shape by providing convex portions 34 that are bent in a shape convex in the stacking direction and extend in the radial direction at predetermined intervals in the circumferential direction. The details thereof will be described below.

[0037] Fig. 4 is a diagram showing an enlarged part of the core sheet 30, where (a) is a plan view of the core sheet 30, and (b) is a cross-sectional view taken along line 4B-4B of (a). As shown in Fig. 4(a), the core sheet 30 generally has a long strip-shaped yoke forming portion 31 that is a part forming the back yoke 21, and a tooth forming portion 32 that is a part forming the teeth 22. By overlapping the yoke forming portions 31 of the core sheet 30 in the axial direction, the back yoke 21 is formed, and by overlapping the tooth forming portions 32 in the axial direction, the teeth 22 are formed. That is, in the stator core 11, the part corresponding to the yoke forming portion 31 of the core sheet 30 becomes the back yoke 21, and the part corresponding to the tooth forming portion 32 becomes the teeth 22. In the core sheet 30, between the tooth forming portions 32 arranged in the circumferential direction, there are slot recesses 33 for forming slots.

[0038] The yoke forming portion 31 is provided with a convex portion 34 that has a bent shape convex in the stacking direction and extends in the radial direction. The convex portion 34 has a larger protruding height on the inner side in the radial direction and a smaller protruding height on the outer side in the radial direction in the yoke forming portion 31, and has a substantially triangular shape that becomes narrower toward the outer side in the radial direction in plan view. The convex portion 34 is provided at a position on the outer side in the radial direction of each slot recess 33. As a result, the convex portions 34 are provided at predetermined intervals in the circumferential direction (see Fig. 4(b)). Also, in the yoke forming portion 31, the portion between adjacent convex portions 34 in the circumferential direction is a flat portion 35. Note that the flat portion 35 of the yoke forming portion 31 and the tooth forming portion 32 are both flat and are provided so as to be continuous in the radial direction.

[0039] Since the convex portions 34 are provided at predetermined intervals in the yoke forming portion 31, the circumferential length of the inner side in the radial direction of the yoke forming portion 31 becomes shorter than the circumferential length of the outer side in the radial direction in plan view, and the core sheet 30 is curved in a substantially arc shape. And in the stator core 11, in a state where the core sheets 30 are laminated in multiple layers, the convex portions 34 and the flat portions 35 overlap each other in the stacking direction. In this case, if the concave side of the convex portion 34 is the inner concave portion 36, the core sheets 30 are laminated such that the convex portion 34 on the lower layer side enters the inner concave portion 36 of the convex portion 34 on the upper layer side.

[0040] Fig. 5 is a diagram showing the manufacturing process of the stator core 11. In Fig. 5, the portion indicated by X1 shows the state before the core sheet 30 is curved in a spiral shape, and the portion on the side further ahead than X1 shows the state after the core sheet 30 is curved in a spiral shape.

[0041] The core sheet 30 is formed into a predetermined flat shape by, for example, press working of a steel plate material before being bent and formed, the yoke forming portion 31 has a straight strip shape, and tooth forming portions 32 are formed at predetermined intervals so as to extend from the yoke forming portion 31 in a direction orthogonal to the longitudinal direction of the yoke forming portion 31. Note that at the stage before bending, the opposing portions facing each other in the yoke longitudinal direction in the slot recess 33 are in a substantially V shape that expands toward the tooth tip side.

[0042] Then, using a bending device (not shown), while bending the yoke forming portion 31 to spirally curve the core sheet 30, a cylindrical stator core 11 is manufactured. That is, by bending convex portions 34 at predetermined intervals in the yoke forming portion 31, the core sheet 30 is curved into a substantially arc shape. At this time, the convex portions 34 are formed such that the radially inner side is wider and the radially outer side is narrower in plan view, so that the circumferential lengths are different between the inside and outside in the radial direction, and the core sheet 30 is curved into a substantially arc shape. After the bending forming, the opposing portions facing each other in the yoke longitudinal direction in the slot recess 33 are parallel to each other.

[0043] The spirally formed core sheets 30 are laminated in multiple layers in a state where the convex portions 34 overlap each other in the stacking direction. Thereby, a cylindrical stator core 11 is manufactured. Thereafter, in the stator core 11, the flat portions 35 are fixed in the axial direction by caulking, welding, adhesion, or the like.

[0044] By the way, in the configuration in which the convex portions 34 are provided on the core sheet 30, if the plate thickness dimensions of the steel plate material are the same for the convex portions 34 and the flat portions 35, the thickness in the stacking direction (that is, the stator axial direction) of the convex portions 34 becomes thicker than the plate thickness dimension of the flat portions 35. Therefore, there is a concern that a gap is generated between the flat portions 35 in the stacked state of the core sheet 30, and as a result, the strength of the stator core 11 is insufficient and the performance of the rotating electric machine deteriorates.

[0045] Therefore, in the present embodiment, the plate thickness dimensions are made different between the convex portions 34 and the flat portions 35 in the core sheet 30, and the configuration is shown in Fig. 6(a). In Fig. 6(a), the plate thickness dimension of the flat portion 35 is T1, and the plate thickness dimension of the convex portion 34 is T2, and the relationship between these T1 and T2 is T1 > T2. Note that the plate thickness dimensions T1 and T2 are dimensions corresponding to the thickness in the direction perpendicular to the plate surface in the steel plate material constituting the core sheet 30.

[0046] In this case, the plate thickness dimension T2 of the convex portion 34 is smaller than the plate thickness dimension T1 of the flat portion 35. As a result, in the core sheet laminated state shown in FIG. 6(b), the formation of a gap between the flat portions 35 is suppressed, and the flat portions 35 are in contact with each other. Further, it is desirable that the thickness T3 of the convex portion 34 in the lamination direction be the same as the plate thickness dimension T1 of the flat portion 35 (that is, T1 = T3). In such a case, it is possible to bring the flat portions 35 into contact with each other in the lamination direction and bring the convex portions 34 into contact with each other.

[0047] Note that the relationship between the plate thickness dimension T1 of the flat portion 35 and the thickness T3 of the convex portion 34 in the lamination direction may be T1 > T3 in addition to T1 = T3. Even with this configuration, the formation of a gap between the flat portions 35 in the laminated state of the core sheet 30 is suppressed.

[0048] Further, in the present embodiment, the convex portion 34 is provided in the range from the innermost diameter to the outermost diameter in the radial direction in the yoke forming portion 31, that is, in the entire radial direction of the yoke forming portion 31, and is formed so as to protrude from the flat portion 35 in the entire radial direction of the yoke forming portion 31. In other words, the convex portion 34 is formed so as to protrude from the flat portion 35 even at the portion that becomes the outermost diameter in the radial direction of the yoke forming portion 31, that is, at the portion where the protrusion height of the convex portion 34 is the smallest.

[0049] Here, in the core sheet 30, when the protrusion height of the convex portion 34 becomes zero at the outermost diameter in the radial direction of the yoke forming portion 31, the convex portion 34 protrudes axially from zero in the protrusion height in the radial direction, which is the direction in which the convex portion 34 extends. In this case, it becomes difficult to form the convex portion 34 by bending and thinning the steel plate material at the starting portion of the convex portion 34. In this regard, as described above, the convex portion 34 is formed so as to protrude from the flat portion 35 even at the portion that becomes the outermost diameter in the radial direction of the yoke forming portion 31, that is, at the portion where the protrusion height of the convex portion 34 is the smallest, which makes it easy to form the convex portion 34 by bending and thinning the steel plate material.

[0050] FIG. 6(c) shows a side view of the core sheet 30 as viewed from the radially outer side of the yoke forming portion 31. As shown in FIG. 6(c), at the radially outermost portion of the convex portion 34, the depth dimension T4 of the inner concave portion 36 is larger than the plate thickness dimension T1 of the flat portion 35. The depth dimension T4 of the inner concave portion 36 may be the same as the plate thickness dimension T1 of the flat portion 35.

[0051] When manufacturing the stator core 11, when the convex portion 34 is formed on the core sheet 30 and the core sheet 30 is bent by a bending device, while the steel plate material is thinned by pressure rolling or the like at the convex portion forming position of the yoke forming portion 31, the convex portion 34 is bent and formed. For example, a pressure jig that sandwiches the core sheet 30 in the thickness direction may be used, and while the steel plate material is thinned by the pressure of the pressure jig, the thickness of the thinned portion is adjusted. Note that the bending device may perform the bending and thinning of the steel plate material as a simultaneous process, or may perform the bending and thinning of the steel plate material as separate processes, such as thinning the steel plate material after bending it or bending the steel plate material after thinning it. In short, the bending device may be any device that completes the bending and thinning of the steel plate material before laminating the core sheet 30.

[0052] In the core sheet 30 of the present embodiment, in consideration of the fact that the steel plate material is thinned in addition to being bent, it is preferable that the bending region before bending is defined in the steel plate material. That is, when thinning the steel plate material, since elongation in the longitudinal direction occurs in the steel plate material, the range of the bending region may be set to be slightly smaller in consideration of the amount of elongation.

[0053] Incidentally, when the core sheet 30 is curved by the convex portions 34 provided at predetermined intervals in the circumferential direction, the yoke forming portion 31 becomes polygonal, and the back yoke 21 is formed in a polygonal cylindrical shape by the polygonal yoke forming portion 31. In addition, in a rotating electrical machine, it is conceivable that the stator core 11 is assembled in a fitted state on the inner peripheral side of a cylindrical housing. In this case, on the outer peripheral side of the stator core 11, the stator core 11 and the housing are in a state of multiple-point contact, and there is a concern that the fitting pressure concentrates at the contact portion between the stator core 11 and the housing, and the fixing force decreases as the contact portion deforms. In addition, there is a concern that an increase in core iron loss due to residual stress and a decrease in motor efficiency may occur due to a partially high fitting stress being applied to the stator core 11.

[0054] Therefore, in the present embodiment, in the core sheet 30, the outer peripheral edge portion of the yoke forming portion 31 (that is, the radial edge portion on the side opposite to the tooth forming portion 32) is partially rolled, and the portion between the convex portions 34 in the circumferential direction is formed into a circular shape in plan view. Specifically, as shown in FIGS. 7(a) and 7(b), a rolling portion 41 extending in the circumferential direction is provided at the outer peripheral edge portion of the yoke forming portion 31. In this case, while realizing the annular forming of the stator core 11 by providing the convex portions 34 on the core sheet 30, the outer peripheral surface of the stator core 11 is suppressed from becoming polygonal by partially rolling the outer peripheral edge portion of the yoke forming portion 31. In the present embodiment, since partial rolling is performed on the core sheet 30, an increase in core iron loss due to rolling is suppressed.

[0055] Further, as shown in FIG. 8, the rolling portion 41 is preferably provided at a position excluding the convex portions 34 at the outer peripheral edge portion of the back yoke 21. In this case, by intermittently providing the rolling portion 41 while avoiding the convex portions 34 in the yoke forming portion 31, deformation of the outer peripheral edge portion due to the convex portions 34 becoming flat is suppressed.

[0056] According to the present embodiment described in detail above, the following excellent effects can be obtained.

[0057] In the core sheet 30, the plate thickness dimensions T1 and T2 are made different between the convex portion 34 and the flat portion 35, and the plate thickness dimension T2 of the convex portion 34 is made smaller than the plate thickness dimension T1 of the flat portion 35. As a result, even if the steel plate material is inclined in the stacking direction (i.e., the stator axis direction) in the convex portion 34, the difference in the thickness of the steel plate material between the convex portion 34 and the flat portion 35 in the stacking direction becomes smaller. Consequently, it is possible to suppress the formation of an unintended gap between the core sheets 30 in the stacked state in the stator core 11.

[0058] In this case, caulking, welding, adhesion, etc. between the core sheets 30 can be performed without problems, and a decrease in the strength of the stator core 11 can be suppressed. Also, a decrease in torque output due to a decrease in the occupancy ratio of the magnetic material and an increase in size due to the gap in the stator core 11 can be suppressed. Furthermore, in the stator core 11, since the core sheets 30 are in close contact in the stacking direction, the heat dissipation performance is improved by reducing the thermal resistance, and high output can be exhibited.

[0059] The convex portion 34 of the core sheet 30 is such that the protruding height is large on the inner side in the radial direction and small on the outer side in the radial direction in the yoke forming portion 31, and is formed so as to protrude from the flat portion 35 also at the portion that is the outermost side in the radial direction of the yoke forming portion 31 (i.e., the portion where the protruding height of the convex portion 34 is the smallest). In this case, in the core sheet 30, compared with a configuration in which the protruding height of the convex portion 34 becomes zero on the outermost side in the radial direction of the yoke forming portion 31, it becomes easier to bend and form the steel plate material and make the convex portion 34 thinner, and the forming of the convex portion 34 due to the thinning of the steel plate material can be properly performed.

[0060] At the outermost portion in the radial direction of the convex portion 34, the depth dimension T4 of the inner concave portion 36 is made the same as or larger than the plate thickness dimension T1 of the flat portion 35. Thereby, the joining between the core sheets 30 can be more appropriately performed over the entire radial range of the yoke forming portion 31.

[0061] A rolling part 41 is provided at the outer peripheral edge of the yoke forming part 31 of the core sheet 30, and the rolling part 41 forms a part between the convex parts 34 in the circumferential direction into an arc shape in a plan view. In this case, by providing the convex parts 34 on the core sheet 30, the annular forming of the stator core 11 is realized, and by partially rolling the outer peripheral edge of the yoke forming part 31, it is possible to suppress the outer peripheral surface of the stator core 11 from becoming polygonal.

[0062] Further, if a configuration is adopted in which the rolling part 41 is provided at a part of the yoke forming part 31 of the core sheet 30 excluding the convex part 34, it is possible to suppress the deformation of the outer peripheral edge of the yoke forming part 31 caused by the convex part 34 becoming flat.

[0063] A modification of the first embodiment is shown below.

[0064] (Modification 1) In the configuration shown in FIGS. 9 and 10, the convex part 34 is formed in a trapezoidal shape, and the upper bottom part 37, which is the top part, is parallel to the flat part 35. In this case, as shown in FIG. 9, in the convex part 34, the upper bottom part 37 is formed by making the top part flat in a predetermined radial range including the innermost side in the radial direction (the slot recess 33 side).

[0065] As shown in FIG. 10, in the convex part 34, the plate thickness dimension T11 of the upper bottom part 37 is larger than the plate thickness dimension T12 of the inclined part. Also, the plate thickness dimension T11 of the upper bottom part 37 is preferably the same as the plate thickness dimension T1 of the flat part 35. However, the plate thickness dimension T11 of the upper bottom part 37 may be the same as the plate thickness dimension T12 of the inclined part, or may be smaller than the plate thickness dimension T1 of the flat part 35.

[0066] FIG. 11 is a longitudinal sectional view showing a state in which a stator winding 12 is assembled to a stator core 11. As shown in FIG. 11, the stator winding 12 is accommodated in a slot 23 of the stator core 11. The stator winding 12 is composed of a plurality of conductor segments 15 arranged side by side in the radial direction. Each conductor segment 15 is arranged at a position close to each other in the radial direction within the slot 23 (coil side CS), and is arranged in a state of being separated from each other in the radial direction outside the slot 23 (coil end CE). In this case, at the coil end CE, since the conductor segment 15 (stator winding 12) is bent and formed on the radially outer side opposite to the rotor air gap, if a convex portion 34 protrudes in the axial direction in the stator core 11, there is a concern about interference between the convex portion 34 and the conductor segment 15. In this regard, as described above, since the convex portion 34 is formed in a trapezoidal shape and the top portion is the upper bottom portion 37, interference between the convex portion 34 and the conductor segment 15 is suppressed.

[0067] Further, by making the convex portion 34 trapezoidal, effects such as reducing the coil end height of the stator winding 12 and enabling miniaturization of the rotating electrical machine can be realized, and the magnetic path length of the convex portion 34 is shorter than that in the case where the convex portion 34 is triangular, and the torque output can be improved by reducing the magnetic resistance.

[0068] (Modification 2) As shown in FIG. 12, one or more core sheets 30 at the axial end of the stator core 11 may be configured such that a portion including at least the top of the convex portion 34 is cut away. In this case, the convex portion 34 of the core sheet 30 at the axial end of the stator core 11 may have the top side cut away along a line orthogonal to the axial direction. In the stator core 11, the core sheet 30 with the top side of the convex portion 34 cut away at the axial end is laminated, and the core sheet 30 with the top side of the convex portion 34 not cut away may be laminated outside the axial end. FIG. 13 shows the core sheet 30 used at the axial end of the stator core 11. In this core sheet 30, as a difference from the core sheet 30 (see FIG. 4) outside the axial end, the top side of the convex portion 34 is cut away to form a notch 38.

[0069] According to the stator core 11 of FIGS. 12 and 13, since the axial length of the stator core 11 is shortened by partially cutting away the convex portion 34, the core mass can be increased without increasing the axial length of the stator core 11. Thereby, the magnetic path width is expanded and the torque output is improved.

[0070] (Modification 3) In the core sheet 30, the angle of the triangular top of the convex portion 34 may be different between the radially inner side and the radially outer side of the yoke forming portion 31. FIG. 14 is a diagram showing that the convex portion shapes are different between the radially inner and outer sides of the convex portion 34 of the core sheet 30, where (a) shows the convex portion shape on the radially inner side and (b) shows the convex portion shape on the radially outer side.

[0071] As shown in FIGS. 14(a) and (b), the protruding height of the convex portion 34 is different between the radially inner side and the radially outer side, and the angle of the triangular top is also different. In this case, if the angle of the triangular top on the radially inner side is θ1 and the angle of the triangular top on the radially outer side is θ2, the relationship between these θ1 and θ2 is θ1 < θ2. Also, the plate thickness dimensions of the convex portion 34 are different between the radially inner side and the radially outer side. In this case, if the plate thickness dimension of the convex portion 34 on the radially inner side is T21 and the plate thickness dimension of the convex portion 34 on the radially outer side is T22, the relationship between these T21 and T22 is T21 < T22. Note that the plate thickness dimension of the flat portion 35 is the same (T23) in both the radially inner and outer directions.

[0072] In the convex portion 34 of the core sheet 30, by making the angle of the triangular top different between the radially inner and outer sides of the yoke forming portion 31 (back yoke 21), the circumferential length can be made different between the inner circumferential side and the outer circumferential side of the yoke forming portion 31, and the bending forming of the yoke forming portion 31 becomes possible. Also, in the convex portion 34, on the radially outer side of the yoke forming portion 31, the angle of the triangular top is made larger and the plate thickness dimension is made larger compared to the radially inner side. As a result, on the radially outer side where the protruding height of the convex portion 34 is small, the angle of inclination with respect to the flat portion 35 becomes small, and the increase in the thickness in the stator axis direction due to the inclination becomes small. Therefore, on the radially outer side where the size of the bend becomes small, the degree of thinning of the steel plate material can be made small, and the thinning of the steel plate material can be appropriately performed.

[0073] (Second Embodiment) In the present embodiment, the configuration for making the plate thickness dimensions different between the convex portion 34 and the flat portion 35 in the core sheet 30 is different from that of the first embodiment. Here, the core sheet 30 is composed of a first sheet 51 and a second sheet 52, each made of a steel plate material and having different shapes from each other, and by overlapping these first sheet 51 and second sheet 52, the plate thickness dimension of the convex portion 34 is made smaller than the plate thickness dimension of the flat portion 35.

[0074] FIG. 15(a) is a plan view of the first sheet 51, and FIG. 15(b) is a plan view of the second sheet 52. As shown in FIG. 15(a), the first sheet 51 has a yoke forming portion 31 and a plurality of tooth forming portions 32, and a slot recess 33 is formed between each tooth forming portion 32. The tooth forming portion 32 is provided with convex portions 34 arranged at predetermined intervals in the circumferential direction, and a flat portion 35A is formed between each convex portion 34. The convex portion 34 is provided on the radially outer side of the slot recess 33. In the yoke forming portion 31 of the first sheet 51, the convex portion 34 and the flat portion 35A are alternately and continuously provided in the circumferential direction.

[0075] On the other hand, as shown in FIG. 15(b), the second sheet 52 has a yoke forming portion 31 and a plurality of tooth forming portions 32, and a slot recess 33 is formed between each tooth forming portion 32. Further, as a difference from the first sheet 51, in the yoke forming portion 31 of the second sheet 52, the radially outer side of the slot recess 33 is a notch portion 53 (blank portion) without the convex portion 34, and a flat portion 35B is formed between the notch portions 53 in the circumferential direction. That is, the second sheet 52 is constituted by a portion of the first sheet 51 excluding the convex portion 34.

[0076] In the present embodiment, the core sheet 30 is formed by overlapping the first sheet 51 and the second sheet 52 with each other, and the core sheet 30 is formed by closely attaching the yoke forming portions 31 and the tooth forming portions 32 of the first sheet 51 and the second sheet 52, respectively. In this case, the first sheet 51 and the second sheet 52 are overlapped with each other in a state where the yoke forming portion 31 and the tooth forming portion 32 are aligned with each other. As a result, in the core sheet 30, the convex portion 34 of the first sheet 51 and the notch portion 53 of the second sheet 52 are arranged at the same position.

[0077] Here, in the first sheet 51, a flat portion 35A is continuously provided in the circumferential direction in the Y portion on the outer peripheral edge side between the radially innermost side and the radially outermost side (outer peripheral edge portion) of the yoke forming portion 31, and a convex portion 34 is provided radially inward of the Y portion. In other words, in the first sheet 51, the convex portion 34 is formed in the range from the radially innermost side to the intermediate position in the radial direction in the yoke forming portion 31. Similarly, in the second sheet 52, a flat portion 35B is continuously provided in the circumferential direction in the Y portion on the outer peripheral edge side between the radially innermost side and the radially outermost side (outer peripheral edge portion) of the yoke forming portion 31, and a notch portion 53 is provided radially inward of the Y portion. As a result, in the second sheet 52, in a state where the second sheet 52 is stacked on the first sheet 51, the portions on both circumferential sides of the convex portion 34 are continuous on the outer peripheral edge side.

[0078] As shown in Fig. 16(a), in the first sheet 51, when the plate thickness dimension of the flat portion 35A is T31 and the plate thickness dimension of the convex portion 34 is T32, the relationship between these T31 and T32 is T31 = T32. That is, in the first sheet 51, the convex portion 34 is formed by bending without thinning the steel plate material.

[0079] Also, as shown in Fig. 16(b), in a state where the first sheet 51 and the second sheet 52 are stacked on each other, the flat portions 35A and 35B of the respective sheets 51 and 52 are overlapped (that is, brought into close contact) to form the flat portion 35. In that state, the plate thickness dimension T41 of the flat portion 35 is larger than the plate thickness dimension T32 of the convex portion 34. That is, the plate thickness dimensions T32 and T41 are in the relationship of T32 < T41. It is desirable that the plate thickness dimension T41 of the flat portion 35 is the same as the thickness T33 in the stacking direction of the convex portion 34. However, T41 > T33 may also be acceptable.

[0080] FIG. 16(c) shows a state in which core sheets 30 each composed of a first sheet 51 and a second sheet 52 are laminated in multiple layers. In this state, the convex portions 34 of the core sheets 30 and the flat portions 35 overlap each other in the stacking direction, and no gaps are formed between the flat portions 35. As shown in FIG. 16(b), the stator core 11 has a configuration in which the first sheet 51 is provided on the first layer which is the axial end face, and the core sheets 30 each composed of the first sheet 51 and the second sheet 52 are laminated from the second layer onward. However, it is also possible to adopt a configuration in which the core sheets 30 each composed of the first sheet 51 and the second sheet 52 are laminated in all layers of the stator core 11 (a configuration in which the second sheet 52 is arranged on the axial end face).

[0081] When manufacturing the stator core 11, for example, the first sheet 51 and the second sheet 52 each formed into a flat plate-like predetermined shape by press working of a steel plate material are prepared. Then, these sheets 51 and 52 are each curved into an arc shape, and while being fed out at the same speed, they are overlapped with each other to form the core sheet 30, and a cylindrical stator core 11 is manufactured by laminating multiple layers of the core sheet 30. In this case, the first sheet 51 is curved into a substantially arc shape while the convex portion 34 is bent and formed in the yoke forming portion 31 using a bending device. In this embodiment, the convex portion 34 is bent and formed without thinning the steel plate material by pressure rolling. On the other hand, the second sheet 52 is curved with the same curvature as the first sheet 51 without performing bending forming. Then, thereafter, the first sheet 51 and the second sheet 52 each curved are overlapped with each other and laminated in multiple layers in that state. Thereby, the cylindrical stator core 11 is manufactured.

[0082] Here, the second sheet 52 has a configuration that is continuous in the circumferential direction at a portion (Y portion in FIG. 15) that is radially outside in the yoke forming portion 31. Therefore, the second sheet 52 is fed out together with the first sheet 51 without interruption, and the operation of overlapping the first sheet 51 and the second sheet 52 with each other is preferably performed.

[0083] Also, in both the first sheet 51 and the second sheet 52, flat portions 35A and 35B are connected in the circumferential direction on the radially outer side of the yoke forming portion 31. Therefore, even in a configuration where bending is performed on the first sheet 51 and no bending is performed on the second sheet 52, the circumferential pitch of the tooth forming portion 32 and the slot recess 33 is suppressed from shifting in each of these sheets 51 and 52.

[0084] According to the present embodiment, the following effects can be obtained.

[0085] The core sheet 30 is configured by overlapping a first sheet 51 having a convex portion 34 and continuous in the circumferential direction and a second sheet 52 formed of a portion of the first sheet 51 excluding the convex portion 34. In this case, by overlapping the first sheet 51 and the second sheet 52, the plate thickness dimension of the flat portion 35 can be relatively increased without reducing the plate thickness of the convex portion 34. Therefore, a configuration in which the plate thickness dimension of the convex portion 34 is smaller than the plate thickness dimension of the flat portion 35 can be easily realized.

[0086] In the first sheet 51, the plate thickness dimension of the convex portion 34 is the same as the plate thickness dimension of the portion other than the convex portion (flat portion 35A), and in the core sheet 30, the plate thickness dimension of the convex portion 34 is smaller than the plate thickness dimension of the flat portion 35 in a state where the second sheet 52 is overlapped on the first sheet 51. In this case, even if the plate thickness dimensions of the convex portion 34 and the flat portion 35A are the same in the first sheet 51, in other words, without thinning the steel plate material, a configuration in which the plate thickness dimension of the convex portion 34 is smaller than the plate thickness dimension of the flat portion 35 in the core sheet 30 can be easily realized.

[0087] In the first sheet 51, the range of the convex portion 34 in the radial direction is set from the radially innermost side to the radially intermediate position of the yoke forming portion 31. As a result, the second sheet 52 is configured such that the portions on both circumferential sides of the convex portion 34 in the yoke forming portion 31 are continuous at the radially outermost side. Thereby, both the first sheet 51 and the second sheet 52 become continuous in the longitudinal direction, and the operation of overlapping these sheets 51 and 52 with each other can be suitably performed.

[0088] (Other embodiments) The above embodiments can be modified as follows, for example.

[0089] · In the above second embodiment, the plate thickness dimension T31 of the flat portion 35A and the plate thickness dimension T32 of the convex portion 34 are made the same in the first sheet 51 (see Fig. 16(a)), but this may be changed. For example, in the first sheet 51, the plate thickness dimension T32 of the convex portion 34 may be made smaller than the plate thickness dimension T31 of the flat portion 35A. In this case, it is preferable that the first sheet 51 is formed with the convex portion 34 by bending and thinning a steel plate material. Also, in the first sheet 51, the convex portion 34 may be configured to be thinned due to stretching accompanying the bending of the steel plate material. In any case, the core sheet 30 only needs to have the plate thickness dimension T32 of the convex portion 34 smaller than the plate thickness dimension T41 of the flat portion 35 in a state where the first sheet 51 and the second sheet 52 are overlapped.

[0090] · In the above second embodiment, the flat portions 35A and 35B are connected in the circumferential direction on the radially outer side of the yoke forming portion 31 in both the first sheet 51 and the second sheet 52 (see Figs. 15(a) and (b)), but this may be changed. For example, in the first sheet 51, the convex portion 34 is provided in the range from the innermost radial side to the outermost radial side of the yoke forming portion 31 (that is, the entire radial region of the yoke forming portion 31). In this case, the second sheet 52 will be divided by the convex portion 34 of the first sheet 51 and is overlapped on both circumferential sides of the convex portion 34 with respect to the first sheet 51.

[0091] · In the above embodiments, the convex portion 34 is provided for each slot recess 33 in the core sheet 30, but this may be changed. For example, in the core sheet 30, the convex portion 34 may be provided for each n slots recesses 33 arranged in the circumferential direction (n is 2 or more). Or, in the core sheet 30, a plurality of convex portions 34 may be provided for each slot recess 33.

[0092] ·In each of the above embodiments, the convex portion 34 is provided on the radially outer side of the slot recess 33 in the yoke forming portion 31 of the core sheet 30, but this may be changed. For example, as shown in FIG. 17, in the core sheet 30, a convex portion 34 extending in the radial direction is provided so as to be continuous between the yoke forming portion 31 and the tooth forming portion 32. In this configuration, in the core sheet 30, as the convex portion 34, a yoke convex portion 61 is provided in the yoke forming portion 31, and a tooth convex portion 62 is provided in the tooth forming portion 32. The yoke convex portion 61 and the tooth convex portion 62 are provided so as to be continuous in the radial direction. Further, between the yoke convex portions 61 adjacent in the circumferential direction, that is, the radially outer side of the slot recess 33 is a flat portion 35. Also in such a configuration, as in the above, the plate thickness dimensions are different between the convex portions 61, 62 and the flat portion 35, and it is preferable that the plate thickness dimensions of the convex portions 61, 62 are smaller than the plate thickness dimension of the flat portion 35.

[0093] ·In each of the above embodiments, the stator core 11 has a helical core structure in which the core sheets 30 are laminated in a spiral shape, but this may be changed. For example, a large number of annular core sheets 30 may be prepared, and the stator core 11 may be manufactured by laminating the core sheets 30. In this case, it is preferable that each core sheet 30 in the lamination direction is curved into an annular shape by the convex portion 34.

[0094] ·The stator core may be used not only in an inner rotor type rotating electric machine but also in an outer rotor type rotating electric machine. In the case of a stator core used in an outer rotor type rotating electric machine, a plurality of teeth are provided so as to project radially outward from a cylindrical back yoke.

[0095] The technical idea extracted from the above embodiments is described below. [Configuration 1] A stator core (11) having an annular back yoke (21) and a plurality of teeth (22) protruding radially from the back yoke, wherein the core sheet (30) is configured by being laminated in multiple layers. The core sheet is provided at predetermined intervals in the circumferential direction, has a bent shape that is convex in the stacking direction and extends in the radial direction, and the convex portions are stacked in a state where they overlap each other in the stacking direction. A stator core of a rotating electrical machine, wherein the plate thickness dimension is different between the convex portion and the flat portion between the convex portions adjacent to each other in the circumferential direction, and the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion. [Configuration 2] In the core sheet, the thickness of the steel plate material constituting the core sheet is different between the convex portion and the flat portion. The convex portion according to Configuration 1, wherein in the back yoke, the protruding height is large on the radially inner side and small on the radially outer side, and is formed so as to protrude from the flat portion also at the radially outermost portion of the back yoke. Stator core of the rotating electrical machine described. [Configuration 3] In the convex portion, the concave side is an inner concave portion (36). The stator core of a rotating electrical machine according to Configuration 2, wherein at the radially outermost portion of the convex portion, the depth dimension of the inner concave portion is the same as or larger than the plate thickness dimension of the flat portion. [Configuration 4] In the core sheet, the convex portion has a triangular mountain shape, and the angle of the triangular top of the convex portion is different between the radially inner side and the radially outer side of the back yoke. The stator core of a rotating electrical machine according to Configuration 2 or 3, wherein in the convex portion, on the radially outer side of the back yoke, the angle of the triangular top is larger and the plate thickness dimension is larger than on the radially inner side. [Configuration 5] The core sheet includes a first sheet (51) having the convex portion and continuous in the circumferential direction, and a second sheet (52) formed of a portion of the first sheet excluding the convex portion, and the first sheet and the second sheet are stacked on each other in the stacking direction. It is configured by being overlapped with each other. The stator core of a rotating electrical machine according to Configuration 1, wherein in the core sheet, in a state where the second sheet is overlapped with the first sheet, the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion. [Configuration 6] The first sheet has the same plate thickness dimension for the convex portion and the plate thickness dimension for the portion other than the convex portion, In the core sheet, in a state where the second sheet is stacked on the first sheet, the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion, the stator core of the rotating electrical machine according to Configuration 5. [Configuration 7] In the first sheet, the convex portion is formed in a range from the innermost position in the radial direction to the intermediate position in the radial direction in the back yoke, In the second sheet, in a state where the second sheet is stacked on the first sheet, the portions on both circumferential sides of the convex portion are continuous at the outermost position in the radial direction, the stator core of the rotating electrical machine according to Configuration 5 or 6. [Configuration 8] A stator core in which the teeth protrude in a direction extending radially inward from the back yoke, The convex portion has a flat top surface formed in a predetermined radial range including the innermost position in the radial direction, the stator core of the rotating electrical machine according to any one of Configurations 1 to 7. [Configuration 9] One layer or a plurality of layers of the core sheets that are axial end portions have a portion including at least the top of the convex portion cut off, the stator core of the rotating electrical machine according to any one of Configurations 1 to 7. [Configuration 10] The core sheet has a yoke forming portion (31) as a portion forming the back yoke and a teeth forming portion (32) as a portion forming the teeth, A rolling portion (41) is provided at a radial edge portion on the side opposite to the teeth forming portion in the yoke forming portion, and by the rolling portion, the portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view, the stator core of the rotating electrical machine according to any one of Configurations 1 to 9. [Configuration 11] The core sheet has a yoke forming portion (31) as a portion forming the back yoke and a teeth forming portion (32) as a portion forming the teeth, In the yoke forming portion, a rolling portion (41) is provided at a radial edge portion on the side opposite to the tooth forming portion and excluding the convex portion, and by the rolling portion, a portion between the convex portions in the circumferential direction is formed in an arc shape in a plan view, the stator core of the rotating electrical machine according to any one of Configurations 1 to 9.

Description of Signs

[0096] 11… Stator core, 21… Back yoke, 22… Teeth, 34… Convex portion, 35… Flat portion.

Claims

1. A stator core (11) having an annular back yoke (21) and a plurality of teeth (22) protruding radially from the back yoke, and the core sheet (30) is formed by laminating multiple layers, The core sheet is provided at predetermined intervals in the circumferential direction, has a bent shape that is convex in the lamination direction and has a convex portion (34) extending in the radial direction, and the convex portions are laminated in a state of overlapping each other in the lamination direction, A stator core of a rotating electrical machine, wherein the plate thickness dimensions are different between the convex portion and the flat portion (35) between the convex portions adjacent to each other in the circumferential direction, and the plate thickness dimension of the convex portion is smaller than the plate thickness dimension of the flat portion.

2. The core sheet is such that the thickness of the steel plate material constituting the core sheet is different between the convex portion and the flat portion, The convex portion has a large protruding height on the radially inner side in the back yoke and a small protruding height on the radially outer side, and is formed so as to protrude from the flat portion also at the radially outermost portion of the back yoke. The stator core of the rotating electrical machine according to Claim 1.

3. In the convex portion, the concave side is an inner concave portion (36), At the radially outermost portion of the convex portion, the depth dimension of the inner concave portion is the same as or larger than the plate thickness dimension of the flat portion. The stator core of the rotating electrical machine according to Claim 2.

4. In the core sheet, the convex portion has a triangular mountain shape, and the angle of the triangular apex of the convex portion is different between the radially inner side and the radially outer side of the back yoke, In the convex portion, on the radially outer side of the back yoke, the angle of the triangular apex is larger and the plate thickness dimension is larger than on the radially inner side. The stator core of the rotating electrical machine according to Claim 2.

5. The core sheet includes a first sheet (51) having the convex portions and continuous in the circumferential direction, and a second sheet (52) formed of portions of the first sheet excluding the convex portions, and the first sheet and the second sheet are overlapped with each other in the stacking direction to form the core sheet. The stator core of the rotating electrical machine according to claim 1, wherein in the core sheet, with the second sheet overlapped on the first sheet, a plate thickness dimension of the convex portion is smaller than a plate thickness dimension of the flat portion.

6. In the first sheet, a plate thickness dimension of the convex portion is the same as a plate thickness dimension of a portion other than the convex portion. The stator core of the rotating electrical machine according to claim 5, wherein in the core sheet, with the second sheet overlapped on the first sheet, a plate thickness dimension of the convex portion is smaller than a plate thickness dimension of the flat portion.

7. In the first sheet, the convex portions are formed in a range from the radially innermost side to a radially intermediate position in the back yoke. The stator core of the rotating electrical machine according to claim 5, wherein in the second sheet, with the second sheet overlapped on the first sheet, portions on both circumferential sides of the convex portion are continuous at the radially outermost side.

8. A stator core in which the teeth protrude in a direction extending radially inward from the back yoke, The stator core of the rotating electrical machine according to any one of claims 1 to 7, wherein a top portion of the convex portion is formed in a flat shape within a predetermined radial range including the radially innermost side.

9. In the stator core of the rotating electrical machine according to any one of claims 1 to 7, in one or a plurality of core sheets that are axial end portions, a portion including at least the top portion of the convex portion is cut off.

10. The core sheet has a yoke forming portion (31) as a portion forming the back yoke, and a teeth forming portion (32) as a portion forming the teeth. In the yoke forming portion, a rolling portion (41) is provided at a radial edge portion on the side opposite to the tooth forming portion, and by this rolling portion, a portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view. The stator core of the rotating electrical machine according to any one of claims 1 to 7.

11. The core sheet has a yoke forming portion (31) as a portion forming the back yoke and a tooth forming portion (32) as a portion forming the teeth. In the yoke forming portion, a rolling portion (41) is provided at a radial edge portion on the side opposite to the tooth forming portion and excluding the convex portion, and by this rolling portion, a portion between the respective convex portions in the circumferential direction is formed in an arc shape in plan view. The stator core of the rotating electrical machine according to any one of claims 1 to 7.

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