Rotary electric machine core, rotary electric machine using the same and manufacturing method of rotary electric machine core

Abstract

To provide a manufacturing method of a rotary electric machine core capable of overcoming the problem that a local thermal deformation occurs while applying e.g., laser cladding, etc., that is a local alloying method for non-magnetizing a material.SOLUTION: A rotary electric machine core manufacturing method includes: a local alloying processing step S1 of forming a locally alloyed location by applying local alloying processing to a leaked magnetic flux reduction target location in which insulation coating is applied to an elementary substance of a steel sheet for lamination and / or a surface of a predetermined number of laminated groups; a press / punching step S2 including a press step of performing press working on the local alloyed location so as to make a thickness thinner than the other portion in the steel sheet for lamination and a punching step of punching the steel sheet for lamination in a shape of a rotary electric machine core; and a lamination and molding step S3 of aligning and laminating the location where the thickness is made thin in the press step in the steel sheet for lamination, disposing the locations so as to form a cavity therebetween, and laminating and molding the other portions in the steel sheet for lamination so as to be in contact via the insulation coating, thereby configuring the rotary electric machine core.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a rotating electric core, a rotating electric machine using the same, and a method for manufacturing the rotating electric core. [Background technology]

[0002] In rotating electrical machines using embedded magnet rotors, there is a demand for minimizing leakage flux around the area around the permanent magnets in the rotor yoke to improve efficiency. In response to this demand, a technique has been proposed in which a non-magnetic material is applied to the area that corresponds to the magnetic path of the leakage flux (see, for example, Patent Document 1). Also, a technique has been proposed in which the area that corresponds to the magnetic path of the eddy current is machined into a concave shape in the thickness direction in order to reduce iron loss caused by eddy currents around the permanent magnets in the rotor yoke (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-331784 [Patent Document 2] Patent No. 4631361 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a demand for a technique that is easier to manufacture and can reduce leakage magnetic flux more effectively than the techniques disclosed in Patent Documents 1 and 2.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide a rotating electric core that can overcome the problem of localized thermal deformation that occurs in cases where local alloying techniques such as laser cladding are applied to demagnetize a material, as well as a rotating electric core using the same, and a method for manufacturing a rotating electric core. [Means for solving the problem]

[0006] (1) A rotating electric core (e.g., rotor core 2 described later) formed by laminating a steel plate for lamination (e.g., steel plate 3 for lamination described later) having a leakage flux reduction area (e.g., local alloyed area 33 described later), in which the steel plate for lamination is provided with an insulating coating (e.g., insulating coating 32 described later) on the surface of each individual plate and a predetermined number of lamination groups, and the leakage flux reduction area forms a local alloyed area (e.g., local alloyed area 33 described later) that has been subjected to a local alloying process, and the local alloyed area is press-formed into a shape that creates a gap between the laminated surfaces of the steel plate for lamination.

[0007] (2) A rotating electric machine (for example, the rotating electric machine 1 described later) whose stator or rotor is constituted by the rotating electric machine core described in (1) above.

[0008] (3) A method for manufacturing a rotating electric core (e.g., rotor core 2 described later) by laminating and molding a steel plate for lamination (e.g., steel plate 3 for lamination described later) having a leakage flux reduction portion (e.g., local alloyed portion 33 described later), the method comprising: a local alloying treatment step (e.g., local alloying treatment step S1 described later) of performing local alloying treatment on the leakage flux reduction target portion in which an insulating coating (e.g., insulating coating 32 described later) is applied to the surface of a single steel plate for lamination and / or a predetermined number of lamination groups to form the local alloyed portion (e.g., local alloyed portion 33 described later); a pressing and punching process (for example, a pressing and punching process S2 described later) including a pressing process of pressing the lamination steel plate so that the plate thickness is thinner than the above-mentioned portions and a punching process of punching the lamination steel plate into the shape of the rotating electric core; and a lamination molding process (for example, a lamination molding process S3 described later) of aligning and stacking the portions of the lamination steel plate where the plate thickness has been reduced by the pressing process so as to form gaps between them, and laminating and molding the other portions of the lamination steel plate in a state where they are in contact with each other via the insulating coating to form a rotating electric core. Effect of the Invention

[0009] (1) According to the rotating electric core of the present disclosure, the lamination steel sheet is provided with an insulating coating on the surface of the single sheet and the surface of the predetermined number of lamination groups, and the local alloyed portion where the leakage flux reduction is performed is formed by pressing, and a gap is formed between the local alloyed portions on the lamination surface of the lamination steel sheet. The large dielectric strength of the air in the gap ensures electrical insulation, and the decrease in electrical efficiency due to eddy currents can be suppressed. That is, although the local alloying process for reducing leakage flux is performed, the electrical insulation of the leakage flux reduction portion where the insulating coating is destroyed can be maintained at a high level. Therefore, it is possible to provide a rotating electric core in which the sheet thickness is compressed to deal with the local thermal deformation of the lamination steel sheet due to the local alloying process, the dimensional accuracy is high, the centrifugal strength is ensured, and further, the leakage flux is reduced and eddy currents are suppressed.

[0010] (2) In the rotating electric machine, leakage flux and eddy currents are effectively reduced, and a rotating electric machine that is small and energy-efficient is realized by using a rotating electric machine core made of laminated steel plate in which the plate thickness of the relevant area is compressed to deal with local thermal deformation.

[0011] In the manufacturing method of the rotating electric core of (3), the local alloying process promotes demagnetization in the target leakage flux reduction area, and the thinned areas of the lamination steel sheets, which are thinned in the pressing and punching process and punched into a predetermined shape, are aligned and laminated in the lamination molding process to form gaps between them. This ensures electrical insulation with a large dielectric strength due to the air in the gap, and suppresses the decrease in electric efficiency due to eddy currents. In addition, the leakage flux can be reduced by maintaining the magnetic resistance of the magnetic flux reduction area, which has been subjected to the local alloying process, at a high level, and the areas thermally deformed by the local alloying process are thinned in the pressing process, making it possible to manufacture a small-sized rotating electric machine with high energy efficiency. [Brief description of the drawings]

[0012] [Figure 1]2 is a diagram showing a part of a lamination steel plate used in a rotor core as a rotating electric machine core constituting a rotating electric machine according to the present disclosure. FIG. [Diagram 2] 2 is a diagram for explaining a magnetic path of leakage magnetic flux occurring in the vicinity of a portion of the rotor core in FIG. 1 facing the stator. [Diagram 3] FIG. 2 is a diagram for explaining a state in which the portion of the steel plate for lamination in FIG. 1 that has been subjected to local alloying treatment is press-formed. [Figure 4A] FIG. 2 is a diagram showing a location where local alloying treatment has been performed on a steel sheet for lamination. [Figure 4B] 4B is a diagram showing a state in which the portion subjected to the local alloying treatment in FIG. 4A is press-processed. FIG. [Figure 4C] FIG. 4C is a diagram showing how a slot is formed by punching, including the relief portion that has been widened during the pressing process of FIG. 4B. [Figure 5A] FIG. 2 is a diagram showing a location where local alloying treatment has been performed on a steel sheet for lamination. [Figure 5B] 5B is a diagram showing how slots are formed by punching after the local alloying treatment of FIG. 5A is performed. FIG. [Figure 5C] 5B is a diagram showing a state in which the portion in FIG. 5A that has been subjected to the local alloying treatment is press-processed. FIG. [Figure 5D] 5D is a diagram showing how the relief portion that has widened during the press working of FIG. 5C is formed by punching. FIG. [Figure 6A] FIG. 2 is a diagram showing a location where local alloying treatment has been performed on a steel sheet for lamination. [Figure 6B] 6B is a diagram showing a state in which a slot is formed by punching a portion including the portion that has expanded when the local alloying treatment is performed in FIG. 6A. FIG. [Figure 6C] 6C is a diagram showing a state in which a yoke portion whose width has become narrower than the specified width due to the punching process in FIG. 6B is press-formed. FIG. [Figure 7] 2 is a schematic diagram showing how lamination steel sheets are laminated to form a rotating electric core according to the present disclosure; FIG. [Figure 8] 4A to 4C are process diagrams showing steps included in a manufacturing method of a rotating electric core according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Next, an embodiment of the present invention will be described with reference to the drawings. In each of the drawings shown below, the same or corresponding parts are given the same reference numerals. FIG. 1 is a diagram showing a part of a lamination steel sheet 3 used in a rotor core 2 as a rotating electric machine core constituting a rotating electric machine 1 of the present disclosure, and FIG. 2 is a diagram explaining a magnetic path of leakage magnetic flux generated in the vicinity of a portion where the rotor core 2 of FIG. 1 faces a stator core 8. The rotating electric machine 1 of the present disclosure is a so-called IPM (Interior Permanent Magnet) motor used in electric vehicles and the like. A plurality of magnets 4 are housed in the rotor core 2, arranged in a circumferential direction, at a position near the outer periphery.

[0014] The rotor core 2 is formed by laminating a plurality of lamination steel plates 3 so that their main surfaces are aligned with each other. Slots 5 that house and hold magnets 4 are formed facing the outer circumferential surface of the rotor core 2. The shapes of the lamination steel plates 3 that form the slots 5 will also be referred to as slots 5 below as appropriate. The magnets 4 are held in the rotor core 2 to form a rotor 6 of the rotating electric machine 1.

[0015] In the rotating electric machine 1 which is an IPM motor, a reinforcing rib 7 that spans the outer and inner peripheries of the slots 5 in the radial direction is provided near the magnets 4 in the lamination steel plates 3 in order to ensure the centrifugal strength of the rotor 6. When the rotating electric machine 1 is in operation, a return flux which is a leakage flux Lf is generated in the reinforcing rib 7, which interacts with the magnetic flux from the coils 9 on the stator core 8 side to reduce the effective magnetic flux Ef which generates torque, thereby deteriorating the performance of the rotating electric machine 1.

[0016] In order to suppress the leakage magnetic flux Lf of the reinforcing rib 7, it is conceivable to make the reinforcing rib 7 as thin as possible. However, this approach reduces the mechanical strength of the reinforcing rib 7, which creates a problem in terms of ensuring centrifugal strength. For this reason, it is effective to make the reinforcing rib 7 non-magnetic. In this case, it is not necessarily necessary to make the reinforcing rib 7 completely non-magnetic, and there is a corresponding effect if the magnetic permeability is significantly reduced to the extent that the leakage magnetic flux Lf is reduced.

[0017] The non-magnetic treatment of the reinforcing ribs 7 is performed, for example, by laser cladding the lamination steel sheet 3, which is an electromagnetic steel sheet, with a non-magnetic forming element. However, since a substance other than the electromagnetic steel sheet is added, deformation (i.e., localized thermal deformation) occurs. In addition, the heat from the laser cladding destroys the insulating coating 32 (see FIG. 3) on the surface of the lamination steel sheet 3.

[0018] If the insulating coating 32 on the surface of the lamination steel plate 3 is destroyed, electrical insulation in the plate thickness direction is lost during lamination molding of the lamination steel plate 3 when forming the rotor 6, causing motor loss (iron loss) due to eddy currents and deteriorating motor efficiency. In addition, the deformation caused by laser cladding mainly increases the plate thickness, making it impossible to satisfy the dimensions required for lamination molding of the lamination steel plate 3 when forming the rotor 6.

[0019] Therefore, in the rotor core 2, which is the rotating electric core of the present disclosure, the plate thickness of the laser cladding portion after laser cladding is reduced by pressing. By performing pressing so that the plate thickness of the laser cladding portion is thinner than that of the non-laser cladding portion, it is possible to satisfy the lamination molding dimensions when forming the rotor core 2. At the same time, it is possible to ensure electrical insulation with a large dielectric strength due to air in the gaps formed between the plates during lamination molding of the lamination steel plates 3, and it is possible to suppress a decrease in electrical efficiency due to eddy currents.

[0020] Fig. 3 is a diagram for explaining the state in which the area where the local alloying treatment has been performed on the steel sheet 3 for lamination in Fig. 1 is pressed. The steel sheet 3 for lamination has an insulating coating 32 applied to a raw material, an electromagnetic steel sheet 31. The local alloying area 33 where the local alloying treatment has been performed is thermally deformed and bulges in the thickness direction, and the insulating coating 32 is destroyed. At the same time that the steel sheet 3 for lamination is press-molded into the shape of the rotor core 2, the thermally deformed local alloying area 33 is pressed from both sides in the plate thickness direction by the same press machine 10.

[0021] The locally alloyed areas 33 thus press-processed have a thickness thinner than the original thickness of the electromagnetic steel sheets 31 which are the raw material of the lamination steel sheets 3. The thinned areas of the lamination steel sheets 3 are aligned and laminated, and are arranged so as to form gaps between them. The gaps thus formed also provide a high insulating effect in the areas where the insulating coating 32 has been destroyed, with the air providing a large dielectric strength.

[0022] Next, referring to Figures 4A, 4B and 4C, an example of a processing procedure will be described in which the lamination steel plate 3 is pressed at the location where the local alloying treatment has been performed, and further a slot (slot 5 for holding magnet 4) is formed by punching. Figure 4A shows a local alloying location 33 formed by performing a local alloying treatment on the lamination steel plate 3. As explained with reference to Figure 3, the local alloying location 33 is thermally deformed and rises in the thickness direction, increasing the thickness dimension of that location when the lamination steel plate 3 is laminated to form the rotor core 2, and hindering regular lamination molding in which the surfaces are in close contact with each other. In other words, when the rotor core 2 is formed, it becomes impossible to satisfy the predetermined dimensions related to the lamination molding of the lamination steel plate 3.

[0023] For this reason, as shown in Fig. 4B, the local alloyed area 33 is crushed by a press die 11 (punch) for press processing of a press machine 10 to an extent that the thickness dimension is smaller than the surrounding areas of the steel sheet for lamination 3 that have not been subjected to local alloying processing. When the local alloyed area 33 that has been thermally deformed by processing in Fig. 4B is compressed in the thickness direction, there are cases in which the material escapes around the local alloyed area 33, resulting in the formation of raised areas 34 that bulge in the thickness direction. The raised areas 34 spread to the front and back sides of the page in Fig. 4B.

[0024] 4C, the protruding portions 34 that have escaped and spread during the press process of FIG. 4B are punched out by the punching press die 12 of the press machine 10 to form the shape of the slots 5 of the rotor core 2. As a result, the portions unnecessarily protruding in the thickness direction are removed from the main surfaces of the lamination steel plates 3, and the lamination steel plates 3 can be tightly adhered and laminated to form a rotor core 2 of standard dimensions.

[0025] Since the compression of the thickness of the raised portion 34 and the punching into the shape of the slot 5 are performed using the press die 11 (punch) for press processing and the press die 12 for punching processing of the same press machine 10, the processing of Figure 4B and the processing of Figure 4C can be performed in the same process, making it possible to manufacture the rotating motor 1 efficiently and at low cost.

[0026] Next, with reference to Figures 5A, 5B, 5C and 5D, another example of a processing procedure will be described in which the parts of the lamination steel plate 3 that have been subjected to the local alloying treatment are pressed, and then the slots 5 of the rotor core 2 are formed by punching. Figure 5A shows a local alloyed part 33 formed by performing a local alloying treatment on the lamination steel plate 3. As explained with reference to Figure 3, the local alloyed part 33 is thermally deformed and rises in the thickness direction, increasing the thickness dimension of that part when the lamination steel plate 3 is laminated to form the rotor core 2, and hindering regular lamination molding in which the surfaces are in close contact with each other.

[0027] In this processing procedure, the punching press die 12 of the press machine 10 then punches out the periphery of the local alloyed portion 33 to form the shape of the slot 5, as shown in FIG. 5B.

[0028] Furthermore, by the processing in Fig. 5C, the local alloyed area 33, which has been thermally deformed and raised in the thickness direction in the processing procedure in Fig. 5B, is crushed by the press die 11 (punch) of the press machine 10 to a degree that makes the thickness dimension smaller than that of an area that has not been subjected to local alloying treatment. When the thermally deformed local alloyed area 33 is compressed in the thickness direction by the processing in Fig. 5C, there are cases where the material escapes around the local alloyed area 33 and the area spreads in the planar direction. The area that spreads in the planar direction may also spread to the front and back sides of the paper surface of Fig. 5C.

[0029] By the processing in Fig. 5D, the parts that have escaped and spread in the surface direction during the press processing in Fig. 5C are punched out by the punching press die 12a of the press machine 10, and the planar shape is adjusted. As a result, the parts that protrude unnecessarily in the thickness direction are removed from the main surfaces of the lamination steel plates 3, and the lamination steel plates 3 can be laminated and molded in close contact to form a rotor core 2 of regular dimensions. Note that there are cases where it is not necessary to remove the parts that have escaped and spread in the surface direction during the press processing in Fig. 5C. In this case, there is no need to perform the processing procedure in Fig. 5D.

[0030] Since the compression of the thickness of the raised portion 34 and the punching into the shape of the slot 5 are performed using the press die 11 (punch) for press processing and the press die 12 for punching processing of the same press machine 10, the processing steps from FIG. 5B to FIG. 5D can be performed as the same process, making it possible to manufacture the rotating motor 1 efficiently and at low cost.

[0031] Next, with reference to Figures 6A, 6B and 6C, a further example of a processing procedure in which a press process is performed on the area of ​​the lamination steel plate 3 where local alloying treatment has been performed, and further a punching process is performed to form the slots 5 of the rotor core 2 will be described. Figure 6A shows a local alloyed area 33 formed by performing a local alloying process on the lamination steel plate 3. As explained with reference to Figure 3, the local alloyed area 33 is thermally deformed and rises in the thickness direction, increasing the thickness dimension of that area when the lamination steel plate 3 is laminated to form the rotor core 2, and hindering regular lamination molding in which the surfaces are in close contact with each other.

[0032] Next, as shown in Fig. 6B, the local alloying area 33 is punched out, including a part of the outer edge portion of the contour of the local alloying area 33 itself, with the punching press die 12 of the press machine 10 to form the shape of the slot 5. In the state immediately after the processing procedure of Fig. 6B is performed, the local alloying area 33 is slightly smaller than the predetermined planar projection shape dimension.

[0033] Furthermore, by the processing in FIG. 6C, the local alloying area 33, which was thermally deformed and kept in a raised state in the thickness direction in the processing procedure in FIG. 6B, is crushed by the press die 11 (punch) of the press machine 10 to an extent that the thickness dimension is smaller than that of the area not subjected to the local alloying treatment. When the thermally deformed local alloying area 33 is compressed in the thickness direction by the processing in FIG. 6C, the material escapes around the local alloying area 33 and spreads in the planar direction. However, after the processing procedure in FIG. 6B is performed, the local alloying area 33 is slightly smaller than the predetermined planar projection shape dimension. Therefore, it spreads in the planar direction by the processing in FIG. 6C to exactly the predetermined planar projection shape dimension.

[0034] Since the compression of the thickness of the raised portion 34 and the punching into the shape of the slot 5 are performed using the press die 11 (punch) for press processing and the press die 12 for punching processing of the same press machine 10, the processing steps from FIG. 6B to FIG. 6C can be performed as the same process, making it possible to manufacture the rotating motor 1 efficiently and at low cost.

[0035] FIG. 7 is a schematic diagram showing how the lamination steel sheets 3 are laminated to form a rotating electrical core (one example of which is the rotor core 2) of the present disclosure. As described with reference to FIG. 3, the lamination steel sheets 3 are electromagnetic steel sheets 31 to which an insulating coating 32 is applied, and parts of the insulating coating 32 are locally alloyed parts 33. Although the insulating coating 32 is destroyed in these locally alloyed parts 33, the plate thickness is thinner than the original thickness of the electromagnetic steel sheets 31, which are the material of the lamination steel sheets 3, due to press working. The parts of the lamination steel sheets 3 where the plate thickness is thinner are aligned and laminated, and arranged so as to form gaps between them. The other parts of the lamination steel sheets 3 are laminated in a state where they are in contact with each other via the insulating coating 32. The parts where the insulating coating 32 is partially destroyed also have a high insulating effect due to the large dielectric strength of air, due to the gaps formed as described above.

[0036] Next, steps included in the method for manufacturing a rotating electric core according to the present disclosure will be described with reference to Fig. 8 which is a process diagram thereof and the above-mentioned drawings as appropriate. The method for manufacturing a rotating electric core according to the present disclosure is a method for manufacturing a rotating electric core (one example of which is rotor core 2) by laminating and molding lamination steel sheets having leakage flux reducing portions.

[0037] First, in the local alloying process S1, a local alloying process is performed on a leakage flux reduction target portion, in which an insulating coating 32 is applied to the surface of a single steel sheet 3 for lamination and / or a group of a predetermined number of laminations, to form a local alloyed portion.

[0038] Next, in the press / punch step S2, the locally alloyed portion 33 is pressed so as to have a thinner plate thickness than other portions of the steel plate 3 for lamination, and is punched into a predetermined shape for the steel plate 3 for lamination. As described above with reference to Figures 4B and 4C, punching may be performed after pressing, but as described above with reference to Figures 5B and 5C and Figures 6B and 6C, punching may be performed first, and then pressing may be performed.

[0039] In the lamination molding process S3, as explained with reference to Figure 7, the local alloyed areas 33, whose plate thickness has been reduced by the press processing in the press and punch process S2, are aligned and laminated so as to form gaps between them, and other parts of the lamination steel plate 3 are laminated in a state of contact with each other via the insulating coating 32 to form the rotating electric core (rotor core 2).

[0040] The rotating electric machine 1 of the present disclosure provides the following advantages.

[0041] According to the rotating electric core (rotor core 2) of (1), the lamination steel plate 3 is provided with an insulating coating 32 on the surface of each single plate and a predetermined number of lamination groups, and the locally alloyed portion (locally alloyed portion 33) where the leakage flux reduction target portion is locally alloyed is formed by pressing, and gaps are formed between the locally alloyed portions on the lamination surface of the lamination steel plate 3. The large dielectric strength of the air in the gaps ensures electrical insulation, and the decrease in electrical efficiency due to eddy currents can be suppressed. That is, although the locally alloyed treatment for reducing leakage flux is performed, the electrical insulation of the leakage flux reduction portion where the insulating coating 32 is broken can be maintained at a high level. Therefore, it is possible to provide a rotating electric core (rotor core 2) in which the plate thickness is compressed to deal with the local thermal deformation of the lamination steel plate 3 due to the local alloying treatment, the dimensional accuracy is high, the centrifugal strength is secured, and further, the leakage flux reduction and the eddy current suppression can be achieved.

[0042] (2) In the rotating motor 1, leakage flux and eddy currents are effectively reduced, and a rotating motor core (rotor core 2) made of laminated steel plate in which the plate thickness of the relevant area is compressed to deal with local thermal deformation is applied, thereby realizing a small-sized, energy-efficient rotating motor 1.

[0043] In the manufacturing method of the rotating electric core of (3), the local alloying process S1 promotes demagnetization in the leakage flux reduction target area, and the thinned areas of the lamination steel sheets, which have been thinned in the pressing and punching process S2 and punched into a predetermined shape, are aligned and laminated in the lamination molding process S3 to form gaps between them. This ensures electrical insulation with a large dielectric strength due to the air in the gap, and suppresses the decrease in electric efficiency due to eddy currents. In addition, the leakage flux can be reduced by maintaining the magnetic resistance of the magnetic flux reduction area, which has been subjected to the local alloying process, at a high level, and the areas thermally deformed by the local alloying process are thinned by the pressing process, making it possible to manufacture a small-sized rotating electric machine with high energy efficiency.

[0044] The rotating electric core and the rotating electric machine using the same and the manufacturing method of the rotating electric core according to the present disclosure have been described above, but the present invention is not limited thereto. The detailed configuration may be appropriately changed within the scope of the spirit of the present invention. For example, in the above description, the rotating electric machine is an IPM (Interior Permanent Magnet) motor, but the same effects can be obtained with a substantially similar configuration even when the rotating electric machine is an IPM generator. [Explanation of symbols]

[0045] 1...Rotary electric machine 2...Rotor core 3…Steel plate for lamination 4…Magnet 5. Slot 6…Rotor 7…Reinforcing rib 8…Stator core 9…Coil 10...Press machine 11... Press die for press processing 12, 12a…Punching press die 31...Electromagnetic steel plate 32...Insulating coating 33... Local alloying area 34...Highlights

Claims

1. A rotating electrical core formed by laminating steel plates having a leakage flux reduction portion, The lamination steel plate has an insulating coating applied to the surface of each of the single steel plate and the surface of each of the predetermined number of lamination groups, and the leakage magnetic flux reducing portion is locally alloyed by locally alloying treatment. The locally alloyed portion is a rotating electrical core that is press-formed into a shape that generates gaps between the lamination surfaces of the lamination steel plates.

2. A rotating electric machine, the stator or rotor of which is constituted by the rotating electric machine core according to claim 1.

3. A method for manufacturing a rotating electric core by laminating and molding a lamination steel plate having a leakage flux reduction portion, comprising the steps of: A local alloying treatment process for forming a local alloyed portion by performing a local alloying treatment on a leakage flux reduction target portion in which an insulating coating is applied to a surface of the single steel plate for lamination and / or a predetermined number of lamination groups; a pressing and punching process including a pressing process for pressing the locally alloyed portion so as to have a plate thickness thinner than that of other portions of the steel plate for lamination, and a punching process for punching the steel plate for lamination into a shape of the rotating electric core; a lamination molding process in which the portions of the lamination steel plates that have been thinned by the pressing process are aligned and laminated to form gaps between the portions, and the other portions of the lamination steel plates are laminated and molded in a state in which the portions are in contact with each other via the insulating coating to form a rotating electrical core; A method for manufacturing a rotating electrical core comprising the steps of:

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