JP2011115014A - Armature core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an armature core produced at low cost for reducing eddy current via a back yoke and teeth. <P>SOLUTION: The teeth 20 has multiple first steel plates 201 stacked in a radial direction. The back yoke 10 has multiple second steel plates stacked in the axial direction. On one end side of the teeth 20 in the circumferential direction, any part that contacts with the teeth 20 in the second steel plate 101 in the circumferential direction contacts with only part of the second steel plate 201 in the circumferential direction and/or any part of the first steel plate 201 that contacts with the back yoke 10 in the circumferential direction contacts with only part of the second steel plate 101 in the circumferential direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an armature core.

  In the illustration of FIG. 17, the armature core includes a back yoke 110 and a plurality of teeth 210. In FIG. 18, only one tooth 210 is shown separated from the back yoke 110 in a direction along the axis P (hereinafter simply referred to as the axial direction).

  The back yoke 110 has a plurality of electromagnetic steel plates 111 stacked in the axial direction. The tooth 210 has a plurality of electromagnetic steel plates 211 stacked in a radial direction (hereinafter simply referred to as a radial direction) about the axis P at that position. The plurality of teeth 210 are annularly arranged around the axis P. The back yoke 110 has a plurality of holes 112 into which the plurality of teeth 210 are inserted. The back yoke 110 magnetically couples the teeth 210 in a circumferential direction around the axis P (hereinafter simply referred to as a circumferential direction).

  The electromagnetic steel plates 111 and 211 are both formed by punching a predetermined steel plate, and the punching direction coincides with the stacking direction. Thereby, the coating which is an electrical resistance is not provided on the surface forming the edge of the hole 112 when viewed in the axial direction and the both end surfaces in the circumferential direction of the tooth 210. Therefore, the contact surface in the circumferential direction between the back yoke 110 and the tooth 210 has a low electrical resistance.

  In such an armature core, magnetic flux flows through the teeth 210 in the axial direction, so that eddy currents easily flow through the path C1 around the axial direction via the back yoke 110 and the teeth 20 as shown in FIG. . In the path C1, eddy currents flow through two electromagnetic steel plates 211 different from each other along directions opposite to each other in the circumferential direction. In addition, at both ends in the circumferential direction of the tooth 210, the electromagnetic steel sheet 111 flows along opposite directions of the substantially radial direction.

  Further, since magnetic flux flows in the circumferential direction between the tooth 210 and the back yoke 110, as shown in FIG. 18, an eddy current easily flows through the path C2 around the circumferential direction via the back yoke 110 and the tooth 210. . In the path C2, eddy currents flow through two different electromagnetic steel plates 211 along opposite directions in the axial direction, respectively, and flow through two different electromagnetic steel plates 111 along opposite directions in the substantially radial direction.

  Patent Document 1 describes an armature core that reduces such eddy currents. In Patent Document 1, an insulating member is interposed between the back yoke 110 and the teeth 210 in the circumferential direction. Since the insulating member is interposed in both the paths C1 and C2, eddy currents flowing in the paths C1 and C2 can be reduced.

JP 2006-166679 A

  However, in Patent Document 1, it is necessary to provide an insulating member between the back yoke 110 and the teeth 210, which causes an increase in manufacturing costs such as material costs.

  Accordingly, an object of the present invention is to provide an armature core that is low in manufacturing cost while reducing eddy currents through a back yoke and a tooth.

  A first aspect of the armature core according to the present invention includes a plurality of first steel plates (201) each of which is laminated in a radial direction around a predetermined axis (P), and the axis is the center. A plurality of teeth (20) having both ends in the circumferential direction, and annularly arranged around the axis, and a plurality of second steel plates (101) stacked in the axial direction along the axis, One end of each of the teeth in the circumferential direction is provided with a yoke (10) in which the plurality of teeth are inserted and a plurality of holes opened on at least one side in the radial direction centered on the shaft are provided. On the (20A) side, any one of the second steel plates that contacts the one tooth in the circumferential direction is in contact with only one of the first steel plates in the circumferential direction, and / or Contact the yoke in the circumferential direction of the first steel plate Those contacts only with the circumferential direction one of the both second steel plate.

  A second aspect of the armature core according to the present invention is the armature core according to the first aspect, wherein the hole (11) opens only on one side in the radial direction and the yoke (10 ) Is continuous in the circumferential direction on the other side in the radial direction with respect to the tooth (20), and the one first steel plate is one second steel plate on the one end (20A) side of the one tooth. And in the circumferential direction, the one first steel plate is separated from the one second steel plate in the circumferential direction on the other end (20B) side of the one tooth.

  A third aspect of the armature core according to the present invention is the armature core according to the first or second aspect, wherein the hole (11) opens only on one side in the radial direction. The yoke (10) is continuous in the circumferential direction on the other radial side with respect to the tooth (20), and the tooth extends from the yoke to the one axial side (A). Of the two steel plates, the one located on one side (A) in the axial direction is in contact with the one located on the other radial side of the first steel plates.

  A fourth aspect of the armature core according to the present invention is the armature core according to any one of the first to third aspects, wherein the one end (20A) of the one tooth (20a). On the side, one of the second steel plates (101a) protrudes in the circumferential direction at a predetermined distance (R) from the shaft and comes into contact with only one of the first steel plates (201a), and the other one of the teeth ( On the one end (20B) side of 20b), the other second steel plate (101b) protrudes in the circumferential direction at the predetermined distance (R) from the shaft, and only one first steel plate (201b). And the other second steel plate is rotated at an angle between the one tooth and the other tooth with respect to the axis, with the axis as the center. In the state, it has the same shape as the one second steel plate.

  A fifth aspect of the armature core according to the present invention is the armature core according to the first aspect, wherein one end of the one tooth (20) is on the one end (20A) side. The two steel plates (101) are in contact with only one of the first steel plates (201), and the other second steel plate is in contact with only the other first steel plate.

  A sixth aspect of the armature core according to the present invention is the armature core according to any one of the first to fifth aspects, wherein the first steel plate (101) of the second steel plates (201). ) That contacts only one of them protrudes and contacts only one of the first steel plates in the circumferential direction.

  A seventh aspect of the armature core according to the present invention is the armature core according to any one of the first to sixth aspects, wherein the teeth are arranged on one side in the axial direction (A ) And the insulating portion (50) provided on the yoke (10) from the other side (B) in the axial direction, and the insulating portion (10) from the other side (B) in the axial direction. And a reinforcing plate (40).

  An eighth aspect of the armature core according to the present invention is the armature core according to any one of the first to sixth aspects, wherein the teeth are arranged on one side in the axial direction (A And a reinforcing plate (40) which is provided on the yoke (10) from the other side (B) in the axial direction and has higher strength than the teeth, and the teeth pivot on the yoke. It penetrates in the direction and the teeth and the reinforcing plate are fixed to each other.

  A ninth aspect of the armature core according to the present invention is the armature core according to the eighth aspect, wherein the reinforcing plate (40) is a nonmagnetic material.

  According to the first aspect of the armature core of the present invention, if the second steel plate is in contact with only one of the first steel plates, the current flows from the one of the first steel plates to the second steel plate. Even if the current flows, the second steel plate and the other first steel plate are separated from each other, so that the current hardly returns from the second steel plate to the other first steel plate. Therefore, the eddy current flowing through the teeth and the yoke as viewed from the axial direction can be efficiently reduced.

  If the first steel plate is in contact with only one of the second steel plates, even if current flows from the one of the second steel plates to the first steel plate, the first steel plate and the other second steel plate Since they are separated from each other, it is difficult for the current to return from the first steel plate to the other second steel plate. Therefore, the eddy current flowing through the teeth and the yoke as viewed from the circumferential direction can be efficiently reduced.

  Moreover, the first steel plate and the second steel plate can be formed by a punching process. Therefore, material costs and assembly processes can be reduced as compared with the case where an electrical insulating member is provided between the yoke and the teeth.

  According to the second aspect of the armature core according to the present invention, even if the yoke is continuous in the circumferential direction on the other side in the radial direction with respect to the tooth, the continuous portion and the first steel plate The eddy current around the axial direction through is difficult to occur.

  According to the third aspect of the armature core according to the present invention, since the yoke is continuous on the other radial side, an eddy current viewed from the axial direction can flow through the portion and the first steel plate. Further, the closer to one side in the axial direction, the larger the magnetic flux flowing in the yoke, so the closer to one side in the axial direction, the larger the value of the eddy current applied.

  Since the first steel plate and the second steel plate are in contact with each other on the one side in the axial direction, the value of the eddy current is relatively large, but the outer circumference of the eddy current is relatively short. Therefore, the influence of eddy current can be efficiently suppressed.

  In addition, since the plurality of second steel plates are in contact with the first steel plate, the yoke is supported in the circumferential direction at a plurality of locations. Therefore, the interval between the teeth and the yoke can be determined with high accuracy.

  According to the 4th aspect of the armature core concerning this invention, using the 2nd steel plate of the same shape, between the other teeth and the yoke, the 1st 2nd steel plate is only one 1st steel plate. Can be contacted. Therefore, the manufacturing cost can be reduced as compared with the case where the second steel plates having different shapes are used.

  According to the fifth aspect of the armature core of the present invention, one end of the tooth can be supported at a plurality of locations. Therefore, the gap between one end of the teeth and the yoke can be determined with high accuracy.

  According to the 6th aspect of the armature core concerning this invention, it is not necessary to make a 1st steel plate protrude to a 2nd steel plate. Accordingly, the circumferential lengths of the first steel plates can be made equal. As a result, it is easy to laminate the first steel plates in the radial direction.

  According to the seventh aspect of the armature core according to the present invention, the reinforcing plate can increase the axial thickness of the structure including the reinforcing plate and the yoke, so that the strength of the structure can be improved. In addition, since an insulating portion is interposed between the reinforcing plate and the yoke, a magnetic body may be employed as the reinforcing plate, and the selectivity of the material of the reinforcing plate can be enhanced.

  According to the eighth aspect of the armature core according to the present invention, since the yoke is fixed to the reinforcing plate having higher strength, the teeth can be more firmly fixed.

  According to the ninth aspect of the armature core of the present invention, the eddy current generated in the reinforcing plate can be reduced.

It is a perspective view which shows an example of a notional structure of the armature core. It is a figure which shows a conceptual example of the armature core in a cross section perpendicular | vertical to an axis | shaft. It is a perspective view which shows the notional structure of the part corresponded to one tooth. It is a figure which shows a conceptual example of the armature core in a cross section perpendicular | vertical to an axis | shaft. It is a perspective view which shows an example of a notional structure of the armature core. It is a perspective view which shows the notional structure of the part corresponded to one tooth. It is a figure which shows a conceptual example of the armature core in a cross section perpendicular | vertical to an axis | shaft. It is a figure which shows a conceptual example of the armature core in the cross section along a circumferential direction. It is a figure which shows a conceptual example of the armature core in the cross section along a circumferential direction. It is a figure which shows a conceptual example of the part corresponded to the hole of the back yoke seen along the circumferential direction. It is a figure which shows a conceptual example of the part corresponded to the hole of the back yoke seen along the circumferential direction. It is a figure which shows a conceptual example of one electromagnetic steel plate of the back yoke seen along the axial direction. It is a figure which shows a conceptual example of the other electromagnetic steel plate of the back yoke seen along the axial direction. It is a figure which shows a conceptual example of the other electromagnetic steel plate of the back yoke seen along the axial direction. It is a perspective view which shows an example of a notional structure of the armature core. It is a figure which shows a conceptual example of the armature core in a cross section perpendicular | vertical to an axis | shaft. It is a perspective view which shows an example of a notional structure of the conventional armature core. It is a perspective view which shows an example of a notional structure of the conventional armature core.

First embodiment.
As shown in FIG. 1, the armature core 1 includes a back yoke 10 and teeth 20. In FIG. 1, only one tooth 20 is shown, but the armature core 1 has a plurality of teeth 20. Although the teeth 20 and the back yoke 10 are shown separated in the axial direction, the teeth 20 are actually inserted into the back yoke 10. This also applies to the drawings in which each component is shown separated in the axial direction.

  The plurality of teeth 20 is a soft magnetic material (for example, iron). The teeth 20 are annularly arranged around the axis P.

  The back yoke 10 is a soft magnetic material (for example, iron). A plurality of holes 11 are formed in the back yoke 10. The hole 11 opens at least on one side A in the axial direction. The plurality of teeth 20 are inserted into the plurality of holes 11 in the above-described arrangement. The back yoke 10 magnetically couples a plurality of teeth 20 in the circumferential direction.

  Any of the plurality of teeth 20 extends from the back yoke 10 to the one side A in the axial direction while being inserted into the back yoke 10. A coil (not shown) is wound around a portion of the tooth 20 that extends from the back yoke 10 to the one side A in the axial direction. In the illustration of FIG. 1, an insulator 21 as an electrical insulator is disposed between the tooth 20 and a coil (not shown). Usually, an insulating film is provided on the coil, but by providing the insulator 21, the insulation between the coil and the tooth 20 is further enhanced.

  The teeth 20 have a plurality of electromagnetic steel plates 201 stacked in the radial direction. In the drawing, the thickness in the radial direction of each electromagnetic steel plate 201 is relatively large for convenience. For example, in FIG. 1, the number of laminated electromagnetic steel plates 201 for the teeth 20 is simplified to about a dozen or more, but in reality, more electromagnetic steel plates 201 may be laminated. The same applies to other drawings, and not only to the teeth 20 but also to other components constituted by electromagnetic steel sheets.

  The plurality of electromagnetic steel plates 201 are fixed to each other by at least one of adhesive, welding, and Karamase, for example. The surface of each electromagnetic steel plate 201 that is substantially perpendicular to the radial direction is coated. Since such a coating functions as an electrical resistance, the electrical resistance in the radial direction of the teeth 20 is relatively high. Thus, if the current path between the back yoke 10 and the tooth 20 is not considered, even if the magnetic flux flows through the tooth 20 in the axial direction, the eddy current generated in the tooth 20 can be reduced.

  The back yoke 10 has a plurality of electromagnetic steel plates 101 stacked in the axial direction. In FIG. 1, drawing of the stacked state in the hole 11 is omitted for simplification of illustration. The plurality of electromagnetic steel plates 101 are fixed to each other, for example, by at least one of adhesive, welding, and karase. Since the surface substantially perpendicular to the axial direction of each electromagnetic steel sheet 101 is coated, the electrical resistance in the axial direction of the back yoke 10 is relatively high. Thus, if the current path between the back yoke 10 and the teeth 20 is not considered, eddy current generated in the back yoke 10 can be reduced even if magnetic flux flows through the back yoke 10 in the circumferential direction.

  The hole 11 is also opened on the inner peripheral side. Thereby, the electrical resistance of the path | route surrounding each teeth 20 in the back yoke 10 can be raised. Therefore, if the current path between the back yoke 10 and the teeth 20 is not considered, even if the magnetic flux flows along the teeth 20 in the axial direction, the eddy current generated in the back yoke 10 can be reduced. 1, the hole 11 may be opened on the side opposite to the axis P (hereinafter also referred to as the outer peripheral side) instead of the inner peripheral side or together with the inner peripheral side.

  In the illustration of FIG. 1, the reinforcing plate 40 is attached to the back yoke 10 from the other side B in the axial direction. The reinforcing plate 40 is, for example, a metal. For example, the reinforcing plate 40 has a disk shape having the same diameter as the outer periphery of the back yoke 10. The reinforcing plate 40 can increase the axial thickness of the structure composed of the back yoke 10 and the reinforcing plate 40. Therefore, the strength of the structure can be improved. The back yoke 10 and the reinforcing plate 40 may be fixed to each other by an arbitrary method, and may be fixed by, for example, an adhesive or welding.

  The reinforcing plate 40 is not expected to function as a magnetic flux path. Therefore, if the reinforcing plate 40 is made of a magnetic material, the reinforcing plate 40 may be made of a magnetic material that has not been subjected to eddy current reduction processing, such as an electromagnetic steel plate or a dust core. The reinforcing plate 40 may be a nonmagnetic material. In this case, since magnetic flux does not flow through the reinforcing plate 40, eddy currents generated in the reinforcing plate 40 can be avoided or suppressed more reliably. In the illustration of FIG. 1, the reinforcing plate 40 also includes electromagnetic steel plates laminated in the axial direction.

  In the illustration of FIG. 1, the hole 11 passes through the back yoke 10 in the axial direction. The reinforcing plate 40 has a hole 41 at a position where the teeth 20 exist when viewed along the axial direction. The hole 41 is continuous with the hole 11 in the axial direction, and penetrates, for example, the reinforcing plate 40 in the axial direction. The teeth 20 are inserted into the holes 11 and 41. With such a structure, the teeth 20 can be fixed to the reinforcing plate 40 by, for example, an adhesive, welding, or press fitting. Therefore, it is possible to avoid the deterioration of the magnetic properties of the back yoke 10 that may occur when the teeth 20 are fixed to the back yoke 10.

  In this case, it is desirable that the strength of the reinforcing plate 40 is higher than the strength of the back yoke 10. This is because the teeth 20 can be fixed more firmly than when the teeth 20 are fixed to the back yoke 10.

  Further, when the hole 41 penetrates the reinforcing plate 40 in the axial direction, the teeth 20 are also inserted into the hole 41, so that the reinforcing plate 40 and the teeth 20 are fixed from the other side B in the axial direction. It can be carried out. Since no coil or the like is provided on the other side B, the fixing work can be easily performed.

  When the strength of the back yoke 10 is sufficient, the reinforcing plate 40 may not be provided. In this case, the back yoke 10 and the teeth 20 are fixed to each other.

  Below, the part inserted in the hole 11 among the teeth 20 is called the part 20b.

  On one end 20 </ b> A side in the circumferential direction of the teeth 20, the back yoke 10 and the portion 20 b of the teeth 20 are in contact with each other in the circumferential direction. Furthermore, all of the electromagnetic steel plates 101 that are in contact with the teeth 20 are in contact with only one of the electromagnetic steel plates 201. In the example of FIGS. 1 and 2, such contact is realized by a protrusion 30 provided on the back yoke 10. The protrusion 30 protrudes in the circumferential direction on the one end 20 </ b> A side of the tooth 20 and abuts on the tooth 20. More specifically, one electromagnetic steel plate 101 protrudes in the circumferential direction on one end 20 </ b> A side and contacts only one of the electromagnetic steel plates 201. The teeth 20 are spaced apart from the back yoke 10 in the circumferential direction except for the protrusions 30 on the one end 20A side.

  In the illustration of FIG. 1, the back yoke 10 and the teeth 20 are also in contact with each other in the circumferential direction on the other end 20B side of the teeth 20, and more specifically, any of the electromagnetic steel plates 101 that are in contact with the teeth 20. Only one of the electromagnetic steel plates 201 is in contact. In the illustration of FIG. 1, such contact is realized by a protrusion 31 provided on the back yoke 10. The protrusion 31 protrudes in the circumferential direction on the other end 20 </ b> B side and comes into contact with the teeth 20. More specifically, one electromagnetic steel plate 101 protrudes in the circumferential direction on the other end 20B side and contacts only one of the electromagnetic steel plates 201. The teeth 20 are separated from the back yoke 10 in the circumferential direction except for the protrusions 31 on the other end 20B side.

  In the example of FIG. 1, the protrusions 30 and 31 are provided on the back yoke 10, but may be provided on the teeth 20. In other words, the electromagnetic steel plate 201 may protrude in the circumferential direction and contact the electromagnetic steel plate 101. In the illustration of FIG. 1, the protrusions 30 and 31 are symmetrical with respect to a cross section D that passes through the center in the circumferential direction of the tooth 20 and is parallel to the axial direction. Therefore, below, the protrusion part 30 is demonstrated typically.

  In the illustration of FIG. 1, the protrusion 30 has a long shape extending in the axial direction when viewed along the circumferential direction. Therefore, the protrusion 30 is provided on the plurality of electromagnetic steel plates 101. Further, as illustrated in FIG. 2, the protrusion 30 has a semicircular shape when viewed along the axial direction. The protrusion 30 is in contact with only one electromagnetic steel plate 201 at a predetermined point on the semicircle as viewed in the axial direction.

  In FIG. 2, the back yoke 10 and the teeth 20 are spaced apart from each other in the radial direction, but may be in contact with each other. In FIG. 2, the gap between the back yoke 10 and the teeth 20 in the circumferential direction is exaggerated.

  When the teeth 20 are inserted into the holes 11, the protrusions 30 may be deformed in the circumferential direction in a direction in which the holes 11 are widened by contact between the teeth 20 and the protrusions 30. This is realized by, for example, the length between the protrusions 30 and 31 being slightly shorter than the length in the circumferential direction of the electromagnetic steel plate 201 in contact therewith. As a result, the back yoke 10 and the teeth 20 come into contact with each other more reliably. Therefore, the back yoke 10 can more reliably support the teeth 20 in the circumferential direction.

  According to the armature core 1, the electrical resistance of the path C <b> 1 can be increased. As shown in FIG. 2, the path C <b> 1 surrounds the axial direction via one electromagnetic steel plate 101 and two different electromagnetic steel plates 201. Each of the electromagnetic steel plates 101 is in contact with one electromagnetic steel plate 201 in the circumferential direction via the protrusion 30, but the electromagnetic steel plate 101 is separated from the other electromagnetic steel plates 201 in the circumferential direction except for the protrusion 30. Therefore, the electrical resistance between the electromagnetic steel sheet 101 and the other electromagnetic steel sheet 201 is high. Therefore, even if a current flows from one electromagnetic steel plate 201 to one electromagnetic steel plate 101 through the protrusion 30, it is difficult for the current to flow from the one electromagnetic steel plate 101 to another electromagnetic steel plate 201. Therefore, the eddy current (current flowing through the path C1) viewed from the axial direction can be reduced.

  In addition, referring to FIG. 3, the electric resistance of path C2 can be increased. In FIG. 3, only the portion 20b of one tooth 20 is shown, and only a portion of the back yoke 10 adjacent to the portion 20b in the circumferential direction is shown. The path C2 surrounds the circumferential direction via two different electromagnetic steel plates 101 and two different electromagnetic steel plates 201. Therefore, the path C <b> 2 passes between two electromagnetic steel plates 201 different from one electromagnetic steel plate 101. The electromagnetic steel plate 101 is continuous with only one electromagnetic steel plate 201 via the protrusions 30 and is separated from the other electromagnetic steel plates 201. Therefore, the electrical resistance can be increased also in the path C2. Therefore, the eddy current (current flowing through the path C2) viewed from the circumferential direction can be reduced.

  Moreover, since the protrusion 30 is provided on the back yoke 10, the protrusion 30 can be formed as the contour of the electromagnetic steel plate 101. The electromagnetic steel plate 101 provided with the protrusions 30 is formed by punching a predetermined steel plate. Therefore, a special process for providing the protrusion 30 is not required. Therefore, the number of processes can be reduced as compared with the case where another member as an insulator is provided between the back yoke 10 and the teeth 20 as in Patent Document 1. Further, in the present application, since the insulator between the tooth 20 and the back yoke 10 is formed by a gap, the material cost can be reduced. Therefore, the manufacturing cost can be reduced.

  If the teeth 20 are fixed to the reinforcing plate 40, a gap can be generated between the teeth 20 and the reinforcing plate 40 regardless of the protrusions 30 and 31. However, there are the following problems. A field element is arranged on one side A in the axial direction so as to face the armature around which the coil is wound around the tooth 20. And by this field element, the magnetic force in the circumferential direction acts on the teeth 20 on one side A in the axial direction. In such a rotating electrical machine, since the teeth 20 are not supported in the circumferential direction by the protrusions 30 and 31, the teeth 20 may vibrate in the circumferential direction. On the other hand, according to the rotating electrical machine provided with the armature core 1, the teeth 20 are supported in the circumferential direction by the protrusions 30 and 31, so that such vibration can be suppressed or prevented.

  In either one of the two ends 20A and 20B, the portion 20b of the tooth 20 and the back yoke 10 may be in contact with each other in the circumferential direction over the entire surface. Even in such a structure, the path C1 passes through one gap between the electromagnetic steel plates 101 and 201, so that the electrical resistance of the path C1 is increased. Further, the electrical resistance of the path C2 can be increased in the direction where the portion 20b of the tooth 20 and the back yoke 10 are separated from each other between the ends 20A and 20B.

  Even if the protrusion 30 is provided on the tooth 20, the protrusion 30 can be formed as the contour of the electromagnetic steel plate 201, and thus the manufacturing cost can be similarly reduced.

  Moreover, since the projection part 30 can be formed by stamping a steel plate, the distance between the back yoke 10 and the teeth 20 can be accurately set to a small value (for example, 0.5 mm). Therefore, an increase in the magnetic resistance between the back yoke 10 and the teeth 20 can be suppressed while reducing the eddy current, thereby suppressing an increase in copper loss.

  In the illustrations of FIGS. 1 to 3, two protrusions 30 a and 30 b are provided on the back yoke 10 on the one end 20 </ b> A side. The two protrusions 30a and 30b are provided on different electromagnetic steel plates 101, respectively. For example, the protrusion 30 a is provided on the electromagnetic steel plate 101 a of the electromagnetic steel plate 101, and the protrusion 30 b is provided on the electromagnetic steel plate 101 b of the electromagnetic steel plate 101. Further, the protrusion 30a abuts only on one of the electromagnetic steel plates 201 in the circumferential direction, and the protrusion 30b abuts on only one of the electromagnetic steel plates 201 in the circumferential direction different from the electromagnetic steel plate 201a. ing.

  As described above, in the paths C <b> 1 and C <b> 2, a current flows between one predetermined electromagnetic steel plate 101 and two different electromagnetic steel plates 201. On the other hand, each of the electromagnetic steel sheets 101a and 101b is continuous with only one of the electromagnetic steel sheets 201a and 201b, and is separated from the other electromagnetic steel sheets 201. Therefore, even if the plurality of protrusions 30a and 30b are provided, the electrical resistance in the paths C1 and C2 can be increased, and as a result, eddy currents flowing through the paths C1 and C2 can be reduced.

  Further, the teeth 20 come into contact with the back yoke 10 via the plurality of protrusions 30a and 30b on the one end 20A side. In other words, the teeth 20 are supported in the circumferential direction by the plurality of protrusions 30a and 30b on the one end 20A side. Therefore, compared with the case where the teeth 20 are supported by one protrusion 30, the teeth 20 can be supported stably. Further, the accuracy of the gap between the teeth 20 and the back yoke 10 can be improved.

  In the illustration of FIGS. 1 to 3, all of the plurality of electromagnetic steel plates 101 are in contact with only one of the electromagnetic steel plates 201, but some of the electromagnetic steel plates 101 are separated from all of the electromagnetic steel plates 201. Also good.

  In the illustration of FIGS. 1-3, although the part 20b and the hole 11 have a rectangular parallelepiped shape, it is not necessarily restricted to this. As illustrated in FIG. 4, the portion 20 b and the hole 11 may have a substantially trapezoidal shape when viewed from the axial direction. In the illustration of FIG. 4, the teeth 20 are arranged in a posture with the upper base of the trapezoid (the shorter side in the circumferential direction) directed toward the inner peripheral side. Even with this structure, it is possible to reduce the eddy current flowing through the interface between the tooth 20 and the back yoke 10 while reducing the manufacturing cost.

  Hereinafter, an armature core 1 according to another embodiment will be described mainly by describing differences from the first embodiment.

Second embodiment.
In the second embodiment, as illustrated in FIGS. 5 and 6, any one of the electromagnetic steel plates 101 that contacts the back yoke 10 among the electromagnetic steel plates 201 on the one end 20 </ b> A side of the teeth 20. Only in contact with. In FIG. 5, only one tooth 20 is illustrated, and drawing of the stacked state in the hole 11 is omitted.

  5 and 6, such contact is realized by a protrusion 30 provided on the tooth 20. The protrusion 30 protrudes in the circumferential direction on the end 20 </ b> A side of the tooth 20 and abuts against the back yoke 10. The teeth 20 are spaced apart from the back yoke 10 in the circumferential direction except for the protrusions 30 on the one end 20A side.

  5 and 6, on the other end 20B side of the tooth 20, the back yoke 10 and the portion 20b of the tooth 20 are in contact with each other in the circumferential direction. Anything in contact is in contact with only one of the electromagnetic steel sheets 101. 5 and 6, such contact is realized by a protrusion 31 provided on the tooth 20. The protrusion 31 protrudes in the circumferential direction on the other end 20 </ b> B side of the tooth 20 and comes into contact with the back yoke 10. The teeth 20 are separated from the back yoke 10 in the circumferential direction except for the protrusions 31 on the other end 20B side.

  Although the protrusions 30 and 31 are provided on the teeth 20, they may be provided on the back yoke 10. Further, either one of the ends 20A and 20B may be such that the portion 20b of the tooth 20 and the back yoke 10 are in contact with each other in the circumferential direction over the entire surface. 5 and 6, the protrusions 30 and 31 are symmetrical with respect to a cross section D that passes through the center in the circumferential direction of the tooth 20 and is parallel to the axial direction. Therefore, below, the protrusion part 30 is demonstrated typically.

  5 and 6, the protrusion 30 has a long shape extending in a direction perpendicular to the axial direction when viewed along the circumferential direction. Therefore, the protrusion 30 is provided on the plurality of electromagnetic steel plates 201. The protrusion 30 has a semicircular shape when viewed in the radial direction. The protrusion 30 is in contact with one of the electromagnetic steel plates 101 at a predetermined point on the semicircle as viewed along the radial direction.

  According to the armature core 1, the electric resistance of the path C2 can be increased. As illustrated in FIG. 6, the path C <b> 2 surrounds the circumferential direction via two different electromagnetic steel plates 101 and two different electromagnetic steel plates 201. According to the armature core 1, each of the electromagnetic steel plates 201 is in contact with one electromagnetic steel plate 101 via the protrusion 30, but is separated from the other electromagnetic steel plates 101. Therefore, the electrical resistance between the electromagnetic steel sheet 201 and the other electromagnetic steel sheet 101 is high. Therefore, even if a current flows from the one electromagnetic steel plate 101 to the electromagnetic steel plate 201 via the protrusion 30, the current hardly flows from the electromagnetic steel plate 201 to another electromagnetic steel plate 101. Therefore, the eddy current (current flowing through the path C2) viewed from the circumferential direction can be reduced.

  Moreover, since the protrusion 30 can be formed as the outline of the tooth 20, no special process for forming the protrusion 30 is required. Therefore, the manufacturing cost can be reduced as in the first embodiment. In addition, the protrusion part 30 may be provided in the back yoke 10 similarly to 1st Embodiment.

  5 and 6, two protrusions 30a and 30b are provided on the tooth 20 on the one end 20A side. The two protrusions 30a and 30b are provided on different electromagnetic steel plates 201, respectively. For example, the protrusion 30 a is provided on the electromagnetic steel plate 201 a of the electromagnetic steel plate 201, and the protrusion 30 b is provided on the electromagnetic steel plate 201 b of the electromagnetic steel plate 201. The protrusion 30a is in contact with only one of the electromagnetic steel plates 101a in the circumferential direction, and the protrusion 30b is in contact with only one of the electromagnetic steel plates 101b in the circumferential direction that is different from the electromagnetic steel plate 101a. .

  Such a structure can also reduce the eddy current flowing through the path C2. Further, as in the first embodiment, since the teeth 20 can be supported at a plurality of locations, the teeth 20 can be stably supported, and the gap between the back yoke 10 and the teeth 20 can be set with high accuracy.

  In the armature core 1, eddy current can flow through the path C1, but the outer circumference of the eddy current can be shortened by shortening the length of the protrusion 30a in the substantially radial direction. Therefore, inhibition of magnetic flux due to eddy current can be suppressed.

  In the illustration of FIG. 5, the armature core 1 includes an insulating member 50 between the reinforcing plate 40 and the back yoke 10. For example, the insulating member 50 has the same shape as the reinforcing plate 40 when viewed in the axial direction. In order to prevent the magnetic flux from flowing into the reinforcing plate 40, the insulating member 50 may employ a magnetic body that is not subjected to eddy current reduction processing as the reinforcing plate 40. In other words, the material selectivity of the reinforcing plate 40 can be improved by the insulating member 50.

Third embodiment.
In the first and second embodiments, the armature core 1 in which the protrusions 30 and 31 are symmetric with respect to the cross section D has been described. However, when the portion of the back yoke 10 located on the inner peripheral side or the outer peripheral side with respect to the teeth 20 is continuous in the circumferential direction, the following problem has occurred. In the illustration of FIG. 2, the hole 11 opens to the inner peripheral side, and the back yoke 10 is continuous in the circumferential direction on the outer peripheral side. Moreover, the electromagnetic steel plate 201a contacts the electromagnetic steel plate 101a through the protrusions 30 and 31 at both ends 20A and 20B. Therefore, the outer peripheral part of the electromagnetic steel plate 101a and the electromagnetic steel plate 201a form a path C3 around the axial direction without a gap. Therefore, a relatively large eddy current can flow through the path C3. Therefore, in the third embodiment, the eddy current flowing through the path C3 is reduced.

  Only one of the two ends 20 </ b> A and 20 </ b> B is in contact with one electromagnetic steel plate 201 in the circumferential direction, and on the other hand, the one electromagnetic steel plate 201 is separated from the one electromagnetic steel plate 101. In the illustration of FIG. 7, the electromagnetic steel plate 201 a is in contact with the electromagnetic steel plate 101 a through the protrusion 30 on the one end 20 </ b> A side. On the other end 20B side, the electromagnetic steel plate 201a is separated from the electromagnetic steel plate 101a in the circumferential direction. This is realized by contacting, for example, the electromagnetic steel plate 201b different from the electromagnetic steel plate 201a on the other end 20B side with the electromagnetic steel plate 201b provided with the protrusion 30b. Since the electromagnetic steel plates 101a and 201a are separated from each other on the other end 20B side, the electrical resistance in the path C3 can be increased. Therefore, the eddy current flowing through the path C3 can be reduced.

  In addition, as illustrated in FIG. 8, one electromagnetic steel plate 201a contacts the electromagnetic steel plate 101a on one end 20A side, one electromagnetic steel plate 201a is separated from the electromagnetic steel plate 101b, and one electromagnetic steel plate 201a on the other end 20B side. One electromagnetic steel plate 201a may be in contact with the electromagnetic steel plate 101b and separated from the electromagnetic steel plate 101a. Even with such a structure, one electromagnetic steel plate 101 is in contact with the electromagnetic steel plate 201a at only one of the ends 20A and 20B, and is separated at the other. Therefore, the electrical resistance in the path C3 can be increased, thereby reducing the eddy current flowing in the path C3.

  The hole 11 may be opened only on the outer peripheral side, and the inner peripheral portion of the back yoke 10 located on the inner peripheral side with respect to the teeth 20 may be continuous in the circumferential direction. Even in this case, the eddy current passing through the inner peripheral portion as viewed in the axial direction can be reduced.

Fourth embodiment.
An example of the armature core 1 according to the fourth embodiment is the same as the armature core of FIG. 1 or FIG. In 3rd Embodiment, the part located in the inner peripheral side or outer peripheral side with respect to the teeth 20 among the back yoke 10 continues in the circumferential direction. 1 and 5, the outer periphery of the back yoke 10 is continuous in the circumferential direction.

  Further, at one end 20A side, at least two electromagnetic steel plates 101 different from each other are in contact with only one of the different electromagnetic steel plates 201. Among the electromagnetic steel plates 101, the one located on the one side A in the axial direction is in contact with the one located on the outer peripheral side in the radial direction among the electromagnetic steel plates 201. Hereinafter, the armature core of FIG. 1 will be described as an example.

  In the illustration of FIG. 1, the plurality of electromagnetic steel plates 101a are in contact with only one electromagnetic steel plate 201a, and the plurality of electromagnetic steel plates 101b are in contact with only one electromagnetic steel plate 201b. In addition, one set of the plurality of electromagnetic steel plates 101a is positioned on one side A in the axial direction than the one set of the plurality of electromagnetic steel plates 101b, and one electromagnetic steel plate 201a is positioned on the outer peripheral side in the radial direction than one electromagnetic steel plate 201b. is doing.

  Normally, as shown in FIG. 9, the magnetic flux flowing from the teeth 20 flows through the back yoke 10 in the circumferential direction. In the back yoke 10, the closer to the one side A in the axial direction, the easier the larger magnetic flux flows. And the larger the magnetic flux flows, the larger the current value of the eddy current generated due to this. The larger the current value of the eddy current and the longer the outer circumference of the eddy current, the more easily the flow of magnetic flux is hindered by the eddy current.

  According to the core 1 for armature, the electromagnetic steel plate 101 is in contact with the magnetic steel plate 201 positioned on the outer peripheral side as the electromagnetic steel plate 101 is positioned on the one side A in the axial direction. Therefore, the amount of magnetic flux hindered by the eddy current flowing through the path C3 can be suppressed.

  Moreover, the length of the outer periphery of the path | route C3 is so long that the electromagnetic steel plate 101 is located in the other side B of an axial direction. However, the current value of the eddy current flowing through the electromagnetic steel sheet 101 located on the other side B in the axial direction is relatively small. Therefore, the amount of magnetic flux that is disturbed by eddy currents is relatively unproblematic.

  In addition, since the back yoke 10 can support the teeth 20 at a plurality of locations, the teeth 20 can be stably supported, and the gap between the back yoke 10 and the teeth 20 can be set with high accuracy.

  As described above, according to the core 1 for armature, when two different electromagnetic steel plates 101 are in contact with only one of the two different electromagnetic steel plates 201, the eddy current that passes through the outer peripheral portion of the back yoke 10 is obtained. Can be effectively suppressed.

  If the inner peripheral portion of the back yoke 10 is continuous in the circumferential direction, the electromagnetic steel plate 101 comes into contact with the electromagnetic steel plate 201 positioned on the inner peripheral side in the radial direction as it is positioned on the one side A in the axial direction. In other words, as the electromagnetic steel sheet 101 is positioned on one side A in the axial direction, the electromagnetic steel sheet 201 is in contact with the electromagnetic steel sheet 201 positioned on the side opposite to the side where the holes 11 are opened in the radial direction.

  If one electromagnetic steel plate 201 is in contact with one electromagnetic steel plate 101 at both ends 20A and 20B, the electrical resistance in the path C3 is relatively small. Therefore, in this case, since the eddy current flowing through the path C3 is large, the effect according to the third embodiment is great.

  Another example will be described with reference to FIGS. 10 and 11 show a view of the surface of the back yoke 10 that faces the teeth 20 in the circumferential direction as seen along the circumferential direction, and the teeth 20 are also shown by a two-dot chain line. 10 and 11 may be regarded as either the surface on the end 20A side or the surface on the other end 20B side. In the following, description will be made by grasping the surface typically on the one end 20A side.

  For example, as shown in FIG. 10, only two different electromagnetic steel sheets 101a and 101b are in contact with each other only in the circumferential direction with only different electromagnetic steel sheets 201a and 201b. Of the electromagnetic steel plates 101a and 101b, the electromagnetic steel plate 101a located on the one side A in the axial direction is in contact with the electromagnetic steel plate 201a close to the radially outer peripheral side of the electromagnetic steel plates 201a and 201b.

  For example, as shown in FIG. 11, when the number of the electromagnetic steel plates 201 is larger than the number of the electromagnetic steel plates 101, all the electromagnetic steel plates 101 may be in contact with only one of the different electromagnetic steel plates 201. Of all the electromagnetic steel sheets 101, the closer to the one side A in the axial direction, the closer to the electromagnetic steel sheet 201 closer to the outer peripheral side in the radial direction.

Fifth embodiment.
12-14, three electromagnetic steel plates 101a-101c are shown among the electromagnetic steel plates 101 which form the back yoke 10, respectively. In the illustrations of FIGS. 12 to 14, three teeth 20 a to 20 c are shown as the plurality of teeth 20.

  As illustrated in FIG. 12, on one end 20 </ b> A side of the tooth 20 a, the electromagnetic steel plate 101 a protrudes in the circumferential direction from a position of a predetermined distance R from the axis P and is in contact with only one electromagnetic steel plate 201 a of the tooth 20. . Such a protrusion is shown as a protrusion 30.

  As illustrated in FIG. 13, on one end 20 </ b> A side of the tooth 20 b, the electromagnetic steel plate 101 b protrudes in the circumferential direction from the position of the distance R from the axis P and contacts only one electromagnetic steel plate 201 b of the tooth 20 b in the circumferential direction. Yes. Such a protrusion is shown as a protrusion 30.

  The radial position at which the electromagnetic steel plate 101b protrudes from the tooth 20b is equal to the radial position at which the electromagnetic steel plate 101a protrudes from the tooth 20a. The electromagnetic steel plate 101b protrudes from the one end 20A side with respect to the teeth 20b, and the electromagnetic steel plate 101a also protrudes from the one end 20A side in the same direction with respect to the teeth 20a.

  Here, an angle formed by a straight line passing through the center in the circumferential direction of the teeth 20a and perpendicular to the axis P and a straight line passing through the center in the circumferential direction of the teeth 20b and perpendicular to the axis P is defined as an angle θ. The angle θ can also be grasped as an angle formed by the teeth 20a and 20b with respect to the axis P.

  Therefore, when the electromagnetic steel sheet 101a is rotated at an angle θ with respect to the axis P, the protrusion 30 of the electromagnetic steel sheet 101a and the protrusion 30 of the electromagnetic steel sheet 101b overlap in the axial direction. The electromagnetic steel sheet 101a has the same shape as the electromagnetic steel sheet 101b when viewed in the axial direction in a state where the electromagnetic steel sheet 101a is rotated at an angle θ about the axis P.

  More specifically, the teeth 20a to 20c are arranged at substantially equal intervals in the circumferential direction. In the illustration of FIG. 12, the electromagnetic steel sheet 101a is spaced apart from the teeth 20b and 20c in the circumferential direction. On the other end 20B side of the tooth 20a, the electromagnetic steel plate 101a protrudes from the axis P in the circumferential direction at a distance R and is in contact with only one electromagnetic steel plate 201a of the tooth 20a in the circumferential direction. In the illustration of FIG. 13, the electromagnetic steel plate 101b is spaced apart from the teeth 20a, 20c in the circumferential direction. On the other end 20B side of the tooth 20a, the electromagnetic steel plate 101a protrudes from the axis P in the circumferential direction at a distance R and is in contact with only one electromagnetic steel plate 201a of the tooth 20a in the circumferential direction. In the illustration of FIG. 14, the electromagnetic steel plate 101c is spaced apart from the teeth 20a, 20b in the circumferential direction. On both ends 20A and 20B of the tooth 20c, the electromagnetic steel plate 101c protrudes in the circumferential direction at a distance R from the axis P, and is in contact with only one electromagnetic steel plate 201c of the tooth 20c in the circumferential direction.

  The gap between the electromagnetic steel sheet 101a and the tooth 20b is realized by the contact between the electromagnetic steel sheet 101b and the tooth 20b, and the gap between the electromagnetic steel sheet 101a and the tooth 20c is realized by the contact between the electromagnetic steel sheet 101c and the tooth 20c. Is done.

  Since the electromagnetic steel plates 101a to 101c have the same shape, the electromagnetic steel plates 101a to 101c can be formed using the same punching member. Then, the back yoke 10 can be manufactured by laminating these by rotating at an angle θ about the axis P. Therefore, the manufacturing cost can be reduced.

  In the illustration of FIG. 15, any one of the electromagnetic steel plates 101 has a distance from the axis P (R1 to R9 in FIG. 15) with respect to each of the plurality of teeth 20 from the same end 20A side. It protrudes and contacts only one electromagnetic steel plate 201 of each of the plurality of teeth 20. In the illustration of FIG. 15, one electromagnetic steel plate 101 protrudes from the same other end 20 </ b> B side at a position where the distances from the axis P are different from each other, and contacts only one electromagnetic steel plate 201 of each of the plurality of teeth 20. Yes.

  Here, an angle formed by the two teeth 20 adjacent to each other in the circumferential direction with respect to the axis P is an angle θ1. In the illustration of FIG. 15, another electromagnetic steel sheet 101 that is adjacent to one electromagnetic steel sheet 101 in the axial direction is in the state in which the one electromagnetic steel sheet 101 is rotated at an angle θ1 about the axis P. 101 and the same shape as seen in the axial direction.

  According to the back yoke 10, a plurality of electromagnetic steel plates 101 can be formed by the same punching member. Further, the back yoke 10 can be manufactured by sequentially laminating the electromagnetic steel sheets 101 at an angle θ1. Therefore, the manufacturing cost can be reduced. Moreover, one tooth 20 is supported at a plurality of positions in a plurality of radial directions by a plurality of electromagnetic steel plates 201 on one end 20A (the other end 20B) side.

Sixth embodiment.
An example of the armature core 1 according to the sixth embodiment is the same as the armature core 1 shown in FIGS. Here, it protrudes from the electromagnetic steel plate 101 and contacts the electromagnetic steel plate 201. In other words, the protrusions 30 and 31 are provided on the back yoke 10. With such a structure, the teeth 20 do not need to be provided with the protrusions 30 and 31. Therefore, the length in the circumferential direction of each electromagnetic steel plate 201 corresponding to the portion 20b can be made equal to each other. Therefore, when the electromagnetic steel plates 201 are laminated in the radial direction, a portion corresponding to the portion 20b of the electromagnetic steel plates 201 can be used for the circumferential positioning of each electromagnetic steel plate 201, and the electromagnetic steel plates 201 are easily laminated.

Seventh embodiment.
FIG. 16 shows the core 1 for an electric element corresponding to one tooth 20 as viewed along the axial direction. In the illustration of FIG. 18, among the electromagnetic steel plates 201, three first to third electromagnetic steel plates 201a are in contact with only one electromagnetic steel plate 101a. In one electromagnetic steel plate 101a, the electromagnetic steel plates 201 other than the electromagnetic steel plate 201a are separated from each other in the circumferential direction.

  The first electromagnetic steel plate 201a is provided with projections 30a on both sides in the circumferential direction, and abuts with one electromagnetic steel plate 101 in the circumferential direction. The second electromagnetic steel plate 201a is provided with a protrusion 30a only at one end in the circumferential direction, and abuts with one electromagnetic steel plate 101a in the circumferential direction. The third electromagnetic steel plate 201a is also provided with a protrusion 30a only at one end in the circumferential direction, and is separated from one electromagnetic steel plate 101a in the circumferential direction.

  In such a configuration, the first and second electromagnetic steel plates 201a and 101a form a path around the axial direction, but the other end of the second electromagnetic steel plate 201a and the electromagnetic steel plate 101a are separated from each other. Therefore, the electrical resistance of such a path can be increased. Therefore, the eddy current flowing through such a path can be reduced. Similarly, although the first and third electromagnetic steel plates 201a and 101a form a path around the axial direction, the other end of the second electromagnetic steel plate 201a and the electromagnetic steel plate 101a are separated from each other. The eddy current flowing through such a path can be reduced.

  In short, in order to reduce the eddy current around the axial direction passing through the two electromagnetic steel plates 201 and one electromagnetic steel plate 101, the following requirements may be satisfied. That is, one end of any two electromagnetic steel plates and any one electromagnetic steel plate 101 need only be separated from each other in the circumferential direction.

  Moreover, in order to reduce the eddy current around the circumferential direction via the two electromagnetic steel plates and the two electromagnetic steel plates 101, the following requirements may be satisfied. That is, at least one of any two electromagnetic steel plates 101 and at least one of any two electromagnetic steel plates 201 may be separated from each other in the circumferential direction on one end side of the teeth 20. For example, in the illustration of FIG. 6, one of the electromagnetic steel plates 201b may be in contact with the electromagnetic steel plate 101a. Even with such a structure, the eddy current around the circumferential direction can be reduced.

DESCRIPTION OF SYMBOLS 1 Armature core 10 Back yoke 20 Teeth 30, 31, 30a, 30b, 31a, 31b Protrusion part 40 Reinforcement plate 50 Insulation member 101, 201 Electrical steel plate

Claims (9)

Each has a plurality of first steel plates (201) stacked in a radial direction around a predetermined axis (P), has both ends in a circumferential direction around the axis, and around the axis A plurality of teeth (20) arranged in a ring;
A plurality of second steel plates (101) laminated in the axial direction along the axis, and a plurality of holes into which the plurality of teeth are inserted and opened on at least one side in a radial direction centering on the axis And a perforated yoke (10),
On one end (20A) side of the one tooth in the circumferential direction, any one of the second steel plates that contacts the one tooth in the circumferential direction is the only one of the first steel plates and the The armature core that contacts in the circumferential direction and / or that contacts the yoke in the circumferential direction among the first steel sheets contacts only one of the second steel sheets in the circumferential direction. . The hole (11) opens only on one side in the radial direction, and the yoke (10) continues in the circumferential direction on the other side in the radial direction with respect to the teeth (20),
The one first steel plate contacts the one second steel plate in the circumferential direction on the one end (20A) side of the one tooth, and the one steel plate on the other end (20B) side of the one tooth. The armature core according to claim 1, wherein the first steel plate is spaced apart from the one second steel plate in the circumferential direction. The hole (11) opens only on one side in the radial direction, and the yoke (10) continues in the circumferential direction on the other side in the radial direction with respect to the teeth (20),
The teeth extend from the yoke to one side (A) in the axial direction,
The electric machine according to claim 1 or 2, wherein a portion of the second steel plate that is positioned on one side (A) in the axial direction is in contact with a portion of the first steel plate that is positioned on the other side of the radial direction. Child core. On the one end (20A) side of the one tooth (20a), the one second steel plate (101a) projects in the circumferential direction at a predetermined distance (R) from the shaft, and the one first steel plate ( 201 a) only, and on the one end (20B) side of the other one of the teeth (20b), the other second steel plate (101b) is separated from the shaft by the predetermined distance (R). Projecting in the direction and contacting only one of the first steel plates (201b) in the circumferential direction,
The other second steel plate is rotated around the axis at an angle formed by the one tooth and the other one of the teeth with respect to the axis. The core for armatures according to any one of claims 1 to 3 which has the same shape as two steel plates.   On the one end (20A) side of the one tooth (20), one second steel plate (101) contacts only one first steel plate (201), and the other second steel plate. The armature core according to claim 1, wherein is in contact with only the other first steel plate.   What contacts only one of the first steel plates (101) among the second steel plates (201) protrudes and contacts only one of the first steel plates in the circumferential direction, The armature core according to any one of claims 1 to 5. The teeth extend from the yoke to one side (A) in the axial direction,
An insulating portion (50) provided on the yoke (10) from the other side (B) in the axial direction;
The armature core according to any one of claims 1 to 6, further comprising a reinforcing plate (40) provided on the insulating portion (10) from the other side (B) in the axial direction. The teeth extend from the yoke to one side (A) in the axial direction,
A reinforcing plate (40) provided on the yoke (10) from the other side (B) in the axial direction and having higher strength than the teeth;
The armature core according to claim 1, wherein the teeth penetrate the yoke in the axial direction, and the teeth and the reinforcing plate are fixed to each other.   The armature core according to claim 8, wherein the reinforcing plate (40) is a non-magnetic material.

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