JP2020188675A - Rotating electric machine and method of manufacturing core - Google Patents

Abstract

To reduce loss of a rotating electric machine by making it difficult for an eddy current to occur in a welded portion of the rotating electric machine.SOLUTION: A rotating electric machine 10 comprises: a rotor 31 having magnets 40 on an outer circumferential portion thereof; a stator core 42 having a plurality of teeth 44 facing the outer circumferential portion of the rotor 31 with a gap therebetween; an electric insulator 45 that covers a portion of the surface of the stator core 42; and a plurality of coils 39 each wound around the stator core 42 via the electric insulator 45. The stator core 42 has a plurality of steel sheets 42A stacked in an axial direction 102. At least two of the steel sheets 42A that are adjacent to each other in the axial direction 102 are welded on a surface of the stator core 42 and at a position outside a closed magnetic circuit generated in the stator core 42. The steel sheets 42A are not welded on the surface of the stator core 42 at a position facing the rotor 31 of each tooth 44.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rotary electric machine which is an electric motor or a generator, and a method for manufacturing a core.

In an inner rotor type electric motor, the core of the stator is usually formed by laminating a plurality of steel plates. The mainstream structure is a structure in which a dovetailed portion is formed on each of the laminated steel sheets. The dowel-caulked portion is recessed from one surface of the steel sheet and protrudes from the other surface. A plurality of steel plates are connected to each other by fitting the dovetailed portions in the laminated direction.

JP-A-2018-11410

As the rotation speed of the electric motor increases, the torque required for the electric motor decreases. As a result, the physique of the electric motor can be reduced. As the rotation speed of the electric motor increases, the loss of the electric motor due to the eddy current generated in the steel plate increases. On the other hand, for example, when a thin steel plate having a thickness of 0.3 mm or less is used, the eddy current generated in the thickness direction of each steel plate can be reduced. However, it is difficult to form a dovetailed portion on a thin steel plate.

Instead of the dovetailed portion, it is conceivable to connect the laminated steel plates by welding with a laser or the like. However, since the adjacent steel plates are continuous in the thickness direction at the welded portion, the eddy current generated at the welded portion becomes large.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a means for reducing a loss of a rotary electric machine by making it difficult for an eddy current to be generated at a welded portion of the rotary electric machine.

(1) The rotary electric machine according to one aspect of the present invention is rotatable around an axis extending in the first direction, and has a plurality of rotors having a magnet on the outer peripheral portion and facing the outer peripheral portion of the rotor via a gap. A core having the teeth of the above, an insulator covering a part of the surface of the core, and a plurality of coils wound around the core via the insulator are provided. The core has a plurality of steel plates laminated in the first direction. Each of the plurality of steel sheets has a thickness of 0.3 mm or less in the first direction. Of the plurality of steel plates, at least two adjacent steel plates in the first direction are welded on the surface of the core at a position outside the closed magnetic circuit generated in the core. The plurality of steel plates are not welded on the outer surface of each of the teeth facing the rotor.

(2) The core includes a plurality of steel plate units having m sheets (where m is an integer of 2 or more) laminated in the first direction and bonded to each other by an adhesive. The steel plate units are laminated in the first direction, and steel plates located at the ends of the steel plate units in the first direction and adjacent to each other in the first direction are welded to each other.

(3) A resin mold that surrounds the portion of each tooth near the gap is further provided.

(4) The rotary electric machine according to another aspect of the present invention can rotate around an axis extending in the first direction, and has a rotor having a magnet on the outer periphery and an outer circumference of the rotor in a second direction intersecting the axis. A yoke separated from the portion and two teeth extending from both ends of the yoke in the third direction intersecting the first direction and the second direction and facing the outer peripheral portion of the rotor via a gap, respectively. Has three or more divided cores, three or more insulators covering each of the yokes, and three or more coils wound around the yoke via each of the insulators. I have. Each of the divided cores has a plurality of steel plates laminated in the first direction. Each of the plurality of steel sheets has a thickness of 0.3 mm or less in the first direction. Of the plurality of steel plates, at least two adjacent steel plates in the first direction are positions outside the closed magnetic circuit generated in the divided core on the surface of the divided core, and the end of the yoke in the third direction. It is welded at the welded part. The plurality of steel plates are not welded on the outer surface of each of the teeth facing the rotor.

(5) Each of the divided cores has three or more steel plate units having m sheets (where m is an integer of 2 or more) laminated in the first direction and bonded to each other by an adhesive. I have. The three or more steel plate units are laminated in the first direction. In each of the steel plate units, the steel plates located at the end in the first direction and adjacent to each other in the first direction are welded at the welded portion. One and the other of the two welds adjacent to each other in the first direction are at one end and the other end of the yoke in the third direction.

(6) Each tooth has a plane extending along the second direction from both ends of the yoke in the third direction to the gap.

(7) The rotary electric machine further includes a resin mold surrounding each of the above-mentioned teeth on the extending end side of each of the above-mentioned teeth.

(8) Another aspect of the present invention is a method for manufacturing a core, which includes a welding step of laminating and welding a plurality of steel plates having a planar shape of the core in the first direction. The welded body produced in the welding step has a yoke and a teeth extending from the yoke in a second direction intersecting the first direction. In the welding step, at least two of the plurality of steel plates adjacent to each other in the first direction are welded on the surface of the yoke at a position outside the closed magnetic circuit generated in the yoke, and welded in the teeth. Not done. Further, the manufacturing method includes a step of covering the surface of the welded body with an insulator, and a jig is attached to a portion of the tooth near the tooth tip to fix the portion of the tooth near the tooth tip in the first direction. In the state, the step of winding a metal wire around the insulator is included.

According to the present invention, it is possible to reduce the loss of the rotary electric machine by making it difficult for an eddy current to be generated at the welded portion of the rotary electric machine.

FIG. 1 is a schematic view showing the configurations of a rotary electric machine 10 and a controller 37 according to an embodiment of the present invention. FIG. 2 is a schematic view of the cross section of the rotary electric machine 10 along the line II-II of FIG. 1 when viewed from the axial direction 102. FIG. 3 is a schematic view showing the arrangement of the magnet 40 of FIG. 1 and the magnetic field distribution in the stator core 42. FIG. 4 is a schematic view showing an example of the closed magnetic circuit 42C in the stator core 42. FIG. 5 is a schematic view showing a manufacturing process of the stator core 42. FIG. 6 is a schematic view showing a modified example of the stator 33. FIG. 7 is a schematic view of the split core 71 of FIG. 6 when viewed from the centrifugal direction 111.

Hereinafter, the rotary electric machine 10 according to the embodiment of the present invention will be described. It goes without saying that the embodiments described below are merely examples of the present invention, and the embodiments can be appropriately changed without changing the gist of the present invention.

[Rough configuration of rotary electric machine 10]
As shown in FIG. 1, the rotary electric machine 10 is an electric motor, and more specifically, an inner rotor type brushless motor 30. The brushless motor 30 includes a rotor 31, a shaft 32, a stator 33, and the like inside the housing 36. The brushless motor 30 is electrically connected to the controller 37 via the harness 38. The controller 37 applies an AC voltage of either U phase, V phase, or W phase to each of the 12 coils 39 of the brushless motor 30 via the harness 38.

[Rotor 31]
In FIGS. 1 and 2, the rotor 31 is rotatable about the axis 104. The axis 104 is indicated by a alternate long and short dash line in FIG. The axial direction 102 in which the axis 104 extends is an example of the first direction. The rotor 31 includes a rotor core 49. The rotor core 49 is a laminated body in which a plurality of thin steel plates having a substantially annular shape are laminated in the axial direction 102. Specifically, the steel plate is an electromagnetic steel plate. The rotor core 49 has a substantially cylindrical shape, and has an outer peripheral surface 53 (an example of an outer peripheral portion) and an inner peripheral surface 55. The outer peripheral surface 53 and the inner peripheral surface 55 are substantially cylindrical surfaces having different diameters from each other. The outer peripheral surface 53 and the inner peripheral surface 55 share an axis 104 as a central axis. The inner peripheral surface 55 partitions the through hole 54.

As shown in FIG. 2, the rotor 31 has eight magnets 40. Each magnet 40 is a permanent magnet. The eight magnets 40 are arranged on the rotor core 49 at equal angular intervals in the circumferential direction 105 about the axis 104 when viewed from the axial direction 102. More specifically, the eight magnets 40 are arranged so that the north and south poles alternately appear on the outer peripheral surface 53 in the circumferential direction 105 (see FIG. 2) and are exposed from the outer peripheral surface 53 (FIG. 2). 3). The eight magnets 40 have the same shape as each other, and have a length extending to both end faces in the axial direction 102 in the rotor 31 (see FIG. 1).

[Shaft 32]
As shown in FIG. 1, the shaft 32 is a member having a cylindrical shape longer than the rotor 31 in the axial direction 102. The shaft 32 has substantially the same diameter as the diameter of the through hole 54 formed in the rotor core 49. The shaft 32 is inserted into the through hole 54. Both ends of the shaft 32 project from the through hole 54 in the axial direction 102. In the state of being inserted in this way, the shaft 32 is fixed to the inner peripheral surface 55 of the rotor core 49. The shaft 32 is supported by the housing 36 via two bearings 52 provided in the housing 36 on both sides in the axial direction 102. As a result, the shaft 32 can rotate with respect to the housing 36 in the circumferential direction 105 together with the rotor 31. One end of the shaft 32 in the axial direction 102 protrudes from the housing 36 in the axial direction 102.

[Rough configuration of stator 33]
As shown in FIGS. 1 and 2, the stator 33 includes a stator core 42 (an example of a core), 12 electrical insulators 45 (an example of an insulator), and 12 coils 39. Note that FIG. 2 shows only three electrical insulators 45 and one coil 39.

[Stator core 42]
The stator core 42 is arranged so as to surround the outer peripheral surface 53 of the rotor 31, and generally has a tubular shape. Inside the stator core 42, a closed magnetic circuit 42C is formed from the north pole to the south pole (see FIG. 4) on the outer peripheral surface 53. Note that FIG. 4 shows only two closed magnetic circuits 42C. The stator core 42 has a stator yoke 43 and 12 teeth 44. In addition, in FIG. 2 and FIG. 3, reference numeral 44 is attached to only one tooth.

The stator yoke 43 has a tubular shape, and has an outer peripheral surface 61 and an inner peripheral surface 62. The outer peripheral surface 61 and the inner peripheral surface 62 are substantially cylindrical surfaces having different diameters from each other. The outer peripheral surface 61 and the inner peripheral surface 62 share an axis 104 as a central axis. The inner peripheral surface 62 has a diameter larger than that of the outer peripheral surface 53 of the rotor 31.

The twelve teeth 44 have the same shape as each other. The twelve teeth 44 are arranged on the inner peripheral surface 62 at equal angular intervals in the circumferential direction 105 when viewed from the axial direction 102. Each tooth 44 extends from the inner peripheral surface 62 toward the axis 104 in the extending direction 108 parallel to the radial direction 103. The radial direction 103 is a direction orthogonal to the axis 104. Note that FIG. 2 and the like show only one example of the radial direction 103. The extension direction 108 is an example of the second direction. In addition, in FIGS. 2 to 4, only one arrow indicating the extension direction 108 is shown. The extending end of each tooth 44 is the tooth tip surface 44A. Each tooth tip surface 44A is separated from the outer peripheral surface 53 of the rotor 31 and each magnet 40. That is, each tooth 44 faces the outer peripheral surface 53 of the rotor 31 via a gap. In addition, in FIG. 2 and FIG. 3, reference numeral 44A is attached only to one tooth tip surface.

In FIG. 2, a part of the stator core 42 when the cross section along the alternate long and short dash line IIB-IIB is viewed from the direction of the arrow 106 is schematically shown in the frame 107 of the alternate long and short dash line. As shown in the frame 107, the stator core 42 is a laminated body in which a plurality of steel plates 42A (specifically, electromagnetic steel plates) are laminated in the axial direction 102. Each steel plate 42A preferably has a thickness of 0.3 mm or less in the axial direction 102. The two adjacent steel plates 42A in the plurality of steel plates 42A are welded at the welded portion 42B by a laser or the like. The two adjacent steel plates 42A are two steel plates 42A adjacent to each other in the axial direction 102.

As shown in the frame 107, the welded portion 42B is a position on the surface of the steel plate 42A which is the outer peripheral surface 61 of the surface of the stator core 42. Further, as shown in FIG. 4, the welded portion 42B is the position of the steel plate 42A on the surface of the stator core 42, which is outside the closed magnetic circuit 42C generated in the stator core 42. Further, as shown in the frame 107, the plurality of steel plates 42A are not welded at a position on the surface of the stator core 42 which is the surface of the teeth 44. More specifically, the plurality of steel plates 42A are not welded at positions facing the outer peripheral surface 53 of the rotor 31 and becoming the tooth tip surface 44A in each tooth 44.

As shown in FIG. 2, the welded portion 42B is also a position on the surface of the steel plate 42A where the virtual line 109 intersects the outer peripheral surface 61 of the stator yoke 43 (an example of the outer surface of the core). The virtual line 109 is a line that intersects the tooth tip surface 44A of each tooth 44 and is parallel to the radial direction 103 and the extension direction 108. The virtual line 109 is also the alternate long and short dash line IIB-IIB in FIG. More specifically, the virtual line 109 intersects the center of the tooth tip surface 44A in the circumferential direction 105.

As shown in the frame 107 of FIG. 2, a part of the adjacent steel plates 42A included in the plurality of steel plates 42A is welded by a laser or the like, and the remaining adjacent steel plates 42A are adhered by the adhesive 42D.

As shown in the frame 107 of FIG. 2, the stator core 42 includes a plurality of steel plate units 42E. Each steel plate unit 42E is composed of m steel plates 42A laminated in the axial direction 102 and bonded with an adhesive 42D. In the present embodiment, when m = 3, that is, three steel plates 42A are bonded by the adhesive 42D to form one steel plate unit 42E. In this embodiment, three steel plate units 42E are laminated in the axial direction 102. In each steel plate unit 42E, the steel plates 42A located at the end in the axial direction 102 and adjacent to each other in the axial direction 102 are welded at the welded portion 42B.

As shown in FIG. 2, the stator core 42 has 12 divided cores 42F divided for each tooth 44. In FIGS. 2 and 3, reference numeral 42E is attached only to the three divided cores. The split position is a position where the virtual surfaces 110 intersect in the stator yoke 43. The virtual surface 110 is a virtual plane that passes through an intermediate position between two teeth 44 adjacent to each other in the circumferential direction 105 and an axis 104. In FIGS. 2 and 3, only one virtual surface 110 is shown. One tooth 44 extends from the inner peripheral surface 62 of each divided core 42F. Further, the two divided cores 42F adjacent to each other in the circumferential direction 105 are adhered by an adhesive (not shown) or the like.

[Electrical Insulator 45]
The 12 electrical insulators 45 cover a part of the surface of the stator core 42. Each of the twelve electrical insulators 45 covers a portion of each of the twelve teeth 44. Each electrical insulator 45 covers a portion of the surface of the corresponding tooth 44 excluding the tooth tip surface 44A. Each electric insulator 45 also covers a part of the inner peripheral surface 62 of the stator yoke. In each electric insulator 45, both ends in the radial direction 103 are longer in the circumferential direction 105 than the intermediate portion between the both ends. This prevents the coil 39 wound around the intermediate portion from coming off the teeth 44. Each electrical insulator 45 is realized by a resin mold that is fixed to the corresponding teeth 44. The resin mold is a molded product of a resin having electrical insulation.

[Coil 39]
As shown in FIG. 2, each coil 39 is wound around each tooth 44 via an electrical insulator 45. Specifically, each coil 39 is wound around an intermediate portion of the electric insulator 45. A U-phase, V-phase, and W-phase AC voltage is applied to each coil 39 by the controller 37 (see FIG. 1). A rotating magnetic field is formed in the space surrounded by the twelve teeth 44. As a result, the rotor 31 rotates.

[Manufacturing method of stator core 42]
Hereinafter, a method of manufacturing the stator core 42 will be described with reference to FIG. The manufacturing method includes a laminating step, a molding step, a welding step and the like.

In the laminating process, a plurality of steel plates are bonded and laminated with an adhesive. The details of the laminating process are as follows.

As shown in FIG. 5, three winding coils 21A are set in the feeder 21. The feeding device 21 is not limited to the three winding coils 21A, and a plurality of winding coils 21A may be set. A strip-shaped steel plate having a thickness of 0.3 mm or less is wound around each winding coil 21A. The feeding device 21 feeds the three strips to the roller pair 23 in a state where the positions of the three strips are aligned in the width direction. A coating device 22 is arranged between the feeding device 21 and the roller pair 23. The coating device 22 applies an adhesive such as an epoxy resin adhesive to the adhesive surfaces of the three strip-shaped steel plates. The roller pair 23 pressurizes the three strip-shaped steel plates fed to the roller pair 23 from the front surface side and the back surface side. As a result, the three strip-shaped steel plates are bonded and laminated in the direction orthogonal to the respective surfaces.

In the molding step, a plurality of laminated strip-shaped steel plates (hereinafter referred to as a laminated body of strip-shaped steel plates) are punched into a predetermined shape corresponding to the split core 42F having the teeth 44 to produce a steel plate unit 44E. The details of the molding process are as follows.

The laminated body of the strip-shaped steel plate is set in the press forming apparatus 25 and conveyed in the press forming apparatus 25. The press forming apparatus 25 is a die corresponding to a predetermined shape, and repeatedly punches a laminated body of strip-shaped steel plates. As a result, the press forming apparatus 25 manufactures a plurality of steel plate units 44E.

In the welding process, a plurality of steel plate units 44E are laminated and welded to each other. The details of the welding process are as follows.

The plurality of steel plate units 44E are laminated in the press forming apparatus 25 so as to form the shape of the divided core 42F. The welding device 26 is provided in the press forming device 25 and welds the welded portion 42B in the split core 42F. In the welding process, 12 divided cores 42F are produced.

The molding process and the welding process are repeated to produce 12 divided cores 42F.

Further, 12 electric insulators 45 are manufactured by a molding device (not shown). The 12 electrical insulators 45 are attached to the 12 welds one by one. Further, a jig is attached to the portion of each welded body that becomes the tooth tip surface 44A. As a result, it is possible to prevent the tooth tip surfaces 44A side of the plurality of steel plate units 44E included in each welded body from opening. Each of the welds to which the jig is attached is set in the coil winding device. The coil winding device winds a metal wire around each electrical insulator 45. As a result, 12 divided cores 42F in which the coil 39 is wound are produced. Twelve split cores 42F are completed. The 12 split cores 42F are joined together in the circumferential direction 105 with an adhesive or the like. As a result, the stator 33 is completed.

[Action and effect of rotary electric machine 10]
In the rotary electric machine 10 (that is, the brushless motor 30), welding is performed at the welded portion 42B of the plurality of steel plates 42A. The plurality of steel plates 42A are not welded on the surface of the stator core 42 at positions facing the outer peripheral surface 53 of the rotor 31 of each tooth 44. The welded portion 42B is located outside the closed magnetic circuit 42C generated in the stator core 42 or outside the closed magnetic circuit 42C. In the stator core 42, the magnetic flux density becomes smaller at the welded portion 42B and the surrounding portion (see the hatched portion in FIG. 3). Therefore, all or most of the magnetic flux passing through the stator core 42 (that is, the closed magnetic circuit 42C (see FIG. 4)) avoids each welded portion 42B. In other words, the welded portion 42B is a position where the density of the magnetic flux generated in the stator core 42 is relatively small while the rotor 31 rotates around the axis 104. As a result, eddy currents are less likely to be generated at the welded portion 42B of the rotary electric machine 10 (that is, the brushless motor 30), and the loss of the rotary electric machine 10 can be reduced. According to the rotary electric machine 10, by welding at the welded portion 42B, the efficiency of the rotary electric machine 10 is improved because the eddy current loss does not become excessively large even at high speed rotation (for example, 5000 rpm or more).

In the stator core 42, not all the steel plates 42A are welded. Further, the stator core 42 includes a plurality of steel plate units 42E. Therefore, the number of welded portions 42B in the stator core 42 can be relatively reduced. As a result, the magnetic flux generated from the magnet 40 is suppressed from passing through the welded portion 42B.

In the press molding process, one strip-shaped steel plate is not punched to produce the steel plate 42A one by one, but a plurality of strip-shaped steel plates are punched to produce the steel plate unit 42E. As a result, the number of punches when the stator core 42 is manufactured is suppressed.

The electric insulator 45 is a resin mold fixed to each tooth 44. The electric insulator 45 prevents the tooth tip surfaces 44A side of the plurality of steel plate units 44E from opening together with the jig in the manufacturing process of the stator core 42. In this state, since the coil 39 is wound around each electric insulator 45, it is possible to prevent the tooth tip surfaces 44A side of the plurality of steel plate units 44E from opening even in the finished product of the stator core 42.

Since the stator core 42 has three or more split cores 42F, more stator cores 42 can be manufactured from the strip-shaped steel plate as compared with the case where the stator core 42 does not have the split core 42F.

[Modification example]
Next, a modified example of the stator 33 will be described with reference to FIG. In the following description of the modified example of the stator 33, the differences from the above-described embodiment will be described.

As shown in FIG. 6, the stator 33 includes four split cores 71 (another example of cores), four electrical insulators 72, and four coils 73.

The four split cores 71 have the same shape as each other. The four divided cores 71 are arranged around the outer peripheral surface 53 of the rotor 31 at equal angular intervals in the circumferential direction 105 when viewed from the axial direction 102. Except for this point, each split core 71 has a configuration similar to each other. Therefore, in the following, one divided core 71 will be described as a representative. The split core 71 has a stator yoke 81 and two teeth 82. The stator yoke 81 is an example of a yoke.

The stator yoke 81 is arranged at a position separated from a predetermined position P1 on the outer peripheral surface 53 of the rotor 31 in the centrifugal direction 111. The predetermined position P1 is a position on the outer peripheral surface 53 at one point in the circumferential direction 105. The centrifugal direction 111 is a direction from the axis 104 toward the predetermined position P1, and is another example of the second direction. The stator yoke 81 extends in the tangential direction 112 and the axial direction 102 at a predetermined position P1 on the outer peripheral surface 53. The tangential direction 112 is another example of the third direction. The stator yoke 81 has a length shorter than the diameter of the outer peripheral surface 53 in the tangential direction 112.

One and the other of the two teeth 82 extend from one end and the other end of the stator yoke 81 in the tangential direction 112 toward the outer peripheral surface 53 of the rotor 31 in parallel with the centrifugal direction 111, respectively. The extending end of each tooth 82 is the tooth tip surface 82A. Each tooth tip surface 82A is separated from the outer peripheral surface 53 of the rotor 31 and each magnet 40. That is, each tooth 82 faces the outer peripheral surface 53 via a gap.

The two teeth 82 are surrounded by two resin molds 74 at positions closer to the tooth tip surface 82A than the electrical insulator 72. This prevents the tooth tip surface 82A side of the teeth 82 from opening.

In FIG. 6, the split core 71 when viewed from the tangential direction 112 is schematically shown in the frame 113 of the alternate long and short dash line. As shown in the frame 113, the split core 71 is a laminated body in which a plurality of steel plates 71A (specifically, electromagnetic steel plates) are laminated in the axial direction 102. More specifically, of the plurality of steel plates 71A, the combination of m steel plates 71A connected in the axial direction 102 constitutes the steel plate unit 71C. In this modification, when m = 3, that is, three steel plates 71A are bonded by the adhesive 71D to form one steel plate unit 71C. Each steel plate 71A has a different shape from each steel plate 42A, and the steel plate 71A located at the end of each steel plate unit 71C in the axial direction 102 and adjacent to the axial direction 102 (hereinafter, may be referred to as an adjacent steel plate 71A). It has a structure similar to that of each steel sheet 42A, except that the steel sheets are welded to each other at the welded portion 71B.

As shown in the frame 113, each welded portion 71B is the position of the steel plate 71A on the surface of the split core 71, which is outside the closed magnetic circuit generated in the split core 71. Further, as shown in the frame 113, the plurality of steel plates 71A are not welded at positions facing the outer peripheral surface 53 of the rotor 31 and becoming the tooth tip surface 82A in each tooth 82. Each weld 71B is at the end of the stator yoke 81 in the tangential direction 112. Further, as shown in FIG. 7, the plurality of welded portions 71B are arranged in a staggered pattern in a plan view from the centrifugal direction 111. Specifically, one of the two adjacent welds 71B in the axial direction 102 is at one end of the stator yoke 81 in the tangential direction 112, and the other is at the other end of the stator yoke 81 in the tangential direction 112.

As shown in FIG. 6, the four coils 73 are wound around the four stator yokes 81 one by one. The coil 73 and the stator yoke 81 are electrically separated by an electrical insulator 72.

In the above modified example, a plurality of welded portions 71B were arranged in a staggered pattern (see FIG. 7). However, the present invention is not limited to this, and the plurality of welded points 71B may be one end or the other end in the tangential direction 112 of the stator yoke 81. In addition, the adjacent steel plates 71A may be welded to each other at both ends (one end and the other end) of the stator yoke 81 in the tangential direction 112.

[Other variants]
In the embodiment, the rotary electric machine 10 is an electric motor, but may be a generator.

In the embodiment, the outer peripheral surface 53 of the rotor core 49 has a substantially cylindrical shape. Not limited to this, the outer peripheral surface 53 may have a regular polygonal prism shape.

In the embodiment, the rotor core 49 is arranged with eight magnetic poles by eight magnets 40. Not limited to this, two magnetic poles may be arranged on the rotor core 49.

In the embodiment, the rotor 31 is a surface magnet type (SPM type). That is, each magnet 40 was attached to the outer peripheral surface 53 and exposed from the outer peripheral surface 53. However, the present invention is not limited to this, and the rotor 31 may be an embedded magnet type (IPM type). That is, each magnet 40 may be embedded in the rotor core 49 along the outer peripheral surface 53 in a state slightly separated from the outer peripheral surface 53. "Having magnets on the outer peripheral portion" means that each magnet 40 is arranged on the outer peripheral surface 53 in a state of being exposed from the rotor core 49 (SPM type), and the outer peripheral surface 53 in a state where each magnet 40 is not exposed from the rotor core 49. It is a concept including a form (IPM type) arranged along the above.

In the embodiment, the stator 33 includes 12 sets of electrical insulators 45 and coils 39, and the stator core 42 includes 12 teeth 44. Not limited to this, the stator 33 may include three or more sets of the electric insulator 45, the coil 39, and the teeth 44.

In the embodiment, a part of the adjacent steel plates 42A was welded, and the remaining adjacent steel plates 42A were bonded by the adhesive 42D. Not limited to this, all adjacent steel plates 42A may be welded.

In the embodiment, the stator core 42 has 12 split cores 42F. Not limited to this, the number of divided cores 42F may be three or more.

10 ... Rotating machine 30 ... Brushless motor 31 ... Rotor 40 ... Magnet 42 ... Stator core (core)
42A ・ ・ ・ Steel plate 42C ・ ・ ・ Closed magnetic circuit 42E ・ ・ ・ Steel plate unit 42F ・ ・ ・ Divided core 44 ・ ・ ・ Teeth 45 ・ ・ ・ Electrical insulator (insulator)
39 ... Coil

Claims (8)

A rotor that is rotatable around an axis extending in the first direction and has a magnet on the outer circumference.
A core having a plurality of teeth facing the outer peripheral portion of the rotor via a gap,
An insulator that covers a part of the surface of the core,
It comprises a plurality of coils wound around the core via the insulator.
The core has a plurality of steel plates laminated in the first direction.
Each of the plurality of steel sheets has a thickness of 0.3 mm or less in the first direction.
Of the plurality of steel plates, at least two adjacent steel plates in the first direction are welded on the surface of the core at a position outside the closed magnetic circuit generated in the core.
The plurality of steel plates are rotary electric machines that are not welded on the outer surface of each of the teeth facing the rotor. The above core is
A plurality of steel plate units having the above steel plates of m sheets (where m is an integer of 2 or more) laminated in the first direction and bonded to each other by an adhesive are provided.
The first aspect of the present invention, wherein the steel plate units are laminated in the first direction, and steel plates located at the end of the first direction in each steel plate unit and adjacent to each other in the first direction are welded to each other. Rotating electric machine. The rotary electric machine according to claim 1 or 2, further comprising a resin mold that surrounds a portion of each tooth near the gap. A rotor that is rotatable around an axis extending in the first direction and has a magnet on the outer circumference.
A yoke separated from the outer peripheral portion of the rotor in the second direction intersecting the axis, and an outer peripheral portion of the rotor extending from both ends of the yoke in the third direction intersecting the first direction and the second direction. Two teeth facing each other through a gap, and three or more split cores, each of which has
With three or more insulators covering each of the above yokes,
It comprises three or more coils wound around the yoke via each of the insulators.
Each of the divided cores has a plurality of steel plates laminated in the first direction.
Each of the plurality of steel sheets has a thickness of 0.3 mm or less in the first direction.
Of the plurality of steel plates, at least two adjacent steel plates in the first direction are positions outside the closed magnetic circuit generated in the divided core on the surface of the divided core, and the end of the yoke in the third direction. It is welded at the welded part that is
The plurality of steel plates are rotary electric machines that are not welded on the outer surface of each of the teeth facing the rotor. Each of the divided cores includes three or more steel plate units having m (where m is an integer of 2 or more) of the above steel plates laminated in the first direction and bonded to each other by an adhesive.
The three or more steel plate units are laminated in the first direction.
In each of the steel plate units, the steel plates located at the end in the first direction and adjacent to each other in the first direction are welded at the welded portion.
The rotary electric machine according to claim 4, wherein one and the other of the two welded portions adjacent to each other in the first direction are at one end and the other end of the yoke in the third direction. The rotary electric machine according to claim 4 or 5, wherein each of the teeth has a plane extending along the second direction from both ends of the yoke in the third direction to the gap. The rotary electric machine according to any one of claims 4 to 6, further comprising a resin mold surrounding each of the above-mentioned teeth on the extending end side of each of the above-mentioned teeth. It ’s a core manufacturing method.
Including a welding step of laminating and welding a plurality of steel plates having a planar shape of the core in the first direction.
The welded body created in the welding step has a yoke and a tooth extending from the yoke in the second direction intersecting the first direction.
In the welding step, at least two of the plurality of steel plates adjacent to each other in the first direction are welded on the surface of the yoke at a position outside the closed magnetic circuit generated in the yoke, and welded in the teeth. not,
The above manufacturing method further
The process of covering the surface of the welded body with an insulator and
This includes a step of winding a metal wire around the insulator in a state where a jig is attached to a portion of the tooth near the tooth tip and the portion of the tooth near the tooth tip is fixed in the first direction. , How to make the core.

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