Magnetic body core, coil-provided magnetic body core, rotary electric machine, and brushless motor

Abstract

This magnetic body core is for use in a rotary electric machine and comprises a tooth part having a shape extending in a first direction. The tooth part includes a wound part around which a coil is wound. The wound part has: a first protruding corner which the coil passes in the process of being wound; a first contact surface with which the coil comes into contact before the coil passes the first protruding corner and which has, as seen from the first direction, a shape curved so as to protrude in a second direction; a first non-contact surface with which the coil does not come into contact and of which the boundary with respect to the first contact surface is the first protruding corner; and a second contact surface with which the coil comes into contact after the coil passes the first protruding corner and which has, as seen from the first direction, a shape curved so as to protrude in a third direction different from the second direction.

Description

Magnetic core, magnetic core with coil, rotating electrical machine and brushless motor

[0001] The present invention relates to a magnetic core, a magnetic core with a coil, a rotating electric machine, and a brushless motor.

[0002] A known example of a conventional invention relating to a magnetic core is the magnetic core described in Patent Document 1. The magnetic core described in Patent Document 1 includes teeth. Coils are wound around the teeth. An insulating coating is formed on the surface of the coil. The teeth have a rectangular shape when viewed in the direction in which the teeth extend. When the coils are wound around the teeth, the insulating coating formed on the surface of the coil contacts the four vertices of the teeth.

[0003] Japanese Patent Application Laid-Open No. 2006-158176

[0004] In the magnetic core described in Patent Document 1, the insulating coating formed on the surface of the coil comes into contact with the four vertices of the teeth, which can cause stress to concentrate at the contact points with the vertices of the insulating coating, potentially damaging the insulating coating and reducing the electrical insulation between the magnetic core and the coil.

[0005] Therefore, the object of the present invention is to provide a magnetic core, a magnetic core with a coil, a rotating electric machine, and a brushless motor that can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil.

[0006] The inventors of the present application considered cases in which electrical insulation between the magnetic core and the coil is reduced due to damage to the insulating coating formed on the surface of the coil, and realized that in the magnetic core described in Patent Document 1, the teeth can be elliptical or circular when viewed in the direction in which the teeth extend. By making the teeth elliptical or circular when viewed in the direction in which the teeth extend, the teeth do not have vertices. This allows the bending angle of each part of the coil to be greater than 90 degrees, and reduces stress concentration in part of the insulating coating formed on the surface of the coil.

[0007] Next, the inventors of the present application investigated a method for manufacturing teeth that are elliptical or circular when viewed in the direction in which the teeth extend. When manufacturing teeth that are elliptical or circular when viewed in the direction in which the teeth extend using the manufacturing method described in Patent Document 1, it is necessary to make the shape of the lower end surface of punch 201 described in Patent Document 1 (hereinafter referred to as the upper punch) semi-elliptical or semi-circular and curved so as to protrude upward, and to make the shape of the upper end surface of punch 202 described in Patent Document 1 (hereinafter referred to as the lower punch) semi-elliptical or semi-circular and curved so as to protrude downward.

[0008] When the shape of the teeth is made elliptical or circular when viewed in the direction in which the teeth extend, ideally, the lower end face of the upper punch is curved in a semi-elliptical or semi-circular shape over the entire area so that no flat portions remain at either end, and the upper end face of the lower punch is curved in a semi-elliptical or semi-circular shape over the entire area so that no flat portions remain at either end.

[0009] However, in reality, due to processing accuracy and mold strength issues, flat portions remain on both ends of the lower end surface of the upper punch and the upper end surface of the lower punch. Therefore, when teeth are formed using the upper and lower punches, convex portions are formed on the teeth, sandwiched between the upper and lower flat portions. When a coil is wound around the teeth, these convex portions can damage the insulating coating of the coil, thereby reducing the electrical insulation between the teeth and the coil.

[0010] Based on the above findings, the inventors of the present invention have investigated a magnetic core that can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil, and have come up with the following invention.

[0011] A magnetic core according to one embodiment of the present invention is a magnetic core used in a rotating electric machine, comprising teeth portions having a shape extending in a first direction, the teeth portions including a wound portion around which a coil is wound, the wound portion having: a first convex angle through which the coil passes during winding; a first contact surface with which the coil comes into contact before passing through the first convex angle, the first contact surface having a shape curved so as to protrude in a second direction when viewed in the first direction; a first non-contact surface with which the coil does not come into contact, the boundary with the first contact surface being the first convex angle; and a second contact surface with which the coil comes into contact after passing through the first convex angle, the second contact surface having a shape curved so as to protrude in a third direction different from the second direction when viewed in the first direction.

[0012] a second contact surface with which the coil comes into contact after passing through the first salient angle; a first non-contact surface with which the coil does not come into contact, the first non-contact surface being provided between the first contact surface and the second contact surface, the first non-contact surface having the first salient angle as its boundary with the second contact surface; a second salient angle different from the first salient angle, the second salient angle through which the coil passes after passing through the second contact surface; and a third contact surface with which the coil comes into contact after passing through the second salient angle, the third contact surface being a third contact surface with which the coil comes into contact after passing through the second salient angle, the third contact surface being a third contact surface with which the coil comes into contact after passing through the second salient angle, the a second non-contact surface that is different from the first non-contact surface, that is provided between the second contact surface and the third contact surface, that does not come into contact with the coil, and whose boundary with the second contact surface is the second convex angle.

[0013] According to the present invention, it is possible to provide a magnetic core, a magnetic core with a coil, a rotating electric machine, and a brushless motor that can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil.

[0014] FIG. 1 is a perspective view of a magnetic core 1 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the magnetic core 1 as viewed from a first direction DIR1. FIG. 3 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 1. FIG. 4 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 1. FIG. 5 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 1. FIG. 6 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 1. FIG. 7 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 1. FIG. 8 is an external perspective view of a brushless motor 100 in which the magnetic core 1 is used. FIG. 9 is an exploded perspective schematic diagram of a brushless motor 100 using the magnetic core 1. FIG. 10 is a cross-sectional view of a magnetic core 6 according to a comparative example, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 11 is a cross-sectional view of a magnetic core 1a, viewed from the first direction DIR1. FIG. 12 is a cross-sectional view of a magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 13 is a cross-sectional view of a magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 14 is a cross-sectional view of a magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 15 is a cross-sectional view of a magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 16 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body 31. Fig. 17 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body 31. Fig. 18 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body 31. Fig. 19 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body 31.Fig. 20 is a cross-sectional view of magnetic core 1a as viewed from the first direction DIR1, showing the process of winding coil 13 around tooth main body portion 31. Fig. 21 is a cross-sectional view of magnetic core 1b as viewed from the first direction DIR1.

[0015] [First Embodiment] (Configuration of Magnetic Core 1) FIG. 1 is a perspective view of a magnetic core 1 according to a first embodiment of the present invention. As shown in FIG. 1, the magnetic core 1 includes a core back portion 2 and teeth portions 3. The teeth portions 3 extend from the core back portion 2 in the first direction DIR1. In this embodiment, the teeth portions 3 include teeth main portions 31 extending from the core back portion 2 in the first direction DIR1 and teeth tip portions 32 formed at the tips of the teeth main portions 31 in the first direction DIR1. The teeth main portions 31 are portions around which the coil 13 is wound and correspond to the "wound portion" of the present invention. The magnetic core 1 of this embodiment is used in a brushless motor 100 (an example of a "rotating electric machine" of the present invention; see FIGS. 8 and 9 ), which will be described later. When magnetic core 1 is incorporated into brushless motor 100, first direction DIR1 faces in the opposite radial direction centered on the rotation axis of brushless motor 100. This will be described in detail below.

[0016] Fig. 2 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1. Fig. 3 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 4 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 5 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 6 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 7 is a cross-sectional view of the magnetic core 1 as viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31.

[0017] The magnetic core 1 is made of a soft magnetic material. When an external magnetic field is applied to the soft magnetic material, the soft magnetic material is magnetized. When the application of the magnetic field is stopped, the soft magnetic material loses its magnetization. An example of a material for such a soft magnetic material is iron.

[0018] The magnetic core 1 is a molded body formed from soft magnetic powder. That is, each of the core back portion 2 and the teeth portion 3 is a molded body formed from soft magnetic powder. The material of the soft magnetic powder includes, for example, iron and a binder. The binder is, for example, resin. The soft magnetic powder is, for example, a mixture of iron powder and epoxy resin, which is an example of a binder. Such a magnetic core 1 is produced, for example, by press molding. Furthermore, an insulating treatment is applied to the outer surface of the magnetic core 1, which comes into contact with other components when the magnetic core 1 is incorporated into the brushless motor 100.

[0019] 1, the core back portion 2 has a first main surface S1 and a second main surface S2 aligned in a first direction DIR1. The second main surface S2 is positioned further in the first direction DIR1 than the first main surface S1. Each of the first main surface S1 and the second main surface S2 has a rectangular shape when viewed in the first direction DIR1.

[0020] As shown in FIG. 1 , the tooth body portion 31 extends from the second main surface S2 of the core back portion 2 in the first direction DIR1.

[0021] As shown in FIG. 2, the tooth body portion 31 has a first contact surface CS1, a first convex angle A1, a first non-contact surface NCS1, a second contact surface CS2, a second convex angle A2, and a second non-contact surface NCS2.

[0022] As shown in FIG. 2 , the first contact surface CS1 has a curved shape that protrudes in the second direction DIR2. More specifically, the first contact surface CS1 has a semi-elliptical shape when viewed in the first direction DIR1. Note that a semicircular shape is included in the semi-elliptical shape. In this embodiment, the first contact surface CS1 has a semi-circular shape when viewed in the first direction DIR1. Therefore, when viewed in the first direction DIR1, the first contact surface CS1 is part of a circle with a radius RCS1 centered at the center OCS1. Note that the second direction DIR2 is orthogonal to the first direction DIR1. Furthermore, the second direction DIR2 is a direction along the rotation axis of the brushless motor 100 when the magnetic core 1 is incorporated into the brushless motor 100.

[0023] As shown in Fig. 2, the first non-contact surface NCS1 is a plane facing the third direction DIR3. That is, the normal direction of the first non-contact surface NCS1 is the third direction DIR3. The third direction DIR3 is a direction perpendicular to the first direction DIR1 and different from the second direction DIR2. The third direction DIR3 is the opposite direction to the second direction DIR2.

[0024] In this embodiment, as shown in FIG. 2 , the first convex angle A1 is the angle formed between the first contact surface CS1 and a tangent to the first non-contact surface NCS1 at the first convex angle A1 when viewed in the first direction DIR1. More specifically, the first convex angle A1 protrudes in a radial direction centered on the central axis CA31 of the tooth main body 31 when viewed in the first direction DIR1. Therefore, the boundary between the first non-contact surface NCS1 and the first contact surface CS1 is the first convex angle A1. The first convex angle A1 is also located on the first contact surface CS1. The central axis CA31 of the tooth main body 31 is a line connecting the centers of cross sections of the tooth main body 31 perpendicular to the first direction DIR1. In this embodiment, the first convex angle A1 is 90 degrees.

[0025] As shown in FIG. 2 , the second contact surface CS2 is located further in the third direction DIR3 than the first contact surface CS1. Furthermore, the second contact surface CS2 has a curved shape that protrudes in the third direction DIR3 when viewed in the first direction DIR1. More specifically, the second contact surface CS2 has a semi-elliptical shape when viewed in the first direction DIR1. Note that a semicircular shape is included in the semi-elliptical shape. In this embodiment, the second contact surface CS2 has a semi-circular shape when viewed in the first direction DIR1. Therefore, the second contact surface CS2 is part of a circle with a radius RCS2 centered at the center OCS2 when viewed in the first direction DIR1. The radius RCS2 of the second contact surface CS2 is equal to the radius RCS1 of the first contact surface CS1. The position of the center OCS2 in the fourth direction DIR4 perpendicular to the first direction DIR1 and the second direction DIR2 is different from the position of the fourth direction DIR4 in the center OCS1.

[0026] 2, the second non-contact surface NCS2 is a flat surface facing the second direction DIR2. That is, the normal direction of the second non-contact surface NCS2 is the second direction DIR2.

[0027] As shown in FIG. 2 , the second convex angle A2 is a convex angle different from the first convex angle A1. More specifically, in this embodiment, the second convex angle A2 is the angle between the second contact surface CS2 and a tangent to the second non-contact surface NCS2 at the second convex angle A2, as viewed in the first direction DIR1. More specifically, the second convex angle A2 protrudes in the radial direction centered on the central axis CA31 of the tooth main body 31, as viewed in the first direction DIR1. Therefore, the boundary between the second non-contact surface NCS2 and the second contact surface CS2 is the second convex angle A2. Furthermore, the second convex angle A2 is located on the second contact surface CS2. In this embodiment, the second convex angle A2 is 90 degrees.

[0028] As shown in FIG. 2, the tooth main body 31 has a point-symmetric shape when viewed in the first direction DIR1.

[0029] As shown in Figures 3 to 7, the coil 13 is wound around the tooth main body 31. The coil 13 is made of a conductive material such as copper. The coil 13 has a structure in which the surface of a copper wire is covered with an insulating coating. Because the surface of the copper wire is covered with an insulating coating, the coil 13 is electrically insulated from the magnetic core 1. When the coil 13 is incorporated into the brushless motor 100, a current flows through the coil 13, generating a magnetic field.

[0030] The following describes the process of winding the coil 13 around the tooth main body 31. First, as shown in Fig. 3, the coil 13 comes into contact with the first contact surface CS1. That is, the coil 13 comes into contact with the first contact surface CS1 before passing through the first convex angle A1.

[0031] Next, the coil 13 passes through the first salient angle A1 as shown in Fig. 4. That is, the coil 13 comes into contact with the first salient angle A1.

[0032] Next, as shown in Fig. 5, the coil 13 comes into contact with the second contact surface CS2. That is, the coil 13 comes into contact with the second contact surface CS2 after passing through the first convex angle A1. The coil 13 does not come into contact with the first non-contact surface NCS1. The bending angle θ1 of the coil 13 between the first convex angle A1 and the second contact surface CS2 is greater than 90 degrees.

[0033] Next, the coil 13 passes through the second convex angle A2 as shown in Fig. 6. That is, the coil 13 passes through the second contact surface CS2 and then passes through the second convex angle A2. The coil 13 also comes into contact with the second convex angle A2.

[0034] Next, as shown in Fig. 7, the coil 13 comes into contact with the first contact surface CS1. That is, after passing through the second convex angle A2, the coil 13 comes into contact with the first contact surface CS1 again. The coil 13 does not come into contact with the second non-contact surface NCS2. The bending angle θ2 of the coil 13 between the first contact surface CS1 and the second convex angle A2 is greater than 90 degrees.

[0035] By repeating the above process, the coil 13 is wound around the tooth main body 31 .

[0036] The tooth tip portions 32 also have a third principal surface S3 and a fourth principal surface S4 aligned in the first direction DIR1. The fourth principal surface S4 is located further in the first direction DIR1 than the third principal surface S3. Each of the third principal surface S3 and the fourth principal surface S4 has a rectangular shape when viewed in the first direction DIR1.

[0037] 1, the outer edge O2 of the core back portion 2 as viewed in the first direction DIR1 surrounds the outer edge O31 of the tooth main body portion 31 as viewed in the first direction DIR1. Also, the outer edge O32 of the tooth tip portion 32 as viewed in the first direction DIR1 surrounds the outer edge O31 of the tooth main body portion 31 as viewed in the first direction DIR1.

[0038] (Configuration of Brushless Motor 100) The configuration of the brushless motor 100 according to the first embodiment of the present invention will be described below with reference to the drawings. Fig. 8 is an external perspective view of the brushless motor 100 that uses the magnetic core 1. Fig. 9 is an exploded perspective schematic view of the brushless motor 100 that uses the magnetic core 1. Note that in Fig. 9, reference symbols are assigned only to representative magnetic cores 1, coils 13, and coil-equipped magnetic cores 14 among the multiple magnetic cores 1, multiple coils 13, and multiple coil-equipped magnetic cores 14.

[0039] As shown in Fig. 9, brushless motor 100 includes rotor 20 and stator assembly 10. As shown in Fig. 9, stator assembly 10 is disposed around rotor 20 when viewed in second direction DIR2. In other words, brushless motor 100 is an inner rotor type.

[0040] As shown in FIG. 9 , the rotor 20 includes a shaft 21 and a rotor member 22. The shaft 21 has a shape that extends in the second direction DIR2. More specifically, the shaft 21 is cylindrical. The rotor member 22 is cylindrical. The central axes of the shaft 21 and the rotor member 22 are the Z-axis. In other words, the rotation axis of the brushless motor 100 is the Z-axis. Therefore, the second direction DIR2 is a direction along the Z-axis.

[0041] 9 , the rotor member 22 includes a soft magnetic material 23 and a hard magnetic material 24. The rotor member 22 is attached to the outer circumferential surface of the shaft 21 in the radial direction centered on the Z axis. More specifically, the soft magnetic material 23 is attached to the outer circumferential surface of the shaft 21 in the radial direction centered on the Z axis. The hard magnetic material 24 is attached to the outer circumferential surface of the soft magnetic material 23 in the radial direction centered on the Z axis.

[0042] The soft magnetic body 23 is a soft magnetic body. The hard magnetic body 24 is a hard magnetic body. A hard magnetic body is magnetized when an external magnetic field is applied. Even if the application of the magnetic field is stopped, the hard magnetic body does not lose its magnetization. Such hard magnetic body materials are magnets.

[0043] 9 , the stator assembly 10 includes a bearing 11, a housing 12, and a plurality of magnetic cores 14 with coils. Each of the plurality of magnetic cores 14 with coils has a magnetic core 1 and a coil 13. In other words, the brushless motor 100 includes the magnetic core 1.

[0044] The bearing 11 supports the shaft 21 so that it can rotate in the circumferential direction around the Z-axis. More specifically, as shown in FIG. 9 , the bearing 11 has a first bearing 11a and a second bearing 11b. Each of the first bearing 11a and the second bearing 11b is, for example, a ball bearing. Each of the first bearing 11a and the second bearing 11b is cylindrical. The central axes of the first bearing 11a and the second bearing 11b are aligned with the Z-axis. That is, the central axes of the first bearing 11a and the second bearing 11b coincide with the central axis of the shaft 21.

[0045] 9, the second bearing 11b is positioned further in the second direction DIR2 than the first bearing 11a. The first bearing 11a is positioned in the opposite direction of the second direction DIR2 than the rotor member 22. The second bearing 11b is positioned further in the second direction DIR2 than the rotor member 22. The second bearing 11b supports the end of the shaft 21 in the second direction DIR2.

[0046] As shown in FIG. 8, the housing 12 has a first housing 12a and a second housing 12b. As shown in FIGS. 8 and 9, the first housing 12a is cylindrical. The central axis of the first housing 12a is the Z-axis. The first housing 12a is located in the opposite direction of the second direction DIR2 from the second housing 12b. The first housing 12a also has an opening OP. As a result, the end of the shaft 21 opposite the second direction DIR2 protrudes from the opening OP in the opposite direction of the second direction DIR2. In other words, the brushless motor 100 is a single-shaft type.

[0047] The first housing 12a supports the first bearing 11a, the plurality of magnetic cores 1, and the plurality of coils 13. The second housing 12b supports the second bearing 11b. The first housing 12a and the second housing 12b are each made of a highly rigid material such as SUS.

[0048] The number of coiled magnetic cores 14 is nine. The nine coiled magnetic cores 14 are arranged in a circumferential direction centered on the Z axis. The nine coiled magnetic cores 14 are arranged around the hard magnetic material 24 with a gap therebetween.

[0049] The magnetic core 1 is magnetized by both the magnetic field generated by the hard magnetic material 24 and the magnetic field generated by the coil 13 (described later). Note that an air gap exists between the magnetic core 1 and the rotor member 22, as shown in FIG.

[0050] A current is supplied from a power source (not shown) to the coil 13. The rotation of the rotor 20 is controlled by controlling this current.

[0051] [Effect] The magnetic core 1 can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil. More specifically, the magnetic core 1 has a first contact surface CS1 that curves to protrude in the second direction DIR2 when viewed in the first direction DIR1 in which the teeth 3 extend, a first convex angle A1 through which the coil 13 passes, a first non-contact surface NCS1 whose boundary with the first contact surface CS1 is the first convex angle A1, and a second contact surface CS2 that curves to protrude in a third direction DIR3 different from the second direction DIR2 when viewed in the first direction DIR1 in which the teeth 3 extend. The coil 13 does not contact the first non-contact surface NCS1. As a result, the bending angle θ1 of the coil 13 between the first convex angle A1 and the second contact surface CS2 is greater than 90 degrees. This reduces stress concentration on a portion of the insulating coating formed on the surface of the coil 13, thereby suppressing damage to the insulating coating. As a result, the magnetic core 1 can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil.

[0052] Furthermore, the magnetic core 1 allows the surface area of ​​the outer surface of the magnetic core 1 to be reduced to be insulated. More specifically, the first non-contact surface NCS1 does not come into contact with the coil 13. Therefore, the first non-contact surface NCS1 does not need to be insulated. Therefore, the magnetic core 1 allows the surface area of ​​the outer surface of the magnetic core 1 to be reduced to be insulated. Furthermore, damage to the insulating coating formed on the surface of the coil 13 can be suppressed, making it possible to eliminate the need to insulate the entire outer surface of the magnetic core 1.

[0053] Furthermore, the magnetic core 1 can further suppress the deterioration of the electrical insulation between the magnetic core and the coil. More specifically, the first non-contact surface NCS1 does not contact the coil 13. Therefore, the contact area between the magnetic core 1 and the coil 13 can be reduced. As a result, the magnetic core 1 can further suppress the deterioration of the electrical insulation between the magnetic core and the coil.

[0054] Furthermore, the magnetic core 1 can further prevent a deterioration in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface. More specifically, the magnetic core 1 further includes a second convex angle A2 through which the coil 13 passes after passing through the second contact surface CS2, and a second non-contact surface NCS2 whose boundary with the second contact surface CS2 is the second convex angle A2. The coil 13 does not contact the second non-contact surface NCS2. As a result, the bending angle θ2 of the coil 13 between the second convex angle A2 and the first contact surface CS1 is greater than 90 degrees. This reduces stress concentration on a portion of the insulating coating formed on the coil 13, thereby preventing damage to the insulating coating. As a result, the magnetic core 1 can prevent a deterioration in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface.

[0055] Furthermore, with the magnetic core 1, when the coil is wound around the tooth main body portion, it is possible to prevent the electrical insulation between the magnetic core and the coil from being reduced due to damage to the insulating coating formed on the surface of the coil. The reason for this will be explained with reference to the drawings. Figure 10 is a cross-sectional view of the process of winding the coil 13 around the tooth main body portion 31 of the magnetic core 6 according to the comparative example, viewed from the first direction DIR1. The shape of the magnetic core 6 according to the comparative example is the same as that of the magnetic core 1.

[0056] In the magnetic core 6 according to the comparative example, when the coil 13 is wound around the tooth main body 31, the coil 13 contacts the first contact surface CS1, the second salient angle A2, the second contact surface CS2, the first salient angle A1, and the first contact surface CS1 in this order. That is, the magnetic core 6 according to the comparative example differs from the magnetic core 1 in that the winding direction of the coil 13 is opposite to the winding direction of the coil 13 in the magnetic core 1. In the magnetic core 6 according to the comparative example, when the coil 13 moves from the first contact surface CS1 to the second salient angle A2, as shown in FIG. 10 , the coil 13 comes into contact with the second salient angle A2, which may damage the insulating coating of the coil 13. Furthermore, when the coil 13 moves from the second contact surface CS2 to the first salient angle A1, the coil 13 comes into contact with the first salient angle A1, which may damage the insulating coating of the coil 13. Therefore, with the magnetic core 1, when the coil 13 is wound around the tooth main body 31, the coil 13 contacts the first contact surface CS1, the first salient angle A1, the second contact surface CS2, the second salient angle A2, and the first contact surface CS1 in this order. Furthermore, the first salient angle A1 is located on the first contact surface CS1. This prevents the coil 13 from contacting the first salient angle A1 when the coil 13 moves from the first contact surface CS1 to the first salient angle A1, thereby preventing the insulating coating of the coil 13 from being damaged by the coil 13 contacting the first salient angle A1. Furthermore, the second salient angle A2 is located on the second contact surface CS2. This prevents the coil 13 from contacting the second salient angle A2 when the coil 13 moves from the second contact surface CS2 to the second salient angle A2, thereby preventing the insulating coating of the coil 13 from being damaged by the coil 13 contacting the second salient angle A2. Therefore, when the magnetic core 1 is used, when the coil is wound around the tooth main body, it is possible to prevent the electrical insulation between the magnetic core and the coil from decreasing due to damage to the insulating coating formed on the surface of the coil.

[0057] When a magnetic core including teeth that are elliptical or circular when viewed in the direction in which the teeth extend is produced by press molding, a surface whose boundary with the first contact surface CS1 is the first convex angle A1 and a surface whose boundary with the second contact surface CS2 is the second convex angle A2 are generated. By making the surface whose boundary with the first contact surface CS1 is the first convex angle A1 and the surface whose boundary with the second contact surface CS2 is the second convex angle A2 into the first non-contact surface NCS1 and the second non-contact surface NCS2 that do not come into contact with the coil 13, respectively, stress concentration on a portion of the insulating coating formed on the surface of the coil 13 can be alleviated, and damage to the insulating coating can be suppressed.

[0058] The magnetic core 1 makes it easy to wind the coil 13 around the tooth main body 31. More specifically, the coil 13 contacts the first contact surface CS1 and the second contact surface CS2. The first contact surface CS1 and the second contact surface CS2 each have a semi-elliptical shape when viewed in the first direction DIR1. Furthermore, during the winding process of the coil 13, the coil 13 only passes through the first salient angle A1 and the second salient angle A2. Therefore, the magnetic core 1 makes it easy to wind the coil 13 around the tooth main body 31.

[0059] According to the magnetic core 1, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having end faces with the same shape. More specifically, the radius RCS2 of the second contact surface CS2 is equal to the radius RCS1 of the first contact surface CS1. As a result, the radius of the semi-elliptical portion of the end face in the third direction DIR3 of the punch located further in the second direction DIR2 than the tooth main body portion 31 is equal to the radius of the semi-elliptical portion of the end face in the second direction DIR2 of the punch located further in the third direction DIR3 than the tooth main body portion 31. Therefore, according to the magnetic core 1, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having end faces with the same shape.

[0060] According to the magnetic core 1, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having the same shape. More specifically, the tooth main body portion 31 has a point-symmetric shape when viewed in the first direction DIR1. As a result, the end face in the third direction DIR3 of the punch located further in the second direction DIR2 than the tooth main body portion 31 and the end face in the second direction DIR2 of the punch located further in the third direction DIR3 than the tooth main body portion 31 have point-symmetric shapes when viewed in the first direction DIR1. Therefore, according to the magnetic core 1, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having the same shape.

[0061] Second Embodiment A magnetic core 1a according to a second embodiment of the present invention will be described below with reference to the drawings. FIG. 11 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1. FIG. 12 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 13 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 14 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 15 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. FIG. 16 is a cross-sectional view of the magnetic core 1a viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 17 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 18 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 19 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Fig. 20 is a cross-sectional view of the magnetic core 1a, viewed from the first direction DIR1, showing the process of winding the coil 13 around the tooth main body portion 31. Note that with regard to the magnetic core 1a according to the second embodiment, only the differences from the magnetic core 1 according to the first embodiment will be described, and the rest will be omitted.

[0062] As shown in FIG. 11, the tooth main body portion 31 has a first contact surface CS1, a first non-contact surface NCS1, a first convex angle A1, a second contact surface CS2, a second convex angle A2, a second non-contact surface NCS2, a third contact surface CS3, a third non-contact surface NCS3, a third convex angle A3, a fourth contact surface CS4, a fourth convex angle A4, and a fourth non-contact surface NCS4.

[0063] As shown in FIG. 11 , the first contact surface CS1 has a curved shape that protrudes in the second direction DIR2 when viewed in the first direction DIR1. More specifically, the first contact surface CS1 has a semi-elliptical shape when viewed in the first direction DIR1. Note that a semi-circular shape is included in the semi-elliptical shape. In this embodiment, the first contact surface CS1 has a semi-circular shape when viewed in the first direction DIR1. Therefore, the first contact surface CS1 is part of a circle with a radius RCS1 centered at a center OCS1 when viewed in the first direction DIR1.

[0064] As shown in FIG. 11 , the third contact surface CS3 is located further in the third direction DIR3 than the first contact surface CS1. Furthermore, the third contact surface CS3 has a curved shape that protrudes in the third direction DIR3 when viewed in the first direction DIR1. More specifically, the third contact surface CS3 has a semi-elliptical shape when viewed in the first direction DIR1. Note that a semicircular shape is included in the semi-elliptical shape. In this embodiment, the third contact surface CS3 has a semi-circular shape when viewed in the first direction DIR1. Therefore, the third contact surface CS3 is part of a circle with a radius RCS3 centered at the center OCS3 when viewed in the first direction DIR1. The radius RCS3 of the third contact surface CS3 is equal to the radius RCS3 of the first contact surface CS1. Note that the position of the center OCS3 in the fourth direction DIR4 is different from the position of the center OCS1 in the fourth direction DIR4.

[0065] As shown in Fig. 11 , the second contact surface CS2 is provided between the first contact surface CS1 and the third contact surface CS3. The second contact surface CS2 is a flat surface facing the opposite direction of the fourth direction DIR4. That is, the normal direction of the second contact surface CS2 is the opposite direction of the fourth direction DIR4. In this modification, the second contact surface CS2 is located in the opposite direction of the fourth direction DIR4 from the first contact surface CS1, the third contact surface CS3, and the fourth contact surface CS4.

[0066] 11 , the first non-contact surface NCS1 is provided between the first contact surface CS1 and the second contact surface CS2. In this modification, the first non-contact surface NCS1 is a flat surface facing the second direction DIR2. That is, the normal direction of the first non-contact surface NCS1 is the second direction DIR2.

[0067] In this embodiment, as shown in Fig. 11 , the first convex angle A1 is the angle formed between the first non-contact surface NCS1 and the second contact surface CS2 when viewed in the first direction DIR1. More specifically, the first convex angle A1 protrudes in the radial direction centered on the central axis CA31 of the tooth main body 31 when viewed in the first direction DIR1. Therefore, the boundary between the first non-contact surface NCS1 and the second contact surface CS2 is the first convex angle A1. In this modified example, the first convex angle A1 is 90 degrees.

[0068] As shown in FIG. 11 , the second non-contact surface NCS2 is located further in the third direction DIR3 than the first non-contact surface NCS1. Therefore, the second non-contact surface NCS2 is a different non-contact surface from the first non-contact surface NCS1. More specifically, the second non-contact surface NCS2 is provided between the second contact surface CS2 and the third contact surface CS3. Furthermore, the second non-contact surface NCS2 is a flat surface facing the third direction DIR3. In other words, the normal direction of the second non-contact surface NCS2 is the third direction DIR3.

[0069] In this embodiment, the second convex angle A2 is a convex angle different from the first convex angle A1, as shown in FIG. 11 . More specifically, the second convex angle A2 is the angle formed between the second contact surface CS2 and the second non-contact surface NCS2 when viewed in the first direction DIR1. More specifically, the second convex angle A2 protrudes in the radial direction centered on the central axis CA31 of the tooth main body 31 when viewed in the first direction DIR1. Therefore, the boundary between the second non-contact surface NCS2 and the second contact surface CS2 is the second convex angle A2. In this modified example, the second convex angle A2 is 90 degrees.

[0070] As shown in FIG. 11 , the fourth contact surface CS4 is located between the first contact surface CS1 and the third contact surface CS3. The fourth contact surface CS4 is a plane facing the fourth direction DIR4. That is, the normal direction of the fourth contact surface CS4 is the fourth direction DIR4. Therefore, the fourth contact surface CS4 is parallel to the second contact surface CS2. The fourth contact surface CS4 is located further in the fourth direction DIR4 than the first contact surface CS1, the second contact surface CS2, and the third contact surface CS3.

[0071] As shown in FIG. 11 , the third non-contact surface NCS3 is provided between the third contact surface CS3 and the fourth contact surface CS4. The third non-contact surface NCS3 is a plane facing the third direction DIR3. That is, the normal direction of the third non-contact surface NCS3 is the third direction DIR3. In this modification, the position of the third non-contact surface NCS3 in the second direction DIR2 is the same as the position of the second non-contact surface NCS2 in the second direction DIR2. The third non-contact surface NCS3 is located further in the fourth direction DIR4 than the second non-contact surface NCS2.

[0072] In this embodiment, as shown in FIG. 11 , the third convex angle A3 is a convex angle different from the first convex angle A1 and the second convex angle A2. More specifically, the third convex angle A3 is an angle formed between the third non-contact surface NCS3 and the fourth contact surface CS4 when viewed in the first direction DIR1. More specifically, the third convex angle A3 protrudes in a radial direction centered on the central axis CA31 of the tooth main body 31 when viewed in the first direction DIR1. Therefore, the boundary between the third non-contact surface NCS3 and the fourth contact surface CS4 is the third convex angle A3. In this modified example, the third convex angle A3 is 90 degrees.

[0073] As shown in FIG. 11 , the fourth non-contact surface NCS4 is located further in the second direction DIR2 than the third non-contact surface NCS3. Therefore, the fourth non-contact surface NCS4 is a different non-contact surface from the third non-contact surface NCS3. More specifically, the fourth non-contact surface NCS4 is provided between the fourth contact surface CS4 and the first contact surface CS1. The fourth non-contact surface NCS4 is a plane facing the second direction DIR2. That is, the normal direction of the fourth non-contact surface NCS4 is the second direction DIR2. In this modification, the position of the fourth non-contact surface NCS4 in the second direction DIR2 is the same as the position of the first non-contact surface NCS1 in the second direction DIR2. The fourth non-contact surface NCS4 is located further in the fourth direction DIR4 than the first non-contact surface NCS1.

[0074] In this embodiment, as shown in FIG. 11 , the fourth convex angle A4 is a convex angle different from the first convex angle A1, the second convex angle A2, and the third convex angle A3. More specifically, the fourth convex angle A4 is the angle formed between the fourth contact surface CS4 and the fourth non-contact surface NCS4 when viewed in the first direction DIR1. More specifically, the fourth convex angle A4 protrudes in the radial direction centered on the central axis CA31 of the tooth main body 31 when viewed in the first direction DIR1. Therefore, the boundary between the fourth non-contact surface NCS4 and the fourth contact surface CS4 is the fourth convex angle A4. In this modified example, the fourth convex angle A4 is 90 degrees.

[0075] As shown in FIG. 11 , the tooth main body 31 has a point-symmetric shape when viewed in the first direction DIR1.

[0076] The following describes the process of winding the coil 13 around the tooth main body 31. First, as shown in Fig. 12, the coil 13 comes into contact with the first contact surface CS1. That is, the coil 13 comes into contact with the first contact surface CS1 before passing through the first convex angle A1.

[0077] Next, the coil 13 passes through the first salient angle A1 as shown in Fig. 13. That is, the coil 13 comes into contact with the first salient angle A1.

[0078] Next, as shown in Fig. 14, the coil 13 comes into contact with the second contact surface CS2. That is, the coil 13 comes into contact with the second contact surface CS2 after passing through the first convex angle A1. The coil 13 does not come into contact with the first non-contact surface NCS1. The bending angle θ1 of the coil 13 at the first convex angle A1 is greater than 90 degrees.

[0079] Next, the coil 13 passes through the second convex angle A2 as shown in Fig. 15. That is, the coil 13 passes through the second contact surface CS2 and then passes through the second convex angle A2. The coil 13 also comes into contact with the second convex angle A2.

[0080] Next, as shown in FIG. 16 , the coil 13 contacts the third contact surface CS3. That is, the coil 13 contacts the third contact surface CS3 after passing through the second convex angle A2. The coil 13 does not contact the second non-contact surface NCS2. The bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3 is greater than 90 degrees. Note that, as shown in FIGS. 14 and 16 , the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3 is smaller than the bending angle θ1 of the coil 13 at the first convex angle A1.

[0081] Next, as shown in Fig. 17, the coil 13 passes through the third convex angle A3. That is, the coil 13 passes through the third contact surface CS3 and then the third convex angle A3. The coil 13 also comes into contact with the third convex angle A3.

[0082] Next, as shown in Fig. 18, the coil 13 comes into contact with the fourth contact surface CS4. That is, the coil 13 comes into contact with the fourth contact surface CS4 after passing through the third convex angle A3. The coil 13 does not come into contact with the third non-contact surface NCS3. The bending angle θ3 of the coil 13 at the third convex angle A3 is greater than 90 degrees.

[0083] Next, as shown in Fig. 19, the coil 13 passes through the fourth convex corner A4. That is, the coil 13 passes through the fourth contact surface CS4 and then passes through the fourth convex corner A4. The coil 13 also comes into contact with the fourth convex corner A4.

[0084] Next, as shown in Fig. 20, the coil 13 comes into contact with the first contact surface CS1. That is, after passing through the fourth convex angle A4, the coil 13 comes into contact with the first contact surface CS1 again. The coil 13 does not come into contact with the fourth non-contact surface NCS4. The bending angle θ4 of the coil 13 between the fourth convex angle A4 and the first contact surface CS1 is greater than 90 degrees.

[0085] By repeating the above process, the coil 13 is wound around the tooth main body 31 .

[0086] The magnetic core 1a can prevent the electrical insulation between the magnetic core and the coil from being reduced due to damage to the insulating coating formed on the surface of the coil. More specifically, the magnetic core 1a has a first contact surface CS1 having a curved shape that protrudes in a second direction DIR2 when viewed in a first direction DIR1 in which the tooth portion 3 extends, a first convex angle A1 through which the coil 13 passes, a second contact surface CS2 through which the coil 13 passes after passing through the first convex angle A1, a first non-contact surface NCS1 whose boundary with the second contact surface CS2 is the first convex angle A1, a second convex angle A2 through which the coil 13 passes after passing through the second contact surface CS2, a third contact surface CS3 having a curved shape that protrudes in a third direction DIR3 different from the second direction DIR2 when viewed in the first direction DIR1 in which the tooth portion 3 extends, and a second non-contact surface NCS2 whose boundary with the second contact surface CS2 is the second convex angle A2. The first non-contact surface NCS1 is located between the first contact surface CS1 and the second contact surface CS2. The second non-contact surface NCS2 is located between the second contact surface CS2 and the third contact surface CS3. The coil 13 does not contact the first non-contact surface NCS1 or the second non-contact surface NCS2. As a result, the bending angle θ1 of the coil 13 at the first convex angle A1 and the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3 are both greater than 90 degrees. This reduces stress concentration on a portion of the insulating coating formed on the surface of the coil 13 and suppresses damage to the insulating coating. As a result, the magnetic core 1a can suppress a deterioration in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil.

[0087] Of the stresses applied to the insulating coating formed on the surface of the coil 13, a large stress is applied to the contact portion with the convex angle (first convex angle A1) through which the coil 13 first passes in the process of winding the coil 13 around the tooth main body 31. Therefore, by making the bending angle θ1 of the coil 13 at the first convex angle A1 larger than the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3, stress concentration can be further alleviated and damage to the insulating coating can be suppressed.

[0088] The magnetic core 1a can further prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil. More specifically, the magnetic core 1a further includes a third convex angle A3 through which the coil 13 passes after passing through the third contact surface CS3, a fourth contact surface CS4 through which the coil 13 passes after passing through the third convex angle A3, a third non-contact surface NCS3 whose boundary with the fourth contact surface CS4 is the third convex angle A3, a fourth convex angle A4 through which the coil 13 passes after passing through the fourth contact surface CS4, and a fourth non-contact surface NCS4 whose boundary with the fourth contact surface CS4 is the fourth convex angle A4. The coil 13 does not contact the third non-contact surface NCS3 or the fourth non-contact surface NCS4. As a result, the bending angle θ3 of the coil 13 at the third convex angle A3 and the bending angle θ4 of the coil 13 between the fourth convex angle A4 and the first contact surface CS1 are both greater than 90 degrees. This reduces stress concentration on a portion of the insulating coating formed on the surface of the coil 13, thereby suppressing damage to the insulating coating. As a result, the magnetic core 1a can suppress a deterioration in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the surface of the coil.

[0089] The magnetic core 1a makes it easier to wind the coil 13 around the tooth main body 31. More specifically, the coil 13 contacts the first contact surface CS1 and the third contact surface CS3. Each of the first contact surface CS1 and the third contact surface CS3 has a semi-elliptical shape when viewed in the first direction DIR1. Furthermore, during the winding process of the coil 13, the coil 13 only passes through the first convex angle A1, the second convex angle A2, the third convex angle A3, and the fourth convex angle A4. Therefore, the magnetic core 1a makes it easier to wind the coil 13 around the tooth main body 31.

[0090] According to the magnetic core 1a, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having end faces with the same shape. More specifically, the radius RCS3 of the third contact surface CS3 is equal to the radius RCS1 of the first contact surface CS1. As a result, the radius of the semi-elliptical portion of the end face in the third direction DIR3 of the punch located further in the second direction DIR3 than the tooth main body portion 31 is equal to the radius of the semi-elliptical portion of the end face in the second direction DIR2 of the punch located further in the third direction DIR3 than the tooth main body portion 31. Therefore, according to the magnetic core 1a, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having end faces with the same shape.

[0091] According to the magnetic core 1a, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having the same shape. More specifically, the tooth main body portion 31 has a point-symmetric shape when viewed in the first direction DIR1. As a result, the end face in the third direction DIR3 of the punch located further in the second direction DIR2 than the tooth main body portion 31 and the end face in the second direction DIR2 of the punch located further in the third direction DIR3 than the tooth main body portion 31 have a point-symmetric shape when viewed in the first direction DIR1. Therefore, according to the magnetic core 1a, when the magnetic core is produced by press molding, the tooth main body portion can be produced using an upper punch and a lower punch having the same shape.

[0092] [First Modification] A magnetic core 1b according to a first modification of the present invention will be described below with reference to the drawings. Fig. 21 is a cross-sectional view of the magnetic core 1b as viewed from the first direction DIR1. Note that for the magnetic core 1b according to the first modification, only the differences from the magnetic core 1a according to the second embodiment will be described, and the rest will be omitted.

[0093] As shown in Figure 21, magnetic core 1b differs from magnetic core 1a in that the second contact surface CS2 is connected to each of the first non-contact surface NCS1 and the second non-contact surface NCS2 via a notch surface, and the fourth contact surface CS4 is connected to each of the third non-contact surface NCS3 and the fourth non-contact surface NCS4 via a notch surface.

[0094] More specifically, as shown in FIG. 21 , the tooth main body portion 31 further includes a first notched surface NS1, a second notched surface NS2, a third notched surface NS3, and a fourth notched surface NS4. Specifically, the first notched surface NS1, the second notched surface NS2, the third notched surface NS3, and the fourth notched surface NS4 each have a shape in which the first convex angle A1, the second convex angle A2, the third convex angle A3, and the fourth convex angle A4 are cut out, respectively. In this modification, the first notched surface NS1, the second notched surface NS2, the third notched surface NS3, and the fourth notched surface NS4 each are flat. As a result, the first non-contact surface NCS1 is connected to the second contact surface CS2 via the first notched surface NS1. The second non-contact surface NCS2 is connected to the second contact surface CS2 via a second cutout surface NS2. The third non-contact surface NCS3 is connected to the fourth contact surface CS4 via a third cutout surface NS3. The fourth non-contact surface NCS4 is connected to the fourth contact surface CS4 via a fourth cutout surface NS4.

[0095] The magnetic core 1b can further prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface. More specifically, the second contact surface CS2 is connected to each of the first non-contact surface NCS1 and the second non-contact surface NCS2 via a notch. This increases the bending angle θ1 of the coil 13 at the first convex angle A1 and the bending angle θ2 of the coil 13 between the second convex angle A2 and the third contact surface CS3. This reduces stress concentration on the insulating coating formed on the coil 13 at the first convex angle A1 and on the coil 13 between the second convex angle A2 and the third contact surface CS3, thereby preventing damage to the insulating coating formed on the coil surface. As a result, the magnetic core 1b can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface.

[0096] The magnetic core 1b can further prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface. More specifically, the fourth contact surface CS4 is connected to each of the third non-contact surface NCS3 and the fourth non-contact surface NCS4 via a notch. This increases the bending angle θ3 of the coil 13 at the third convex angle A3 and the bending angle θ4 of the coil 13 between the fourth convex angle A4 and the first contact surface CS1. This reduces stress concentration on the insulating coating formed on the coil 13 at the third convex angle A3 and on the insulating coating formed on the coil 13 between the fourth convex angle A4 and the first contact surface CS1, thereby preventing damage to the insulating coating formed on the coil surface. As a result, the magnetic core 1b can prevent a decrease in electrical insulation between the magnetic core and the coil due to damage to the insulating coating formed on the coil surface.

[0097] Other Embodiments The magnetic core according to the present invention is not limited to the magnetic cores 1, 1a, and 1b, and may be modified within the scope of the present invention. The structures of the magnetic cores 1, 1a, and 1b may be combined arbitrarily.

[0098] The rotating electric machine may have a structure in which the rotor is rotated by electricity or a structure in which electricity is generated by the rotation of the rotor. In this case, the rotating electric machine may include at least one of the magnetic cores 1, 1a, and 1b, and may also include brushes.

[0099] Each of the first main surface S1 and the second main surface S2 of the core back portion 2 does not have to have a rectangular shape when viewed in the first direction DIR1.

[0100] In the magnetic core 1, the tooth main body portion 31 does not necessarily have to have the second convex angle A2 and the second non-contact surface NCS2.

[0101] In the magnetic core 1, each of the first contact surface CS1 and the second contact surface CS2 does not have to have a semi-elliptical shape when viewed in the first direction DIR1.

[0102] The second direction DIR2 does not have to be perpendicular to the first direction DIR1. Furthermore, the second direction DIR2 does not have to be a direction along the rotation axis of the brushless motor 100 when the magnetic core 1 is incorporated into the brushless motor 100.

[0103] In the magnetic core 1, the first non-contact surface NCS1 does not have to be a flat surface facing the third direction DIR3. Therefore, the first non-contact surface NCS1 may be a flat surface facing a direction different from the third direction DIR3, or may be a curved surface.

[0104] The third direction DIR3 does not have to be the opposite direction to the second direction DIR2.

[0105] In addition, in the magnetic core 1, the first convex angle A1 does not have to be the angle formed by the first contact surface CS1 and the tangent to the first non-contact surface NCS1 at the first convex angle A1 when viewed in the first direction DIR1.

[0106] It should be noted that each of the first convex angle A1, the second convex angle A2, the third convex angle A3, and the fourth convex angle A4 does not have to be 90 degrees.

[0107] In the magnetic core 1, the radius RCS2 of the second contact surface CS2 may be different from the radius RCS1 of the first contact surface CS1.

[0108] In the magnetic core 1, the second non-contact surface NCS2 does not have to be a flat surface facing the second direction DIR2. Therefore, the second non-contact surface NCS2 may be a flat surface facing a direction different from the second direction DIR2, or may be a curved surface.

[0109] In addition, in the magnetic core 1, the second convex angle A2 does not have to be the angle formed by the second contact surface CS2 and the tangent to the second non-contact surface NCS2 at the second convex angle A2 when viewed in the first direction DIR1.

[0110] The tooth main body portion 31 does not have to have a point-symmetric shape when viewed in the first direction DIR1.

[0111] It should be noted that each of the third main surface S3 and the fourth main surface S4 of the tooth tip portion 32 does not have to have a rectangular shape when viewed in the first direction DIR1.

[0112] The outer edge O2 of the core back portion 2 as viewed in the first direction DIR1 does not have to surround the outer edge O31 of the tooth main body portion 31 as viewed in the first direction DIR1. Also, the outer edge O32 of the tooth tip portion 32 as viewed in the first direction DIR1 does not have to surround the outer edge O31 of the tooth main body portion 31 as viewed in the first direction DIR1.

[0113] The brushless motor 100 may be an outer rotor type.

[0114] The brushless motor 100 is not limited to a single-shaft type, but may be, for example, a double-shaft type.

[0115] It should be noted that the first bearing 11a and the second bearing 11b are not limited to ball bearings.

[0116] The first housing 12a and the second housing 12b may be made of any material as long as it has high rigidity.

[0117] The number of coil-equipped magnetic cores 14 is not limited to nine.

[0118] In the magnetic core 1a, the tooth main body portion 31 does not necessarily have to have the third convex angle A3, the fourth convex angle A4, the fourth contact surface CS4, the third non-contact surface NCS3, and the fourth non-contact surface NCS4.

[0119] In the magnetic core 1a, each of the first contact surface CS1 and the third contact surface CS3 does not have to have a semi-elliptical shape when viewed in the first direction DIR1.

[0120] In the magnetic core 1a, the radius RCS3 of the third contact surface CS3 may be different from the radius RCS1 of the first contact surface CS1.

[0121] In the magnetic core 1 a, the second contact surface CS2 does not have to be a flat surface facing the opposite direction to the fourth direction DIR4. Therefore, the second contact surface CS2 may be a flat surface facing a direction different from the opposite direction to the fourth direction DIR4, or may be a curved surface.

[0122] In the magnetic core 1 a, the first non-contact surface NCS1 does not have to be a flat surface facing the second direction DIR2. Therefore, the first non-contact surface NCS1 may be a flat surface facing a direction different from the second direction DIR2, or may be a curved surface.

[0123] In the magnetic core 1a, the first convex angle A1 does not have to be the angle formed by the first non-contact surface NCS1 and the second contact surface CS2 when viewed in the first direction DIR1.

[0124] In the magnetic core 1 a, the second non-contact surface NCS2 does not have to be a flat surface facing the third direction DIR3. Therefore, the second non-contact surface NCS2 may be a flat surface facing a direction different from the third direction DIR3, or may be a curved surface.

[0125] In the magnetic core 1a, the second convex angle A2 does not have to be the angle formed by the second contact surface CS2 and the second non-contact surface NCS2 when viewed in the first direction DIR1.

[0126] In the magnetic core 1 a, the fourth contact surface CS4 does not have to be a flat surface facing the fourth direction DIR4. Therefore, the fourth contact surface CS4 may be a flat surface facing a direction different from the fourth direction DIR4, or may be a curved surface.

[0127] In the magnetic core 1 a, the third non-contact surface NCS3 does not have to be a flat surface facing the third direction DIR3. Therefore, the third non-contact surface NCS3 may be a flat surface facing a direction different from the third direction DIR3, or may be a curved surface.

[0128] In the magnetic core 1a, the position of the third non-contact surface NCS3 in the second direction DIR2 may be different from the position of the second non-contact surface NCS2 in the second direction DIR2.

[0129] In the magnetic core 1a, the third convex angle A3 does not have to be the angle formed by the third non-contact surface NCS3 and the fourth contact surface CS4 when viewed in the first direction DIR1.

[0130] In the magnetic core 1 a, the fourth non-contact surface NCS4 does not have to be a flat surface facing the second direction DIR2. Therefore, the fourth non-contact surface NCS4 may be a flat surface facing a direction different from the second direction DIR2, or may be a curved surface.

[0131] In the magnetic core 1a, the position of the fourth non-contact surface NCS4 in the second direction DIR2 may be different from the position of the first non-contact surface NCS1 in the second direction DIR2.

[0132] In the magnetic core 1a, the fourth convex angle A4 does not have to be the angle formed by the fourth contact surface CS4 and the fourth non-contact surface NCS4 when viewed in the first direction DIR1.

[0133] In the magnetic core 1a, the bending angle θ2 of the coil 13 between the second salient angle A2 and the third contact surface CS3 does not have to be smaller than the bending angle θ1 of the coil 13 at the first salient angle A1.

[0134] In the magnetic core 1b, the first convex angle A1, the second convex angle A2, the third convex angle A3, or the fourth convex angle A4 may be chamfered. That is, the first notched surface NS1, the second notched surface NS2, the third notched surface NS3, and the fourth notched surface NS4 may each be a curved surface.

[0135] In the magnetic core 1b, the tooth body portion 31 does not necessarily have to have the third cutout surface NS3 and the fourth cutout surface NS4. That is, the fourth contact surface CS4 does not necessarily have to be connected to the third non-contact surface NCS3 and the fourth non-contact surface NCS4 via a cutout surface.

[0136] The present invention has the following configuration.

[0137] (1) A magnetic core for use in a rotating electric machine, comprising: teeth portions having a shape extending in a first direction, the teeth portions including a wound portion around which a coil is wound, the wound portion having: a first convex angle through which the coil passes during winding; a first contact surface with which the coil comes into contact before passing through the first convex angle, the first contact surface having a shape curved so as to protrude in a second direction when viewed in the first direction; a first non-contact surface with which the coil does not come into contact, the boundary with the first contact surface being the first convex angle; and a second contact surface with which the coil comes into contact after passing through the first convex angle, the second contact surface having a shape curved so as to protrude in a third direction different from the second direction when viewed in the first direction.

[0138] (2) The magnetic core according to (1), wherein the wound portion further includes: a second convex angle that is different from the first convex angle and through which the coil passes after passing through the second contact surface; and a second non-contact surface with which the coil does not come into contact, the boundary between the second non-contact surface being the second convex angle; and the coil again comes into contact with the first contact surface after passing through the second convex angle.

[0139] (3) The magnetic core according to (1) or (2), wherein each of the first contact surface and the second contact surface has a semi-elliptical shape when viewed in the first direction.

[0140] (4) The magnetic core according to (3), wherein the radius of the first contact surface and the radius of the second contact surface are equal to each other.

[0141] (5) The magnetic core according to any one of (1) to (4), wherein the wound portion has a shape that is point-symmetric when viewed in the first direction.

[0142] (6) A magnetic core for use in a rotary electric machine, comprising: teeth having a shape extending in a first direction, the teeth including a wound portion around which a coil is wound, the wound portion including: a first salient angle through which the coil passes during winding; a first contact surface with which the coil comes into contact before passing through the first salient angle, the first contact surface having a curved shape so as to protrude in a second direction as viewed in the first direction; a second contact surface with which the coil comes into contact after passing through the first salient angle; a first non-contact surface provided between the first contact surface and the second contact surface with which the coil does not come into contact, the first non-contact surface having the first salient angle as its boundary with the second contact surface; a second salient angle different from the first salient angle, through which the coil passes after passing through the second contact surface; and a third contact surface with which the coil comes into contact after passing through the second salient angle, the third contact surface having a curved shape so as to protrude in a third direction different from the second direction as viewed in the first direction. a second non-contact surface that is different from the first non-contact surface, that is provided between the second contact surface and the third contact surface, that does not come into contact with the coil, and whose boundary with the second contact surface is the second convex angle.

[0143] (7) The magnetic core according to (6), wherein the wound portion further includes: a third convex angle, which is different from each of the first convex angle and the second convex angle, and through which the coil passes after passing through the third contact surface; a fourth contact surface with which the coil comes into contact after passing through the third convex angle; a third non-contact surface, which is provided between the third contact surface and the fourth contact surface and with which the coil does not come into contact, the boundary with the fourth contact surface being the third convex angle; a fourth convex angle, which is different from each of the first convex angle, the second convex angle, and the third convex angle, and through which the coil passes after passing through the fourth contact surface; and a fourth non-contact surface, which is different from the third non-contact surface, and is provided between the fourth contact surface and the first contact surface and with which the coil does not come into contact, the boundary with the fourth contact surface being the fourth convex angle; and the coil comes into contact with the first contact surface again after passing through the fourth convex angle.

[0144] (8) The magnetic core according to (6) or (7), wherein each of the first contact surface and the third contact surface has a semi-elliptical shape when viewed in the first direction.

[0145] (9) The magnetic core according to (8), in which the radius of the first contact surface and the radius of the third contact surface are equal to each other.

[0146] (10) The magnetic core according to any one of (6) to (9), wherein the wound portion has a shape that is point-symmetric when viewed in the first direction.

[0147] (11) The magnetic core according to any one of (6) to (10), wherein the second contact surface is connected to each of the first non-contact surface and the second non-contact surface via a notched surface.

[0148] (12) The magnetic core according to (7), wherein the fourth contact surface is connected to each of the third non-contact surface and the fourth non-contact surface via a notched surface.

[0149] (13) The magnetic core according to any one of (1) to (12), wherein the teeth are formed of a molded body made of soft magnetic powder.

[0150] (14) A magnetic core with a coil, comprising: the magnetic core according to any one of (1) to (13); and the coil.

[0151] (15) A rotating electrical machine comprising the magnetic core according to any one of (1) to (13).

[0152] (16) A brushless motor including the magnetic core according to any one of (1) to (13).

[0153] 1, 1a, 1b: Magnetic core 2: Core back portion 3: Teeth portion 10: Stator assembly 11: Bearing 11a: First bearing 11b: Second bearing 12: Housing 12a: First housing 12b: Second housing 13: Coil 14: Magnetic core with coil 20: Rotor 21: Shaft 22: Rotor member 23: Soft magnetic material 24: Hard magnetic material 31: Teeth main body portion 32: Teeth tip portion 100: Brushless motor A1: First convex angle A2: Second convex angle A3: Third convex angle A4: Fourth convex angle CA31: Central axis CS1: First contact surface CS2: Second contact surface CS3: Third contact surface CS4: Fourth contact surface DIR1: First direction DIR2: Second direction DIR3: Third direction DIR4: Fourth direction NCS1: First non-contact surface NCS2: Second non-contact surface NCS3: Third non-contact surface NCS4: Fourth non-contact surface NS1: First notch surface NS2: Second notch surface NS3: Third notch surface NS4: Fourth notch surface O2, O31, O32: Outer edge OCS1, OCS2, OCS3: Center OP: Opening RCS1, RCS2, RCS3: Radius S1: First principal surface S2: Second principal surface S3: Third principal surface S4: Fourth principal surface θ1, θ2, θ3, θ4: Bending angle

Claims

1. A magnetic core used in a rotating electrical machine, comprising a tooth portion having a shape extending in a first direction, wherein the tooth portion includes a wound portion around which a coil is wound, and the wound portion has a first convex angle through which the coil passes during the winding process of the coil, a first contact surface that contacts the coil before the coil passes through the first convex angle, and has a shape that curves so as to protrude in a second direction when viewed in the first direction, a first non-contact surface that the coil does not contact, and the boundary with the first contact surface is the first convex angle, a second contact surface that contacts the coil after the coil passes through the first convex angle, and has a shape that curves so as to protrude in a third direction different from the second direction when viewed in the first direction, and a magnetic core.

2. The wound portion has a convex angle different from the first convex angle, a second convex angle through which the coil passes after passing through the second contact surface, a second non-contact surface that the coil does not contact, and the boundary with the second contact surface is the second convex angle, and further has the coil contacts the first contact surface again after passing through the second convex angle, The magnetic core according to claim 1.

3. Each of the first contact surface and the second contact surface has a semi-elliptical shape when viewed in the first direction, The magnetic core according to claim 1 or claim 2.

4. The radius of the first contact surface and the radius of the second contact surface are equal to each other, The magnetic core according to claim 3.

5. The wound portion has a point-symmetrical shape when viewed in the first direction, The magnetic core according to claim 1 or claim 2.

6. A magnetic core used in a rotating electrical machine, comprising a tooth portion having a shape extending in a first direction, wherein the tooth portion includes a wound portion around which a coil is wound, and the wound portion has a first convex angle through which the coil passes during the winding process of the coil, a first contact surface that contacts the coil before the coil passes through the first convex angle, and has a shape that curves so as to protrude in a second direction when viewed in the first direction, a second contact surface that contacts the coil after the coil passes through the first convex angle, and a first non-contact surface provided between the first contact surface and the second contact surface and not contacted by the coil, and the boundary with the second contact surface is the first convex angle, a convex angle different from the first convex angle, a second convex angle through which the coil passes after passing through the second contact surface, a third contact surface that contacts the coil after the coil passes through the second convex angle, and has a shape that curves so as to protrude in a third direction different from the second direction when viewed in the first direction; a non-contact surface different from the first non-contact surface, a second non-contact surface provided between the second contact surface and the third contact surface and not contacted by the coil, and the boundary with the second contact surface is the second convex angle; having the position of the tip of the first contact surface in the second direction and the position of the tip of the third contact surface in the third direction are offset in a fourth direction orthogonal to the first direction and the second direction. a magnetic core.

7. The wound portion is a convex angle different from each of the first convex angle and the second convex angle, a third convex angle through which the coil passes after passing through the third contact surface, a fourth contact surface that contacts the coil after the coil passes through the third convex angle, a third non-contact surface provided between the third contact surface and the fourth contact surface and not contacted by the coil, and the boundary with the fourth contact surface is the third convex angle; is a convex angle different from each of the first convex angle, the second convex angle, and the third convex angle, a fourth convex angle through which the coil passes after passing through the fourth contact surface, a fourth non-contact surface different from the third non-contact surface, provided between the fourth contact surface and the first contact surface and not contacted by the coil, and the boundary with the fourth contact surface is the fourth convex angle; further having the coil contacts the first contact surface again after passing through the fourth convex angle. The magnetic core according to claim 6.

8. Each of the first contact surface and the third contact surface has a semi-elliptical shape when viewed in the first direction. The magnetic core according to claim 6 or claim 7.

9. The radius of the first contact surface and the radius of the third contact surface are equal to each other. The magnetic core according to claim 8.

10. The wound portion has a point-symmetrical shape when viewed in the first direction. The magnetic core according to claim 6 or claim 7.

11. The second contact surface is connected to each of the first non-contact surface and the second non-contact surface via a notch surface. The magnetic core according to claim 6 or claim 7.

12. The fourth contact surface is connected to each of the third non-contact surface and the fourth non-contact surface via a notch surface. The magnetic core according to claim 7.

13. The tooth portion is a molded body formed from soft magnetic powder. The magnetic core according to any one of claims 1, 2, 6, 7, and 12.

14. The magnetic core according to any one of claims 1, 2, 6, 7, and 12, and the coil, are provided. Magnetic core with coil.

15. Comprising the magnetic core according to any one of claims 1, 2, 6, 7, and 12. Rotating electrical machine.

16. Comprising the magnetic core according to any one of claims 1, 2, 6, 7, and 12. Brushless motor.