Magnetic material core, stator assembly, rotary electric machine, and brushless motor

Abstract

This magnetic material core, which is used in a rotary electric machine, comprises: a core back portion; and teeth portions that include teeth body portions extending in a first direction from the core back portion, and teeth tip portions provided to the tips of the teeth body portions in the first direction. When the magnetic material core is incorporated into a rotary electric machine, the position of the geometric center of the teeth portions in a second direction that follows a rotary shaft of the rotary electric machine is equal to the position of the geometric center of the core back portion. The position of a first line at the tips of the teeth body portions and the position of the first line at the ends of the teeth body portions on the opposite side from the tips are offset in the second direction, where the first line is a line that connects the geometric centers of cross-sections of the teeth body portions perpendicular to a third direction, and the third direction is an orthogonal projection of the first direction onto a plane that is orthogonal to the second direction.

Description

[Technical field]

[0001] The present invention relates to a magnetic core used in a rotating electric machine, a stator assembly including the magnetic core, a rotating electric machine including the magnetic core, and a brushless motor including the magnetic core. [Background technology]

[0002] As an example of a conventional invention related to a magnetic core, the magnetic core described in Patent Document 1 is known. The magnetic core described in Patent Document 1 includes teeth extending from an inner peripheral surface of a cylindrical yoke extending in a direction along the rotation axis in a direction opposite to the radial direction of the yoke, or teeth extending from an outer peripheral surface of a cylindrical yoke extending in a direction along the rotation axis in a radial direction of the yoke. Here, the rotation axis is the rotation axis of a rotating electric machine when the magnetic core is incorporated in the rotating electric machine. The teeth have a teeth main body portion around which a coil is wound, and teeth tip portions that protrude from the teeth main body portion in a direction along the rotation axis and in a circumferential direction of the yoke. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-060395 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the magnetic core described in Patent Document 1, there is a demand for miniaturizing the rotating electrical machine.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a magnetic core, a stator assembly, a rotating electric machine, and a brushless motor that enable the rotating electric machine to be miniaturized. [Means for solving the problem]

[0006] A magnetic core according to one embodiment of the present invention includes: A magnetic core for use in a rotating electrical machine, comprising: A core back portion, a teeth portion including a teeth main body portion extending in a first direction from the core back portion and a teeth tip portion provided at a tip of the teeth main body portion in the first direction; Equipped with a position of a geometric center of the teeth portion is equal to a position of a geometric center of the core back portion in a second direction that is a direction along a rotation axis of the rotating electric machine when the magnetic core is incorporated in the rotating electric machine, An orthogonal projection of the first direction onto a plane perpendicular to the second direction is defined as a third direction; A line connecting geometric centers of cross sections of the teeth main body portions perpendicular to the third direction is defined as a first line, A position of the first line at the tip of the tooth main body and a position of the first line at an end of the tooth main body opposite the tip are shifted in the second direction. Effect of the Invention

[0007] According to the present invention, it is possible to provide a magnetic core, a stator assembly, a rotating electric machine, and a brushless motor that can reduce the size of a rotating electric machine. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a magnetic core 1. FIG. [Diagram 2] FIG. 2 is a cross-sectional view of the magnetic core 1 as viewed in a fourth direction DIR4. [Diagram 3] FIG. 3 is an external perspective view of a brushless motor 100 in which the magnetic core 1 is used. [Figure 4] FIG. 4 is an exploded perspective schematic view of a brushless motor 100 in which the magnetic core 1 is used. [Diagram 5] FIG. 5 is a cross-sectional view of a magnetic core 6 according to a comparative example viewed in a fourth direction DIR4. [Figure 6]FIG. 6 is a cross-sectional view of a magnetic core 6 around which a coil 13 is wound and a connecting member 15 according to a comparative example, as viewed in a fourth direction DIR4. [Figure 7] FIG. 7 is a cross-sectional view of the magnetic core 1 around which the coil 13 is wound and the connecting member 15, as viewed in a fourth direction DIR4. [Figure 8] FIG. 8 is a perspective view of the magnetic core 1a. [Figure 9] FIG. 9 is a cross-sectional view of the magnetic core 1a viewed in a fourth direction DIR4. [Figure 10] FIG. 10 is an example of a cross-sectional view of the magnetic core 1 around which the coil 13 is wound, the connection member 15, and the wiring member 16, as viewed in the fourth direction DIR4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] (Configuration of magnetic core 1) Hereinafter, the configuration of a magnetic core 1 according to a first embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of the magnetic core 1. Fig. 2 is a cross-sectional view of the magnetic core 1 as viewed in a fourth direction DIR4.

[0010] In this specification, the directions are defined as follows. The direction in which the teeth main body 31 extends is defined as a first direction DIR1. The direction along the rotation axis of the brushless motor 100 when the magnetic core 1 is assembled in the brushless motor 100 is defined as a second direction DIR2. The orthogonal projection of the first direction DIR1 onto a plane perpendicular to the second direction DIR2 is defined as a third direction DIR3. The third direction DIR3 is different from the first direction DIR1. In addition, the direction perpendicular to the second direction DIR2 and the third direction DIR3 is defined as a fourth direction DIR4. However, the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 are directions defined for the purpose of explanation. Therefore, the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 during actual use of the magnetic core 1 do not necessarily have to coincide with the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 in this embodiment.

[0011] The magnetic core 1 is used in a brushless motor 100. The brushless motor 100 is an example of the "rotating electric machine" of the present invention.

[0012] As shown in Fig. 1, the magnetic core 1 includes a core back portion 2 and teeth portions 3. The magnetic core 1 is made of a soft magnetic material. When a magnetic field is applied from the outside, the soft magnetic material is magnetized. When the application of the magnetic field is then stopped, the soft magnetic material loses its magnetization. An example of the material of such a soft magnetic material is iron.

[0013] The magnetic core 1 is a molded body made of soft magnetic powder. That is, each of the core back portion 2 and the teeth portion 3 is a molded body made of soft magnetic powder. The material of the soft magnetic powder includes, for example, iron and a binder. The binder is, for example, a 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. Also, an insulating treatment is applied to the outer surface of the magnetic core 1.

[0014] As shown in Figs. 1 and 2, the core back portion 2 has a first main surface S1 and a second main surface S2 aligned in the third direction DIR3. The second main surface S2 is located in the third direction DIR3 further than the first main surface S1. As shown in Fig. 1, each of the first main surface S1 and the second main surface S2 has a rectangular shape when viewed in the third direction DIR3. As shown in Fig. 2, the core back portion 2 has a geometric center GC2. The geometric center GC2 is the position of the arithmetic mean taken over all points belonging to the core back portion 2. The core back portion 2 has a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction DIR2.

[0015] As shown in FIG. 1, the teeth portion 3 includes a teeth main body portion 31 and a teeth tip portion 32. As shown in FIG. 2, the teeth portion 3 has a geometric center GC3. The geometric center GC3 is the position of the arithmetic mean taken over all points belonging to the teeth portion 3. The teeth main body portion 31 extends in a first direction DIR1 from the core back portion 2. More specifically, the teeth main body portion 31 extends in the first direction DIR1 from the second main surface S2. The first direction DIR1 is not perpendicular to the second direction DIR2. Therefore, the third direction DIR3 is different from the first direction DIR1. The teeth main body portion 31 is in the shape of a quadrangular prism. The teeth main body portion 31 has a geometric center GC31. The geometric center GC31 is the position of the arithmetic mean taken over all points belonging to the teeth main body portion 31.

[0016] The teeth main body 31 is shown in FIG. 2 As shown in FIG. 2, the teeth main body portion 31 has a first end E1 and a second end E2, which are both ends in the second direction DIR2. The first end E1 is located further in the second direction DIR2 than the second end E2. As shown in FIG. 2, the teeth main body portion 31 has a geometric center GC31. Also, the position PGC31 of the geometric center GC31 of the teeth main body portion 31 in the second direction DIR2 is equal to the position PGC31 of the geometric center GC31 of the core back portion 2. As shown in FIGS. 3 and 4, the second direction DIR2 is a direction along the rotation axis of the brushless motor 100 when the magnetic core 1 is assembled in the brushless motor 100.

[0017] As shown in Figs. 1 and 2, the tooth tip portion 32 has a third principal surface S3 and a fourth principal surface S4 aligned in the third direction DIR3. The fourth principal surface S4 is located further in the third direction DIR3 than the third principal surface S3. Also, as shown in Fig. 1, each of the third principal surface S3 and the fourth principal surface S4 has a rectangular shape when viewed in the third direction DIR3. Note that the tooth tip portion 32 has a geometric center GC32 as shown in Fig. 2. The geometric center GC32 is the position of the arithmetic mean taken over all points belonging to the tooth tip portion 32. Also, the position PGC of the geometric center GC32 of the tooth tip portion 32 in the second direction DIR2 32is equal to the position PGC2 of the geometric center GC2 of the core back portion 2. In addition, the teeth tip portions 32 have a shape that is plane-symmetric with respect to a plane perpendicular to the second direction DIR2.

[0018] 1, the tooth tip portions 32 have a first end face EF1 facing the second direction DIR2 and a second end face EF2 facing the opposite direction to the second direction DIR2. The first end face EF1 is located further in the second direction DIR2 than the second end face EF2. The tooth tip portions 32 are provided at the ends of the tooth main bodies 31 in the first direction DIR1 as shown in FIG.

[0019] An outer edge O2 of the core back portion 2 as viewed in the third direction DIR3 surrounds an outer edge O31 of the tooth main body portion 31 as viewed in the third direction DIR3, as shown in Fig. 1. In addition, an outer edge O32 of the tooth tip portion 32 as viewed in the third direction DIR3 surrounds the outer edge O31 of the tooth main body portion 31 as viewed in the third direction DIR3. In addition, the length of the tooth main body portion 31 in the second direction DIR2 is uniform in the third direction DIR3, as shown in Fig. 2.

[0020] In the second direction DIR2, the position PGC3 of the geometric center GC3 of the teeth portion 3 is equal to the position PGC2 of the geometric center GC2 of the core back portion 2, as shown in FIG.

[0021] Here, a line connecting the geometric centers of the cross sections of the teeth main body 31 perpendicular to the third direction DIR3 is defined as the first line L1. The geometric center of the cross section of the teeth main body 31 perpendicular to the third direction DIR3 is the position of the arithmetic mean taken over all points belonging to the cross section of the teeth main body 31 perpendicular to the third direction DIR3. In this embodiment, the first line L1 is a straight line as shown in FIG. 2. In addition, the position of the first line L1 at the tip of the teeth main body 31 in the first direction DIR1 and the position of the first line L1 at the end of the teeth main body 31 opposite to the tip are shifted in the second direction DIR2. More specifically, in this embodiment, the first line L1 at the tip of the teeth main body 31 in the first direction DIR1 is located in the opposite direction to the second direction DIR2 than the first line L1 at the end of the teeth main body 31 opposite to the tip of the teeth main body 31 in the first direction DIR1.

[0022] (Configuration of brushless motor 100) The configuration of a brushless motor 100 according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 3 is an external perspective view of the brushless motor 100 using a magnetic core 1. Fig. 4 is an exploded perspective schematic view of the brushless motor 100 using a magnetic core 1. Note that in Fig. 4, reference symbols are given only to representative magnetic cores 1, coils 13, and insulating members 14 out of the multiple magnetic cores 1, multiple coils 13, and multiple insulating members 14.

[0023] As shown in Fig. 4, the brushless motor 100 includes a rotor 20 and a stator assembly 10. As shown in Fig. 4, the stator assembly 10 is disposed around the rotor 20 when viewed in the second direction DIR2. In other words, the brushless motor 100 is an inner rotor type.

[0024] As shown in Fig. 4, the rotor 20 includes a shaft 21 and a rotor member 22. The shaft 21 has a shape extending 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.

[0025] As shown in FIG. 4, the rotor member 22 includes a soft magnetic body 23 and a hard magnetic body 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 body 23 is attached to the outer circumferential surface of the shaft 21 in the radial direction centered on the Z axis. The hard magnetic body 24 is attached to the outer circumferential surface of the soft magnetic body 23 in the radial direction centered on the Z axis. The rotor member 22 is disposed such that the position PGC22 in the second direction DIR2 of the geometric center GC22 of the rotor member 22 is equal to the position PGC2 in the second direction DIR2 of the geometric center GC2 of the core back portion 2. The geometric center GC22 is the position of the arithmetic mean taken over all points belonging to the rotor member 22.

[0026] 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 a magnetic field is applied from the outside. Even if the application of the magnetic field is stopped thereafter, the hard magnetic body does not lose its magnetization. Such a hard magnetic body material is a magnet.

[0027] 4, the stator assembly 10 includes a bearing 11, a housing 12, a plurality of magnetic cores 1, a plurality of coils 13, a plurality of insulating members 14, and connecting members 15. That is, the brushless motor 100 includes the magnetic core 1.

[0028] 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. 4, 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 axis of each of the first bearing 11a and the second bearing 11b is the Z-axis. In other words, the central axis of each of the first bearing 11a and the second bearing 11b coincides with the central axis of the shaft 21.

[0029] 4, the first bearing 11a is positioned further in the second direction DIR2 than the second bearing 11b. Also, the first bearing 11a is positioned further in the second direction DIR2 than the rotor member 22. The second bearing 11b is positioned on the opposite side of the second direction DIR2 than the rotor member 22. The second bearing 11b supports the end of the shaft 21 on the opposite side in the second direction DIR2.

[0030] As shown in Fig. 3, the housing 12 has a first housing 12a and a second housing 12b. As shown in Figs. 3 and 4, the first housing 12a is cylindrical. The central axis of the first housing 12a is the Z-axis. The first housing 12a is positioned further in the second direction DIR2 than the second housing 12b. The first housing 12a also has an opening OP. As a result, the end of the shaft 21 in the second direction DIR2 protrudes from the opening OP in the second direction DIR2. In other words, the brushless motor 100 is a single-shaft type.

[0031] The first housing 12a supports the first bearing 11a, the multiple magnetic cores 1, the multiple coils 13, and the multiple insulating members 14. The second housing 12b supports the second bearing 11b. The material of each of the first housing 12a and the second housing 12b is a highly rigid material such as SUS.

[0032] The number of the magnetic cores 1, the coils 13, and the insulating members 14 is nine. The nine coils 13 and the nine insulating members 14 are provided corresponding to the nine magnetic cores 1. More specifically, if a set including one magnetic core 1, one coil 13, and one insulating member 14 is defined as one set, the nine sets are arranged in the circumferential direction centered on the Z axis. Each set is disposed around the hard magnetic body 24 with a gap therebetween. The structures of the sets are the same. Therefore, one set including one magnetic core 1, one coil 13, and one insulating member 14 will be described.

[0033] 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. As a result, the magnetic core 1 generates a magnetic force that rotates the rotor. Note that an air gap exists between the magnetic core 1 and the rotor member 22, as shown in Fig. 4. In this embodiment, the first direction DIR1 is a direction toward the rotation axis of the brushless motor 100 when the magnetic core 1 is incorporated in the brushless motor 100.

[0034] As shown in Fig. 4, the coil 13 is wound around the tooth main body 31 so as to be located around the magnetic core 1 when viewed in the radial direction centered on the Z-axis. 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 film. The coil 13 generates a magnetic field when a current flows through the coil 13.

[0035] The insulating member 14 is an insulator. As shown in FIG. 4, the insulating member 14 is disposed between the magnetic core 1 and the coil 13. This electrically insulates the magnetic core 1 and the coil 13. In this embodiment, the insulating member 14 is in the form of a film, but may be in the form of a plate. The insulating member 14 may be disposed such that a part of the insulating member 14 is disposed between the magnetic core 1 and the coil 13. Therefore, the insulating member 14 may be disposed on the entire surface of the coil 13.

[0036] The connecting member 15 is electrically connected to the coil 13. The connecting member 15 is, for example, a substrate. The substrate includes a substrate body (not shown) and a plurality of mounting electrodes (not shown) provided on the surface of the substrate body. The substrate body is a glass epoxy substrate. The plurality of mounting electrodes are copper electrodes. The coil 13 is electrically connected to each of the plurality of mounting electrodes.

[0037] 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.

[0038] [effect] The magnetic core 1 allows the brushless motor 100 to be made smaller. The reason why the brushless motor 100 can be made smaller will be described with reference to the drawings. FIG. 5 is a cross-sectional view of the magnetic core 6 according to a comparative example, viewed in the fourth direction DIR4. FIG. 6 is a cross-sectional view of the magnetic core 6 according to the comparative example around which the coil 13 is wound, and the connecting member 15, viewed in the fourth direction DIR4. FIG. 7 is a cross-sectional view of the magnetic core 1 around which the coil 13 is wound, and the connecting member 15, viewed in the fourth direction DIR4. Note that the number of turns of the coil 13 is equal in FIG. 6 and FIG. 7.

[0039] First, the magnetic core 6 according to the comparative example will be described. Note that, for the magnetic core 6 according to the comparative example, only the parts different from the magnetic core 1 will be described, and the rest will be omitted. In the magnetic core 6 according to the comparative example, the third direction DIR3 is equal to the first direction DIR1 as shown in FIG. 5. Therefore, in the magnetic core 6 according to the comparative example, the position of the first line L1 in the second direction DIR2 at the tip of the tooth main body 31 in the first direction DIR1 is equal to the position of the first line L1 in the second direction DIR2 at the end of the tooth main body 31 opposite to the tip. In other words, the position of the first line L1 at the tip of the tooth main body 31 in the first direction DIR1 and the position of the first line L1 at the end of the tooth main body 31 opposite to the tip are not shifted in the second direction DIR2.

[0040] When the magnetic core 6 according to the comparative example is incorporated into the brushless motor 100, the coil 13 is wound around the tooth main body 31 as shown in Fig. 6. When the connecting member 15 is disposed in a region that overlaps with the tooth portion 3 when viewed in the second direction DIR2 and is located in the opposite direction of the second direction DIR2 from the tooth portion 3, the end of the connecting member 15 in the opposite direction of the second direction DIR2 may be located in the opposite direction of the second direction DIR2 from the end of the core back portion 2 in the opposite direction of the second direction DIR2. This increases the length of the brushless motor 100 in the second direction DIR2.

[0041] In the magnetic core 1, the position of the first line L1 at the tip of the tooth main body 31 in the first direction DIR1 and the position of the first line L1 at the end of the tooth main body 31 opposite to the tip are shifted in the second direction DIR2. More specifically, the first line L1 at the tip of the tooth main body 31 in the first direction DIR1 is located in the opposite direction to the second direction DIR2 than the first line L1 at the end of the tooth main body 31 opposite to the tip of the tooth main body 31 in the first direction DIR1. As a result, the coil 13 according to the first embodiment of the present invention is located further in the second direction DIR2 than the coil 13 according to the comparative example, as shown in FIG. Therefore, even if the connecting member 15 is disposed in a region overlapping with the teeth portion 3 as viewed in the second direction DIR2 and located in the opposite direction of the second direction DIR2 from the teeth portion 3, the end of the connecting member 15 in the opposite direction of the second direction DIR2 can be located in the second direction DIR2 further than the end of the core back portion 2 in the opposite direction of the second direction DIR2. In this case, the connecting member 15 is located on the core back portion 2 side between the teeth tip portion 32 and the core back portion 2, and in the opposite direction of the second direction DIR2 from the teeth main body portion 31. As a result, the length in the second direction DIR2 of the brushless motor 100 according to the first embodiment of the present invention can be made shorter than the length in the second direction DIR2 of the brushless motor 100 according to the comparative example. Therefore, the magnetic core 1 allows the brushless motor 100 to be made low-profile and small-sized.

[0042] The magnetic core 1 can be easily formed. More specifically, each of the core back portion 2 and the tooth tip portion 32 has a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction DIR2. Therefore, for example, when the magnetic core 1 is manufactured by press molding, the magnetic core 1 can be manufactured by using a die having a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction DIR2 and a punch having a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction DIR2. As a result, the magnetic core 1 can be easily formed.

[0043] [First Modification] A magnetic core 1a according to a first modified example of the present invention will be described below with reference to the drawings. Fig. 8 is a perspective view of the magnetic core 1a. Fig. 9 is a cross-sectional view of the magnetic core 1a viewed in the fourth direction DIR4. Note that, regarding the magnetic core 1a according to the first modified example, only the parts different from the magnetic core 1 according to the first embodiment will be described, and the rest will be omitted.

[0044] As shown in FIGS. 8 and 9, the magnetic core 1a differs from the magnetic core 1 in that the first line L1 is a broken line.

[0045] The magnetic core 1a as described above also provides the same effects as the magnetic core 1.

[0046] [Second embodiment] A stator assembly 10a according to a second embodiment of the present invention will be described below with reference to the drawings. Fig. 10 is an example of a cross-sectional view of the magnetic core 1 around which the coil 13 is wound and the wiring member 16, as viewed in the fourth direction DIR4. Note that, regarding the stator assembly 10a according to the second embodiment, only the parts that are different from the stator assembly 10 according to the first embodiment will be described, and the rest will be omitted.

[0047] The stator assembly 10a differs from the stator assembly 10 in that the stator assembly 10a further includes a wiring member 16. The wiring member 16 is, for example, a bus bar.

[0048] As shown in FIG. 10, the wiring members 16 are disposed in regions that overlap with the teeth portions 3 when viewed in the second direction DIR2 and that are located further in the second direction DIR2 than the teeth portions 3.

[0049] According to the stator assembly 10a, even if the wiring member 16 is disposed in a region overlapping with the teeth portion 3 as viewed in the second direction DIR2 and located further in the second direction DIR2 than the teeth portion 3, the end of the wiring member 16 in the second direction DIR2 can be located in the opposite direction of the second direction DIR2 than the end of the core back portion 2 in the second direction DIR2. In this case, the wiring member 16 is located on the tooth tip portion 32 side between the tooth tip portion 32 and the core back portion 2, and further in the second direction DIR2 than the tooth main body portion 31. As a result, the length of the brushless motor 100 in the second direction DIR2 can be made shorter than the length of the brushless motor 100 in the second direction DIR2 according to the comparative example. Therefore, according to the stator assembly 10a, the brushless motor 100 can be made low-profile and small-sized.

[0050] Alternatively, the connecting members 15 may be located on the tooth tip portions 32 side between the tooth tip portions 32 and the core back portion 2, and further in the second direction DIR2 than the tooth main body portion 31, and the wiring members 16 may be located on the core back portion 2 side between the tooth tip portions 32 and the core back portion 2, and further in the opposite direction in the second direction DIR2 than the tooth main body portion 31. Even in this case, the brushless motor 100 can be made low-profile and small-sized.

[0051] [Other embodiments] The magnetic core according to the present invention is not limited to the magnetic cores 1 and 1a, and may be modified within the scope of the present invention. Furthermore, the structures of the magnetic cores 1 and 1a may be combined in any manner.

[0052] The stator assembly according to the present invention is not limited to the stator assemblies 10 and 10a, and may be modified within the scope of the present invention. Furthermore, the structures of the stator assemblies 10 and 10a may be combined in any manner.

[0053] The rotating electric machine may have a structure in which the rotor is rotated by electricity or the rotor is rotated to generate electricity. In this case, the rotating electric machine may have at least one of the magnetic cores 1 and 1a, and may have brushes.

[0054] The magnetic cores 1, 1a may be made by laminating electromagnetic steel sheets. The magnetic cores 1, 1a may be made of any soft magnetic material.

[0055] The outer surfaces of the magnetic cores 1 and 1a do not necessarily need to be subjected to insulation treatment.

[0056] 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 third direction DIR3.

[0057] The core-back portion 2 does not necessarily have to have a shape symmetrical with respect to a plane perpendicular to the second direction DIR2.

[0058] The tooth main body 31 does not have to be in the shape of a quadrangular prism.

[0059] The position PGC31 of the geometric center GC31 of the tooth main body portion 31 in the second direction DIR2 may be different from the position PGC31 of the geometric center GC31 of the core back portion 2.

[0060] 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 third direction DIR3.

[0061] The position PGC of the geometric center GC32 of the tooth tip portion 32 in the second direction DIR2 32 may be different from the position PGC2 of the geometric center GC2 of the core-back portion 2.

[0062] It should be noted that tooth tip portions 32 do not necessarily have a shape that is symmetrical with respect to a plane perpendicular to second direction DIR2.

[0063] The outer edge O2 of the core back portion 2 as viewed in the third direction DIR3 does not have to surround the outer edge O31 of the tooth main body portion 31 as viewed in the third direction DIR3. Moreover, the outer edge O32 of the tooth tip portion 32 as viewed in the third direction DIR3 does not have to surround the outer edge O31 of the tooth main body portion 31 as viewed in the third direction DIR3.

[0064] The length of the tooth main body 31 in the second direction DIR2 does not have to be uniform in the third direction DIR3.

[0065] The first line L1 is not limited to a straight line or a broken line, and may be a curved line. Moreover, the first line L1 may include a straight line or a curved line.

[0066] In addition, the first line L1 at the tip of the tooth main body 31 in the first direction DIR1 may be located in the second direction DIR2 further than the first line L1 at the end of the tooth main body 31 opposite to the tip of the tooth main body 31 in the first direction DIR1. In this case, even if the connecting member 15 is arranged in a region that overlaps with the tooth portion 3 as viewed in the second direction DIR2 and is located in the opposite direction of the second direction DIR2 from the tooth portion 3, the end of the connecting member 15 in the opposite direction of the second direction DIR2 can be located in the second direction DIR2 further than the end of the core back portion 2 in the opposite direction of the second direction DIR2. Therefore, even in this case, the length of the brushless motor 100 in the second direction DIR2 can be made shorter than the length of the brushless motor 100 in the second direction DIR2 according to the comparative example. As a result, the brushless motor 100 can be made smaller in size.

[0067] The brushless motor 100 may be an outer rotor type. In this case, the first direction DIR1 is the opposite direction to the direction toward the rotation shaft of the brushless motor 100 when the magnetic core 1 is assembled in the brushless motor 100.

[0068] It should be noted that the brushless motor 100 is not limited to a single-shaft type, but may be, for example, a double-shaft type.

[0069] It should be noted that each of the first bearing 11a and the second bearing 11b is not limited to a ball bearing.

[0070] The materials for first housing 12a and second housing 12b may be any materials having high rigidity.

[0071] The number of each of the magnetic cores 1, the coils 13, and the insulating members 14 is not limited to 9. It is sufficient that each of the coils 13 and each of the insulating members 14 is provided corresponding to each of the magnetic cores 1.

[0072] The connecting member 15 is not limited to a substrate. For example, the connecting member 15 may be a terminal block. Furthermore, the connecting member 15 is not an essential component of the stator assembly 10a.

[0073] The wiring member 16 is not limited to a bus bar, and may be, for example, a cable.

[0074] The present invention has the following configuration.

[0075] (1) A magnetic core for use in a rotating electrical machine, comprising: A core back portion, a teeth portion including a teeth main body portion extending in a first direction from the core back portion and a teeth tip portion provided at a tip of the teeth main body portion in the first direction; Equipped with a position of a geometric center of the teeth portion is equal to a position of a geometric center of the core back portion in a second direction that is a direction along a rotation axis of the rotating electric machine when the magnetic core is incorporated in the rotating electric machine, An orthogonal projection of the first direction onto a plane perpendicular to the second direction is defined as a third direction; A line connecting geometric centers of cross sections of the teeth main body portions perpendicular to the third direction is defined as a first line, a position of the first line at the tip of the tooth main body portion and a position of the first line at an end of the tooth main body portion opposite to the tip are shifted in the second direction. Magnetic core.

[0076] (2) The first line is a straight line. The magnetic core according to (1).

[0077] (3) The first line is a broken line. The magnetic core according to (1).

[0078] (4) The core back portion has a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction, The tip portions of the teeth have a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction. A magnetic core according to any one of (1) to (3).

[0079] (5) The length of the tooth main body portion in the second direction is uniform in the third direction. A magnetic core according to any one of (1) to (4).

[0080] (6) Each of the core back portion and the teeth portion is a molded body formed from soft magnetic powder. A magnetic core according to any one of (1) to (5).

[0081] (7) The material of the soft magnetic powder includes iron and resin; The magnetic core according to (6).

[0082] (8) A magnetic core according to any one of (1) to (7); A connecting member; Equipped with the first line at an end of the tooth body opposite to the tip is positioned in the second direction further than the first line at the tip of the tooth body, the connecting member is located on the core back portion side between the tooth tip portion and the core back portion, and in a direction opposite to the second direction from the tooth main body portion. Stator assy.

[0083] (9) A magnetic core according to any one of (1) to (7); A wiring member; Equipped with the first line at an end of the tooth body opposite to the tip is positioned in the second direction further than the first line at the tip of the tooth body, the wiring member is located on the tooth tip side between the tooth tip portion and the core back portion and further in the second direction than the tooth main body portion. Stator assy.

[0084] (10) A magnetic core according to any one of (1) to (7), Rotating electrical machines.

[0085] (11) A magnetic core according to any one of (1) to (7), Brushless motor. [Explanation of symbols]

[0086] 1, 1a, 6: Magnetic core 2: Core back part 3: Teeth 10, 10a: Stator assembly 11: Bearings 11a: First bearing 11b: Second bearing 12: Housing 12a: First cabinet 12b: Second cabinet 13: Coil 14: Insulating material 15: Wiring material 16: Wiring materials 20:Rota 21: Shaft 22: Rotor parts 23: Soft magnetic material 24:Hard magnetic material 31: Teeth body 32: Teeth tip 100: Brushless motor DIR1: 1st direction DIR2:Second direction DIR3: Third direction DIR4: Fourth direction E1: 1st end E2: 2nd end EF1: 1st end face EF2: 2nd end face GC2,GC22,GC3,GC31,GC32: Geometric center L1: 1st line O2, O31, O32: Outer periphery OP: Opening S1: First main surface S2: 2nd principal surface S3: Third main surface S4: Fourth main surface

Claims

1. A magnetic core for use in a rotating electrical machine, comprising: A core back portion, a teeth portion including a teeth main body portion extending in a first direction from the core back portion and a teeth tip portion provided at a tip of the teeth main body portion in the first direction; It is equipped with a position of a geometric center of the teeth portion is equal to a position of a geometric center of the core back portion in a second direction that is a direction along a rotation axis of the rotating electric machine when the magnetic core is assembled in the rotating electric machine; An orthogonal projection of the first direction onto a plane perpendicular to the second direction is defined as a third direction; A line connecting geometric centers of cross sections of the teeth main body portions perpendicular to the third direction is defined as a first line, a position of the first line at the tip of the tooth main body portion and a position of the first line at an end of the tooth main body portion opposite to the tip are shifted in the second direction. Magnetic core.

2. The first line is a straight line. The magnetic core according to claim 1 .

3. The first line is a broken line. The magnetic core according to claim 1 .

4. The core back portion has a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction, The tip end portion of the teeth has a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction. The magnetic core according to claim 1 .

5. The length of the tooth main body portion in the second direction is uniform in the third direction. The magnetic core according to claim 1 .

6. Each of the core back portion and the teeth portion is a molded body formed from soft magnetic powder. The magnetic core according to claim 1 .

7. The material of the soft magnetic powder includes iron and resin; The magnetic core according to claim 6.

8. A magnetic core according to any one of claims 1 to 3, A connecting member; It is equipped with the first line at an end of the tooth body portion opposite to the tip is positioned in the second direction further than the first line at the tip of the tooth body portion, the connecting member is located on the core back portion side between the tooth tip portion and the core back portion and in a direction opposite to the second direction from the tooth main body portion. Stator assy.

9. A magnetic core according to any one of claims 1 to 3, A wiring member; It is equipped with the first line at an end of the tooth body portion opposite to the tip is positioned in the second direction further than the first line at the tip of the tooth body portion, the wiring member is located on the tooth tip portion side between the tooth tip portion and the core back portion and further in the second direction than the tooth main body portion. Stator assy.

10. A magnetic core comprising the magnetic core according to any one of claims 1 to 3. Rotating electrical machines.

11. A magnetic core comprising the magnetic core according to any one of claims 1 to 3. Brushless motor.