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

Abstract

A magnetic core, a stator assembly, a rotary electrical machine and a brushless motor are provided. This magnetic core is used in a rotary electric machine, and is provided with: a core back; and a tooth portion including a tooth main body portion extending in a first direction from the core back portion, and a tooth tip portion provided at a tip of the tooth main body portion in the first direction, the tooth tip portion being provided at a tip of the tooth main body portion in the first direction, the tooth tip portion being provided in a second direction that is a direction along a rotation axis of the rotating electrical machine when the magnetic core is assembled in the rotating electrical machine. The position of the geometric center of the tooth portion is equal to the position of the geometric center of the iron core back portion, an orthographic projection obtained by projection of the first direction in a plane orthogonal to the second direction is defined as a third direction, and a line connecting geometric centers of cross sections perpendicular to the third direction of the tooth main body portion is defined as a first line. The position of the first line at the tip of the tooth body and the position of the first line at the end of the tooth body on the opposite side from the tip are shifted in 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 Art

[0002] As an existing invention related to a magnetic core, for example, a magnetic core described in Patent Document 1 is known. The magnetic core described in Patent Document 1 includes: a tooth portion extending from the inner peripheral surface of a cylindrical yoke portion extending in the direction along the rotation axis toward the opposite direction of the radial direction of the yoke portion, or a tooth portion extending from the outer peripheral surface of a cylindrical yoke portion extending in the direction along the rotation axis toward the radial direction of the yoke portion. Here, the rotation axis is the rotation axis of the rotating electrical machine when the magnetic core is assembled in the rotating electrical machine. The tooth portion includes: a tooth body portion for winding a coil, and a tooth tip portion protruding in the direction along the rotation axis and in the circumferential direction of the yoke portion relative to the tooth body portion.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-060395

[0004] However, in the magnetic core described in Patent Document 1, it is desired to reduce the size of the rotating electrical machine. Summary of the invention

[0005] Therefore, an object of the present invention is to provide a magnetic core, a stator assembly, a rotating electric machine, and a brushless motor capable of miniaturizing a rotating electric machine.

[0006] A magnetic core according to one embodiment of the present invention is a magnetic core used in a rotating electrical machine, and comprises: a core back; and a tooth portion, comprising a tooth body portion extending from the core back in a first direction and a tooth terminal portion provided at an end of the tooth body portion in the first direction, wherein in a second direction which is a direction along the axis of rotation of the rotating electrical machine when the core is assembled in the rotating electrical machine, the position of the geometric center of the tooth portion is equal to the position of the geometric center of the core back, an orthographic projection of the first direction onto a plane orthogonal to the second direction is defined as a third direction, a line connecting the geometric centers of the tooth body portions in a cross section perpendicular to the third direction is defined as a first line, and a position of the first line at the terminal of the tooth body portion and a position of the first line at an end of the tooth body portion on the opposite side to the terminal are offset in the second direction.

[0007] According to the present invention, it is possible to provide a magnetic core, a stator assembly, a rotary electric machine, and a brushless motor capable of miniaturizing a rotary electric machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1It is a three-dimensional diagram of the magnetic core 1.

[0009] Figure 2 This is a cross-sectional view of the magnetic core 1 when viewed in the fourth direction DIR4.

[0010] Figure 3 1 is a perspective view of the appearance of a brushless motor 100 using the magnetic core 1 .

[0011] Figure 4 It is an exploded perspective schematic diagram of a brushless motor 100 using the magnetic core 1 .

[0012] Figure 5 This is a cross-sectional view of the magnetic core 6 according to the comparative example when viewed in the fourth direction DIR4.

[0013] Figure 6 This is a cross-sectional view of the magnetic core 6 and the wiring member 15 according to the comparative example around which the coil 13 is wound, as viewed in the fourth direction DIR4.

[0014] Figure 7 This is a cross-sectional view of the magnetic core 1 and the wiring member 15 around which the coil 13 is wound, as viewed in the fourth direction DIR4.

[0015] Figure 8 It is a perspective view of the magnetic core 1a.

[0016] Fig. 9 This is a cross-sectional view of the magnetic core 1a when viewed in the fourth direction DIR4.

[0017] Fig.10 This is an example of a cross-sectional view of the magnetic core 1 around which the coil 13 is wound, the wiring member 15, and the wiring member 16 as viewed in the fourth direction DIR4. DETAILED DESCRIPTION

[0018] [First embodiment]

[0019] (Structure of magnetic core 1)

[0020] Hereinafter, the structure of the magnetic core 1 according to the first embodiment of the present invention will be described with reference to the drawings. Figure 1 It is a three-dimensional diagram of the magnetic core 1. Figure 2 This is a cross-sectional view of the magnetic core 1 when viewed in the fourth direction DIR4.

[0021] In this specification, directions are defined as follows. The direction in which the tooth body portion 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 orthographic projection obtained by projecting the first direction DIR1 onto a plane orthogonal 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 orthogonal 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 when the magnetic core 1 is actually used may not necessarily be consistent with the first direction DIR1, the second direction DIR2, the third direction DIR3, and the fourth direction DIR4 of the present embodiment.

[0022] The core 1 is used for a brushless motor 100. The brushless motor 100 is an example of the "rotating electric machine" of the present invention.

[0023] like Figure 1 As shown, the magnetic core 1 includes a core back 2 and a tooth portion 3. The magnetic core 1 is a soft magnetic body. If a magnetic field is applied from the outside, the soft magnetic body is magnetized. Thereafter, if the application of the magnetic field is stopped, the soft magnetic body loses magnetization. The material of such a soft magnetic body is, for example, iron.

[0024] The magnetic core 1 is a molded body formed of soft magnetic powder. That is, the core back 2 and the tooth 3 are each a molded body formed 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 material obtained by mixing iron powder and epoxy resin as an example of a binder. Such a magnetic core 1 is made, for example, by press molding. In addition, an insulation treatment is applied to the outer surface of the magnetic core 1.

[0025] like Figure 1 and Figure 2 As shown in FIG. 1 , the core back 2 has a first main surface S1 and a second main surface S2 arranged in the third direction DIR3. The second main surface S2 is located closer to the third direction DIR3 than the first main surface S1. Figure 1 As shown in FIG. 1 , when viewed in the third direction DIR3, the first main surface S1 and the second main surface S2 each have a rectangular shape. Figure 2 As shown, the core back 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 2. In addition, the core back 2 has a shape that is plane-symmetrical with respect to a plane orthogonal to the second direction DIR2.

[0026] like Figure 1 As shown in FIG. 1 , the tooth portion 3 includes a tooth body portion 31 and a tooth tip portion 32. Figure 2 As shown, the tooth 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 tooth portion 3. The tooth body portion 31 extends from the core back 2 to the first direction DIR1. In more detail, the tooth body portion 31 extends from the second main surface S2 to the first direction DIR1. In addition, the first direction DIR1 is not orthogonal to the second direction DIR2. Therefore, the third direction DIR3 is different from the first direction DIR1. In addition, the tooth body portion 31 is a quadrangular prism. In addition, the tooth 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 tooth body portion 31.

[0027] like Figure 1 As shown in FIG. 1 , the tooth body portion 31 has two ends in the second direction DIR2, namely, a first end E1 and a second end E2. The first end E1 is located closer to the second direction DIR2 than the second end E2. Figure 2 As shown, the tooth body 31 has a geometric center GC31. In addition, the position PGC31 of the geometric center GC31 of the tooth body 31 in the second direction DIR2 is equal to the position PGC31 of the geometric center GC31 of the core back 2. Figure 3 and Figure 4 As shown, the second direction DIR2 is a direction along the rotation axis of the brushless motor 100 when the core 1 is assembled in the brushless motor 100 .

[0028] like Figure 1 and Figure 2 As shown in FIG. 1 , the tooth end portion 32 has a third main surface S3 and a fourth main surface S4 arranged in the third direction DIR3. The fourth main surface S4 is located closer to the third direction DIR3 than the third main surface S3. Figure 1 As shown in FIG. 1 , the third main surface S3 and the fourth main surface S4 each have a rectangular shape. Figure 2 As shown, the tooth end portion 32 has a geometric center GC32. The geometric center GC32 is the position of the arithmetic mean taken over all points belonging to the tooth end portion 32. In addition, the position PGC2 of the geometric center GC32 of the tooth end portion 32 in the second direction DIR2 is equal to the position PGC2 of the geometric center GC2 of the core back 2. In addition, the tooth end portion 32 has a symmetrical shape with respect to a plane orthogonal to the second direction DIR2.

[0029] In addition, if Figure 1As shown in FIG. 1 , the tooth end portion 32 has a first end surface EF1 facing in the second direction DIR2 and a second end surface EF2 facing in the opposite direction to the second direction DIR2. The first end surface EF1 is located closer to the second end surface EF2 in the second direction DIR2. Figure 1 As shown, such a tooth terminal portion 32 is provided at the terminal end of the tooth main body portion 31 in the first direction DIR1.

[0030] like Figure 1 As shown, the outer edge O2 of the core back 2 observed in the third direction DIR3 surrounds the outer edge O31 of the tooth body 31 observed in the third direction DIR3. In addition, the outer edge O32 of the tooth tip 32 observed in the third direction DIR3 surrounds the outer edge O31 of the tooth body 31 observed in the third direction DIR3. In addition, as Figure 2 As shown, in the third direction DIR3 , the length of the tooth body portion 31 in the second direction DIR2 is uniform.

[0031] like Figure 2 As shown, in the second direction DIR2, the position PGC3 of the geometric center GC3 of the tooth portion 3 is equal to the position PGC2 of the geometric center GC2 of the core back 2.

[0032] Here, a line connecting the geometric centers of the cross sections of the tooth body 31 perpendicular to the third direction DIR3 is defined as the first line L1. The geometric center of the cross section of the tooth body 31 perpendicular to the third direction DIR3 is the position of the arithmetic mean of all points of the cross section perpendicular to the third direction DIR3 belonging to the tooth body 31. Figure 2 As shown, the first line L1 is a straight line. In addition, the position of the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 is offset from the position of the first line L1 at the end of the tooth body portion 31 on the opposite side of the end in the second direction DIR2. More specifically, in the present embodiment, the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 is located in the opposite direction of the second direction DIR2 than the first line L1 at the end of the tooth body portion 31 on the opposite side of the end of the tooth body portion 31 in the first direction DIR1.

[0033] (Structure of Brushless Motor 100)

[0034] Hereinafter, the structure of the brushless motor 100 according to the first embodiment of the present invention will be described with reference to the drawings. Figure 3 1 is a perspective view of the appearance of a brushless motor 100 using the magnetic core 1 . Figure 4 1 is an exploded perspective schematic diagram of a brushless motor 100 using the magnetic core 1. Figure 4In the drawings, only representative magnetic cores 1 , coils 13 , and insulating members 14 among the plurality of magnetic cores 1 , the plurality of coils 13 , and the plurality of insulating members 14 are denoted by reference numerals.

[0035] like Figure 4 As shown, the brushless motor 100 includes a rotor 20 and a stator assembly 10. Figure 4 As shown, when viewed in the second direction DIR2, the stator assembly 10 is disposed around the rotor 20. That is, the brushless motor 100 is an inner rotor type.

[0036] like Figure 4 As shown, the rotor 20 includes a shaft body 21 and a rotor member 22. The shaft body 21 has a shape extending in the second direction DIR2. In more detail, the shaft body 21 is cylindrical. The rotor member 22 is cylindrical. The central axis of each of the shaft body 21 and the rotor member 22 is the Z axis. That is, the rotation axis of the brushless motor 100 is the Z axis. Therefore, the second direction DIR2 is a direction along the Z axis.

[0037] like Figure 4 As shown, the rotor component 22 includes a soft magnetic body 23 and a hard magnetic body 24. The rotor component 22 is mounted on the outer peripheral surface of the shaft body 21 in the radial direction with the Z axis as the center. In more detail, the soft magnetic body 23 is mounted on the outer peripheral surface of the shaft body 21 in the radial direction with the Z axis as the center. The hard magnetic body 24 is mounted on the outer peripheral surface of the soft magnetic body 23 in the radial direction with the Z axis as the center. In addition, the rotor component 22 is configured so that the position PGC22 of the geometric center GC22 of the rotor component 22 in the second direction DIR2 is equal to the position PGC2 of the geometric center GC2 of the core back 2 in the second direction DIR2. In addition, the geometric center GC22 is the position of the arithmetic mean taken over all points belonging to the rotor component 22.

[0038] The soft magnetic body 23 is a soft magnetic body. In addition, the hard magnetic body 24 is a hard magnetic body. If a magnetic field is applied from the outside, the hard magnetic body is magnetized. Thereafter, even if the application of the magnetic field is stopped, the hard magnetic body does not lose its magnetization. The material of such a hard magnetic body is a magnet.

[0039] like Figure 4 As shown, the stator assembly 10 includes a bearing 11, a housing 12, a plurality of cores 1, a plurality of coils 13, a plurality of insulating members 14, and a connection member 15. That is, the brushless motor 100 includes the core 1.

[0040] The bearing 11 supports the shaft body 21 so that it can rotate around the Z axis. Figure 4As shown, the bearing 11 has a first bearing 11a and a second bearing 11b. The first bearing 11a and the second bearing 11b are each, for example, a ball bearing. The first bearing 11a and the second bearing 11b are each cylindrical. The center axis of each of the first bearing 11a and the second bearing 11b is the Z axis. That is, the center axis of each of the first bearing 11a and the second bearing 11b is consistent with the center axis of the shaft body 21.

[0041] like Figure 4 As shown, the first bearing 11a is located closer to the second direction DIR2 than the second bearing 11b. In addition, the first bearing 11a is located closer to the second direction DIR2 than the rotor member 22. The second bearing 11b is located in the opposite direction of the second direction DIR2 than the rotor member 22. The second bearing 11b supports the end of the shaft body 21 in the opposite direction of the second direction DIR2.

[0042] like Figure 3 As shown in FIG. 1 , the housing 12 includes a first housing 12a and a second housing 12b. Figure 3 and Figure 4 As shown, the first housing 12a is cylindrical. The central axis of the first housing 12a is the Z axis. The first housing 12a is located closer to the second direction DIR2 than the second housing 12b. In addition, the first housing 12a has an opening OP. Thus, the end of the shaft body 21 in the second direction DIR2 protrudes from the opening OP toward the second direction DIR2. That is, the brushless motor 100 is a single-axis type.

[0043] The first housing 12a supports the first bearing 11a, the plurality of magnetic cores 1, the plurality of coils 13, and the plurality of insulating members 14. 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.

[0044] The number of each of the plurality of magnetic cores 1, the plurality of coils 13 and the plurality of insulating members 14 is 9. Each of the 9 coils 13 and the 9 insulating members 14 is respectively provided corresponding to each of the 9 magnetic cores 1. In more detail, if a group including a magnetic core 1, a coil 13 and an insulating member 14 is regarded as a set, the 9 sets are arranged in a circumferential direction centered on the Z axis. Each set is arranged around the hard magnetic body 24 at intervals from the hard magnetic body 24. In addition, the structure of each set is the same. Therefore, a set including a magnetic core 1, a coil 13 and an insulating member 14 is described.

[0045] The core 1 is magnetized by the magnetic field generated by the hard magnetic body 24 and the magnetic field generated by the coil 13. As a result, the core 1 generates a magnetic force that rotates the rotor. Figure 4As shown, there is a gap (air gap) between the core 1 and the rotor member 22. In the present embodiment, the first direction DIR1 is a direction toward the rotation axis of the brushless motor 100 when the core 1 is assembled in the brushless motor 100.

[0046] like Figure 4 As shown, when viewed in the radial direction with the Z axis as the center, the coil 13 is located around the magnetic core 1 and is wound around the tooth body 31. The coil 13 is made of a conductive material such as copper. In addition, the coil 13 has a structure in which the surface of the copper wire is covered with an insulating film. The coil 13 generates a magnetic field by flowing an electric current in the coil 13.

[0047] The insulating member 14 is an insulator. Figure 4 As shown, the insulating member 14 is arranged between the magnetic core 1 and the coil 13. Thus, the magnetic core 1 and the coil 13 are electrically insulated. In the present embodiment, the insulating member 14 is in the form of a film, but it may also be in the form of a sheet. In addition, it may also be that the insulating member 14 is arranged so that a part of the insulating member 14 is arranged between the magnetic core 1 and the coil 13. Therefore, it may also be that the insulating member 14 is arranged on the entire surface of the coil 13.

[0048] Wiring member 15 is electrically connected to coil 13. Wiring 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. Coil 13 is electrically connected to each of the plurality of mounting electrodes.

[0049] A current is supplied from a power source (not shown) to the coil 13. The rotation of the rotor 20 is controlled by controlling the current.

[0050] [Effect]

[0051] According to the magnetic core 1, the brushless motor 100 can be miniaturized. The reason why the brushless motor 100 can be miniaturized will be described with reference to the drawings. Figure 5 This is a cross-sectional view of the magnetic core 6 according to the comparative example when viewed in the fourth direction DIR4. Figure 6 This is a cross-sectional view of the magnetic core 6 and the wiring member 15 according to the comparative example around which the coil 13 is wound, as viewed in the fourth direction DIR4. Figure 7 This is a cross-sectional view of the magnetic core 1 and the wiring member 15 around which the coil 13 is wound, as viewed in the fourth direction DIR4. Figure 6 and Figure 7 In the embodiment, the numbers of turns of the coils 13 are equal to each other.

[0052] First, the magnetic core 6 involved in the comparative example will be described. In addition, for the magnetic core 6 involved in the comparative example, only the parts that are different from the magnetic core 1 will be described, and the rest will be omitted. Figure 5 As shown, in the magnetic core 6 involved in the comparative example, the third direction DIR3 is equal to the first direction DIR1. Therefore, in the magnetic core 6 involved in the comparative example, the position of the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 in the second direction DIR2 is equal to the position of the first line L1 at the end of the tooth body portion 31 on the opposite side to the end in the second direction DIR2. That is, the position of the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 and the position of the first line L1 at the end of the tooth body portion 31 on the opposite side to the end are not offset in the second direction DIR2.

[0053] like Figure 6 As shown in FIG. 1 , when the magnetic core 6 according to the comparative example is assembled in the brushless motor 100, the coil 13 is wound around the tooth body 31. If the connection member 15 is arranged in a region overlapping with the tooth portion 3 when viewed in the second direction DIR2 and located in a region located in the opposite direction of the second direction DIR2 than the tooth portion 3, the end of the connection member 15 in the opposite direction of the second direction DIR2 may be located in the opposite direction of the second direction DIR2 than the end of the core back 2 in the opposite direction of the second direction DIR2. As a result, the length of the brushless motor 100 in the second direction DIR2 becomes larger.

[0054] In the magnetic core 1, the position of the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 is offset from the position of the first line L1 at the end of the tooth body portion 31 on the opposite side to the end in the second direction DIR2. More specifically, the first line L1 at the end of the tooth body portion 31 in the first direction DIR1 is located in the opposite direction of the second direction DIR2 than the first line L1 at the end of the tooth body portion 31 on the opposite side to the end of the tooth body portion 31 in the first direction DIR1. Thus, as Figure 7As shown, the coil 13 involved in the first embodiment of the present invention is located at a position closer to the second direction DIR2 than the coil 13 involved in the comparative example. Therefore, even if the wiring member 15 is arranged in an area overlapping with the tooth portion 3 when viewed in the second direction DIR2 and located in an area located in the opposite direction of the second direction DIR2 than the tooth portion 3, the end of the wiring member 15 in the opposite direction of the second direction DIR2 can be located in a position closer to the second direction DIR2 than the end of the core back 2 in the opposite direction of the second direction DIR2. At this time, the wiring member 15 is located on the core back 2 side between the tooth tip portion 32 and the core back 2 and in the opposite direction of the second direction DIR2 than the tooth body portion 31. As a result, the length of the brushless motor 100 involved in the first embodiment of the present invention in the second direction DIR2 can be made shorter than the length of the brushless motor 100 involved in the comparative example in the second direction DIR2. Therefore, according to the magnetic core 1, the brushless motor 100 can be made low-profile and small-sized.

[0055] According to the magnetic core 1, the magnetic core 1 can be easily formed. More specifically, the core back 2 and the tooth end portion 32 each have a shape symmetrical with respect to a plane surface orthogonal to the second direction DIR2. Therefore, for example, in the case of manufacturing the magnetic core 1 by press forming, the magnetic core 1 can be manufactured by a mold having a shape symmetrical with respect to a plane surface orthogonal to the second direction DIR2 and a punch having a shape symmetrical with respect to a plane surface orthogonal to the second direction DIR2. As a result, according to the magnetic core 1, the magnetic core 1 can be easily formed.

[0056] [First Modification]

[0057] Hereinafter, a magnetic core 1 a according to a first modified example of the present invention will be described with reference to the drawings. Figure 8 It is a perspective view of the magnetic core 1a. Fig. 9 It is a cross-sectional view of the magnetic core 1a as viewed in the fourth direction DIR4. In addition, regarding the magnetic core 1a according to the first modification, only the portion that is different from the magnetic core 1 according to the first embodiment will be described, and the remaining portion will be omitted.

[0058] like Figure 8 and Fig. 9 As shown, the core 1a is different from the core 1 in that the first line L1 is a broken line.

[0059] The magnetic core 1 a as described above also exhibits the same effects as those of the magnetic core 1 .

[0060] [Second embodiment]

[0061] Hereinafter, a stator assembly 10 a according to a second embodiment of the present invention will be described with reference to the drawings. Fig.10This is an example of a cross-sectional view of the core 1 and the wiring member 16 around which the coil 13 is wound, as viewed in the fourth direction DIR4. In addition, only the parts of the stator assembly 10a according to the second embodiment that are different from the stator assembly 10 according to the first embodiment will be described, and the rest will be omitted.

[0062] The stator assembly 10a is different from the stator assembly 10 in that it further includes a wiring member 16. The wiring member 16 is, for example, a bus bar.

[0063] like Fig.10 As shown, the wiring member 16 is arranged in a region overlapping with the teeth portion 3 when viewed in the second direction DIR2 and located closer to the teeth portion 3 in the second direction DIR2.

[0064] According to the stator assembly 10a, even if the wiring member 16 is arranged in an area overlapping with the tooth portion 3 when viewed in the second direction DIR2 and located in an area closer to the tooth portion 3 in the second direction DIR2, the end of the wiring member 16 in the second direction DIR2 can be located in a position in the opposite direction of the end of the core back 2 in the second direction DIR2. In this case, the wiring member 16 is located on the tooth end portion 32 side between the tooth end portion 32 and the core back 2 and closer to the tooth body portion 31 in the second direction DIR2. As a result, the length of the brushless motor 100 in the second direction DIR2 can be made smaller than the length of the brushless motor 100 in the second direction DIR2 of the comparative example. Therefore, according to the stator assembly 10a, the brushless motor 100 can be made low-profile and small-sized.

[0065] Alternatively, the connection member 15 may be located on the tooth end portion 32 side between the tooth end portion 32 and the core back 2 and closer to the tooth body portion 31 in the second direction DIR2, and the wiring member 16 may be located on the core back 2 side between the tooth end portion 32 and the core back 2 and closer to the tooth body portion 31 in the opposite direction of the second direction DIR2. In this case, the brushless motor 100 can also be made low-profile and small-sized.

[0066] [Other embodiments]

[0067] The magnetic core according to the present invention is not limited to the magnetic cores 1 and 1a, and can be modified within the scope of the gist thereof. In addition, the structures of the magnetic cores 1 and 1a can be arbitrarily combined.

[0068] The stator assembly according to the present invention is not limited to the stator assemblies 10 and 10a, and can be modified within the scope of the gist thereof. In addition, the structures of the stator assemblies 10 and 10a can be arbitrarily combined.

[0069] The rotary electric machine may have a structure that rotates the rotor by electricity or a structure that generates electricity by the rotation of the rotor. In this case, the rotary electric machine may have at least one of the cores 1 and 1 a , and may have a brush.

[0070] Alternatively, the magnetic cores 1 and 1a may be produced by laminating electromagnetic steel sheets. The magnetic cores 1 and 1a may be made of a soft magnetic material.

[0071] In addition, the outer surfaces of the magnetic cores 1 and 1 a may not be subjected to insulation treatment.

[0072] Furthermore, each of the first main surface S1 and the second main surface S2 of the core back 2 may not have a rectangular shape when viewed in the third direction DIR3.

[0073] In addition, the core back 2 may not have a shape that is plane-symmetrical with respect to a plane perpendicular to the second direction DIR2.

[0074] In addition, the tooth body portion 31 does not need to be in the shape of a quadrangular prism.

[0075] In addition, the position PGC31 of the geometric center GC31 of the tooth body portion 31 in the second direction DIR2 may be different from the position PGC31 of the geometric center GC31 of the core back 2 .

[0076] Furthermore, each of the third main surface S3 and the fourth main surface S4 of the tooth tip portion 32 may not have a rectangular shape when viewed in the third direction DIR3.

[0077] In addition, the position PGC2 of the geometric center GC32 of the tooth tip portion 32 in the second direction DIR2 may be different from the position PGC2 of the geometric center GC2 of the core back 2 .

[0078] In addition, the tooth tip portion 32 may not have a shape that is plane-symmetrical with respect to a plane that is orthogonal to the second direction DIR2.

[0079] In addition, the position PGC2 of the geometric center GC32 of the tooth tip portion 32 in the second direction DIR2 may be different from the position PGC2 of the geometric center GC2 of the core back 2 .

[0080] In addition, the outer edge O2 of the core back 2 observed in the third direction DIR3 may not surround the outer edge O31 of the tooth body 31 observed in the third direction DIR3. In addition, the outer edge O32 of the tooth tip 32 observed in the third direction DIR3 may not surround the outer edge O31 of the tooth body 31 observed in the third direction DIR3.

[0081] Furthermore, in the third direction DIR3 , the length of the tooth body portion 31 in the second direction DIR2 may be non-uniform.

[0082] In addition, the first line L1 is not limited to a straight line or a broken line, and may be a curved line. In addition, the first line L1 may include a straight line or a curved line.

[0083] In addition, the first line L1 at the end of the tooth body 31 in the first direction DIR1 may be located closer to the second direction DIR2 than the first line L1 at the end of the tooth body 31 on the opposite side to the end of the tooth body 31 in the first direction DIR1. In this case, even if the wiring member 15 is arranged in a region overlapping with the tooth portion 3 when viewed in the second direction DIR2 and located in a region located in the opposite direction of the second direction DIR2 than the tooth portion 3, the end of the wiring member 15 in the opposite direction of the second direction DIR2 can be located closer to the second direction DIR2 than the end of the core back 2 in the opposite direction of the second direction DIR2. Therefore, in this case, the length of the brushless motor 100 in the second direction DIR2 can be made smaller than the length of the brushless motor 100 in the second direction DIR2 of the comparative example. As a result, the brushless motor 100 can be miniaturized.

[0084] In addition, 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 axis of the brushless motor 100 when the core 1 is assembled in the brushless motor 100 .

[0085] In addition, the brushless motor 100 is not limited to a single-shaft type, and the brushless motor 100 may be a dual-shaft type, for example.

[0086] In addition, each of the first bearing 11 a and the second bearing 11 b is not limited to a ball bearing.

[0087] In addition, the material of each of the first housing 12a and the second housing 12b may be a material having high rigidity.

[0088] The number of the plurality of magnetic cores 1 , the plurality of coils 13 , and the plurality of insulating members 14 is not limited to 9. It is sufficient that each of the plurality of coils 13 and each of the plurality of insulating members 14 is provided corresponding to each of the plurality of magnetic cores 1 .

[0089] In addition, wiring member 15 is not limited to a substrate. Wiring member 15 may be, for example, a terminal block. In addition, in stator assembly 10a, wiring member 15 is not an essential structural element.

[0090] In addition, the wiring member 16 is not limited to the bus bar, and the wiring member 16 may be, for example, a cable.

[0091] The present invention has the following structure.

[0092] (1) A magnetic core for use in a rotating electrical machine, comprising: a core back; and a tooth portion, comprising a tooth body portion extending from the core back in a first direction and a tooth tip portion provided at a tip of the tooth body portion in the first direction, wherein in a second direction which is a direction along a rotation axis of the rotating electrical machine when the magnetic core is assembled in the rotating electrical machine, a position of a geometric center of the tooth portion is equal to a position of a geometric center of the core back, an orthographic 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 tooth body portion perpendicular to the third direction is defined as a first line, and a position of the first line at the tip of the tooth body portion is offset from a position of the first line at an end of the tooth body portion on the opposite side to the tip in the second direction.

[0093] (2) In the magnetic core described in (1), the first line is a straight line.

[0094] (3) In the magnetic core described in (1), the first line is a broken line.

[0095] (4) In the magnetic core described in any one of (1) to (3), the core back has a shape symmetrical with respect to a plane perpendicular to the second direction, and the tooth tip has a shape symmetrical with respect to a plane perpendicular to the second direction.

[0096] (5) In the magnetic core described in any one of (1) to (4), the length of the tooth body portion in the second direction is uniform in the third direction.

[0097] (6) In the magnetic core described in any one of (1) to (5), each of the core back and the teeth is a molded body formed of soft magnetic powder.

[0098] (7) In the magnetic core described in (6), the material of the soft magnetic powder includes iron and resin.

[0099] (8) A stator assembly comprising: a magnetic core as described in any one of (1) to (7); and a wiring member, wherein the first line at the end of the tooth body portion on the opposite side to the end is located closer to the second direction than the first line at the end of the tooth body portion, and the wiring member is located on the core back side between the tooth end portion and the core back and is located closer to the second direction than the tooth body portion.

[0100] (9) A stator assembly comprising: a magnetic core as described in any one of (1) to (7); and a wiring member, wherein the first line at the end of the tooth body portion on the opposite side to the end is located closer to the second direction than the first line at the end of the tooth body portion, and the wiring member is located on the tooth end portion side between the tooth end portion and the core back and closer to the second direction than the tooth body portion.

[0101] (10) A rotating electrical machine comprising the magnetic core described in any one of (1) to (7).

[0102] (11) A brushless motor comprising the magnetic core described in any one of (1) to (7).

[0103] Description of Reference Numerals

[0104] 1, 1a, 6... magnetic core; 2... back of the core; 3... tooth; 10, 10a... stator assembly; 11... bearing; 11a... first bearing; 11b... second bearing; 12... housing; 12a... first housing; 12b... second housing; 13... coil; 14... insulating member; 15... wiring member; 16... wiring member; 20... rotor; 21... shaft; 22... rotor member; 23... soft magnetic body; 24... hard magnetic body; 31... tooth body; 32... tooth end End; 100...brushless motor; DIR1...1st direction; DIR2...2nd direction; DIR3...3rd direction; DIR4...4th 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 edge; OP...opening; S1...1st main surface; S2...2nd main surface; S3...3rd main surface; S4...4th main surface.

Claims

1. A magnetic core used for a rotating electrical machine, characterized in that: have: Core back; and a tooth portion including a tooth body portion extending from the core back in a first direction and a tooth terminal portion provided at a terminal of the tooth body portion in the first direction, In a second direction that is a direction along the rotation axis of the rotating electrical machine when the magnetic core is assembled in the rotating electrical machine, the position of the geometric center of the tooth portion is equal to the position of the geometric center of the core back. The orthographic projection of the first direction onto a plane orthogonal to the second direction is defined as the third direction. A line connecting geometric centers of cross sections of the tooth body portion perpendicular to the third direction is defined as a first line, The position of the first line at the terminal end of the tooth body portion and the position of the first line at an end portion of the tooth body portion on the opposite side to the terminal end are offset in the second direction.

2. The magnetic core according to claim 1, characterized in that The first line is a straight line.

3. The magnetic core according to claim 1, characterized in that: The first line is a broken line.

4. The magnetic core according to any one of claims 1 to 3, characterized in that: The core back has a shape that is symmetrical with respect to a plane perpendicular to the second direction. The tooth tip portion has a shape that is symmetrical with respect to a plane perpendicular to the second direction.

5. The magnetic core according to any one of claims 1 to 4, characterized in that: In the third direction, the length of the tooth body portion in the second direction is uniform.

6. The magnetic core according to any one of claims 1 to 5, characterized in that: The core back and the teeth are each a molded body formed of soft magnetic powder.

7. The magnetic core according to claim 6, characterized in that: The material of the soft magnetic powder includes iron and resin.

8. A stator assembly, characterized in that: have: The magnetic core according to any one of claims 1 to 7; and Wiring components, The first line at the end of the tooth body portion opposite to the terminal end is located closer to the second direction than the first line at the terminal end of the tooth body portion. The connecting member is located between the tooth tip portion and the core back on the core back side and is located in a direction opposite to the second direction relative to the tooth body portion.

9. A stator assembly, characterized in that: have: The magnetic core according to any one of claims 1 to 7; and Wiring components, The first line at the end of the tooth body portion opposite to the terminal end is located closer to the second direction than the first line at the terminal end 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 is located closer to the tooth body portion in the second direction.

10. A rotating electrical machine, characterized in that: A magnetic core according to any one of claims 1 to 7 is provided.

11. A brushless motor, characterized in that: A magnetic core according to any one of claims 1 to 7 is provided.

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