motor

Abstract

To provide a motor capable of improving torque while suppressing an increase in physique.SOLUTION: A motor 10 includes a rotor 12 having a magnet 18, a plurality of coils 16, and a stator core 26. A coil end part 38 of a short coil 32 is formed as a bent coil end part 380 which is bent to one side in a radial direction with respect to a pair of opposing parts 36 and arranged to face the magnet 18 in a radial direction. The stator core 26 is formed annually and the dimension in an axial direction thereof is set to a dimension smaller than the dimension of the magnet 18 in an axial direction. In addition, the stator core 26 has a core end part 26B located on a bent coil end part 380 side with respect to a boundary between the pair of opposing parts 36 and the bent coil end part 380.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a motor. [Background technology]

[0002] Patent Document 1 below discloses a motor including a rotor with a magnet and a stator with a so-called teethless structure. In the motor described in this document, multiple coils formed by distributed winding are arranged along a stator core. Furthermore, the coil ends of some of the multiple coils are bent toward the axial end face of the stator core and are arranged radially overlapping the coil end portions of the other coils. Furthermore, in the motor described in this document, the axial dimension of the stator core and the axial dimension of the rotor magnet are set to be approximately the same. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-078167 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the motor described in Patent Document 1, the coil ends of the coils are portions that do not contribute to the torque of the rotor or contribute little to the torque of the rotor. Therefore, the motor described in Patent Document 1 has room for improvement in terms of increasing the torque while suppressing an increase in the motor's size.

[0005] In consideration of the above, an object of the present disclosure is to provide a motor that can improve torque while suppressing an increase in size. [Means for solving the problem]

[0006] The motor (10, 50, 52, 54, 60, 66, 68, 70) that solves the above problem includes a rotor (12) having a magnet (18) and rotatably supported, a plurality of coils (16) each formed by annularly winding a conductive winding (30), each having a pair of opposing portions (36) that form an axial center portion, are arranged spaced apart in the circumferential direction, and are arranged so that the entirety of the opposing portions faces the magnet in the radial direction, and a pair of coil end portions (38) that circumferentially connect the pair of opposing portions on one axial side and the other axial side, respectively, and the coil end portions of at least some of the coils are bent radially toward one side with respect to the pair of opposing portions and are arranged forward. a stator core (26) including: a plurality of coils each serving as a curved coil end portion (380) disposed radially opposite the magnet; and a stator core (26) formed in an annular shape and having an axial dimension set to be smaller than the axial dimension of the magnet, wherein the pair of opposing portions of the plurality of coils are disposed along a radially inner surface or a radially outer surface, and the curved coil end portion is disposed along an axial end face, and having core ends (26B, 64A) located on the curved coil end portion side with respect to a boundary between the pair of opposing portions and the curved coil end portion, wherein the axial dimension of the magnet is set to be larger than the axial dimension of the opposing portions. In a configuration in which a pair of the opposing portions of the plurality of coils is arranged along the radially inner surface of the stator core, the inner diameter of the core end gradually increases toward the curved coil end portion, and in a configuration in which a pair of the opposing portions of the plurality of coils is arranged along the radially outer surface of the stator core, the outer diameter of the core end gradually decreases toward the curved coil end portion, the pair of the curved coil end portions are arranged radially opposite a portion of the magnet that is located on one axial side of the end face on one axial side of the stator core and a portion that is located on the other axial side of the end face on the other axial side of the stator core, and the pair of opposing portions at the curved coil end portion are curved along the core end portion.

[0007] By configuring it in this way, it is possible to improve torque while suppressing an increase in the size of the motor. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a partially sectional perspective view showing a rotor and a stator of a motor according to a first embodiment. FIG. [Figure 2] FIG. 2 is a side cross-sectional view showing a cross section of the motor taken along the axial direction. [Figure 3] FIG. 2 is a plan view showing a stator and a rotor. [Figure 4] FIG. 2 is a cross-sectional view showing a stator and a rotor. [Figure 5]FIG. [Figure 6A] FIG. [Figure 6B] FIG. 2 is a side cross-sectional view showing a short coil. [Figure 7] FIG. [Figure 8] FIG. 2 is an enlarged side cross-sectional view showing a portion of the stator and rotor. [Figure 9] FIG. 2 is a schematic diagram for explaining the connections of U-phase, V-phase, and W-phase. [Figure 10] FIG. 2 is a schematic diagram for explaining the connections and arrangement of U-phase, V-phase, and W-phase wires. [Figure 11] FIG. 2 is a perspective view showing an insulator and a coil supported by a stator core via the insulator. [Figure 12] 3 is a perspective view showing an insulator and a U-phase coil, a V-phase coil, and a W-phase coil supported by a stator core via the insulator. FIG. [Figure 13] FIG. 2 is an enlarged perspective view showing a state in which short coils are arranged along a stator core. [Figure 14] FIG. 2 is an enlarged perspective view showing a state in which short coils and long coils are arranged along a stator core. [Figure 15] FIG. 2 is an enlarged perspective view showing long coils and short coils connected by a plurality of bus bars. [Figure 16] FIG. 2 is a perspective view showing a stator core. [Figure 17] FIG. 2 is an enlarged perspective view showing a part of the stator core. [Figure 18] FIG. 2 is an enlarged side cross-sectional view showing a portion of the stator on one axial side thereof; [Figure 19] FIG. 10 is an enlarged cross-sectional view showing a core end portion of a stator core of another embodiment. [Figure 20] FIG. 10 is an enlarged cross-sectional view showing a core end portion of a stator core of another embodiment. [Figure 21] FIG. 10 is an enlarged cross-sectional view showing a core end portion of a stator core of another embodiment. [Figure 22] FIG. 4 is an enlarged cross-sectional side view schematically showing the flow of magnetic flux from a magnet toward a stator core. [Figure 23] FIG. 6 is an enlarged side cross-sectional view showing a motor according to a second embodiment. [Figure 24] FIG. 10 is an enlarged side cross-sectional view showing a motor according to a third embodiment. [Figure 25] FIG. 10 is an enlarged side cross-sectional view showing a motor according to a fourth embodiment. [Figure 26] FIG. 11 is a perspective view showing a part of a stator core of a motor according to a fifth embodiment. [Figure 27] 27 is an enlarged side cross-sectional view showing the motor of the fifth embodiment taken along a line corresponding to line 5A-5A shown in FIG. 26. [Figure 28] 27 is an enlarged side cross-sectional view showing the motor of the fifth embodiment taken along a line corresponding to line 5B-5B shown in FIG. 26. [Figure 29] FIG. 28 is an enlarged cross-sectional side view corresponding to FIG. 27, showing a motor according to a sixth embodiment. [Figure 30] FIG. 29 is an enlarged cross-sectional side view corresponding to FIG. 28, showing a motor according to a sixth embodiment. [Figure 31] FIG. 13 is a schematic view of a stator core of a motor according to a seventh embodiment, viewed from the radially inner side. [Figure 32] FIG. 13 is a schematic diagram of a stator core of a motor according to an eighth embodiment, viewed from the radially inner side. [Figure 33] FIG. 13 is an enlarged side cross-sectional view showing a motor according to a ninth embodiment. [Figure 34] FIG. 23 is an enlarged side cross-sectional view showing a motor according to a tenth embodiment. [Figure 35] 10A and 10B are enlarged perspective views illustrating variations of the terminal portions of the windings that form the coil. [Figure 36] 10A and 10B are enlarged perspective views illustrating variations of the terminal portions of the windings that form the coil. [Figure 37] 10A and 10B are enlarged perspective views illustrating variations of the terminal portions of the windings that form the coil. [Figure 38]1 is a side cross-sectional view schematically showing a stator core formed by stacking core constituent plates having burrs and sagging portions caused by press working; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] (First embodiment) A motor 10 according to a first embodiment of the present disclosure will be described using Figures 1 to 12. Note that the arrow Z direction, arrow R direction, and arrow C direction shown as appropriate in the figures respectively indicate one side in the rotational axis direction, the outer side in the rotational radial direction, and one side in the rotational circumferential direction of a rotor 12, which will be described later. Furthermore, hereinafter, when simply referring to an axial direction, a radial direction, or a circumferential direction, this refers to the rotational axis direction, rotational radial direction, or rotational circumferential direction of the rotor 12, unless otherwise specified.

[0010] 1 to 3, motor 10 of this embodiment is an inner rotor brushless motor in which rotor 12 as a rotating body is disposed radially inside stator 14. Note that the drawings shown in FIGS. 1 to 5 are drawings of motor 10 etc. shown as an example, and there are some parts that do not match the numbers of coils 16, magnets 18 and detailed shapes that will be described later.

[0011] The rotor 12 is composed of a rotating shaft 22 rotatably supported via a pair of bearings 20, a rotor core 24 formed in a bolt-like cylindrical shape and fixed to the rotating shaft 22, and a plurality of magnets 18 fixed to the radially outer surface of the rotor core 24.

[0012] The rotor core 24 includes a cylindrical first cylindrical portion 24A to which the rotating shaft 22 is fixed by press-fitting or the like, a cylindrical second cylindrical portion 24B disposed radially outward of the first cylindrical portion 24A, and a disc-shaped connecting plate portion 24C that radially connects one axial end of the first cylindrical portion 24A to one axial end of the second cylindrical portion 24B. The outer peripheral surface, which is the radially outer surface of the second cylindrical portion 24B, is formed into a cylindrical surface along the circumferential direction. A magnet 18, which will be described later, is fixed to the outer peripheral surface of the second cylindrical portion 24B.

[0013] The magnets 18 are formed using a magnetic compound having an intrinsic coercivity Hc of 400 kA / m or more and a residual magnetic flux density Br of 1.0 T or more. As an example, the magnets 18 of this embodiment are made of NdFe 11 TiN, Nd2Fe 14 B, SmFe 17 The rotor core 24 is formed using a magnetic compound such as N3 or FeNi. A plurality of magnets 18 are fixed to the outer peripheral surface of the second cylindrical portion 24B of the rotor core 24. The magnets 18 whose radially outer surfaces are N poles and the magnets 18 whose radially outer surfaces are S poles are arranged alternately in the circumferential direction. The number of magnets 18 may be set appropriately taking into consideration the output required of the motor 10, etc.

[0014] 5, the stator 14 includes a stator core 26 as a core formed in an annular shape, an insulator 28 attached to the stator core 26 by adhesive bonding, fitting, or the like, and a plurality of coils 16 attached to the stator core 26 via the insulators 28. The stator 14 of this embodiment has a teethless structure in which no part of the stator core 26 is disposed inside the coils 16.

[0015] 1 and 5, stator core 26 is formed in an annular shape using a magnetic material such as steel. The radial thickness of stator core 26 is set to be larger than the radial dimension of coil end portions 38 of coils 16, which will be described later. Stator core 26 is disposed coaxially with rotor 12, and the axial center position of stator core 26 and the axial center position of the multiple magnets 18 fixed to rotor core 24 coincide with each other in the axial direction.

[0016] The insulator 28 is made of a highly insulating material such as a resin material. The insulator 28 covers the radially inner surface and both axial end surfaces of the stator core 26 when the insulator 28 is attached to the stator core 26. The specific configuration of the insulator 28 will be described in detail later.

[0017] As shown in FIGS. 5 to 7, the multiple coils 16 are formed by winding conductive wires (conductor wires) in a circular shape. Here, as shown in FIGS. 6A and 7, the windings 30 forming the coils 16 of this embodiment have a rectangular cross section in a longitudinal cross section, in which the dimension L1 of the windings 30 in a first direction (arrow A1 direction) is larger than the dimension L2 in a second direction (arrow A2) perpendicular to the first direction. The windings 30 may also be a wire assembly formed by bundling conductive wires. The resistance between the bundled wires is greater than the resistance of the wires themselves. The cross-sectional shape of the windings 30 may be oval or elliptical. Generally, enameled wires are preferably used for the windings 30, and the conductive material may be copper or aluminum.

[0018] As shown in Figures 5 to 7, the stator 14 of this embodiment is configured to include two types of coils 16 with different axial dimensions. Here, the coils 16 shown in Figure 6A are referred to as short coils 32. The coils 16 shown in Figure 7 are referred to as long coils 34. The number of coils 16 may be set appropriately taking into consideration the output required of the motor 10, etc.

[0019] 6A and 6B , the short coil 32 is formed by winding the wire 30 in a rectangular shape so as to be stacked in the second direction (the direction of arrow A2), and then bending both axial ends radially outward. As a result, the short coil 32 has a pair of opposing portions 36 in which parts of the wire 30 are arranged side by side in the circumferential direction and spaced apart in the circumferential direction, one coil end portion 38 circumferentially connecting ends of one axial side of the pair of opposing portions 36, and the other coil end portion 38 circumferentially connecting ends of the other axial side of the pair of opposing portions 36. Furthermore, a terminal portion 40 on one side of the wire 30 that forms the short coil 32 is drawn out from one circumferential side of the opposing portion 36 on the other circumferential side between the pair of opposing portions 36 to one axial side. Furthermore, a terminal portion 40 on the other side of the wire 30 that forms the short coil 32 is drawn out from the opposing portion 36 on the one circumferential side opposite the opposing portion 36 on the other circumferential side (one circumferential side) to one axial side. In the following description, the terminal portion 40 on one side of the winding 30 that forms the short coil 32 may be referred to as the "winding start terminal portion 40A," and the terminal portion 40 on the other side of the winding 30 that forms the short coil 32 may be referred to as the "winding end terminal portion 40B." Furthermore, by routing the terminal portions 40 in this manner, in the short coil 32 of this embodiment, the number of laminations of the winding 30 at the coil end portion 38 on one axial side is fewer than the number of laminations of the winding 30 at the coil end portion 38 on the other axial side. More specifically, the number of laminations of the winding 30 at the coil end portion 38 on one axial side is six, and the number of laminations of the winding 30 at the coil end portion 38 on the other axial side is seven. The number of laminations of the winding 30 at the pair of opposing portions 36 is seven.

[0020] As shown in FIG. 6B , the pair of opposing portions 36 refer to axially central portions of the short coil 32 that extend linearly in the axial direction. The coil end portion 38 on one axial side refers to a portion of the short coil 32 that is located axially to one side of the axial ends of the pair of opposing portions 36. The coil end portion 38 on one axial side includes a pair of curved portions 38A that are curved radially outward from the axial ends of the pair of opposing portions 36, respectively, and a coil end portion 38B that extends radially outward from the end of the pair of curved portions 38A opposite the opposing portions 36. The boundary between the pair of opposing portions 36 and the pair of curved portions 38A of the coil end portion 38 on one axial side is referred to as a bending start point 38C. The boundary between the pair of curved portions 38A and the coil end portion 38B is referred to as a bending end point 38D.

[0021] The other axially-side coil end portion 38 refers to a portion of the short coil 32 that is located on the other axial side of the other axially-side ends of the pair of opposing portions 36. The other axially-side coil end portion 38 includes a pair of curved portions 38A that are curved radially outward from the other axially-side ends of the pair of opposing portions 36, and a coil end portion 38B that extends radially outward from the end of the pair of curved portions 38A opposite the opposing portions 36. The boundary between the pair of opposing portions 36 and the pair of curved portions 38A of the other axially-side coil end portion 38 is referred to as a bending start point 38C. The boundary between the pair of curved portions 38A and the coil end portion 38B is referred to as a bending end point 38D.

[0022] In order to distinguish the coil end portions 38 of the short coils 32 from the coil end portions 38 of the long coils 34 described below, the coil end portions 38 of the short coils 32 are sometimes referred to as curved coil end portions 380. The curved coil end portion 380 refers to the coil end portion 38 that is positioned closest to the axial end face of the stator core 26 among the coil end portions 38 of the multiple coils 16 that make up the stator 14.

[0023] 6A and 7, the long coil 34 has the same configuration as the short coil 32, except that the axial dimension H2 of the long coil 34 is larger than the axial dimension H1 of the short coil 32. Here, the parts of the long coil 34 that correspond to the short coil 32 are given the same reference numerals as the short coil 32, and a description of these parts will be omitted. The long coil 34 is manufactured through the same process as the short coil 32. The length of the winding 30 that forms the long coil 34 is longer than the length of the winding 30 that forms the short coil 32. As a result, the electrical resistance of the long coil 34 is higher than the electrical resistance of the short coil 32.

[0024] Next, the wiring of the multiple coils 16 will be described.

[0025] As shown in FIG. 9 , the multiple coils 16 are connected in a star configuration, for example. In this example, the U-phase 42U, V-phase 42V, and W-phase 42W each include two short coils 32 and two long coils 34. In the U-phase 42U, the four coils 16 are connected in series in the following order from the neutral point 44: long coil 34, short coil 32, long coil 34, short coil 32. In the V-phase 42V, the four coils 16 are connected in series in the following order from the neutral point 44: long coil 34, short coil 32, long coil 34, short coil 32. In the W-phase 42W, the four coils 16 are connected in series in the following order from the neutral point 44: short coil 32, long coil 34, short coil 32, long coil 34. The coils 16 are connected together using bus bars 96, as described below, for example.

[0026] Here, in the U-phase 42U, the range extending from the short coil 32 farthest from the neutral point 44 to the neutral point 44 is referred to as the U-phase coil connection body 46U. In addition, in the V-phase 42V, the range extending from the short coil 32 farthest from the neutral point 44 to the neutral point 44 is referred to as the V-phase coil connection body 46V. Furthermore, in the W-phase 42W, the range extending from the long coil 34 farthest from the neutral point 44 to the neutral point 44 is referred to as the W-phase coil connection body 46W. In this embodiment, the number of long coils 34 and the number of short coils 32 are set to be the same in the coil connection bodies 46U, 46V, and 46W of each phase, so that the combined resistances of the coil connection bodies 46U, 46V, and 46W of each phase are the same. Here, the combined resistance of the coil connectors 46U, 46V, and 46W of each phase being the same means that the difference between the combined resistance of the coil connector 46U of one phase and the combined resistance of the coil connectors 46V and 46W of the other phases is within plus or minus 5%.

[0027] Fig. 10 shows the relative positions of the coils 16 in the U phase 42U, the coils 16 in the V phase 42V, and the coils 16 in the W phase 42W. As shown in Fig. 10 (also see Fig. 8), the short coil 32 farthest from the neutral point 44 in the U phase 42U and the short coil 32 farthest from the neutral point 44 in the V phase 42V are arranged adjacent to each other in the circumferential direction along the stator core 26. In addition, the long coil 34 farthest from the neutral point 44 in the W phase 42W is arranged so as to straddle the short coil 32 farthest from the neutral point 44 in the U phase 42U and the short coil 32 farthest from the neutral point 44 in the V phase 42V.

[0028] Furthermore, the short coil 32 farthest from the neutral point 44 in the V-phase 42V and the short coil 32 on the opposite side of the neutral point 44 in the W-phase 42W are arranged adjacent to each other in the circumferential direction along the stator core 26. Furthermore, the long coil 34 on the opposite side of the neutral point 44 in the U-phase 42U is arranged so as to straddle the short coil 32 farthest from the neutral point 44 in the V-phase 42V and the short coil 32 on the opposite side of the neutral point 44 in the W-phase 42W.

[0029] In addition, the short coil 32 on the opposite side of the neutral point 44 in the W phase 42W and the short coil 32 on the neutral point 44 side in the U phase 42U are arranged adjacent to each other in the circumferential direction along the stator core 26. Furthermore, the long coil 34 on the opposite side of the neutral point 44 in the V phase 42V is arranged so as to straddle the short coil 32 on the opposite side of the neutral point 44 in the W phase 42W and the short coil 32 on the neutral point 44 side in the U phase 42U.

[0030] In addition, the short coil 32 on the neutral point 44 side in the U phase 42U and the short coil 32 on the neutral point 44 side in the V phase 42V are arranged adjacent to each other in the circumferential direction along the stator core 26. Furthermore, the long coil 34 on the neutral point 44 side in the W phase 42W is arranged so as to straddle the short coil 32 on the neutral point 44 side in the U phase 42U and the short coil 32 on the neutral point 44 side in the V phase 42V.

[0031] In addition, the short coil 32 on the neutral point 44 side in the V phase 42V and the short coil 32 on the neutral point 44 side in the W phase 42W are arranged adjacent to each other in the circumferential direction along the stator core 26. Furthermore, the long coil 34 on the neutral point 44 side in the U phase 42U is arranged so as to straddle the short coil 32 on the neutral point 44 side in the V phase 42V and the short coil 32 on the neutral point 44 side in the W phase 42W.

[0032] In addition, the short coil 32 on the neutral point 44 side in the W phase 42W and the short coil 32 farthest from the neutral point 44 in the U phase 42U are arranged adjacent to each other in the circumferential direction along the stator core 26. Furthermore, the long coil 34 on the neutral point 44 side in the V phase 42V is arranged so as to straddle the short coil 32 on the neutral point 44 side in the W phase 42W and the short coil 32 farthest from the neutral point 44 in the U phase 42U.

[0033] 8 and 11, the insulator 28 to which each coil 16 is attached includes an inner surface covering portion 28A covering the radially inner surface of the stator core 26, a pair of axial end surface covering portions 28B covering both axial end surfaces of the stator core 26, and a pair of outer peripheral flange portions 28C extending axially from radially outer ends of the pair of axial end surface covering portions 28B. The insulator 28 also includes a plurality of circumferential positioning portions 28D for circumferentially positioning the short coils 32. The plurality of circumferential positioning portions 28D are formed in a convex shape extending radially inward from the outer peripheral flange portion 28C and are arranged at equal intervals along the circumferential direction. The coil end portions 38 of the short coils 32 are arranged between a pair of circumferential positioning portions 28D adjacent to each other in the circumferential direction, thereby positioning the short coils 32 in the circumferential direction. The plurality of circumferential positioning portions 28D may be provided on one outer circumferential flange portion 28C, but may be provided on both outer circumferential flange portions 28C.

[0034] 8, 10, and 12, the facing portions 36 of the short coils 32 and the facing portions 36 of the long coils 34 are arranged along the radially inner surface of the stator core 26 via the inner covering portion 28A of the insulator 28, and are arranged at the same radial position. More specifically, in the state shown in FIG. 12, the facing portions 36 on one circumferential side of the U-phase short coil 32 and the facing portions 36 on the other circumferential side of the V-phase short coil 32 that are adjacent in the circumferential direction are arranged adjacent to each other in the circumferential direction, and the facing portions 36 on one circumferential side of the U-phase short coil 32 and the facing portions 36 on the other circumferential side of the V-phase short coil 32 that are adjacent in the circumferential direction are arranged between a pair of facing portions 36 of the W-phase long coil 34. As shown in FIGS. 10 and 12, the facing portions 36 of the other short coils 32 and the facing portions 36 of the other long coils 34 are also arranged along the radially inner surface of the stator core 26 in a similar relationship. Furthermore, with the axial center positions of the opposing portions 36 of the short coil 32 and the long coil 34 and the axial center position of the magnet 18 aligned with each other in the axial direction, the opposing portions 36 of the short coil 32 and the long coil 34 and the magnet 18 are arranged facing each other in the radial direction. Furthermore, the first direction of the windings 30 constituting the opposing portions 36 of the short coil 32 and the long coil 34 is directed towards the magnet 18.

[0035] As shown in FIGS. 8 , 10 , and 12 , the pair of coil end portions 38 of the short coil 32 are respectively arranged along both axial end surfaces of the stator core 26 via the pair of axial end surface covering portions 28B of the insulator 28. Furthermore, the pair of coil end portions 38 of the long coil 34 are respectively arranged along both axial end surfaces of the stator core 26 via the coil end portions 38 of two circumferentially adjacent short coils 32 and the pair of axial end surface covering portions 28B of the insulator 28. That is, the pair of coil end portions 38 of the long coil 34 are arranged to overlap in the axial direction with the pair of coil end portions 38 of two circumferentially adjacent short coils 32. More specifically, in the state shown in FIG. 12 , the pair of coil end portions 38 of the W-phase long coil 34 are arranged to overlap in the axial direction with one circumferential side portion of the pair of coil end portions 38 of the circumferentially adjacent U-phase short coil 32 and the other circumferential side portion of the pair of coil end portions 38 of the V-phase short coil 32. As shown in FIGS. 10 and 12, the coil end portions 38 of the other short coils 32 and the coil end portions 38 of the other long coils 34 are also arranged along both axial end surfaces of the stator core 26 in a similar relationship.

[0036] Next, the step of arranging each coil 16 along the stator core 26, which is one of the steps in the method of manufacturing the stator 14, will be briefly described with reference to FIGS.

[0037] In this embodiment, as shown in Fig. 13, first, the short coils 32 are arranged along the stator core 26, and then, as shown in Fig. 14, the long coils 34 are arranged along the stator core 26. Note that the insulators 28 are not shown in Figs. 13 and 14.

[0038] 13, first, a plurality of short coils 32 are arranged along the stator core 26. This step is the first coil arrangement step. In this embodiment, in this step, the opposing portions 36 of the short coils 32 that are adjacent in the circumferential direction are brought into contact with each other in the circumferential direction.

[0039] 14, multiple long coils 34 are arranged along the stator core 26. This process is the second coil arrangement process. Here, in the second coil arrangement process, when the long coils 34 are arranged along the stator core 26, the long coils 34 are not brought into contact with the terminal portions 40 of the short coils 32.

[0040] Each coil 16 is arranged along the stator core 26 in the procedure described above.

[0041] 14 shows the coils 16 arranged along the stator core 26 through the above-described steps. As shown in this figure, the terminal portions 40 of the coils 16 are arranged at the same radial position. In addition, the winding start terminal portion 40A of the short coil 32 is adjacent to the winding end terminal portion 40B of the long coil 34, and the winding start terminal portion 40A of the long coil 34 is adjacent to the winding end terminal portion 40B of the short coil 32. The winding start terminal portion 40A and the winding end terminal portion 40B are arranged alternately in the circumferential direction, and the circumferential distance between the winding start terminal portion 40A and the winding end terminal portion 40B that are adjacent in the circumferential direction is a constant distance P1.

[0042] As shown in FIG. 15 , the terminal portions 40 of each coil 16 are connected in the aforementioned star connection (see FIG. 9 ) via multiple bus bars 96 serving as connecting portions. The bus bars 96 are formed by, for example, bending a metal plate. The bus bars 96 include a pair of joint portions 96A spaced apart in the circumferential direction and to which the terminal portions 40 of the coils 16 are joined, and a circumferential connection portion 96B circumferentially connecting the pair of joint portions 96A. The multiple bus bars 96 are arranged along the coil end portions 38 on one axial side of each coil 16, connecting predetermined terminal portions 40 together. In this embodiment, the multiple bus bars 96 are arranged circumferentially in two overlapping rows in the axial direction. The multiple bus bars 96 arranged circumferentially in the row on one axial side and the multiple bus bars 96 arranged circumferentially in the row on the other axial side are arranged offset in the circumferential direction.

[0043] (Actions and Effects of This Embodiment) Next, the operation and effects of this embodiment will be described.

[0044] 3, 6A, 7, 9, and 10, in the motor 10 of this embodiment, switching the energization of the U-phase coil connection body 46U, the V-phase coil connection body 46V, and the W-phase coil connection body 46W, which constitute part of the stator 14, generates a rotating magnetic field on the inner periphery of the stator 14. This causes the rotor 12 to rotate.

[0045] In the motor 10 of this embodiment, the number of long coils 34 and the number of short coils 32 in each of the coil connections 46U, 46V, and 46W of each phase are set to be the same, so that the combined resistance of the coil connections 46U, 46V, and 46W of each phase is the same. This makes it less likely that electrical imbalance will occur among the coil connections 46U, 46V, and 46W of each phase. As a result, it is possible to prevent the torque ripple of the motor 10 from worsening.

[0046] Furthermore, in the motor 10 of this embodiment, the coil end portions 38 of the long coils 34 and the coil end portions 38 of the short coils 32 are configured to be bent radially outward at right angles relative to the opposing portions 36, and the coil end portions 38 of the long coils 34 and the coil end portions 38 of the short coils 32 are configured to overlap in the axial direction. This prevents the stator 14 from becoming larger in size in the axial direction. As a result, the motor 10 can be prevented from becoming larger in size in the axial direction.

[0047] Furthermore, in the motor 10 of this embodiment, the cross-sectional shape of the winding 30 forming the coil 16 is rectangular with its longitudinal direction aligned in the first direction (the direction of arrow A1). In addition, the first direction of the winding 30, which defines the opposing portions 36 of the short coils 32 and the long coils 34, faces the magnet 18. This allows the area of ​​the portion of the winding 30 facing the magnet 18 to be reduced while maintaining the cross-sectional area of ​​the winding 30. This prevents an increase in the electrical resistance of the winding 30 and prevents an increase in AC copper loss due to eddy currents generated in the opposing portions 36. Furthermore, in the motor 10 of this embodiment, the opposing portions 36 have a single-layer structure along the radially inner surface of the stator core 26. This makes it easier to form the opposing portions 36 in a curved shape corresponding to the radially inner surface of the stator core 26 when viewed from the axial direction, as shown in FIG. 8 . This improves the space factor.

[0048] Furthermore, in the motor 10 of this embodiment, the pair of terminal portions 40 are arranged on one axial side in a state in which the number of laminations of the winding 30 at the coil end portion 38 on one axial side of the coil 16 is smaller than the number of laminations of the winding 30 at the coil end portion 38 on the other axial side. With this configuration, the length of the portion of the coil 16 around which the winding 30 is wound can be shortened. This makes it possible to suppress an increase in the electrical resistance of the coil 16.

[0049] 14 and 15, in this embodiment, the terminal portions 40 of each coil 16 are disposed at the same radial position. This prevents the length of the connection portion connecting the terminal portions 40 of the coils 16 from increasing. More specifically, in a configuration in which the terminal portions 40 of the coils 16 are connected using multiple bus bars 96, the length of the connection by the multiple bus bars 96 can be prevented from increasing. As a result, it is possible to prevent the motor 10 from being hindered in terms of increasing output and miniaturization.

[0050] In this embodiment, the winding start terminal portions 40A and the winding end terminal portions 40B are alternately arranged in the circumferential direction, which allows the coils 16 to be arranged in a space-saving manner in a so-called distributed winding configuration such as this embodiment.

[0051] Furthermore, in this embodiment, the circumferential distance between the winding start terminal portion 40A and the winding end terminal portion 40B that are adjacent in the circumferential direction is a constant distance P1. As a result, in the connection pattern of this embodiment, the coils 16 can be connected using bus bars 96 of the same size.

[0052] Furthermore, multiple bus bars 96 are arranged circumferentially in a state where they are stacked in two axial rows. This prevents the stator 14 from becoming too large in the radial direction, and as a result, prevents the motor 10 from becoming too large in the radial direction. Furthermore, by combining this configuration with a configuration in which the coil end portions 38 on one axial side are stacked in the axial direction, as in this embodiment, the axial size of the motor 10 can also be prevented from becoming too large.

[0053] (Structure that improves torque while suppressing increases in size) Next, a configuration for improving torque while suppressing an increase in the physical size, which is applied to the motor 10 of the first embodiment, will be described with reference to FIG. 8 and FIGS.

[0054] 8, 16, and 17, the stator core 26 of the motor 10 of this embodiment is formed by stacking core constituent plates 27, each having an axial thickness direction, in the axial direction and integrating them by crimping, welding, etc. In this embodiment, all of the core constituent plates 27 that make up the stator core 26 have the same thickness.

[0055] Here, the area of ​​the stator core 26 that is arranged radially opposite the pair of opposing portions 36 of the short coil 32 is referred to as the core central portion 26A. The inner and outer diameters of the multiple core constituent plates 27 that make up the core central portion 26A are the same as each other.

[0056] In addition, the range of the stator core 26 that is located radially opposite the pair of curved portions 38A of the short coil 32 and is closer to the coil end 38B than the bending start point 38C of the short coil 32 is referred to as the core end 26B. The outer diameters of the multiple core constituent plates 27 that make up the core end 26B are the same as the outer diameters of the multiple core constituent plates 27 that make up the core center portion 26A. The inner diameters of the multiple core constituent plates 27 that make up the core end 26B gradually increase toward the coil end 38B side. In this embodiment, as shown in FIG. 18 , if the amount of change in the inner diameter of the core end 26B relative to the amount of change in position in the axial direction is defined as the amount of diameter change, the amount of diameter change on the side opposite the opposing portion 36 (the coil end 38B side) is greater than the amount of diameter change on the opposing portion 36 side.

[0057] As an example, in this embodiment, the core end portion 26B is composed of three core constituent plates 27. These three core constituent plates 27 are, in order from the core center portion 26A side, a first core constituent plate 27A, a second core constituent plate 27B, and a third core constituent plate 27C. When the axial position changes from the core center portion 26A to the position of the first core constituent plate 27A by the thickness of the core constituent plate 27, the inner diameter (radius) of the first core constituent plate 27A becomes larger than the inner diameter (radius) of the core center portion 26A by a diameter change amount Δa. When the axial position changes from the position of the first core constituent plate 27A to the position of the second core constituent plate 27B by the thickness of the core constituent plate 27, the inner diameter (radius) of the second core constituent plate 27B becomes larger than the inner diameter (radius) of the first core constituent plate 27A by a diameter change amount Δb. Furthermore, when the axial position changes by the thickness of core constituent plate 27 from the position of second core constituent plate 27B to the position of third core constituent plate 27C, the inner diameter (radius) of third core constituent plate 27C becomes larger than the inner diameter (radius) of second core constituent plate 27B by a diameter change amount Δc. Note that in this embodiment, the relationship between these diameter changes is Δa<Δb<Δc.

[0058] As described above, by setting the inner diameters of the first core constituent plate 27A, the second core constituent plate 27B, and the third core constituent plate 27C as described above, the inner diameter of the core end portion 26B gradually increases toward the coil end portion 38B. As a result, the radially inner corner portions 26C on both axial sides of the stator core 26 are curved in a manner that conforms to the shape of the curved portions 38A of the short coils 32. Note that the curved shape of the radially inner corner portions 26C on both axial sides of the stator core 26 is not limited to the above. For example, depending on the shape of the curved portions 38A of the short coils 32, the corner portions 26C of the stator core 26 may have the shapes shown in FIGS. 19, 20, and 21. Note that the corner portions 26C of the stator core 26 shown in FIGS. 19, 20, and 21 have dimensions corresponding to those of the corner portions 26C of the stator core 26 shown in FIG. 18.

[0059] 8, in this embodiment, the axial dimension of the stator core 26 is set to be smaller than the axial dimension of the magnet 18 of the rotor 12. In addition, in this embodiment, the entire stator core 26 is disposed radially opposite the magnet 18 of the rotor 12. Note that the portion of the magnet 18 of the rotor 12 that is located on one axial side of the end face on one axial side of the stator core 26 and the portion that is located on the other axial side of the end face on the other axial side of the stator core 26 are referred to as overhang portions 18A.

[0060] In addition, in this embodiment, the entire pair of opposing portions 36 of the short coil 32 arranged along the stator core 26 are arranged radially opposite the magnets 18 of the rotor 12, and the entire pair of bent coil end portions 380 (curved portions 38A and coil ends 38B) of the short coil 32 arranged along the stator core 26 are arranged radially opposite the magnets 18 of the rotor 12. Furthermore, in this embodiment, the entire pair of opposing portions 36 of the long coil 34 arranged along the stator core 26 are arranged radially opposite the magnets 18 of the rotor 12, and portions of the pair of coil end portions 38 of the long coil 34 arranged along the stator core 26 are arranged radially opposite the magnets 18 of the rotor 12.

[0061] As shown in FIGS. 8 and 22, in the motor 10 of this embodiment to which the above-described configuration is applied, the stator core 26 includes a core center portion 26A disposed radially opposite the pair of opposing portions 36 of the short coil 32, as well as core end portions 26B disposed radially opposite the pair of curved portions 38A of the short coil 32. This allows the magnetic flux of the overhanging portion 18A of the magnet 18 to be introduced toward the core end portion 26B of the stator core 26, thereby reducing the magnetic resistance between the overhanging portion 18A of the magnet 18 and the stator core 26. This allows the magnetic flux of the magnet 18 to be effectively utilized, thereby increasing the torque and reducing the size of the motor 10. Note that in FIG. 22, the magnetic flux of the magnet 18 is indicated by arrow B.

[0062] In addition, in this embodiment, the inner diameter of the core end 26B of the stator core 26 gradually increases toward the coil end 38B. This prevents magnetic flux from the magnet 18 flowing toward the core end 26B from concentrating on a portion of the core end 26B. This also prevents magnetic flux from the magnet 18 from being introduced into the stator core 26 from the axial end face of the stator core 26. This also prevents the so-called iron loss generated in the stator core 26 from increasing. This also contributes to increasing the torque and miniaturizing the motor 10. Furthermore, because the inner diameter of the core end 26B of the stator core 26 gradually increases toward the coil end 38B, the shape of the corners 26C of the stator core 26 can correspond to the shape of the curved portions of the short coils 32.

[0063] Furthermore, in this embodiment, the stator core 26 has a laminated structure made up of multiple core constituent plates 27. With this configuration, by going through the simple manufacturing process of stacking core constituent plates 27 with different inner diameters, it is possible to obtain a stator core 26 having a configuration in which the inner diameter of the core end portion 26B gradually increases toward the coil end portion 38B.

[0064] (Motor 50 of the second embodiment) Next, a motor 50 according to a second embodiment of the present disclosure will be described with reference to Figure 23. Note that members and parts of the motor 50 according to the second embodiment that correspond to those of the motor 10 according to the first embodiment will be assigned the same reference numerals as those used in the description of the motor 10 according to the first embodiment, and their description may be omitted.

[0065] 23, in the motor 50 of this embodiment, the thickness of the core constituent plates 27 that constitute the core end portions 26B of the stator core 26 is thinner than the thickness of the core constituent plates 27 that constitute the core center portion 26A. This configuration allows the shape of the corner portions 26C of the stator core 26 to be curved closer to the shape of the curved portions 38A of the short coils 32. Furthermore, by arranging the thin core constituent plates 27 in areas where the magnetic flux of the overhanging portions 18A of the magnets 18 tends to concentrate and the magnetic flux density tends to be high, the area of ​​the magnetic flux inflow (outflow) portion to the stator core 26 is divided and reduced. This makes it possible to suppress iron loss (mainly eddy current loss) that occurs in the stator core 26.

[0066] In order to adjust the axial dimension of stator core 26, core constituent plates 27 having the same thickness as core constituent plates 27 constituting core end portions 26B may be used in part of core center portion 26A.

[0067] (Motor 52 of the third embodiment and motor 54 of the fourth embodiment) Next, a motor 52 according to a third embodiment and a motor 54 according to a fourth embodiment of the present disclosure will be described with reference to Figures 24 and 25. Note that components and parts of the motor 52 according to the third embodiment and the motor 54 according to the fourth embodiment that correspond to those of the motor 10 and the like that have already been described will be assigned the same reference numerals as those used in the description of the motor 10 and the like, and their description may be omitted.

[0068] As shown in FIG. 24, the motor 52 of the third embodiment is configured similarly to the motor 10 described above, except that it includes a first coil 56 having both axial ends formed as bent coil end portions 380, and a second coil 58 having both axial coil end portions 38 that are not bent relative to the pair of opposing portions 36.

[0069] The coil end portion 38 (bent coil end portion 380) of the first coil 56 includes a curved portion 38A in which the radially inner portion is bent radially outward and the radially outer portion is bent in the axial direction, and a coil end portion 38B extending in the axial direction from the curved portion 38A. The coil end portion 38B of the first coil 56 and the coil end portion 38 of the second coil 58 are arranged to overlap in the radial direction.

[0070] As shown in FIG. 25, the motor 54 of the fourth embodiment is configured similarly to the motor 10 described above, except that it includes a first coil 56 and a second coil 58 having the configuration described below, and a stator core 26 having a core end 26B on only one axial side, the inner diameter of which gradually increases toward the coil end 38B of the first coil 56.

[0071] The first coil 56 has a coil end portion 38 on one axial side bent radially outward, and a coil end portion 38 on the other axial side bent radially inward. Here, the coil end portion 38 on one axial side of the first coil 56 is a bent coil end portion 380. Furthermore, the second coil 58 has a coil end portion 38 on one axial side bent radially outward, and a coil end portion 38 on the other axial side bent radially inward. The coil end portion 38 on the other axial side of the first coil 56 and the coil end portion 38 on the other axial side of the second coil 58 are arranged to overlap in the axial direction on the other axial side of the magnet 18. Furthermore, the coil end portion 38 on the other axial side of the first coil 56 is arranged on the other axial side of the coil end portion 38 on the other axial side of the second coil 58.

[0072] In the motor 52 of the third embodiment and the motor 54 of the fourth embodiment described above, the torque of the motors 52 and 54 can also be increased and the motors 52 and 54 can be made smaller.

[0073] (Motor 60 of the fifth embodiment to the motor of the eighth embodiment) Next, a motor 60 according to a fifth embodiment to a motor according to an eighth embodiment of the present disclosure will be described using Figures 26 to 32. Note that members and parts of the motor 60 according to the fifth embodiment to the motor according to the eighth embodiment that correspond to those of the motor 10 and the like already described will be assigned the same reference numerals as those used in the description of the motor 10 and the like already described, and their description may be omitted.

[0074] 26 to 28, a motor 60 of the fifth embodiment includes a stator core 26 having one axial side and the other axial side formed in an uneven shape, and a first coil 56 and a second coil 58 arranged along the stator core 26. The first coil 56 and the second coil 58 are configured similarly to the first coil 56 and the second coil 58 of the motor 52 of the third embodiment described above, except for differences in detailed dimensions.

[0075] As shown in FIG. 26 , the stator core 26 of this embodiment includes a plurality of first coil arrangement sections 62 each having an axial dimension of H3 and a plurality of second coil arrangement sections 64 each having an axial dimension of H4, which is larger than H3. The circumferential dimensions of the first coil arrangement sections 62 and the second coil arrangement sections 64 are set to be the same. The first coil arrangement sections 62 and the second coil arrangement sections 64 are alternately arranged in the circumferential direction with their axial centers aligned. Here, a portion of the second coil arrangement section 64 that protrudes toward one axial side beyond the end face on one axial side of the first coil arrangement section 62 and a portion of the second coil arrangement section 64 that protrudes toward the other axial side beyond the end face on the other axial side of the first coil arrangement section 62 are referred to as a convex core end section 64A.

[0076] As shown in Figures 26 and 27, a pair of opposing portions 36 of the second coil 58 are arranged circumferentially across the first coil arrangement portion 62, along the second coil arrangement portion 64 arranged on one circumferential side of the first coil arrangement portion 62 and the second coil arrangement portion 64 arranged on the other circumferential side of the first coil arrangement portion 62.

[0077] 26 and 28 , the pair of opposing portions 36 of the first coil 56 are arranged circumferentially across the second coil arrangement portion 64, along the first coil arrangement portion 62 arranged on one circumferential side of the second coil arrangement portion 64 and the first coil arrangement portion 62 arranged on the other circumferential side. Furthermore, the coil end portion 38B on one axial side of the first coil 56 is arranged on one axial side of the first coil arrangement portion 62 and is arranged between a pair of convex core end portions 64A on one axial side of the second coil arrangement portion 64. Furthermore, the coil end portion 38B on the other axial side of the first coil 56 is arranged on the other axial side of the first coil arrangement portion 62 and is arranged between a pair of convex core end portions 64A on the other axial side of the second coil arrangement portion 64.

[0078] In the motor 60 of the fifth embodiment described above, the convex core end portion 64A of the stator core 26 functions in the same manner as the core end portion 26B of the motor 10 of the first embodiment, etc. This allows the motor 60 to have an increased torque and be made smaller.

[0079] 29 and 30 show cross sections of a motor 66 of the sixth embodiment. As shown in these figures, the motor 66 of this embodiment is configured similarly to the motor 60 of the fifth embodiment, except that both axial ends of the first coil arrangement section 62 are core end portions 26B similar to those of the motor 10 described above. In the motor 66 of this configuration, the torque of the motor 66 can be increased and the motor 66 can be made smaller, similar to the motor 60 of the fifth embodiment. Furthermore, in this motor 66, the core end portions 26B can be arranged along the curved portion 38A of the first coil 56.

[0080] FIG. 31 is a schematic diagram of a stator core 26 constituting a part of a motor of the seventh embodiment, viewed from the radially inner side. As shown in this figure, in the motor of the seventh embodiment, both circumferential ends of the convex core end 64A of the second coil arrangement portion 64 are inclined with respect to the axial direction. As a result, the shape of the convex core end 64A on one axial side, viewed from the radially inner side, is a trapezoid that narrows toward one axial side. Furthermore, the shape of the convex core end 64A on the other axial side, viewed from the radially inner side, is a trapezoid that narrows toward the other axial side. The rest of the configuration of the motor of the seventh embodiment is the same as that of the motor 60 of the fifth embodiment.

[0081] 32 is a schematic diagram of the stator core 26, which constitutes part of the motor of the eighth embodiment, viewed from the radially inner side. As shown in this figure, in the motor of the eighth embodiment, the convex core end 64A of the second coil arrangement portion 64 is configured in the same manner as in the motor of the seventh embodiment. The other configurations of the motor of the eighth embodiment are configured in the same manner as the motor 66 of the sixth embodiment.

[0082] The motors of the seventh and eighth embodiments described above can also be made more compact and have increased torque. Furthermore, by configuring the convex core end 64A of the second coil arrangement section 64 as described above, it is possible to smooth out magnetic flux fluctuations at the boundary between the first coil arrangement section 62 and the second coil arrangement section 64. This makes it possible to suppress the cogging torque of the motor.

[0083] (Motor 68 of the 9th embodiment and motor 70 of the 10th embodiment) Next, a motor 68 according to a ninth embodiment and a motor 70 according to a tenth embodiment of the present disclosure will be described with reference to Figures 33 and 34. Note that members and parts of the motor 68 according to the ninth embodiment and the motor 70 according to the tenth embodiment that correspond to those of the motor 10 and the like that have already been described will be assigned the same reference numerals as those used in the description of the motor 10 and the like, and their description may be omitted.

[0084] As shown in FIG. 33 , a motor 68 of the ninth embodiment is configured similarly to the motor 10 described above, except that a portion of the stator core 26 is an integrally molded portion 72 formed by integral molding using a soft magnetic material or a material containing a soft magnetic material. In this embodiment, the core end portion 26B on one axial side and the end portion on one axial side of the core central portion 26A are the integrally molded portion 72, and the core end portion 26B on the other axial side and the end portion on the other axial side of the core central portion 26A are also the integrally molded portion 72. Here, the integrally molded portion 72 can be formed by casting, forging, or cutting an iron-based steel material, or by compression molding or sintering an iron-based powder. Alternatively, the integrally molded portion 72 can be formed by injection molding or compression molding a resin containing an iron-based powder. Alternatively, the integrally molded portion 72 can be formed by injection molding or compression molding a resin containing an iron-based powder.

[0085] 34, the motor 70 of the tenth embodiment is configured similarly to the motor 10, except that the entire stator core 26 is formed by integral molding using a soft magnetic material or a material containing a soft magnetic material. Here, the stator core 26 of the present embodiment is, as one example, a powder magnetic core formed by compressing magnetic particles 98 having insulating coatings 98A on their surfaces.

[0086] In the motor 68 of the ninth embodiment and the motor 70 of the tenth embodiment described above, the torque of these motors 68, 70 can also be increased and the motors 68, 70 can be made smaller.

[0087] Although the above-described embodiments have been described as examples in which the configuration of the present disclosure is applied to an inner rotor brushless motor, the configuration of the present disclosure can also be applied to an outer rotor brushless motor in which pairs of opposing portions of multiple coils are arranged along the radially outer surface of the stator core. In this case, for example, it is preferable that the outer diameter of the core end of the stator core gradually decreases toward the curved coil end portion of the coil.

[0088] Furthermore, in each of the embodiments described above, a distributed winding configuration is used in which the opposing portions 36 of each phase are adjacent to each other in the circumferential direction and the coil end portions 38 overlap in the axial or radial direction, but the configuration of the present disclosure is not limited to this. For example, the configuration of the present disclosure may be applied to a concentrated winding configuration in which the coil end portions 38 do not overlap and which has the curved coil end portions 380.

[0089] Alternatively, the coil 16 may be configured using the winding 30 shown in Fig. 35 to Fig. 37. In the example shown in Fig. 35, the winding 30 that forms the coil 16 is configured from two winding configurations 88 that are stacked in the second direction (the direction of arrow A2). In the example shown in Fig. 36, the winding 30 that forms the coil 16 is configured from two winding configurations 88 that are stacked in the first direction (the direction of arrow A1). Furthermore, in the example shown in Fig. 37, the winding 30 that forms the coil 16 is configured from four winding configurations 88 that are stacked in the first and second directions.

[0090] In the motor 10 and the like described above, an example has been described in which the stator core 26 is formed by stacking multiple core constituent plates 27. When the core constituent plates 27 are formed by punching using a press, as shown in FIG. 38 , a processing sag 27D and a processing burr 27E may occur at the ends of the core constituent plates 27. Therefore, it is preferable to stack the core constituent plates 27 so that the processing burr 27E of one core constituent plate 27 does not abut the axial surface of an adjacent core constituent plate 27. In the example shown in FIG. 38 , the core constituent plates 27 are stacked with the punching direction of the core constituent plates 27 constituting the core center portion 26A and the core end portion 26B on the other axial side facing the other axial side. Furthermore, the core constituent plates 27 are stacked with the punching direction of the core constituent plate 27 constituting the core end portion 26B on one axial side facing the one axial side.

[0091] In the above-described embodiments, the configuration has been described in which the side on which the magnet 18 is provided is the rotor 12 (rotor) and the side on which the coil 16 is provided is the stator 14 (stationary element), but the configuration of the present disclosure can also be applied to a configuration in which the side on which the coil 16 is provided is the rotor 12 (rotor) and the side on which the magnet 18 is provided is the stator 14 (stationary element). Needless to say, the configuration of the present disclosure can also be applied to a generator in which the rotor (rotor) is rotated by an external force.

[0092] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above, and it goes without saying that various modifications other than those described above can be implemented without departing from the spirit of the present disclosure. Furthermore, the configurations of the present disclosure described above can also be combined with each other. [Explanation of symbols]

[0093] 10 motor, 12 rotor (rotating body), 16 coil, 18 magnet, 26 stator core, 26B core end, 27 core constituent plate, 30 winding, 36 opposing portion, 38 coil end portion, 38A curved portion, 50 motor, 52 motor, 54 motor, 66 motor, 68 motor, 70 motor, 98 magnetic particles, 98A insulating coating, 380 curved coil end portion, A1 first direction, A2 second direction

Claims

1. a rotating body (12) having a magnet (18) and rotatably supported; a plurality of coils (16) each formed by winding a conductive winding (30) in an annular shape, each having a pair of opposing portions (36) that form an axial center portion, are spaced apart in the circumferential direction, and are arranged so that the entire coil faces the magnet in the radial direction, and a pair of coil end portions (38) that connect the pair of opposing portions in the circumferential direction on one axial side and the other axial side, respectively, wherein the coil end portions of at least some of the coils are bent radially toward one side with respect to the pair of opposing portions, forming bent coil end portions (380) that are arranged so that the coil end portions face the magnet in the radial direction; a stator core (26) formed in an annular shape, with its axial dimension set to be smaller than the axial dimension of the magnet, with the pair of opposing portions of the plurality of coils being arranged along a radially inner surface or a radially outer surface, and the curved coil end portion being arranged along an axial end face, and having core ends (26B, 64A) located on the curved coil end portion side with respect to a boundary between the pair of opposing portions and the curved coil end portion; Equipped with The axial dimension of the magnet is set to be larger than the axial dimension of the opposing portion, In a configuration in which the pair of opposing portions of the plurality of coils are arranged along a radially inner surface of the stator core, an inner diameter of the core end portion gradually increases toward the curved coil end portion, In a configuration in which the pair of opposing portions of the plurality of coils are arranged along the radially outer surface of the stator core, the outer diameter of the core end portion gradually decreases toward the curved coil end portion, the pair of curved coil end portions are disposed radially opposite a portion of the magnet that is located on one axial side of an end face on one axial side of the stator core and a portion of the magnet that is located on the other axial side of an end face on the other axial side of the stator core, The pair of opposing portions of the curved coil end portion are curved along the core end portion. Motors (10, 50, 52, 54, 60, 66, 68, 70).

2. A motor as described in claim 1, wherein, when the change in the inner or outer diameter of the core end relative to the change in axial position is defined as the change in diameter, the change in diameter on the side opposite the opposing portion is greater than the change in diameter on the opposing portion side.

3. A motor as described in claim 1 or claim 2, wherein the stator core is formed by stacking core constituent plates (27) in the axial direction, with the axial direction being the thickness direction.

4. A motor as described in Claim 3, wherein the thickness of the core constituent plate that constitutes the core end portion in the stator core is thinner than the thickness of the core constituent plate that constitutes the axial central portion in the stator core.

5. A motor as described in claim 1 or claim 2, wherein at least the core end of the stator core is formed by integral molding using a soft magnetic material or a material containing a soft magnetic material.

6. A motor as described in Claim 5, wherein the portion of the stator core that is formed by integral molding using the soft magnetic material or the entire stator core is formed of magnetic particles (98) having an insulating coating (98A) on the surface.

7. In a cross-sectional view of the winding cut along a plane perpendicular to the axial direction at a portion extending in the axial direction, the dimension in a first direction (A1), which is the vertical direction of the cross section of the winding, is set to be larger than the dimension in a second direction (A2), which is the horizontal direction of the cross section of the winding; the curved coil end portion is bent in the first direction relative to the pair of opposing portions, The motor according to any one of claims 1 to 6, wherein the pair of opposing portions of the curved coil end portion are curved portions (38A) that are curved along the core end portion.

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