Stator and motor

Abstract

To suppress a bonding defect that occurs between a coil and a bus bar of a stator.SOLUTION: A stator 2 of a motor 1 comprises: a yoke core 4; a tooth core 5; a coil 6 wound around the tooth core 5; and a bus bar 7 mechanically and electrically connected with the coil 6. The coil 6 comprises a flat-wire shaped coil terminal 62. The bus bar 7 comprises a flat-wire shaped bus bar terminal 72 joined with the coil terminal 62. One or both of the coil terminal 62 and the bus bar terminal 72 is a terminal 8 comprising a wide part 85 and a narrow part 86. A tip part of the terminal 8 is constituted of the wide part 85.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a stator and a motor.

Background Art

[0002] In a motor including a stator and a rotor, a bus bar is used to electrically connect the coil of the stator to an external circuit. Both the coil and the bus bar have terminal portions. The terminal portion of the coil and the terminal portion of the bus bar are welded to each other (see Patent Document 1, etc.).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When welding the terminal portion of the coil and the terminal portion of the bus bar, the welding beads may fall off. When the welding beads fall off, poor connection is likely to occur between the coil and the bus bar.

[0005] The problem to be solved by the present disclosure is to suppress the occurrence of poor connection between the coil of the stator and the bus bar.

Means for Solving the Problems

[0006] A stator according to one aspect of the present disclosure is a stator having an axial direction and a radial direction, and includes a yoke core that is annular around a virtual axis extending in the axial direction, a tooth core protruding from the yoke core, a coil wound around the tooth core, and a bus bar mechanically and electrically connected to the coil. The coil includes a flat linear coil terminal portion protruding to one side in the axial direction. The bus bar includes a flat linear bus bar terminal portion protruding to the one side in the axial direction and joined to the coil terminal portion. Both or one of the coil terminal portion and the bus bar terminal portion is a terminal portion including a wide portion constituting a tip portion in the axial direction and a narrow portion constituting a portion excluding the tip portion. The wide portion is wider than the narrow portion.

[0007] A motor according to one aspect of the present disclosure includes the stator and a rotor disposed inside the stator in the radial direction.

Advantages of the Invention

[0008] The present disclosure has an effect of suppressing the occurrence of a poor joint between the coil and the bus bar of the stator.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

[0010] 1. Embodiment 1-1. First Embodiment The motor 1 of the first embodiment will be described with reference to FIGS. 1 to 6.

[0011] As shown in FIG. 1, the motor 1 of the first embodiment includes a stator 2 and a rotor 3. The motor 1 of the first embodiment is an inner rotor type motor.

[0012] The motor 1 has an axial direction D1, a radial direction D2, and a circumferential direction D3. The axial direction D1, the radial direction D2, and the circumferential direction D3 are orthogonal to each other. That is, the axial direction D1, the radial direction D2, and the circumferential direction D3 are each orthogonal to the other two directions.

[0013] In the radial direction D2, the rotor 3 is disposed inside the stator 2.

[0014] The axial direction D1 of the motor 1 is the axial direction D1 of the stator 2 and the axial direction D1 of the rotor 3. Similarly, the radial direction D2 of the motor 1 is the radial direction D2 of the stator 2 and the radial direction D2 of the rotor 3. The circumferential direction D3 of the motor 1 is the circumferential direction D3 of the stator 2 and the circumferential direction D3 of the rotor 3.

[0015] (Stator) A more detailed structure of the stator 2 will be described below. The stator 2 includes a stator core 22, a stator wiring 24, and a connection unit 26.

[0016] (Stator Core) As shown in FIG. 2, the stator core 22 has an annular yoke core 4 and a plurality of tooth cores 5 attached to the yoke core 4. In the motor 1 of the first embodiment, the plurality of tooth cores 5 are 18 tooth cores 5.

[0017] (Yoke Core) The yoke core 4 is annular around a virtual axis A1 extending in the axial direction D1. The yoke core 4 is formed of a magnetic material. A plurality of grooves 45 are formed in the yoke core 4.

[0018] The plurality of grooves 45 are arranged at intervals in the circumferential direction D3. The plurality of grooves 45 correspond one-to-one with the plurality of tooth cores 5. In the motor 1 of the first embodiment, the plurality of grooves 45 are 18 grooves 45.

[0019] The groove 45 is open towards the inside in the radial direction D2. The groove 45 penetrates the yoke core 4 in the axial direction D1. The groove 45 has a shape that is wider in the circumferential direction D3 towards the outside portion in the radial direction D2.

[0020] (Tooth core) A plurality of tooth cores 5 are arranged at equal intervals in the circumferential direction D3. In the following, the common structure of the plurality of tooth cores 5 will be described.

[0021] The tooth core 5 protrudes from the yoke core 4 towards the inside in the radial direction D2. In other words, the tooth core 5 protrudes from the yoke core 4 towards the axis A1. The tooth core 5 is formed of a magnetic material.

[0022] As shown in FIG. 3, the tooth core 5 includes a body portion 51, a tip piece 53, and a connecting piece 55.

[0023] The body portion 51 protrudes from the yoke core 4 towards the inside in the radial direction D2. In other words, the body portion 51 protrudes from the yoke core 4 towards the axis A1. The body portion 51 has a rectangular parallelepiped shape.

[0024] The tip piece 53 extends from the tip portion of the body portion 51 in a direction intersecting the protruding direction of the body portion 51 (specifically, the circumferential direction D3).

[0025] The connecting piece 55 protrudes from the base end portion of the body portion 51 towards the outside in the radial direction D2. The connecting piece 55 has a shape that is wider in the circumferential direction D3 towards the portion away from the body portion 51. By fitting the connecting piece 55 into the corresponding groove 45 of the yoke core 4, the tooth core 5 is attached to the yoke core 4.

[0026] (Stator wiring) The stator wiring 24 is wound around the stator core 22. The stator wiring 24 includes a plurality of coils 6 wound one-to-one around a plurality of tooth cores 5.

[0027] In the motor 1 of the first embodiment, the plurality of coils 6 are 18 coils. The 18 coils 6 are divided into three groups corresponding to each of the three phases.

[0028] Hereinafter, the common structure of the plurality of coils 6 will be described.

[0029] The coil 6 is wound around the corresponding tooth core 5 via an insulator 58 having insulation properties.

[0030] The coil 6 is mainly composed of a rectangular wire 60. The coil 6 is a coil formed by multilayer winding of a rectangular wire 60 made of, for example, copper, copper alloy, or aluminum.

[0031] The coil 6 includes two coil terminal portions 62 formed at both ends of the rectangular wire 60. When the coil 6 is viewed in a direction orthogonal to the axial direction D1, the two coil terminal portions 62 respectively protrude outward from the stator core 22 and are located. The two coil terminal portions 62 protrude and are located on one side of the axial direction D1. The two coil terminal portions 62 are linear terminal portions parallel to each other.

[0032] Hereinafter, one side of the axial direction D1 will be referred to as the first side of the axial direction D1. The side opposite to one side of the axial direction D1 will be referred to as the second side of the axial direction D1. The first side and the second side of the axial direction D1 are opposite sides to each other.

[0033] (Connection unit) As shown in FIG. 4 and the like, the connection unit 26 is annular around the axis A1. The connection unit 26 includes a plurality of busbars 7. The plurality of busbars 7 are mechanically and electrically connected to the corresponding plurality of coils 6.

[0034] Hereinafter, the common structure of the busbar 7 will be described.

[0035] The bus bar 7 is formed of a flat wire-shaped conductor 70 made of, for example, copper or a copper alloy, and its main body is constituted (see FIG. 5).

[0036] The bus bar 7 includes a flat wire-shaped bus bar terminal portion 72 formed at an end portion of the conductor 70. The bus bar terminal portion 72 protrudes on the first side in the axial direction D1. The bus bar terminal portion 72 is located so as to protrude on the first side in the axial direction D1 from the stator core 22.

[0037] The bus bar terminal portion 72 is constituted by a flat wire-shaped conductor 720. The conductor 720 is one end portion of the conductor 70 that constitutes the main body of the bus bar 7.

[0038] (Connection structure between coil and bus bar) The coil terminal portion 62 of the coil 6 and the corresponding bus bar terminal portion 72 of the bus bar 7 are positioned side by side in the radial direction D2. In the one-to-one corresponding coil terminal portion 62 and bus bar terminal portion 72, the bus bar terminal portion 72 is located outside the coil terminal portion 62 in the radial direction D2.

[0039] The bus bar terminal portion 72 is joined to the coil terminal portion 62 located adjacent to the inside of the bus bar terminal portion 72 in the radial direction D2.

[0040] In the motor 1 of the first embodiment, the tips of the coil terminal portion 62 and the bus bar terminal portion 72 are joined by heat conduction type welding. Thereby, the coil 6 and the bus bar 7 are mechanically and electrically connected. The tip of the coil terminal portion 62 is the tip on the first side in the axial direction D1. The tip of the bus bar terminal portion 72 is the tip on the first side in the axial direction D1.

[0041] In the motor 1 of the first embodiment, the tips of the coil terminal portion 62 and the bus bar terminal portion 72 are joined by arc welding.

[0042] More specifically, the tips of the coil terminal portion 62 and the bus bar terminal portion 72 are joined by TIG (Tungsten Inert Gas) welding. That is, the tips of the coil terminal portion 62 and the bus bar terminal portion 72 are joined by welding using a tungsten electrode and an inert gas.

[0043] (Terminal portion) In the motor 1 of the first embodiment, the bus bar terminal portion 72 located outside in the radial direction D2 is constituted by the terminal portion 8.

[0044] The terminal portion 8 is a terminal portion provided such that the width in the radial direction D2 is non-uniform in the axial direction D1.

[0045] The terminal portion 8 includes a wide portion 85 and a narrow portion 86. In the motor 1 of the first embodiment, the terminal portion 8 is constituted by the wide portion 85 and the narrow portion 86.

[0046] The wide portion 85 constitutes the tip portion on the first side in the axial direction D1 of the terminal portion 8. The narrow portion 86 constitutes the portion of the terminal portion 8 excluding the tip portion on the first side in the axial direction D1 (that is, the wide portion 85). The narrow portion 86 is the portion of the terminal portion 8 located on the second side in the axial direction D1 with respect to the wide portion 85.

[0047] In the radial direction D2, the wide portion 85 is wider than the narrow portion 86. In the motor 1 of the first embodiment, the wide portion 85 is about twice as wide as the narrow portion 86 in the radial direction D2.

[0048] The wide portion 85 of the terminal portion 8 does not have a shape that extends straight on the first side in the axial direction D1, but has a shape that bends midway toward the second side in the axial direction D1. That is, the wide portion 85 of the terminal portion 8 has a U-shaped shape bent 180 degrees toward the second side in the axial direction D1. The wide portion 85 is formed in a U shape by folding back a straight conductor at a right angle by 180 degrees.

[0049] The terminal portion 8 includes a first portion 81 that extends linearly toward the first side in the axial direction D1, a second portion 82 that extends after bending from the first portion 81, and a third portion 83 that extends linearly from the second portion 82.

[0050] In the first embodiment, the second portion 82 is bent in a U shape from the tip of the first portion 81, and the third portion 83 extends from the tip of the second portion 82 toward the second side in the axial direction D1.

[0051] The third portion 83 is positioned to overlap a part 811 of the first portion 81 in the radial direction D2. The part 811 of the first portion 81 is the portion of the first portion 81 on the first side in the axial direction D1. In the radial direction D2, the third portion 83 is located outside the first portion 81.

[0052] The wide portion 85 of the terminal portion 8 is composed of a part 811 of the first portion 81, the second portion 82, and the third portion 83. The wide portion 85 of the terminal portion 8 forms a U shape as a whole when viewed in the circumferential direction D3.

[0053] The narrow portion 86 of the terminal portion 8 is composed of another part 812 of the first portion 81. The another part 812 is the portion of the first portion 81 that does not overlap the third portion 83 in the radial direction D2.

[0054] In the connection structure between the coil 6 and the bus bar 7 of the first embodiment, the tip portion of the coil terminal portion 62 and the tip portion of the terminal portion 8 (that is, the wide portion 85) constituting the bus bar terminal portion 72 are joined by thermally conductive welding.

[0055] Generally, when welding the tips of flat rectangular conductors, there is a problem that the welding beads are likely to fall off. However, as described above, by welding the coil terminal portion 62 to the wide portion 85 of the terminal portion 8, the falling off of the welding beads can be suppressed.

[0056] (Rotor) As shown in FIG. 1, the rotor 3 has a cylindrical rotor core 32 and an output shaft 35 held inside the rotor core 32. The rotor core 32 and the output shaft 35 rotate integrally about an axis A1 that is the center of rotation of the output shaft 35 with respect to the stator 2.

[0057] The rotor core 32 is formed of a magnetic material. A plurality of magnets are arranged at intervals in the circumferential direction D3 on the rotor core 32 such that N poles and S poles are alternately positioned.

[0058] (Manufacturing method) The manufacturing method of the motor 1 of the first embodiment includes the manufacturing method of the stator 2.

[0059] The manufacturing method of the stator 2 includes a step of attaching a coil 6 to the body portion 51 of each of the plurality of tooth cores 5 in a state separated from the yoke core 4, and a step of attaching the plurality of tooth cores 5 to which the coils 6 are attached to the yoke core 4.

[0060] The manufacturing method of the stator 2 further includes a joining step. In the joining step, a plurality of bus bars 7 included in the connection unit 26 are mechanically and electrically connected to the plurality of coils 6 attached to the plurality of tooth cores 5. More specifically, the coil terminal portion 62 of each coil 6 and the bus bar terminal portion 72 of the corresponding bus bar 7 are joined by thermally conductive welding.

[0061] At this time, the coil terminal portion 62 and the bus bar terminal portion 72 are held in a posture where their tips face upward.

[0062] In the motor 1 of the first embodiment, as described above, the tip portion of the bus bar terminal portion 72 in the axial direction D1 is constituted by a wide portion 85 having a width about twice that of the other portions. Therefore, in the motor 1 of the first embodiment, it is possible to prevent the welding beads generated during welding from falling off and causing poor joining.

[0063] 1-2. Second Embodiment The motor 1 of the second embodiment will be described with reference to FIG. 7. In the description of the motor 1 of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0064] In the motor 1 of the second embodiment, the configuration of the wide portion 85 of the terminal portion 8 forming the bus bar terminal portion 72 is different from that in the first embodiment.

[0065] In the motor 1 of the second embodiment, the wide portion 85 of the terminal portion 8 has a shape bent in a direction orthogonal to the axial direction D1.

[0066] Specifically, the wide portion 85 of the terminal portion 8 has a shape bent 180 degrees in the circumferential direction D3.

[0067] That is, in the motor 1 of the second embodiment, the second portion 82 is bent in a U shape from a part 811 on the tip side of the first portion 81 in the circumferential direction D3 and extends. The third portion 83 extends from the tip of the second portion 82 in the circumferential direction D3. The third portion 83 may contact a part 811 of the first portion 81, or a slight gap may be interposed between the third portion 83 and a part 811 of the first portion 81.

[0068] The wide portion 85 of the terminal portion 8 is composed of a part 811 of the first portion 81, the second portion 82, and the third portion 83. The wide portion 85 of the terminal portion 8 forms a U shape as a whole when viewed in the axial direction D1.

[0069] Also in the connection structure between the coil 6 and the bus bar 7 of the second embodiment, by welding the coil terminal portion 62 to the wide portion 85 of the terminal portion 8, even though welding is performed between flat wire-shaped conductors, it is possible to suppress the dropout of the welding beads.

[0070] 1-3. Third Embodiment The motor 1 of the third embodiment will be described with reference to FIG. 8. In the description of the motor 1 of the third embodiment, the same components as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0071] In the motor 1 of the third embodiment, the wide portion 85 of the terminal portion 8 has a shape bent in a direction orthogonal to the axial direction D1 (specifically, the circumferential direction D3), similar to the second embodiment. However, in the third embodiment, the direction in which the wide portion 85 is bent into a U shape is opposite to the direction in which the wide portion 85 is bent into a U shape in the second embodiment.

[0072] The terminal portion 8 includes a first portion 81, a second portion 82, and a third portion 83, which are the same as those in the second embodiment. The third portion 83 is located overlapping a part 811 of the first portion 81 in the radial direction D2.

[0073] In the circumferential direction D3, the direction in which the second portion 82 is located with respect to the first portion 81 is opposite to the direction in which the second portion 82 is located with respect to the first portion 81 in the second embodiment.

[0074] Also in the connection structure between the coil 6 and the bus bar 7 of the third embodiment, by welding the coil terminal portion 62 to the wide portion 85 of the terminal portion 8, even though it involves welding between flat rectangular conductors, the occurrence of the weld beads falling off can be suppressed.

[0075] 1-4. Fourth Embodiment The motor 1 of the fourth embodiment will be described with reference to FIG. 9. In the description of the motor 1 of the fourth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0076] In the motor 1 of the fourth embodiment, both the coil terminal portion 62 and the bus bar terminal portion 72 that are joined to each other are constituted by the terminal portion 8.

[0077] The terminal portion 8 constituting the bus bar terminal portion 72 includes a first portion 81, a second portion 82, and a third portion 83, which are the same as those in the first embodiment.

[0078] The wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 does not have a shape that extends straight to the first side in the axial direction D1, like the wide portion 85 of the terminal portion 8 constituting the bus bar terminal portion 72, but has a shape that bends midway toward the second side in the axial direction D1. That is, the wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 has a U-shaped configuration that is bent 180 degrees toward the second side in the axial direction D1.

[0079] In the terminal portion 8 constituting the bus bar terminal portion 72, similar to the first embodiment, the third portion 83 is located outside the first portion 81 in the radial direction D2. In contrast, in the terminal portion 8 constituting the coil terminal portion 62, the third portion 83 is located inside the first portion 81 in the radial direction D2.

[0080] In the terminal portion 8 constituting the bus bar terminal portion 72, the direction in which the third portion 83 is located with respect to the first portion 81 and the direction in which the third portion 83 is located with respect to the first portion 81 in the terminal portion 8 constituting the coil terminal portion 62 are opposite to each other.

[0081] The first portion 81 of the terminal portion 8 constituting the bus bar terminal portion 72 and the first portion 81 of the terminal portion 8 constituting the coil terminal portion 62 are butted against each other in the radial direction D2.

[0082] In the connection structure between the coil 6 and the bus bar 7 of the fourth embodiment, since the wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 constituting the bus bar terminal portion 72 are welded, even though it is a welding between flat wire-shaped conductors, it is possible to suppress the dropout of the weld beads.

[0083] 1-5. Fifth Embodiment The motor 1 of the fifth embodiment will be described with reference to FIG. 10. In the description of the motor 1 of the fifth embodiment, the same components as those in the second embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

[0084] In the motor 1 of the fifth embodiment, both the coil terminal portion 62 and the bus bar terminal portion 72 joined to each other are constituted by the terminal portion 8.

[0085] The terminal portion 8 constituting the bus bar terminal portion 72 includes a first portion 81, a second portion 82, and a third portion 83 similar to those of the second embodiment.

[0086] The wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 has a U-shaped configuration bent 180 degrees in the circumferential direction D3, similar to the wide portion 85 of the terminal portion 8 constituting the bus bar terminal portion 72.

[0087] In the terminal portion 8 constituting the bus bar terminal portion 72, similar to the second embodiment, the third portion 83 is located on the outer side in the radial direction D2 with respect to the first portion 81. On the other hand, in the terminal portion 8 constituting the coil terminal portion 62, the third portion 83 is located on the inner side in the radial direction D2 with respect to the first portion 81.

[0088] In the terminal portion 8 constituting the bus bar terminal portion 72, the direction in which the third portion 83 is located with respect to the first portion 81 and the direction in which the third portion 83 is located with respect to the first portion 81 in the terminal portion 8 constituting the coil terminal portion 62 are opposite to each other.

[0089] Also, in the terminal portion 8 constituting the bus bar terminal portion 72, the circumferential direction D3 direction in which the second portion 82 is located with respect to the first portion 81 and the circumferential direction D3 direction in which the second portion 82 is located with respect to the first portion 81 in the terminal portion 8 constituting the coil terminal portion 62 are the same as each other.

[0090] The second portion 82 of the terminal portion 8 constituting the bus bar terminal portion 72 and the second portion 82 of the terminal portion 8 constituting the coil terminal portion 62 are located side by side in the radial direction D2.

[0091] The first portion 81 of the terminal portion 8 constituting the bus bar terminal portion 72 and the first portion 81 of the terminal portion 8 constituting the coil terminal portion 62 are abutted against each other in the radial direction D2.

[0092] In the connection structure between the coil 6 and the bus bar 7 according to the fifth embodiment, the wide portion 85 of the terminal portion 8 that constitutes the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 that constitutes the bus bar terminal portion 72 are welded. Thus, even though welding is performed between flat rectangular conductors, the welding beads can be prevented from falling off.

[0093] 1-6. Sixth Embodiment The motor 1 according to the sixth embodiment will be described with reference to FIG. 11. In the description of the motor 1 according to the sixth embodiment, the same components as those in the fifth embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0094] In the motor 1 according to the sixth embodiment, both the coil terminal portion 62 and the bus bar terminal portion 72 that are joined to each other are constituted by the terminal portion 8. The wide portion 85 of the terminal portion 8 that constitutes the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 that constitutes the bus bar terminal portion 72 both have a U-shaped configuration that is bent 180 degrees in the circumferential direction D3.

[0095] However, in the motor 1 according to the sixth embodiment, the direction of the circumferential direction D3 in which the second portion 82 is located with respect to the first portion 81 of the terminal portion 8 that constitutes the bus bar terminal portion 72 is opposite to that in the fifth embodiment. Also, the direction of the circumferential direction D3 in which the second portion 82 is located with respect to the first portion 81 of the terminal portion 8 that constitutes the coil terminal portion 62 is opposite to that in the fifth embodiment.

[0096] In the connection structure between the coil 6 and the bus bar 7 according to the sixth embodiment, the wide portion 85 of the terminal portion 8 that constitutes the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 that constitutes the bus bar terminal portion 72 are welded. Thus, even though welding is performed between flat rectangular conductors, the welding beads can be prevented from falling off.

[0097] 1-7. Seventh Embodiment The motor 1 according to the seventh embodiment will be described with reference to FIG. 12. In the description of the motor 1 according to the seventh embodiment, the same components as those in the fifth embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0098] In the motor 1 of the seventh embodiment, as in the fifth embodiment, both the coil terminal portion 62 and the bus bar terminal portion 72 joined to each other are constituted by the terminal portion 8. The wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 constituting the bus bar terminal portion 72 both have a U-shaped configuration bent 180 degrees in the circumferential direction D3.

[0099] However, in the motor 1 of the seventh embodiment, the direction of the circumferential direction D3 in which the second portion 82 is located with respect to the first portion 81 of the terminal portion 8 constituting the bus bar terminal portion 72 and the direction of the circumferential direction D3 in which the second portion 82 is located with respect to the first portion 81 of the terminal portion 8 constituting the coil terminal portion 62 are opposite to each other.

[0100] In the connection structure between the coil 6 and the bus bar 7 of the seventh embodiment, since the wide portion 85 of the terminal portion 8 constituting the coil terminal portion 62 and the wide portion 85 of the terminal portion 8 constituting the bus bar terminal portion 72 are welded, it is possible to prevent the weld beads from falling off even though welding is performed between flat linear conductors.

[0101] 1-8. Eighth Embodiment The motor 1 of the eighth embodiment will be described with reference to FIG. 13. In the description of the motor 1 of the eighth embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0102] In the motor 1 of the eighth embodiment, among the coil terminal portion 62 and the bus bar terminal portion 72 joined to each other, the coil terminal portion 62 located inside in the radial direction D2 is constituted by the terminal portion 8.

[0103] In the motor 1 of the eighth embodiment, the wide portion 85 of the terminal portion 8 is formed to be wider in the radial direction D2 than the narrow portion 86 via the step 87. The step 87 is formed on the surface facing the inside in the radial direction D2 of the terminal portion 8 constituting the coil terminal portion 62.

[0104] The terminal portion 8 has a linear shape extending toward the first side in the axial direction D1. Both the narrow-width portion 86 and the wide-width portion 85 have linear shapes extending toward the first side in the axial direction D1.

[0105] The step 87 of the terminal portion 8 can be formed, for example, by thinly forming a part of the coil terminal portion 62 by rolling in the process of manufacturing the coil 6. Here, the portion thinly formed constitutes the narrow-width portion 86, and the other part of the coil terminal portion 62 constitutes the wide-width portion 85. A step 87 is formed between the narrow-width portion 86 and the wide-width portion 85.

[0106] The surface 850 facing the inner side in the radial direction D2 of the wide-width portion 85 is located more on the inner side in the radial direction D2 than the surface 860 facing the inner side in the radial direction D2 of the narrow-width portion 86. In the motor 1 of the eighth embodiment, the surface 850 of the wide-width portion 85 is a flat surface. The surface 860 of the narrow-width portion 86 is a flat surface. The surface facing the outer side in the radial direction D2 of the wide-width portion 85 and the surface facing the outer side in the radial direction D2 of the narrow-width portion 86 are continuously flush without a step.

[0107] Also in the connection structure between the coil 6 and the bus bar 7 of the eighth embodiment, by welding the bus bar terminal portion 72 to the wide-width portion 85 of the terminal portion 8, even though it is welding between flat-strip conductors, the occurrence of the weld bead falling off can be suppressed.

[0108] 1-9. Ninth Embodiment The motor 1 of the ninth embodiment will be described with reference to FIG. 14. In the description of the motor 1 of the ninth embodiment, the same components as those in the eighth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0109] In the motor 1 of the ninth embodiment, similar to the eighth embodiment, among the coil terminal portion 62 and the bus bar terminal portion 72 joined to each other, the coil terminal portion 62 located on the inner side in the radial direction D2 is constituted by the terminal portion 8.

[0110] As described above, in the motor 1 of the eighth embodiment, the terminal portion 8 is formed such that the wide portion 85 is wider than the narrow portion 86 via the step 87. On the other hand, in the motor 1 of the ninth embodiment, the terminal portion 8 is formed such that the wide portion 85 gradually becomes wider than the narrow portion 86.

[0111] The surface 850 facing the inner side in the radial direction D2 of the wide portion 85 is composed of a flat surface 853. The flat surface 853 is inclined so as to be located more inside in the radial direction D2 as the portion is farther from the narrow portion 86 in the axial direction D1.

[0112] Also in the connection structure between the coil 6 and the bus bar 7 of the ninth embodiment, by welding the bus bar terminal portion 72 to the wide portion 85 of the terminal portion 8, even though it is welding between flat rectangular conductors, the drop-off of the welding beads can be suppressed.

[0113] 1-10. Tenth Embodiment The motor 1 of the tenth embodiment will be described with reference to FIG. 15. In the description of the motor 1 of the tenth embodiment, the same components as those of the ninth embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

[0114] In the motor 1 of the tenth embodiment, the terminal portion 8 is formed such that the wide portion 85 gradually becomes wider than the narrow portion 86.

[0115] The surface 850 facing the inner side in the radial direction D2 of the wide portion 85 is not a flat surface 853 as in the ninth embodiment, but is composed of a concave curved surface 855. The concave curved surface 855 is curved in a concave shape so as to be located more inside in the radial direction D2 as the portion is farther from the narrow portion 86 in the axial direction D1. The cross section of the concave curved surface 855 is arc-shaped. The cross section here is a cross section cut by a plane orthogonal to the circumferential direction D3.

[0116] Also in the connection structure between the coil 6 and the bus bar 7 of the tenth embodiment, by welding the bus bar terminal portion 72 to the wide portion 85 of the terminal portion 8, even though it is welding between flat rectangular conductors, the drop-off of the welding beads can be suppressed.

[0117] 1-11. Embodiment 11 The motor 1 of Embodiment 11 will be described with reference to FIG. 16. In the description of the motor 1 of Embodiment 11, the same components as those of Embodiment 9 will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0118] In the motor 1 of Embodiment 11, the terminal portion 8 is formed such that the wide portion 85 gradually becomes wider than the narrow portion 86.

[0119] The surface 850 facing the inner side in the radial direction D2 of the wide portion 85 is composed of a plurality of surfaces 857 and 858 having different orientations. The plurality of surfaces 857 and 858 include a concave curved surface 857 and a flat surface 858.

[0120] The concave curved surface 857 is curved so as to be located more inside in the radial direction D2 as the portion is farther from the narrow portion 86 in the axial direction D1. The cross section of the concave curved surface 857 is arc-shaped. Here, the cross section is a cross section cut by a plane orthogonal to the circumferential direction D3.

[0121] The flat surface 858 is located on the first side in the axial direction D1 with respect to the concave curved surface 857. The concave curved surface 857 and the flat surface 858 are continuous in the axial direction D1.

[0122] In the portion of the wide portion 85 where the concave curved surface 857 is located, it is wider in the radial direction D2 as the portion is farther from the narrow portion 86 in the axial direction D1. In the portion of the wide portion 85 where the flat surface 858 is located, the width in the radial direction D2 is constant.

[0123] Also in the connection structure between the coil 6 and the bus bar 7 of Embodiment 11, by welding the bus bar terminal portion 72 to the wide portion 85 of the terminal portion 8, even though welding is performed between flat wire-shaped conductors, it is possible to suppress the dropout of the weld beads.

[0124] 2. Modification The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be variously modified according to the design and the like as long as the object of the present disclosure can be achieved.

[0125] In the following, modification examples of the above-described embodiment will be listed. In the description of the modification examples, the same components as those described in the above-described embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted. The various modification examples listed below can be applied in appropriate combinations.

[0126] In the above-described embodiment, the tooth core 5 protrudes from the yoke core 4 toward the inside in the radial direction D2, but the direction in which the tooth core 5 protrudes is not limited thereto. For example, the tooth core 5 may protrude toward the outside in the radial direction D2.

[0127] In the above-described embodiment, the stator core 22 has 18 tooth cores 5, but the number of tooth cores 5 is not limited thereto. For example, the stator core 22 may have 12 tooth cores 5, or the stator core 22 may have 24 tooth cores 5.

[0128] In the above-described embodiment, the yoke core 4 of the stator core 22 and the plurality of tooth cores 5 are formed separately, but the yoke core 4 and the plurality of tooth cores 5 may be integrally formed. That is, the stator core 22 may be of an integral type, and in this case, each tooth core 5 may not have a tip piece 53. Further, when the stator core 22 is of an integral type, each tooth core 5 does not have a connecting piece 55, and the yoke core 4 does not have a groove 45.

[0129] In the above-described embodiment, the motor 1 is of an inner rotor type, but is not limited thereto. The motor 1 may be of an outer rotor type.

[0130] In the above-described embodiment, the heat conduction type welding performed to join the coil terminal portion 62 and the bus bar terminal portion 72 is TIG welding, but it is not limited thereto. For example, laser welding may be performed as the heat conduction type welding.

[0131] In the above-described embodiment, the coil terminal portion 62 and the bus bar terminal portion 72 are positioned side by side in the radial direction D2, but it is not limited thereto. For example, the coil terminal portion 62 and the bus bar terminal portion 72 may be positioned side by side in the circumferential direction D3.

[0132] The structure of the terminal portion 8 in the above-described embodiment is merely an example, and as long as it includes the wide portion 85 and the narrow portion 86 and the tip portion is formed by the wide portion 85, it is also possible to have other structures.

[0133] In the first embodiment, the coil terminal portion 62 is not constituted by the terminal portion 8 including the wide portion 85, but the coil terminal portion 62 may be constituted by the terminal portion 8. In this case, for example, it is also preferable that the coil terminal portion 62 is constituted by the terminal portion 8 disclosed in any one of the fifth to eleventh embodiments.

[0134] In the second embodiment, the coil terminal portion 62 is not constituted by the terminal portion 8 including the wide portion 85, but the coil terminal portion 62 may be constituted by the terminal portion 8. In this case, for example, it is also preferable that the coil terminal portion 62 is constituted by the terminal portion 8 disclosed in any one of the fourth, sixth to eleventh embodiments.

[0135] In the second embodiment, the coil terminal portion 62 is not constituted by the terminal portion 8 including the wide portion 85, but the coil terminal portion 62 may be constituted by the terminal portion 8. In this case, for example, it is also preferable that the coil terminal portion 62 is constituted by the terminal portion 8 disclosed in any one of the fourth, sixth to eleventh embodiments.

[0136] In the third embodiment, the coil terminal portion 62 is not configured by the terminal portion 8 including the wide portion 85, but the coil terminal portion 62 may be configured by the terminal portion 8. In this case, for example, it is also preferable that the coil terminal portion 62 is configured by the terminal portion 8 disclosed in any one of the fourth to eleventh embodiments.

[0137] In the eighth to eleventh embodiments, the bus bar terminal portion 72 is not configured by the terminal portion 8 including the wide portion 85, but the bus bar terminal portion 72 may be configured by the terminal portion 8. In this case, it is also preferable that the bus bar terminal portion 72 is configured by the terminal portion 8 having the same configuration as the coil terminal portion 62 in any one of the eighth to eleventh embodiments. Further, it is also preferable that the bus bar terminal portion 72 is configured by the terminal portion 8 having the same configuration as the coil terminal portion 62 in any one of the first to third embodiments.

[0138] 3. Summary As described based on the above first to eleventh embodiments and various modifications, the stator (2) according to the first aspect of the present disclosure is a stator (2) having an axial direction (D1) and a radial direction (D2), and includes a yoke core (4) that is annular around a virtual axis (A1) extending in the axial direction (D1), a tooth core (5) protruding from the yoke core (4), a coil (6) wound around the tooth core (5), and a bus bar (7) mechanically and electrically connected to the coil (6). The coil (6) includes a flat linear coil terminal portion (62) protruding to one side in the axial direction (D1). The bus bar (7) includes a flat linear bus bar terminal portion (72) protruding to one side in the axial direction (D1) and joined to the coil terminal portion (62). Both or one of the coil terminal portion (62) and the bus bar terminal portion (72) is a terminal portion (8) including a wide portion (85) constituting the tip portion in the axial direction (D1) and a narrow portion (86) constituting the portion excluding the tip portion. The wide portion (85) is wider than the narrow portion (86).

[0139] According to this aspect, since the tip portions of both or one of the coil terminal portion (62) and the bus bar terminal portion (72) are formed by the wide portion (85), when the tip portions of the coil terminal portion (62) and the bus bar terminal portion (72) are welded together, it is possible to suppress the drop-off of the weld bead. Therefore, it is possible to suppress the occurrence of a poor connection between the coil (6) and the bus bar (7) of the stator (2).

[0140] In the stator (2) according to the second aspect of the present disclosure, in the first aspect, the coil terminal portion (62) and the bus bar terminal portion (72) are joined by heat conduction welding.

[0141] According to this aspect, when the coil terminal portion (62) and the bus bar terminal portion (72) are joined by heat conduction welding, it is possible to suppress the drop-off of the weld bead and the occurrence of a poor connection.

[0142] In the stator (2) according to the third aspect of the present disclosure, in the first aspect or the second aspect, the coil terminal portion (62) and the bus bar terminal portion (72) are positioned side by side in the radial direction (D2).

[0143] According to this aspect, when the coil terminal portion (62) and the bus bar terminal portion (72) arranged side by side in the radial direction (D2) are joined, it is possible to suppress the drop-off of the weld bead and the occurrence of a poor connection.

[0144] In the stator (2) according to the fourth aspect of the present disclosure, in any one of the first aspect to the third aspect, the wide portion (85) of the terminal portion (8) has a shape bent to the side opposite to one side in the axial direction (D1).

[0145] According to this aspect, the wide portion (85) of the terminal portion (8) can be formed by bending a flat conductor wire.

[0146] In the stator (2) according to the fifth aspect of the present disclosure, in any one of the first aspect to the third aspect, the wide portion (85) of the terminal portion (8) has a shape bent in a direction orthogonal to the axial direction (D1).

[0147] According to this aspect, the wide portion (85) of the terminal portion (8) can be formed by bending a flat wire-shaped conductor.

[0148] In the stator (2) according to the sixth aspect of the present disclosure, in any one of the first to third aspects, the wide portion (85) of the terminal portion (8) is formed to be wider than the narrow portion (86) via a step (87).

[0149] According to this aspect, the wide portion (85) of the terminal portion (8) can be formed by processing a flat wire-shaped conductor.

[0150] In the stator (2) according to the seventh aspect of the present disclosure, in any one of the first to third aspects, the wide portion (85) of the terminal portion (8) is formed to be gradually wider than the narrow portion (86).

[0151] According to this aspect, since the wide portion (85) gradually becomes wider, the strength of the terminal portion (8) is easily ensured.

[0152] The motor (1) according to the eighth aspect of the present disclosure includes a stator (2) according to any one of the first to seventh aspects and a rotor (3) disposed inside the stator (2) in the radial direction (D2).

[0153] According to this aspect, in the stator (2) included in the motor (1), when the coil terminal portion (62) and the bus bar terminal portion (72) are welded, the occurrence of the dropout of the welding beads is suppressed. Therefore, the occurrence of a poor connection between the coil (6) and the bus bar (7) of the stator is suppressed.

Explanation of Reference Numerals

[0154] 1 Motor 2 Stator 3 Rotor 4 Yoke Core 5 Tooth Core 6 Coil 62 Coil Terminal Portion 7 Bus bar 72 Bus bar terminal part 8 Terminal part 85 Wide part 86 Narrow part 87 Step Axis A1 Axis direction D1 Radial direction D2

Claims

1. A stator having an axial direction and a radial direction, comprising: a yoke core that is annular around a virtual axis extending in the axial direction; tooth cores protruding from the yoke core; coils wound around the tooth cores; and busbars mechanically and electrically connected to the coils, wherein the coils include flat-linear coil terminal portions protruding to one side in the axial direction, the busbars include flat-linear busbar terminal portions protruding to the one side in the axial direction and joined to the coil terminal portions, both or one of the coil terminal portions and the busbar terminal portions are terminal portions including a wide portion constituting a tip portion in the axial direction and a narrow portion constituting a portion excluding the tip portion, and the wide portion is wider than the narrow portion, a stator.

2. The stator according to claim 1, wherein the coil terminal portions and the busbar terminal portions are joined by thermally conductive welding.

3. The stator according to claim 1, wherein the coil terminal portions and the busbar terminal portions are positioned side by side in the radial direction.

4. The stator according to claim 1, wherein the wide portion of the terminal portion has a shape bent to the side opposite to the one side in the axial direction.

5. The stator according to claim 1, wherein the wide portion of the terminal portion has a shape bent in a direction orthogonal to the axial direction.

6. The stator according to claim 1, wherein the wide portion of the terminal portion is formed to be wider than the narrow portion via a step.

7. The stator according to claim 1, wherein the wide portion of the terminal portion is formed to be gradually wider than the narrow portion.

8. A motor comprising the stator according to any one of claims 1 to 7 and a rotor disposed inside the stator in the radial direction.

9. The motor according to claim 8, wherein the rotor includes a plurality of permanent magnets arranged in a circumferential direction around a rotation axis, and a magnetic flux path of the stator is formed by the yoke core, the tooth cores, and the coils, and a magnetic flux of the permanent magnets passes through the magnetic flux path of the stator.

10. The motor according to claim 8, wherein the rotor includes a plurality of salient poles arranged in a circumferential direction around a rotation axis, and a magnetic flux path of the stator is formed by the yoke core, the tooth cores, and the coils, and a magnetic flux of the salient poles passes through the magnetic flux path of the stator.

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