Motor

Abstract

This motor comprises a rotor, a stator located on the radially outer side of the rotor, and a bus bar assembly positioned on one side of the stator in the axial direction. The insulator of the stator has an inner side insulator portion positioned radially inward of a coil. The bus bar assembly has a bus bar and a bus bar holder that holds the bus bar. The bus bar holder has an annular holder body portion surrounding the central axis. The bus bar has a coil connection portion connected to a coil lead-out line led out from the coil. The coil connection portion protrudes radially outward from the holder body portion. One of the inner side insulator portion and the bus bar holder has a first recess. The other of the inner side insulator portion and the bus bar holder has a first protrusion. At least a part of the first protrusion is inserted into the first recess. The bus bar holder is supported by the inner side insulator portion in the axial direction.

Description

motor

[0001] The present invention relates to a motor.

[0002] 2. Description of the Related Art A motor having a resin molded body that holds bus bars is known (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2009-290921

[0004] In the motor described above, for example, to facilitate the connection of the busbars to the coils, a structure may be adopted in which the portions of the busbars connected to the coils protrude radially outward from a busbar holder such as the resin molded body described above. When such a structure is adopted, the busbar holder may be provided with legs that protrude radially outward, and the busbar holder may be supported by the radially outer portions of the insulators of the stator via the legs. However, this may make it difficult to stably support the busbar holder relative to the stator.

[0005] In view of the above circumstances, one object of the present invention is to provide a motor having a structure that can stably support a bus bar holder.

[0006] One aspect of the motor of the present invention includes a rotor rotatable about a central axis, a stator positioned radially outward of the rotor, and a busbar assembly positioned axially on one side of the stator. The stator includes a stator core, an insulator attached to the stator core, and a coil attached to the stator core via the insulator. The insulator has an inner insulator portion positioned radially inward of the coil. The busbar assembly includes a busbar and a busbar holder that holds the busbar. The busbar holder has an annular holder main body portion surrounding the central axis. The busbar has a coil connection portion connected to a coil lead wire drawn from the coil. The coil connection portion protrudes radially outward from the holder main body portion. One portion of the inner insulator portion and the busbar holder has a first recess. The other portion of the inner insulator portion and the busbar holder has a first protrusion. At least a portion of the first protrusion is inserted into the first recess, and the bus bar holder is supported in the axial direction by the inner insulator portion.

[0007] According to one aspect of the present invention, for example, in a motor, a bus bar holder can be stably supported.

[0008] FIG. 1 is a cross-sectional view showing a motor according to a first embodiment. FIG. 2 is a view of a stator and a bus bar assembly according to the first embodiment, as viewed from above. FIG. 3 is a perspective view showing a portion of an insulator and a portion of a bus bar holder according to the first embodiment. FIG. 4 is a cross-sectional view showing a portion of a motor according to the first embodiment. FIG. 5 is a perspective view showing a portion of a bus bar holder according to the first embodiment. FIG. 6 is a cross-sectional view showing a portion of a motor according to a second embodiment. FIG. 7 is a perspective view showing a portion of an insulator and a portion of a bus bar holder according to the second embodiment. FIG. 8 is a cross-sectional view showing a portion of a motor according to a third embodiment. FIG. 9 is a perspective view showing a portion of an insulator according to the third embodiment. FIG. 10 is a perspective view showing a portion of a bus bar holder according to the third embodiment. FIG. 11 is a cross-sectional view showing a portion of a motor according to a fourth embodiment. FIG. 12 is a perspective view showing a portion of an insulator according to the fourth embodiment. FIG. 13 is a perspective view showing a portion of a bus bar holder according to the fourth embodiment. FIG. 14 is an exploded perspective view showing a portion of a motor according to a fifth embodiment.

[0009] Each figure shows an imaginary central axis J of a motor according to an embodiment described below. In the following description, unless otherwise specified, the axial direction of the central axis J will be simply referred to as the "axial direction," the radial direction about the central axis J will be simply referred to as the "radial direction," and the circumferential direction about the central axis J will be simply referred to as the "circumferential direction." The Z axis shown in each figure indicates the direction in which the central axis J extends. In the following description, the side of the axial direction toward which the Z-axis arrow points (+Z side) will be referred to as the "upper side," and the side of the axial direction opposite to the side toward which the Z-axis arrow points (-Z side) will be referred to as the "lower side."

[0010] In the following embodiments, the upper side corresponds to the “one axial side,” and the lower side corresponds to the “other axial side.” Note that the terms “upper side” and “lower side” are simply names used to describe the relative positional relationship of each part, and the actual positional relationship may be one other than the positional relationship indicated by these names.

[0011] First Embodiment As shown in FIG. 1 , a motor 100 of this embodiment includes a housing 10, a rotor 20, a stator 30, a bus bar assembly 40, and a control device 80. The housing 10 accommodates the rotor 20, the stator 30, the bus bar assembly 40, and the control device 80. The rotor 20 is rotatable about a central axis J. The rotor 20 has a shaft 21 and a rotor body 22. The shaft 21 is cylindrical and extends axially about the central axis J. The shaft 21 is supported by a pair of bearings 11 and 12 so as to be rotatable about the central axis J. The bearing 11 is held by a lower wall of the housing 10. The bearing 12 is held by a bearing holder 13 provided within the housing 10. The bearing holder 13 is located above the stator 30 and the bus bar assembly 40 and below the control device 80. The rotor body 22 is fixed to the outer peripheral surface of the shaft 21. Although not shown, the rotor body 22 has a rotor core fixed to the shaft 21 and a magnet held by the rotor core.

[0012] The stator 30 is located radially outside the rotor 20. The stator 30 is annular and surrounds the rotor 20. In this embodiment, the stator 30 is substantially annular and centered on the central axis J. The stator 30 includes a stator core 31, an insulator 50, and coils 32.

[0013] The stator core 31 has a core back 31a and a plurality of teeth 31b. As shown in FIG. 2 , the core back 31a has an annular shape surrounding the central axis J. In this embodiment, the core back 31a has a substantially circular annular shape centered on the central axis J. The plurality of teeth 31b extend radially inward from the core back 31a. The plurality of teeth 31b are spaced apart in the circumferential direction. More specifically, the plurality of teeth 31b are spaced apart in the circumferential direction. Each tooth 31b has a tooth main body portion 31c and an umbrella portion 31d. The tooth main body portion 31c extends radially inward from the radially inner surface of the core back 31a. The umbrella portion 31d is connected to the radially inner end of the tooth main body portion 31c. The umbrella portion 31d protrudes on both sides in the circumferential direction beyond the tooth main body portion 31c. The radially inner surface of the umbrella portion 31d is the radially inner surface of the teeth 31b and faces the radially outer surface of the rotor body 22 via a gap.

[0014] In this embodiment, the stator core 31 is configured into an annular shape by connecting a plurality of circumferentially divided core piece portions 31p in the circumferential direction. Each of the plurality of core piece portions 31p has a portion of the circumferential direction of the core back 31a and one tooth 31b.

[0015] The insulator 50 is attached to the stator core 31. The insulator 50 is an insulating member. In this embodiment, the insulator 50 is made of resin. In this embodiment, the insulator 50 has a plurality of insulator piece portions 50p. The plurality of insulator piece portions 50p are arranged side by side in the circumferential direction. The plurality of insulator piece portions 50p are arranged at equal intervals around one circumference in the circumferential direction. The plurality of insulator piece portions 50p are attached to the plurality of teeth 31b, respectively. In this embodiment, the plurality of insulator piece portions 50p are separate from one another. Note that the plurality of insulator piece portions 50p may be connected to one another in the circumferential direction. Although not shown in the drawings, each insulator piece portion 50p is composed of two members divided in the axial direction. The two members, for example, have the same shape and are arranged opposite each other in the axial direction.

[0016] As shown in FIG. 1 , each of the multiple insulator piece parts 50p has a tooth cover part 51, an inner wall part 52p, and an outer wall part 53p. The tooth cover part 51 is attached to the tooth 31b. The tooth cover part 51 covers the tooth 31b from both axial and circumferential sides. The tooth cover part 51 is generally cylindrical and surrounds the tooth 31b around an axis extending in the direction in which the teeth 31b extend. The coil 32 is attached to the tooth cover part 51. As shown in FIG. 3 , a groove part 51a extending in the axial direction is provided on the circumferential side surface of the tooth cover part 51. A plurality of groove parts 51a are provided radially aligned on each of the circumferential side surfaces of the tooth cover part 51.

[0017] As shown in FIG. 1 , the inner wall portion 52p is connected to the radially inner end of the tooth cover portion 51. The inner wall portion 52p is located radially inward of the coil 32. The inner wall portion 52p protrudes on both axial sides from the tooth cover portion 51. As shown in FIG. 3 , the inner wall portion 52p protrudes on both circumferential sides from the tooth cover portion 51. When viewed in the axial direction, the inner wall portion 52p has an arc shape extending in the circumferential direction. In this embodiment, the radial dimension of the inner wall portion 52p is constant throughout the circumferential direction. Note that the radial dimension of the inner wall portion 52p may vary depending on the circumferential position. For example, the radial dimension of the inner wall portion 52p may increase with increasing distance from the circumferential center of the inner wall portion 52p to both circumferential sides.

[0018] As shown in FIG. 1 , the inner wall portion 52p has a first inner protrusion 52a and a second inner protrusion 52b. The first inner protrusion 52a is a portion of the inner wall portion 52p that protrudes upward relative to the tooth cover portion 51. The second inner protrusion 52b is a portion of the inner wall portion 52p that protrudes downward relative to the tooth cover portion 51. As shown in FIG. 3 , in this embodiment, the first inner protrusion 52a is plate-shaped with its plate surface facing radially. When viewed in the axial direction, the first inner protrusion 52a has an arc shape extending circumferentially. The second inner protrusion 52b has a shape symmetrical to the first inner protrusion 52a in the axial direction.

[0019] As shown in FIG. 2 , the inner wall portions 52p of the multiple insulator piece portions 50p are arranged side by side in the circumferential direction. A gap is provided between the circumferentially adjacent inner wall portions 52p. In this embodiment, the multiple inner wall portions 52p form an inner insulator portion 52. That is, the insulator 50 has an inner insulator portion 52, and the inner insulator portion 52 has each of the inner wall portions 52p of the multiple insulator piece portions 50p. The inner insulator portion 52 is located radially inward of the coil 32. In this embodiment, the inner insulator portion 52 has a substantially annular shape centered on the central axis J.

[0020] As shown in FIG. 3 , the inner insulator portion 52 has a first recess 54. In this embodiment, the first recess 54 is provided at the upper end of the first inner protruding portion 52a. The first recess 54 is recessed downward from the upper end surface of the first inner protruding portion 52a. The first recess 54 penetrates the first inner protruding portion 52a in the radial direction. The first recess 54 opens radially inward and radially outward. The interior of the first recess 54 is rectangular when viewed radially. In this embodiment, the first recess 54 is provided at the circumferential center of the first inner protruding portion 52a. The circumferential center of the first recess 54 is located at the same position in the circumferential direction as the circumferential center of the first inner protruding portion 52a.

[0021] The inner surface of the first recess 54 has a pair of side surfaces 54a, 54b and a bottom surface 54c. The bottom surface 54c is a lower portion of the inner surface of the first recess 54. The bottom surface 54c faces upward. In this embodiment, the bottom surface 54c is a flat surface perpendicular to the axial direction. The pair of side surfaces 54a, 54b are portions of the inner surface of the first recess 54 located on both circumferential sides. The pair of side surfaces 54a, 54b face the circumferential direction. The pair of side surfaces 54a, 54b are flat surfaces perpendicular to the circumferential direction. The pair of side surfaces 54a, 54b oppose each other in the circumferential direction with a gap between them. The pair of side surfaces 54a, 54b extend upward from the edges of the bottom surface 54c on both circumferential sides. The upper ends of the pair of side surfaces 54a, 54b are connected to the upper end surface of the first inner protrusion 52a. The pair of side surfaces 54a, 54b sandwich a first protrusion 61, which will be described later, in the circumferential direction.

[0022] As shown in FIG. 2 , in this embodiment, the first recesses 54 are provided in the inner wall portion 52p of each insulator piece portion 50p. That is, in this embodiment, the inner insulator portion 52 has multiple first recesses 54. The multiple first recesses 54 are circumferentially spaced apart. The multiple first recesses 54 are circumferentially spaced apart at equal intervals. By providing the multiple insulator piece portions 50p with the first recesses 54, all of the multiple insulator piece portions 50p can be formed with the same shape. Therefore, unlike a case where the multiple insulator piece portions 50p include insulator piece portions 50p with different shapes, each of the multiple insulator piece portions 50p can be manufactured using a single mold. This reduces the manufacturing cost of the insulator 50 and the motor 100. Furthermore, since it is not necessary to consider to which tooth 31b the insulator piece portion 50p with the first recesses 54 should be attached, the assembly workability of the stator 30 can be improved. The first recess 54 does not have to be provided on each inner wall portion 52p of each insulator piece portion 50p, but may be provided only on the insulator piece portion 50p that axially faces a first protrusion 61 (described later).

[0023] As shown in FIG. 1 , the outer wall portion 53p is connected to the radially outer end of the tooth cover portion 51. The outer wall portion 53p is located radially outward from the coil 32. The outer wall portion 53p protrudes in both axial directions beyond the tooth cover portion 51. Although not shown, the outer wall portion 53p protrudes in both circumferential directions beyond the tooth cover portion 51. As shown in FIG. 2 , the outer wall portions 53p of the multiple insulator piece portions 50p are arranged side by side in the circumferential direction. A gap is provided between the circumferentially adjacent outer wall portions 53p. In this embodiment, the multiple outer wall portions 53p form an outer insulator portion 53. That is, the insulator 50 has an outer insulator portion 53. The outer insulator portion 53 is located radially outward from the coil 32. In this embodiment, the outer insulator portion 53 has a substantially annular shape centered on the central axis J.

[0024] The coil 32 is attached to the stator core 31 via an insulator 50. A plurality of coils 32 are provided. The plurality of coils 32 are attached to the plurality of teeth 31b via tooth cover portions 51 of the plurality of insulator piece portions 50p. Each coil 32 is configured by winding a conductor around the tooth cover portion 51 attached to the tooth 31b. In other words, each coil 32 is configured by winding a conductor around the tooth 31b via the insulator piece portion 50p. A coil lead wire 32a is drawn upward from at least one coil 32 of the plurality of coils 32. The coil lead wire 32a is formed by the end of the conductor wire that constitutes the coil 32. For example, the coil lead wire 32a is drawn upward from six coils 32.

[0025] 1 , the busbar assembly 40 is located above the stator 30. The busbar assembly 40 is supported from below by the stator 30. The busbar assembly 40 includes a busbar holder 60 and a busbar 70.

[0026] The busbar 70 is electrically connected to the coil 32. The busbar 70 is a plate-shaped metal member. As shown in FIG. 2 , a plurality of busbars 70 are provided. In the present embodiment, three busbars 70 are provided. Each busbar 70 has a busbar main body 71, a coil connection portion 72, and a terminal portion 73. The busbar main body 71 is held by the busbar holder 60. In the present embodiment, the busbar main body 71 is embedded and held in the busbar holder 60. More specifically, the busbar main body 71 is embedded and held in a holder main body 63, which will be described later. The busbar main body 71 is plate-shaped, with its plate surface facing the axial direction. The busbar main body 71 has an arc portion 71a extending in the circumferential direction and an extension portion 71b extending radially outward from the arc portion 71a. The extension portions 71b of the bus bars 70 are arranged side by side in a direction perpendicular to both the direction in which the terminal holding portions 64 (described later) protrude from the bus bar main body 71 and the axial direction.

[0027] The coil connection portion 72 is a portion to which the coil lead wire 32a drawn from the coil 32 is connected. The coil connection portion 72 extends radially outward from the busbar main body 71. More specifically, the coil connection portion 72 extends radially outward from the arc portion 71a. The coil connection portion 72 protrudes radially outward from the holder main body 63, which will be described later. The coil connection portion 72 has an arm portion 72a and a pair of clamping portions 72b, 72c. The arm portion 72a extends radially outward from the radially outer edge of the busbar main body 71. The arm portion 72a is plate-shaped with its plate surface facing the axial direction.

[0028] The pair of clamping portions 72b, 72c are connected to the radially outer end of the arm portion 72a. The pair of clamping portions 72b, 72c face each other with a gap in the circumferential direction. The radially outer end of the arm portion 72a and the pair of clamping portions 72b, 72c form a generally U-shape that opens radially outward when viewed in the axial direction, with the radially outer end of the coil connection portion 72. The pair of clamping portions 72b, 72c circumferentially clamp the coil lead wire 32a. The pair of clamping portions 72b, 72c are connected to the coil lead wire 32a by, for example, welding. Note that the pair of clamping portions 72b, 72c may be crimped toward each other in the circumferential direction and contact each other with the coil lead wire 32a sandwiched between the pair of clamping portions 72b, 72c. In this embodiment, two coil connection portions 72 are provided on each bus bar 70. The coil connection portion 72 is exposed to the outside of the bus bar holder 60 except for the radially inner end portion.

[0029] The terminal portions 73 extend upward from the busbar main body 71. More specifically, the terminal portions 73 extend upward from the radially outer ends of the extension portions 71b. The terminal portions 73 are plate-shaped with their plate surfaces facing the radial direction. The terminal portions 73 protrude upward from the terminal holders 64 (described later). As shown in FIG. 1, the upper ends of the terminal portions 73 are electrically connected to the control device 80. This electrically connects the coils 32 and the control device 80 via the busbars 70. The control device 80 has an inverter circuit that supplies power to the coils 32. Power is supplied from the control device 80 to each coil 32 via the busbars 70. The terminal portions 73 are axially passed through holes (not shown) provided in the bearing holder 13. As shown in FIG. 2, the terminal portions 73 of each busbar 70 are arranged side by side in the direction in which the extension portions 71b of each busbar 70 are arranged.

[0030] The busbar holder 60 holds the busbar 70. In this embodiment, the busbar holder 60 is made of resin. The busbar holder 60 is manufactured by, for example, insert molding using the busbar 70 as an insert member. The busbar holder 60 includes a holder main body 63 and a terminal holding portion 64. The holder main body 63 has an annular shape surrounding the central axis J. In this embodiment, the holder main body 63 has a substantially circular annular shape centered on the central axis J. As shown in FIG. 1 , the holder main body 63 is located radially outward from the inner insulator portion 52. More specifically, the lower end of the holder main body 63 is located radially outward from the upper end of the inner insulator portion 52. The upper end of the inner insulator portion 52 is inserted radially inward at the lower end of the holder main body 63. For example, the upper end of the inner insulator portion 52 is loosely fitted radially inward at the lower end of the holder main body 63.

[0031] The holder main body 63 faces the coil 32 in the axial direction. The holder main body 63 is located above the coil 32. As shown in FIG. 4 , more specifically, the holder main body 63 is located above the radially inner portion of the coil 32. A second recess 63a recessed upward is provided in a portion of the lower surface of the holder main body 63 that faces the coil 32 in the axial direction. The provision of the second recess 63a prevents the holder main body 63 from contacting the coil 32. In this embodiment, the second recess 63a is provided radially outward from a portion of the lower surface of the holder main body 63 where a second protrusion 62 (described later) is provided. The downward-facing surface of the second recess 63a is positioned upward as it extends radially outward. The downward-facing surface of the second recess 63a is curved when viewed circumferentially. Note that the downward-facing surface of the second recess 63a may be linear when viewed circumferentially.

[0032] 2, the terminal holding portion 64 protrudes radially outward from the holder main body 63. The terminal holding portion 64 has a generally rectangular parallelepiped shape. The terminal holding portion 64 holds the extension portion 71b and the terminal portion 73 of each bus bar 70. The entire extension portion 71b and the lower end of the terminal portion 73 are embedded in and held in the terminal holding portion 64.

[0033] As shown in FIG. 5 , the bus bar holder 60 has a first protrusion 61. In the present embodiment, the first protrusion 61 protrudes radially inward from the radially inner surface of the holder main body 63. The first protrusion 61 is provided at a lower end of the radially inner surface of the holder main body 63. The first protrusion 61 has a substantially rectangular parallelepiped shape. As shown in FIG. 3 , at least a portion of the first protrusion 61 is inserted into the first recess 54. In the present embodiment, the entire first protrusion 61 is inserted into the first recess 54. Note that only a portion of the first protrusion 61 may be inserted into the first recess 54, with the other portion of the first protrusion 61 being outside the first recess 54. The first protrusion 61 contacts the bottom surface 54 c. As a result, the bus bar holder 60 is axially supported by the inner insulator portion 52 via the first protrusion 61. The lower surface of the first protrusion 61 is a flat surface perpendicular to the axial direction, and contacts the bottom surface 54c from above.

[0034] In this embodiment, as described above, the coil connection portions 72 protrude radially outward from the holder main body 63. This allows the connection work between the coil connection portions 72 and the coil lead wires 32a to be performed radially outward from the holder main body 63. This makes it easier to ensure a larger space for the connection work compared to when the coil connection portions 72 protrude radially inward from the holder main body 63. This prevents jigs and other devices used in the connection work from coming into contact with the bus bar holder 60 and other coil connection portions 72, allowing workers and other personnel to easily perform the connection work. In this specification, the term "workers and other personnel" includes workers and assembly devices that perform each task. Each task may be performed by a worker alone, by an assembly device alone, or by a worker and an assembly device together.

[0035] When the coil connection portions 72 protrude radially outward from the holder main body portion 63 as described above, the outer diameter of the holder main body portion 63 is likely to be smaller than when the coil connection portions 72 protrude radially inward from the holder main body portion 63. In such a case, it is conceivable to provide the bus bar holder 60 with legs extending radially outward from the holder main body portion 63 and to support the bus bar holder 60 in the axial direction on the outer insulator portion 53 via the legs. However, in this case, the support of the bus bar holder 60 is likely to become unstable. As a result, the bus bar holder 60 may bend due to its own weight or an external load or stress, which may cause the position of the bus bar 70 held by the bus bar holder 60 to shift. This may result in a problem such as a shift in the position of the terminal portions 73, making it difficult to connect the terminal portions 73 to the control device 80.

[0036] In contrast, according to the present embodiment, the bus bar holder 60 is positioned relative to the inner insulator part 52 by inserting at least a portion of the first protrusion 61 into the first recess 54, while the bus bar holder 60 is supported in the axial direction by the inner insulator part 52. This makes it possible to more stably support the bus bar holder 60 in the axial direction relative to the insulator 50 than when the coil connection parts 72 protrude radially outward from the holder main body part 63 and the bus bar holder 60 is supported in the axial direction by the outer insulator part 53 via the legs as described above. Therefore, according to the present embodiment, the bus bar holder 60 can be stably supported in the motor 100.

[0037] In the present embodiment, the first protrusion 61 contacts a lower portion of the inner surface of the first recess 54, i.e., the bottom surface 54c. Therefore, the busbar holder 60 can be supported in the axial direction by the inner insulator portion 52 by utilizing the first protrusion 61 inserted into the first recess 54. This eliminates the need to provide a portion in another portion of the busbar holder 60 that supports the inner insulator portion 52 in the axial direction, and prevents the shape of the busbar holder 60 from becoming complicated.

[0038] The first protrusion 61 is sandwiched in the circumferential direction by a pair of side surfaces 54a, 54b on the inner surface of the first recess 54. Therefore, by inserting the first protrusion 61 into the first recess 54, the bus bar holder 60 can be positioned in the circumferential direction with respect to the inner insulator portion 52. In the present embodiment, the first protrusion 61 is fitted into the first recess 54. This allows the bus bar holder 60 to be more suitably positioned in the circumferential direction with respect to the inner insulator portion 52. The first protrusion 61 may be in contact with only one of the pair of side surfaces 54a, 54b, or may be in contact with both of the pair of side surfaces 54a, 54b, or may not be in contact with both of the pair of side surfaces 54a, 54b.

[0039] As described above, in this embodiment, the holder main body portion 63 is located radially outside the inner insulator portion 52. The first recess 54 opens radially outward. The first protrusion 61 protrudes radially inward from the holder main body portion 63. Therefore, by positioning the inner insulator portion 52 radially inside the holder main body portion 63, the first protrusion 61 can be easily inserted into the first recess 54 while the holder main body portion 63 is radially positioned relative to the inner insulator portion 52 to a certain extent. When the inner insulator portion 52 is positioned radially inside the holder main body portion 63 as in this embodiment, the holder main body portion 63 is positioned axially closer to the coil 32 than when the entire holder main body portion 63 is positioned above the inner insulator portion 52. However, in this embodiment, as described above, by providing the second recess 63a on the lower surface of the holder main body portion 63, contact between the holder main body portion 63 and the coil 32 can be suppressed.

[0040] As shown in FIG. 2 , in this embodiment, a plurality of first protrusions 61 are provided at intervals in the circumferential direction. The plurality of first protrusions 61 are arranged at equal intervals around the circumference. In this embodiment, three first protrusions 61 are provided. The plurality of first protrusions 61 are inserted into different first recesses 54. Because the plurality of first protrusions 61 are inserted into the respective first recesses 54, the bus bar holder 60 can be more appropriately positioned with respect to the inner insulator part 52. In this embodiment, the plurality of first protrusions 61 enable the bus bar holder 60 to be more stably supported in the axial direction with respect to the inner insulator part 52. The number of first protrusions 61 is smaller than the number of first recesses 54. Therefore, the plurality of first recesses 54 includes first recesses 54 into which the first protrusions 61 are inserted and first recesses 54 into which the first protrusions 61 are not inserted.

[0041] As shown in FIG. 5 , the bus bar holder 60 has a second protrusion 62 that protrudes in the axial direction. The second protrusion 62 protrudes downward from the holder main body 63. In this embodiment, the second protrusion 62 protrudes downward from a radially inner edge of the lower surface of the holder main body 63. The second protrusion 62 extends in the circumferential direction. The radially inner surface of the second protrusion 62 is located at the same radial position as the radially inner surface of the holder main body 63. The radially inner surface of the second protrusion 62 is connected to the radially inner surface of the holder main body 63. In this embodiment, the second protrusion 62 is located on the surface of the holder main body 63 below the portion where the first protrusion 61 is located. The second protrusion 62 is not directly connected to the first protrusion 61.

[0042] As shown in FIG. 4 , the second protrusion 62 contacts the inner insulator portion 52 in the radial direction. Therefore, the second protrusion 62 can radially position the bus bar holder 60 relative to the inner insulator portion 52. In the present embodiment, the second protrusion 62 contacts the inner insulator portion 52 from the radially outer side. The radially inner surface of the second protrusion 62 contacts the radially outer surface of the inner insulator portion 52. More specifically, the radially inner surface of the second protrusion 62 contacts a portion of the radially outer surface of the first inner protrusion 52a that is located below the first recess 54. The portion of the radially outer surface of the first inner protrusion 52a that contacts the radially inner surface of the second protrusion 62 includes a portion adjacent to the lower side of the first recess 54. The radially inner surface of the second protrusion 62 is a surface that extends circumferentially and is perpendicular to the radial direction.

[0043] Here, for example, the busbar holder 60 can be positioned radially relative to the inner insulator portion 52 by bringing a portion of the radially inner surface of the holder main body portion 63 that is located radially outward of the inner insulator portion 52 into radial contact with the inner insulator portion 52. However, in this case, the radially inner surface of the holder main body portion 63 needs to be manufactured with high precision over a wide circumferential range, which may increase the manufacturing cost of the busbar holder 60. In contrast, by configuring the second protrusion portion 62 to be in radial contact with the inner insulator portion 52, it is only necessary to manufacture with high precision the portion of the second protrusion portion 62 that contacts the inner insulator portion 52, i.e., the radially inner surface. This makes it possible to prevent an increase in the manufacturing cost of the busbar holder 60.

[0044] 3 , the circumferential dimension of the second protrusion 62 is larger than the circumferential dimension of the first protrusion 61. This makes it easier to increase the contact area between the second protrusion 62 and the inner insulator portion 52. This allows the bus bar holder 60 to be more stably positioned radially relative to the inner insulator portion 52. The second protrusion 62 protrudes on both sides in the circumferential direction beyond the first protrusion 61. In this embodiment, the circumferential center of the second protrusion 62 is located at the same position in the circumferential direction as the circumferential center of the first protrusion 61.

[0045] As shown in FIG. 4 , the radially outer surface of the second convex portion 62 has an inclined portion 62a that is positioned radially inward as it extends downward. Therefore, the lower portion of the radially outer surface of the second convex portion 62, which is closer to the coil 32, can be positioned radially inward. This prevents the second convex portion 62 from contacting the coil 32. This prevents the second convex portion 62 from axially contacting the coil 32 and causing the bus bar holder 60 to lift upward, and prevents the first convex portion 61 from contacting the bottom surface 54c of the first recess 54. This makes it easier to more suitably support the bus bar holder 60 in the axial direction on the inner insulator portion 52 via the first convex portion 61. When the inner insulator portion 52 is positioned radially inward of the holder main body portion 63 as in this embodiment, the second convex portion 62 is more likely to be positioned near the coil 32. However, in the present embodiment, the provision of the inclined portion 62a on the radially outer surface of the second convex portion 62 can suitably prevent the second convex portion 62 from coming into contact with the coil 32. In the present embodiment, the inclined portion 62a is a lower portion of the radially outer surface of the second convex portion 62. In the present embodiment, the inclined portion 62a is a curved surface that is convex radially outward and downward.

[0046] As shown in Fig. 2, a plurality of second protrusions 62 are provided at intervals in the circumferential direction. The plurality of second protrusions 62 are arranged at equal intervals around the circumference. In the present embodiment, three second protrusions 62 are provided. Each of the plurality of second protrusions 62 contacts the radially outer surface of a different inner wall portion 52p. A second protrusion 62 is provided for each first protrusion 61.

[0047] Below, embodiments different from the above-described embodiments will be described. In the following description of each embodiment, the same configurations as those described above in the description of each embodiment may be omitted by appropriately assigning the same reference numerals. Furthermore, parts corresponding to the respective parts of the configurations described above in the description of each embodiment may be assigned the same names but different reference numerals, and differences from the above-described configurations may be described, while similar configurations to the above-described configurations may be omitted. Note that, as the configurations whose description is omitted in each of the following embodiments, configurations similar to the configurations described above in the description of each embodiment may be adopted within the scope of not being inconsistent.

[0048] Second Embodiment As shown in FIGS. 6 and 7 , in a bus bar assembly 240 of a motor 200 according to this embodiment, a bus bar holder 260 includes a first protrusion 261 and a second protrusion 262. In this embodiment, the first protrusion 261 protrudes downward from a holder main body 263. More specifically, the first protrusion 261 protrudes downward from a radially inner edge of the lower surface of the holder main body 263. The holder main body 263 is similar to the holder main body 63 of the first embodiment, except that it does not include a second recess 63a. The radially inner surface of the first protrusion 261 is located at the same radial position as the radially inner surface of the holder main body 263. The radially inner surface of the first protrusion 261 is connected to the radially inner surface of the holder main body 263.

[0049] The first protrusion 261 has a generally rectangular parallelepiped shape extending in the axial direction. At least a portion of the first protrusion 261 is inserted into the first recess 54. In the present embodiment, a lower portion of the first protrusion 261 is inserted into the first recess 54. An upper portion of the first protrusion 261 is located above the first recess 54. The lower surface of the first protrusion 261 contacts the bottom surface 54c of the first recess 54. This allows the bus bar holder 260 to be supported in the axial direction by the inner insulator portion 52.

[0050] The second protrusion 262 protrudes downward from the holder main body 263. The second protrusion 262 is located radially outward of the first protrusion 261. The second protrusion 262 is connected to the radially outer surface of the first protrusion 261. The second protrusion 262 has a generally rectangular parallelepiped shape extending in the axial direction. The second protrusion 262 protrudes downward from the first protrusion 261. As shown in FIG. 7 , in this embodiment, the circumferential dimension of the second protrusion 262 is the same as the circumferential dimension of the first protrusion 261. A portion of the second protrusion 262 located below the first protrusion 261 contacts the inner insulator part 52 from the radially outer side. In this embodiment, the second protrusion 262 contacts a portion of the radially outer surface of the first inner protrusion 52a adjacent to the lower side of the first recess 54. As shown in FIG. 6 , the second protrusion 262 has an inclined portion 262a, similar to the first embodiment. The inclined portion 262a is provided on the radially outer surface of the second convex portion 262 at a portion that is located below the first convex portion 261. Other configurations of the inclined portion 262a are similar to other configurations of the inclined portion 62a in the first embodiment.

[0051] Other configurations of the bus bar assembly 240 are similar to other configurations of the bus bar assembly 40 in the first embodiment. Other configurations of the motor 200 are similar to other configurations of the motor 100 in the first embodiment.

[0052] Third Embodiment As shown in FIGS. 8 and 9 , in a motor 300 according to this embodiment, an inner insulator portion 352 of an insulator 350 has a third protrusion 355 that protrudes in the axial direction. The third protrusion 355 is provided on an inner wall portion 352p. In this embodiment, the third protrusion 355 protrudes upward from the upper surface of a first inner protrusion 352a. As shown in FIG. 9 , the third protrusion 355 is provided on a portion of the inner wall portion 352p that is located on one circumferential side of the circumferential center of the inner wall portion 352p. In this embodiment, the third protrusion 355 is provided on an end portion on one circumferential side of the upper surface of the first inner protrusion 352a. The third protrusion 355 has a substantially rectangular shape when viewed in the axial direction. The upper surface of the third protrusion 355 is perpendicular to the axial direction.

[0053] In this embodiment, one circumferential side refers to the side moving counterclockwise around the central axis J as viewed from above. In Fig. 9, Fig. 12 (described later), and Fig. 14 (described later), the circumferential direction is indicated by arrow θ. In this embodiment, one circumferential side refers to the side toward which the arrow θ points (+θ side). The side opposite to the side toward which the arrow θ points (-θ side) refers to the other circumferential side.

[0054] As shown in FIGS. 8 and 9 , the inner insulator portion 352 has a first recess 354. In this embodiment, the first recess 354 provided in the inner insulator portion 352 is provided in a portion of the inner wall portion 352p that is located on one circumferential side of the circumferential center of the inner wall portion 352p. Here, in order to improve the space factor of the coil 32, the circumferential central portion of the inner wall portion 352p is likely to be thinner in the radial direction than the circumferential ends of the inner wall portion 352p. In other words, a portion of the inner wall portion 352p that is circumferentially shifted from the circumferential central portion is likely to be thicker in the radial direction than the circumferential central portion of the inner wall portion 352p. Therefore, by providing the first recess 354 in a portion of the inner wall portion 352p that is located on one circumferential side of the circumferential center of the inner wall portion 352p, the first recess 354 can be easily provided in a portion of the inner wall portion 352p that has a relatively large radial dimension. As a result, even when the first protrusion 361 is inserted into the first recess 354 and a force is applied from the first protrusion 361 to the inner surface of the first recess 354, the force is likely to be received by a portion of the inner wall 352p that has a relatively high rigidity. Therefore, the bus bar holder 360 can be more stably supported by the inner wall 352p.

[0055] In this embodiment, the first recess 354 is provided in a portion of the inner wall portion 352p that includes the third protrusion 355. The first recess 354 is a hole that is recessed downward and has a bottom on the lower side. The first recess 354 opens to an axial end surface of the third protrusion 355. In this embodiment, the first recess 354 opens to an upper end surface of the third protrusion 355. The first recess 354 has a circular shape when viewed in the axial direction. In this embodiment, the radial dimension of the portion of the inner wall portion 352p where the first recess 354 is provided is larger than the radial dimension of the other portions of the inner wall portion 352p. The portion of the inner wall portion 352p where the first recess 354 is provided protrudes radially outward more than the other portions of the inner wall portion 352p.

[0056] As shown in Fig. 8 , the inner surface of the first recess 354 has a circumferential surface 354d that surrounds the first protrusion 361 around an imaginary axis IL1 that extends in the axial direction. Therefore, by inserting the first protrusion 361 into the first recess 354, the bus bar holder 360 can be positioned radially and circumferentially with respect to the inner insulator portion 352. The imaginary axis IL1 passes through the center of the first recess 354, which is circular when viewed in the axial direction. In this embodiment, the circumferential surface 354d is a cylindrical surface centered on the imaginary axis IL1. The circumferential surface 354d is the inner circumferential surface of the first recess 354.

[0057] As shown in FIG. 9 , a groove 356 extending in the axial direction is provided in the circumferential center portion of the radially inner surface of the inner wall portion 352p. Therefore, even if a sink mark occurs in the inner wall portion 352p and the inner wall portion 352p warps when molding the insulator 350 using a mold, the circumferential center portion of the inner wall portion 352p can be prevented from contacting the rotor 20 located radially inside the stator 30. When the groove 356 is provided, the radial dimension of the circumferential center portion of the inner wall portion 352p is further reduced. Therefore, in a configuration in which the groove 356 is provided, the effect of disposing the first recess 354 circumferentially shifted from the circumferential center portion of the inner wall portion 352p can be more effectively obtained.

[0058] In the present embodiment, the radial dimension of the inner wall portion 352p is smallest at the circumferential portion of the inner wall portion 352p where the groove 356 is provided. The radial dimension of the portions of the inner wall portion 352p adjacent to both sides of the groove 356 in the circumferential direction increases with increasing distance from the groove 356 in the circumferential direction.

[0059] In this embodiment, the winding start end 32b of the conductor 32c that constitutes the coil 32 is located on the other circumferential side (-θ side) of the circumferential center of the inner wall portion 352p. In other words, the winding start end 32b is located on the opposite circumferential side of the first recess 354, across the circumferential center of the inner wall portion 352p. Therefore, by providing the first recess 354, even if the portion on one circumferential side (+θ side) of the inner wall portion 352p becomes thicker in the radial direction, the thickened portion is less likely to get in the way when starting to wind the conductor 32c. This makes it easier for workers to wind the conductor 32c.

[0060] As shown in FIG. 10 , in the busbar assembly 340 of this embodiment, the busbar holder 360 has a first protrusion 361 and a second protrusion 362. The second protrusion 362 protrudes in the axial direction. In this embodiment, the second protrusion 362 protrudes downward from the lower surface of the holder main body 63. When viewed in the axial direction, the second protrusion 362 has a circular shape centered on the imaginary axis line IL1, with the radially inner edge of the second protrusion 362 cut out along the radially inner edge of the holder main body 63. In a direction perpendicular to the axial direction, the dimension of the second protrusion 362 is larger than that of the first protrusion 361. The outer diameter of the second protrusion 362 is larger than that of the first protrusion 361.

[0061] As shown in FIG. 8 , the lower surface of the second protrusion 362 contacts the upper end surface of the third protrusion 355. This brings the second protrusion 362 into axial contact with the inner insulator portion 352. Therefore, the busbar holder 360 can be axially positioned relative to the inner insulator portion 352 via the second protrusion 362. Furthermore, the third protrusion 355 is provided in a portion of the inner wall portion 352p that is located on one circumferential side (+θ side) of the circumferential center of the inner wall portion 352p. Therefore, the second protrusion 362 can be axially supported in a portion of the inner wall portion 352p that tends to have a larger radial dimension than the circumferential center portion. This allows the load of the busbar holder 360 to be stably supported by the inner wall portion 352p, thereby more stably supporting the busbar holder 360 relative to the inner insulator portion 352.

[0062] The first protrusion 361 protrudes in the axial direction from the axial end of the second protrusion 362. In the present embodiment, the first protrusion 361 protrudes downward from the lower end face of the second protrusion 362. As shown in FIG. 10 , in the present embodiment, the first protrusion 361 has a substantially cylindrical shape centered on the imaginary axis IL1. In the radial direction centered on the imaginary axis IL1, the outer surface of the first protrusion 361 is spaced further inward than the outer surface of the second protrusion 362. As shown in FIG. 8 , at least a portion of the first protrusion 361 is inserted into the first recess 354. In the present embodiment, the entire first protrusion 361 is inserted into the first recess 354. The first protrusion 361 is fitted into the first recess 354. For example, the first protrusion 361 is loosely fitted into the first recess 354. The outer circumferential surface of the first protrusion 361 may be in contact with the circumferential surface 354d of the first recess 354, or may face the circumferential surface 354d with a gap therebetween. The first protrusion 361 may be press-fitted into the first recess 354.

[0063] In this embodiment, the first convex portion 361 protrudes in the axial direction from the axial end of the second convex portion 362. The inner insulator portion 352 has a third convex portion 355 protruding in the axial direction. The first recess 354 opens at the axial end surface of the third convex portion 355. The second convex portion 362 contacts the axial end surface of the third convex portion 355. Therefore, it is easier to form the first convex portion 361 and the second convex portion 362 than when the first convex portion 361 and the second convex portion 362 are formed in separate locations. Furthermore, because the first recess 354 opens at the axial end surface of the third convex portion 355, the first convex portion 361 can be inserted into the first recess 354 while the second convex portion 362 can contact the peripheral portion of the first recess 354 on the axial end surface of the third convex portion 355. This makes it easy to position the bus bar holder 360 in the circumferential and radial directions by inserting the first protrusions 361 into the first recesses 354, and then to position the bus bar holder 360 in the axial direction by bringing the second protrusions 362 into contact with the third protrusions 355. Therefore, the bus bar holder 360 can be easily positioned relative to the inner insulator portion 352. Furthermore, by providing the third protrusions 355 as the portions with which the second protrusions 362 contact, if the third protrusions 355 are manufactured with precision, the bus bar holder 360 can be accurately positioned in the axial direction via the second protrusions 362. Therefore, the number of steps required to manufacture the insulator 350 can be reduced compared to, for example, manufacturing the entire upper surface of the first inner protrusions 352a with precision. This reduces the manufacturing cost of the motor 300.

[0064] The axial dimension of the first protrusion 361 is smaller than the axial dimension of the first recess 354. The lower end of the first protrusion 361 is provided above and spaced apart from the lower portion of the inner surface of the first recess 354. The other configurations of the bus bar assembly 340 are the same as the other configurations of the bus bar assembly 40 in the first embodiment. The other configurations of the motor 300 are the same as the other configurations of the motor 100 in the first embodiment.

[0065] Fourth Embodiment As shown in FIG. 11 , in an insulator 450 of a motor 400 according to this embodiment, an inner insulator portion 452 has a first protrusion 454 and a second protrusion 455. The second protrusion 455 is provided on an inner wall portion 452p. In this embodiment, the second protrusion 455 protrudes upward from the upper surface of the first inner protrusion 352a. As shown in FIG. 12 , the second protrusion 455 is provided on a portion of the inner wall portion 452p that is located on one circumferential side (+θ side) of the circumferential center of the inner wall portion 452p. In this embodiment, the second protrusion 455 is provided at an end portion on one circumferential side of the upper surface of the first inner protrusion 352a. The upper surface of the second protrusion 455 is perpendicular to the axial direction.

[0066] The first protrusion 454 protrudes in the axial direction from the axial end of the second protrusion 455. In the present embodiment, the first protrusion 454 protrudes upward from the radially outer end of the upper end face of the second protrusion 455. The first protrusion 454 is generally cylindrical.

[0067] As shown in FIG. 13 , the busbar holder 460 in the busbar assembly 440 has a third protrusion 464 that protrudes in the axial direction. The third protrusion 464 protrudes downward from the lower surface of the holder main body 63. The third protrusion 464 has a substantially circular shape when viewed in the axial direction. The third protrusion 464 has a first recess 465 that is recessed upward from the lower surface of the third protrusion 464. That is, in this embodiment, the first recess 465 opens to the lower end surface of the third protrusion 464. The first recess 465 is a hole that is recessed upward and has a bottom on the upper side. The first recess 465 has a circular shape when viewed in the axial direction. As shown in FIG. 11 , the inner surface of the first recess 465 has a peripheral surface 465d that surrounds the first protrusion 454 around an imaginary axis IL2 extending in the axial direction. Therefore, by inserting the first protrusion 454 into the first recess 465, the bus bar holder 460 can be positioned radially and circumferentially with respect to the inner insulator portion 452. The imaginary axis IL2 passes through the center of the circular first recess 465 when viewed in the axial direction. In this embodiment, the circumferential surface 465d is a cylindrical surface centered on the imaginary axis IL2. The circumferential surface 465d is the inner circumferential surface of the first recess 465.

[0068] At least a portion of the first protrusion 454 is inserted into the first recess 465. In the present embodiment, the entire first protrusion 454 is inserted into the first recess 465. The first protrusion 454 is fitted into the first recess 465. The first protrusion 454 is, for example, loosely fitted into the first recess 465. The outer circumferential surface of the first protrusion 454 may be in contact with a peripheral surface 465d of the first recess 465, or may face the peripheral surface 465d via a gap. The first protrusion 454 may be press-fit into the first recess 465.

[0069] The axial dimension of the first convex portion 454 is smaller than the axial dimension of the first recessed portion 465. The upper end of the first convex portion 454 is located lower than the upper portion of the inner surface of the first recessed portion 465. The lower end face of the third convex portion 464 on which the first recessed portion 465 is located contacts the upper end face of the second convex portion 455. As a result, the second convex portion 455 contacts the bus bar holder 460 on which the first recessed portion 465 is located in the axial direction.

[0070] Other configurations of the bus bar assembly 440 are similar to other configurations of the bus bar assembly 40 in the first embodiment. Other configurations of the motor 400 are similar to other configurations of the motor 100 in the first embodiment.

[0071] According to the present embodiment, the inner insulator portion 452 has the first convex portion 454, and the bus bar holder 460 has the first concave portion 465. Therefore, compared to when the inner insulator portion 452 has the first concave portion 465, it is possible to prevent the inner insulator portion 452 from having a thin portion. This makes it easier to ensure the strength of the inner insulator portion 452 and to enable the inner insulator portion 452 to favorably support the bus bar assembly 440. Furthermore, because it is possible to prevent the inner insulator portion 452 from having a thin portion, it is possible to prevent the resin from flowing poorly in a mold when molding the insulator 450 using a mold. This improves the yield of the insulator 450.

[0072] 14 , in a stator 530 of a motor 500 according to this embodiment, a first recess 554 provided in an inner insulator portion 552 of an insulator 550 is provided across two circumferentially adjacent inner wall portions 552p. Therefore, the load of the bus bar holder 560 received by the first recess 554 via the first protrusion 561 can be distributed and received by the two inner wall portions 552p. This allows the bus bar holder 560 to be supported more stably.

[0073] The first recess 554 is recessed downward and penetrates radially through circumferentially adjacent inner wall portions 552p. The first recess 554 has a first portion 554a and a second portion 554b. The first portion 554a is provided on the inner wall portion 552p located on one circumferential side (+θ side) of the circumferentially adjacent inner wall portions 552p. The second portion 554b is provided on the inner wall portion 552p located on the other circumferential side (−θ side) of the circumferentially adjacent inner wall portions 552p. The first portion 554a is provided at the other circumferential end of the first inner protrusion 552a on the inner wall portion 552p located on one circumferential side, and penetrates radially through the first inner protrusion 552a. The second portion 554b is provided at an end portion on one circumferential side of the first inner protrusion 552a on the inner wall portion 552p located on the other circumferential side, and penetrates the first inner protrusion 552a in the radial direction.

[0074] The first protrusion 561 and the second protrusion 562 provided on the busbar holder 560 of the busbar assembly 540 protrude downward from the lower surface of the holder main body 63, similar to the first protrusion 261 and the second protrusion 262 of the second embodiment. The first protrusion 561 has a first portion 561a and a second portion 561b. The first portion 561a is located on one circumferential side (+θ side) of the second portion 561b and is connected to the second portion 561b. The first portion 561a is inserted from above into the first portion 554a of the first recess 554. The second portion 561b is inserted from above into the second portion 554b of the first recess 554. The first portion 561a of the first protrusion 561 contacts the lower surface of the first portion 554a of the first recess 554 from above. The second portion 561b of the first convex portion 561 contacts the lower surface of the second portion 554b of the first concave portion 554 from above.

[0075] The second protrusion 262 has a first portion 562a and a second portion 562b. The first portion 562a contacts the inner wall portion 552p located on one circumferential side (+θ side) from the radially outer side. The second portion 562b contacts the inner wall portion 552p located on the other circumferential side (-θ side) from the radially outer side. The other configurations of the bus bar assembly 540 are the same as the other configurations of the bus bar assembly 240 in the second embodiment. The other configurations of the motor 500 are the same as the other configurations of the motor 200 in the second embodiment.

[0076] The present invention is not limited to the above-described embodiments, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The shape of the first recess is not particularly limited. The first protrusion may have any shape as long as at least a portion of the first recess is inserted into the first recess. The direction in which the first recess is recessed is not particularly limited. The first recess may be recessed in a direction other than the axial direction. The direction in which the first protrusion protrudes is not particularly limited. In each of the first, second, and fifth embodiments described above, the first protrusion and the second protrusion may be provided on the inner insulator portion, and the first recess may be provided on the bus bar holder. The number of first protrusions and the number of first recesses are not particularly limited, as long as they are one or more. The number of second protrusions is also not particularly limited, as long as they are one or more. The second protrusion may not be provided.

[0077] Any part of the bus bar holder may contact the inner insulator portion as long as the bus bar holder is supported in the axial direction by the inner insulator portion. For example, in the second embodiment described above, the first convex portion 261 may not contact the bottom surface 54 c, and the lower surface of the holder main body portion 263 may contact the upper end surface of the first inner protrusion 52 a, thereby supporting the bus bar holder 260 in the axial direction by the inner insulator portion 52. The use of the motor in the above embodiment is not particularly limited.

[0078] The present technology can be configured as follows: (1) A rotor rotatable about a central axis, a stator positioned radially outward of the rotor, and a busbar assembly positioned on one axial side of the stator, wherein the stator has a stator core, an insulator attached to the stator core, and a coil attached to the stator core via the insulator, the insulator having an inner insulator portion positioned radially inward of the coil, the busbar assembly having a busbar and a busbar holder that holds the busbar, (2) The motor according to (1), wherein the bus bar holder has an annular holder main body portion surrounding the central axis, the bus bar has a coil connection portion connected to a coil lead wire drawn from the coil, the coil connection portion protruding radially outward from the holder main body portion, one portion of the inner insulator portion and the bus bar holder has a first concave portion, and the other portion of the inner insulator portion and the bus bar holder has a first convex portion, at least a portion of the first convex portion is inserted into the first concave portion, and the bus bar holder is supported in the axial direction by the inner insulator portion. (3) The motor according to (2), wherein the inner insulator portion has the first concave portion, the bus bar holder has the first convex portion, the first concave portion is recessed on the other axial side, and the first convex portion contacts a portion of the inner surface of the first concave portion located on the other axial side. (4) The motor according to (2) or (3), wherein the holder main body portion is located radially outward of the inner insulator portion, the first recessed portion opens radially outward, and the first protruding portion protrudes radially inward from the holder main body portion.(5) The motor according to any one of (2) to (4), wherein the stator core includes an annular core back surrounding the central axis and a plurality of teeth extending radially inward from the core back and spaced apart in a circumferential direction, the insulator includes a plurality of insulator piece portions attached to the plurality of teeth, each of the plurality of insulator piece portions having an inner wall portion located radially inward of the coil, the inner insulator portion includes each of the inner wall portions in the plurality of insulator piece portions, and the first recess is provided across the circumferentially adjacent inner wall portions. (6) The motor according to (1), wherein the inner insulator portion includes the first protrusion portion, and the bus bar holder includes the first recess. (7) The motor according to (1) or (6), wherein an inner surface of the first recess has a circumferential surface that surrounds the first protrusion portion around an imaginary axis extending in the axial direction. (8) The motor according to any one of (1) to (4), (6), and (7), wherein the stator core has an annular core back surrounding the central axis and a plurality of teeth extending radially inward from the core back and spaced apart in a circumferential direction, the insulator has a plurality of insulator piece portions attached to the plurality of teeth, each of the plurality of insulator piece portions having an inner wall portion located radially inward of the coil, the inner insulator portion has the inner wall portions of the plurality of insulator piece portions, and portions of the first recessed portion and the first protruding portion provided on the inner insulator portion are provided on a portion of the inner wall portion located on one circumferential side of a circumferential center of the inner wall portion. (9) The motor according to (8), wherein the coil is configured by winding a conducting wire around the tooth via the insulator piece portion, and a winding start end of the conducting wire constituting the coil is located on the other circumferential side of the circumferential center of the inner wall portion. (10) The motor according to (8) or (9), wherein a groove extending in the axial direction is provided in a circumferential center portion of a radially inner surface of the inner wall portion.(11) The motor according to any one of (1) to (10), wherein the other portion has a second convex portion protruding in the axial direction, and the second convex portion contacts the one portion in the radial direction. (12) The motor according to (11), wherein a circumferential dimension of the second convex portion is larger than a circumferential dimension of the first convex portion. (13) The motor according to (11) or (12), wherein the second convex portion protrudes from the holder main body portion to the other axial side and contacts the inner insulator portion from the radially outer side, and a radially outer surface of the second convex portion has an inclined portion that is positioned radially inward as it approaches the other axial side. (14) The motor according to any one of (1) to (10), wherein the other portion has a second convex portion protruding in the axial direction, and the second convex portion contacts the one portion in the axial direction. (15) The motor according to (14), wherein a dimension of the second convex portion in a direction perpendicular to the axial direction is larger than that of the first convex portion, the first convex portion protrudes in the axial direction from an end of the second convex portion in the axial direction, the one portion has a third convex portion protruding in the axial direction, the first concave portion opens into an axial end face of the third convex portion, and the second convex portion contacts the axial end face of the third convex portion. (16) The motor according to any one of (1) to (15), wherein the holder main body portion faces the coil in the axial direction, and a second concave portion recessed toward one axial side is provided in a portion of the surface on the other axial side of the holder main body portion that faces the coil in the axial direction.

[0079] The configurations and methods described in this specification can be combined as appropriate within the scope of not being mutually contradictory.

[0080] 20... rotor, 30, 530... stator, 31... stator core, 31a... core back, 31b... teeth, 32... coil, 32a... coil lead wire, 32c... conducting wire, 40, 240, 340, 440, 540... bus bar assembly, 50, 350, 450, 550... insulator, 50p... insulator piece portion, 52, 352, 452, 552... inner insulator portion, 52p, 352p, 452p, 552p... inner wall portion, 54, 354, 465, 554... first recess, 54a , 54b...pair of side surfaces, 60, 260, 360, 460, 560...bus bar holder, 61, 261, 361, 454, 561...first convex portion, 62, 262, 362, 455, 562...second convex portion, 62a, 262a...inclined portion, 63, 263...holder main body portion, 63a...second concave portion, 70...bus bar, 72...coil connection portion, 100, 200, 300, 400, 500...motor, 354d, 465d...circumferential surface, 355, 464...third convex portion, 356...groove, IL1, IL2...imaginary axis, J...central axis

Claims

1. A motor comprising a rotor rotatable about a central axis, a stator located radially outside the rotor, and a busbar assembly located on one axial side of the stator, wherein the stator has a stator core, an insulator attached to the stator core, and a coil attached to the stator core via the insulator, the insulator has an inner insulator portion located radially inside the coil, the busbar assembly has a busbar and a busbar holder for holding the busbar, the busbar holder has an annular holder body portion surrounding the central axis, the busbar has a coil connection portion connected to a coil lead wire drawn from the coil, the coil connection portion projects radially outward from the holder body portion, one part of the inner insulator portion and the busbar holder has a first recess, the other part of the inner insulator portion and the busbar holder has a first protrusion, at least a part of the first protrusion is inserted into the first recess, and the busbar holder is axially supported by the inner insulator portion.

2. The motor according to claim 1, wherein the inner insulator portion has the first recess, the busbar holder has the first protrusion, the first recess is recessed toward the other axial side, and the first protrusion contacts a portion of the inner surface of the first recess located on the other axial side.

3. The motor according to claim 2, wherein the inner surface of the first recess has a pair of side surfaces sandwiching the first protrusion in the circumferential direction.

4. The motor according to claim 2, wherein the holder body portion is located radially outside the inner insulator portion, the first recess opens radially outward, and the first protrusion projects radially inward from the holder body portion.

5. The stator core has an annular core back surrounding the central axis, and a plurality of teeth extending radially inward from the core back and arranged at intervals in the circumferential direction. The insulator has a plurality of insulator piece portions respectively attached to the plurality of teeth. Each of the plurality of insulator piece portions has an inner wall portion located radially inward of the coil. The inner insulator portion has each of the inner wall portions in the plurality of insulator piece portions. The first recess is provided across the inner wall portions adjacent to each other in the circumferential direction. The motor according to claim 2.

6. The inner insulator portion has the first convex portion, and the bus bar holder has the first recess. The motor according to claim 1.

7. The inner surface of the first recess has a circumferential surface surrounding the first convex portion around a virtual axis extending in the axial direction. The motor according to claim 1.

8. The stator core has an annular core back surrounding the central axis, and a plurality of teeth extending radially inward from the core back and arranged at intervals in the circumferential direction. The insulator has a plurality of insulator piece portions respectively attached to the plurality of teeth. Each of the plurality of insulator piece portions has an inner wall portion located radially inward of the coil. The inner insulator portion has each of the inner wall portions in the plurality of insulator piece portions. The portion provided in the inner insulator portion among the first recess and the first convex portion is provided in a portion of the inner wall portion located on one side in the circumferential direction rather than the circumferential center of the inner wall portion. The motor according to claim 1.

9. The coil is formed by winding a conducting wire around the teeth via the insulator piece portion. The starting end of the conducting wire constituting the coil is located on the other side in the circumferential direction rather than the circumferential center of the inner wall portion. The motor according to claim 8.

10. A groove extending in the axial direction is provided at the circumferential central portion on the radially inner surface of the inner wall portion. The motor according to claim 8.

11. The other portion has a second convex portion protruding in the axial direction. The second convex portion is in radial contact with the one portion. The motor according to any one of claims 1 to 10.

12. The motor according to claim 11, wherein a dimension in the circumferential direction of the second convex portion is larger than a dimension in the circumferential direction of the first convex portion.

13. The second convex portion projects axially from the holder main body portion to the other side in the axial direction and contacts the inner insulator portion from the radially outer side. A radially outer surface of the second convex portion has an inclined portion that is located radially inward as it goes toward the other side in the axial direction. The motor according to claim 11.

14. The other portion has a second convex portion that projects axially. The second convex portion contacts the one portion axially. The motor according to any one of claims 1 to 10.

15. In a direction orthogonal to the axial direction, a dimension of the second convex portion is larger than that of the first convex portion. The first convex portion projects axially from an axial end portion of the second convex portion. The one portion has a third convex portion that projects axially. The first concave portion opens to an axial end surface of the third convex portion. The second convex portion contacts the axial end surface of the third convex portion. The motor according to claim 14.

16. The holder main body portion faces the coil axially. A second concave portion that is recessed axially on one side is provided in a portion of a surface on the other side in the axial direction of the holder main body portion that faces the coil axially. The motor according to any one of claims 1 to 10.

Images