Method for manufacturing busbar unit, busbar, busbar unit, and electric machine

Abstract

This bus bar is to be used for an electric machine. The bus bar comprises a first electrically conductive bar and a first insulating part. The first electrically conductive bar has a first coupling portion and a first insulating portion. The first insulating part is provided on the surface of the first insulating portion. The first electrically conductive bar is coupled to and insulated from the second electrically conductive bar via the first insulating part.

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a busbar unit, a busbar, a busbar unit, and an electric machine. [Background technology]

[0002] Conventionally, busbar units for use in electric machines have been known (see, for example, Patent Document 1). Such busbar units include a plurality of conductive bars and an insulating part that houses and holds each of the conductive bars and electrically insulates the conductive bars from one another. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-176213 Summary of the Invention [Problem to be solved by the invention]

[0004] In the bus bar unit described above, multiple conductive bars overlap each other in the axial direction, and further, a single insulating part accommodates almost all of these conductive bars, so the bus bar unit tends to be large.

[0005] The present disclosure describes a method for manufacturing a busbar unit that can achieve miniaturization, a busbar, a busbar unit, and an electric machine. [Means for solving the problem]

[0006] The manufacturing method of a busbar unit disclosed herein is a manufacturing method of a busbar unit used in an electric machine, and includes: a first step of preparing a first conductive bar including a first connecting portion and a first insulating portion, and a second conductive bar including a second connecting portion and a second insulating portion; a second step of forming a first busbar by providing a first insulating portion on the surface of the first insulating portion, and a second busbar by providing a second insulating portion on the surface of the second insulating portion; and a third step of forming a busbar unit having the first busbar and the second busbar by connecting the second connecting portion to the first insulating portion via the first insulating portion so that the first insulating portion and the second connecting portion are insulated from each other.

[0007] The bus bar of the present disclosure is a bus bar used in an electric machine, and comprises a conductive bar including a connecting portion and an insulating portion, and an insulating portion provided on the surface of the insulating portion, and the conductive bar is connected to and insulated from another conductive bar via the insulating portion.

[0008] The busbar unit of the present disclosure is a busbar unit used in an electric machine, and includes a first busbar and a second busbar separate from the first busbar. The first busbar has a first conductive bar including a first connecting portion and a first insulating portion, and a first insulating portion provided on the surface of the first insulating portion. The second busbar has a second conductive bar including a second connecting portion and a second insulating portion, and a second insulating portion provided on the surface of the second insulating portion. The first insulating portion is connected to and insulated from the second connecting portion via the first insulating portion.

[0009] The electric machine of the present disclosure comprises a rotor, a stator including a first coil and a second coil arranged to surround the rotor, and the above-mentioned busbar unit, wherein the first conductive bar is electrically connected to and supported by the first coil, the second conductive bar is electrically connected to and supported by the second coil, and the first insulating portion and the second insulating portion are spaced apart from the rotor and the stator, respectively. [Effects of the Invention]

[0010] According to the present disclosure, miniaturization can be achieved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the internal structure of an electric machine according to one embodiment. [Figure 2] FIG. 2 is a perspective view of the busbar unit shown in FIG. [Figure 3] FIG. 3 is a plan view of a first bus bar of the bus bar unit shown in FIG. [Figure 4] FIG. 4 is a bottom view of the first bus bar shown in FIG. [Figure 5] FIG. 5 is a plan view of the busbar unit shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI shown in FIG. [Figure 7] FIG. 7 is a side view of a portion of the busbar unit shown in FIG. [Figure 8] FIG. 8 is a diagram illustrating steps in a method for manufacturing the busbar unit shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view of a busbar unit according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] The manufacturing method of a busbar unit disclosed herein is a manufacturing method of a busbar unit used in an electric machine, and includes: a first step of preparing a first conductive bar including a first connecting portion and a first insulating portion, and a second conductive bar including a second connecting portion and a second insulating portion; a second step of forming a first busbar by providing a first insulating portion on the surface of the first insulating portion, and a second busbar by providing a second insulating portion on the surface of the second insulating portion; and a third step of forming a busbar unit having the first busbar and the second busbar by connecting the second connecting portion to the first insulating portion via the first insulating portion so that the first insulating portion and the second connecting portion are insulated from each other.

[0013] In this manufacturing method, in the second step, a first insulating portion is provided on the first insulating portion of the first conductive bar, and a second insulating portion is provided on the surface of the second insulating portion of the second conductive bar. In addition, in the third step, the second connecting portion is connected to the first insulating portion via the first insulating portion so that the first insulating portion and the second connecting portion are insulated from each other. This ensures the function of the first insulating portion, which is to insulate the first conductive bar from the second conductive bar, while also achieving a reduction in the size of the first insulating portion. This therefore enables a reduction in the size of the busbar unit.

[0014] The bus bar of the present disclosure is a bus bar used in an electric machine, and comprises a conductive bar including a connecting portion and an insulating portion, and an insulating portion provided on the surface of the insulating portion, and the conductive bar is connected to and insulated from another conductive bar via the insulating portion.

[0015] In this bus bar, the insulating portion is provided in the insulating portion of the conductive bar, and the conductive bar is connected to and insulated from another conductive bar via the insulating portion. This allows the insulating portion to be miniaturized while maintaining its function of insulating between the conductive bars, thereby enabling the bus bar to be miniaturized.

[0016] The insulating portion may be bonded to the surface of the insulating portion so as to be integral with the conductive bar, which allows the conductive bar and the insulating portion to be treated as a single component, thereby reducing the number of components.

[0017] The insulating portion may include an exposed region that is exposed from the insulating part, thereby enabling further miniaturization of the insulating part.

[0018] The conductive bar may be a plate-like bar having a width greater than a thickness, and the exposed region may be at least a part of one of the main surfaces of the conductive bar, thereby increasing the area of ​​the exposed region and improving the cooling efficiency of the conductive bar.

[0019] The insulating portion may be made of resin, which makes it possible to easily obtain an inexpensive insulating portion.

[0020] The insulating portion may be an insulating film, which allows the insulating portion to be made thinner.

[0021] The conductive bar may be arc-shaped, and the length of the insulating portion in the circumferential direction of the conductive bar may be less than half the length of the conductive bar in the circumferential direction, thereby reducing the area in which the insulating portion is provided and enabling further miniaturization of the insulating portion.

[0022] The busbar unit of the present disclosure is a busbar unit used in an electric machine, and includes a first busbar and a second busbar separate from the first busbar. The first busbar has a first conductive bar including a first connecting portion and a first insulating portion, and a first insulating portion provided on the surface of the first insulating portion. The second busbar has a second conductive bar including a second connecting portion and a second insulating portion, and a second insulating portion provided on the surface of the second insulating portion. The first insulating portion is connected to and insulated from the second connecting portion via the first insulating portion.

[0023] In this busbar unit, the first insulating portion is provided in the first insulating portion of the first conductive bar, and the first insulating portion is connected to and insulated from the second connecting portion via the first insulating portion. This ensures the function of the first insulating portion, which is to insulate between the first insulating portion and the second connecting portion, while achieving a reduction in the size of the first insulating portion. This therefore enables a reduction in the size of the busbar unit.

[0024] The second connecting portion may be engaged with the first insulating portion, which facilitates assembly of the first bus bar and the second bus bar.

[0025] The first insulating portion may include a first exposed region exposed from the first insulating portion, and the second insulating portion may include a second exposed region exposed from the second insulating portion, and the areas of the first exposed region and the second exposed region may be the same, thereby suppressing variations in cooling between the first conductive bar and the second conductive bar.

[0026] The first conductive bar and the second conductive bar may have the same shape, and the first insulating portion and the second insulating portion may have the same shape, which allows for commonality of parts and reduces manufacturing costs.

[0027] The first insulating portion and the second insulating portion may be separated from each other, thereby exposing the portion of the second conductive bar between the first insulating portion and the second insulating portion, thereby improving the efficiency of cooling the second conductive bar.

[0028] The busbar unit may further include a third busbar separate from the first and second busbars, the third busbar having a third conductive bar including a third connecting portion and a third insulating portion, and a third insulating portion provided on a surface of the third insulating portion, the second insulating portion being connected to and insulated from the third connecting portion via the second insulating portion, the third insulating portion being connected to and insulated from the first connecting portion via the third insulating portion, and the first, second, and third busbars connected to one another may have an annular shape having an axis. This annular shape of the busbar unit makes it easy to attach the busbar unit to an electric machine.

[0029] The first connecting portion may be located at a first position in the axial direction along the axis, the first insulating portion may be located at a second position in the axial direction, the second connecting portion may be located at the first position in the axial direction, the second insulating portion may be located at the second position in the axial direction, the third connecting portion may be located at the first position in the axial direction, the third insulating portion may be located at the second position in the axial direction, the first conductive bar may include a first step portion provided between the first connecting portion and the first insulating portion, the second conductive bar may include a second step portion provided between the second connecting portion and the second insulating portion, and the third conductive bar may include a third step portion provided between the third connecting portion and the third insulating portion, and when viewed in the axial direction, the first insulating portion and the second connecting portion may overlap each other, the second insulating portion and the third connecting portion may overlap each other, and the third insulating portion and the first connecting portion may overlap each other. This prevents an increase in the axial thickness of the annular busbar unit.

[0030] The electric machine of the present disclosure comprises a rotor, a stator including a first coil and a second coil arranged to surround the rotor, and the above-mentioned busbar unit, wherein the first conductive bar is electrically connected to and supported by the first coil, the second conductive bar is electrically connected to and supported by the second coil, and the first insulating portion and the second insulating portion are spaced apart from the rotor and the stator, respectively.

[0031] As described above, this electric machine enables the busbar unit to be downsized by miniaturizing the first insulating portion and the second insulating portion, thereby enabling the electric machine to be downsized. Furthermore, because the first insulating portion and the second insulating portion are downsized, the busbar unit can be supported by the first conductive bar supported by the first coil and the second conductive bar supported by the second coil. This allows the portion of the insulating portion for connecting to the stator or the like to be omitted, compared to when the insulating portion is supported by the stator or the like, and simplifies the structure of the first insulating portion and the second insulating portion.

[0032] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0033] [Busbar unit] As shown in Fig. 1, an electric machine 1 includes a rotating shaft 2 and a motor 3. The rotating shaft 2 is rotatable about an axis L. The electric machine 1 is used, for example, in an electric supercharger or an electric-assisted supercharger. In this case, a compressor impeller is attached to the rotating shaft 2.

[0034] The motor 3 includes a rotor 4, a stator 5, and a busbar unit 6. The rotor 4 is fixed to a rotating shaft 2. The stator 5 surrounds the rotor 4 in the direction of rotation of the rotating shaft 2 (hereinafter simply referred to as the "rotation direction"). The stator 5 has a plurality of teeth 51 and a plurality of coils 52. In this embodiment, the stator 5 has six teeth 51 and six coils 52.

[0035] The multiple teeth 51 are arranged to surround the rotor 4 in the rotational direction. The teeth 51 are arranged at equal intervals in the rotational direction. The teeth 51 are arranged, for example, every 60 degrees in the rotational direction. In other words, the stator 5 has three pairs of teeth 51 that face each other.

[0036] A coil 52 is provided on each tooth 51. That is, the multiple coils 52 are arranged to surround the rotor 4 in the rotational direction. The coils 52 are arranged at equal intervals in the rotational direction. The coils 52 are arranged, for example, every 60 degrees in the rotational direction. That is, the stator 5 has three pairs of coils 52 facing each other.

[0037] The busbar unit 6 has, for example, an annular shape. The busbar unit 6 has an axis L as its axis. The busbar unit 6 is arranged to surround the plurality of teeth 51 and the plurality of coils 52 in the rotational direction. The busbar unit 6 electrically connects the opposing coils 52 of each of three pairs of coils 52. As shown in FIG. 2 , the busbar unit 6 has a first busbar 7, a second busbar 8, and a third busbar 9. The first busbar 7, the second busbar 8, and the third busbar 9 are connected to each other to form the annular busbar unit 6.

[0038] The first bus bar 7 has a first conductive bar 71 and a first insulation 72. The first conductive bar 71 has, for example, an arc shape with the axis L as its axis. The circumferential direction of the first conductive bar 71 coincides with the direction of rotation. The central angle of the first conductive bar 71 is, for example, approximately 180 degrees. The first conductive bar 71 has, for example, a plate shape. The thickness direction of the first conductive bar 71 coincides with the direction along the axis L (hereinafter referred to as the "axial direction"). The first conductive bar 71 is made of, for example, copper. The first insulation 72 is provided on a portion of the surface of the first conductive bar 71. The first insulation 72 is made of, for example, resin.

[0039] The second bus bar 8 is a bus bar separate from the first bus bar 7, and has the same configuration as the first bus bar 7. Specifically, the second bus bar 8 includes a second conductive bar 81 and a second insulation 82. The second conductive bar 81 has, for example, an arc shape with the axis L as its axis. The circumferential direction of the second conductive bar 81 coincides with the direction of rotation. The central angle of the second conductive bar 81 is, for example, approximately 180 degrees. The second conductive bar 81 has, for example, a plate shape. The thickness direction of the second conductive bar 81 coincides with the axial direction. The second conductive bar 81 is made of, for example, copper. The second insulation 82 is provided on a portion of the surface of the second conductive bar 81. The second insulation 82 is made of, for example, resin.

[0040] The third bus bar 9 is a bus bar separate from the first bus bar 7 and the second bus bar 8, and has the same configuration as the first bus bar 7 and the second bus bar 8. Specifically, the third bus bar 9 includes a third conductive bar 91 and a third insulation 92. The third conductive bar 91 has, for example, an arc shape with the axis L as its axis. The circumferential direction of the third conductive bar 91 coincides with the direction of rotation. The central angle of the third conductive bar 91 is, for example, approximately 180 degrees. The third conductive bar 91 has, for example, a plate shape. The thickness direction of the third conductive bar 91 coincides with the axial direction. The third conductive bar 91 is made of, for example, copper. The third insulation 92 is provided on a portion of the surface of the third conductive bar 91. The third insulation 92 is made of, for example, resin.

[0041] When viewed from the axial direction, the first conductive bar 71 and the second conductive bar 81 partially overlap. When viewed from the axial direction, the second conductive bar 81 and the third conductive bar 91 partially overlap. When viewed from the axial direction, the third conductive bar 91 and the first conductive bar 71 partially overlap. The first insulating portion 72 connects and insulates the first conductive bar 71 and the second conductive bar 81. The second insulating portion 82 connects and insulates the second conductive bar 81 and the third conductive bar 91. The third insulating portion 92 connects and insulates the third conductive bar 91 and the first conductive bar 71. In this embodiment, insulation refers to electrical insulation.

[0042] Next, the first busbar 7 will be described in detail. In this embodiment, as described above, the first busbar 7, second busbar 8, and third busbar 9 have the same configuration, and therefore, description of the second busbar 8 and the third busbar 9 may be omitted. Note that in each drawing, only the components of the first busbar 7 are shown, and the reference numerals of the components of the second busbar 8 corresponding to the components of the first busbar 7, and the reference numerals of the components of the third busbar 9 corresponding to the components of the first busbar 7, may be written in parentheses after the reference numerals of the components of the first busbar 7.

[0043] As shown in FIGS. 3 and 4 , the first conductive bar 71 includes one main surface 71a and another main surface 71b opposite to the main surface 71a. The first conductive bar 71 includes a first connecting portion 73, a first insulating portion 74, a first middle portion 75, and first protruding portions 76 and 77. The first connecting portion 73 is a portion of the first conductive bar 71 located at one end in the circumferential direction (hereinafter simply referred to as the “circumferential direction”) of the first conductive bar 71. The first connecting portion 73 has an arc shape extending along the circumferential direction. The first insulating portion 74 is a portion of the first conductive bar 71 located at the other end in the circumferential direction. The first insulating portion 74 has an arc shape extending along the circumferential direction. The length of the first insulating portion 74 in the circumferential direction is shorter than half the length of the first conductive bar 71 in the circumferential direction. The first intermediate portion 75 is a portion of the first conductive bar 71 that is provided between the first connecting portion 73 and the first insulating portion 74. The first intermediate portion 75 has an arc shape that extends along the circumferential direction.

[0044] The first protruding portion 76 is located at one end of the first connecting portion 73 in the circumferential direction. The first protruding portion 76 protrudes from the first connecting portion 73 toward the inside in the radial direction of the first conductive bar 71 (hereinafter simply referred to as the "radial direction"). The first protruding portion 77 is located at the other end of the first insulating portion 74 in the circumferential direction. The first protruding portion 77 protrudes from the first insulating portion 74 toward the inside in the radial direction of the first conductive bar 71. The first protruding portion 76 and the first protruding portion 77 face each other.

[0045] The first connecting portion 73, the first insulating portion 74, and the first intermediate portion 75 of the first conductive bar 71 have the same width in the radial direction. The first protruding portion 76 and the first protruding portion 77 have the same length in the circumferential direction. The first protruding portion 76 and the first protruding portion 77 have the same width in the radial direction. The first connecting portion 73, the first insulating portion 74, the first intermediate portion 75, and the first protruding portions 76 and 77 have the same thickness. The width of the first conductive bar 71 in the radial direction is greater than the thickness of the first conductive bar 71. The first connecting portion 73, the first insulating portion 74, the first intermediate portion 75, and the first protruding portions 76 and 77 are integrally formed from the same material.

[0046] The first insulating portion 72 is provided on the surface of the first insulating part 74. The first insulating part 72 is joined to the first insulating part 74 so as to be integral with the first conductive bar 71. The first insulating part 72 is formed integrally with the first conductive bar 71, for example, by insert molding. The first insulating part 72 is fixed directly to the first conductive bar 71 without using an adhesive or the like. The first insulating part 72 has an arc shape extending along the circumferential direction. The first insulating part 72 is provided over the entire area of ​​the first insulating part 74 in the circumferential direction. In the circumferential direction, the part of the first conductive bar 71 where the first insulating part 72 is provided is the first insulating part 74. In other words, in the circumferential direction, the area of ​​the first conductive bar 71 occupied by the first insulating part 74 is defined by the first insulating part 72.

[0047] The first insulating portion 72 is provided in a region of the main surface 71b of the first conductive bar 71 that corresponds to the first insulating portion 74, and in a region of each side surface (the radially inner surface and the radially outer surface) of the first conductive bar 71 that corresponds to the first insulating portion 74. The first insulating portion 72 covers each of these regions of the first conductive bar 71. The first insulating portion 74 includes a first exposed region 74a that is exposed from the first insulating portion 72. The first exposed region 74a is at least a part of the main surface 71a of the first conductive bar 71. In this embodiment, the first exposed region 74a is the entire region of the main surface 71a that corresponds to the first insulating portion 74. In other words, the first insulating portion 72 is not provided in a region of the main surface 71a that corresponds to the first insulating portion 74.

[0048] The first insulating portion 72 is provided on a portion of the base end side of the first protruding portion 77. The first insulating portion 72 is provided on a region of the main surface 71b corresponding to a portion of the base end side of the first protruding portion 77 and on each side surface of the first conductive bar 71 corresponding to a portion of the base end side of the first protruding portion 77. The first insulating portion 72 covers these regions of the first conductive bar 71. A portion of the base end side of the first protruding portion 77 includes an exposed region that is exposed from the first insulating portion 72. This exposed region is a region of the main surface 71a that corresponds to a portion of the base end side of the first protruding portion 77. The first insulating portion 72 is not provided on a region of the main surface 71a that corresponds to a portion of the base end side of the first protruding portion 77. The first insulating portion 72 is not provided on a portion of the tip end side of the first protruding portion 77. A portion of the tip end side of the first protruding portion 77 protrudes from the first insulating portion 72 toward the inside of the first conductive bar 71.

[0049] A recess 72b is formed on a surface 72a of the first insulating portion 72 opposite to the first conductive bar 71. The recess 72b does not penetrate the first insulating portion 72 in the axial direction. In other words, the recess 72b does not reach the main surface 71b of the first conductive bar 71. The depth of the recess 72b is approximately the same as the thickness of the first connecting portion 73. The recess 72b includes a first region 72c and a second region 72d. The first region 72c has an arc shape extending in the circumferential direction.

[0050] The first region 72c extends from a position on the other end side of the first insulating portion 72 in the circumferential direction relative to one end of the first insulating portion 72 in the circumferential direction to the other end of the first insulating portion 72 in the circumferential direction. The first region 72c does not open to one end of the first insulating portion 72 in the circumferential direction. The first region 72c opens to the other end of the first insulating portion 72 in the circumferential direction. The first region 72c does not penetrate the first insulating portion 72 in the radial direction. The first region 72c does not reach both ends of the first insulating portion 72 in the radial direction.

[0051] When viewed in the axial direction, the first region 72c overlaps with the first insulating portion 74. When viewed in the axial direction, the outer edge of the first region 72c coincides with the outer edge of the first insulating portion 74. When viewed in the axial direction, the inner edge of the first region 72c coincides with the inner edge of the first insulating portion 74. The length of the first region 72c in the circumferential direction is approximately the same as the length of the first connecting portion 73 in the circumferential direction. The width of the first region 72c in the radial direction is approximately the same as the width of the first connecting portion 73 in the radial direction.

[0052] The second region 72d is located at one end of the first region 72c in the circumferential direction. The second region 72d is located radially inward of the first region 72c. The second region 72d is in communication with the first region 72c. The second region 72d reaches the inner edge of the first insulating portion 72. The second region 72d opens to the inner edge of the first insulating portion 72. The length of the second region 72d in the circumferential direction is approximately the same as the length of the first protruding portion 76 in the circumferential direction. The width of the second region 72d in the radial direction is smaller than the width of the first protruding portion 76 in the radial direction.

[0053] The first insulating portion 72 is not provided on the first connecting portion 73 and the first intermediate portion 75. In other words, the first connecting portion 73 and the first intermediate portion 75 are exposed from the first insulating portion 72. The length of the first insulating portion 72 in the circumferential direction is smaller than half the length of the first conductive bar 71 in the circumferential direction. The volume of the first insulating portion 72 is smaller than the volume of the first conductive bar 71. The weight of the first insulating portion 72 is smaller than the weight of the first conductive bar 71.

[0054] The second conductive bar 81 is the same as the first conductive bar 71. The shape of the second conductive bar 81 is the same as the shape of the first conductive bar 71. The size of the second conductive bar 81 is the same as the size of the first conductive bar 71. The main surface 81a of the second conductive bar 81 is the same as the main surface 71a of the first conductive bar 71. The main surface 81b of the second conductive bar 81 is the same as the main surface 71b of the first conductive bar 71. The second connecting portion 83 is the same as the first connecting portion 73. The second insulating portion 84 is the same as the first insulating portion 74. The second middle portion 85 is the same as the first middle portion 75. The second protruding portion 86 is the same as the first protruding portion 76. The second protruding portion 87 is the same as the first protruding portion 77. The second insulating portion 82 is the same as the first insulating portion 72. The shape of the second insulating portion 82 is the same as the shape of the first insulating portion 72. The size of the second insulating portion 82 is the same as the size of the first insulating portion 72. The recess 82b of the second insulating portion 82 is the same as the recess 72b of the first insulating portion 72. The first region 82c of the recess 82b is the same as the first region 72c of the recess 72b. The second region 82d of the recess 82b is the same as the second region 72d of the recess 72b.

[0055] The third conductive bar 91 is the same as the first conductive bar 71. The shape of the third conductive bar 91 is the same as the shape of the first conductive bar 71. The size of the third conductive bar 91 is the same as the size of the first conductive bar 71. The main surface 91a of the third conductive bar 91 is the same as the main surface 71a of the first conductive bar 71. The main surface 91b of the third conductive bar 91 is the same as the main surface 71b of the first conductive bar 71. The third connecting portion 93 is the same as the first connecting portion 73. The third insulating portion 94 is the same as the first insulating portion 74. The third middle portion 95 is the same as the first middle portion 75. The third protruding portion 96 is the same as the first protruding portion 76. The third protruding portion 97 is the same as the first protruding portion 77. The third insulating portion 92 is the same as the first insulating portion 72. The shape of the third insulating portion 92 is the same as the shape of the first insulating portion 72. The size of the third insulating portion 92 is the same as the size of the first insulating portion 72. The recess 92b of the third insulating portion 92 is the same as the recess 72b of the first insulating portion 72. The first region 92c of the recess 92b is the same as the first region 72c of the recess 72b. The second region 92d of the recess 92b is the same as the second region 72d of the recess 72b.

[0056] As described above, the first bus bar 7, the second bus bar 8, and the third bus bar 9 are all identical in shape, size, material, etc. The first bus bar 7, the second bus bar 8, and the third bus bar 9 are all made of the same components.

[0057] As shown in FIGS. 5 and 6 , the first bus bar 7, the second bus bar 8, and the third bus bar 9 are connected to one another. Specifically, the first insulating portion 74 of the first bus bar 7 is connected to the second connecting portion 83 of the second bus bar 8 via the first insulating portion 72. The second connecting portion 83 is disposed in the first region 72c of the recess 72b of the first insulating portion 72. The second connecting portion 83 is engaged with the first region 72c. The second connecting portion 83 is pressed into the first region 72c. The first insulating portion 72 is elastically deformed by the pressing of the second connecting portion 83. The second connecting portion 83 receives a load from the first insulating portion 72. The second connecting portion 83 is fixed to the first insulating portion 72 by frictional force generated between the second connecting portion 83 and the first insulating portion 72. The second connecting portion 83 is in contact with the bottom surface of the first region 72c. An area of ​​the main surface 81 b of the second conductive bar 81 corresponding to the second connecting portion 83 is exposed from the first insulating portion 72 .

[0058] A portion of the base end side of the second protruding portion 86 of the second bus bar 8 is disposed in the second region 72d of the recess 72b (see FIG. 4). A portion of the base end side of the second protruding portion 86 is engaged with the second region 72d. As a result, the second protruding portion 86 is fixed to the first insulating portion 72, similar to the second connecting portion 83. A portion of the tip end side of the second protruding portion 86 protrudes from the first insulating portion 72 toward the inside in the radial direction of the first insulating portion 72. The second protruding portion 86 is in contact with the bottom surface of the second region 72d. A region of the main surface 81b of the second conductive bar 81 corresponding to the portion of the base end side of the second protruding portion 86 and a portion of the tip end side of the second protruding portion 86 are exposed from the first insulating portion 72.

[0059] The first insulating portion 74 and the second connecting portion 83 are insulated by the first insulating part 72. The first protruding portion 77 of the first bus bar 7 and the second connecting portion 83 are insulated by the first insulating part 72. The second protruding portion 86 of the second bus bar 8 and the first insulating portion 74 are insulated by the first insulating part 72.

[0060] Similar to the first bus bar 7, the second insulating portion 84 of the second bus bar 8 is connected to the third connecting portion 93 of the third bus bar 9 via the second insulating portion 82. The third connecting portion 93 is disposed in a first region 82c of the recess 82b of the second insulating portion 82. The third connecting portion 93 is engaged with the first region 82c. The third connecting portion 93 is pressed into the first region 82c. The second insulating portion 82 is elastically deformed by the third connecting portion 93 being pressed in. The third connecting portion 93 receives a load from the second insulating portion 82. The third connecting portion 93 is fixed to the second insulating portion 82 by frictional force generated between the third connecting portion 93 and the second insulating portion 82. The third connecting portion 93 is in contact with the bottom surface of the first region 82c. A region of the main surface 91b of the third conductive bar 91 corresponding to the third connecting portion 93 is exposed from the second insulating portion 82.

[0061] A portion of the base end side of the third protruding portion 96 of the third bus bar 9 is disposed in the second region 82d of the recess 82b (see FIG. 4). A portion of the base end side of the third protruding portion 96 is engaged with the second region 82d. As a result, the third protruding portion 96 is fixed to the second insulating portion 82, similar to the third connecting portion 93. A portion of the tip end side of the third protruding portion 96 protrudes from the second insulating portion 82 toward the inside in the radial direction of the second insulating portion 82. The third protruding portion 96 is in contact with the bottom surface of the second region 82d. A region of the main surface 91b of the third conductive bar 91 corresponding to the portion of the base end side of the third protruding portion 96 and a portion of the tip end side of the third protruding portion 96 are exposed from the second insulating portion 82.

[0062] The second insulating portion 84 and the third connecting portion 93 are insulated by the second insulating portion 82. The second protruding portion 87 of the second bus bar 8 and the third connecting portion 93 are insulated by the second insulating portion 82. The third protruding portion 96 of the third bus bar 9 and the second insulating portion 84 are insulated by the second insulating portion 82.

[0063] Similar to the first bus bar 7, the third insulating portion 94 of the third bus bar 9 is connected to the first connecting portion 73 of the first bus bar 7 via the third insulating portion 92. The first connecting portion 73 is disposed in a first region 92c of the recess 92b of the third insulating portion 92. The first connecting portion 73 is engaged with the first region 92c. The first connecting portion 73 is pressed into the first region 92c. The third insulating portion 92 is elastically deformed by the first connecting portion 73 being pressed in. The first connecting portion 73 receives a load from the third insulating portion 92. The first connecting portion 73 is fixed to the third insulating portion 92 by frictional force generated between the first connecting portion 73 and the third insulating portion 92. The first connecting portion 73 is in contact with the bottom surface of the first region 92c. A region of the main surface 71b of the first conductive bar 71 corresponding to the first connecting portion 73 is exposed from the third insulating portion 92.

[0064] A portion of the base end side of the first protruding portion 76 of the first bus bar 7 is disposed in the second region 92d of the recess 92b (see FIG. 4). A portion of the base end side of the first protruding portion 76 is engaged with the second region 92d. As a result, the first protruding portion 76 is fixed to the third insulating portion 92, similar to the first connecting portion 73. A portion of the tip end side of the first protruding portion 76 protrudes from the third insulating portion 92 toward the inside in the radial direction of the third insulating portion 92. The first protruding portion 76 is in contact with the bottom surface of the second region 92d. A region of the main surface 71b of the first conductive bar 71 corresponding to the portion of the base end side of the first protruding portion 76 and a portion of the tip end side of the first protruding portion 76 are exposed from the third insulating portion 92.

[0065] The third insulating portion 94 and the first connecting portion 73 are insulated by the third insulating portion 92. The third protruding portion 97 of the third bus bar 9 and the first connecting portion 73 are insulated by the third insulating portion 92. The first protruding portion 76 of the first bus bar 7 and the third insulating portion 94 are insulated by the third insulating portion 92.

[0066] When viewed in the axial direction, the first insulating portion 74 and the second connecting portion 83 overlap each other. The first insulating portion 74 and the second connecting portion 83 sandwich a portion of the first insulating section 72 between them. When viewed in the axial direction, the second insulating portion 84 and the third connecting portion 93 overlap each other. The second insulating portion 84 and the third connecting portion 93 sandwich a portion of the second insulating portion 82 between them. When viewed in the axial direction, the third insulating portion 94 and the first connecting portion 73 overlap each other. The third insulating portion 94 and the first connecting portion 73 sandwich a portion of the third insulating portion 92 between them.

[0067] The first insulating portion 72, the second insulating portion 82, and the third insulating portion 92 are separated from one another. The circumferential length of the portion of the first conductive bar 71 between the third insulating portion 92 and the first insulating portion 72 (first intermediate portion 75), the circumferential length of the portion of the second conductive bar 81 between the first insulating portion 72 and the second insulating portion 82 (second intermediate portion 85), and the circumferential length of the portion of the third conductive bar 91 between the second insulating portion 82 and the third insulating portion 92 (third intermediate portion 95) are all the same.

[0068] In the bus bar unit 6, the exposed areas of the first conductive bar 71, the second conductive bar 81, and the third conductive bar 91 are the same as one another. Specifically, the surface areas of the first intermediate portion 75, the second intermediate portion 85, and the third intermediate portion 95 are the same as one another. The areas of the first exposed region 74a of the first insulating portion 74, the second exposed region 84a of the second insulating portion 84, and the third exposed region 94a of the third insulating portion 94 are the same as one another. The areas of the region of the main surface 71b of the first conductive bar 71 corresponding to the first connecting portion 73, the region of the main surface 81b of the second conductive bar 81 corresponding to the second connecting portion 83, and the region of the main surface 91b of the third conductive bar 91 corresponding to the third connecting portion 93 are the same as one another.

[0069] The surface areas of the portion of the first protruding portion 77 exposed from the first insulating portion 72, the portion of the second protruding portion 87 exposed from the second insulating portion 82, and the portion of the third protruding portion 97 exposed from the third insulating portion 92 are the same. The surface areas of the portion of the first protruding portion 76 exposed from the third insulating portion 92, the portion of the second protruding portion 86 exposed from the first insulating portion 72, and the portion of the third protruding portion 96 exposed from the second insulating portion 82 are the same.

[0070] Next, the first intermediate portion 75 of the first bus bar 7 will be described. As shown in FIG. 7 , the first intermediate portion 75 is located between the first connecting portion 73 and the first insulating portion 74. The first connecting portion 73 is located at a first position P1 in the axial direction. The first connecting portion 73 is located at the first position P1 and extends in a plane perpendicular to the axial direction. The first insulating portion 74 is located at a second position P2 in the axial direction. The second position P2 is a position different from the first position P1. The first insulating portion 74 is located at the second position P2 and extends in a plane perpendicular to the axial direction. When viewed in the axial direction, the first connecting portion 73 and the first insulating portion 74 are spaced apart from each other in the circumferential direction.

[0071] The first intermediate portion 75 includes a first portion 75a located at the first position P1, a second portion 75b located at the second position P2, and a first step portion 75c spanning the first position P1 and the second position P2. The first portion 75a extends in a plane perpendicular to the axial direction. The first portion 75a is connected to the first connecting portion 73. The second portion 75b extends in a plane perpendicular to the axial direction. The second portion 75b is connected to the first insulating portion 74. The first step portion 75c is located between the first portion 75a and the second portion 75b and is connected to the first portion 75a and the second portion 75b. The first step portion 75c obliquely intersects with each of the first portion 75a and the second portion 75b.

[0072] The second intermediate portion 85 of the second busbar 8 is the same as the first intermediate portion 75. The first portion of the second intermediate portion 85 is the same as the first portion 75a. The second portion of the second intermediate portion 85 is the same as the second portion 75b. The second step portion of the second intermediate portion 85 is the same as the first step portion 75c. The third intermediate portion 95 of the third busbar 9 is the same as the first intermediate portion 75. The first portion of the third intermediate portion 95 is the same as the first portion 75a. The second portion of the third intermediate portion 95 is the same as the second portion 75b. The second step portion of the third intermediate portion 95 is the same as the first step portion 75c.

[0073] Thus, in the busbar unit 6, the first connecting portion 73 of the first conductive bar 71, the second connecting portion 83 of the second conductive bar 81, and the third connecting portion 93 of the third conductive bar 91 are each located at a first position P1, and the first insulating portion 74 of the first conductive bar 71, the second insulating portion 84 of the second conductive bar 81, and the third insulating portion 94 of the third conductive bar 91 are each located at a second position P2. This makes it possible to form the busbar unit 6 in an annular shape while suppressing an increase in the thickness of the busbar unit 6 in the axial direction.

[0074] As shown in FIG. 1, the motor 3 has a plurality of connecting members 53. In this embodiment, the motor 3 has six connecting members 53. The plurality of connecting members 53 are arranged so as to surround the rotor 4 in the rotational direction. The connecting members 53 are arranged at equal intervals in the rotational direction. The connecting members 53 are arranged, for example, every 60 degrees in the rotational direction. The connecting members 53 are arranged between adjacent teeth 51. The connecting members 53 are, for example, plate-shaped. The connecting members 53 are arranged so as to extend in the radial direction. The connecting members 53 are made of, for example, copper.

[0075] Each connecting member 53 is electrically connected to a corresponding coil 52. Each connecting member 53 is fixed to a corresponding coil 52 by, for example, welding. Each connecting member 53 is supported by a corresponding coil 52. The first protruding portions 76, 77 of the first conductive bar 71 are electrically connected to a pair of coils (first coils) 52 facing each other. The first protruding portions 76, 77 are fixed to a pair of coils (first coils) 52 facing each other by, for example, welding. The first protruding portions 76, 77 are supported by the pair of coils 52.

[0076] The second protruding portions 86, 87 of the second conductive bar 81 are electrically connected to a pair of coils (second coils) 52 that face each other. The second protruding portions 86, 87 are fixed to the pair of coils (second coils) 52 that face each other by, for example, welding. The second protruding portions 86, 87 are supported by the pair of coils 52. The third protruding portions 96, 97 of the third conductive bar 91 are electrically connected to a pair of coils (third coils) 52 that face each other. The third protruding portions 96, 97 are fixed to the pair of coils (third coils) 52 that face each other by, for example, welding. The third protruding portions 96, 97 are supported by the pair of coils 52.

[0077] The first insulating portion 72, the second insulating portion 82, and the third insulating portion 92 are each spaced apart from the rotor 4 and the stator 5. The first insulating portion 72, the second insulating portion 82, and the third insulating portion 92 are each spaced apart from the respective components of the motor 3. The first insulating portion 72 is in contact only with the first conductive bar 71 and the second conductive bar 81. The first insulating portion 72 is supported by the first conductive bar 71 and the second conductive bar 81. The second insulating portion 82 is in contact only with the second conductive bar 81 and the third conductive bar 91. The second insulating portion 82 is supported by the second conductive bar 81 and the third conductive bar 91. The third insulating portion 92 is in contact only with the third conductive bar 91 and the first conductive bar 71. The third insulating portion 92 is supported by the third conductive bar 91 and the first conductive bar 71.

[0078] As described above, in the first bus bar 7, the first insulating portion 72 is provided in the first insulating part 74 of the first conductive bar 71. The first conductive bar 71 is connected to and insulated from the second conductive bar 81 via the first insulating portion 72. This ensures the function of the first insulating portion 72, which is to insulate the first conductive bar 71 from the second conductive bar 81, while also making it possible to reduce the size of the first insulating portion 72. This makes it possible to reduce the size of the first bus bar 7.

[0079] The first insulating portion 72 is joined to the surface of the first insulating part 74 so as to be integrated with the first conductive bar 71. This allows the first conductive bar 71 and the first insulating portion 72 to be treated as a single component, thereby reducing the number of components. Furthermore, for example, connecting members and the like for providing the first insulating portion on the surface of the first insulating part 74 are no longer necessary, thereby reducing the number of components and simplifying the structure of the first bus bar 7.

[0080] The first insulating portion 74 includes a first exposed region 74a that is exposed from the first insulating section 72. This makes it possible to further reduce the size of the first insulating section 72. It also makes it possible to reduce the amount of material used for the first insulating section 72.

[0081] The first conductive bar 71 has a plate shape with a width greater than a thickness. The first exposed region 74a is at least a part of one main surface 71a of the first conductive bar 71. This increases the area of ​​the first exposed region 74a, thereby improving the cooling efficiency of the first conductive bar 71.

[0082] The material of the first insulating portion 72 is resin, which makes it possible to easily obtain the first insulating portion 72 at low cost.

[0083] The first conductive bar 71 has an arc shape. The length of the first insulating portion 74 in the circumferential direction of the first conductive bar 71 is shorter than half the length of the first conductive bar 71 in the circumferential direction. This reduces the area in which the first insulating portion 72 is provided, thereby enabling the first insulating portion 72 to be further miniaturized.

[0084] In the busbar unit 6, the first insulating portion 72 is provided in the first insulating part 74 of the first conductive bar 71. The first insulating part 74 is connected to and insulated from the second connecting part 83 via the first insulating part 72. This ensures the function of the first insulating part 72, which is to insulate between the first insulating part 74 and the second connecting part 83, while also reducing the size of the first insulating part 72. This therefore makes it possible to reduce the size of the busbar unit 6.

[0085] The second connecting portion 83 is engaged with the first insulating portion 72. This makes it easy to assemble the first bus bar 7 and the second bus bar 8 together.

[0086] The first insulating portion 74 includes a first exposed region 74a exposed from the first insulating part 72. The second insulating portion 84 includes a second exposed region 84a exposed from the second insulating part 82. The area of ​​the first exposed region 74a and the area of ​​the second exposed region 84a are the same. This makes it possible to suppress variations in cooling between the first conductive bar 71 and the second conductive bar 81.

[0087] The first conductive bar 71 has the same shape as the second conductive bar 81. The first insulating portion 72 has the same shape as the second insulating portion 82. This allows for standardization of parts, thereby reducing manufacturing costs.

[0088] The first insulating portion 72 and the second insulating portion 82 are separated from each other. This allows the portion of the second conductive bar 81 between the first insulating portion 72 and the second insulating portion 82 to be exposed from the first insulating portion 72 and the second insulating portion 82, thereby improving the cooling efficiency of the second conductive bar 81. Furthermore, compared to when the first insulating portion and the second insulating portion are connected, for example, the insulating portion can be made smaller, and the amount of material used for the insulating portion can be reduced.

[0089] The busbar unit 6 includes a third busbar 9 separate from the first busbar 7 and the second busbar 8. The third busbar 9 includes a third conductive bar 91 and a third insulating portion 92. The third conductive bar 91 includes a third connecting portion 93 and a third insulating portion 94. The third insulating portion 92 is provided on the surface of the third insulating portion 94. The second insulating portion 84 is connected to and insulated from the third connecting portion 93 via the second insulating portion 82, and the third insulating portion 94 is connected to and insulated from the first connecting portion 73 via the third insulating portion 92. The first busbar 7, second busbar 8, and third busbar 9 connected to one another in this manner form an annular shape. The annular shape of the busbar unit 6 allows the busbar unit 6 to be easily attached to the electric machine 1.

[0090] The first connecting portion 73 is located at a first position P1 in the axial direction. The first insulating portion 74 is located at a second position P2 in the axial direction. The second connecting portion 83 is located at a first position P1 in the axial direction. The second insulating portion 84 is located at a second position P2 in the axial direction. The third connecting portion 93 is located at a first position P1 in the axial direction. The third insulating portion 94 is located at a second position P2 in the axial direction. The first conductive bar 71 includes a first step portion 75c provided between the first connecting portion 73 and the first insulating portion 74. The second conductive bar 81 includes a second step portion 85c provided between the second connecting portion 83 and the second insulating portion 84. The third conductive bar 91 includes a third step portion 95c provided between the third connecting portion 93 and the third insulating portion 94. When viewed from the axial direction, the first insulating portion 74 and the second connecting portion 83 overlap each other. When viewed from the axial direction, the second insulating portion 84 and the third connecting portion 93 overlap each other. When viewed from the axial direction, the third insulating portion 94 and the first connecting portion 73 overlap each other. This makes it possible to prevent the thickness of the annular busbar unit 6 in the axial direction from increasing.

[0091] As described above, according to the electric machine 1, the busbar unit 6 can be downsized by reducing the size of the first insulating portion 72 and the second insulating portion 82, thereby enabling the electric machine 1 to be downsized. Furthermore, because the first insulating portion 72 and the second insulating portion 82 are downsized, the busbar unit 6 can be supported by the first conductive bar 71 supported by the coil 52 and the second conductive bar 81 supported by the coil 52. This makes it possible to omit the portion of the insulating portion for connecting to the stator 5, etc., compared to when the insulating portion is supported by the stator 5, etc., and thus simplifies the structure of the first insulating portion 72 and the second insulating portion 82. Furthermore, it is possible to reduce the amount of material used for the first insulating portion 72 and the second insulating portion 82.

[0092] [Busbar unit manufacturing method] Next, a method for manufacturing the bus bar unit 6 will be described. As shown in FIG. 8 , first, a first conductive bar 71, a second conductive bar 81, and a third conductive bar 91 are prepared (step S1, first process). Next, a first insulating portion 72, a second insulating portion 82, and a third insulating portion 92 are provided (step S2, second process). Specifically, the first insulating portion 72 is formed on the surface of the first insulating portion 74 of the first conductive bar 71. The first insulating portion 72 is formed integrally with the first conductive bar 71 by, for example, insert molding. In this way, the first bus bar 7 is formed. The second insulating portion 82 is formed on the surface of the second insulating portion 84 of the second conductive bar 81. The second insulating portion 82 is formed integrally with the second conductive bar 81 by, for example, insert molding. In this way, the second bus bar 8 is formed. The third insulating portion 92 is formed on the surface of the third insulating portion 94 of the third conductive bar 91. The third insulating portion 92 is formed integrally with the third conductive bar 91 by, for example, insert molding, thereby forming the third bus bar 9.

[0093] Next, the first bus bar 7, the second bus bar 8, and the third bus bar 9 are connected to each other (step S3, third process). Specifically, the second connecting portion 83 is connected to the first insulating portion 74 via the first insulating portion 72. The second connecting portion 83 is engaged with the first region 72c of the recess 72b of the first insulating portion 72. The second protruding portion 86 of the second conductive bar 81 is engaged with the second region 72d of the recess 72b. The first insulating portion 74 and the second connecting portion 83 are insulated by the first insulating portion 72. Furthermore, the third connecting portion 93 is connected to the second insulating portion 84 via the second insulating portion 82. The third connecting portion 93 is engaged with the first region 82c of the recess 82b of the second insulating portion 82. The third protruding portion 96 of the third conductive bar 91 is engaged with the second region 82d of the recess 82b. The second insulating portion 84 and the third connecting portion 93 are insulated from each other by the second insulating portion 82. Furthermore, the first connecting portion 73 is connected to the third insulating portion 94 via the third insulating portion 92. The first connecting portion 73 is engaged with a first region 92c of the recess 92b of the third insulating portion 92. The first protruding portion 76 of the first conductive bar 71 is engaged with a second region 92d of the recess 92b. The third insulating portion 94 and the first connecting portion 73 are insulated from each other by the third insulating portion 92. As a result of the above, a busbar unit 6 having an annular shape is formed.

[0094] As described above, in step S2 of the method for manufacturing the busbar unit 6, the first insulating portion 72 is provided on the first insulating portion 74 of the first conductive bar 71, and the second insulating portion 82 is provided on the surface of the second insulating portion 84 of the second conductive bar 81. In addition, in step S3, the second connecting portion 83 is connected to the first insulating portion 74 via the first insulating portion 72 so that the first insulating portion 74 and the second connecting portion 83 are insulated from each other. This ensures the function of the first insulating portion 72, which is to insulate the first conductive bar 71 and the second conductive bar 81, while also achieving a reduction in the size of the first insulating portion 72. This therefore enables the busbar unit 6 to be reduced in size.

[0095] The above has described the effects focusing on the first bus bar 7 or the second bus bar 8, but these effects are similarly achieved for any of the first bus bar 7, the second bus bar 8 and the third bus bar 9.

[0096] [Variations] Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment.

[0097] 9, the first bus bar 7A may have a first insulating portion 72A instead of the first insulating portion 72. The second bus bar 8A may further have an insulating film 88. The first insulating portion 72A is an insulating film formed on the surface of the first insulating portion 74. The first insulating portion 72A may be formed in a part of a region of the main surface 71a of the first conductive bar 71 that corresponds to the first insulating portion 74.

[0098] The insulating film 88 is formed on a region of the main surface 81a of the second conductive bar 81 that corresponds to the second connecting portion 83, on each side of the second connecting portion 83, and on a part of a region of the main surface 81b of the second conductive bar 81 that corresponds to the second connecting portion 83. The first insulating portion 72A and the insulating film 88 are each formed by, for example, a vapor deposition method using a mask.

[0099] The first bus bar 7 and the second bus bar 8 are fixed by a connecting portion 78 provided between the first insulating portion 72A and the insulating film 88. The connecting portion 78 is, for example, an adhesive. In this case, the first insulating portion 72A can be made thinner. Furthermore, the amount of material used for the first insulating portion 72 can be reduced.

[0100] Similar to the first busbar 7A, the second busbar 8 may have a second insulating portion similar to the first insulating portion 72A instead of the second insulating portion 82. Similar to the second busbar 8A, the third busbar 9 may further have an insulating film similar to the insulating film 88. The second busbar 8 and the third busbar may be fixed by a connecting portion similar to the connecting portion 78. Similar to the first busbar 7A, the third busbar 9 may have a third insulating portion similar to the first insulating portion 72A instead of the third insulating portion 92. Similar to the second busbar 8A, the first busbar 7 may further have an insulating film similar to the insulating film 88. The third busbar 9 and the first busbar 7A may be fixed by a connecting portion similar to the connecting portion 78.

[0101] In the embodiment, an example has been shown in which the first insulating portion 72 is formed integrally with the first conductive bar 71 by insert molding, but the first insulating portion 72 may, for example, be engaged with the first conductive bar 71. The second insulating portion 82 may be engaged with the second conductive bar 81 in the same way as the first insulating portion 72. The third insulating portion 92 may be engaged with the third conductive bar 91 in the same way as the first insulating portion 72.

[0102] In the embodiment, an example has been shown in which the busbar unit 6 includes three busbars 7, 8, and 9, but the busbar unit 6 may include four or more busbars. The busbar unit 6 may include two busbars. Furthermore, an example has been shown in which the first conductive bar 71, the second conductive bar 81, and the third conductive bar 91 partially overlap when viewed in the axial direction, but the first conductive bar 71, the second conductive bar 81, and the third conductive bar 91 do not have to partially overlap when viewed in the axial direction.

[0103] In the embodiment, an example has been shown in which the electric machine 1 includes the motor 3, but the electric machine 1 may include a generator instead of the motor 3. The generator, like the motor 3, includes a rotor 4, a stator 5, and a busbar unit 6.

[0104] [Note] The present disclosure includes the following configurations.

[0105] The manufacturing method of a busbar unit according to the present disclosure is [1] "a manufacturing method of a busbar unit to be used in an electric machine, comprising: a first step of preparing a first conductive bar including a first connecting portion and a first insulating portion, and a second conductive bar including a second connecting portion and a second insulating portion; a second step of forming a first busbar by providing a first insulating portion on a surface of the first insulating portion, and a second busbar by providing a second insulating portion on a surface of the second insulating portion; and a third step of forming the busbar unit having the first busbar and the second busbar by connecting the second connecting portion to the first insulating portion via the first insulating portion so that the first insulating portion and the second connecting portion are insulated from each other."

[0106] The busbar of the present disclosure is [2] "a busbar for use in an electric machine, comprising a conductive bar including a connecting portion and an insulating portion, and an insulating portion provided on a surface of the insulating portion, wherein the conductive bar is connected to and insulated from another conductive bar via the insulating portion."

[0107] The bus bar of the present disclosure may be [3] "the bus bar according to the above [2], wherein the insulating portion is joined to a surface of the insulating portion so as to be integral with the conductive bar."

[0108] The busbar of the present disclosure may be [4] "the busbar according to the above [2] or [3], wherein the insulating portion includes an exposed region exposed from the insulating portion."

[0109] The bus bar of the present disclosure may be [5] "the bus bar described in [4] above, wherein the conductive bar is plate-shaped with a width greater than a thickness, and the exposed area is at least a part of one main surface of the conductive bar."

[0110] The bus bar of the present disclosure may be [6] "the bus bar according to any one of the above [2] to [5], wherein the material of the insulating portion is resin."

[0111] The bus bar of the present disclosure may be [7] "the bus bar according to any one of the above [2] to [6], wherein the insulating portion is an insulating film."

[0112] The bus bar of the present disclosure may be [8] "the bus bar according to any one of the above [2] to [7], wherein the conductive bar has an arc shape, and the length of the insulating portion in the circumferential direction of the conductive bar is smaller than half the length of the conductive bar in the circumferential direction."

[0113] The busbar unit of the present disclosure is [9] "a busbar unit for use in an electric machine, comprising: a first busbar; and a second busbar separate from the first busbar, wherein the first busbar has a first conductive bar including a first connecting portion and a first insulating portion, and a first insulating portion provided on a surface of the first insulating portion; the second busbar has a second conductive bar including a second connecting portion and a second insulating portion, and a second insulating portion provided on a surface of the second insulating portion, wherein the first insulating portion is connected to and insulated from the second connecting portion via the first insulating portion."

[0114] The busbar unit of the present disclosure may be

[10] "the busbar unit according to the above [9], wherein the second connecting portion is engaged with the first insulating portion."

[0115] The busbar unit of the present disclosure may be

[11] "the busbar unit according to the above [9] or

[10] , wherein the first insulating portion includes a first exposed area exposed from the first insulating portion, the second insulating portion includes a second exposed area exposed from the second insulating portion, and the area of ​​the first exposed area and the area of ​​the second exposed area are the same."

[0116] The busbar unit of the present disclosure may be the busbar unit according to any one of the above items [9] to

[11] , wherein

[12] the first conductive bar and the second conductive bar have the same shape, and the first insulating portion and the second insulating portion have the same shape.

[0117] The busbar unit of the present disclosure may be

[13] "the busbar unit according to any one of the above [9] to

[12] , wherein the first insulating portion and the second insulating portion are separated from each other."

[0118] The busbar unit of the present disclosure may be

[14] "the busbar unit according to any one of items [9] to

[13] above, further including a third busbar separate from the first busbar and the second busbar, the third busbar having a third conductive bar including a third connecting portion and a third insulating portion, and a third insulating portion provided on a surface of the third insulating portion, the second insulating portion being connected to and insulated from the third connecting portion via the second insulating portion, the third insulating portion being connected to and insulated from the first connecting portion via the third insulating portion, and the first busbar, the second busbar, and the third busbar that are connected to one another have an annular shape having an axis."

[0119] The busbar unit of the present disclosure is

[15] "the first connecting portion is located at a first position in the axial direction along the axis, the first insulating portion is located at a second position in the axial direction, the second connecting portion is located at the first position in the axial direction, the second insulating portion is located at the second position in the axial direction, the third connecting portion is located at the first position in the axial direction, and the third insulating portion is located at the second position in the axial direction, and the first conductive bar is connected to the first connecting portion and the The busbar unit may be the busbar unit described in

[14] above, wherein the second conductive bar includes a first step portion provided between the first connecting portion and the first insulating portion, the second conductive bar includes a second step portion provided between the second connecting portion and the second insulating portion, and the third conductive bar includes a third step portion provided between the third connecting portion and the third insulating portion, and when viewed from the axial direction, the first insulating portion and the second connecting portion overlap each other, the second insulating portion and the third connecting portion overlap each other, and the third insulating portion and the first connecting portion overlap each other.

[0120] The electric machine of the present disclosure is

[16] "an electric machine comprising: a rotor; a stator including a first coil and a second coil arranged to surround the rotor; and a busbar unit according to any one of [9] to

[15] above, wherein the first conductive bar is electrically connected to the first coil and supported by the first coil, the second conductive bar is electrically connected to the second coil and supported by the second coil, and the first insulating portion and the second insulating portion are spaced apart from the rotor and the stator, respectively." [Explanation of symbols]

[0121] 1 Electric machines 4 rotors 5 Stator 6 Busbar Unit 7 No. 1 bus bar 8 Second bus bar 9. 3rd bus bar 52 Coil 71 First conductive bar 71a Main surface 72 First insulation section 73 1st connection part 74 First insulating part 74a 1st exposure area 75c 1st step part 81 Second conductive bar 82 Second insulation section 83 Second connection part 84 Second insulating part 84a 2nd exposure area 85c 2nd step 91 Third Conductive Bar 92 Third insulation section 93 Third connection part 94 Third insulating part 95c 3rd step P1 1st position P2 2nd position

Claims

1. A method for manufacturing a busbar unit used in an electric machine, comprising: a first step of preparing a first conductive bar, the first conductive bar being made of a single plate and including a first connecting portion entirely located at a first position in an axial direction along an axis, a first insulating portion entirely located at a second position in the axial direction, and a first step portion provided between the first connecting portion and the first insulating portion; and a second conductive bar, the second conductive bar being made of a single plate and including a second connecting portion entirely located at the first position in the axial direction, a second insulating portion entirely located at the second position in the axial direction, and a second step portion provided between the second connecting portion and the second insulating portion; a second step of forming a first bus bar by providing a first insulating portion on a surface of the first insulating portion, the first insulating portion being joined to the first conductive bar so as to be integral with the first conductive bar and having a recess with which the second connecting portion is engaged, and forming a second bus bar by providing a second insulating portion on a surface of the second insulating portion; and a third step of connecting the second connecting portion to the first insulating portion via the first insulating part so that the first insulating portion and the second connecting portion are insulated from each other and so that the first insulating portion and the second connecting portion overlap each other when viewed from the axial direction, thereby forming the busbar unit having the first busbar and the second busbar.

2. A busbar for use in an electric machine, comprising: a conductive bar including a connecting portion, an insulating portion, and a step portion provided between the connecting portion and the insulating portion, the conductive bar being formed from a single plate; an insulating portion having a recess on a surface of the insulating portion, the insulating portion being joined integrally with the conductive bar and adapted to receive a connecting portion of a conductive bar other than the conductive bar; the conductive bar is connected to and insulated from another conductive bar via the insulating portion; the connecting portion is entirely located at a first position in the axial direction along the axis, the insulating portion is entirely located at a second position in the axial direction, When viewed from the axial direction, the insulating portion and the connecting portion of the other conductive bar overlap each other.

3. The busbar of claim 2 , wherein the insulating portion includes an exposed area exposed from the insulating portion.

4. The conductive bar has a plate shape with a width greater than a thickness, The bus bar of claim 3 , wherein the exposed area is at least a portion of one major surface of the conductive bar.

5. The bus bar according to claim 2 , wherein the insulating portion is made of a resin.

6. The bus bar according to claim 2 , wherein the insulating portion is an insulating film.

7. The conductive bar has an arc shape, The bus bar according to claim 2 , wherein a length of the insulating portion in a circumferential direction of the conductive bar is smaller than half a length of the conductive bar in the circumferential direction.

8. A busbar unit for use in an electric machine, A first bus bar; a second bus bar separate from the first bus bar, the first bus bar includes a first conductive bar formed from a single plate, the first connecting portion, a first insulating portion, and a first step portion provided between the first connecting portion and the first insulating portion, and a first insulating portion provided on a surface of the first insulating portion, the second bus bar includes a second conductive bar formed from a single plate, the second connecting portion, the second insulating portion, and a second step portion provided between the second connecting portion and the second insulating portion, and a second insulating portion provided on a surface of the second insulating portion, the first insulating portion is connected to and insulated from the second connecting portion via the first insulating part; the first connecting portion is entirely located at a first position in the axial direction along the axis, the first insulating portion is entirely located at a second position in the axial direction, the second connecting portion is entirely located at the first position in the axial direction, the second insulating portion is entirely located at the second position in the axial direction, When viewed from the axial direction, the first insulating portion and the second connecting portion overlap each other.

9. the first insulating portion includes a first exposed region exposed from the first insulating section; the second insulating portion includes a second exposed region exposed from the second insulating section, The busbar unit according to claim 8 , wherein an area of ​​the first exposed region and an area of ​​the second exposed region are the same.

10. the first conductive bar and the second conductive bar have the same shape; The busbar unit according to claim 8 , wherein the first insulating portion and the second insulating portion have the same shape.

11. The busbar unit according to claim 8 , wherein the first insulating portion and the second insulating portion are spaced apart from each other.

12. further comprising a third bus bar separate from the first bus bar and the second bus bar; the third bus bar includes a third conductive bar including a third connecting portion and a third insulating portion, and a third insulating portion provided on a surface of the third insulating portion, the second insulating portion is connected to and insulated from the third connecting portion via the second insulating part, the third insulating portion is connected to and insulated from the first connecting portion via the third insulating section, The bus bar unit according to claim 8 , wherein the first bus bar, the second bus bar, and the third bus bar, which are connected to each other, have an annular shape having an axis.

13. the third connecting portion is located at the first position in the axial direction, the third insulating portion is located at the second position in the axial direction, the third conductive bar includes a third step portion disposed between the third connecting portion and the third insulating portion; 13. The busbar unit according to claim 12, wherein, when viewed from the axial direction, the first insulating portion and the second connecting portion overlap each other, the second insulating portion and the third connecting portion overlap each other, and the third insulating portion and the first connecting portion overlap each other.

14. A rotor; a stator including a first coil and a second coil arranged to surround the rotor; The busbar unit according to claim 8, the first conductive bar is electrically connected to and supported by the first coil; the second conductive bar is electrically connected to and supported by the second coil; The electric machine, wherein the first insulating portion and the second insulating portion are spaced apart from the rotor and the stator, respectively.

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