Busbar unit

Abstract

The present invention aims to provide a busbar unit that utilizes a simple busbar structure while ensuring positional accuracy of the connection portion of the busbar that is connected to the substrate relative to the busbar holder. [Solution] The busbar unit B comprises a busbar 7 that connects the windings 5 ​​of the stator core 3 to the substrate 12, and a busbar holder 6 having a holding portion 61d. The busbar 7 has a flat bar body 71 having a held portion 71a that is held by the holding portion 61d and a connecting portion 71b that is connected to the substrate 12 and formed on the same plane as the held portion 71a, a winding connecting portion 72 that is connected to the windings 5, and an elastic portion 73 that is elastic in the width direction. The holding portion 61d comprises a positioning portion F that abuts against the bar body 71 to position the busbar 7, a biasing portion S that presses the held portion 71a of the bar body 71 against a flat surface, and a slit (fitting portion) 61d5 that allows insertion of the elastic portion 73 and whose width direction length is shorter than the width of the elastic portion 73.

Description

Technical Field

[0001] The present invention relates to a bus bar unit.

Background Art

[0002] A motor generally includes a cylindrical stator core, an insulator mounted on a plurality of teeth provided on the inner periphery of the stator core, a winding wound around the insulator, a bus bar unit disposed on the opposite side of the insulator from the stator core, and a rotor rotatably disposed within the stator core.

[0003] In addition, in a conventional motor, for example, a substrate is provided for applying current to each phase of the winding in a 120-degree power supply drive method or a sine wave power supply drive method, and each of the U, V, and W phase windings is connected to the substrate through a bus bar held by the bus bar unit (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a conventional bus bar unit, the bus bar includes three annular rings corresponding to three-phase windings, a gripping portion that protrudes from the outer periphery of each ring and grips the end of a conductor constituting the winding, and connection terminals that rise from each ring and are connected to the substrate, respectively. And the three bus bars configured in this way are integrated with a mold resin by insert molding, and a bus bar holder is formed by the mold resin.

[0006] Conventional busbar units have the problem of high manufacturing costs because the busbars have a complex structure and are formed by insert molding. There are also busbar units in which the busbars are inserted into pre-molded resin busbar holders, but the complexity of the busbar structure remains unchanged. Furthermore, since the part that determines the position of the busbar relative to the busbar holder and the connection part that connects to the circuit board are on different surfaces that involve bending, any variation in their relative positioning can cause problems in connecting to the circuit board.

[0007] Therefore, the present invention aims to provide a busbar unit that can utilize a busbar with a simple structure while ensuring positional accuracy of the busbar, particularly the connection portion connected to the substrate, relative to the busbar holder. [Means for solving the problem]

[0008] To solve the aforementioned problems, the busbar unit of the present invention comprises a busbar connecting windings mounted on a stator core to a substrate, and a busbar holder having a holding portion for holding the busbar. The busbar has a flat bar body having a held portion held by the holding portion and a connecting portion connected to the substrate and formed on the same plane as the held portion, winding connecting portions provided at both left and right ends of the bar body and connected to the windings, and an elastic portion extending from the lower end of the bar body and having elasticity in the width direction. The holding portion comprises a positioning portion having a plane that abuts against one surface of the bar body, a biasing portion that presses the held portion of the bar body against the positioning portion, and a fitting portion that allows insertion of the elastic portion and whose width direction length is shorter than the width of the elastic portion.

[0009] With this busbar unit configuration, the biasing portion presses the bar body against the positioning portion, and the elastic portion penetrates the fitting portion and receives a compressive force. As a result, the positioning portion and fitting portion position the busbar to the busbar holder at a predetermined correct position. Furthermore, since the held portion of the busbar and the connection portion connected to the substrate are on the same plane, the position of the busbar's connection portion is also correctly positioned relative to the busbar holder.

[0010] Furthermore, the biasing portion of the busbar unit may include a gate-shaped frame that faces the positioning portion with a gap that allows the insertion of the bar body, and an arm that extends inclined from the center of the frame toward the positioning portion and contacts the bar body.

[0011] With a busbar unit configured in this way, the arms that press against the busbar are supported by a robust gate-shaped frame, allowing the busbar to be biased toward the positioning part with great force. This suppresses busbar wobble and vibration, so there is no need to worry about damage to the windings due to vibration input from the busbar.

[0012] Furthermore, the busbar in the busbar unit may have fitting holes in the bar body that allow the ends of the arms to be fitted into them. With a busbar unit configured in this way, it is possible to prevent the busbar from falling out of the busbar holder. [Effects of the Invention]

[0013] According to the motor of the present invention, it is possible to ensure positional accuracy of the connection portion of the busbar that is connected to the substrate relative to the busbar holder while utilizing a busbar with a simple structure. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a longitudinal cross-sectional view of the motor according to this embodiment. [Figure 2] Figure 2 is a plan view of the stator core with the insulator attached in the motor of this embodiment. [Figure 3] Figure 3(a) is a perspective view of the insulator in the motor of this embodiment, seen from the inside. Figure 3(b) is a perspective view of the insulator in the motor of this embodiment, seen from the outside. [Figure 4] Figure 4 is a plan view of the busbar holder in the motor of this embodiment. [Figure 5] Figure 5 is a bottom view of the busbar holder in the motor of this embodiment. [Figure 6] Figure 6 is a perspective cross-sectional view of the busbar holder in the motor of this embodiment. [Figure 7] Figure 7 is a perspective view of the busbar in the motor of this embodiment. [Figure 8] Figure 8 shows the process of attaching the busbar holder to the insulator in the motor of this embodiment. [Figure 9] Figure 9 is a perspective view of the stator with the busbar holder and busbars attached in the motor of this embodiment. [Modes for carrying out the invention]

[0015] The present invention will be described below based on the embodiments shown in the figures. In this embodiment, the busbar unit B is used to connect the winding 5 mounted on the stator core 3 of the motor 1 to the substrate 12, as shown in Figure 1. The motor 1 comprises a stator 2 having a stator core 3 and an insulator 4 mounted on the stator core 3 around which the winding 5 is wound, and a busbar unit B having a busbar 7 mounted on the upper side in Figure 1, opposite the stator core of the insulator 4 and connected to the winding 5, and a busbar holder 6 that holds the busbar 7. The motor 1 is a rotary type motor 1 that can rotate a rotor 20 rotatably inserted into the stator core 3 by energizing the winding 5 in the stator 2. In this specification, unless otherwise specified, the top and bottom in Figure 1 will be described as the top and bottom of the motor 1.

[0016] The following describes in detail each part of the motor 1 equipped with the busbar unit B. The stator 2 is housed in a cylindrical case 10, as shown in Figure 1. The case 10 is a bottomed cylinder with a bottom 10a and a cylindrical part 10b rising from the outer circumference of the bottom 10a. The case 10 has a hole 10c provided in the bottom 10a, a mounting piece 10d on the outer circumference of the bottom 10a that allows the motor 1 to be attached to external equipment, and an annular bearing holding part 10e on the inner circumference of the bottom 10a that holds the ball bearing 11.

[0017] In case 10, the diameter of the cylindrical portion 10b is reduced on the bottom side compared to the open end at the upper end. The stator core 3 is shrink-fitted or press-fitted into the reduced-diameter portion of the cylindrical portion 10b, and the stator 2 is fixed in the case 10. Further, on the inner circumference of the open end of the cylindrical portion 10b of the case 10, a bearing holder 13 is attached that holds a substrate 12 on which electronic components (not shown) constituting a controller for driving the motor 1 are mounted and closes the open end of the cylindrical portion 10b.

[0018] As shown in FIG. 1, the bearing holder 13 includes a plate-shaped main body 13a that closes the open end of the cylindrical portion 10b of the case 10, a cylindrical insertion portion 13b that protrudes from the lower end of the main body 13a and fits into the inner circumference of the open end of the cylindrical portion 10b of the case 10, a cylindrical bearing holding portion 13c that is inside the insertion portion 13b of the main body 13a and extends downward with a ball bearing 14 mounted on its inner circumference, an arc-shaped through hole 13d that is provided inside the insertion portion 13b of the main body 13a and through which the bus bar 7 is inserted, and a plurality of mounts 13e that protrude upward from the upper end of the main body 13a and on which the substrate 12 is placed at the upper end. The substrate 12 includes connection terminals 12a that are connected to the tips of the bus bar 7 described later. After being placed on the mounts 13e, the substrate 12 is fixed to the bearing holder 13 by screws 15 that are screwed to the mounts 13e respectively.

[0019] When the insertion portion 13b of the bearing holder 13 is fitted into the cylindrical portion 10b of the case 10, the open end of the cylindrical portion 10b is closed, and a seal ring 13f mounted on the outer circumference of the insertion portion 13b is brought into close contact with the inner circumference of the cylindrical portion 10b to seal the space between the case 10.

[0020] Above the bearing holder 13, a cap 16 is attached that covers the upper part of the main body 13a and forms a space for accommodating the substrate 12 between the bearing holder 13. A seal ring 17 for sealing the inside of the motor 1 in a liquid-tight manner is provided between the main body 13a and the cap 16.

[0021] The rotor 20 comprises a shaft 21, a cylindrical yoke 22 formed of laminated steel plates and mounted on the outer circumference of the shaft 21, and a plurality of permanent magnets 23 mounted on the outer circumference of the yoke 22 such that north poles and south poles alternately appear on the outer circumference in the circumferential direction. The rotor 20 is housed in a case 10, and the top and bottom of the shaft 21 are supported by ball bearings 11 held in the case 10 and ball bearings 14 held in bearing holders 13, allowing it to rotate circumferentially within the case 10.

[0022] Furthermore, the upper end of the shaft 21 of the rotor 20 is inserted into the bearing holding portion 13c of the bearing holder 13 and faces a magnetic sensor, such as a Hall element (not shown), mounted on the lower surface of the substrate 12. A permanent magnet 18 is attached to the upper end of the shaft 21, and a controller (not shown) can determine the rotational position of the rotor 20 using the magnetic sensor.

[0023] In this embodiment, the motor 1 is an SPM motor equipped with permanent magnets 23 on the outer circumference of the yoke 22 of the rotor 20, but it may also be an IPM motor in which the permanent magnets 23 are embedded inside the yoke 22.

[0024] As shown in Figures 1 and 2, the stator core 3 comprises a cylindrical yoke 31 and 12 teeth 32 projecting radially from the inner circumference of the yoke 31, and is cylindrical in shape. The stator core 3 is constructed by combining 12 core segments, each with a tooth 32 in the center, in a cylindrical shape, and the yoke 31 is divided into 12 segments. The number of teeth 32 can be appropriately changed according to the number of magnetic poles in the rotor 20.

[0025] The insulator 4 is made of resin and has a box-like shape that covers the top, bottom, and sides of each tooth 32, and is attached to each of the 12 teeth 32. More specifically, each of the 12 insulators 4 is divided into upper and lower pieces 41, 41 so that it can cover the upper and lower ends of the core segment and the sides of the teeth 32 and be attached to the stator core 3. The upper piece 41 of one insulator 4 covers the top surface of the tooth 32 of the core segment and the upper end of the part corresponding to the yoke 31, as well as the upper half of the side of the tooth 32, while the lower piece 41 covers the bottom surface of the tooth 32 of the core segment and the lower end of the part corresponding to the yoke 31, as well as the lower half of the side of the tooth 32.

[0026] Each piece 41, as shown in Figure 3, has a portion forming the yoke 31 in the core division and a bottom portion 41a facing the upper and lower ends of the teeth 32, a side portion 41b extending downward in Figure 3 from the side of the bottom portion 41a and facing the side of the teeth 32, an inner wall 41c rising vertically from the portion of the bottom portion 41a facing the tip of the teeth 32 and the portion of the side portion 41b facing the tip of the teeth 32, and teeth 3 in the bottom portion 41a The device comprises an outer wall 41d that rises vertically from the portion of the tooth 32 facing the base end of the 2 and the portion of the side portion 41b facing the base end of the tooth 32, a protruding portion 41e that rises upward from the center of the upper end of the outer wall 41d and has a fitting projection 41f on the surface facing outward at the tip, a pair of guide portions 41g, 41g that are at the upper end of the outer wall 41d and protrude from both sides of the protruding portion 41e toward the opposite side of the inner wall, and concave notches 41h provided on both shoulders of the upper end of the inner wall 41c.

[0027] When the upper and lower pieces 41, 41 configured in this way are attached to the teeth 32 of the core division from above and below, respectively, the top, bottom, and sides of the teeth 32 are covered by the bottom portion 41a and the side portion 41b, and an annular recess is formed on the outer circumference of the teeth 32 by these bottom portion 41a, the side portion 41b, the inner wall 41c, and the outer wall 41d, around which the winding 5 is wound.

[0028] After attaching the insulator 4, composed of pieces 41, 41, to the core division in this manner, copper wire is wound around the annular recess of the insulator 4 to attach the winding 5 to the teeth 32 of the stator core 3, thereby insulating the winding 5 from the stator core 3. When the 12 core divisions, each fitted with an insulator 4 around which the winding 5 is wound, are assembled, a cylindrical stator core 3 is formed. At the same time, the 12 insulators 4, each fitted to the stator core 3 and with the winding 5, form an annular insulator assembly. Thus, the stator 2, composed of the stator core 3, the 12 insulators 4, and the 12 windings 5, is completed. Furthermore, when the insulators 4 are arranged circumferentially to form the insulator assembly in this manner, the notches 41h, 41h of the inner walls 41c, 41c of adjacent insulators 4, 4 face each other, forming a recess between the inner walls 41c, 41c. Furthermore, the outer peripheral end of the bottom portion 41a of the insulator 4 protrudes further outward from the outer wall 41d towards the outer peripheral side of the stator 2, and a guide portion 41g is provided at the upper end of the outer wall 41d of the insulator 4. Therefore, a lead wire mounting portion is provided on the outer circumference of the insulator assembly, which is an annular recess formed by the outer peripheral portion of the bottom portion 41a, the outer wall 41d, and the guide portion 41g.

[0029] In this embodiment of the motor 1, the stator core 3 is constructed by combining core segments that are divided circumferentially, and the windings 5 ​​can be easily attached by attaching an insulator 4 to each core segment and winding copper wire around the annular recess of the insulator 4. Alternatively, the insulator 4 may be formed by only a pair of pieces, each having an annular portion facing the yoke 31 of the stator core 3 and a box-shaped portion divided into upper and lower sections that are connected to the inner circumference of the annular portion and cover each tooth 32, and the insulator 4 may be attached to the stator core 3 by attaching the pieces to the stator core 3 from the top and bottom, respectively.

[0030] In the motor 1 of this embodiment, a winding 5 is attached to each of the 12 teeth 32 via an insulator 4. One end of four windings 5 ​​is connected to each other to form a U-phase winding, one end of another four windings 5 ​​is connected to each other to form a V-phase winding, and one end of the remaining four windings 5 ​​is connected to each other to form a W-phase winding. Furthermore, although not shown in the figures, one end of the interconnected windings 5 ​​that make up the U-phase, one end of the interconnected windings 5 ​​that make up the V-phase, and one end of the interconnected windings 5 ​​that make up the W-phase are connected to each other to form a neutral point.

[0031] The other ends of the four interconnected windings 5 ​​that constitute the U phase are drawn out above the stator core 3 and wound around the outer surface of the outer wall 41d of the insulator assembly facing the outer circumference of the stator core 3, and gathered at one point in the circumferential direction of the insulator assembly. The other ends of the four interconnected windings 5 ​​that constitute the V phase are drawn out above the stator core 3 and wound around the outer surface of the outer wall 41d of the insulator assembly, and gathered at one point in the circumferential direction of the insulator assembly, avoiding the point where the other ends of the U phase windings 5 ​​are gathered. The other ends of the four interconnected windings 5 ​​that constitute the V phase are drawn out above the stator core 3 and wound around the outer surface of the outer wall 41d of the insulator assembly, and gathered at one point in the circumferential direction of the insulator assembly, avoiding the point where the other ends of the U phase windings 5 ​​and the other ends of the V phase windings 5 ​​are gathered. Furthermore, the other ends of the windings 5 ​​of each phase are housed in the lead wire mounting sections provided on the outer circumference of the insulator assembly, so they are gathered at their respective designated locations without falling off the outer circumference of the insulator 4.

[0032] The busbar unit B, which is placed on the side of the insulator 4 opposite the stator core, consists of a busbar holder 6 and three busbars 7 held by the busbar holder 6.

[0033] As shown in Figures 4 to 6, the busbar holder 6 is mounted on the insulator 4 and includes a holding portion 61d for holding the busbar 7. More specifically, the busbar holder 6 comprises an annular main body portion 61 on which the holding portion 61d is provided, twelve mounting portions 62 arranged on the outer circumference of the main body portion 61 and attached to the insulator 4, five elastic connecting portions 63 provided between the main body portion 61 and five of the mounting portions 62, and a total of seven fixed connecting portions 64a, 64b provided between the main body portion 61 and seven of the mounting portions 62. The busbar holder 6 is made of synthetic resin and the main body portion 61, mounting portions 62, elastic connecting portions 63 and fixed connecting portions 64a, 64b are integrally formed by injection molding.

[0034] In this embodiment, the main body 61 comprises an annular plate 61a, an annular seat portion 61b that protrudes downward from the inner circumference of the plate 61a in Figure 4 and abuts against the upper end of the inner wall 41c of the insulator 4, 12 protrusions 61c that protrude downward from the lower end of the seat portion 61b and are installed at equal intervals in the circumferential direction relative to the seat portion 61b, and a holding portion 61d that holds three busbars 7 arranged in a row on the upper end of the plate 61a.

[0035] When the main body 61 is placed on the insulator 4 with the lower end surface of the seat portion 61b in contact with the upper end surface of the inner wall 41c, the protrusion 61c fits into the recess formed by the notches 41h, 41h of the inner walls 41c, 41c of the adjacent insulators 4, 4. Therefore, when the busbar holder 6 is placed on the insulator 4, the protrusion 61c engages with the upper side surface of the inner wall 41c, preventing the busbar holder 6 from rotating circumferentially relative to the insulator 4.

[0036] The holding portion 61d includes a rectangular support plate 61d1 that rises from the plate 61a and functions as a positioning portion, a biasing portion S that is installed on the plate 61a so as to face the support plate 61d1, and a slit 61d5 that is provided between the support plate 61d1 and the biasing portion S of the plate 61a and serves as a fitting hole that penetrates the plate 61a in the axial direction.

[0037] The three retaining parts 61d are arranged along the circumferential direction of the plate 61a at predetermined intervals and are installed within half of the circumferential range of the plate 61a.

[0038] The support plate 61d1 is a rectangular flat plate and has a positioning portion F on its outer circumference in the radial direction of the plate 61a that is flush with the upper surface of the plate 61a and perpendicular to it. In this embodiment, the support plate 61d1 rises vertically from the inner circumference of the plate 61a, very close to the annular seat portion 61b, and together with the seat portion 61b it also serves to improve the strength of the plate 61a. However, if there is no problem with the strength of the plate 61a, the installation location of the support plate 61d1 on the plate 61a can be arbitrarily changed.

[0039] In this embodiment, the biasing section S includes a gate-shaped frame 61d2 that rises from the radial outer circumference of the support plate 61d1 of the plate 61a and faces the support plate 61d1 with a gap in the radial direction of the plate 61a, and an arm 61d3 that extends inclined downward and toward the support plate 61d1 from the center of the upper end of the frame 61d2. The arm 61d3 also has a claw 61d4 at its tip that protrudes toward the support plate 61d1. The width of the gap between the tip of the arm 61d3 and the plane that is the positioning section F of the support plate 61d1 is set to be narrower than the thickness of the busbar 7, which will be described later.

[0040] The slit 61d5 is located between the support plate 61d1 and the frame 61d2 in the plate 61a, and penetrates the plate 61a vertically from the top surface to the bottom surface, functioning as a fitting portion into which the busbar 7 is fitted.

[0041] Next, these 12 connection parts, the elastic connection part 63 and the fixed connection parts 64a and 64b, are provided on the outer circumference of the plate 61a of the main body part 61 at 30-degree intervals in the circumferential direction, and connect the mounting part 62 to the main body part 61. The elastic connection part 63 and the fixed connection parts 64a and 64b are provided in positions axially opposite to the corresponding insulator 4 in order to connect the mounting part 62, which hooks onto a fitting projection 41f provided on a protrusion 41e rising from the upper end of the outer wall 41d of the insulator 4, to the main body part 61, while the 12 protrusions 61c provided on the seat part 61b are inserted into recesses between the inner walls 41c, 41c of the insulator 4. Therefore, in the circumferential direction of the main body part 61, the elastic connection part 63 and the fixed connection parts 64a and 64b are arranged with a 15-degree phase difference between the protrusions 61c, 61c, respectively.

[0042] The elastic connecting portion 63 is U-shaped, with both ends connected to the plate 61a of the main body portion 61 and integrated with the main body portion 61, and a mounting portion 62 is installed in the center. The elastic connecting portion 63 forms a ring together with the main body portion 61, and in this embodiment, it is oval-shaped together with the main body portion 61. Thus, the elastic connecting portion 63 is formed in a U-shape with both ends connected to the main body portion 61, rather than being plate-shaped, making it easily elastically deformable. When a bending force is applied, deflection in the axial direction on the tip side where the mounting portion 62 is installed, in the direction that penetrates the plane of the paper in Figure 4, is permitted relative to the main body portion 61, and when a tensile force is applied, deflection in the radial direction on the tip side is permitted. The elastic connecting portion 63 is connected to the outer circumference of the main body portion 61, and as long as axial and radial deflection of the main body portion 61 is permitted, the shape and structure can be modified to that extent. However, by making the elastic connecting portion 63 U-shaped with both ends connected to the outer circumference of the main body portion 61, not only is axial and radial deflection of the main body portion 61 permitted, but elastic deformation in the radial direction as well as the axial direction is facilitated. When the elastic connecting portion 63 is U-shaped with both ends connected to the outer circumference of the main body portion 61, the elastic connecting portion 63 may form other shapes such as circles, ellipses, rectangles, etc., in addition to the oval shape, together with the main body portion 61.

[0043] As shown in Figure 6, the mounting portion 62, which is connected to the main body portion 61 via the elastic connecting portion 63, is configured to include a leg 62a that protrudes downward from the lower central end of the elastic connecting portion 63, and a hook 62b provided at the tip of the surface of the leg 62a that faces the inner circumference of the main body portion 61.

[0044] The fixed connection parts 64a and 64b each permanently connect each mounting part 62, other than the mounting part 62 connected by the elastic connection part 63, to the outer circumference of the main body part 61. In the motor 1 of this embodiment, the fixed connection parts 64a and 64b are rectangular or fan-shaped flat plates with the same thickness as the plate 61a and are integrated with the outer circumference of the plate 61a, protruding radially from the outer circumference of the plate 61a. The fixed connection parts 64a and 64b are provided in a range of more than half the circumference of the main body part 61 relative to the plate 61a, and the three holding parts 61d provided on the plate 61a are installed in the range in the circumferential direction of the plate 61a where the fixed connection parts 64a and 64b are provided.

[0045] More specifically, the three rectangular fixed connection parts 64a and the four fan-shaped fixed connection parts 64b are alternately provided on the plate 61a in the circumferential direction, and a gap of a constant width is formed between the fixed connection parts 64a and 64b. The retaining parts 61d are provided on the inner circumference side of the three fixed connection parts 64a on the plate 61a, and adjacent retaining parts 61d are installed on the plate 61a with a gap of approximately one circumferential width of the fan-shaped fixed connection parts 64b between them. Fixed connection parts 64b that do not have retaining parts 61d on their inner circumference side are provided with a rib 64b1 that is provided radially at the lower end to ensure bending rigidity, but the rib 64b1 may not be provided if sufficient bending rigidity is already provided. Fixed connection parts 64a that have retaining parts 61d on their inner circumference side do not have a rib because the bending rigidity is increased by the provision of retaining parts 61d on the plate 61a, but a rib may be provided if the rigidity is insufficient.

[0046] The mounting portion 62, which is connected to the main body portion 61 via fixed connection portions 64a and 64b, is configured as shown in Figures 5 and 6, with a leg 62a protruding downward from the lower end of the fixed connection portions 64a and 64b, and a hook 62b provided at the tip of the surface of the leg 62a facing the inner circumference of the main body portion 61. The fixed connection portions 64a and 64b are provided with holes 64a1 and 64b2 into which a mold for molding the mounting portion 62 is inserted, due to the manufacturing process by injection molding. Furthermore, the height of the hook 62b on the mounting portion 62 installed on the fixed connection portions 64b at both ends in the circumferential direction in Figure 5, that is, the height of the protruding portion of the hook 62b, is lower than the height of the hook 62b installed on the other five fixed connection portions 64a and 64b.

[0047] The fixed connection parts 64a and 64b have higher rigidity than the elastic connection part 63. While the elastic connection part 63 actively allows for radial and axial deflection of the main body part 61, the fixed connection parts 64a and 64b exhibit only slight radial and axial deflection of the main body part 61 even when bending or tensile forces are applied, thus permanently connecting the mounting part 62 to the main body part 61.

[0048] In the motor 1 of this embodiment, the stator 2 is equipped with 12 insulators 4 mounted on 12 teeth 32, and the busbar holder 6 is attached to each insulator 4. Therefore, in the motor 1 of this embodiment, the busbar holder 6 is equipped with 12 mounting parts 62 corresponding to each insulator 4, and the total number of elastic connection parts 63 and fixed connection parts 64a, 64b is also 12. Note that as long as the busbar holder 6 can be fixed to the insulators 4, the number of mounting parts 62 can be changed to any number of 3 or more, regardless of the number of insulators 4 installed.

[0049] Next, as shown in Figure 7, the bus bar 7 comprises an inverted T-shaped bar body 71, two U-shaped winding connection parts 72 provided at both ends of the horizontal side of the bar body 71, a bifurcated elastic part 73 extending downward from the center of the lower end of the bar body 71 in Figure 7, and a fitting hole 74 provided at the lower end of the bar body 71 that penetrates the bar body 71.

[0050] The bar body 71 is formed from an inverted T-shaped flat plate, and as shown in Figures 1 and 7, it has a held portion 71a along the horizontal direction that is held by the holding portion 61d, and a connecting portion 71b that extends vertically upward from the upper center end of the held portion 71a and is connected to the substrate 12 and formed on the same plane as the held portion 71a. Overall it is flat and extends in a straight line in the vertical direction and does not have any bent portions. Therefore, the bar body 71 has a flat, flush surface on the back of the held portion 71a and the connecting portion 71b in Figure 7.

[0051] Each winding connection portion 72 is U-shaped and is connected to both the left and right sides of the holding portion 71a that runs horizontally along the bar body 71. The winding connection portion 72 is connected to the winding 5 by crimping from the outside with the other ends of the two windings 5 ​​housed inward, thereby gripping the other ends of the two windings 5 ​​together. In this embodiment, since there are four windings 5 ​​for each phase, four windings 5 ​​of the same phase are connected to one busbar 7 by connecting the other ends of two windings 5 ​​of the same phase to each winding connection portion 72.

[0052] The elastic portion 73 is composed of a pair of protruding pieces 73a, 73a that project downward from the lower end of the bar body 71, forming a bifurcated shape, and is integrally provided with the bar body 71 to provide elasticity. When the elastic portion 73 is subjected to compressive forces from the left and right in the left-right direction in Figure 7, it bends so as to approach each other in the left-right direction, exhibiting a resilient force due to its self-restoring force. Furthermore, the width of the elastic portion 73 in the left-right direction in Figure 7 is narrower than the width of the slit 61d5 in the holding portion 61d. In other words, the widthwise length of the fitting portion, the slit 61d5, is shorter than the width of the elastic portion 73. In addition, two pointed bars 73b are provided vertically on the side opposite to the mutually facing sides of each protruding piece 73a, 73a.

[0053] When the bus bar 7 configured in this way is inserted into the gap between the support plate 61d1 and the frame 61d2 from above the holding portion 61d of the main body portion 61 with the elastic portion 73 facing downwards, the tip of the claw 61d4 comes into contact with the tip of the bar body 71, causing the arm 61d3 to bend and allowing the bus bar 7 to penetrate between the support plate 61d1 and the frame 61d2.

[0054] Furthermore, as the bus bar 7 is pushed between the support plate 61d1 and the frame 61d2, the elastic part 73 enters the slit 61d5 provided in the plate 61a, and eventually the claw 61d4 of the frame 61d2 enters the fitting hole 74, causing the arm 61d3 to exert elastic force and press the held portion 71a of the bar body 71 against it, biasing it toward the positioning portion F, which is the inner plane of the support plate 61d1. The positioning portion F is composed of the entire inner plane of the support plate 61d1, but may be composed of a part of the plane of the portion of the support plate 61d1 facing the biasing portion S, as long as it can contact the bar body 71 and position the bus bar 7.

[0055] In this way, the bus bar 7 is positioned radially relative to the plate 61a by the biasing part S, which presses the flat back surface of the held portion 71a of the bar body 71 against the plane facing the outer circumference of the support plate 61d1, which is the positioning part F. When the elastic part 73 enters the slit 61d5, it receives compressive forces from the left and right directions, and the protruding pieces 73a, 73a tend to spread out due to their own restoring force, thus fixing it to the slit 61d5 and positioning it in the circumferential direction relative to the plate 61a. Thus, the slit 61d5, which is the fitting part, allows the insertion of the elastic part 73 of the bus bar 7, but since the widthwise length of the slit 61d5 is shorter than the width of the elastic part 73, when the elastic part 73 enters the slit 61d5, it exerts a self-restoring force that causes the protruding pieces 73a, 73a to spread out and fixes it to the slit 61d5.

[0056] When the elastic part 73 is inserted into the slit 61d5, the return 73b provided on the side surface of the elastic part 73 bites into the side wall of the hole forming the slit 61d5 in the plate 61a. Also, when the bus bar 7 is inserted until it reaches a predetermined position between the support plate 61d1 and the biasing part S, the claw 61d4 at the tip of the arm 61d3 fits into the fitting hole 74 provided in the bus bar 7. As a result, the bus bar 7 is firmly fixed to the holding part 61d, preventing it from falling out of the holding part 61d, and is positioned in the correct position relative to the bus bar holder 6 by the pressing of the arm 61d3 and the fitting of the elastic part 73 into the slit 61d5 as a fitting part, and is fixed without rattling.

[0057] When the three busbars 7 are fixed to the holding portion 61d of the main body 61 as described above, the connection portion 71b of the bar body 71 is positioned appropriately on the substrate 12 fixed to the case 10 and connected to terminals not shown on the substrate 12. Also, when the three busbars 7 are fixed to the holding portion 61d of the main body 61 as described above, the winding connection portion 72 is positioned above the gap between the fixed connection portion 64a and the fixed connection portion 64b of the busbar holder 6.

[0058] The busbar unit B, consisting of the busbar holder 6 and the three busbars 7 configured in this way, is mounted on the stator 2 by the following procedure. As shown in Figure 8, the busbar holder 6 is tilted relative to the stator 2 so that the lower end of the seat portion 61b abuts against the upper end of the inner wall 41c of the insulator 4, and the projection 61c is inserted into the recess between the inner walls 41c of the insulator 4, while the hook 62b of the mounting portion 62 of the central fixing connection portion 64a of the fixing connection portions 64a, 64b is hooked onto the fitting projection 41f provided on the outer circumference of the outer wall 41d of the insulator 4. The insulator 4 is provided with a fitting projection 41f onto which the hook 62b is hooked, but it may also be provided with a recess that allows the hook 62b to be fitted instead of the fitting projection 41f, or it may have other shapes and structures as long as the hook 62b can be fitted.

[0059] Next, using the hook 62b of the mounting portion 62 of the central fixed connection portion 64a, which is hooked onto the fitting projection 41f of the insulator 4, as a pivot point, the entire busbar holder 6 is rotated in the direction indicated by the arrow in Figure 8, bringing it closer to the insulator 4. Then, the mounting portions 62 connected to the fixed connection portions 64a, 64b, and elastic connection portion 63, which are closest to the central fixed connection portion 64a in the circumferential direction of the main body portion 61, are sequentially hooked onto the corresponding fitting projection 41f of the insulator 4.

[0060] In the case of the mounting portion 62 connected to the fixed connection portions 64a and 64b, as the busbar holder 6 approaches the insulator 4, the mounting portion 62 rides onto the corresponding protrusion 41e of the insulator 4, but the leg 62a bends outward, causing the hook 62b to overcome the fitting projection 41f and hook onto the fitting projection 41f. Note that the height of the hook 62b on the mounting portion 62 installed on the fixed connection portions 64b at both ends of the fixed connection portions 64a and 64b, which are arranged in a row around the circumference of the main body portion 61, is set lower than the height of the hook 62b installed on the other five fixed connection portions 64a and 64b. Therefore, when the busbar holder 6 is tilted relative to the insulator 4 and the mounting portion 62 located in the center of the main body 61 is hooked onto the fitting projection 41f of the insulator 4, and then the busbar holder 6 is rotated around the central mounting portion 62 to approach the insulator 4, the amount of deformation of the legs 62a of the mounting portions 62 installed at both ends becomes smaller, making it easier for the hook 62b to fit onto the fitting projection 41f of the insulator 4, and thus easier to attach the hook 62b to the fitting projection 41f of the insulator 4.

[0061] In the case of the mounting portion 62 connected to the elastic connection portion 63, as the busbar holder 6 approaches the insulator 4, the mounting portion 62 rides up onto the corresponding protrusion 41e of the insulator 4, but the elastic connection portion 63 flexes radially and axially, causing the hook 62b to overcome the fitting projection 41f and hook onto the fitting projection 41f.

[0062] Furthermore, with respect to the central fixed connection portion 64a, of the circumferential sides of the protrusions 61c that are within the left half-circle of the main body portion 61 as viewed from the fixed connection portion 64a, the side z opposite to the central fixed connection portion 64a is inclined such that the circumferential width of the protrusion 61c narrows towards the tip. Also, with respect to the central fixed connection portion 64a, of the circumferential sides of the protrusions 61c that are within the right half-circle of the main body portion 61 as viewed from the fixed connection portion 64a, the side opposite to the central fixed connection portion 64a is inclined such that the circumferential width of the protrusion 61c narrows towards the tip. Therefore, when the entire busbar holder 6 is rotated using the hook 62b of the mounting portion 62 provided on the central fixed connection portion 64a as a pivot point to approach the insulator 4, the side z opposite to the protrusion 61c as seen from the central fixed connection portion 64a can enter the recess between the inner walls 41c, 41c without interfering with the inner wall 41c.

[0063] When all mounting parts 62 engage with the fitting projections 41f of the insulator 4, the seat portion 61b of the busbar holder 6 is placed on the upper end surface of the inner wall 41c of the insulator 4, and the protrusions 61c are fitted into the recesses between the inner walls 41c, 41c, fixing the busbar holder 6 to the insulator 4 in a state where rotation in the circumferential direction is restricted.

[0064] The elastic connecting portion 63, which connects the mounting portion 62 to the main body portion 61, allows for radial and axial deflection of the main body portion 61. Therefore, even if machining errors occur in the position of the mounting portion 62 connected to the fixed connecting portions 64a and 64b, the position of the mounting portion 62 connected to the elastic connecting portion 63, and the position of the fitting projection 41f of each insulator 4, these errors are absorbed by the deflection of the elastic connecting portion 63, and the busbar holder 6 can be firmly fixed to the insulator 4 by the elastic force exerted by the elastic connecting portion 63.

[0065] After fixing the busbar holder 6 to the insulator 4, the other ends of the four U-phase windings 5 ​​wound around each insulator 4 are routed through the annular recess on the outer circumference of the insulator assembly to the vicinity of the left busbar 7 shown in Figure 9. The other ends of the windings 5 ​​are bundled in pairs and pulled out from the left and right sides of the fixing connection part 64a towards the top of the main body 61, and each bundle is gripped by the winding connection part 72. In the same manner, the other ends of the four V-phase windings 5 ​​are bundled in pairs and gripped by the winding connection part 72 of the central busbar 7 in Figure 9, and the other ends of the four W-phase windings 5 ​​are bundled in pairs and gripped by the winding connection part 72 of the right busbar 7 in Figure 9.

[0066] Then, the busbar holder 6 is fixed to the stator 2, and the busbars 7 are connected to each winding 5, completing the stator assembly with the stator 2, busbar holder and busbars 7. The stator assembly is then housed and fixed in the case 10, and the motor 1 is completed by assembling the bearing holder 13, rotor 20, circuit board 12 and cap 16 into the case 10. Because the busbars 7 are positioned correctly relative to the busbar holder 6, when the circuit board 12 is mounted in the case 10, the ends of the connection portions 71b that extend vertically upwards from each busbar 7 are automatically connected to the connection terminals 12a of the circuit board 12.

[0067] As described above, the busbar unit B of this embodiment comprises a busbar 7 that connects windings 5 ​​mounted on a stator core 3 to a substrate 12, and a busbar holder 6 having a holding portion 61d for holding the busbar 7. The busbar 7 has a flat bar body 71 having a held portion 71a held by the holding portion 61d and a connecting portion 71b that is connected to the substrate 12 and formed on the same plane as the held portion 71a, winding connecting portions 72 provided at both the left and right ends of the bar body 71 and connected to the windings 5, and an elastic portion 73 that extends from the lower end of the bar body 71 and has elasticity in the width direction. The holding portion 61d comprises a positioning portion F having a plane that abuts against one surface of the bar body 71 to position the busbar 7, a biasing portion S that presses the held portion 71a of the bar body 71 against the plane, and a slit (fitting portion) 61d5 that allows insertion of the elastic portion 73 and compresses the elastic portion 73 in the width direction.

[0068] With the busbar unit B configured in this way, the biasing part S presses the bar body 71 against the positioning part F, and the elastic part 73 enters the slit (fitting part) 61d5 and receives a compressive force, so the positioning part F and the slit (fitting part) 61d5 position the busbar 7 to a predetermined correct position relative to the busbar holder 6. Furthermore, since the held portion 71a of the busbar 7 and the connecting portion 71b connected to the substrate 12 are on the same plane, the position of the connecting portion 71b of the busbar 7 is also positioned to the correct position relative to the busbar holder 6.

[0069] Furthermore, the busbar 7 has a simple structure comprising a flat bar body 71, winding connection parts 72 provided at both the left and right ends of the bar body 71 and connected to the winding 5, and an elastic part 73 extending from the lower end of the bar body 71 and having elasticity in the width direction.

[0070] Based on the above, the busbar unit B of this embodiment allows for the use of a simple busbar 7 while ensuring positional accuracy of the busbar 7 relative to the busbar holder 6, enabling reliable connection to the substrate 12, and also reducing manufacturing costs.

[0071] Furthermore, the biasing section S in the busbar unit B of this embodiment includes a gate-shaped frame 61d2 that faces the positioning section F with a gap that allows the insertion of the bar body 71, and an arm 61d3 that extends inclined from the center of the frame 61d2 toward the positioning section and contacts the bar body 71.

[0072] With the busbar unit B configured in this way, the strong gate-shaped frame 61d2 supports the arm 61d3 that presses against the busbar 7, allowing the busbar 7 to be biased toward the positioning part F with great force, thereby suppressing rattling of the busbar 7 and suppressing vibration of the busbar 7, so there is no need to worry about damaging the winding 5 with vibration input from the busbar 7. In addition, since the biasing part S only needs to bias the busbar 7 and bring it into contact with the positioning part F, it may be composed of an arm that rises directly from the plate 61a and biases the busbar 7 without having a frame 61d2.

[0073] Furthermore, in the busbar unit B of this embodiment, the busbar 7 is provided with a fitting hole 74 in the bar body 71 that allows the tip of the arm 61d3 to be fitted into it. With the busbar unit B configured in this way, it is possible to prevent the busbar 7 from falling out of the busbar holder 6.

[0074] In this embodiment, the busbar unit B includes a main body 61, a mounting portion 62 attached to the insulator 4, and an elastic connecting portion 63 connecting the main body 61 and the mounting portion 62. However, the attachment of the busbar holder 6 to the insulator 4 is not limited to the specific configuration described above and can be arbitrarily modified.

[0075] However, if the motor 1 of this embodiment comprises a stator 2 having a stator core 3 and an insulator 4 mounted on the stator core 3 around which windings 5 ​​are wound, and a busbar holder 6 placed on the side of the insulator 4 opposite the stator core and holding busbars 7 connected to the windings 5, and the busbar holder 6 comprises an annular main body portion 61 that holds the busbars 7, a plurality of mounting portions 62 arranged on the outer circumference of the main body portion 61 and attached to the insulator 4 respectively, and one or more elastic connecting portions 63 provided between the main body portion 61 and one or more mounting portions 62, allowing radial and axial deflection of the main body portion 61, then the following advantages can be enjoyed.

[0076] In the motor 1 configured as described above, the elastic connecting portion 63 that connects the mounting portion 62 to the main body portion 61 is allowed to deflect radially and axially. Therefore, even if there are machining errors in the position of the mounting portion 62 and the insulator 4 to which the mounting portion 62 is attached, these errors are absorbed by the deflection of the elastic connecting portion 63, and the busbar holder 6 can be firmly fixed to the insulator 4 by the elastic force exerted by the elastic connecting portion 63.

[0077] Therefore, according to the motor 1 of this embodiment, the busbar holder 6 can be fixed by attaching the mounting part 62 to the insulator 4 without employing a fixing method that would complicate assembly processes such as bonding or screw fastening. Furthermore, the busbar holder 6 can be fixed to the insulator 4 without any looseness by utilizing the elastic force exerted by the elastic connection part 63. As a result, even if vibration is input from the motor 1 itself or from an external source, the busbar holder 6 and the busbar 7 held by the busbar holder 6 will vibrate relative to the stator 2, preventing the winding 5 from breaking.

[0078] Furthermore, in the motor 1 of this embodiment, the elastic connection portion 63 is connected to the main body portion 61 and is formed in an annular shape together with the main body portion 61, with its intermediate portion connected to the mounting portion 62. With the motor 1 configured in this way, axial and radial deflection of the main body portion 61 at the elastic connection portion 63 is permitted. In addition, since the elastic connection portion 63 can undergo elastic deformation not only in the axial direction but also in the radial direction, it is possible to prevent assembly defects caused by machining errors in the busbar holder 6 and insulator 4.

[0079] Furthermore, in the motor 1 of this embodiment, elastic connecting portions 63 are provided for a plurality of mounting portions 62 located in a range of half a circumference or less in the circumferential direction of the main body portion 61, and the busbar holder 6 includes a plurality of fixed connecting portions 64a, 64b that fix each of the mounting portions 62 other than those connected by the elastic connecting portions 63 to the outer circumference of the main body portion 61, and the busbar 7 is held in the portion of the main body portion 61 within the range where the fixed connecting portions 64a, 64b are located on the outer circumference.

[0080] With the motor 1 configured in this way, the portion of the busbar holder 6 that holds the busbar 7 is located within the range where the fixed connection portions 64a and 64b that fix the mounting portion 62 to the main body portion 61 are located on the outer circumference, the installation range of the elastic connection portion 63 is limited to less than half the circumference of the main body portion 61 of the busbar holder 6, and the installation range of the fixed connection portions 64a and 64b is limited to more than half the circumference of the main body portion 61 of the busbar holder 6. As a result, the installation location of the busbar 7 can be sufficiently far from the installation location of the elastic connection portion 63, and even if the elastic connection portion 63 vibrates, the vibration is less likely to be transmitted to the busbar 7, further preventing breakage of the winding 5.

[0081] Even when fixed connection parts 64a and 64b are provided, the ratio of fixed connection parts 64a and 64b to the elastic connection part 63 can be arbitrarily designed and changed as long as the busbar holder 6 can be fixed to the insulator 4 without any play. In addition, all mounting parts 62 may be connected to the main body part 61 by the elastic connection part 63. Even with this configuration, the elastic connection part 63 allows for radial and axial deflection of the main body part 61, so it can absorb machining errors between the busbar holder 6 and the insulator 4, and the elastic force of the elastic connection part 63 can firmly fix the busbar holder 6 to the insulator 4.

[0082] Furthermore, in the motor 1 of this embodiment, the mounting portion 62 is equipped with a hook 62b that hooks onto a fitting projection 41f provided on the surface of the insulator 4 facing the outer circumference of the stator 2, and the hook 62b is connected to the elastic connection portion 63 with the inner circumference facing. With the motor 1 configured in this way, the mounting portion 62 hooks onto the fitting projection 41f from the outer circumference side of the stator 2 relative to the insulator 4, so that the mounting portion 62 does not interfere with the winding 5, and compared to the case in which the fitting projection 41f is provided on the inner circumference side of the outer wall 41d of the insulator 4, it is possible to avoid increasing the radial size of the insulator 4, so the motor 1 can be made smaller, and the fitted state of the mounting portion 62 and the fitting projection 41f can be seen from the outer circumference side of the stator 2, so it is easy to check whether the busbar holder 6 is fixed to the insulator 4. Furthermore, unless there is a demand for miniaturization of the motor 1, the location of the fitting projection 41f of the insulator 4 into which the mounting portion 62 is fitted can be arbitrarily changed in the design. For example, it can be provided on the surface of the outer wall 41d facing the inner wall 41c.

[0083] Furthermore, in the motor 1 of this embodiment, the mounting portion 62 has a hook 62b that hooks onto the insulator 4, and the height of the hook 62b in the mounting portions 62 that are connected by fixed connection portions 64a, 64b and located at both ends in the circumferential direction of the main body portion 61 is lower than the height of the hook 62b in the mounting portions 62 that are connected by fixed connection portions 64a, 64b and located at locations other than both ends in the circumferential direction of the main body portion 61.

[0084] With the motor 1 configured in this way, when attaching the busbar holder 6 to the insulator 4, the amount of deformation of the legs 62a of the mounting portion 62 of the fixed connection portion 64b installed at both ends of the fixed connection portion 64a, 64b of the main body portion 61 is reduced. Therefore, when the busbar holder 6 is tilted relative to the insulator 4 and the mounting portion 62 located in the center of the main body portion 61 is hooked onto the fitting projection 41f of the insulator 4, and then the busbar holder 6 is rotated around the central mounting portion 62 to approach the insulator 4, the hooks 62b of the mounting portion 62 installed at both ends are more likely to fit onto the fitting projection 41f of the insulator 4, making it easier to attach the hooks 62b to the fitting projection 41f of the insulator 4.

[0085] Although preferred embodiments of the present invention have been described in detail above, modifications, alterations, and changes are permitted as long as they do not deviate from the scope of the claims. [Explanation of Symbols]

[0086] 3... Stator core, 5... Winding, 6... Busbar holder, 7... Busbar, 12... Substrate, 61d... Holding part, 61d2... Frame, 61d3... Arm, 61d5... Slit (fitting part), 71... Bar body, 71a... Retained part, 71b... Connection part, 72... Winding connection part, 73... Elastic part, 74... Fitting hole, B... Busbar unit, F... Positioning part, S... Biasing part

Claims

1. A busbar that connects the windings mounted on the stator core to the circuit board, The busbar holder comprises a busbar holder having a holding portion for holding the busbar, The aforementioned busbar is A flat bar body having a portion to be held by the holding part and a connecting portion connected to the substrate and formed on the same plane as the portion to be held, Winding connection parts are provided at both the left and right ends of the bar body and connected to the winding, It has an elastic portion that extends from the lower end of the bar body and has elasticity in the width direction, The aforementioned retaining part is A positioning portion having a plane that contacts one surface of the bar body, A biasing part that presses the portion of the bar body to be held against the positioning part, It has a fitting portion that allows insertion of the elastic portion and whose widthwise length is shorter than the width of the elastic portion. A busbar unit characterized by the following features.

2. The biasing unit is, The positioning portion has a gate-shaped frame facing it, with a gap that allows the insertion of the bar body to be made between them. The frame has an arm that extends inclined from the center toward the positioning portion and contacts the bar body. The busbar unit according to feature 1.

3. The aforementioned busbar is The bar body has a fitting hole that allows the tip of the arm to be fitted into it. The busbar unit according to feature 2.

Images