WO2019021678A1

WO2019021678A1 - Motor

Info

Publication number: WO2019021678A1
Application number: PCT/JP2018/022983
Authority: WO
Inventors: 丹下　宏司
Original assignee: 日本電産株式会社
Priority date: 2017-07-26
Filing date: 2018-06-15
Publication date: 2019-01-31
Also published as: CN211606232U

Abstract

[Problem] To ensure satisfactory conduction between a coil and a busbar in a motor. [Solution] A motor 100 is provided with a rotor 20 having a rotary shaft; a stator 30 having a plurality of coils 33; and a busbar 53. The busbar 53 has at least one contact part 71, which partially has a contact region 71a that comes into contact with a second lead wire 33b that is drawn out of the coils 33. The contact region 71a in the contact part 71 of the busbar 53 has a wider width, in the direction in which the second lead wire 33b extends, than the width of portions of the busbar 53 other than the contact part 71.

Description

motor

The present invention relates to a motor.

Some motors have a plurality of bus bars. The plurality of bus bars are used to electrically connect the ends of the plurality of conductive wires that are leads from the coil. The bus bar disclosed in Patent Document 1 is formed by bending a wire, and has a connection portion connected to an end of a conductive wire. The connection portion is formed to surround the outer periphery of the end portion of the conductive wire.

Japanese Patent No. 3650372

Since the connecting portion of the bus bar of Patent Document 1 is formed by bending the wire, the contact area in contact with the end portion of the conductive wire is small. For this reason, there is a possibility that conduction between the bus bar and the conductive wire may be insufficient.

An object of the present invention is to ensure good conduction between a coil and a bus bar in a motor.

A motor according to an exemplary embodiment of the present invention includes a rotor having a rotating shaft, a stator having a plurality of coils, and a bus bar. The bus bar has at least one contact portion having a contact area at one portion for contacting the lead wire drawn from the coil. Further, the contact area of the contact portion of the bus bar has a width wider than the width of the portion other than the contact portion of the bus bar in the extending direction of the lead wire.

According to an exemplary embodiment of the present invention, the area of the contact area of the bus bar with the lead wire drawn from the coil can be increased, and good conduction can be ensured between the coil and the bus bar.

FIG. 1 is a cross-sectional view of a motor of the present embodiment. FIG. 2 is a perspective view of the stator. FIG. 3 is a perspective view of the stator. FIG. 4 is a perspective view of the bus bar unit. FIG. 5 is a plan view of the bus bar. FIG. 6 is an enlarged perspective view of the first contact portion. FIG. 7 is a rear view of the first contact portion. FIG. 8 is a developed view of the first contact portion. FIG. 9 is a schematic view illustrating a manufacturing process of the bus bar.

Hereinafter, an embodiment of the present invention will be described based on the drawings. In the drawings used in the following description, for the purpose of emphasizing the characteristic portions, the characteristic portions may be enlarged and shown for convenience, and the dimensional ratio of each component may be limited to the same as the actual Absent. Also, for the same purpose, parts that are not characteristic may be omitted and illustrated.

In the following description, the direction in which the central axis A of the rotor 20 extends is simply referred to as “axial direction”, the direction orthogonal to the central axis A is simply referred to as “radial direction”, and the circumference of the central axis A is simply referred to as “axial direction”. It is called "circumferential direction". Further, the upper side of FIG. 1 in the “axial direction” is simply referred to as “upper side”, and the lower side is simply referred to as “lower side”. Note that the vertical direction does not indicate the positional relationship and direction when it is incorporated into an actual device.

FIG. 1 is a cross-sectional view of a motor 100 according to the present embodiment. The motor 100 of the present embodiment is a brushless motor having three phases of U phase, V phase and W phase. The motor 100 includes a housing 10, a rotor 20, a stator 30, a pair of bearings 40, and a bus bar unit 50. In FIG. 1, a part of the bus bar unit 50 is omitted.

[Housing 10]
The housing 10 accommodates the rotor 20, the stator 30, the pair of bearings 40, and the bus bar unit 50 in an internal space. The housing 10 has a cylindrical portion 11 and a bottom portion 12. The cylindrical portion 11 is cylindrical and extends in the axial direction along the central axis A. The bottom 12 is disposed at the lower end of the cylindrical portion 11. The bottom portion 12 has a shaft through hole 12 a and a bearing holding portion 12 b. The shaft through hole 12 a is formed at the center of the bottom 12. The bearing holding portion 12b is formed around the shaft through hole 12a.

[Rotor 20]
The rotor 20 has a shaft 21, a rotor core 22, and a magnet 23. The shaft 21 extends axially along the central axis A. The shaft 21 is supported by a pair of bearings 40 and rotates about a central axis A. The pair of bearings 40 is held by the bearing holding portion 12 b of the housing 10 and the bearing holding portion 51 a of the bus bar holder 51 described later.

The rotor core 22 is a laminated steel plate in which a plurality of electromagnetic steel plates are laminated in the axial direction. The rotor core 22 is fixed to a shaft 21 penetrating the center of the rotor core 22 and rotates with the shaft 21. The magnet 23 is fixed to the outer surface of the rotor core 22 and rotates with the rotor core 22 and the shaft 21.

[Stator 30]
The stator 30 surrounds the radially outer side of the rotor 20. 2 and 3 are perspective views of the stator 30. FIG. The stator 30 has a stator core 31, an insulator 32, and a coil 33. In FIG. 2, the insulator 32 is omitted.

The stator core 31 is a laminated steel plate in which a plurality of electromagnetic steel plates are laminated in the axial direction. The stator core 31 has a core back 31a and teeth 31b. A plurality of core backs 31 a and teeth 31 b are arranged in the circumferential direction. The core back 31 a has a cylindrical shape concentric with the central axis A. The teeth 31 b extend radially inward from the inner side surface of the core back 31 a, and are formed in plural at equal intervals in the circumferential direction. In the present embodiment, twelve teeth 31 b are provided.

The insulator 32 is attached to each tooth 31 b and covers at least a part of the stator core 31. The insulator 32 is formed of, for example, an insulating resin having an insulating property. The insulator 32 has a flange portion 32 a at the radially outer side. The flange portion 32a extends in the axial direction and also in the circumferential direction. The flange portion 32a has a groove portion 32b which is recessed downward in the axial direction. The groove 32 b is formed to extend in the circumferential direction. Four neutral point bus bars 60 are arranged at equal intervals in the circumferential direction in the groove 32b.

The neutral point bus bar 60 is formed of a conductive metal material and extends in a plate shape in the circumferential direction. Each neutral point bus bar 60 has a plurality of coil wire holding portions 60 a extending in a plate shape radially inward from the upper end surface of the neutral point bus bar 60. A plurality of coil wire holding parts 60a are formed at intervals in the circumferential direction. In the present embodiment, three coil wire holding portions 60 a are provided on each neutral point bus bar 60. The end portion of the coil wire holding portion 60a is substantially U-shaped in a plan view, and is recessed radially outward.

The coil 33 is configured by winding a conductive wire around the teeth 31 b via the insulator 32. The coil 33 is formed of a coil corresponding to any one of the U phase, the V phase, and the W phase, and arranged in the circumferential direction in the order of the U phase, the V phase, and the W phase. The number of coils 33 is twelve, which is the same as the number of teeth 31 b. Therefore, in the present embodiment, there are four coil sets each including the U-phase coil, the V-phase coil, and the W-phase coil. The connection method of the coil 33 is a so-called delta connection method.

As shown in FIG. 3, from each coil 33, two lead wires of a first lead wire 33 a and a second lead wire 33 b are drawn toward the axial direction upper side. Therefore, the total of the first lead wire 33a and the second lead wire 33b drawn from each coil 33 is twenty four.

Three first lead wires 33a are drawn out from one coil set. The ends of the three first lead wires 33 a drawn from one coil set are electrically connected to the coil wire holding portion 60 a of one neutral point bus bar 60. Thus, the neutral point bus bar 60 connects one coil set to form an electrical neutral point. It is desirable that the coil wire holding portion 60a and the first lead wire 33a be temporarily fixed by caulking. Thereafter, the coil wire holding portion 60a and the end of the first lead 33a are firmly fixed by laser welding or the like. Here, since the first lead wire 33a can be sandwiched by the U-shaped coil wire holding portion 60a, the coil wire holding portion 60a and the first lead wire 33a can be easily connected.

<Bus Bar Unit 50>
FIG. 4 is a perspective view of the bus bar unit 50. As shown in FIG. The bus bar unit 50 includes a bus bar holder 51, a plurality of terminals 52, and a plurality of bus bars 53 to 58.

[Bus bar holder 51]
The bus bar holder 51 is formed of an insulating material such as resin, and is disposed above the insulator 32 and the coil 33. The bus bar holder 51 has a bearing holding portion 51a, a disc portion 51b, a plurality of bus bar holding portions 51c, and a plurality of terminal holding portions 51d. The bearing holding portion 51a is shown in FIG. 1, but is omitted in FIG. As shown in FIG. 1, the bearing holding portion 51 a is provided around the upper end portion of the shaft 21 and holds one of the pair of bearings 40.

The disc portion 51 b has an annular shape concentric with the central axis A. The disc portion 51 b is provided with a shaft through hole 51 e and a plurality of passage holes 51 f. The shaft through holes 51 e and the plurality of through holes 51 f axially penetrate the disc portion 51 b. The shaft through hole 51 e is formed at the center of the disc portion 51 b, and the shaft 21 penetrates. The plurality of passage holes 51f are located radially outward of the shaft through hole 51e, and are spaced apart in the circumferential direction. The number of the through holes 51 f in the present embodiment is twelve, which is the same as the number of the second lead lines 33 b. One second lead-out wire 33b drawn from each coil passes through the plurality of passage holes 51f.

The plurality of bus bar holding portions 51 c are provided on the disc portion 51 b of the bus bar holder 51. In detail, the plurality of bus bar holding portions 51c are located radially inward of the plurality of passage holes 51f, and here, six bus bar holding portions 51c are provided at intervals in the circumferential direction. Each of the bus bar holding portions 51c engages with substantially the lower half of the bus bars 53 to 58 to hold the bus bars 53 to 58.

The plurality of terminal holding portions 51 d are provided on the disc portion 51 b of the bus bar holder 51. The plurality of terminal holding portions 51d are located radially outward of the passage hole 51f. Here, three terminal holding portions 51d are provided at intervals of 120 degrees in the circumferential direction.

[Terminal 52]
The terminal 52 is connected to a circuit board or the like (not shown). In the present embodiment, three terminals 52 corresponding to the U phase, the V phase, and the W phase are respectively held by the terminal holding portion 51 d. The terminal holding portion 51 d is a plate-like member, and includes two conductor connection portions 52 a. The conducting wire connecting portion 52a is provided at a lower portion close to the disc portion 51b. The conducting wire connecting portion 52a is a through hole penetrating the plate-like portion in the direction orthogonal to the radial direction. Bus bars 53 to 58 corresponding to the phases of the respective terminals are connected to the conductor connection portion 52a.

[Bus bars 53 to 58]
In the bus bar holder 51, a plurality of bus bars 53 to 58 are disposed on the disc portion 51b of the bus bar holder 51. Each of the bus bars 53 to 58 electrically connects the two second lead wires 33 b and the terminal 52. Each of the bus bars 53 to 58 corresponds to one of the U phase, the V phase and the W phase, and two bus bars corresponding to each phase are provided. The bus bars 53 to 58 are wire members made of conductive metal, and include ones in which the shapes of the bus bars are different from each other. In addition, although the wire of this embodiment is a round wire of a cross-sectional round shape, a wire may be a rectangular wire of a cross-sectional rectangular shape.

Below, an example of the shape of the bus bar will be described using the bus bar 53 as an example. The bus bar 53 extends perpendicularly to the direction in which the second lead 33b extends. The direction in which the second lead-out wire 33b in the present embodiment extends is substantially the same as the axial direction.

The bus bar 53 has a first contact portion 71, a second contact portion 72, a first extending portion 73, and a second extending portion 74, as shown in FIG. 4, FIG. 5 and FIG. Each of the other bus bars 53 to 58 has the same configuration as the first contact portion 71, the second contact portion 72, the first extending portion 73, and the second extending portion 74 of the bus bar 53. 5 is a plan view of the bus bar 53, and FIG. 6 is a schematic view of the first contact portion 71 in which a portion surrounded by a two-dot chain line in FIG. 4 is enlarged.

The first contact portion 71 surrounds at least a part of the second lead 33b. In detail, a part of the first contact portion 71 is bent along the outer periphery of the second lead-out wire 33b, and opens inward in the radial direction. The first contact portion 71 is U-shaped when viewed from the direction in which the second lead 33b extends.

FIG. 7 is a schematic view of the first contact portion 71 surrounding the second lead 33b as viewed from the back. FIG. 8 is a developed view of the first contact portion 71. As shown in FIG. Although the second contact portion 72 is not shown in FIGS. 7 and 8, the shape of the second contact portion 72 is the same as the shape of the first contact portion 71.

The first contact portion 71 partially includes a contact area 71 a that contacts the second lead 33 b drawn from the coil 33. The first contact portion 71 also has an adjacent area 71b adjacent to the contact area 71a. The contact area 71a and the adjacent area 71b surround at least a part of the second lead 33b.

Here, as schematically shown in FIG. 9, the contact area 71 a of the first contact portion 71 is formed by plastically working the wire 70 with a press device or the like. Thereby, as shown in FIGS. 7 and 8, the width W1 of the contact area 71a of the first contact portion 71 is the first contact portion 71 and the second contact portion of the bus bar 53 in the direction in which the second lead 33b extends. It is provided wider than the width W2 of portions other than 72. As described above, the wire 70 may be not only a round wire but also a flat wire.

Here, “width” in “width W1” and “width W2” is the same direction as the direction in which the second lead-out wire 33b extends in the bus bar 53 of a portion extending in the direction intersecting the extending direction of the second lead-out wire 33b. Means the length of The “width W1” in the case of the plate-like member in which the bus bar 53 extends in a strip shape is the same as the case of the wire, and is the direction intersecting with the strip extending direction and the same as the direction in which the second lead 33b extends. It is the length of the direction. When the bus bar 53 is the wire 70, the width of the wire means the wire diameter of the wire. Therefore, in the present embodiment, the width W2 of the portion other than the first contact portion 71 of the bus bar 53 is the same as the wire diameter of the material of the wire 70, and the contact region 71a of the first contact portion 71 is the second lead 33b. In the extending direction, the width of the bus bar 53 is wider than that of the bus bar 53. Thus, the bus bar 53 and the end of the second lead 33b can be electrically connected with a width wider than the wire diameter of the wire 70. That is, in the present embodiment, the contact area between the second lead 33b and the contact area 71a can be wider than in the case where the raw material of the wire is brought into contact with the second lead 33b. As a result, good conduction can be ensured between the coil 33 and the bus bars 53 to 58.

Further, as shown in FIG. 8, the adjacent region 71 b of the first contact portion 71 surrounding a portion of the second lead-out wire 33 b is the first contact portion 71 and the second contact portion in the direction in which the second lead-out wire 33 b extends. It has a width wider than the width W2 of the portion other than 72. Thereby, even when the contact position between the first contact portion 71 and the second lead-out wire 33b is shifted, the conduction between the coil 33 and the bus bar 53 can be easily obtained. Further, since the first contact portion 71 surrounds the second lead 33b in a U-shape, and the contact area 71a has a width wider than the diameter of the bus bar 53, the first contact 71 and the second lead 33b Can be easily connected. The first contact portion 71 of the bus bar 53 and the end portion of the second lead 33b are fixed by laser welding or the like.

As shown in FIGS. 4 and 5, the second contact portion 72 is connected to an end of another second lead 33 b different from the second lead 33 b to which the first contact 71 is connected. Since the shape of the second contact portion 72 is the same as the shape of the first contact portion 71, the description will be omitted.

The first extending portion 73 linearly extends when viewed from the axial direction. The first end 73 a of the first extending portion 73 is connected to the first contact portion 71. The second end 73 b of the first extending portion 73 is connected to the second contact portion 72.

The second extending portion 74 connects the second contact portion 72 and the terminal 52. The second extending portion 74 is at least partially curved and is connected to one end of the second contact portion 72 not connected to the first extending portion 73. The second extending portion 74 has a first straight portion 74a, a second straight portion 74b, and a curved portion 74c.

The first straight portion 74 a extends radially outward from one end of the second contact portion 72 not connected to the first extending portion 73 in parallel to the first extending portion 73. The second straight portion 74 b linearly extends toward the wire connection portion 52 a of the terminal 52. The end 74 d of the second straight portion 74 b is connected to the wire connection portion 52 a of the terminal 52. The curved portion 74c connects the first straight portion 74a and the second straight portion 74b. The curved portion 74c curves at 90 degrees when viewed from the axial direction.

Other Embodiments
The present invention is not limited to the embodiments as described above, and the respective configurations and combinations thereof in the embodiments are merely examples, and addition, omission, and substitution of configurations are possible within the scope of the present invention. And other changes are possible.

In the embodiment, the neutral point bus bar 60 is a plate-like member, but the neutral point bus bar is formed of a wire, and the coil wire holding portion 60a of the neutral point bus bar 60 is the first contact portion of the bus bar 53 A configuration similar to that of 71 may be adopted. That is, a contact area having a width larger than the wire diameter of the wire may be provided in the direction in which the first lead 33a extends.

In the embodiment described above, the two contact portions of the first contact portion 71 and the second contact portion 72 are provided on the bus bar 53, but the number of contact portions provided on the bus bar 53 is not limited to this. One or three or more contact portions may be provided on the bus bar according to the configuration of the motor.

A motor according to an exemplary embodiment of the present invention includes at least one contact having, in part, a rotor having a rotating shaft, a stator having a plurality of coils, and a contact area contacting a lead wire drawn from the coils. A bus bar having a portion, and a contact area of the contact portion of the bus bar has a width wider than a width of a portion other than the contact portion of the bus bar in a direction in which the lead wire extends.

In the motor according to an exemplary embodiment of the present invention, a contact area of the contact portion of the bus bar is formed by plastic working of a material.

In the motor according to an exemplary embodiment of the present invention, the material of the bus bar is a wire, and the contact area of the contact portion of the bus bar is wider than the wire diameter of the wire in the extending direction of the lead wire. Have.

In the motor according to an exemplary embodiment of the present invention, a direction in which a contact area of the contact portion of the bus bar extends is a direction orthogonal to a direction in which the lead-out line extends.

In the motor according to an exemplary embodiment of the present invention, the direction in which the lead-out line extends is the same as the direction in which the rotation axis extends.

In the motor according to an exemplary embodiment of the present invention, the contact portion of the bus bar surrounds at least a part of the lead wire.

In the motor according to an exemplary embodiment of the present invention, the portion surrounding the lead wire of the contact portion of the bus bar is wider than the width of the portion other than the contact portion of the bus bar in the extending direction of the lead wire It has a width.

In the motor according to an exemplary embodiment of the present invention, the contact portion of the bus bar is U-shaped when viewed from the direction in which the lead wire extends.

In the motor according to an exemplary embodiment of the present invention, the contact portion of the bus bar includes a first contact portion contacting the first coil, a second contact portion contacting the second coil, and one end And a first extending portion connected to the first contact portion and the other end connected to the second contact portion.

In the motor according to an exemplary embodiment of the present invention, the first extending portion extends linearly when viewed from the axial direction of the rotation shaft.

In the motor according to an exemplary embodiment of the present invention, the bus bar further includes a second extending portion connected with one end of the second contact portion not connected with the first extending portion.

In the motor according to an exemplary embodiment of the present invention, at least a portion of the second extending portion of the bus bar is curved.

21 shaft 30 stator 33 coil 53 to 58 bus bar 71 first contact portion 71 a contact region 72 second contact portion 73 first extending portion 74 second extending portion 100 motor central axis A

Claims

A rotor having a rotating shaft,
A stator having a plurality of coils;
And a bus bar having at least one contact portion partially having a contact area contacting a lead wire drawn from the coil,
The motor according to claim 1, wherein a contact area of the contact portion of the bus bar has a width larger than a width of a portion other than the contact portion of the bus bar in a direction in which the lead wire extends.
The motor according to claim 1, wherein a contact area of the contact portion of the bus bar is formed by plastic working of a material.
The material of the bus bar is a wire,
The motor according to claim 1, wherein a contact area of the contact portion of the bus bar has a width larger than a wire diameter of the wire in a direction in which the lead wire extends.
The motor according to any one of claims 1 to 3, wherein a direction in which a contact area of the contact portion of the bus bar extends is a direction orthogonal to a direction in which the lead-out line extends.
The motor according to any one of claims 1 to 4, wherein a direction in which the lead-out line extends is the same as a direction in which the rotation shaft extends.
The motor according to any one of claims 1 to 5, wherein the contact portion of the bus bar surrounds at least a part of the lead wire.
The motor according to claim 6, wherein a portion surrounding the lead wire of the contact portion of the bus bar has a width wider than a width of a portion other than the contact portion of the bus bar in a direction in which the lead wire extends.
The motor according to claim 6, wherein the contact portion of the bus bar is U-shaped when viewed from the direction in which the lead wire extends.
The contact portion of the bus bar is
A first contact portion in contact with the first coil;
A second contact portion in contact with the second coil;
The motor according to any one of claims 1 to 8, further comprising: a first extending portion having one end connected to the first contact portion and the other end connected to the second contact portion.
The motor according to claim 9, wherein the first extending portion extends linearly when viewed in the axial direction of the rotation shaft.
The motor according to claim 9, wherein the bus bar further includes a second extending portion connected to one end of the second contact portion not connected to the first extending portion.
The motor according to claim 11, wherein the second extending portion of the bus bar is at least partially curved.