WO2019021679A1

WO2019021679A1 - Motor

Info

Publication number: WO2019021679A1
Application number: PCT/JP2018/022984
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: CN211701655U

Abstract

[Problem] To provide a motor in which even in the case where multiple busbars are disposed crisscross with each other, insulation between the busbars is ensured. [Solution] A motor 100 is provided with a first busbar 53 made of a conductive wire rod and a second busbar 54 made of a conductive wire rod. The second busbar 54 has a crossing part 83c which crosses the first busbar 53 at a distance therefrom, and the crossing part 83c has a first flattened section 83d that is more flattened than the other portions of the second busbar 54, toward the direction in which the distance to the first busbar 53 increases.

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 lines. For example, the plurality of bus bars disclosed in Patent Document 1 are formed by bending a wire. Further, the plurality of bus bars are stacked in the direction of the rotation shaft of the motor at a constant distance from one another in order to ensure insulation between the bus bars.

Japanese Patent No. 3650372

By the way, when arranging a plurality of bus bars, adjacent bus bars may be arranged to cross each other in the rotation axis direction of the motor in order to reduce the dimension in the rotation axis direction of the motor. When adjacent bus bars are arranged to intersect with each other in the rotational axis direction of the motor, it is difficult to ensure sufficient insulation between the bus bars at the intersections. In particular, when the wire is not covered with the insulating film, it is even more so.

An object of the present invention is to ensure insulation between bus bars even when a plurality of bus bars are arranged to intersect in a motor.

A motor according to an exemplary embodiment of the present invention includes a first bus bar which is a conductive wire and a second bus bar which is a conductive wire. The second bus bar has a crossing portion which intersects the first bus bar at intervals, and the crossing portion is a flat portion which is flatter in a direction in which the distance with the first bus bar is wider than other portions of the second bus bar Have.

According to an exemplary embodiment of the present invention, even when a plurality of bus bars are arranged to cross each other, insulation between the bus bars can be ensured.

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 schematic view enlarging a portion where the first bus bar 53 and the second bus bar 54 intersect. FIG. 6 is a diagram showing a first modification of FIG. FIG. 7 is a view of FIG. 6 as viewed from the direction along which the first extending portion 83 extends. FIG. 8 is a view showing a second modification of FIG. FIG. 9 is a view showing a third modification of FIG.

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 plurality of divided stator cores 31, a plurality of insulators 32, and a plurality of coils 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 plurality of stator cores 31 are arranged in the circumferential direction, and each have a core back 31 a and teeth 31 b. The plurality of core backs 31 a have 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. 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. The plurality of coil wire holding parts 60a are arranged 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]
The plurality of bus bars 53 to 58 are disposed in the disc portion 51 b of the bus bar holder 51. In the present embodiment, the plurality of bus bars 53 to 58 are arranged on the same plane except for the portions where the bus bars intersect. 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 wires having conductivity, and the wires used for the bus bars 53 to 58 are bare wires. That is, the bus bars 53 to 58 are not covered with the insulating film or the like. The bus bars 53 to 58 are formed by plastic working of a wire, and include those 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.

Hereinafter, an example of the configuration of the first bus bar 53 and the second bus bar 54 will be described by using the bus bar 53 as the first bus bar 53 and the bus bar 54 intersecting the first bus bar 53 as the second bus bar 54.

[First bus bar 53]
The first 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.

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. The first contact portion 71 is fixed to the end of the second lead 33b by laser welding or the like.

The second contact portion 72 is connected to an end of another second lead 33b different from the second lead 33b 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.

[Second bus bar 54]
A part of the second bus bar 54 is disposed to intersect with the first bus bar 53 in the axial direction. The second bus bar 54 has a first contact portion 81, a second contact portion 82, a first extending portion 83, and a second extending portion 84. The configurations of the first contact portion 81, the second contact portion 82, and the second extending portion 84 are the same as those of the corresponding

portions

71, 72, 74 of the first bus bar 53, and thus the description thereof is omitted. The second bus bar 54 is different from the first extending portion 73 of the first bus bar 53 in the configuration of the first extending portion 83.

FIG. 5 is an enlarged schematic view of a portion where the first bus bar 53 and the second bus bar 54 intersect. The first extending portion 83 of the second bus bar 54 has a first rising portion 83a, a second rising portion 83b, and a crossing portion 83c.

As the first rising portion 83 a and the second rising portion 83 b approach the first bus bar 53, the first rising portion 83 a and the second rising portion 83 b gradually incline in a direction away from the disc portion 51 b of the bus bar holder 51. The first rising portion 83 a and the second rising portion 83 b are provided to space the first bus bar 53 and the crossing portion 83 c of the second bus bar 54. The first rising portion 83 a and the second rising portion 83 b are arranged at intervals in the direction in which the first extending portion 83 extends with respect to the first bus bar 53. The first rising portion 83 a and the second rising portion 83 b extend longer than the wire diameter of the bus bar 53 in the axial direction.

The first bus bar 53 and the crossing portion 83 c of the second bus bar 54 are arranged to overlap in the extension direction of the rotation center of the motor 100. The extension direction of the rotation center of the motor 100 in the present embodiment is substantially the same as the axial direction. Therefore, the intersection 83 c of the second bus bar 54 intersects the first bus bar 53 at a distance in the axial direction.

The crossing portion 83c of the second bus bar 54 connects the first rising portion 83a and the second rising portion 83b. The crossing portion 83c of the second bus bar 54 has a first flat portion 83d which is flatter than the other portions of the second bus bar 54 in the direction in which the distance to the first bus bar 53 is wider. The direction side in which the gap in the present embodiment is spread is the side in which the gap between the intersection 83 c of the second bus bar 54 and the first bus bar 53 is spread in the axial direction. Specifically, in the first flat portion 83 d, the side of the intersection 83 c facing the first bus bar 53 is crushed in the axial direction above the other portions of the second bus bar 54 and becomes thinner. It is flattened. Thus, the distance between the first flat portion 83 d and the first bus bar 53 is increased. The first flat portion 83 d extends longer than the wire diameter of the first bus bar 53 in the direction intersecting the first bus bar 53.

Here, since the first flat portion 83 d is flat in the direction in which the axial distance from the first bus bar 53 extends, the motor 100 is disposed even when the first bus bar 53 and the second bus bar 54 are crossed. The axial distance between the first bus bar 53 and the intersection 83 c of the second bus bar 54 can be secured while suppressing the axial dimension of the second bus bar 54. Thereby, the insulation between the first bus bar 53 and the second bus bar 54 can be secured, and a short circuit between the bus bars can be prevented.

[Bus bars 55 to 58]
The bus bars 55 to 57 have crossing portions 83c similar to the second bus bar 54 at portions where the bus bars intersect. Further, the two busbars 56 and the busbars 57 are provided with two crossing portions 83c. The bus bar 58 has a configuration similar to that of the first bus bar 53. In FIG. 4, the reference numerals of the intersections 83c of the bus bars 55 to 57 are omitted.

First Modified Example
6 and 7 show a first modification of the embodiment. FIG. 6 is a schematic view when a portion where the first bus bar 153 and the second bus bar 54 intersect is viewed from the direction along the first extending portion 73 of the first bus bar 153. Further, FIG. 7 is a schematic view when a portion where the first bus bar 153 and the second bus bar 54 intersect is viewed from the direction along the first extending portion 83 of the second bus bar 54. In FIG. 6 and FIG. 7, the same elements as the constituent elements of the embodiment are given the same reference numerals, and the description thereof is omitted.

The first bus bar 153 has a facing portion 73c facing the crossing portion 83c of the second bus bar 54, and the facing portion 73c is a direction in which the distance to the second bus bar 54 is wider than the other portions of the first bus bar 153. It has the 2nd flat part 73d flattened on the side. In the present embodiment, the second flat portion 73 d of the first bus bar 153 is flat in the extending direction. More specifically, the second flat portion 73 d of the first bus bar 153 is flat in the direction in which the axial distance between the second bus bar 54 and the intersecting portion 83 c is wider. Specifically, the second flat portion 73 d is flattened by the opposing portion 73 c being crushed axially lower than the other portions of the first bus bar 153 to be thinned. In this case, the axial distance between the first bus bar 153 and the second bus bar 54 can be further secured.

Second Modified Example
FIG. 8 is a view showing a second modified example of the embodiment. The crossing portion 183c of the second bus bar 154 straddles the first bus bar 53, and connects the first upright portion 83a and the second upright portion 83b. Specifically, the first flat portion 183 d of the intersection portion 183 c extends in a convex arc shape in the direction intersecting the first bus bar 53 from the first upright portion 83 a and the second upright portion 83 b. Also in this case, an axial distance between the first bus bar 53 and the second bus bar 154 can be further secured.

Third Modified Example
Although the bus bar 53 is described as the first bus bar 53 and the bus bar 54 intersecting the first bus bar 53 is described as the second bus bar 54 in the embodiment, for example, the bus bar 54 as the first bus bar 54 and the bus bar 53 as the second bus bar It may be configured as 53. That is, in this case, as shown in FIG. 9, the second bus bar 53 has a crossing portion 83 c which intersects the first bus bar 54 with a gap, and the first bus bar 54 forms the crossing portion 83 c of the second bus bar 53. Straddle. Further, in the first bus bar 54, the portion facing the intersection 83c is not flattened. The crossing portion 83c of the second bus bar 53 has a first flat portion 83d which is flatter than the other portions of the second bus bar 53 in the direction in which the distance to the first bus bar 54 is wider. The first flat portion 83 d of the second bus bar 53 has a configuration similar to that of the second flat portion 73 d of the first modification. Specifically, the first flat portion 83 d of the second bus bar 53 is flat in the direction in which the axial distance from the first bus bar 54 extends, and axially lower than the other portions of the second bus bar 53. It is flattened by being crushed and becoming thinner.

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 wires used for the bus bars 53 to 58 are bare wires, but wires subjected to insulation processing may be used for the bus bars 53 to 58.

A motor according to an exemplary embodiment of the present invention is a conductive wire having a first bus bar which is a conductive wire and a crossing portion which intersects the first bus bar at intervals. A bus bar is provided, and the crossing portion of the second bus bar has a flat portion which is flatter in a direction in which the distance from the first bus bar is wider than the other portion of the second bus bar.

In the motor according to an exemplary embodiment of the present invention, the wire used for the first bus bar and the second bus bar is a bare wire.

In the motor according to an exemplary embodiment of the present invention, the first bus bar and the intersection portion of the second bus bar are overlapped in the extending direction of the rotation center of the motor, and the flat portion of the second bus bar Is flat in the extending direction.

In the motor according to an exemplary embodiment of the present invention, the crossing portion of the second bus bar straddles the first bus bar.

In the motor according to an exemplary embodiment of the present invention, the first bus bar straddles the intersection of the second bus bar.

In the motor according to an exemplary embodiment of the present invention, the first bus bar has a facing portion facing the intersection of the second bus bar, and the facing portion of the first bus bar is the first bus bar The first flat portion is flatter in the direction in which the distance to the second bus bar extends than the other portion of the second bus bar.

The motor according to an exemplary embodiment of the present invention is characterized by further comprising a bus bar holder for holding the first bus bar and the second bus bar.

51 bus bar holder 53 to 58 bus bar 73 c facing portion 73 d second

flat portion

83 c, 183

c intersection portion

83 d, 183 d first flat portion 100 motor

Claims

A first bus bar which is a conductive wire;
And a second bus bar, which is a wire having conductivity, having crossing portions that cross the first bus bar at intervals.
The motor according to claim 1, wherein the crossing portion of the second bus bar has a flat portion which is flatter in a direction in which the gap with the first bus bar is wider than the other portion of the second bus bar.
The motor according to claim 1, wherein the wire used for the first bus bar and the second bus bar is a bare wire.
The first bus bar and the crossing portion of the second bus bar are overlapped in the extending direction of the rotation center of the motor,
The motor according to claim 1, wherein the flat portion of the second bus bar is flat in the extending direction.
The motor according to any one of claims 1 to 3, wherein the crossing portion of the second bus bar straddles the first bus bar.
The first bus bar straddles the crossing portion of the second bus bar.
The motor according to any one of claims 1 to 3.
The first bus bar has a facing portion facing the crossing portion of the second bus bar,
The said opposing part of the said 1st bus bar has the 1st flat part flattered in the direction side in which the said space | interval with the said 2nd bus bar spreads rather than the other part of the said 1st bus bar. The motor according to item 1 or 2.
The motor according to any one of claims 1 to 6, further comprising a bus bar holder for holding the first bus bar and the second bus bar.