WO2019021680A1

WO2019021680A1 - Motor

Info

Publication number: WO2019021680A1
Application number: PCT/JP2018/022985
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

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, a second busbar 54 made of a conductive wire rod, and an insulation member 90. The second busbar 54 has a crossing section 83c which crosses the first busbar 53 at a distance therefrom. The insulation member 90 is provided to the crossing section 83c of the second busbar 54. The wire rods used for the first busbar 53 and the second busbar 54 may be bare wires.

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, and the outer periphery is covered with an insulating film. Further, the plurality of bus bars are stacked on the same circumference at a constant interval in the vertical direction, and an insulating tube is provided in a part of a portion where the upper and lower bus bars overlap.

Japanese Published Patent Application Publication No. 2008-061345

By the way, when arrange | positioning a several bus-bar, the bus-bar adjacent to an up-down direction may be crossed and arrange | positioned. As described above, when the bus bars vertically adjacent to each other are arranged to cross each other, it is difficult to sufficiently ensure the insulation between the bus bars at the intersection. 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 that is a conductive wire, a second bus bar that is a conductive wire, and an insulating member. The second bus bar has crossing portions that cross the first bus bar at intervals. The insulating member is provided at the intersection of the second bus bars.

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 showing a second modification of FIG. FIG. 8 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. 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 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. Crossing portion 83 c extends longer than the wire diameter of first bus bar 53 in the direction intersecting first bus bar 53. An insulating member 90 is provided at the intersection 83c. Crossing portion 83 c is in contact with first bus bar 53 via insulating member 90. The insulating member 90 is a member that can be assembled to the intersection 86 c. The insulating member 90 of the present embodiment is a heat-shrinkable tube. The insulation between the first bus bar 53 and the intersection 83 c of the second bus bar 54 is secured by the insulating member 90. Further, by bringing the intersection 83 c of the second bus bar 54 into contact with the first bus bar 53 via the insulating member 90, an increase in the axial dimension of the motor 100 can be suppressed. Furthermore, since the crossing portion 83c is connected to the first rising portion 83a and the second rising portion 83b across the first bus bar 53, the crossing portion 83c is more unidirectional than the other portions of the first extending portion 83. Project to In the present embodiment, as shown in FIG. 5, the intersection portion 83 c protrudes axially above the other portions of the first extending portion 83. This facilitates positioning of the insulating member 90 when the insulating member 90 is disposed at the intersection 83c.

[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. The two busbars 56 and the busbars 57 are provided with two crossing portions 83c. Similarly to the crossing portion 83c of the second bus bar 54, the insulating member 90 is provided at the crossing portion 83c of the bus bars 55 to 57. The intersection 83 c of the bus bars 55 to 57 contacts the intersecting bus bars via the insulating member 90. The bus bar 58 has a configuration similar to that of the first bus bar 53. In FIG. 4, the reference numerals of the crossing portions 83c of the bus bars 55 to 57 and the insulating member 90 are omitted.

First Modified Example
FIG. 6 is a view showing a first modified example of the embodiment. In FIG. 6, the same elements as the constituent elements of the embodiment are given the same reference numerals, and the description thereof is omitted. The insulating member 190 in the first modification is an insulating film member in a state of being applied to the intersection portion 83 c of the second bus bar 54. The insulating member 190 is provided on the side of the intersection 83 c facing the first bus bar 53. The intersection 83 c contacts the first bus bar 53 via the insulating member 190. The insulating member 190 may be provided on the entire circumference of the intersection portion 83c.

Second Modified Example
FIG. 7 is a view showing a second modified example of the embodiment. In FIG. 7, the same elements as the constituent elements of the embodiment are given the same reference numerals, and the description thereof will be omitted. The insulating member 290 in the second modified example is an insulating paper provided at the intersection 83 c of the second bus bar 54. The insulating member 290 is provided on the side of the intersection 83 c facing the first bus bar 53. Crossing portion 83 c is in contact with first bus bar 53 via insulating member 290. The insulating member 290 is fixed to the intersection 83 c by fixing means such as adhesion. The insulating member 290 may be provided on the entire circumference of the intersection portion 83c.

Third Modified Example
In the embodiment, the insulating

members

90, 190, and 290 are provided at the intersection 83c of the second bus bar 54, but as shown in FIG. 8, the first bus bar 53 facing the intersection 83 c of the second bus bar 54. Insulating

members

90, 190, and 290 may be provided at the intersection 73c. Crossing portion 73 c is in contact with second bus bar 54 via insulating

members

90, 190 and 290. In addition, in FIG. 4, the structure which provided the heat contraction tube in the cross | intersection part 73c is shown as an example of an insulation member.

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. And a second bus bar, and an insulating member provided at the crossing 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 crossing portion of the second bus bar contacts the first bus bar via the insulating member.

In the motor according to an exemplary embodiment of the present invention, the intersection between the first bus bar and the second bus bar is overlapped in a direction in which the rotation center of the motor extends.

In the motor according to an exemplary embodiment of the present invention, the insulating member is a member that can be assembled to the intersection.

In the motor according to an exemplary embodiment of the present invention, the insulating member is an insulating film member in a state of being applied to the intersection.

In the motor of an exemplary embodiment of the present invention, the insulating member is a heat-shrinkable tube.

In the motor of an exemplary embodiment of the present invention, the insulating member is an insulating paper.

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.

53 to 58

bus bars

73c,

83c intersections

90, 190, 290 insulation member 100 motor

Claims

A first bus bar which is a conductive wire;
A second bus bar, which is a conductive wire rod, having crossing portions which cross the first bus bar at intervals;
And an insulating member provided at the intersection 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 motor according to claim 1, wherein the intersection portion of the second bus bar contacts the first bus bar via the insulating member.
The motor according to claim 3, wherein the intersection between the first bus bar and the second bus bar is overlapped in a direction in which the rotation center of the motor extends.
The motor according to any one of claims 1 to 4, wherein the insulating member is a member that can be assembled to the intersection.
The motor according to any one of claims 1 to 4, wherein the insulating member is an insulating film member in a state of being applied to the intersection portion.
The motor according to any one of claims 1 to 5, wherein the insulating member is a heat shrinkable tube.
The motor according to any one of claims 1 to 5, wherein the insulating member is an insulating paper.
The motor according to any one of claims 1 to 8, wherein the crossing portion of the second bus bar straddles the first bus bar.