JP7803532B2 - Busbar Unit - Google Patents

Description

This invention relates to a busbar unit.

A busbar unit such as that described in Patent Document 1 is known as a conventional motor busbar unit. The motor busbar unit described in Patent Document 1 has U-phase, V-phase, and W-phase busbars connected to the motor's U-phase, V-phase, and W-phase coils, respectively.

JP 2009-219335 A

However, in the busbar unit for the motor described in Patent Document 1, the U-, V-, and W-phase busbars are formed to extend circumferentially around the motor from the U-, V-, and W-phase coils to connector portions that protrude to the side of the motor, which poses a problem in that the busbars occupy a large amount of space in the motor, preventing the motor from being made more compact.

This invention was made to solve these problems, and aims to provide a busbar unit that allows motors to be made smaller.

In order to solve the above-mentioned problems, the present invention provides a busbar unit that is provided in a rotating electric machine having a winding for each phase, the busbar unit including: an annular busbar holder; accommodation portions that are provided at intervals in the circumferential direction of the annular busbar holder and extend along the axial direction of the rotating electric machine; and busbars that are provided for each phase of the rotating electric machine and at least a portion of which is accommodated in the accommodation portions, the busbars having a winding connection portion formed at one end and connected to the winding; an external connection portion formed at the other end and connected to the outside of the rotating electric machine; and an external connection portion formed between the one end and the other end, which connects the winding to the outside of the rotating electric machine. The rotating electric machine has an intermediate portion extending along the axial direction of the rotating electric machine and an insertion portion connected to the external connection portion and facing the intermediate portion, the intermediate portion extending perpendicular to the external connection portion, the winding connection portion extending parallel to the external connection portion, the accommodating portion having a pair of side wall portions extending along the axial direction of the rotating electric machine, a pair of support portions spaced apart from the side wall portions and extending along the axial direction of the rotating electric machine, a gap portion provided between the side wall portions and the support portions, and a bending portion provided at one end of the support portions, the external connection portion being supported by the other end of the support portions, and the intermediate portion and the insertion portion being supported by the bending portions .

Also, at least two bus bars may be provided, and at least two of the bus bars may have the same shape.
The annular bus bar holder may also include a winding holding portion formed along the circumferential direction and configured to hold the winding connected to the winding connection portion.
The intermediate portion of the bus bar may be plate-shaped.
The intermediate portion of the bus bar may be columnar.
The winding connection portion of the bus bar may have a hook-shaped portion.

With the busbar unit according to this invention, the busbar provided in the rotating electric machine has a winding connection portion formed at one end and connected to the winding, an external connection portion formed at the other end and connected to the outside of the rotating electric machine, and an intermediate portion formed between the one and other ends and extending along the axial direction of the rotating electric machine, thereby enabling the motor to be made more compact.

1 is a perspective view of a motor according to a first embodiment of the present invention; FIG. 1 is a perspective view of a busbar unit according to a first embodiment of the present invention. FIG. 3 is a perspective view of the storage section shown in FIG. 2 . FIG. 3 is a perspective view of first to third bus bars shown in FIG. 2. FIG. 10 is a perspective view of a busbar unit according to a second embodiment of the present invention. FIG. 6 is a perspective view of the storage section shown in FIG. 5 . FIG. 6 is a perspective view of the first to third bus bars shown in FIG. 5 . FIG. 10 is a perspective view of first to third bus bars according to a third embodiment of the present invention. FIG. 10 is a perspective view of an annular bus bar holder according to a fourth embodiment of the present invention.

Embodiment 1.
A motor according to a first embodiment of the present invention will be described below with reference to the accompanying drawings.
1 is a perspective view of a motor according to the first embodiment. Motor 1, which constitutes a rotating electric machine, has a ring-shaped end plate 12 with a rotary shaft 11 protruding from the center of the upper part, and a cylindrical motor case 13 with end plate 12 attached to one end. End plate 12 constitutes the upper end of motor 1. Motor 1 also has three phases.

The upper parts of the external connection parts 31 provided on the upper parts of the first bus bar 30a, second bus bar 30b, and third bus bar 30c (described in detail below), and the upper part of the accommodation part 22, protrude from the upper side of the end plate 12 through through holes formed in the end plate 12.

Figure 2 is a perspective view of a busbar unit according to embodiment 1 of the present invention. The busbar unit 20 is provided directly below the end plate 12 of the motor 1 (see Figure 1). The busbar unit 20 has an annular busbar holder 21 made of resin. Three accommodating portions 22 are formed around the inner diameter portion 28a of the annular busbar holder 21, spaced apart circumferentially, and protrude upward along the axial direction of the rotating shaft 11 of the motor 1. Each accommodating portion 22 accommodates a first busbar 30a, a second busbar 30b, and a third busbar 30c, respectively. The first bus bar 30a is connected to a U-phase stator coil (not shown) housed inside the motor case 13 on the lower side of the bus bar unit 20, the second bus bar 30b is connected to a V-phase stator coil (not shown) housed inside the motor case 13 on the lower side of the bus bar unit 20, and the third bus bar 30c is connected to a W-phase stator coil (not shown) housed inside the motor case 13 on the lower side of the bus bar unit 20.

A horizontal portion 28b extending horizontally radially outward is provided at the lower end of the inner diameter portion 28a of the annular busbar holder 21. An outer diameter portion 28c extending upward along the axial direction is provided at the radially outermost portion of the horizontal portion. The inner diameter portion 28a, horizontal portion 28b, and outer diameter portion 28c form an annular groove 23 that is open at the top. A plurality of slits 24 extending along the axial direction are provided at circumferential intervals in the outer diameter portion 28c of the annular groove 23. The annular groove 23 forms a winding holding portion.

Figure 3 is a perspective view of the accommodating portion 22 shown in Figure 2. The accommodating portion 22 has two side wall portions 25 that protrude radially outward from the inner diameter portion 28a of the annular busbar holder 21 and extend along the axial direction, and two support portions 26 that are spaced apart from each side wall portion 25 and protrude radially outward and extend along the axial direction. A gap 27 is formed between the side wall portions 25 and the support portions 26. The support portions 26 have an upper end portion 26a and a bent portion 26b at their lower end that is bent toward the side wall portions 25. Note that while Figure 3 shows only one of the accommodating portions 22 of the busbar unit 20, the other accommodating portions 22 have the same shape.

Figure 4 is a perspective view of the first, second, and third bus bars 30a, 30b, and 30c shown in Figure 2. The first, second, and third bus bars 30a, 30b, and 30c are formed from bent copper plates. The first, second, and third bus bars 30a, 30b, and 30c each have an external connection portion 31 formed at the top and extending horizontally. The external connection portion 31 has a female screw hole 32. The first, second, and third bus bars 30a, 30b, and 30c each have an insertion portion 35 extending perpendicular to the external connection portion 31, an intermediate portion 33 facing the insertion portion 35 and extending perpendicular to the external connection portion 31, and a winding connection portion 34 extending horizontally from the lower end of the intermediate portion 33. In this embodiment, the first, second, and third bus bars 30a, 30b, and 30c are made of copper plates, but they may also be made of other materials, such as aluminum alloy plates, as long as they are plate-shaped conductors.

2, in the busbar unit 20, the insertion portions 35 (see FIG. 4) and intermediate portions 33 of the first, second, and third busbars 30a, 30b, and 30c are inserted into the gaps 27 (see FIG. 3) of the respective accommodation portions 22, the lower ends of the insertion portions 35 and intermediate portions 33 are supported by the respective bent portions 26b, and the external connection portions 31 are supported by the respective upper ends 26a, thereby accommodating the first, second, and third busbars 30a, 30b, and 30c in the respective accommodation portions 22 of the annular busbar holder 21. Note that the intermediate portions 33 extend along the axial direction of the motor 1, and the external connection portions 31 and winding connection portions 34 extend perpendicular to the axial direction of the motor 1. Furthermore, as a method for manufacturing the busbar unit 20 by accommodating the first, second, and third busbars 30a, 30b, and 30c in the respective accommodating portions 22 of the annular busbar holder 21, any method can be used, such as a method of integrally molding the busbar unit 20 in which the first, second, and third busbars 30a, 30b, and 30c are accommodated in the respective accommodating portions 22, or a method of inserting and assembling the first, second, and third busbars 30a, 30b, and 30c into the respective accommodating portions 22 of a pre-formed annular busbar holder 21.

The first, second, and third bus bars 30a, 30b, and 30c housed in each housing 22 are connected to electrical circuits external to the motor 1 (see FIG. 1), such as a control board for controlling the motor 1 or a rotation sensor for detecting the rotation of the motor 1, via unillustrated conductors screwed into female threaded holes 32 formed in the external connection portion 31. Furthermore, stator windings (not shown) provided for each phase of the motor 1 are joined by soldering or the like to the winding connection portions 34 of the first, second, and third bus bars 30a, 30b, and 30c housed in each housing 22. Furthermore, the stator windings (not shown) are housed and held in the annular groove portion 23, pass through the slit portion 24, and are wound around a stator core (not shown) inside the motor 1. In other words, the first, second, and third bus bars 30a, 30b, and 30c are bus bars that connect electrical circuits external to the motor 1 with the internal stator windings.

In the invention according to the first embodiment, the first, second, and third bus bars 30a, 30b, and 30c have the same shape, allowing for commonality. Furthermore, the first, second, and third bus bars 30a, 30b, and 30c have simpler shapes than bus bars of conventional technology, making it possible to reduce the number of parts and molds required for the motor 1, as well as the number of manufacturing steps for the motor 1, and thus reducing the manufacturing costs of the motor 1.

Furthermore, in the invention according to the first embodiment, the external connection portions 31 and winding connection portions 34 of the first, second, and third bus bars 30a, 30b, and 30c are integrally formed, and the intermediate portions 33 between the external connection portions 31 and the winding connection portions 34 extend along the axial direction of the motor 1. Therefore, compared to bus bars of the prior art that have intermediate portions that extend along the circumferential direction of the motor so as not to come into contact with each other, the first, second, and third bus bars 30a, 30b, and 30c have shorter intermediate portions 33, reducing the space occupied by the bus bars and enabling the motor 1 to be made more compact.

In addition, in the invention according to the first embodiment, the first, second, and third busbars 30a, 30b, and 30c are housed in the respective housing portions 22 of the annular busbar holder 21 in the busbar unit 20, making it possible to reduce the size of the busbar unit 20. Furthermore, the first, second, and third busbars 30a, 30b, and 30c are integrally molded with the annular busbar holder 21 in the busbar unit 20, making it possible to easily assemble the motor 1.

As such, the busbar unit according to the first embodiment is a busbar unit 20 provided in a motor 1 having a winding for each phase, and includes an annular busbar holder 21, housing portions 22 spaced apart circumferentially on the annular busbar holder 21 and extending along the axial direction of the motor 1, and first, second, and third busbars 30a, 30b, and 30c provided for each phase of the motor 1, at least a portion of which is housed in the housing portion 22. The first, second, and third busbars 30a, 30b, and 30c each have a winding connection portion 34 formed at one end and connected to the winding, an external connection portion 31 formed at the other end and connected to the outside of the motor 1, and an intermediate portion 33 formed between the one end and the other end and extending along the axial direction of the motor 1, thereby enabling the motor to be made more compact.

In addition, the motor 1 is provided with three bus bars (first, second, and third bus bars 30a, 30b, and 30c), all of which have the same shape, which reduces the manufacturing cost of the motor 1.

In addition, the annular busbar holder 21 is formed along the circumferential direction and has an annular groove portion 23 that holds the winding connected to the winding connection portion 34, making it easy to route the winding and facilitating the manufacture of the motor 1.

In addition, because the intermediate portions 33 of the first, second, and third bus bars 30a, 30b, and 30c are plate-shaped, the first, second, and third bus bars 30a, 30b, and 30c can be formed inexpensively and lightweight by bending.

Embodiment 2.
Next, a busbar unit according to a second embodiment of the present invention will be described with reference to the accompanying drawings. In the following embodiments, the same reference numerals as those in Figures 1 to 4 of the first embodiment denote the same or similar components, and detailed description thereof will be omitted. The busbar unit according to the second embodiment is different from the first embodiment in that the shapes of the busbar unit and busbars are modified.

Figure 5 is a perspective view of a busbar unit 20a according to the second embodiment. Cylindrical housing portions 22a extending along the axial direction of the motor 1 (see Figure 1) are arranged around the inner diameter portion 28a of the busbar unit 20a at intervals in the circumferential direction. The housing portions 22a house a first busbar 40a, a second busbar 40b, and a third busbar 40c.

Figure 6 is a perspective view of the accommodating section 22a shown in Figure 5. The accommodating section 22a has two side walls 25 that protrude radially outward from the inner diameter portion 28a of the annular bus bar holder 21 and extend along the axial direction. Each side wall 25 is connected to an inner wall 25b that extends along the axial direction on the radially inner side. The accommodating section 22a also has an outer wall 25a that extends along the axial direction on the radially outer side, partially facing the inner wall 25b. The outer wall 25a has a curved portion at its end and is connected to each side wall 25 via this curved portion. The accommodating section 22a is cylindrically formed by the outer wall 25a, inner wall 25b, and side wall 25, and has an inner wall 25c on the inside. Note that Figure 6 shows only one of the accommodating sections 22a, but the other accommodating sections 22a have the same shape.

Figure 7 is a perspective view of the first to third bus bars shown in Figure 5. The first, second, and third bus bars 40a, 40b, and 40c are formed into a columnar shape by cutting copper material. The first, second, and third bus bars 40a, 40b, and 40c each have an external connection portion 41 formed at their top and extending horizontally. A female screw hole 42 is formed in the external connection portion 41. The first, second, and third bus bars 40a, 40b, and 40c each have a columnar intermediate portion 43 extending downward from the external connection portion 41 and a winding connection portion 44 formed at their bottom end and protruding horizontally. The outer periphery of the intermediate portion 43 of each of the first, second, and third bus bars 40a, 40b, and 40c is configured to fit into the inner wall portion 25c of each accommodation portion 22a of the annular bus bar holder 21b (see Figure 6). In the second embodiment, the first, second, and third bus bars 40a, 40b, and 40c are formed by cutting copper material, but they may also be formed by cutting other types of conductors, such as aluminum alloys, or by any other method, such as casting.

Referring again to Figure 5, in the busbar unit 20a, the intermediate portions 43 of the first, second and third busbars 40a, 40b and 40c are inserted into the respective accommodating portions 22a of the annular busbar holder 21a, thereby accommodating the first, second and third busbars 40a, 40b and 40c in the respective accommodating portions 22a. Note that the busbar unit 20a can be manufactured by accommodating the first, second, and third busbars 40a, 40b, and 40c in the respective accommodating portions 22a of the annular busbar holder 21a using any method, such as integrally molding the busbar unit 20a in which the first, second, and third busbars 40a, 40b, and 40c are accommodated in the respective accommodating portions 22a of the annular busbar holder 21a, or by inserting and assembling the first, second, and third busbars 40a, 40b, and 40c into the respective accommodating portions 22a of a pre-formed annular busbar holder 21a. The remaining configuration is the same as in embodiment 1.

The busbar unit 20a according to the second embodiment has the same effects as the busbar unit 20 according to the first embodiment, and in addition, because the first, second, and third busbars 40a, 40b, and 40c are formed by cutting, the strength of the first, second, and third busbars 40a, 40b, and 40c can be improved.

In this way, the intermediate portions 43 of the first, second, and third bus bars 40a, 40b, and 40c are columnar, thereby improving the strength of the first, second, and third bus bars 40a, 40b, and 40c.

Embodiment 3.
Next, a busbar unit according to a third embodiment of the present invention will be described with reference to the accompanying drawings. The busbar unit according to the third embodiment differs from the busbar unit according to the first embodiment in that the shape of the busbars is changed.

Figure 8 is a perspective view of the first to third bus bars according to the third embodiment. The first, second, and third bus bars 50a, 50b, and 50c are formed by bending copper plates. The first, second, and third bus bars 50a, 50b, and 50c each have an external connection portion 51 formed at the top and extending horizontally. A female screw hole 52 is formed in the external connection portion 51. The first, second, and third bus bars 50a, 50b, and 50c each have an intermediate portion 53 extending downward from the external connection portion 51 and a winding connection portion 54 formed below the intermediate portion 53 and protruding horizontally. This winding connection portion 54 protrudes radially outward from the bus bar unit 20 (see Figure 2) and forms a hook-shaped portion that opens radially inward. The rest of the configuration is the same as in the first embodiment.

As such, the winding connection portions 54 of the first, second, and third bus bars 50a, 50b, and 50c have hook-shaped portions, making it easy to connect the stator winding to the winding connection portions 54.

In this embodiment, the first, second, and third bus bars 50a, 50b, and 50c are formed by bending copper plates, but they may also be formed by bending other types of conductors, such as aluminum alloy plates. Furthermore, as long as the winding connection portion 54 forms a hook-shaped portion, the intermediate portion 53 may be a columnar member (see Figure 7) as in embodiment 2.

Embodiment 4.
Next, a busbar unit according to a fourth embodiment of the present invention will be described with reference to the accompanying drawings. The busbar unit according to the fourth embodiment differs from the busbar unit according to the second embodiment in that the shape of the annular busbar holder is modified. In the fourth embodiment, the same reference numerals as those in Figures 5 to 7 of the second embodiment indicate the same or similar components, and detailed description thereof will be omitted.
The annular bus bar holder 21b has an annular edge portion 23b connected to the inner diameter portion 28a and extending horizontally. The annular edge portion 23b is characterized in that it does not have an outer diameter portion 28c that defines the shape of the annular groove portion 23 (see FIG. 2) of the second embodiment. The other configurations are the same as those of the second embodiment.

In this way, by having the annular edge portion 23b on the annular busbar holder 21b, the annular busbar holder 21b can hold the windings with a simpler configuration.

The configuration of the annular busbar holder 21b having the annular edge portion 23b according to embodiment 4 of the present invention can be used in appropriate combination with the accommodating portion 22 of the annular busbar holder 21 according to embodiment 1 of the present invention.

Furthermore, in embodiments 1 to 4 of the present invention, motor 1 is a three-phase motor and is provided with three first, second, and third bus bars 30a, 30b, and 30c and three housings 22, 22a, but this is not limited to this, and the number of motor phases, the number of bus bars, and the number of housings may be changed as needed.

The busbar unit according to the first embodiment is a busbar unit (20) provided in a motor (1) having windings for each phase. The busbar unit (20) includes an annular busbar holder (21), housing portions (22) spaced apart circumferentially around the annular busbar holder (21) and extending along the axial direction of the motor (1), and first, second, and third busbars (30a, 30b, 30c) provided for each phase of the motor (1), at least a portion of which is housed in the housing portion (22). The first, second, and third busbars (30a, 30b, 30c) each have a winding connection portion (34) formed at one end and connected to the winding, an external connection portion (31) formed at the other end and connected to the outside of the motor (1), and an intermediate portion (33) formed between the one end and the other end and extending along the axial direction of the motor (1). This allows the length of the busbar to be shortened, making the busbar suitable for use in small motors.

20 Busbar unit 21 Annular busbar holder 21a Annular busbar holder 21b Annular busbar holder 22 Receiving portion 22a Receiving portion 23 Annular groove portion (winding holding portion)
23b Annular edge portion (winding holding portion)
30a First bus bar 30b Second bus bar 30c Third bus bar 31 External connection portion 33 Intermediate portion 34 Winding connection portion 40a First bus bar 40b Second bus bar 40c Third bus bar 41 External connection portion 43 Intermediate portion 44 Winding connection portion 50a First bus bar 50b Second bus bar 50c Third bus bar 51 External connection portion 53 Intermediate portion 54 Winding connection portion

Claims (4)

A busbar unit (20) provided in a rotating electric machine (1) having a winding for each phase,
An annular busbar holder (21);
a housing portion (22) provided at intervals in the circumferential direction of the annular bus bar holder (21) and extending along the axial direction of the rotating electric machine (1);
bus bars (30a, 30b, 30c) provided for each of the phases of the rotating electric machine (1), at least a portion of which is accommodated in the accommodation portion (22);
The bus bars (30a, 30b, 30c) are
a winding connection portion (34) formed at one end and connected to the winding;
an external connection portion (31) formed at the other end and connected to the outside of the rotating electric machine (1);
an intermediate portion (33) formed between the one end portion and the other end portion and extending along the axial direction of the rotating electric machine (1);
an insertion portion (35) connected to the external connection portion (31) and facing the intermediate portion (33);
and
The intermediate portion (33) extends in a direction perpendicular to the external connection portion (31), and the winding connection portion (34) extends in a direction parallel to the external connection portion (31);
The storage section (22) is
a pair of side wall portions (25) extending along the axial direction of the rotating electric machine (1);
a pair of support portions (26) spaced apart from the side wall portions (25) and extending along the axial direction of the rotating electric machine (1);
a gap (27) provided between the side wall portion (25) and the support portion (26);
A bending portion (26b) is provided at one end of the support portion (26),
The external connection portion (31) is supported by the other end of the support portion (26),
The busbar unit , wherein the intermediate portion (33) and the insertion portion (35) are supported by the bent portion (26b) . The busbar unit according to claim 1, comprising at least two busbars (30a, 30b, 30c), each of which has at least two identical shapes. A busbar unit as described in claim 1 or 2, wherein the annular busbar holder (21) is provided with a winding holding portion (23) formed along the circumferential direction and holding the winding connected to the winding connection portion (34). A busbar unit according to claim 1 or 2, wherein the intermediate portion (33) of the busbar (30a, 30b, 30c) is plate-shaped.