Patent Application
20220416615
The present invention relates to a bus bar and a motor.
There is known a bus bar that relays electrical connection between a coil of a motor and an external terminal.
For example, a conventional bus ring (bus bar) has a ring body and a plate-like piece. The ring body has a plate-like shape included in a plane orthogonal to an axial direction of the ring body. The plate-like piece is formed by being bent from one circumferential end of the ring body in a direction along the axial direction of the ring body. The ring body includes a terminal part that extends radially outward of the ring body and is to be connected to a coil terminal of the motor. The plate-like piece is connected at its leading end portion to a control circuit as an external terminal using a connection terminal of a coupler.
To reduce manufacturing cost of the bus bar, members constituting the bus bar are preferably shared by being standardized in thickness, material, and the like. Unfortunately, for example, an external terminal such as a control circuit or an external power supply is supplied from a user in many cases. In this case, the user may designate thickness, material, and the like of a connection portion of the bus bar to the external terminal.
When the connection portion to the external terminal is changed in thickness, material, and the like according to a specification, the members of the bus bar cannot be shared. As a result, reduction of the manufacturing cost of the bus bar is hindered.
A bus bar according to an exemplary embodiment of the invention of the present application is used for a motor, the bus bar including: a motor connection member that is electrically connected to a coil provided in the motor; and a terminal member that is formed of a separate member from the motor connection member and is electrically connected to an external terminal, the motor connection member including a body portion electrically connected to the coil, and a bent portion bent at a first end portion of the body portion in a direction intersecting the body portion, and the terminal member being connected to the bent portion.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The following description of a preferable embodiment is merely exemplary in nature and is not intended to limit the present invention, its application product, or its use.
Hereinafter, a central axis of a motor 1 is indicated as J, and a direction parallel to the central axis J is referred to as an “axial direction”. A radial direction centered on the central axis J is referred to as a “radial direction”, and a direction around the central axis J is referred to as a “circumferential direction”.
As illustrated in
The stator 4 is disposed radially outside the rotor 3. The shaft 2, the rotor 3, and the stator 4 are accommodated in a housing 20. The housing 20 has a bottom portion 23 and a wall portion 21 extending axially from the bottom portion 23. The housing 20 has, for example, a bottomed substantially cylindrical shape. The housing 20 has an opening 22 on the one axial side. The opening 22 is covered with a bracket (not illustrated). The stator 4 is fitted to an inner wall surface 21a of the wall portion 21 of the housing 20.
The motor 1 includes a first bearing 5 and a second bearing 6 that rotatably support the shaft 2. Specifically, the motor 1 includes the first bearing 5 located on the other axial side with respect to the stator 4, and a second bearing 6 located on the one axial side with respect to the stator 4. The first bearing 5 is held by the housing 20. Specifically, the first bearing 5 is held by a holding portion 23a provided on the bottom portion 23. The second bearing 6 is held by a bearing holder 7 fixed to the housing 20 on the one axial side with respect to the stator 4. The bearing holder 7 is fitted to an inner wall surface 21a of the housing 20.
The stator 4 is formed by stacking metal plates such as electromagnetic steel plates. The stator 4 includes a core back 4a extending in the circumferential direction, and a plurality of teeth 4b extending radially inward from an inner peripheral surface of the core back 4a and arranged in the circumferential direction over the entire circumference of stator 4. In the present embodiment, the stator 4 includes twelve teeth 4b. The stator 4 is provided with an insulator 8. The insulator 8 is made of insulative resin, and configured to cover both axial end surfaces and both circumferential end surfaces of each of the teeth 4b. Each of the teeth 4b is wound with conductive wire 9 with the insulator 8 interposed therebetween to form a coil 10. The motor 1 includes twelve coils 10 arranged in the circumferential direction over the entire circumference of the motor 1.
The motor 1 includes a bus bar holder 70 and a bus bar 30 accommodated in the bus bar holder 70 on the one axial side with respect to the stator 4 and on the other axial side with respect to the bearing holder 7. Details of the bus bar 30 and the bus bar holder 70 will be described later.
As conceptually illustrated in
As illustrated in
As illustrated in
As illustrated in
Details of the bus bar 30 used for the motor 1 will be described with reference to
As illustrated in
As illustrated in
Such structure allows the body portion 41 to extend in an arc shape, so that each motor connection member 40 can be disposed along the circumferential direction of the motor 1. Then, the coils 10 are arranged along the circumferential direction of the motor 1. That is, the motor connection members 40 can be disposed along a direction in which the coils 10 are arranged, so that the conductive wire 9 extending from each coil 10 can be connected to each motor connection member 40 while being reduced in extension as much as possible.
The bent portion 42 is bent at a first end portion 41a of the body portion 41 in a direction intersecting with an extending direction of the body portion 41, specifically, in a direction orthogonal to the extending direction. Each motor connection member 40 is disposed such that a central axis of the arc shape of the body portion 41 is concentric with the central axis J of the motor 1. That is, the body portion 41 extends in the circumferential direction along a plane A orthogonal to the axial direction of the motor 1. The bent portion 42 is bent in the axial direction of the motor 1. In the present embodiment, the body portion 41 of each motor connection member 40 has a thickness direction coinciding with the axial direction of the motor 1. That is, each motor connection member 40 is disposed in so-called horizontal placement (hereinafter, referred to as horizontally placed).
According to such structure, when the motor connection member 40 formed of the plate-like member is horizontally placed, the body portion 41 extends along the plane A orthogonal to the axial direction, and the bent portion 42 is bent in the axial direction instead of the radial direction. This enables preventing the bus bar 30 from enlarging in the radial direction.
Each motor connection member 40 includes two coil connection terminals 44 that are each provided radially outside an outer peripheral portion 41c of the body portion 41 with a connection portion 43 in a substantially L-shape. The two coil connection terminals 44 are arranged at an interval in the circumferential direction.
The two coil connection terminals 44 provided in the body portion 41 of each motor connection member 40 are electrically connected to the coil 10 provided in the motor 1. Specifically, as illustrated in
The body portion 41 of each motor connection member 40 is provided with a plurality of holes 45. These holes 45 are used for inserting an instrument (not illustrated) for positioning each motor connection member 40 in the bus bar holder 70.
Each terminal member 50 is formed of a member that is separate from each motor connection member 40, and that is in a plate-like shape made of a conductive metal material such as copper. Each terminal member 50 includes a first extending portion 51 and a second extending portion 52 intersecting with each other. In the present embodiment, each terminal member 50 has a substantially L shape in which the first extending portion 51 and the second extending portion 52 are orthogonal to each other.
The first extending portion 51 includes an end portion 51a that is connected to a first surface 42a of the bent portion 42 facing the body portion 41 by resistance welding, for example. The first extending portion 51 extends radially outward from the end portion 51a and is connected to the second extending portion 52. The second extending portion 52 extends in the axial direction. The second extending portion 52 includes an end portion 52a that is connected to a connection terminal 91 of the external terminal 90. The connection terminal 91 is connected to a surface 50b of the end portion 52a of the second extending portion 52, the surface 50b being opposite to a surface 50a facing the body portion 41. Thus, respective terminal members 50 are electrically connected to the motor connection members 40 and external terminals 90. The term, a “surface facing the body portion”, refers to a surface located on a side close to the body portion 41 with respect to a direction in which the bent portion 42 is bent (direction in which the bent portion 42 extends), and does not necessarily face the body portion 41. The term, a “surface opposite to the surface facing the body portion” refers to a back surface with respect to the “surface facing the body portion”.
The terminal member 50 and the motor connection member 40 are welded as follows, for example. As illustrated in
According to such structure, as illustrated in
As illustrated in
The neutral point member 60 includes six coil connection terminals 63 that are each provided on radially outside an outer peripheral portion 61a of the body portion 61 with a connection portion 62 in a substantially L-shape. The six coil connection terminals 63 are arranged at intervals in the circumferential direction.
The neutral point member 60 is electrically connected to each of the coils 10 provided in the motor 1 to constitute a neutral point. Specifically, as illustrated in
Such structure enables the neutral point N to be formed only by connecting the U-phase, V-phase, and W-phase coils to the neutral point member 60, and thus the structure is simple.
As illustrated in
Such structure enables preventing the bus bar 30 from enlarging as compared with when the motor connection members 40 are arranged in a width direction of the body portion 41. In particular, when the thickness direction of the body portion 41 coincides with the axial direction of the motor 1, the motor connection members 40 can be disposed overlapping each other in the axial direction being the thickness direction of the body portion 41. This enables preventing the bus bar 30 from enlarging in the radial direction as compared with when the motor connection members 40 are arranged in the radial direction being the width direction of the body portion 41. This also enables the coil connection terminals 44 of the motor connection members 40 to be aligned with each other in the radial direction.
The neutral point member 60 is disposed overlapping the motor connection member 40V from the one axial side. The neutral point member 60 includes a portion partially overlapping the motor connection member 40V in the circumferential direction.
The motor connection members 40U, 40V, and 40W are each disposed having the body portion 41 extending in the same direction. Specifically, as illustrated in
Such structure enables the terminal members 50U, 50V, and 50W provided close to the first end portion 41a to be collectively disposed at one place. This enables welding work between external terminals 90 and the respective terminal members 50 to be collectively performed at the one place, so that the welding work is facilitated.
As illustrated in
The connecting portion 72 extends toward the one axial side from the body portion 71 and holds the three terminal members 50U, 50V, and 50W. Connecting portions 72U, 72V, and 72W are configured to cover rising portions of the terminal members 50U, 50V, and 50W, respectively. That is, the connecting portion 72 is configured to cover at least a connection portion between the terminal member 50 and the motor connection member 40. The connecting portions 72U, 72V, and 72W are connected in the circumferential direction. Providing the connecting portion 72 enables reducing positional deviation of the terminal member 50. Although in the present embodiment, the connecting portion 72 is provided at one place, it may be provided at two or more places depending on structure of the bus bar 30.
The three leg portions 73 are disposed at substantially equal intervals in the circumferential direction of the body portion 71. Each leg portion 73 protrudes radially outward from the coil connection terminals 44 and 63 and is supported on an outer peripheral side of the stator 4 as illustrated in
As described above, the motor 1 includes the bus bar 30 in the present embodiment. The bus bar 30 includes the motor connection member 40 electrically connected to the coil 10 provided in the motor 1, and the terminal member 50 that is formed of a separate member from the motor connection member 40 and is electrically connected to the external terminal 90. The motor connection member 40 includes the body portion 41 electrically connected to the coil 10, and the bent portion 42 that is bent at the first end portion 41a of the body portion 41 in a direction intersecting with the body portion 41. The terminal member 50 is connected to the bent portion 42.
Such structure enables the terminal member 50 to use a member selected each time according to specifications. In contrast, the motor connection member 40 can use an identical common member regardless of specifications. That is, the motor connection member 40 can be standardized and mass-produced. Thus, the connection portion to the external terminal 90 (connection terminal 91) can be flexibly changed in thickness, material, and the like according to specifications, and manufacturing cost can be reduced by sharing members.
The bent portion 42 is provided in the motor connection member 40 that is standardized and mass-produced instead of the terminal member 50 for which thickness, material, and the like are selected each time according to specifications. This enables a bending process of the member to be incorporated in a mass production process of the motor connection member 40, so that the manufacturing cost can be further reduced.
Typically, the terminal member 50, which is a connection portion to the external terminal 90, is often made of a more expensive material than the motor connection member 40. When the bent portion 42 is provided in the motor connection member 40, a dimension L of the terminal member 50 can be reduced accordingly. This enables reducing use of an expensive material and manufacturing cost.
When the bus bar 30 according to the present embodiment is applied to the motor 1, the manufacturing cost of the bus bar 30 is reduced, and thus accordingly manufacturing cost of the entire motor 1 can be reduced.
In the present embodiment, the terminal member 50 and the motor connection member 40 are different in thickness and material. The neutral point member 60 and the motor connection member 40 are identical in thickness and material. The neutral point member 60 and the terminal member 50 are different in thickness and material. That is, the terminal member 50 is different in thickness from the motor connection member 40 and the neutral point member 60. The terminal member 50 is different in material from the motor connection member 40 and the neutral point member 60. For example, a plate material made of tough pitch copper (C1100) and having a thickness of 1.0 mm may be used for each motor connection member 40 and the neutral point member 60. In contrast, a plate material made of a Cu—Fe-based alloy (C19400) and having a thickness of 0.8 mm may be used for the terminal member 50.
According to such structure, the motor connection member 40 and the terminal member 50 are different in thickness, so that the terminal member 50, which is a connection portion to the external terminal 90, can be flexibly changed in thickness according to specifications while the manufacturing cost is reduced by standardizing thickness of the motor connection member 40.
When the motor connection member 40 and the terminal member 50 are each made of a different material, effect as with that described above can be obtained.
The neutral point member 60 and the motor connection member 40 each having an identical thickness enables manufacturing using the same member, so that manufacturing cost can be reduced. Additionally, welded portions of the neutral point member 60 and the motor connection member 40 to the conducting wire 9 (coil 10) are identical in thickness, so that welding workability is improved.
Even when the neutral point member 60 and the motor connection member 40 are made of the same material, effect as with that described above can be obtained.
The combination of thickness and material described above is merely an example, and other combinations may be applied. For example, the terminal member 50 and the motor connection member 40 may be identical in at least one of thickness and material. The neutral point member 60 and the motor connection member 40 may be different in at least one of thickness and material. The neutral point member 60 and the terminal member 50 may be identical in at least one of thickness and material. Members identical in thickness and material may be used for all the members.
As described above, each motor connection member 40 is formed by bending one plate-like member in a shape in which the bent portion 42 intersects the body portion 41. Thus, a spring back force F allowing the motor connection member 40 to return to an original shape before being bent acts on the motor connection member 40. The spring back force F acts on a direction from a side close to the body portion toward a side far from the body portion 41 with reference to a direction in which the bent portion 42 is bent (a direction in which the bent portion 42 extends). That is, the direction of the spring back force F is counterclockwise from the second end portion 41b to the first end portion 41a as viewed from the one axial side. Then, when the terminal member 50 is connected to the second surface 42b of the bent portion 42 as in the present modification, the terminal member 50 resists the spring back force F allowing the bent portion 42 to return to an original attitude. That is, the bent portion 42 is prevented from returning to the original attitude before being bent. This causes the bent portion 42 to be less likely to be displaced as compared with when each terminal member 50 is connected to the first surface 42a of the bent portion 42 (see
Although the present invention has been described above with reference to the preferable embodiment, such description is not a limitation, and thus various modifications can be made. In the present embodiment, the bent portion 42 is bent in the direction orthogonal to the extending direction of the body portion 41, but is not limited thereto, and may be bent at an acute angle or an obtuse angle, for example, as long as it is bent in an intersecting direction.
Each motor connection member 40 may be disposed in so-called vertical placement in which the body portion 41 has a width direction coinciding with the axial direction of the motor 1.
Each motor connection member 40 may include a body portion 41 that extends in a linear shape, an L shape, or an S shape, for example, instead of extending in an arc shape.
Each motor connection member 40 may extend in an opposite direction. In this case, the terminal members 50U, 50V, and 50W are dispersedly disposed at a plurality of places.
The motor connection members 40 may be arranged along the plane A instead of being disposed overlapping each other in the axial direction.
Each motor connection member 40 is not limited to a plate-like shape and may have any shape such as a rod-like shape as long as it includes the bent portion 42 bent at the first end portion 41a of the body portion 41 in the direction intersecting with the body portion 41. Similarly, each terminal member 50 and the neutral point member 60 are not limited to a plate-like shape, and may have any shape such as a rod-like shape.
The motor 1 is not limited to a three-phase motor, and may be, for example, a single-phase motor or a multiphase motor.
The structure in the present embodiment and the modification may be appropriately combined as long as they do not contradict each other.
Application of the motor 1 of the present embodiment is not particularly limited, and the motor 1 can be used as, for example, a motor for an automobile, an industrial, or a home appliance. The motor 1 of the present embodiment can be preferably used for an electric vehicle (EV) drive motor, a hybrid electric vehicle (HEV) drive motor, and the like.
Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.
While preferred embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-120776 | Jun 2019 | JP | national |
This is the U.S. national stage of application No. PCT/JP2020/021083, filed on May 28, 2020, and priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Patent Application No. 2019-120776, filed on Jun. 28, 2019.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2020/021083 | 5/28/2020 | WO |
