Motor busbar assembly and motor

Abstract

The utility model provides a motor busbar assembly and a motor. The motor busbar assembly comprises a bolt, a nut, a first bus and a second bus. The bolt comprises a head part, a flange part and a screw rod. A screw is inserted through the first bus bar and the second bus bar and threadably coupled with the nut such that the first bus bar and the second bus bar are relatively fixed. The flange portion has a first surface facing the first bus bar and a second surface facing away from the first bus bar. At least a portion of the first surface is pressed against the first bus bar. The second surface is formed with a circumferential groove. The diameter of the outer periphery of the circumferential groove is smaller than the outer diameter of the flange part, and the diameter of the inner periphery of the circumferential groove is larger than the outer diameter of the screw and the outer diameter of the head. In this way, the possibility that metal chips are generated in the process of connecting the bus of the motor control unit and the bus of the motor stator through bolts can be greatly reduced or even eliminated, and therefore the motor can basically avoid the high-voltage breakdown phenomenon caused by the metal chips generated in the process of connecting the buses through the bolts.

Description

Technical Field

[0001] This application relates to the field of electric motors, and particularly to an electric motor bus assembly and an electric motor including the electric motor bus assembly. Background Technology

[0002] Today, electric motors can function as generators to output torque and power, and they can also act as generators to charge batteries. Therefore, electric motors can be used in the power systems of pure electric vehicles or hybrid vehicles. Typically, an electric motor includes a motor housing, a motor rotor, a motor stator, and a motor control unit (PEU). The motor stator is fixed to the motor housing, and the motor rotor can rotate relative to the motor stator to output torque. The motor control unit is used to control the operation of the motor, including the power control of the motor stator.

[0003] To achieve the control function of the motor control unit, the busbars of the motor control unit and the stator of the motor are connected to each other for electrical connection. Taking Korean patent application KR2020100002038U, entitled "Busbar Connection Device," as an example, these two busbars are typically fixed together using bolts and nuts passing through them. In the bolt and nut configuration, where the bolts are so-called flange bolts, during the initial tightening process, the outer periphery of the flange portion of the bolt first contacts the surface of the busbar. Then, during further tightening, the force generated between the bolt and the busbar is concentrated primarily at the part of the busbar in contact with the aforementioned outer periphery for a period of time. This may cause material peeling off from the busbar, resulting in metal debris such as copper shavings. These metal debris may reduce the safety clearance between multiple busbars of the motor control unit and multiple busbars of the motor stator, potentially leading to high-voltage breakdown. Utility Model Content

[0004] This application is made in view of the aforementioned state of the prior art. One object of this application is to provide a motor bus assembly that can significantly reduce or even eliminate the possibility of metal debris being generated during the process of connecting the busbars of the motor control unit and the busbars of the motor stator by bolts.

[0005] Another objective of this application is to provide a motor including the above-described motor bus assembly, which can substantially avoid high-voltage breakdown caused by metal debris generated during the bolted connection of the busbar.

[0006] To achieve the above objectives, the present application may adopt the following technical solutions.

[0007] This application provides a motor bus assembly including a bolt, a nut, a first busbar, and a second busbar. The bolt includes a head, a flange, and a threaded rod that are fixed to each other. The head and the threaded rod are located on opposite sides of the flange in the axial direction of the bolt. The flange extends radially outward relative to the head and the threaded rod. The threaded rod is inserted through the first busbar and the second busbar and threadedly connected to the nut, such that the first busbar and the second busbar are clamped between the flange and the nut and fixed relative to each other in the axial direction.

[0008] The flange portion has a first surface facing the first busbar and a second surface facing away from the first busbar. At least a portion of the first surface, including its outer periphery, presses against the first busbar. The second surface has an annular circumferential groove that extends continuously along the circumference of the bolt. The diameter of the outer periphery of the circumferential groove is smaller than the outer diameter of the flange portion, and the diameter of the inner periphery of the circumferential groove is larger than the outer diameter of the screw and the outer diameter of the head.

[0009] In one alternative, the shape and size of the circumferential groove remain constant in all sections containing the central axis of the bolt.

[0010] In another alternative embodiment, the outline of the circumferential groove in the cross-section is an arc.

[0011] In another alternative embodiment, when the bolt is in its unassembled initial state, in all sections containing the central axis of the bolt, the outline of the first face extends radially outward while extending obliquely relative to the axial direction toward the side where the screw is located.

[0012] In another alternative embodiment, when the bolt is in its unassembled initial state, in all sections containing the central axis of the bolt, the outline of the second face extends radially outward while extending obliquely relative to the axial direction toward the side where the screw is located.

[0013] In another alternative embodiment, when the bolt is in the assembled state, the first surface presses against the surface of the first busbar.

[0014] The angle α between the portion of the first face spaced apart from the surface and the surface satisfies 1.5 degrees ≥ α ≥ 0.5 degrees, and

[0015] The included angle b between the second surface and the surface satisfies 20 degrees ≥ b ≥ 10 degrees.

[0016] In another alternative embodiment, the first busbar includes a flat first connecting portion, and the second busbar includes a flat second connecting portion, with the first connecting portion and the second connecting portion stacked in the axial direction.

[0017] In another alternative embodiment, the first connecting portion has a first connecting hole through which the screw is inserted, the inner diameter of the first connecting hole being larger than the outer diameter of the screw; and

[0018] The second connecting portion has a second connecting hole through which the screw is inserted, and the inner diameter of the second connecting hole is larger than the outer diameter of the screw.

[0019] This application also provides an electric motor, including the motor bus assembly described in any of the above technical solutions.

[0020] In one alternative embodiment, the first busbar of the motor busbar assembly is the busbar of the motor controller, and the second busbar of the motor busbar assembly is the busbar of the motor stator.

[0021] By adopting the above technical solution, this application provides a motor bus assembly. The motor bus assembly includes bolts, nuts, a first busbar, and a second busbar assembled together. Specifically, the bolt includes a head, a flange, and a threaded rod that are fixed to each other. The head and the threaded rod are located on either side of the flange in the axial direction of the bolt, and the flange protrudes radially outward relative to the head and the threaded rod. The threaded rod is inserted through the first and second busbars and threadedly connected to the nut, such that the first and second busbars are clamped between the flange and the nut and fixed relative to each other in the axial direction. Further, the flange has a first surface facing the first busbar and a second surface facing away from the first busbar. At least a portion of the first surface, including its outer periphery, presses against the first busbar. The second surface has an annular circumferential groove that extends continuously along the circumference of the bolt. Furthermore, the diameter of the outer periphery of the circumferential groove is smaller than the outer diameter of the flange, and the diameter of the inner periphery of the circumferential groove is larger than the outer diameter of the threaded rod and the outer diameter of the head.

[0022] Thus, because a circular circumferential groove is formed on the second surface of the bolt facing away from the busbar, the force generated between the bolt and the busbar during bolt tightening is initially concentrated at the contact point where the busbar contacts the outer periphery of the first surface of the flange. However, because the part with the circumferential groove has lower rigidity and is more prone to deformation, the stress at the contact point can be reduced and alleviated. Therefore, the stress at the contact point is less likely to exceed the maximum allowable stress of the busbar, thereby significantly reducing or even eliminating the possibility of metal debris being generated during the bolted connection between the busbar of the motor control unit and the busbar of the motor stator.

[0023] Furthermore, this application also provides a motor including a motor bus assembly. Since the aforementioned motor bus assembly can significantly reduce or even eliminate the possibility of metal debris being generated during the process of bolting the busbars of the motor control unit to the busbars of the motor stator, this motor can essentially avoid high-voltage breakdown caused by metal debris generated during the bolted busbar connection process. Attached Figure Description

[0024] Figure 1 This is a perspective view of an electric motor according to an embodiment of the present application.

[0025] Figure 2 It shows Figure 1 The diagram shows an enlarged view of a portion of the motor's structure, with the motor bus assembly being the main focus.

[0026] Figure 3 It shows along Figure 2 The diagram shows a cross-sectional view taken by line SS, where the section lines are omitted.

[0027] Figure 4 It shows Figure 3 An enlarged schematic diagram of region M in the diagram.

[0028] Figure 5 It shows Figure 2 A three-dimensional schematic diagram of the bolts of the motor busbar assembly.

[0029] Explanation of reference numerals in the attached figures

[0030] BA motor bus assembly;

[0031] 1 Bolt; 11 Head; 12 Flange; 12s1 First face; 12s2 Second face; 12c Circumferential groove; 13 Threaded rod;

[0032] 2 nuts;

[0033] 3 First busbar; 31 First connecting part; 31h First connecting hole;

[0034] 4. Second busbar; 41. Second connecting part; 41h. Second connecting hole;

[0035] A is axial; R is radial;

[0036] MH motor housing Detailed Implementation

[0037] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaust all possible methods of this application, nor to limit the scope of this application.

[0038] In this application, unless otherwise specified, "axial," "radial," and "circumferential" refer to the axial, radial, and circumferential directions of the bolts in the motor busbar assembly, respectively. "One side of the axial direction" refers to... Figure 3 and Figure 4 The upper side, that is, the side where the bolt head is located; "the other side axially" refers to... Figure 3 and Figure 4 The lower side, that is, the side where the bolt shank is located. "Radially outer" refers to the side that is radially away from the bolt's central axis, while "radially inner" refers to the side that is radially closer to the bolt's central axis.

[0039] The structure of a motor, and in particular a motor bus assembly, according to an embodiment of this application will be described below with reference to the accompanying drawings.

[0040] According to one embodiment of this application, the motor is a multi-phase AC motor (e.g., a three-phase AC motor). Reference Figure 1 and Figure 2 The motor includes a motor housing MH, a motor stator (not shown), a motor rotor (not shown), a motor control unit (not shown), and a motor bus assembly BA, all assembled together. The motor housing MH supports and protects the other components. The motor stator and motor control unit are fixedly mounted to the motor housing MH, and the motor rotor is rotatable relative to the motor stator. The motor bus assembly BA is fixedly mounted to the motor housing MH and provides a stable electrical connection between the motor stator and the motor control unit.

[0041] like Figures 2 to 4 As shown, the motor bus assembly BA includes bolts 1, nuts 2, a first busbar 3, and a second busbar 4 assembled together.

[0042] In this embodiment, as Figures 2 to 5 As shown, bolt 1 is a so-called flange bolt, and bolt 1 is integrally formed as a rotating body with a central axis. Specifically, bolt 1 includes a head 11, a flange portion 12, and a threaded rod 13, which are integrally formed and fixed to each other. The head 11, flange portion 12, and threaded rod 13 are arranged coaxially. In the axial direction A, the head 11 and threaded rod 13 are located on both sides of the flange portion 12, with the head 11 located on one axial side of the flange portion 12 and the threaded rod 13 located on the other axial side of the flange portion 12. The flange portion 12 protrudes radially outward relative to the head 11 and threaded rod 13, that is, the outer diameter of the flange portion 12 is larger than the outer diameter of the head 11 and the outer diameter of the threaded rod 13, and the flange portion 12 extends continuously along its entire circumference. Figure 5As shown, the head 11 can be configured for engagement with an operating tool, and this configuration can be formed into a petal structure by alternating recesses and protrusions arranged in the circumferential direction. The screw 13 can be formed with external threads that mate with the nut 2. The screw 13 can be inserted through the first generatrix 3 and the second generatrix 4 and threadedly connected to the nut 2, such that the first generatrix 3 and the second generatrix 4 are clamped between the flange 12 and the nut 2 and fixed relative to each other in the axial direction A.

[0043] like Figures 3 to 5 As shown, the flange 12 has a first surface 12s1 facing the first generatrix 3 and a second surface 12s2 facing away from the first generatrix 3. That is, the first surface 12s1 is the surface of the flange 12 facing the other side of the axial direction, and the second surface 12s2 is the surface of the flange 12 facing one side of the axial direction. In this embodiment, a portion of the first surface 12s1, including its outer periphery, presses against the first generatrix 3, while the other portions of the first surface 12s1 are spaced apart from the first generatrix 3. When the bolt 1 is in the assembled state, the first surface 12s1 presses against one side of the axial direction of the first generatrix 3. In all sections including the central axis of the bolt 1, the angle α between the outline of the aforementioned other portion of the first surface 12s1 and the outline of one side of the axial direction of the first generatrix 3 is... Figure 4 The angle between the single-dotted line and the double-dotted line located on the lower side can be 1.0 degrees, that is, the angle α between the portion of the first surface 12s1 that is spaced apart from the axial side of the first generatrix 3 and that axial side can be 1.0 degrees. Furthermore, when the bolt 1 is in the assembled state, in all sections including the central axis of the bolt 1, the angle b between the outline of the second surface 12s2 and the outline of the axial side of the first generatrix 3... Figure 4 The angle between the single-dotted line and the double-dotted line on the upper side can be 15 degrees, meaning the angle b between the second surface 12s2 and one axial side of the first generatrix 3 can be 15 degrees. It should be noted that in this embodiment, when the bolt 1 is in its initial, unassembled state (e.g., ... Figure 5 As shown in the diagram, in all cross-sections including the central axis of bolt 1, the outline of the first face 12s1 extends radially outward while extending obliquely towards the side where the screw 13 is located relative to the axial direction, and the outline of the second face 12s2 extends radially outward while extending obliquely towards the side where the screw 13 is located relative to the axial direction. Thus, the first face 12s1 is configured with the above-described shape to prevent excessive deformation of the first busbar 3 and the second busbar 4 after bolt 1 is tightened, thereby reducing the contact area of ​​these two busbars and increasing the contact resistance; the second face 12s2 is configured with the above-described shape to ensure that the flange portion 12 has sufficient structural strength and does not undergo undesirable deformation during bolt 1 tightening.

[0044] like Figures 3 to 5As shown, the second surface 12s2 has an annular circumferential groove 12c, which extends continuously along the circumference. The diameter of the outer periphery of the circumferential groove 12c is smaller than the outer diameter of the flange portion 12, and the diameter of the inner periphery of the circumferential groove 12c is larger than the outer diameter of the screw 13 and the outer diameter of the head 11. Thus, the circumferential groove 12c can be provided in the portion of the flange portion 12 that extends radially outward from the head 11 and the screw 13, and is located radially R outside the head 11 and the screw 13, and the central axis of the annular circumferential groove 12c is collinear with the central axis of the entire bolt 1. Furthermore, in all sections (which may be referred to as the axial section or longitudinal section of the bolt 1) containing the central axis of the bolt 1, the cross-sectional shape and cross-sectional dimensions of the circumferential groove 12c remain unchanged, and the outline of the circumferential groove 12c in the cross-section is an arc. It is understandable that, in other alternative solutions, the cross-section of the circumferential groove 12c can be an elliptical arc or a parabola, or other curved shapes such as a triangle or a square.

[0045] In this embodiment, the first busbar 3 is the busbar of the motor control unit. The first busbar 3 can be made of a metal material such as copper, formed into a flat shape, and there are multiple first busbars 3. Figures 1 to 4 As shown, the first busbar 3 includes a first connecting portion 31, which has a first connecting hole 31h extending along its thickness direction for the insertion of a screw 13. The inner diameter of the first connecting hole 31h is larger than the outer diameter of the screw 13. The thickness direction of the first connecting portion 31 is the same as the axial direction of the bolt 1. Thus, after the first busbar 3 and the second busbar 4 are fixed by the bolt 1 and the nut 2, the other axial side (first surface 12s1) of the flange portion 12 of the bolt 1 presses against one axial side of the first busbar 3, and the other axial side of the first busbar 3 abuts against one axial side of the second busbar 4.

[0046] In this embodiment, the second busbar 4 is the busbar of the motor stator. The second busbar 4 can be made of a metal material such as copper, formed into a flat shape, and multiple second busbars 4 exist. Figures 1 to 4 As shown, the second busbar 4 includes a second connecting portion 41, which has a second connecting hole 41h extending along its thickness direction for the insertion of a screw 13. The inner diameter of the second connecting hole 41h is larger than the outer diameter of the screw 13. The thickness direction of the second connecting portion 41 is the same as the axial direction of the bolt 1, and it is stacked with the first connecting portion 31 along the axial direction A of the bolt 1. Thus, after the first busbar 3 and the second busbar 4 are fixed by the bolt 1 and the nut 2, the other axial side of the first busbar 3 abuts against one axial side of the second busbar 4, and the axial side of the nut 2 presses against the other axial side of the second busbar 4.

[0047] In this embodiment, the nut 2 is made of metal, and the nut 2 has an internal thread that mates with the external thread of the screw 13. For example... Figure 2 and Figure 3 As shown, the nut 2 is located on the opposite side of the head 11 and the flange 12 relative to the first busbar 3 and the second busbar 4. Specifically, the nut 2 is located on the other side of the axial direction of the first busbar 3 and the second busbar 4.

[0048] By adopting the above scheme, since an annular circumferential groove 12c is formed on the second surface 12s2 of the bolt 1 facing away from the generatrix, the force generated between the bolt 1 and the generatrix during the tightening process is initially concentrated at the contact point where the generatrix contacts the outer periphery of the first surface 12s1 of the flange portion 12 (see...). Figure 4 (The hollow arrow in the image), but because the part with the circumferential groove 12c has low rigidity and is prone to deformation, the stress at the contact point can be reduced and alleviated. Therefore, the stress at the contact point is less likely to exceed the maximum allowable stress of the busbar, thus significantly reducing or even eliminating the possibility of metal debris being generated during the connection of the motor control unit busbar and the motor stator busbar via bolt 1. Furthermore, the motor according to this application can substantially avoid high-voltage breakdown caused by metal debris generated during the connection of the busbar via bolt 1.

[0049] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application. The technical solutions of this application are further described below.

[0050] i. It is understood that the motor of this application can typically be applied to vehicles, not only to pure electric vehicles but also to hybrid vehicles. The power system of a pure electric vehicle can be an electric axle drive system, which may further include a transmission mechanism such as a gearbox, with the motor drivingly connected to the input shaft of the gearbox to achieve bidirectional torque transmission. The power system of a hybrid vehicle may further include an engine, and the motor according to this application can be used in conjunction with the engine to constitute a hybrid power system for the hybrid vehicle.

[0051] ii. It is understood that in the above embodiments, a portion of the outer periphery of the first surface 12s1 presses against the first busbar 3, but this application is not limited thereto.

[0052] For example, in a variant of the above embodiment, the first surface 12s1 can be pressed against the first busbar 3 as a whole.

[0053] In a variant of the above embodiment, the included angle α between the portion of the first face 12s1 of the flange portion 12 that is spaced apart from the axial side of the first generatrix 3 and the axial side can be any value within the following range: 1.5 degrees ≥ α ≥ 0.5 degrees.

[0054] In a variant of the above embodiment, the included angle b between the second face 12s2 of the flange 12 and one axial side of the first generatrix 3 can be any value within the following range: 20 degrees ≥ b ≥ 10 degrees.

[0055] iii. In the solution of this application, a circumferential groove 12c is formed in the flange portion 12 of the bolt 1, which has little impact on the structure of the bolt 1. Moreover, in the manufacturing process of the bolt 1, not only can existing extrusion molding processes be used, but costs can also be saved due to material savings. Furthermore, the bolt 1 according to this application can ensure that the first busbar 3 and the second busbar 4 have sufficient contact area after assembly, and has a high anti-loosening capability.

[0056] It is understandable that, for different situations, the circumferential groove 12c can be selected with different cross-sectional shapes and dimensions (e.g., depth) to make the bolt 1 of this application more applicable.

[0057] It is understandable that, in the case of multiple pairs of first busbars 3 and second busbars 4, each pair of first busbars 3 and second busbars 4 can be connected and fixed using a set of bolts 1 and nuts 2.

Claims

1. A motor bus assembly, characterized in that, The device includes a bolt, a nut, a first busbar, and a second busbar. The bolt comprises a head, a flange, and a threaded rod that are fixed to each other. The head and the threaded rod are located on either side of the flange in the axial direction of the bolt. The flange extends radially outward relative to the head and the threaded rod. The threaded rod is inserted through the first busbar and the second busbar and is threadedly connected to the nut, such that the first busbar and the second busbar are clamped between the flange and the nut in the axial direction and are relatively fixed. The flange portion has a first surface facing the first busbar and a second surface facing away from the first busbar. At least a portion of the first surface, including its outer periphery, presses against the first busbar. The second surface has an annular circumferential groove that extends continuously along the circumference of the bolt. The diameter of the outer periphery of the circumferential groove is smaller than the outer diameter of the flange portion, and the diameter of the inner periphery of the circumferential groove is larger than the outer diameter of the screw and the outer diameter of the head.

2. The motor bus assembly according to claim 1, characterized in that, The shape and size of the circumferential groove remain constant in all cross-sections containing the central axis of the bolt.

3. The motor bus assembly according to claim 2, characterized in that, In the cross-section, the outline of the circumferential groove is an arc.

4. The motor bus assembly according to any one of claims 1 to 3, characterized in that, When the bolt is in its unassembled initial state, in all sections containing the central axis of the bolt, the outline of the first face extends radially outward while extending obliquely relative to the axial direction toward the side where the screw is located.

5. The motor bus assembly according to claim 4, characterized in that, When the bolt is in its unassembled initial state, in all sections containing the central axis of the bolt, the outline of the second face extends radially outward while extending obliquely relative to the axial direction toward the side where the screw is located.

6. The motor bus assembly according to claim 5, characterized in that, When the bolt is in the assembled state, the first surface presses against the surface of the first busbar. The angle α between the portion of the first face spaced apart from the surface and the surface satisfies 1.5 degrees ≥ α ≥ 0.5 degrees, and The included angle b between the second surface and the surface satisfies 20 degrees ≥ b ≥ 10 degrees.

7. The motor bus assembly according to any one of claims 1 to 3, characterized in that, The first busbar includes a flat first connecting portion, and the second busbar includes a flat second connecting portion, with the first connecting portion and the second connecting portion stacked in the axial direction.

8. The motor bus assembly according to claim 7, characterized in that, The first connecting portion has a first connecting hole through which the screw is inserted, and the inner diameter of the first connecting hole is larger than the outer diameter of the screw; and The second connecting portion has a second connecting hole through which the screw is inserted, and the inner diameter of the second connecting hole is larger than the outer diameter of the screw.

9. An electric motor, characterized in that, Includes the motor bus assembly according to any one of claims 1 to 8.

10. The motor according to claim 9, characterized in that, The first busbar of the motor busbar assembly is the busbar of the motor controller, and the second busbar of the motor busbar assembly is the busbar of the motor stator.

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