Device having two welded components, electric machine, and method for producing the device and the electric machine

Abstract

The invention relates to an electric device (1) having a power input (2), a power output (3), and an electrical interface (4) disposed between the power input (2) and the power output (3), wherein the interface (4) comprises a wire (5) as a first component (6) and a rail-like connection element (7) welded to the wire (5) as a second component (8), wherein one of the two components (8) rests against a shoulder (9) of the other component (6) and a weld seam (10) connecting the two components (6, 8) extends from the shoulder (9) over the entire thickness (11) of the other component (8) resting against the shoulder (9). The invention also relates to an electric machine (23) comprising this device (1), to a method for producing the electric device (1), and to a method for producing the electric machine (23).

Description

[0001] Device with two welded components; electrical machine and manufacturing method for the device and the electrical machine

[0002] The invention relates to an electrical device having a power input, i.e., preferably an input connected to a power source during operation, a power output, preferably in the form of an electrical load, and an electrical interface arranged between the power input and the power output. The interface has a wire as the first component and a rail-shaped connecting element welded to the wire as the second component. Furthermore, the invention relates to an electrical machine having this electrical device. The invention also relates to methods for producing this electrical device and an electrical machine.

[0003] Devices of this type with corresponding interfaces are well known in the art. For example, WO 2020 / 104701 A1 discloses an electrically conductive connecting component with a cap-shaped connecting region in which the free ends of at least two conductor bars can be accommodated. It is also known to weld certain sections in this connecting region to connect the components to one another.

[0004] However, it has been discovered that the geometric design of the connecting components means that the welds cannot be applied across the entire thickness / depth of the components. This, in turn, can lead to increased stress concentrations at these welds during operation due to typical loads, thus weakening the welded joint. A simple through-weld, i.e., forming the weld across the entire thickness of the component, is also usually not possible due to the risk of damaging adjacent components during the welding process.

[0005] It is therefore an object of the present invention to provide an electrical device with a welded interface whose fatigue strength is significantly increased, whereby the risk of damage to adjacent components during the welding process is at least greatly reduced.

[0006] This is achieved according to the invention in that one of the two components rests on a shoulder of the other component, and a weld connecting the two components runs from the shoulder across the entire thickness of the other component resting on the shoulder. The depth of the weld is thus at least as great as the thickness of the other component.

[0007] This weld seam design, originating from the shoulder, significantly reduces notch effects between the welded components. Furthermore, the shoulder provides a rear impact surface for the melting tool, through which a thermal beam is reflected or at least redirected, thus protecting components located below or behind the shoulder from damage caused by the thermal beam.

[0008] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0009] Therefore, it is also advantageous if the first component / wire is provided with a shoulder. The shoulder can thus be incorporated into the wire, which is relatively easy to form in the usual way, using relatively simple means.

[0010] To further increase the strength of the welded joint, it is beneficial if the shoulder is incorporated into at least two sides / spatial directions (in the transverse direction of one component, preferably the first component). It is also advantageous if the shoulder is incorporated into the component on three sides. The sides typically represent the sides of a quadrilateral at right angles to each other.

[0011] Assembly is further simplified if the shoulder is inserted at one end of one component. It is also advantageous if the second component placed on the shoulder has a recess (preferably open toward one end of the second component) that at least partially surrounds / accommodates the first component. This facilitates assembly and the application of the weld seam.

[0012] Furthermore, it is advantageous if the first component and the second component are aligned with their interconnected end regions obliquely, preferably perpendicularly, to one another.

[0013] The second component / connecting element is further preferably a busbar which is further connected to a power electronics system or directly forms a component of this power electronics system.

[0014] In addition, the invention relates to an electrical machine, which is preferably designed as an electric drive machine of a motor vehicle, with a stator, a rotor rotatably mounted relative to the stator and an electrical device according to the invention according to at least one of the previously described embodiments, wherein the first component is part of a coil winding of the stator or the rotor.

[0015] Furthermore, the invention relates to a method for producing an electrical device with an electrical interface, which interface in turn has a wire as the first component and a rail-shaped connecting element as the second component, comprising the steps of a) providing one of the two components with a shoulder, b) placing the other of the two components on the shoulder, and c) welding the two components to one another, wherein a weld seam runs from the shoulder over the entire thickness of the other component placed on the shoulder.

[0016] In this context, it has proven particularly expedient to join the components together by laser welding. This enables a precise weld seam. The invention also relates to a method for producing an electrical machine by forming an electrical device according to the above method.

[0017] The invention will now be explained in more detail below with reference to figures.

[0018] They show:

[0019] Fig. 1 is a highly simplified representation of an electrical device according to the invention according to a preferred embodiment comprising an interface designed according to the invention between two components connected to one another by welding,

[0020] Fig. 2 is a plan view of the interface shown in Fig. 1,

[0021] Fig. 3 is a side view of the interface according to Fig. 1,

[0022] Fig. 4 is a simplified longitudinal sectional view of an electrical machine with an electrical device according to Fig. 1, and

[0023] Fig. 5 is a flow chart illustrating a method according to the invention for producing the electrical device.

[0024] The figures are merely schematic in nature and therefore serve solely to clarify the invention. The same elements are designated by the same reference numerals.

[0025] Fig. 1 initially shows an abstract representation of an electrical device 1 according to the invention (also referred to as an electronic component), in particular in the area of ​​an interface 4 / connection point / coupling point implemented according to the invention, which is explained in more detail below.

[0026] The electrical device 1 further comprises an abstractly depicted (electrical) power input 2 and a likewise abstractly depicted (electrical) power output 3. During operation, the power input 2 is electrically connected to a power source, such as a battery, in the usual way. The power output 3 is connected to an electrical load or preferably directly forms this load. The interface 4 is arranged between the power input 2 and the power output 3.

[0027] With reference to Fig. 4, it should first be noted that said electrical device 1 is preferably used in an electrical machine 23. The power input 2 can then, for example, comprise control electronics with an inverter, etc. The power output 3 is preferably a direct component of a stator 16 of the electrical machine 23, namely, more preferably, a coil winding 18 arranged on the stator 16.

[0028] The electric machine 23 is further configured as an electric drive motor of a motor vehicle and, in addition to the stator 16, has a rotor 17 that is rotatably mounted relative to the stator 16. For the sake of completeness, it should be noted that, according to further embodiments, it is of course also possible to provide the coil winding 18 in the rotor 17. In this case, the power output 3 would again be the rotor 17 itself.

[0029] The coil winding 18 is connected to a first component 6 of the interface 4. In this regard, it should be noted that in this embodiment, a wire 5 preferably directly forms the coil winding 18 and the first component 6 (as a single piece). The component of the interface 4 that is further connected to the power input 2 is referred to as the second component 8. The second component 8 here is a rail-shaped connecting element 7 (also referred to as a busbar).

[0030] Finally, with reference to Figs. 1 to 3, the welded connection implemented according to the invention in the interface 4 can be seen in more detail. The first component 6 in the form of the wire 5 has an end region 13. This end region 13 has a shoulder 9 designed according to the invention. The shoulder 9 forms a step-like taper / a step-like recess in the diameter of the wire 5. The shoulder 9 is thus formed / introduced perpendicular to a longitudinal direction of the wire 5. The shoulder 9 therefore forms a support surface 19 directed towards an end side (seen in the longitudinal direction of the wire 5), on which support surface the second component 8 / the connecting element 7 rests. In principle, several shoulders 9 can also be formed offset in the longitudinal direction of the wire 5.

[0031] It can also be seen that a thickness 11 of the second component 8 is less than a longitudinal section 21 of the first component 6 extending from the shoulder 9 to the free end 20 of the first component 6.

[0032] When examining Fig. 2, it is noticeable that the shoulder 9 is essentially L-shaped and thus surrounds the longitudinal section 21 of the first component 6 from two sides 12a, 12b. However, in further embodiments, it is also possible to have the shoulder extend additionally to a third side 12c or even completely, so as to surround all four sides 12a, 12b, 12c, 12d. Viewed in the cross-section of the first component 6, these sides 12a, 12b, 12c, 12d form four sides of a rectangle, each offset by 90 degrees from one another.

[0033] It can also be seen that the second component 8 has a recess 15 at its end region 14, which is larger than the (rectangular) cross-section of the longitudinal section 21. The second component 8 finally comes to rest on the longitudinal section 21 at the respective sides 12a, 12b, to which the shoulder 9 also extends.

[0034] The weld seam 10 indicated in the figures, which connects the first component 6 to the second component 8, is introduced with reference to Fig. 2 into the (previous) gap region 24 between the longitudinal section 21 and the recess 15 above the shoulder 9. The weld seam 10, as shown / indicated in Fig. 1, runs in its depth 25 over the entire thickness 11 of the second component 8 and thus extends in the depth direction / thickness direction from the shoulder 9 to the surface 22 of the second component 8 facing away from the shoulder 9. In this regard, it is advantageous if the weld seam 10 is introduced by means of laser welding.

[0035] Fig. 5 then schematically refers to a manufacturing method according to the invention, wherein the electrical device 1 of Figs. 1 to 4 is achieved by a method in which, in a step a), one of the two components, preferably the first component 6, is provided with the shoulder 9. The shoulder 9 can be introduced, for example, by machining or shaping the end region 13. In a second step b), the other of the two components, here the second component 8, is then placed on the shoulder 9 and finally, in a third step c), the two components 6, 8 are welded together, the weld seam 10 running from the shoulder 9 over the entire thickness 11 of the other component 8 placed on the shoulder 9.

[0036] It is therefore self-evident that the two components 6, 8 can in principle also be interchanged and thus the second component 8 can be formed over the previously described first component, namely in particular can be provided with the shoulder 9 and then the first component 6 is placed accordingly on this shoulder 9 and welded to the second component 8.

[0037] This method is then used / applied analogously in a method for producing the electrical machine 23.

[0038] In other words, according to the invention, an overlap is created by adding a shoulder 9 to one of the two components 6, 8 to be welded (e.g., the wire 5). This overlap ensures that the laser beam does not penetrate and damage underlying components during welding. The penetration depth (depth 25) can then be increased to the full material thickness, forming a weld root with a lower notch effect.

[0039] In the preferred embodiment of Figures 1 to 3, the wire

[0040] 5 is provided with a shoulder 9, onto which the busbar to be welded (second component 8) is placed. The shoulder 9 can be attached to one side 12a of the wire 5, to all four sides 12a, 12b, 12c, 12d of the wire 5, or any position in between. Figures 1 to 3 show an example with a shoulder 9 on two sides 12a, 12b of the wire 5.

[0041] The laser then welds from above onto the joining gap (gap area 24) with the underlying shoulder 9 of the wire 5. In Figures 1 to 3, this creates an L-shaped weld seam 10.

[0042] List of reference symbols for electrical devices

[0043] Power input

[0044] Power output

[0045] interface

[0046] Wire first component

[0047] Connecting element second component

[0048] Paragraph

[0049] Weld seam

[0050] Thickness a first page b second page c third page d fourth page

[0051] End area of ​​the first component

[0052] End area of ​​the second component

[0053] recess

[0054] stator

[0055] rotor

[0056] Coil winding

[0057] Support surface

[0058] End

[0059] Longitudinal section

[0060] Surface electrical machine

[0061] gap area

[0062] depth

Claims

Patent claims 1. Electrical device (1) with a power input (2), a power output (3) and an electrical interface (4) arranged between the power input (2) and the power output (3), wherein the interface (4) has a wire (5) as the first component (6) and a rail-shaped connecting element (7) welded to the wire (5) as the second component (8), characterized in that one of the two components (8) rests on a shoulder (9) of the other component (6) and a weld seam (10) connecting the two components (6, 8) runs from the shoulder (9) over the entire thickness (11) of the other component (8) placed on the shoulder (9).

2. Device (1) according to claim 1, characterized in that the first component (6) is provided with the shoulder (9).

3. Device (1) according to claim 1 or 2, characterized in that the shoulder (9) is introduced into the one component (6) from at least two sides (12a, 12b).

4. Device (1) according to one of claims 1 to 3, characterized in that the shoulder (9) is introduced at an end region (13) of the one component (6).

5. Device (1) according to one of claims 1 to 4, characterized in that the second component (8) placed on the shoulder (9) has a recess (15) which at least partially encompasses the first component (6).

6. Device (1) according to one of claims 1 to 5, characterized in that the first component (6) and the second component (8) are aligned with their interconnected end regions (13, 14) perpendicular to each other.

7. Electrical machine (23) with a stator (16), a rotor (17) rotatably mounted relative to the stator (16) and an electrical device (1) according to a of claims 1 to 6, wherein the first component (6) is part of a coil winding (18) of the stator (16) or the rotor (17).

8. A method for producing an electrical device (1) with an electrical interface (4), which interface (4) in turn has a wire (5) as the first component (6) and a rail-shaped connecting element (7) as the second component (8), comprising the steps of a) providing one of the two components (6) with a shoulder (9), b) placing the other of the two components (8) on the shoulder (9), and c) welding the two components (6, 8) to one another, wherein a weld seam (10) runs from the shoulder (9) over the entire thickness (11) of the other component (8) placed on the shoulder (9).

9. Method according to claim 8, characterized in that the components (6, 8) are joined together by laser welding.

10. A method for producing an electrical machine (23) to form an electrical device (1) according to the method of claim 8 or 9.

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