DRIVE ARRANGEMENT, METHOD FOR PRODUCEING A DRIVE ARRANGEMENT AND A VEHICLE WITH A DRIVE ARRANGEMENT

Description

State of the art

[0001] The invention relates to a drive arrangement for a vehicle having the features of claim 1, a method for producing a drive arrangement having the features of claim 8, and a vehicle having a drive arrangement having the features of claim 10.

[0002] An electric axle drive (e-axle) essentially consists of power electronics, an electric motor, and a transmission. Such a drive is shown, for example, in DE 20 2017 003 396 U1.

[0003] The heat generated in the gearbox can be dissipated using an external heat exchanger, for example. This may be necessary, for example, in a completely oil-cooled machine.

[0004] The disadvantage is that an additional heat exchanger can be expensive, as it usually requires a mechanical or electric pump. Furthermore, the heat exchanger must be connected via additional pipes or ducts. An (external) heat exchanger requires additional installation space, which isn't always available.

[0005] A drive arrangement according to the preamble of claim 1 is known from US 2021 / 394600 A1. Disclosure of the invention

[0006] According to the invention, a drive arrangement for a vehicle, in particular for an electric vehicle, is proposed, comprising at least one electric machine for generating a torque and at least one transmission coupled to the electric machine for transmitting and / or translating the torque generated by the electric machine. The transmission is coupled to the electric machine in such a way that the transmission can be driven in rotation by means of the electric machine.

[0007] The drive assembly also comprises a housing in which the electric motor and the transmission are arranged, with an intermediate wall of the housing arranged between the electric motor and the transmission. The housing can be designed as a cast part, in particular as a die-cast aluminum part.

[0008] The drive assembly further comprises at least one insert cast into the housing, having at least one hollow structure for creating at least one cooling channel. The hollow structure can be self-contained. The insert is arranged on or in the intermediate wall of the housing.

[0009] The insert can be arranged on or in the intermediate wall in such a way that the intermediate wall at least partially or completely embeds the insert. The intermediate wall can be designed, in particular, as a bearing wall (bearing A-side (ALS)). The hollow structure created by the insert within the intermediate wall can represent at least one cooling channel and be used to cool the intermediate wall. This allows the intermediate wall between the electrical machine, which runs dry (without oil), and the gearbox, which is filled with oil, to be cooled.

[0010] The insert can be produced using additive manufacturing (e.g., L-PBF-M (powderbed fusion of metals with laser)). The insert can be made of a metallic alloy with good thermal performance. This could be an aluminum-based alloy, for example. Production with an iron-based alloy (steel) is also conceivable. Due in particular to the flexible production capabilities of additive manufacturing, cavity structures with complex, different geometries can be realized in an externally identical insert. This allows for a high degree of shape variation.

[0011] The drive arrangement may comprise power electronics (or a control module / control unit) for controlling the electric machine and / or a parking lock for blocking the torque transmission.

[0012] The drive arrangement can, for example, be designed as an electric axle or form part of an electric axle.

[0013] According to a further development, the insert can have a flat, in particular planar, base body. The base body can have rounded areas and / or edges. The base body can be round or rectangular. The hollow structure can extend within the base body. The hollow structure within the base body can have a winding and / or straight shape (contour).

[0014] According to a further development, the insert can have a cantilever. The cantilever can protrude from the base body. The cantilever can be oriented orthogonally to the base body. The hollow structure can run within the cantilever. This allows even hard-to-reach areas and / or hot spots of the component to be cooled (e.g., the gearbox) to be reached and cooled.

[0015] According to a further development, the insert can have at least one opening (or recess). The insert can have multiple openings or recesses. The opening(s) can penetrate the insert outside the hollow structure. The opening(s) can be arranged entirely within the base body of the insert (or run within the base body).

[0016] The openings in the insert allow for connection to the housing (casting) and save material during the costly additive manufacturing of the insert. Furthermore, cooling performance can be increased (larger contact areas between the insert and the housing or its intermediate wall).

[0017] According to a further development, the insert can be made from two joined, e.g. soldered and / or welded, sheets.

[0018] The insert can be optimized with regard to mass and load paths using topology optimization software to save manufacturing costs.

[0019] According to a further development, the insert part can be a component produced by internal high pressure and / or a hydroforming process.

[0020] Depending on the assembly orientation, manufacturing parameters, technology, material selection, and the applied hydrodynamic pressure, the minimum wall thickness of the insert can be as low as 300 µm (with no upper limit). This material-saving approach can reduce manufacturing costs.

[0021] According to a further development, the drive assembly can include a cooling circuit for cooling the electric motor. The cooling channel created by the insert can be fluidly connected to the cooling circuit of the electric motor. Thus, the intermediate wall and thus the transmission can be cooled by means of the cooling circuit of the electric motor.

[0022] In the present case, a fluidic connection or flow connection means that a gas and / or a fluid (liquid) can flow between two fluidically coupled or flow-connected elements or between two elements in fluidic connection or flow connection.

[0023] According to the invention, a method for producing a drive arrangement, in particular a drive arrangement according to the above statements, is proposed. Regarding the advantages thereby achievable, reference is made to the relevant statements regarding the drive arrangement. The measures described in connection with the drive arrangement and / or those explained below can be used to further refine the method. The procedure includes the following steps:

[0024] Providing an electrical machine to generate torque.

[0025] Providing a transmission coupled to the electric machine for transmitting and / or translating the torque generated by the electric machine.

[0026] Providing a housing to accommodate the electric machine and the gearbox.

[0027] Providing an insert with at least one, in particular self-contained, cavity structure for producing at least one cooling channel.

[0028] Filling the cavity structure with a filling medium, in particular with metallic powder.

[0029] Casting the insert into the housing, particularly into an intermediate wall of the housing. The insert is, in particular, partially or completely encapsulated.

[0030] Drilling and / or milling the cavity structure of the insert so that the cavity structure, in particular the closed cavity structure, is accessible.

[0031] Removing the filling medium from the cavity structure of the insert.

[0032] The filling medium within the cavity structure of the insert prevents the cavity structure from being destroyed during the die-casting process. The insert can also be assembled after the die-casting process. The housing can be manufactured using an aluminum die-casting process, whereby the insert can be inserted and completely encapsulated.

[0033] At an appropriate time, the drive assembly can be assembled, in particular by attaching and / or installing components, such as the electric motor, the gearbox, and any other components, onto or into the housing of the drive assembly. This can be done, for example, after removing the filling medium from the cavity structure.

[0034] According to a further development, the method may further comprise the step of fluidly connecting (or fluidically connecting / coupling) the hollow structure of the insert to a cooling circuit, particularly intended for cooling the electrical machine. The cooling circuit of the electrical machine may be a liquid cooling circuit, e.g., a water cooling circuit.

[0035] According to the invention, a vehicle, in particular an electric vehicle, is proposed with a drive arrangement as described above. Regarding the advantages achievable thereby, reference is made to the relevant explanations regarding the drive arrangement. The measures described in connection with the drive arrangement and / or those explained below can be used to further configure the vehicle.

[0036] Embodiments of the invention are explained below with reference to the accompanying drawings. They show: Figure 1 shows a perspective view of a drive arrangement; Figure 2 shows a section of a sectional view of the drive arrangement according to Figure 1 with an enlarged detail; Figure 3 shows a perspective sectional view of a first embodiment of an insert; Figure 4 shows a perspective view of a second embodiment of the insert; and Figure 5 shows a perspective view of a third embodiment of the insert.

[0037] Figure 1 shows a perspective view of a drive assembly 10. The drive assembly 10 comprises an electric machine 12 for generating a torque and a transmission 14 coupled to the electric machine 12 for transmitting and / or translating the torque generated by the electric machine 12. The electric machine 12 and the transmission 14 are arranged in a housing 16.

[0038] The drive assembly 10 in this case has power electronics 13 (or a control module) for controlling and / or regulating the drive assembly 10. The drive assembly 10 also has a parking lock 15 for blocking the torque transmission.

[0039] Figure 2 shows a section of a sectional view of the drive arrangement 10 according to Figure 1 For better clarity, an enlarged section is shown.

[0040] The housing 16 has an intermediate wall 18 arranged between the electric motor 12 and the transmission 14. An insert 20 is completely cast into the intermediate wall 18. The insert 20 is thus arranged entirely within the intermediate wall 18. The insert 20 has a hollow structure 22 for creating at least one cooling channel 24.

[0041] Figure 3shows a perspective sectional view of a first embodiment of the insert 20. The illustrated insert 20 corresponds to the insert 20 from Figure 2 The insert has a flat, circular base body 26. A section along the diameter of the circular insert 22 is shown. The cavity structure 22 is formed in the form of three circularly arcuate channels (later cooling channels 24).

[0042] Figure 4 shows a perspective view of a second embodiment of the insert 20. The insert 20 according to the second embodiment has a flat, essentially rectangular base body 26. Some corners and / or edges of the base body 26 are rounded. The insert 20 has an extension arm 28, which in this case extends perpendicularly from the base body 26.

[0043] The cavity structure 22 has a channel (later the cooling channel 24) that has a serpentine (winding), particularly meandering, shape in sections and a straight (rectilinear) shape in sections. The cavity structure 22 also extends through the cantilever 28.

[0044] Figure 5 shows a perspective view of a third embodiment of the insert 20. The third embodiment of the insert 20 differs from that in Figure 4 shown second embodiment in that the insert part 20 according to the third embodiment has three openings 30.

[0045] The three openings 30 are arranged in the base body 26 of the insert 20 and extend through the entire thickness of the base body 26. The three openings 30 are arranged outside the cavity structure 22 (or its subsequent cooling channel 24). In this case, the cavity structure 22 (or its subsequent cooling channel 24) winds around the openings 30. This further increases the cooling effect.

Claims

1. Drive assembly (10) for a vehicle, in particular for an electric vehicle, comprising: - at least one electric machine (12) for generating a torque, - at least one gearbox (14) coupled to the electric machine (12) for transmitting and / or transferring the torque generated by the electric machine (12), - a housing (16) in which the electric machine (12) and the gearbox (14) are arranged, wherein an intermediate wall (18) of the housing (16) is arranged between the electric machine (12) and the gearbox (14), characterized in that - at least one insert part (20) which is cast into the housing (16) and has at least one, in particular self-contained, cavity structure (22) for producing at least one cooling duct (24), wherein the insert part (20) is arranged on or in the intermediate wall (18) of the housing (16).

2. Drive assembly (10) according to Claim 1, characterized in that the insert part (20) has a flat basic body (26).

3. Drive assembly (10) according to Claim 2, characterized in that the insert part (20) has an extension arm (28), wherein the extension arm (28) protrudes from the basic body (26), in particular is oriented orthogonally to the basic body (26).

4. Drive assembly (10) according to any one of the preceding claims, characterized in that the insert part (20) has at least one opening (30), in particular a plurality of openings (30), wherein the opening (30) passes through the insert part (20) outside the cavity structure (22), wherein the opening (30) in particular is completely arranged in the basic body (26) of the insert part (20).

5. Drive assembly (10) according to any one of the preceding claims, characterized in that the insert part (20) is produced from two metal sheets joined together.

6. Drive assembly (10) according to any one of Claims 1 to 4, characterized in that the insert part (20) is a component produced by internal high pressure and / or hydroforming.

7. Drive assembly (10) according to any one of the preceding claims, characterized in that the drive assembly (10) comprises a cooling circuit for cooling the electric machine (12), wherein the cooling duct (24) produced by the insert part (20) is connected in terms of flow to the cooling circuit of the electric machine (12).

8. Method for producing a drive assembly (10) according to any one of the preceding claims, comprising the steps of: - providing an electric machine (12) for generating a torque; - providing a gearbox (14) coupled to the electric machine (12) for transmitting and / or transferring the torque generated by the electric machine (12); - providing a housing (16) for accommodating the electric machine (12) and the gearbox (14); - providing an insert part (20) with at least one, in particular self-contained, cavity structure (22) for producing at least one cooling duct (24); - filling the cavity structure (22) with a filling medium, in particular with metallic powder; - casting the insert part (20) into the housing (16), in particular into an intermediate wall (18) of the housing (16); - opening up the cavity structure (22) of the insert part (20) by drilling and / or milling; and - removing the filling medium from the cavity structure (22) of the insert part (20).

9. Method according to Claim 8, characterized in that the method further comprises the step of: - connecting the cavity structure (22) of the insert part (20) in terms of flow to a cooling circuit, in particular provided for cooling the electric machine (12).

10. Vehicle, in particular electric vehicle, having at least one drive assembly according to one of Claims 1 to 7.