Housing for an electric drive, and electric drive for a vehicle

Abstract

A housing (10) for accommodating an electric drive (1) for a vehicle, the electric drive (1) comprising an electric machine (12) and comprising a transmission (11) mechanically coupled to the electric machine (12) and an electronics system (13) electrically coupled to the electric machine (12), wherein the housing (10) has a first housing part (51) and a second housing part (52); each of the two housing parts (51, 52) are provided at least for accommodating one of the components electric machine (12), transmission (11) and electronics system (13); and the housing (10) comprises a cooling duct (22) which is formed between the first housing part (51) and the second housing part (13).

Description

[0001] Description

[0002] title

[0003] Housing for an electric drive and electric drive for a vehicle

[0004] State of the art

[0005] Electric drives are known from the prior art that include an electric machine and other components, such as a gearbox or electronics, to which separate cooling channels are assigned. For example, the electric machine of the electric drive may be provided with a cooling channel running along a helix on a cylindrical surface.

[0006] From the applicant's DE10 2021 210330 A1, a housing for an e-axle module with at least one electric motor and a gearbox is already known. The electric motor is cooled by means of a coolant circuit, and at least one cooling channel extends in at least one housing wall from a first transfer point to at least one further transfer point, running along thermally critical bearing points.

[0007] From DE 10 2022206 440 A1 of the applicant, a drive arrangement is known which comprises an electric machine, a gearbox and a housing in which the electric machine and the gearbox are arranged. An intermediate wall of the housing is arranged between the electric machine and the gearbox, in or on which an insert cast into the housing with at least one cavity structure for creating a cooling channel is arranged.

[0008] From DE 10 2020 209 761 A1, an electric drive system is known which comprises an electric machine, a gearbox and an inverter, wherein the electric drive system includes a housing with at least two parts and two separate cooling circuits for the inverter and the electric machine. The two cooling circuits are thermally connected via a heat exchanger which is installed between the inverter and the electric machine in the housing.

[0009] Disclosure of the invention

[0010] The present invention is based on the observation that the manufacture and sealing of cooling channels in housings for electric drives in a vehicle are technically complex. For example, it is complex to integrate such cooling channels into the housings by machining or to create such cooling channels during casting or die casting of the housing using so-called slides. If the electric drive comprises, in addition to an electric motor, another component or several other components, such as a gearbox and / or electronics, each of which in turn requires its own separate cooling channels in the housing, this technical effort increases significantly during its manufacture.

[0011] To reduce the technical effort in the manufacture of the housing of the electric drive, which comprises an electric machine and further comprises a gearbox mechanically coupled to the electric machine and electronics electrically coupled to the electric machine, it is therefore provided according to the invention that the housing has a first sub-housing and a second sub-housing, wherein each of the two sub-housings is provided for receiving at least one of the components electric machine, gearbox and electronics, wherein the housing includes a cooling channel formed between the first sub-housing and the second sub-housing.

[0012] For example, an electric machine can be arranged in the first sub-housing and electronics can be arranged in the second sub-housing.

[0013] For example, a gearbox can be located in the first sub-housing and electronics can be located in the second sub-housing.

[0014] For example, an electric motor can be housed in the first housing section and a gearbox in the second. Because the cooling channel is located between the two housing sections, it can simultaneously cool both components. Therefore, no additional cooling channel is required, and it does not need to be integrated into the housing or sealed. Overall, this reduces the technical effort required to manufacture the housing and / or the electric drive.

[0015] Advantageously, the first housing sub-case may have a first recess on its side facing the second housing sub-case, and / or the second housing sub-case may have a second recess on its side facing the first housing sub-case, wherein the cooling channel is formed during assembly of the first and second housing sub-cases by the first and second recesses coinciding. Advantageously, the recesses on the housing sub-cases can be produced with very little effort, for example, directly by the appropriate shaping of a casting or injection mold.

[0016] The recesses can, for example, be partially or semi-tubular in shape, so that they can be assembled to form a tubular cooling channel, for example a tubular cooling channel running meandering between the first partial housing and the next partial housing.

[0017] The cooling channel can, for example, have a round, oval, or rectangular cross-section.

[0018] Alternatively, it can also be provided that the first recess and the second recess together form a cooling chamber between the first partial housing and the second partial housing, which as such does not necessarily constitute a cooling channel within the meaning of the invention.

[0019] For example, it could be a cooling chamber that has a first extension in the direction from the first sub-housing to the second sub-housing and has second extensions in the two directions perpendicular to it, wherein the first extension is smaller than the second extensions, for example, at most one third of the second extensions. In this respect, the cooling chamber could be a flat cooling bag.

[0020] However, an insert can be placed in this cooling chamber in such a way that the cooling channel is formed in it; or between it and the first housing part; or between it and the second housing part; or between it and the first housing part and the second housing part.

[0021] The insert could be, for example, a plastic part, such as a part or injection-molded part made of a thermoplastic material, for example, polypropylene. It could also be recycled material.

[0022] The cooling channel can guide a cooling fluid along a three-dimensionally designed path. This can result, for example, from the shape of the insert, particularly in its interaction with the housing part and / or other housing parts. The cooling effect, and the associated heat transfer, is then optimized.

[0023] The cooling channel may thus be provided to have at least a first section through which cooling fluid can be passed in a first spatial direction, and a second section through which cooling fluid can be passed in a second spatial direction which is neither parallel nor antiparallel to the first spatial direction, and a third section through which cooling fluid can be passed in a third spatial direction which lies outside a plane spanned by the first spatial direction and the second spatial direction.

[0024] For example, the first spatial direction, the second spatial direction and the third spatial direction can be perpendicular to each other in pairs.

[0025] For example, the cooling channel can have several first sections, several second sections, and several third sections, with second or third sections always arranged between first sections, first or third sections arranged between second sections, and first or second sections arranged between third sections.

[0026] For example, the housing can have a coolant inlet to influence

[0027] The housing has coolant in it and a coolant outlet for the outflow of coolant from the housing, wherein the cooling channel is arranged fluidically between the coolant inlet and the coolant outlet.

[0028] Therefore, the cooling channel can be identical to the fluidic connection of the inlet with the outlet, but it is also possible that the fluidic connection of the inlet with the outlet includes a further fluid guide through the first and / or second partial housing, which are arranged fluidically in series or parallel with the cooling channel.

[0029] Additionally or alternatively, the electric drive may also include a fluid pump that pumps a cooling fluid through the cooling channel and, if necessary, through a fluid guide arranged fluidically in series or parallel with the cooling channel.

[0030] Exemplary embodiments of the invention are explained below with reference to the drawing. The drawing shows:

[0031] Figure 1 is a schematic representation of a first embodiment of the invention.

[0032] Figure 2 shows a schematic representation of a second embodiment of the invention.

[0033] Figure 1 shows an electric drive 1 for a (not shown) vehicle as a first embodiment of the invention. The electric drive has a housing 10, which is composed of a first sub-housing 51, which accommodates an electric machine 12, and a second sub-housing 52, which has electronics 13 electrically coupled to the electric machine 12, and a third sub-housing 53, which has a transmission 11 mechanically coupled to the electric machine 12.

[0034] The electronics 13 can, for example, include an inverter. The gearbox 11 can, for example, include an input shaft 11a, an intermediate shaft 11b, a differential 11c, and an output shaft 11d.

[0035] To simultaneously cool the first 51 and second sub-housing 52 or to simultaneously cool the electrical machine 12 and the electronics 13, the example provides that the housing 10 includes a cooling channel 22 which is formed between the first sub-housing 51 and the second sub-housing 52.

[0036] In the example shown in Figure 1, the first partial housing 51 has a first recess 21 on its side facing the second partial housing 52, and the second partial housing 52 has a second recess 23 on its side facing the first partial housing 51. The recesses 21, 23 are relatively shallow and extend laterally, for example, over a substantial part of the interface between the first partial housing 51 and the second partial housing 52. By assembling the first partial housing 51 with the second partial housing 52, a cooling compartment 44 in the shape of a shallow cooler bag is created between these two partial housings 51, 52, into which, in this example, an insert 46 made of recycled polypropylene is placed.

[0037] The insert 46 is shaped in such a three-dimensional way that, in the example, together with the walls of the flat cooling bag, i.e., together with the first partial housing 51 and the second partial housing 52, it forms a cooling channel 22, which each has a plurality of first, second and third sections through which cooling fluid can be passed in the three mutually perpendicular spatial directions.

[0038] Alternatively, it is possible to design the recesses of the first partial housing 51 and the second partial housing 52 in such a way as, for example, a channel or a half-pipe shape, that after assembly of the partial housings 51, 52 they form a cooling channel 22, which, for example, runs in a meandering shape, directly (without the need for an insert).

[0039] In a second example, which is explained below with reference to Figure 2, with regard to the cooling channel 22, the third sub-housing 53 and the component transmission contained therein take the place of the first sub-housing 51 and the component electric machine 12 contained therein, and vice versa.

[0040] In the example shown in Figure 2, the third sub-housing 53, in which the gearbox 11 is housed, has a first recess 21 on its side facing the second sub-housing 52, in which the electronics 13 are housed, and the second sub-housing 52 has a second recess 23 on its side facing the third sub-housing 53. The recesses 21 and 23 are relatively shallow and extend laterally, for example, over a substantial part of the interface between the third sub-housing 53 and the second sub-housing 52. By assembling the third sub-housing with the second sub-housing 52, a cooling compartment 44 in the form of a shallow cooling bag is created between these two sub-housings 53 and 52, into which, in this example, an insert 46 made of recycled polypropylene is placed.

[0041] The insert 46 is shaped in such a three-dimensional way that, in the example, together with the walls of the flat cooling bag, i.e., together with the third partial housing 53 and the second partial housing 52, it forms a cooling channel 22, which each has a plurality of first, second and third sections through which cooling fluid can be passed in the three mutually perpendicular spatial directions.

[0042] Alternatively, in the second embodiment, it is also possible to design the recesses 21, 23 of the third partial housing and the second partial housing in such a way, for example in a channel shape or as a half-tube shape, that after assembly of the partial housings 53, 52 they form a cooling channel 22, which for example runs in a meandering shape, directly (without the need for an insert part 46).

Claims

Claims 1. Housing (10) for accommodating an electric drive (1) for a vehicle, wherein the electric drive (1) comprises an electric machine (12) and a transmission (11) mechanically coupled to the electric machine (12) and electronics (13) electrically coupled to the electric machine (12), wherein the housing (10) has a first sub-housing (51) and a second sub-housing (52), wherein each of the two sub-housings (51, 52) is provided for accommodating at least one of the components electric machine (12), transmission (11) and electronics (13), wherein the housing (10) includes a cooling channel (22) formed between the first sub-housing (51) and the second sub-housing (52).

2. Housing according to claim 1, wherein the first partial housing (51) has a first recess (21) on its side facing the second partial housing (52) and / or wherein the second partial housing (52) has a second recess (23) on its side facing the first partial housing (51).

3. Housing according to claim 2, wherein the first recess (21) and the second recess (23) together form the cooling channel (22), wherein the cooling channel (22) is formed by assembling the first partial housing (51) with the second partial housing (52).

4. Housing according to claim 3, wherein the first recess (21) and the second recess (23) are each partially or semi-tubular in shape.

5. Housing according to claim 2, wherein the first recess (21) and the second recess (23) together form a cooling chamber (44) between the first partial housing (51) and the second partial housing (52), wherein the cooling chamber (44) is formed by assembling the first partial housing (51) with the second partial housing (52), wherein an insert (46) is inserted into the cooling chamber (44), such that the cooling channel (22) is in the insert (46) and / or between the insert (46) and the is formed in the first sub-housing (51) and / or the second sub-housing (52).

6. Housing according to claim 5, wherein the insert (46) is made of plastic.

7. Housing according to one of the preceding claims, wherein the cooling channel (22) has at least a first section through which cooling fluid can be passed in a first spatial direction, and a second section through which cooling fluid can be passed in a second spatial direction which is neither parallel nor antiparallel to the first spatial direction, and a third section through which cooling fluid can be passed in a third spatial direction which lies outside a plane spanned by the first spatial direction and the second spatial direction.

8. Housing according to claim 7, wherein the first spatial direction, the second spatial direction and the third spatial direction are pairwise perpendicular to each other.

9. Housing according to claim 7 or 8, wherein the cooling channel (22) has several first sections, several second sections and several third sections.

10. Housing according to one of the preceding claims, wherein the housing (10) has a coolant inlet for introducing coolant into the housing (10) and a coolant outlet for allowing coolant to flow out of the housing (10), wherein the cooling channel (22) is arranged fluidically between the coolant inlet and the coolant outlet.

11. Electric drive (1) for a vehicle with a housing (10) according to one of the preceding claims, wherein at least one of the components electric machine (12), transmission (11), electronics (13) is arranged in the first sub-housing (51) and at least one other of the components electric machine (12), transmission (11), electronics (13) is arranged in the second sub-housing (52).

12. Electric drive according to claim 11, wherein the housing (10) comprises a third sub-housing (53) in which the remaining components electrical machine (12), gearbox (11), electronics (13) is arranged.

13. Electric drive according to claim 11, wherein the electric drive further comprises a fluid pump that conveys cooling fluid through the cooling channel (22).

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