Housing arrangement and electric drive with such a housing arrangement

Abstract

The invention relates to a housing arrangement for an electric drive, comprising: a motor housing part (3) with a casing section (6) and a first gear housing section (7) integrally formed thereon, a housing (4) connectable to the casing section (6), an inverter housing part (5) with an inverter housing section (13) and a second gear housing section (14) integrally formed therewith, wherein the inverter housing section (13) is arranged axially next to the second gear housing section (14), wherein the second gear housing section (14) has a gear cooling channel (22) which is fluidically connected to a cooling chamber (17) of the inverter housing part (5), wherein the motor housing part (3) and the inverter housing part (5) are connectable to one another by connecting elements,and wherein, in the assembled state, a closed cooling circuit is formed from a fluid connection (16) of the inverter housing part (5) via the cooling chamber (17) and the gear cooling channel (22) to a motor cooling channel (8) of the motor housing part (3).

Description

[0001] The invention relates to a housing arrangement for an electric drive for driving a motor vehicle. Furthermore, the invention relates to an electric drive with such a housing arrangement.

[0002] US 2021 394 600 A1 discloses an electric drive comprising a housing assembly, an electric machine with a hollow shaft, a planetary gear, and a differential gear. The housing assembly comprises a motor-side first housing part, a transmission-side second housing part, and an intermediate housing part arranged therebetween. The intermediate housing part comprises an integrally formed partition wall, a motor-side shell section, and a transmission-side shell section. A sealed cavity for a coolant flowing through is formed between an outer surface of the motor-side shell section and the inner surface of the first transmission part.

[0003] WO 2019 182 622 A1 discloses a drive unit comprising an electric motor and a first circulation channel for a first coolant for cooling the electric motor and, separately, a second circulation channel for a second coolant. The second circulation channel has a heat exchange section with the circulation channel for the first coolant. The drive unit is equipped with an inverter for controlling the motor. The circulation channel for the second coolant has a cooling section for cooling the inverter. The inverter comprises a power module with a switching transistor for converting the direct current for the battery power source into a three-phase alternating current for the electric motor.

[0004] A motor-integrated inverter is known from US 2022 190 764 A1. The inverter comprises a motor with a shaft arranged in a horizontal direction and a power module configured to generate drive energy for driving the motor and coupled to the motor in a direction in which the shaft is arranged.

[0005] US 2022006349 A1 discloses a power generation module comprising: an electric motor having a motor housing; an inverter disposed on a first side of the motor housing and comprising an inverter housing configured to house an insulated gate bipolar transistor (IGBT) and a capacitor; and an inner housing disposed within the motor housing and configured to house a stator and a rotor. A dual flow path is provided on a circumferential surface of the motor housing. A similar module is known from US 2022006350 A1.

[0006] DE 10 2020 207 101 A1 discloses an electric drive with power electronics and electrical connections. The power electronics are arranged on top of the housing, forming a T-shaped structure.

[0007] DE 10 2015 219 669 A1 discloses an electric machine with a stator, a rotor, and power electronics for controlling the stator. The power electronics are arranged axially in front of or behind the stator with respect to the motor axis.

[0008] In addition to the functionality and efficiency of the power electronics, space requirements and weight are also important criteria in development. To ensure that electric and hybrid vehicles operate with particularly high efficiency, it is necessary to maintain not only the temperature of the electric motor and battery, but also that of the power electronics within an efficiency-optimized temperature range. To ensure this, a powerful thermal management system is required to cool the components accordingly and keep them within the optimal temperature window.

[0009] The present invention is based on the object of proposing a housing arrangement for an electric drive for a motor vehicle that ensures reliable cooling of the components of the electric drive and has a compact design. Furthermore, a corresponding electric drive for a motor vehicle is to be provided that has high efficiency with good cooling properties and a compact design.

[0010] According to the invention, to achieve the object, a housing arrangement for an electric drive for driving a motor vehicle is proposed, which housing arrangement comprises: a motor housing part with a shell section for receiving a stator of the electric machine and a first transmission housing section for receiving parts of a transmission, wherein the shell section and the first transmission housing section are formed in one piece; an outer shell part which can be connected to the shell section, wherein in an assembled state the outer shell part and the shell section are arranged coaxially with respect to a motor axis and comprise a motor cooling channel through which cooling fluid can flow to cool the electric machine;an inverter housing part with an inverter housing section for accommodating an inverter of the electric machine and a second transmission housing section formed integrally with the inverter housing section, wherein the inverter housing section is arranged axially adjacent to the second transmission housing section and has a fluid connection that is fluidly connected to a cooling chamber within the inverter housing section, wherein the second transmission housing section has a transmission cooling channel that is fluidly connected to the cooling chamber; wherein the first transmission housing section and the second transmission housing section are mechanically connectable to one another by connecting elements; wherein, in the connected state, a closed cooling circuit is formed from the fluid connection of the inverter housing part via the cooling chamber and the transmission cooling channel to the motor cooling channel.

[0011] An advantage of the proposed housing arrangement is its compact design, which can have a substantially cylindrical shape with respect to the motor axis. The housing volume can be concentrated to the same height or the same radial distance, thereby avoiding irregularities in the radial direction. This achieves good packaging, and the housing arrangement makes it possible to reduce the number of housing parts to just three, for example, two pots and one cover. The first and the inverter housing part and / or the outer shell part can be cast from a light metal such as aluminum or an aluminum alloy. In one embodiment, the arrangement can be designed as a housing arrangement with two pots and three covers, wherein the motor and inverter housing parts form the two pots, and the housing and two optional additional covers of the inverter housing part form the three covers.

[0012] In a preferred embodiment, the inverter housing section forms one axial end of the housing assembly relative to the motor axis. The inverter housing section can be open in the axial direction, allowing the inverter to be mounted axially. A cover can be provided to close the inverter housing section.

[0013] The motor housing part forms a housing for the electric machine and half of the housing for the gearbox. The inverter housing part forms a housing for the inverter and the other housing half for the gearbox. The motor and inverter housing parts are connected to one another by their gearbox housing sections. For this purpose, the first and second gearbox housing sections can have connecting elements, such as flanges and / or bolts, distributed around the circumference with which they can be mechanically connected to one another. When assembled, the two gearbox housing halves together form an interior space in which the gearbox is housed. The cooling structure of the inverter housing part is fluidly connected to the cooling structure of the motor housing part. When assembled, both cooling structures are part of a closed cooling circuit through which a cooling fluid flows during operation of the arrangement.The coolant flows through the inverter housing part to cool the inverter and part of the gearbox, and through the motor housing part to cool the electric machine.

[0014] The closed cooling system is located within the walls of the housing and has no contact with the internal chambers of the housing assembly. For example, a gearbox located within the gearbox housing can be cooled or lubricated by a second fluid that is different from the cooling fluid of the housing assembly. The cooling fluid can be water or a water-based coolant, such as ethylene glycol. The fluid for lubricating the gearbox can be an oil, for example. The electric machine can be cooled and lubricated with the same fluid as the gearbox. However, in the case of a dry-running electric machine, the electric machine can also be lubricant-free.

[0015] According to one embodiment, the first gear housing section can have a first through-opening for a first output shaft, and the second gear housing section can have a second through-opening for a second output shaft. The first and second shaft openings can be arranged such that the opening axes run parallel to the motor axis. The gear cooling channel of the inverter housing part can have a C-shaped form in a cross-sectional view. The C-shaped gear cooling channel can extend circumferentially over at least 180° with respect to the axis of the through-opening of at least one of the first and second gear housing sections.

[0016] The inverter housing part can have an intermediate cooling channel, which can be arranged between the inverter cooling chamber and the transmission cooling channel. The cooling fluid can thus flow from the inverter cooling chamber through the intermediate cooling channel into the transmission cooling channel. The intermediate cooling chamber cools a larger section of the inverter housing part. The intermediate cooling channel can have a C-shaped cross section. The intermediate cooling channel can be arranged axially and / or radially offset from the transmission cooling channel. In particular, the intermediate cooling channel can be arranged such that it extends circumferentially around the motor axis, for example, over at least 180°.

[0017] A first connecting channel can be formed between the motor housing part and the inverter housing part to fluidically connect the cooling structure of the motor housing part to the cooling structure of the inverter housing part. A return path can be arranged between an outlet port of the motor channel and an inlet port of the inverter housing part. A heat exchanger can be arranged in the return path to cool the cooling fluid that has absorbed heat from the transmission and the motor as it flows through the housing. The first connecting channel can be formed from an end portion of the transmission cooling channel to an inlet portion of the motor cooling channel.

[0018] According to a first embodiment, there is only one connecting channel between the motor housing part and the inverter housing part, so that the cooling liquid flows through them in series, first through the cooling structure of the inverter housing part and then through the cooling structure of the motor housing part.

[0019] According to another embodiment, a second connecting channel can be formed between the motor housing part and the inverter housing part. In this case, the cooling fluid flows functionally parallel, with a first coolant flow from the inverter cooling chamber flowing indirectly via the transmission channel to the motor housing part, and a second coolant flow flowing directly to the motor housing part, bypassing the transmission channel. During operation of an electric drive, more heat is generated by the electric machine. The cooling structure of the inverter housing part is therefore preferably designed such that at least 30%, in particular more than 40%, of the coolant flowing into the inverter housing part flows through the second connecting channel directly to the motor cooling channel, while the remainder of the coolant flows indirectly through the transmission cooling channel to the motor cooling channel.

[0020] According to one specification, the second connecting channel can connect the intermediate cooling channel of the inverter housing part to a second inlet of the motor cooling channel. According to an alternative specification, the second connecting channel can connect the cooling chamber of the inverter housing part to a second inlet of the motor cooling channel.

[0021] Furthermore, with regard to the above object, an electric drive for driving a motor vehicle is proposed, comprising: a housing arrangement, which can be designed according to one of the above embodiments; an electric machine with a stator and a rotor, wherein the stator is connected in a rotationally fixed manner to the casing section of the motor housing part, wherein the rotor is drivingly connected to a rotor shaft which is rotatably mounted in the housing arrangement about the motor axis; a gear for transmitting a rotary movement of the rotor shaft to a first output shaft and a second output shaft of the gear; and an inverter which is arranged in the inverter housing section of the inverter housing part. The stator can be connected axially to the motor housing part, in particular such that it is supported axially thereon.

[0022] The electric drive has the same advantages as those mentioned with regard to the housing arrangement, so reference is made to the above description.

[0023] The inverter, which can also be referred to as power electronics, is functionally located between the electric vehicle's battery and the electric machine. The inverter controls and monitors the electric machine and ensures that the torque supply and speed control of the drivetrain meet requirements. When the electric machine is operating in motor mode, the inverter supplies the electric motor with power from the battery. When the electric machine is operating in generator mode, the inverter feeds power into the battery. In this process, known as recuperation, the inverter converts the alternating current (AC) generated by the electric machine into direct current (DC), thus charging the battery. When the motor is operating, the inverter converts the direct current from the battery into the alternating current required by the electric motor.

[0024] Preferred embodiments of the invention are described below with reference to the drawing figures. Fig. 1A shows a housing arrangement according to the invention in a first embodiment in a 3D exploded view; Fig. 1B the housing arrangement Fig. 1A in assembled state in a 3D view (without cover); Fig. 1C the cooling structure of the housing arrangement of the Fig. 1A and Fig. 1B in a 3D view according to Fig. 1B; Fig. 1D the housing arrangement of Fig. 1A in an axial view; Fig. 1E the cooling structure of the housing arrangement in an axial view according to Fig. 1D; Fig. 1F the inverter housing part in a longitudinal section according to the section line 1F-1F of Fig. 1D; Fig. 1G the housing arrangement Fig. 1A in plan view; Fig. 1H the cooling structure of the housing arrangement in a plan view according to Fig. 1G; Fig. 1J the housing arrangement of Fig. 1A in a cross-section according to the section line 1J-1J of Fig. 1G; Fig. 1K a connection between an inverter cooling channel and a motor cooling channel; Fig. 2A shows a housing arrangement according to the invention in a second embodiment in a 3D view; Fig. 2B the cooling structure of the housing arrangement of Fig. 2A in a 3D view; Fig. 2C shows the cooling structure of the housing arrangement in a plan view; Fig. 3A shows a housing arrangement according to the invention in a third embodiment in a 3D view; and Fig. 3B the cooling structure of the housing assembly of Fig. 3A in a 3D view.

[0025] The Fig. 1A to 1K, which are described jointly below, show a housing arrangement 2 according to the invention in a first embodiment. The housing arrangement 2 is provided for an electric drive of a motor vehicle (not shown). The components of the housing arrangement are shown in the Fig. 1A, Fig. 1B, Fig. 1D, Fig. 1F, Fig. 1G, Fig. 1 year and Fig. 1K. The cooling liquid hollow structure formed by the components is shown in the Fig. 1C, Fig. 1E and Fig. 1H. The fluid sections are designated F, supplemented by the respective reference symbol of the associated component. This also applies to the Fig. 2A to 2C and the Fig. 3A to 3B illustrated embodiments.

[0026] The housing assembly 2 comprises a motor housing part 3, a housing 4 and an inverter housing part 5.

[0027] The motor housing part 3 comprises a casing section 6 for accommodating a stator of the electric machine and a first transmission housing section 7 for accommodating parts of a transmission. The casing section 6 and the first transmission housing section 7 are formed integrally, for example, by casting a light metal.

[0028] The housing 4 can be connected to the shell section 6 by suitable connecting elements 11, e.g. by circumferentially distributed flange and / or bolt connections. In the assembled state, the housing 4 and the inner shell section 6 are arranged coaxially and form a motor cooling channel 8 through which coolant F can flow to cool the electric machine (not shown). The cooling channel 8 is arranged radially between the inner shell section 6 and the outer housing 4 and extends helically around the motor axis A1. In this way, the heat transferred from the electric machine to the inner shell section 6 can be absorbed by the coolant F flowing through the motor shell. The housing 4 can also be referred to as the outer shell part.

[0029] The first gear housing section 7 comprises connecting elements 9 distributed over the circumference. The connecting elements 9 are designed as flange connections, which are to be mounted on corresponding second connecting elements 10 of the inverter housing part 5, which can also be designed as flange connections. The first gear housing section 7 further comprises a through-opening 12 for a first output shaft of the gear unit (not shown). The axis A2 of the through-opening 12 runs parallel to the motor axis A1. Furthermore, the first gear housing section can optionally have a bearing seat 36 for an intermediate shaft of the gear unit (not shown).

[0030] The inverter housing part 5 comprises an inverter housing section 13 for accommodating an inverter of the electrical machine (not shown) and a second gear housing section 14. The inverter housing section 13 and the second gear housing section 14 are formed as a single piece and can be manufactured, for example, as a cast part made of light metal material. The inverter housing section 13 is arranged axially adjacent to the second gear housing section. In particular, the inverter housing section 13 forms an axial end of the housing arrangement 2 with respect to the motor axis A1. The inverter housing section 13 has an opening in the axial direction so that the inverter can be axially mounted therein. A cover 15 can be provided to close the inverter housing section 13 so that the inverter is encapsulated in the inverter housing.The cover 15 can be attached to the inverter housing section 13 by means of corresponding connecting elements 24. The inverter housing section 13 can optionally have a chamber 39 for accommodating, for example, electronic components, which can be closed by a cover 40.

[0031] An inverter supplies the electric machine with power from a battery when the machine is operating in motor mode. When the electric machine is operating in generator mode, the inverter feeds power into the vehicle's battery. The inverter can convert the alternating current generated by the electric machine into direct current to charge the battery, and vice versa. An inverter may include a capacitor, an intelligent power generation module (IPGM), and busbars. During operation, the inverter components heat up, and the resulting heat must be dissipated via the cooling system.

[0032] For this purpose, the inverter housing part 5 comprises a fluid connection 16, which is fluidically connected to a cooling chamber 17 in the inverter housing section 13. The cooling chamber 17 has an inlet 18 and an outlet 19, so that cooling fluid can flow from the connection 16 through the cooling chamber 17 and then on to the gear housing section 14. The cooling chamber 17 has a circumferential connection surface 20 to which a component of the inverter can be connected in a fluid-tight manner. Thus, the inverter component protruding into the cooling chamber 17 is cooled by the fluid flowing through the chamber.

[0033] The second transmission housing section 14 comprises a transmission cooling channel 22, which is in fluid communication with the outlet 19 of the inverter cooling chamber 17. The transmission cooling channel 22 has a C-shaped cross section, as shown in the Fig. 1C, Fig. 1E and Fig. 1J. The second transmission housing section 14 further comprises a second through-opening 23 for a second output shaft, wherein the axis A2 of the shaft opening runs parallel to the motor axis A1. The C-shaped transmission cooling channel 22 extends circumferentially over at least 180° with respect to the axis A2 of the shaft opening of the second transmission housing section 14. The second transmission housing section 14 can optionally comprise a second bearing seat 37 for an intermediate shaft of the transmission, wherein the second bearing seat 37 and the first bearing seat 36, in the assembled state, form a rotational axis A3 running parallel to the motor axis A1.

[0034] The inverter housing part 5 can optionally have an intermediate cooling channel 29 (in Fig. 1D shown in dashed lines), which can be arranged between the inverter cooling chamber 17 and the transmission cooling channel 22. The cooling liquid can thus flow from the cooling chamber 17 through the intermediate cooling channel 29 into the transmission cooling channel 22. The intermediate cooling channel 22 can have a C-shaped cross-section similar to the transmission cooling channel 22. Preferably, however, the intermediate cooling channel 29 is arranged axially offset from the transmission cooling channel 22. In particular, the intermediate cooling channel 29 is arranged such that it extends in the circumferential direction around the motor axis A1, for example over at least 180°.

[0035] On its side facing the first gear housing section 7, the second gear housing section 14 has, distributed in the circumferential direction, the second connecting elements 10 to establish a mechanical connection with the motor housing part 3. Furthermore, a connecting channel 26 is formed between the motor housing part 3 and the inverter housing part 5 to fluidically connect the cooling structure of the housing parts.

[0036] The first connecting elements 9 and the second connecting elements 10 can be connected to one another to tightly connect the motor housing part 3 and the inverter housing part 5. In the assembled state, the motor housing part 3 forms a first housing half of the gearbox, and the inverter housing part 5 forms the second housing half of the gearbox. In other words, the interface between the two housing parts 3, 5 is located in the area of the gearbox housing. The first and second connecting elements 9, 10 can include, but are not limited to, flanges and bolts. For example, the two housing parts could also be welded together.

[0037] In the connected state, the cooling structure 35 of the inverter housing part 5 is fluidly connected to the cooling structure 33 of the motor housing part 3 via the connecting channel 26. The first connecting channel 26 can be formed from an end section of the transmission cooling channel 22 to an inlet section 28 of the motor cooling channel 8. The cooling structures of the motor and inverter housing parts 3, 5 form parts of a closed cooling circuit from the fluid connection 16 of the inverter housing part 5 via the inverter cooling chamber 17, the transmission cooling channel 22, the motor cooling channel 8 to a fluid connection 31 of the motor housing part 3. The flow path P of the cooling liquid F is in Fig. 1C by arrows. A return path (not shown) may be arranged between the connection 31 of the motor housing and the connection 16 of the inverter housing. The return path may include a heat exchanger to cool the cooling fluid that has absorbed heat while flowing through the housing assembly 2. The heat exchanger may be arranged outside the housing assembly 2.

[0038] An exemplary fluid coupling between the inverter housing part 5 and the motor housing part 3 is shown in Fig. 1K as a detail. The fluid coupling can comprise a sleeve-shaped connector 21, which is connected by a first section 38 to the motor-side cooling channel and by a second section 38' to the inverter-side cooling channel. The connector 21 is in particular designed such that it forms a liquid-tight seal between the motor-side cooling channel and the inverter-side cooling channel. The connector 21 or connecting piece can be made of an elastic material, such as rubber or a similar plastic. The connector 21 can have sealing lips or other sealing features at its axial ends in order to sealingly contact a circumferential surface of the channel connecting section 25 of the motor housing part 3 or the opposite channel connecting section 25' of the inverter housing part 5.The inverter housing part 5 can have an optional auxiliary bore 41, which forms part of the connection channel 26 and can be closed to the outside with a plug (not shown). Alternatively, the two opposite channel connection sections 25, 25' can also be fluidically connected to one another without a separate connecting piece, e.g., by a sealing ring in the contact area between the two housing parts 3, 5.

[0039] When installed, the housing arrangement 2 is part of an electric drive configured to drive a motor vehicle. The electric drive comprises an electric machine accommodated in the motor housing part 3, a gearbox for transmitting the rotary motion of the electric machine, and an inverter for controlling and monitoring the electric machine and ensuring a demand-oriented torque supply and speed control. The electric machine comprises a stator and a rotor (not shown), wherein the stator is connected in a rotationally fixed manner to the housing 4 of the motor housing part 3. The rotor is drive-connected to a rotor shaft that is rotatably mounted in the housing part 2 about the motor axis A1. The gearbox (not shown) is designed to transmit a rotary motion from the rotor shaft to a first and second output shaft.For this purpose, the transmission can comprise a gear unit with an optional intermediate shaft rotatable about axis A3 and a differential unit for distributing the input motion between the two output shafts. The inverter (not shown) is arranged in the inverter housing section 13 of the inverter housing part 5.

[0040] The special features of the various embodiments are described below. Fig. In the first embodiment shown in Figures 1A to 1K, there is only one connecting channel 26 between the motor housing part 3 and the inverter housing part 5. The entire cooling liquid F flows from the inverter housing part 5 through the channel 26 to the motor housing part 3, where it leaves the housing arrangement 2 and can return to the inverter housing part 5 via a return path (not shown).

[0041] The Fig. 2A to 2C largely corresponds to the embodiment shown in the Fig. 1A to 1K, so that with regard to the common features, reference is made to the above description. In this context, the same or corresponding details have been provided with the same reference numerals as in the Fig. 1A to 1K.

[0042] A special feature of the Fig. 2A to 2C is that, in addition to the first connecting channel 26, a second connecting channel 30 is provided for fluidically connecting the first and second cooling structures. In this case, the cooling fluid F flows functionally parallel, with a first coolant flow F26 flowing indirectly from the inverter cooling chamber 17 via the transmission cooling channel 22 to the motor housing part 3, and a second coolant flow F30 flowing directly, i.e., bypassing the transmission cooling channel 22, to the motor housing part 3. The cooling structure 35 of the inverter housing part 5 is designed such that preferably at least 30%, for example 50%, of the coolant flowing into the inverter housing part 3 through the connection 16 is branched off in the flow path behind the cooling chamber 17 and guided directly to the motor cooling channel 8 through the second connecting channel 30. The other part of the coolant flows indirectly through the transmission cooling channel 22 into the motor cooling channel 8.In the engine cooling channel 8, the two fluid flows F26, F30 are combined and flow together through the engine jacket.

[0043] As in the Fig. 2B and Fig. As can be seen in Figure 2C, a connecting channel (F32) is formed between the outlet 19 of the inverter cooling chamber 17 and the intermediate cooling channel 29. At an end portion (F34), the intermediate channel 29 is connected to the second cooling channel 30. Thus, the first coolant flow F1 flows through the intermediate channel 29 to the transmission channel 22, and the second coolant flow F30 flows from the end portion (F34) of the intermediate channel 29 through the second connecting channel 30.

[0044] The Fig. 3A and Fig. The embodiment shown in Figure 3B corresponds largely to that shown in Fig. 2A to 2C, so that with regard to the common features, reference is made to the above description. In this context, the same or corresponding details have been provided with the same reference numerals as in the Fig. 2A to 2C or 1A to 1 K.

[0045] The only difference to the one in the Fig. 3A and Fig. 3B is that the outlet 19 of the cooling chamber 17 is directly connected to the engine cooling channel 8 via the second connecting channel 30. List of reference symbols 2 Housing arrangement 3 Motor housing part 4 housings 5 Inverter housing part 6 Sheath section 7 first gearbox housing section 8 engine cooling duct 9 first connecting elements 10 second connecting elements 11 Connecting element 12 passage opening 13 Inverter housing section 14 second gearbox housing section 15 lids 16 Fluid connection (5) 17 Cooling chamber 18 Entrance 19 Outlet 20 connection surface 21 Fluid connection 22 Transmission cooling duct 23 Passage opening 24 connecting elements 25, 25' connecting section 26 first connecting channel 27 End section (22) 28 Inlet section (8) 29 Intermediate cooling channel 30 second connecting channel 31 Fluid connection 32 connecting channel 33 Cooling structure (3) 34 End section (32) 35 Cooling structure (5) 36 bearing seat (7) 37 bearing seat (14) 38, 38' section 39 Chamber 40 lids 41 Auxiliary bore A axis F Cooling fluid P Flow path QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2021 394 600 A1

[0002] WO 2019 182 622 A1

[0003] US 2022 190 764 A1

[0004] US 2022006349 A1

[0005] US 2022 006350 A1

[0005] DE 10 2020 207 101 A1

[0006] DE 10 2015 219 669 A1

[0007]

Claims

[1] Housing arrangement for an electric drive for driving a motor vehicle, comprising: a motor housing part (3) with a casing section (6) for receiving a stator of the electric machine and a first gear housing section (7) for receiving parts of a transmission, wherein the casing section (6) and the first gear housing section (7) are formed in one piece, a housing (4) which can be connected to the casing section (6), wherein in an assembled state the housing (4) and the casing section (6) are arranged coaxially with respect to a motor axis (A1) and comprise a motor cooling channel (8) through which cooling fluid (F) can flow to cool the electric machine, an inverter housing part (5) with an inverter housing section (13) for accommodating an inverter of the electrical machine and a second gear housing section (14) which is formed integrally with the inverter housing section (13), wherein the inverter housing section (13) is arranged axially adjacent to the second gear housing section (14) and has a fluid connection (16) which is fluidly connected to a cooling chamber (17) within the inverter housing section (13), wherein the second gear housing section (14) has a gear cooling channel (22) which is fluidly connected to the cooling chamber (17), wherein the first gear housing section (7) and the second gear housing section (14) can be mechanically connected to one another by connecting elements (9, 10), wherein in the connected state a closed cooling circuit is formed from the fluid connection (16) of the inverter housing part (5) via the cooling chamber (17) and the gear cooling channel (22) to the motor cooling channel (8). [2] Housing arrangement according to claim 1, characterized by that the inverter housing section (13) forms an axial end of the housing arrangement (2) with respect to the motor axis (A1). [3] Housing arrangement according to claim 1 or 2, characterized by that the transmission cooling channel (22) has a C-shaped cross section and extends in the circumferential direction over at least 180° with respect to a transmission axis (A2) parallel to the engine axis (A1). [4] Housing arrangement according to one of claims 1 to 3, characterized by that the inverter housing part (5) has an intermediate cooling channel (29) arranged fluidically between the inverter cooling chamber (17) and the gear cooling channel (22). [5] Housing arrangement according to claim 4, characterized by that the intermediate cooling channel (29) has a C-shaped form in a cross-sectional view and extends in the circumferential direction over at least 180° with respect to the motor axis (A1). [6] Housing arrangement according to one of claims 1 to 5, characterized by that a first connecting channel (26) is formed between the motor housing part (3) and the inverter housing part (5) in order to fluidically connect the cooling structure (33) of the motor housing part (3) to the cooling structure (35) of the inverter housing part (5). [7] Housing arrangement according to one of claims 1 to 6, characterized bythat a return path is provided between the fluid connection (31) of the motor housing part (3) and the fluid connection (16) of the inverter housing part (5), wherein a heat exchanger is arranged in the return path outside the motor housing part (3) and the inverter housing part (5) in order to cool the cooling fluid flowing through. [8] Housing arrangement according to claim 6 or 7, characterized by that the first connecting channel (26) is formed from an end portion of the transmission cooling chamber (22) to an inlet portion (18) of the engine cooling channel (8). ( Fig. 1) [9] Housing arrangement according to one of claims 6 to 8, characterized by that a second connecting channel (30) is formed between the motor housing part (3) and the inverter housing part (5), which is arranged functionally parallel to the first connecting channel (26). ( Fig. 2 and Fig. 3) [10] Housing arrangement according to claim 9, characterized bythat at least 30% of the cooling fluid flowing through the inverter housing part (5) flows through the second connecting channel (30) directly to the motor cooling channel (8) and the rest of the cooling fluid flows indirectly through the first connecting channel (26) to the motor cooling channel (8). ( Fig. 2 and Fig. 3) [11] Housing arrangement according to claim 9 or 10, characterized by that the second connecting channel (26) connects the intermediate cooling channel (29) of the inverter housing part (5) with a second inlet (18) of the motor cooling channel (8). ( Fig. 2) [12] Housing arrangement according to claim 9 or 10, characterized by that the second connecting channel (30) connects the cooling chamber (17) of the inverter housing part (5) with a second inlet of the motor cooling channel (8). ( Fig. 3) [13] Housing arrangement according to one of claims 1 to 12, characterized by that a cover (15) is provided for closing the inverter housing section (13). [14] Electric drive for driving a motor vehicle, comprising: a housing arrangement (2) according to one of claims 1 to 13, an electrical machine having a stator and a rotor, wherein the stator is connected in a rotationally fixed and axial manner to the casing section (6) of the motor housing part (3), wherein the rotor is drivingly connected to a rotor shaft which is rotatably mounted in the housing arrangement (2) about the motor axis (A1), a gear for transmitting a rotary movement of the rotor shaft to a first output shaft extending through a first opening (12) of the motor housing part (3) and a second output shaft extending through a second opening (23) of the inverter housing part (5), an inverter arranged in the inverter housing section (13) of the inverter housing part (5).

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