Drive unit and drive assembly

Abstract

The invention relates to a drive unit for a powertrain of an electrically drivable motor vehicle, in particular a hybrid motor vehicle, and to a drive assembly. The drive unit (1) has a first rotary electric machine (10) and a second rotary electric machine (20) and a first shaft (40) and a second shaft (41), wherein the first rotary electric machine (10) is arranged at least partially radially and axially within a region which is radially delimited by the second rotary electric machine (20), and a stator (12) of the first rotary electric machine (10) and a stator (22) of the second rotary electric machine (20) are mechanically fixed to one another. The invention is characterized in that the drive unit (1) comprises a coolant supply device (200) which is arranged adjacent to the stators (12, 22) in the axial direction, and by means of which coolant can be supplied axially between the stators (12, 22) and / or into the stators. By means of the drive unit and the drive assembly according to the invention, optimum operation and optimum cooling function and thus effective operation can be ensured in an inexpensive design and in a space-saving manner.

Description

TECHNICAL FIELD

[0001] The present application relates to a drive unit for a powertrain of an electrically drivable motor vehicle, in particular a hybrid motor vehicle, and a drive assembly. BACKGROUND

[0002] Various drive units integrated in a drive assembly or a powertrain are known from the prior art.

[0003] DE 11 2015 006 071 T5 discloses a hybrid vehicle drive system having a generator capable of generating electric power using power of an internal combustion engine, an electric motor driven by the electric power to drive a wheel, a housing accommodating the generator and the electric motor, and a power control unit for controlling the generator and the electric motor. The generator and the electric motor are arranged side by side on the same axis in the housing.

[0004] US 2016 / 0218584 A1 describes a control unit for controlling an electric machine, wherein the control unit is mounted on a housing of a drive unit comprising the electric machine. The drive unit comprises two electric machines arranged coaxially and axially adjacent to each other.

[0005] WO 2019 101 264 A1 discloses a powertrain for a hybrid motor vehicle. The powertrain comprises a gear box input shaft which is operatively connected to a first electric machine and to an internal combustion engine via a first sub-powertrain in order to transmit torque, and which is operatively connected to a second electric machine via a second sub-powertrain in order to transmit torque. The two electric machines are arranged coaxially and axially adjacent to each other.

[0006] Integrating a drive unit with a plurality of rotary electric machines in a drive assembly for a hybrid motor vehicle is subject to strict installation space requirements, in particular in axial direction.

[0007] A drive assembly which is particularly short in axial direction is advantageous, in particular when such a drive unit is used in a so-called front transverse arrangement in a motor vehicle, in which the rotary electric machines and the internal combustion engine serve as front drive means and the respective rotational axes of the rotary electric machines and the internal combustion engine are arranged transversely to the longitudinal direction of the motor vehicle.

[0008] It is often necessary to cool the rotary electric machines. For example, it is known to provide a first flow system for realizing a flow of a first fluid used for at least partially cooling at least one rotary electric machine and a second flow system for realizing a flow of a second fluid, wherein heat can be transferred from the first flow system to the second flow system via a heat exchanger.

[0009] The first fluid can also be used to cool both rotary electric machines and to flow through the drive unit, such that at least one outlet of the first flow system directs cooling fluid to the first rotary electric machine and at least one other outlet of the first flow system directs cooling fluid to the second rotary electric machine. Due to the axial side-by-side arrangement of the rotary electric machines, the outlet for cooling the first rotary electric machine is clearly spaced apart from the other outlet for cooling the second rotary electric machine in the axial direction. SUMMARY

[0010] Based on this, it is the object of the present application to provide a drive unit and a drive assembly equipped with the drive unit which ensures optimal cooling and thus effective operation in a cheap design and space-saving manner.

[0011] This object is achieved by the drive unit according to the application according to claim 1. Advantageous embodiments of the drive unit are indicated in the dependent claims 2 to 9.

[0012] In addition, a drive assembly with a drive unit according to claim 10 is provided.

[0013] The features of the claims can be combined in any technically useful manner, including features from the explanations below and from the figures including additional embodiments of the application.

[0014] In the context of the present application, the terms "axial" and "radial" are always mentioned with respect to the rotational axis of the drive unit, which corresponds to the rotational axis of at least one of the rotary electric machines comprised by the drive unit.

[0015] The application relates to a drive unit for a powertrain of an electrically drivable motor vehicle, in particular a hybrid motor vehicle, having a first rotary electric machine and a second rotary electric machine and a first shaft and a second shaft, wherein a rotor of the first rotary electric machine is connected to the first shaft in a non-rotatable manner and a rotor of the second rotary electric machine is connected to the second shaft in a non-rotatable manner. The first rotary electric machine is arranged at least partially radially and axially within an area radially delimited by the second rotary electric machine. The first rotary electric machine is designed as an inner rotor motor and the second rotary electric machine is designed as an outer rotor motor, wherein a stator of the first rotary electric machine and a stator of the second rotary electric machine are mechanically fixed to one another. The drive unit comprises a coolant supply device which is arranged adjacent to the stators in the axial direction and by means of which coolant can be supplied axially between the stators and / or into the stators.

[0016] This means that the stators of the two rotary electric machines are arranged radially between the rotors of the two rotary electric machines.

[0017] In one embodiment, it can be provided that the radially inner rotary electric machine is arranged radially and axially completely within an area which is radially delimited by the respective other rotary electric machine.

[0018] In particular, it is provided that the drive unit further comprises a disconnect clutch, through which the rotor of the first rotary electric machine can be connected or is connected to the second shaft for torque transmission.

[0019] The disconnect clutch is arranged in a torque transmission path which extends from the first rotary electric machine to the second shaft or opens and closes this torque transmission path. The drive unit can comprise an actuation system for actuating the disconnect clutch, wherein the release bearing of the actuation system can be implemented in a single row or in a double row.

[0020] Advantageously, the rotational axis of the rotor of the rotary electric machine is positioned coaxially.

[0021] The radial nesting of the two rotary electric machines has the advantage that, during the stamping of the individual metal sheets of the rotor package and the stator package of the two rotary electric machines, the metal sheets of the rotor of the radially inner rotary electric machine and the stator of the radially inner rotary electric machine as well as the stator of the radially outer rotary electric machine and the rotor of the radially outer rotary electric machine can be cut out of the blank by means of a stamping stroke.

[0022] For the purpose of its connection to the second shaft, the rotor of the radially outer rotary electric machine can be supported by a rotor carrier which is connected to the second shaft, wherein the rotor is connected to the rotor carrier in particular in a force-fit and / or form-fit manner and the rotor carrier is connected to the second shaft in a force-fit and / or form-fit manner.

[0023] In order to mount the first shaft and / or the second shaft in a rotatable manner, the drive unit can have a central bearing or bearing unit which is designed to comprise one or more components and by means of which the first shaft and / or the second shaft is mounted on the housing of the drive unit. The rotor carrier of the radially outer rotary electric machine can be supported directly via the central bearing or indirectly via the second shaft on the central bearing. The central bearing is designed, for example, as a roller bearing, a ball bearing or an angular contact ball bearing.

[0024] The drive unit can comprise a fastening element which is bolted to the first shaft or to the second shaft in order to fix the position of the rotor carrier of the radially outer rotary electric machine relative to the position of the second shaft.

[0025] Advantageously, the radially inner rotary electric machine can be operated as a generator. The rotor of the radially inner rotary electric machine is relatively small and thus has a lower moment of mass inertia than the rotor of the radially outer rotary electric machine.

[0026] Thus, a radially outer rotating electric machine can advantageously be used as a drive unit, since the rotor of the rotating electric machine is relatively large and can generate a correspondingly large torque.

[0027] This does not exclude the possibility of using both a radially inner rotating electric machine and a radially outer rotating electric machine for driving a motor vehicle equipped with a drive unit. For example, a radially inner rotating electric machine can be used to supply torque to the input side of the drive unit, so that starting of an internal combustion engine that can be connected to the input side can be achieved. Alternatively, one or both rotating electric machines can also provide torque and, together with a connected internal combustion engine, achieve a hybrid operation of the drive unit.

[0028] In one embodiment, the rotor of the first rotating electric machine is arranged within an area radially delimited by the stator of the second rotating electric machine.

[0029] In one embodiment of the drive unit, the stators of the two rotating electric machines are arranged on a common stator carrier, wherein the coolant can be supplied to the stator carrier by means of a coolant supply device, and the coolant supply device is designed to distribute the coolant in the axial direction.

[0030] Thus, it is provided here that the two stators are arranged radially on both sides of the stator carrier.

[0031] In this case, the distribution in the axial direction is not limited to generating a volume flow that has only an axial component, but rather a coolant volume flow can be generated by the axially extending stator carrier with at least one directional component.

[0032] The stator carrier is in turn fixed to the housing of the drive unit.

[0033] In particular, the stator carrier can be arranged with respect to its radial position between the stators of the two rotating electric machines and mechanically connected to the stators of the two rotating electric machines, so that the stator carrier fixes the two stators.

[0034] The stator carrier can form a helical channel on its radially inner side and / or on its radially outer side for conducting coolant.

[0035] The stator carrier is a component having a substantially hollow cylindrical shape and thus has a radially inner side and a radially outer side. The channel can be formed by a groove on the respective side of the stator carrier, which is closed on the outside when the respective stator package or its body is in contact with the respective side of the stator carrier, thus forming the channel.

[0036] When the helical channels are arranged on the radially inner side and the radially outer side of the stator carrier, at least one radial connecting channel can be provided between the helical channel on the radially inner side and the helical channel on the radially outer side.

[0037] This embodiment provides an effective cooling of the two stators by means of grooves or channels formed in the stator carrier.

[0038] Furthermore, the coolant supply device can comprise a distribution device which is arranged axially adjacent to the rotary electric machine for supplying coolant to the stator carrier, wherein the distribution device is fluidically coupled to at least one connection channel formed axially in the stator carrier by means of at least one connection sleeve.

[0039] The axial connection channel is in turn fluidically connected to the spiral channel.

[0040] When a plurality of axial connection channels is arranged, said plurality of axial connection channels is fluidically coupled to a plurality of spiral channels.

[0041] The distribution device can be realized by means of an annular channel formed in or on the housing of the drive unit.

[0042] In particular, the distribution device is an integral component of the housing to which the stator carrier is fixed.

[0043] In an alternative embodiment of the coolant supply device, instead of the connection sleeve, it can be provided that the stator carrier is in contact with a housing forming the distribution device, so that the distribution device and the connection channel formed axially in the stator carrier are essentially directly fluidically coupled to each other. Advantageously, a seal, for example in the form of a sealing ring, should be arranged between the stator carrier and the housing forming the distribution device, so that the fluidic connection between the distribution device and the connection channel is sealed with respect to the environment.

[0044] In an alternative embodiment of the present drive unit, the stators of the two rotary electric machines are an integral component of a stator unit, wherein the coolant supply device comprises an annular channel having a plurality of axial outlets generating a partial coolant flow, the flow channels in at least one of the stators being fluidically coupled to said plurality of axial outlets.

[0045] Such a flow channel can be realized by means of an axial bore in the respective stator.

[0046] In particular, such a flow channel is arranged radially between the stator of the first rotary electric machine and the stator of the second rotary electric machine. This means that the coolant is guided in the stator unit in such a way that the optimal cooling of the two stators is achieved in an essentially equal manner.

[0047] The annular channel can be realized by a plastic component. In particular, the annular channel corresponds to an annular tube. It can also be provided that the annular channel is formed as an integral component of the housing.

[0048] The stator unit can further be fixed to the housing of the drive unit. This alternative embodiment thus does not use an additional stator carrier between the individual stators, but comprises a compact unit formed by only two stators.

[0049] The stator unit can be fixed to the housing of the drive unit by means of a plurality of screw connections. The respective screws of the screw connections pass through the stator unit, in particular in the axial direction, and are screwed into the housing of the drive unit.

[0050] In one embodiment, the drive unit comprises a first housing and a second housing, which together define a housing interior, in which the two rotary electric machines are arranged and in which the first and second shafts are at least partially arranged.

[0051] In particular, the shared stator carrier or stator unit is mechanically connected to the first housing, wherein the rotors of the two rotary electric machines are supported on the second housing.

[0052] In particular, the second shaft can be supported on the second housing, wherein the first shaft can be supported on the first housing and the second shaft.

[0053] In addition, the power electronics for controlling the rotary electric machines can be carried by the second housing.

[0054] Furthermore, the first shaft can have an axially extending shaft flow channel, which adjoins at least one first lateral bore having a radial extension, through which the cooling agent can be supplied from the shaft flow channel to the rotor of the first rotary electric machine.

[0055] In particular, the at least one first lateral bore can overlap the rotor of the first rotary electric machine in the radial direction, so that the rotor can be optimally cooled by the cooling agent. Advantageously, an axially extending cooling channel is provided between the first shaft and the rotor in the radial direction, which is fluidically coupled to the at least one first lateral bore, so that the cooling agent flowing to the rotor between the two axial end faces of the rotor is distributed as evenly as possible over the axial extent of the rotor.

[0056] In one embodiment, the first shaft can have a plurality of first lateral bores with radial extensions, wherein it is provided that the first lateral bores end at regular angular intervals from one another in the circumference and that a group of first lateral bores has substantially the same axial position. This axial position can in particular correspond to an axial center position relative to the rotor.

[0057] In particular, it can be provided that at least the first lateral bore overlaps the first rotor carrier in the radial direction for rotatably arranging the rotor of the first rotary electric machine, wherein the first rotor carrier comprises grooves and / or bores for axially distributing coolant in or at the rotor of the first rotary electric machine.

[0058] According to another embodiment, the rotor of the second rotary electric machine is rotatably mounted by means of a rotor carrier, wherein the rotor carrier has grooves and / or bores for axially distributing coolant in or on the rotor of the second rotary electric machine.

[0059] Alternatively or additionally, it can be provided that the rotor of the second rotary electric machine has grooves and / or bores for the same purpose.

[0060] The coolant is in particular transported to the radially outer portion of the rotor of the second rotary electric machine by centrifugal force, wherein the coolant thereby preferably flows along the radial section of the substantially pot-shaped rotor carrier.

[0061] In addition, the coolant collects in the pot-shaped rotor carrier due to gravity and is then distributed along the circumference as the rotor carrier rotates.

[0062] In particular, it is provided that grooves are formed at a radial position radially outside the rotor of the second rotary electric machine and / or on the contact surface of the rotor of the second rotary electric machine on the rotor carrier. Bores in the rotor can be realized radially more inside with respect to the grooves in the rotor, whereby the bores are closer to the region where the most heat is generated than the grooves, so that the coolant guided in such bores can achieve a more effective cooling effect.

[0063] Furthermore, at least one further lateral bore can be formed in the first shaft for flowing out coolant axially adjacent to the rotary electric machine.

[0064] The coolant flowing out of the at least one further lateral bore can be used, for example, to cool a decoupling clutch and / or to cool bearings such as a central bearing unit.

[0065] In particular, a plurality of further lateral bores can be formed, wherein the plurality of further lateral bores are distributed on the same axial position of the circumference and / or arranged on different axial positions. A further lateral bore can also be used to distribute coolant for the purpose of cooling the rotor of the second rotary electric machine.

[0066] The respective flow channels in the stator carrier or stator can have at least one outlet pointing to the winding head of the associated stator in order to be able to cool the winding head of the stator by means of the fluid volume flow exiting from the stator carrier or the stator itself.

[0067] Advantageously, the two shafts of the drive unit are arranged coaxially.

[0068] To this end, it is provided that the second shaft is designed as a hollow shaft and that the first shaft extends partially inside the second shaft.

[0069] Furthermore, the drive unit can comprise a first gear stage, wherein the first gear stage is formed by a connecting element of the drive unit comprising an internal toothed gear and a first shaft comprising an element having an external toothing. The toothing of the internal toothed gear and the external toothing engage with each other to transmit a rotational movement from the connecting element to the first shaft.

[0070] Accordingly, the drive unit according to the invention is designed as a so-called hybrid gear box. This means, therefore, that in addition to the electric rotating machines and the shafts, the drive unit comprises a gear box.

[0071] In particular, the element having the external toothing can be a gear wheel arranged in a non-rotatable manner on the first shaft.

[0072] In addition, the drive unit can have a second gear stage, which is formed by the toothing, in particular the external toothing, of the second shaft and a first gear wheel engaging with the toothing of the second shaft.

[0073] In one embodiment, in which the drive unit comprises a gear box, the first gear wheel can be coupled in a non-rotatable manner to an intermediate shaft of the gear box.

[0074] The gear box can comprise a differential gear in the output section. In this case, the external toothing of the intermediate shaft can engage with an input gear of the differential gear, thereby implementing a third gear stage.

[0075] Accordingly, the second shaft serves here as a gear box input shaft and is in operative connection with the gear box, so that the torque provided by the second shaft or the rotational movement implemented by the second shaft can be transmitted in an increasing or decreasing manner via the gear box to a further gear box unit of the motor vehicle or also directly to a drive wheel of the motor vehicle.

[0076] The drive unit according to the invention offers the advantage that due to the radial nesting of the electric rotating machines, comparatively less installation space is required in the axial direction compared to conventional drive units having two electric rotating machines, wherein the coolant supply device provided according to the invention ensures optimal cooling of the stators and rotors of the two nested electric rotating machines.

[0077] A further aspect of the invention is a drive assembly having a drive unit according to the invention and an internal combustion engine, which is coupled or can be coupled in a non-rotatable manner to the rotor of the first electric rotating machine by means of an output element of the internal combustion engine.

[0078] The drive assembly can comprise a vibration damper connected to the connecting element of the drive unit in a non-rotatable manner and a housing element mechanically connected to the combustion engine, wherein the vibration damper is arranged in the housing element.

[0079] In this regard, the housing element is advantageously connected to a second housing of the drive unit.

[0080] It is also possible for the intermediate shaft and / or the wheel drive shaft to be mounted axially in the housing element on the one hand and axially in the second housing on the other hand.

[0081] When operating a motor vehicle, in particular a hybrid vehicle, having a drive assembly according to the application, which comprises a drive unit according to the application and a combustion engine, for example the following drive operating modes are enabled:

[0082] - electric drive and recovery:

[0083] The disconnect clutch is open, so that the second rotary electric machine is uncoupled from the first rotary electric machine and the combustion engine. The second rotary electric machine is thus controlled as a traction machine or as a generator. The combustion engine and the first rotary electric machine are not operated.

[0084] - series drive and charging:

[0085] The disconnect clutch is open. The combustion engine is started by means of the first rotary electric machine, wherein the combustion engine can drive the first rotary electric machine and the first rotary electric machine is thus controlled as a generator to charge the battery of the motor vehicle. The second rotary electric machine is controlled as a traction machine.

[0086] - parallel hybrid drive, charging and boosting:

[0087] The disconnect clutch is closed, so that the first rotary electric machine, the second rotary electric machine and the combustion engine are coupled to one another. The motor vehicle is driven by means of the combustion engine and / or one or both rotary electric machines. The two rotary electric machines can be controlled here as traction machines or as generators.

[0088] In a further embodiment, the drive assembly further comprises at least one wheel drive shaft, on which the wheels of the motor vehicle equipped with the drive assembly are arranged, and which is connected to the second shaft of the drive unit via the gear box of the drive unit, so that the rotary motion effected by the second shaft can be transmitted to the wheel drive shaft and thus to the wheels by means of the gear box.

[0089] In this regard, the coolant supply of the drive unit is fluidically coupled to or part of the coolant circuit of the drive assembly. The pump actuator circulates the coolant in the cooling circuit, wherein the heat exchanger enables heat transfer.

[0090] The pump actuator can be mounted in the housing element and the heat exchanger can be arranged radially outside the second housing.

[0091] The delivery of the coolant in the cooling circuit can be carried out in such a way that the pump actuator sucks in warm coolant from a so-called coolant sump or coolant reservoir, which is collected / intermediately stored in the coolant sump or coolant reservoir after the heat absorption. The warm coolant is fed by the pump actuator to the heat exchanger, where the heat is released. The now cooled coolant is fed via the second housing into the first housing and at the first housing to the coolant supply device and into the axially extending axial flow channel in the first shaft. BRIEF DESCRIPTION OF DRAWINGS

[0092] The application described above is explained in greater detail below based on the relevant technical background, with reference to the relevant drawings showing preferred embodiments. The application is in no way restricted to the purely exemplary embodiments shown in the drawings, although it should be noted that the exemplary embodiments shown in the drawings are not limited to the dimensions shown. In the drawings:

[0093] Figure 1 Fig. 1 shows a schematic view of a drive assembly with a drive unit according to the application,

[0094] Figure 2 Fig. 2 shows a cross section of a drive assembly according to the application in a cross-sectional side view,

[0095] Figure 3 Fig. 3 shows a cross section of a drive unit according to the application in the region of a rotary electric machine,

[0096] Figure 4 Fig. 4 shows a cross section of a drive unit according to the application in the region of a rotary electric machine in an alternative embodiment,

[0097] Figure 5 Fig. 5 shows a cross section of a drive assembly according to the application with a drive unit according to the application in a cross-sectional side view, with the coolant flow highlighted,

[0098] Figure 6 Fig. 6 shows a cross section of a drive unit according to the application in the region of a rotary electric machine, with the coolant flow highlighted, and

[0099] Figure 7 Fig. 7 shows a cross section of a drive unit according to the application in the region of a rotary electric machine in an alternative embodiment, with the coolant flow highlighted. DETAILED DESCRIPTION

[0100] In Figures 1 to 4In the middle, the drive assembly is initially shown for general illustration purposes without reference to cooling or coolant supply.

[0101] Figure 1 A schematic view of a drive assembly 100 according to the application is shown with a drive unit 1 according to the application.

[0102] The drive unit 1 comprises a first rotary electric machine 10, a second rotary electric machine 20, a first shaft 40 and a second shaft 41.

[0103] Furthermore, the drive assembly 100 comprises an internal combustion engine 103 and a vibration damper 101, wherein an output element 104 of the internal combustion engine 103 is coupled to the vibration damper 101. The vibration damper 101 is further connected to a connection element 4 of the drive assembly 1, which connection element serves as an input side 2 of the drive assembly 1. Thus, the internal combustion engine 103 is coupled to the drive assembly 1 via the vibration damper 104.

[0104] The connection element 4 is coupled to the first shaft 40 such that a first transmission stage 70 is formed between the connection element 4 and the first shaft 40.

[0105] The rotor 11 of the first rotary electric machine 10 is connected to the first shaft 40 in a non-rotatable manner and the rotor 21 of the second rotary electric machine 20 is connected to the second shaft 41 in a non-rotatable manner. The connection of the rotor 11 of the first rotary electric machine 10 to the first shaft 40 is realized such that the rotor 11 of the first rotary electric machine 10 is arranged directly on the first shaft 40. In contrast, the rotor 21 of the second rotary electric machine 20 is supported by a rotor carrier 30 and the rotor carrier 30 is connected to the second shaft 41.

[0106] The first rotary electric machine 10 is arranged radially and partially axially within an area radially delimited by the second rotary electric machine 20. In this respect, the first rotary electric machine 10 is designed as an inner rotor motor and the second rotary electric machine 20 is designed as an outer rotor motor, wherein the stator 12 of the first rotary electric machine 10 and the stator 22 of the second rotary electric machine 20 are mechanically fixed to each other.

[0107] The decoupling clutch 50 of the drive unit 1 is connected with its input side 51 to the first shaft 40 and with its output side 52 to the second shaft 41. The decoupling clutch 50 is thus used to transmit torque between the first shaft 40 and the second shaft 41. Thus, the decoupling clutch 50 can be used to open or close a torque transmission path between the rotor 11 of the first rotary electric machine 10 and the rotor 21 of the second rotary electric machine 20.

[0108] The second shaft 41 is designed as a hollow shaft, and the first shaft 40 extends partially inside the second shaft 41 radially. The two shafts 40, 41 thus extend coaxially to each other, wherein the rotors 11, 21 of the two rotary electric machines 10, 20 are also arranged coaxially to each other and coaxially with respect to the shafts 40, 41.

[0109] The second shaft 41 is connected to an intermediate shaft 81 via a second transmission stage 71. In this respect, the intermediate shaft 81 extends parallel to the second shaft 41.

[0110] The intermediate shaft 81 is connected to an input element of a differential gear 80 of the drive unit 1 via a third transmission stage 72 for the purpose of transmitting torque. The differential gear 80 forms an output side 3 of the drive unit 1.

[0111] A wheel drive shaft 105 on which a wheel of the motor vehicle equipped with the drive assembly 100 is to be arranged forms an output end of the differential gear 80, such that a rotational movement effected by the second shaft 41 can be transmitted via the second transmission stage 71 and the third transmission stage 72 and via the differential gear 80 to the wheel drive shaft 105 and thus to the wheel.

[0112] Torque provided by the internal combustion engine 103 is transmitted via the vibration damper 101 and via the first transmission stage 70 to the first shaft 40 of the drive unit 1. In this respect, if the disconnect clutch 50 is open, the torque of the internal combustion engine 103 is only directed to the rotor 11 of the first rotary electric machine 10. In this way, the first rotary electric machine 10 can be used in generator operation for charging the battery. When the disconnect clutch 50 is closed, the torque provided by the internal combustion engine 103 is transmitted from the first shaft 40 to the second shaft 41. From the second shaft 41, the torque of the internal combustion engine 103 is transmitted via the second transmission stage 71 to the intermediate shaft 81 and via the third transmission stage 72 to the differential gear 80. Via the differential gear 80, the torque is transmitted to the wheels of the motor vehicle equipped with the drive assembly 100 by means of the wheel drive shaft 103.

[0113] When the disconnect clutch 50 is open, torque provided by the rotor 11 of the first rotary electric machine 10 can be transmitted via the first transmission stage 70 to the internal combustion engine 103. When the disconnect clutch 50 is closed, the torque is transmitted via the second transmission stage 71 and the third transmission stage 72 to the differential gear 80 and thus to the wheel drive shaft 105.

[0114] Torque provided by the rotor 21 of the second rotary electric machine 20 is transmitted via the second transmission stage 71 and the third transmission stage 72 to the differential gear 80 and thus to the wheel drive shaft 105, independently of the switching state of the disconnect clutch 50.

[0115] Thus, the drive assembly 100 can be operated in various drive operation modes.

[0116] Figure 2 A cross section of the drive assembly 100 according to the application is shown in a cross-sectional side view.

[0117] Figure 2 The individual components shown in Figure 1 Fig. 1 are shown in more detail, wherein Figure 2 In Fig. 1 the internal combustion engine is not shown and only the output element 104 of the internal combustion engine coupled to the vibration damper 101 is shown.

[0118] In Figure 2 Fig. 1 the first housing 60, the second housing 61 and the housing element 62 can be seen, which are connected to each other and form the entire housing of the drive assembly 100 or the drive unit 1. The first housing 60 and the second housing 61 serve to accommodate the two rotary electric machines 10, 20, wherein the housing element 62 serves to couple the first housing 60 and the second housing 61 to the housing of the internal combustion engine (not shown). For this purpose, the first housing 60 is fixedly connected to the second housing 61 in axial direction, wherein the housing element 62 is fixedly connected to the second housing 61 on the side of the second housing 61 which is axially opposite to the first housing 60.

[0119] The first shaft 40 has its first axial end portion 42 which is supported in the first housing 60 by a single-row bearing 92 and its second axial end portion 43 which is supported radially inside the second axial end portion 45 of the second shaft 41 by a needle bearing 91.

[0120] The second shaft 41 is supported via a central bearing unit 90 on the second housing 61 with its first axial end portion 44. This central bearing unit 90 comprises two coaxially arranged rolling bearings which are positioned closely next to each other in axial direction.

[0121] Furthermore, a common stator carrier 32 which supports the stators 12, 22 of the rotary electric machines 10, 20 is fixedly connected to the first housing 60, so that the stators 12, 22 of the rotary electric machines 10, 20 are supported by the first housing 60. The rotor carrier 30 of the rotor 21 of the second rotary electric machine 20 is supported on the second housing 61 by means of the rolling bearings of the central bearing unit 90. An encoder element of the rotor position sensor 34 is also connected to the rotor carrier 30, wherein a detector element of the rotor position sensor 34 is connected to the second housing 61, so that the detection of the angular position and / or the rotational speed of the rotor 21 or the rotor carrier 30 of the second rotary electric machine 20 can be performed by the rotor position sensor 34.

[0122] Further, the intermediate shaft 81 and the wheel drive shaft 105 are each supported in the second housing 61 on the axial side thereof facing the electric rotating machines 10, 20 and in the housing element 62 on the opposite axial side thereof. The connecting element 4 of the drive unit 1 is supported on the housing element 62 via a double-row bearing unit 93. This double-row bearing unit 93 comprises two coaxially arranged rolling bearings positioned next to each other in axial direction. A vibration damper 101 is arranged in the housing element 62.

[0123] The central bearing unit 90 and the double-row bearing unit 93 are each shown in different possible designs to illustrate their possible embodiments. The central bearing unit 90 is shown with a tapered roller bearing and an angular contact ball bearing, wherein the double-row bearing unit 93 is shown with a tapered roller bearing. However, as mentioned with respect to the central bearing unit 90, other bearings can also be used here, such as an angular contact ball bearing.

[0124] Further, power electronics 102 are arranged radially on the outside of the first housing 60 and the second housing 61, wherein the power electronics 102 are configured to control the electric rotating machines 10, 20. A heat exchanger 204 of a cooling circuit for cooling at least one of the electric rotating machines 10, 20 is also arranged on the second housing 61 and between the second housing 61 and the power electronics 102. A pump actuator 203 of the cooling circuit is supported by the housing element 62.

[0125] Figure 2 The detailed structure of the transmission stages 70, 71, 72 is also shown.

[0126] The first transmission stage 70 is configured such that the connecting element 4 comprises an inner toothed gear 5 which meshes with an outer toothing 46 on the second axial end portion 43 of the first shaft 40.

[0127] The second shaft 41 also has an outer toothing 47 at its second axial end portion 45, with which it meshes with a first gear wheel 82 which is arranged in a rotationally fixed manner on the intermediate shaft 81, such that a second transmission stage 71 is formed between the second shaft 41 and the intermediate shaft 81.

[0128] An outer toothing 84 of the intermediate shaft 81 engages with a second gear wheel 83 which is an input element of a differential gear 80, such that a third transmission stage 72 is formed between the intermediate shaft 81 and the differential gear 80.

[0129] The disconnect clutch 50 corresponds to a frictionally lockable multi-plate clutch, the input side 51 of which is formed by an inner plate which is arranged axially adjacent to the rotor 11 of the first electric rotating machine 10 on the first shaft 40, wherein an outer plate of the disconnect clutch 50 is connected as its output side 52 to the second shaft 41.

[0130] On the radially outer side of the central bearing unit 90, an actuation system 53 for actuating the disengagement clutch 50 is arranged on the second housing 61, wherein the pressure tank of the actuation system 53 is axially engaged by the rotor carrier 30 to transmit the actuating force provided by the actuation system 53 to the disengagement clutch 50 for disengaging the disengagement clutch.

[0131] In addition, a locking screw 35 is provided, which is screwed into the second shaft at the first axial end portion 44 of the second shaft 41, such that the screw head of the locking screw 35 applies an axial preload to the two rolling bearings of the rotor carrier 30 and the central bearing unit 90, thereby fixing the axial position of the rotor carrier 30 and the central bearing unit 90 relative to the second shaft 41.

[0132] Figure 3 A cross-section of the drive unit 1 according to the invention is shown in the region of the rotary motors 10 and 20.

[0133] The cross section shows the... Figure 2 The implementation of the drive unit 1 is the same as that of the drive unit 1 in the text.

[0134] from Figure 3 As can be seen, the common stator support 32 is connected to the first housing 60 by means of support screws 33. For this purpose, the support screws 33 are axially guided through the radially extending section of the common stator support 32 and screwed into the first housing 60 in the axial direction.

[0135] In addition, the stator 12 of the first rotary motor 10, which is mounted on the radially inner side 36 of the common stator support 32, is axially offset relative to the stator 22 of the second rotary motor 20, which is mounted on the radially outer side 37 of the common stator support 32.

[0136] As Figure 3 An alternative to drive unit 1, Figure 4 A cross-section of the region of the rotary motors 10, 20 in an alternative embodiment of the drive unit 1 according to the invention is shown.

[0137] and Figure 3 Conversely, the stators 12 and 22 of the two rotary motors 10 and 20 are integral components of the stator unit 31.

[0138] The stator unit 31 is fixed to the first housing 60 by a carrier screw 33, which passes through the entire stator unit 31 in the axial direction and is screwed into the first housing 60 in the axial direction. Therefore, this alternative embodiment does not use additional stator carriers between the individual stators 12, 22, but includes a compact unit formed by only two stators 12, 22.

[0139] Figure 5 and Figure 6 A drive assembly according to the application is shown, which has a drive unit according to the application and a cooling circuit which is illustrated by arrows. Figure 7 A drive assembly according to the application is shown, which has a drive unit according to the application in an alternative embodiment, and also a cooling circuit which is illustrated by arrows.

[0140] Figure 5 Corresponds essentially to Figure 2 Wherein only partly the power electronics 102 are shown and the differential gear is not shown at all.

[0141] Figure 5 It is shown that by means of the pump actuator 203 as part of the cooling circuit, coolant can be conveyed through the first guide channel 205 and the second guide channel 206 to the heat exchanger 204.

[0142] For this purpose, the pump actuator 203 conveys warm coolant from a reservoir, which is not shown here. The first guide channel 205 is formed as a tube arranged within the housing element 62, which is fluidically connected to the second guide channel 206 in the interior of the housing. The second guide channel 206 is formed as an integral component of the second housing 61 and extends substantially in axial direction in the second housing.

[0143] The warm coolant supplied from the pump actuator 203 to the heat exchanger 204 is cooled by the heat exchanger 204 and is then guided to the third guide channel 207. Like the second guide channel 207, the third guide channel 207 is formed as an integral component of the second housing 61 and extends in a substantially axial direction.

[0144] The third guide channel 207 is fluidically connected to the fourth guide channel 208, wherein the fourth guide channel 208 extends in a substantially radial direction and is an integral component of the first housing 60.

[0145] The fourth guide channel 208 allows the coolant cooled by the heat exchanger 204 to be guided to the stators 12, 22 of the two rotary electric machines 10, 20, which is shown in more detail in Figure 6 and is guided radially to the interior, wherein the fourth guide channel 208 is fluidically coupled to a shaft flow channel 230 extending axially in the first shaft 40.

[0146] The shaft flow channel 230 serves to supply coolant to the rotors 11, 21 of the two rotary machines 10, 20, the split clutch 50 and the central bearing unit 90.

[0147] For the purpose of supplying coolant to the rotor 11 of the first electric rotating machine 10, the first shaft 40 comprises radially extending first lateral holes 231 fluidically connected to the shaft flow channel 230 and axially centrally located with respect to the rotor 11 of the first electric rotating machine 10 and thus radially superimposed with the rotor 11 of the first electric rotating machine 10.

[0148] In the radial direction and between the first shaft 40 and the rotor 11 of the first electric rotating machine 10, the first shaft 40, the rotor 11 or the first shaft 40 and the rotor 11 further form a plurality of axial cooling channels 214 extending from one end face to the opposite end face of the rotor 11 and each fluidically coupled to at least one of the first lateral holes 231.

[0149] Thus, coolant guided in the shaft flow channel 230 can pass through the first lateral holes 231 into the axial cooling channels 214 and thus to the rotor 11 of the first electric rotating machine 10. The axial cooling channels 214 evenly distribute coolant in the axial direction along the radially inner side of the rotor 11 of the first electric rotating machine 10, thereby achieving an optimal cooling of the rotor of the first electric rotating machine. Coolant flows axially out of the axial cooling channels 214 close to both sides of the rotor 11 of the first electric rotating machine 10 and there is guided radially outward along the respective end face of the rotor 11 to the winding heads of the stator 12 of the first electric rotating machine 10 in order to cool the winding heads.

[0150] For the purpose of supplying coolant to the rotor 21 of the second electric rotating machine 20, the further lateral holes 232 are radially inclined to the area delimited by the rotor carrier 30 carrying the rotor 21 of the second electric rotating machine 20. Coolant flowing out of these further lateral holes 232 is carried radially outward by centrifugal force and / or gravity, wherein the rotor carrier 30 of the rotor 21 of the second electric rotating machine 20 effects a guiding of the coolant to the axial side of the rotor 21 facing away from the first housing 60.

[0151] For this purpose, the further lateral holes 232 are arranged at different axial positions in the first shaft 40, wherein the further lateral holes 232 for supplying coolant are radially superimposed with the separating clutch 50 or the central bearing unit 90 for a targeted cooling.

[0152] For the purpose of supplying coolant to the rotor 21 of the second electric rotating machine 20, the further lateral holes 232 are radially inclined to the area delimited by the rotor carrier 30 carrying the rotor 21 of the second electric rotating machine 20. Coolant flowing out of these further lateral holes 232 is carried radially outward by centrifugal force and / or gravity, wherein the rotor carrier 30 of the rotor 21 of the second electric rotating machine 20 effects a guiding of the coolant to the axial side of the rotor 21 facing away from the first housing 60.

[0153] In this regard, a plurality of grooves 23 are provided on the contact surface of the rotor 21 of the second rotary electric machine 20 on the rotor carrier 30 in the axial direction, wherein the grooves are formed by the rotor 21 or by the rotor carrier 30 or by the rotor 21 and the rotor carrier 30.

[0154] The grooves 23 thus allow an axial distribution of the coolant in the rotor 21 of the second rotary electric machine 20 or on the rotor of the second rotary electric machine.

[0155] The coolant, which is reheated after cooling the respective unit, is collected in the second housing 61, from which the coolant is returned to the reservoir.

[0156] Figure 6 A cross section of the drive unit 1 according to the application in the region of the rotary electric machines 10, 20 is shown. As Figure 5 In addition, Figure 6 A detailed representation of the coolant flow for cooling the stators 12, 22 of the two rotary electric machines 10, 20 is shown.

[0157] A coolant supply device 200 of the drive unit 1 is shown, by means of which coolant can be supplied axially between and / or into the stators 12, 22.

[0158] The cross section shows a drive unit 1 corresponding to the embodiment of the drive unit 1 in Figure 3 The cross section shows a drive unit 1 corresponding to the embodiment of the drive unit 1 in

[0159] In this regard, the fourth guide channel 208 is fluidically coupled to a distribution device 201 of the coolant supply device 200 as a component of the coolant supply device 200, wherein the distribution device 201 is configured as at least one axially extending channel in the first housing 60. The distribution device 201 is in turn fluidically coupled to at least one axial connection channel 210 formed in the stator carrier 32 of the coolant supply device 200 by means of at least one connection sleeve 202. The connection sleeve 202 is designed as a hollow cylindrical shape and has a smaller diameter than the distribution device 201 and the axial connection channel 210 for the purpose of fluidically connecting the distribution device 201 to the axial connection channel 210, so that the connection sleeve 202 is inserted into the distribution device 201 and the axial connection channel 210 partially in the axial direction to ensure a fluid-tight connection.

[0160] The axial connection channel 210 is in turn fluidically connected to a radial inner spiral channel 211 for conducting coolant, which is formed on the radial inner side 36 of the stator carrier 32. Furthermore, a radial outer spiral channel 212 for conducting coolant is formed on the radial outer side 37 of the stator carrier 32, wherein the radial inner spiral channel 211 is connected to the radial outer spiral channel 212 via a radial connection channel 213 through the stator carrier 32.

[0161] The two spiral channels 211, 212 are formed by respective grooves on the respective sides of the stator carrier 32, which are closed on the outside by the respective stator 12, 22 in contact with the respective side of the stator carrier 32, thus forming the channels.

[0162] The radial inner spiral channel 211 has an axial extension or axial position on the stator carrier 32 such that it extends substantially along the stator 12 of the first rotary electric machine 10, which is supported by the stator carrier 32 on its radial inner side 36. Accordingly, the radial outer spiral channel 212 has an axial extension or axial position on the stator carrier 32 such that it extends substantially along the stator 22 of the second rotary electric machine 20, which is supported by the stator carrier 32 on its radial outer side 37.

[0163] Thus, in this embodiment, the effective cooling of the stator 12 of the first rotary electric machine 10 can be achieved by means of the coolant guided in the radial inner spiral channel 211, and the effective cooling of the stator 22 of the second rotary electric machine 20 can be achieved by means of the coolant guided in the radial outer spiral channel 212.

[0164] Figure 7 A cross-section in the region of the rotary electric machines 10, 20 in an alternative embodiment of the drive unit 1 according to the application is shown. Figure 7 A coolant flow in the drive unit according to Figure 4 is shown.

[0165] A coolant supply device 200 of the drive unit 1 is shown, wherein the coolant supply device comprises an annular channel 220 having a plurality of axial outlets 221 generating a partial coolant flow 222, wherein the flow channels 223 in the stator unit 31 are fluidically coupled to the respective axial outlets 221.

[0166] The flow channel 223 is thus configured as an axial bore, wherein the flow channel 223 is arranged radially between the stator 12 of the first rotary electric machine 10 and the stator 22 of the second rotary electric machine 20. Thus, the coolant can be guided in the stator unit 31 such that an optimal cooling of both stators 12, 22 is achieved in an essentially equal manner.

[0167] In this regard, the axial outlets 221 are formed at an essentially regular angular interval and distributed around the circumference of the annular channel 220, such that the most uniform possible distribution of the partial coolant flows 222 and thus the optimal cooling can be achieved along the entire circumference of the stator 12 of the first rotary electric machine 10 and along the entire circumference of the stator 22 of the second rotary electric machine 20.

[0168] By means of the drive unit and the drive assembly according to the application, an optimal cooling function and thus an effective operation can be ensured in an inexpensive design and in a space-saving manner.

[0169] List of reference signs

[0170] 1 drive unit 2 input side of the drive unit 3 output side of the drive unit 4 connecting element of the drive unit 5 inner toothing of the connecting element 10 first rotary electric machine 11 rotor of the first rotary electric machine 12 stator of the first rotary electric machine 20 second rotary electric machine 21 rotor of the second rotary electric machine 22 stator of the second rotary electric machine 23 recess 30 rotor carrier of the second rotary electric machine 31 stator carrier 32 common stator carrier 33 carrier screw 34 rotor position sensor 35 locking screw 36 radially inner side of the stator carrier 37 radially outer side of the stator carrier 40 first shaft 41 second shaft 42 first axial end portion of the first shaft 43 second axial end portion of the first shaft 44 first axial end portion of the second shaft 45 second axial end portion of the second shaft 46 outer toothing of the first shaft 47 outer toothing of the second shaft 50 split clutch 51 input side of the split clutch 52 output side of the split clutch 53 actuation system 60 first housing 61 second housing 62 housing element 70 first transmission stage 71 second transmission stage 72 third transmission stage 80 differential gear 81 intermediate shaft 82 first gear wheel 83 second gear wheel 84 outer toothing of the intermediate shaft 90 central bearing unit 91 needle bearing 92 support bearing 93 double-row bearing unit 100 drive assembly 101 vibration damper 102 power electronics 103 internal combustion engine 104 output element of the internal combustion engine 105 wheel drive axle 200 coolant supply device 201 distribution device 202 connecting sleeve 203 pump actuator 204 heat exchanger 205 first guide channel 206 second guide channel 207 third guide channel 208 fourth guide channel 210 axial connection channel 211 radially inner spiral channel 212 radially outer spiral channel 213 radial connection channel 214 axial cooling channel 220 annular channel 221 axial outlet 222 partial coolant flow 223 flow channel 230 axial flow channel 231 first lateral bore 232 further lateral bore

Claims

1. A drive unit (1) for a power transmission system of an electrically driven motor vehicle, the drive unit having a first rotary motor (10) and a second rotary motor (20) and a first shaft (40) and a second shaft (41), wherein, The rotor (11) of the first rotary motor (10) is non-rotatably connected to the first shaft (40), and the rotor (21) of the second rotary motor (20) is non-rotatably connected to the second shaft (41), wherein the first rotary motor (10) is arranged at least partially radially and axially within a region radially defined by the second rotary motor (20), and the first rotary motor (10) is designed as an inner rotor motor and the second rotary motor (20) is designed as an outer rotor motor, wherein the stator (12) of the first rotary motor (10) and the stator (22) of the second rotary motor (20) are mechanically fixed to each other, characterized in that the drive unit (1) includes a coolant supply device (200) arranged axially adjacent to the stator (12, 22), and by means of the coolant supply device, coolant can be axially supplied to the stator (12, 22). The stators (12, 22) of the two rotating motors (10, 20) are arranged on a common stator support (32) between and axially supplied to the stator. The coolant is supplied to the stator support (32) by means of the coolant supply device (200), and the coolant supply device is designed to distribute the coolant in the axial direction. The stator support (32) has helical channels (211, 212) formed by grooves on the radially inner side (36) and the radially outer side (37) of the stator support. The grooves are closed by the corresponding stators (12, 22) that contact the corresponding sides of the stator support (32), thereby forming channels for conducting coolant. At least one radial connecting channel (213) is provided between the helical channel (211) on the radially inner side (36) and the helical channel (212) on the radially outer side (37).

2. The driving unit (1) according to claim 1, characterized in that, The coolant supply device (200) includes a dispensing device (201) arranged axially adjacent to the rotary motor (10, 20) for supplying coolant to the stator support (32), wherein the dispensing device (201) is fluidly connected by means of at least one connecting sleeve (202) to at least one connecting channel (210) axially formed in the stator support (32).

3. The driving unit (1) according to claim 1, characterized in that, The first shaft (40) has an axially extending shaft flow channel (230) adjacent to at least one first transverse hole (231) having a radial extension, through which coolant can be supplied from the shaft flow channel (230) to the rotor (11) of the first rotary motor (10).

4. The driving unit (1) according to claim 3, characterized in that, The rotor (21) of the second rotary motor (20) is rotatably mounted by means of a rotor carrier (30), wherein the rotor carrier (30) has a groove (23) and / or a hole for axial distribution of coolant in the rotor (21) of the second rotary motor (20) or on the rotor of the second rotary motor.

5. The drive unit (1) according to any one of claims 3 and 4, characterized in that, At least one additional transverse hole (232) is formed in the first shaft (40) for the purpose of allowing coolant axially adjacent to the rotary motor (10, 20) to flow out.

6. A drive assembly (100) having a drive unit (1) according to any one of claims 1 to 5 and having an internal combustion engine (103) that is non-rotatably coupled or capable of being coupled to the rotor (11) of the first rotary motor (10) by means of an output element (104) of the internal combustion engine (103).

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