Electrically operable final drive train, method for controlling final drive train, computer program product and control unit for controlling final drive train

Abstract

The invention relates to an electrically operable final drive powertrain (1) of a motor vehicle, comprising: an electric machine (3) which can be coupled to: at least one wheel (4) of the motor vehicle; and a transmission assembly (5) arranged in the torque flow between the wheel (4) and the electric machine (3); and a brake device (6) by means of which the wheels (4) can be braked; wherein a first clutch device (7) is arranged in the torque flow between the electric machine (3) and the brake device (6), by means of which first clutch device the brake device (6) can be coupled into and uncoupled from the torque flow, and a second clutch device (8) is arranged in the torque flow between the electric machine (3) and the transmission arrangement (5), by means of which second clutch device the brake device (6) can be coupled into and uncoupled from the torque flow. The transmission assembly (5) can be coupled into and uncoupled from the torque flow; alternatively, a first clutch device (7) is arranged in the torque flow between the electric machine (3) and the brake device (6), by means of which first clutch device the brake device (6) can be coupled into and uncoupled from the torque flow, and a second clutch device (8) is arranged in the torque flow between the brake device (6) and the transmission assembly (5), by means of which second clutch device the brake device (6) can be coupled into and uncoupled from the torque flow. By means of the second clutch device, the transmission assembly (5) can be coupled into and uncoupled from the torque flow.

Description

Technical Field

[0001] The invention relates to an electrically operable final drive powertrain of a motor vehicle, comprising an electric machine which can be coupled to at least one wheel of the motor vehicle in a torque-transmitting manner, a transmission assembly which is arranged in the torque flow between the wheel and the electric machine, and a braking device by means of which the wheel can be braked. The invention also relates to a method for controlling the final drive powertrain, a computer program product and a control unit for controlling the final drive powertrain. Background Art

[0002] Electric motors are increasingly being used to drive motor vehicles in order to create an alternative to internal combustion engines that require fossil fuels. Considerable efforts have been made to increase the suitability of electric drives for everyday use while also being able to provide users with the driving comfort they are accustomed to.

[0003] A detailed description of the electric drive can be found in the article entitled Hochintegrativ und Flexibel Elektrische Antriebseinheit für E-Fahrzeuge [Highly integrative and flexible electric drive unit for e-vehicles] by Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold in the German automobile magazine ATZ, Vol. 113, May 2011, pp. 360 to 365. The article describes a drive unit for an axle of a vehicle, the drive unit comprising: an electric motor, which is arranged concentrically and coaxially with respect to a bevel gear differential; a shiftable 2-speed planetary gear set, which is arranged in the drive train between the electric motor and the bevel gear differential and is also positioned coaxially with the electric motor and the bevel gear differential or the spur gear differential. The drive unit is very compact and, due to the shiftable 2-speed planetary gear set, enables a good compromise between gradeability, acceleration and energy consumption. Such drive units are also referred to as electric axles or electrically operable drivetrains.

[0004] Such electric vehicles already have a good level of efficiency compared to conventional "internal combustion engine vehicles", and the technology that is constantly developing in this field makes it possible to further reduce energy consumption. However, not only the technology used is responsible for the energy saving of autonomous and / or manually controlled motor vehicles. The driving style also has a strong influence on the consumption of such motor vehicles.

[0005] It is already known that a so-called "coasting mode" in a motor vehicle can further reduce energy consumption. Studies have shown that up to 25% of energy can be saved in an electrically operated motor vehicle by means of a "coasting mode". In "coasting mode", the kinetic energy of the vehicle is used to travel a certain distance without active propulsion.

[0006] DE 10 2017 100 988 A1 discloses a method for controlling a coasting mode of a vehicle having an automatic clutch, wherein, to enter the coasting mode with a gear engaged, the clutch is opened to decouple the internal combustion engine from the powertrain, and to exit the coasting mode, the clutch is closed. In the method for automatically adjusting the coasting mode, entering or exiting the coasting mode is automatically determined depending on the driver's behavior.

[0007] DE 10 2016 209 230 A1 discloses a method for controlling a gliding mode of a vehicle with an automatic clutch, wherein a vehicle-specific parameter is determined, which is compared with a threshold value. Based on the comparison with the threshold value, the activation or deactivation of the overrun mode is determined. In the method, in which the decision to activate or deactivate the gliding mode is made solely for technical reasons, a vehicle-specific parameter is selected for the comparison, which parameter is partially influenced by the actuation state of at least one accelerator pedal.

[0008] There is a continuing need for such final drive powertrains to provide the driver or vehicle controller with a multitude of different operating modes to deliver the highest levels of energy efficiency, comfort and safety. Summary of the invention

[0009] It is therefore an object of the present invention to provide an electrically operable final drive powertrain of a motor vehicle which enables a large number of different selectable operating modes with a structure that is as simple and cost-effective as possible. It is also an object of the present invention to provide an improved method for controlling a final drive powertrain, an optimized computer program product for controlling a final drive powertrain and an improved control unit for controlling a final drive powertrain.

[0010] The object is achieved by an electrically operable final drive powertrain of a motor vehicle, the electrically operable final drive powertrain comprising: an electric machine which can be coupled to at least one wheel of the motor vehicle in a torque-transmitting manner; a transmission assembly which is arranged in the torque flow between the wheel and the electric machine; and a braking device by means of which the wheel can be braked, and

[0011] a) a first clutch device is arranged in the torque flow between the electric machine and the brake device, by means of which the brake device can be coupled into and decoupled from the torque flow, and a second clutch device is arranged in the torque flow between the electric machine and the transmission assembly, by means of which the transmission assembly can be coupled into and decoupled from the torque flow, or

[0012] b) A first clutch device is arranged in the torque flow between the motor and the braking device, by means of which the braking device can be connected to and disconnected from the torque flow, and a second clutch device is arranged in the torque flow between the braking device and the transmission component, by means of which the transmission component can be connected to and disconnected from the torque flow.

[0013] This has the advantage that a large number of different operating modes can be achieved, as will be described in more detail below.

[0014] The embodiment denoted by a) has the advantage that the rotatable part of the braking device can be deactivated during driving, so that it does not generate any drag torque and a particularly efficient drive can be achieved.

[0015] In a design alternative of the final drive powertrain, denoted b), a fully integrated variant is realized which also has a shiftable clutch device. For example, the arrangement of the clutch device realized in variant b) makes it possible to completely decouple the engine from the powertrain when only the braking device is used to brake the wheels.

[0016] The electrically operable powertrain comprises an electric machine and preferably a transmission assembly coupled to the electric machine. The transmission assembly and the electric machine in particular form a structural unit. The structural unit can be formed, for example, by means of a powertrain housing in which the transmission assembly and the electric machine are accommodated together. The structural unit is sometimes also referred to as an electric axle.

[0017] An electric machine is used to convert electrical energy into mechanical energy and / or mechanical energy into electrical energy and generally comprises a fixed part called a stator and a part called a rotor which is arranged movably, in particular rotatably, relative to the fixed part. An electric machine can be configured as a radial flux machine or an axial flux machine.

[0018] In particular, the electric machine is dimensioned such that a vehicle speed of more than 50 km / h, preferably more than 80 km / h, and in particular more than 100 km / h can be achieved. The electric motor particularly preferably has an output of more than 30 kW, preferably more than 50 kW, and in particular more than 70 kW. Furthermore, it is preferred that the electric machine provides a speed of more than 5000 rpm, particularly preferably more than 10,000 rpm, very particularly preferably more than 12,500 rpm.

[0019] For the purposes of this application, a motor vehicle is a land vehicle that moves by machine power and is not constrained by railway tracks. The motor vehicle may for example be selected from the group consisting of a passenger car, a truck, a scooter, a light motor vehicle, a motorcycle, a bus / coach or a tractor.

[0020] The powertrain may also include a control unit. The control unit used in the invention is used in particular for electronic open-loop and / or closed-loop control of one or more technical systems of the powertrain, in particular an electric machine and / or a clutch and / or a brake.

[0021] For example, the control unit has in particular a wired or wireless signal input for receiving in particular electrical signals, such as sensor signals. In addition, the control unit also preferably has a wired or wireless signal output for transmitting in particular electrical signals, such as to an electric actuator or an electrical consumer of an electrically operable final drive powertrain of the motor vehicle.

[0022] Open-loop control operations and / or closed-loop control operations can be performed in the control unit. Very particularly preferably, the control unit comprises hardware designed to run the software. The control unit preferably comprises at least one electronic processor for executing program sequences defined in the software.

[0023] The control unit may also have one or more electronic memories in which the data contained in the signals transmitted to the control unit may be stored and read out again. In addition, the control unit may have one or more electronic memories in which data may be stored in a modifiable and / or non-modifiable manner.

[0024] The control unit may comprise a plurality of controllers which are arranged in particular in a spatially separated manner in the motor vehicle. The controllers are also referred to as electronic control units (ECU) or electronic control modules (ECM) and preferably have an electronic microcontroller for carrying out computing operations for processing data, particularly preferably using software. The controllers may preferably be interconnected with one another, such that wired and / or wireless data exchange between the controllers is possible. In particular, the controllers may also be interconnected with one another via a bus system present in the motor vehicle, such as, for example, a CAN bus or a LIN bus.

[0025] Very particularly preferably, the control unit has at least one processor and at least one memory, in particular containing a computer program code, the memory and the computer program code being configured in such a way that the control unit executes the computer program code by means of the processor.

[0026] The control unit may particularly preferably include a power electronics module for supplying power to the motor. The power electronics module is preferably a combination of different components that provide open-loop control or closed-loop control of the current to the motor, preferably including peripheral components such as cooling elements or power supply units required for this purpose. In particular, the power electronics module contains a power electronics system or one or more power electronics components configured to provide open-loop control or closed-loop control of the current. These power electronics systems or power electronics components are particularly preferably one or more power switches, such as power transistors. The power electronics system particularly preferably has more than two phases or current paths, particularly preferably three phases or current paths, which are separated from each other and each has at least one separate power electronics component. The power electronics system is preferably designed for open-loop control or closed-loop control of the power of each phase, wherein the peak power is preferably at least 100W, preferably at least 1000W, particularly preferably at least 10000W of continuous power.

[0027] The clutch device can be a manual clutch device, a semi-automatic clutch device or an automatic clutch device. Preferably, the clutch device can be a disengaged clutch. The clutch device can be an electronic clutch. An electronic clutch is an electronically controlled and actuated automatic clutch device. The clutch device can also be a dual clutch or a multi-plate clutch. In addition, the clutch device can be designed as a friction type and / or an interlocking type. According to another preferred further improvement of the present invention, the clutch device can be actuated by means of a hydraulic release system. The hydraulic release system usually has a master cylinder, which transmits the pressure generated on the master cylinder to the slave cylinder via a hydraulic pressure line, preferably to a central release mechanism. In particular, the hydraulic pressure can also be provided by means of a so-called power group, which includes a hydraulic pump and a hydraulic accumulator that can be acted on by the hydraulic pump. In this case, the pressure chamber of the slave cylinder can also be pressurized hydraulically, for example, by a master cylinder controlled by an electric motor of a controller or by a hydraulic pump, optionally with the cooperation of a pressure accumulator. A power group can be used in an advantageous manner, which switches multiple pressure circuits, in particular via a central hydraulic pump and corresponding valves.

[0028] The slave cylinder, which in the present case is particularly designed as a central release mechanism, preferably transmits hydraulic pressure to a clutch device in a hydraulic separation system by means of an axially displaceable piston, for example to form a friction connection and to close the friction clutch or to open it when the friction connection is released.

[0029] The hydraulic clutch release system particularly preferably actuates the clutch device hydraulically through the action of a master cylinder. As explained, this can be achieved by means of an actuator controlled by a control unit or by manual actuation by a driver.

[0030] Advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technically meaningful manner and can define further embodiments of the invention. In addition, the features indicated in the claims are specified and explained in more detail in the description, wherein further preferred embodiments of the invention are shown.

[0031] According to an advantageous embodiment of the invention, the brake device is encapsulated in a housing. This embodiment has the advantage that wear from the brake device cannot enter the environment through the encapsulated housing, thereby avoiding environmental and health effects caused by brake wear during operation of the final drive powertrain.

[0032] According to another preferred development of the invention, the brake device, the transmission assembly, the motor, the first clutch device and the second clutch device can also form a structural unit. This makes it possible to provide a preassembled functional module, which can then be integrated into the vehicle with relatively little installation effort.

[0033] Furthermore, according to a likewise advantageous embodiment of the invention, the final drive drive train can have a control unit which is connected to the brake device, the first clutch device and the second clutch device and which is configured such that

[0034] The control unit is able to switch the final drive powertrain into a plurality of different operating states by coupling and decoupling the clutch device and by releasing and actuating the brake device. The advantageous effect of this embodiment is based on the fact that the various operating modes allowed by the final drive powertrain due to its architecture can be provided by an electronic open-loop control system.

[0035] According to another particularly preferred embodiment of the present invention, the control unit can be configured such that: for the design alternative a) of the final drive powertrain, the control unit switches the final drive powertrain to

[0036] i. a first operating state in which the first clutch device and the second clutch device are in a disconnected state and the brake device is released, and / or

[0037] ii. a second operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is released, and / or

[0038] iii. a third operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is actuated, and / or

[0039] iv. a fourth operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is actuated,

[0040] or

[0041] The control unit is configured such that: for the design alternative b) of the final drive powertrain, the control unit switches the final drive powertrain to

[0042] i. a first operating state in which the first clutch device and the second clutch device are in a disconnected state and the brake device is released, and / or

[0043] ii. a second operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is released, and / or

[0044] iii. a third operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is actuated, and / or

[0045] iv. a fourth operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is actuated, and / or

[0046] v. A fifth operating state, in which the first clutch device is in a coupled state and the second clutch device is in a decoupled state, and the brake device is actuated.

[0047] In the first operating state (i) of the design alternatives a) and b), the final drive drive train is switched to a so-called coasting mode, in which the electric machine is decoupled from the wheels in order to avoid a corresponding resistance generated by the electric machine.

[0048] A coasting process of a vehicle means a driving state of the vehicle in which the wheels are at least disconnected from the electric machine of the powertrain by opening the corresponding clutch device or devices, whereby in particular the torque loss of the electric machine and possibly the brake device are disconnected from the wheels and thus the energy efficiency of the motor vehicle can be increased and the energy consumption can be reduced. During the coasting process, the electric machine can be switched off or put into operation. Thus, the coasting process can, for example, reduce the speed of the motor vehicle without actively braking the wheels, for example by the air resistance and rolling resistance of the motor vehicle.

[0049] In the second operating state (ii) of the first design alternative a) and the second embodiment b), a “standard” drive mode can be set, in which the electric machine drives the wheels in motor mode and / or brakes the wheels in generator mode (regenerative braking).

[0050] In the third operating state (iii) of the first embodiment a) and the second embodiment b), the braking device is coupled to the wheel so that a "mechanical" braking of the wheel is achieved. The electric machine can be switched to generator mode and thus support the braking effect of the mechanical braking device. In this third operating state, the electric machine can also be switched to motor mode, for example to achieve a thermal heating and / or cooling circuit in the vehicle via the increased friction heat of the braking device during driving, in particular for climate control of the passenger compartment.

[0051] In the fourth operating state (iv) of the first embodiment a) and the second embodiment, for example when the vehicle is stationary, an auxiliary heating function can be implemented, with which the electric machine drives the brake device in motor mode, thereby generating corresponding friction heat. This friction heat can then be used, for example, via a thermal heating and / or cooling circuit in the vehicle, in particular for climate control of the passenger compartment.

[0052] It should be appreciated that the final drive powertrain may be transitioned into one and / or more of these operating states.

[0053] In addition, the present invention can be further improved so that in the third operating state of the final drive powertrain, the electric machine is in a torque generating operating state to implement some of the above operating modes, such as an auxiliary heating function when the vehicle is stationary.

[0054] In an equally preferred embodiment of the invention, the brake device can also be connected to a fluid circuit by means of which the heat generated by the brake device during operation of the final drive powertrain can be dissipated. This makes it possible to simplify the thermal management system in the vehicle, for example by eliminating the PTC heating element.

[0055] The object of the invention is also achieved by a method for controlling a final drive powertrain of a motor vehicle, the final drive powertrain comprising: an electric machine which can be coupled to at least one wheel of the motor vehicle in a torque-transmitting manner; a transmission assembly which is arranged in the torque flow between the wheel and the electric machine; and a braking device by means of which the wheel can be braked.

[0056] a) arranging a first clutch device in the torque flow between the electric machine and the brake device, by means of which the brake device can be coupled into and decoupled from the torque flow, and arranging a second clutch device in the torque flow between the electric machine and the transmission assembly, by means of which the transmission assembly can be coupled into and decoupled from the torque flow,

[0057] or

[0058] b) arranging a first clutch device in the torque flow between the electric machine and the brake device, by means of which the brake device can be coupled into and decoupled from the torque flow, and arranging a second clutch device in the torque flow between the brake device and the transmission assembly, by means of which the transmission assembly can be coupled into and decoupled from the torque flow,

[0059] and the final drive powertrain comprises a control unit connected to the brake device, the first clutch device and the second clutch device and configured so that

[0060] The control unit is capable of switching the final drive powertrain into a plurality of different operating states by coupling and decoupling the clutch device and by releasing and actuating the brake device,

[0061] And the control unit is configured so that: for the design alternative a of the final drive powertrain, the control unit switches the final drive powertrain to

[0062] i. a first operating state in which the first clutch device and the second clutch device are in a disconnected state and the brake device is released, and / or

[0063] ii. a second operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is released, and / or

[0064] iii. a third operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is actuated, and / or

[0065] iv. a fourth operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is actuated,

[0066] or

[0067] i. The control unit is configured such that: for the design alternative b of the final drive powertrain, the control unit converts the final drive powertrain to

[0068] ii. a first operating state in which the first clutch device and the second clutch device are in a decoupled state and the brake device is released, and / or

[0069] iii. a second operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is released, and / or

[0070] iv. a third operating state in which the first clutch device and the second clutch device are in a coupled state and the brake device is actuated, and / or

[0071] v. a fourth operating state in which the first clutch device is in a decoupled state and the second clutch device is in a coupled state, and the brake device is actuated, and / or

[0072] vi. A fifth operating state, in which the first clutch device is in a coupled state and the second clutch device is in a decoupled state, and the brake device is actuated.

[0073] Furthermore, the object of the present invention can be achieved by a computer data signal embodied by electromagnetic waves or a computer program product stored on a machine-readable carrier, which has a computer program code suitable for executing the method according to claim 8.

[0074] Finally, the object of the present invention can also be achieved by a control unit for controlling a final drive powertrain of a motor vehicle, the control unit comprising a processor and a memory containing computer program code, wherein the memory and the computer program code are configured to cause the control unit to execute the method according to claim 8 using the processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] The invention is explained in more detail below with reference to the accompanying drawings without limiting the general concept of the invention.

[0076] In the attached picture:

[0077] Figure 1 A first embodiment of a final drive powertrain in a first operating state is shown in a schematic block diagram;

[0078] Figure 2 A first embodiment of a final drive powertrain in a second operating state is shown in schematic block diagram form;

[0079] Figure 3 A first embodiment of a final drive powertrain in a third operating state is shown in a schematic block diagram;

[0080] Figure 4 A first embodiment of a final drive powertrain in a fourth operating state is shown in schematic block diagram form;

[0081] Figure 5 A second embodiment of a final drive powertrain in a first operating state is shown in schematic block diagram form;

[0082] Figure 6 A second embodiment of a final drive powertrain in a second operating state is shown in schematic block diagram form;

[0083] Figure 7 A second embodiment of a final drive powertrain in a third operating state is shown in schematic block diagram form;

[0084] Figure 8 A second embodiment of a final drive powertrain in a fourth operating state is shown in schematic block diagram form;

[0085] Fig. 9 A second embodiment of the final drive powertrain is shown in a schematic block diagram in a fifth operating state. DETAILED DESCRIPTION

[0086] Figures 1 to 9 An electrically operable final drive powertrain 1 of a motor vehicle is shown, comprising: an electric motor 3, which can be coupled to at least one wheel 4 of the motor vehicle in a torque-transmitting manner; a transmission assembly 5, which is arranged in the torque flow between the wheel 4 and the electric motor 3; and a braking device 6, by means of which the wheel 4 can be braked.

[0087] exist Figures 1 to 4 In the first embodiment (design alternative a)) of the final drive powertrain 1 in different operating states shown in FIG, a first clutch device 7 is arranged in the torque flow between the electric machine 3 and the brake device 6, by means of which the brake device 6 can be coupled into and decoupled from the torque flow. In addition, a second clutch device 8 is also arranged in the torque flow between the electric machine 3 and the transmission assembly 5, by means of which the transmission assembly 5 can be coupled into and decoupled from the torque flow.

[0088] exist Figures 5 to 9 In the second embodiment (design alternative b) of the final drive powertrain 1 in different operating states shown in the figure, a first clutch device 7 is arranged in the torque flow between the motor 3 and the braking device 6, by means of which the braking device 6 can be connected to the torque flow and disconnected from the torque flow, and in addition, a second clutch device 8 is arranged in the torque flow between the braking device 6 and the transmission component 5, by means of which the transmission component 5 can be connected to the torque flow and disconnected from the torque flow.

[0089] from Figures 1 to 9 It is also evident that the brake device 6 in both embodiments is enclosed in a housing 9. Figures 1 to 4 In a first embodiment, the brake device 6 is accommodated in a separate housing 9 which is associated with the brake device 6 and which can be connected, for example, to a motor housing 12 of the electric motor 3. Figures 5 to 9 In the second embodiment, the housing 9 surrounds the motor 3, the transmission assembly 5 and the brake device 6. It should be understood that in this embodiment, the brake device 6 can also have a separate housing for packaging, but it is not shown in the figure.

[0090] exist Figures 1 to 9In the embodiment shown, the brake device 6 , the transmission assembly 5 , the electric machine 3 , the first clutch device 7 and the second clutch device 8 form a structural unit 10 and can therefore be supplied as a module and installed on a vehicle.

[0091] In the embodiment shown, the braking device 6 is connected to a fluid circuit 22 by means of which the heat generated by the braking device 6 during operation of the final drive powertrain 1 can be dissipated, for example in order to cool the braking device 6 and / or use the dissipated heat for climate control of the vehicle's passenger compartment.

[0092] In both embodiments, the final drive powertrain 1 has a control unit 11 which is connected to the brake device 6, the first clutch device 7 and the second clutch device 8 and is configured such that

[0093] The control unit 11 can switch the final drive powertrain 1 to a plurality of different operating states by coupling and decoupling the clutch devices 7, 8 and by releasing and actuating the brake device 6. The control unit 11 comprises a processor 23 and a memory 24 containing computer program code, and the memory 24 and the computer program code are configured to use the processor 23 to cause the control unit 11 to perform the method of setting different operating states described below.

[0094] Figure 1 A first operating state 13 is shown, into which the control unit 11 switches the final drive powertrain 1 for the design alternative a). In this first operating state 13, the first clutch device 7 and the second clutch device 8 are in a decoupled state. The brake device 6 is released, so that a coasting mode of the final drive powertrain 1 can be achieved.

[0095] exist Figure 2 In, from Figure 1 The known final drive powertrain is switched to a second operating state 14 in which the first clutch device 7 is in a disconnected state and the second clutch device 8 is in a coupled state, and the brake device 6 is still released, so that conventional driving or regenerative braking can be achieved depending on whether the electric machine 3 is in a motor operating state or a generator operating state.

[0096] exist Figure 3In the third operating state 15 shown in FIG, the first clutch device 7 and the second clutch device 8 are in a coupled state. In addition, the brake device 6 is actuated so that the brake device 6 is coupled to the wheel 4 and a "mechanical" braking of the wheel is achieved. The electric machine 3 can be switched to generator mode and thus support the braking effect of the mechanical brake device 6. In this third operating state 15, the electric machine 3 can also be switched to motor mode, for example to achieve a thermal heating and / or cooling circuit (fluid circuit 22) in the vehicle via the increased friction heat of the brake device 6 during driving, in particular for climate control of the passenger compartment.

[0097] exist Figure 4 , the final drive powertrain 1 is switched to a fourth operating state 16, in which the first clutch device 7 is in a disconnected state and the second clutch device 8 is in a coupled state, and the brake device 6 is actuated. In the fourth operating state 16 of the first embodiment, for example when the vehicle is stationary, a parking heater function can be realized, wherein the electric machine 3 drives the brake device 6 in motor mode, thereby generating corresponding friction heat. This friction heat can then be used, for example, via a thermal heating and / or cooling circuit (fluid circuit 22) in the vehicle, in particular for climate control of the passenger compartment.

[0098] Figure 5 A first operating state 17 is shown, into which the control unit 11 switches the final drive powertrain 1 for the design alternative b). In this first operating state 17, the first clutch device 7 and the second clutch device 8 are in a decoupled state, and the brake device 6 is released. This realizes a coasting mode of the final drive powertrain 1.

[0099] exist Figure 6 middle, Figure 5 The final drive powertrain in the embodiment is converted to the second operating state 18, in which the first clutch device 7 and the second clutch device 8 are in the coupled state and the brake device 6 is released. This enables conventional driving or regenerative braking depending on whether the electric machine 3 is in the motor operating state or the generator operating state.

[0100] exist Figure 7In the third operating state 19 shown in FIG. 1 , the first clutch device 7 and the second clutch device 8 are in the coupled state, and the brake device 6 is actuated, so that the brake device 6 is coupled to the wheel 4 and a “mechanical” braking of the wheel 4 is achieved. The electric machine 3 can be switched to generator mode and thus support the braking effect of the mechanical brake device 6. In this third operating state 15, the electric machine 3 can also be switched to motor mode, for example to achieve a thermal heating and / or cooling circuit (fluid circuit 22) in the vehicle via the increased friction heat of the brake device 6 during driving, in particular for climate control of the passenger compartment.

[0101] exist Figure 8 , the final drive powertrain 1 is placed in a fourth operating state 20, in which the first clutch device 7 is in a disconnected state and the second clutch device 8 is in a coupled state, and the brake device 6 is actuated so that the wheel 4 can be braked only by the brake device 6 without the brake device 6 being additionally subjected to the drag torque of the motor 3.

[0102] The second embodiment of the final drive powertrain 1 can also be converted to Fig. 9 , and in this fifth operating state, the first clutch device 7 is in the coupled state and the second clutch device 8 is in the decoupled state, and the brake device 6 is actuated. In the fifth operating state 21 of the second embodiment, for example when the vehicle is stationary, a parking heater function can be realized, wherein the electric machine 3 drives the brake device 6 in motor mode, thereby generating corresponding friction heat. This friction heat can then be used, for example, via a thermal heating and / or cooling circuit (fluid circuit 22) in the vehicle, in particular for climate control of the passenger compartment.

[0103] The terms "radial", "axial", "tangential" and "circumferential" used in this application always refer to the axis of rotation of the rotor of the electric machine. The terms "left", "right", "above", "below" and "above", "below" are used here only to clarify the area of ​​the illustration currently described in the text. Later embodiments of the invention may also be arranged in different ways. The present invention is also not limited to the embodiments shown in the drawings. Therefore, the above description should not be regarded as restrictive, but as illustrative. The attached claims should be understood to mean that the stated features are present in at least one embodiment of the invention. This does not exclude the presence of other features. In the case where the claims and the above description define a "first" feature and a "second" feature, this naming is used to distinguish between two features of the same type without limiting the order of priority.

[0104] Reference numerals list

[0105] 1 Final drive powertrain

[0106] 3 Motor

[0107] 4 wheels

[0108] 5 Transmission components

[0109] 6 Braking device

[0110] 7 Clutch device

[0111] 8 Clutch device

[0112] 9 Housing

[0113] 10 units

[0114] 11 Control Unit

[0115] 12 Motor housing

[0116] 13 Operation Status

[0117] 14 Operation Status

[0118] 15 Operation Status

[0119] 16 Operation Status

[0120] 17 Operation Status

[0121] 18 Operation Status

[0122] 19 Operation Status

[0123] 20 Operation Status

[0124] 21 Operation Status

[0125] 22 Fluid circuit

[0126] 23 Processor

[0127] 24 Memory.

Claims

1. An electrically operable final drive powertrain (1) for a motor vehicle, the electrically operable final drive powertrain comprising: an electric machine (3) which can be coupled to at least one wheel (4) of the motor vehicle in a torque-transmitting manner; and a transmission assembly (5) arranged in the torque flow between the wheel (4) and the electric motor (3); and a braking device (6) by means of which the wheel (4) can be braked, It is characterized in that a) a first clutch device (7) is arranged in the torque flow between the electric machine (3) and the brake device (6), by means of which the brake device (6) can be coupled into and disconnected from the torque flow, and a second clutch device (8) is arranged in the torque flow between the electric machine (3) and the transmission assembly (5), by means of which the transmission assembly (5) can be coupled into and disconnected from the torque flow, or b) a first clutch device (7) is arranged in the torque flow between the motor (3) and the brake device (6), by means of which the brake device (6) can be connected to and disconnected from the torque flow, and a second clutch device (8) is arranged in the torque flow between the brake device (6) and the transmission assembly (5), by means of which the transmission assembly (5) can be connected to and disconnected from the torque flow.

2. The final drive powertrain (1) according to claim 1, It is characterized in that The braking device (6) is encapsulated in a housing (9).

3. The final drive powertrain (1) according to claim 1 or 2, It is characterized in that The brake device (6), the transmission assembly (5), the electric motor (3), the first clutch device (7) and the second clutch device (8) form a structural unit (10).

4. Final drive powertrain (1) according to any one of the preceding claims, It is characterized in that The final drive powertrain (1) has a control unit (11) which is connected to the brake device (6), the first clutch device (7) and the second clutch device (8) and is configured such that The control unit (11) is capable of switching the final drive powertrain (1) into a plurality of different operating states by coupling and decoupling the clutch devices (7, 8) and by releasing and actuating the brake device (6).

5. The final drive powertrain (1) according to claim 4, It is characterized in that The control unit (11) is configured such that: for the design alternative a) of the final drive powertrain (1), the control unit switches the final drive powertrain to i. a first operating state (13), in which the first clutch device (7) and the second clutch device (8) are in a disconnected state and the brake device (6) is released, and / or ii. a second operating state (14), in which the first clutch device (7) is in a disconnected state and the second clutch device (8) is in a coupled state, and the brake device (6) is released, and / or iii. a third operating state (15), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is actuated, and / or iv. a fourth operating state (16), in which the first clutch device (7) is in a decoupled state and the second clutch device (8) is in a coupled state, and the brake device (6) is actuated, or The control unit (11) is configured such that: for the design alternative b) of the final drive powertrain (1), the control unit switches the final drive powertrain to i. a first operating state (17), in which the first clutch device (7) and the second clutch device (8) are in a disconnected state and the brake device (6) is released, and / or ii. a second operating state (18), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is released, and / or iii. a third operating state (19), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is actuated, and / or iv. a fourth operating state (20), in which the first clutch device (7) is in a disconnected state and the second clutch device (8) is in a coupled state, and the brake device (6) is actuated, and / or v. A fifth operating state (21), in which the first clutch device (7) is in a coupled state and the second clutch device (8) is in a decoupled state, and the brake device (6) is actuated.

6. The final drive powertrain (1) according to claim 5, It is characterized in that In the third operating state (15, 19) of the final drive powertrain (1), the electric machine (3) is in a torque generating operating state.

7. Final drive powertrain (1) according to any one of the preceding claims, It is characterized in that The brake device (6) is connected to a fluid circuit (22), by means of which heat generated by the brake device (6) during operation of the final drive powertrain (1) can be dissipated.

8. A method for controlling a final drive powertrain (1) of a motor vehicle, the final drive powertrain comprising: an electric machine (3) which can be coupled to at least one wheel (4) of the motor vehicle in a torque-transmitting manner; and a transmission assembly (5) arranged in the torque flow between the wheels (4) and the motor (3); and a braking device (6), by means of which the wheel (4) can be braked, wherein: a) arranging a first clutch device (7) in the torque flow between the electric machine (3) and the brake device (6), by means of which the brake device (6) can be coupled into and decoupled from the torque flow, and arranging a second clutch device (8) in the torque flow between the electric machine (3) and the transmission assembly (5), by means of which the transmission assembly (5) can be coupled into and decoupled from the torque flow, or b) arranging a first clutch device (7) in the torque flow between the electric machine (3) and the brake device (6), by means of which the brake device (6) can be coupled into and decoupled from the torque flow, and arranging a second clutch device (8) in the torque flow between the brake device (6) and the transmission assembly (5), by means of which the transmission assembly (5) can be coupled into and decoupled from the torque flow, The final drive powertrain (1) has a control unit (11) connected to the brake device (6), the first clutch device (7) and the second clutch device (8) and configured so that The control unit (11) is capable of switching the final drive powertrain (1) into a plurality of different operating states by coupling and decoupling the clutch devices (7, 8) and by releasing and actuating the brake device (6), The control unit (11) is configured such that: for the design alternative a) of the final drive powertrain (1), the control unit switches the final drive powertrain to i. a first operating state (13), in which the first clutch device (7) and the second clutch device (8) are in a disconnected state and the brake device (6) is released, and / or ii. a second operating state (14), in which the first clutch device (7) is in a disconnected state and the second clutch device (8) is in a coupled state, and the brake device (6) is released, and / or iii. a third operating state (15), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is actuated, and / or iv. a fourth operating state (16), in which the first clutch device (7) is in a decoupled state and the second clutch device (8) is in a coupled state, and the brake device (6) is actuated, or The control unit (11) is configured such that: for the design alternative b) of the final drive powertrain (1), the control unit switches the final drive powertrain to i. a first operating state (17), in which the first clutch device (7) and the second clutch device (8) are in a disconnected state and the brake device (6) is released, and / or ii. a second operating state (18), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is released, and / or iii. a third operating state (19), in which the first clutch device (7) and the second clutch device (8) are in a coupled state and the brake device (6) is actuated, and / or iv. a fourth operating state (20), in which the first clutch device (7) is in a disconnected state and the second clutch device (8) is in a coupled state, and the brake device (6) is actuated, and / or v. A fifth operating state (21), in which the first clutch device (7) is in a coupled state and the second clutch device (8) is in a decoupled state, and the brake device (6) is actuated.

9. A computer data signal embodied by an electromagnetic wave or a computer program product stored on a machine-readable carrier, having a computer program code adapted to execute the method according to claim 8.

10. A control unit (11) for controlling a final drive powertrain (1) of a motor vehicle, wherein: The control unit (11) comprises a processor (23) and a memory (24) containing computer program code, and the memory (24) and the computer program code are configured to cause the control unit (11) to perform the method according to claim 8 with the processor (23).

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