A powertrain for a motor vehicle, a motor vehicle and a method

Abstract

A powertrain 14, for a motor vehicle 10, with a transmission 15, an electric motor 16 and an internal combustion engine (ICE) 18 that can each drive a wheel 12, and an electromagnetic clutch 20. The c

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a powertrain for a motor vehicle. Furthermore, the present invention relates to a corresponding motor vehicle as well as to a corresponding method for operating a powertrain for a motor vehicle. BACKGROUND INFORMATION

[0002] In the state of the art, a powertrain of a motor vehicle may comprise at least one electric engine and an internal combustion engine in order to drive the motor vehicle. In cases in which the motor vehicle is driven by the electric motor and the internal combustion engine is not needed it may be possible to uncouple the internal combustion engine, in particular an output shaft of the internal combustion engine, by a clutch of the said powertrain. In the state of the art, the said clutch may be designed as a hydraulically or pneumatically operated clutch. However, this may not be energy efficient. Furthermore, coupling and decoupling the internal combustion engine or the output shaft, respectively, may not be possible in an efficient and time-saving manner. SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a powertrain for a motor vehicle, a corresponding motor vehicle, as well as a method for operating a powertrain for a motor vehicle by which the powertrain can be operated in a particularly energy-saving manner.

[0004] This object is solved by a powertrain for a motor vehicle, a corresponding motor vehicle, as well as a method for operating a powertrain for a motor vehicle according to the independent claims. Advantageous embodiments are presented in the dependent claims. One aspect of the invention relates to a powertrain for a motor vehicle. Preferably, the motor vehicle is designed as a passenger car.

[0005] The powertrain comprises at least one electric motor which may be referred to as electrical machine. At least one vehicle wheel of the motor vehicle is capable of being driven by the said electric motor in order to drive the motor vehicle. In other words, the electric motor is capable of providing a torque in order to drive the motor vehicle or the said vehicle wheel, respectively. This means that there may be a torque transfer from the electric motor to the vehicle wheel. As a result, the said vehicle wheel may be driven by the electric motor in order to drive the motor vehicle. The said vehicle wheel may also be referred to as driving wheel or just as wheel. Furthermore, the powertrain comprises at least one internal combustion engine, by which at least one of the vehicle wheels and / or the said vehicle wheel is capable of being driven in order to drive the motor vehicle. In other words, the internal combustion engine is capable of providing a torque in order to drive the motor vehicle or the said vehicle wheel, respectively. This means that there may be a torque transfer from the internal combustion engine, in particular from an output shaft of the internal combustion engine, to the said wheel. As a result, the said vehicle wheel or the motor vehicle, respectively, may be driven by the internal combustion engine. The motor vehicle is designed as a hybrid vehicle, for example as a plugin hybrid vehicle (PHEV). The said driving of the motor vehicle or the said respective wheel, respectively, may be understood as a propelling or powering of the said motor vehicle or the said respective wheel, respectively.

[0006] Furthermore, the powertrain comprises at least one transmission. The said transmission may contain multiple gear ratios (such as first gear, second gear, etc.) that can be engaged or disengaged to control speed and torque output of the internal combustion engine and / or the electric motor. When the driver shifts gears, the transmission may select an appropriate gear ratio to match the speed of the vehicle and load conditions. This may allow the engine to operate at an optimal speed range for efficiency and performance.

[0007] The powertrain comprises at least one electromagnetic clutch, which is capable of being actuated or is actuated between a first and a second state. In other words, the electric clutch is capable of being moved or adjusted between the said first and the said second state. The first and the second state are different from each other.

[0008] The electromagnetic clutch comprises an input member, which is capable of being rotated about an axis of rotation. Therefore, the input member may rotate about the said axis of rotation. The input member may also be referred to as input part or drive part. The input member comprises at least one first coupling region via which the input member is capable of being coupled or is coupled, in particular at least indirectly or directly, to the output shaft of the internal combustion engine in a torque-transmitting manner, whereby the input member is capable of being driven or is driven by the internal combustion engine. In other words, the input member and the output shaft of the internal combustion engine are, in particular mechanically, connectable or connected, whereby the input member may be driven by the internal combustion engine or the output shaft, respectively. As a consequence, there may be a torque transfer from the output shaft to the input member.

[0009] Furthermore, the electromagnetic clutch comprises an output member, which is capable of being rotated about the said axis of rotation. This means that the output member may rotate about the said axis of rotation. The output member may also be referred to as output part. The output member comprises at least one second coupling region via which the output member is capable of being coupled or is coupled, in particular at least indirectly or directly, in a torque-transmitting manner to the said respective vehicle wheel in order to drive the motor vehicle. This respective vehicle wheel may be understood as at least the one of the vehicle wheels, which is capable of being driven by the internal combustion engine. In other words, the output member and the output shaft of the internal combustion engine are, in particular mechanically, connectable or connected, whereby the said vehicle wheel or the motor vehicle, respectively, may be driven via the output member. The input member and the output member are formed separately from each other.

[0010] Furthermore, the electromagnetic clutch comprises a rotor connected, in particular directly, to the said input member in a rotationally fixed manner. This means that the rotor and the input member are, in particular mechanically, coupled to each other, whereby the rotor is capable of being driven or is driven by the input member or via the input member, respectively. The rotor comprises at least one friction lining, which may be referred to as friction material. Preferably, the friction lining is, in particular directly, installed on a surface of the rotor, in particular a surface of a main body of the rotor. The said surface may be referred to as rotor surface. The friction lining may be understood as a material which comprises a friction coefficient which is larger than a friction coefficient of other regions of the rotor, for example the said main body. In other words, the friction lining is designed for a frictional connection.

[0011] Furthermore, the electromagnetic clutch comprises an armature connected, in particular at least indirectly or directly, to the output member in a torque-transmitting manner. In other words, the armature and the output member are, in particular mechanically, coupled with each other, whereby the output member may be driven via the said armature. The rotor and the armature are formed separately from each other. Preferably, the rotor and the armature are capable of being rotated about the said axis of rotation.

[0012] Furthermore, the electromagnetic clutch comprises at least one coil, by which the rotor is capable of being magnetized or is magnetized. As a result, the rotor, in particular at least one part of the rotor, for example the said main body, may be magnetized by the said coil, in particular when the coil is supplied with current. In other words, the electromagnetic clutch comprises at least one electromagnet formed at least of the said rotor and the said coil.

[0013] In particular in order to operate the powertrain or the motor vehicle, respectively, in an energy saving manner, the coil is capable of being supplied or is supplied with current in the first state, whereby the, in particular magnetized, rotor and the armature are, in particular directly, coupled to one another in a torque-transmitting manner via the said friction lining, as a result of which the vehicle wheel is capable of being driven or is driven by the internal combustion engine via the magnetic clutch in the first state. This means the motor vehicle is capable of being driven or is driven in the first state by the internal combustion engine via the electromagnetic clutch. In other words, the armature and the rotor are connected, in particular frictionally engaged, with each other via the friction lining in the first state. Therefore, the said torque may be transferred from the output shaft of the internal combustion engine via the magnetic clutch to the said wheel in the first state. This torque transfer runs via the rotor or the said electromagnet, respectively, whereby the said electromagnet may be understood as an, in particular direct, torque transfer device. The friction lining may transfer the said torque from the rotor to the armature, in particular directly. Thus, the said wheel may be driven by the internal combustion engine via the electromagnetic clutch in the first state. The said supplying of the coil with current may be understood as an energizing of the said coil.

[0014] In the second state the said supply of current to the coil is omitted. This means the coil is not supplied with current in the second state. Therefore, the rotor and the armature are decoupled from one another in the second state, as a result of which the driving of the said vehicle wheel or the motor vehicle, respectively, by the internal combustion engine is omitted in the second state. This means the said wheel or the motor vehicle, respectively, is not being driven by the internal combustion engine, in particular via the electromagnetic clutch, in the second state. In other words, in the second state there is no torque transfer from the output shaft of the internal combustion engine, in particular via the electromagnetic clutch, to the respective wheel.

[0015] When the coil is supplied with current in the first state, it generates a magnetic field that magnetizes the rotor, creating a strong attraction force between the rotor and the armature. This attraction force presses on the friction lining which allows torque to be efficiently transmitted from the internal combustion engine to the vehicle wheel. Conversely, when the coil is not energized, the magnetic field dissipates, resulting in the decoupling of the rotor and the armature, thereby disengaging the internal combustion engine from the powertrain.

[0016] The powertrain or the electromagnetic clutch, respectively, according to the invention may allow a quick disengagement of the internal combustion engine in the motor vehicle from the rest of the powertrain when the internal combustion engine is not needed for propulsion. Therefore, engine drag losses may be reduced. As a result of this, the electromagnetic clutch may also be referred to as quick release clutch. The electromagnetic clutch may also be designed for a quick engagement of the internal combustion engine with the rest of the powertrain, of course. In other words, the electromagnetic clutch is designed for quick coupling and decoupling of the output shaft of the internal combustion engine with the said wheel. Furthermore, the electromagnetic clutch may be particularly energy-efficient as it requires less energy to operate. For example, the electromagnetic clutch may require less energy to operate as opposed to a similar hydraulic or pneumatic operated clutch known from the state of the art. In addition, the electromagnetic clutch may comprise a compact design. Preferably, the electromagnetic clutch is designed as a self-contained single drop-in unit, which may enable a very easy assembly. Furthermore, the electromagnetic clutch may only need 12 V current supply to operate. This may also lead to the said easy assembly. Moreover, manufacturing costs of the powertrain may be reduced by usage of the electromagnetic clutch because a number of components of the clutch may be reduced, in particular compared to hydraulic or pneumatic clutches, which may need an external pump or accumulator as force generators.

[0017] By varying the current supplied to the coil, a level of magnetic force and thus a degree of clutch engagement may be controlled. This may allow smooth and precise control over the transmission of power between the engine and the transmission components.

[0018] According to an embodiment, in the second state, the said vehicle wheel is capable of being driven or is driven by the electric motor, in particular by bypassing the electromagnetic clutch. In other words, at least one of the vehicle wheels is capable of being driven or is driven by the electric motor in the second state.

[0019] In another embodiment, the friction lining is formed separately from the main body of the rotor and is attached, in particular directly, to the said main body of the rotor.

[0020] In another embodiment, the armature and the output member are connected to each other, in particular directly, via an intermediate part in a torque-transmitting manner.

[0021] In another embodiment, the intermediate part is designed as a spring element, via which the armature is attached to the output member so as to be capable of being translationally moved relative to the rotor by elastic deformation of the said spring element.

[0022] In another embodiment, the said intermediate part is screwed together with the output element and / or the armature.

[0023] In another embodiment, the rotor is screwed together with the input member.

[0024] Another aspect of the invention relates to a motor vehicle comprising at least the powertrain according to the first aspect of the invention. This means that the motor vehicle comprises at least one powertrain according to the first aspect of the invention. Advantageous embodiments of the motor vehicle are to be regarded as advantageous embodiments of the powertrain and vice versa.

[0025] Another aspect of the invention relates to a method for operating a powertrain for a motor vehicle according to the first aspect of the invention. Advantageous embodiments of the method are to be regarded as advantageous embodiments of the powertrain and the motor vehicle and vice versa.

[0026] Further advantages, features, and details of the invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The novel features and characteristic of the disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0028] The drawings show in:

[0029] Fig. 1 a schematic view of an embodiment of a motor vehicle;

[0030] Fig. 2 a schematic front view of an embodiment of an electromagnetic clutch;

[0031] Fig. 3 a schematic sectional view of an embodiment of an electromagnetic clutch;

[0032] Fig. 4 another schematic sectional view of an embodiment of an electromagnetic clutch.

[0033] In the figures the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0034] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0035] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0036] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0037] In the following detailed description of the embodiment of the disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0038] Fig. 1 shows a schematic view of a motor vehicle 10, which is at least in part electrically operated or fully electrically operated. In the example shown in Fig. 1 the motor vehicle 10 comprises four vehicle wheels 12. Two of the vehicle wheels 12 are designed as respective front wheels. The others of the vehicle wheels 12 are designed as respective rear wheels. Furthermore, the motor vehicle 10 comprises a powertrain 14, which may be referred to as drive train. The powertrain 14 comprises at least one transmission 15, which may be referred to as gearbox. Furthermore, the powertrain 14 comprises at least one electric motor 16 by which at least one of the vehicle wheels 12 of the motor vehicle 10 is capable of being driven, for example via the said transmission 15, in order to drive the motor vehicle 10. In addition, the powertrain 14 comprises at least one internal combustion engine 18, by which at least the said vehicle wheel 12 and / or at least one of the other vehicle wheels 12 is capable of being driven, in particular via the said transmission 15, in order to drive the motor vehicle 10. It should be noted that the arrangement and the driving of the wheels 12 in Fig. 1 are only to be understood as an example. It is therefore also possible for other wheels 12 shown in Fig. 1 to be driven by the electric motor 16 and / or the combustion engine 18. Preferably, the internal combustion engine 18 is designed as a gasoline engine which may be referred to as gas engine.

[0039] Furthermore, the powertrain 14 comprises at least one electromagnetic clutch 20 which is capable of being actuated between a first state and a second state which is different from the first state. The electromagnetic clutch 20 is shown in Fig. 2 in a schematic perspective front view. Fig. 2 shows the electromagnetic clutch 20 in a schematic sectional view which may be referred to as section A-A which is illustrated in Fig. 2. The electromagnetic clutch 20 comprises an input member 22 which is capable of being rotated or is rotated about an axis of rotation 24. The input member 22 comprises a first coupling region 26 via which the said input member 22 is capable of being coupled or is coupled to an output shaft of the internal combustion engine 18 in a torque-transmitting manner, for example via an intermediate shaft. Preferably, the first coupling region 26 is designed as a receiving space for at least a foam fit connection with the output shaft or the intermediate shaft, respectively. For example, the first coupling region 26 comprises an output spline for coupling with the output shaft or the intermediate shaft, respectively. In other words, the input member 22, in particular the first coupling region 26, may be designed as a spline input hub. For example, the input member 22 is made of steel. Therefore, the input member 22 is capable of being driven or is driven by the internal combustion engine 18, in particular via the first coupling region 26.

[0040] Furthermore, the electromagnetic clutch 20 comprises an output member 28 which is capable of being rotated or is rotated about the said axis of rotation 24. This means that the input member 22 and the output member 28 are arranged coaxially to each other. The output member 28 comprises a second coupling region 30 via which the output member 28 is capable of being coupled or is coupled in a torque-transmitting manner to at least one the said vehicle wheels 12 in order to drive the motor vehicle 10. For example, the second coupling region 30 comprises a spline which may be referred to as input spline for coupling with a shaft of the powertrain 14. So, the output member 28 may be designed as a carrier. For example, the output member 28 is made of steel.

[0041] Furthermore, the electromagnetic clutch 20 comprises a rotor 32 which is connected to the input member 22 in a rotationally fixed manner, for example directly. In the example shown in Fig. 3, the rotor 32 is screwed together with the input member 22. This means the rotor 32 and the input member 22 are connected via at least one screw 34 with each other which may be referred to as bolt. Preferably, the electromagnetic clutch 20 comprises at least one bearing 36 via which the rotor 32 and the output member 28 are mounted rotatably. The said bearing 36 may be designed as a needle roller bearing. Fig. 4 shows another embodiment of the electromagnetic clutch 20 a schematic sectional view. As shown in Fig. 4, a bearing retaining 38 may be arranged at the bearing 36.

[0042] As illustrated in Figs. 3 and 4, the rotor 32 is capable of being rotated or is rotated about the said axis of rotation 24. In other words, the rotor 32 and the input member 22 are arranged coaxially to each other. As shown in Figs. 3 and 4, the rotor 32 comprises at least one friction lining 40, which may be formed separately from a main body 42 of the rotor 32 and may be attached, in particular directly, to the said main body 42. The friction lining 40 may be attached directly on the rotor 32 or the main body 42, respectively.

[0043] Furthermore, the electromagnetic clutch 20 comprises an armature 44 connected to the output member 28 in a torque-transmitting manner, for example in a rotationally fixed manner. In the present example, the armature 44 is capable of being rotated or is rotated about the said axis of rotation 24. This means that the armature 44 and the output member 28 are arranged coaxially to each other. In addition, the electromagnetic clutch 20 comprises a coil 46 by which the rotor 32, in particular at least the main body 42 of the rotor 32, is capable of being magnetized or is magnetized. Therefore, the rotor 32 may be referred to as electromagnetic rotor. Preferably, the said coil 46 is securely housed within the electromagnetic clutch housing 48, ensuring proper alignment and stability. Mounting brackets or fixtures may be utilized to firmly position the coil 46 within the housing 48 in order to prevent movement or misalignment during operation. The input member 22, the rotor 32, the armature 44 and the output member 28 are capable of being rotated or is rotated about the said axis of rotation 24 relative to the housing 48. The housing 48 may comprise a bolt pattern.

[0044] In the first state, the coil 46 is supplied with current, whereby the rotor 32 and the armature 44 are coupled to one another in a torque-transmitting manner via the said friction lining 40. As a result of which at least the said respective wheel 12 is capable of being driven or is driven by the internal combustion engine 18 via the electromagnetic clutch 20, in particular via the input member 22, the rotor 32, the armature 44 and the output member 28, in the first state. This means there may be an, in particular direct, torque transfer from the internal combustion engine 18 via the electromagnetic clutch 20, in particular via the rotor 32 and the armature 44, the respective wheel 12. In the second state, the supply of current to the coil 46 is omitted, whereby the rotor 32 and the armature 44 are decoupled from one another, as a result of which the said driving of the respective wheel 12 by the internal combustion engine 18 is omitted in the second state. For example, in the second state is a gap between the friction lining 40 and the armature 44, whereby the rotor 32 and the armature 44 are not coupled to each other in the second state. This means that there is no torque transfer possible between the rotor 32 and the armature 44 in the second state. The respective gap may be referred to as nominal air gap. A size of the said gap may be 0.12 mm. Preferably, a change between the first and the second state is accompanied by a relative movement between the rotor 32 and the armature 44 in a direction parallel to the said axis of rotation 24. For example, the change from the second state to the first state is accompanied by the said relative movement caused by the magnetization of the rotor 32. In the present example, the said relative movement is a movement of the armature 44 relative to the rotor 32 about the said axis of rotation 24. So, the said relative movement is a translational movement. As a result, the said gap between the rotor 32 and the armature 44 may be closed, whereby the rotor 32 and the armature 44 are coupled to each other in a torque-transmitting manner via the said friction lining 40. In particular in a method for operating the said powertrain 14 there may be a change from the first state to the second state and / or from the second state to the first state.

[0045] In the second state, at least the said respective wheel 12 of the motor vehicle 10 is capable of being driven or is driven by the electric motor 16. In other words, the motor vehicle 10 is capable of being driven or is driven by the electric motor 16 in the second state. As a result, the said current may not always need to be on for driving the motor vehicle 10 or the said respective wheel 12, respectively.

[0046] In the present example, the armature 44 and the output member 28 are connected to each other via an intermediate part 50 in a torque-transmitting manner. This intermediate part 50 may be designed as a spring element 52, via which the armature 44 is attached to the output member 28 so as to be capable of being translationally moved or is moved, in particular about the said axis of rotation 24, relative to the rotor 32 by elastic deformation of the spring element 52. The spring element 52 may be designed plate shaped, for example like a metal sheet. For example, the said intermediate part 50 is screwed together with the armature 44. This means the intermediate part 50 and the armature 44 are connected with each other via a screw 54 which may be referred to as bolt. In the present example, the intermediate part 50 is screwed together with the output member 28. This means that the intermediate part 50 and the output member 28 are connected to each other via a screw 56 which may be referred to as bolt. As seen in Fig. 2 several such screws 54, 56 are provided. Preferably, the said screws 54, 56 are arranged alternately in a circumferential direction of the electromagnetic clutch 20.

[0047] As shown in Figs. 2 and 3 the electromagnetic clutch 20 may comprise at least one electric wire 58 which may be referred to as lead wire. Preferably, the said wire comprises two conductors. The wire 58 protrudes from the housing 48. The housing 48 may comprise a bolt pattern 60 in order to mount the electromagnetic clutch 20 to a component of the motor vehicle 10 and / or to ground the electromagnetic clutch 20 or in particular to ground a stator of the electromagnetic clutch 20. As shown in Fig. 4 spacers 62 may be arranged at the bolt pattern 60. As shown in Fig. 4 snap rings 64 and shims 66 for adjusting air gap rings may be arranged at the input member 22.

[0048] Preferably, the electromagnetic clutch 20 fulfills at least one of the following requirements: • torque capacity of 250 Nm • maximum speed of 3000 rpm for standard lining • max speed of 3600 rpm for high-speed lining • balanced assembly • ability to handle small torque spikes which are for example smaller than 30 nm • operating voltage of 12 V DC • on / off control • input inertia of 0.015 kg m2 (not including electromagnetic clutch rotating parts) • a clutch engagement which is smaller than 150 ms.

[0049] The following equation applies to the torque of the electromagnetic clutch 20:

[0050] Tq = Fa* mu * Rm * N; Rm = 0,5 * (Ro + Ri)

[0051] The parameters of the electromagnetic clutch 20 may have the following values: • N = 1 • Mu = 0.2 • Tq = 250 Nm • Rm = —m= 0.079 m 2 • Af = Rm2 * n- = 0.0792 * n = 0.0196 m2

[0052] Fa may therefore be calculated as follows:

[0053] Fa =--—--N = 63775 N 1 1 0.2*0.0196 *1

[0054] The resultant pressure may be calculated as follows:

[0055] P = - = ^^ Kp = 3253.777Kp 1 1 Af 0.0196 ' ' Reference Signs motor vehicle vehicle wheel powertrain transmission electric motor internal combustion engine electromagnetic clutch input member axis of rotation first coupling region output member second coupling region rotor screw bearing bearing retaining friction lining main body armature coil housing intermediate part spring element screw screw wire bolt pattern spacer snap ring shim

Claims

1. A powertrain (14) for a motor vehicle (10), comprising at least one transmission (15), at least one electric motor (16), by which at least one vehicle wheel (12) of the motor vehicle (10) is capable of being driven in order to drive the motor vehicle (10), and an internal combustion engine (18), by which at least one of the vehicle wheels (12) is capable of being driven in order to drive the motor vehicle (10), and an electromagnetic clutch (20), which is capable of being actuated between a first and a second state and which comprises:• an input member (22) which is capable of being rotated about an axis of rotation (24) and which comprises a first coupling region (26) via which the input member (22) is capable of being coupled or is coupled to an output shaft of the internal combustion engine (18) in a torque-transmitting manner, whereby the input member (22) is capable of being driven by the internal combustion engine (18),• an output member (28) which is capable of being rotated about the axis of rotation (24) and which comprises a second coupling region (30) via which the output member (28) is capable of being coupled or is coupled in a torque-transmitting manner to the vehicle wheel (12) in order to drive the motor vehicle (10),• a rotor (32) connected to the input member (22) in a rotationally fixed manner and comprising a friction lining (40),• an armature (44) connected to the output member (28) in a torquetransmitting manner, and• a coil (36) by which the rotor (32) is capable of being magnetized,wherein in the first state the coil (36) is supplied with current, whereby the rotor (32) and the armature (44) are coupled to one another in a torque-transmitting manner via the friction lining (40), as a result of which the said vehicle wheel (12) is capable of being driven by the internal combustion engine (18) via the electromagnetic clutch (20) in the first state, and in the second state the supply of current to the coil (36) is omitted, whereby the rotor (32) and the armature (44) are decoupled from one another, as a result of which the driving of the said vehicle wheel (12) by the internal combustion engine (18) is omitted in the second state.

2. The powertrain (14) according to claim 1, characterized in thatin the second state, the said vehicle wheel (12) is capable of being driven by the electric motor (16).

3. The powertrain (14) according to claim 1 or 2, characterized in thatthe friction lining (40) is formed separately from a main body (42) of the rotor (32) and is attached to the main body (42).

4. The powertrain (14) according to any one of claims 1 to 3, characterized in thatthe armature (44) and the output member (28) are connected to each other via an intermediate part (50) in a torque-transmitting manner.

5. The powertrain (14) according to claim 4, characterized in thatthe intermediate part (50) is designed as a spring element (52), via which the armature (44) is attached to the output member (28) so as to be capable of being translationally moved relative to the rotor (32) by elastic deformation of the spring element (52).

6. The powertrain (14) according to claim 4 or 5, characterized in thatthe intermediate part (50) is screwed together with the output element (28) and / or the armature (44).

7. The powertrain (14) according to any one of claims 1 to 6, characterized in thatthe rotor (32) is screwed together with the input member (22).

8. A motor vehicle (10), comprising at least the powertrain (14) according to any one of claims 1 to 7.

9. A method for operating a powertrain (14) for a motor vehicle (10) according to any one of claims 1 to 8.18

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