Drive unit for a motor vehicle, in particular for a motor car

Abstract

The invention relates to a drive unit (10) for a motor vehicle, comprising a vehicle axle (12) which has two vehicle wheels (16, 18), namely a first vehicle wheel (16) rotatable about a first wheel axis of rotation (22) relative to a base element (20) of the drive unit (10) and a second vehicle wheel (18) rotatable about a second wheel axis of rotation (24) relative to the base element (20). An electric machine (26) is provided, comprising a stator (28) rotatable about a machine axis of rotation (32) relative to the base element (20) and having a first winding, and a rotor (30) rotatable about the machine axis of rotation (32) relative to the base element (20) and relative to the stator (28) and having a second winding.A first coupling device (34) is provided, by means of which the stator (28) can be connected to the base element (20) in a rotationally fixed manner, while the rotor (30) can be rotated about the machine axis of rotation (32) relative to the base element (20) and relative to the stator (28).

Description

[0001] The invention relates to a drive device for a motor vehicle, in particular for a motor car.

[0002] The prior art includes DE 10 2023 004 145 A1, EP 2 847 849 A1, EP 4 214 818 A1, EP 3 939 139 A1, EP 4 494 242 A2, WO 2025166461 A1, US 20240128998 A1 and US 20240162753 A1.

[0003] The object of the present invention is to create an advantageous drive system for a motor vehicle.

[0004] This problem is solved by a drive device with the features of claim 1. An advantageous embodiment of a further development of the invention is specified in the dependent claim.

[0005] The invention relates to a drive device for a motor vehicle, also referred to simply as a vehicle, preferably a motor car, in particular a passenger car. This means that the motor vehicle, in its fully manufactured state, has the drive device and can be driven by means of the drive device. The drive device has a vehicle axle, which, in particular, has two vehicle wheels, namely a first vehicle wheel and a second vehicle wheel. The aforementioned vehicle axle is also referred to as the first vehicle axle. When the vehicle axle is mentioned before and below, unless otherwise specified, this refers to the first vehicle axle. When the vehicle wheels are mentioned before and below, unless otherwise specified, this refers to the first vehicle wheel and the second vehicle wheel.

[0006] For example, in its fully manufactured state, a motor vehicle has exactly two axles arranged consecutively in its longitudinal direction, namely the first axle and a second axle. Each axle has exactly two wheels. The wheels of each axle are located on opposite sides of the vehicle in its transverse direction. The wheels are ground contact elements by which the vehicle can be supported or is supported downwards against the ground. When the vehicle is driven along the ground while supported downwards by these ground contact elements, the ground contact elements roll along the ground, in particular directly.In particular, each ground contact element has a tire, especially made of rubber, which rolls on the ground, especially directly.

[0007] The drive unit also includes a base element, which can be, for example, a housing and / or a chassis. The first wheel is rotatable about a first axis of rotation relative to the base element. The second wheel is rotatable about a second axis of rotation relative to the base element. In particular, when the vehicle is driven along the ground while supported downwards by the ground contact elements, each wheel rotates about its respective axis of rotation relative to the base element.

[0008] The drive unit also includes an electric machine comprising a stator and a rotor. The stator is rotatable about a machine axis relative to the base element. Furthermore, the stator has a first winding, also referred to as the stator winding. For example, a first magnetic field, particularly a rotating one, can be generated and provided by means of the first winding. This first magnetic field can then be used to drive the rotor, allowing it to rotate about the machine axis relative to both the stator and the base element. Thus, the rotor is rotatable about the machine axis relative to both the base element and the stator. The stator is rotatable about the machine axis relative to the rotor. The rotor has a second winding, also referred to as the rotor winding.In particular, the first magnetic field can be generated and provided by supplying the first winding with electrical energy via the first winding. For example, a second magnetic field can be generated and provided by supplying the second winding with electrical energy via the second winding, whereby, for example, the rotor can be driven by means of the second magnetic field and is thereby rotatable about the machine's axis of rotation relative to the stator and relative to the base element. For example, the second magnetic field is an excitation field, or the second magnetic field is also referred to as the excitation field. In particular, the second magnetic field can, for example, interact with the first magnetic field, thereby making the rotor driveable and thus rotatable about the machine's axis of rotation relative to the stator and relative to the base element. The electric machine is thus preferably designed as a separately excited synchronous machine.

[0009] The drive unit comprises a first coupling device by means of which the stator can be connected to the base element in a rotationally fixed manner, while the rotor is rotatable about the axis of rotation relative to the base element and relative to the stator. The drive unit also comprises a second coupling device by means of which the rotor can be connected to the base element in a rotationally fixed manner, while the stator is rotatable about the axis of rotation relative to the base element and relative to the rotor.

[0010] By rotating the stator around the machine's axis of rotation and relative to the base element, the stator can drive the first wheel of the vehicle, bypassing the rotor, and the second wheel of the vehicle. Similarly, by rotating the rotor around the machine's axis of rotation and relative to the base element, the rotor can drive the second wheel of the vehicle, bypassing the stator and the first wheel of the vehicle. The electric machine can thus function as a differential gear, or be designed to do so, eliminating the need for an additional differential gear. The stator and rotor are collectively referred to as machine components.If one of the machine parts is fixed in place by means of the associated coupling device, that is, rotationally fixed to the base element, then, for example, the other machine part can drive both vehicle wheels, particularly simultaneously, especially via a coupled axle, that is, particularly if or because the vehicle wheels are torque-transmittingly coupled by means of a third coupling device. If the axle between the two vehicle wheels is separated, that is, decoupled, meaning that the vehicle wheels are not torque-transmittingly coupled to each other by means of the third coupling device, bypassing the rotor and the stator, but are decoupled from each other, then the respective machine part can drive the respective, assigned vehicle wheel, bypassing the other machine part and the other vehicle wheel.Depending on the drive situation, both vehicle wheels can be driven simultaneously, or only one of the vehicle wheels can be driven by locking the other machine part, or both vehicle wheels can be driven simultaneously, but at different speeds, by partially braking the machine parts to achieve a differential speed.

[0011] The drive unit also includes a transmission device designed for contactless, i.e., touchless, transmission of electrical energy. The transmission of electrical energy is also referred to as power transmission. Electrical energy can be, for example, electrical power. The transmission device includes a first transmitting unit provided on the base element, by means of which electrical energy can be supplied, particularly contactlessly. The transmission device includes a first receiving unit provided on the stator, by means of which the electrical energy supplied by the first transmitting unit, which can supply the first winding, can be received contactlessly.The transmission device also includes a second transmitter unit provided on the base element or the stator, by means of which electrical energy can be supplied, in particular contactlessly and thus without physical contact. The transmission device also includes a second receiver unit provided on the rotor, by means of which the electrical energy supplied by the second transmitter unit, with which the second winding can be supplied, can be received contactlessly, i.e., without physical contact. The feature that the electrical energy supplied by the respective transmitter unit can be received contactlessly by means of the respective receiver unit means that the respective receiver unit can receive the respective electrical energy supplied by the respective transmitter unit without the respective transmitter unit and the respective receiver unit touching each other.This allows for a particularly efficient, and therefore low-loss, operation.

[0012] The electric machine is a traction machine that drives the vehicle wheels. Thus, the drive unit is a traction drive that eliminates the need for an additional mechanical differential gear. The invention provides a means of power transmission to the stator, allowing the stator to be rotatably mounted around the machine's axis of rotation relative to the base element. The electric machine, also known as an electric motor, therefore simultaneously fulfills the functions of an electromechanical converter and a differential gear. Although the term "stator" is conventionally used for a non-rotating part of an electric machine, in the present invention the stator is rotatable around the machine's axis of rotation relative to the base element.Nevertheless, the term "stator" is used because the rotor can be driven by means of the first winding of the stator and is thus rotatable around the machine's axis of rotation relative to the stator. For example, the electric machine is designed as an internal rotor because, for instance, the rotor is arranged radially inside the stator and axially overlapping the stator, so that at least a length of the rotor is completely surrounded by the stator on its outer circumference and in the circumferential direction around the machine's axis of rotation.

[0013] The transmission device, also simply referred to as a system, is a transmission system that can supply the stator and rotor with electrical energy without physical contact. It utilizes, for example, an electric and / or magnetic field, also called a transmission field, by means of which the electrical energy is provided by the respective transmitting unit and received by the respective receiving unit. Thus, the electrical energy can be transferred wirelessly, i.e., without physical contact, to the stator, allowing it to be mounted so that it can rotate freely. When torque is generated by known mechanisms within the electric machine, the stator and rotor rotate in opposite directions at the same speed around the machine's axis of rotation and relative to the base element, particularly neglecting friction.If the direction of rotation of one of the machine parts is reversed, for example by a gearbox, the stator and the rotor become outputs with the same direction of rotation, behaving equivalently to the outputs of a differential gearbox. Power is transmitted to the stator by means of a system that utilizes the transmission field for power transfer. The receiving and transmitting units are also referred to as antennas. The antennas for power transmission to the stator are arranged, for example, axially and / or radially relative to the machine's axis of rotation and transmit, for example, the required stator power. In the case of machines with impressed rotor current (for example, slip-ring rotor machines or separately excited synchronous machines), wireless transmission to the rotor is also possible (either directly to the rotor from the base element, which may be designed as a housing, for example, or via the rotatable stator to the rotor).The stator and rotor are mounted on rotatable bearings and coupled, for example, to one or more gearboxes that reverse the direction of rotation, either for a rotor shaft or a stator shaft. For traction drives, both resulting outputs can then be used to drive, for example, one of the vehicle wheels (function: traction motor and axle differential) or one axle (function: traction motor and center differential). In the latter case, the reversal of the device's direction of rotation may be omitted, and it can be used directly. Arrangements with spur gears, single-sided gearboxes, gearless configurations, or any combination thereof are also conceivable, depending on the application.

[0014] Since an additional mechanical differential gear can be omitted compared to conventional solutions, a particularly weight-, cost- and space-saving design of the drive unit can be created.

[0015] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the single figure alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0016] The drawing shows in the only Fig. 1 A schematic representation of a drive system of a motor vehicle.

[0017] The only Fig. Figure 1 shows a schematic representation of a drive unit 10, also referred to as an axle drive, of a motor vehicle, also referred to simply as a vehicle, which is designed as a motor car, in particular as a passenger car. The motor vehicle has exactly two axles arranged consecutively in the longitudinal direction of the motor vehicle, namely a first axle and a second axle. The drive unit has exactly one of the axles, namely the first axle, which is in Fig. The vehicle is designated 12. Each driving condition has exactly two vehicle wheels. The respective vehicle wheels of each vehicle axle are arranged on opposite sides of the vehicle in the transverse direction of the vehicle. The transverse direction of the vehicle is illustrated by a double arrow 14. A first vehicle wheel of vehicle axle 12 is designated 16, and a second vehicle wheel of vehicle axle 12 is designated 18. The vehicle wheels are the ground contact elements of the vehicle. The drive unit 10 has a base element 20, which is, for example, a housing or comprises a housing. The first vehicle wheel 16 is rotatable about a first wheel axis 22 relative to the base element 20, and the second vehicle wheel 18 is rotatable about a second wheel axis 24 relative to the base element 20.

[0018] The drive unit 10 comprises an electric machine 26, which is arranged, for example, in the aforementioned housing. The electric machine 26 has a stator 28 and a rotor 30. The stator 28 is rotatable about a machine axis of rotation 32 relative to the base element 20 and relative to the rotor 30. The rotor 30 is rotatable about the machine axis of rotation 32 relative to the base element 20 and relative to the stator 28. The stator 28 has a first winding, which is also referred to as the stator winding. The rotor 30 has a second winding, which is also referred to as the rotor winding.

[0019] The drive unit 10 has a first coupling device 34 by means of which the stator 28 can be connected to the base element 20 in a rotationally fixed manner, while the rotor 30 is rotatable about the machine axis of rotation 32 relative to the base element 20 and relative to the stator 28. The drive unit 10 has a second coupling device 36 by means of which the rotor 30 can be connected to the base element 20 in a rotationally fixed manner, while the stator 28 is rotatable about the machine axis of rotation 32 relative to the base element 20 and relative to the rotor 30. By rotating the stator 28 about the machine axis of rotation 32 and relative to the base element 20 and relative to the rotor 30, the first vehicle wheel 16 can be driven by the stator 28, bypassing the rotor 30 and bypassing the second vehicle wheel 18.By rotating the rotor 30 around the machine axis 32 and relative to the base element 20 and relative to the stator 28, the second vehicle wheel 18 can be driven by the rotor 30, bypassing the stator 28 and bypassing the first vehicle wheel 16.

[0020] This allows the electric machine 26 to function, operate, or be configured as the differential gear, thus avoiding the need for an additional, mechanical, separate differential gear.

[0021] The drive unit 10 also has a Fig.Figure 1 shows a transmission device 38, which is particularly schematically depicted and is designed for the contactless transmission of electrical energy. The transmission device 38 has a first transmitting unit provided on the base element 20, by means of which electrical energy can be supplied. The transmission device 38 has a first receiving unit provided on the stator 28, by means of which the electrical energy provided by the first transmitting unit, with which the first winding can be supplied, can be received contactlessly, i.e., without contact. The transmission device has a second transmitting unit provided on the base element 20 or on the stator 28, by means of which electrical energy can be supplied.Furthermore, the transmission device 38 has a second receiving unit provided on the rotor 30, by means of which the electrical energy provided by the second transmitting unit, with which the second winding can be supplied, can be received without contact, and is therefore receivable.

[0022] For example, a third coupling device is provided, by means of which the vehicle wheels 16 and 18 can be coupled to each other in a torque-transmitting manner, bypassing the rotor 30 and the stator 28, so that both vehicle wheels 16 and 18 can optionally be driven simultaneously by means of the rotor 30 bypassing the stator 28, while the stator 28 is connected to the base element 20 in a rotationally fixed manner by means of the first coupling device 34, or simultaneously by means of the stator 28 and bypassing the rotor 30, while the rotor 30 is connected to the base element 20 in a rotationally fixed manner by means of the second coupling device 36. Reference symbol list 10 Drive unit 12 vehicle axle 14 Double Arrow 16 first vehicle wheel 18 second vehicle wheel 20 basic element 22 first wheel pivot 24 second wheel pivot 26 electric machine 28 Stator 30 Rotor 32 Machine rotary axis 34 first coupling device 36 second coupling device 38 Transmission device QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2023 004 145 A1

[0002] EP 2 847 849 A1

[0002] EP 4 214 818 A1

[0002] EP 3 939 139 A1

[0002] EP 4 494 242 A2

[0002] WO 2025166461 A1

[0002] US 20240128998 A1

[0002] US 20240162753 A1

[0002]

Claims

[1] Drive unit (10) for a motor vehicle, comprising: - a vehicle axle (12) which has two vehicle wheels (16, 18), namely a first vehicle wheel (16) rotatable about a first wheel axis (22) relative to a base element (20) of the drive device (10) and a second vehicle wheel (18) rotatable about a second wheel axis (24) relative to the base element (20); - an electric machine (26) which has: ◯ a stator (28) rotatable about a machine rotation axis (32) relative to the base element (20) and having a first winding; and ◯ a rotor (30) rotatable about the machine axis of rotation (32) relative to the base element (20) and relative to the stator (28) and having a second winding; - a first coupling device (34) by means of which the stator (28) can be connected to the base element (20) in a rotationally fixed manner, while the rotor (30) can be rotated about the machine axis of rotation (32) relative to the base element (20) and relative to the stator (28); - a second coupling device (36) by means of which the rotor (30) can be connected to the base element (20) in a rotationally fixed manner, while the stator (28) can be rotated about the machine axis of rotation (32) relative to the base element (20) and relative to the rotor (30), wherein: ◯ by rotating the stator (28) about the machine axis of rotation (32) and relative to the base element (20), the first vehicle wheel (16) can be driven by the stator (28) by bypassing the rotor (30) and by bypassing the second vehicle wheel (18); and ◯ by rotating the rotor (30) around the machine axis of rotation (32) and relative to the base element (20) the second vehicle wheel (18) can be driven by the rotor (30) by bypassing the stator (28) and by bypassing the first vehicle wheel (16); - a transmission device (38) designed for the contactless transmission of electrical energy, which includes: ◯ a first transmitting unit provided on the base element (20), by means of which electrical energy can be provided; ◯ a first receiving unit provided on the stator (28), by means of which the electrical energy provided by the first transmitting unit, with which the first winding can be supplied, can be received without contact; ◯ a second transmitting unit provided on the base element (20) or on the stator (28), by means of which electrical energy can be supplied; and ◯ a second receiving unit provided on the rotor (14), by means of which the electrical energy provided by the second transmitting unit, with which the second winding can be supplied, can be received without contact. [2] Drive device (10) according to claim 1, characterized by a third coupling device by means of which the vehicle wheels (16, 18) can be coupled to each other in a torque-transmitting manner, bypassing the rotor (30) and bypassing the stator (28), so that both vehicle wheels (16, 18) can be selected to: - can be driven simultaneously by means of the rotor (30) bypassing the stator (28), while the stator (28) is connected to the base element (20) in a rotationally fixed manner by means of the first coupling device (34); or - can be driven simultaneously by means of the stator (28) bypassing the rotor (30), while the rotor (30) is connected to the base element (20) in a rotationally fixed manner by means of the second coupling device (36).

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