Vehicle drive for vehicle

Abstract

The invention relates to a vehicle drive (100) for a vehicle, comprising: a wheel (10); a transmission (12) having an input shaft (14) and an output shaft (16), the output shaft (16) being coupled to the wheels (10) in order to drive the wheels (10) at an output rotational speed (n2); a brake device (18); the brake device (18) and the electric motor (20) are coupled to the input shaft (14) or are arranged on the input shaft (14), the electric motor (20) is designed to drive the input shaft (14) at an input rotational speed (n1), the brake device (18) is provided for braking the input shaft (14) in order to reduce the input rotational speed (n1) in such a way, and the transmission (12) is provided for converting the input rotational speed (n1) into an output rotational speed (n2).

Description

Field of the Invention

[0001] The present invention relates to a vehicle drive for a vehicle and a vehicle having such a vehicle drive. Background Art

[0002] In recent years, the increasing popularity of electric single-wheel drives in modern vehicles has fundamentally changed the automotive industry. Vehicles such as the Mercedes eSLS, Rimac, and Tesla have shown that single-wheel drives offer an efficient and powerful viable solution for shaping future mobility. Additionally, the latest developments in the industry have enabled single-wheel drives to be directly integrated into the wheels themselves, as is the case in vehicles such as Lightyear, Lordstown, and Hyundai. These innovative systems offer numerous advantages, including increased energy efficiency and effective power.

[0003] A common feature of single-wheel drives is the use of a variable transmission ratio to transfer torque to a single wheel. However, some manufacturers, such as Lordstown and Lightyear, have adopted direct drives without a transmission to achieve a more efficient drive system. Despite these technological advancements, the braking systems in conventional passenger cars (PKW) are still generally designed to be complex and imprecise. The braking system is typically connected to the driven wheel in a rotationally fixed manner and requires a high braking torque to reliably stop the vehicle. This makes the braking system large and heavy, regardless of whether it is in the form of a drum brake or a disc brake.

[0004] In the prior art, single-wheel drives are typically combined with brakes, which are generally designed as disc brakes with friction linings. These brakes are usually large, heavy, and not precisely controllable because they must apply a high wheel torque through the friction linings, which are affected by fluctuations in the coefficient of friction. During the braking process, the brakes cause wear and thus generate dust and losses. Additionally, the controllability of the brakes becomes complex because the friction value of the brake lining changes due to aging and / or the operating mode. Therefore, the precise distribution of the clamping force and / or braking torque at the brakes is usually difficult and may be faulty.

[0005] Therefore, in principle, weight reduction and better adjustability of the braking torque are advantageous. In particular, for drives in wheels, it is also preferable to reduce the structural size of the brakes. Another objective is to avoid wear and thus reduce maintenance requirements and dust emissions.

[0006] Exemplary vehicle drives are known from DE 102009006196 A1, DE 69913281 T2, or DE 102018106479A1, respectively.

[0007] Therefore, the task on which the present invention is based is to provide an improved vehicle drive.

[0008] This task is solved by a vehicle drive according to the features of claim 1 of the patent. This task is solved by a vehicle having at least one such vehicle drive. Summary of the Invention

[0009] According to a first aspect, a vehicle drive for a vehicle is proposed. The vehicle drive has wheels, a transmission with an input shaft and an output shaft. The output shaft is coupled to the wheels in order to drive the wheels at an output speed. The vehicle drive has a braking device and an electric motor. The braking device and the electric motor are coupled to the input shaft or arranged on the input shaft. The electric motor is configured to drive the input shaft at an input speed. The braking device is provided for braking the input shaft in order to reduce the input speed in such a way. The transmission is provided for converting the input speed into the output speed.

[0010] The vehicle drive describes a system for driving a vehicle and enabling it to move. At least one wheel represents a rotatable element for moving the vehicle. The wheel can preferably have a rim and a tire lining. The transmission describes a mechanical system having an input shaft and an output shaft.

[0011] It is possible to vary the speed and torque between the input and the output. The input shaft describes a shaft or a rotatable shaft body which is part of the transmission or can be coupled to the transmission in a motion-transmitting manner and serves as an input for the driving force or driving torque. The output shaft describes a shaft or a rotatable shaft body which is part of the transmission or can be coupled to the transmission in a motion-transmitting manner and provides an output force or output torque. The coupling to the wheels is effected directly or indirectly via the output shaft.

[0012] The output shaft is preferably connected or coupled to the wheels in order to drive the wheels at a determined speed. The coupling can be effected with at least one further component interposed. The braking device describes a system or mechanism for slowing down or stopping the movement of the input shaft and also, via the transmission, the movement of the output shaft. The electric motor describes a device or system which converts electrical energy into mechanical energy and is used to drive the input shaft. Preferably, the coupling to the input shaft is effected directly or indirectly.

[0013] The braking device and the electric motor are either directly connected to the input shaft or mounted on the input shaft in order to influence its movement. The electric motor is preferably designed to drive the input shaft at a determined input speed. In order to provide the function of the braking device, the braking device is designed and arranged such that it can slow down or stop the movement of the input shaft, which reduces the input speed.

[0014] To provide the transmission function of the transmission, the transmission has the ability to convert the input speed into the output speed, thereby being able to control the speed and torque of the wheels.

[0015] The present invention is thus directed to using the transmission, in particular the reduction transmission of a vehicle drive, also in a braking device. Thereby, the rotational speed of the brake is increased to a higher level, and accordingly the braking torque requirement is reduced. In a conventional brake, this enables a smaller and lighter construction (e.g., in a drum brake or a disc brake), or enables the introduction of new braking technologies (e.g., a plate brake, a low-wear and dust-free wet plate brake, a wear-free and dust-free eddy current brake).

[0016] It is particularly advantageous here that a smaller structural size and a lighter weight can be achieved. In addition, a brake with reduced wear that may require no maintenance during its service life can be achieved. In addition, it is possible to reduce or avoid microdust emissions. The possibility of integrating an electric motor and a brake in a vehicle drive, in particular configured as a drive module, is also provided.

[0017] According to one embodiment, the braking device is arranged between the transmission and the electric motor. Alternatively, the electric motor is arranged between the transmission and the braking device.

[0018] Therefore, the arrangement of the braking device and the electric motor can also be interchanged. Thus, the described embodiment preferably relates more precisely to the sequence of actions rather than to the structural arrangement of the components. For example, this enables the use of a wear-free and dust-free, in particular precisely adjustable, eddy current brake.

[0019] According to one embodiment, the transmission has a planetary transmission or a stepped planetary transmission or a spur gear transmission.

[0020] A planetary transmission preferably describes a transmission having a central sun gear, planetary gears, and a ring gear. It can achieve different transmission ratios and is used in automatic transmissions and other applications. A stepped planetary transmission preferably describes a special variant of the planetary transmission, in which the planetary gears are arranged in a stepped manner to achieve a larger transmission ratio. A spur gear transmission describes a transmission in which power transmission is achieved by spur gears meshing with each other. The possible and purely exemplary transmission ratio i can vary between 3 and 15.

[0021] According to one embodiment, the braking device has a friction brake, in particular a drum brake, or a disc brake, or a plate brake, or in particular an encapsulated, preferably dust-free, brake, in particular an eddy current brake or a wet plate brake.

[0022] A friction brake preferably describes a brake in which deceleration is produced by the friction between two surfaces. This friction brake can be implemented in different embodiments. A drum brake preferably describes a special type of friction brake in which brake linings are contained within a drum and pressed against the drum when needed to slow down motion. A disc brake preferably describes a brake in which deceleration is produced by the friction between brake linings and a rotating brake disc. This disc brake often appears in modern vehicles. A plate brake preferably describes a brake in which brake linings or brake pads are used to slow down motion. It can be implemented in different configurations. An encapsulated brake preferably describes a brake that is especially protected against dust and dirt in order to increase the service life and efficiency of the brake.

[0023] A dust-free brake preferably describes a brake that is designed such that it produces or absorbs as little dust as possible in order to improve cleanliness and maintenance friendliness. An eddy current brake preferably describes a special type of brake in which eddy currents are generated to convert kinetic energy into heat and slow down motion. A wet plate brake preferably describes a brake in which brake linings and / or brake pads operate in an oil bath in order to reduce friction and increase the service life.

[0024] An eddy current brake preferably has a conductive disc or drum with an electromagnet arranged beside it. The electromagnet can be arranged such that an axial or radial air gap is formed. Variations in the arrangement and / or number of electromagnets are possible. For example, the electromagnets can be arranged on both sides of the disc and separated from the disc by axial air gaps respectively.

[0025] An eddy current brake can achieve precise adjustability of the braking torque. In addition, the use of brake fluid can be dispensed with. Moreover, there is a high degree of freedom in product design because the accessibility of the brake for maintenance situations does not have to be considered.

[0026] According to one embodiment, an electric motor has a permanent magnet synchronous motor (PSM), or an asynchronous motor (ASM), or an electrically excited synchronous motor (ESM).

[0027] A permanent magnet synchronous motor (PSM) is a synchronous motor in which the rotor is magnetized by permanent magnets. This type of motor is known for its high efficiency and high power density. An asynchronous motor (ASM) is a motor in which the rotor runs out of sync with the rotating magnetic field of the stator. This motor is also known as an induction motor and is widely used in different applications due to its simple structure and maintenance. An electrically excited synchronous motor (ESM) is a synchronous motor in which the rotor is magnetized by an electric field winding rather than by permanent magnets. This enables more precise control of the motor power.

[0028] In the present context, the term "electric motor" can also be replaced by the term "electrical machine", especially in cases where the electric motor is capable of operating not only as a motor but also as a generator. If the electric motor is configured, for example, for braking energy recovery, it involves an electrical machine that can operate as a motor and a generator.

[0029] According to one embodiment, the transmission has a planetary transmission, in particular a stepped planetary transmission, and the braking device has an eddy current brake which has a rotor and a stator. The electric motor has a rotor and a stator, wherein the rotor of the eddy current brake is integrally formed with the rotor of the electric motor, or wherein the stator of the eddy current brake is integrally formed with the stator of the electric motor.

[0030] Currently, an eddy current brake describes a special type of brake in which eddy currents are generated to convert kinetic energy into heat and slow down the movement. The eddy current brake includes a rotor and a stator. An electric motor describes a device that converts electrical energy into mechanical movement for driving a shaft, currently the input shaft. The electric motor includes a rotor and a stator.

[0031] The rotor is preferably part of the electric motor and / or the eddy current brake, which rotates and contributes to generating or slowing down the movement. The stator is preferably the stationary part of the electric motor and / or the eddy current brake, which generates or influences the magnetic field acting on the rotor. It is characterized in that either the rotor of the eddy current brake is integrally formed with the rotor of the electric motor, or the stator of the eddy current brake is integrally formed with the stator of the electric motor. This affects the integration and efficiency of the system.

[0032] In other words, a transmission between the eddy current brake and the electric motor is not required and can be saved. A structure space-optimized planetary transmission is particularly preferably used. Due to the omission of the transmission between the eddy current brake and the electric motor, the rotor of the electric motor and the rotor of the eddy current brake can be integrally designed. Alternatively, the stator of the eddy current brake can be combined with the stator of the electric motor. This results in advantages and synergies with respect to the electrical contact and / or cooling of the stator, since in particular a common plug and / or a common cooling circuit can be used.

[0033] According to one embodiment, the eddy current brake has an axially or radially arranged air gap.

[0034] An axially arranged air gap preferably describes an air gap whose air gap height is measured parallel to the axis of rotation. The axially arranged air gap can be used to configure an eddy current brake so that it acts in the axial direction. A radially arranged air gap preferably describes an air gap whose air gap height is measured perpendicular to the axis of rotation (i.e., in the radial direction). The radially arranged air gap can be used to configure an eddy current brake so that it acts in the radial direction. The choice between these two arrangements affects the functionality and usability of the eddy current brake in different situations.

[0035] According to one embodiment, the transmission and / or the braking device and / or the electric motor are arranged in a structural space provided in the wheel.

[0036] The structural space preferably describes a space or a specific area within the wheel, for example, provided in the inner region of the rim, which is provided for accommodating the above-mentioned components (transmission, braking device, electric motor). This embodiment describes that, in the described embodiment, at least one of the mentioned components (transmission and / or braking device and / or electric motor) is arranged in a structural space specifically provided in the wheel.

[0037] This means that these components are installed within the wheel, especially within the rim, which saves space and enables easier integration into the vehicle. This can be beneficial for saving space or reducing the weight of the drive system in different vehicle applications. In other words, according to this embodiment, at least one of the components (transmission and / or braking device and / or electric motor) can be integrated into the rim of the wheel.

[0038] Thus, particularly preferably, the entire unit (transmission, braking device, and electric motor) is not arranged in the vehicle body, i.e., the elastic mass, but in the area or structural space within the rim of the wheel, i.e., the inelastic mass.

[0039] In the present case, a vehicle having at least one such vehicle drive is also proposed.

[0040] Furthermore, a vehicle having at least one such vehicle drive is proposed, wherein the vehicle has a vehicle body, wherein the transmission, the braking device, and the electric motor are arranged at or in the vehicle body, and wherein the wheel is coupled to the output shaft via a universal joint.

[0041] The vehicle body preferably describes the external structure or framework of a vehicle, which protects and / or houses passengers, cargo, and other components and forms and / or influences the external appearance of the vehicle. The vehicle body also provides the support structure of the vehicle. A cardan shaft describes a shaft that is used to transmit rotational motion from one source to another through a connection. This embodiment relates to the presence of at least one such vehicle drive in a vehicle. In this vehicle, a transmission, a braking device, and an electric motor are arranged at or in the vehicle body.

[0042] The wheels are coupled to the output shaft of the drive via a cardan shaft, which means that the driving force of the drive system is transmitted to the wheels in order to drive the vehicle. This arrangement can be used in different types of vehicles in order to integrate the drive components in an efficient and space-saving manner.

[0043] The vehicle can be a commercial vehicle, such as a truck, a passenger car, a transport vehicle, a bus, a heavy goods vehicle, a minibus, a two-wheeled vehicle, a three-wheeled vehicle, a multi-wheeled vehicle, a military vehicle, a heavy goods vehicle-tractor, or a similar vehicle. Generally speaking, a vehicle describes a means of transport for transporting people and / or cargo.

[0044] The statements made with respect to the vehicle drive correspondingly apply to a vehicle having such a vehicle drive. It should be understood here that the linguistic variants of the features can be used to rephrase the vehicle according to common linguistic usage without having to explicitly list such formulations here.

[0045] The described design solutions and improvements can be combined with one another arbitrarily.

[0046] Other possible design solutions, improvements, and implementations of the present invention also include combinations of features of the present invention that are not explicitly mentioned above or below with respect to the embodiments. Description of the Drawings

[0047] The drawings are intended to provide a further understanding of the embodiments of the present invention. They show embodiments and, in conjunction with the description, serve to explain the principles and concepts of the present invention.

[0048] Other embodiments and many of the mentioned advantages can be derived from the drawings. The elements shown in the drawings are not necessarily shown in proportion to one another.

[0049] Where:

[0050] Figure 1 A vehicle with an embodiment of a vehicle drive is schematically shown;

[0051] Figure 2 An embodiment of the vehicle drive is schematically shown;

[0052] Figure 3Schematically shows an embodiment of a vehicle drive;

[0053] Figure 4 Schematically shows an embodiment of a vehicle drive;

[0054] Figure 5 Schematically shows an embodiment of a vehicle drive; and

[0055] Figure 6 Schematically shows an embodiment of a vehicle drive. Detailed Description

[0056] In the figures of the drawings, unless otherwise stated, the same reference numerals denote the same or functionally identical elements, components or assemblies.

[0057] Figure 1 Schematically shows a vehicle 1000 having an embodiment with at least one vehicle drive 100. Currently, the vehicle 1000 includes two vehicle drives 100, which can be seen in Figures 2 to 6 multiple embodiments. The vehicle 1000 has a vehicle body 1002.

[0058] Figure 2 Schematically shows an embodiment of the vehicle drive 100. The vehicle drive 100 has a wheel 10 and a transmission 12. The transmission 12 has at least one input shaft 14 and an output shaft 16. The output shaft 16 is coupled to the wheel to drive the wheel 10 at an output speed n2. In addition, the vehicle drive 100 has a braking device 18 and an electric motor 20. The braking device 18 and the electric motor 20 are coupled to or arranged on at least one input shaft 14.

[0059] In some embodiments, the input shaft 14 can be constructed integrally or in one piece or in multiple pieces. Thus, the braking device 18 can have an input shaft portion, for example, and the electric motor 20 can have an input shaft portion. The electric motor 20 is configured to drive at least one input shaft 14 at an input speed n1. The braking device 18 is provided for braking at least one input shaft 14 so as to reduce the input speed n1. The transmission 12 is provided for preferably converting the input speed n1 into the output speed n2 according to the transmission ratio i.

[0060] In principle, the braking device 18 can be arranged between the transmission 12 and the electric motor 20 (see Figures 2 to 4 and Figure 6 ). Alternatively, the electric motor 20 can be arranged between the transmission 12 and the braking device 18 (see Figure 5 ).

[0061] The transmission 12 can in principle be configured as a planetary transmission or a stepped planetary transmission or a spur gear transmission.

[0062] The braking device 18 can in principle be configured as a friction brake, in particular a drum brake, or a disc brake, or a plate brake, or in particular an encapsulated, preferably dust-free brake, in particular an eddy current brake or a wet plate brake.

[0063] The electric motor 20 can be of any structural type, preferably a permanent magnet synchronous motor PSM, or an asynchronous motor ASM, or an electrically excited synchronous motor ESM.

[0064] Figure 3 Another embodiment of the vehicle drive 100 is schematically shown. According to Figure 3 , the transmission 12, the braking device 18 and the electric motor 20 are arranged in a structural space 22 provided in the wheel 10. The structural space 22 can be provided in the rim 24 of the wheel 10.

[0065] Alternatively, the transmission 12, the braking device 18 and the electric motor 20 can be arranged at the vehicle body 1002. The wheel 10 can be coupled to the output shaft 16 via a cardan shaft 26 (see Figure 1 for the left-hand embodiment of the vehicle drive 100 in

[0066] Figure 4 Another embodiment of the vehicle drive 100 is schematically shown. According to Figure 4 , the transmission 12, the braking device 18 and the electric motor 20 are arranged in a structural space 22 provided in the wheel 10. The transmission 12 is a planetary transmission, in particular a stepped planetary transmission. The braking device 18 is an eddy current brake 28, which has a rotor 30 configured in the form of a brake disc and a stator 32 configured in the form of an electromagnet. The electric motor 20 includes a rotor 34 and a stator 36 (see Figure 6 ). According to Figure 4 , the eddy current brake 28 has an axially arranged air gap 38.

[0067] Figure 5 Another embodiment of the vehicle drive 100 is schematically shown. According to Figure 4 , the transmission 12, the braking device 18 and the electric motor 20 are arranged in a structural space 22 provided in the wheel 10. The electric motor 20 is arranged between the transmission 12 and the braking device 18. The transmission 12 is a planetary transmission, in particular a stepped planetary transmission. According to Figure 5 , the eddy current brake 28 has a radially arranged air gap 40 between the rotor 30 and the stator 32.

[0068] Figure 6 Another embodiment of the vehicle drive 100 is schematically shown. According to Figure 6, the transmission 12, the braking device 18, and the electric motor 20 are arranged in a structural space 22 provided in the wheel 10. The braking device 18 is arranged between the electric motor 20 and the transmission 12. The transmission 12 is a planetary transmission, in particular a stepped planetary transmission. According to Figure 6 , the eddy current brake 28 has a radially arranged air gap 40 between the rotor 30 and the stator 32. The stator 32 of the eddy current brake 28 is integrally constructed with the stator 36 of the electric motor 20.

[0069] Alternatively, it is also conceivable that the rotor 30 of the eddy current brake 28 is integrally constructed with the rotor 34 of the electric motor 20 (not shown).

[0070] Alternatively, it is also possible to mount the components of the drive in the wheel, and other components at the vehicle body and connect them by means of a cardan shaft (not shown).

Claims

1. A vehicle drive (100) for a vehicle (1000), comprising: - a wheel (10), - A transmission (12) having an input shaft (14) and an output shaft (16), wherein: The output shaft (16) is coupled to the wheel (10) so as to drive the wheel (10) at an output speed (n2), - a brake device (18), and - an electric motor (20), A brake device (18) and an electric motor (20) are coupled to the input shaft (14) or are arranged on the input shaft (14), wherein the electric motor (20) is designed to drive the input shaft (14) at an input speed (n1). The braking device (18) is provided for braking the input shaft (14) in order to reduce the input speed (n1) in such a way that The transmission (12) is configured to convert an input rotational speed (n1) into an output rotational speed (n2).

2. The vehicle drive according to claim 1, wherein: The brake device (18) is arranged between the transmission (12) and the electric motor (20), or the electric motor (20) is arranged between the transmission (12) and the brake device (18).

3. The vehicle drive according to claim 1 or 2, wherein: The transmission (12) has a planetary transmission, a stepped planetary transmission or a spur gear transmission.

4. A vehicle drive according to any one of the preceding claims, wherein: The brake device (18) has a friction brake, in particular a drum brake, or a disk brake, or a multi-disk brake, or in particular an encapsulated, preferably dust-free brake, in particular an eddy current brake or a wet multi-disk brake.

5. A vehicle drive according to any one of the preceding claims, wherein: The electric motor (20) has a permanently excited synchronous motor PSM, an asynchronous motor ASM, or an electrically excited synchronous motor ESM.

6. The vehicle drive according to any one of claims 1 or 2, wherein: The transmission (12) has a planetary transmission, in particular a stepped planetary transmission, and the braking device (18) has an eddy current brake (28) having a rotor (30) and a stator (32), wherein the electric motor (20) has a rotor (34) and a stator (36), wherein the rotor (30) of the eddy current brake (28) is integrally formed with the rotor (34) of the electric motor (20), or wherein the stator (32) of the eddy current brake (28) is integrally formed with the stator (36) of the electric motor (20).

7. The vehicle drive according to claim 4 or 6, wherein: The eddy current brake (28) has an axially arranged air gap (38) or a radially arranged air gap (40).

8. The vehicle drive according to claim 7, wherein: The air gap height of the axially arranged air gap extends parallel to the axis of rotation, and the air gap height of the radially arranged air gap extends perpendicularly to the axis of rotation.

9. A vehicle drive according to any one of the preceding claims, wherein: A transmission (12) and / or a brake device (18) and / or an electric motor (20) are arranged in a structural space (22) provided in a wheel (10), in particular in a wheel rim (24).

10. The vehicle drive according to any one of claims 1 to 8, wherein: A transmission (12), a brake device (18) and an electric motor (20) are arranged on a vehicle body (1002), wherein a wheel (10) is coupled to an output shaft (16) via a cardan shaft (26).

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