Thermal management system, electric axle drive train and electrically powered motor vehicle

Abstract

The invention relates to a thermal management system (1) for an electrically operated motor vehicle (2), comprising an electric machine (3) for driving the motor vehicle (2), a brake (5) with a brake cooling circuit (6) for dissipating or supplying heat from or to the brake (5), a hydraulic control system (7) for influencing the volume flow in the brake cooling circuit (6), an electronic control unit (8) for controlling the hydraulic control system (7), wherein the brake cooling circuit (6) is coupled to a first thermal energy store (9).

Description

[0001] The present invention relates to a thermal management system for an electrically powered motor vehicle comprising an electric machine for driving the motor vehicle, a brake with a brake cooling circuit for dissipating or supplying heat from or to the brake, a hydraulic control system for influencing the volume flow in the brake cooling circuit, and an electronic control unit for controlling the hydraulic control system.

[0002] Electric motors are increasingly being used to power motor vehicles as alternatives to combustion engines that require fossil fuels. Considerable efforts have already been made to improve the everyday suitability of electric drives and also to offer users the same driving comfort they are accustomed to. A detailed description of an electric drive can be found, for example, in an article in the magazine ATZ, Volume 113, May 2011, pages 360-365, by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold, entitled "Highly Integrative and Flexible Electric Drive Unit for E-Vehicles." This article describes a drive unit for one axle of a vehicle that includes an electric motor arranged coaxially with a bevel gear differential.

[0003] In vehicles with such an electric drive, the heating and cooling system for the passenger compartment is the largest secondary energy consumer, since fully electric drive concepts generally do not require the combustion engine as a heat source. In addition, additional temperature control requirements arise for drive components such as the battery, power electronics, and the electric drive itself.

[0004] In particular, the ambient temperature constraint can lead to significant range loss in vehicles with electric propulsion. Depending on the situation, the temperature control system may consume more electrical energy than is required to power the vehicle. The energy efficiency of heating and cooling systems for fully electric vehicles is therefore increasingly the focus of development efforts.

[0005] In particular, preconditioning the battery by heating, which is necessary for an upcoming rapid charging phase, is one of the energy-intensive thermal management functions, along with heating the passenger compartment. A thermal management system consisting of a coolant circuit with two circuits is described, for example, in US8402776. Another example of such a thermal management system can be found in DE102012208992A1. The energy-intensive and thus range-reducing heating of the coolant or the interior air of the passenger compartment via additional heaters is generally undesirable. A thermal management system according to the preamble of claim 1 is disclosed in DE 10 2012 112 377 A1. Further prior art can be found in DE 10 2020 133 638 A1, US 2005 / 0 167 169 A1, DE 20 2010 001 201 U1, DE 10 2021 203 125 A1, DE 10 2020 106 000 A1 and US 2021 / 0 036 342 A1.

[0006] In this context, devices for storing heat in motor vehicles have also become known, e.g., from DE819334C. A so-called PCM material (Phase Change Material) can be used to store thermal energy.

[0007] It is therefore the object of the invention to provide an improved thermal management system for an electrically powered motor vehicle. Furthermore, the object of the invention is to realize an optimized electric axle drive train and an improved electrically powered motor vehicle.

[0008] This object is achieved by a thermal management system for an electrically operated motor vehicle comprising an electric machine for driving the motor vehicle, a brake with a brake cooling circuit for dissipating or supplying heat from or to the brake, a hydraulic control system for influencing the volume flow in the brake cooling circuit, an electronic control unit for controlling the hydraulic control system, wherein the brake cooling circuit is coupled to a first thermal energy store.

[0009] This provides the advantage of storing thermal energy generated during braking, thus making it possible to use the brake as a heat source for the thermal management system of a motor vehicle. The invention utilizes brakes equipped with a thermal energy recovery device, such as a brake cooling circuit.

[0010] First, the individual elements of the claimed subject matter of the invention will now be explained and particularly preferred embodiments of the subject matter of the invention will be described below.

[0011] A hydraulic control system directs the volume flows within a motor vehicle's thermal management system using switching elements that hydraulically act on a fluid, such as valves, slides, pumps, and the like. For this purpose, the hydraulic control system can, for example, completely or partially throttle a volume flow and / or distribute it to the relevant heat sources and sinks in subcircuits of the motor vehicle's thermal management system. For this purpose, the hydraulic switching elements are preferably controlled and switched by an electronic control unit.

[0012] A hydraulic switching element can be a hydraulic pump, a switching valve, a controllable throttle valve, and the like. Preferably, a hydraulic switching element is electrically controllable. Furthermore, a hydraulic switching element preferably has at least two different, switchable operating states in which the hydraulic switching element acts in different ways on the corresponding fluid in a circuit.

[0013] The brake of the thermal management system according to the invention has the function of decelerating a shaft to be braked, for example, by means of a frictional connection. The brake can be designed, in particular, based on the functional principle of a dry or wet multi-disk brake, a disc brake, or even a drum brake.

[0014] A brake can also have a brake actuator. A brake actuator has the particular function of actuating the brake, i.e., placing it in a frictionally engaged operating state and a frictionally released operating state. For this purpose, the brake actuator can be actuated pneumatically, hydraulically, by electric motor, mechanically, electromagnetically, or any combination thereof. The brake actuator can preferably have at least one linearly displaceable piston, which is preferably displaceable in the axial direction.

[0015] The brake has a brake cooling circuit for dissipating or supplying heat from or to the brake, wherein the hydraulic control unit acts on the brake cooling circuit by means of at least one hydraulic switching element to influence the volume flows in the brake cooling circuit.

[0016] The brake is preferably arranged in a brake housing. The brake housing encloses the brake. A brake housing can also accommodate one or more brake actuators. The brake housing can also be part of a cooling system and be designed such that cooling fluid is supplied to the braking system via the brake housing and / or the heat can be dissipated to the outside via the housing surfaces. Furthermore, the brake housing protects the brake from external mechanical and / or chemical influences. A brake housing can in particular be formed from a metallic material. Advantageously, the brake housing can be formed from a metallic cast material, such as gray cast iron or cast steel. In principle, it is also conceivable to form the brake housing entirely or partially from a plastic. Furthermore, it is possible for the brake housing to be designed in one piece or in multiple parts.The brake housing can also be designed completely or partially as part of a motor housing of an electric machine or a transmission housing of a transmission coupled to the electric machine. The brake housing and the motor housing or the transmission housing preferably form a structural unit. For this purpose, the brake housing can be screwed to the motor housing or the transmission housing, for example. The brake housing is preferably designed such that abrasion generated during braking cannot escape from the brake housing. This can prevent unwanted environmental pollution with brake abrasion. Furthermore, such encapsulation of the brake system can also reduce braking noise emitted to the environment. A further advantageous aspect of this encapsulation is that the braking performance of the brake system is independent of the weather conditions outside the motor vehicle.

[0017] The brake can be designed as a disc brake. The brake disc is the rotating part of a disc brake, with the brake shoes releasably engaging the front surfaces of the disc brake to decelerate the rotational movement of the brake disc by means of frictional engagement during operation of the disc brake. The brake disc preferably has a brake disc body.

[0018] Brake discs can preferably be formed from a cast metal, such as gray cast iron, ductile iron, or cast steel, and then machined, preferably by turning and / or milling. To achieve a particularly low weight of the brake disc, it is also possible to use carbon fiber-reinforced silicon carbide and / or a carbon fiber-reinforced ceramic material. It is also conceivable, particularly for a particularly cost-effective production of the brake disc, to stamp it from sheet metal.

[0019] A brake disc preferably has a hollow cylindrical shape, the axial extent of which is significantly smaller than its diameter. The brake disc can be constructed in one piece or in multiple pieces. In a multi-piece brake disc, the individual brake disc elements can preferably be arranged in layers in the axial direction, resulting in a type of sandwich construction.

[0020] The brake disc body is the part of the brake disc on which the brake shoes act with friction to reduce the rotational speed of the brake disc. The brake disc body can have a plurality of brake disc cooling channels, by means of which, in particular, heat and / or brake wear can be dissipated from the brake disc body.

[0021] The braking system may further comprise a shaft connection. The shaft connection of the brake disc connects the brake disc body to the rotating shaft to be braked, which is also referred to as the brake shaft. The shaft connection may be designed as a separate component that is arranged in the torque flow between the brake disc body and the shaft to be braked, or as a connection between the brake disc body and the shaft to be braked. In this case, it is possible for the shaft to be braked and the shaft connection to be formed as a single piece, in particular monolithically. In principle, it is also conceivable for the shaft connection and the brake disc body to be formed as a single piece. It may also be preferred for the shaft to be braked, the shaft connection, and the brake disc body to be formed as a single piece, in particular monolithically.The shaft connection can also be established, for example, by means of a positive fit, a frictional fit, and / or a material connection between the shaft to be braked and the brake disc body. For example, the shaft connection can be achieved by means of a press fit, spline engagement, or even welding.

[0022] The disc brake can have a hydraulic brake disc cooling system. A hydraulic brake disc cooling system uses a brake disc cooling fluid to cool the brake disc. The brake disc cooling fluid can act on the brake disc at least in sections and / or be passed through the brake disc. Preferably, the hydraulic brake disc cooling system is designed so that the brake disc cooling fluid cannot reach the friction surfaces between the brake shoes and the brake disc body.

[0023] For this purpose, the hydraulic brake disc cooling system can have at least one, but preferably a plurality of brake disc cooling channels in which the brake disc cooling fluid is guided.

[0024] It is further preferred that the hydraulic brake disc cooling system is connected to a brake disc cooling circuit, within which the frictional heat absorbed by the brake disc cooling fluid is dissipated from the disc brake and fed to a heat sink, such as a heat exchanger. The brake disc cooling circuit can preferably form part of the brake cooling circuit of the thermal management system. Most preferably, the brake disc cooling circuit is the brake cooling circuit of the thermal management system.

[0025] In order to create a frictional connection between the brake shoes and the brake disc, the brake shoes, in particular with their brake shoe friction linings, are pressed preferably axially against the brake disc by means of a brake actuator.

[0026] The brake can preferably also be designed as a multi-disk brake. A multi-disk brake has the function of establishing a detachable, frictionally engaged connection between a brake shaft and a connecting structure, which is generally arranged in a rotationally fixed manner, to support a braking torque. The alternating inner and outer discs of the disc pack can be brought into force-locking or frictional contact by axially displacing and pressing together via their respective friction linings through an engagement process, so that the inner discs rotate relative to the outer discs around the common axis of rotation of the corresponding disc pack with friction, or are arranged in a rotationally fixed manner with respect to one another in the case of a complete frictional engagement.If, however, the inner and outer plates are pushed axially away from each other by a disengagement process, there is no longer any frictional contact between the inner and outer plates, so that they can rotate freely against each other and consequently no rotational or braking torque is transmitted between the inner and outer plates.

[0027] A multi-disk brake typically consists of at least two inner and / or two outer discs. The inner discs are preferably arranged in a rotationally fixed manner on an inner disc carrier, and the outer discs are preferably arranged in a rotationally fixed manner on an outer disc carrier. The inner disc carrier is particularly preferably connected to a brake shaft, and the outer disc carrier is particularly preferably connected to a rotationally fixed connection structure, or vice versa.

[0028] The inner and outer discs form the disc pack of the multi-disk brake. In the disc pack, a plurality of inner and outer discs are preferably arranged, generally alternating in the axial direction. The torque or braking torque that can be transmitted between the inner and outer discs by the multi-disk brake can be adjusted by the number and design of the inner and outer discs.

[0029] The inner plates function to transmit torque, particularly through force or friction, from the outer plates to the inner plate carrier. The inner plates can be designed, in particular, as circular disks. The inner plates can be connected in a rotationally fixed manner to the inner plate carrier of the multi-disk brake. It can also be provided that the inner plates can be displaced axially relative to the inner plate carrier, for example, via a corresponding toothing, in order to establish frictional engagement with the outer plates.

[0030] The outer plates have the function of transmitting torque, particularly by force or friction, from the inner plates to the outer plate carrier. The outer plates can be designed, in particular, as circular disks. The outer plates can be connected in a rotationally fixed manner to the outer plate carrier of the multi-plate clutch. It can also be provided that the outer plates can be displaced axially relative to the outer plate carrier, for example via appropriate toothing, in order to establish frictional engagement with the inner plates. The outer plate carrier can, for example, be designed as an outer plate clutch cage.

[0031] A plate pack can be accommodated in one or more plate carriers and, in particular, guided for linear movement. For this purpose, the inner plates can be accommodated in an inner plate carrier, and the outer plates in an outer plate carrier. To create a linearly movable offset of the inner plates relative to the outer plates (or vice versa), the inner plates can be connected to the inner plate carrier via an internal spline and / or the outer plates can be connected to the outer plate carrier via an external spline in a torque-transmitting manner.

[0032] The multi-disk brake can preferably comprise a spring element. The spring element's task is to move the inner and outer discs to a predefined position relative to each other using spring force. This predefined position typically corresponds to a "normally open" or "normally closed" operating state of the multi-disk brake, meaning that when the brake actuator is not actuated, the inner and outer discs are either pressed against each other or released by the spring element.

[0033] Furthermore, a multi-disk brake can also have a switching piston. The switching piston converts the engagement and disengagement processes specified by the brake actuator into an axial displacement of the inner and / or outer discs for the purpose of establishing a frictional connection when braking or releasing a frictional connection when releasing the multi-disk brake.

[0034] The brake can particularly preferably comprise a brake actuator. A brake actuator has the particular function of actuating the brake, i.e., placing it in a frictionally engaged operating state and a frictionally released operating state. For this purpose, the brake actuator can be actuated pneumatically, hydraulically, by an electric motor, mechanically, electromagnetically, or any combination thereof. The brake actuator is preferably configured as an electromechanical brake actuator.

[0035] The brake is intended for a motor vehicle electrically driven by an electric machine. Electric machines within the meaning of this application serve to convert electrical energy into mechanical energy and / or vice versa, and generally comprise a stationary part referred to as a stator, stand, or armature, and a part referred to as a rotor or runner, which is arranged to be movable relative to the stationary part. In the context of this invention, an electric machine can be designed, in particular, as a rotary machine. In such rotary electric machines, a distinction is made, in particular, between radial flux machines and axial flux machines.A radial flux machine is characterized in that the magnetic field lines in the air gap formed between the rotor and stator extend in the radial direction, whereas in the case of an axial flux machine the magnetic field lines in the air gap formed between the rotor and stator extend in the axial direction. In connection with the present invention, an electric machine is provided in particular for use within a drive train of a hybrid or fully electric motor vehicle. In particular, the electric machine is dimensioned such that vehicle speeds of greater than 50 km / h, preferably greater than 80 km / h and in particular greater than 100 km / h can be achieved. The electric machine particularly preferably has an output of greater than 30 kW, preferably greater than 50 kW and in particular greater than 70 kW. It is further preferred that the electric machine has speeds of greater than 5.000 rpm, particularly preferably greater than 10,000 rpm, most preferably greater than 12,500 rpm.

[0036] The electric machine can have a housing, which is also referred to as a motor housing. The motor housing encloses the electric machine. A motor housing can also accommodate the control and power electronics, and preferably also at least parts of the braking system. The motor housing can also be part of a cooling system for the electric machine and can be designed such that cooling fluid is supplied to the electric machine via the motor housing and / or the heat can be dissipated to the outside via the motor housing surfaces. Furthermore, the motor housing protects the electric machine and any electronics present from external mechanical and / or chemical influences. A motor housing of the electric machine can in particular be formed from a metallic material. Advantageously, the motor housing can be formed from a metallic cast material, such as gray cast iron or cast steel.In principle, it is also conceivable for the motor housing to be constructed entirely or partially from plastic. Furthermore, the motor housing of the electric machine can be constructed in one piece or in multiple parts.

[0037] A rotor is the rotating part of an electrical machine. The rotor comprises, in particular, a rotor shaft and one or more rotor bodies formed from rotor cores, which are arranged on the rotor shaft in a rotationally fixed manner. The rotor shaft can be hollow, which, on the one hand, results in weight savings and, on the other hand, allows the supply of lubricant or coolant to the rotor body. The rotor shaft can be coupled, in particular, to the brake shaft of the braking system.

[0038] According to an advantageous embodiment of the invention, it can be provided that the electric machine has an engine cooling circuit for dissipating or supplying heat from or to the electric machine, wherein the hydraulic control unit acts on the engine cooling circuit by means of at least one hydraulic switching element in order to influence the volume flows in the engine cooling circuit.

[0039] The electric motor can preferably be coupled to a transmission designed to generate a drive torque for the motor vehicle. The drive torque is particularly preferably a main drive torque, so that the motor vehicle is driven exclusively by the drive torque.

[0040] In particular, it can be provided that the electric machine and the transmission are arranged in a common drive train housing. Alternatively, it would of course also be possible for the electric machine to have a motor housing and the transmission to have a transmission housing, in which case the structural unit can be effected by fixing the transmission arrangement relative to the electric machine. This structural unit is occasionally also referred to as an e-axle. The drive train housing is preferably formed from a metallic material, particularly preferably from aluminum, gray cast iron or cast steel, in particular by means of a primary forming process such as casting or die casting. In principle, however, it would also be possible to form the drive train housing from a plastic.The drive train housing can particularly preferably have a pot-like basic shape so that the electric machine and the transmission can be inserted into the drive train housing via the open front side of the housing.

[0041] The electric machine preferably has a motor housing and / or the gearbox a gearbox housing, whereby the structural unit is then achieved by fixing the gearbox relative to the electric machine. The gearbox housing is a housing for accommodating a gearbox. Its task is to guide existing shafts via the bearings and to grant the wheels (and possibly cam disks) the degrees of freedom they require under all loads without hindering their rotational and possibly path-related movement, as well as to absorb bearing forces and support moments. A gearbox housing can be single- or multi-shell, i.e., undivided or split. In particular, the gearbox housing should also dampen noise and vibrations and be able to safely accommodate hydraulic fluid.The gear housing is preferably formed from a metallic material, particularly preferably from aluminum, gray cast iron or cast steel, in particular by means of a primary forming process such as casting or die casting.

[0042] The transmission can further preferably be configured as a planetary gear or comprise a planetary gear. The planetary gear can preferably have a sun gear and a plurality of planetary gears meshing with the sun gear and rotatably mounted in a planetary gear carrier, which rotate around the sun gear, as well as a ring gear arranged coaxially to the sun gear, in which the planetary gears roll.

[0043] The transmission may also include a differential. A differential is a planetary gear with one input and two outputs. Its function is typically to drive two wheels of a motor vehicle so that they can turn at different speeds while cornering, but with the same propulsive force.

[0044] According to an advantageous embodiment of the invention, it can be provided that the transmission has a transmission cooling circuit for dissipating or supplying heat from or to the transmission, wherein the hydraulic control unit acts on the transmission cooling circuit by means of at least one hydraulic switching element to influence the volume flows in the transmission cooling circuit.

[0045] In order to implement different drive or operating modes for the motor vehicle, one or more separating clutches can be provided within the torque path between the electric machine and a vehicle wheel. A separating clutch can, for example, be arranged between the output of the electric machine and the input of the transmission, such that the electric machine can be decoupled from the transmission, thereby enabling coasting operation of the motor vehicle. It would also be conceivable to arrange a separating clutch between the output of the transmission and a vehicle wheel or wheels, thereby also enabling coasting operation of the motor vehicle. Finally, it is also possible to arrange a separating clutch between the input of the braking system and the output of the electric machine, whereby the braking system can be completely decoupled from the electric machine.

[0046] For the purposes of this application, motor vehicles are defined as land vehicles that are propelled by mechanical power without being tied to railway tracks. A motor vehicle can, for example, be selected from the group of passenger cars (PCs), trucks (HGVs), mopeds, light motor vehicles, motorcycles, buses (KOMs), or tractors.

[0047] According to an advantageous embodiment of the invention, it can be provided that the thermal management system further comprises an inverter with an inverter cooling circuit for dissipating or supplying heat from or to the inverter, wherein the hydraulic control unit acts on the inverter cooling circuit by means of at least one hydraulic switching element in order to influence the volume flows in the inverter cooling circuit.

[0048] The electric machine for driving the motor vehicle can be powered by an inverter. The power electronics of the inverter are preferably accommodated in an inverter housing. The inverter housing can preferably be formed from a metallic material, particularly preferably from aluminum, gray cast iron, or cast steel, in particular by means of a primary forming process such as casting or die casting. The inverter housing particularly preferably has a pot-like spatial shape. In this context, it is particularly preferable for the housing cover to be insertable into the pot-like inverter housing. Alternatively, it would also be conceivable for the housing cover to rest on the pot-like inverter housing and cover its opening. The inverter housing can also be part of the motor housing of an electric machine, or vice versa. This means that the inverter housing is formed entirely or partially in one piece, in particular monolithically, with the motor housing.

[0049] The power electronics accommodated in the inverter housing can be provided in particular for an electric machine for driving a motor vehicle. The power electronics is preferably a combination of various components which control or regulate a current to the electric machine of the axle drive train, preferably including the peripheral components required for this purpose, such as cooling elements or power supplies. In particular, the power electronics contains one or more power electronics components which are designed to control or regulate a current. These are particularly preferably one or more power switches, e.g. power transistors. The power electronics particularly preferably has more than two, particularly preferably three separate phases or current paths, each with at least one separate power electronics component.The power electronics are preferably designed to control or regulate a power per phase with a peak power, preferably continuous power, of at least 10 W, preferably at least 100 W, particularly preferably at least 1000 W. Preferably, the power electronics additionally comprises a control unit, for example in the form of control electronics and / or sensor electronics, for the electrical machine.

[0050] A thermal energy storage device can in particular be selected from the group of sensible heat storage devices, latent heat storage devices, thermochemical heat storage devices, sorption storage devices and / or thermovoltaic storage devices.

[0051] For the purposes of this application, a high-temperature energy storage device is a thermal energy storage device for temperatures >500°C, and a low-temperature energy storage device is a thermal energy storage device for temperatures <120°C. These temperatures are the loading temperatures in the respective thermal energy storage device or the temperature of the corresponding thermal energy storage material.

[0052] 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 technologically expedient manner and can define further embodiments of the invention. Furthermore, the features specified in the claims are further specified and explained in the description, where further preferred embodiments of the invention are presented.

[0053] According to an advantageous embodiment of the invention, it can be provided that the first thermal energy storage device is a low-temperature energy storage device.

[0054] According to the invention, it is also provided that the electric machine is electrically coupled to a second thermal energy store. This makes it possible for electrical energy recovered, for example through recuperation, to be fed back into a useful function, for example thermal utilization. This can be used, for example, in such a way that electrical energy can be stored in the form of thermal energy in the thermal energy store in the vehicle. Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the second thermal energy store is a high-temperature energy store. In this case, the thermal energy for storage in the energy store is provided by converting electrical energy, for example by an electrical heating element.

[0055] According to another particularly preferred embodiment of the invention, the electric machine may have an engine cooling circuit for dissipating or supplying heat from or to the electric machine, and the engine cooling circuit may be coupled to the first thermal energy storage device. This allows for further optimization of thermal management.

[0056] Furthermore, the invention can also be further developed in such a way that the brake forms a structural unit with the electric machine, which can simplify the assembly of the system.

[0057] In a likewise preferred embodiment of the invention, the brake can also be housed in a brake housing and encapsulated from the environment. This provides the advantage that brake wear from the brake can be contained within the brake housing, which directly contributes to reducing environmental pollution.

[0058] It may also be advantageous to further develop the invention in such a way that the electric motor has a rotor that can be driven by a vehicle wheel and subjected to a braking torque by the brake. An advantage of this embodiment is that the unsprung mass on the vehicle wheel can be reduced. It is also possible to increase the steering angle of the corresponding vehicle wheels by eliminating a brake on the vehicle wheel.

[0059] The object of the invention can further be achieved by an electric axle drive train for an electrically powered motor vehicle, comprising an electric machine and a transmission arrangement transmitting torque with the electric machine, as well as a thermal management system according to one of claims 1-7.

[0060] Finally, the object of the invention can also be achieved by an electrically operated motor vehicle comprising a thermal management system according to one of claims 1-7.

[0061] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0062] It shows: Fig. 1 an electrically driven motor vehicle with a thermal management system in a schematic block diagram, Fig. 2 a thermal management system with an electrical machine in a schematic block diagram, Fig. 3 a thermal management system with an electrical machine in a schematic block diagram, Fig. 4 a thermal management system with an electrical machine in a schematic block diagram.

[0063] The Fig. 1 shows a thermal management system 1 for an electrically powered motor vehicle 2 comprising an electric machine 3, which can be powered by the vehicle battery 17, for driving the motor vehicle 2 and a brake 5 with a brake cooling circuit 6 for dissipating or supplying heat from or to the brake 5. In the figures, electrical connections are indicated by dashed lines and thermal connections by solid lines.

[0064] The Fig. 2 shows that from the Fig. 1 shows a more detailed view of a known thermal management system 1. The thermal management system 1 is integrated into an electric axle drive train 15 for an electrically powered motor vehicle 2, which has an electric machine 3 and a transmission arrangement 16 that transmits torque to the electric machine 3, forming a structural unit.

[0065] The thermal management system 1 further comprises a hydraulic control system 7 for influencing the volume flow in the brake cooling circuit 6, as well as an electronic control unit 8 for controlling the hydraulic control system 7. It is clearly visible that the brake cooling circuit 6 is coupled to a first thermal energy storage device 9. The first thermal energy storage device 9 is configured as a low-temperature energy storage device, which is indicated by a slightly smaller line width in the corresponding circuit.

[0066] The Fig. Figure 2 also clearly shows that the electric motor 3 is electrically coupled to a second thermal energy storage device 10, which is designed as a high-temperature energy storage device, as indicated by a slightly thicker line in the corresponding circuit. The brake 5 forms a structural unit 11 with the electric motor 3 and is housed in a brake housing 12 and encapsulated from the environment.

[0067] Also in the Fig. 2 shows that the electric machine 3 has a rotor 14 which can drive a vehicle wheel 13 and which can be subjected to a braking torque by the brake 5.

[0068] The Fig. 3 shows the Fig. 2 already basically known configuration in a block diagram.

[0069] The Fig.4 shows an embodiment of the invention in which the electric machine 3 has an engine cooling circuit 4 for dissipating or supplying heat from or to the electric machine 3 and the engine cooling circuit 4 is coupled to the first thermal energy storage device 9.

[0070] The electric machine 3 is arranged in the thermal management system 1 such that, when the motor vehicle 2 decelerates, recuperated electrical energy can be fed back into the vehicle battery 17. If the energy absorption capacity of the vehicle battery 17 is not present, electrical energy can be used to charge the second thermal energy storage device 10, which is configured as a high-temperature storage device, by converting the electrical energy into thermal energy. This can be done, for example, via a resistance heater.

[0071] During braking, thermal energy can be directly recuperated via the brake 5, which then transfers thermal energy via the brake cooling circuit 6 to the first thermal energy storage device 9, which is configured as a low-temperature energy storage device. The energy stored in the vehicle battery 17 can be supplied to a useful function as needed, such as the operation of the electric motor 3, while the energy stored in the thermal energy storage devices 9, 10 can be supplied to a useful function as needed, primarily in the thermal management of the motor vehicle 2.

[0072] The invention is not limited to the embodiments illustrated in the figures. The above description is therefore not to be considered restrictive, but rather explanatory. The following claims are to be understood in such a way that a stated feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. Where the claims and the above description define 'first' and 'second' features, this designation serves to distinguish between two similar features without establishing a priority. List of reference symbols 1 thermal management system 2 motor vehicles 3 electric machine 4 Engine cooling circuit 5 Brake 6 Brake cooling circuit 7 hydraulic control system 8 Control unit 9 Energy storage 10 energy storage 11 structural unit 12 brake housing 13 Vehicle wheel 14 Rotor 15 Axle drive train 16 Gear arrangement 17 Vehicle battery

Claims

[1] Thermal management system (1) for an electrically powered motor vehicle (2) comprising • an electric machine (3) for driving the motor vehicle (2), • a brake (5) with a brake cooling circuit (6) for dissipating or supplying heat from or to the brake (5), • a hydraulic control system (7) for influencing the volume flow in the brake cooling circuit (6), • an electronic control unit (8) for controlling the hydraulic control system (7), characterized by that the brake cooling circuit (6) is coupled to a first thermal energy store (9) and that the electric machine (3) is electrically coupled to a second thermal energy store (10). [2] Thermal management system (1) according to claim 1, characterized by that the first thermal energy storage device (9) is a low-temperature energy storage device. [3] Thermal management system (1) according to one of the preceding claims, characterized bythat the second thermal energy storage device (10) is a high-temperature energy storage device. [4] Thermal management system (1) according to one of the preceding claims characterized by that the electric machine (3) has an engine cooling circuit (4) for dissipating or supplying heat from or to the electric machine (3) and the engine cooling circuit (4) is coupled to the first thermal energy store (9). [5] Thermal management system (1) according to one of the preceding claims, characterized by that the brake (5) forms a structural unit (11) with the electrical machine (3). [6] Thermal management system (1) according to one of the preceding claims, characterized by that the brake (5) is accommodated in a brake housing (12) and encapsulated against the environment. [7] Thermal management system (1) according to one of the preceding claims, characterized bythat the electric machine (3) has a rotor (14) which can be driven by a vehicle wheel (13) and which can be subjected to a braking torque by the brake (5). [8] Electric axle drive train (15) for an electrically powered motor vehicle (2) comprising an electric machine (3) and a transmission arrangement (16) transmitting torque with the electric machine (3), as well as a thermal management system (1) according to one of the preceding claims. [9] Electrically powered motor vehicle (2) comprising a thermal management system (1) according to one of claims 1-7.

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