Thermal management system for an electrically powered motor vehicle

Abstract

The invention relates to a thermal management system (1) for an electrically powered motor vehicle (2) comprising an electric machine (3) with an engine cooling circuit (4) for dissipating or supplying heat from or to the electric machine (3), a battery (5) with a battery cooling circuit (6) for dissipating or supplying heat from or to the battery (5), a passenger compartment (7) with a passenger compartment air conditioning circuit (8) for dissipating or supplying heat from or to the passenger compartment (7), a hydraulic control system (9) for influencing the volume flows in the engine cooling circuit (4) and / or the battery cooling circuit (6) and / or the passenger compartment air conditioning circuit (8) by means of at least one hydraulic switching element (10), an electronic control unit (11) for controlling the at least one hydraulic switching element (10) of the hydraulic control unit (9), wherein the thermal management system (1) further comprises a brake (12) with a brake cooling circuit (13) for dissipating or supplying heat from or to the brake (12), wherein the hydraulic control system (9) acts on the brake cooling circuit (13) by means of at least one hydraulic switching element (10) in order to influence the volume flow in the brake cooling circuit (13).

Description

[0001] The present invention relates to a thermal management system for an electrically powered motor vehicle comprising an electric machine with an engine cooling circuit for dissipating or supplying heat from or to the electric machine, a battery with a battery cooling circuit for dissipating or supplying heat from or to the battery, a passenger compartment with a passenger compartment air conditioning circuit for dissipating or supplying heat from or to the passenger compartment, a hydraulic control system for influencing the volume flows in the engine cooling circuit and / or the battery cooling circuit and / or the passenger compartment air conditioning circuit by means of at least one hydraulic switching element in each case, an electronic control unit for controlling the at least one hydraulic switching element of 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 generic 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 US 2021 / 0 036 342 A1 comprises an electric motor, transmission, and a retarder brake, with the transmission and The brakes are tempered jointly via an oil cooling circuit with an oil cooler. Further prior art is disclosed in DE 10 2021 203 125 A1, DE 10 2019 117 329 A1, DE 10 2019 124 280 A1, DE 10 2012 112 377 A1, WO 2020 / 185 138 A1, DE 10 2012 208 992 A1, and US Pat. No. 8,402,776 B2.

[0006] It is therefore the object of the invention to provide an improved thermal management system for an electrically powered motor vehicle.

[0007] This object is achieved by a thermal management system for an electrically powered motor vehicle comprising an electric machine with an engine cooling circuit for dissipating or supplying heat from or to the electric machine, a battery with a battery cooling circuit for dissipating or supplying heat from or to the battery, a passenger compartment with a passenger compartment air conditioning circuit for dissipating or supplying heat from or to the passenger compartment, a hydraulic control system for influencing the volume flows in the engine cooling circuit and / or the battery cooling circuit and / or the passenger compartment air conditioning circuit by means of at least one hydraulic switching element, an electronic control unit for controlling the at least one hydraulic switching element of the hydraulic control system, wherein the thermal management system further comprises a brake with a brake cooling circuit for dissipating or supplying heat from or to the brake,wherein the hydraulic control system for influencing the volume flow in the brake cooling circuit acts on the brake cooling circuit by means of at least one hydraulic switching element.

[0008] This provides the advantage that the brakes of an electrically powered vehicle can be used as a heat source for the thermal management system and integrated into it. This involves brakes equipped with a thermal energy recovery device.

[0009] 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.

[0010] 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 a motor vehicle's thermal management system. For this purpose, the hydraulic switching elements are controlled and switched by the electronic control unit.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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 disc brake operation. The brake disc preferably has a brake disc body.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] The braking system can 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 can 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 can 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Particularly preferably, the electric machine has a power output greater than 30 kW, preferably greater than 50 kW, and in particular greater than 70 kW. It is further preferred that the electric machine provides rotational speeds greater than 5,000 rpm, particularly preferably greater than 10,000 rpm, and most preferably greater than 12,500 rpm.

[0026] 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, it is possible for the motor housing of the electric machine to be constructed in one piece or in multiple parts.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] According to the invention, it is 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.

[0037] 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.

[0038] 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.

[0039] According to the invention, it can also be provided that the brake cooling circuit is coupled to the inverter cooling circuit via a first heat exchanger.

[0040] Furthermore, according to the invention, it is provided that the engine cooling circuit is coupled to the inverter cooling circuit via a second heat exchanger.

[0041] According to a further particularly preferred embodiment of the invention, it can be provided that the battery cooling circuit is coupled to the passenger compartment air conditioning circuit via a third heat exchanger.

[0042] Furthermore, the brake cooling circuit is designed with the engine cooling circuit so that the brake and the electric machine are arranged in a common cooling circuit.

[0043] According to the invention, it is also provided that a hydraulic switching element is arranged in the common cooling circuit to influence the volume flows led to the brake and the electric machine, whereby the thermal management within this sub-circuit can be further optimized.

[0044] It may also be advantageous to further develop the invention in such a way that a first ambient heat transfer unit is arranged in the brake cooling circuit, which can also contribute to improved thermal management.

[0045] According to a further preferred embodiment of the subject matter of the invention, it can be provided that the brake cooling circuit is formed with the inverter cooling circuit, so that the brake and the inverter are arranged in a common cooling circuit.

[0046] Finally, the invention can also be advantageously implemented in such a way that the hydraulic control unit further comprises a distribution device to which the engine cooling circuit and / or the battery cooling circuit and / or the brake cooling circuit and / or the inverter cooling circuit are connected, wherein the distribution device is configured to connect two or more cooling circuits to one another.

[0047] The invention will be explained in more detail below with reference to figures without limiting the general inventive concept.

[0048] It shows: Fig. 1 an electrically powered motor vehicle with a thermal management system in a schematic block diagram, Fig. 2 shows a first embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 3 shows a second embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 4 shows a third embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 5 shows a fourth embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 6 shows a fifth embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 7 shows a sixth embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 8 shows a seventh embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram, Fig. 9 an eighth embodiment of a thermal management system for an electrically powered motor vehicle in a schematic hydraulic circuit diagram.

[0049] The Fig. 1 shows a thermal management system 1 for an electrically powered motor vehicle 2.

[0050] In Fig. Figure 2 shows a first embodiment of a thermal management system 1. It comprises an electric machine 3 with an engine cooling circuit 4 for dissipating or supplying heat from or to the electric machine 3. a battery 5 with a battery cooling circuit 6 for dissipating or supplying heat from or to the battery 5, and a passenger compartment 7 with a passenger compartment air conditioning circuit 8 for dissipating or supplying heat from or to the passenger compartment 7.

[0051] In addition to these fluidic circuits, the thermal management system 1 further has a hydraulic control system 9 for influencing the volume flows in the engine cooling circuit 4, the battery cooling circuit 6 and the passenger compartment air conditioning circuit 8 by means of a hydraulic switching element 10, which in the case shown is a hydraulic pump.

[0052] These hydraulic switching elements 10 are controlled by an electronic control unit 11.

[0053] The thermal management system 1 further comprises a brake 12 with a brake cooling circuit 13 for dissipating or supplying heat from or to the brake 12. The hydraulic control system 9 acts on the brake cooling circuit 13 by means of at least one hydraulic switching element 10 to influence the volume flow in the brake cooling circuit 13. This switching element 10 is also designed as a hydraulic pump, which can be clearly seen from the corresponding circuit diagram.

[0054] From the Fig. 2 further shows that the thermal management system 1 also has an inverter 14 with an inverter cooling circuit 15 for dissipating or supplying heat from or to the inverter 14. The hydraulic control system 9 acts on the inverter cooling circuit 15 by means of at least one hydraulic switching element 10 to influence the volume flows in the inverter cooling circuit 15. In the inverter cooling circuit 15, the hydraulic switching element 10 is also designed as a hydraulic pump.

[0055] In the embodiment of the Fig. 2, the brake cooling circuit 13 is connected to the inverter cooling circuit 15 via a first heat exchanger 16. The engine cooling circuit 4 is also coupled to the inverter cooling circuit 15 in a similar manner via a second heat exchanger 17. The Fig. 1 further shows that the battery cooling circuit 6 is coupled to the passenger compartment air conditioning circuit 8 via a third heat exchanger 18.

[0056] The hydraulic control system 9 further comprises a distribution device 22 to which the battery cooling circuit 6 and the inverter cooling circuit 15 are connected, wherein the distribution device 22 is configured to connect at least the two cooling circuits 6, 15 to one another.

[0057] Furthermore, an on-board charger 23 and the inverter 14 are connected in series in the inverter cooling circuit 15. The second heat exchanger 17 of the separate motor cooling circuit 4 of the electric machine 3 is arranged downstream of the inverter cooling circuit 15 in the same subcircuit of the thermal management system 1.

[0058] Heat exchange between the battery cooling circuit 6 and the passenger compartment air conditioning circuit 8 is possible via the third heat exchanger 18. The passenger compartment air conditioning circuit 8 and the battery cooling circuit 6 are switchably connected at the third heat exchanger 18. This enables both the heating and cooling of the battery 5, which is provided for supplying power to the electric motor 3. Also arranged in the inverter cooling circuit 15 is an ambient heat transfer unit 20, which enables heat to be dissipated to the environment. This provides two options for lowering the temperature of the inverter cooling circuit 15: via the ambient heat transfer unit 20 and via the third heat exchanger 18 by means of the passenger compartment air conditioning circuit 8.To heat the interior air in the passenger compartment 7, a heating element 26 with a heating heat exchanger is arranged in the air flow 25 of the interior ventilation system, which converts electrical energy into thermal energy. The air flow 25 of the interior ventilation system is cooled by a cooling heat exchanger 27, which is also arranged directly in the air flow 25.

[0059] In the Fig. The arrangements according to the invention of a thermal management system 1 for electrically powered motor vehicles 2 with a brake 12 as a heat source are shown. Fig. 2-9 each show variants of a thermal management system 1 with different arrangements of a brake 12 as a heat source and corresponding possibilities for transferring the thermal energy, for example to the air flow 25 of the interior ventilation.

[0060] In the Fig. 2 shows an embodiment of the thermal management system 1, which represents the brake "heat source" 12 in the thermal management system 1 of a motor vehicle 2. In this case, in a subcircuit referred to as the inverter cooling circuit 15, starting from the hydraulic switching element 10 designed as a hydraulic pump, the on-board charger 23, the inverter 14 with the power electronics for supplying current to the electric machine 3, the second heat exchanger, and the first heat exchanger 16 are connected in series in the direction of fluid flow. The brake heat source 12 is arranged in a separate brake cooling circuit 13 in conjunction with a hydraulic switching element 10 designed as a hydraulic pump, which is coupled to the inverter cooling circuit 15 via the first heat exchanger 16.This also allows, in particular, the use of a brake cooling fluid in the brake cooling circuit 13 whose material composition differs from the inverter cooling fluid used in the inverter cooling circuit 15. An ambient heat transfer unit 20 and the third heat exchanger 18 are arranged as permanent heat sinks in subcircuits of the inverter cooling circuit 15. These can be switched on and off via the distribution device 22.

[0061] In Fig. Figure 3 shows an embodiment of the thermal management system 1 in which the brake cooling circuit 13 is formed with the engine cooling circuit 4, so that the brake 12 and the electric machine 3 are arranged in a common cooling circuit 19. The brake 12 is arranged such that the coolant flows through it downstream of the electric machine 3 and is connected in series. A hydraulic switching element 10 designed as a hydraulic pump is provided to provide the volume flow of the coolant in the common cooling circuit 19. The exchange of thermal energy into the inverter cooling circuit 15 takes place via the heat exchanger 17. This requires the use of a coolant in the common cooling circuit 19 whose material composition is equally compatible with the requirements of the brake 12 and the requirements of the electric machine 3.

[0062] A variation of the Fig. 3 known configuration of a thermal management system 1 is in the Fig. 4. Here, too, the brake 12 is located in the shared coolant circuit 19 with the electric machine 3. The coolant flow rate is distributed downstream of the switching element 10, which is designed as a hydraulic pump—the brake 12 is arranged parallel to the electric machine 3. The coolant flow rate can be switched on or off via the switching element 10, which is designed as a switching valve, of the hydraulic control system 9. Thus, a hydraulic switching element 10 is arranged in the shared cooling circuit 19 to influence the flow rates directed to the brake 12 and the electric machine 3.

[0063] The embodiment of the thermal management system 1 as shown in the Fig. 5 is shown, corresponds in principle to the one shown in Fig. 2, but is expanded by an additional ambient heat transfer unit 20 in the brake cooling circuit 13. This is arranged such that it can be switched to bypass via the switching element 10, which is designed as a switching valve, as long as the thermal energy of the brake 12 can be completely absorbed by the brake cooling circuit 13.

[0064] In the version of the thermal management system 1, which is in the Fig. 6, the brake 12 is arranged directly in the inverter cooling circuit 15. In other words, the brake cooling circuit 13 is formed with the inverter cooling circuit 15, so that the brake 12 and the inverter 14 are arranged in a common cooling circuit 21. The arrangement is such that the coolant first flows through the on-board charger 23, then through the inverter 14 with the power electronics, subsequently through the heat exchanger 17 of the engine cooling circuit 4, and only then through the brake 12. This requires the use of a coolant in the inverter cooling circuit 15 whose material composition complies equally with the requirements of the brake 12 and the requirements of the rest of the inverter cooling circuit 15.

[0065] In the Fig. In the embodiment shown in Figure 7, the thermal management system 1 is expanded by a further sub-circuit, namely the brake cooling circuit 13, in which, in addition to one or more brakes 12, a switching element 10 configured as a hydraulic pump is arranged. The brake cooling circuit 13 is controlled via the distribution device 22. Here, too, the requirements of the brake 12 and the remaining components that can be acted upon by this coolant regarding the material composition of the coolant used must be taken into account.

[0066] An extension of the embodiment of the Fig. 7 is in the Fig. 8, in which an ambient heat transfer unit 20, which can be activated via the switching element 10, is arranged parallel to the brake cooling circuit 13. This allows the use of the brake 12 even if no further heat energy can be absorbed by the brake cooling circuit 13.

[0067] In the design variant of the Fig. 9, a heat exchanger 24 is arranged in the air flow 25 of the interior ventilation system. This heat exchanger exchanges the heat directly from the coolant circuit 28 with the air flow 25. The coolant circuit 28 is connected to the distribution device 22 and can be switched on or off by it.

[0068] 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 Battery 6 Battery cooling circuit 7 Passenger compartment 8 Passenger compartment air conditioning circuit 9 hydraulic control system 10 Switching element 11 electronic control unit 12 Brake 13 Brake cooling circuit 14 inverters 15 Inverter cooling circuit 16 heat exchangers 17 heat exchangers 18 heat exchangers 19 Cooling circuit 20 Ambient heat transfer unit 21 Cooling circuit 22 Distribution direction 23 On-board charger 24 heat exchangers 25 Airflow 26 Heating element 27 cooling heat exchangers 28 Coolant circuit

Claims

[1] Thermal management system (1) for an electrically powered motor vehicle (2) comprising • an electrical machine (3) with a motor cooling circuit (4) for removing or supplying heat from or to the electrical machine (3), • a battery (5) with a battery cooling circuit (6) for removing or supplying heat from or to the battery (5), • a passenger compartment (7) with a passenger compartment air conditioning circuit (8) for removing or supplying heat from or into the passenger compartment (7), • a hydraulic control system (9) for influencing the volume flows in the engine cooling circuit (4) and / or the battery cooling circuit (6) and / or the passenger compartment air conditioning circuit (8) by means of at least one hydraulic switching element (10), wherein the hydraulic switching element is an electrically controllable hydraulic pump, • an electronic control unit (11) for controlling the at least one hydraulic switching element (10) of the hydraulic control system (9), wherein • the thermal management system (1) further comprises a brake (12) with a brake cooling circuit (13) for dissipating or supplying heat from or to the brake (12), wherein the hydraulic control system (9) acts on the brake cooling circuit (13) by means of at least one hydraulic switching element (10) to influence the volume flow in the brake cooling circuit (13), • the thermal management system (1) further comprises an inverter (14) with an inverter cooling circuit (15) for dissipating or supplying heat from or to the inverter (14), wherein the hydraulic control system (9) acts on the inverter cooling circuit (15) by means of at least one hydraulic switching element (10) to influence the volume flows in the inverter cooling circuit (15), • the brake cooling circuit (13) is coupled to the inverter cooling circuit (15) via a first heat exchanger (16), the engine cooling circuit (4) is coupled to the inverter cooling circuit (15) via a second heat exchanger (17), • the brake cooling circuit (13) is designed with the engine cooling circuit (4) so ​​that the brake (12) and the electric machine (3) are arranged in a common cooling circuit (19) and • a hydraulic switching element (10) for influencing the volume flows led to the brake (12) and to the electric machine (3) is arranged in the common cooling circuit (19). [2] Thermal management system (1) according to claim 1, characterized by that the battery cooling circuit (6) is coupled to the passenger compartment air conditioning circuit (8) via a third heat exchanger (18). [3] Thermal management system (1) according to one of the preceding claims, characterized bythat a first ambient heat transfer unit (20) is arranged in the brake cooling circuit (13). [4] Thermal management system (1) according to one of the preceding claims, characterized by that the brake cooling circuit (13) is formed with the inverter cooling circuit (15) so that the brake (12) and the inverter (14) are arranged in a common cooling circuit (21). [5] Thermal management system (1) according to one of the preceding claims, characterized by in that the hydraulic control system (9) further comprises a distribution device (22) to which the engine cooling circuit (4) and / or the battery cooling circuit (6) and / or the brake cooling circuit (13) and / or the inverter cooling circuit (15) are connected, wherein the distribution device (22) is configured to connect two or more cooling circuits (4, 6, 13, 15) to one another.

Images