Cooling system, axle unit, vehicle and method

Abstract

The invention relates to a cooling system (10) for cooling at least one component of a vehicle, in particular an electric vehicle or a hybrid vehicle, comprising: a heat pump (11) having at least one evaporator and at least one condenser, a first cooling circuit (K1) associated with the evaporator, a second cooling circuit (K2) associated with the condenser, and at least one valve element (12) arranged in the first cooling circuit (K1) and / or in the second cooling circuit (K2), wherein the valve element (12) is designed to associate the at least one component with the first cooling circuit (K1) or the second cooling circuit (K2).

Description

[0001] Cooling system, axle assembly, vehicle and process

[0002] The present invention relates to a cooling system, in particular for a vehicle, especially for an electric vehicle or a hybrid vehicle, an axle assembly, a vehicle with such a cooling system, and a method for cooling components of a vehicle.

[0003] Vehicles, especially electric and hybrid vehicles, require a cooling system to dissipate the heat generated in various components, such as the battery, electric motor, and other electronic components like inverters, DC / DC converters, AC / DC converters, and the like, during operation and charging. Vehicle systems typically have multiple cooling circuits to form a controlled thermal management system. Usually, at least one coolant circuit using a water-glycol-based coolant is present, allowing heat from the individual components to be dissipated to the environment. Another cooling circuit includes a heat pump or an AC compressor for air conditioning the passenger compartment or for assisting in heat dissipation from the components.A third cooling circuit may be provided in some systems for heat dissipation from the lubrication and cooling oil system of the gearbox.

[0004] In known systems, two fundamental principles govern interior climate control and the cooling of power electronics. According to the first principle, the passenger compartment is heated via a coolant heat exchanger from the cooling circuit of the electric motor, such as an electric drive, and cooled via the refrigerant circuit of the air conditioning system or heat pump. Therefore, additional heat exchangers are required for interior climate control. For higher heating output, additional electric heaters are usually provided, which either heat the coolant or the interior air directly. According to the second principle, the heating and cooling functions are combined via the refrigerant circuit, in which a condenser heat exchanger is used. Depending on the requirements, the air is either heated by the condenser heat exchanger or cooled by an evaporator heat exchanger.Energy storage devices, specifically rechargeable batteries / high-voltage batteries (current technology), also experience energy losses due to the chemical and physical processes within the cell. The impact of these losses is power-dependent; that is, at low power levels, the power loss is also low, while the higher the energy consumption, the greater the internal losses. Therefore, most systems utilize liquid cooling. A disadvantage of current thermal management systems is that the supply of coolant at varying temperatures cannot be flexibly adjusted. Consequently, component temperature control often requires compromises and is therefore inefficient.

[0005] It has therefore become apparent that there is a need to provide an improved cooling system in this respect.

[0006] The object of the present invention is therefore to provide an improved cooling system.

[0007] The problem is solved with a cooling system having the features of claim 1, with an axle assembly having the features of claim 8, with a vehicle having the features of claim 9, and with a method having the features of claim 10.

[0008] One aspect of the present invention relates to a cooling system for cooling at least one component of a vehicle, in particular an electric vehicle or a hybrid vehicle, comprising: a heat pump with at least one evaporator and at least one condenser, a first cooling circuit associated with the evaporator and forming a low-temperature circuit, a second cooling circuit associated with the condenser and forming a high-temperature circuit, and at least one valve element arranged in the first cooling circuit and / or in the second cooling circuit, wherein the valve element is configured to assign the at least one component to the first cooling circuit or the second cooling circuit. The low-temperature circuit is characterized in that the average temperature level is lower than in the high-temperature circuit. Preferably, the heat pump has an expansion device for adjusting a fluid pressure.The expansion device may, for example, include an expansion valve.

[0009] In contrast to the prior art, the present invention allows for more flexible adjustment of the cooling of at least one component. By appropriately adjusting the valve element, the at least one component can be selectively assigned, for example, to the low-temperature circuit or the high-temperature circuit. This enables demand-based cooling, temperature control, heating, or cooling. This overcomes the problem known from the prior art, where compromises often have to be made when temperature-controlling components.

[0010] The cooling system can be part of a thermal management system. In particular, the thermal management system can be designed for a vehicle. A thermal management system can be defined as a system with one or more cooling circuits that are thermally coupled or can be coupled to at least one component or to several components. The component can also be referred to as a consumer. The component or consumer is therefore a device to be cooled, heated, and / or temperature-controlled. In this context, temperature control can be understood as maintaining a specific temperature.

[0011] The heat pump of the cooling system comprises its own self-contained circuit. The heat pump is designed so that a fluid, in particular a refrigerant, circulates within it. The heat pump is thermally coupled to both the first and second cooling circuits, or connected in such a way that thermal energy can be at least partially transferred.

[0012] The heat pump is preferably designed to be circulated by a fluid, in particular a refrigerant, for example propane (R-290), carbon dioxide (R-744), or R-1234yf. A refrigerant is characterized by its use in a thermodynamic cycle (heat pump) to cool a medium below ambient temperature. The first and second cooling systems are designed to be circulated by a coolant. A coolant is used in a cooling cycle to transfer enthalpy (heat energy) along the temperature gradient to a heat sink. Ambient air, for example, is suitable as a heat sink. The coolant can also be referred to as a heat transfer medium, heating medium, or heat transfer fluid.

[0013] The heat pump includes an evaporator to vaporize a refrigerant. It also includes a condenser to liquefy the refrigerant. The condenser can also be called a condenser. The heat pump may have a compressor that compresses a gaseous refrigerant, such as propane (R-290), carbon dioxide (R-744), or R-1234yf. In a downstream condenser, the compressed refrigerant is cooled and thereby converted into a predominantly liquid state. This process extracts thermal energy from the refrigerant in the form of heat, which is then transferred to the second cooling circuit. The heat pump has at least one expansion valve downstream of the condenser, which expands the liquefied refrigerant and reduces its pressure. This lowers the pressure and thus the temperature of the refrigerant in the refrigeration circuit.In a downstream heat exchanger or evaporator, thermal energy is absorbed from the first cooling circuit, thus cooling the first cooling circuit. From there, the cycle can be repeated in the heat pump, starting with the compressor. In other words, both the first and second cooling circuits can exchange thermal energy with the heat pump.

[0014] The first cooling circuit is associated with the evaporator of the heat pump. This means that the first cooling circuit is thermally coupled to the refrigeration circuit via the evaporator. In other words, the evaporator is located within or operates within the first cooling circuit. More precisely, thermal energy is preferably transferred from the first cooling circuit to the refrigerant. This transferred thermal energy allows the refrigerant in the evaporator to be converted into a gaseous state. The first cooling circuit is thermally coupled to the evaporator either directly or indirectly.

[0015] The second cooling circuit is connected to the condenser of the heat pump. This means that the second cooling circuit is thermally coupled to the refrigerant via the condenser. In other words, the condenser is located within or operates within the second cooling circuit. More precisely, thermal energy is preferably transferred from the condenser to the second cooling circuit. This transferred thermal energy allows the refrigerant in the condenser to be liquefied. The second cooling circuit is thermally coupled to the condenser either directly or indirectly.

[0016] The valve element can be arranged in the first cooling circuit and / or the second cooling circuit and is configured to assign the at least one component to the first or the second cooling circuit. The valve element can, for example, comprise a multi-way valve. In particular, the valve element can be designed as a multi-way valve. The valve element is designed to assign the at least one component to exactly one cooling circuit. In other words, the at least one component can be assigned exclusively and / or uniquely to one cooling circuit. "Assignment" in this case can mean that the valve element can influence the first cooling circuit and / or the second cooling circuit in such a way that coolant from the respective circuit is supplied to the at least one component, enabling the coolant to exchange thermal energy with the at least one component.This means that at least one component is thermally coupled to either the first or the second cooling circuit at any given time. The valve element can be designed, for example, as a piston valve or a solenoid valve.

[0017] In one embodiment, the first and second cooling circuits are independent of each other. More precisely, the first and second cooling circuits are fluidically and thermally separated. This means that the first and second cooling circuits do not mix and are not thermally coupled. Consequently, no thermal energy, or virtually no thermal energy, is transferred from the first to the second cooling circuit or vice versa, except via the heat pump. This allows for more efficient and flexible cooling, temperature control, and / or heating of at least one component.

[0018] In one embodiment, the first cooling circuit and the second cooling circuit comprise different temperature levels. In one embodiment, the first cooling circuit is a high-temperature circuit and the second cooling circuit is a low-temperature circuit. This means that in the heat pump's supply line, the first cooling circuit has a lower temperature than the second cooling circuit. The high-temperature circuit can contain a refrigerant with a temperature in the range of 35 to 95 °C. The low-temperature circuit can contain a refrigerant with a temperature in the range of -30 to 45 °C. The low-temperature circuit is cooled to a lower temperature than the high-temperature circuit. This allows the cooling capacity to be concentrated on the low-temperature circuit, to which the highest-demanding component, such as power electronics, can be connected.This optimizes the provision of cooling capacity and allows, for example, a smaller compressor to be used. The aforementioned temperatures refer to the "normal" operating condition. Different temperatures may be present, for example, when the system is started. Preferably, the low-temperature circuit is intended for cooling an energy storage device, in particular a battery, and the high-temperature circuit is intended for cooling an electric motor and / or power electronics. A different arrangement of the components in the cooling circuit is also conceivable. Furthermore, the low-temperature circuit can be used to cool a passenger compartment and the high-temperature circuit to heat a passenger compartment.

[0019] In one embodiment, the cooling system comprises several components, in particular a drive component and / or, in particular, an energy storage device and / or, in particular, power electronics and / or a heat exchanger. Power electronics can be, for example, an inverter. The heat exchanger can be, for example, a water-to-air heat exchanger, in particular a radiator. Other components or types of components are possible.

[0020] In one embodiment, the valve element can be configured to switch between the first cooling circuit and the second cooling circuit, in particular so that the at least one component can be assigned to either the first or the second cooling circuit. In other words, the valve element can switch the assignment of the at least one component from the first cooling circuit to the second cooling circuit and vice versa.

[0021] In one embodiment, at least one heat exchanger is provided, which is thermally coupled to the first cooling circuit and / or the second cooling circuit. The heat exchanger is, for example, a heater or a cooler, particularly part of an HVAC system. This allows, for example, a passenger compartment of a vehicle to be heated or cooled and excess heat to be dissipated to the environment. A further heat exchanger, i.e., a radiator, may be provided to exchange thermal energy with the ambient air.

[0022] In one embodiment, a first pump is arranged in the first cooling circuit and / or a second pump is arranged in the second cooling circuit, wherein the first and / or second pump is preferably a circulation pump. The pumps allow, for example, the cooling circuits to be operated independently of one another or the coolant to be circulated. Preferably, the first pump and the second pump are each arranged upstream of the heat pump in the direction of coolant flow. At least one pump can be designed as a volumetric pump, e.g., a gerotor pump. At least one pump can be designed as a vane pump or a centrifugal pump.

[0023] In one embodiment, at least one component is permanently assigned to either the first or the second cooling circuit. This means that the corresponding cooling circuit is permanently assigned to the at least one component. In other words, the assignment of the at least one component to one of the two cooling circuits cannot be changed. Furthermore, several components or all components can be permanently assigned to a specific cooling circuit. For example, in one embodiment, a drive component, such as an electric machine or an electric motor, can be permanently assigned to either the first or the second cooling circuit. This ensures sufficient or appropriate cooling for components subjected to particularly high thermal stress. Preferably, the drive component is assigned to the high-temperature circuit.In other words, all components can only be connected to one of the cooling circuits in a specific valve position, thus making it possible to operate these cooling circuits independently without risk to the component's cooling. Under sufficiently favorable conditions, it is therefore possible to shut off the circulation of the other cooling circuit and, furthermore, to switch off the heat pump, enabling highly efficient operation that can lead to an increase in a vehicle's range.

[0024] In one embodiment, the components assigned to the first cooling circuit and / or the components assigned to the second cooling circuit are each arranged in series within their respective cooling circuits. In other words, the components in a cooling circuit are not arranged parallel to each other.

[0025] In one embodiment, the at least one valve element is configured to control the first cooling circuit and the second cooling circuit in such a way that it is possible to switch between a single-circuit circuit or a dual-circuit circuit.

[0026] In one embodiment, the valve element comprises a multi-way valve, in particular a 6-2-way valve or a 6-3-way valve. A 6-2-way valve has six ports and two positions into which it can be set, and a 6-3-way valve has six ports and three positions into which it can be set. The multi-way valve can regulate the flow of the fluid, in particular the coolant. The regulation can be controlled by changing the flow direction, by opening one path, and / or by blocking one path. Another aspect of the present invention relates to an axle assembly with a cooling system according to one of the preceding embodiments.

[0027] Another aspect of the present invention relates to a vehicle with a cooling system according to one of the preceding embodiments and / or an axle assembly according to the preceding embodiment.

[0028] Another aspect of the present invention relates to a method for cooling at least one component of a vehicle, in particular an electric vehicle or a hybrid vehicle, with a cooling system according to one of the preceding embodiments, comprising: transferring thermal energy from the first cooling circuit to the evaporator, in particular to a refrigeration circuit in the evaporator; transferring thermal energy from the condenser, in particular from a refrigeration circuit in the condenser, to the second cooling circuit; switching the valve element to assign the at least one component to either the first cooling circuit or the second cooling circuit.

[0029] The cooling system can alternatively be installed in a stationary position, for example, within a building. In other words, the cooling system can be part of a building's thermal management system. In other words, one aspect of the invention relates to a building with a cooling system. The building is characterized by the fact that the cooling system is designed as described.

[0030] In one embodiment of the present invention, a thermal management system is provided with at least two, preferably independent, coolant circuits. The circuits preferably have different temperature levels but can exhibit any temperature ratio to each other. Each circuit is circulated by a circulation pump. The components of a vehicle, and / or its drive components and / or energy storage devices, can be at least partially and freely assigned to the circuits. It is not excluded that some components are permanently assigned to a specific circuit if the thermal requirements permit. This avoids unnecessary complexity. Preferably, the thermal management system includes a refrigeration circuit that can thermally couple the two circuits.In this system, the second refrigerant circuit is thermally coupled to the liquid-cooled condenser (LCC), and the first refrigerant circuit is thermally coupled to the liquid-cooled evaporator or chiller. The heat pump extracts energy from the first refrigerant circuit via the evaporator, causing it to cool (low-temperature circuit or LT circuit), and transfers this energy via the condenser to the second circuit (high-temperature circuit or HT circuit), which is thereby heated. The adjustable heat pump output allows for flexible regulation of different temperature levels in the two circuits. Suitable devices (e.g., valves) allow the components to be selectively assigned to either the LT or the HT circuit, thus enabling demand-based cooling or temperature control / heating.

[0031] In another embodiment, in addition to the flexibly switchable components, further components are present, but these are permanently assigned to one of the circuits. This reduces the number of control devices required and the installation space needed. It must be ensured that the temperature control requirements for all components are still met by assigning them to either the low-temperature (LT) or high-temperature (HT) circuit (e.g., electronics in the LT circuit and electrical machinery in the HT circuit). This allows for a corresponding reduction in complexity (e.g., the number of valves) without compromising thermal performance.

[0032] In another embodiment, all components are integrated into only one of the circuits when the valves are in a specific position. This allows one circuit to be operated independently without compromising cooling performance. Under sufficiently favorable conditions, it is therefore possible to switch off the circulation of the other cooling circuit and, furthermore, to switch off the heat pump, enabling highly efficient operation and thus increasing the operating range.

[0033] In a further embodiment, an additional device, for example a valve, or the design of one of the existing valves enables fluidic coupling of the two circuits, resulting in a serial flow through the components. This also allows for highly efficient operation with the heat pump switched off.

[0034] Individual features and embodiments of the present invention can be combined with other features in other embodiments to form new embodiments. Advantages and further developments mentioned for the features or embodiments also apply analogously to the new embodiments. Further developments and advantages mentioned in connection with the apparatus also apply analogously to the method and vice versa.

[0035] The invention is described below by way of example with reference to the accompanying figures, in which they show

[0036] Figure 1: a schematic view of an embodiment of a cooling system according to the invention;

[0037] Figure 2: a schematic view of an embodiment of a cooling system according to the invention;

[0038] Figure 3: a schematic view of an embodiment of a cooling system according to the invention;

[0039] Figure 4: a schematic view of an embodiment of a cooling system according to the invention;

[0040] Figure 5: a schematic view of an embodiment of a cooling system according to the invention;

[0041] Figure 6: a schematic view of an embodiment of a cooling system according to the invention; Figure 7: a schematic view of an embodiment of a cooling system according to the invention;

[0042] Figure 8: a schematic view of an embodiment of a cooling system according to the invention;

[0043] Figure 9 shows a schematic view of an embodiment of a cooling system according to the invention;

[0044] Figure 10a shows a schematic view of a valve element;

[0045] Figure 10b shows another schematic view of the valve element according to Figure 10a; and

[0046] Figure 11 shows a schematic view of an embodiment of a method according to the invention.

[0047] Fig. 1 shows a cooling system 10 for a vehicle. The cooling system comprises a first cooling circuit K1 and a second cooling circuit K2. The first cooling circuit K1 and the second cooling circuit K2 are fluidically and thermally separated. The two circuits K1 and K2 are each thermally coupled to a heat pump 11. The first cooling circuit K1 is associated with an evaporator 13. The second cooling circuit K2 is arranged with a condenser 14. The first cooling circuit can thus be referred to as a low-temperature circuit. The second cooling circuit K2 can thus be referred to as a high-temperature circuit. The first cooling circuit K1 is represented by a solid line in Figure 1 and the following figures. The second cooling circuit K2 is represented by a dashed line in Figure 1 and the following figures.

[0048] In the second cooling circuit K2, two electric machines 20, or electric motors or traction machines, are arranged. More precisely, the two electric machines 20 are arranged in series upstream of the heat pump 11 in the second cooling circuit K2, in the direction of coolant flow. In the first cooling circuit K1, a first pump P1 is arranged. The first pump P1 is arranged upstream of the heat pump 11, in the direction of coolant flow. In the second cooling circuit K2, a second pump P2 is arranged. The second pump P2 is arranged upstream of the two electric machines 15, in the direction of coolant flow. The pumps P1 and P2 are designed to circulate the coolant in the cooling circuits K1 and K2.

[0049] Downstream of the heat pump 11, a first valve element 12a is arranged in the first cooling circuit K1. The first valve element 12a is switchable. In other words, the first valve element 12a can switch back and forth between different positions. The first valve element 12a is configured such that the first cooling circuit K1 flows through a cooling unit 16 of a climate control module in a passenger compartment. Downstream of the cooling unit 16, the coolant flows through the first valve element 12a again. This allows the first cooling circuit K2 to be further connected. The valve element 12a is, for example, configured as a multi-way valve. In this case, the first valve element 12a is configured such that the first cooling circuit K1 flows through a cooling unit 16. The second cooling circuit K2 flows through a heating unit 15 of the climate control module. The second cooling circuit K2 does not flow through the first valve element 12a.The second cooling circuit K2 is permanently assigned to the heating unit 15. The heating unit 15 and the cooling unit 16 are used to climate control the air in the vehicle's passenger compartment. Each heating unit 16 and the cooling unit 15 includes a heat exchanger.

[0050] Downstream of the cooling unit 16 in the first cooling circuit K1, a power electronics unit 17 is arranged. The power electronics unit 17 comprises several electronic elements. The individual elements of the power electronics unit 17 can be connected in series and / or in parallel to each other by the first cooling circuit K1. The power electronics unit can, for example, include an inverter and / or an on-board charger (OBC) and / or a transformer. Alternatively or additionally, the power electronics unit can include a processing unit or computer unit. The processing unit or computer unit can, for example, be configured to operate control software, in particular to execute intelligent software algorithms, especially artificial intelligence.

[0051] Downstream of the power electronics 17 in the first cooling circuit K1 and downstream of the heating unit 15 in the second cooling circuit K2, a second valve element 12b is arranged. The second valve element 12b is configured such that an energy storage device 18, in particular a battery, is supplied with water from the first cooling circuit K1. Alternatively, the second valve element 12b can be configured such that the energy storage device 18 is supplied with water from the second cooling circuit K2. In the present case, the second cooling circuit K2 is routed through the second valve element 12b to a third valve element 12c.

[0052] Downstream of the second valve element 12b, the third valve element 12c is located in the first cooling circuit. The third valve element 12c is configured so that a radiator 19 is supplied with coolant from the second cooling circuit K2. Alternatively, the third valve element 12c can be configured so that the radiator 19 is supplied with coolant from the first cooling circuit.

[0053] Downstream of the third valve element 12c in the first cooling circuit K1 is the first pump P1, and in the second cooling circuit is the second pump P2. In the first cooling circuit, the heat pump 11, or rather the evaporator 13 of the heat pump 11, follows the pump P1. In the second cooling circuit, after the second pump P2, there is a first electric motor 20a and a second electric motor 20b, which are arranged in series. After the electric motors 20a and 20b, the second cooling circuit flows through the heat pump 11, or rather the condenser 14. The second pump P2 circulates the coolant in the second cooling circuit K2, whereby the coolant is circulated through the electric motors 20a and 20b and subsequently through the condenser 14 of the heat pump 11, thereby absorbing heat or thermal energy from the heat pump 11 circuit.The first pump P1 circulates the refrigerant in the first cooling circuit K1, whereby the refrigerant is circulated through the evaporator 13 of the heat pump 11 and can thereby transfer heat or thermal energy to the refrigerant circuit of the heat pump 11. The second cooling circuit K2 absorbs energy from the refrigerant circuit when the heat pump 11 is operating and thus represents a heat sink, while the first cooling circuit K1 represents the heat source in the refrigeration circuit.

[0054] The components and units to be cooled and / or heated are fluidically coupled to either the first cooling circuit K1 or the second cooling circuit K2 as required by means of the switchable valve element 12. The components integrated into the respective cooling circuits are subjected to a series flow, resulting in different temperatures depending on the power losses of the components in the flow direction.

[0055] Therefore, it is advantageous to coordinate the components with regard to the flow sequence according to the requirements of the respective applications. When cooling or air conditioning is required, the cooling unit 16 of the FGZ in the so-called HVAC module is supplied with cold refrigerant to cool the supply air to the cabin and also reduce humidity by cooling the air below the dew point. The supply temperature must be as low as possible, preferably < 5°C, so that the supply air temperature can be cooled below 10°C. When the FGZ is heating, dehumidification of the air is of secondary importance, as the water content of the outside air is already low. Therefore, it is advantageously proposed to switch off the FGZ cooler, bypass it, or, particularly advantageously, to integrate it into the second cooling circuit K2 or the high-temperature circuit. This allows the heating surface for the FGZ air to be increased and thus the heating capacity to be significantly enhanced.

[0056] In heating mode, the radiator is assigned to the second cooling circuit K2 so that it can transfer energy from the ambient air to the coolant. This energy, together with the heat loss from the components, is transferred by the heat pump 11 to the first cooling circuit K1, thus generating a temperature level required for heating.

[0057] The embodiment shown in Figure 2 illustrates a further development of the climate module. In Figure 2, the first cooling circuit K1 and the second cooling circuit K2 can be switched by the first valve element 12a. In other words, the cooling unit 16 can be selectively assigned to either the first cooling circuit K1 or the second cooling circuit K2. This allows, for example, an increase in heating capacity. Furthermore, in the embodiment shown in Figure 2, the power electronics 17 are arranged downstream of the radiator 19 or the third valve element 12c in the first cooling circuit K1.

[0058] In Figure 3, the cooling system has a fourth valve element 12d. The fourth valve element 12d is located downstream of the first valve element 12a in both the first cooling circuit and the second cooling circuit K2. The fourth valve element 12d is configured so that the heating unit 15 is selectively supplied with water from either the first or the second cooling circuit. Similarly, the cooling unit 16 can be selectively assigned to either the first or the second cooling circuit by means of the valve element 12a. When both units 15 and 16 are assigned to the first cooling circuit, an increase in cooling capacity is possible, while assignment to the second circuit allows for an increase in heating capacity. In the embodiment shown in Figure 3, the components are arranged so that all components requiring temperature control can be simultaneously assigned to one of the two cooling circuits K1 and K2.In other words, each component to be cooled is assigned a valve element 12. This allows operation with the heat pump 11 switched off and only one cooling circuit circulating, a so-called single-circuit. Efficient operation is possible in this way, since only one of the two pumps P1, P2 is in operation. The electric motors 20 and the power electronics are arranged downstream in the first cooling circuit K1 after the radiator 19 and the third valve element 12c.

[0059] In the embodiment shown in Figure 4, the second electric machine 20b is arranged in series with the energy storage device 18 in the first cooling circuit K1 and is associated with the second valve element 12b. More precisely, the second electric machine 20b is arranged upstream of the energy storage device 18 in the direction of flow. Thus, by means of a suitable operating strategy, thermal energy can be provided to this electric machine 20b for temperature control of the battery. A further advantage of this arrangement is that it allows for the disconnection / switching off (e.g., a bypass) of the battery supply, and the drive unit is simultaneously decoupled. This arrangement is not recommended for primary drives, as their cooling is thereby eliminated. Figure 5 discloses an embodiment that essentially corresponds to the embodiment according to Figure 4.In Figure 5, a third pump P3 is arranged upstream of the electric machine 20 and downstream of the second valve element 12b. Furthermore, the second valve element 12b is configured such that the energy storage device 18, the third pump P3, the power electronics 17, and the second electric machine 20b are arranged in a closed circuit. This closed circuit is represented by a dotted line. This closed circuit can be fluidically coupled to either the first cooling circuit K1 or the second cooling circuit K2 by switching the second valve element 12b. This allows for improved temperature control of the battery. In addition, the second electric machine 20b can be cooled to a limited extent, and the heat capacity of the energy storage device 18 can be used as a heat sink and thermal storage. Conversely, the thermal mass of the second electric machine 20b can also be used as a heat sink / storage unit for power losses.

[0060] Figure 6 shows an embodiment in which the energy storage unit 18 has its own coolant supply. In this embodiment, the second valve element 12b is arranged upstream of the first pump P1 and the second pump P2 in the direction of flow. The second valve unit 12b is configured to divert a fluid flow and direct it to the energy storage unit 18. This allows the energy storage unit 18 to be supplied with a coolant at a defined temperature, independent of the first cooling circuit K1 and the second cooling circuit K2. A reservoir 21 is arranged downstream of the energy storage unit. The return flow from the energy storage unit 18 is fed to the suction side of the first pump P1 and the second pump P2 or is initially directed into the reservoir 21. The reservoir 21 can also be referred to as an expansion tank.The reservoir can be designed to compensate for a difference in coolant flow between the first and second pumps P1 and P2. This allows the supply temperature to the energy storage unit 18 to be controlled within narrow limits, thus enabling homogeneous cooling. The embodiment shown in Figure 7 is essentially the same as the embodiment shown in Figure 3. The embodiment according to Figure 7 differs in that the electric motors 20a and 20b and the power electronics 17 are arranged downstream of a fifth valve element 12e. This allows the electric motors 20a and 20b and the power electronics 17 to be selectively assigned to either the first coolant circuit K1 or the second coolant circuit K2. This ensures that the cooling capacity can be adjusted according to demand.Furthermore, a series connection of all components is possible, enabling operation without an active heat pump 11 and requiring only the operation of one of the two pumps P1, P2. The electronic components are arranged downstream of the radiator 19 in the direction of flow to keep the temperature at the electric motors 20a, 20b as low as possible. This allows for both very efficient operation and high cooling capacity. In contrast to the embodiment shown in Figure 3, in Figure 7 the first cooling circuit K1 and the second cooling circuit K2 can be switched by the first valve element 12a. In other words, similar to the illustration in Figure 2, the cooling unit 16 can be selectively assigned to either the first cooling circuit K1 or the second cooling circuit K2, so that the cooling unit 16 can function as a heater.

[0061] The embodiment shown in Figure 8 is similar to the embodiment shown in Figure 7. In contrast to Figure 7, in Figure 8 the electric motors 20 and the power electronics 17 are permanently assigned to one of the two cooling circuits, here the first cooling circuit K1. As can be seen in Figure 8, the electric motors 20 and the power electronics 17 are arranged upstream of the first pump P1 and the second pump P2 in the direction of flow. The electric motors 20 and the power electronics 17 are the last parts of the system to be cooled before the coolant is returned to the evaporator 13 of the heat pump 11. This has the advantage that the highest power losses are introduced after the radiator 19, and thus the radiator receives a lower supply temperature during heating than if the electric motors 20 and the power electronics 17 were integrated upstream in one of the cooling circuits.This significantly improves energy extraction from ambient air. At the same time, fewer valves are required, thus reducing the effort needed to control the fluid, especially the coolant.

[0062] Figure 9 shows a setup identical to that of Figure 8. However, in Figure 9, the fifth valve element 12e is configured such that the electric motors 20 and the power electronics are located in the second cooling circuit K2. If the electronic components are permanently assigned to the second cooling circuit K2, then a sequence that provides the lowest possible coolant temperature is preferable. Here, too, integration after the radiator 19 is particularly suitable, as this is where the lowest temperature in the circuit is found in the relevant operating modes.

[0063] Figures 10a and 10b show a valve element 12. In Figure 10a, the valve element 12 is shown in a first position, and in Figure 10b, it is shown in a second position. The valve element 12 is designed as a slide valve in Figures 10a and 10b. The valve element 12 comprises a piston 22 and a housing 23 in which the piston 22 is axially movable (see double arrow in Figure 10a). The valve element 12 is a multi-way valve. The valve element 12 has two positions and six paths. In the first position, two paths are closed and four paths are open. The two paths of the four open paths are each connected by a channel in the piston. The two closed paths are closed by the piston. In the second position, all paths are open, with each pair of paths forming two connections through a channel in the piston 22 and two paths forming a connection through the housing 23.

[0064] Figure 11 shows a schematic diagram of a method for cooling at least one component. The method comprises the following steps. In a first step S1, a cooling system 10 is provided. In step S2, thermal energy is transferred from the evaporator 13 to the first cooling circuit K1. In a second step S3, thermal energy is transferred from the condenser 14 to the second cooling circuit K2. In a third step S4, the valve element 12 is switched to assign the at least one component to either the first cooling circuit K1 or the second cooling circuit K2. Other embodiments of the present invention are possible and can be understood and carried out by persons skilled in the art when applying the claimed subject matter by studying the figures, the disclosure, and the appended claims.In particular, the respective parts / functions of each embodiment described above can also be combined with one another. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are mentioned in interdependent claims does not mean that a combination of these measures cannot be advantageous. Any reference numerals in the claims should not be interpreted as limiting the scope of the claims.

[0065] Reference mark

[0066] K1 first cooling circuit

[0067] K2 second cooling circuit

[0068] P1 first pump

[0069] P2 second pump

[0070] 10 Cooling system

[0071] 11 Heat pump

[0072] 12 Valve element

[0073] 12a first valve element

[0074] 12b second valve element

[0075] 12c third valve element

[0076] 12d fourth valve element

[0077] 12e fifth valve element

[0078] 13 evaporators

[0079] 14 liquefiers

[0080] 15 heating units

[0081] 16 cooling units

[0082] 17 Power Electronics

[0083] 18 Energy storage

[0084] 19 Radiator

[0085] 20a first electric machine

[0086] 20b second electric machine

[0087] 21 Reservoir

[0088] 22 pistons

[0089] 23 cases

Claims

Patent claims 1. Cooling system (10) for cooling at least one component of a vehicle, in particular an electric vehicle or a hybrid vehicle, comprising: a heat pump (11) with at least one evaporator and at least one condenser, a first cooling circuit (K1) assigned to the evaporator (13), a second cooling circuit (K2) assigned to the condenser (14), at least one valve element (12) arranged in the first cooling circuit (K1) and / or in the second cooling circuit (K2), wherein the valve element (12) is configured to assign the at least one component to the first cooling circuit (K1) or the second cooling circuit (K2).

2. Cooling system according to claim 1, wherein the first cooling circuit (K1) and the second cooling circuit (K2) are independent of each other.

3. Cooling system according to claim 1 or 2, wherein the first cooling circuit (K1) and the second cooling circuit (K2) comprise different temperature levels.

4. Cooling system according to one of the preceding claims, wherein the cooling system (10) comprises several components, in particular a drive component and / or in particular an energy storage device (18) and / or in particular a power electronics unit (17) and / or a heat exchanger.

5. Cooling system (10) according to one of the preceding claims, wherein at least one heat exchanger is provided which is thermally coupled to the first cooling circuit (K1 ) and / or the second cooling circuit (K2).

6. Cooling system (10) according to one of the preceding claims, wherein at least one of the components is permanently assigned to the first cooling circuit (K1 ) or the second cooling circuit (K2).

7. Cooling system (10) according to one of the preceding claims, wherein the drive component is permanently assigned to the first cooling circuit (K1) or the second cooling circuit (K2).

8. Axle assembly with a cooling system (10) according to one of the preceding claims.

9. Vehicle with a cooling system (10) according to one of claims 1 to 7 and / or an axle assembly according to claim 8.

10. Method for cooling at least one component of a vehicle, in particular an electric vehicle or a hybrid vehicle, with a cooling system according to any one of claims 1 to 7, comprising: Transferring thermal energy from the first cooling circuit (K1) to an evaporator (13). Transferring thermal energy from the condenser (14) to the second cooling circuit (K2). Switching the valve element (12) to assign at least one component to either the first cooling circuit (K1 ) or the second cooling circuit (K2).

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