WO2022184321A1

WO2022184321A1 - A motor vehicle powertrain with an electric machine and a continuously variable transmission

Info

Publication number: WO2022184321A1
Application number: PCT/EP2022/025076
Authority: WO
Inventors: Caiyang WEI; Esin ILHAN CAARLS
Original assignee: Robert Bosch Gmbh
Priority date: 2021-03-03
Filing date: 2022-03-03
Publication date: 2022-09-09

Abstract

The invention relates to a powertrain for a hybrid or fully electric motor vehicle (1), in particular a passenger car, provided with an electric machine (EM) and a continuously variable transmission (CVT). According to the invention, the powertrain includes means for passively or actively promoting a transfer of heat from the electric machine (EM) to the continuously variable transmission (CVT), which means are preferably also capable of promoting a transfer of heat from the continuously variable transmission (CVT) to the electric machine (EM).

Description

A MOTOR VEHICLE POWERTRAIN WITH AN ELECTRIC MACHINE AND A CONTINUOUSLY VARIABLE TRANSMISSION

The present invention relates to a powertrain for motor vehicles, in particular passenger cars, including an electric machine also known as a motor/generator-device that serves or, at least, can serve as a prime mover of the motor vehicle and a continuously variable transmission (CVT) that drivingly connects, i.e. rotationally couples the prime mover to a driven wheel of the motor vehicle while providing a controllable variable speed ratio there between. It is noted that the present invention covers both fully electric motor vehicles, such as battery electric vehicles (BEV) or fuel cell electric vehicles (FCEV), and hybrid motor vehicles, such as mild (48-Volt) or strong hybrid electric vehicles (sHEV) and plug-in hybrid electric vehicles (PHEV).

The CVT is mostly known from its widespread application in conventional passenger cars with an internal combustion engine as their sole prime mover. Nevertheless, the CVT can also be advantageously applied in combination with the electric machine as the prime mover in the said fully electric and in the said hybrid electric vehicles as well. The CVT greatly contributes to the launch and hill-climbing performance or gradeability and/or the top speed of the motor vehicle and, moreover, can reduce the manufacturing and/or the operating cost of the overall powertrain.

A commonly applied type of CVT includes a primary pulley and a secondary pulley, as well as a flexible drive element that is wrapped around and in friction contact with the said pulleys. The flexible drive element comes in several known types, such as a segmented belt or chain made of metal. Each such pulley comprises two (frusto-)conical pulley discs arranged on a shaft, whereof at least one pulley disc is axially moveable and can be urged towards the pulley disc by actuation means associated with that pulley, such as an hydraulic piston/cylinder assembly. During operation of the CVT, an electronic control system of the motor vehicle determines and -via the pulley actuation means- sets the forces with which the flexible drive element is clamped at each pulley between the respective pulley discs thereof. A rotational speed and an accompanying drive torque can then be transmitted between the pulleys by means of friction between the flexible drive element and the pulleys. Also by the said forces, in particular by a ratio there between, a running radius of the flexible drive element at each pulley is determined. In turn, these running radii determine a speed ratio between the pulleys of the CVT, which speed ratio can be adjusted by the pulley actuation means to an arbitrary value within a range of speed ratios provided by the CVT.

In the motor vehicle, the CVT thus allows the electric machine to be operated within a continuous range of rotational speeds -as determined by the speed ratio range of the CVT- in relation to a given vehicle speed, i.e. in relation to a given rotational speed of the driven wheel. The electric machine can for example be controlled -by controlling the speed ratio of CVT- towards an operating point in terms of the torque and speed of the electric machine that provides maximum efficiency, that provides maximum vehicle acceleration or even that emulates a geared, i.e. stepped transmission. In either case, a desired rotational speed of the electric machine is determined by the electronic control system of the motor vehicle based on, at least, the current vehicle speed and an acceleration demand. The CVT speed ratio is then adjusted by the said pulley actuation means and under the command of the electronic control system, to match the actual rotational speed of the electric machine as closely as possible with the said desired rotational speed. In particular, an accelerator pedal position is often interpreted as the acceleration demand (that can be positive, zero or negative) provided by the driver of the motor vehicle. In this case, the electronic control system is typically pre-programmed with a characteristic curve, look-up table, or the like, wherein the desired speed of the electric machine is linked to a torque thereof that is required for realising the demanded acceleration at the current vehicle speed. Inter alia it is noted that in case the powertrain is automatically operated, such as by a cruise control function or an autonomous driving function of the electronic control system, such system will provide the said acceleration demand in lieu of the driver.

In practice, more sophisticated control methods are typically employed by the electronic control system that not only take into account the operating characteristics of the electric machine, such as it energy efficiency, but also those of other parts of the motor vehicle such as the CVT and/or a so-called power electronics unit that (electrically) connects the electric machine to a battery pack for electrically driving and braking the electric machine. Nevertheless, i.e. regardless of the control method employed, energy losses unavoidably occur to a certain extent in each powertrain component in the form of thermal losses, i.e. in the form of waste heat being generated (mechanically, electrically or chemically) and subsequently lost to ambient by passive or active cooling.

According to the present invention, such thermal losses in the powertrain can be favourably reduced by enhancing a heat transfer between the powertrain components of electric machine and CVT. In particular according to the present invention, heat transfer from the electric machine to the CVT is passively or actively promoted when the temperature of the CVT is below its optimum operating temperature of around 80 degree Celsius or, at least, is below the lower bound of its preferred operating temperature range between 60 and 90 °C. In this respect, it is noted that the CVT is lubricated by a liquid lubricant that also serves as coolant, such as oil, having an undesirably high viscosity at lower temperatures, e.g. when the coolant is at ambient temperature in so-called cold- start conditions. In comparison, in conventional motor vehicles, the internal combustion engine generates abundant waste heat to quickly heat not only itself at cold-start, but also the CVT and even the interior of the motor vehicle, such as the passenger cabin.

Preferably according to the present invention, heat transfer is promoted in both directions between the electric machine and the CVT, since these powertrain components are preferably operated at a similar temperature or, at least, in a similar temperature range compared to other parts of the motor vehicle, such as the said battery pack -that is preferably operated at a lower temperature of, typically, less than 50 °C -, or the internal combustion engine of the hybrid electric vehicle -that is preferably operated at a higher temperature of, typically, more than 100 °C-. In particular according to the present invention, the typically applied, separate metal outer housings of the electric machine and of the CVT respectively, which respective housings are bolted together in the powertrain, are joined together with a thermally conductive sealant, i.e. thermal paste, provided there between, rather than a conventionally applied gasket that has thermally insulating properties. Alternatively, the pulleys and belt of the CVT share a common outer housing with a rotor and a stator of the electric machine. Either way, the heat transfer between the electric machine and the CVT is promoted, as desired.

Moreover, to further shorten the desired (rapid) heating of the CVT at cold-start to its optimum operating temperature, the metal outer housing of, at least, the CVT can be additionally encapsulated in, or at least partially covered by a comparatively thermally insulating material (that is to say in comparison with the thermal conductivity of metal). Preferably, such CVT encapsulation is provided with a smooth outer surface, in particular such that the outer surface area thereof that is exposed to the ambient, is smaller than the outer surface area of the metal outer housing of the CVT.

Alternatively or additionally according to the present invention, the powertrain is provided with a thermal management system that is conceptually known as such, but that in its present application is specifically capable of actively transferring heat from the electric machine to the CVT.

In a first, favourably simple embodiment of the powertrain according to the present invention, the thermal management system is composed of -only- a fan that forces air to flow from the electric machine to the CVT. Preferably the fan and, thus, the airflow are reversible, such that also heat can be transferred from the CVT to the electric machine.

In an alternative embodiment of the powertrain according to the present invention, the thermal management system includes piping containing a heat transfer medium, such as water or oil, that can be made to flow through the piping by means of a pump or a compressor that is also included in the system. In particular, the said piping is associated with, in particular connected to both the electric machine and the CVT for heat exchange between these powertrain components and the heat transfer medium and thus also for heat exchange between these powertrain components mutually. Preferably, such piping associated with both the electric machine and CVT provides a closed loop there between, with a heat exchange device included therein, such as in the form of a heat pump or a radiator, that is arranged to cool the heat transfer medium with, for example, ambient air. A fan can be included in the thermal management system for -preferably selectively- forcing a -preferably controllable- flow of air to the heat exchange device.

Inter alia it is noted that the said heat pump as a specific type of heat exchange device is well-known as such and includes a compressor and a condenser on its hot (i.e. on the low temperature reservoir) side and an expander (e.g. expansion valve) and an evaporator on its cold (i.e. on the high temperature reservoir) side. In case of such heat pump, the heat transfer medium that is circulated therein is typically referred to as refrigerant.

It is further noted that a bypass pipe and bypass valve can be included in the thermal management system in parallel with the said heat exchange device thereof, for selectively allowing a -preferably controllable- flow of the heat transfer medium to bypass the device. Such option to bypass heat exchange device helps to quickly warm the heat transfer medium to the preferred operating temperature range of the electric machine and the CVT, e.g. at cold-start, while also favourably reducing power consumed by the pump of the thermal management system.

Preferably, the heat exchange device is placed between the CVT and the electric machine as seen in a pumping direction, i.e. a flow direction of the heat transfer medium in the system, since the CVT is generally operated at a slightly higher (i.e. optimum operating) temperature than the electric machine. More preferably such order of the CVT and the electric machine in the said flow direction can be reversed in dependence on the instantaneous temperatures of the CVT and the electric machine, for example by means of switch valves included in the said piping or by reversing the pump of the heat exchange device. In this case, the heat transfer medium is directed to flow from the heat exchange device to the relatively cooler powertrain component first. Additionally, if the heat exchange device is in the form of the heat pump, it can be preferably be operated in reverse for (pre-)heating the electric machine and the CVT in the said cold-start conditions.

In another alternative embodiment of the powertrain according to the present invention, the piping of the thermal management system defines two independent, i.e. separately closed loops that are respectively associated with, in particular connected to only one of the electric machine and the CVT, with another heat exchange device being arranged between these two piping loops. The piping loop associated with the electric machine preferably still includes the above-mentioned heat exchange device. This alternative powertrain embodiment favourably allows the electric machine and the CVT to be operated at individually optimized temperatures. Also this embodiment has the advantage that different heat transfer media can be applied in the said piping loops, which media can thus be selected in relation to the specific cooling and/or lubrication requirements of the respective powertrain component.

In an elaboration of the above powertrain embodiments according to the present invention also the said power electronics unit of the motor vehicle is included in the thermal management system thereof, i.e. can be actively heated and/or cooled thereby. In this case, the piping loop associated with the electric machine can additionally be associated with, in particular connected to the power electronics unit that has similar cooling requirements. It is noted that the power electronics unit is often integrated with the electric machine, e.g. shares a common housing with the electric machine, such that thermal management of the electric machine by means of the heat exchange medium in the piping loop associated with the electric machine is easily converted to also include the power electronics unit.

In another elaboration of the above powertrain embodiments according to the present invention also the battery pack of the motor vehicle is included in the thermal management system thereof, i.e. can be actively heated and/or cooled thereby, as a subsystem thereof that can be operated independently of the above-described (sub-)system for the active heat transfer from the electric machine to the CVT. Nevertheless, a heat exchange device between these two subsystems is preferably included in the overall thermal management system according to the present invention.

For such battery pack thermal management subsystem, air is the preferred heat transfer medium and a further fan and circulation channelling are provided for the circulation thereof respectively. Moreover, a further heat exchange device is provided in the form of a heat pump for cooling the heat transfer medium, ideally in addition to a radiator that then provides a more energy-efficient alternative for such heat pump, e.g. in case ambient temperature is low enough for cooling the battery pack. Preferably, such heat pump is reversible. After all, ambient temperature can be both higher and lower than the optimum operating temperature of the battery pack.

In particular in this latter elaboration, the said interior of the motor vehicle can be favourably included in the thermal management system by being actively heated or cooled by the same heat transfer medium as the battery pack, i.e. by being included in the said battery pack thermal management subsystem. Afterall, these parts of the motor vehicle are typically operated at in a similar temperature range that is considerably lower than the preferred operating temperature range of the internal combustion engine, the electric machine, the CVT and/or the power electronics unit. Nevertheless, the vehicle interior is normally maintained at a somewhat lower temperature than the battery pack, whereto the circulation channelling preferably includes a flow control valve for both the vehicle interior and the battery pack, i.e. for allowing controllable flows of the heat transfer medium to these respective motor vehicle parts.

As mentioned above, waste heat of the electric machine, the CVT and/or the power electronics unit can preferably be (selectively) directed to the battery pack and/or to the vehicle interior by a further heat exchange device being provided between the said two subsystems of the thermal management system. Hereby the thermal efficiency of the motor vehicle as a whole can be improved further, in particular when ambient temperature is low. In this case, the said heat pump of the further heat exchange device need not be reversible, since now it only needs to (selectively) cool the battery pack and the vehicle interior.

In the hybrid motor vehicle, the internal combustion engine is provided with its own cooling circuit as part of the thermal management system, since its optimum operating temperature is considerably higher than that of other powertrain components. According to the present invention, yet another heat exchange device can be advantageously provided between the said piping loop or piping loops associated with the electric machine and the CVT and the said cooling circuit of the internal combustion engine. In this case, at least the CVT and preferably also the electric machine, the power electronics unit, the vehicle interior and/or the battery pack can be heated above ambient with waste heat from the internal combustion engine, in particular when only such engine is in operation as part of the normal operation of the powertrain in the hybrid motor vehicle. Ideally, the yet another heat exchange device is reversible, such that alternatively waste heat of the electric machine, the CVT and of the power electronics unit can be directed to the internal combustion engine when it is switched-off (as part of the normal operation of the powertrain in the hybrid motor vehicle), to heat such engine above ambient temperature and thus to favourably avoid the cold (re-)start thereof. Alternatively and in case the said yet another heat exchange device is a heat pump, it may be fitted with a turbine that is driven by the expanding refrigerant in the expander of that heat pump and that drives an electric generator. Electric power that is thus generated from the waste heat of the internal combustion engine (including its exhausted gases) will exceed the electric power that is consumed by the compressor of the heat pump and can be conveniently stored in the battery pack of the motor vehicle.

These and other aspects of the present invention are explained in detail hereinafter with reference to the drawing figures, whereof:

Figure 1 diagrammatically illustrates the basic components of a powertrain for motor vehicles;

Figure 2 schematically illustrates an assembly of an electric motor and a continuously variable transmission according to the present invention for use in the motor vehicle powertrain;

Figure 3 schematically illustrates a first embodiment of a thermal management system according to the present invention for use in the motor vehicle;

Figure 4 schematically illustrates a second embodiment of the thermal management system according to the present invention for use in the motor vehicle;

Figure 5 schematically illustrates a preferred additional feature of the thermal management system according to the present invention for use in the motor vehicle; and

Figure 6 schematically illustrates a preferred, more detailed embodiment of the additional feature of the thermal management system illustrated in figure 5.

In figure 1 the presently relevant parts of a motor vehicle 1 are diagrammatically illustrated. The known motor vehicle 1 has a closable interior, such as a passenger cabin or freight space, that can at least be heated during operation of the motor vehicle 1 , but typically also cooled. The motor vehicle 1 can be fully electric, in which case it is driven by an electric machine “EM” that receives or supplies electric energy from or to a battery pack via a power electronics unit “PEU”, as indicated by the dashed arrows, which PEU regulates such flow of energy between the EM and the battery pack by means of a DC/DC- converter and a DC/AC-inverter. The EM is rotationally, i.e. mechanically coupled to the driven wheels of the motor vehicle via a continuously variable transmission “CVT”, as indicated by the solid arrows, which CVT regulates the (rotational) speed ratio and the (drive) torque ratio between the EM and the drive wheels.

Optionally, an internal combustion engine “ICE” can be included in such powertrain, for driving the motor vehicle 1 instead of, or in addition to the EM. Thereto, the ICE receives fuel from a fuel tank, as indicated by the dashed arrow. In figure 1, the ICE is illustrated in an upstream series arrangement relative to the EM in the hybrid version of the motor vehicle 1. However, it is also known to arrange the ICE in the powertrain of the hybrid motor vehicle either in parallel with the EM, or in a downstream series arrangement therewith. Moreover, in the said upstream series and parallel arrangements of the ICE, the EM can be directly rotationally coupled to the driven wheels rather than via the CVT that is in this case provided (only) between the ICE and the driven wheels. Also in such hybrid motor vehicle, a (dis-)engageable coupling, i.e. clutch will be present (not illustrated) to selectively connect or disconnect the ICE from the driven wheels when it is driven solely by the EM.

In the known motor vehicle 1, heat is generated by and during operation of the EM that can be advantageously employed to heat the CVT, at least at a so-called cold-start of the electric motor vehicle 1 and/or when the ICE is switched-off, i.e. is not operated in the hybrid motor vehicle 1. To this end, according to the present invention, a heat transfer between the powertrain components of the EM and the CVT is enhanced relative to the state of the art powertrain design by passive or active means. In particular according to the present invention and as schematically illustrated in figure 2, a thermally conductive sealant 4 is provided between the outer housing 2 of the EM and the outer housing 3 of the CVT. Also in figure 2, the outer housing 3 of the CVT is encapsulated in a thermally insulating material 5.

Alternatively or additionally according to the present invention, a thermal management system is provided for actively transferring heat from the EM to the CVT, whereof a first embodiment is schematically illustrated in figure 3. The novel thermal management system is provided with a piping circuit 10 that runs between and connects the EM and the CVT in a closed loop and that contains a heat transfer medium. A pump 11 is provided to actively transport the heat transfer medium through the piping circuit 10, the EM and the CVT and thus to transfer heat between the EM and the CVT during operation of the motor vehicle 1. A heat exchange device 12 is provided to cool the heat transfer medium with ambient air. A fan 13 is provided to actively supply such ambient air to the heat exchange device 12. The heat exchange device 12 is placed between the CVT and the EM as seen in a pumping direction of the pump 11 (as indicated by the black arrowhead) that determines the flow direction of the heat exchange medium through the piping circuit 10. Nevertheless, in its presently illustrated, preferred embodiment, the pump 11 can be reversed (as indicated by the outlined arrowhead) to reverse the said flow direction when desired.

Further, in this first embodiment, a bypass pipe 14 and bypass valve 15 are provided in parallel with the said heat exchange device 12, for selectively allowing a -preferably controllable- flow of the heat transfer medium to bypass the heat exchange device 12 when the temperature of the heat transfer medium is below the preferred, i.e. optimum operating temperature (range) of the EM and CVT.

A second, i.e. alternative embodiment of the thermal management system according to the present invention is schematically illustrated in figure 4. In this second embodiment thereof, the thermal management system is provided with a second piping circuit 20, wherein heat transfer medium is circulated by means of a second pump 21. This second piping circuit 20 is connected to the CVT, whereas the first-mentioned piping circuit 10 is connected to only the EM in this alternative embodiment of the thermal management system. Moreover, a further heat exchange device 22 is provided between these two heat transfer medium circuits 10, 20 for transfer heat therebetween. Favourably in this alternative embodiment, the heat transfer medium can be different for the EM and the CVT, e.g. such as optimised for the lubrication and the (hydraulic) actuation of the CVT in addition to the cooling thereof. Also these powertrain components can now be operated at a different temperature, or at least within a different temperature range. In particular, the operating temperature of the EM is maintained below a specified thermal limit of, typically, around 65 °C, whereas the operating temperature of the CVT is maintained at around 80 °C.

In figure 5 a preferred additional feature of the thermal management system according to the present invention is schematically illustrated. In particular, also the battery pack and the interior of the motor vehicle are both included in the thermal management system by way of a subsystem thereof. Hereto, the system is provided with an air channelling circuit 30 that connects the battery pack and the vehicle interior vehicle. A circulation fan 31 is provided for circulating an air flow through such air channelling circuit 30. Heat exchange devices 32, 33 are provided to cool or heat the circulated air flow that include both a radiator 32 and a heat pump 33, preferably a reversible heat pump 33. A secondary fan 34 is provided to actively supply ambient air to the heat exchange devices 32, 33. These heat exchange devices 32, 33 of the said thermal management subsystem can be arranged in series, however and as illustrated in figure 5, preferably a selector valve 35 is provided for directing the air flow in the channelling circuit 30 to either one of such devices 32, 33. The radiator 32 is selected by the selector valve 35 for cooling the circulated air flow with ambient air, whereas such circulated air flow can be cooled below or heated above ambient temperature by instead selecting the heat pump 33.

Additionally, waste heat of the EM can be (selectively) directed to the vehicle interior and/or the battery pack when ambient temperature is low, to further improve the thermal efficiency of the motor vehicle as a whole. As illustrated in figure 6, hereto a further air channelling circuit 40 with a further air circulation fan 41 are provided, which further channelling circuit 40 is connected to the aforementioned heat exchange device 12 associated with the said piping circuit 10 connected to the EM.

Claims

1. A powertrain for a hybrid or fully electric motor vehicle (1), in particular a passenger car, comprising an electric machine (EM) and a continuously variable transmission (CVT), characterized in that the powertrain includes means for passively or actively promoting a transfer of heat from the electric machine (EM) to the continuously variable transmission (CVT), which means are preferably also capable of promoting a transfer of heat from the continuously variable transmission (CVT) to the electric machine (EM).

2. The powertrain according to claim 1 , characterized in that a metal outer housing (2) of the electric machine (EM) and a metal outer housing (3) of the continuously variable transmission (CVT) are joined together with a thermally conductive sealant (4) provided therebetween.

3. The powertrain according to claim 1, whereof the electric machine (EM) comprises a rotor and a stator and whereof the continuously variable transmission (CVT) comprises two pulleys and a drive belt wrapped, characterized in that the rotor and the stator of the electric machine (EM) and the pulleys and the belt of the continuously variable transmission (CVT) share a common outer housing.

4. The powertrain according to claim 1 , 2 or 3, characterized in that a metal outer housing (3) of the continuously variable transmission (CVT) is encapsulated in, or at least is partially covered by a thermally insulating material (5), which insultation material (5) preferably has a smooth outer surface.

5. The powertrain according to a preceding claim, characterized in that the powertrain further comprises a thermal management system for actively transferring heat from the electric machine (EM) to the continuously variable transmission (CVT), which thermal management system is preferably also capable of actively transferring heat from the continuously variable transmission (CVT) to the electric machine (EM).

6. The powertrain according to claim 5, characterized in that the thermal management system is provided with a fan for realizing an flow of air from the electric machine (EM) to the continuously variable transmission (CVT), which fan is preferably reversible.

7. The powertrain according to claim 5, characterized in that the thermal management system is provided with a piping (10, 20) containing a heat transfer medium, with a pump (6) or a compressor for realizing a flow of the heat transfer medium through the said piping (10, 20) and with a heat exchange device (12) for heating and/or cooling the said flow of the heat transfer medium, which piping (10, 20) is connected to both the electric machine (EM) and the continuously variable transmission (CVT).

8. The powertrain according to claim 7, characterized in that the said piping (10, 20) of the thermal management system includes a bypass valve (15) and a bypass pipe (14), provided in parallel with the said heat exchange device (12), for selectively allowing the heat transfer medium to bypass such device (12).

9. The powertrain according to claim 7 or 8, characterized in that the said piping (10,

20) of the thermal management system includes two separates piping loops (10; 20), each containing a respective heat transfer medium, each provided with a respective pump (11 ;

21) or compressor and each respectively connected to either the electric machine (EM) or the continuously variable transmission (CVT), and in that the thermal management system is further provided with another heat exchange device (22) for heat exchange between the heat transfer media in the said two separate piping loops (10; 20) of the thermal management system.

10. The powertrain according to claim 7, 8 or 9, characterized in that a respective pump (11 ; 21) or compressor mentioned therein is reversible.

11. The powertrain according to any one of the claims 7-10, further comprising an internal combustion engine (ICE) with a separate cooling circuit containing a cooling liquid, characterized in that the thermal management system is provided with yet another heat exchange device for heat exchange between the cooling liquid in the ICE cooling circuit and the heat transfer media in the said piping (10, 20) of the thermal management system includes, which yet another heat exchange device preferably is in the form of a heat pump with a reversible compressor, more preferably is fitted with a turbine on an expander side of the heat pump, which turbine drives an electric generator.

12. The powertrain according to claim 11 , characterised in that the internal combustion engine (ICE) is rotationally coupled to the continuously variable transmission (CVT) and in that both the internal combustion engine (ICE) and the continuously variable transmission (CVT) are arranged in the powertrain upstream of, or in parallel with the electric machine (EM), at least as seen from the driven wheel of the motor vehicle wherein the powertrain is to be applied.

13. A motor vehicle (1) including the powertrain according to any one of the claims 7- 12, a battery pack for storing electric energy and a power electronics unit (PEU) that electrically connects the battery pack to the electric machine (EM) for electrically driving and braking the electric machine (EM), characterized in that the said piping (10, 20) of the thermal management system is also connected to the power electronics unit (PEU).

14. The motor vehicle (1) according to claim 13, characterized in that the thermal management system is further provided with means for actively heating and/or cooling of the battery pack, which means include a channelling (30) containing air, a circulation fan (31) for realizing a flow of air through the said channelling (30) and a further heat exchange device (32; 33) for heating and/or cooling the said flow of air.

15. The motor vehicle (1) according to claim 14, characterized in that the said further heat exchange device (32; 33) comprises both a radiator (32) and a heat pump (33) with a selector valve (35) being provided as part of the thermal management system for selectively directing the said flow of air to either one of the said radiator (32) and the said heat pump (33).

16. The motor vehicle (1) according to claim 14 or 15, characterized in that the said flow of air that is involved in the heating and/or cooling of the battery pack is also involved in the heating and/or cooling of an interior of the motor vehicle (1).

17. The motor vehicle (1) according to claim 14, 15 or 16, characterized in that the said means for actively heating and/or cooling of the battery pack include a further channelling (40) containing air and a further circulation fan (31) for realizing a flow of air through the further channelling (40), which further channelling (40) passes through the said heat exchange device (12) associated with the said the piping (10, 20) that is connected to the electric machine (EM) and the continuously variable transmission (CVT).