Patent Publication Number: US-2019170158-A1

Title: Motor-fan assembly comprising a hydraulic heat transfer fluid cooling circuit

Description:
The present invention concerns the field of motor-fan assemblies equipping motor vehicles in order to cool at least one component of same that experiences a temperature variation during operation. More specifically, the present invention relates to the field of blower wheels equipping such motor-fan assemblies and systems for driving the blower wheel, comprising an electric motor combining a stator and a rotor. 
     Motor vehicles comprise components that needs to be cooled due to the fact that they increase in temperature during operation. Such components include, for example, a battery providing the vehicle with electrical power, one or more power electronic components, or indeed the propulsion engine of the vehicle, which may be an electric motor or an internal combustion engine. 
     To this end, it is common to use a cooling system comprising a radiator inside which a heat transfer fluid circulates. The fluid collects calories released by the component and is conveyed in a closed circuit between the component and the radiator. The fluid is cooled inside the radiator as a result of heat exchange between the radiator and the ambient air. Depending on the component to be cooled, the radiator is commonly ventilated by a motor-fan assembly generating an air flow that increases the heat exchange between the radiator and the ambient air. 
     The motor-fan assembly conventionally comprises a base that is used to mount it on the vehicle. The base carries a drive motor for rotating at least one blower wheel. The blower wheel typically comprises a hub provided with means for rotationally linking with a drive shaft driven by the drive motor. The hub carries a plurality of blades distributed around the periphery of same, which extend radially. Control means control the implementation of the drive motor depending on the cooling requirements of the component. 
     Reference can be made, for example, to document FR 3 008 132 (VALEO SYSTEMES THERMIQUES), which describes such a motor-fan assembly used to cool a radiator. 
     Preferably, the performances obtained should be improved as far as possible in order to cool the component quickly and effectively. The present invention belongs to such a research context, taking into consideration economic constraints that require a trade-off to be found between achieving the performances expected in order to cool the component, organizing the cooling system in a simple manner and ensuring the structure of its components allow them to be obtained at lower costs. 
     In such a research context, the present invention concerns a motor-fan assembly dedicated to cooling a motor vehicle component, comprising an air propelling device, incorporating a hydraulic circuit through which a heat transfer fluid flows. The air propelling device comprises, in particular, a blower wheel and a system for driving the blower wheel. The present invention further concerns a system for cooling a component of the vehicle, comprising a motor-fan assembly according to the present invention. 
     The approach taken in present invention has led its designers to use the motor-fan assembly to cool a heat transfer fluid circulating therethrough, by using the air flow generated by the motor-fan assembly. 
     More particularly, the air propelling device of the motor-fan assembly is structured as a heat exchange member, capable of cooling the fluid conveyed from the component and circulating through the blower wheel. 
     Therefore, the motor-fan assembly equipped with the air propelling device of the present invention provides a dual function. A first function is that of generating an air flow and a second function is that of constituting a heat exchange member exchanging heat by means of the circulation of the fluid through the air propelling device. In other words, the motor-fan assembly is used not only to generate the forced air flow that passes through the radiator, but also to cool the fluid used to cool the component, as a result of its circulation at least in a hydraulic circuit incorporated into the air propelling device. The air flow and the fluid cooled by the air propelling device are used in conjunction to cool the component, moreover via a heat exchanger. Such a heat exchanger, used as the main radiator helping to cool the fluid, is positioned, in particular, on the circuit conveying the fluid between the component and the air propelling device. The main radiator can be mounted indiscriminately in series or parallel with the hydraulic circuit incorporated into the air propelling device. 
     Thus, the main radiator and the air propelling device form a set of heat exchange members together helping, for example, to cool the fluid circulating through the component. The heat exchanger can also additionally comprise an auxiliary radiator and/or a condenser cooled by the air flow. 
     The cooling of the component is thus more effective, due to the combined use of the air flow ventilating the heat exchanger, and the fluid cooled by the air propelling device, which now behaves like an additional heat exchanger. 
     The present invention therefore generally proposes to provide a hydraulic circuit channeling the fluid through the air propelling device of the motor-fan assembly. More particularly, the air propelling device is arranged to provide channels for the circulation of the fluid inside one or more of its components. The hydraulic circuit can, in particular, be incorporated into the blower wheel of the motor-fan assembly and/or into the blower wheel drive system. It should be noted that the components of the blower wheel comprise at least one hub and at least one blade, or indeed a plurality of blades, and preferably a crown, the latter linking an end of the blades opposite that which attaches the blades to the hub. 
     The hydraulic circuit is, in particular, arranged as a loop through which the fluid circulates between an inlet through which the fluid enters the blower wheel and/or the blower wheel drive system and a fluid outlet through which the fluid flows out of the blower wheel and/or the blower wheel drive system. A rotating hydraulic connector mounted coaxially on the hub of the blower wheel can provide the connection between the hydraulic circuit of the blower wheel and a circuit conveying the fluid between the component and the blower wheel. The inlet pipe and the discharge pipe can also be connected to a circuit conveying the fluid between the component and the stator. The fluid conveying circuit can advantageously comprise said heat exchanger mounted in series or parallel with the internal hydraulic circuit of the blower wheel and/or the stator, and can advantageously be ventilated by the air flow generated by the motor-fan assembly. 
     The components of the blower wheel used for the internal circulation of the fluid are advantageously arranged as hollow members, the internal recesses of which form channels through which the fluid circulates. Such hollow members can be obtained at lower costs by simplifying their individual structures by means of a double shell arrangement comprising two shells formed by molding and assembled together. Moreover, the shells respectively forming the component or components of the blower wheel can be produced in the form of one-piece blower wheel elements. These elements can be a part of the hub, a part of one or more blades, and/or a part of a crown encircling the blades. 
     The blower wheel elements can be formed at lower costs by molding and can be assembled together, for example axially. The blower wheel elements can be assembled together axially by sealing, in particular by bonding or welding. Such an assembly by sealing produces a sealed join between the shells. This prevents any fluid from leaking from the components of the blower wheel through which the channels are provided. 
     The components of the blower wheel can be made from a material that promotes heat exchange between the air flow and the heat transfer fluid present inside the blower wheel. The material can be metal or synthetic, for example. Such a synthetic material consists, in particular, of a resin filled with mineral fibers arranged into layers or fragmented. Such mineral fibers are, for example, glass fibers or carbon fibers. 
     Optimizing the path traveled by the fluid through the blower wheel is also proposed, in order to cool the fluid circulating inside same as much as possible. To this end, the fluid circulation channels extend between the hub of the blower wheel, the blades of the blower wheel mounted on the hub at the proximal end of same, and the crown linking the blades together at the distal end of same. 
     From such a proposition, various configurations extending the hydraulic circuit through the air propelling device can be envisaged in order to define the path traveled by the fluid through the motor-fan assembly, i.e. the hydraulic circuit of the air propelling device. Various configurations described below as illustrative examples correspond to respective trade-offs between:
         the performance achieved in terms of the cooling of the fluid,   the speed of circulation of the fluid through the blower wheel, for a given fluid circulation speed, thus defining the loss of pressure of the heat transfer fluid through the blower wheel,   the power generated by the motor-fan assembly and the arrangements for operating same, and/or   the power of the main radiator helping cool the component being cooled in conjunction by the fluid circulating through the blower wheel and by the air flow generated by the motor-fan assembly.       

     Thus, the present invention can be in the form of a first embodiment in which the hydraulic circuit is incorporated into a blower wheel of the motor-fan assembly. 
     Such a blower wheel comprises a hub carrying a plurality of blades by the proximal ends of same. The blades preferably extend radially, being linked together at the distal end of same by a crown. It is understood that the axial and radial directions are relative concepts considered relative to the rotational axis of the blower wheel. 
     The hydraulic circuit preferably extends in a loop between the hub, the blades and the crown. 
     The hydraulic circuit thus forms a path where the heat transfer fluid travels, this path being able to extend through several blades, consecutively and/or concurrently, depending on the configuration of the hydraulic circuit. 
     The connection device advantageously comprises the following features taken alone or in combination:
         the hub can comprise at least one heat transfer fluid inlet port and at least one heat transfer fluid outlet port,   the inlet port is connected to at least one first channel and the outlet port is connected to at least one last channel extending inside respective blades, in particular a first blade and a last blade,   the first channel and the last channel are connected to each other by at least one peripheral channel provided at least partially, or indeed entirely, inside the crown,   the first channel and the last channel are connected to together by at least one channel provided in an additional blade arranged between a first blade, in which the first channel is provided, and a last blade, in which the last channel is provided. Thus, the fluid is able to circulate consecutively along several channels provided inside consecutively adjacent blades. At the end of its journey, the fluid is conveyed from a peripheral channel of the crown to a last channel distributing the fluid to the outlet pipe provided inside the hub. Such measures make it possible to optimize the length of the path traveled by the fluid inside the blower wheel, i.e. the length of the hydraulic circuit. Indeed, the fluid circulates inside the blower wheel along a path extending consecutively along the blades, via the hub and the crown,   the hub is arranged as at least two bodies assembled together, between them providing at least one inlet pipe connected to the inlet port and to at least the first channel, and at least one outlet pipe connected to the outlet port and to at least the last channel. One of the bodies of the hub advantageously forms a bottom comprising, in particularly on one of the axial faces of same, a housing for receiving a drive motor for rotating the blower wheel. The other body of the hub advantageously forms a lid covering the bottom on the other axial face of same. Between them, the bottom and the lid provide the inlet pipe and the outlet pipe,   according to one embodiment, said at least one inlet pipe and said at least one outlet pipe are formed by partitioning a chamber provided in the lid. The partitioning of the chamber delimits at least two compartments inside the hub, which respectively form the inlet pipe and the outlet pipe,   according to another embodiment, said at least one inlet pipe and said at least one outlet pipe are formed by separate grooves provided indiscriminately in the thickness of the lid and/or in the thickness of the bottom. Said grooves can, for example, be provided side by side in the thickness of the lid,   the hub is provided with a rotating hydraulic connector conveying the heat transfer fluid between the outside of the blower wheel and the hydraulic circuit of the blower wheel. Such a hydraulic connector is preferably mounted on a lid of the hub. Given the arrangement of the housing intended to receive the drive motor, the rotating hydraulic connector and the housing are preferably each arranged at axially opposing ends of the hub,   the hub comprises at least one intermediate channel connecting together at least two channels provided in two immediately adjacent blades,   the hub is, in particular, arranged as a recessed member. At least one recess of the hub is delimited radially by at least one partition that extends in the axial direction of the blower wheel. At least one first recess forms the inlet pipe and one second recess forms the outlet pipe. The axially extending partition can be a peripheral wall of the hub or an inner wall of the hub,   at least one recess of the hub is delimited axially between closing walls arranged facing each other and extending in a plane orthogonal to the rotational axis of the blower wheel. The closing walls are preferably incorporated respectively into two bodies constituting the hub that are assembled together axially. One of the bodies forms a bottom covered axially by the other body formed from a lid,   the intermediate channel forms a cavity that brings at least three channels into communication, each provided in a blade. It should be understood in this instance that the blower wheel is arranged such that the fluid circulates in the same direction through at least two immediately adjacent blower wheels, in particular from the hub to the crown,   the blower wheel comprises, provided inside the crown, at least one peripheral channel connecting together at least two channels provided in two immediately adjacent blades. The crown can comprise one or more peripheral channels, depending on the configuration of the hydraulic circuit. To this end, the crown can comprise at least one internal recess forming the peripheral channel delimited by at least one partition closing the recess of the crown. More particularly, the peripheral channel extends at least partially along the annular extension of the crown. Said at least one peripheral channel can be provided between two partitions closing the recess of the crown. Several peripheral channels can be provided at least partially around the crown, consecutively and/or in parallel along the annular extension of the crown,   according to one embodiment, the blades are hollow and each comprise, at the proximal end of same, a first mouth that opens on an inlet pipe and, at the distal end of same, a second mouth that opens on a peripheral channel provided at least partially inside the crown, the heat transfer fluid being able to circulate through the blades between the inlet pipe and the peripheral channel,   at least one blade incorporates at least one baffle that extends the part of the hydraulic circuit through which the heat transfer fluid passing through the blade travels. This cools the fluid more than if the fluid were circulating through the blades along a radially direct path between the blade ends,   at least one blade incorporates protrusions for disturbing the flow of the heat transfer fluid passing through the blade,   the blower wheel is constituted by two blower wheel elements assembled together, each of said blower wheel elements incorporating, securely attached to each other, at least one blade portion, one crown portion and one of the bodies constituting the hub.       

     According to another configuration of the hydraulic circuit, a channel of a first blade and a channel of a second blade are connected together by a peripheral channel of the crown that is allocated to them. The fluid thus circulates between a plurality of sets of channels each comprising two blade channels and one peripheral channel. In this context, the blades of a pair of adjacent blades are, for example, connected respectively with an inlet pipe and with an outlet pipe that are allocated individually to them. 
     According to another configuration of the hydraulic circuit, the blades of a first group of adjacent blades are in communication with a shared inlet pipe. The blades of a second group of adjacent blades are in communication with a shared outlet pipe. The channels of the first group of blades and the channels of the second group of blades are connected together by a single peripheral channel of the crown. According to this configuration, the fluid circulates through the channels of the first group of blades to the peripheral channel, which then conducts the fluid to the channels of the second group of blades. The set of channels of the first group of blades is advantageously supplied with fluid by a single inlet pipe and the set of channels of the second group of blades is advantageously connected to a single outlet pipe. 
     According to an advantageous embodiment, the blades are each arranged as double blade shells assembled together axially. These shells form blower wheel portions. One of the blade shells forms the pressure side of the blade and the other blade shell forms the suction side of the blade. Between them, the blade shells provide the channel for the circulation of heat transfer fluid allocated to the blade that the blade shells together delimit when they are assembled together. 
     According to another advantageous embodiment, the crown is arranged as double crown shells assembled together axially, between them providing at least one peripheral channel, and optionally a plurality of peripheral channels. 
     The double shell arrangement of the components of the blower wheel delimiting the hydraulic circuit allows the blower wheel to be formed by assembling the two blower wheel elements together axially. It should be noted that such components of the blower wheel comprise the hub, formed from the bottom and the lid, the blades each formed from two blade shells, and the crown formed from two crown shells. The blower wheel elements can be obtained separately by molding and can be assembled together by sealing. Thus, the blower wheel is advantageously constituted by two blower wheel elements assembled together axially. Each of said blower wheel element incorporates, securely attached to each other, one blade shell, one crown shell and one of the bodies constituting the hub. 
     The present invention also concerns a system for cooling a motor vehicle component, that comprises at least one circuit for conveying the heat transfer fluid between the component and at least one blower wheel according to the invention above. Such a cooling system can comprise at least one heat exchanger arranged in the circuit for conveying the heat transfer fluid between the component and the blower wheel, the heat exchanger being traversed by the air flow generated by the blower wheel. 
     According to the present invention, at least one heat exchange member comprises the blower wheel of a motor-fan assembly according to the present invention. In other words, the cooling system comprises at least one first heat exchange member constituted by the blower wheel of the motor-fan assembly. 
     In this context, the heat exchanger constitutes a second heat exchange member equipping the cooling system. 
     The heat exchanger is, in particular, in the form of at least one main radiator, and optionally an auxiliary radiator and/or a condenser. The main radiator is potentially a high-temperature or low-temperature radiator, through which the fluid originating from the component circulates before it is conveyed to the blower wheel of the motor-fan assembly. The heat exchanger, and in particular said at least one main radiator, is positioned, in order to exchange heat with the air, in the path of the air flow generated by the air propelling device of the motor-fan assembly, the air being set in motion by the blower wheel driven by the drive system. 
     It should be noted that the air flow can pass through the heat exchanger by suction or blowing of the air flow. 
     According to one embodiment, the fluid circulates from the component to the heat exchanger, and then to the blower wheel of the motor-fan assembly. The fluid is then sent back to the component, supplying cooled fluid in order collect calories released by the component. 
     The fluid conveying circuit comprises a first portion interposed between the component and the main radiator, then a second portion between the main radiator and the blower wheel of the motor-fan assembly. The main radiator and the blower wheel are potentially mounted on the fluid conveying circuit in series or in parallel. 
     According to one embodiment, the main radiator and the blower wheel are mounted in parallel on the fluid conveying circuit. The second portion of the fluid conveying circuit can then be connected to a fluid inlet box for the fluid to enter the main radiator and to a fluid outlet box for the fluid to exit the main radiator to the component. 
     According to an alternative or additional variant, the main radiator and the blower wheel are mounted in series on the fluid conveying circuit. The second portion of the fluid conveying circuit can then be connected to a fluid inlet box for the fluid to enter the main radiator. 
     According to one embodiment, the rotating hydraulic connector is preferably arranged axially opposite the blower wheel drive motor intended to be positioned on the base, facing the heat exchanger. 
     The present invention can also be in the form of a second embodiment in which the hydraulic circuit is incorporated into a system for driving a blower wheel of the motor-fan assembly. The motor-fan assembly is, in particular, dedicated to cooling a motor vehicle component, at least by generating an air flow circulating through at least one heat exchanger used for cooling it. The drive system comprises an electric motor comprising a rotor and a stator, for example, at least partially coaxial. 
     The stator can be equipped with a cooling unit ventilated by the air flow generated by the motor-fan assembly. Such a cooling unit is suitable for cooling the heat transfer fluid that experiences a temperature increase as a result of circulating through the vehicle component. In this context, the cooling unit can, for example, be formed from fins that extend radially between a peripheral ring of the stator and a shaft of the stator providing a passage for the rotor of the motor and/or for the hub of the blower wheel. It is understood that the axial and radial directions are relative concepts considered relative to the rotational axis of the rotor. 
     The fins of the cooling unit can advantageously be used to provide, through same, radial channels of the hydraulic circuit, connecting together external channels that may, for example, be annular, provided inside the ring, and internal channels that may, for example, be annular, provided inside the shaft. 
     The cooling of the fluid circulating through the stator is enhanced by extending the hydraulic circuit and therefore the path travelled by the heat transfer fluid through the stator. The components of the stator through which the channels making up the hydraulic circuit are provided are arranged as hollow members. The internal recesses of such hollow members delimit the channels constituting the hydraulic circuit. Such hollow members can be obtained at lower costs by simplifying their individual structures by means of a double shell arrangement comprising two shells formed by molding and assembled together axially. Moreover, the shells respectively forming the components of the stator can each be incorporated into one-piece stator elements. 
     Certain stator elements can be formed at lower costs by molding and can be assembled together axially. The stator elements can be assembled together axially by sealing, in particular by bonding or welding in a sealed manner. Such an assembly by sealing produces a sealed join between the different shells that constitute the stator component or components housing the channel or channels of the hydraulic circuit. This prevents any fluid from leaking from the components of the stator through which the channels are provided. 
     Since the stator is subjected to the air flow generated by the motor-fan assembly, the heat transfer fluid circulating inside the stator is cooled by this air flow. 
     The hydraulic circuit provided in the stator comprises, in particular, consecutively, an inlet pipe for the heat transfer fluid to enter the stator, at least one channel, that may, for example, be annular, provided inside at least one component of the stator and, advantageously, a discharge pipe for discharging the fluid out of the stator. 
     The stator can thus be connected to a circuit conveying the fluid between the component and the stator via the inlet pipe and the discharge pipe. The channel at least partially delimits a path where the heat transfer fluid circulates inside the stator between the inlet pipe and the discharge pipe. 
     According to one embodiment, at least one extension channel, for example an annular extension channel, referred to as an external channel, is provided inside a peripheral ring of the stator. It should naturally be understood that the ring constitutes one of the components of the stator. According to various configurations of the hydraulic circuit, the external channel can extend at least partially or virtually all the way along the ring. The ring can comprise a plurality of external channels, for extending the path travelled by the fluid through the stator. The peripheral ring of the stator can also surround the blower wheel, peripherally, the inner diameter of the ring then being strictly greater than the outer diameter of the blower wheel. 
     According to one embodiment, the external channels can extend indiscriminately concentrically or parallel to the inside of the ring, being connected together consecutively. In other words, the external channel can be arranged substantially as a spiral, each of the turns of the channel extending substantially along the ring. The fluid therefore travels along a path that extends several times around the ring. 
     According to another embodiment, the ring can comprise a plurality of external channels separate from each other. More particularly, such external channels can send the fluid consecutively from the ring to another component of the stator. Another such component of the stator can, in particular, be formed by a shaft delimiting a passage for the rotor and/or for the hub of the blower wheel intended to rotated by the drive system. 
     The stator is preferably equipped with a cooling unit extending radially between the ring and the shaft through which the rotor passes. It should naturally be understood that the shaft constitutes a second component of the stator, while the cooling unit represents a third component of the stator. According to one embodiment of the invention, the cooling unit is used as a heat exchanger, in particular extending in the radial plane of the stator. 
     Such a cooling unit is capable of dissipating the calories of the heat transfer fluid after this fluid has circulated through the stator. The cooling unit then restores the calories that it absorbs to the ambient air, being cooled by the air flow generated by the motor-fan assembly. 
     According to one embodiment, the cooling unit is arranged as a plurality of radial fins distributed angularly between the ring and the shaft, around the rotational axis of the rotor. 
     The cooling unit constituted in this way therefore comprises radial channels interposed between the external annular channel provided in the ring and the internal annular channel provided inside a cylindrical wall delimiting the shaft. 
     According to an advantageous embodiment using the cooling unit, the radial channels extend respectively into the fins constituting the cooling unit. The hydraulic circuit thus extends consecutively at least between one external channel and one internal channel by means of at least one radial channel. 
     In the context of such an arrangement of the cooling unit and according to various embodiments, the fluid can enter and/or be discharged via the ring and/or the shaft. Indeed, the inlet pipe and the discharge pipe can be connected indiscriminately:
         to first channels provided in the ring,   to a first channel provided in the ring and to a second channel,   to second channels provided in the shaft.       

     According to one embodiment, the hydraulic circuit is provided between two stator elements formed by molding and assembled together axially. The stator elements then together form the component or components of the stator housing the channel or channels that constitute the hydraulic circuit. 
     The stator elements are, in particular, arranged as two respective shells, at least one of which is recessed. Between them, the shells provide said at least one channel. The stator elements constitute two axial sections that delimit at least the ring, and optionally also the shaft and optionally also the cooling unit, in particular the fins. Between them, the stator elements provide said at least one external channel, said at least one internal channel, and/or the radial channel or channels. 
     The present invention also concerns a motor-fan assembly comprising a blower wheel and a system for driving the blower wheel according to the present invention. The motor of the drive system is, in particular, mounted on a base that constitutes a member for mounting the motor-fan assembly on the vehicle. 
     The present invention further concerns a system for cooling a motor vehicle component. Such a cooling system comprises a circuit conveying the fluid between the component and at least the stator incorporating the hydraulic circuit. 
     More particularly, the fluid circulates in the environment of the component in order to collect calories that it releases. The fluid is then conveyed to at least one heat exchanger in order to be cooled. The cooled fluid is then sent back to the component. 
     In this context, the cooling system of the present invention is mainly distinguished in that it comprises a stator of a motor-fan assembly according to the present invention and used to cool the heat transfer fluid. In other words, the cooling system comprises a heat exchange member constituted by the stator of the electric motor that the motor-fan assembly comprises. 
     The cooling system preferably comprises a heat exchanger used as a radiator, in particular as the main radiator. The main radiator is interposed on the circuit for conveying fluid between the component and the stator constituting the electric motor equipping the motor-fan assembly. 
     The main radiator is also preferably positioned, in order for it to cool, in the path of the air flow generated by the motor-fan assembly. It should be noted that the air flow generated by this motor-fan assembly can function by suction or blowing of the air flow. 
     The cooling system can also comprise an auxiliary radiator and/or a condenser, in addition to the main radiator. This main radiator is potentially a low-temperature or high-temperature radiator, through which the heat transfer fluid originating from the component circulates before or after being conveyed to the stator according to the invention. 
     The fluid conveying circuit comprises, in particular, a first portion interposed between the component and the main radiator, then a second portion interposed between the main radiator and the stator. The second portion can then be connected to a fluid inlet pipe for the fluid to enter the main radiator and extend to the stator. The second portion can also then be connected to a fluid outlet pipe for the fluid to exit the main radiator and channeling the heat transfer fluid to the component to be cooled. 
     The main radiator and the stator are preferably mounted in series on the fluid conveying circuit. In this case, the second portion can comprise a downstream pipe that connects the stator directly to the component. The invention also covers the possibility of mounting the main radiator and the stator in parallel on the fluid conveying circuit. 
    
    
     
       Other features, details and advantages of the invention will become clearer on reading the description that follows as an example, with reference to the figures in the appended plates in which: 
         FIG. 1  consists of two diagrams (a) and (b), which respectively show, in perspective, various arrangements of a first embodiment of a system for cooling a motor vehicle component according to the present invention. 
         FIG. 2  is an exploded perspective view of a motor-fan assembly according to the first embodiment of the present invention. 
         FIG. 3  consists of two diagrams (c) and (d), showing an example of a configuration of a hydraulic circuit incorporated into a blower wheel according to the first embodiment of the present invention. 
         FIG. 4  consists of two perspective views (e) and (f), which respectively show bodies that together form a hub of a blower wheel according to the first embodiment of the present invention. 
         FIG. 5  consists of three diagrams (g), (h) and (i), showing another example of a configuration of a hydraulic circuit incorporated into a blower wheel according to the first embodiment of the present invention. 
         FIG. 6  consists of three diagrams (j), (k) and (l), showing another example of a configuration of a hydraulic circuit incorporated into a blower wheel according to the first embodiment of the present invention. 
         FIG. 7  is an exploded perspective view of a blower wheel according to the first embodiment of the present invention. 
         FIG. 8  consists of three diagrams (m), (n) and (o), which respectively show various configurations of a cooling system according to the first embodiment of the invention. 
         FIG. 9  consists of two diagrams (a) and (b), which respectively show perspective views of various arrangements of a system for cooling a motor vehicle component according to the second embodiment of the present invention. 
         FIG. 10  is a front view of a motor-fan assembly according to the second embodiment of the present invention. 
         FIG. 11  consists of three diagrams (c), (d) and (e), which respectively show various arrangements of a hydraulic circuit incorporated into a stator comprised in a motor-fan assembly according to the second embodiment of the present invention. 
         FIG. 12  consists of four diagrams (f), (g) and (h), which respectively show various configurations of a cooling system shown in diagram (b) of  FIG. 9 . 
     
    
    
     It should be noted that the figures show the present invention in a detailed manner and according to specific arrangements for the implementation of same, and that said figures can naturally be used, if necessary, to better define the present invention, both in terms of its specific features and in general. 
     Moreover, in order to clarify and facilitate the reading of the following description of the present invention, the same members shown in different figures are identified respectively, in the descriptions specific to these figures, with the same reference numbers and/or letters, without this necessarily implying that the embodiment is identical. 
     In diagrams (a) and (b) of  FIG. 1  and in diagrams (m) to (o) of  FIG. 8 , a motor vehicle component  1  is provided with a cooling system  2  that cools by heat exchange between a heat transfer fluid Fe and an air flow Fx. The component  1  to be cooled is potentially:
         an internal combustion engine, a turbocompressor or an air-conditioning loop and, generally, any components of the power train of the vehicle provided by a combustion drive system, and/or   an electric motor and, generally, any components of the power train of the vehicle provided by an electric drive system, and/or   one or more power electronic components, in cases where the vehicle&#39;s propulsion is provided by an electric drive system, a combustion drive system or a hybrid drive system combining a combustion drive system and an electric drive system.       

     It should be noted that the examples listed above of applications of the present invention are mentioned for reference purposes, and should not be considered to be exhaustive. Indeed, the present invention can be applied to the cooling, by heat exchange by means of a heat transfer fluid, of at least one of any motor vehicle component that needs to be cooled. 
     In this context, the system  2  for cooling the component  1  implements a motor-fan assembly  3  setting in motion an air flow Fx that passes through a heat exchanger  8  intended to dissipate calories generated by the component  1 . Such a heat exchanger can, for example, be in the form of at least one main radiator  8   a  preferably helping cool the component  1 . The heat exchanger can also, for example, be formed by a gas cooler or a condenser of an air-conditioning loop. 
     The cooling system  2  comprises a circuit  4  for conveying the heat transfer fluid Fe between the component  1  and a hydraulic circuit included in a blower wheel  5  equipping the motor-fan assembly  3 . It should be noted that the hydraulic circuit included in the blower wheel  5 , described below with reference to  FIGS. 3 to 7 , is not shown in the diagrams of  FIG. 1  and  FIG. 8 , in order not to overload these figures. 
     More particularly, the motor-fan assembly  3  essentially comprises a base  6  carrying a drive motor  7  for rotating the blower wheel  5 . The base  6  constitutes a member for mounting the motor-fan assembly  3  on a structural element of the vehicle or on the heat exchanger. The drive motor  7  is, indiscriminately, a hydraulic motor or an electric motor engaged on a hub  9  of the blower wheel  5 . 
     In the diagrams of  FIG. 1  and in  FIG. 2 , the hub  9  carries blades  10  that set in motion the air flow Fx as a result of the blower wheel  5  being set in rotation. The blades  10  extend radially between their proximal end secured to the hub  9  and their distal end secured to a crown  11  extending at the periphery of the blower wheel  5 . In  FIG. 2 , the hub  9  comprises, for example, a housing  12  for receiving the drive motor  7 . This housing  12  can, in particular, be provided with members  13  for rotationally linking the hub  9  of the blower wheel  5  and a drive shaft equipping the motor  7 , as shown, for example, in diagram (e) of  FIG. 4 . 
     In the diagrams of  FIG. 1  and  FIG. 8 , the cooling system  2  essentially comprises a source of calories formed by the component  1 . The calories released by the component  1  as a result of its increase in temperature are transferred by the conveying circuit  4  to the hydraulic circuit incorporated into the blower wheel  5  of the motor-fan assembly  3 . At least some of these calories are dissipated in the air flow Fx by the blower wheel  5  of the invention. The heat transfer fluid Fe can also be conveyed to a heat exchanger  8 , for example used as a radiator  8   a  to dissipate the calories in the air flow Fx. The heat transfer fluid Fe can be conveyed into the heat exchanger  8  and into the blower wheel  5  in series or in parallel, and the heat exchanger  8  can be upstream or downstream of the blower wheel  5 , depending on the direction of circulation of the fluid Fe. 
     In diagram (a) of  FIG. 1 , the conveying circuit  4  comprises an upstream pipe  16  for conveying the heat transfer fluid Fe from the component  1  to the blower wheel  5  of the motor-fan assembly  3 , and a downstream pipe  17  conveying the heat transfer fluid Fe from the blower wheel  5  of the motor-fan assembly  3  to the component  1 . 
     In diagram (b) of  FIG. 1  and in diagrams (m) to (o) of  FIG. 8 , the conveying circuit  4  comprises a first portion  16   a ,  17   a  of the conveying circuit  4  and a second portion  16   b ,  17   b  of the conveying circuit  4 . The first portion  16   a ,  17   a  extends between the component  1  and the heat exchanger  8 , which comprises, to this effect, a fluid inlet box  16   c  for the heat transfer fluid Fe in order for the heat transfer fluid Fe circulating through it to enter same. The second portion  16   b ,  17   b  extends between the heat exchanger  8  and the blower wheel  5 , the latter being connected to the heat exchanger  8  via a fluid outlet box  17   c  for the heat transfer fluid Fe constituting the heat exchanger  8 . The outlet box  17   c  concentrates the heat transfer fluid Fe with a view to it being discharged from the heat exchanger  8 , and is connected to the first portion  17   a  of the circuit  4  for conveying the heat transfer fluid Fe in order to return it to the component  1 . 
     In this context, the component  1  is cooled by the heat exchanger  8  and/or by the blower wheel  5 . 
     The second portion  16   b ,  17   b  of the circuit  4  for conveying the heat transfer fluid Fe is connected to the hydraulic circuit integrated into the blower wheel  5  by a rotating hydraulic connector  18  equipping the motor-fan assembly  3 . 
     The hydraulic connector  18  constitutes a member for conveying the heat transfer fluid Fe from outside the blower wheel  5  to the hydraulic circuit that it incorporates. The hydraulic connector  18  is mounted coaxially on the hub  9  of the blower wheel  5 . Such a rotating hydraulic connector  18  comprises at least two hydraulic elements  18   a ,  18   b  comprising heat transfer fluid Fe passages between them. A first hydraulic element  18   a  is mounted coaxially secured to the hub  9 , so as to rotate with the blower wheel  5 . The second hydraulic element  18   b  is mounted stationary around the first hydraulic element  18   a.    
     In the diagrams of  FIG. 1  and  FIG. 8 , it should be noted that the hydraulic connector  18  is preferably arranged at a first end of the motor-fan assembly  3  situated axially opposite a second end carrying the drive motor  7 . The blower wheel  5  is this interposed between the drive motor  7  and the rotating hydraulic connector  18 . 
     Concerning the relative positions of the motor-fan assembly  3  and the component  1 , the drive motor  7  is arranged axially facing the component  1  whereas the rotating hydraulic connector  18  is arranged axially on the motor-fan assembly  3  opposite the drive motor  7 . 
     In diagram (b) of  FIG. 1 , the heat exchanger  8  and the blower wheel  5  are mounted in parallel relative to each other on the circuit  4  for conveying the heat transfer fluid. In this case, the two pipes forming the second portion  16   b ,  17   b  connect the heat exchanger  8  and the hydraulic circuit incorporated into the blower wheel  5 . In diagrams (m) to (o) of  FIG. 8 , the heat exchanger  8  and the blower wheel  5  are mounted in series relative to each other on the circuit  4  for conveying the heat transfer fluid. In this case, a first pipe  16   b  of the second portion  16   b ,  17   b  of the conveying circuit  4  channels the heat transfer fluid Fe to the blower wheel  5  and a second pipe  16   b  of this second portion  16   b ,  17   b  conveys the heat transfer fluid Fe directly from the blower wheel  5  to the component  1 . 
       FIGS. 3 and 4 ,  FIG. 5  and  FIG. 6  show configuration examples of the hydraulic circuit extending inside the blower wheel  5 . 
     In these figures, the hub  9  comprises recesses to allow the heat transfer fluid Fe to circulate between the blower wheel  5  and rotating hydraulic connector  18 . The hub  9  comprises at least one inlet port  19   a  and at least one outlet port  19   b . The inlet port or ports  19   a  delimit an inlet of the heat transfer fluid Fe from the rotating hydraulic connector  18  into at least one inlet pipe  20   a  formed by a first recess of the hub  9 . The inlet pipe  20   a  connects the inlet port  19   a  with at least one first channel  21   a  extending inside a blade  10 , in this instance the first blade traversed by the hydraulic circuit of the blower wheel  5 . The outlet port or ports  19   b  delimit an outlet of the heat transfer fluid Fe to the rotating hydraulic connector  18  from at least one outlet pipe  20   b  formed by a second recess of the hub  9 . The outlet pipe  21   b  connects the outlet port  19   b  with at least one last channel  21   b  extending inside a blade  10 , in particular the last blade traversed by the hydraulic circuit of the blower wheel  5 . 
     According to one embodiment, the inlet port  19   a , the inlet pipe  20   a , the outlet pipe  20   b  and the outlet port  19   b  are part of the hydraulic circuit incorporated into the blower wheel according to the invention. 
     In  FIG. 4 , the hub  9  is arranged as two bodies  9   a ,  9   b  assembled together, for example by moving one body in an axial direction towards the other. One of the bodies of the hub  9  forms a bottom  9   a  and is axially covered by a lid  9   b  constituting the other body of the hub  9 . The engagement between the bottom  9   a  and the lid  9   b  is supplemented by a sealed connection, for example ultrasonic bonding or welding, providing the hub  9  with a seal between its internal volume and the outside. 
     The bottom  9   a  and the lid  9   b  each comprise a closing wall  23   a ,  23   b  between which the inlet pipe  20   a  and the outlet pipe  20   b  are provided. The closing walls  23   a ,  23   b  are designed to be positioned axially against each other once the bottom  9   a  and the lid  9   b  have been assembled together axially. The inlet pipe  20   a  and the outlet pipe  20   b  are provided in the thickness of the lid  9   b , extending axially between the respective closing walls  23   a ,  23   b  of the bottom  9   a  and the lid  9   b.    
     The bottom  9   a  comprises the housing  12  for receiving the drive motor  7 . The housing  12  opens on the outside of the hub  9 , on one of its axial faces opposite its other axial face covered by the lid  9   b.    
     As previously indicated, link members  13  are provided on the inside of the housing  12  in order to prevent the hub  9  and the drive motor  7  from rotating relative to each other. In the embodiment shown, such link members  13  form notches that extend axially and are provided along a peripheral wall of the bottom  9   a  and facing radially towards the inside of the housing  12 . The bottom  9   a  preferably also comprises a centering shaft  25 . 
     It should be noted that the arrangements that have just been described in reference to  FIG. 4  can be transferred to various configurations of the hydraulic circuit, such as the configurations shown respectively in  FIG. 3 ,  FIG. 5  and  FIG. 6 . 
     In  FIG. 4  and diagram (d) of  FIG. 3 , the inlet pipe  20   a  and the outlet pipe  20   b  are, more specifically, formed by respective grooves  26   a ,  26   b  provided in the thickness of the closing wall  23   b  of the lid  9   b.    
     In  FIG. 5  and  FIG. 6 , the inlet pipe  20   a  and the outlet pipe  20   b  are provided by internally partitioning a chamber  27  formed in the thickness of the lid  9   b . At least one partition  28  that extends axially divides the chamber  27  into at least two compartments respectively forming the inlet pipe  20   a  and the outlet pipe  20   b . In  FIG. 5 , the chamber  27  is divided by a single partition  28  into two compartments respectively forming a single inlet pipe  20   a  and a single outlet pipe  20   b . In  FIG. 6 , the chamber  27  is divided by several partitions  28  into a plurality of compartments providing several inlet channels  20   a  and several outlet channels  20   b.    
     In this context, in  FIG. 3 ,  FIG. 5  and  FIG. 6 , at least one inlet pipe  20   a  distributes the heat transfer fluid Fe to at least one channel provided in a first blade  10 , this channel then forming a first channel  21   a . The channel or channels  21   a  of the blades  10  are respectively connected to at least one peripheral channel  29  extending around the crown  11 . According to one embodiment, the crown  11  is internally recessed so as to delimit at least the peripheral channel  29 , comprising one or more partitions  30  for closing this recess. Such partitions  30  extend, for example, radially in order to segment the internal recess of the crown  11  into at least one peripheral channel  29 . 
     Thus, one or more peripheral channels  29  extend at least partially around the crown  11 . The peripheral channel or channels  29  are, moreover, respectively connected to at least one channel opening on an outlet pipe  20   b , referred to as the last channel  21   b.    
     The reference S shows the direction in which the heat transfer fluid Fe circulates from its inlet into the interior of the blower wheel  5  through the inlet port  19   a  until it is discharged out of the blower wheel  5  through the outlet port  19   b . Taking into consideration the direction S in which the heat transfer fluid Fe circulates through the blower wheel  5 , hydraulic circuits  31   a ,  31   b ,  31   c  shown respectively in  FIGS. 3, 5 and 6  at least each consist consecutively of at least one inlet port  19   a , at least one inlet pipe  20   a , at least one first channel  21   a , at least one peripheral channel  29 , at least one last channel  21   b , at least one outlet pipe  20   b  and at least one outlet port  19   b.    
     More particularly, in diagrams (c) and (d) of  FIG. 3 , a first hydraulic circuit  31   a  comprises an inlet port  19   a  distributing the heat transfer fluid Fe to the inlet pipe  20   a . The latter distributes the heat transfer fluid Fe to a first blade  10  housing the first channel  21   a . The first channel  21   a  opens on a first peripheral channel  32   a  provided inside the crown  11 , extending partially along its annular extension. The first peripheral channel  32   a  connects the first channel  21   a  with a second channel  21   a  provided inside a second blade  10  adjacent to the first blade  10 . Thus, a pair of channels  21   a , respectively provided inside a pair of adjacent blades  10 , are connected together by the first peripheral channel  32   a.    
     The second channel  21   a  opens on an intermediate channel  33   a  provided inside the hub  9 . The intermediate channel  33   a  is formed by a recess provided in the thickness of the closing wall  23   b  of the lid  9   b , as shown particularly clearly in diagram (f) of  FIG. 4 . The intermediate channel  33   a  is connected to a third channel  21   a  provided inside a third blade  10  adjacent to the pair of blades  10  made up by the first blade  10  and the second blade  10 . The third channel  21   a  opens on a second peripheral channel  32   b . The second peripheral channel  32   b  is a channel for conveying the heat transfer fluid Fe to a fourth channel  21   a  provided in an adjacent blade  10 . 
     Thus, the heat transfer fluid Fe travels along a plurality of channels  21   a  provided respectively in a series of adjacent blades  10 , via one or more intermediate channels  33   a ,  33   b  and one or more peripheral channels  32   a ,  32   b , forming the peripheral channel  29 . At the end of the flow of the heat transfer fluid Fe inside the blower wheel  5 , an end peripheral channel sends the heat transfer fluid Fe to the outlet pipe  20   b  via a last channel  21   b  provided in a last blade  10 . 
     Moreover, in diagram (d) of  FIG. 3 , the blades  10  are provided with one or more baffles  34  that extend the path traveled by the heat transfer fluid Fe along the channel or channels  21   a ,  21   b , compared with a path following a straight line in a radial direction passing through the blade  10 . Moreover, protrusions  35  can be provided projecting into the part of the hydraulic circuit provided in the blades  10  in order to disturb the linear flow of the heat transfer fluid Fe through them. Although such arrangements are only shown in  FIG. 3 , it should be noted that the respective formations of the baffles  34  and/or the protrusions  35  inside the channels of the blades  10  can be transferred to any configuration of the hydraulic circuit  31   b ,  31   c , such as the other configurations shown respectively in  FIG. 5  and  FIG. 6 . 
     In diagrams (g), (h) and (i) of  FIG. 5 , the hub  9  comprises an inlet port  19   a  and an outlet port  19   b  respectively connected to an inlet pipe  20   a  and an outlet pipe  20   b . The inlet pipe  20   a  distributes the heat transfer fluid Fe to a plurality of first channels  21   a  provided respectively inside first adjacent blades  10 , of which there are three in this instance. 
     The first channels  21   a  open on a single peripheral channel  29  extending around the whole of the crown  11 . Moreover, the outlet pipe  20   b  is connected to a plurality of last channels  21   b  provided respectively inside adjacent blades  10  and opening on the peripheral channel  29 , these last blades being three in number, in this example. 
     Thus, the second hydraulic circuit  31   b  comprises a first group of adjacent blades  10 , inside which channels  21   a  are respectively provided, and a second group of adjacent blades  10  inside which last channels  21   b  are respectively provided. The heat transfer fluid Fe circulates from the inlet pipe  20   a  simultaneously through the plurality of first channels  21   a , then into the peripheral channel  29  distributing the heat transfer fluid Fe simultaneously to a plurality of last channels  21   b  opening on the outlet pipe  21   b.    
     In diagrams (i), (j) and (k) of  FIG. 6 , a third hydraulic circuit  31   c  comprises a plurality of inlet ports  19   a  opening on respective inlet channels  20   a  and a plurality of outlet ports  19   b  opening on a plurality of respective outlet channels  20   b . Each inlet channel  19   a  is connected individually to a single first channel  21   a . Each outlet channel  19   b  is connected individually to a last channel  21   b . The first channels  21   a  and the last channels  21   b  are grouped together consecutively two by two into a set of channels provided respectively inside adjacent blades  10 . Each set of channels comprises a first channel  21   a  connected to an inlet pipe  20   a  and a last channel  21   b  connected to an outlet pipe  20   b . The first channel  21   a  and the last channel  21   b  of a same set of channels are connected together by a portion of peripheral channel  29  allocated to them. 
     The heat transfer fluid Fe circulates from the inlet channels  20   a  to first channels  21   a  belonging to sets of channels allocated respectively to the inlet channels  20   a . The heat transfer fluid Fe circulates from the first channels  21   a  to the portions of peripheral channel  29 , then to the last channels  21   b  with which the first channels  21   a  respectively make up the sets of channels. The heat transfer fluid Fe is then conveyed to the outlet channels  20   b  connected respectively with the last channels  21   b.    
     In diagram (h) of  FIG. 5  and in diagram (k) of  FIG. 6 , the hollow nature of the blades  10  can be seen. In order to allow the heat transfer fluid Fe to circulate between the hub  9  and the crown  11 , the blades  10  comprise a first mouth  22   a  that opens on the inside of the hub  9  and a second mouth  22   b  that opens on the inside of the crown  11 . The blades  10  are each arranged, generally, as a tubular member, the ends of which open respectively on the inside of the hub  9  and on the inside of the crown  11 . The channels of the blades are, for example, implemented by this hollow nature of the blades  10 . 
     According to the example of  FIG. 5 , the heat transfer fluid Fe travels simultaneously through several first blades  10  and several last blades  10 . In other words, the first channels  21   a  are in parallel to each other, according to the path of the heat transfer fluid Fe. 
     According to the example of  FIG. 3 or 6 , the heat transfer fluid Fe travels consecutively through the blades  10  that make up the blower wheel  5 . In other words, the channels of each blade are in series one after another, according to the path of the heat transfer fluid Fe. 
     In  FIG. 7 , the blower wheel  5  consists of two blower wheel elements  5   a ,  5   b  formed, for example, by molding, and designed to be assembled together axially, in particular by ultrasonic bonding or welding. Mechanically connecting the blower wheel elements  5   a ,  5   b  together in this way seals the blower wheel  5 , preventing any heat transfer fluid Fe from leaking out of the blower wheel  5 . Each of the blower wheel elements  5   a ,  5   b  is shown in exploded view but it should be understood that the blower wheel elements  5   a ,  5   b  are each constituted by a monolithic or one-piece body, so as to form a unitary part. 
     Each of the blower wheel elements  5   a ,  5   b  comprises one of the bodies  9   a ,  9   b  constituting the hub  9 , at least one blade portion  10   a ,  10   b  constituting the blades  10  and at least one crown portion  11   a ,  11   b  constituting the crown  11 . The blade portions  10   a ,  10   b  can each consist of a set of elementary shells. 
     According to one embodiment, a first element  5   a  comprises the bottom  9   a  of the hub  9 , a first crown portion  11   a  and at least one first blade portion  10   a  forming a pressure side of the blades  10 . A second element  5   b  comprises the lid  9   b  of the hub  9 , a second crown portion  11   b  and at least one second blade portion  10   b  forming a suction side of the blades. In this particular example, the first blade portion  10   a  and the second blade portion  10   b  each delimit a plurality of blades  10 . 
     When the blower wheel elements  5   a ,  5   b  are assembled together, for example axially:
         between them, the bottom  9   a  and the lid  9   b  provide at least one inlet pipe  20   a  and at least one outlet pipe  20   b , and, if required, the intermediate channels  33   a - 33   b  as shown.   between them, the blade portions  10   a ,  10   b  provide the first channel or channels  21   a  and the last channel or channels  21   b  that are respectively allocated to them. It should be noted that the baffles  34  and/or the protrusions  35  provided inside the channels  21   a ,  21   b  are advantageously formed by molding in conjunction with the formation of the blower wheel elements  5   a ,  5   b.      between them, the crown portions  11   a ,  11   b  provide the peripheral channel or channels  29  or peripheral channel portion  29 , and, if required, the first and second peripheral channel or channels  32   a ,  32   b.          

     Regardless of the embodiment shown above, it should be noted that each blade  10  has a curved profile, in the radial direction of the blower wheel  5 . The suction side and the pressure side of each blade  10  form blade walls that are inclined relative to the rotational axis A of the blower wheel  5 . 
     Diagrams (m) to (o) of  FIG. 8  respectively show various embodiments of a cooling system  2  according to the present invention. The heat transfer fluid Fe circulates along or in the component  1  in order to collect calories released by this component  1  during operation. The heat transfer fluid Fe circulates through the conveying circuit  4  between the component  1 , a heat exchanger  8  and the blower wheel  5  of the motor-fan assembly  3 . 
     According to the embodiment in diagrams (n) or (o), the heat exchanger  8  can be used as a radiator  8   a ,  8   b , or indeed as a condenser  8   c , or indeed as a combination of these means. 
     More particularly, the heat exchanger  8  is used at least as a main radiator  8   a , in particular dedicated to cooling the component  1 , through which the heat transfer fluid Fe conveyed to the blower wheel  5  circulates. The main radiator  8   a  can be a high-temperature or low-temperature radiator. The heat exchanger  8  can also be used as an auxiliary radiator  8   b  dedicated to cooling an auxiliary component  1 . 
     The radiator or radiators  8   a ,  8   b , and optionally the condenser  8   c , are arranged consecutively one after another in the direction of movement of the air flow Fx, in particular parallel to their general plane. The air flow Fx generated by the motor-fan assembly  3  passes consecutively through the condenser  8   c , if it is present, the auxiliary low-temperature radiator  8   b , if it is present, then the main radiator  8   a , referred to as the high-temperature radiator. The air flow Fx can be generated by blowing, as shown in diagrams (m) to (o). In this embodiment, the air flow Fx is pushed by the blower wheel  5  towards the heat exchanger or exchangers, the blower wheel  5  being arranged in front of the exchangers. According to another embodiment, the air flow Fx can be generated by suction. In this embodiment, the air flow Fx is sucked by the blower wheel  5  through the heat exchanger or exchangers, the blower wheel  5  being arranged after the heat exchangers, in particular between them and the component  1 . 
     For example, in diagram (m), the heat exchanger  8  comprises only the main low-temperature radiator  8   a , for example. However, it should be understood that, according to the embodiment shown in diagram (m), the main radiator  8   a  can also be a high-temperature radiator. 
     According to the example shown in diagram (n), the heat exchanger  8  comprises the main radiator  8   a , the auxiliary radiator  8   b , and indeed, additionally, the condenser  8   c . This condenser  8   c  is then arranged facing the motor-fan assembly  3 . The auxiliary radiator  8   b  is a low-temperature radiator, interposed between the high-temperature radiator  8   a  and the condenser  8   c , if it is present. The air flow Fx is generated by blowing and passes consecutively through the condenser  8   c , the auxiliary radiator  8   b  and then the main radiator  8   a.    
     According to the variant in diagram (n), the conveying circuit comprises the high-temperature radiator  8   a  and the blower wheel  5 . 
     According to the variant in diagram (o), the conveying circuit comprises the low-temperature radiator  8   b  and the blower wheel  5 . 
     In all of the diagrams of  FIG. 8 , the implementation of the motor-fan assembly  3  is controlled by control means  36 . The control means  36  process various pieces of information based on which the control means  36  control the operation of the motor-fan assembly  3 . Such control essentially concerns the possibilities in terms of activating the motor-fan assembly  3 , and optionally the speed of rotation of the blower wheel  5 . 
     For reference purposes, results of obtained measurements are provided below, taking into account:
         the physical characteristics of the air flow Fx, the density of which is, for example, 0.9 kg/s, and the temperature of which measured upstream of the first exchanger, either the heat exchanger  8   a  or the condenser  8   c , is 40° C.   a high-temperature radiator  8   a  with a power of between 30 kW and 31 kW, which can be used as the main radiator  8   a . For this radiator, the heat transfer fluid Fe is considered to enter the radiator at a temperature of the order of 107° C.   a low-temperature radiator  8   b  with a power of between 5 kW and 6 kW, which can be used as the auxiliary radiator  8   b . For this radiator, the heat transfer fluid Fe is considered to enter the radiator at a temperature of the order of 65° C.   a condenser  8   c  with a power of between 8 kW and 9 kW.       

     According to these hypotheses, it has been observed that, at the outlet of the high-temperature radiator  8   a , the temperature of the heat transfer fluid Fe is of the order of 98° C. It has also been observed that, at the outlet of the low-temperature radiator  8   b , the temperature of the heat transfer fluid Fe is of the order of 52° C. 
     If the condenser  8   c  is present, as shown in diagrams (n) and (o) of  FIG. 8 , the temperature of the air flow Fx downstream from the condenser  8   c  is of the order of 48° C. If the radiator that follows it in the direction of the air flow Fx is a single radiator, the temperature of the air flow Fx downstream from this radiator is of the order of 53° C. In this case, it is understood that this radiator constitutes the main radiator  8   a  or the auxiliary radiator  8   b . If, in the direction of movement of the air flow Fx, the high-temperature radiator  8   a  follows the low-temperature radiator  8   b , as shown in diagram (n) or (o), the temperature of the air flow Fx downstream from the high-temperature radiator is of the order of 82° C. In this case, it is understood that the low-temperature radiator constitutes the auxiliary radiator  8   b  and that the high-temperature radiator constitutes the main radiator  8   a.    
     In diagrams (a) and (b) of  FIG. 9  and in diagrams (f) to (h) of  FIG. 12 , another motor vehicle component  1  is provided with a cooling system  2  that cools by heat exchange between a heat transfer fluid Fe and an air flow Fx. The component  1  to be cooled is potentially:
         an internal combustion engine, a turbocompressor or an air-conditioning loop and, generally, any components of the power train of the vehicle provided by a combustion drive system, and/or   an electric motor and, generally, any components of the power train of the vehicle provided by an electric drive system, and/or   one or more power electronic components, in cases where the vehicle&#39;s propulsion is provided by an electric drive system, a combustion drive system or a hybrid drive system combining a combustion drive system and an electric drive system.       

     It should be noted that the examples listed above of applications of the present invention are mentioned for reference purposes, and should not be considered to be exhaustive. Indeed, the present invention can be applied to the cooling, by heat exchange by means of a heat transfer fluid, of at least one of any motor vehicle component that needs to be cooled. 
     In this context, the system  2  for cooling the component  1  implements a motor-fan assembly  3  setting in motion an air flow Fx that passes through a heat exchanger  8  intended to dissipate calories generated by the component  1 . Such a heat exchanger can, for example, be in the form of at least one main radiator  8   a  preferably helping cool the component  1 . The heat exchanger can also, for example, be formed by a gas cooler or a condenser of an air-conditioning loop. 
     The cooling system  2  also implements a circuit  4  for conveying a heat transfer fluid Fe between the component  1  and a hydraulic circuit incorporated into the stator of the electric motor. The stator that is the subject matter of the invention provides heat exchange between its external environment and the heat transfer fluid Fe circulating through it. 
     According to the present invention, the stator  7   a  of an electric motor  7  equipping the motor-fan assembly  3  acts as a heat exchanger arranged to dissipate the calories present in a heat transfer fluid Fe in an air flow Fx. The stator  7   a  cooperates with a rotor  7   b  provided with a drive shaft for rotating the blower wheel  5 . It should be noted that the hydraulic circuit incorporated into the stator  7   a , described below with reference to diagrams (c) to (e) of  FIG. 11 , is not shown in the diagrams of  FIG. 9  and  FIG. 12 , in order not to overload these figures. 
     Referring more specifically to diagrams (a) and (b) of  FIG. 9 , the motor-fan assembly  3  essentially comprises a base  6  carrying the electric drive motor  7  for rotating the blower wheel  5 . The base  6  constitutes a member for mounting the motor-fan assembly  3  on a structural element of the vehicle. 
     The electric motor  7  is provided with means  7   c  for electrical connection to a power source of the vehicle. The electric motor  7  comprises the stator  7   a  and the rotor  7   b  mounted coaxially along the rotational axis A of the rotor  7   b  and the blower wheel  5 . The rotor  7   b  carries the blower wheel  5  and the stator  7   a  is attached to the base  6 , for example via fastening brackets  7   d.    
     In the diagrams of  FIG. 9  and  FIG. 12 , the cooling system  2  essentially comprises the component  1 , the circuit for conveying the heat transfer fluid, the stator  7   a  of the invention and, optionally, one or more heat exchangers. The calories released by the component  1  as a result of its increase in temperature are transferred by the conveying circuit  4  to the hydraulic circuit incorporated into the stator  7   a  of the motor-fan assembly  3 . At least some of these calories are dissipated in the air flow Fx by this stator  7   a  of the invention. The heat transfer fluid Fe can also be conveyed to a heat exchanger  8 , for example used as a radiator  8   a  to dissipate the calories from said heat transfer fluid in the air flow Fx. The heat transfer fluid Fe can be conveyed into the heat exchanger  8  and into the stator  7   a  in series or in parallel, and the heat exchanger  8  can be upstream or downstream of the stator  7   a , depending on the direction of circulation of the fluid Fe. 
     In diagram (a) of  FIG. 9 , the conveying circuit  4  comprises an upstream pipe  16  for conveying the heat transfer fluid Fe from the component  1  to the stator  7   a  of the motor-fan assembly  3 , and a downstream pipe  17  conveying the heat transfer fluid Fe from the stator  7   a  to this component  1 . 
     In diagram (b) of  FIG. 9  and in diagrams (f) to (h) of  FIG. 12 , the conveying circuit  4  comprises a first portion  16   a ,  17   a  and a second portion  16   b ,  17   b . The first portion  16   a ,  17   a  extends between the component  1  and the heat exchanger  8 . The second portion  16   b ,  17   b  extends between the heat exchanger  8  and the stator  7   a.    
     In this context, the component  1  is cooled by the heat exchanger  8  and/or by the stator  7   a  according to the invention. 
     In diagram (b) of  FIG. 9 , the heat exchanger  8  and the stator  7   a  are mounted in series on the circuit  4  for conveying the fluid. In this case, the two pipes forming the second portion  16   b ,  17   b  connect the heat exchanger  8  and the hydraulic circuit incorporated into the stator  7   a.    
     In  FIG. 10 , the stator  7   a  comprises, at its periphery, a recessed ring  50  provided with a fluid inlet pipe  18   a  for the heat transfer fluid Fe to enter the stator  7   a . The ring is also provided with a fluid discharge pipe  18   b  for discharging the heat transfer fluid Fe out of the stator  7   a . The stator  7   a  also comprises a shaft  51  providing an axial passage for the rotor  7   b . The stator  7   a  is also equipped with a cooling unit  52  intended to dissipate the calories from the heat transfer fluid Fe in the air flow Fx. 
     In diagrams (a) and (b) of  FIG. 9 , and in diagrams (c), (d) and (e) of  FIG. 11 , the cooling unit  52  is arranged as a plurality of fins  52   b  distributed radially relative to the axially extending axis A of the stator  7   a , or in other words relative to the rotational axis A of the rotor  7   b.    
     Diagrams (c), (d) and (e) of  FIG. 11  respectively show various arrangement examples of the hydraulic circuit  31   a ,  31   b  and  31   c  provided inside the stator  7   a . At least one first annular channel  50   a  extends at least partially around the ring  50 . In order to provide the hydraulic circuit  31   a ,  31   b  and  31   c , the component or components  50 ,  51  and/or  52   b  of the stator  7   a  are arranged, individually or together, as double shells assembled together axially, in particular by sealing. 
     In diagram (c) of  FIG. 11 , the ring  50  is provided with a single first annular channel  50   a  constituting the hydraulic circuit  31   a . The stator  7   a  comprises an inner radial partition  49   a  in order to cause the heat transfer fluid Fe to move in the direction S of circulation along the first annular channel  50   a . The inlet pipe  18   a  and the discharge pipe  18   b  open on the first annular channel  50   a  to either side of the radial partition  49   a . In this case, the hydraulic circuit  31   a  is constituted by a single first annular channel  50   a , the stator  7   a  thus formed then acting as a heat exchanger exchanging heat between the heat transfer fluid Fe and the air flow Fx outside the stator. 
     In diagram (d) of  FIG. 11 , the ring  50  is provided with a plurality of concentric annular partitions  49   b . Between them, the annular partitions  49   b  consecutively provide, two by two, a plurality of first annular channels  50   a  that constitute the hydraulic circuit  31   b . Fluid passages  13  are provided through the annular partitions  49   b  in order to allow the heat transfer fluid Fe to flow consecutively between the first annular channels  50   a . The inlet pipe  18   a  opens on a first annular channel  50   a  referred to as the upstream annular channel and the discharge pipe  18   b  opens on a first annular channel  50   a  referred to as the downstream annular channel. The concepts of upstream and downstream should be understood according to the direction S of circulation of the fluid through the stator  7   a . In this case, the hydraulic circuit  31   b  is constituted by a plurality of first annular channels  50   a  connected together consecutively, the stator  7   a  thus formed then acting as a heat exchanger exchanging heat between the heat transfer fluid Fe and the air flow Fx outside the stator. 
     In diagram (e) of  FIG. 11 , the stator  7   a  is provided with the cooling unit  52  interposed between the ring  50  and the shaft  51  and comprising a plurality of radial channels  14 . The ring  50  comprises radial partitions  49   a  which, between them, consecutively provide a plurality of external annular channels  50   a  aligned with one another in an annular manner. Moreover, the fins  52   a  are used to extend the hydraulic circuit  31   c . To this end, the cooling unit  52  comprises radial channels  14  extending inside the fins  52   a.    
     The radial channels  14  open, at their distal end, on the external annular channels  50   a . The radial channels  14  also open, at their proximal end, on internal annular channels  51   a  provided inside a cylindrical wall  59  delimiting the shaft  51 . The internal recess of the cylindrical wall  59  is segmented by radial partitions  49   a  distributed radially around the axis A in the recess of the cylindrical wall  59 . In this way, a plurality of internal annular channels  51   a  is formed, forming chambers that bring two adjacent radial channels  14  into communication. 
     The heat transfer fluid Fe circulates from an external annular channel  50   a , referred to as the first external annular channel, connected to the inlet pipe  18   a , to a first radial channel  14 . The heat transfer fluid Fe then circulates through an internal annular channel  51   a , referred to as the first internal annular channel, then through a second radial channel  14  provided inside a fin adjacent to the first fin  52   a  comprising the first radial channel  14 . The heat transfer fluid Fe then enters another external annular channel  50   a  that sends the heat transfer fluid Fe on again to another internal annular channel  51   a  via a radial channel  14 . This arrangement for circulating the heat transfer fluid Fe through the stator  7   a  is repeated successively until the fluid enters a last radial channel  14  opening on a last external annular channel  50   a  connected to the discharge pipe  18   b.    
     The hydraulic circuit  31   c  thus consists of a plurality of consecutive sets of channels  50   a ,  14 ,  51   a . Each set of channels consists consecutively of an external annular channel  50   a , a radial channel  14  of a fin  52   a , and an internal annular channel  51   a.    
     It should be noted that other variants not shown here can be implemented from sets of channels similar to the hydraulic circuit  31   c  shown in diagram (e) of  FIG. 11 . For example, the inlet pipe  18   a  can be connected to one or more external annular channels  50   a  and the discharge pipe  18   b  can be connected indiscriminately to one or more external annular channel  50   a . The discharge pipe  18   b  can also be connected directly or by means of a radial channel to one or more internal annular channels  51   b . For example, the inlet pipe  18   a  can be connected to an internal annular channel  51   a  and the discharge pipe  18   b  can be connected indiscriminately to an external annular channel  50   a  or to an internal annular channel  51   b.    
     Diagrams (f) to (h) of  FIG. 12  show various embodiments of a cooling system  2  according to the present invention. The heat transfer fluid Fe circulates along or in the component  1  in order to collect calories released by this component  1  during operation. The heat transfer fluid Fe circulates through the conveying circuit  4  between the component  1 , a heat exchanger  8  and the stator  7   a  of the motor  7  constituting the motor-fan assembly  3 . 
     According to the embodiment in diagrams (g) or (h), the heat exchanger  8  can be used as a radiator  8   a ,  8   b , or indeed as a condenser  8   c , or indeed as a combination of these means. 
     More particularly, the heat exchanger  8  is used at least as a main radiator  8   a , in particular dedicated to cooling the component  1 , through which the heat transfer fluid Fe conveyed to the stator  7   a  circulates. The main radiator  8   a  can be a high-temperature or low-temperature radiator. The heat exchanger  8  can also be used as an auxiliary radiator  8   b  dedicated to cooling an auxiliary component  1 . 
     The radiator or radiators  8   a ,  8   b , and optionally the condenser  8   c , are arranged consecutively one after another in the direction of movement of the air flow Fx, in particular parallel to their general plane. The air flow Fx generated by the motor-fan assembly  3  passes consecutively through the condenser  8   c , if it is present, the auxiliary low-temperature radiator  8   b , if it is present, then the main radiator  8   a , referred to as the high-temperature radiator. The air flow Fx can be generated by blowing, as shown in diagrams (f) to (h). In this embodiment, the air flow Fx is pushed by the blower wheel  5  towards the heat exchanger or exchangers, the blower wheel  5  being arranged in front of the exchangers. According to another embodiment, the air flow Fx can be generated by suction. In this embodiment, the air flow Fx is sucked by the blower wheel  5  through the heat exchanger or exchangers, the blower wheel  5  being arranged after the heat exchangers, in particular between them and the component  1 . 
     For example, in diagram (f), the heat exchanger  8  comprises only the main low-temperature radiator  8   a , for example. However, it should be understood that, according to the embodiment shown in diagram (f), the main radiator  8   a  can also be a high-temperature radiator. 
     According to the example shown in diagram (g), the heat exchanger  8  comprises the main radiator  8   a , the auxiliary radiator  8   b , and indeed, additionally, the condenser  8   c . This condenser  8   c  is then arranged facing the motor-fan assembly  3 . The auxiliary radiator  8   b  is a low-temperature radiator, interposed between the high-temperature radiator  8   a  and the condenser  8   c , if it is present. The air flow Fx is generated by blowing and passes consecutively through the condenser  8   c , the auxiliary radiator  8   b  and then the main radiator  8   a.    
     According to the variant in diagram (g), the conveying circuit comprises the high-temperature radiator  8   a  and the stator  7   a.    
     According to the variant in diagram (h), the conveying circuit comprises the low-temperature radiator  8   b  and the stator  7   a.    
     In all of the diagrams of  FIG. 12 , the implementation of the motor-fan assembly  3  is controlled by control means  36 . The control means  36  process various pieces of information based on which the control means  36  control the operation of the motor-fan assembly  3 . Such control essentially concerns the possibilities in terms of activating the motor-fan assembly  3 , and optionally the speed of rotation of the blower wheel  5 .