Patent Publication Number: US-2023147766-A1

Title: Ventilation device module for a motor vehicle cooling module, ventilation device comprising such a module, and cooling module for a motor vehicle comprising such a ventilation device

Description:
TECHNICAL FIELD 
     The invention relates to a ventilation device for a motor vehicle cooling module and to a cooling module for a motor vehicle, in particular electric, comprising such a ventilation device. The invention also relates to a motor vehicle provided with such a cooling module. 
     PRIOR ART 
     Motor vehicles, whether of the combustion engine or electric motor type, have to discharge the heat generated by their operation, and are provided with heat exchangers for this purpose. A motor vehicle heat exchanger generally comprises tubes, in which a heat transfer fluid, in particular a liquid such as water, is intended to circulate, and heat exchange elements connected to these tubes, often designated by the term “fins”. The fins are used to increase the exchange surface between the tubes and the ambient air. 
     However, in order to further increase the heat exchange between the heat transfer fluid and the ambient air, a ventilation device is often used in addition, to generate or increase a flow of air directed toward the tubes and the fins. 
     In a known manner, such a ventilation device comprises a blower-wheel fan. 
     The air flow generated by the blades of such a fan is turbulent, in particular because of the circular geometry of the blower wheel, and generally reaches only part of the surface of the heat exchanger (the circular region of the exchanger that faces the blower wheel of the fan). The exchange of heat is therefore not uniform across the entire surface of the tubes and of the fins. 
     In addition, when it is not necessary for the fan to be switched on (typically when the exchange of heat with non-accelerated ambient air is sufficient to cool the heat transfer fluid circulating in the exchanger), the blades partially obstruct the flow of the ambient air toward the tubes and the fins, thus impeding the circulation of air toward the exchanger and thus limiting the exchange of heat with the heat transfer fluid. 
     Such a fan also has a relatively large footprint, in particular because of the dimensions of the blower wheel that are necessary in order to obtain effective engine cooling, and this makes incorporating it into a motor vehicle a lengthy and difficult process. 
     The object of the invention is to at least partially overcome these drawbacks. 
     SUMMARY OF THE INVENTION 
     To this end, the invention relates to a ventilation device module for a motor vehicle cooling module, comprising at least one, preferably a single, tangential turbomachine comprising a bladed wheel and a motor for rotating the bladed wheel, a frame forming an opening, preferably a single opening, and shut-off means suitable for selectively shutting off the opening, the shut-off means having at least two regions which are in contact in a position in which the shut-off means leave the opening clear and are separated in a position in which the opening is shut off. 
     A ventilation device module thus advantageously has a reduced footprint, making it easier to incorporate into a motor vehicle. 
     In addition, the position in which the shut-off means leaves the opening in the frame clear makes it possible to reduce the pressure losses of the air flow passing through the cooling module, in particular when the tangential turbomachine does not need to be switched on. 
     According to another aspect, the shut-off means comprise a covering body suitable for being wound on itself about an axis, in order to leave the opening clear. 
     According to another aspect, the module comprises a motor rotating a shaft fastened to the covering body, so that the rotation of the motor winds the covering body around the shaft. 
     According to another aspect, the module further comprises winders, connected to the covering body by means of cables, the winders elastically urging the covering body towards the position in which the opening is shut off. 
     According to another aspect, the movement of the covering body relative to the frame is guided, and in particular the covering body is received in a groove in the frame. 
     According to another aspect, the covering body is flexible. 
     According to another aspect, the covering body is a single piece, in the form of a flexible sheet, suitable for covering the opening. 
     According to another aspect, the tangential turbomachine includes an air guiding portion and an air outlet from the ventilation device module. 
     According to another aspect, the tangential turbomachine includes an air guiding portion and an air outlet from the ventilation device module. 
     The invention also relates to a ventilation device for a motor vehicle cooling module, comprising at least one ventilation device module as described above. 
     According to another aspect, the device comprises two ventilation device modules, each ventilation device module defining a separate opening. 
     According to another aspect, the turbomachines of the two ventilation device modules are arranged so that the air outlet of the turbomachine of a first ventilation device module is positioned facing the air outlet of the turbomachine of the second ventilation device module. 
     According to another aspect, the turbomachines of the two ventilation device modules are arranged so that the air outlet of the turbomachine of a first ventilation device module is positioned facing the guiding portion of the turbomachine of the second ventilation device module. 
     According to another aspect, the turbomachines of the two ventilation device modules are arranged so that the guiding portion of the turbomachine of a first ventilation device module is positioned facing the guiding portion of the turbomachine of the second ventilation device module. 
     The invention also relates to a cooling module for a motor vehicle, particularly having an electric motor, comprising at least one heat exchanger, and a ventilation device as described above, suitable for creating an air flow through the at least one heat exchanger. 
     According to another aspect, the volute of each turbomachine comprises a shell consisting of a wall configured to house the bladed wheel and guide the air around the turbomachine to an air outlet, intended to be an air outlet from the cooling module. 
     According to another aspect, said wall is in the shape of a truncated spiral. 
     According to another aspect, the module comprises a protective grille, preferably fastened to said opening. 
     According to another aspect, the frame defines an opening, intended to be positioned facing, in a longitudinal direction of the vehicle, at least part of the heat exchanger of the cooling module. Alternatively, the opening can be intended to be positioned facing a specific heat exchanger. 
     According to another aspect, the frame comprises a cross-member, which extends on one side of the opening, opposite the side on which the turbomachine is situated. 
     According to another aspect, the cross-member extends in a transverse direction of the vehicle. 
     According to another aspect, the covering body can have a limited thickness. 
     According to another aspect, the covering body is air-tight. 
     According to another aspect, the covering body takes the form of a flexible sheet, the sheet preferably being a single piece. 
     According to another aspect, the shaft configured to be rotated by the motor extends in the vicinity of a first end of the opening, in the vicinity of said at least one turbomachine. 
     According to another aspect, the shaft preferably extends in the vicinity of a first end of the opening, in the vicinity of the first or the second turbomachine. 
     According to another aspect, the covering body is fastened at one end to a bar. 
     According to another aspect, the bar is mounted slidably on the frame. 
     According to another aspect, a groove is made in the frame, on each side thereof. 
     According to another aspect, each groove receives a spur of the bar. 
     According to another aspect, the covering body is also received in these grooves on each side of the frame. 
     According to another aspect, the bar is connected, in particular by two cables, to at least one winder. 
     According to another aspect, the winder is mounted elastically urged to rotate towards a position in which the cables are wound in the associated winder. 
     According to another aspect, the cables are arranged so that they are wound on pulleys provided in each case between the cross-member and a winder. 
     According to another aspect, the module is configured so that, in the fully wound position of the cables, the covering body fully covers the opening. 
     According to another aspect, the covering body forms an angle of between 5° and 20°, preferably substantially equal to 12.5°, with an air intake surface, normal to the flow of air entering the ventilation device. 
     According to another aspect, the device comprises two modules, and the frame of the ventilation device is made from a single, integral part, a cross-member preferably separating the openings of each module, or alternatively, the frame of the ventilation device is formed by frames of the separate modules, fastened together. 
     According to another aspect, the turbomachines are positioned so that they are dedicated to respective exchangers. 
     According to another aspect, the device is configured so that the openings can be just partially shut off. 
     According to another aspect, the device is configured so that the openings of the two modules can be fully or partially shut off independently of each other. 
     According to another aspect, the device is configured to make it possible to allow part of an air flow through the opening of a module having smaller dimensions, another part of the air flow being guided towards the turbomachine of another module. 
     According to another aspect, the covering body is made up of slats connected to each other by articulations so that the slats can be pivoted relative to each other. 
     According to another aspect, the covering body is arranged so that, in a position in which the opening is left clear, the covering body is wound around a shaft or retracted or folded back. 
     According to another aspect, the ventilation device  24  comprises two modules or a single module or more than two modules. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features, details and advantages of the invention will become apparent upon reading the detailed description below, and upon analyzing the appended drawings, in which: 
         FIG.  1    schematically depicts the front part of a motor vehicle, viewed from the side; 
         FIG.  2    is a schematic perspective view of a first example of a cooling module, which can be implemented in the motor vehicle in  FIG.  1   , comprising a ventilation device in a first configuration in which two openings through the frame of the ventilation device are left clear; 
         FIG.  3    is a perspective view of a ventilation device module forming the ventilation device in  FIG.  3   , in a configuration in which an opening through its frame is left clear; 
         FIG.  4    is a perspective view of the ventilation device module in  FIG.  3   , in a configuration in which the opening through its frame is shut off; 
         FIG.  5    is a perspective view of the cooling module in  FIG.  2   , in a second configuration in which the openings through the frame of the ventilation device are shut off; 
         FIG.  6    is a longitudinal cross-sectional view of the ventilation module, in the configuration in  FIG.  5   ; 
         FIG.  7    is a similar view to  FIG.  5   , in a configuration in which the openings are partially clear; 
         FIG.  8    is a similar view to  FIGS.  6  and  7   , in another configuration of the ventilation device in which one opening in the frame is left clear while a second opening is shut off; 
         FIG.  9    is a schematic perspective view of a second example of a cooling module, which can be implemented in the motor vehicle in  FIG.  1   ; 
         FIG.  10    is a schematic perspective view of a third example module of a cooling module, which can be implemented in the motor vehicle in  FIG.  1   . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the remainder of the description, elements that are identical or perform identical functions have been designated with the same reference sign. In the present description, for the sake of conciseness, these elements are not described in detail in each embodiment. Rather, only the differences between the variant embodiments are described in detail. 
     The figures show a frame of reference (X, Y, Z). The direction X corresponds to a longitudinal direction of forward travel of the motor vehicle. The transverse direction Y is defined as being perpendicular to the longitudinal direction X. More specifically, the longitudinal X and transverse Y directions can for example belong to a horizontal plane. The direction Z corresponds to a vertical direction. 
       FIG.  1    schematically illustrates the front part of a motor vehicle  10  with a motor  12 . The vehicle  10  includes in particular a body  14  and a bumper  16  that are carried by a chassis (not shown) of the motor vehicle  10 . The body  14  defines a cooling opening  18 , that is, an opening through the body  14 . The cooling opening  18  can be a single opening as in the example illustrated. Alternatively, however, the body  14  can define a plurality of cooling openings. Here, the cooling opening  18  is situated in the lower part of the front face  14   a  of the body  14 . In the example illustrated, the cooling opening  18  is situated below the bumper  16 . A grille  20  can be positioned in the cooling opening  18  to prevent projectiles from being able to pass through the cooling opening  18 . A cooling module  22  is positioned facing the cooling opening  18 . The grille  20  in particular provides protection for this cooling module  22 . 
     The cooling module  22  is more clearly visible in  FIG.  2   . 
     The cooling module  22  comprises a ventilation device  24  associated with at least one heat exchanger  26 , in this case two heat exchangers  26 . 
     In this case, the two heat exchangers  26  are positioned one behind the other in the longitudinal direction X. Here, the two heat exchangers  26  are identical. Each heat exchanger  26  is generally in the shape of a parallelepiped, the length of which extends parallel to the transverse direction Y, the depth of which extends parallel to the longitudinal direction X, and the height of which extends parallel to the vertical direction Z. Each heat exchanger  26  defines a substantially rectangular surface S, known as the working surface, extending in a plane (Y, Z). The surface S is defined by two opposite sides  26 - 1 ,  26 - 2  corresponding to the length of the exchanger  26  in question, and by another two opposite sides corresponding to the height of the exchanger  26  in question. 
     It will be noted that the invention is not limited to a particular number of heat exchangers, or to configurations comprising identical heat exchangers only. It is thus possible to juxtapose several heat exchangers vertically and/or horizontally, in which case the height of the surface S is the sum of the heights of the vertically juxtaposed exchangers, and the length of the surface S is the sum of the lengths of the horizontally juxtaposed exchangers. 
     In addition, here the ventilation device  24  is formed by two ventilation device modules  100 - 1 ,  100 - 2 , of the type illustrated in  FIGS.  3  and  4   . 
     The module  100 - 1  in  FIGS.  3  and  4    will be described in greater detail below, the module  100 - 2  being similar. Unless otherwise stated, the elements of the second module  100 - 2  that are identical to the elements of the first module  100 - 1 , have the same reference sign in the figures, with the suffix “-2” instead of the suffix “-1”. 
     As can be seen in  FIG.  3   , the module  100 - 1  comprises a tangential fan  28 - 1 , or more generally a tangential turbomachine, intended to suck in a flow of air in contact with the heat exchangers  26  of the cooling module  22 . Of course, the invention is not limited to this configuration, and the turbomachine can be mounted as a blower, in which case the ventilation device is placed between the radiator grille and the exchangers. 
     The tangential turbomachine  28 - 1  comprises a rotor  32 - 1 . Here, the rotor consists of a turbine  32 - 1 , more specifically a tangential blower-wheel or bladed wheel. The turbine  32 - 1  has a cylindrical shape. The turbine  32 - 1 ,  32 - 2  advantageously includes several stages of blades (or vanes). The turbine  32 - 1  is rotatably mounted about an associated axis of rotation A 32 - 1 . The turbine  32 - 1  is rotated by an associated motor  33 - 1 . Here, the axis of rotation A 32 - 1  of the turbine  32 - 1  is oriented in the direction of the Y axis. 
     The module  100 - 1  also includes a frame  30 - 1  forming an internal air channel. The frame  30 - 1  makes it possible to house the turbine  32 - 1 . In one embodiment, a rear portion of the frame  30 - 1  forms the volute of the tangential turbomachine  28 - 1 . 
     Here, the volute of the turbomachine  28 - 1  comprises a shell  40 - 1  consisting of a wall  42 - 1  configured to house the bladed wheel  32 - 1  and guide the air around the turbomachine  28 - 1  to an air outlet  46 - 1 , intended to be an air outlet from the cooling module  22 . In a known manner, the wall  42 - 1  is in the shape of a truncated spiral. 
     Advantageously, a grille is fastened to the outlet  46 - 1 . Such a grille makes it possible in particular to prevent projectiles from entering the housing receiving the turbine  32 - 1  and damaging said turbine  32 - 1 . 
     As illustrated in  FIG.  3   , in particular, the frame  30 - 1  defines an opening  60 - 1 , intended to be positioned facing, in a longitudinal direction X, at least part of the heat exchanger  26  of the cooling module  22 . Alternatively, however, the opening  60 - 1 ,  60 - 2  can be intended to be positioned facing a specific heat exchanger  26 . 
     The frame  30 - 1  comprises a cross-member  61 - 1 , which extends on one side of the opening  60 - 1 , opposite the side on which the turbomachine  28 - 1  is situated. Here, the cross-member  61 - 1  extends substantially in the transverse direction Y. 
     The module  100 - 1  illustrated in  FIGS.  3  and  4    further includes shut-off means  62 - 1  for shutting off the opening  60 - 1 . The shut-off means  62 - 1  are suitable for selectively shutting off the opening  60 - 1 . Notably, here, the shut-off means  62  are configured to have at least two regions  63 - 1 ,  65 - 1 , which are in contact in a position in which the shut-off means  62 - 1  leave the opening  60 - 1  clear and are separated in a position in which the opening  60 - 1  is shut off. 
     For example, in  FIG.  6   , the region  63 - 1  is not touching the region  65 - 1 , as the shut-off means  62 - 1  are in the closed position. In the open position (not shown), these two regions would be in contact with each other. The same applies to the shut-off means  62 - 2 , which comprise two similar regions  63 - 2  and  65 - 2 . 
     Here, the shut-off means  62  essentially include a covering body  64 - 1 , here in the form of a sheet, fastened at one end to a bar  66 - 1 . The covering body  64 - 1  is for example made from plastic. The covering body  64 - 1  is preferably flexible relative to the bar  66 - 1 . The covering body  64 - 1  can have a limited thickness. The covering body  64 - 1  is advantageously air-tight. Here, the covering body  64 - 1  takes the form of a flexible sheet, the sheet preferably being a single piece. At its opposite end to the bar  66 - 1 , the covering body  64 - 1  is fastened to a shaft  68 - 1 , connected to a motor  70 - 1 . The rotation of the motor  70 - 1  can thus control the winding of the covering body  64 - 1  around the shaft  68 - 1 . The shaft  68 - 1  preferably extends in the vicinity of a first end of the opening  60 - 1 , in the vicinity of the first or the second turbomachine  28 - 1  respectively. The shaft  68 - 1  extends parallel to the direction Y, like the axis A 32 - 1  of the turbomachine  28 - 1 . 
     The bar  66 - 1  is slidably mounted on the frame  30 - 1  of the module  100 - 1 . Here, to this end, a groove is made in the frame  30 - 1 , on each side thereof. Each groove receives a spur of the bar  66 - 1 . Advantageously, the covering body  64 - 1  is also received in these grooves on each side of the frame  30 - 1 . 
     In addition, the bar  66 - 1  is connected by two cables  72  to a winder  73 - 1 ,  74 - 1 , elastically urged to rotate towards a position in which the cables  72  are wound in the associated winder  73 - 1 ,  74 - 1 . The winders  73 - 1 ,  74 - 1  are preferably positioned in the vicinity of the shaft  68 - 1 , the cables  72  being wound on pulleys  75 - 1  provided in each case between the bar  66 - 1  and a winder  73 - 1 ,  74 - 1 . In the position in which the cables  72  are fully wound in the winders  73 - 1 ,  74 - 1 , the covering body  64 - 1  thus fully covers the opening  60 - 1 , as illustrated in  FIG.  3   . 
     The motor  70 - 1  controls the winding of the covering body  64 - 1  around the shaft  68 - 1 , to leave the opening  60 - 1  clear, against the force of the winders  73 - 1 ,  74 - 1 . In the absence of any action by the motor  70 - 1 , the winders  73 - 1 ,  74 - 1  make it possible to wind the cables  72  and return the covering body  64 - 1  to the position in which it shuts off the associated opening  60 - 1 . Intermediate configurations, between the fully shut-off position of the opening  60 - 1  and the fully retracted configuration of the covering body  64 - 1  leaving the opening  60 - 1  completely clear, are possible. These intermediate configurations can be transient, during the transition from one extreme configuration to the other, or maintained over time. 
     As can be seen in  FIG.  6   , in the shut-off position, the covering body  64 - 1 ,  64 - 2  forms an angle α 1 , α 2  of between 5° and 20°, preferably substantially equal to 12.5°, with an air intake surface S 2 - 1 , S 2 - 2 , normal to the flow of air entering the ventilation device  22 . 
     As stated above, the ventilation device illustrated in  FIGS.  2  and  5  to  8    is made up of two modules  100 - 1 ,  100 - 2  of the type described above. 
     Here, the two modules  100 - 1  and  100 - 2  are associated so that the frame  30  of the ventilation device  24  is made up of a single, integral part, a cross-member  61  separating the openings  60 - 1 ,  60 - 2 . In other words, here, the frames  30 - 1 ,  30 - 2  of the two modules  100 - 1 ,  100 - 2  are formed by a single frame  30  of the ventilation device  24  and a cross-member  61  separating the two openings  60 - 1 ,  60 - 2 . According to an alternative embodiment, however, the frame  30  of the ventilation device  24  can be formed by frames  30 - 1 ,  30 - 2  of the separate modules  100 - 1 ,  100 - 2 , fastened together. 
     Here, the two modules  100 - 1 ,  100 - 2  are positioned so that the first and second turbomachines  28 - 1 ,  28 - 2  are mounted parallel to each other, that is, the air flow F 1  discharged from the first turbine  32 - 1  of the first turbomachine  28 - 1  is separate from the air flow F 2  discharged from the second turbine  32 - 2  of the second turbomachine  28 - 2 . In other words, the air flow F 1  discharged from the first turbine  32 - 1  does not pass through the second turbine  32 - 2 , and vice versa. 
     In this example, the two modules  100 - 1 ,  100 - 2  are positioned so that the axes of rotation A 32 - 1 , A 32 - 2  of the turbines  32 - 1 ,  32 - 2  are parallel to the direction Y. The two turbines  32 - 1 ,  32 - 2  are thus mounted horizontally, in this case in a transverse direction Y. Alternatively, the axes of rotation A 32 - 1 , A 32 - 2  can be vertical, namely parallel to the axis Z. 
     As is also evident from the figures, the axis of rotation A 32 - 1  of the turbomachine  28 - 1  of a first module  100 - 1 , is positioned substantially facing the upper longitudinal edge  26 - 1  of the surface S. The axis of rotation A 32 - 2  of the turbomachine  28 - 2  of the second module  100 - 2  is positioned substantially facing the lower longitudinal edge  26 - 2  of the surface S. 
     Nevertheless, depending on the configuration of the heat exchangers and/or the cooling power required for each exchanger, it is possible to position the turbomachines  28 - 1 ,  28 - 2  so that they are dedicated to respective exchangers  26 . Other relative positions of turbomachines  28 - 1 ,  28 - 2  are also possible. 
     According to the embodiment illustrated in  FIGS.  2  and  5  to  8   , the outlets  46 - 1 ,  46 - 2  of the turbomachines  28 - 1 ,  28 - 2  of the modules  100 - 1 ,  100 - 2  are positioned facing each other, oriented substantially towards the same point, but in opposite directions. This configuration ensures that a first air flow F 1  originating from the first turbomachine  28 - 1  via the associated first outlet  46 - 1  is moving substantially towards the same point and in an opposite direction to a second air flow F 2  originating from the second turbomachine  28 - 2  via the associated second outlet  46 - 2 . In this case, the first and second air flows F 1  and F 2  are substantially vertical. 
     Each turbomachine  28 - 1 ,  28 - 2  extends along the opening  60 - 1 ,  60 - 2  of the associated module  100 - 1 ,  100 - 2 . Each opening  60 - 1 ,  60 - 2  allows at least part of the air flow F that has passed through the heat exchanger(s)  26  to leave the cooling module  22  without passing through one of the turbomachines  28 - 1 ,  28 - 2 . The bypassing of the turbomachines  28 - 1 ,  28 - 2  by the air flow F that has passed through the exchanger(s)  26  makes it possible to limit the pressure losses of the air flow F, in particular when the turbomachines  28 - 1 ,  28 - 2  are switched off, for example when the motor vehicle  10  is travelling at high speed, the speed of the vehicle  10  being sufficient to create an air flow F allowing the cooling of the heat exchanger(s)  26 . 
     However, for example at low speed, it can be necessary to switch on one or both of the turbomachines  28 - 1 ,  28 - 2 . It is then useful to guide the air flow passing through the heat exchanger(s)  26  through the turbomachine(s)  28 - 1 ,  28 - 2  switched on. In this case, the openings  60 - 1 ,  60 - 2  can be shut off, the shutting off of the openings  60 - 1 ,  60 - 2  also making it possible to guide the air flow towards the turbomachines  28 - 1 ,  28 - 2 . 
     As illustrated in  FIG.  7   , the openings  60 - 1 ,  60 - 2  can be just partially shut off. 
     In addition, as illustrated in  FIG.  8   , the openings  60 - 1 ,  60 - 2  of the two modules  100 - 1 ,  100 - 2  can be fully or partially shut off, independently of each other. In other words, the shut-off means  62 - 1 ,  62 - 2  of the two modules  100 - 1 ,  100 - 2  are advantageously separate and/or independent. In  FIG.  8   , it is thus possible in particular for the opening  60 - 1  of one module  100 - 1  to be fully or partially shut off, while the opening  60 - 2  of the other module  100 - 2  is left fully or partially clear. 
     In the configuration in which the openings  60 - 1 ,  60 - 2  are shut off by the covering bodies  64 - 1 ,  64 - 2 , the covering bodies  64 - 1 ,  64 - 2  make it possible to direct the air flow created towards the turbomachine  28 - 1 ,  28 - 2  of the associated module  100 - 1 ,  100 - 2 . By contrast, in the configuration in which the covering bodies  64 - 1 ,  64 - 2  leave the openings  60 - 1 ,  60 - 2  of the two modules  100 - 1 ,  100 - 2  fully open, generally attained when the turbomachines  28 - 1 ,  28 - 2  are switched off, at least part of the air flow created, for example by the speed of the vehicle, on which the cooling module  22  is mounted, can be directed through the openings  60 - 1 ,  60 - 2  in the frame  30 , without passing through the turbomachines  28 - 1 ,  28 - 2 . The air flow is thus “diverted” from the turbomachines  28 - 1 ,  28 - 2 . An intermediate configuration can make it possible to cause part of the air flow to pass through the opening  60 - 1 ,  60 - 2  of a module  100 - 1 ,  100 - 2  having smaller dimensions, another part of the air flow being guided towards the turbomachine  28 - 1 ,  28 - 2  of a module  100 - 1 ,  100 - 2 . 
       FIG.  9    illustrates a second example of a ventilation device  24 , in which the two modules  100 - 1 ,  100 - 2  are arranged so that the air outlet  46 - 1  of the turbomachine  28 - 1  of a first module  100 - 1  is positioned facing the guiding portion  42 - 2  of the turbomachine  28 - 2  of the second module  100 - 2 . This thus limits the risk of the air flows F 1 , F 2  originating from the two turbomachines  28 - 1 ,  28 - 2  interfering with each other. 
       FIG.  10    illustrates a third example of a ventilation device  24 , in which the two modules  100 - 1 ,  100 - 2  are arranged so that the guiding portion  42 - 1  of the turbomachine  28 - 1  of a first module  100 - 1  is positioned facing the guiding portion  42 - 2  of the turbomachine  28 - 2  of the second module  100 - 2 . Here, the two air outlets  46 - 1 ,  46 - 2  of the two turbomachines  28 - 1 ,  28 - 2  are thus oriented in opposite directions, so that the risk of the air flows F 1 , F 2  originating from the two turbomachines  28 - 1 ,  28 - 2  interfering with each other is further reduced. 
     The invention is not limited to the examples described above. Rather, the invention can be the subject of numerous variants accessible to a person skilled in the art. 
     In particular, in the example illustrated, the covering body  64 - 1 ,  64 - 2  is a single piece. Alternatively, the covering body can be made up of slats connected to each other by articulations so that the slats can be pivoted relative to each other. 
     In addition, in the example illustrated, the covering body moves from the position in which the opening  60 - 1 ,  60 - 2  is shut off to the position in which the opening  60 - 1 ,  60 - 2  is left clear by being wound around a shaft. Alternatively, the covering body can be retracted or folded back. 
     Likewise, in the example illustrated, the ventilation device  24  comprises two modules  100 - 1 ,  100 - 2 . Alternatively, the ventilation device  24  can be made up of a single module  100 - 1 ,  100 - 2  or more than two modules  100 - 1 ,  100 - 2 .