Support frame holding arm

Abstract

Exemplary embodiments including a support frame for a ventilation device for cooling fluid passing through a cooling circuit of a motor vehicle are disclosed. The frame has an opening for receiving an impeller and a central support for receiving a motor actuating the impeller. The central support is attached to the frame by at least six retaining arms, at least three first retaining arms being placed in a first plane or cone of rotation and at least three second retaining arms being placed in a second plane or cone of rotation different from the first plane or cone of rotation. Each first retaining arm is separated from all second retaining arms by a space covering a distance corresponding at least to a chord of the first retaining arm.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of automobiles, and more specifically to the circulation of air for cooling an engine. BACKGROUND

[0002] According to the prior art, motor vehicles expel the thermal energy resulting from their operation, and are therefore equipped with heat exchangers, in particular cooling radiators, for example placed in the front of the vehicle, through which external air passes. In order to force the circulation of this air through the exchanger, a fan is placed upstream or downstream. A impeller can be used to force the circulation of air. In some examples, the impeller generates a relatively high flow rate and a relatively low pressure, and its flow is axially oriented, that is to say in the direction of the axis of rotation of the impeller. SUMMARY

[0003] The present description describes a support frame for a ventilation device for cooling a fluid circulating through a cooling circuit of a motor vehicle, said frame comprising an opening defining an opening perimeter for receiving an impeller, and a central support located at the center of said opening, the shape of which is arranged to receive a motor actuating said impeller so as to generate a ventilation airflow, said central support being attached to the frame by at least six retaining arms, at least three first retaining arms being placed in a first plane or cone of rotation (or cone herein), and at least three second retaining arms being placed in a second plane or cone of rotation different from the first plane or cone of rotation, the first retaining arms each being separated from any second retaining arm by a space at the opening perimeter, the space covering a distance corresponding at least to the chord of said first retaining arms.

[0004] The described structure makes it possible to reinforce the frame by distributing the retaining network formed by the retaining arms, while allowing the airflow to flow between the retaining arms. This reinforcement of the frame makes it possible to reduce the stresses related to the shape of said retaining arms, or to avoid a phenomenon called pumping, which corresponds to a periodic, unwanted movement of the central support in the direction of the axis of rotation of the impeller, caused by the oscillation of the retaining arms.

[0005] In some embodiments, the first retaining arms are placed in a first plane, and the second retaining arms are placed in a second plane parallel to the first plane. This distribution of the retaining arms in different planes makes it possible to consolidate the structure for retaining the central support, any oscillation of the retaining arms placed in the first plane being counteracted or blocked by the retaining arms placed in the second plane. In particular, this structure improves the axial stiffness of the frame along the axis of rotation of the impeller.

[0006] In some embodiments, the first retaining arms are placed in a first rotation cone and the second retaining arms are placed in a second rotation cone different from the first rotation cone. This arrangement allows to limit the mechanical biasing of the aforementioned pumping effect, on the one hand by using different angles between the first and second retaining arms, and on the other hand by using the rotation axis of the impeller, any movement of the first arms being at least partially counteracted by the tension generated by the second arms and vice versa. In some particular cases, the first retaining arms form a first angle with the plane defined by the opening and the second retaining arms form a second angle with the plane defined by the opening, the first and second angles having the same sign. This arrangement can limit the pumping phenomenon while facilitating the demolding without draft due to the use of angles in the same direction. In some particular cases, the first retaining arms form a first angle with the plane defined by the opening and the second retaining arms form a second angle with the plane defined by the opening, the first and second angles having opposite signs. This arrangement can allow an interdigitation between the first and second retaining arms, allowing to improve the torque transmission between the central support and the opening periphery.

[0007] In some embodiments, each first retaining arm is separated from another first retaining arm by at least one second retaining arm. This distribution makes it possible to improve the stiffness of the assembly, the tension on the first retaining arms being counteracted by the second retaining arms placed between them.

[0008] In some embodiments, the first retaining arms form groups of first retaining arms following each other along the opening periphery, each group of first retaining arms being separated from another group of first retaining arms by at least a second retaining arm or a group of second retaining arms. This distribution allows a partial interdigitation between the first and second retaining arms, which makes it possible to simplify the structure while benefiting from the distribution between the first and second retaining arms along the opening periphery.

[0009] In some embodiments, the first and second retaining arms are regularly distributed along the opening periphery. This contributes to the balance of the structure, which will facilitate the reduction or prevention of the pumping phenomenon.

[0010] In some embodiments, the opening has an annular shape comprising three complementary portions, each complementary portion covering 120 degrees of the annulus, each complementary portion comprising the same number of first and second retaining arms. This distribution makes it possible to obtain a particularly well-balanced structure, facilitating the regular rotation of the assembly.

[0011] In some embodiments, the retaining arms have an aerodynamic shape. This shape allows the retaining arms not only to act as retainers of the central support, but also to help generate a cooling flow by interacting with the aerodynamic shape of the impeller blades.

[0012] In some embodiments, the holding arms have a double-twisted aerodynamic shape. This shape has a particularly positive effect on the generation of the required cooling flow. The mechanical flexibility introduced by the use of this shape is counteracted by the rigidity of the arrangement such as the holding arms in this description.

[0013] In some embodiments, each holding arm is connected to the frame by a respective upright, said uprights extending perpendicular to the opening, some of said uprights connected to the first holding arms having a first height, perpendicular to the opening, starting from the plane comprising the opening, others of said uprights connected to the second holding arms having a second height, perpendicular to the opening, starting from the plane comprising the opening, the first height being different from the second height. This arrangement of uprights allows the first and second arms to be placed at different heights at the point where they are connected to the frame, in order to obtain the structure described, while allowing the passage of the air flow between the uprights.

[0014] This description also describes a ventilation device comprising an impeller, the motor of which is carried by a support frame according to this description. Such a device can for example allow a synergy between the shape of the impeller and the shape and position of the holding arms as described.

[0015] This description also describes a cooling module for a heat engine of a motor vehicle, comprising a ventilation device as described, which allows an aerodynamic synergy between its various components, in particular the holding arms as described. BRIEF DESCRIPTION OF DRAWINGS

[0016] Further features, details and advantages will become apparent from the following detailed description, taken in conjunction with the appended drawings, in which:

[0017] Figure 1A An example of a support frame as disclosed herein is shown.

[0018] Figure 1B An example of a cross section through a support frame as shown in Figure 1A is shown.

[0019] Figure 1C An example of a cross section through a support frame as shown in Figure 1A is shown.

[0020] Figure 1D An example of a cross section through a support frame as shown in Figure 1A is shown.

[0021] Figure 1E An example of a cross section through a support frame as shown in Figure 1A is shown.

[0022] Figure 1F An example of a support frame as disclosed herein is shown.

[0023] Figure 2A An example of a support frame disclosed herein is shown.

[0024] Figure 2B An example of a support frame disclosed herein is shown. Figure 2A A portion of the frame is shown.

[0025] Figure 3 An example of a ventilation device disclosed herein is shown.

[0026] Figure 4 An example of a ventilation device disclosed herein is shown. DETAILED DESCRIPTION

[0027] The present invention relates to a support frame for a ventilation device for cooling a fluid circulating through a cooling circuit of a motor vehicle. In some cases, the frame can be integrated into a motor fan unit. The motor vehicle can have a thermal or electric propulsion or a hybrid propulsion. The frame can correspond to a base comprising a nozzle. The frame can have a substantially parallelepiped shape, for example with external dimensions of 1 to 8 cm thick in the axial direction of rotation of the impeller, and dimensions of each side in a plane perpendicular to said axial direction between 20 and 60 cm. The frame can have a substantially parallelepiped shape, for example with external dimensions of 2 to 6 cm thick in the axial direction of rotation of the impeller, and dimensions of each side in a plane perpendicular to said axial direction between 45 and 55 cm.

[0028] The frame disclosed herein comprises an opening defining an opening perimeter, the opening being for receiving an impeller. Such an opening can have a substantially circular opening perimeter, for example with a diameter between 30 and 50 cm. Such an opening can have a substantially circular opening perimeter, for example with a diameter between 35 and 45 cm. Such an opening can have a substantially circular opening perimeter, for example with a diameter between 38 and 42 cm. The opening allows the passage of a flow of air, for example the air flow generated by the rotation of the impeller. In some examples, the shape of the opening corresponds to the shape of the impeller, the opening appearing in a plane perpendicular to the axis of rotation of the impeller. In some cases, the opening has a substantially torus shape, the opening perimeter corresponding to the outer perimeter of the torus.

[0029] The perimeter of the opening defines the wall of a hollow cylindrical cavity in which the impeller is positioned, the axis of the cylindrical cavity corresponding to the axial direction or rotation axis of the impeller. The frame can be used to attach to a support, for example a cooling radiator or a vehicle chassis, and to support the electric motor that actuates the impeller and the shaft around which the impeller rotates. In addition, aerodynamically, the frame can form a wall and limit or prevent the recirculation between upstream and downstream of the impeller. The appendices for attaching the electric motor to the frame can be constituted by a plurality of retaining arms having a mechanical retaining function. Such retaining arms can be in the form of aerofoils or stator blades that, in addition to their mechanical function, confer on them an aerodynamic function. For example, the stator blades can straighten the airflow.

[0030] The frame disclosed here comprises a central support located at the center of the opening. The center of the opening can correspond to the center of the circle corresponding to the perimeter of the opening. The center of the opening can comprise the location of the rotation axis of the impeller intersecting the plane comprising the opening. This central support is shaped to receive a motor that actuates the impeller in order to generate the ventilation airflow. The frame disclosed here can not only define a nozzle through which the airflow generated by the impeller flows, but also anchor the motor, such as an electric motor that actuates the impeller.

[0031] The central support is attached to the frame by at least six retaining arms through the opening. Such retaining arms have a mechanical function of attaching the central support to the perimeter of the frame through the opening. In order to ensure a certain degree of rigidity of the assembly, the number of retaining arms must be sufficient. Each retaining arm forms a bridge between the central support and the peripheral part of the frame that defines the opening. Each retaining arm has two ends, one connected to the central support and the other possibly connected to the perimeter of the opening through a post. Between the two ends, the retaining arm extends radially from the rotation axis of the impeller. In some cases, the central support is attached to the frame by at least eight retaining arms through the opening. In some cases, the central support is attached to the frame by at least ten retaining arms through the opening. In some cases, the central support is attached to the frame by at least twelve retaining arms through the opening. The use of a greater number of retaining arms can contribute to a better mechanical balance of the assembly and can offer greater freedom to the retaining arms to use, in particular, aerodynamic shapes.

[0032] Such a retaining arm has a mechanical action of retaining the central support. As such a retaining arm passes through the opening and is thus in the airflow generated by the impeller, the retaining arm has an influence on the aerodynamics of the assembly. It is thus in some cases desirable to adapt the shape of the retaining arm for example to the aerodynamics of the assembly. This can have an influence on the mechanical properties of the retaining arm. It is thus in some cases necessary to find a compromise in order to obtain on the one hand a mechanical property suitable for the retaining arm and on the other hand a specific aerodynamic shape for the retaining arm. The support frame disclosed here makes it possible to achieve such a compromise by the different positioning of the retaining arms as described above, which improves the rigidity of the structure. This different positioning makes it possible in particular to limit a phenomenon known as "pumping", which in some cases consists of an unwanted periodic movement of the central support in the direction of the rotation axis of the impeller, due to the excessive flexibility of the retaining arms. The different positioning of the retaining arms disclosed here makes it possible to reduce the occurrence of such "pumping". This different positioning makes it possible to improve the rigidity of the assembly and thus offers greater freedom in the choice of shape of the retaining arms, for example allowing the use of retaining arms that are light in weight or retaining arms with a particularly thin aerodynamic shape.

[0033] As disclosed here, at least three first retaining arms are placed in a first plane or cone of rotation and at least three second retaining arms are placed in a second plane or cone of rotation different from the first plane or cone of rotation. This different placement of the retaining arms improves the rigidity of the structure, limiting the aforementioned pumping phenomenon. It is possible to obtain this improvement in rigidity due to the fact that the natural frequency of oscillation of the first retaining arms is different from the natural frequency of oscillation of the second retaining arms, resulting in a synergistic stabilization of the assembly and thus limiting or even suppressing the unwanted pumping phenomenon. The introduction of this difference in positioning increases the freedom of choice of shape or even material for the retaining arms for a given rigidity of the structure. The use of the same first plane or cone of rotation for the first three retaining arms makes it possible to obtain a certain uniformity of placement of the first three retaining arms, which contributes to the mechanical stability of the assembly and to its ease of manufacture. Similarly, the use of the same second plane or cone of rotation for the three second retaining arms makes it possible to obtain a certain uniformity of placement of the three second retaining arms, which contributes to the mechanical stability of the assembly and to its ease of manufacture. In some cases, the first rotation cone has as its axis the rotation axis of the impeller corresponding to the center of the periphery of the opening. In some cases, the second rotation cone has as its axis the rotation axis of the impeller corresponding to the center of the periphery of the opening. In some cases, the first plane is parallel to the plane comprising the periphery of the opening. In some cases, the second plane is parallel to the plane comprising the periphery of the opening. In some cases, the number of first retaining arms is equal to the number of second retaining arms. In some cases, the number of first retaining arms is greater than the number of second retaining arms. In some cases, the number of first retaining arms is less than twice the number of second retaining arms. In some cases, the number of first retaining arms is less than three times the number of second retaining arms.

[0034] As disclosed herein, each of the first retaining arms is separated from any of the second retaining arms by a space at the opening perimeter, the space covering at least a distance corresponding to a chord of said first retaining arm. In one aspect, arranging such a space between the first retaining arms and each of the second retaining arms makes it possible to obtain satisfactory mechanical properties of each type of retaining arm, preventing an excessive proximity between the first and second retaining arms leading to properties similar to those of a single separate retaining arm, which would not make it possible to obtain the structural stiffness properties sought in the present disclosure. The chord of said first retaining arm corresponds for example to the thickness of the first retaining arm in a direction tangent to the opening perimeter, corresponding to the angular direction of the rotating impeller movement. This chord can be measured at different points along the retaining arm, at different distances from the axis of rotation of the impeller. Thus, for a given first retaining arm, the distance corresponding to this chord can vary. In some cases, the chord in question is an average chord of the various chords of the first retaining arm in question. In some cases, the chord in question is an intermediate chord of the various chords of the first retaining arm in question. In some cases, the chord in question is the largest chord of the various chords of the first retaining arm in question. In some cases, the chord in question is the smallest chord of the various chords of the first retaining arm in question. In some cases, the chord in question is the chord of the first retaining arm in question at its point of attachment to the opening perimeter, opposite the central support. In certain cases, the chord in question is the chord of the first retaining arm in question at its point of attachment to the central support. The distance corresponding to the chord in question is related to the opening perimeter in order to determine the distance by which the first retaining arms must be separated from any of the second retaining arms. It will be understood that, due to the structure of the assembly, the same first retaining arms will be closer to any of the second retaining arms at the central support. In addition to the mechanical consequences, this spacing allows the flow of gas to flow between the retaining arms in question. In some cases, each of the first retaining arms is separated from any of the second retaining arms by a space at the opening perimeter, the space covering at least twice the distance corresponding to the chord of said first retaining arm. In some cases, each of the first retaining arms is separated from any of the second retaining arms by a space at the opening perimeter, the space covering at least three times the distance corresponding to the chord of said first retaining arm. In some cases, each of the first retaining arms is separated from any of the second retaining arms by a space at the opening perimeter, the space covering at least four times the distance corresponding to the chord of said first retaining arm.

[0035] Figure 1AThe frame disclosed herein is shown as a support frame 100 for a ventilation device used to cool fluid passing through a cooling circuit of a motor vehicle. The frame 100 includes an opening defining a circular periphery 103 for receiving an impeller (not shown), and a cylindrical central support 102 located at the center of the opening, shaped to accommodate a motor (not shown) that actuates the impeller to generate a ventilation airflow. The central support 102 is attached to the frame through the opening by six retaining arms 111-116. At least three first retaining arms 111, 113, 115 are placed in a first plane of rotation or cone, and at least three second retaining arms 112, 114, 116 are placed in a second plane of rotation or cone, different from the first plane of rotation or cone. Each first retaining arm is separated from any second retaining arm at the periphery of the opening by a space 131, which covers a distance at least corresponding to a chord of the first retaining arm.

[0036] exist Figure 1A In this configuration, the frame includes first arms 111, 113, and 115 alternating with second arms 112, 114, and 116. In other words, each first retaining arm is separated from the other first retaining arm by a second retaining arm. This configuration is particularly mechanically balanced.

[0037] In some cases, each first retaining arm is separated from the other first retaining arm by at least one second retaining arm.

[0038] The frame may include additional retaining arms that are neither the first retaining arm nor the second retaining arm, and such additional retaining arms have their own configuration and placement.

[0039] Figure 1A The framework shown can have a variety of different configurations.

[0040] Figure 1B It shows that in the perpendicular to Figure 1A Passing through the plane of the view according to Figure 1Apossible cross section of the frame of the cross section S, including the first holding arm 115 and the second holding arm 112. In this case, the first holding arm, such as the first holding arm 115, is placed in a first plane 141. In this case, the second holding arm, such as the second holding arm 112, is placed in a second plane 142. It is of course to be understood here that placing a holding arm in a plane of rotation or in a cone means placing the overall axis of such holding arm in such plane or cone, and not the arm itself, i.e. a plane or cone of theoretical zero thickness. Such overall axis of the arm can correspond to a theoretical line segment connecting the end of the respective arm in contact with the central support and the opposite end of the same arm in contact with the opening perimeter. In this example, the first plane and the second plane are planes perpendicular to the rotation axis 101 of the impeller or to the central axis of the frame or to the central axis of the central support. The first plane and the second plane are separated by a distance which in some cases can be at least the thickness of the first holding arm, measured at the junction between such first holding arm and the opening perimeter in the direction of rotation of the impeller. In some cases, the first and second planes can be separated by a distance which is at least twice the thickness of the first holding arm, measured at the junction between such first holding arm and the opening perimeter in the direction of rotation of the impeller. In some cases, the first and second planes can be separated by a distance which is at least three times the thickness of the first holding arm, measured at the junction between such first holding arm and the opening perimeter in the direction of rotation of the impeller. A larger difference between said planes contributes to mechanical stability. An excessively large distance can make the frame excessively bulky. In some cases, the first and second planes can be separated by a distance which is at most four times the thickness of the first holding arm, measured at the junction between such first holding arm and the opening perimeter in the direction of rotation of the impeller. In some cases, the first and second planes can be separated by a distance which is at most three times the thickness of the first holding arm, measured at the junction between such first holding arm and the opening perimeter in the direction of rotation of the impeller.

[0041] Figure 1C is shown in a view in a plane perpendicular to the rotation axis 101 of the impeller. Figure 1A Figure 1A ​the frame of the cross section S, including the first retaining arm 115 and the second retaining arm 112. In this case, the first retaining arm, such as the first retaining arm 115, is placed in a first cone represented in part by the generatrix 151 of the first cone, the axis of the cone being the rotation axis 101 of the impeller. In this case, the second retaining arm, such as the second retaining arm 112, is placed in a second cone represented in part by the generatrix 152 of the second cone, the axis of the cone being the rotation axis 101 of the impeller. The first rotation cone is different from the second cone in order to obtain the effects sought in the present disclosure. In this example, the first and second cones are cones having the same impeller rotation axis 101 or central axis of the frame or central axis of the central support. In this example, the first retaining arm forms a first angle 161 with the plane 104 defined by the opening and the second retaining arm forms a second angle 162 with the plane 104 defined by the opening, the first and second angles having the same sign.

[0042] In some cases, the first angle and the second angle differ by at least 5 degrees. In some cases, the first angle and the second angle differ by at least 10 degrees. In some cases, the first angle and the second angle differ by at least 15 degrees. In some cases, the first angle and the second angle differ by at least 20 degrees. In some cases, the first angle and the second angle differ by at least 30 degrees. In some cases, the first angle and the second angle differ by at least 45 degrees. In some cases, the first angle and the second angle differ by less than 90 degrees. In some cases, the first angle and the second angle differ by less than 60 degrees. A larger difference between the first and second angles contributes to mechanical stability. Too large a difference can make the frame too bulky. The first or second angle can be between -5 degrees and +5 degrees. The first or second angle can be between -15 degrees and +15 degrees. The first or second angle can be between -20 degrees and +20 degrees. The first or second angle can be between -30 degrees and +30 degrees.

[0043] Figure 1D a view perpendicular to the plane of the view of Figure 1A a view perpendicular to the plane of the view of Figure 1AThe possible cross-section of the frame with section S includes a first retaining arm 115 and a second retaining arm 112. In this case, the first retaining arm, such as the first retaining arm 115, is placed in a first cone represented by the generatrix 153 of the first cone, the axis of which is the axis of rotation 101 of the impeller. In this case, the second retaining arm, such as the second retaining arm 112, is placed in a second cone represented by the generatrix 154 of the second cone, the axis of which is the axis of rotation 101 of the impeller. The first rotating cone is different from the second cone in order to achieve the effect sought in this disclosure. In this example, the first cone and the second cone are cones having the same impeller axis of rotation 101 or the central axis of the frame or the central axis of the central support. In this example, the first retaining arm forms a first angle 163 with the plane 104 defined by the opening, and the second retaining arm forms a second angle 164 with the plane 104 defined by the opening, the first and second angles having opposite signs.

[0044] Figure 1E It shows that in the perpendicular to Figure 1A Passing through the plane of the view according to Figure 1A The possible cross-section of the frame with section S includes a first retaining arm 115 and a second retaining arm 112. In this case, the first retaining arm, such as the first retaining arm 115, is placed in a cone represented by the generatrix 155 of the first cone, the axis of which is the axis of rotation 101 of the impeller. In this case, the second retaining arm, such as the second retaining arm 112, is placed in a plane 144 parallel to the plane including the opening.

[0045] Figure 1F It shows something similar to Figure 1A The example shown is a frame 105, which includes six first retaining arms 117 and six second retaining arms 118. The first retaining arms 117 form a group of two first retaining arms that follow each other along the periphery of the opening. Each group of two retaining arms 117 is separated from another group of two first retaining arms 117 by at least one group of second retaining arms 118.

[0046] In some cases, such as in Figure 1F In the case shown, the first retaining arms form a group of first retaining arms that follow each other along the periphery of the opening, and each group of first retaining arms is separated from another group of first retaining arms by at least a second retaining arm or a group of second retaining arms. This allows for an increase in the number of retaining arms while maintaining a uniform structure.

[0047] In some cases, such as Figure 1A , 1F As shown in 2A, the opening has a ring shape, the ring comprising three complementary portions, each complementary portion covering a 120-degree ring, and each complementary portion comprising the same number of first and second retaining arms. Figure 1FThe frame 105 shown is an example of a ring forming an opening, the ring being delimited by the circumference of the central support 102 and the opening perimeter 103. In this same Figure 1F ring, three complementary portions of 120 degrees of the ring are limited by the axis 160. Each of these three portions shown comprises four retaining arms, an identical number of first retaining arms and second retaining arms, in this case specifically two retaining arms 117 and two retaining arms 118 per portion. This provides a balanced structure, preventing or reducing vibrations during the rotating movement of the impeller. In some cases, the ring comprises six complementary portions, each complementary portion covering 60 degrees of the ring, each complementary portion comprising an identical number of first and second retaining arms.

[0048] In some cases, for example as shown in the frame 200 in Figure 2A , the retaining arms have an aerodynamic shape, such as the twelve retaining arms 210-221 between the opening perimeter 203 and the central support 202 of the frame 200. This can improve the air flow obtained by using the frame by adding an aerodynamic action to the retaining arms beyond their mechanical support action. The retaining arms 210-221 comprise six first retaining arms 211, 213, 215, 217, 219 and 221 and six second retaining arms 210, 212, 214, 216, 218 and 220. In this case, the first and second retaining arms are alternating. In this case, as shown in more detail in Figure 2B , the first retaining arms are attached to a first level N1 of the central support, the second retaining arms are attached to a second level N2 of the central support, the level N1 being different from the level N2 along the rotation axis 201 of the impeller, said axis 201 being perpendicular to the plane comprising the opening. In this case, as further shown in Figure 2B , the first retaining arms are attached to a third level N3 of the central support, the second retaining arms are attached to a fourth level N4 of the central support, the level N3 being different from the level N4 along the rotation axis 201 of the impeller. These staggered levels result in an embodiment disclosed herein which avoids placing all the retaining arms in the same rotation plane or cone in order to obtain a particularly rigid structure, which is particularly effective in the case of retaining arms using aerodynamic shapes which tend to be more flexible.

[0049] In some cases, each retaining arm is connected to the frame by a respective stud, said studs extending perpendicularly to the opening, some of said studs connected to the first retaining arms having a first height perpendicularly to the opening starting from the plane comprising the opening, and others of said studs connected to the second retaining arms having a second height perpendicularly to the opening starting from the plane comprising the opening, the first height being different from the second height. The use of such studs can help to create a flow in the radial direction between consecutive studs.

[0050] InFigure 2A and 2B In the case of the frame shown in FIGS. 1-3, each of the holding arms 210-221 is connected to the frame 200 by a respective upright extending perpendicular to the opening, some of the uprights connected to the first holding arms having a first height perpendicular to the opening from a plane including the opening (corresponding to level N3), and others of the uprights connected to the second holding arms having a second height perpendicular to the opening from the plane including the opening (corresponding to level N4), the first height being different than the second height.

[0051] The aerodynamic shape can include a leading edge and a trailing edge, a flow incident with the leading edge, a pressure side and a suction side along which the flow travels. The pressure side and the suction side meet at the trailing edge, and the flow flows over the trailing edge. The aerodynamic shape includes a chord line following a straight line connecting the leading edge and the trailing edge, and an arc line being a curved line connecting the leading edge and the trailing edge, the arc line being a curve intermediate the pressure side and the suction side. The leading edge continues to a point of maximum thickness.

[0052] In some cases, the holding arms have a double-twisted shape that particularly conforms to aerodynamics.

[0053] The retaining arms 210-221 have for example a double-twisted shape, the purpose of which is to reduce the drag due to the friction of the air on said retaining arms during the operation of the impeller. Such arms can have a dual aerodynamic and acoustic function in addition to their mechanical function. Instead of arms in the form of flat plates oriented according to the direction of the airflow passing through the impeller, the retaining arms of aerodynamic shape are in some cases constituted by thin blades of large span and of elongated section, the length of the chord of which is at least 1.5 times its thickness, in particular at the point of its maximum thickness. These retaining arms have an aerodynamic profile to reduce their drag, and the helix angle of this profile varies along their span between their root carried by the central support 202 and their tip connected to the opening perimeter 203. The helix angle of the profile of the section of said retaining arms can for example vary along their span, from a substantially radial orientation at their root and the central support 202, to a more axial orientation along the middle of the span of the retaining arms, before returning to a substantially radial orientation at their tip and the opening perimeter 203. The helix angle law, i.e. the angle formed by the chord of this portion with the axial direction of the rotation of the impeller, perpendicular to the plane defined by the opening, develops along the span in order to adapt to the direction of the airflow and the revolution at the outlet of the impeller. This is beneficial both for the aerodynamic efficiency and for reducing instabilities that generate noise. In certain cases, the root helix angle, just like the tip helix angle, has a high value (for example greater than 70°), while the central portion of the blade, i.e. the portion between 25% and 75% of the span, has a relatively low helix angle (for example less than 20°). The retaining arms 210-221 have a double-twisted shape for example along the line connecting the middle chord points of the retaining arms, this twist being formed by the rotation of the stator portion in the tangential plane when this line is described from the root to the tip of the retaining arms. It is said to be double-twisted because the twist increases from the root to the middle of the span, then decreases from the middle of the span to the tip, to become again slightly twisted. According to an embodiment not shown, the evolution of the helix angle can be interrupted in the central portion of the stator, or follow another law. This double-twisted shape reduces the stiffness of the arms, which therefore particularly benefit from the different configurations disclosed herein.

[0054] In some cases, the first retaining arm connects the central support at a first level of the impeller rotation axis, the second retaining arm connects the central support at a second level of the impeller rotation axis, the first level and the second level being separated by at least 50% of the maximum thickness of the first retaining arm, this thickness being measured along the span of the retaining arm (or stator), without taking into account its ends.

[0055] In some cases, the first retaining arm connects the opening perimeter at a first level of the impeller rotation axis, the second retaining arm connects the central support at a second level of the impeller rotation axis, the first level and the second level being separated by at least 50% of the maximum thickness of the first retaining arm, this thickness being measured along the span of the retaining arm (or stator), without taking into account its ends.

[0056] In some cases, the first retaining arm connects the central support at a first level of the impeller rotation axis, the second retaining arm connects the central support at a second level of the impeller rotation axis, the first level and the second level being separated by at most three times the maximum length of a chord of the first retaining arm, the chord being between the leading edge and the respective trailing edge of said retaining arm.

[0057] In some cases, the first retaining arm connects the central support at a first level of the impeller rotation axis, the second retaining arm connects the central support at a second level of the impeller rotation axis, the first level and the second level being separated by at most three times the maximum length of a chord of the first retaining arm, the chord being between the leading edge and the respective trailing edge of said retaining arm.

[0058] In some cases, the first retaining arm intersects the second retaining arm. This configuration is particularly rigid while ensuring compactness.

[0059] Figure 3 A simplified view of an example of a cooling module 40 for a heat engine of a motor vehicle is shown, comprising a ventilating device 30 as disclosed herein, the ventilating device comprising an impeller 310, the motor 320 of which is carried by a support frame 300. The impeller 310 has a rotation axis 301, which can for example correspond to the axis 101 or 201 of the preceding figures. The impeller can be placed between the frame and the motor to be cooled. The frame can also be placed between the impeller and the motor to be cooled. The combination of the aerodynamic function of the impeller and the aerodynamic shape of the pillars disclosed herein makes it possible to obtain an improvement in the overall performance of the system. This performance is further improved by combining the aerodynamic capabilities of the impeller, the aerodynamic shape of the pillars and retaining arms disclosed herein.

[0060] Figure 4 A simplified view of an example of a cooling module 40 for a heat engine of a motor vehicle is shown, comprising a ventilating device 30 as disclosed herein, the ventilating device comprising an impeller 310, the motor 320 of which is carried by a support frame 300. The impeller 310 has a rotation axis 301, which can for example correspond to the axis 101 or 201 of the preceding figures. The impeller can be placed between the frame and the motor to be cooled. The frame can also be placed between the impeller and the motor to be cooled. The combination of the aerodynamic function of the impeller and the aerodynamic shape of the pillars disclosed herein makes it possible to obtain an improvement in the overall performance of the system. This performance is further improved by combining the aerodynamic capabilities of the impeller, the aerodynamic shape of the pillars and retaining arms disclosed herein. Figure 3 A simplified view of an example of a cooling module 40 for a heat engine of a motor vehicle is shown, comprising a ventilating device 30 as disclosed herein, the ventilating device comprising an impeller 310, the motor 320 of which is carried by a support frame 300. The impeller 310 has a rotation axis 301, which can for example correspond to the axis 101 or 201 of the preceding figures. The impeller can be placed between the frame and the motor to be cooled. The frame can also be placed between the impeller and the motor to be cooled. The combination of the aerodynamic function of the impeller and the aerodynamic shape of the pillars disclosed herein makes it possible to obtain an improvement in the overall performance of the system. This performance is further improved by combining the aerodynamic capabilities of the impeller, the aerodynamic shape of the pillars and retaining arms disclosed herein.

Claims

1. A support frame for a ventilation device for cooling a fluid circulating through a cooling circuit of a motor vehicle, said frame comprising an opening defining an opening perimeter for receiving an impeller, and a central support located at the center of said opening, the shape of said central support being arranged to receive a motor actuating said impeller so as to generate a ventilation airflow, said central support being attached to the frame by said opening by at least six retaining arms, at least three first retaining arms being placed in a first plane of rotation or cone and at least three second retaining arms being placed in a second plane of rotation or cone different from the first plane of rotation or cone, the first retaining arms each being separated from any second retaining arm by a space at the opening perimeter, the space covering a distance corresponding at least to a chord of said first retaining arm, the chord of said first retaining arm corresponding to a thickness of this first retaining arm in a direction tangential to said opening perimeter.

2. The frame according to claim 1, said first retaining arms being placed in a first plane, said second retaining arms being placed in a second plane parallel to the first plane.

3. The frame according to claim 1, said first retaining arms being placed in said first rotational cone, said second retaining arms being placed in a second rotational cone different from the first rotational cone.

4. The frame according to claim 3, said first retaining arms forming a first angle with a plane defined by said opening, said second retaining arms forming a second angle with the plane defined by said opening, the first and second angles having opposite signs.

5. The frame according to claim 3, said first retaining arms forming a first angle with a plane defined by said opening, said second retaining arms forming a second angle with the plane defined by said opening, the first and second angles having the same sign.

6. The frame according to any one of claims 1 to 5, said first retaining arms forming groups of first retaining arms following each other along said opening perimeter, each group of first retaining arms being separated from another group of first retaining arms by at least a second retaining arm or a group of second retaining arms.

7. The frame according to any one of claims 1 to 5, said opening having a ring shape, said ring comprising three complementary portions, each complementary portion covering 120 degrees of the ring, each complementary portion comprising the same number of first and second retaining arms.

8. The frame according to any one of claims 1 to 5, each retaining arm being connected to the frame by a respective stud, said studs extending perpendicularly to the opening, some of said studs connected to first retaining arms having a first height perpendicularly to the opening starting from a plane comprising the opening, others of said studs connected to second retaining arms having a second height perpendicularly to the opening starting from the plane comprising the opening, the first height being different from the second height.

9. A ventilation device comprising an impeller, the motor of which is carried by a support frame according to any one of the preceding claims.

10. A cooling module for a heat engine of a motor vehicle, comprising a ventilation device according to claim 9.

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