Fan impeller

Abstract

The invention relates to a fan impeller (1), the impeller (1) comprising a hub (2) having an axis of rotation (XR) and blades (3) extending generally radially outward from the hub (2), the hub (2) comprising a plate (6) extending perpendicular to the axis of rotation (XR), the plate (6) being bordered in particular by an annular rim (7), the plate (6) being provided with damping ridges (8) configured to dampen, or eliminate, the transmission of vibro-acoustic noise on the hub (2).

Description

[0001] Fan propeller

[0002] [1] The present invention relates to a fan impeller, in particular an axial-type fan. The fan is specifically configured for integration into a front cooling module of a thermal or electric vehicle.

[0003] [2] Generally, the propeller hub, which is roughly bowl-shaped, is attached to the fan's electric motor by several screws, for example, three screws. The operating propeller produces a vibro-acoustic noise. Specifically, vibrations from the motor are transmitted (through the screw mounting points) and amplified by the propeller hub, and noise is thus produced. In particular, when the fan is operating at low speeds, the noise produced by the motor vibrations is predominant, especially compared to the airflow noise, which is more noticeable at higher speeds.

[0004] [3] The present invention aims in particular to reduce noise in such a fan.

[0005] [4] The invention thus relates to a fan propeller, the propeller comprising a hub having an axis of rotation and blades extending globally radially outwards from the hub, the hub comprising a plate extending perpendicularly to the axis of rotation, the plate being in particular bordered by an annular rim, the plate being provided with attenuating reliefs configured to attenuate, or eliminate, a transmission of vibro-acoustic noise on the hub.

[0006] [5] In the invention, the damping features make it possible, in particular, to block the transmission and amplification of vibrations from an electric motor to which the propeller is connected. The hub's damping features thus make it possible to reduce, or even eliminate, the unwanted noise caused by these vibrations from the electric motor. These vibrations are transmitted from the motor to the propeller, notably through attachment points such as screws, between a motor shaft and the propeller, and these vibrations are not blocked by a flat, smooth plate of a propeller known in the prior art.

[0007] [6] The invention is particularly advantageous when the fan is operating at low speeds, because the noise created by vibrations from the motor is predominant, especially compared to the noise of the air blowing which appears more at high speeds.

[0008] [7] According to one aspect of the invention, the hub with the plate bordered by an annular rim has a general bowl shape.

[0009] [8] According to one aspect of the invention, the attenuation reliefs are formed in the thickness of the plate.[9] According to one aspect of the invention, the attenuation reliefs have a substantially constant thickness.

[0010]

[0010] According to one aspect of the invention, the attenuation reliefs have the same thickness as the thickness of the plate.

[0011]

[0011] According to one aspect of the invention, the attenuation reliefs are defined, in cross-section in a plane containing the axis of rotation, between two relief profiles respectively on the two opposite faces of the plate. These relief profiles are notably substantially parallel to each other, and define the thickness of the attenuation reliefs.

[0012]

[0012] In particular, one of the faces (rear face) of the plate is turned towards an electric motor (in particular the face turned towards the inside of the bowl).

[0013]

[0013] According to one aspect of the invention, the attenuation reliefs comprise undulations formed on the plate.

[0014]

[0014] According to one aspect of the invention, the undulations have, in cross-section in a plane which contains the axis of rotation, a thickness which is substantially constant or which has a variation of at most 10% or at most 20% compared to an average thickness.

[0015]

[0015] In particular, when traversing the undulations one after another in this cross-section, the thickness is substantially constant, or exhibits a variation of at most 10% or at most 20% compared to an average thickness.

[0016]

[0016] According to one aspect of the invention, the undulations are defined, in cross-section in a plane which contains the axis of rotation, between two undulating profiles respectively on the two opposite faces of the plate.

[0017]

[0017] In other words, the undulations are present on both faces of the plate.

[0018]

[0018] According to one aspect of the invention, the corrugated profiles (respectively on the two faces of the plate) which define, in cross-section, the undulations, are formed by rounded shapes, in particular arcs of circles, in particular semicircles.

[0019]

[0019] For example, the peaks and troughs of the undulations are defined by arcs of circles, in particular semicircles.

[0020]

[0020] Alternatively, the undulations may have a substantially sinusoidal profile.

[0021]

[0021] According to one aspect of the invention, the hub plate has a front face which is turned towards the outside of the fan, this front face having a peripheral flat which delimits the external perimeter of the plate, this peripheral flat being tangent to a front plane of the plate, and the attenuation reliefs, in particular the undulations, are recessed from this front plane of the plate or tangent to this front plane of the plate.

[0022]

[0022] In other words, the undulations do not extend beyond this frontal plane. This is advantageous for preventing the attenuation reliefs from accidentally coming into contact with components in the immediate vicinity of the propeller.

[0023]

[0023] According to one aspect of the invention, the undulations have a greater amplitude on the rear face of the plate than on the front face of the plate.

[0024]

[0024] According to one aspect of the invention, the undulations have, in view along the axis of rotation of the helix, a circular shape centered on the center of the plate.

[0025]

[0025] According to one aspect of the invention, the circular shape of each undulation can be a complete circle or a discontinuous circle, for example the circle being cut by the presence of a fixing point on the plate.

[0026]

[0026] The undulations can thus form, in view along the axis of rotation of the helix, concentric circles centered on the center of the plate.

[0027]

[0027] According to one aspect of the invention, the number of undulations is between 2 and 20, in particular between 3 and 15, in particular between 4 and 8.

[0028]

[0028] According to one aspect of the invention, the undulations all have the same amplitude.

[0029]

[0029] Alternatively, some undulations may have a greater amplitude than other undulations.

[0030]

[0030] According to one aspect of the invention, the pitch between the undulations is constant.

[0031]

[0031] Alternatively, the pitch between the undulations is variable so that some undulations are closer together than other undulations.

[0032]

[0032] According to one aspect of the invention, the attenuation reliefs have a rotational symmetry around the axis of rotation of the helix.

[0033]

[0033] According to one aspect of the invention, the undulations follow one another without leaving flat areas between the undulations.

[0034]

[0034] Alternatively, between at least two successive undulations, a flat connects these two undulations.

[0035]

[0035] According to one aspect of the invention, the attenuation reliefs, in particular the undulations, extend at least in a peripheral area of ​​the plate, in particular between, on the one hand, fixing points for fixing the propeller to a motor and, on the other hand, the outer perimeter of the plate.

[0036] This helps to stop the transmission of vibrations from the fixing points which radiate towards the blades.

[0036]

[0037] According to one aspect of the invention, the plate has a central zone, which is surrounded by the peripheral zone, in particular this central zone extending from the center of the plate to fixing points for fixing the propeller to a motor, this central zone being substantially smooth, namely being devoid of attenuating reliefs.

[0037]

[0038] According to another aspect of the invention, the attenuation reliefs can have various orientations and / or shapes.

[0038]

[0039] The shapes are, for example, straight or curved lines, instead of the concentric undulations described above.

[0039]

[0040] Thus, the shapes of attenuation reliefs are straight or curved lines, different from concentric undulations.

[0040]

[0041] The attenuation reliefs can be arranged in an irregular or random pattern.

[0041]

[0042] According to one aspect of the invention, the attenuation reliefs can be arranged in an irregular pattern or a random pattern in one area and in a regular pattern in another area of ​​the plate.

[0042]

[0043] It is possible that the randomly arranged attenuation reliefs extend over the entire surface of the turntable.

[0043]

[0044] According to one aspect of the invention, the propeller is produced by injection molding, in particular in plastic material.

[0044]

[0045] The invention also relates to an electric fan, in particular for a motor vehicle, comprising a propeller such as the one mentioned above.

[0045]

[0046] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and several illustrative and non-limiting examples of embodiments given with reference to the attached schematic drawings on the other hand, in which:

[0046] • Figure 1 is a representation of a propeller according to an example of an embodiment of the invention;

[0047] • Figure 2 is a cross-sectional view of the helix in Figure 1;

[0048] • Figure 3 shows another example of attenuation reliefs according to the invention;

[0049] • Figure 4 shows yet another example of attenuation reliefs according to the invention; • Figure 5 shows attenuation reliefs according to another example of the invention.

[0050]

[0047] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0051]

[0048] Figure 1 shows a propeller 1 fitted to an axial-type fan 100. The fan 100, driven by an electric motor, is configured for integration into a front cooling module of a combustion engine or electric vehicle. Other applications are of course conceivable.

[0052]

[0049] The propeller 1 comprises a hub 2 having an axis of rotation XR and blades 3 extending globally radially (along a radius Ra) outwards from the hub 2 to a rim 4. The number of blades is for example between 5 and 20, being here 7. The blades 3 are regularly distributed (with a regular angular pitch) around the hub 2, or distributed non-regularly around the axis XR, thus creating an asymmetrical distribution.

[0053]

[0050] Each blade 3 is defined by a span, a leading edge and a trailing edge, in a manner known per se. The blade 3 is further defined by a stack of airfoil profiles constructed with a thickness law around a neutral fiber connecting the leading edge to the trailing edge of the blade 3.

[0054]

[0051] The hub 2 includes a plate 6 extending perpendicularly to the axis of rotation XR, the plate 6 being bordered by an annular rim 7, the plate 6 being provided with attenuation reliefs 8 configured to attenuate, or eliminate, a transmission of vibro-acoustic noise on the hub 2.

[0055]

[0052] In the invention, the damping ridges 8 make it possible, in particular, to block the transmission and amplification of vibrations from an electric motor to which the propeller 1 is connected. The damping ridges 8 of the hub 2 thus make it possible to reduce, or even eliminate, the unwanted noise caused by these vibrations from the electric motor. These vibrations are transmitted from the motor to the propeller 1, notably through attachment points such as screws, between a shaft of the motor and the propeller 1, and these vibrations are not blocked by a flat and smooth plate 6 of a propeller known in the prior art.

[0053] The invention is particularly advantageous when the fan operates at low speeds, because the noise created by the vibrations from the motor is predominant, especially compared to the noise of the air blowing, which is more noticeable at high speeds.

[0056]

[0054] The hub 2 with the plate 6 bordered by an annular rim 7, has a general bowl shape.

[0057]

[0055] The attenuation reliefs 8 are formed in the thickness of the plate 6, and have a substantially constant thickness w, as can be seen in figure 2.

[0058]

[0056] As also illustrated in figure 2, the attenuation reliefs 8 have the same thickness w as the thickness of the plate 6.

[0059]

[0057] The attenuation reliefs 8 are defined, in cross-section in a plane P which contains the axis of rotation XR, between two relief profiles PF1 and PF2 respectively on the two opposite faces 11 and 12 of the plate 6. These relief profiles PF1 and PF2 are substantially parallel to each other, and define the thickness w of the attenuation reliefs 8.

[0060]

[0058] The thickness w is preferably between 1 mm and 3 mm, advantageously being equal to 2.2 mm or 2.5 mm.

[0061]

[0059] The rear face 12 of the plate 6 is turned towards an electric motor (here the face 12 is turned towards the inside of the bowl).

[0062]

[0060] In the example of figures 1 and 2, the attenuation reliefs 8 include undulations 14 formed on the plate 6.

[0063]

[0061] According to one aspect of the invention, the undulations 14 have, in cross-section in the plane P which contains the axis of rotation XR, a thickness which is substantially constant or which has a variation of at most 10% or at most 20% compared to an average thickness.

[0064]

[0062] When we go through the undulations 14 one after the other in this cross-section, the thickness is substantially constant, or shows a variation of at most 10% or at most 20% compared to an average thickness.

[0065]

[0063] The undulations 14 are defined, in cross-section in the plane P which contains the axis of rotation XR, between the two corrugated profiles PF1 and PF2 respectively on the two opposite faces 11, 12 of the plate 6.

[0066]

[0064] In other words, the undulations 14 are present and visible on both faces 11, 12 of the plate 6.

[0067]

[0065] The corrugated profiles PF1 and PF2 (respectively on the two faces 11, 12 of the plate 6) which define, in cross-section, the undulations 14, are formed by rounded shapes, here semicircles. These semicircles have, for example, a radius of up to 10 mm, the radius being in particular between 1 mm and 5 mm.

[0068]

[0066] For example, the peaks and troughs of the undulations 14 are defined by semicircles, as can be clearly seen in Figure 2.

[0069]

[0067] Alternatively, the undulations 14 may have a substantially sinusoidal profile.

[0070]

[0068] The front face 11 which is turned towards the outside of the fan has a peripheral flat 17 which delimits the external perimeter of the plate 6, this peripheral flat 17 being tangent to a front plane PP of the plate 6, and the attenuation reliefs 8, here the undulations 14, are tangent to this front plane PP of the plate 6.

[0071]

[0069] In other words, the undulations 14 do not extend beyond this frontal plane PP. This is advantageous for preventing the attenuation reliefs 8 from accidentally coming into contact with components in the immediate vicinity of the propeller.

[0072]

[0070] The undulations 14 have, in view along the axis of rotation XR of the helix, a circular shape centered on the center C of the plate 6.

[0073]

[0071] The circular shape of each undulation 14 can be a complete circle or a discontinuous circle, for example the circle being cut by the presence of a fixing point 18 on the plate 6.

[0074]

[0072] The undulations 14 can thus form, in view along the axis of rotation XR of the helix, concentric circles centered on the center C of the plate 6.

[0075]

[0073] The number of undulations 14 is between 2 and 20, being in particular between 3 and 15, being in particular between 4 and 8.

[0076]

[0074] The undulations 14 all have the same amplitude.

[0077]

[0075] Alternatively, some undulations 14 may have a greater amplitude than other undulations 14.

[0078]

[0076] The pitch between the undulations 14 is constant.

[0079]

[0077] Alternatively, the pitch between the undulations 14 is variable so that some undulations 14 are closer together than other undulations 14.

[0080]

[0078] The attenuation reliefs 8 exhibit a rotational symmetry around the axis of rotation XR of the helix 1.

[0081]

[0079] In the example described, the undulations 14 follow one another without leaving flat areas between the undulations 14.

[0082]

[0080] Alternatively, between at least two successive undulations 14, a flat connects these two undulations 14.

[0081] The attenuation reliefs 8, here the undulations 14, extend at least in a peripheral zone 19 of the plate 6, radially between, on the one hand, fixing points 18 for fixing the propeller 1 to a motor and, on the other hand, the outer perimeter of the plate 6.

[0083]

[0082] This makes it possible to stop the transmission of vibrations from the fixing points and which radiate towards the blades.

[0084]

[0083] The plate 6 has a central zone 20, which is surrounded by the peripheral zone 19, this central zone 20 extending from the center C of the plate 6 to fixing points 18 for fixing the propeller 1 to a motor, this central zone 20 being substantially smooth, namely being devoid of attenuation reliefs 8.

[0085]

[0084] Alternatively, as illustrated in Figure 3, the central area 20 can also be provided with concentric undulations 14.

[0086]

[0085] The propeller 1 is made by injection molding, here in plastic material.

[0087]

[0086] In a variant illustrated in figure 4, the central zone 20 can be provided with different attenuation reliefs 28, for example extending along non-circular curves, for example which cut the concentric undulations 14.

[0088]

[0087] Of course, the attenuation reliefs 8 can have various orientations and / or shapes.

[0089]

[0088] In general, the shapes are for example straight or curved lines, instead of the concentric undulations 14 described above.

[0090]

[0089] The attenuation reliefs 8 can be arranged in an irregular pattern or a random pattern.

[0091]

[0090] The attenuation reliefs 8 can be arranged in an irregular pattern or a random pattern in one area and in a regular pattern in another area of ​​the plate 6.

[0092]

[0091] As illustrated in figure 5, the attenuation reliefs 38 can be arranged in an irregular or random pattern over the entire plate 6.

Claims

9 DEMANDS

1. Fan propeller (1), the propeller (1) comprising a hub (2) having an axis of rotation (XR) and blades (3) extending generally radially outwards from the hub (2), the hub (2) comprising a plate (6) extending perpendicularly to the axis of rotation (XR), the plate (6) being in particular bordered by an annular rim (7), the plate (6) being provided with attenuating reliefs (8; 28; 38) configured to attenuate, or suppress, vibro-acoustic noise transmission on the hub (2).

2. Propeller (1) according to the preceding claim, wherein the hub (2) with the plate (6) bordered by an annular rim (7), has a general bowl shape.

3. Propeller (1) according to any one of the preceding claims, wherein the attenuation reliefs (8; 28; 38) are formed in the thickness of the plate (6), and the attenuation reliefs (8; 28; 38) have in particular a substantially constant thickness.

4. Propeller (1) according to any one of the preceding claims, wherein the attenuation reliefs (8; 28; 38) are defined, in cross-section in a plane which contains the axis of rotation, between two profiles (PF1, PF2) in relief respectively on the two opposite faces (11, 12) of the plate (6), these relief profiles being in particular substantially parallel to each other, and defining the thickness of the attenuation reliefs (8; 28; 38).

5. Propeller (1) according to any one of the preceding claims, wherein the attenuating reliefs (8) comprise undulations (14) formed on the plate (6), and the crests and troughs of the undulations (14) are in particular defined by arcs of circles, in particular semicircles.

6. Propeller (1) according to any one of the preceding claims, wherein the hub plate (6) has a front face (11) which is turned outwards from the fan, this front face (11) having a peripheral flat (17) which delimits the outer perimeter of the plate (6), this peripheral flat (17) being tangent to a front plane (PP) of the plate (6), and the attenuation reliefs (8; 28; 38), in particular the undulations, are recessed from this front plane of the plate (6) or tangent to this front plane of the plate (6).

7. Propeller (1) according to any one of the preceding claims, wherein the undulations (8) have, in view along the axis of rotation (XR) of the propeller (1), a circular shape centered on the center of the plate (6), the circular shape of each undulation (14) being in particular a complete circle or a discontinuous circle, for example the circle being cut by the presence of a fixing point (18) on the plate (6), and the undulations (14) form in particular, in view along the axis of rotation of the propeller (1), concentric circles centered on the center of the plate (6).

8. Helix (1) according to any one of claims 1 to 6, wherein the shapes of the attenuation reliefs (28; 38) are straight or curved lines, different from concentric undulations.

9. Propeller (1) according to any one of claims 1 to 6 or 8, wherein the attenuating reliefs (38) are arranged in an irregular pattern or a random pattern.

10. Propeller (1) according to any one of the preceding claims, wherein the damping reliefs (8; 28; 38), in particular the undulations, extend at least in a peripheral area of ​​the plate (6), in particular between, on the one hand, fixing points for fixing the propeller (1) to a motor and, on the other hand, the outer perimeter of the plate (6).

11. Electric fan (100), in particular for motor vehicles, comprising a propeller (1) according to any one of the preceding claims.

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