EP3450716A1 - Fan wheel and cooling fan module comprising such a fan wheel - Google Patents

Abstract

The present invention relates to a fan wheel 1, comprising a hub pot 10 and a plurality of blade leaves 30, which are arranged on the hub pot 10 and extend from a, in particular at least substantially cylindrical, outer wall 12 of the hub pot 10 in a radially outward direction, wherein each airfoil 30 has a front edge VK and a rear edge HK, wherein for at least one airfoil 30 the course of a relative position of the leading edge POS rel_VK and / or the course of a relative position of the trailing edge POS rel_HK of the airfoil has an aperiodically wavy shape. Furthermore, the present invention relates to a radiator fan module with a fan of the type described above and the use of such a fan in a motor vehicle.

Description

The present invention relates to a fan wheel, in particular with backward-angled blade leaves, for a radiator fan module, in particular an electrically operated radiator fan module, in particular for motor vehicles.

The cooling system of an internal combustion engine, in particular of a motor vehicle, mainly dissipates the heat which is given off to the walls of combustion chambers and cylinders because the combustion process is not ideal. Since too high temperatures would damage the engine (tearing off the lubricating film, burning the valves, etc.), the combustion engine must be actively cooled.

Modern internal combustion engines, especially four-stroke engines in motor vehicles are liquid-cooled, with a few exceptions, with a mixture of water, antifreeze and corrosion inhibitor is usually used as the cooling liquid.

The coolant is pumped via hoses, pipes and / or ducts through the engine (cylinder head and engine block) as well as, if necessary, by thermally stressed engine attachments, such as exhaust gas turbocharger, generator or exhaust gas recirculation cooler. In this case, the cooling liquid absorbs heat energy and dissipates it from the above-mentioned components. The heated coolant continues to flow to a cooler. This cooler - formerly often made of brass, today mostly aluminum - is usually mounted on the front of the motor vehicle, where an air stream absorbs heat energy from the coolant and cools it before it flows back to the engine, whereby the coolant circuit is closed.

To propel the air through the radiator is seen upstream of the radiator (ie, upstream) or downstream of the radiator (ie, downstream) Cooler fan module provided, which can be driven mechanically via a belt drive or electrically via an electric motor. The following statements relate to an electrically driven radiator fan module.

A radiator fan module conventionally consists of a fan cowl, which has a fan wheel recess, and a fan wheel, which is rotatably held in the fan wheel recess.

The geometry of the fan wheel significantly influences both the volume of air delivered and the acoustic properties of the radiator fan module.

Classic fan wheels (s. Figures 1A and 1B ) have on the blades on at least a substantially flat or slightly curved edge geometry.

The present invention has for its object to provide an advantageous fan, which is particularly advantageous in terms of its Luftfördereigenschafen and / or its acoustic properties.

This object is achieved by a fan according to claim 1 and a radiator fan module according to claim 10. Preferred developments of the fan wheel and the radiator fan module are the subject matter of the subclaims and the following description.

wobei R_i ein Außenradius des Nabentopfes ist, was insbesondere wenigstens im Wesentlichen einem Innenradius des Schaufelblattes entspricht; R_a ein Außenradius des Schaufelblattes ist; und r der Abstand zwischen der Rotationsachse und der zu betrachtenden, insbesondere zylinderförmigen, Schnittebene, welche im Abstand r von der Rotationsachse auf der zugehörigen Referenzgerade senkrecht steht, wobei r ∈ [R_i ;R_a ], wobei der Verlauf der Relativposition der Vorderkante POS_{rel_VK}(t) und/oder der Verlauf der Relativposition der Hinterkante POS_{rel_HK}(t) eine aperiodisch wellige Form aufweist.According to the invention the object is achieved by a fan wheel, in particular for a motor vehicle, comprising a hub cup, in particular rotationally symmetrical about a rotation axis; and a plurality of airfoils disposed on the hub shell and extending radially outward from an outer wall, in particular at least substantially cylindrical, of the hub pot, each airfoil having a leading edge and a trailing edge, wherein for at least one airfoil, in particular some of the airfoils, in particular all airfoils, applies: a reference straight line is defined by: a first point on an axis of rotation of the fan wheel; a radial extent through the first point and perpendicular to the axis of rotation; and a second point which divides a circular-arc-shaped edge at the transition from the hub pot to the blade into two segments of equal length, a reference plane being defined by a straight line parallel to the rotation axis and a straight line parallel to the reference straight line, the displacement being such These are in the direction of rotation of the fan considered fully in front of the airfoil, wherein in the reference plane an orthogonal projection of the leading edge of the airfoil and an orthogonal projection of the trailing edge of the airfoil are depicted; wherein in the reference plane a z-axis is defined by an orthogonal projection of the axis of rotation in the reference plane, which is displaced parallel in the reference plane from the orthogonal projection of the axis of rotation about an outer radius of the hub pot in the radial outward direction; wherein in the reference plane a y-axis is defined by an orthogonal projection of the radial extent in the reference plane; wherein on the y-axis a relative unit radius t (r) is plotted, which is defined as follows: $$t\left(r\right)=\frac{r-R_i}{R_a-R_i}$$

wherein R _{i is} an outer radius of the hub pot, which corresponds in particular at least substantially to an inner radius of the airfoil; R _a is an outer radius of the airfoil; and r is the distance between the axis of rotation and the sectional plane to be considered, in particular cylindrical, which is perpendicular at a distance r from the axis of rotation on the associated reference straight line, where r ∈ [ R _i ; R _a ], wherein the course of the relative position of the leading edge POS _{rel_VK} (t) and / or the course of the relative position of the trailing edge POS _{rel_HK} (t) has an aperiodically wavy shape.

This is particularly advantageous according to an embodiment of the present invention, since in this way a favorable air volume flow can be achieved. Comparative measurements, which are explained in detail in the figure description, have shown that a fan according to the present invention can achieve a higher air flow rate, in particular achieved, compared to an otherwise identical fan with flat or curved trailing edge. In other words, the same air volume flow can be generated with a power saving or a slower running fan according to the present invention. Alternatively, a higher air volume flow can be achieved with the same power.

A "fan" in the context of the present invention is in particular a rotationally symmetrical component which a hub, in particular a hub pot, which connects the fan to a motor, in particular via a protruding from this shaft, in such a way that the torque which of the Motor is generated, at least substantially completely transferred to the fan. Furthermore, the fan has a plurality of blades on which provided, in particular are set up to generate an air flow volume as soon as the fan wheel is set in a rotational movement. The blades are preferably inclined relative to the axis of rotation in an angular range of -90 ° to + 90 °.

A "hub pot" in the sense of the present invention is in particular a central part of the fan wheel, which is arranged at least substantially in the middle of the fan wheel, a connection to a drive, in particular a motor, in particular an electric motor provides, this drive, in particular motor , in particular electric motor, at least partially covering and which, like a classical pot, forms an at least substantially flat base surface and a cylindrical surface adjoining it. In particular, the airfoils are arranged on this cylindrical outer wall, in particular integrally formed.

An "airfoil" within the meaning of the present invention is a relative to a plane on which the axis of rotation is perpendicular, inclined flat body, which is arranged on the hub pot and which is provided, in particular adapted to generate a volume of air flow, as soon as the fan in a rotational movement is added. In the context of the present invention, blades are also understood to mean, in particular, blades or rotor blades.

A "leading edge" of the airfoil in the sense of the present invention is in particular that edge which leads in the direction of rotation.

A "trailing edge" of an airfoil in the sense of the present invention is in particular that edge of the airfoil which lags viewed in the direction of rotation.

An "orthogonal projection" in the sense of the present invention is an image of a point on a plane, so that the connecting line between the point and its image forms a right angle with this plane. The image then has the shortest distance to the starting point of all points of the plane. The orthogonal projection is thus a special case of a parallel projection, in which the direction of projection is equal to the normal direction of the plane.

A "relative unit radius" in the sense of the present invention describes a point or a, in particular cylindrical, plane at a defined distance from the rotation axis in a normalized manner, which leads to improved comparability between different fan wheels.

"Aperiodic" in the sense of the present invention is in particular a shape that extends asymmetrically over the relative unit radius, that is, in other words, no symmetry axis can be found which the course of the relative position of the leading edge POS _{rel_VK} (t) and / or the course of the relative position of the trailing edge POS _{rel_HK} (t) divided into two mutually identical sub-functions. In other words, the course of the relative position of the leading edge POS _{rel_VK} (t) and / or the course of the relative position of the trailing edge POS _{rel_HK} (t) is not a function whose function values are repeated at regular intervals.

"Wavy" form in the sense of the present invention is characterized in particular by the fact that the second derivative of the underlying function is always continuous.

In other words, the basic idea of the present invention is to give the leading edge and / or the trailing edge an aperiodically wavy shape, which leads to a unique configuration of the airfoil, as determined by the edge geometry (course of the relative position of the leading or trailing edge). is described. In this form according to the invention is the key to increased air performance and the above-described performance savings.

According to an embodiment of the present invention, the relative position of the leading edge POS _{rel_VK} (t) is referenced to a third point which, viewed in the direction of rotation of the fan wheel, is the foremost point at the transition from the hub cup to the airfoil and / or the relative position of the trailing edge POS _{rel_VK} ( _FIG. t) is referred to a fourth point, which, viewed in the direction of rotation of the impeller, is the rearmost point at the transition from the hub pot to the blade. This is particularly advantageous because in this way the relative position of the leading and / or trailing edge is related back to a defined point in order to be able to determine an absolute position in dependence on the third and / or fourth point from the relative position.

According to a further embodiment of the present invention, the fan wheel on one or more seen in the direction of rotation backward sickle blades. This is particularly important because there are fundamentally different aerodynamic conditions for fan wheels with forward and backward-angled blades, which, inter alia, have a significant influence on the delivered air volume flow. Reverse-sickled in the sense of the present invention means in particular that the tip of the airfoil with the outer radius R _a in the direction of rotation lags the middle of the airfoil.

According to a preferred embodiment of the present invention, the fan wheel has an at least substantially circular outer ring, which connects blade tips of the blades together. This is particularly advantageous because in this way an increased mechanical strength of the fan wheel is achieved and a defined, at least substantially constant, gap between a Zargenring and the outer ring is provided, which in turn leads to advantageous aerodynamic and / or acoustic effects.

According to one embodiment of the present invention, the profile of the relative position of the trailing edge POS _{rel_HK} (t) in the range of 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5%, of the relative unit _radius t ( _FIG. R) of the airfoil (30) on, in particular local, maximum on. This is particularly advantageous because extensive experimental studies have shown that a, in particular local, maximum in the specified range contributes a substantial share to the increase in the air volume flow.

According to one embodiment of the present invention, the profile of the relative position of the leading edge POS _{rel_VK} (t) in the range of 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5%, of the relative unit _radius t ( _FIG. R) of the airfoil (30), in particular a local minimum. This is particularly advantageous since extensive experimental studies have shown that a, in particular local, minimum in the specified range contributes to a substantial proportion to the increase in the air volume flow.

According to a further embodiment of the present invention, the course of the relative position of the trailing edge POS _{rel_HK} (t) in the y-direction after the, in particular local, maximum has no or at most a low point. This is particularly advantageous because in this way the fan expires at least substantially rectilinearly, since extensive tests have shown that more waves after the maximum, especially local, achieve no further significant power savings.

According to a further embodiment of the present invention, the course of the relative position of the leading edge POS _{rel_VK} (t) in the y-direction after the, in particular local, minimum has no or at most a high point. This is particularly advantageous because in this way the fan expires at least substantially rectilinear, since extensive tests have shown that more waves after the, in particular local, minimum achieve no further significant power savings.

According to a further embodiment of the present invention, the course of the relative position of the leading edge POS _{rel_VK} (t) and the course of the relative position of the trailing edge POS _{rel_HK} (t) are at least substantially axisymmetric to one another, in particular the trailing edge POS _{rel_HK} (t) is in a range a geometrically exactly mirrored curve at the symmetry axis of +/- 20%, in particular +/- 10%, of the value of the relative position of the leading edge POS _{rel_VK} (t) . In particular, the symmetry axis corresponds to a line, in particular horizontal, having the following property: $${\mathit{POS}}_{\mathit{rel}}\left(t\right)=0$$

This is particularly advantageous since extensive tests have shown that an at least substantially axisymmetric course of front and rear edge to each other achieves particularly positive results.

In other words, a curved pivot axis runs through the blade leaf centrally or slightly off-center, eg at 40% of the blade airfoil in the direction of rotation, around which incremental disks of the airfoil, which are perpendicular to the pivot axis, are aligned individually. This results in a functional relationship between the course of the relative position of the leading edge POS _{rel_VK} (t) and the course of the relative position of the trailing edge POS _{rel_HK} (t) via the pivot axis .

wobei gilt:

• t ₀ ∈[0;0,5], insbesondere t ₀ ∈[0;0,25], insbesondere t ₀ ∈[0;0,1]
• N ∈[1;8], insbesondere N ∈[2;5], insbesondere N ∈[2;4]
• a ∈[-1,5;1,5], insbesondere a ∈[-1,0;1,0], insbesondere a ∈[-0,5;0,5]
• A₁ ∈[-10;10], insbesondere A₁ ∈[-8;8], insbesondere A₁ ∈[-5;5]
• A₂ ∈[-10;10], insbesondere A₂ ∈[-8;8], insbesondere A₂ ∈[-5;5]
• A₃ ∈[-10;10], insbesondere A₃ ∈[-8;8], insbesondere A₃ ∈[-5;5]; und
• A ₄ ∈[-10;10], insbesondere A ₄ ∈[-8;8], insbesondere A ₄ ∈[-5;5].

According to a further embodiment of the present invention, the profile of the relative position of the leading edge POS _{rel_VK} (t) as a function of the relative unit radius t (r) satisfies the following condition: $${\mathit{POS}}_{\mathit{rel\_VK}}\left(t\right)=\frac{-\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where:

• t ₀ ∈ [0, 0,5], in particular t ₀ ∈ [0, 0,25], in particular t ₀ ∈ [0, 0,1]
• N ∈ [1; 8], in particular N ∈ [2; 5], in particular N ∈ [2; 4]
• a ∈ [-1,5; 1,5], in particular a ∈ [-1,0; 1,0], in particular a ∈ [-0,5; 0,5]
• A ₁ ∈ [-10; 10], in particular A ₁ ∈ [-8; 8], in particular A ₁ ∈ [-5; 5]
• A ₂ ∈ [-10; 10], in particular A ₂ ∈ [-8; 8], in particular A ₂ ∈ [-5; 5]
• A ₃ ∈ [-10; 10], in particular A ₃ ∈ [-8; 8], in particular A ₃ ∈ [-5; 5]; and
• A ₄ ∈ [-10; 10], in particular A ₄ ∈ [-8; 8], in particular A ₄ ∈ [-5; 5].

t ₀ describes an offset of the relative unit radius for setting the vertex at the hub, N the number of oscillations over the axial unit radius, a a vibration coefficient for scaling the wavelength and the adjustment of the position of, in particular local, minimum A ₁ a quadratic polynomial coefficient, A _{2 is} a linear polynomial coefficient, A _{3 is} a coefficient of axial threading, ie for adjusting the linear course of the leading edge of the hub cup to the blade tip and the outer ring and A _{4 is} a relative Basisauslenkung ("start" deflection) of the leading edge of the hub pot. The above function describes the aperiodically wavy shape of the course of the relative position of the leading edge POS _{rel_VK} (t). Using the specified parameters, it is possible to adapt the course of the relative position of the leading edge POS _{rel_VK} (t) to the external conditions in the course of the fan wheel design, in order thus to achieve an advantageous power _saving or equivalent increase in air volume flow.

wobei gilt:

• t ₀ ∈[0;0,5], insbesondere t ₀ ∈[0;0,25], insbesondere t ₀ ∈[0;0,1]
• N ∈[1;8], insbesondere N ∈[2;5], insbesondere N ∈[2;4]
• a ∈[-1,5;1,5], insbesondere a ∈[-1,0;1,0], insbesondere a ∈[-0,5;0,5]
• A ₁ ∈[-10;10], insbesondere A₁ [-8; 8], insbesondere A ₁ ∈[-5;5]
• A ₂ ∈[-10;10], insbesondere A ₂ ∈[-8;8], insbesondere A ₂ ∈[-5;5]
• A ₃ ∈[-10;10], insbesondere A ₃ ∈[-8;8], insbesondere A ₃ ∈[-5;5]; und
• A ₄ ∈[-10;10], insbesondere A ₄ ∈[-8;8], insbesondere A ₄ ∈[-5;5].

According to a further embodiment of the present invention, the profile of the relative position of the trailing edge POS _{rel_HK} (t) as a function of the relative unit radius t (r) fulfills the following condition: $${\mathit{POS}}_{\mathit{rel\_HK}}\left(t\right)=\frac{\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where:

• t ₀ ∈ [0, 0,5], in particular t ₀ ∈ [0, 0,25], in particular t ₀ ∈ [0, 0,1]
• N ∈ [1; 8], in particular N ∈ [2; 5], in particular N ∈ [2; 4]
• a ∈ [-1,5; 1,5], in particular a ∈ [-1,0; 1,0], in particular a ∈ [-0,5; 0,5]
• A ₁ ∈ [-10; 10], in particular A ₁ [-8; 8], in particular A ₁ ∈ [-5; 5]
• A ₂ ∈ [-10; 10], in particular A ₂ ∈ [-8; 8], in particular A ₂ ∈ [-5; 5]
• A ₃ ∈ [-10; 10], in particular A ₃ ∈ [-8; 8], in particular A ₃ ∈ [-5; 5]; and
• A ₄ ∈ [-10; 10], in particular A ₄ ∈ [-8; 8], in particular A ₄ ∈ [-5; 5].

t ₀ describes an offset of the relative unit radius for setting the vertex at the hub, N the number of oscillations over the axial unit radius, a a vibration coefficient for scaling the wavelength and the adjustment of the position of, in particular local, maximum, A ₁ a quadratic polynomial coefficient, A ₂ a linear polynomial coefficient, A ₃ a coefficient of axial Auffädelung, ie for adjusting the linear course of the trailing edge of the hub cup to the blade tip and the outer ring and A ₄ a relative Basisauslenkung ("Start" -Auslenkung) of the trailing edge of the hub pot. The above function describes the aperiodically wavy shape of the course of the relative position of the trailing edge POS _{rel_HK} (t). Using the specified parameters, it is possible to adapt the course of the relative position of the trailing edge POS _{rel_HK} (t) to the external conditions in the course of the fan wheel design in order to achieve an advantageous power _saving or equivalent increase in air volume flow.

The fan according to the invention according to one of the embodiments described here is particularly intended for use in conjunction with a fan cowl with front struts, i. the struts are seen in the main direction of flow in front of the fan.

A further aspect of the present invention relates to a radiator fan module, in particular for a motor vehicle, comprising a fan cowl, a fan wheel recess which is formed in the fan cowl, wherein the fan wheel recess is delimited by a frame ring, a motor holder which is arranged inside the fan wheel recess and which Struts with the fan cowl is mechanically connected, a motor, in particular an electric motor, which is at least partially held in the motor holder, and a fan wheel, which is arranged in the Lüfterradausnehmung and which is rotationally driven by the motor, wherein the fan wheel according to an embodiment of the present Invention is formed.

A "radiator fan module" in the sense of the present invention is in particular an assembly which, viewed in the flow direction, is arranged before or after a radiator of a vehicle and which is provided, in particular adapted, to generate an air volume flow which passes through or around the radiator extends around the radiator, wherein the air volume flow receives thermal energy from the radiator.

A "fan cowl" in the sense of the present invention is in particular a frame in which the fan wheel is held, and in turn is preferably arranged on or in the vicinity of a radiator, in particular fastened. A fan cowl according to the present invention preferably has a plastic material, in particular a plastic compound, in particular, the fan cowl is formed from this. Additionally and / or alternatively, the fan cowl comprises a metal material, for example iron, steel, Aluminum, magnesium or the like, on, in particular is at least partially, in particular at least substantially, in particular completely, formed from this. According to one embodiment, a fan shroud may also have more than one Lüfterradausnehmung, a motor holder, a motor and a fan, in particular, the present invention is suitable for use in radiator fan modules with two or more, in particular two, fan wheels. According to one embodiment, the fan frame additionally has at least one closable opening, in particular at least one flap, in particular a plurality of the same. This is particularly advantageous since further air-guiding properties can be realized in this way.

A "Lüfterradausnehmung" within the meaning of the present invention is in particular a material recess within the fan cowl. In the Lüfterradausnehmung extend according to an embodiment of the present invention struts, which mechanically, in particular and electrically and / or electronically connect a likewise arranged in the Lüfterradausnehmung motor holder with the fan frame. According to the present invention, the Lüfterradausnehmung is limited by a Zargenring.

A "Zargenring" within the meaning of the present invention limits the Lüfterradausnehmung in a plane perpendicular to the axis of rotation of the fan wheel, wherein the plane is at least substantially identical, in particular with the extension direction of the fan cowl. The Zargenring can either be formed by an edge of Lüfterradausnehmung and / or have an expanding cylinder in the axial direction, which is preferably formed integrally with the fan cowl.

A "motor holder" in the sense of the present invention is in particular a device for mechanically fixing the motor to the fan cowl, in particular for providing the torque counteracting the fan wheel. According to one embodiment, the motor holder is an at least substantially annular structure in which the motor is held. This is particularly advantageous because in this way an advantageous cooling air flow is not affected by the engine.

"Struts" in the sense of the present invention are in particular beam or crescent-shaped structures which provide a mechanical connection between the engine mount and the fan cowl. By way of example, the struts may have a drop-shaped cross section in order to achieve advantageous aerodynamic and / or acoustic effects.

A "motor" in the sense of the present invention is in particular a machine that performs mechanical work by converting an energy form, for example thermal / chemical or electrical energy, into kinetic energy, in particular a torque. This is particularly advantageous, since in this way the fan cowl can be operated at least substantially independently, except for the supply of energy, that is, without being supplied externally with kinetic energy, such as a wedge or toothed belt.

An "electric motor" in the sense of the present invention is an electromechanical converter (electric machine), which converts electrical power into mechanical power, in particular into a torque. The term electric motor within the meaning of the present invention includes, but is not limited to, DC motors, AC motors and three-phase motors or brushless and brushless electric motors or internal rotor and external rotor motors. This is particularly advantageous since electrical energy represents an energy form that is easy to transmit compared to mechanical or chemical energy, with which the required torque is provided for driving the fan wheel.

For the advantages of such a designed radiator fan module reference is made to avoid repetition of the above statements.

According to one embodiment of the present invention, the struts of the radiator fan module are arranged in front of the fan as seen in the flow direction. This is particularly relevant, since front and rear struts lead to substantially different aerodynamic conditions and the fan described here can be used particularly advantageously in vorne leaning struts, as extensive experiments showed.

Another aspect of the present invention relates to the use of a fan wheel of the type described herein or a radiator fan module of the type described herein in a motor vehicle. This is particularly important because the type of a fan wheel described here comes into play in a particularly advantageous manner with the external conditions at the installation.

Fig. 1A

ein Lüfterrad aus dem Stand der Technik in einer perspektivischen Darstellung mit Blick auf die Oberseite;

Fig. 1B

eine Vorderansicht auf ein Schaufelblatt des bekannten Lüfterrades der Fig. 1A mit Blickrichtung aus der Referenzebene in einer perspektivischen Darstellung, wobei die Oberseite des Lüfterrades nach unten weist;

Fig. 2A

ein Lüfterrad nach einer Ausführungsform der vorliegenden Erfindung in einer perspektivischen Darstellung mit Blick auf die Oberseite;

Fig. 2B

eine Vorderansicht auf ein Schaufelblatt des Lüfterrades der Fig. 2A mit Blickrichtung aus der Referenzebene in einer perspektivischen Darstellung, wobei die Oberseite des Lüfterrades nach unten weist;

Fig. 3

ein Lüfterrad aus dem Stand der Technik in einer perspektivischen Darstellung zur Beschreibung einer Referenzebene;

Fig. 4

den Verlauf der Relativposition der Vorderkante POS_{rel_VK}(t) und der Relativposition der Hinterkante POS_{rel_HK}(t) über den relativen Einheitsradius eines Lüfterrades gemäß einer Ausführung der vorliegenden Erfindung;

Fig. 5

einen Vergleich eines vorbekannten Lüfterrades mit einem Lüfterrad nach einer Ausführung der vorliegenden Erfindung; und

Fig. 6

ein Kühlerlüftermodul mit dem Lüfterrad gemäß der vorliegenden Erfindung gemäß dem zweiten Aspekt der vorliegenden Erfindung.

Further advantageous developments of the present invention will become apparent from the dependent claims and the following description of preferred embodiments. This shows, partially schematized:

Fig. 1A

a fan from the prior art in a perspective view overlooking the top;

Fig. 1B

a front view of an airfoil of the known fan of the Fig. 1A with view from the reference plane in a perspective view, the top of the fan wheel facing down;

Fig. 2A

a fan according to an embodiment of the present invention in a perspective view facing the top;

Fig. 2B

a front view of an airfoil of the fan wheel of Fig. 2A with view from the reference plane in a perspective view, the top of the fan wheel facing down;

Fig. 3

a fan wheel of the prior art in a perspective view for describing a reference plane;

Fig. 4

the course of the relative position of the leading edge POS _{rel_VK} (t) and the relative position of the trailing edge POS _{rel_HK} (t) on the relative unit _{radius of} a fan wheel according to an embodiment of the present invention;

Fig. 5

a comparison of a prior art fan with a fan wheel according to an embodiment of the present invention; and

Fig. 6

a radiator fan module with the fan according to the present invention according to the second aspect of the present invention.

Fig. 1A shows a fan 1 of the prior art in a perspective view with a view of the top and Fig. 1B shows a front view of an airfoil 30 of the known fan of the Fig. 1A with a view from the reference plane in a perspective view, wherein the top (corresponding to the suction side) of the fan wheel 1 points downward.

The fan 1 has according to the Fig. 1A . 1B . 2A . 2 B and 3 a about a rotational axis R rotationally symmetrical hub pot 10. At the hub pot 10, a plurality of blades 30 is arranged, extending from a cylindrical outer wall 12th of the hub pot 10 extend in the radial direction to the outside. One direction of rotation D is in the Fig. 1A and 2A indicated by an arrow. Accordingly, the direction of rotation is counterclockwise. A main flow direction of the conveyed air is marked with HSR. The fan wheel 1 has an at least substantially circular outer ring 20 which connects blade tips of the blades 30 together.

Regarding the Fig. 1B (and the Fig. 2B ), it should be noted that the position of the axis of rotation R with respect to its distance from the cylindrical outer wall 12 of the hub cup 10 or the inner edge of the blade 30 (indicated by the points P3 and P4) is not to scale, ie the orientation is binding, the situation is not.

Like that Fig. 1A and 1B can be seen, the blades 30 according to the prior art in an orthogonal projection flat or curved leading edges VK and planar or curved trailing edges HK.

Fig. 2A shows a fan 1 according to an embodiment of the present invention in a perspective view and Fig. 2B a front view of an airfoil 30 of the fan wheel of Fig. 2A with view from the reference plane E_REF in a perspective view.

In comparison with embodiments of a fan wheel 1 according to the prior art (see Figures 1A and 1B ) has the fan 1 according to an embodiment of the present invention according to the Fig. 2A . 2 B Blades 30 with an aperiodic wavy trailing edge HK on.

Regarding the perspective of the sectional view is to the following comments to Fig. 3 directed.

Fig. 3 shows a fan 1 of the prior art in a perspective view for describing a reference plane E_REF.

In the following, the viewing plane for the description of leading edge VK and trailing edge HK is to be defined. This in Fig. 3 shown impeller has no inventive blade geometry, which is not relevant to the description of the reference plane E_REF, since the relevant embodiments apply in the same way for embodiments of the invention.

Starting from the axis of rotation R, a reference straight line G_REF is defined by a first point P1 on the axis of rotation R of the fan wheel 1, a radial extent E through the first point P1 and perpendicular to the axis of rotation R and a second point P2, which forms an arcuate edge at the junction divided from the hub pot 10 to the blade 30 in two equal lengths sections. In other words, the radius which passes through the point P2 is determined. The point P2 represents the midpoint of the transition edge of hub pot 10 to blade 30, in particular the edge of the blade 30 facing the bottom of the pot. Another at least substantially identical definition of P2 can be derived from an angle: two auxiliary radii are required, the first one Auxiliary radius through P1 and a third point P3 of the transition edge between the cylindrical outer wall and the blade extends and a second auxiliary radius which passes through a fourth point P4 of the transition edge of the hub pot 10 to the blade 30 and from this angle, which is enclosed between the two auxiliary radii , the bisecting line is formed. The point at which said bisector intersects the cylindrical outer wall 12, in particular at an outer side thereof, is P2. Starting from G_REF, a reference plane E_REF is defined by a straight line parallel to the rotation axis R and a straight line parallel to the reference straight line G_REF, wherein the displacement is such that, viewed in the direction of rotation D of the fan wheel 1, it is located completely in front of the airfoil 30. On the reference plane E_REF, an orthogonal projection of the leading edge VK of the airfoil 10 and an orthogonal projection of the trailing edge HK of the airfoil 10 are depicted. The viewing direction B shows, as in the Fig. 1B and 2 B is looked at in each case an airfoil segment of the fan wheel 1.

In the reference plane E_REF, a coordinate system consisting of z-axis and y-axis is spanned. This is _decisive for the description of the course of the relative position of the leading edge POS _{rel_VK} (t) and the course of the relative position of the trailing edge POS _{rel_ HK} ( t ). The z-axis is defined by an orthogonal projection of the axis of rotation R in the reference plane E_REF, which is displaced in a second step in the reference plane E_REF from the orthogonal projection of the axis of rotation R by an outer radius R _{i of} the hub pot 10 in the radial direction outward in parallel. In other words, the z-axis is unchanged in its orientation but is shifted in parallel in two steps, namely once by the orthogonal projection to the reference plane E_REF and then by the shift in the reference plane E_REF by R _i . This means that the z-axis passes through the orthogonal projection from P2 to E_REF. The y-axis is defined by an orthogonal projection of the radial extent E in the reference plane E_REF. The origin This yz coordinate system is defined by the intersection of the two axes.

wobei

R_i

ein Außenradius des Nabentopfes 10 ist, was insbesondere wenigstens im Wesentlichen einem Innenradius des Schaufelblattes 30 entspricht;

R_a

ein Außenradius des Schaufelblattes 30 ist; und

r

der Abstand zwischen der Rotationsachse R und der zu betrachtenden Schnittebene S, welche im Abstand r von der Rotationsachse R auf der zugehörigen Referenzgerade G_REF senkrecht steht, wobei r ∈[R_i;R_a ].

On the y-axis, a relative unit radius t (r) is plotted, which is defined as follows: $$t\left(r\right)=\frac{r-R_i}{R_a-R_i}$$

in which

R _i

is an outer radius of the hub pot 10, which corresponds in particular at least substantially to an inner radius of the blade 30;

R _a

an outer radius of the airfoil 30 is; and

r

the distance between the axis of rotation R and the sectional plane S to be considered, which is perpendicular at a distance r from the axis of rotation R on the associated reference line G_REF, where r ∈ [ R _i ; R _a ] .

Fig. 4 ₁ shows the profile of the relative position of the leading edge POS _{reL_VK} (t) and the relative position of the trailing edge POS _{rel_HK} (t) via the relative unit _{radius of} a fan wheel according to an embodiment of the present invention.

The horizontal axis corresponds to the y-axis described above, and the vertical axis corresponds to the z-axis described above. On the horizontal axis, the relative unit radius t (r) is plotted.

On the vertical axis, the profile of the relative position of the leading edge POS _{reL_VK} (t) and the course of the relative position of the trailing edge POS _{rel_HK} (t) are each presented in standardized form.

und die Relativposition der Hinterkante POS_{rel_HK}(t) ergibt sich durch $${\mathit{POS}}_{\mathit{rel\_HK}}\left(t\right)=\frac{\left(A_1{t}^2+A_{2}t\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+t_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

wobei jeweils t ₀ einen Offset des relativen Einheitsradius zur Einstellung des Scheitelpunktes am Nabentopf, N die Anzahl der Schwingungen über den axialen Einheitsradius, a einen Schwingungskoeffizienten zur Skalierung der Wellenlänge und der Einstellung der Lage des , insbesondere lokalen, Extrempunkts (d.h. für die Vorderkante: Minimum; für die Hinterkante: Maximum), A₁ einen quadratischen Polynomkoeffizienten, A₂ einen linearen Polynomkoeffizienten, A₃ einen Koeffizienten der axialen Auffädelung, d.h. zur Einstellung des linearen Verlaufs der Vorder- bzw. Hinterkante vom Nabentopf zur Schaufelblattspitze bzw. zum Außenring und A ₄ eine relative Basisauslenkung ("Start"-Auslenkung) der Vorder- bzw. Hinternkante am Nabentopf beschreibt. Die oben genannten Funktionen beschreiben die aperiodisch wellige Form des Verlaufs der Relativposition der Vorderkante POS_{rel_VK}(t) sowie der Hinterkante POS_{rel_HK}(t). The relative position of the leading edge POS _{reL_VK} (t) is given by $${\mathit{POS}}_{\mathit{rel\_VK}}\left(t\right)=\frac{-\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

and the relative position of the trailing edge POS _{rel_HK} (t) is given by $${\mathit{POS}}_{\mathit{rel\_HK}}\left(t\right)=\frac{\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where each t _{0 is} an offset of the relative unit radius for adjusting the vertex at the hub, N is the number of oscillations over the axial unit radius, a is a vibration coefficient for scaling the wavelength and adjusting the position of, in particular local, extreme point (ie for the leading edge: Minimum for the trailing edge: maximum), A ₁ a quadratic polynomial coefficient, A ₂ a linear polynomial coefficient, A ₃ a coefficient of axial threading, ie for adjusting the linear course of the leading edge and trailing edge of the hub pot to the blade tip and the outer ring and A _{4 describes} a relative base deflection ("start" deflection) of the front and rear edges at the hub pot. The functions described above describe the aperiodically wavy shape of the course of the relative position of the leading edge POS _{rel_VK} (t) and the trailing edge POS _{rel_HK} (t).

It can be seen that the profile of the relative position of the trailing edge POS _{rel_HK} (t) ranges from 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5%, of the relative unit radius t (r ) of the airfoil (30), in particular local, maximum and the course of the relative position of the leading edge POS _{reL_VK} (t) in the range of 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5 %, of the relative unit radius t (r) of the airfoil (30), in particular local minimum.

As the exemplary embodiment of Fig. 4 can also be seen, the course of the relative position of the trailing edge POS _{rel_HK} (t) in the y direction after the, in particular local, maximum no or at most a low point and / or the course of the relative position of the leading edge POS _{rel_VK} (t) in y Direction according to, in particular local, minimum no or at most a high point on.

Again Fig. 4 It can also be seen that the course of the relative position of the leading edge POS _{rel_VK} (t) and the course of the relative position of the trailing edge POS _{rel_HK} (t) are at least substantially axisymmetric to each other; in particular, the trailing edge POS _{rel_HK} (t) _extends in a region around a geometric one uniquely determined course of a mirrored curve of +/- 20%, in particular +/- 10%, of the value of the relative position of the leading edge POS _{rel_VK} (t).

wobei gilt:

• t ₀ ∈[0;0,5]
• N ∈[1;8]
• a ∈[-1,5;1,5]
• A ₁ ∈[-10;10]
• A ₂ ∈[-10;10]
• A ₃ ∈[-10;10] und
• A ₄ ∈[-10;10].

The course of the relative position of the leading edge POS _{rel_VK} (t) of the exemplary embodiment of the Fig. 4 follows as a function of the relative unit radius t (r) the following condition: $${\mathit{POS}}_{\mathit{rel\_VK}}\left(t\right)=\frac{-\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where:

• t ₀ ∈ [0, 0.5]
• N ∈ [1; 8]
• a ∈ [-1,5; 1,5]
• A ₁ ∈ [-10; 10]
• A ₂ ∈ [-10; 10]
• A ₃ ∈ [-10; 10] and
• A ₄ ∈ [-10; 10].

wobei gilt:

• t ₀ ∈[0;0,5]
• N ∈[1;8]
• a ∈[-1,5;1,5]
• A ₁ ∈[-10;10]
• A ₂ ∈[-10;10]
• A ₃ ∈[-10;10] und
• A ₄ ∈[-10;10]

The course of the relative position of the trailing edge POS _{rel_HK} (t) of the exemplary embodiment of the Fig. 4 follows as a function of the relative unit radius t (r) the following condition: $${\mathit{POS}}_{\mathit{rel\_HK}}\left(t\right)=\frac{\left(A_1{\mathrm{<figure-callout\; id="2"\; label="t"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t</figure-callout>}}^2+A_2\mathrm{<figure-callout\; id="2"\; label="t\; cos"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">t\; </figure-callout>}\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+{\mathrm{<figure-callout\; id="0"\; label="t"\; filenames="imgf0006.png,imgf0007.png"\; state="\{\{state\}\}">t</figure-callout>}}_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where:

• t ₀ ∈ [0, 0.5]
• N ∈ [1; 8]
• a ∈ [-1,5; 1,5]
• A ₁ ∈ [-10; 10]
• A ₂ ∈ [-10; 10]
• A ₃ ∈ [-10; 10] and
• A ₄ ∈ [-10; 10]

• t ₀ = 0,04
• N = 4
• a = 0
• A ₁ = 0
• A ₂ = 2
• A ₃ = 4 und
• A ₄ = 0.

The in Fig. 4 illustrated course of the relative position of the leading edge POS _{rel_VK} (t) is at least substantially, in particular absolute, on the basis of the following parameters:

• t ₀ = 0.04
• N = 4
• a = 0
• A ₁ = 0
• A ₂ = 2
• A ₃ = 4 and
• A ₄ = 0.

• t ₀ = 0,04
• N = 4
• a = 0
• A ₁ =0
• A ₂ =2
• A ₃ =-5 und
• A ₄ = 0.

The in Fig. 4 illustrated course of the relative position of the trailing edge POS _{rel_HK} (t) is at least substantially, in particular absolute, based on the following parameters:

• t ₀ = 0.04
• N = 4
• a = 0
• A ₁ = 0
• A ₂ = 2
• A ₃ = -5 and
• A ₄ = 0.

The Fig. 5 shows a comparison of a prior art impeller 1 with a fan 1 according to an embodiment of the present invention.

• eine Druckzahl Ψ, welche als dimensionslose, von wirksamem Lüfterraddurchmesser D_W, der Luftdichte ρ und der Drehzahl n unabhängige Kennzahl das durch das Lüfterrad erzeugte Totaldruckgefälle Δp_t (setzt sich zusammen aus statischen und dynamischen Anteilen) zwischen stromaufwärtiger und stromabwärtiger Seite desselben beschreibt: $$\psi =\frac{2{\mathrm{\Delta }\mathit{<figure-callout\; id="2"\; label="p\; t\; \pi "\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">p</figure-callout>}}_t}{{\pi }^{}}$$
  
• eine Leistungszahl λ, welche als dimensionslose, von wirksamem Lüfterraddurchmesser D_W, der Luftdichte ρ und der Drehzahl n unabhängige Kennzahl eine Eingangs-Leistung P_wel beschreibt: $$\lambda =\frac{8P_{\mathit{wel}}}{{\pi }^4{\mathit{\rho D}}_w^s{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}$$
  
  Als Eingangs-Leistung P_wel wird hier die Wellenleistung des Elektromotors herangezogen, wobei entsprechende Verluste (Wärme, Reibung etc.) des Elektromotors nicht berücksichtigt sind.

Being represented:

• a pressure factor Ψ, which as dimensionless, of effective fan diameter D _W , the air density ρ and the rotational speed n independent Characteristic number the total pressure gradient Δp _t generated by the fan wheel (made up of static and dynamic portions) between the upstream and the downstream side of the same: $$\psi =\frac{2{\mathrm{\Delta }\mathit{<figure-callout\; id="2"\; label="p\; t\; \pi "\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">p\; </figure-callout>}}_t}{{\pi }^{}}$$
  
• a coefficient of performance λ, which describes an input power P _wel as dimensionless, independent of effective fan diameter D _W , the air density ρ and the rotational speed n: $$\lambda =\frac{\mathrm{8th}{P}_{\mathit{wel}}}{{\pi }^4{\mathit{\rho D}}_w^s{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="imgf0007.png,imgf0008.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}$$
  
  As the input power P _wel here the shaft power of the electric motor is used, with corresponding losses (heat, friction, etc.) of the electric motor are not taken into account.

Furthermore it is shown:
an overall efficiency η which relates the input power P _wel with the generated total pressure drop Δp _t via the delivered volume flow V̇ . $$\eta =\frac{{\mathrm{\Delta }\mathit{p}}_t\dot{V}}{P_{\mathit{wel}}}$$

On the x-axis of the diagram, a volume number φ is plotted, which describes the funded volume flow V̇ as a dimensionless, independent of effective fan diameter D _W and the speed n characteristic number: $$\phi =\frac{4\dot{V}}{{\pi }^2{D}_w^{3}n}$$

In other words: The given indices are diminished with the circle number π , the air density ρ in kg / m ³ , the effective diameter ( D _w = 2 R _a ) in m and the speed n in 1 / s. Thus, the comparability with non-identical fan wheels is given.

As can be seen, with almost the same power (similar coefficient of performance), a higher pressure factor (=> total pressure increase) is achieved, resulting in a significant increase in efficiency in the relevant volume number range.

Fig. 6 shows a radiator fan module 100 with the fan 1 according to the present invention according to the second aspect of the present invention.

The cooling fan module 100 has a fan frame 2, wherein a Lüfterradausnehmung 40 is formed in the fan frame 2, which is bounded by a Zargenring 42. A motor holder (hidden by the hub 10) is disposed within the Lüfterradausnehmung 40 and mechanically connected by struts 44 with the fan frame 2. In the motor holder, a motor, in particular an electric motor, at least partially held (also hidden by the hub pot 10). A fan 1 is disposed in the Lüfterradausnehmung 40 and is rotationally driven by the motor. The fan 1 corresponds to an embodiment of a fan 1 according to the present invention. For detailed design of the fan wheel 1, reference is made to the above statements. The struts 44 are according to the embodiment of the Fig. 6 Seen in the flow direction in front of the fan, wherein the flow direction perpendicular from the figure of Fig. 6 shows out.

Although exemplary embodiments have been explained in the foregoing description, it should be understood that a variety of modifications are possible. In particular, such an inventive design of the fan cowl is also suitable to dissipate waste heat from components of a purely electrically operated vehicle. It should also be noted that the exemplary embodiments are merely examples that are not intended to limit the scope, applications and construction in any way. Rather, the expert is given by the preceding description, a guide for the implementation of at least one exemplary embodiment, with various changes, in particular with regard to the function and arrangement of the components described, can be made without departing from the scope, as it turns out according to the claims and these equivalent combinations of features. <B> LIST OF REFERENCES </ b> 1 fan 2 frame 10 hub pot 12 (Cylindrical) outer wall of the hub pot 10 20 outer ring 30 airfoil 40 Lüfterradausnehmung 42 Frame ring 44 pursuit 100 Cooling fan module HK trailing edge VK leading edge B line of sight D direction of rotation e Radial extent E_REF reference plane G_REF reference line HSR Main current direction P1 First point P2 Second point P3 third point P4 Fourth point POS _{reL_VK} (t) Relative position of the leading edge POS _{rel_HK} (t) Relative position of the trailing edge r Distance between axis of rotation R and section plane S R axis of rotation R _a Outer radius of the airfoil 30 R _i Outer radius of the hub 10 S cutting plane y y-axis z z-axis

Claims (12)

Fan (1), in particular for a motor vehicle, comprising
a, in particular about an axis of rotation (R) rotationally symmetrical, hub pot (10); and
a plurality of blade leaves (30), which are arranged on the hub pot (10) and extend radially outwardly from a, in particular at least substantially cylindrical, outer wall (12) of the hub pot (10),
each blade (30) having a leading edge (VK) and a trailing edge (HK),
wherein for at least one airfoil (30), in particular some of the airfoils (30), in particular all airfoils (30), the following applies: a reference line (G_REF) is defined by: a first point (P1) on an axis of rotation (R) of the fan wheel (1); a radial extent (E) through the first point (P1) and perpendicular to the axis of rotation (R); and a second point (P2), which divides a circular arc-shaped edge at the transition from the hub pot (10) to the blade (30) into two sections of equal length, wherein a reference plane (E_REF) is defined by a straight line parallel to the axis of rotation (R) and a straight line parallel to the reference line (G_REF), the displacement being such that it is completely in the direction of rotation (D) of the fan wheel (1) located in front of the airfoil (30), wherein in the reference plane (E_REF) an orthogonal projection of the leading edge (VK) of the airfoil (30) and an orthogonal projection of the trailing edge (HK) of the airfoil (30) are depicted; wherein in the reference plane (E_REF) a z-axis is defined by an orthogonal projection of the rotation axis (R) in the reference plane (E_REF), which in the reference plane (E_REF) from the orthogonal projection of the rotation axis (R) around an outer radius (R _i ) of the hub pot (10) is displaced in the radial direction outwards in parallel; wherein in the reference plane a y-axis is defined by an orthogonal projection of the radial extent (E) in the reference plane (E_REF); wherein on the y-axis a relative unit radius t (r) is plotted, which is defined as follows: $$t\left(r\right)=\frac{r-R_i}{R_a-R_i}$$

in which R _{i is} an outer radius of the hub pot (10), which corresponds in particular at least substantially to an inner radius of the airfoil (30); R _a is an outer radius of the airfoil (30); and r is the distance between the axis of rotation (R) and the sectional plane (S) to be considered, which is perpendicular to the associated reference line (G_REF) at a distance r from the axis of rotation (R), where r ∈ [ R _i ; R _a ] wherein on the z-axis a relative position of the leading edge POS _{rel_VK} and / or a relative position of the trailing edge POS _{rel_HK is} applied
wherein the course of the relative position of the leading edge POS _{reL_VK} (t) and / or the course of the relative position of the trailing edge POS _{rel_HK} (t) has an aperiodically wavy shape. Fan wheel according to claim 1, wherein
the relative position of the leading edge POS _{rel_VK} (t) is referenced to a third point (P3) which, viewed in the direction of rotation (D) of the fan wheel (1), is the foremost point at the transition from the hub cup (10) to the airfoil (30); and or
the relative position of the trailing edge POS _{rel_HK} (t) is referenced to a fourth point (P4), which in the direction of rotation (D) of the fan wheel (1) is the rearmost point at the transition from the hub pot (10) to the blade (30). Fan impeller according to one of claims 1 or 2, wherein the airfoil (30) in the direction of rotation (D) seen backward sickle blade (30). Fan wheel according to one of the preceding claims, wherein the fan wheel (1) has an at least substantially circular outer ring (20), which leaf tips of the blades (30) interconnects. Fan wheel according to one of the preceding claims, wherein
the course of the relative position of the trailing edge POS _{rel_HK} (t) in the range of 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5%, of the relative unit radius t (r) of the airfoil (30) a, in particular local, maximum has; and or
the course of the relative position of the leading edge POS _{rel_VK} (t) in the range of 80% to 100%, in particular 90% to 100%, in particular 92.5% to 97.5%, of the relative unit radius t (r) of the airfoil (30) a, in particular local, minimum has. Fan wheel according to the preceding claim, wherein the course of the relative position of the trailing edge POS _{rel_HK} (t) in the y-direction after the, in particular local, maximum has no or at most one low point; and or
the course of the relative position of the leading edge POS _{rel_VK} (t) in the y-direction after the, in particular local, minimum has no or at most one high point. Fan wheel according to one of the preceding claims, wherein the course of the relative position of the leading edge POS _{rel_VK} (t) and the course of the relative position of the trailing edge POS _{rel_HK} (t) are at least substantially axisymmetric to each other, in particular the trailing edge POS _{rel_HK} (t) in a range a geometrically uniquely determined course of a mirrored curve of +/- 20%, in particular +/- 10%, of the value of the relative position of the leading edge POS _{rel_VK} (t). Fan wheel according to one of the preceding claims, wherein the profile of the relative position of the leading edge POS _{rel_VK} (t) in dependence on the relative unit radius t (r) satisfies the following condition: $${\mathit{POS}}_{\mathit{rel\_VK}}\left(t\right)=\frac{-\left(A_1{t}^2+A_{2}t\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+t_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where: t ₀ ∈ [0; 0.5] N ∈ [1; 8] a ∈ [-1,5; 1,5] A ₁ ∈ [-10; 10] A ₂ ∈ [-10; 10] A ₃ ∈ [-10; 10] and A ₄ ∈ [-10; 10]. Fan impeller according to one of the preceding claims, wherein the course of the relative position of the trailing edge POS _{rel_HK} (t) in dependence on the relative unit radius t (r) satisfies the following condition: $${\mathit{POS}}_{\mathit{rel\_HK}}\left(t\right)=\frac{\left(A_1{t}^2+A_{2}t\right)\cos \left[2\mathit{\pi N}\left(a\left(1-t\right)+1\right)\left(t+t_0\right)\right]+A_{3}t+A_4}{R_a-R_i}$$

where: t ₀ ∈ [0, 0.5] N ∈ [1; 8] a ∈ [-1,5; 1,5] A ₁ ∈ [-10; 10] A ₂ ∈ [-10; 10] A ₃ ∈ [-10; 10] and A ₄ ∈ [-10; 10]. Radiator fan module (100), in particular for a motor vehicle, comprising: a fan cowl (2); a Lüfterradausnehmung (40) which is formed in the fan frame (2), wherein the Lüfterradausnehmung (40) by a Zargenring (42) is limited; a motor holder which is disposed within the Lüfterradausnehmung (40) and which is connected via struts (44) with the fan frame (2) mechanically connected; a motor, in particular an electric motor, which is at least partially held in the motor holder; and a fan wheel (1) which is arranged in the Lüfterradausnehmung (40) and which is rotationally driven by the motor, characterized in that
the fan wheel (1) is designed according to one of the preceding claims. Radiator fan module according to the preceding claim, wherein the struts (44), viewed in the flow direction, are arranged in front of the fan wheel (1). Use of a fan wheel according to one of claims 1 to 9 or a radiator fan module according to one of claims 10 or 11 in a motor vehicle.

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