EP3486499A1 - Cooler ventilation module - Google Patents

Abstract

The present invention relates to a radiator fan module 1, comprising: a fan frame 2, a fan wheel recess 4 which is formed in the fan frame 2, a motor holder 3, which is mechanically connected to the fan frame 2 via struts 10 located downstream in the flow direction, a motor 5, which is at least partially mounted in the motor holder 3, a fan 6, which is arranged in the Lüfterradausnehmung 4 and which is rotationally driven by the motor 5 about a rotation axis R, where-the fan has a plurality of wing elements 6a, wherein all elements a group comprising at least one of the struts 10 and at least one of the wing elements 6a, forward-angled or reverse-angled.

Description

FIELD OF THE INVENTION

The present invention relates to a radiator fan module, in particular an electrically operated radiator fan module, in particular for motor vehicles, with rear struts located in the main flow direction.

TECHNICAL BACKGROUND

The cooling system in an internal combustion engine, in particular a motor vehicle, mainly discharges the heat that is given off to the walls of the combustion chamber and cylinder 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 a coolant.

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 out Aluminum - is usually mounted on the front of the vehicle where an airflow absorbs heat energy from the coolant and cools it before returning to the engine, closing the coolant circuit.

In order to drive the air through the radiator, a radiator fan module is provided in the (main) flow direction before (upstream) or downstream (downstream) of the radiator, which may be mechanically driven 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. In the Lüfterradausnehmung a motor holder is arranged, which is mechanically connected via struts with the fan frame. The struts can be arranged starting from the air volume flow on the downstream or upstream side of the fan cowl. In the motor holder, a motor, in particular an electric motor, held. On an output shaft of the electric motor, a fan wheel is arranged, which - driven by the electric motor - rotates in the Lüfterradausnehmung.

In the design and development of radiator fan modules in addition to the volume of air delivered per unit time and the available space, especially its arrangement based on the air flow upstream or downstream of the radiator and / or its dimensions, and the noise relevant.

In particular, with regard to the noise, it is essential whether the struts on the upstream or downstream side of the fan frame are arranged, which is due to the fundamentally different aerodynamic properties of these two variants: While the air on the upstream side (suction side) of the fan cowl rather slow and at least Essentially laminar flows, it is on the downstream side (pressure side) of the fan cowl, ie after passing through the Lüfterradausnehmung, faster, denser and more swirled than before. For this reason, apart from the main requirement of holding the motor holder, the requirements for front and rear struts are fundamentally different: While forward struts can also take on supply and / or air conduction functions, those for rear struts are at least essentially irrelevant. It is more important to make the struts as "aerodynamically" as possible "invisible", i. to design the struts so that they affect the downstream airflow as little as possible.

The DE 10 2012 112 211 A1 relates to a blower unit for a heat exchanger. The disclosed blower unit has straight, rear spokes which connect an annular support member for receiving an electric drive motor with a plate-like support structure.

Against this background, the object of the present invention is to make available an improved radiator fan module, which is advantageous, in particular with regard to noise development.

According to the invention this object is achieved by a radiator fan module having the features of patent claim 1.

Accordingly, a radiator fan module according to the invention comprises a fan cowl, a fan wheel recess which is formed in the fan cowl, a motor holder which is mechanically connected to the fan cowl via rear braces viewed in the flow direction, a motor, in particular an electric motor, which is at least partially mounted in the engine mount, and a fan wheel disposed in the fan wheel recess and rotationally driven by the motor about a rotation axis, the fan wheel having a plurality of wing members, wherein at least all elements of a group comprise at least one of the struts and at least one of the wing members have foreshortened or back-splayed.

A "radiator fan module" in the sense of the present invention is in particular an assembly, which is arranged upstream of or behind a radiator of a vehicle and which is designed, in particular adapted, to generate an air volume flow which passes through the radiator and / or or extending 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 the 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 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 an embodiment of the present invention, the Lüfterradausnehmung is limited by a Zargenring.

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.

"Flow direction" in the sense of the present invention designates in particular the so-called main flow direction, ie the flow which passes parallel to the axis of rotation of the fan through the Lüfterradausnehmung the fan cowl, and is used to cool the radiator.

"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. According to an embodiment of the present invention, the struts may have a teardrop-shaped cross-section 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 because electrical energy is easy to transfer compared to mechanical or chemical energy Represents energy form, with which the required torque is provided for driving the fan wheel.

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.

In the context of the present invention, a "wing element" is a plane inclined on the axis of rotation, inclined at least substantially flat body, which is arranged on the hub pot and which is provided, in particular adapted, for generating an air volume flow. as soon as the fan wheel is put in a rotary motion. The wing elements are preferably inclined relative to the axis of rotation in an angular range of -90 ° to + 90 °, in particular from -75 ° to + 75 °, in particular from -60 ° to + 60 °, in particular from -45 ° to + 45 ° , in particular from -30 ° to + 30 ° and more preferably from -15 ° to + 15 °. In the context of the present invention, wing elements are also understood to mean, in particular, vanes, airfoils or rotor blades.

For the purposes of the present invention, "forward-splayed" means, in particular, that the tip of the vane element, viewed in the direction of rotation, leads the middle of the vane element.

For the purposes of the present invention, "reverse-angled" means, in particular, that the tip of the wing element, viewed in the direction of rotation, lags the middle of the wing element.

In other words, the geometry of the at least one strut follows at least substantially the geometry of the at least one wing element with respect to the expansion in a plane perpendicular to the axis of rotation. In particular, the geometry of the strut skeleton line of the at least one strut follows at least substantially the geometry of the wing element skeleton line of the at least one wing element with respect to the extent in a plane perpendicular to the axis of rotation
This is particularly advantageous, since in this way at least one of the negative effects of, in particular behind, struts can be reduced, in particular with respect to the acoustics. You have to know that efforts to develop fan shrouds are always annoying. The volume flow, which is generated by the fan, especially in the direction of flow seen shortly after the fan has an increased density and the individual air molecules move at very high speed and a swirl generated by the fan forward. In this initial situation, the air molecules hit the "standing in the way" struts, causing a deceleration and change in direction of the air molecules. This creates unwanted noise, especially when the wing, in particular its leading edge, sweeps over the strut. This produces unwanted noise, in particular the so-called "blocking", which will be described again in detail below. By the geometry of the strut with respect to the radial extent at least substantially follows the geometry of the wing element, it can be achieved that the leading edge of the wing element does not meet the strut at the same time on the entire length, but that there is only one point of overlap, which in radial Direction wanders. For example, consider a commercial one Paper scissors in which the intersection of the two cutting edges travels along the direction of extension as soon as the scissors are closed.

According to one embodiment of the present invention, the group comprises a plurality, in particular all, of the struts and / or a plurality, in particular all, of the wing elements.

This is particularly advantageous because in this way the effect described above is enhanced. The more struts or wing elements are matched to one another according to the invention, the more advantageous the properties of the cooling fan module are in terms of noise development.

$$Y-\mathit{Koordinate}=f\left({\alpha }_S\left(n\right),{\alpha }_R,D_H,L_P,n,{\beta }_S\left(n\right),{\beta }_R\left(n\right)\right)=\cos \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{D_H}{2}+\frac{L_P\cdot n}{n_{\mathit{max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_R}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

wobei gilt:

• X-Koordinate beschreibt die X-Koordinate des Schnittpunktes der Strebenskelettlinie mit einer Schnittebene in einem x-y-Koordinatensystem in der Schnittebene
• Y-Koordinate beschreibt die Y-Koordinate des Schnittpunktes der Strebenskelettlinie mit einer Schnittebene in einem x-y-Koordinatensystem in der Schnittebene
• n beschreibt einen aktuell betrachteten Profilschnitt
• n_max beschreibt, in wie viele äquidistante Profilschnitte die Strebe und das Flügelelement über ihre radiale Erstreckung hinweg unterteilt werden; wobei $$n_{\max }\in \left[5;25\right]$$
  
• α_s (n) beschreibt einen Sichelungswinkel am Profilschnitt n des Flügelelements, d.h. einen Winkel zwischen einem zur Rotationsachse parallel verschobenen ersten Schenkel und einem zweiten Schenkel, welcher durch die Punkte von Vorder- und Hinterkante der Strebe in der Schnittebene definiert ist;
• D_H beschreibt den Außendurchmesser des Motorhalters (3) ;
• L_P beschreibt die Profillänge der Strebe (10), d.h. den Abstand zwischen Vorder- und Hinterkante der Strebe in der Schnittebene;
• β_s(n) beschreibt einen Korrekturfaktor der Sichelung, wobei $${\beta }_s\left(n\right)\in \left[-5;5\right]$$
  
• β_R(n) beschreibt einen Korrekturfaktor der Profilrotation, wobei $${\beta }_R\left(n\right)\in \left[-30;30\right]$$
  

According to a further embodiment of the present invention, a wing element skeleton line of the wing elements of the group and a strut skeleton line of the struts of the group in a profile section are related to each other: $$X-\mathit{coordinate}=f\left({\alpha }_s\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\sin \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D\; </figure-callout>}}_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">R</figure-callout>}}}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

$$Y-\mathit{coordinate}=f\left({\alpha }_S\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\cos \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D\; </figure-callout>}}_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">R</figure-callout>}}}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

where:

• X coordinate describes the X coordinate of the intersection of the strut skeleton line with a section plane in an xy coordinate system in the section plane
• Y-coordinate describes the Y-coordinate of the intersection of the strut skeleton line with a section plane in an xy-coordinate system in the section plane
• n describes a currently considered profile section
• n _max describes in how many equidistant profile sections the strut and the wing element are subdivided over their radial extent; in which $$n_{\mathrm{Max}}\in \left[5;25\right]$$
  
• α _s (n) describes a sickle angle at the profile section n of the wing element, ie an angle between a parallel to the rotation axis first leg and a second leg, which is defined by the points of the front and rear edge of the strut in the cutting plane;
• D _H describes the outer diameter of the motor holder (3);
• L _P describes the profile length of the strut (10), ie the distance between the front and rear edge of the strut in the cutting plane;
• β _s (n) describes a correction factor of the sickle, wherein $${\beta }_s\left(n\right)\in \left[-5;5\right]$$
  
• β _R (n) describes a correction factor of the profile rotation, wherein $${\beta }_R\left(n\right)\in \left[-30;30\right]$$
  

A "strut skeleton line" in the sense of the present invention, also called profile center line, camber line or curvature line, designates the connecting line of the circle center points inscribed in a profile, the skeleton line running straight from the nose circle center point to the profile nose. Another alternative definition, which in the sense is explicitly encompassed by the invention defines the strut skeleton line in that it consists of the midpoints between the top and bottom perpendicular to the X-coordinate or chord. The course of the skeleton line essentially determines the flow properties. Important geometric figures are the curvature height and the buckling reserve, with strut profiles with a straight or S-shaped skeleton line having a pressure point that changes only slightly with the angle of attack.

A "wing element skeleton line" in the sense of the above invention, also referred to as profile centerline, camber line or curvature line, denotes the connecting line of the circle center points inscribed in a profile, wherein the skeleton line runs straight from the nose circle center point to the profile nose. Another alternative definition, which is explicitly included within the meaning of the invention, defines the wing element skeleton line as consisting of the midpoints between the top and bottom perpendicular to the X-coordinate or chord. The course of the skeleton line essentially determines the flow properties. Important geometric characteristics are the curvature height and the curvature reserve, with wing element profiles with a straight or S-shaped skeleton line having a pressure point that changes only slightly with the angle of attack.

The above-mentioned functional relationships are the result of extensive scientific investigations and experiments which for the first time describe a relationship between strut skeleton line and wing element skeleton line. For this purpose, the radial extension direction of the wing elements or struts is subdivided into a number n _max equidistant profile sections, wherein the relationships described here for at least one, in particular a plurality, in particular a vast majority, n _max profile sections must be fulfilled.

About the wing element skeleton line which generates the sickle of the wing element, the geometry of the wing element flows directly into the design of the strut with a.

The formula includes parameters of the wing element skeleton line in the form of the sickle angle α _s (n) at the profile section n of the wing element. Thus, for the first time there is a functional relationship between the geometry of the wing element and the strut, resulting in a particularly advantageous sound pattern of the overall system. This is particularly relevant for electrically powered vehicles, which have a significantly lower noise emission, which is why a previously known radiator fan module would lead to an unpleasant noise perception, since the overlapping noise of the classic main drive system, ie the internal combustion engine omitted.

According to a further embodiment of the present invention, the defined functional relationships for X and Y coordinates apply to all sections n ∈ [0; n _max ].

This is particularly advantageous because in this way the defined functional relationships for X and Y coordinates, which have been found to be advantageous in extensive test series, apply to the entire radial extension of wing element and strut. Thus, the beneficial effect of noise reduction can be further improved since the sweeping of the struts through the wing member can be "smooth", i. with a reduced influence on the flow vector of the main volume flow.

According to a further embodiment of the present invention, the struts have a semi-symmetrical profile.

A "profile" in the sense of the present invention is in particular the shape of the cross section of the strut, wherein the sectional plane is perpendicular to a radial vector of the radiator fan module. This radial vector is defined on the one hand by the orientation of the axis of rotation on which this vector is perpendicular, as well as the point of the strut skeleton line in the sectional plane to be considered.

As a "semi-symmetrical profile" in the context of the present invention, also called biconvex profile, a profile of low curvature, in particular in the range of 1-3%, to understand, which has a curvature, but no concave contours.

This is particularly advantageous because in this way the above-described advantages of the radiator fan module according to the invention can be further improved by not only the position of the strut is optimized in relation to the wing element, but also the design of the strut, so that they are as advantageous as possible in the main volume flow inserts, so as to avoid a deflection and / or deflection of the air flow as good as possible.

According to a further embodiment of the present invention, the struts are arranged to the rotation axis with an angle of attack α in the range between 5 degrees and 45 degrees, preferably between 10 degrees and 25 degrees.

The "angle of attack" in the context of the present invention also called "angle of attack" is the angle between the direction of the inflowing fluid and the soul of the profile, ie the imaginary linear connection between the profile nose and the profile trailing edge.

This is particularly advantageous because in this way a further parameter is specified with which the strut can be designed so that the diversion and / or deflection of the main volume flow is further reduced.

According to a further embodiment of the present invention, the struts exiting the motor holder with an angle β, which has a value in the range of -30 ° to + 30 °, in particular in the range of -20 ° to + 20 °, in particular in the range of 10 ° to + 10 °.

This is particularly advantageous since extensive experimental and comparative studies have shown that too steep a leakage of the strut out of the motor holder causes the length to be considerably increased, thus providing a positive effect resulting from a "gentle" sliding of the edges through the Length of the strut lifted again or possibly reversed.

According to a further embodiment of the present invention, the struts enter the fan cowl with a predetermined angle φ, which has a value in the range of -90 ° and + 30 °, in particular in the range of -75 ° and + 15 °, in particular in the range of -60 ° to 0 °. This is particularly advantageous, since in this way the struts can also be arranged as engagement protection and can be adapted to the available installation space when designing the system.

According to a further embodiment of the present invention, a reinforcement is provided, which is formed between the motor holder and one of the struts, in particular between the motor holder and a plurality of the struts, in particular between the motor holder and each strut.

This is particularly advantageous because in this way the rigidity of the radiator fan module as a whole and in particular the struts can be improved. This stiffening just between the motor holder and strut is particularly advantageous because high shear forces occur due to the counter-torque to the drive torque of the motor just at the transition between the engine mount and strut. Furthermore, the o.g. Advantages of material accumulation in the strut region directly on the engine mount, the associated aerodynamic disadvantages, at least partially, since the rotational and flow rate in this area compared to the outer radius of the wing elements is comparatively low.

The reinforcement is formed in particular in the form of a collection of material, which increases the radius at the transition from the strut to the motor holder, in order to thus allow in particular an improved introduction of force.

This is particularly advantageous according to one embodiment, since the reinforcement increases the strength of a strut, so that the strut is very dimensionally stable. The reinforcement is preferably formed integrally with the strut and / or the motor holder.

According to a further embodiment of the present invention, the fan cowl, the engine mount and the struts are formed as a one-piece plastic injection molded part.

This is particularly advantageous since in this way a cost-effective near-to-end-shape forming method can be used to provide the fan cowl together with the engine mount and struts.

According to a further embodiment of the present invention, the struts have a reinforcement.

According to a further embodiment, the reinforcement has at least partially metal. For example, the reinforcement is in the form of a steel sheet. This is particularly advantageous according to an embodiment, since in this way the dimensional stability and the strength of the struts can be increased.

According to a further embodiment of the present invention, the number of struts is different from the number of wing elements, in particular the radiator fan module has more struts than wing elements, in particular the radiator fan module has two struts more than wing elements, in particular the radiator fan module comprises eleven struts and nine wing elements , This embodiment is particularly advantageous, since in this way each wing element is in a different phase of sweeping the strut, resulting in a more homogeneous noise emission with a view to the overall system.

The above refinements and developments can, as long as the description of the skilled person does not unambiguously state otherwise, be combined as desired. Further possible refinements, developments and implementations of the invention also include combinations, not explicitly mentioned, of features of the invention described above or below with regard to the exemplary embodiments. In particular, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the present invention.

CONTENT OF THE DRAWING

Fig. 1

eine schematische Draufsicht auf eine Lüfterzarge aus dem Stand der Technik mit einer angedeuteten Strebe gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 2

eine schematische Draufsicht auf einen Ausschnitt einer Lüfterzarge nach einer Ausführungsform der vorliegenden Erfindung;

Fig. 3

eine schematische Draufsicht auf einer Lüfterzarge nach einer weiteren Ausführungsform der vorliegenden Erfindung, nebst zweier Schnittdarstellungen;

Fig. 4

eine schematische perspektivische Darstellung einer einzelnen Strebe gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 5

eine schematische perspektivische Darstellung des Profils und des Verlaufs der Strebenskelettlinie einer einzelnen Strebe gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 6

eine schematische dreidimensionale Detailansicht einer einzelnen Strebe zwischen Motorhalter und Lüfterzarge gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 7

eine schematische Schnittansicht einer einzelnen Strebe gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 8

eine schematische Schnittansicht einer einzelnen Strebe mit Armierung gemäß einer weiteren Ausführungsform der vorliegenden Erfindung;

Fig. 9a

ein Diagramm mit Messwerten eines Kühlerlüftermoduls des Standes der Technik; und

Fig. 9b

ein Diagramm mit Messwerten eines Kühlerlüftermoduls gemäß einer Ausführung der vorliegenden Erfindung.

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows:

Fig. 1

a schematic plan view of a fan cowl from the prior art with an indicated strut according to an embodiment of the present invention;

Fig. 2

a schematic plan view of a section of a fan frame according to an embodiment of the present invention;

Fig. 3

a schematic plan view of a fan cowl according to another embodiment of the present invention, together with two sectional views;

Fig. 4

a schematic perspective view of a single strut according to an embodiment of the present invention;

Fig. 5

a schematic perspective view of the profile and the course of the strut skeleton line of a single strut according to an embodiment of the present invention;

Fig. 6

a schematic three-dimensional detail view of a single strut between the engine mount and fan cowl according to an embodiment of the present invention;

Fig. 7

a schematic sectional view of a single strut according to an embodiment of the present invention;

Fig. 8

a schematic sectional view of a single strut with reinforcement according to another embodiment of the present invention;

Fig. 9a

a diagram with measurements of a cooling fan module of the prior art; and

Fig. 9b

a diagram with measurements of a radiator fan module according to an embodiment of the present invention.

The accompanying figures of the drawing are intended to convey a further understanding of the embodiments of the invention. They illustrate embodiments and, together with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the stated advantages will become apparent with reference to the drawings. The elements of the drawings are not necessarily shown to scale to each other.

In the figures of the drawing are the same, functionally identical and same-acting elements, features and components - unless otherwise stated - each provided with the same reference numerals.

Fig. 1 shows a schematic plan view of a fan frame 2 of a radiator fan module 1 of the prior art with an indicated strut 10 according to one embodiment of the present invention. The cooling fan module 1 has a fan frame 2, a Lüfterradausnehmung 4, which is formed in the fan frame 2, a motor holder 3, which is seen in the flow direction behind lying (previously known, straight) struts 100 mechanically connected to the fan frame 2, a motor, in particular Electric motor, 5, which is at least partially mounted in the motor holder 3, a fan 6, which is arranged in the Lüfterradausnehmung 4, and which is rotatably driven by the motor 5 about an axis of rotation R, wherein the fan 6 has a plurality of wing elements 6a ,

The motor holder 3 is connected to the fan frame 2 via straight struts 100, as they are well known from the prior art. The reference numeral 10 is in the Fig. 1 already indicated a strut according to the invention, as will be described in detail below. In Fig. 1 In particular, the geometric difference between previously known struts 100 and the struts 10 according to the invention can be seen.

Fig. 2 shows a schematic plan view of a section of a fan frame 2 according to an embodiment of the present invention.

The fan frame 2 is made of plastic, in particular in the form of a one-piece plastic injection molded part.

The struts 10 extend parabolic from the edge of Lüfterradausnehmung 4 to the motor holder 3 and hold the motor holder in the Lüfterradausnehmung 4 in position. The struts 10 each have a reinforcement 11, which is the connection between the motor holder 3 and one of the Struts 10 reinforced. The reinforcement 11 is preferably formed integrally with the strut 10. Preferably, the fan frame 2, the struts 10 and the motor holder 3 are a one-piece plastic injection molded part. On the motor holder 3 mounting interfaces 30 are provided, to which a motor 5 can be attached. Further, the angle β is shown, which indicates at what angle the strut 10 enters the motor holder 3. Legs of the angle β are on the one hand an extension vector 14 of the strut 10 at the exit point of the strut 10 from the motor holder 3 and on the other hand a radial vector 15 through the exit point of the strut 10 from the motor holder 3. According to one embodiment of the present invention, β has a Value in the range of -30 ° to + 30 °.

Further, an angle φ is shown, which indicates at what angle the strut 10 enters the edge of the Lüfterradausnehmung 4. Legs of the angle φ are on the one hand an extension vector 16 of the strut 10 at the entry point of the strut 10 in the fan frame 2 and on the other hand a radial vector 16a through the entry point of the strut 10 in the fan frame 2. According to one embodiment of the present invention, φ has a value in the range of -90 ° and + 30 °.

In the further course, in connection with the embodiment of the strut 10 according to the invention, there is occasional talk of a starting point 17 and an end point 18. The starting point 17 is the exit point of the strut 10 from the motor holder 3 and the end point 18 is defined by the entry point of the strut 10 in the fan frame second

Fig. 3 shows a schematic plan view of a fan frame 2 according to another embodiment of the present invention Invention together with two sectional views. That in the Fig. 3 illustrated radiator fan module 1 is a radiator fan module with rear struts 10, ie viewed in the flow direction, which as shown in the Fig. 3 pointed out from the sheet, the air is first accelerated and compressed by the rotating fan 6 before it hits the struts 10, which is the particular challenge in the design of such cooling fan modules and in particular the struts 10, makes.

In this figure, the fan 6 with the plurality of wing elements 6a is shown for the first time. It can be seen in this illustration particularly well the effect of the invention, as the wing elements 6a -. From the perspective of the representation of Fig. 3 - move past the struts 10 past them. According to the preferred embodiment of Fig. 3 the fan frame 2 eleven struts invention 10 and the fan 6 6 nine wing elements 6a on. This constructive property ensures that each wing element 6a is at any time during the rotation of the fan wheel in a different phase of sweeping one of the struts 10. This leads to an advantageous, in particular more homogeneous, noise emission of the overall system.

Fig. 4 shows a schematic perspective view of a single strut 10 according to an embodiment of the present invention. This connects the motor holder 3 with the fan frame 2 and holds the motor holder 3 in the Lüfterradausnehmung 4 of the fan frame 2 in position. The struts 10 provide the counter torque which is opposite to the torque generated by the motor with which the fan 6 is driven. Because of this, be on the pursuit 10 high forces, which leads to increased stiffness requirements of these. The strut 10 has a parabolic shape. A skeleton line 12 of the strut 10 extends from the starting point 17 on the motor holder to the end point 18 on the fan frame 2. The apex 13 of the strut is located in the axial direction at least substantially in the middle of the strut 10th

The strut 10 also has an airfoil profile. An area around a front edge 26 of a profile 20, in particular a cross-sectional profile, is thicker than an area around a trailing edge 27 of the profile 20. According to a particularly preferred embodiment, the airfoil profile of the strut 10 is a semi-symmetrical profile.

Fig. 5 shows a schematic perspective view of the profile and the Verlaus stringer skeleton line of a single strut 10 according to an embodiment of the present invention. The profile 20 of the strut 10 is formed according to this embodiment as a semi-symmetrical profile, the skeleton line 12 of the strut 10 is parabolic.

$$Y-\mathit{Koordinate}=f\left({\alpha }_S\left(n\right),{\alpha }_R,D_H,L_P,n,{\beta }_S\left(n\right),{\beta }_R\left(n\right)\right)=\cos \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{D_H}{2}+\frac{L_P\cdot n}{n_{\mathit{max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_R}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

wobei gilt:

• X-Koordinate beschreibt die X-Koordinate des Schnittpunktes der Strebenskelettlinie mit einer Schnittebene in einem x-y-Koordinatensystem in der Schnittebene
• Y-Koordinate beschreibt die Y-Koordinate des Schnittpunktes der Strebenskelettlinie mit einer Schnittebene in einem x-y-Koordinatensystem in der Schnittebene
• n beschreibt einen aktuell betrachteten Profilschnitt
• n_max beschreibt, in wie viele äquidistante Profilschnitte die Strebe und das Flügelelement über ihre radiale Erstreckung hinweg unterteilt werden; wobei $$n_{\max }\in \left[5;25\right]$$
  
• α_s(n)beschreibt einen Sichelungswinkel am Profilschnitt n des Flügelelements, d.h. einen Winkel zwischen einem zur Rotationsachse parallel verschobenen ersten Schenkel und einem zweiten Schenkel, welcher durch die Punkte von Vorder- und Hinterkante der Strebe in der Schnittebene definiert ist;
• D_H beschreibt den Außendurchmesser des Motorhalters (3);
• L_P beschreibt die Profillänge der Strebe (10), d.h. den Abstand zwischen Vorder- und Hinterkante der Strebe in der Schnittebene;
• β_s(n) beschreibt einen Korrekturfaktor der Sichelung, wobei $${\beta }_s\left(n\right)\in \left[-5;5\right];$$
  
  und
• β_R(n) beschreibt einen Korrekturfaktor der Profilrotation, wobei $${\beta }_R\left(n\right)\in \left[-30;30\right],$$
  

wobei die definierten funktionalen Zusammenhänge für X- und Y-Koordinaten für alle Schnitte n ∈[0;n _max] bei n_max=10 gelten.In particular, a wing element skeleton line of the wing element 6a and the strut skeleton line 12 in a profile section are related to one another via the following mathematical relationships: $$X-\mathit{coordinate}=f\left({\alpha }_s\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\sin \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D\; </figure-callout>}}_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">R</figure-callout>}}}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

$$Y-\mathit{coordinate}=f\left({\alpha }_S\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\cos \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">D\; </figure-callout>}}_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="imgf0001.png,imgf0002.png"\; state="\{\{state\}\}">R</figure-callout>}}}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

where:

• X coordinate describes the X coordinate of the intersection of the strut skeleton line with a section plane in an xy coordinate system in the section plane
• Y-coordinate describes the Y-coordinate of the intersection of the strut skeleton line with a section plane in an xy-coordinate system in the section plane
• n describes a currently considered profile section
• n _max describes in how many equidistant profile sections the strut and the wing element are subdivided over their radial extent; in which $$n_{\mathrm{Max}}\in \left[5;25\right]$$
  
• α _s (n) describes a sickle angle at the profile section n of the wing element, ie an angle between a parallel to the rotation axis first leg and a second leg, which is defined by the points of the front and rear edge of the strut in the cutting plane;
• D _H describes the outer diameter of the motor holder (3);
• L _P describes the profile length of the strut (10), ie the distance between the front and rear edge of the strut in the cutting plane;
• β _s (n) describes a correction factor of the sickle, wherein $${\beta }_s\left(n\right)\in \left[-5;5\right];$$
  
  and
• β _R (n) describes a correction factor of the profile rotation, wherein $${\beta }_R\left(n\right)\in \left[-30;30\right].$$
  

where the defined functional relationships for X and Y coordinates for all sections n ∈ [0; n _max ] at n _max = 10.

Fig. 6 shows a schematic three-dimensional detail view of a single strut 10 between the motor holder 3 and the fan frame 2 according to an embodiment of the present invention. In this illustration, one can see the reinforcement 11 between the strut 10 and the motor holder 3. The reinforcement 11 has a wall 19 which extends from the strut 10 at an angle. According to one embodiment, this angle is equal to the angle β, so that the strut 10 and the wall 19 are arranged mirror-symmetrically to a perpendicular of the circular motor holder 3. The strut 10 becomes more stable through the wall 19 and thereby can securely hold the motor 5 in the motor holder 3 in position. The reinforcement 11 is integrally formed with the strut 10 and the motor holder 3 according to the embodiment shown.

Fig. 7 shows a schematic sectional view of a single strut 10 according to an embodiment of the present invention. The profile 20 of the strut 10 according to this embodiment is a semi-symmetrical profile 20. A profile curvature of the top 21 and a profile curvature of the bottom 22 of the profile 20 extend in the same direction. The top 21 is concavely curved while the bottom 22 has a convex curvature. Furthermore, the profile 20 has a profile thickness 23 and a profile depth 25. Moreover, the profile 20 has a nose radius 24, which indicates the radius of the nose of the profile. The region of the trailing edge 27 of the profile 20 is narrower than the area of the leading edge 26 of the profile 20. The angle of attack α of the profile according to this embodiment is about 45 degrees normal to the blade surface. The air flows in the direction of the arrow 29 around the strut 10 around.

Fig. 8 shows a schematic sectional view of a single strut 10 according to another embodiment of the present invention. In this embodiment of the strut 10, a reinforcement 31 is provided in the strut 10. The reinforcement 31 may at least partially comprise metal. For example, the reinforcement 31 is formed from a steel sheet. Alternatively, the reinforcement 31 may also be formed of aluminum. By this design, the strut 10 can be formed particularly dimensionally stable.

Fig. 9a shows a diagram with measurements of a cooling fan module of the prior art and Fig. 9b a diagram with measurements of a radiator fan module according to an embodiment of the present invention.

In the Fig. 9a and 9b Diagrams shown each show the course of a sum level and a fan blade order generated by the system. The sum level indicates the total noise emission over all frequencies. In both figures, this is the eleventh fan blade order, which depends on the number of wings, their geometric arrangement and sickle.

Furthermore, the so-called 10 dB criterion is specified, which runs at a distance of 10 dB below the sum level. The 10 dB criterion is particularly relevant for evaluating the sound of fan noise: the 10 dB criterion states that those frequency components which are below this 10 dB criterion are not perceived as disturbing. It can be imagined as in an open-plan office, where individual voices sink into a general murmur. Conversely, noise components that violate this 10 dB criterion are perceived as particularly disturbing. If all frequency components are below the 10 dB criterion, the noise emission is perceived as a pleasant, "full" hum.

The pictured Fig. 9a and 9b have been measured at the component level in a semi-anechoic room with a heat exchanger. By designing the struts in accordance with one embodiment of the present invention, the eleventh fan blade order improves significantly as compared to the prior art. The sum level improves by up to 4 dB compared to the state of the art and thus meets the 10 dB criterion for the first time.

Although the present invention has been fully described above with reference to preferred embodiments, it is not limited thereto but is modifiable in a variety of ways.

The struts may be provided for example on the pressure side and / or on the negative pressure side. Furthermore, the fan may be adapted to the shape of the struts. For example, the leading edge and / or the trailing edge of the fan wheel has a curvature which corresponds to the curvature of the struts.

LIST OF REFERENCE NUMBERS

1

Cooling fan module

2

shroud

3

Motorhalter

4

Lüfterradausnehmung

5

fan

5a

wing elements

10

strut

11

reinforcement

12

skeleton line

13

Vertex of the skeleton line

14

Extension vector of the strut at the exit point of the strut from the engine mount

15

Radial vector through the exit point of the strut from the engine mount

16

Extension vector of the strut at the entry point of the strut into the fan cowl

16a

Radial vector through the entry point of the strut in the fan cowl

17

starting point

18

endpoint

19

reinforcing wall

20

profile

21

Profile buckle of the top

22

Profile curvature of the bottom

23

profile thickness

24

nose radius

25

tread depth

26

leading edge

27

trailing edge

28

Plumb to the engine mount

29

Direction of air flow

30

Mounting interface

31

reinforcement

100

previously known, straight struts

1

Section length

r2

Radius top curvature

r3

Radius bottom curvature

H

height

d1

Profile nose diameter

d2

Trailing edge diameter

R

axis of rotation

α

angle of attack

β

corner

φ

corner

Claims (11)

Radiator fan module (1), comprising: a fan cowl (2); a Lüfterradausnehmung (4) which is formed in the fan frame (2); a motor holder (3) which is mechanically connected to the fan frame (2) via rearward struts (10) viewed in the flow direction; a motor, in particular an electric motor (5), which is at least partially mounted in the motor holder (3); a fan wheel (6), which is arranged in the Lüfterradausnehmung (4) and which is rotationally driven by the motor (5) about an axis of rotation (R), wherein the fan wheel has a plurality of wing elements (6a), characterized in that at least all elements of a group comprising at least one of the struts (10) and at least one of the wing elements (6a) are forward-angled or reverse-angled. Radiator fan module according to claim 1, wherein the group comprises a plurality, in particular all, the struts and / or a plurality, in particular all, of the wing elements (6a). A radiator fan module according to either one of claims 1 or 2, wherein a wing element skeleton line of the wing members of the group and a strut skeleton line of the struts of the group in profile intersection are related to each other via: $$X-\mathit{coordinate}=f\left({\alpha }_s\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\sin \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{D_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_R}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

$$Y-\mathit{coordinate}=f\left({\alpha }_S\left(n\right).{\alpha }_R.D_H.L_P.n.{\beta }_S\left(n\right).{\beta }_R\left(n\right)\right)=\cos \left({\alpha }_{S\left(n\right)}\cdot \left(\frac{D_H}{2}+\frac{L_P\cdot n}{n_{\mathit{Max}}}\right)\right)+{\beta }_S\left(n\right)+\cos \left({\alpha }_S\left(n\right)+\frac{{\alpha }_R}{2}\right)\cdot \frac{L_P\cdot n}{n_{\mathit{Max}}}\cdot \sqrt{2}\cdot \sqrt{1-\cos \left({\alpha }_R\right)}+{\beta }_R\left(n\right)$$

where: X coordinate describes the X coordinate of the intersection of the strut skeleton line with a section plane in an xy coordinate system in the section plane Y-coordinate describes the Y-coordinate of the intersection of the strut skeleton line with a section plane in an xy-coordinate system in the section plane n describes a currently considered profile section n _max describes in how many equidistant profile sections the strut and the wing element are subdivided over their radial extent; in which $$n_{\mathrm{Max}}\in \left[5;25\right]$$

α _s (n) describes a sickle angle at the profile section n of the wing element, ie a Angle between a first leg parallel to the rotation axis and a second leg, which is defined by the points of leading and trailing edges of the strut in the cutting plane; D _H describes the outer diameter of the motor holder (3); Lp describes the profile length of the strut (10), ie the distance between the front and rear edge of the strut in the cutting plane; β _s (n) describes a correction factor of the sickle, wherein $${\beta }_s\left(n\right)\in \left[-5;5\right]$$

β _R (n) describes a correction factor of the profile rotation, wherein $${\beta }_R\left(n\right)\in \left[-30;30\right]$$

Radiator fan module according to claim 3, wherein the defined functional relationships for X and Y coordinates for all sections n∈ [0; n _max ]. Radiator fan module according to one of the preceding claims, wherein the struts (10) have a semi-symmetrical airfoil profile. Radiator fan module according to one of the preceding claims, wherein the struts (10) to the rotation axis (R) with an angle of attack α in the range between 5 degrees and 45 Degrees, preferably between 10 degrees and 25 degrees, are arranged. Radiator fan module according to one of the preceding claims, wherein the struts (10) emerge from the motor holder (3) at an angle β, which has a value in the range of -30 ° to + 30 °. Radiator fan module according to one of the preceding claims, wherein the struts (10) in the fan shroud (2) enter with a predetermined angle φ, which has a value in the range of -90 ° and + 30 °. Radiator fan module according to one of the preceding claims, wherein a reinforcement (11) is provided, which is formed between the motor holder (3) and one of the struts (10). Radiator fan module according to one of the preceding claims, wherein the fan frame (2), the motor holder (3) and the struts (10) are formed as a one-piece plastic injection molded part. Radiator fan module according to one of the preceding claims, wherein the struts (10) have a reinforcement (31).

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