DE102019202116A1 - Motor vehicle cooling fan - Google Patents

Abstract

The invention relates to a cooling fan, in particular a cooling fan module (1) of a motor vehicle, having a fan frame (2) with a fan wheel recess (4) which is surrounded by a frame ring (5), a fan wheel (3) rotatably arranged in the fan wheel recess (4) ), which has a hub cup (6) and a number of blade blades (7) oriented in the radial direction (R) starting from the hub cup (6) and an outer ring (11) which connects the blade tips (7c) of the blade blades (7) to one another, wherein a locking structure (16) with in the circumferential direction (U), in particular periodically, ramp-shaped locking elements (17) is provided on the frame ring (5), and wherein the or each locking element (17) has a rising first ramp surface (17a) and a ramp surface thereon via a Has leading edge (17c) subsequent sloping second ramp surface (17b).

Description

The invention relates to a preferably electrically (electric motor) driven radiator fan, in particular of a motor vehicle, with a fan frame having a fan wheel recess and with a fan wheel comprising an outer ring (casing ring) which is rotatably arranged (positioned) in the fan wheel recess.

Modern internal combustion engines, in particular four-stroke engines in motor vehicles, are typically cooled with a cooling liquid, for which purpose a mixture of water, antifreeze and anti-corrosion agent is used as a rule. The cooling liquid is conveyed through hoses, pipes and / or channels through the internal combustion engine (cylinder head and engine block) and, if necessary, through thermally stressed add-on parts of the internal combustion engine, for example an exhaust gas turbocharger, a generator or an exhaust gas recirculation cooler. The coolant absorbs the thermal energy generated by the internal combustion engine and removes it from the components mentioned. The heated coolant flows through a radiator, which is attached to the front of the vehicle, and by means of which, according to the heat exchanger principle, an air flow absorbs the heat energy from the coolant and cools it down before the cooled coolant flows back to the internal combustion engine, whereby the coolant circuit is closed.

Such a cooling system of an internal combustion engine, in particular of a motor vehicle, mainly dissipates that heat which is given off to the walls of combustion chambers and cylinders. Since excessive temperatures would damage the internal combustion engine, for example by tearing off a lubricating film, burning inlet and / or outlet valves for the fuel-air mixture or the like, the internal combustion engine must be actively cooled. In order to convey the air through the radiator, a radiator fan is provided in the flow direction in front of the radiator (i.e. upstream) or behind the radiator (i.e. downstream), which is driven mechanically via a belt drive or electrically via an electric motor.

The following statements relate to a cooling fan with a fan frame, which has a fan wheel recess, and with a fan wheel which is rotatably arranged in the fan wheel recess.

While the geometry of the fan wheel can influence both the amount of air conveyed and the acoustic properties of the cooling fan (cooling fan module), a backflow from the pressure side facing away from the conveyed air flow acts on the suction side of the cooling fan facing the conveyed air flow due to the known reducing effect on the efficiency the cooling fan and negatively affect the cooling performance of the cooling system.

In order to maintain the flow rate of the fan wheel even with a high pressure loss as a result of strong throttling when the cooling fan is operating, it is from the EP 2 886 873 B1 known to provide an inlet nozzle in the area of the annular gap between the frame ring and the outer ring (casing ring) of the fan wheel, which instead of the one mentioned in the above EP 2 886 873 B1 treated prior art is not formed on the fan wheel or on its outer or jacket ring, but on the frame ring.

From the DE 10 2006 037 641 A1 It is known, in order to avoid or to reduce a re-entry of the air flow generated by the cooling fan into the cooler, and thereby to improve the cooling performance, to expand the frame ring on the air outflow side into a flow guide device.

From the DE 10 2015 216 335 A1 It is known to design the radiator fan as a so-called nozzle jacket fan and for this purpose to design the fan frame at an inlet opening leading to the fan wheel with an annular circumferential nozzle contour. In addition, a diffuser segment is provided, which is attached to the outside of the fan frame facing away from the (suction-side) inflow channel. For this purpose, the diffuser segment can have several guide vanes which, even with several diffuser segments, do not extend over the entire circumference of the inlet opening of the fan and protrude into a main flow of the fan flowing away from the pressure side of the fan wheel. This is intended to guide the outflow around flow obstacles in a targeted manner when the fan is in operation and to improve the outflow of the airflow and to increase the efficiency of the fan.

The invention is based on the object of specifying a particularly suitable cooling fan, in particular an electrically (electric motor) driven, modular cooling fan as a cooling fan module. In particular, mixing losses, for example on the pressure side, especially those dependent on the throttle state, should be reduced as far as possible.

This object is achieved according to the invention with the features of claim 1. Advantageous refinements and developments are the subject matter of the subclaims and the following description.

For this purpose, the cooling fan, in particular of a motor vehicle, has a fan frame with a fan wheel recess and a fan wheel with an outer ring, which connects the blade tips of blade blades that extend in the radial direction from a (central) hub or a hub cup. The fan wheel is rotatably arranged in the fan wheel recess of the fan frame. An annular gap - hereinafter referred to as an annular gap - is formed between the outer ring of the fan wheel and a frame ring surrounding or delimiting the fan wheel recess of the fan shroud.

A locking structure with ramp-shaped (wedge-shaped) locking elements in the (vertical) circumferential direction as a mixture lock is provided on the frame ring. Preferably, the barrier structure is locally periodic, i.e. H. regularly repeating, preferably identical, locking elements executed (formed), wherein further advantageously the locking elements are arranged equidistant in the circumferential direction, particularly preferably adjacent to one another without any spacing.

The or each locking element has a rising first ramp surface in the circumferential direction of the frame ring and a falling second ramp surface adjoining it via a guide edge. The blocking structure and the blocking elements can also be referred to as guide structure or guide elements for the (pressure-side) air flow, in particular they can be effective as such. In relation to the direction of rotation of the fan wheel, the first ramp surface is located in front of the second ramp surface. Relative to the direction of rotation, the first ramp surface is leading and the second ramp surface is lagging.

The invention is based on the idea that on the pressure side of the cooling fan, and in particular on the outflow side of the annular gap between the frame ring and the outer ring of the fan wheel, mixing losses that are dependent on the respective throttle state can be prevented or at least reduced if the flow back into the annular gap is mixed Volume flow (air flow) comparatively low speed is prevented as far as possible with the volume flow (air flow) flowing out on the pressure side of comparatively high speed. This speed is high compared to the speed of the volume flow (air flow) flowing back into the annular gap.

This can be achieved by a ring-shaped barrier (guide structure), so that the (suction-side) volume flow flowing back into the annular gap - with comparatively low speed and little swirl - from the downstream (pressure-side) volume flow - with comparatively high speed and strong or high swirl - separated from each other.

A “fan wheel” in the sense of the present invention is in particular a rotationally symmetrical component which has a hub, in particular in the form of a hub cup, and a number of blade blades connected to it. In the case of a fan wheel driven by an electric motor, the hub represents the connection to the electric motor, in particular via a shaft protruding therefrom, so that a torque generated by this is transmitted to the fan wheel. The impeller blades are provided and / or set up to generate an air volume flow as soon as the fan wheel is set in a rotational movement.

A “hub pot” in the sense of the present invention is in particular a central part of the fan wheel, which is composed of a base surface and an adjoining cylinder surface in the manner of a classic pot. In particular, the blades are arranged, in particular molded, on this cylindrical outer wall. The hub pot is arranged in the center of the fan wheel and provides a connection to a drive, in particular to an electric motor, if the fan wheel is driven by an electric motor. In this case, the hub pot covers this drive at least partially.

An “airfoil” in the sense of the present invention is a flat body which is oriented in a radial direction in a plane on which the axis of rotation is perpendicular and is curved in a sickle shape in this plane and / or inclined with respect to this plane. In the context of the present invention, an impeller blade is also understood to mean a wing (fan blade) or a rotor blade. The blade is arranged on the hub pot and is provided, in particular set up, to generate an air volume flow as soon as the fan wheel is set in a rotary motion.

In an advantageous embodiment, the second ramp surface of the respective blocking element (guide element) is larger, in particular at least twice as large, as the first ramp surface of the blocking element. The leading edge runs appropriately at an angle of inclination obliquely to the radius (to an imaginary radius line). The angle of inclination is preferably oriented in the direction of rotation of the fan wheel, d. H. starting from the radius or the radius line spanned in the direction of rotation of the fan wheel.

Between the second ramp surface, the slope of which is smaller (less) than that of the first ramp surface of the respective locking element, and one to the plane of the fan wheel recess parallel reference surface is an angle (ramp angle) that is smaller than 45 °. The ramp angle is expediently between 20 ° and 40 °, preferably (25 ± 5) °. In other words, the ramp angle can be defined as the angle between a reference line running in the plane of the fan wheel recess and a ramp or wedge line representing the slope or the slope of the ramp surface.

The blocking structure (guiding structure) with the ramp-shaped or wedge-shaped blocking elements (guiding elements) recurring in the (vertical) circumferential direction and directly adjacent to one another is similar to a lamellar structure of a lamellar curtain with completely or almost completely closed lamellae. While passages are deliberately and intentionally formed between these lamellae in the longitudinal direction of the lamellae on the one hand and in the transverse direction of the lamellae, i.e. on their narrow or front sides on the other hand, in the blocking or guiding structure with the ramp-shaped or wedge-shaped blocking or guiding elements on the pressure side (outflow side), which acts as a mixture barrier, is ) Zargenring of the cooling fan at least one of the radial end faces of the locking elements designed as a closed end face. In particular, at least the end face of the blocking elements facing the fan wheel recess is closed. However, both radially opposite end faces of the locking elements are suitably designed to be closed.

The blocking structure (guide structure) can be made in one piece with the fan shroud. In an advantageous development, however, the blocking structure (guide structure) is provided on a separate structural ring which can be placed on the frame ring and, in the assembled state, is placed on the frame ring. The separate structural ring can be attached to the fan frame by means of a snap or clip attachment. A screw fastening is also suitable for holding the structural ring on the fan frame, a number of, in particular axially oriented, fixing struts (retaining webs) with screw feet at the ends being provided on the rear of the structural ring facing away from the locking structure. In this case, six holding webs are preferably evenly distributed, in particular equidistantly, formed on the back of the structural ring on the latter.

In an advantageous embodiment, the structural ring has a front side carrying the locking structure and a rear side opposite this with an annular groove. The frame ring has corresponding joining elements which, when joined, sit in this annular groove. For this purpose, the frame ring suitably has an axially oriented ring section which positively engages in the ring groove of the structural ring.

The invention provides in particular a cooling fan module as a pre-assembled unit, which is composed of the cooling fan and an electric motor, preferably designed as an external rotor, which is held in the fan wheel recess of the fan frame by means of radially oriented struts. The rotor of the external rotor motor is arranged in a rotationally fixed manner in the hub of the fan wheel, while the stator is held fixed to the frame by means of the struts.

In the context of the invention, “cooling fan module” is therefore understood to mean a cooling fan that is driven (operated) electrically or by an electric motor and is provided as a preassembled component (module) together with the electric motor. The fan wheel is preferably held by means of (radially oriented) struts which connect the stationary part of a drive, in particular the stator of an electric motor, to the cooler frame, while the rotating part of the drive, in particular the rotor of the electric motor, rotatably connects to the central hub cup is connected to which the radially oriented blades of the fan wheel are connected, in particular formed in one piece (one-piece, monolithic).

• 1 ein Kühlerlüftermodul mit einer Lüfterzarge und mit einem in einer zargenseitigen Ausnehmung drehbar angeordneten Lüfterrad, das einen Nabentopf zur Aufnahme eines Elektromotors und eine Anzahl von Schaufelblättern aufweist, deren Blattspitzen mit einem Außenring verbunden sind,
• Fug. 2 in einer Schnittdarstellung den Bereich eines Ringspaltes zwischen dem Außenring des Lüfterrades und einem die zargenseitige Ausnehmung begrenzenden Zargenring mit aufgesetztem Strukturring mit einer Sperrstruktur, und
• 3 und 4 den die Sperrstruktur aufweisenden Strukturring in perspektivischer Vorderansicht bzw. in entsprechender Rückansicht.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. Show in it:

• 1 a cooling fan module with a fan frame and with a fan wheel rotatably arranged in a frame-side recess, which has a hub pot for receiving an electric motor and a number of blades, the blade tips of which are connected to an outer ring,
• Fug. 2 in a sectional view the area of an annular gap between the outer ring of the fan wheel and a frame ring delimiting the recess on the frame side with an attached structural ring with a locking structure, and
• 3 and 4th the structural ring having the locking structure in a perspective front view or in a corresponding rear view.

Corresponding parts and directions are provided with the same reference symbols in all figures.

1 shows a cooling fan module 1 with a fan shroud 2 and with a fan wheel 3 . The fan shroud 2 and the fan wheel 3 make up the cooling fan. In the fan shroud 2 is a fan wheel recess 4th formed, which by a Zargenring 5 is or is limited. The fan wheel 3 has a central hub pot 6th on the outside a number of blades (fan blades) 7th are formed, which are oriented in the radial direction R. One from the hub pot 6th concealed motor mount is inside the Fan wheel recess 4th arranged and above struts 8th with the fan shroud 2 mechanically connected. An electric motor is held in the motor holder, its stator 9 from the rotor 10 - each also from the hub pot 6th hidden - surrounded. The cooling fan module 1 is intended and designed to be installed at the front of a motor vehicle.

The striving 8th are in the direction of the cooling fan module 1 air flow L ( 2 ) seen, ie in the axial direction A behind the fan wheel 3 arranged. The stator 9 is thus on the back of the fan wheel 3 directly or indirectly via the motor mount to the struts 8th connected, which in turn with the fan shroud 2 are connected. The stator 9 the electric motor is thus rigid with the fan frame 2 connected, and the rotor 10 the electric motor is together with the fan wheel 3 rotatable in the air wheel recess 4th the fan shroud 2 held.

That in the fan wheel recess 4th arranged fan wheel 3 is rotationally driven by the electric motor in the direction of rotation symbolized by the arrow D. The shovel blades 7th are in this direction of rotation D at their leading edges 7a concave and at their rear edges 7b configured convex.

The shovel blades 7th are at their leaf tips 7c by means of an outer ring 11 connected with each other. Among other things, this serves to stabilize the blades 7th during the rotation of the fan wheel 3 . By means of the outer ring 11 the air flow L is also guided, and the aerodynamic properties of the fan wheel 3 are improved. Between the outer ring (on the fan wheel side) 11 and the frame ring (on the outside) 5 is an annular gap 12 educated.

The cooling fan module 1 , which is preferably provided as a mounted unit, thus has one of the fan frame 2 and the fan wheel 3 formed cooling fan and the electric motor, its rotor 10 in the hub cup (in the fan hub) 6 of the fan wheel 3 Is rotatably arranged, and the stator 9 by means of the struts oriented in the radial direction R (radial) 8th in the fan wheel recess 4th the fan shroud 2 is held fixed to the frame.

2 shows the area of the annular gap in a sectional view 12 between the outer ring 11 of the fan wheel 3 and the frame ring 5 . The right and left of the dashed line 13th The arrows shown symbolize the pressure side P and suction side S of the cooling fan module that are established during fan operation 1 . To the frame ring 5 is a (radial) frame ring leg oriented in the radial direction R. 14th integrally formed, the end of the pressure side P is formed arc-shaped. Also on the outer ring 11 is a (radial) outer ring leg inclined at an angle of approx. 45 ° to the axial direction A and in the radial direction R to the suction side S. 15th molded into the annular gap 12 protrudes. To this is the frame ring leg 14th axially spaced. This and the outer ring leg overlap 15th in the axial direction A, so that an L-shaped annular gap 12 is formed, the short L-leg is oriented radially and the long L-leg is axially oriented.

On the frame ring 5 is a locking structure 16 with in circumferential direction U ( 3 ) ramp or wedge-shaped locking elements 17th intended. The respective locking element 17th has a first ramp surface 17a and a second ramp surface 17b on. This closes over a locking or leading edge 17c to the first ramp area 17a on. The annular gap 12 and thus the fan wheel recess 4th facing radial end faces of the locking elements 17th and preferably also the opposite end face of the respective locking element 17th is or are as a closed face 17d executed.

In the in 3 Circumferential direction U drawn as a curved arrow, which is the direction of rotation D of the fan wheel 3 corresponds, which is to the leading edge 17c subsequent second ramp area 17b is lagging and sloping, while the first ramp surface 17a is leading and increasing. The second ramp area 17b is preferably at least twice as large as the first ramp area 17a . The first ramp surface also runs 17a at least approximately perpendicular to the radial direction R. In the exemplary embodiment, the first ramp surface runs 17a perpendicular to the radial direction R.

The arrangement or sequence of the locking elements 17th the lock structure 16 in the circumferential direction U of the frame ring 5 is periodic (spatially or spatially). Adjacent locking elements border on this 17th without a gap to each other by the lower end of the second ramp surface 17b directly at the foot of the adjacent first ramp surface 17a connects.

As in 3 indicated in the drawing, the leading edge runs 17c of the respective locking element 17th the locking structure on the side of the bezel ring 16 at an angle of inclination α obliquely to the radius r of the frame ring 5 . The angle of inclination α is in the direction of rotation D of the fan wheel 3 - and in the drawn circumferential direction U of the frame ring 5 - oriented or exhibited. The ramp angle β between the second ramp surface 17b and one to the plane of the fan wheel recess 4th parallel reference surface or reference straight line G is smaller than 45 ° and is in particular between 20 ° and 40 °.

The barrier structure (lead structure) 16 is preferably on a separate structured ring 18th intended. This is on the bezel ring 5 put on ( 1 ).

The 3 and 4th show the structure ring 18th in a perspective front view or in a corresponding rear view. 3 thus grants a view of the front 19th and 4th on the back 20th of the structure ring 18th , with its front 19th the lock structure 16 wearing. On the back side 20th shows the structure ring 18th an annular groove 21st on, in which a radially oriented ring section 22nd of the bezel ring 5 engages positively.

The structure ring 18th points to its holder on the fan shroud 2 a number of fixing struts or retaining tabs arranged on the rear and distributed around the circumference 23 on that to the structural ring 18th are molded and oriented in the axial direction A. The one for screw fastening the structural ring 18th on the fan shroud 2 serving fixing struts 23 have support or screw feet at the end 24 with openings 25th for screws (not shown).

By means of the locking structure 17th are on the pressure side P of the cooling fan module 1 and on the outflow side of the annular gap 12 between the frame ring 5 and the outer ring 11 of the fan wheel 3 Mixing losses depending on the throttle state are reduced. A mixing of one in the annular gap takes place 12 Back-flowing air flow L at low speed largely prevented with the air flow L flowing out on the pressure side at high speed. The ring-shaped barrier structure 17th this separates the one in the annular gap 12 The volume flow of the air flowing back on the suction side or air flow L at low speed and little swirl from the outflow-side pressure-side volume flow at high speed and strong swirl, so that mixing losses are reduced.

Although exemplary embodiments were explained in the preceding description, it should be pointed out that a large number of modifications are possible. In particular, such a design of the fan shroud according to the invention is also suitable for dissipating waste heat from components of a purely electrically operated vehicle. It should also be pointed out that the exemplary designs are merely examples that are not intended to restrict the scope of protection, the applications and the structure in any way. Rather, the preceding description provides a person skilled in the art with guidelines 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, being able to be made without departing from the scope of protection as it emerges from the claims and these equivalent combinations of features.

List of reference symbols

1

Cooling fan module

2

Fan shroud

3

Fan wheel

4th

Fan wheel recess

5

Bezel ring

6th

Hub pot

7th

Shovel blade

7a

Leading edge

7b

Trailing edge

7c

Leaf tip

8th

strut

9

stator

10

rotor

11

Outer ring

12

Annular gap

13

line

14th

Frame ring legs

15th

Outer ring leg

16

Lock structure

17th

Locking element

17a

first ramp area

17b

second ramp area

17c

Barrier / leading edge

17d

Face

18th

Structure ring

19th

front

20th

back

21st

Ring groove

22nd

Ring section

23

Fixing strut / retaining strap

24

Support / screw base

25th

opening

A.

Axial direction

D.

Direction of rotation

G

Reference line

L.

Air / flow direction

P

Print side

R.

Radial direction

S.

Suction side

U

Circumferential direction

α

Inclination angle

β

Ramp angle

r

radius

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 2886873 B1 [0006]
• DE 102006037641 A1 [0007]
• DE 102015216335 A1 [0008]

Claims (10)

Cooling fan, in particular of a motor vehicle, comprising - a fan frame (2) with a fan wheel recess (4) which is surrounded by a frame ring (5), - a fan wheel (3) which is rotatably arranged in the fan wheel recess (4) and which has a hub cup (6 ) and a number of blade blades (7) oriented in the radial direction (R) starting from the hub cup (6) and an outer ring (11) which connects the blade tips (7c) of the blade blades (7) to one another, characterized in that the frame ring (5 ) a locking structure (16) with ramp-shaped locking elements (17) in the circumferential direction (U), in particular periodically, is provided, the or each locking element (17) having a rising first ramp surface (17a) and an adjoining it via a guide edge (17c) having sloping second ramp surface (17b). Cooling fan Claim 1 , characterized in that the second ramp surface (17b) is larger, in particular at least twice as large, as the first ramp surface (17a). Cooling fan Claim 1 or 2 , characterized in that the leading edge (17c) runs at an angle of inclination (a) obliquely to the radius (r), the angle of inclination (a) in the direction of rotation (D) of the fan wheel (3) and / or in the circumferential direction (U) of the frame ring (5) is oriented (stretched). Cooling fan after one of the Claims 1 to 3 , characterized in that the ramp angle (β) between the second ramp surface (17b) and a reference surface or reference straight line (G) parallel to the plane of the fan wheel recess (4) is less than 45 °, in particular between 20 ° and 40 °, preferably (25 ± 5) °. Cooling fan after one of the Claims 1 to 4th , characterized in that the first ramp surface (17a) extends at least approximately perpendicularly in the radial direction (R). Cooling fan after one of the Claims 1 to 5 , characterized in that at least one of the radial end faces of the locking elements (17), in particular the end face facing the fan wheel recess (4), is designed as a closed end face (17d). Cooling fan after one of the Claims 1 to 6th , characterized in that the locking structure (16) is provided on a structural ring (18) which is placed or can be placed on the frame ring (5). Cooling fan Claim 7 , characterized in that the structural ring (18) has a front side (19) carrying the locking structure (17) and a rear side (20) with an annular groove (21) into which an annular section (22) of the frame ring (5) engages. Cooling fan Claim 7 or 8th , characterized in that the structural ring (18) has a number of, preferably axially oriented, fixing struts (23), in particular arranged on the rear, to hold it on the fan frame (2). Cooling fan module (1), in particular as a pre-assembled unit, comprising - a cooling fan according to one of the Claims 1 to 9 and - an electric motor held in the fan wheel recess (4) of the fan frame (5) by means of radially oriented struts (8), in particular as an external rotor motor, with a rotor (10) arranged in a rotationally fixed manner in the hub cup (6) of the fan wheel (3) and with a Frame-fixed stator (9).

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