Fan wheel, radiator fan module and motor vehicle having the radiator fan module

Abstract

A fan wheel has a hub cup and a plurality of blades which are arranged on the hub cup and extend radially outward from an outer wall of the hub cup which is in particular at least substantially cylindrical. Each blade has a leading edge and a trailing edge, wherein for at least one blade, an axial unit depth z*(t) of the blade has an aperiodically wave-like shape. A radiator fan module has a fan wheel of the type described above, and the fan wheel can be used in a motor vehicle.

Claims

1. A fan wheel, comprising: a hub cup having an outer wall; and a plurality of blades disposed on said hub cup and extending radially outwardly from said outer wall of said hub cup, each of said blades having a leading edge and a trailing edge, wherein for at least one of said blades, the following applies: a reference line is defined by: a first point on an axis of rotation of said fan wheel; a radial extent of the reference line goes through the first point and perpendicular to the axis of rotation; and a second point that bisects an arcuate edge into two equal sections at a transition from said hub cup to said at least one blade; a reference plane being defined by a line displaced parallel to the axis of rotation and a line displaced parallel to the reference line, a displacement being such that, viewed in a direction of rotation of the fan wheel, it is located entirely behind said one at least one blade; an orthogonal projection of said leading edge of said at least one blade and an orthogonal projection of said trailing edge of said at least one blade are mapped in the reference plane; a z-axis is defined in the reference plane by an orthogonal projection of the axis of rotation in the reference plane, which is displaced parallel outward in a radial direction in the reference plane from the orthogonal projection of the axis of rotation around an outer radius of the hub cup; wherein in the reference plane a y-axis is defined by an orthogonal projection of a radial extent in the reference plane; wherein a relative unit radius t(r) is plotted on the y-axis, and is defined as follows: $t (r) = \frac{r - R_{i}}{R_{a} - R_{i}}$ wherein: R.sub.i is the outer radius of said hub cup, which corresponds at least substantially to an inner radius of said at least one blade; R.sub.a is an outer radius of said at least one blade; and r is a distance between the axis of rotation and a sectional plane under consideration, which is at distance r perpendicular from the axis of rotation on the reference line, wherein r[R.sub.i;R.sub.a]; wherein an axial unit depth z*(t) of said at least one blade is plotted on the z-axis, and is defined as follows: $z^{*} (t) = \frac{z_{HK} (t) - z_{VK} (t)}{R_{a} - R_{i}},$ wherein z.sub.VK(t) is a z-coordinate of the orthogonal projection of the leading edge in the sectional plane passing through t; and z.sub.HK(t) is a z-coordinate of the orthogonal projection of the trailing edge in the section plane passing through t; wherein a progression of the axial unit depth z*(t) has an aperiodically wave-like shape.

2. The fan wheel according to claim 1, wherein said orthogonal projection of said leading edge is flat or curved.

3. The fan wheel according to claim 1, wherein said at least one blade, viewed in a direction of rotation, is a forward-swept blade.

4. The fan wheel according to claim 1, further comprising an at least substantially circular outer ring which links to tips of said blades.

5. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has a global minimum in a range of 65% to 90% of the relative unit radius t(r) of said at least one blade.

6. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has no or at most one high point in a y-direction after a global minimum.

7. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has an at least substantially continuously rising or falling profile in a range of 0% to 50% of the relative unit radius t(r) of said at least one blade.

8. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t), as a function of the relative unit radius t(r), satisfies the following condition: $z^{*} (t) = \frac{(A_{1} t^{2} + A_{2} t) \cos [2 N (a (1 - t) + 1) (t + t_{0})] + A_{3} t + A_{4}}{R_{a} - R_{i}}$ where: t.sub.0[0;0.5] N[1;8] a[1.5;1.5] A.sub.1[2;10] A.sub.2[10;10] A.sub.3[10;10] and A.sub.4[5;50].

9. The fan wheel according to claim 1, wherein an entire length of said at least one blade is divided into the following sections: Section I from 0% to 65% of an entire length of said at least one blade; Section II from 65% to 77.5% of the entire length of said at least one blade; and Section III from 77.5% to 100% of the entire length of said at least one blade; wherein a total axial unit depth z*(t), plotted over the entire length as a function of the relative unit radius t(r), is bounded above by an upper limit function G.sub.O defined as follows: Section I G.sub.O extends from the axial unit depth z*(t) of 0.175 linearly to the axial unit depth z*(t) of 0.175; Section II G.sub.O extends from the axial unit depth z*(t) of 0.175 linearly to the axial unit depth z*(t) of 0.13; and Section III G.sub.O extends from the axial unit depth z*(t) of 0.13 linearly to the axial unit depth z*(t) of 0.23.

10. The fan wheel according to claim 9, wherein the entire length of said at least one blade is divided into the following sections: Section I from 0% to 65% of the entire length of said at least one blade; Section II from 65% to 77.5% of the entire length of said at least one blade; and Section III from 77.5% to 100% of the entire length of said at least one blade; wherein the axial unit depth z*(t) as a function of the relative unit radius t(r), plotted over the entire length, is bounded below by a lower limit function G.sub.U, defined as follows: Section I G.sub.U extends from the axial UNIT depth z*(t) of 0.05 linearly to the axial unit depth z*(t) of 0.05; Section II G.sub.U extends from the axial unit depth z*(t) of 0.05 linearly to the axial unit depth z*(t) of 0.02; and Section III G.sub.U extends from the axial unit depth z*(t) of 0.02 linearly to the axial unit depth z*(t) of 0.10.

11. The fan wheel according to claim 10, wherein: the axial unit depth z*(t) over the entire length of said at least one blade is always less than an associated value of the upper limit function G.sub.O; and the axial unit depth z*(t) over the entire length of said blade is always greater than an associated value of the lower limit function G.sub.U.

12. The fan wheel according to claim 1, wherein: said hub cup is rotationally symmetrical around an axis of rotation; and said is at least substantially cylindrical in shape.

13. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has a global minimum in a range of 70% to 85% of the relative unit radius t(r) of said at least one blade.

14. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has an at least substantially continuously rising or falling profile in a range of 0% to 40% of the relative unit radius t(r) of said at least one blade.

15. The fan wheel according to claim 1, wherein the progression of the axial unit depth z*(t) has an at least substantially continuously rising or falling profile in a range of 0% to 30% of the relative unit radius t(r) of said at least one blade.

16. The fan wheel according to claim 1, wherein all of said blades are configured as said at least one blade.

17. A radiator fan module, comprising: a fan cowl ring; a fan cowl having a fan wheel recess formed therein, said fan wheel recess being bounded by said cowl ring; struts; a motor holder disposed within said fan wheel recess and mechanically connected with said fan cowl via said struts; a motor at least partially held in said motor holder; and a fan wheel disposed in said fan wheel recess and is rotationally driven by said motor, said fan wheel being configured according to claim 1.

18. The radiator fan module according to claim 17, wherein said struts as seen in a flow direction are disposed behind said fan wheel.

19. A motor vehicle, comprising: a radiator fan module according to claim 17.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1A is a perspective view of a front side of a fan wheel according to the prior art;

(2) FIG. 1B is a rear, perspective view of a blade of the fan wheel known in the prior art from FIG. 1A, viewed from the reference plan, with the front or upper side of the fan wheel facing downward;

(3) FIG. 2A is a diagrammatic, perspective view of a front or upper side of a fan wheel according to an embodiment of the invention;

(4) FIG. 2B is a rear, perspective view of a blade of the fan wheel shown in FIG. 2A, viewed from the reference plane, with the front or upper side of the fan wheel facing downward;

(5) FIG. 3 a perspective view of the fan wheel of the prior art for illustrating a reference plane;

(6) FIG. 4 is a graph showing a progression of an axial unit depth over the relative unit radius of the fan wheel according to an embodiment of the invention;

(7) FIG. 5 is a graph showing a comparison of the fan wheel previously known in the art with a fan wheel according to an embodiment of the invention; and

(8) FIG. 6 is a front view of a radiator fan module with the fan wheel according to the invention, according to a second aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(9) Referring now to the figures of the drawings in detail and first, particularly to FIG. 1A thereof, there is shown a fan wheel 1 of the prior art in a perspective view from a front or upper side and FIG. 1B shows a rear view of a blade 30 of the known fan wheel of FIG. 1A in a perspective view from the reference plane, wherein the upper side of the fan wheel 1 points down.

(10) The fan wheel 1, according to FIGS. 1A, 1B, 2A, 2B and 3, has a hub cup 10 that is rotationally symmetrical around an axis of rotation R. At the hub cup 10, a plurality of blades 30 are arranged, which extend radially outward from a cylindrical outer wall 12 of the hub cup 10. A direction of rotation D is indicated by the arrow on the hub cup in FIGS. 1A and 2A. Accordingly, the direction of rotation is clockwise. A main flow direction of the supplied air is marked with HSR. The fan wheel 1 has an at least substantially circular outer ring 20 which links the tips of the blades 30 together.

(11) With regard to FIG. 1B (and FIG. 2B), it should be noted that the position of the axis of rotation R, with regard to its distance from the cylindrical outer wall 12 of the hub cup 10 is not true to scale; in other words, the orientation is binding, but the position is not.

(12) As may be seen in FIGS. 1A and 1B, the prior art blades 30 have flat or curved leading edges VK and flat or curved trailing edges HK in an orthogonal projection.

(13) FIG. 2A shows a fan wheel 1 according to one embodiment of the present invention in a perspective view, and FIG. 2B shows a rear view of a blade 30 of the fan wheel of FIG. 2A viewed from the reference plane, in a perspective view.

(14) Compared to embodiments of the fan wheel 1 according to the prior art (see FIGS. 1A and 1B), the fan wheel 1 according to an embodiment of the present invention as shown in FIGS. 2A, 2B has blades 30 with an aperiodic wave-shaped trailing edge.

(15) As regards the perspective of the sectional view, reference is made to the following statements regarding FIG. 3. As is apparent in FIGS. 2A and 2B, the orthogonal projection of the leading edge has a flat or curved shape.

(16) FIG. 3 shows a fan wheel 1 from the prior art in a perspective view for illustrating a reference plane E_REF.

(17) In the following will be described the viewing plane for describing the leading edge VK and trailing edge HK or the resulting axial unit depth z*(t). The fan wheel shown in FIG. 3 does not have any blade geometry according to this invention, which is not relevant to the description of the reference plane E_REF, because the statements relevant thereto apply in the same way for embodiments of the invention.

(18) Starting from the axis of rotation R, a reference 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 is defined by the first point P1, perpendicular to the axis of rotation R, and a second point P2, which bisects an arcuate edge at the transition from the hub cup 10 to the blade 30 into two equal sections. In other words: The radius is determined that passes through the point P2. Point P2 represents the midpoint of the transition edge from hub cup to blade, in particular the edge of the blade 30 facing the bottom of the cup. Another at least substantially identical definition of P2 may be derived via an angle: Two auxiliary radii are required, the first auxiliary radius passing through P1 and the foremost point on the transitional edge between the cylindrical outer wall and the blade, and a second auxiliary radius passing through the rearmost point on the transitional edge from the hub cup to the blade, and the line is constructed that bisects the angle enclosed between the two auxiliary radii. The point at which the aforementioned 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 line displaced parallel to the axis of rotation and a line displaced parallel to the reference line G_REF, the displacement being such that, viewed in the direction of rotation D of the fan wheel 1, it is located entirely behind the blade 30. On the reference plane E_REF are mapped an orthogonal projection of the leading edge VK of the blade 10 and an orthogonal projection of the trailing edge HK of the blade 10. The viewing direction B shows the view in FIGS. 1B and 2B respectively of a blade segment of the fan wheel.

(19) A coordinate system consisting of a z-axis and y-axis is spanned in the reference plane. This is significant for the description of the leading and trailing edges. The z-axis is defined by an orthogonal projection of the axis of rotation R in the reference plane E_REF, which in a second step is displaced in parallel outward in the reference plane E_REF in the radial direction from the orthogonal projection of the axis of rotation R about an outer radius R.sub.i of the hub cup 10. In other words: The z-axis is unchanged in orientation, but is displaced in parallel in two steps, i.e. a first time through orthogonal projection onto the reference plane E_REF and then through displacement by R.sub.i in the reference plane E_REF. This means that the z-axis passes through the orthogonal projection of P2 onto E_REF. The y-axis is defined through an orthogonal projection of the radial extent E in the reference plane E_REF. The origin of this y-z coordinate system is defined by the intersection of the two axes.

(20) A relative unit radius t(r) is plotted on the y-axis, and is defined as follows:

(21) $t (r) = \frac{r - R_{i}}{R_{a} - R_{i}}$
wherein
R.sub.i is an outer radius of the hub cup 10, which corresponds in particular at least substantially to an inner radius of the blade 30;
R.sub.a is an outer radius of the blade 30; and
r is the distance between the axis of rotation R and the sectional plane S under consideration, which is perpendicular at the distance r perpendicular from the axis of rotation R along the associated reference line G_REF, where r[R.sub.i;R.sub.a].

(22) FIG. 4 shows the progression of the axial unit depth over the relative unit radius of a fan wheel according to an embodiment of the present invention.

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

(24) The axial unit depth z*(t) of the blade is plotted on the vertical axis. The axial unit depth z*(t) is given by

(25) $z^{*} (t) = \frac{z_{HK} (t) - z_{VK} (t)}{R_{a} - R_{i}}$
wherein
z.sub.VK(t) is the z-coordinate of the orthogonal projection of the leading edge VK in the sectional plane S passing through t; and
z.sub.HK(t) is the z-coordinate of the orthogonal projection of the trailing edge HK in the sectional plane S passing through t.

(26) The progression of the axial unit depth z*(t) shown in this way has an aperiodically wave-like shape. It will be apparent that the axial unit depth z*(t), analogously to the orthogonal projection of the trailing edge HK, has a global minimum in the range from 65% to 90%, in particular from 70% to 85%, in particular 75% to 80%, of the relative unit radius t(r) of the blade.

(27) As is also apparent from the progression of the axial unit depth z*(t) of the exemplary embodiment of FIG. 4, the orthogonal projection of the trailing edge HK and likewise the axial unit depth, has no or at most one high point in the y-direction after the global minimum.

(28) As also shown in FIG. 4, the exemplary embodiment of the axial unit depth z*(t), and likewise the orthogonal projection of the trailing edge HK, has an at least substantially continuously falling progression in the range from 0% to 50%, in particular from 0% to 40%, in particular 0% to 30%, of the relative unit radius t(r) of the blade 30. A slight waviness is explicitly provided for here, in particular up to a maximum amplitude height of 0.05. The progression of the axial unit depth z*(t) of the exemplary embodiment of FIG. 4, as a function of the relative unit radius t(r), meets the following condition:

(29) $z^{*} (t) = \frac{(A_{1} t^{2} + A_{2} t) \cos [2 N (a (1 - t) + 1) (t + t_{0})] + A_{3} t + A_{4}}{R_{a} - R_{i}}$
where:

(30) t.sub.0[0;0.5]

(31) N[1;8]

(32) a[1,5;1,5]

(33) A.sub.1[2;10]

(34) A.sub.2[10;10]

(35) A.sub.3[10;10] and

(36) A.sub.4[5;50].

(37) The axial unit depth shown in FIG. 4 results at least substantially, in particular absolutely, from the following parameters:

(38) t.sub.0=0

(39) N=3

(40) a=0,4

(41) A.sub.1=10

(42) A.sub.2=2

(43) A.sub.3=5

(44) A.sub.4=16

(45) FIG. 5 shows a comparison of a fan wheel 1 previously known in the art with a fan wheel 1 according to an embodiment of the present invention.

(46) Shown are:

(47) a pressure coefficient , which is a characteristic for a total pressure difference:

(48) $= \frac{2 p_{t}}{^{2} D^{2} n^{2}}$
a coefficient of performance , which is a characteristic for an input power;

(49) $= \frac{8 P_{el}}{^{4} D^{5} n^{3}}$
and an efficiency over a volume coefficient that quantifies a volumetric flow.

(50) $= \frac{p_{t} \dot{V}}{P_{el}}$

(51) For the input power, here the shaft power of the electric motor is used; corresponding losses (heat, friction, etc.) of the electric motor are taken into account and represented in the overall efficiency .

(52) As is apparent, with almost the same performance (similar coefficient of performance) a higher pressure coefficient (=>total pressure difference) is achieved, yielding a significant increase in efficiency in the relevant volume coefficient range.

(53) FIG. 6 shows a radiator fan module 100 with the fan wheel 1 according to the present invention, according to the second aspect of the present invention.

(54) The radiator fan module 100 has a fan cowl 2; a fan wheel recess 40 is formed in the fan cowl 2, and is bounded by a cowl ring 42. A motor holder (hidden by the hub cup 10) is arranged within the fan wheel recess 40 and is mechanically connected with the fan cowl 2 via struts 44. A motor (likewise hidden by the hub cup 10), in particular an electric motor, is at least partially held in the motor holder. A fan wheel 1 is arranged in the fan wheel recess 40 and is driven rotationally by the motor. The fan wheel 1 corresponds to an embodiment of a fan wheel according to the present invention. The detailed configuration of the fan wheel has been described above. According to the embodiment of FIG. 6, the struts 44 are arranged behind the fan wheel in the flow direction, with the flow direction running perpendicularly into the illustration of FIG. 6.

(55) Although exemplary embodiments have been explained in the foregoing specification, it should be noted that numerous modifications are possible. In particular, such a configuration of the fan cowl according to the invention is also suitable for dissipating waste heat from components of a purely electrically powered vehicle. It should additionally be noted that the exemplary embodiments are merely examples that are not intended to limit the scope, applications and structure in any way. Rather, the preceding description gives the person of ordinary skill in the art a guide for implementing at least one exemplary embodiment, and various changes, in particular with regard to the function and arrangement of the components described, may be made without departing from the scope of the patent, as set forth in the Claims and equivalent feature combinations.

(56) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Fan wheel 2 Cowl 10 Hub cup 12 (Cylindrical) outer wall of the hub cup 10 20 Outer ring 30 Blade 40 Fan wheel recess 42 Cowl ring 44 Struts 100 Radiator fan module HK Trailing edge VK Leading edge B Line of vision D Direction of rotation E Radial extent E_REF Reference plane G_REF Reference line G.sub.O Upper limit function for z*(t) G.sub.U Lower limit function for z*(t) HSR Main flow direction P1 First point P2 Second point r Distance between axis of rotation R and section plane S R Axis of rotation R.sub.a Outer radius of the blade 30 R.sub.i Outer radius of the hub cup 10 S Section plane y y-axis z z-axis z*(t) Axial unit depth

Fan wheel, radiator fan module and motor vehicle having the radiator fan module

Assignee

Inventors

Cpc classification

Classification Explorer

F01P5/02

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

F04D29/384

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

F04D29/326

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

F01P5/06

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

F04D29/388

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

International classification

Classification Explorer

F04D29/38

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

F01P5/02

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Abstract

Claims

Description