Flat flow-conducting grille

Abstract

The invention relates to a flow-conducting grille designed as a pre-conducting grille for arranging on a suction region of a fan, wherein the flow-conducting grille has a grille web structure about an axial center line, which grille web structure comprises radial webs spaced apart in the circumferential direction and coaxial circumferential webs spaced apart in the radial direction and an outer ring, wherein an inflow side of the flow-conducting grille extends flat and parallel to a radial plane of the flow-conducting grille.

Claims

1. A flow-conducting grille comprising a grille web structure about an axial center line, the grille web structure includes radial webs spaced apart in a circumferential direction, coaxial circumferential webs spaced apart in a radial direction and an outer ring, wherein the flow-conducting grille is designed flat and a ratio D.sub.3/H of a maximum outer diameter (D.sub.3) thereof to an axial height (H) is defined to be in a range of 6-25, and an inflow side of the flow-conducting grille extends flat and parallel to a radial plane of the flow-conducting grille, a first coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from an inflow side to an outflow side and is inclined radially outward with respect to the axial center line by an angle (), and a second coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from the inflow side to the outflow side, and is inclined radially inward with respect to the axial center line by an angle ().

2. The flow-conducting grille according to claim 1, wherein the flow-conducting grille is formed, in a central region, about the axial center line, with a central opening having an inflow-side central diameter (D.sub.1), wherein a ratio with respect to the maximum outer diameter (D.sub.3) of the flow-conducting grille is defined to be in a range of D.sub.3/D.sub.1=1.5-6.0.

3. The flow-conducting grille according to claim 1, wherein the extents of the first and second coaxial circumferential webs viewed in the radial direction form, in an imaginary extension at a spacing (L) from the inflow side, an intersection point, which determines an intersection point diameter (D.sub.4) radially spaced apart with respect to the axial center line.

4. The flow-conducting grille according to claim 3, wherein a ratio D.sub.4/D.sub.3 of the intersection point diameter (D.sub.4) with respect to an outflow-side outer diameter (D.sub.3) of the flow-conducting grille is defined to be in a range of 0.01-0.8.

5. The flow-conducting grille according to claim 3, wherein a ratio D.sub.4/L of the intersection point diameter (D.sub.4) with respect to the spacing (L) between the intersection point and the inflow side is defined to be in a range of 0-1.6.

6. The flow-conducting grille according to claim 3, wherein a ratio H/L of an axial height (H) of the flow-conducting grille with respect to the spacing (L) between the intersection point (7) and the inflow side is defined to be in a range of 0.01-0.5.

7. The flow-conducting grille according to claim 6, wherein the first and second coaxial circumferential webs viewed in the radial direction each have an axial extent (H.sub.1, H.sub.2) parallel to the axial center line, a ratio of which with respect to the axial height of the flow-conducting grille is defined to be H.sub.1<H.sub.2<H.

8. The flow-conducting grille according to claim 1, wherein the first and second coaxial webs viewed in the radial direction are designed to be curved convexly in the direction of the axial center line.

9. The flow-conducting grille according to claim 1, wherein the respective radial webs are spaced apart by a circumferential angle () of 20.

10. The flow-conducting grille according to claim 1, wherein in an axial top view from the inflow side, between respective adjacent radial webs and between the first and second coaxial circumferential webs viewed in the radial direction, grille meshes having a first diagonal extent (L.sub.1) are formed, and, between respective adjacent radial webs and between the second coaxial circumferential web viewed in the radial direction and the outer ring (5), respective grille meshes having a second diagonal extent (L.sub.2) are formed, wherein a length ratio L.sub.1<L.sub.2 is defined.

11. The flow-conducting grille according to claim 1, characterized in in that, in an axial top view from the outflow side, between respective adjacent radial webs and between the first and second coaxial circumferential webs viewed in the radial direction, grille meshes having a first diagonal extent (L.sub.3) are formed, and, between respective adjacent radial webs and between the second coaxial circumferential web viewed in the radial direction and the outer ring (5), respective grille meshes having a second diagonal extent (L.sub.4) are formed, wherein a length ratio L.sub.3<L.sub.4 is defined.

12. A fan having a drive unit as well as a flow-conducting grille according to claim 1, wherein the drive unit extends at least in certain sections in the axial direction into a region of the flow-conducting grille, and a ratio of a radial distance (SPm) between a radial outer edge of the drive unit and an outflow-side central diameter (D.sub.2) of a central opening and an inflow-side central diameter (D.sub.1) is defined to have a value SPm/D.sub.10.15.

13. A flow-conducting grille comprising a grille web structure about an axial center line, the grille web structure includes radial webs spaced apart in a circumferential direction, coaxial circumferential webs spaced apart in a radial direction and an outer ring, wherein an inflow side of the flow-conducting grille extends flat and parallel to a radial plane of the flow-conducting grille, a first coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from an inflow side to an outflow side and is inclined radially outward with respect to the axial center line by an angle (), a second coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from the inflow side to the outflow side, and is inclined radially inward with respect to the axial center line by an angle (), the extents of the first and second coaxial circumferential webs viewed in the radial direction form, in an imaginary extension at a spacing (L) from the inflow side, an intersection point, which determines an intersection point diameter (D.sub.4) radially spaced apart with respect to the axial center line, a ratio D.sub.4/D.sub.3 of the intersection point diameter (D.sub.4) with respect to an outflow-side outer diameter (D.sub.3) of the flow-conducting grille is defined to be in a range of 0.01-0.8.

14. A flow-conducting grille comprising a grille web structure about an axial center line, the grille web structure includes radial webs spaced apart in a circumferential direction, coaxial circumferential webs spaced apart in a radial direction and an outer ring, wherein an inflow side of the flow-conducting grille extends flat and parallel to a radial plane of the flow-conducting grille, a first coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from an inflow side to an outflow side and is inclined radially outward with respect to the axial center line by an angle (), a second coaxial circumferential web from the axial center line when viewed in the radial direction has an extent from the inflow side to the outflow side, and is inclined radially inward with respect to the axial center line by an angle (), the extents of the first and second coaxial circumferential webs viewed in the radial direction form, in an imaginary extension at a spacing (L) from the inflow side, an intersection point, which determines an intersection point diameter (D.sub.4) radially spaced apart with respect to the axial center line, and a ratio D.sub.4/L of the intersection point diameter (D.sub.4) with respect to the spacing (L) between the intersection point and the inflow side is defined to be in a range of 0-1.6.

Description

(1) Other advantageous developments of the invention are characterized in the dependent claims or described in further detail below together with the description of the preferred design of the invention in reference to the figures.

(2) FIG. 1 shows a top view onto the inflow side of a flow-conducting grille;

(3) FIG. 2 shows a lateral cross-sectional view of half of the flow-conducting grille from FIG. 1;

(4) FIG. 3 shows a top view onto the inflow side of a flow-conducting grille;

(5) FIG. 4 shows a top view onto the outflow side of a flow-conducting grille;

(6) FIG. 5 shows an installation situation of the flow-conducting grille on a fan in a lateral view;

(7) FIG. 6 shows a comparison of the characteristic curves of the flow-conducting grille according to the invention.

(8) In FIG. 1, a top view onto the inflow side of a flow-conducting grille 1 is shown. The flow-conducting grille 1 is designed as a pre-conducting grille for arranging on the suction region of a fan 50, as represented as an example in FIG. 5. About an axial center line ML, the flow-conducting grille 1 has a grille web structure with radial webs 2 spaced part in the circumferential direction and circumferential webs 3, 4 spaced apart in the radial direction and coaxially arranged and an outer ring 5 closing off the outer edge. In the central region about the axial center line ML, a central opening 6 delimited by the innermost radial web 3 is provided.

(9) FIG. 2 shows a lateral cross-sectional view of half of the flow-conducting grille 1 from FIG. 1. The inflow side of the flow-conducting grille 1, which is at the top in FIG. 2, is designed to be planar flat and extends parallel to the radial plane thereof, wherein all the elements of the flow-conducting grille 1, i.e., the outer ring 5, the radial webs 2, and the circumferential webs 3, 4, end in a radial plane of the inflow side. The outer ring 5 forms the radial and axial closure, wherein the transition is determined by a predetermined rounding R of R=10 mm, in the embodiment example. The radial webs 2 extend on the inflow side over a diameter D.sub.6 and on the outflow side almost up to the outer ring 5 which, in this region, is determined by the diameter D.sub.3. The circumferential webs 3, 4 extend on the inflow side in the radial direction over the diameters D.sub.1, D.sub.5 and on the outflow side over the diameters D.sub.2, D.sub.7. In the axial direction, the circumferential webs 3, 4 extend from the inflow side in the direction of the outflow side, curved convexly in the direction of the center line, wherein the radially inner circumferential web 3 has a curvature in the direction of the outflow side, and the circumferential web 4 has a curvature in the direction of the inflow side. Furthermore, the circumferential web 3 extends from the inflow side to the outflow side inclined radially outward with respect to the axial center line at an angle of =18. The radially farther outward circumferential web 4 extends from the inflow side to the outflow side inclined radially inward with respect to the axial center line at an angle of =12, so that the circumferential webs 3, 4 form, in an imaginary extension at a spacing L from the inflow side, the intersection point 7. The intersection point 7 is radially spaced apart from the axial center line ML and extends in the circumferential direction at the intersection point diameter D.sub.4. The axial height H.sub.1 of the innermost circumferential web 3 is smaller than the axial height H.sub.2 of the second circumferential web 4, which in turn is smaller than the total axial height H of the flow-conducting grille 1, which is determined by the outer ring 5 in the embodiment shown. The radial webs 2 are designed in such a manner that the axial height thereof, starting from the innermost circumferential web 3, increases in radial outward direction up to the outer ring 5.

(10) In the flow-conducting grille 1 shown in FIGS. 1 and 2, the ratio of the maximum outer diameter D.sub.3 to the axial height H assumes a value of 12.14. The ratio of the inflow-side central diameter D.sub.1 with respect to the maximum outer diameter D.sub.3 is 2.19. The ratio of the intersection point diameter D.sub.4 with respect to the outflow-side outer diameter D.sub.3 is defined to have a value of 0.74. The ratio of the intersection point diameter D.sub.4 with respect to the spacing L from the inflow side assumes a value of 1.55. The ratio of the axial height H with respect to the spacing L from the inflow side is 0.47.

(11) FIGS. 3 and 4 each show a top view onto the inflow side or the outflow side of the flow-conducting grille 1 of FIGS. 1-2. The radial webs 2 are each spaced apart by a circumferential angle =15, so that 24 radial webs 2 are provided in the embodiment example represented. The grille meshes determined by the radial webs 2 and circumferential webs 3, 4 each have a diagonal extent which is defined such that the radially farther outward grille meshes are larger both on the inflow side and on the outflow side. Therefore, the applicable ratio is L.sub.1<L.sub.2 on the inflow side and L.sub.3<L.sub.4 on the outflow side.

(12) In FIG. 5, an installation situation of the flow-conducting grille 1 from FIG. 1 on a fan 50 is represented in a lateral view. The fan 50 comprises a motor, which comprises a rotor housing 51 having a diameter D.sub.M. In the axial direction, the rotor housing 51 extends into the central opening 6 of the flow-conducting grille 1, but, radially, a radial distance SPm between the radial outer edge of the rotor housing 51 and the outflow-side central diameter D.sub.2 of the central opening (which corresponds to the outflow-side diameter of the inner circumferential web 3) is provided. The ratio thereof to the inflow-side central diameter D.sub.1 (which corresponds to the inflow-side diameter of the inner circumferential web 3) is defined to have a value 0.13.

(13) FIG. 6 shows a comparison of the characteristic curves, in each case using an inflow box, of the flow-conducting grille 1 according to the invention, wherein the characteristic curves of the flow-conducting grille of FIG. 1-4 are provided with reference numeral 200. By comparison, characteristic curves without flow-conducting grille are marked with reference numeral 100 and characteristic curves with a flow-conducting grille known from the prior art are marked with reference numeral 300. The positive effect of the flow-conducting grille 1 according to the invention with regard to noise reduction in dBA manifests itself particularly in flow coefficients (phi) of 0.04-0.1. The total pressure difference is particularly advantageous in the case of high flow coefficients.

(14) The invention, in the embodiment thereof, is not limited to the above-indicated preferred embodiment examples. Instead, many variants which make use of the solution represented are conceivable, even in designs of fundamentally different type. For example, the number of the circumferential webs is not limited to two; rather any number of additional circumferential webs can be provided instead.