AXIAL FAN WITH OPENINGS IN THE HUB

Abstract

The invention relates to an axial fan, having: a fan hub which is rotatable about a centre axis and has a bottom wall and an annularly circumferential side wall, a plurality of fan blades, which protrude from the annularly circumferential side wall of the fan hub, wherein the fan hub has a plurality of outlet openings for letting out gaseous, liquid and/or solid accumulations from the interior of the fan hub to the outside of the fan hub, wherein the plurality of passage openings are provided on the annularly circumferential side wall of the fan hub.

Claims

1. An axial fan, comprising: a fan hub which is rotatable about a center axis and comprises a bottom wall and an annularly circumferential side wall, a plurality of fan blades which protrude from the annularly circumferential side wall of the fan hub, wherein the fan hub comprises a plurality of outlet openings for letting out gaseous, liquid and/or solid accumulations from the interior of the fan hub to the outside of the fan hub, wherein the plurality of passage openings are provided on the annularly circumferential side wall of the fan hub.

2. The axial fan according to claim 1, wherein at least one outlet opening per fan blade is provided on the annularly circumferential side wall of the fan hub.

3. The axial fan according to claim 1, wherein the outlet openings are directly adjacent to the fan blades.

4. The axial fan according to claim 1, wherein one outlet opening is provided on each of the opposite outer sides of the fan blades.

5. The axial fan according to claim 1, wherein next to the outlet openings, elevations are provided which protrude from the annularly circumferential side wall.

6. The axial fan according to claim 5, wherein the elevations rise towards the outlet openings.

7. The axial fan according to claim 6, wherein the elevations each comprise a substantially constant slope or a slope increasing towards the respective outlet opening.

8. The axial fan (1) according to claim 1, wherein the fan hub comprises a plurality of sector elements which are connected to one another via interlocking connecting elements.

9. The axial fan according to claim 8, wherein strip elements and recesses are provided as interlocking connecting elements.

10. The axial fan according to claim 8, wherein the interlocking connecting elements extend substantially over the entire height of the annularly circumferential side wall.

11. The axial fan according to claim 8, wherein at least four sector elements are provided.

12. The axial fan according to claim 1, wherein the fan hub comprises ribs on the inside of the bottom wall.

13. The axial fan (1) according to claim 1, wherein a motor is connected to the fan hub.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0025] The invention is further explained below with reference to two exemplary embodiments, which are illustrated in the drawings.

[0026] FIG. 1 shows a top view of an axial fan according to the invention.

[0027] FIG. 2 shows a perspective view of the axial fan of FIG. 1.

[0028] FIG. 3 shows a view of the axial fan of FIGS. 1, 2 in the disassembled state of individual sector elements of the axial fan.

[0029] FIG. 4 shows a side view of the axial fan of FIGS. 1 to 3.

[0030] FIG. 5 shows detail A of FIG. 2 in enlarged view.

[0031] FIG. 6 shows detail B of FIG. 4 in enlarged view.

[0032] FIG. 7 and FIG. 8 show perspective views of a single sector element of the axial fan of FIGS. 1 to 4.

[0033] FIG. 9 shows a rear view of the sector element of FIGS. 7 and 8.

[0034] FIG. 10 shows a side view of the sector element of FIGS. 7 to 9.

[0035] FIG. 11 shows detail C of FIG. 7 in enlarged view.

[0036] FIG. 12 shows detail D of FIG. 7 in enlarged view.

[0037] FIG. 13 shows detail E of FIG. 8 in enlarged view.

[0038] FIG. 14 shows detail F of FIG. 8 in enlarged view.

[0039] FIG. 15 shows detail G of FIG. 9 in enlarged view.

[0040] FIG. 16 shows detail H of FIG. 9 in enlarged view.

[0041] FIG. 17 shows a top view of another axial fan according to the invention.

[0042] FIG. 18 shows a rear view of the axial fan of FIG. 17.

[0043] FIG. 19 shows a schematic view of the axial fan of FIG. 17 and FIG. 18.

[0044] FIG. 20 shows detail I of FIG. 20 in enlarged view.

[0045] FIG. 21 shows a section along line XXI-XXI in FIG. 17.

[0046] FIG. 22 shows detail J of FIG. 21 in enlarged view.

[0047] FIG. 23 shows detail K of FIG. 19 in enlarged view.

DETAILED DESCRIPTION

[0048] FIG. 1 shows an axial fan 1 with a fan hub 2 which rotates about a center axis 3 (cf. FIG. 4). In the embodiment shown, the axial fan can be operated effectively in both directions of rotation. A direction of rotation is shown by way of example with an arrow. The fan hub 2 has a central lead-through 4 for a shaft of a motor (not shown). The fan hub 2 has a bottom wall 5, which is circular in plan view, and a cylinder-jacket-shaped side wall 6. The bottom wall 5 is arranged substantially perpendicular to the center axis 3. The side wall 6 extends axially symmetrically about the center axis 3. Thus, the fan hub 2 is cup-shaped, with the bottom wall 5 and the side wall 6 defining an interior 2a. The motor can be arranged at least partially within the interior 2a. The axial fan 1 also has a plurality of fan vanes or fan blades 7, in the example shown eight fan blades 7, which protrude radially outwards from the side wall 6 of the fan hub 2.

[0049] The fan hub 2 has a plurality of outlet openings 8 which are arranged to transport gaseous, liquid and/or solid accumulations produced during operation from the interior 2a of the fan hub 2 to the outside 2b of the fan hub 2. Such accumulations can be, for example, water, dirt or gases, which could impair the operation of the axial fan 1 if they remain in the interior 2a. In the embodiment shown, the passage openings 8 are formed on the annularly circumferential side wall 6, thus not on the bottom wall 5. At least one outlet opening 8 is provided for each fan blade 7. In the embodiment shown, two outlet openings 8 are provided on both sides of each fan blade 7. The outlet openings 8 are formed here as slots. Since the outlet openings 8 in the embodiment shown are directly adjacent to the outer sides of the fan blades 7, the air flows are guided along the outer sides of the fan blades 7 after passing through the outlet openings, as indicated in the drawings by flow lines 9.

[0050] In the embodiment of FIGS. 1 to 16, the fan hub 2 is composed of several sector elements 10, here for example eight sector elements 10. The individual sector elements 10 are connected to each other via interlocking connecting elements 11. The connecting elements 11 can be inserted into one another in the axial direction (i.e. in the direction of the center axis 3). In the embodiment shown, outer connecting elements 11a are provided on the side wall 6 and inner connecting elements 11b are provided on a projection 12 which delimits the lead-through 4 for the motor shaft. In the embodiment shown, strip elements 13 (cf. in particular FIG. 16) and recesses 14 (cf. in particular FIG. 15) are provided as interlocking connecting elements 11, which have matching cross sections, in this case round cross sections, so that the connecting elements can be connected to one another in a substantially precisely fitting manner. The connecting elements 11 extend substantially over the entire height of the annularly circumferential side wall 6.

[0051] As can be seen in particular from FIG. 2, the fan hub 2 has individual ribs 15 on the inside 6a (facing the interior 2a) of the bottom wall 6. For example, one rib 15 can be provided per fan blade 7. Thus, in the exemplary embodiment shown, eight ribs 15 are provided in the interior 2a of the fan hub 2.

[0052] In FIGS. 17 to 23, a further embodiment of the axial fan 1 is shown. In this embodiment, outlet openings 8 are also provided on the annular side wall 6 of the fan hub 2, whereas the bottom wall 5 is free of such outlet openings. Here, the outlet openings 8 are spaced apart from the fan blades 7. Furthermore, next to the outlet openings, individual (and separate from the fan blades 7) elevations 16 are formed (cf. in particular FIG. 23), which protrude outward from the outside of the annularly circumferential side wall 6. The elevations 23 rise in a ramp-like manner towards the outlet openings 8. In the embodiment shown, the elevations 23 each have a substantially constant slope. However, the slope can also increase in the direction of the adjacent outlet opening 8 (not shown).

[0053] As can be seen from FIG. 18 and FIG. 19, ribs 15 are also provided in this embodiment, wherein, on the one hand, stiffening ribs 15a extend as far as the side wall 6 and air guide ribs are arranged in between, which end in front of the side wall 6.