Fan clutch

Abstract

A fan clutch, in particular for a fan of a cooling system of a motor vehicle having a housing and an annular flange for connecting the fan, wherein the flange is arranged centrally around a housing axis, wherein the flange forms a flat flange-ring plane substantially perpendicular to the housing axis and has a flange-ring inner side and a flange-ring outer side which bound the flange-ring plane, wherein the flange is contorted in the flange-ring plane in certain areas in a direction substantially parallel to the housing axis.

Claims

1. A fan clutch for a fan of a cooling system of a motor vehicle, the fan clutch comprising: an annular flange connecting the fan, the flange being arranged centrally around an axis, the flange forming a flange-ring surface substantially perpendicular to the axis and has a flange-ring inner side and a flange-ring outer side that bound the flange-ring surface, the flange being contorted in the flange-ring surface in certain areas in a direction substantially parallel to the axis, wherein the flange-ring surface has first flange-ring planes and second flange-ring planes that alternate around the flange to form a continuous flange-ring surface, the first flange-ring planes and the second flange-ring planes each respectively extend from the flange-ring inner side to the flange-ring outer side, wherein the first flange-ring planes form the certain areas of the flange that are contorted in the direction substantially parallel to the axis, wherein each of the first flange-ring planes, on each side thereof, are connected to a respective one of the second flange-ring planes by a flange ring section, and wherein the flange-ring inner side has projections and/or recesses that are formed substantially uniformly over the circumference.

2. The fan clutch as claimed in claim 1, wherein the flange-ring surface has a substantially step-shaped form, wherein the flange ring section is an angled plane.

3. The fan clutch as claimed in claim 1, wherein the flange-ring surface has a substantially wave-shaped form.

4. The fan clutch as claimed in claim 1, wherein the first flange-ring planes and the second flange-ring planes form wave troughs and/or wave peaks.

5. The fan clutch as claimed in claim 1, wherein the projections and/or recesses are formed in the flange-ring surface.

6. A cooling system for a motor vehicle comprising the fan and the fan clutch as claimed in claim 1 for connecting the fan to a drive shaft of an engine.

7. The fan clutch as claimed in claim 1, further comprising a fan clutch housing, the axis being a housing axis of the fan clutch housing, wherein the fan clutch housing has cooling ribs radially oriented and mounted about the housing axis, wherein a gap is formed between the second flange-ring planes and the cooling ribs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 shows a conventional fan;

(3) FIG. 2 shows a section of the fan from FIG. 1;

(4) FIG. 3 shows the fan of FIG. 1 in a perspective view;

(5) FIG. 4 shows a fan according to an embodiment the invention;

(6) FIG. 5 shows a flow simulation in the fan according to the conventional art; and

(7) FIG. 6 shows a flow simulation in the fan according to an embodiment of the invention.

DETAILED DESCRIPTION

(8) FIG. 1 shows a fan 10 according to the conventional art in a perspective view. The fan 10 is preferably designed as a ring fan, in particular as an axial fan. The fan 10 is part of a cooling system (not shown) for an internal combustion engine of a motor vehicle. The fan 10 has fan blades 12 which are arranged on a sleeve ring 14. The sleeve ring 14 is movably connected by means of a fan clutch 17, which is arranged in a housing 18 and of which only a flange 16 is shown, to a drive shaft (not shown) which is mounted along a housing axis 20.

(9) In a schematic view, FIG. 2 shows a section of the fan 10 from FIG. 1, more accurately of one of the fan blades 12 which is arranged on the sleeve ring 14. The fan clutch 17 is arranged between the sleeve ring 14 and the drive shaft (not shown) which runs substantially on the housing axis 20.

(10) FIG. 3 shows the fan 10 according to the prior art in perspective view looking at the rear of the fan 10. The flange 16 is part of the fan clutch 17 which is formed in particular as a friction clutch or viscous coupling. The flange 16 is designed as a flat ring and, on a flange-ring inner side 24, has projections 26 with openings 28 or recesses 28 which are designed to accept screws (not shown). Ribs 30, in particular cooling ribs, are arranged in the form of a circle around the housing axis 20. The ribs 30 rest against the flange 16.

(11) FIG. 4 shows a fan 110 with fan blades 112 according to the invention. The fan 110 is shown schematically looking at the rear of the fan 110. The housing axis 120, which is shown by a dot, runs centrally through the fan 110. As well as the flange-ring inner side 124, the flange 116 has a flange-ring outer side 134, wherein a first flange-ring plane 136 and a second flange-ring plane 138 extend between the flange-ring inner side 124 and the flange-ring outer side 134. The two flange-ring planes 136 and 138 are brought about by a contortion of the flange 116 in a direction parallel to the housing axis 120.

(12) On the other hand, the flange 16 according to the prior art, shown in FIG. 3, has only one planar flange-ring plane 40.

(13) Seen with respect to a direction parallel to the housing axis 120, the second flange-ring plane 138 is arranged at a distance from the first flange-ring plane 136. The two flange-ring planes 136 on 138 are connected by means of a flange-ring section 142. The flange-ring plane 136, the angled flange-ring sections 142 and the flange-ring plane 138 therefore form a continuous flange-ring surface 144. In the exemplary embodiment of FIG. 4, the flange-ring section 142 is formed as a sloping surface 146 or angled plane 146. However, the flange-ring section 142 can also be formed as a step with a surface running substantially perpendicular to the flange-ring planes 136 and 138.

(14) In an embodiment, the flange-ring surface 144 can also be designed in the form of a wave, wherein the flange-ring plane 136 is formed by wave troughs and the flange-ring plane 138 by wave crests. Here, the wave troughs and the wave crests preferably have a substantially flat, planar plateau and thus form the flange-ring planes 136 and 138.

(15) As a result of the contortion and the design of the two flange-ring planes 136 and 138, a gap 148 is formed between the ribs 130 and the flange 116.

(16) FIG. 5 shows a flow simulation 50 in a sectional view in the fan 10 according to the prior art. The fan blades 12 of the fan 10 and the flange 16 are shown schematically. The flange 16 is part of the fan clutch 17. The air flow is shown by arrows. A displacement of the air marked with arrows 52 can be seen at an edge of the flange 16. The height of the ribs is only partially utilized here.

(17) FIG. 6 shows a flow simulation 54 of the fan 110 according to the invention. The gap 148 is formed between the flange 116, more accurately between the flange-ring plane 138, and the top edge of the ribs 130. The displacement of the air shown by the arrows 156 is significantly less. The rib height of the ribs 130 can be fully utilized.

(18) Overall, a return flow can be increased and therefore the cooling capacity of the fan clutch 117 can be further improved as a result of the contortion of the flange 116 and the formation of the gap 148 in the region of the flange-ring plane 138.

(19) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.