Heat dissipating fan

Abstract

A heat dissipating fan has a round disk. The bottom of the round disk has a receiving portion concave upwards for receiving a motor 14. A periphery of the round disk has a plurality of cambered extending blades which are arranged regularly. The plurality of blades extends along a cambered path. Each blade has a convex surface and a concave surface. Each convex surface has a protruding flow guide opposite to the concave surface of the blade; and at a connection of the flow guide and the blade has at least one cambered surface.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a heat dissipating fan, and especially to a heat dissipating fan having cambered blades each having a convex surface.

BACKGROUND OF THE INVENTION

[0002] In order to match the compact size of current notebook computer, air flow of heat dissipating fan is changed from the longitudinal output to a transversal output (such as a blower). The prior art heat dissipating fan is illustrated in FIGS. 8 and 9. The periphery of the rotary disk 81 is extended with blades 82 with cambered surfaces. Each blade 82 has a tilt wind cutting angle &agr;. Furthermore, wind is guided along the cambered surface of the blade and wind pressure is boosted so that air is boosted to be pushed out. However, this kind of fan has only the function of absorbing air at the upper side and outputting air from the lateral side. Therefore, it only dissipates heat at a single direction. It is not suitable for the device which needs to dissipate heat at the upper and lower sides. Furthermore, the blade 82 only cuts a little air in a cutting angle &agr;. Although the noise generated is smaller, the absorbing air is small. Next, this heat dissipating fan is made by injecting plastics for reducing cost. However, the molds used in injection must match with the cambered surface of the blade 82 having a complex shape. Therefore, the mold can not be formed by an upper and a lower mold. Thus, a plurality of mold cores (not shown) must be designed to be inserted into the blades 82. However, the mold has a complex structure and a high cost. This is not suitable for the parts necessary to reduce cost.

[0003] Another prior art design is illustrated in FIGS. 10 and 11, in that a plurality of straight blades 92 are protruded slightly from the periphery of the rotary disk 91 so that air is absorbed at the upper and lower sides. As a result, heat is dissipated from the upper and lower sides. In manufacturing, the complex structure of the mold in the cutting type heat dissipating fan is improved. The mold can be formed by an upper and lower molds. However, as this kind of blades 92 rotates, instead of cutting air, they beat air to induce a large amount of air. Furthermore, as the blades 92 beat air, the air at the upper and lower edges of the blades will be extruded out so as to be formed with a resisting force. This resisting force will affect the load of the motor (not shown), and thus, the lifetime of the motor is reduced.

SUMMARY OF THE INVENTION

[0004] Accordingly, the primary object of the present invention is to provide a heat dissipating fan, wherein by the cambered surfaces of the blades, air from the upper and lower wind inlets can be driven so as to have a preferred heat dissipating effect.

[0005] To achieve above objects, the present invention provides a heat dissipating fan, the cambered surface of the blade will cut air and increase the flow guiding. Therefore, noise is reduced and moreover, the air will not be turbulent to the upper and lower sides. The resistance to the absorbed air is reduced and further air is increased. Thus, the load of the motor is reduced, thereby causing the lifetime of the motor to be prolonged.

[0006] The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 is a perspective view of the first embodiment in the present invention.

[0008] FIG. 2 is a top view of the first embodiment in the present invention, wherein the arrow indicates the direction of air flow.

[0009] FIG. 3 is a lateral view of the first embodiment of the present invention, wherein the arrow shows the direction of air flow.

[0010] FIG. 4 is a schematic view showing the application of the first embodiment of the present invention.

[0011] FIG. 5 is a cross sectional view along the line V-V of FIG. 4.

[0012] FIG. 6 is a lateral view of the second embodiment of the present invention.

[0013] FIG. 7 is a lateral view of the third embodiment of the present invention.

[0014] FIG. 8 is a perspective view of a prior art heat dissipating fan.

[0015] FIG. 9 is a lateral view of FIG. 8.

[0016] FIG. 10 is a perspective view of another prior art heat dissipating fan.

[0017] FIG. 11 is a lateral view of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Referring to FIGS. 1 to 5, the heat dissipating fan of the present invention is illustrated. The heat dissipating fan of the present invention is installed to a casing 10. The top of the bottom of the casing 10 has respective wind inlets 13. The lateral side of the casing 10 has a wind outlet 12. The inner side of the wind inlet at the bottom of the casing 10 is installed with a retaining disk 13. The center of the retaining disk 13 is installed with a motor 14. The motor 14 has a rotary shaft 141 extending upwards. The upper end of the rotary shaft 141 is combined to a center of a round disk. The bottom of the round disk 20 has a receiving portion 22 concave upwards. The motor 14 is received in the receiving portion 22. The periphery of the round disk 20 has a plurality of cambered extending blades 21. The plurality of blades 21 are extended counterclockwise (viewing downwards). An angle of 15 to 75 degrees is formed between each blade and the normal line L at the connection of the round disk. Each blade is installed with a convex surface 211 and a concave surface 212. The middle portion of one side of the convex surface 211 has a flow guide 213 projected at an opposite position of the concave surface 212 of the blade 21. At the connecting portion of the flow guide 213 and the blades 21 has a cambered surface 214.

[0019] It should be appreciated that as the present invention is driven by the motor 14 so as to rotate counterclockwise (viewing downwards), the periphery of the casing 10 is formed with a turbulent space H. Each blade 21 at the periphery of the round disk 20 will cut the wind at the front end of the rotating path. As the air is cut, it is pushed forwards by the convex surface 211 of the blade 21. Then, the air is driven away, while air at other portion flows into the wind inlet 11. Another, the air cut away flows to the opening end of the blade 21 along the cambered surface 214 of the convex surface 211 (as FIGS. 2 and 3). After the air is left from the blade 21, it become as a boosting pressure in the turbulent space H of the casing 10. Then the boosted air is vented out from the wind outlet 12.

[0020] In one application of the present invention, it is installed within a notebook computer (not shown), since as the present invention is driven by a motor 14, the flow guide 213 of the blade 12 will separate a space into two cambered surfaces 214 so that air flows from the upper and lower wind inlets 11 are driven by the blade 21. The upper and lower side of the blade 21 can cut the air. Therefore, the upper and lower wind inlets 11 of the casing 10 have the function of absorbing heat. Therefore, in the present invention, air is inputted from the upper and lower sides so as to have a preferred heat dissipating effect. Furthermore, as each blade 21 cuts air, air flows to the inner side thereof and the outer edge (as illustrated in FIG. 3) of the blade 21. The cut air do not flow to the upper and lower sides and therefore, it makes no resistance force to the absorbed air from the wind inlet 11. When the resistance of the inlet air is decreased, the load of the motor 14 is also reduced. Thus, the lifetime of the motor 14 will increase. The blade 21 of the present invention cuts air by the cambered surface 214 thereof to increase the guide of air. It is not by beating, and thus noise is reduced. Next, since the blade 21 of the present invention has no complex curved surface, it can be made by an upper and a lower mold so that the cost is low.

[0021] In summary, the blades 21 of the heat dissipating fan according to the present invention may drive the air from the upper and lower wind inlets 11 so as to have a preferred heat dissipating effect. The cambered surface 214 of the blade 21 will cut air and increase the flow guiding. Therefore, noise is reduced and moreover, the air will not be turbulent to the upper and lower sides. The resistance to the absorbed air is reduced and further air is increased. Thus, the load of the motor 14 is reduced, thereby causing the lifetime of the motor 14 to be prolonged. Furthermore, by the design of the flow guide 213 of the blade 21, the mold can be designed easily and therefore, manufacturing cost is increased.

[0022] Of course, many embodiments may embody the present invention. One of the embodiment is illustrated in FIG. 6, which is the second embodiment of the present invention. In the present invention, the flow guide 32 of the blade 31 is installed at the bottom edge. Only an upper cambered surface 34 is formed between the flow guide 32 and the convex surface 33. That is, the blade 31 has a preferred effect to drive air from the upper wind inlet (not shown) so that the present invention has the same function as the prior art.

[0023] Referring to FIG. 7, a third embodiment of the present invention is illustrated. In this embodiment, a flow guide 41 is installed to be near the top edge of the blade 42 so that the each blade 42 has different cambered surface 43, thereby causing the flow guides 41 of the blade 42 to have different widths in the upper and lower sides to match the areas of the wind inlets (not shown).

[0024] The present invention are 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 present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. A heat dissipating fan having a round disk, a bottom of the round disk having a receiving portion concave upwards; a periphery of the round disk having a plurality of cambered extending blades; the plurality of blades extending along a cambered path; each blade having a convex surface and a concave surface; each convex surface having a protruding flow guide opposite to the concave surface of the blade; and at a connection of the flow guide and the blade having at least one cambered surface.

2. The heat dissipating fan as claimed in claim 1, wherein the round disk and the plurality of blades are installed in a casing, an top and a bottom of the casing having a wind inlet, respectively, and one lateral side of the casing has a wind outlet; an inner side of the wind inlet at the bottom of the casing has a retaining disk; a center of the round disk being installed with a motor; the motor having a rotary shaft extending upwards; and an upper end of the rotary shaft being combined to a center of the round disk.

3. The heat dissipating fan as claimed in claim 2, wherein the receiving portion of the round disk receives the motor.

4. The heat dissipating fan as claimed in claim 1, wherein an angle of 15 to 75 degrees is formed between each blade and a normal line L of a connection of the round disk.

5. The heat dissipating fan as claimed in claim 1, wherein the flow guide is installed at the upper and lower sides of the blade.

6. The heat dissipating fan as claimed in claim 1, wherein the flow guide is installed at a lower edge of the blade.

7. The heat dissipating fan as claimed in claim 1, wherein the flow guide is installed at the blade near a lower edge or a top edge.