Patent Grant
9568015
1. Field of the Invention
The present invention generally relates to a centrifugal fan and, more particularly, to a centrifugal fan capable of providing an improved cooling effect with reduced noise.
2. Description of the Related Art
Wind-reducing ring 93 of fan 9 may be arranged in a location which is just outside of a radial extent of air inlet 911 under an upper wall 91a of housing 91, as shown in
It is therefore the objective of this invention to overcome the above problems of conventional centrifugal fans, where the rotating impeller is too close to the upper wall of the housing, by providing a centrifugal fan capable of preventing the impeller from making contact with the upper wall of the housing.
It is another objective of this invention to provide a centrifugal fan capable reducing the wind noise generated during the rotation of the impeller.
In a preferred embodiment, a centrifugal fan comprises a fan frame, a stator assembly and an impeller. The fan frame has a base plate portion, a cover plate portion, and a lateral wall portion arranged between the base plate portion and the cover plate portion. The cover plate portion has an inner edge forming an air inlet, and the lateral wall portion has an air outlet. The stator assembly is mounted in the fan frame. The impeller is mounted in the fan frame and comprises a rotating member, a plurality of blades and a connection ring. The rotating member is rotatably coupled with the stator assembly. The plurality of blades is arranged on an outer periphery of the rotating member. Each blade has a windward edge and a lateral edge. The windward edge faces the air inlet, the lateral edge faces the lateral wall portion, and the connection ring is arranged on the windward edges of the plurality of blades. The windward edge of each blade has a first coupling edge, and the connection ring has a second coupling edge. A part of the windward edge between the first coupling edge and the lateral edge extends downwards in a curved manner, thereby forming a truncating portion between the connection ring and the lateral edge.
In a preferred form shown, the air inlet has a first radial extent from a center of the impeller, the connection ring has a second radial extent from the center of the impeller, and the second radial extent is smaller than the first radial extent.
In the preferred form shown, a part of the outer periphery of the rotating member that is coupled with the windward edge of each blade is defined as a connecting edge. The connecting edges are spaced from the inner edge of the cover plate portion by a radial range. An axial reference plane is arranged at a center of the radial range. The connection ring is located between the axial reference plane and the inner edge of the cover plate portion.
In the preferred form shown, the connection ring has a top edge and a bottom edge, and the first and second coupling edges are located on the top edge.
In the preferred form shown, the connection ring has a top edge and a bottom edge, and the first and second coupling edges are located on the bottom edge.
In the preferred form shown, the connection ring has a top edge and a bottom edge, and the first and second coupling edges are located between the top edge and the bottom edge.
In the preferred form shown, the windward edge of each blade has an arcuate section connected to the lateral edge.
In the preferred form shown, the arcuate section extends downwards in an arcuate manner from the first coupling edge to the lateral edge, thereby forming the truncating portion.
In the preferred form shown, the windward edge of each blade has an inclined section connected to the lateral edge.
In the preferred form shown, the inclined section extends downwards in an inclined manner from the first coupling edge to the lateral edge, thereby forming the truncating portion.
In the preferred form shown, the windward edge of each blade has a bending section connected to the lateral edge.
In the preferred form shown, the bending section extends downwards in an inclined manner after the first coupling edge and then extends radially to the lateral edge, thereby forming the truncating portion.
In the preferred form shown, the plurality of blades is coupled with an inner periphery of the connection ring.
In the preferred form shown, the plurality of blades extends upon and around the connection ring in a manner that the plurality of blades is coupled with inner and outer peripheries of the connection ring.
In the preferred form shown, the lateral edge of each blade has an end connected to the truncating portion, and the end is relatively distant to a bottom face of the cover plate portion among a part of the blade between the first coupling edge and the end.
In the preferred form shown, the connection ring has cross sections in the form of a round shape or an oval shape.
The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “third”, “fourth”, “inner”, “outer”, “top”, “bottom”, “front”, “rear” and similar terms are used hereinafter, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings, and are utilized only to facilitate describing the invention.
Fan frame 1 is of any hollow frame structure so that air can flow into the frame structure in an axial direction and flow out of the frame structure in a radial direction. The frame structure may have various geometric shapes, such as a polygonal shape, a round shape, an oval shape, etc. In this embodiment, fan frame 1 has a rectangular shape.
Fan frame 1 includes a base plate portion 11 and a cover plate portion 12 spaced from the base plate portion 11 at a distance. The distance allows a lateral wall portion 13 to be arranged between base plate portion 11 and cover plate portion 12. Base plate portion 11, cover plate portion 12 and lateral wall portion 13 can be coupled with each other in any manner without limitations. In this embodiment, lateral wall portion 13 is integrally formed on an outer periphery of base plate portion 11 by injection molding. Cover plate portion 12 is in the form of a cover plate that can be affixed to or detached from lateral wall portion 13.
Cover plate portion 12 of fan frame 1 has an inner edge forming an air inlet 121. As shown in
Stator assembly 2 is disposed between base plate portion 11 and cover plate portion 12 in fan frame 1. Stator assembly 2 can be of any structure capable of driving impeller 3 to rotate when coupled with impeller 3. Referring to
Impeller 3 is rotatably coupled with stator assembly 2. In this embodiment, impeller 3 is rotatably coupled with shaft seat 21 of stator assembly 2. Preferably, impeller 3 is completely installed in fan frame 1. Impeller 3 includes a rotating member 31, a plurality of blades 32 and a connection ring 33.
Rotating member 31 may be of any device that can be rotatably coupled with stator assembly 2 and the plurality of blades 32, such as a plastic impeller or a metal base plate. In this embodiment, rotating member 31 has a shaft 311 and a permanent magnet 312. Shaft 311 is rotatably coupled with stator assembly 2. Preferably, shaft 311 is rotatably coupled with shaft seat 21 of stator assembly 2. Permanent magnet 312 is coupled with an inner face of rotating member 31 and is spaced from stator assembly 2 by an air gap.
The plurality of blades 32 may be affixed to or integrally formed on rotating member 31. In this embodiment, the plurality of blades 32 is integrally formed on an outer periphery of rotating member 31. Each blade 32 has a windward edge 321 and a lateral edge 322. Windward edge 321 faces air inlet 121, and lateral edge 322 faces an inner wall of fan frame 1 (namely, faces lateral wall portion 13 of fan frame 1).
Connection ring 33 of impeller 3 is coupled with windward edges 321 of the plurality of blades 32. Specifically, connection ring 33 of impeller 3 may be affixed to or integrally formed on windward edges 321 of the plurality of blades 32. Connection ring 33 may have cross sections in the form of a geometric shape, such as a rectangular shape, a round shape, an oval shape, a polygonal shape, etc. In this embodiment, connection ring 33 has cross sections in the form of a rectangular shape. When connection ring 33 has cross sections in the form of a round shape or an oval shape, connection ring 33 is able to better guide air into the fan.
Based on the disclosed structure of impeller 3 shown in
Windward edge 321 has a first coupling edge 323 and connection ring 33 has a second coupling edge 323. Windward edge 321 of blade 32 starts to extend downwards in a curved manner after the first coupling edge 323 until lateral edge 322 is met, thereby forming a truncating portion 34. In this arrangement, lateral edge 322 of each blade 32 has an end 322a connected to the truncating portion 34. End 322a is relatively distant to a bottom face of cover plate portion 12 among the part of blade 32 between the first coupling edge 323 and end 322a. Therefore, when the connection ring 33 is located within the radial extent of air inlet 121, windward edges 321 of blades 32 can be kept from the bottom face of cover plate portion 12 due to the arrangement of the truncating portion 34. Lateral edge 322 is more distant to the bottom face of cover plate portion 12 than windward edge 321 is to the bottom face of cover plate portion 12. Thus, windward edge 321 and lateral edge 322 can be kept from the bottom face of cover plate portion 12 at proper distances, preventing blades 32 from making contact with fan frame 1 during the rotation of impeller 3. Furthermore, since windward edge 321 is kept from the bottom face of cover plate portion 12 at a proper distance, wind noise can be reduced when impeller 3 guides air into the fan via air inlet 121, improving the operation of the fan. In addition, assume base plate portion 11 has an air inlet, the truncating portion 34 may also be arranged in a corresponding location on a bottom edge of each blade 32.
Based on the disclosed technique concepts above, the truncating portion 34 may have different implementations, as described below. Referring to
Referring to
Referring to
Referring to
Referring to
Based on the above various implementations of the centrifugal fan, stator assembly 2 is able to drive impeller 3 to rotate. In this manner, the centrifugal fan can be installed in an electronic device for cooling purposes. The principle on how stator assembly 2 drives impeller 3 to rotate, as well as the detailed structures of stator assembly 2 and impeller 3, are of conventional skills and therefore are not described herein again. In addition, although the centrifugal fan with an axial air gap is shown as a preferred example in
It can be recognized from the above description that, when connection ring 33 is located within the radial extent of air inlet 121, windward edge 321 of impeller 3 can be kept from the bottom face of cover plate portion 12 at a proper distance via the truncating portion 34 formed by arcuate section 321a, inclined section 321b and bending section 321c. This prevents blades 32 from making contact with fan frame 1 during the rotation of impeller 3. In addition, windward edges 321 of blades 32 are spaced from the bottom face of cover plate portion 12 at proper distances under the arrangement of the truncating portion 34, effectively reducing the wind noise generated when impeller 3 draws air into the fan. As such, the operation and cooling effect of the centrifugal fan can be improved. Moreover, since connection ring 33 is coupled with blades 32 of impeller 3, reinforced coupling between connection ring 33 and blades 32 is achieved.
Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102104394 A | Feb 2013 | TW | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7083387 | Chen | Aug 2006 | B2 |
| 8562297 | Yen et al. | Oct 2013 | B2 |
| 20050249604 | Wu et al. | Nov 2005 | A1 |
| 20070222331 | Horng | Sep 2007 | A1 |
| Number | Date | Country |
|---|---|---|
| 101328904 | Dec 2008 | CN |
| 101818739 | Sep 2010 | CN |
| M250230 | Nov 2004 | TW |
| 200903233 | Jan 2009 | TW |
| Number | Date | Country | |
|---|---|---|---|
| 20140219789 A1 | Aug 2014 | US |
