Patent Application
20110180240
1. Technical Field
The disclosure generally relates to centrifugal blowers; and more particularly to a centrifugal blower which can provide a large amount of airflow, and a heat dissipation device incorporating the centrifugal blower.
2. Description of Related Art
It is well known that heat is produced by electronic components, such as integrated circuit chips, during normal operation. If such heat is not quickly removed, these electronic components may overheat. Therefore, heat dissipation devices are often used to cool these electronic components.
As an example, a heat dissipation device in the related art generally includes a fin assembly having a plurality of fins, and a centrifugal blower for creating an airflow through the fin assembly. The fin assembly is thermally connected to a heat generating electronic component such as a central processing unit (CPU) or a graphic processing unit (GPU) of a computer. Heat generated by the heat generating electronic component is transferred to the fins of the fin assembly, and then dissipated to the ambient atmosphere via the airflow flowing through the fin assembly.
Increasing the amount of airflow provided by the centrifugal blower is an effective way to improve the heat dissipation efficiency of the heat dissipation device. Conventional ways of satisfying such requirement are to change the configurations of blades of the centrifugal blower and change the parameters of the motor of the centrifugal blower. However, such changes complicate the design and the manufacture of the centrifugal blower and further increase the cost thereof.
What is needed, therefore, is a centrifugal blower capable of providing a large amount of airflow and having a simple structure and a low manufacturing cost.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
When the flow field of the airflow produced by the centrifugal blower was simulated by using computational fluid dynamics (CFD) software, it was found that a marked air-sucking phenomenon occurs at a region indicated by the closed broken line A. In other words, a sucking force at region A is stronger than at other regions of the top air inlet 111. Therefore, enlarging the area of the top air inlet 111 at region A to increase the amount of the air entering into the centrifugal blower 100 is at least desirable if not feasible. This is the guiding concept of the present invention.
Referring to
The housing 20 includes a bottom plate 21, an opposite top plate 22, and a sidewall 23 interconnecting the bottom plate 21 and the top plate 22. The bottom plate 21, the top plate 22 and the sidewall 23 cooperatively define a space 24 therebetween for receiving the impeller 30. The top plate 22 and the bottom plate 21 respectively define a first air inlet 221 and a second air inlet 25 therein. Exterior air enters the space 24 of the centrifugal blower 200 via the first and second air inlets 221, 25. The first and the second air inlets 221, 25 are both round-shaped in profile. The first air inlet 221 is concentric with the second air inlet 25, and has a diameter larger than that of the second air inlet 25.
A bracket 40 is disposed in the second air inlet 25 and mounted to the bottom plate 21. The impeller 30 is arranged in the space 24, and is located corresponding to the first air inlet 221 and the second air inlet 25. The impeller 30 includes a hub 31, and a plurality of blades 32 extending radially and outwardly from the hub 31. The hub 31 is concentric with the first air inlet 221 and the second air inlet 25. In other words, the center of the first air inlet 221 and the center of the second air inlet 25 are both located on a rotation axis of the impeller 30.
The bottom plate 21 is made of metal having a high thermal conductivity, such as copper or aluminum. The bottom plate 21 has an inner surface 211 facing the top plate 22, and an outer surface 212. The fins 20 are disposed on the inner surface 211 of the bottom plate 21, and are located at a side of the impeller 30. A plurality of air passages 51 are formed between adjacent fins 50. The bottom plate 21 thermally contacts the fins 50 for transferring heat to the fins 50. The top plate 22 extends outwardly to cover the fins 50. The bottom plate 21 has a heat absorbing block 213 formed on the outer surface 212 thereof, corresponding to the fins 50. The heat absorbing block 213 is used for thermally contacting a heat generating electronic component directly, or via a heat conducting member such as a heat pipe. Heat generated by the heat generating electronic component is transferred to the heat absorbing block 213 and then to the fins 50 through the bottom plate 21.
The sidewall 23 defines an air outlet 231 at a position corresponding to the fins 50, thereby allowing airflow created by the centrifugal blower 200 to flow into the air passages 51 between the fins 50. The sidewall 23 has a tongue 232 formed thereon at one side of the air outlet 231. In this embodiment, the sidewall 23 is integrally formed with the top plate 22 as a monolithic piece. In other embodiments, the sidewall 23 can be integrally formed with the bottom plate 21 as a monolithic piece.
The top plate 22 further defines an elongated opening 222 therein between the first air inlet 221 and the air outlet 231. The opening 222 is located adjacent to the other side of the air outlet 231 farthest from the tongue 232. The opening 222 is spaced from the first air inlet 221 by an arc-shaped partition rib 223. The opening 222 is crescent-shaped and extends along a periphery of the first air inlet 221. The top plate 22 forms a plurality of connecting ribs 224 in the opening 222. The connecting ribs 224 are arranged along a direction of extension of the crescent shape of the opening 222, and are spaced from each other. The opening 222 is divided into a plurality of small-sized apertures (not labeled) by the connecting ribs 224. A distance between two adjacent connecting ribs 224, i.e., a length of each aperture, is substantially equal to a distance between two adjacent blades 32 of the impeller 30. In the illustrated embodiment, the two endmost apertures are slightly longer than the other apertures.
During operation of the centrifugal blower 200, the impeller 30 rotates to generate forced airflow. Air in the ambient environment can be sucked into the space 24 not only through the first air inlet 221 and the second air inlet 25, but also through the opening 222 of the top plate 22. In the centrifugal blower 200, due to the presence of the opening 222, the amount of air sucked into the space 24 of the centrifugal blower 200 can be greatly increased. Thus the centrifugal blower 200 is capable of providing a large amount of airflow. Further, the opening 222 is spaced from the first air inlet 221 by the partition rib 223, thereby maintaining the profile of the first air inlet 221. Thus, noise produced by the centrifugal blower 200 is lower than that of a centrifugal blower with a side of an air inlet directly enlarged. Moreover, the connecting ribs 224 can firmly connect the partition rib 223 with the top plate 22 and allow the exterior air to evenly enter the space 24 to further reduce noise. The opening 222 of the top plate 22 can be easily formed during the process of manufacturing the top plate 22. Such a modification is quite simple, which facilitates easy manufacture of the centrifugal blower 200 and therefore decreases the cost of the centrifugal blower 200. Accordingly, the centrifugal blower 200 has an advantageously simple structure.
Operation of the conventional centrifugal blower 100 of
It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201010300626.6 | Jan 2010 | CN | national |
