Patent Application
20080121369
1. Field of the Invention
The present invention relates generally to a heat dissipation assembly, and particularly to a heat dissipation assembly having a ventilating strip for preventing airflow generated by a fan from being dispersed therefrom.
2. Description of Related Art
Electronic devices such as central processing units (CPUs) generate a lot of heat during normal operation. If the heat generated by the electronic devices is not properly dissipated, it can deteriorate their operational stability and damage associated electronic devices. Thus the heat must be quickly and efficiently removed to ensure the normal operation of these electronic devices. Oftentimes, a heat dissipation assembly is used to dissipate heat from electronic devices. The heat dissipation assembly frequently comprises a heat sink and a fan. The heat sink can be mounted in contact with the CPU inside a computer. The fan is usually positioned on the heat sink and generates a high-pressured airflow blowing downwards into the heat sink, causing the heat to be dissipated into the surroundings.
A related heat dissipation assembly 90 is disclosed in
According to a preferred embodiment of the present invention, a heat dissipation assembly comprises a heat sink having a plurality of fins, a fan mounted onto the heat sink for generating an airflow flowing into a plurality of channels between the fins of the heat sink, and a ventilating strip encircling an outer periphery of the fins to prevent the airflow generated by the fan from being prematurely dispersed out of the fins via the channels.
Other advantages and novel features of the present invention will become more apparent from the following detailed description of the preferred embodiment when taken in conjunction with the accompanying drawings, in which:
Many aspects of the present device 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 device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The heat sink 10 has a cylindrical configuration and comprises a central core 110 with a cylinder-like shape and a plurality of radial fins 120 radially extending outwardly from the core 12. The fins 120 are all curved in a similar direction, such as the clockwise direction, and are of same extension length. The fins 120 have a height H, which is the same as that of the core 120. Each fin 120 has a main portion 122 integrally connecting with the core 12 and two offsetting portions 125 integrally branching outwardly from a free end of the main portion 122. The fins 120 are spaced from each other at uniform intervals, thus a plurality of channels 126 for the airflow to flow therein is defined between the fins 120. A locking device 15 is attached to a bottom portion of the heat sink 10 and adapted to secure the heat sink 10 onto a printed circuit board (not shown) having a heat-generating electronic device (not shown) thereon.
The fan 20 has a frame 24 and a plurality of rotor blades 22 radially arranged in the frame 24. The frame 24 has a square configuration and comprises four corners. A locating hole 26 is defined in each corner of top and bottom portions of the frame 24. A fan guard 28 can be arranged on the top portion of the frame 24 to prevent hands from touching the rotor blades 22 when the fan 20 is operated. The fan guard 28 can have a square and grill-like construction corresponding to the frame 24 of the fan 20 and can be made of metal wire. Four through holes (not labeled), corresponding to the locating holes 26 of the fan 20, are defined at four corners of the fan guard 28. Four screws 25 are inserted through the through holes of the fan guard 28 and engaged in the locating holes 26 of the top portion of the frame 24 of the fan 20, thus attaching the fan guard 28 to the fan 20.
The fan bracket 30 comprises an annular frame 32 and a central opening 34 defined therein. A collar flange 322 extends inwardly and horizontally from a top edge of the frame 32. Four symmetrical ears 36 outwardly and horizontally extend from an outer edge of a top portion of the frame 32. Four catches 362 perpendicularly extend upwardly from top surfaces of the ears 36 for engaging with lower corners of the fan 20. A pin 364 spaced from each catch 362 is formed upwardly on each ear 36 for engaging in each corresponding locating hole 26 of the fan 20. Thus the fan 20 can be fittingly mounted on the fan bracket 30 via the ears 36 and exposed to the heat sink 10 through the opening 34 of the fan bracket 30. Two opposite holes 331 are defined through the frame 32 in a horizontal direction, each located in a middle of two neighboring ears 36. Two pairs of elongated ribs 333 extend vertically, each protruding out in parallel beside each through hole 331 from an inner surface of the frame 32. Each through hole 331 is located between the pair of ribs 333. A top portion of the heat sink 10 is received in the opening 34 of the fan bracket 30 with the collar flange 322 of the bracket 30 abutting an edge of the top portion of the heat sink 10. Thus the frame 32 embraces the outer circumferential periphery of the top portion of the heat sink 10. Two self-tapping screws 38 are inserted into the through holes 331 and further threadedly engage in the channel 126 between two adjacent offsetting portions 125 of the fin 120 sandwiched between the pair of ribs 333 by self-tapping. Thus the fan bracket 30 is attached to the heat sink 10 securely.
The ventilating strip 40 is formed as a circular loop by connecting two ends of a strap. The ventilating strip 40 can be made of a substance chosen from the group consisting of, but is not limited to, adhesive tape, fabric, elastoplastic, metal and any suitable combination of these substances. The ventilating strip 40 is arranged intimately extending away from a bottom edge of the fan bracket 30 and encircling the outer circumferential periphery of the heat sink 10, thus forming a fan duct around the heat sink 10. The ventilating strip 40 has a height B that is determined according to the height H of the heat sink 10 in order to conduct the airflow generated by the fan 20 to the heat-generating electronic device located below the heat sink 10 more efficiently.
In use, the heat generated by the heat-generating electronic device is absorbed by the core 12 and the fins 120 of the heat sink 10, and subsequently transferred to the top portion of the heat sink 10. The fan 20 generates an airflow and blows the airflow into the channels 126 of the heat sink 10 through the opening 34 of the fan bracket 30. Because the channels 126 are enclosed by the fins 120, the fan bracket 30 and the ventilating strip 40. The airflow is thus forced to flow downwardly along side surfaces of the fins 120. Furthermore, a large amount of the airflow having high pressure can reach the bottom portion of the heat sink 10 where a large amount of heat accumulates. It is obvious that heat-dissipation efficiency of the heat dissipation assembly having the ventilating strip 40 is enhanced compared with the one without the ventilating strip 40. In addition, the ventilating strip 40 can be applied in other heat sinks 10 having different shapes or sizes by simply changing the size of the ventilating strip 40. Thus, the ventilating strip 40 can be fittingly used in a variety of heat dissipation assemblies.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, 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 invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
