Patent Publication Number: US-2006011330-A1

Title: Heat dissipating device

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims priority of Taiwanese Application No. 093210992, filed on Jul. 13, 2004.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates to a heat dissipating device, more particularly to a heat dissipating device having a relatively high heat-dissipating efficiency.  
      2. Description of the Related Art  
       FIG. 1  illustrates a conventional heat dissipating device for dissipating heat generated by a heat-generating device  1 , such as a CPU. The conventional heat dissipating device includes a base plate  11  and a plurality of parallel heat-dissipating fin plates  12 . The base plate  11  has an upper surface, and a lower surface coated with thermal conducting paste  10  and disposed to conduct heat from the heat-generating device  1 . Each of the fin plates  12  extends from the top surface of the base plate  11 . In such a configuration, the conventional heat dissipating device is not able to dissipate efficiently heat generated by a CPU with a high processing speed.  
     SUMMARY OF THE INVENTION  
      Therefore, the object of the present invention is to provide a heat dissipating device that can provide a relatively high heat-dissipating efficiency.  
      According to the present invention, a heat dissipating device comprises:  
      an air flow tube having an air inlet, an air outlet, and a mounting hole between the air inlet and the air outlet;  
      a heat-conducting member mounted in the mounting hole in the air flow tube and adapted to be disposed in close proximity with a heat-generating component; and  
      a fan unit mounted in the air outlet of the air flow tube and operable so as to draw air into the air flow tube via the air inlet for cooling the heat-conducting member in the mounting hole and to expel air in the air flow tube via the air outlet. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:  
       FIG. 1  is a schematic view of a conventional heat dissipating device;  
       FIG. 2  is an exploded perspective view showing the first preferred embodiment of a heat dissipating device according to the present invention;  
       FIG. 3  is a schematic sectional view showing the first preferred embodiment;  
       FIG. 4  is a partly enlarged view of  FIG. 3 ;  
       FIG. 5  is a fragmentary schematic top view showing the second preferred embodiment of a heat dissipating device according to the present invention;  
       FIG. 6  is a schematic sectional view showing the third preferred embodiment of a heat dissipating device according to the present invention; and  
       FIG. 7  is a schematic sectional view showing the fourth preferred embodiment of a heat dissipating device according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.  
      Referring to  FIGS. 2 and 3 , the first preferred embodiment of a heat dissipating device according to the present invention is shown to include an elongate air flow tube  2 , a heat-conducting member  3 , and a fan unit  4 . In this embodiment, the heat-dissipating device is adapted to be mounted in a housing  50  of an electronic apparatus, such as a notebook computer, for dissipating heat generated by a heat-generating device, such as a CPU  6 . The CPU  6  has an exposed die portion  60 .  
      The air flow tube  2 , which is made of a dielectric and heat-isolating material, has an air inlet  20  that is in fluid communication with an opening  510  in the housing  51 , an air outlet  21  that is in fluid communication with an opening  520  in the housing  5 , and a mounting hole  23  between the air inlet  20  and the air outlet  21 . In this embodiment, the air flow tube  2  is provided with an inner partition wall  22  therein for dividing the air flow tube  2  into a first tube portion  24  that has the air inlet  20  and that is formed with the mounting hole  23 , and a second tube portion  25  that has the air outlet  21 . The first tube portion  24  cooperates with the inner partition wall  22  so as to confine a first inner space  241 . The second tube portion  25  cooperates with the inner partition wall  22  so as to confine a second inner space  251 . The inner partition wall  22  is formed with a through hole  220  that is disposed adjacent to the mounting hole  23  and that permits fluid communication between the first and second inner spaces  241 ,  251  therethrough.  
      The heat-connecting member  3  is mounted in the mounting hole  23  in the air flow tube  2 , is adapted to be disposed in close proximity with the CPU  6 , and is supported by a plurality of posts  61  on the CPU  6 . In this embodiment, the heat-connecting member  3  is a rectangular metal plate  30  that is made of aluminum and that is punched to form a central projection  301  projecting toward the through hole  220  in the inner partition wall  22  and adapted to be disposed in close proximity with the exposed die portion  60  of the CPU  6 , an annular groove  303  surrounding the central projection  301 , and a plurality of ribs  302  extending radially from the annular groove  303 , as best shown in  FIG. 4 . Each rib  302  has an inverted-V shaped cross section.  
      The fan unit  4  is mounted in the air outlet  21  of the air flow tube  2 , and is operable so as to draw external air into the air flow tube  2  via the air inlet  20  for cooling the heat-conducting member  3  in the mounting hole  23  and to expel air in the air flow tube  2  via the air outlet  21 . As such, heat conducted from the CPU  6  to the heat conducting member  3  can be effectively dissipated, thereby resulting in a relatively high heat-dissipating efficiency.  
      The heat dissipating device further includes a gasket  29  to retain the heat-conducting member  3  in the mounting hole  23 .  
       FIG. 5  illustrates the second preferred embodiment of a heat dissipating device according to this invention, which is a modification of the first preferred embodiment. Unlike the previous embodiment, the air flow tube ( 2   a ) is L-shaped. The air inlet  20 ′ and the air outlet  21 ′are disposed at opposite ends of the air flow tube ( 2   a ).  
       FIG. 6  illustrates the third preferred embodiment of a heat dissipating device according to this invention, which is modification of the first preferred embodiment. In this embodiment, the inner partition wall  22 ′ of the air flow tube ( 2   b ) is provided with a surrounding wall  221  that extends from a periphery of the through hole  220  to the annular groove  303  in the heat-conducting member  3 . The surrounding wall  221  is formed with a plurality of radial vent holes  222 . As such, during operation of the fan unit  4 , air in the first inner space  241  can be effectively guided toward the second inner space  251  by the surrounding wall  221 , thereby resulting in a relatively good heat-dissipating efficiency.  
       FIG. 7  illustrates the fourth preferred embodiment of a heat dissipating device according to this invention, which is modification of the first preferred embodiment. In this embodiment, the heat dissipating device further includes an air filter layer  8  installed in the air inlet  20  of the air flow tube  2  so as to prevent dust from entering into the air flow tube  2 .  
      While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.