Patent Publication Number: US-8540497-B2

Title: Fan self-cooling structure with heat pipe

Description:
FIELD OF THE INVENTION 
     The present invention relates to a fan self-cooling structure, and more particularly to a fan self-cooling structure with heat pipe for lowering the temperature of the electronic elements in a fan and enhancing the characteristics of the fan. 
     BACKGROUND OF THE INVENTION 
     In recent years, with the development in the electronic industrial field, all kinds of electronic devices have quickly upgraded performance and largely increased computing speed. To enable constantly increased computing speed, the number of chips included in the chip set inside the electronic devices also increases. These chips would produce a large amount of heat when they work, and the produced heat must be timely removed from the chips to avoid any adverse influence on the performance of the electronic devices, such as reducing the computing speed of the electronic devices. Moreover, heat accumulated inside the electronic devices would cause burnout thereof. Therefore, it has become an important issue to efficiently dissipate the heat from the electronic devices. 
     Among various kinds of heat dissipating devices, the cooling fan is able to quickly remove the heat absorbed by the radiation fins to enable good air circulation and accordingly, has become a requisite part of most electronic devices. 
     Conventionally, the cooling fan mainly includes a rotor assembly, a stator assembly, and a fan circuit board. The rotor assembly is located to one side of the stator assembly, and the fan circuit board is located to the other side of the stator assembly opposite to the rotor assembly. The stator assembly includes a silicon steel seat and a plurality of insulating posts radially outward extended from the silicon steel seat. The insulating posts each are wounded by an enamel wire, which is electrically connected to the fan circuit board and electronic elements provided thereon. When the cooling fan is driven to rotate, the fan circuit board and the electronic elements thereon are electrically connected to one another to thereby drive the enamel wires wound around the insulating posts to generate magnetic polarities. The rotor assembly rotates under the effect of the magnetic polarities generated by the enamel wires. The electronic elements would produce heat and have higher temperature while driving the enamel wires to generate magnetic polarities. However, in the conventional cooling fan structure, there is not any means nearby the electronic elements for dissipating the heat produced by the electronic elements. Thus, the produced heat would accumulate on the fan circuit board and the electronic elements thereon to adversely affect the operation performance of the cooling fan, resulting in damaged electronic elements and shortened service life thereof. 
     In brief, the conventional cooling fan has the following disadvantages: (1) the fan circuit board and the electronic elements thereon are subject to poor heat dissipation; (2) the operation performance of the cooling fan is adversely affected; and (3) the electronic elements thereof are subject to damage and shortened service life. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a fan self-cooling structure with heat pipe for lowering the temperature of electronic elements mounted on a fan circuit board. 
     Another object of the present invention is to provide a fan self-cooling structure with heat pipe for enhancing the characteristics of a fan. 
     To achieve the above and other objects, the fan self-cooling structure with heat pipe provided according to a preferred embodiment of the present invention includes a stator assembly, a fan circuit board, and at least one heat pipe. The fan circuit board is flatly connected to a bottom end of the stator assembly and has at least one heat-producing electronic element provided thereon. The at least one heat pipe is provided on the fan circuit board for absorbing and transferring heat energy produced by the at least one electronic element. With these arrangements, it is able to lower the temperature of the electronic elements in a fan and enhance the characteristics of the fan. 
     To achieve the above and other objects, the fan self-cooling structure with heat pipe provided according to another preferred embodiment of the present invention includes a stator assembly, a fan circuit board, a heat plate, and at least one heat pipe. The fan circuit board is flatly connected to a bottom end of the stator assembly and has at least one heat-producing electronic element provided thereon. The heat plate has a first side correspondingly contacting with the at least one heat-producing electronic element and an opposite second side contacting with the at least one heat pipe. Thus, the heat plate absorbs the heat energy produced by the electronic element and transfers the absorbed heat energy to the heat pipe. The heat energy transferred by the heat pipe is finally dissipated from the heat pipe into ambient air to thereby lower the temperature of the electronic elements in a fan and enhance the characteristics of the fan. 
     Therefore, the present invention has the following advantages: (1) lowering the temperature of the electronic elements in a fan; and (2) enhancing the characteristics of the fan. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
         FIG. 1  is a top perspective view of a fan self-cooling structure with heat pipe according to a first preferred embodiment of the present invention; 
         FIG. 2  is a bottom perspective view of the fan self-cooling structure with heat pipe according to the first preferred embodiment of the present invention; 
         FIG. 3  is an exploded perspective view showing the use of the fan self-cooling structure according to the first preferred embodiment of the present invention; 
         FIG. 4  is an exploded perspective view showing the use of a variant of the fan self-cooling structure with heat pipe according to the first preferred embodiment of the present invention; 
         FIG. 5  is an assembled view of  FIG. 4 ; 
         FIG. 6  is a perspective view of a fan self-cooling structure with heat pipe according to a second preferred embodiment of the present invention; 
         FIG. 7  is an exploded perspective view showing the use of the fan self-cooling structure with heat pipe according to the second preferred embodiment of the present invention; 
         FIG. 8  is an exploded perspective view of a fan self-cooling structure with heat pipe according to a third preferred embodiment of the present invention; and 
         FIG. 9  is an exploded perspective view of a variant of the fan self-cooling structure with heat pipe according to the third preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described with some preferred embodiments thereof by referring to the accompanying drawings. For the purpose of easy to understand, elements that are the same in the preferred embodiments are denoted by the same reference numerals. 
     Please refer to  FIGS. 1 and 2  that are top and bottom perspective views, respectively, of a fan self-cooling structure with heat pipe according to a first preferred embodiment of the present invention. As shown, in the first preferred embodiment, the fan self-cooling structure includes a stator assembly  1 , a fan circuit board  2 , and at least one heat pipe  3 . In the illustrated preferred embodiment, there are four heat pipes  3 . The stator assembly  1  includes a silicon steel seat  11 , from which a plurality of insulating posts  12  is radially outward extended (four insulting posts  12  are shown in the drawings). Each of the insulating posts  12  has a coil  121  wound therearound. The fan circuit board  2  is flatly connected to a bottom end of the stator assembly  1  to electrically connect to the coils  121 , and there is at least one heat-producing electronic element  21  provided on the fan circuit board  2 . The heat pipes  3  are provided on the fan circuit board  2  corresponding to the heat-producing electronic elements  21 , and each include a heat-absorbing section  31  and a heat-dissipating section  32 . As can be seen from  FIG. 2 , the heat-absorbing section  31  of each heat pipe  3  is in contact with one side of the heat-producing electronic element  21  to transfer the heat produced by the electronic element  21  to the heat-dissipating section  32 , from where the heat is dissipated into ambient air. In the illustrated first preferred embodiment, the heat-dissipating sections  32  of the heat pipes  3  are not extended beyond an outer periphery of the fan circuit board  2 . 
     Please refer to  FIGS. 3 to 5  that show the use of the fan self-cooling structure with heat pipe according to the first preferred embodiment of the present invention. As shown, the fan self-cooling structure is assembled to a fan framework  4 , which has an outer frame  41  and a base  42 . The base  42  defines a first recess  421  therein, from which a plurality of ribs  43  is radially outward extended to connect at respective distal end to an inner side of the outer frame  41  (four ribs  43  are shown in the drawings). Further, at least one second recess  422  is formed in the first recess  421  (four second recesses  422  are shown in the drawings). 
     The stator assembly  1  is mounted on the base  42 , such that the fan circuit board  2  connected to the bottom end of the stator assembly  1  is received in the first recess  421  of the base  42  with the heat pipes  3  correspondingly received in the second recesses  422 . 
     In a variant of the first preferred embodiment as shown in  FIGS. 4 and 5 , the heat-dissipating sections  32  of the heat pipes  3  are extended beyond the outer periphery of the fan circuit board  2 . In this case, the second recesses  422  are separately extended from the first recess  421  into the ribs  43 . That is, the fan circuit board  2  is received in the first recess  421  with the heat pipes  3  correspondingly received in the second recesses  422  and extended from the fan circuit board  2  into the ribs  43 . More specifically, the heat-dissipating sections  32  of the heat pipes  3  are extended along the ribs  43  to the outer frame  41 . In the case of a metal-made fan framework  4 , the heat transferred via the heat-dissipating sections  32  extended to the outer frame  41  can be dissipated into ambient air from the outer frame  41 . 
     When the fan circuit board  2  and the heat-producing electronic elements  21  are electrically connected to one another, the coils  121  wound around the insulating posts  12  are caused to generate magnetic polarities. The heat energy produced by the electronic elements  21  during the operation thereof is absorbed and transferred by the heat-absorbing sections  31  of the heat pipes  3  to the heat-dissipating sections  32 . The heat is then dissipated from the heat-dissipating sections  32  into ambient air to achieve the effects of lowering the temperature of the electronic elements  21  on the fan circuit board  2  and enhancing the fan characteristics. Further, when a fan (not shown) assembled to the stator assembly  1  is driven via the coils  121  to produce air flows, the air flows can also carry the heat away from the heat-dissipating sections  32  that are extended to the outer frame  41 . 
       FIGS. 6 and 7  illustrate a second preferred embodiment of the present invention. Since the fan self-cooling structure in the second preferred embodiment has overall structure and element connection manner generally similar to the first preferred embodiment, the portions of the second embodiment that are the same as the first embodiment are not repeatedly discussed herein. The second embodiment is different from the first embodiment in that a plurality of radiation fins  5  is assembled to each of the heat-dissipating sections  32  of the heat pipes  3  that are extended beyond the fan circuit board  2 . The heat transferred to the heat pipes  3  can be further efficiently radiated into ambient air via the radiation fins  5 . In the fan framework  4  to be used with the fan self-cooling structure of the second preferred embodiment, each of the second recesses  422  is provided on the first recess  421  at a position between two adjacent ribs  43 , so that the heat pipes  3  are correspondingly received in the second recesses  422 . Similarly, when a fan (not shown) assembled to the stator assembly  1  is driven via the coils  121  to produce air flows, the air flows can also carry the heat away from the heat-dissipating sections  32  and the radiation fins  5 . 
       FIGS. 8 and 9  illustrate a third preferred embodiment of the present invention. Since the fan self-cooling structure in the third preferred embodiment has overall structure and element connection manner generally similar to the first preferred embodiment, the portions of the third embodiment that are the same as the first embodiment are not repeatedly discussed herein. The third embodiment is different from the first embodiment in that a heat plate  6  having a first side attached to the fan circuit board  2  on the side having the electronic elements  21  provided thereon. The heat plate  6  is capable of absorbing the heat energy produced by the electronic elements  21 , and transferring the absorbed heat to the heat pipes  3 , which are attached to an opposite second side of the heat plate  6 , so that the heat is finally dissipated from the heat pipes  3 . 
     As can be seen from  FIG. 8 , the second side of the heat plate  6  having the heat pipes  3  attached thereto is a plane surface. On the other hand, according to a variant of the third embodiment as shown in  FIG. 9 , the heat plate  6  is provided on the second side with a plurality of grooves  61  for fixedly receiving the heat pipes  3  therein. Similarly, the heat energy absorbed by the heat plate  6  is transferred to and dissipated from the heat pipes  3 . 
     The present invention has been described with some preferred embodiments thereof and it is understood that many changes and modifications in the described embodiments can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims.