Abstract:
A fan holder for mounting a fan, includes two opposite sidewalls defining a receiving area therebetween, each of the sidewalls defining a through hole therein; two or more polygonal auxiliary members arranged in the through hole of each of the sidewalls and located about an axis; and wherein the polygonal auxiliary members are rotationally offset from each other.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to fan holders, and particularly to a fan holder capable of alleviating noise disturbances caused by the fan. 
         [0003]    2. Description of Related Art 
         [0004]    Traditionally, a fan is mounted to an electronic device for dissipating large amounts of heat generated by components of the electronic device. The fan is generally mounted to the electronic device via a bracket. The bracket defines two circular openings in opposite sides thereof. An inlet of the fan aligns with one of the openings of the bracket, and an outlet of the fan aligns with the other opening of the bracket. 
         [0005]    Generally, the vibration generated from the movement of the fan, along with air passing therethrough, may lead to noise disturbances. 
         [0006]    Consequently, it is desired to provide a fan holder capable of alleviating noise disturbances caused by the fan. 
       SUMMARY 
       [0007]    In one embodiment, a fan holder for mounting a fan, includes two opposite sidewalls defining a receiving area therebetween, each of the sidewalls defining a through hole therein; two or more polygonal auxiliary members arranged in the through hole of each of the sidewalls and located about an axis; and wherein the polygonal auxiliary members are rotationally offset from each other. 
         [0008]    Other advantages and novel features of the present invention will become more apparent from the following detailed description of embodiment when taken in conjunction with the accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is an isometric view of a fan holder according to a first embodiment of the present invention, together with two fans; 
           [0010]      FIG. 2  is an isometric view of the fan holder of  FIG. 1 , but viewed from another aspect; 
           [0011]      FIG. 3  is an isometric view of a fan holder according to a second embodiment of the present invention; and 
           [0012]      FIG. 4  is an isometric view of a fan holder according to a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIG. 1 , in a first embodiment of the present invention, a fan holder  20  is provided for mounting a fan  10 . The fan holder  20  includes a bottom wall (not labeled), a first sidewall  21 , a second sidewall  23 , a third sidewall  25 , and a fourth sidewall  27 . The four sidewalls  21 ,  23 ,  25 ,  27  extend up from four sides of the bottom wall, respectively. The first sidewall  21  is opposite to the third sidewall  25 . The second sidewall  23  is opposite to the fourth sidewall  27  and comprise a hollow section. A receiving space is surrounded by the bottom wall and the four sidewalls  21 ,  23 ,  25 ,  27 . An opening opposite to the bottom wall is defined in a top of the fan holder  20 , for the fan  10  passing therethrough to enter into the receiving space. The first sidewall  21  defines an air inlet  211  therein, and the third sidewall  25  defines an air outlet  251  therein aligning with the air inlet  211 . Two triangular auxiliary members  213 ,  253  are arranged in the air inlet  211  and the air outlet  251  respectively. Three corners of each of the auxiliary members  213 ,  253  are connected to a circumference of a corresponding air inlet  211  or air outlet  251 . Each of the auxiliary members  213 ,  253  includes three flanges connected end to end. Each flange of the auxiliary member  213  is not parallel to any one of the flanges of the auxiliary member  253 . Thus the triangular auxiliary members  213  and  215  are offset from each other. 
         [0014]    Referring also to  FIG. 2 , the second sidewall  23  and the fourth sidewall  27  are hollow, each with an opening  232 ,  272  defined in a bottom thereof for communicating with an inner space of the second and fourth sidewalls  23 ,  27 . A plurality of through holes  215  is defined in the first sidewall  21  at opposite sides of the air inlet  211  and communicates with the inner spaces of the second and fourth sidewalls  23 ,  27 , respectively. Two elongate through holes defined at opposite sides of the air inlet  211  are capable of substituting for the through holes  215  of the first sidewall  21 , as shown in  FIG. 4 . 
         [0015]    In assembling the fan  10  to the fan holder  20 , the fan  10  passes through the opening at the top of the fan holder  20  to be accommodated in the receiving space of the fan holder  20 , with an air inlet thereof aligning with the air inlet  213  of the first sidewall  21  of the fan holder  20 , and an air outlet thereof aligning with the air outlet  253  of the third sidewall  25  of the fan holder  20 . While in use, air outside of the first sidewall  21  is sucked into the fan  10  through the air inlet  211  of the fan holder  20 . Air below the fan holder  20  is also sucked into the fan  10  through the openings  232 ,  272  at the bottoms of the second and fourth sidewalls  23 ,  27 , the inner space of the second and fourth sidewalls  23 ,  27 , the through holes  215  of the first sidewall  21 , and the air inlet  211  of the first sidewall  21 . Therefore, there is enough air being sucked into the fan  10 . A phase of each of the auxiliary members  213 ,  253  of the fan holder  20  is different from a phase of blades of the fan  10 . As a result, noise caused by the fan  10  is reduced, and a better dynamic balance of the holder  20  is achieved. 
         [0016]    Referring to  FIG. 3 , in a second embodiment of the present invention, two pentagonal auxiliary members  213   a ,  253   a  are arranged in the air inlet  211  and the air outlet  251 , respectively. Five corners of each of the auxiliary members  213   a ,  253   a  are connected to a circumference of a corresponding air inlet  211  or air outlet  251 . Each of the auxiliary members  213   a ,  253   a  includes five flanges connected end to end. Each flange of the auxiliary member  213   a  is not parallel to any one of the flanges of the auxiliary member  253   a . Therefore, the auxiliary members  213   a ,  253   a  may take the shape of any polygon. 
         [0017]    In the present invention, a testing method uses a head measure system (HMS) for testing the sound quality of the fan in a half-silent room. A spectrum analyzer is used for a series of analyses. The testing method includes the following steps: 
         [0018]    putting an assembly of the fan and the fan holder into the half-silent room; 
         [0019]    testing the sound of the fan via a head-shaped microphone; 
         [0020]    analyzing the sound of the fan via the spectrum analyzer; and 
         [0021]    computing the modulation (modulation is a criterion of the sound quality in Psychoacoustics, a smaller modulation value is associated with a lesser degree of noise) of the sound. 
         [0022]    Seven traditional holders together with seven types of fans being respectively mounted thereto, and seven holders of this present invention together with seven types of fans being respectively mounted thereto are put in a same testing system, values of the modulations of the fans as following: 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 fan types 
               
             
          
           
               
                 holders 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
               
               
                   
               
               
                 holders of this present 
                 27.83 
                 28.65 
                 30.00 
                 28.87 
                 28.42 
                 31.90 
                 29.26 
               
               
                 invention 
               
               
                 holders of prior art 
                 35.72 
                 32.16 
                 30.35 
                 32.81 
                 35.69 
                 34.08 
                 37.01 
               
               
                   
               
             
          
         
       
     
         [0023]    As shown in the above table, the modulation of the holder mounting a type of fan of this present invention is smaller than the modulation of the traditional holder mounting a same type of fan. Therefore, the holders of this present invention produce a lower level of noise disturbances compared to that of traditional holders. 
         [0024]    While several embodiments have been disclosed, it is understood that any element disclosed in any one embodiment is easily adapted to other embodiments. It is also 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.