Abstract:
An exemplary fan apparatus includes a cooling fan and a fan gate attached to the cooling fan. The cooling fan defines an air inlet and an air outlet at two opposite sides thereof. The fan gate includes a mounting frame fixed on the cooling fan and surrounding the air outlet, and an airflow valve extending from the mounting frame. The airflow valve is bendable relative to the mounting frame. When the cooling fan works, an airflow produced by the cooling fan flows to the fan gate and pushes the airflow valve to bend with respect to the cooling fan to cause the air outlet to be exposed. When the cooling fan does not work, the airflow valve covers the air outlet.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The disclosure generally relates to cooling devices for electronic apparatuses, and particularly to a fan apparatus incorporating a fan gate. 
         [0003]    2. Description of Related Art 
         [0004]    Cooling fans are often applied in electronic devices, such as a computers or servers, to dissipate heat from electronic components of the electronic devices. Typically, the cooling fans are arranged side by side, in parallel. Air outlets of the cooling fans are located at a same side of the bank of cooling fans, thus increasing an area that airflow of the cooling fans flows to. Accordingly, the cooling fans are capable of cooling many more electronic components simultaneously. 
         [0005]    During operation, one or another of the cooling fans may fail, due to, e.g., aging. At that time, the other cooling fans continue working and drive air from their air inlets to their air outlets. Accordingly, air pressure at the air outlets of the bank of cooling fans exceeds that at the air inlets of the bank of cooling fans, and an air pressure difference is thus formed between the air inlet and the air outlet of the failed cooling fan. Therefore, the air at the air outlet of the failed cooling fan has a tendency to flow to the air inlet of such cooling fan due to the air pressure difference. This results in a reduction of the total airflow provided by the other cooling fans to the electronic components. Accordingly, the heat dissipation of the electronic components is further impaired. 
         [0006]    Therefore, an improved fan apparatus is needed to overcome the described limitations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an exploded, isometric view of a fan apparatus in accordance with an exemplary embodiment, wherein the fan apparatus includes a fan gate and a fixing frame. 
           [0008]      FIG. 2  is an assembled view of the fan gate and the fixing frame of the fan apparatus of  FIG. 1 . 
           [0009]      FIG. 3  is a cross section of the assembled fan gate and fixing frame of  FIG. 2 , taken along line thereof. 
           [0010]      FIG. 4  is an assembled view of the fan apparatus of  FIG. 1 , showing positions of flaps of the fan gate when the fan apparatus is working. 
           [0011]      FIG. 5  is a right side plan view of the fan apparatus of  FIG. 4 . 
           [0012]      FIG. 6  is a front plan view of the fan apparatus of  FIG. 4 , but showing the positions of the flaps of the fan gate when the fan apparatus is not working. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]      FIG. 1  shows a fan apparatus  100  according to an embodiment of the disclosure. In typical use, a plurality of the fan apparatuses  100  can be installed in an electronic device, such as a server or a computer, side by side in parallel to dissipate heat from electronic components of the electronic device. 
         [0014]    The fan apparatus  100  includes a cooling fan  10 , a fan gate  20 , and a fixing frame  30  for fixing the fan gate  20  onto the cooling fan  10 . 
         [0015]    The cooling fan  10  includes a fan housing  11 , and a rotor  12  for generating a forced airflow. The fan housing  11  is square-shaped and hollow, and the rotor  12  is received in the fan housing  11 . A rear side of the fan housing  11  defines an air inlet  14  of the cooling fan  10  for the forced airflow to enter the fan housing  11 , and a front side of the fan housing  11  defines an air outlet  15  of the cooling fan  10  for the forced airflow to exit the fan housing  11 . 
         [0016]    A base  16  is received in the fan housing  11  and arranged at the air outlet  15  of the cooling fan  10 . The base  16  is substantially circular. An outer periphery of the base  16  is spaced from an inner surface of the fan housing  11 . A plurality of ribs  17  is connected between the outer periphery of the base  16  and the inner surface of the fan housing  11 , thereby fixing the base  16  in the fan housing  11 . A stator (not shown) is received in the fan housing  11  and mounted on the base  16 . The rotor  12  is rotatably mounted on the stator. A passage  13  is defined between the inner surface of the fan housing  11  and the rotor  12  for allowing the forced airflow through the cooling fan  10 . 
         [0017]    The fan gate  20  includes an outer mounting frame  22 , and an inner airflow valve  24  extending substantially from an inner periphery of the mounting frame  22 . Referring also to  FIGS. 2 and 3 , in the illustrated embodiment, the fan gate  20  is a single, monolithic body of the same material which comprises the mounting frame  22  and the airflow valve  24  (see also below). The mounting frame  22  is attached to the fan housing  11  of the cooling fan  10 , to fix the fan gate  20  to the cooling fan  10 . The airflow valve  24  has a square periphery. The mounting frame  22  is substantially in the shape of a square frame. The mounting frame  22  includes four elongated, straight beams  225  joined end to end. Each two neighboring beams  225  are perpendicular to each other. The mounting frame  22  has an inner dimension matching an outer dimension of the outer periphery  112  of the fan housing  11  of the cooling fan  10 . 
         [0018]    In an original state, the airflow valve  24  is substantially flat and generally square-shaped. The airflow valve  24  includes four flaps  25  extending inwardly substantially from inner edges of the beams  225  of the mounting frame  22 , respectively. In the illustrated embodiment, the flaps  25  integrally extend from the beams  225  of the mounting frame  22 . The flaps  25  extend towards the center of the mounting frame  22 . Each flap  25  is generally isosceles trapezoid, except that an inmost side of the flap  25  is concave. In the illustrated embodiment, the inmost side is arc-shaped. Each flap  25  includes a connected end extending from the mounting frame  22 , and a free end which has the concave side. 
         [0019]    More particularly, each flap  25  defines a top edge  252  at the free end, a bottom edge  254  at the connected end, and two side edges  256  each running between the top edge  252  and the bottom edge  254 . The bottom edge  254  extends from a corresponding beam  225  of the mounting frame  22 . The top edge  252  is located at a central area of the mounting frame  22 , far away from the beam  225  of the mounting frame  22 . The top edge  252  is shorter than the bottom edge  254 . A width of each flap  25 , measured from one side edge  256  to the other side edge  256 , gradually decreases from the bottom edge  254  to the top edge  252 . The side edges  256  of each flap  25  abut the side edges  256  of two neighboring flaps  25  when the fan apparatus is not working. Neighboring side edges  256  of neighboring flaps  25  are connected at the connected ends, but unconnected at the free ends. 
         [0020]    The top edges  252  of the flaps  25  cooperatively define a ventilating hole  27  therebetween. The ventilating hole  27  is aligned with the base  16  of the cooling fan  10 . A size of the ventilating hole  27  is slightly smaller than that of the base  16 . In this embodiment, the top edge  252  of each flap  25  is one fourth of a circle, and the top edges  252  of the flaps  25  cooperatively form a whole circle  28 . 
         [0021]    The airflow valve  24  is made of light and soft material which is hard to tear, such as cloth or Mylar™ (i.e., polyester). When the cooling fan  10  produces a forced airflow flowing to the fan gate  20 , the airflow valve  24  of the fan gate  20  is blown open. In such a state, the flaps  25  move away from the cooling fan  10  and extend obliquely outwardly along directions corresponding to the direction of the airflow due to a force of the airflow. In this embodiment, the fan gate  20  is made of cloth to achieve low noise during operation of the cooling fan  10 , and the airflow valve  24  is integrally formed with the mounting frame  22 . 
         [0022]    The fixing frame  30  includes a four-sided front plate  32 , and a four-sided side plate  34  extending rearward from an outer circumference of the front plate  32 . The front plate  32  corresponds to a circumferential portion of the airflow valve  24  of the fan gate  20 , and the side plate  34  corresponds to the mounting frame  22  of the fan gate  20 . In the present embodiment, the front plate  32  is flat and substantially square shaped. An opening  35  defined in the front plate  32 , corresponding to a central portion of the airflow valve  24  of the fan gate  20 . The front plate  32  has an outer dimension slightly greater than that of the airflow valve  24  of the fan gate  20 . 
         [0023]    The side plate  34  extends perpendicularly rearward from an outer circumference of the front plate  32 . The side plate  34  has a shape similar to the mounting frame  22  of the fan gate  20 . That is, the side plate  34  is substantially in the shape of a square frame. The side plate  34  has an inner dimension matching an outer dimension of the mounting frame  22  of the fan gate  20 , such that the mounting frame  22  of the fan gate  20  can be fittingly attached to an inner side of the side plate  34 . 
         [0024]    Referring to  FIGS. 2 and 3 , in preassembly of the fan apparatus  100 , the fan gate  20  is fixed to the inner side of the fixing frame  30 , with the mounting frame  22  of the fan gate  20  attached to the inner side of the side plate  34  of the fixing frame  30 . In particular, the side plate  34  of the fixing frame  30  fittingly surrounds and abuts against the mounting frame  22  of the fan gate  20 . The front plate  32  of the fixing frame  30  abuts against the outer circumferential portion of the airflow valve  24  of the fan gate  20 . The central portion of the airflow valve  24  of the fan gate  20  is aligned with the opening  35  of the fixing frame  30 . 
         [0025]    Referring to  FIG. 4 , in assembly of the fan apparatus  100 , the combined fan gate  20  and fixing frame  30  is attached to the fan housing  11  of the cooling fan  10 , with the mounting frame  22  of the fan gate  20  fittingly surrounding and abutting against the outer periphery  112  of the fan housing  11 . Thus the mounting frame  22  of the fan gate  20  is sandwiched between the outer periphery  112  of the fan housing  11  and the side plate  34  of the fixing frame  30 . A tight fit is formed between the fixing frame  30  and the fan housing  11  of the cooling fan  10 , such that the fan gate  20  is stably fixed on the fan housing  11 . 
         [0026]    Referring to  FIGS. 4 and 5 , during operation of the fan apparatus  100 , the rotor  12  is driven to rotate by the stator to produce the forced airflow flowing from the air inlet  14  to the air outlet  15 . The airflow pushes the flaps  25  to bend with respect to the mounting frame  22  of the fan gate  20  to cause the air outlet  15  to be exposed. The flaps  25  extend through the opening  35  of the fixing frame  30 , and slant forward along directions corresponding to the direction of the airflow. The free ends of the flaps  25  are spaced from each other, and thus the size of the ventilating hole  27  of the fan gate  20  is increased to facilitate the passage of the airflow through the fan gate  20 . In such a state, the airflow valve  24  of the fan gate  20  is generally funnel-shaped. An area of a cross section of a passage defined between the flaps  25  gradually decreases along the direction of the airflow. 
         [0027]    Referring to  FIG. 6 , if the cooling fan  10  fails, the airflow pushing force applied to the flaps  25  of the fan gate  20  is removed. In the above-described typical use of the fan apparatus  100 , there are also other fan apparatuses  100  that continue working. That is, the cooling fans  10  of the other fan apparatuses  100  continue driving air from their air inlets  14  to their air outlets  15 . As a result, air pressure at the air outlets  15  of the bank of cooling fans  10  exceeds that at the air inlets  14  of the bank of cooling fans  10 , and an air pressure difference is thus formed between the air inlet  14  and the air outlet  15  of the failed cooling fan  10 . Accordingly, the air at the air outlet  15  of the failed cooling fan  10  has a tendency to flow to the air inlet  14  of the failed cooling fan  10 . 
         [0028]    Since the airflow valve  24  of the fan gate  20  of the failed cooling fan  10  is made of light and soft material, when the air at the air outlet  15  flows towards the air inlet  14 , the flaps  25  are pushed to move towards the cooling fan  10  until the fan gate  20  resumes to its original state as indicated in  FIG. 1 . In that state, the neighboring side edges  256  of the neighboring flaps  25  abut each other. The flaps  25  are coplanar and cooperatively cover the whole air outlet  15  of the cooling fan  10 , thus preventing the air at the air outlet  15  from flowing to the air inlet  14  of the cooling fan  10 . Therefore, reduction of the total airflow provided by the other cooling fans  10  to the electronic components is avoided, and accordingly, the heat dissipation of the electronic components is prevented from being further impaired. 
         [0029]    It is to be understood, however, that even though numerous characteristics and advantages of certain 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.