Abstract:
A housing for an axial flow heat-dissipating fan includes an annular wall including an air inlet in a first end thereof and an air outlet in a second end thereof. A motor of an axial flow heat-dissipating fan is received in the annular wall. A plurality of axially extending slits are defined in a circumference of the annular wall. At least two assembling sections are formed on the circumference of the annular and spaced from each other. One of the at least two assembling sections of the housing is engaged with one of at least two assembling sections of a similarly constructed housing.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a housing for an axial flow heat-dissipating fan. In particular, the present invention relates to a housing for an axial flow heat-dissipating fan for increasing an inlet amount of air and for providing a reinforced structure.  
         [0003]     2. Description of Related Art  
         [0004]     U.S. Pat. No. 6,132,171 discloses a blower that sucks air inside a wall through radial slits as a fan rotates. The wall is formed away from ends of fan blades. Outer peripheral sections of the wall are planar and substantially flush with a rectangular casing body at a middle of upper, lower, right, and left sides of the body. The radial slits are formed in the wall for increasing the air inlet amount. A plurality of annular plates are spaced from each other and stacked in a direction along an axis of rotation of the fan to form the wall with radial slits. Spacers forming and supporting the slits are arranged toward the middle of each of the four sides of the casing body and located on the outer peripheral sections.  
         [0005]     When mounted in a personal computer housing for dissipating heat, several blowers may be connected in parallel. In this case, a planar outer peripheral section of one of the blowers is in contact with and thus engaged with an associated peripheral section of another blower. Airflow passing through the radial slits of one of the blowers interferes with airflow passing through the radial slits of another blower, causing turbulences. Further, the spacers include portions projected outwardly from the wall, which protruded portions result in unstable contact and unstable connection between two adjacent planar peripheral sections respectively of two adjacent blowers.  
         [0006]     U.S. Pat. No. 6,710,486 discloses a housing structure for a heat-dissipating fan. The housing structure comprises a housing, a plurality of axial guide blades, and a rotor. A radial air inlet is formed between two adjacent axial guide blades for increasing the inlet air amount. When the rotor is rotated, major airflow is sucked through an air inlet into the housing. Also, blades of the rotor change airflow sucked through the radial air inlets from radial direction to the axial direction of the housing. Due to the additional airflow, airflow between the upstream and the downstream of the blades can be balanced and air noise is lowered. However, reliable connection between two heat-dissipating fans of this type is impossible, as the axial guide blades of the heat-dissipating fan provide no structure for such connection.  
       OBJECTS OF THE INVENTION  
       [0007]     An object of the present invention is to provide a housing for an axial flow heat-dissipating fan with improved assembling stability.  
         [0008]     Another object of the present invention is to provide a housing for an axial flow heat-dissipating fan with improved assembling flexibility.  
         [0009]     A further object of the present invention is to provide a housing for an axial flow heat-dissipating fan with increased air inlet amount.  
         [0010]     Still another object of the present invention is to provide a housing for an axial flow heat-dissipating fan with lowered blowing noise.  
       SUMMARY OF THE INVENTION  
       [0011]     In accordance with an aspect of the present invention, a housing for an axial flow heat-dissipating fan comprises an annular wall including an air inlet in a first end thereof and an air outlet in a second end thereof. A motor of an axial flow heat-dissipating fan is received in the annular wall. A plurality of axially extending slits are defined in a circumference of the annular wall. At least two assembling sections are formed on the circumference of the annular and spaced from each other. One of the at least two assembling sections of the housing is engaged with one of at least two assembling sections of a similarly constructed housing.  
         [0012]     Each axially extending slit may be inclined according to a blowing direction of the fan motor. The assembling sections are spaced from each other by 90 degrees or 180 degrees.  
         [0013]     In an embodiment of the invention, at least one of the axially extending slits includes an end extending through an end face of the first end of the annular wall and communicated with the air inlet. The annular wall further includes a reinforcing rib extending along the circumference of the annular wall and across the axially extending slits to reinforce structure of the annular wall.  
         [0014]     Two of the axially extending slits adjacent to each other may be communicated with each other, forming a slit with an enlarged end to increase air intake efficiency in an axial direction and to increase air intake efficiency in a radial direction. The enlarged end of the slit extends through an end face of the first end of the annular wall and is communicated with the air inlet.  
         [0015]     In another embodiment of the invention, the annular wall further includes at least one engaging plate extending radially outward from the first end that defines the air inlet. Further, the annular wall further includes at least one engaging plate extending radially outward from the second end that defines the air outlet. The engaging plate includes at least one side that is coplanar with an associated assembling section. Each axially extending slit includes an outer end and an inner end narrower than the outer end, providing a pressurizing effect while drawing air through the axially extending slits.  
         [0016]     Other objects, advantages and novel features of this invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]      FIG. 1  is a perspective view of a first embodiment of a housing for an axial flow heat-dissipating fan in accordance with the present invention;  
         [0018]      FIG. 2  is a sectional view illustrating connection of two housings in  FIG. 1 ;  
         [0019]      FIG. 3  is a sectional view illustrating connection of two housings of a modified embodiment in accordance with the present invention;  
         [0020]      FIG. 4  is a sectional view illustrating connection of four housings of another modified embodiment in accordance with the present invention;  
         [0021]      FIG. 5  is a perspective view of a further modified embodiment of the housing in accordance with the present invention;  
         [0022]      FIG. 6  is a top view of the housing in  FIG. 5 ; and  
         [0023]      FIG. 7  is an enlarged view of a circled portion in  FIG. 6 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]      FIG. 1  is a perspective view of a first embodiment of a housing for an axial flow heat-dissipating fan in accordance with the present invention.  FIG. 2  is a sectional view illustrating connection of two housings in  FIG. 1 .  
         [0025]     The housing  1  for an axial flow heat-dissipating fan in accordance with the present invention comprises an annular wall  10  that is substantially circular when viewed in section. The annular wall  10  includes an air inlet  101  in an end thereof and an air outlet  102  in the other end thereof. A base  104  is mounted in the air outlet  102  and supported by a plurality of ribs  103  between the base  104  and the annular wall  10 . The annular wall  10  further includes a plurality of axially extending slits  11  equispaced along a circumference of the annular wall  10  for drawing ambient air surrounding the annular wall  10 . Each axially extending slit  11  includes an end  111  extending through an end face of the annular wall  10  and communicated with the air inlet  101 . In an embodiment, each axially extending slit  11  may be inclined according to the blowing direction of a rotor (not shown) of a motor (not shown) of the axial flow heat-dissipating fan mounted in the annular wall  10 .  
         [0026]     The annular wall  10  further includes two assembling sections  12  that are spaced by, e.g., 90 degrees. Each assembling section  12  is planar without any slit or opening. Further, a reinforcing rib  13  extends along the circumference of the annular wall  10  and across the axially extending slits  11 . The reinforcing rib  13  reinforces the structure of the annular wall  10  with axially extending slits  11 .  
         [0027]     Two of the axially extending slits  11  adjacent to each other may be communicated with each other (see triangular slits  11 ′ with an enlarged end  111 ′ communicated with the air inlet  101 ). Thus, the air inlet efficiency in the axial direction and the air inlet efficiency in the radial direction are both improved without adversely affecting the structural strength of the annular wall  10 .  
         [0028]     As illustrated in  FIG. 1 , when a single housing  1  is used, air is drawn into the housing  1  via the air inlet  101  and the axially extending slits  11  and  11 ′ when the motor of the heat-dissipating fan turns. The airflow from the air inlet  101  and the airflow from the axially extending slits  11  and  11 ′ merge with each other and flow toward the air outlet  102 . By such an arrangement, the overall air inlet amount is increased, generation of turbulent is avoided, and the wind noise of the incoming air is reduced.  
         [0029]     As illustrated in  FIG. 2 , when two housings  1  are connected in parallel (i.e., disposed side by side), an assembling section  12  of one of the housings  1  is in contact with and securely connected to an assembling section  12  of the other housing  1 . Since the assembling sections  12  are planar and have a relatively wide area without any slit or opening, a sufficiently strong engagement between the housings  1  is provided without adversely affecting the air inlet effects of the housings  1  and without generation of turbulent. Namely, the air intake operations of the housings  1  would not interfere with each other, and no wind noise would be incurred accordingly. The other assembling section  12  of each housing  1  can be fixed to an appropriate position in, e.g., a computer housing. Accordingly, the air inlet amount is increased, the assembling reliability is improved, the wind noise resulting from the intake of air and from mutual interference of intake operations is avoided, and the assembling flexibility is improved.  
         [0030]      FIG. 3  is a sectional view illustrating connection of two housings  1  of a modified embodiment in accordance with the present invention. In this embodiment, the annular wall  10  of each housing  1  includes two assembling sections  12  that are spaced by 180 degrees, allowing different connection of the housings  1 . An assembling section  12  of one of the housings  1  is in contact with and securely connected to an assembling section  12  of the other housing  1 . Since the assembling sections  12  are planar and have a relatively wide area without any slit or opening, a sufficiently strong engagement between the housings  1  is provided without adversely affecting the air inlet effects of the housings  1  and without generation of turbulent. Namely, the air intake operations of the housings  1  would not interfere with each other, and no wind noise would be incurred accordingly. The other assembling section  12  of each housing  1  can be fixed to an appropriate position in, e.g., a computer housing. Accordingly, the air inlet amount is increased, the assembling reliability is improved, the wind noise resulting from the intake of air and from mutual interference of intake operations is avoided, and the assembling flexibility is improved. More housings  1  can be connected one by one to meet different needs.  
         [0031]      FIG. 4  is a sectional view illustrating connection of four housings of another modified embodiment in accordance with the present invention. In this embodiment, the annular wall  10  of each housing  1  includes three assembling sections  12  that are spaced by 90 degrees, allowing different connection of the housings  1 . Two assembling sections  12  of each housing  1  are in contact with and securely connected to two assembling sections  12  of two other housings  1 . Since the assembling sections  12  are planar and have a relatively wide area without any slit or opening, a sufficiently strong engagement between the housings  1  is provided without adversely affecting the air inlet effects of the housings  1  and without generation of turbulent. Namely, the air intake operations of the housings  1  would not interfere with one another, and no wind noise would be incurred accordingly. The remaining assembling section  12  of each housing  1  can be fixed to an appropriate position in, e.g., a computer housing. Accordingly, the air inlet amount is increased, the assembling reliability is improved, the wind noise resulting from the intake of air and from mutual interference of intake operations is avoided, and the assembling flexibility is improved. More housings  1  can be connected in this way to meet different needs.  
         [0032]      FIG. 5  is a perspective view of a further modified embodiment of the housing in accordance with the present invention.  FIG. 6  is a top view of the housing in  FIG. 5 .  FIG. 7  is an enlarged view of a circled portion in  FIG. 6 . In this embodiment, the annular wall  10  of each housing  1  includes four assembling sections  12  that are spaced by 90 degrees, allowing different connection of the housings  1 . Further, the annular wall  10  includes four engaging plates  140  extending radially outward from the end defining the air inlet  101 . Similarly, the annular wall  10  includes four engaging plates  14  extending radially outward from the other end defining the air outlet  102 . Each engaging plate  14  includes a fixing hole  141  to allow the housing  1  to be fixed in the axial direction. Preferably, each engaging plate  14  includes two edges  140  that are coplanar with two of the assembling sections  12 . The assembling sections  12  and the edges  140  provide an increased engaging area for two housings  1  connected to each other. Further, the assembling sections  12  and the edges  140  provide a larger area, allowing easy fixing of the housing  1  to an appropriate position.  
         [0033]     Referring to  FIG. 7 , each axially extending slit  11  includes an outer end  11   a  and an inner end  11   b  narrower than the outer end  11   a  to provide a pressurizing effect while drawing air into the housing  1  via the axially extending slit  11  without adversely affecting the strength of the annular wall  10 . Also, each axially extending slit  11  may be inclined according to the blowing direction of the rotor.  
         [0034]     While the principles of this invention have been disclosed in connection with specific embodiments, it should be understood by those skilled in the art that these descriptions are not intended to limit the scope of the invention, and that any modification and variation without departing the spirit of the invention is intended to be covered by the scope of this invention defined only by the appended claims.