Patent Publication Number: US-6710486-B1

Title: Housing structure for a heat-dissipation fan

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is related to a housing structure for a heat-dissipation fan and more particularly to the housing structure having a plurality of axial guide blades to form radial air inlets therebetween that air inflow is increased and air noise is reduced. 
     2. Description of the Related Art 
     Referring to FIG. 1, a conventional axial-flow type fan mainly includes a housing  10 , a stator  20  and a rotor  30 . The housing  10  is provided with an air inlet  11 , an air outlet  12 , a bearing seat  13  and a plurality of ribs  14 . The stator  20  is fittingly connected to the bearing seat  13 . The rotor  30  includes a hub  31  and blades  32  surrounding therearound; a shaft  33  is rotatably received in the stator  20  so that an alternative magnetic field generated by the stator  20  is able to rotate the rotor  30 . When the blades  32  are rotated, air may be sucked into the housing  10  from the air inlet  11  and blown out of the housing  10  from the air outlet  12 . The fan, has been widely used, is simplified for structure and manufacture, but it allows air inflow only sucked into the air inlet  11  that air inlet amount is limited by the measurements of the air inlet  11 . Moreover, it is apparent that the rotations of the distal ends of the blades  32  may cause air turbulence and wind shear on the inner wall of the housing  10 ; airflow between the upstream and the downstream of the blades  32  may be unbalanced. Due to these drawbacks, the static pressure-flow rate characteristic (P-Q characteristic) of the fan is undesired. 
     Another conventional fan of U.S. Pat. No. 6,132,171, issued on Oct. 17, 2000, titled “a blower and method for molding housing thereof” discloses a fan housing with air inlet. A plurality of annular plates, proximate the air inlet, are equi-spaced and stacked to form radial annular gaps therebetween. When the blower is rotated, ambient air may be sucked into the housing through the annular gaps so that air inlet amount is increased. However, an additional airflow through the annular gaps is perpendicular to airflow through the air inlet that the convergence of the airflow may cause air turbulence and air noise. The P-Q characteristic of the blower is still undesired although it is provided with an additional air inlet amount. There is a need for the conventional housing to improve the P-Q characteristic. 
     The present invention intends to provide a housing structure for a heat-dissipation fan having axial guide blades which are equi-spaced to form radial air inlets therebetween. Airflow through the radial air inlets is guided parallel to an axis of the housing in such a way to mitigate and overcome the above problem. 
     SUMMARY OF THE INVENTION 
     The primary objective of this invention is to provide a housing structure for a heat-dissipation fan having axial guide blades, proximate an air inlet, adapted to form radial air inlets through which to guide airflow along an axis so as to increase air inlet amount and reduce air noise. 
     The secondary objective of this invention is to provide a housing structure for a heat-dissipation fan having inclined guide blades adapted to form radial air inlets and to face a rotational direction of the fan so as to increase air inlet amount and reduce air noise. 
     The another objective of this invention is to provide a housing structure for a heat-dissipation fan having an expanded air outlet shaped as a bell so as to increase measurements. 
     The another objective of this invention is to provide a housing structure for a heat-dissipation fan having axial guide blades made of metal so as to increase heat-dissipation efficiency. 
     The housing structure for the heat-dissipation fan in accordance with the present invention mainly comprises a housing, a plurality of axial guide blades and a plurality of radial air inlets. The housing is provided with an air inlet and an air outlet between which receiving a stator and a rotor. The axial guide blades are equi-spaced and radially extended outward from the housing proximate the air inlet. Each of the radial air inlets is formed between any two axial guide blades. When the rotor is rotated, airflow sucked through the radial air inlets is guided parallel to an axis of the housing running from the air inlet to the air outlet so as to increase air inlet amount and reduce air noise. 
    
    
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will now be described in detail with reference to the accompanying drawings herein: 
     FIG. 1 is an exploded perspective view of a conventional fan in accordance with the prior art; 
     FIG. 2 is an exploded perspective view of a housing structure for a heat-dissipation fan in accordance with a first embodiment of the present invention; 
     FIG. 3 is a top view of the housing structure for the heat-dissipation fan in accordance with the first embodiment of the present invention; 
     FIG. 4 is a cross-sectional view, taken along line  4 — 4  in FIG. 3, of the housing structure for the heat-dissipation fan in accordance with the first embodiment of the present invention; 
     FIG. 5 is an exploded perspective view of a housing structure for a heat-dissipation fan in accordance with a second embodiment of the present invention; 
     FIG. 6 is a top view of the housing structure for the heat-dissipation fan in accordance with the second embodiment of the present invention; 
     FIG. 7 is a cross-sectional view, taken along line  7 — 7  in FIG. 6, of the housing structure for the heat-dissipation fan in accordance with the second embodiment of the present invention; 
     FIG. 8 is a top view of a housing structure for a heat-dissipation fan in accordance with a third embodiment of the present invention; and 
     FIG. 9 is a top view of a housing structure for a heat-dissipation fan in accordance with fourth embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, there are four embodiments of the present invention shown therein, which include generally a primary housing member and a secondary fan member. 
     Referring to FIG. 2, reference numerals of the embodiments have applied the identical numerals of the conventional fan. The housing and the fan of the embodiments have the similar configuration and same function as the conventional fan and the detailed descriptions are omitted. 
     Referring to FIGS. 2 and 3, a housing structure for a heat-dissipation fan in accordance with the first embodiment of the present invention includes a housing  10 , a plurality of axial guide blades  15  and a plurality of radial air inlets  16 . The housing  10  is provided with an air inlet  11  and an air outlet  12  between which receiving a stator  20  and a rotor  30 . The axial guide blades  15  are equi-spaced and radially extended outward from the housing  10  proximate the air inlet  11 . Each of the radial air inlets  16  is formed between any two axial guide blades  15 . When the rotor  30  is rotated, airflow sucked through the radial air inlets  16  is guided parallel to an axis of the housing  10  running from the air inlet  11  to the air outlet  12  so as to increase air inlet amount and reduce air noise. 
     Referring again to FIGS. 2 and 3, the housing  10  includes a space defined between the air inlet  11  and the air outlet  12  adapted to contain the stator  20  and the rotor  30 . The housing  10  further includes a base plate  17  arranged therearound proximate the air outlet  12 . The axial guide blades  15  are formed as regular flat pieces and extended outward from the housing  10  to define an annular wall with respect to the base plate  17 . Meanwhile, the radial air inlets  16  are regularly formed on the annular wall of the housing  10 . When the rotor  30  is rotated, the blades  32  suck airflow through the radial air inlets  16  in addition to the air inlet  11 . Therefore, total air inlet amount is increased, as best shown in FIG.  4 . 
     Referring to FIG. 4, when the rotor  30  is rotated, major airflow is sucked through the air inlet  11  into the housing  10 . Also, the blades  32  change airflow, sucked though the radial air inlets  16  on the base plate  17 , from radial direction to the axis direction of the housing  10 . Due to the additional airflow, airflow between the upstream and the downstream of the blades  32  can be balanced. Consequently, the P-Q characteristic of the rotor  30  is improved and air noise is reduced. 
     In order to intensify the entire structure, the housing  10  further includes an annular support  18  integrally connected to top portions of the axial guide blades  15 . Alternatively, the axial guide blades  15  and the annular support  18  are formed as sectional elements and assembled on the base plate  17 . The axial guide blades  15  and the radial air inlets  16  are punched if the housing  10  is made of metal or alloy. Meanwhile, the axial guide blades  15  may be formed as heat-dissipation fins to increase heat-dissipation efficiency while the airflow passing through between the axial guide blades  15 . Moreover, the housing  10  includes a plurality of assembling holes  19  for conveniently assembling. 
     Referring to FIGS. 5 through 7, a housing structure for a heat-dissipation fan in accordance with the second embodiment of the present invention includes an air inlet  11 , an air outlet  12 , a plurality of axial guide blades  15 ′ and a plurality of radial air inlets  16 ′. In contrast with the first embodiment, the axial guide blades  15 ′ of the second embodiment are slanted and thereby the radial air inlets  16 ′ are aligned with a rotational direction of the blades  32  of the rotor  30  so as to increase air inlet amount and reduce air noise. Moreover, the air outlet  12  is expanded and shaped as a bell so as to increase measurements. Preferably, the housing  10  further includes a circumferential wall  171  to define the expanded air outlet  12  to thereby intensify the entire structure. 
     Referring to FIG. 8, a housing structure for a heat-dissipation fan in accordance with the third embodiment of the present invention includes a plurality of axial guide blade  151  and a plurality of radial air inlets  161 . In contrast with the first embodiment, each of the axial guide blades  151  of the third embodiment is formed as a post and has a circular cross section. Consequently, circular surfaces of the guide blades  151  may increase airflow passed through the air inlets  161 . 
     Referring to FIG. 9, a housing structure for a heat-dissipation fan in accordance with the fourth embodiment of the present invention includes a plurality of axial guide blade  152  and a plurality of radial air inlets  162 . In contrast with the first embodiment, each of the axial guide blades  152  of the fourth embodiment is formed as a prism and has a triangular cross section. Consequently, inclined surfaces of the guide blades  152  may increase airflow passed through the air inlets  162 . 
     Referring again to FIGS. 2 and 1, the housing  10  of the present invention includes axial guide blades  15  to form radial air inlets  16  therebetween that air inflow is increased and air noise is reduced. However, the housing design of the conventional axial-flow type fan is limited in measurements and causes air turbulence and wind shear. By contrast, P-Q characteristic and efficiency of the present invention is improved. 
     Although the invention has been described in detail with reference to its presently preferred embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.