Passive fan assembly

Abstract

A passive fan assembly includes an impeller and a plurality of guide blades disposed in front of the impeller. The impeller includes a plurality of blades extending at about 90 degrees relative to the guide blades. Thus, when airflow enters the passive fan assembly, the guide blades guide the airflow to effectively impact on blades of the impeller.

1 . A passive fan assembly comprising: 
 a base;    an impeller mounted on the base and comprising a hub and a plurality of blades disposed around the hub; and    a cover placed over the base and comprising a plurality of guide blades corresponding to the plurality of blades of the impeller.    
   
   
       2 . The passive fan assembly as claimed in  claim 1 , wherein each guide blade extends at an angle relative to the corresponding blade of the impeller.  
   
   
       3 . The passive fan assembly as claimed in  claim 2 , wherein the angle is approximately  90  degrees.  
   
   
       4 . The passive fan assembly as claimed in  claim 1 , wherein the impeller further comprises a plurality of active blades disposed around the plurality of blades.  
   
   
       5 . The passive fan assembly as claimed in  claim 4 , wherein the impeller further comprises a partition disposed between the plurality of blades and the active blades.  
   
   
       6 . The passive fan assembly as claimed in  claim 1 , wherein the base comprises a frame, a bearing seat for receiving at least one bearing therein, and a plurality of connecting elements connecting the frame and the bearing seat, and the impeller includes a rotary shaft extending into the bearing seat.  
   
   
       7 . The passive fan assembly as claimed in  claim 1 , wherein the cover further comprises a frame connected to the base, a stationary part around which the plurality of guide blades are disposed, a stationary ring connected to ends of the plurality of guide blades, and a plurality of supporting elements connecting the stationary ring and the frame.  
   
   
       8 . The passive fan assembly as claimed in  claim 1 , wherein the plurality of guide blades have inclined surfaces.  
   
   
       9 . The passive fan assembly as claimed in  claim 1 , wherein the passive fan assembly is driven by an airflow generated by an airflow-providing system, and the airflow passes through the plurality of guide blades into the passive fan assembly.  
   
   
       10 . The passive fan assembly as claimed in  claim 9 , wherein the airflow-providing system comprises an axial fan or an air blower.  
   
   
       11 . The passive fan assembly as claimed in  claim 9 , wherein the airflow-providing system comprises an airflow outlet connected to the cover of the passive fan assembly.  
   
   
       12 . A passive fan assembly comprising: 
 a housing comprising a plurality of guide blades on a side thereof;    an impeller installed in the housing, comprising a hub, a plurality of blades encircling the hub, a partition connected to ends of the plurality of blades, and a plurality of active blades encircling the partition.    
   
   
       13 . The passive fan assembly as claimed in  claim 12 , wherein the plurality of guide blades corresponds to the plurality of blades of the impeller.  
   
   
       14 . The passive fan assembly as claimed in  claim 13 , wherein each guide blade extends at an angle relative to the corresponding runner blade of the impeller.  
   
   
       15 . The passive fan assembly as claimed in  claim 14 , wherein the angle is approximately 90 degrees.  
   
   
       16 . The passive fan assembly as claimed in  claim 12 , wherein the housing further comprises a stationary part around which the plurality of guide blades are disposed, a stationary ring connected to ends of the plurality of guide blades, and a plurality of supporting elements connecting the stationary ring and the housing.  
   
   
       17 . The passive fan assembly as claimed in  claim 12 , wherein the plurality of guide blades have inclined surfaces.  
   
   
       18 . The passive fan assembly as claimed in  claim 12 , wherein the passive fan assembly is rotated by airflow generated from an airflow-providing system and the airflow passes through the plurality of guide blades into the passive fan assembly.  
   
   
       19 . The passive fan assembly as claimed in  claim 18 , wherein the airflow-providing system comprises an axial fan or air blower.  
   
   
       20 . The device as claimed in  claim 18 , wherein the airflow-providing system comprises an airflow outlet connected to the side of the housing.