Cooling fan with rotor blade flanges for controlling rotor movement

Abstract

An exemplary cooling fan includes a housing having an air inlet and an air outlet opposite to the air inlet, a rotor received in the housing, and a stator received in the housing and rotatably supporting the rotor. The rotor includes a hub, blades extending outwardly from an outer periphery of the hub, and flanges slantwise extending from top edges of end portions of the blades. In operation of the cooling fan, air located at an outside of the cooling fan enters the air inlet and flows towards the blades and along the flanges thereby pressing the rotor towards a bottom of the stator along an axial direction of the cooling fan, and the air subsequently flows out of the cooling fan via the air outlet.

What is claimed is: 
     
         1 . A cooling fan comprising:
 a housing having an air inlet and an air outlet opposite to the air inlet;   a rotor received in the housing and comprising a hub, a plurality of blades extending outwardly from an outer periphery of the hub, and a plurality of flanges slantwise extending from top edges of end portions of the blades; and   a stator received in the housing and rotatably supporting the rotor;   wherein in operation of the cooling fan, air located at an outside of the cooling fan enters the air inlet and flows towards the blades and along the flanges thereby pressing the rotor towards a bottom of the stator along an axial direction of the cooling fan, and the air subsequently flows out of the cooling fan via the air outlet.   
     
     
         2 . The cooling fan of  claim 1 , wherein the flanges are arranged along a counterclockwise direction. 
     
     
         3 . The cooling fan of  claim 1 , wherein each blade comprises a connecting section extending from the hub and an extending section extending from the connecting section, and the flange slantwise extends from a top end of the extending section. 
     
     
         4 . The cooling fan of  claim 3 , wherein each connecting section is in the form of a tapering sheet. 
     
     
         5 . The cooling fan of  claim 4 , wherein the blade is straight. 
     
     
         6 . The cooling fan of  claim 4 , wherein a transverse width of the connecting section generally increases from an inner end connected to the hub to an outer end away from the hub. 
     
     
         7 . The cooling fan of  claim 6 , wherein the extending section is in the form of a rectangular sheet and extends from the outer end of the connecting section. 
     
     
         8 . The cooling fan of  claim 3 , wherein a length of the connecting section along a longitudinal direction of the blade is larger than that of the extending section along the longitudinal direction. 
     
     
         9 . The cooling fan of  claim 3 , wherein the flange is an elongated sheet and slantwise extends from the top end of the extending section and oriented towards the air inlet of the housing. 
     
     
         10 . The cooling fan of  claim 9 , wherein an outer end of the flange is coplanar with an outer end of the extending section. 
     
     
         11 . The cooling fan of  claim 10 , wherein a length of the flange along the longitudinal direction is less than that of the extending section. 
     
     
         12 . The cooling fan of  claim 1 , wherein the blades radially extend from the hub and are spaced from each other. 
     
     
         13 . A cooling fan comprising:
 a rotor comprising a hub, a plurality of blades extending outwardly from an outer periphery of the hub, and a plurality of flanges slantwise extending from top edges of end portions of the blades; and   a stator rotatably supporting the rotor;   wherein in operation of the cooling fan, the flanges of the blades provide resistance to airflow arriving from above the cooling fan thereby pressing the rotor towards a bottom of the stator along an axial direction of the cooling fan while still allowing the airflow to pass out beyond bottoms of the blades.   
     
     
         14 . The cooling fan of  claim 13 , wherein the flanges are arranged along a counterclockwise direction. 
     
     
         15 . The cooling fan of  claim 13 , wherein the flange is an elongated sheet and slantwise extends from a top end of the blade. 
     
     
         16 . The cooling fan of  claim 13 , wherein each blade comprises a connecting section extending from the hub and an extending section extending from the connecting section, and the flange slantwise from the extending section. 
     
     
         17 . The cooling fan of  claim 16 , wherein each connecting section is in a form of a tapering sheet. 
     
     
         18 . The cooling fan of  claim 18 , wherein the connecting sections extend obliquely along a counterclockwise direction. 
     
     
         19 . The cooling fan of  claim 17 , wherein a transverse width of the connecting section generally increases from an inner end connected to the hub to an outer end away from the hub. 
     
     
         20 . The cooling fan of  claim 17 , wherein the extending section is in a form of a rectangular sheet and extends outwardly from the outer end of the connecting section.