mixed flow fan

Abstract

A mixed flow fan having a housing, a stator, and an impeller, with the housing having a downward extending skirt and an upper perimeter as air inlet and a lower perimeter as air exhaust, a central hub with an outer edge, and a plurality of struts connected to the upper perimeter of the skirt and to the outer edge of the central hub. The outer edge of the central hub may be concave or curvilinear or conical. A stator cup which houses the motor is connected to the outer wall of the impeller and to the central hub.

1 . A mixed flow fan having a housing, a stator, and an impeller,: said mixed flow fan comprising:
 (a) said housing having a downward extending skirt with an upper perimeter as air inlet and a lower perimeter as air exhaust, a central hub with an outer edge, and a plurality of struts connected to said upper perimeter of said skirt at a first end and to the outer edge of said central hub at a second end;   (b) said impeller having an outer wall with a plurality blades attached thereto and a stator cup with an inner cup wall and an outer cup wall further comprising a permanent magnet disposed on said inner cup wall, said stator cup connected to said outer wall of said impeller; and   (c) said stator connected to said central hub.   
     
     
         2 . The mixed flow fan of  claim 1  wherein said outer edge of said central hub is curvilinear. 
     
     
         3 . The mixed flow fan of  claim 1  wherein said outer edge of said central hub is conical. 
     
     
         4 . The mixed flow fan of  claim 1  wherein a diameter of said upper perimeter is smaller than a diameter of said lower perimeter. 
     
     
         5 . The mixed flow fan of  claim 1  further comprising a space between said outer cup wall of said stator cup and said outer wall of said impeller. 
     
     
         6 . The mixed flow fan of  claim 5  further comprising a plurality of ribs in said space, said ribs attached to said outer cup wall of said stator cup at a first side and attached to said outer wall of said impeller at a second side. 
     
     
         7 . The mixed flow fan of  claim 1  wherein said outer wall of said impeller is approximately normal to an axis of rotation of said impeller. 
     
     
         8 . The mixed flow fan of  claim 1  further comprising a planar gap between a leading edge of each one of said plurality of blades and a trailing edge of each adjacent one of said plurality of blades. 
     
     
         9 . The mixed flow fan of  claim 1  wherein said downward extending skirt bears an angle of between approximately 5.0° to approximately 15.0° to an axis of rotation of said impeller. 
     
     
         10 . The mixed flow fan of  claim 9  wherein said downward extending skirt bears an angle of approximately 8.6° to said axis of rotation of said impeller. 
     
     
         11 . The mixed flow fan of  claim 9  wherein said blades have a tip bearing an angle of approximately 5.0° to approximately 15.0° from its leading edge to its trailing edge in relation so said axis of rotation of said impeller. 
     
     
         12 . The mixed flow fan of  claim 9  wherein said blades have a tip bearing an angle of 8.6° from its leading edge to its trailing edge in relation so said axis of rotation of said impeller.