Fan shroud and/or fan blade assembly

Abstract

Briefly, embodiments of a fan for moving a volume of compressible fluid from an upstream side to a downstream side may comprise a vortex circulation channel formed within a shroud substantially surrounding the blades of the fan. As a portion of one or more blades of the fan moves within the vortex circulation channel, a vortex that is formed and confined within the channel may reduce formation of a vortex within the fan working area, thereby bringing about an increase in a volume of the compressible fluid capable of being moved by the fan. In an embodiment, a fin or other protrusion disposed on a tip portion of a blade may additionally increase flow of a compressible fluid through a fan. In an embodiment, use of a wraparound leading edge of a fan shroud may bring about further increases in volume of compressible fluid flow.

1 - 20 . (canceled) 
     
     
         21 . A fan, comprising:
 a shroud to surround an axis of rotation of one or more blades of the fan, the shroud comprising a forward edge portion having a cross-section that approximates at least a portion of a circular arc; and   one or more vanes, arranged at an inlet portion of the fan, to subtend in a spaced relation from a location within the cross-section of the forward edge portion, the one or more vanes having respective arc-shaped curvatures and positioned at the inlet portion so as to align airflow with the axis of rotation of the fan.   
     
     
         22 . The fan of  claim 21 , wherein the at least the portion of the circular arc comprises a radius of between about 1.0% and about 7.5% of a diameter of the inlet portion of the fan. 
     
     
         23 . The fan of  claim 21 , wherein an angle subtended by the cross-section of the forward edge portion comprises less than 90.0°. 
     
     
         24 . The fan of  claim 21 , wherein an angle subtended by the cross-section of the forward edge portion comprises between 90.0° and 360.0°. 
     
     
         25 . The fan of  claim 21 , wherein an angle subtended by the cross-section of the forward edge portion comprises between 180.0° and 360.0°. 
     
     
         26 . The fan of  claim 21 , wherein the one or more vanes comprise at least a first vane, arranged at a first distance from the forward edge portion and having a greater curvature than a second vane of the one or more vanes, the second vane arranged at a distance from the forward edge portion that is greater than the first distance from the forward edge portion. 
     
     
         27 . The fan of  claim 26 , wherein the one or more vanes and the shroud cooperate to provide substantially laminar flow through a volume defined by the inlet portion and the shroud in a direction along the axis of the fan. 
     
     
         28 . A fan, comprising:
 a cylindrically-shaped shroud having a forward edge at least partially surrounding an inlet portion of the fan, a cross-section of the forward edge to align airflow with a curvature of the inlet portion of the cylindrically-shaped shroud; and   one or more vanes, arranged within the inlet portion of the fan, the one or more vanes having respective arc-shaped curvatures to cooperate with the forward edge in alignment with ambient air from the inlet portion and to redirect the ambient air to an axis of the cylindrically-shaped shroud.   
     
     
         29 . The fan of  claim 28 , wherein the forward edge comprises a circular arc subtended from a first point positioned within the cross-section of the forward edge comprises between 90° and 360°. 
     
     
         30 . The fan of  claim 28 , wherein the forward edge comprises a circular arc subtended from a first point positioned within the cross-section of the forward edge comprises about 180.0°. 
     
     
         31 . The fan of  claim 28 , wherein the forward edge comprises a circular arc subtended from a first point positioned within the cross-section of the forward edge comprises about 360.0°. 
     
     
         32 . The fan of  claim 28 , wherein the forward edge comprises a circular arc subtended from a first point positioned within the cross-section of the forward edge and wherein the circular arc comprises a radius of between about 1.0% and about 7.5% of the diameter of the inlet portion of the fan. 
     
     
         33 . The cylindrically-shaped shroud of  claim 28 , wherein the cylindrically-shaped shroud and the one or more vanes cooperate to provide substantially laminar flow from the inlet portion of the fan to a downstream portion of the fan in a direction along the axis of the cylindrically-shaped shroud. 
     
     
         34 . A fan, comprising:
 a shroud for directing flow of a compressible fluid from an upstream side to a downstream side of one or more blades of the fan, the shroud having a radiused forward edge, a cross-section of the radiused forward edge to cooperate with the one or more blades of the fan to draw ambient compressible fluid towards the downstream side; and   one or more vanes having arc-shaped curvatures arranged at substantially uniform intervals within an inlet portion of the fan, the one or more vanes to subtend from a location within the cross-section of the radiused forward edge, the one or more vanes to align the drawn compressible fluid along an inner surface of the shroud.   
     
     
         35 . The fan of  claim 34 , wherein the one or more vanes comprise at least a first vane, disposed at least a first distance from the radiused forward edge, having a greater curvature than a second vane of the one or more vanes, the second vane disposed at a distance greater than the first distance from the radiused forward edge. 
     
     
         36 . The fan of  claim 34 , wherein the radius of the radiused forward edge comprises a length of between about 1.0% and about 7.5% of a diameter of the inlet portion of the fan. 
     
     
         37 . The fan of  claim 34 , wherein the shroud and the one or more vanes are capable of providing substantially laminar flow through a volume defined by the shroud from the inlet portion of the fan to the downstream side of the fan. 
     
     
         38 . The fan of  claim 34 , wherein the cross-section of the radiused forward edge comprises an arc subtending an angle of between 90.0° and 360.0°. 
     
     
         39 . The fan of  claim 34 , wherein the location within the cross-section of the radiused forward edge, from which the one or more vanes subtend, coincides with a center of the radiused forward edge. 
     
     
         40 . The fan of  claim 39 , wherein the radiused forward edge operates to preclude formation of one or more vortices in a forward direction of the radiused forward edge.