Patent ID: 8052386

Claim:
A mixed flow fan wheel comprising: a convex hub; an axially-spaced away, concave annular shroud; a plurality of angularly distributed blades extending between and interconnecting the hub and shroud, all which cooperatively define a plurality of inter-blade flow channels; wherein each blade has a pressure surface and spaced suction surface extending not only between spaced leading and trailing edges but also, transversely thereto, spaced hub-side and shroud-side edges; wherein the blades are arranged in backwardly-swept formations; wherein each blade divides space into two spaces, pressure-side space interfacing the pressure surface and suction-side space interfacing the suction surface; wherein both the leading edge and the trailing edge trace a respective span between the hub-side and shroud-side edges respectively; and wherein each blade is warped into the pressure- and suction-side spaces such that at least twenty-five percent (25%) of the leading edge's span is convex into pressure-side space and, conversely, at least twenty-five percent (25%) of the trailing edge's span is concave into pressure-side space.