Patent ID: 8317497

Claim:
A motor-fan unit comprising: an end plate assembly; a motor assembly supported by said end plate assembly; a shaft rotated by said motor assembly and extending through said end plate assembly; and a fan assembly supported by said end plate assembly, said fan assembly comprising: a discharge shell attached to said end plate assembly; a rotating fan secured to said rotatable shaft, said rotating fan having a fan disc with a substantially frusto-conical shape, a fan ring and a plurality of vanes connecting said fan disc to said fan ring; a tapered stationary fan having a tapered fan side opposite a shell side and supported by said discharge shell, said tapered fan side positioned adjacent said fan disc, wherein said shell side has a concave shape with a plurality of curvilinear walls extending downwardly therefrom; a fan shroud mounted on said discharge shell so as to substantially enclose said rotating fan and said tapered stationary fan, said fan shroud having an intake port; and a tapered fan shell interposed between said discharge shell and said shell side of said stationary fan, wherein said plurality of curvilinear walls have edges in contact with said tapered fan shell, and wherein said tapered fan shell has a conical portion and a flat portion, and wherein each said curvilinear wall has a flat edge that contacts said flat portion and a tapered edge that contacts said conical portion.