Fan for narrow environments

Claim 1

A blower assembly for use in narrow environments comprising, a housing; a stator assembly; a rotor assembly in operative relation with said stator assembly to form a motor and including an outer portion concentrically surrounding the stator assembly; and an impeller carried on the periphery of said outer portion of the rotor assembly for converting an axial airflow to a radial airflow, said impeller including a plurality of blades and means for supporting the blades and guiding an axial input airflow to a radial output flow, said means being integrally formed with said blades and including a radially extending support plate coupled to said rotor assembly adjacent one end thereof, the surface of said plate facing the other end of said rotor assembly being gradually curved from its inner periphery near the one end of the rotor assembly towards its outer edge to guide the axial input airflow to a radial output flow while permitting cooling airflow near the rotor outer portion for a substantial axial distance, said support plate being thickened from its inner periphery toward its outer edge for a substantial portion of the distance between said inner periphery and said outer edge to add rigidity To said support plate, and said plate supporting said blades in cantilever fashion from said surface, the thickening of the support plate forming a rearward projecting reinforcing annular section where the plate joins the rotor assembly to provide means resisting stresses applied by operation of the impeller to the plate near its joinder with the rotor assembly, the housing having a central opening for admitting said axial airflow to the interior of the housing substantially adjacent to the inner periphery of said impeller, and an exhaust opening for said radial output flow, and wherein said motor and impeller are mounted within said housing in an operative relationship to said openings, the central opening is substantially concentric with and larger than the rotor assembly and defines a substantially annular axial flow opening adjacent the outer surface of the rotor assembly aligned with the gradually curved portion of the plate to introduce air into the blower assembly toward the curved plate portion, and said housing includes a rearward section supporting the stator assembly, rotor assembly and impeller within the housing and defining an outer planar mounting surface adapted for cooperation with fastening means for mounting flush against an exterior planar surface to support the blower assembly thereon.