Patent ID: 7034418

Claim:
An axial fan motor for a cooling unit, adapted to air-cool a heat sink of a heat generating device, said axial fan motor being disposed on one side of said heat sink opposite said heating element and adapted to direct cooling air into the interior of said heat sink, said axial fan motor comprising: a motor including rotatable about a central axis and having a plurality of fan blades attached to an outer circumferential surface of the rotor; a casing having an outer peripheral surface extending coaxial with said rotor between axially opposing inlet and outlet end faces, an air inlet located in said inlet end face, and an air outlet located in said outlet end face and axially opposite said air inlet, said casing surrounding said rotor and blades and defining an axial flow passage coaxial with said rotor for flow of cooling air entering through said air inlet, passing axially through said casing between said rotor and said casing, and exiting through said air outlet, said inlet and outlet being centered on said central axis; a bearing holder on which a stator of said motor, disposed inside said rotor, is fixed, said bearing holder supporting a rotary shaft of said motor via a bearing and connecting said stator to said casing, said rotor being fixed to said rotary shaft, wherein: said casing comprising a plurality of identical metal plates, each of said identical metal plates having an outer edge continuous around and coincident with said outer peripheral surface and having opposing continuous planar surfaces oriented perpendicular to said central axis and having a central opening surrounding said axial flow path and centered on said central axis, said plurality of identical metal plates laminated together with said continuous planar surfaces in continuous face-to-face contact with each other and arranged side-by-side along the axial direction of said rotary shaft.