Patent ID: 8007234

Claim:
An axial fan unit comprising first and second axial fans coaxial with and connected to each other, wherein the fan unit has a center axis along which the first and second fans are coaxial, and four sides each parallel to the center axis such that the fan unit has the approximate form of a quadrangular prism, the first axial fan includes: a first impeller having first blades disposed about the center axis; a first motor operable to rotate the first impeller about the center axis to generate an axial air flow; a first group of electrically wires connected to the first motor; and a first housing member including a hollow, approximately cylindrical first body surrounding the first impeller and first flanges provided at axial ends of the first body, respectively; the second axial fan includes: a second impeller having second blades disposed about the center axis; a second motor operable to rotate the second impeller about the center axis to generate an axial air flow in the same direction as that generated by rotation of the first impeller; a second group of wires electrically connected to the second motor; and a second housing member including a hollow, approximately cylindrical second body surrounding the second impeller and second flanges provided at axial ends of the second body, respectively; and the first flanges of the first housing member and the second flanges of the second housing member have approximately the same outer square shape as seen along the center axis such that each of the flanges has four outer peripheral side surfaces and four corners, the first and second housing members are joined together such that the outer peripheral side surfaces of the first flanges are axially aligned with the outer peripheral side surfaces of the second flanges, respectively, and the outer peripheral side surfaces of each of the flanges are respectively substantially coextensive with sides of the quadrangular prism, respectively, one of the first flanges of the first housing member has first and second receiving portions disposed along different sides of the fan unit, the first receiving portion receiving therein the first group of wires and the second receiving portion receiving therein the second group of wires, and the first group of wires extending approximately axially along one of said different sides of the fan unit and the second group of wires extending approximately axially along the other of said different sides of the fan unit without the wires of either of said groups protruding beyond outer peripheries of the first flanges respectively.