US Patent 7324339 Dual impeller push-pull axial fan heat sink

A fan sink that includes a dual impeller push-pull axial fan and a heat sink to cool a hot electronic device is presented. The axial fan has a hub motor, a first impeller that is radially proximate to the hub motor, and a second impeller that is radially distal to the hub motor, wherein the first impeller pushes air in a first direction and the second impeller pulls air in a second direction. The heat sink is oriented between the axial fan and the hot electronic device such that the hot electronic device, the heat sink, and the axial fan are axially oriented, wherein cool air is forced onto the heat sink by one impeller in the axial fan, and wherein heated air from the heat sink is removed by an other impeller in the axial fan.