Patent ID: 8360735

Claim:
A serial axial fan comprising: a first impeller including a plurality of first blades radially extending from a first hub with a rotation axis as a center; a first motor portion arranged to drive and rotate the first impeller to generate an air flow in an axial direction of the rotation axis; a first housing arranged to accommodate the first impeller and the first motor portion, the first housing being defined by a cylinder having openings in both end portions in the axial direction; a second impeller including a plurality of second blades radially extending from a second hub with the rotation axis as a center; a second motor portion arranged to drive and rotate the second impeller to generate an air flow in the axial direction of the rotation axis; and a second housing, aligned with the first housing in the axial direction to define a fan assembly, the second housing arranged to accommodate the second impeller and the second motor portion, the second housing being defined by a cylinder having openings in both end portions in the axial direction; wherein the first motor portion includes a first circuit board on which at least one electronic component arranged to drive the first impeller is mounted; the second motor portion includes a second circuit board on which at least one electronic component arranged to drive the second impeller is mounted; the first circuit board and the second circuit board are directly electrically connected to each other such that at least one electrical signal is transmitted between the first circuit board and the second circuit board; at least one electronic component mounted on one of the first and second circuit boards is arranged to control both the driving of the first impeller and the driving of the second impeller; and the serial axial fan further includes a conductive member arranged to electrically connect the first circuit board and the second circuit board, the conductive member being completely radially within a largest outermost circumferential surface of the first hub or the second hub and the fan assembly.