Patent ID: 7456541

Claim:
A fan device having an ultra thin-type structure, comprising: a base plate including an axial hole and at least two stator coils; a shaft member having a first distal end and a second distal end arranged in opposite directions; a flat-type impeller including a center through hole, an annular supporting plate and a plurality of bent vanes; an assembling member formed with an assembling hole and an annular flange, the annular flange disposed on an outer periphery of the assembling hole; and a magnet sheet providing with a center through hole and at least one pair of alternatively opposite magnetic poles axially aligning with the stator coil; wherein the first distal end of the shaft member is successively extended through the center through holes of the flat-type impeller and the magnet sheet, and is inserted into the assembling hole of the assembling member; wherein the second distal end of the shaft member is inserted into the axial hole of the base plate so as to constitute the thin-type structure; and wherein a minimum air gap is formed between the stator coils and the magnet sheet relative to an axis of the fan device such that the minimum air gap so formed between the stator coils and the magnet sheet occupies a minimum length of an axial thickness of the fan device.