Patent ID: 7967575
Filing Date: 2011-06-28
Classification: F04D,H01L

Abstract:
1. A centrifugal fan comprising: a shaft rotating around a rotation axis; a cup-shaped portion opening downward and attached to the shaft; a plurality of blades provided outside the cup-shaped portion, the blades extending in a radial direction, the blades rotating together with the shaft and generating an airflow, each of the blades has a radially outer edge; a magnet and an armature both arranged within an opening of the cup-shaped portion and generating a torque for rotating the shaft, the cup-shaped portion, and the blades; a circuit board supplying an electrical power to the armature, a housing having top and bottom faces axially opposed to each other and a side face, and accommodating the shaft, the cup-shaped portion, the blades, and the magnet and armature, wherein the bottom face has a first air inlet for taking an air into the housing, the blades being opposed to a part of the circuit board provided on the bottom face such that the radially outer edge moves across the circuit board, wherein the side face has an air outlet for discharging the air.