Patent ID: 7364411
Filing Date: 2008-04-29
Classification: F01D,F04D

Abstract:
1. A centrifugal fan motor for cooling a device, comprising: a motor component having a rotary section, a stationary section and a bearing supporting the rotary section rotatably against the stationary section for rotation about a rotational axis; and an impeller connected to the rotary section, wherein said impeller includes: a rotational force transmission portion provided on an impeller lower end, for receiving driving force from the motor component; a lower endwall portion fixed correspondingly to said rotational force transmission portion, for structuring a wall; and an impeller blade unit having plural blades, each of the blades at its lower end being fixed outer-marginally to the upper surface of the lower endwall portion and each of the blades extending axially to its upper end, the blades together defining an opening at an impeller upper end, and rotation of said impeller blade unit therein generating an airflow streaming along the rotational axis through the opening and outward in a radial direction perpendicular to the rotational axis, said impeller blade unit being dimensioned such that given that 2r represents the diameter to the outer circumference of the impeller blade unit, h represents the axial height of the impeller blade unit, and α represents a parameter, the relationships 2πrh=απr