Patent ID: 6400049
Filing Date: 2002-06-04
Classification: F04D,H02K

Abstract:
A cooling fan comprising:a housing, said housing comprising a center shaft suspended at the center of a circular open chamber defined therein, and two mounting rods spaced from said center shaft at two sides within said circular open chamber, said center shaft having an annular groove around the periphery thereof; a circuit board mounted on said center shaft inside said circular open chamber of said housing, said circuit board comprising two mounting holes respectively fastened to said mounting rods of said housing; a winding assembly fixedly mounted on said circuit board around said shaft; a fan blade assembly adapted to turn about said shaft, said fan blade assembly comprising a hub coupled to said center shaft of said housing, and two sets of blades radially extended from the periphery of said hub and alternatively arranged at different elevations, said hub having a countersunk center hole coupled to said center shaft; a ring magnet fixedly mounted in said hub of said fan blade assembly and driven to rotate with said fan blade assembly about said center shaft upon connection of electricity to said winding assembly; an axle bearing mounted on said center shaft within said countersunk hole to support said hub of said fan blade assembly on said center shaft; a washer mounted on said center shaft and supported on said axle bearing in said countersunk hole; and a C-shaped retainer fastened to the annular groove of said center shaft to secure said washer and said axle bearing to said center shaft inside said countersunk hole.