Patent ID: 6585497
Filing Date: 2003-07-01
Classification: F04D

Abstract:
A cooling fan dust structure comprising:a frame having a motor base located in the center; a stator coil unit having a bottom end fixed to said motor base; a magnetic bit located on a top end of said stator coil unit; a fan blade unit provide with two or more concentrically spaced ribs protruding from a bottom side of said fan blade unit closest to said stator unit, such that a winding slit is formed between said ribs and said magnetic bit; and a spindle supporting said fan blade unit; a hollow bushing surrounded by said stator coil unit and extending above a top extent of said magnetic bit, such that a second winding slit is formed between the bottom side of the fan blade unit and said bushing; wherein an overcut height difference is established between the ribs and the bushing increasing the distance air has to flow to reach the spindle preventing ingression of dust.