Cooling fan having improved oil sealing structure

摘要

A cooling fan includes a frame ( 30 ), a stator ( 20 ) and a rotor ( 10 ). The frame includes a base ( 32 ) having a central tube ( 34 ). A bearing ( 22 ) is received in the central tube. The rotor includes a hub ( 11 ) having a shaft ( 15 ) extending from the hub into the bearing. An oil retaining ring ( 40 ) is mounted on the hub around the shaft and near a top of the central hub.