Patent ID: 8100673
Filing Date: 2012-01-24
Classification: F04D,F16C,Y10S

Abstract:
1. A cooling fan, comprising: a tube; a stator mounted around the tube; a bearing assembly comprising a ball bearing and a sleeve bearing being respectively received in two ends of the tube, an elastic element arranged adjacent to the ball bearing to provide a pressing force on the ball bearing, and an oil retaining element arranged adjacent to the sleeve bearing to provide oil for the sleeve bearing; and a rotor having a shaft extending into and rotatably supported by the bearing assembly; wherein a groove is defined in an outer circumference of the sleeve bearing to receive the oil retaining element therein, the oil retaining element being radially sandwiched between the sleeve bearing and the tube; wherein the sleeve bearing has a closed bottom end, the sleeve bearing being coupled to a bottom end of the tube to seal the bottom end of the tube; and wherein the closed bottom end of the sleeve bearing is coplanar to the bottom end of the tube.