An electric fan includes a fan base (10), a bearing (40) and a rotor assembly (20). The fan base forms a central tube (11) receiving the bearing therein. The rotor assembly includes a fan hub (22), and a pivot axle (23) joined to the fan hub. The pivot axle pivotably extends into the bearing. The bearing has an outer wall (41) with a plurality of bulwarks (45) circumferentially formed thereon. At least one partition hole (424, 43a) corresponding to the bulwarks is defined in the bearing. The at least one partition hole effectively prevents a radially inward pressure exerted by the central tube on the bearing from being exerted to the pivot axle via the bearing. Therefore, a friction between the bearing and the pivot axle is reduced.

 
Web www.patentalert.com

< Hydraulic actuator for a vehicular power train

> Mobile concrete pump and corresponding building frame

> Hydraulically-actuated diaphragm pump with a leak compensation device

~ 00578