COOLING FAN WITH INTERNALLY TAPERED HOUSING

摘要

A cooling fan includes a fan housing and a rotor. The fan housing includes an inner surface defining an inner space therein. The inner surface expands along a direction parallel to a central axis of the fan housing. The rotor is received in the inner space and surrounded by the inner surface of the fan housing. The rotor includes a hub and a plurality of rotary blades extending outwardly from the hub. Each of the rotary blades has an outer edge confronting the inner surface of the fan housing. The outer edge of each rotary blade slants towards the central axis of the fan housing.