Patent ID: 7443065
Filing Date: 2008-10-28
Classification: F04D,H02K

Abstract:
1. A cooling fan comprising: a casing defining an accommodating space, and having a base wall and a surrounding wall that extends transversely from said base wall, and that has an inner wall surface, a side opening for passage of fluid flow out of said accommodating space, and a top opening defined by a top end face; a stator mounted on said inner wall surface of said surrounding wall; a shaft protruding from said base wall into said accommodating space and defining a rotation axis; a fan blade unit disposed in said accommodating space and including an annular hub that is journalled rotatably to said shaft, a supporting ring that surrounds said hub, and a plurality of blades that extend between and that are connected to said hub and said supporting ring; a rotor mounted on said supporting ring and coupled magnetically to said stator; and a cover in the form of a circuit board disposed opposite to said base wall, mounted on said top end face of said surrounding wall for covering said top opening in said casing, and including a substrate and a control circuit disposed on said substrate and coupled to said stator, said substrate being formed with a central opening for passage of fluid flow into said accommodating space when said fan blade unit is driven to rotate about said rotation axis.