Patent ID: 7134839

Claim:
A radial-flow heat-dissipating fan comprising: a casing including a compartment and a side air outlet, the casing including a side; a cover mounted to the side of the casing and including an air inlet; a primary fan wheel rotatably mounted in the compartment, the primary fan wheel including a hub and a plurality of radial-flow blades surrounding the hub of the primary fan wheel; and a separate auxiliary fan wheel mounted in the air inlet of the cover, the auxiliary fan wheel including a hub and a plurality of axial-flow blades, the separate auxiliary fan wheel being attached to the hub of the primary fan wheel; an airflow transition area being defined between a circumference of the hub of the primary fan wheel, the radial-flow blades of the primary fan wheel, and the axial-flow blades of the auxiliary fan wheel; the axial-flow blades of the auxiliary fan wheel increasing axial inlet airflow via the air inlet, with the airflow transition area changing a direction of the axial inlet airflow into centrifugal airflow which is outputted via the side air outlet by the radial-flow blades of the primary fan wheel.