Airflow guiding structure varying in inclinations of air-guiding rings for a heat-dissipating fan

摘要

A heat-dissipating fan includes a casing having an air outlet, a base mounted in the air outlet, an impeller being mounted on the base and having a plurality of blades, a plurality of ribs each extending between the base and the casing along a radial direction of the base, and at least two air-guiding ring fixedly mounted to the ribs. The air-guiding rings vary in inclinations along a longitudinal direction of the casing. The air-guiding ring guides airflow in various directions, and divides airflow passing through the air outlet when the impeller is turning.