Centrifugal fan comprising a sidewall and plurality of air deflectors forming a plurality of airflow entry tunnels to sequentially expand a flow channel outwardly in a radial direction

摘要

A centrifugal fan includes an impeller, a motor and a fan frame. The motor is connected with the impeller and configured to drive the impeller. The fan frame includes a base plate, a top plate, a sidewall and air deflectors. The impeller is disposed between the base plate and the top plate. The sidewall is disposed on the base plate between the base plate and the top plate. A flow channel is between the impeller and the sidewall. The air deflectors are directly connected to the base plate and the top plate, and disposed toward an air outlet and sequentially at different radial positions outwardly from the sidewall along a forward circumferential direction toward an air outlet with respect to the impeller to sequentially expand the flow channel outwardly in a radial direction at different circumferential positions along the forward circumferential direction with respect to the impeller. The airflow entry tunnels are formed by the air deflectors between the base plate and the top plate.