Blower fan blade passage rate noise control scheme

摘要

An blower of the squirrel cage type that includes a baffle extending from the cut-off area between the impeller and the air outlet for providing a gradual decrease in air flow area between the impeller and the housing. The baffle decreases in width with a leading edge that follows a linear or non-linear curve to effect the gradual change in air flow area. This gradual change in the air flow area reduces the pressure pulse at the cut-off area and thereby reduces noise and vibration and improves the efficiency of the blower.