Airfoil blade and method for its manufacture

摘要

This centrifugal blower fan wheel has extruded-aluminum airfoil blades. The preferred blades have two hollow regions, separated by an angled mid-load support beam, inside the blade. The nose section of the blade (at the leading edge) and the tail section of the blade (at the trailing edge) have open semi-circular grooves which face the adjacent hollow sections and are designed to accept thread cutting or thread forming screws for attachment of the blade to a ring-shroud and back-plate.