Abstract: An airflow guide stator vane for an axial flow fan and a shrouded axial flow fan assembly having such stator vanes are disclosed. The airflow guide stator vane has a leading edge line, a trailing edge line, and an airflow guide surface extending from the leading edge line to the trailing edge line. The stator vane is radially positioned in an axial flow fan and is curved so that its leading edge line is perpendicular to oblique velocity components of an airflow each of which is a sum vector of a rotation-directional velocity component and a radius-directional component of an air particle of the airflow. The axial flow fan assembly comprises an axial flow fan and a shroud. The axial flow fan consists of a circular central hub connected with a driving shaft of a motor and a plurality of blades radially arranged along the circumference of the hub.

Abstract: An axial flow fan is disclosed. The axial flow fan comprises a hub, a plurality of blades extending radially outwardly from the hub, and an outer band surrounding peripheral ends of the blades. The median sweep angle of each blade increases gradually from 0° along the outward radial direction. The leading sweep angle of each blade starts from an angle of less than 0°, increases gradually and terminates at an angle of more than 40°. The trailing sweep angle of each blade increases along the outward radial direction after it decreases from an angle of more than 0° along the outward radial direction. The chord length of each blade gradually increases along the outward radial direction. The pitch angle of each blade gradually decreases along the outward radial direction.