Abstract: A fan includes a hub rotatable about an axis; an annular band concentric with the hub and spaced radially outward from the hub; seven fan blades distributed circumferentially around the hub and extending radially from the hub to the annular band.

Abstract: A high efficiency axial flow fan includes a hub, fan blades and a circular band. The hub rotates about a rotational axis when torque is applied from a shaft rotatably driven by a power source. The circular band is concentric with the hub, connected to the tip of each blade, and is spaced radially outward from the hub. The blades are configured to produce an airflow when rotated about the rotational axis. Each blade has a chord length distribution, stagger angle and dihedral distribution which varies along the length of the blade. The dihedral distance of each blade varies as a function of blade radius from the rotational axis.

Abstract: A high efficiency, low solidity, low weight, axial flow fan (100, 200, 300) includes a hub (102, 202, 302), fan blades (104, 204, 304) and a circular band (106, 206, 306). The hub (102, 202, 302) rotates about a rotational axis (110, 210, 310) when torque is applied from a shaft (not shown) rotatably driven by a power source (not shown). The circular band (106, 206, 306) is concentric with the hub (102, 202, 302) and is spaced radially outward from the hub. The blades (104, 204, 304) are distributed circumferentially around the hub (102, 202, 302) and extend radially from the hub to the circular band (106, 206, 306). The blades (104, 204, 304) are configured to produce an airflow when rotated about the rotational axis (110, 210, 310). Each blade (104, 204, 304) has a chord length distribution which varies along the length of the blade, such that the chord length has a local minimum value at a predetermined location between the ends of the blade.

Abstract: A high efficiency fan and stator arrangement for generating an airflow through a heat exchanger is disclosed herein. The fan is rotated about its rotational axis by an electric motor, and includes eight blades extending radially from a hub to a circular band. Each fan blade has a stagger angle and chord lengths which vary along the span of the blades. Each fan blade also includes a trailing edge having a flat surface extending along the edge. The flat surfaces of each fan blade are coincident with a plane perpendicular to the rotational axis. The fan produces an airflow when rotated about the rotational axis, wherein a component of the airflow occurs at a first angle to the rotational axis. The fan support has a central bearing support and twenty elongated airfoils extending radially outward from the bearing support. Each airfoil has substantially the same length as the fan blades and includes a curved airflow guiding surface having a leading edge and a trailing edge downstream from the leading edge.