Screw pump and impeller fan assemblies and method of operating

An impeller fan assembly comprising:

• a housing having an inner peripheral wall defining a flow through passage;
• a stator located within the flow through passage and having an annular array of stationary blades provided along the inner peripheral wall;
• a rotor having a hub and an annular array of non-stationary blades extending from the hub;
• at least two spaced apart bearings mounted to the stator;
• a shaft having a hollow portion rotatably supported by the bearings for rotation about a rotational axis;
• a sump provided in the stator;
• a screw pump provided within the hollow portion of the shaft and having a screw pump inlet fluidly coupled to the sump and a screw pump outlet in fluid communication with the bearings, whereby rotation of the screw pump about a screw pump rotational axis pumps fluid from the sump to the bearings;
• and
• a de-swirler located within the sump and configured to reduce rotational movement of the fluid within the sump as compared to movement of the fluid within the sump in an absence of the de-swirler;
• wherein the de-swirler includes a deswirler hub having a centerline coaxial with the rotational axis and having fixed vanes extending radially from the deswirler hub, the vanes being curved relative to the centerline of the deswirler hub and wherein the curved vanes include curvature in a direction opposite from a rotational direction of the screw pump to redirect fluid toward the centerline.