Patent ID: 6514052
Filing Date: 2003-02-04
Classification: F04D,H02K

Abstract:
A fan having a center axis of rotation, the center axis defining axial and radial directions, the fan comprising: a first plurality of blades on a first axial side of the fan, the first plurality of blades each extending radially straight from the center axis to push air radially outwardly and draw a flow of air in a first direction axially toward the first axial side of the fan on rotation of the fan; and, a second plurality of blades on a second axial side of the fan that is opposite the first axial side of the fan, the second plurality of blades each extending radially straight from the center axis to push air radially outwardly and draw a flow of air in a second direction, opposite the first direction axially toward the second axial side of the fan on rotation of the fan; and, an annular ring intersecting the plurality of blades, the annular ring having axially opposite first and second edges and a cross-section that angles obliquely away from the center axis as the cross-section extends from the first edge of the ring to the second edge of the ring.