High strength fan
AssigneeAirflow Research and Manufacturing Corporation
InventorLeslie M. Gray, III
Life of this patent
Estimating the term…
Abstract
A fan in which the root-to-tip net blade skew angle (A.sub.b) (either forward or rearward) is less than 1/2 of the blade spacing; in a first radially inward region of the blade, the blade is rearwardly skewed as indicated by the leading edge skew angle (A.sub.e); in a second region radially outward of the first region, the leading edge skew angle indicates a forward skew.
Claims5
A cooling fan, and means for maintaining said fan in association with a heat exchanger in position to move air through the heat exchanger, said fan comprising a hub rotatable on an axis, a plurality of plastic blades, each of which extends radially outward from a root region attached to said hub to a tip region, and a cylindrical band extending concentrically around said fan axis, said band connecting said blade tip regions, said blades being characterized in that:
- (a) the leading edge of each said blade is rearwardly angled in said root region and forwardly angled in said tip region, said blades having a leading edge skew angle of at least 30.degree. rearwardly in at least one portion of said root region and a leading edge skew angle of at least 30.degree. forwardly in at least one portion of said tip region;
- (b) said blades having a net mid-chord line blade skew less than 1/2 of the blade spacing angle;
- and
- (c) said blades have a blade angle which is approximately constant for the position of the blade where r/R is greater than 0.7.
Dependencies are inferred from the claim text.