The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 29, 1994
Filed:
Apr. 28, 1993
Martin G Yapp, Needham, MA (US);
Robert Van Houten, Winchester, MA (US);
Robert I Hickey, Concord, NH (US);
Airflow Research and Manufacturing Corporation, Watertown, MA (US);
Abstract
An improvement to forwardly skewed axial fans whereby blade camber and rake are coordinated with skew. The blades are characterized in that a line defined by the points of maximum chordwise camber (f.sub.max) as a function of changing radial position (r) is on the leading edge side of the mid-chord line (M.sub.CL) at values of r toward the root of the blade, and is less forwardly skewed than the leading edge (LE), the mid-chord line (M.sub.CL), and the trailing edge (TE) of said blade; the blade is raked forwardly so that the trailing edge of the blade tip is axially forward of the trailing edge at the blade root; rake (k) increases monotonically as radial position r increases from 0.75R to 1.0R, R being the fan radius; the blade has a relatively large pitch ratio (P/D); and rake is corrected to reflect the chordwise position of maximum camber. As a result, the fan produces a flow that is generally in radial equilibrium having a reduced component of flow normal to the2 desired axial flow and normal to the tangential flow. The coordinated fan can be (but need not be) combined with a housing/band configuration for controlling airflow that recirculates (i.e., counter to the desired axial airflow) in a channel formed between the band and housing.