Michael C Dexter

US Patent:

20070098558, May 3, 2007

Filed:

Nov 3, 2005

Appl. No.:

11/265278

Inventors:

Robert Vanderhye - McLean VA, US
Michael Dexter - Fairfax Station VA, US
Aaron Aldrich - Little Falls NY, US
Brad Rotsky - Somerset MA, US
Justin Hascup - Boston MA, US

International Classification:

F03D 3/06

US Classification:

41619700A

Abstract:

A Savonius three bladed vertical axis wind turbine rotor has operational characteristics superior to those of conventional three bladed rotors. The blades have high curvature and a high skew factor, for example a curvature of greater than about 7:1 (preferably at least 5.5:1, e. g. 2:1-5:1), and a skew factor of greater than about 0.6 (preferably at least 0.7, e. g. about 0.75-0.9). Preferably the rotor also includes at least one substantially vertical shaft, the blades operatively connected to the shaft. The rotor typically has an aspect ratio of at least about 0.8:1, preferably at least about 2:1 (with the aspect ratio of each blade about twice that of the rotor). The blades desirably comprise a plurality of substantially aligned spokes axially spaced along the shaft each spoke comprising three generally radially extending ribs arcuately spaced from each other approximately 120 degrees. The rotor typically has a maximum power coefficient (Cp) of at least about twice that of an otherwise identical rotor with a skew factor of 0.5 or less The Savonius rotor may be used in combination with a generator or other driven element, with a drive (which automatically increases the effective gear ratio as the rotational speed of the rotor increases) operatively connecting the generator to the rotor. The rotor may alternatively be connected to a propeller of a multihull wind powered boat.