Rotor for an electricity generator

Abstract

A rotor (10) for a hydro-powered electricity generator. The rotor (10) includes a hub (12) and a plurality of blades (16). The hub (12) has a circular cross sectional shape and a longitudinal rotational axis (14). The plurality of blades (16) each have proximal root (16a) and a distal tip (16b). Each of the blade roots (16a) are mounted to the hub (12) at the widest part thereof (D1). The ratio between the diameter of the tips (16b) of the blades to the diameter of the widest part (D1) of the hub (12) is less than about 2:1.

What is claimed is: 
     
         1 . A rotor for a hydro-powered electricity generator suitable for installation in a free stream, the rotor including:
 a hub formed of a shape with a circular cross section and a longitudinal rotational axis, wherein the circular cross section increases in radius from a front of the hub to a maximum radius and decreasing in radius from the maximum radius to a back of the hub,   a plurality of blades protruding out around the hub at the maximum radius wherein each blade in the plurality of blades has a proximal root and a distal tip and each blade in the plurality of blades protrudes from the hub at the proximal root.   wherein each blade in the plurality of blades is tapered, such that each blade in the plurality of blades is widest at the proximal root and narrowest at the distal tip, and   wherein the ratio of a blade tip diameter to a hub diameter is less than 2:1.   wherein a profile radius of the hub between the blade and the back of the hub is ⅙ of the maximum radius; and   wherein a mounted position of the proximal root of each blade in the plurality of blades is configured so that energy in the free stream of a fluid is concentrated in a region of the plurality of blades.