A 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 a proximal root ( 16 a ) and a distal tip ( 16 b ). Each of the blade roots ( 16 a ) are mounted to the hub ( 12 ) at the widest part thereof (D 1 ). The ratio between the diameter of the tips ( 16 b ) of the blades to the diameter of the widest part (D 1 ) of the hub ( 12 ) is less than about 2:1.

1 . A rotor for a hydro-powered electricity generator, the rotor including:
 a hub with a circular cross sectional shape and a longitudinal rotational axis, a plurality of blades, each having a proximal root and a distal tip, each of the blade roots being mounted to the hub at the widest part thereof,   wherein the ratio between the diameter of the tips of the blades to the diameter of the widest part of the hub is less than about 2:1.   
     
     
         2 . The rotor as claimed in  claim 1 , wherein the ratio between the diameter of the tips of the blades to the diameter of the widest part of the hub is between about 1.2:1 and 2:1. 
     
     
         3 . The rotor as claimed in  claim 1 , wherein the ratio between the diameter of the tips of the blades to the diameter of the widest part of the hub is about 1.5:1 or about 1.6:1. 
     
     
         4 . The rotor as claimed in  claim 1 , wherein the diameter of the tips of the blades is between 3.6 and 4.8 metres and the diameter of the widest part of the hub is 2.4 metres. 
     
     
         5 . The rotor as claimed in  claim 1 , wherein the diameter of the tips of the blades is between 30 and 32 metres and the diameter of the widest part of the hub is 20 metres. 
     
     
         6 . The rotor as claimed in  claim 1 , wherein the profile radius of the hub surface, in the region where each of the blade roots are mounted to the hub, is between ⅙th of and equal to the radius of the widest part of the hub.