Power generating device

A power generating installation including:

• a rotatably mounted support structure being rotatable about a first axis of rotation;
• a plurality of aerofoil blades rotatably mounted on the support structure and freely rotatable relative thereto about a respective second axis of rotation being substantially parallel to and radially spaced from the first axis of rotation;
• the support structure being drivable in repeating 360 degree rotary cycles by lift forces imparted thereon by the aerofoil blades and generated from fluid flow passing there over in a fluid flow direction;
• wherein the aerofoil blades, in a transition region of the support structure where a transition line that passes through the first axis of rotation is perpendicular to the fluid flow direction, is deformable or invertible between:
• (i) a first condition, during a primary phase of the rotary cycle, in which the aerofoil blades have a first reflexed camber aerofoil section for generating a lift force in a first direction thereby to impart a torque on the support structure in a first rotational direction;
• and
• (ii) a second condition, during a secondary phase of the rotary cycle, in which the aerofoil blades have a second reflexed camber aerofoil section for generating a lift force in a second direction thereby to impart a torque on the support structure in the first rotational direction;
• and further wherein the aerofoil blades are freely rotatable throughout the rotary cycle in response to forces induced on the aerofoil blades by fluid flow passing there over;
• and
• a power generation means for operably converting the mechanical energy of the support structure into electrical energy.

A power generating method including the steps of:

• (A) exposing a plurality of aerofoil blades rotatably mounted on a support structure to a fluid flow thereby to generate lift forces and rotatably drive the support structure about a first axis of rotation in repeating 360 degree rotary cycles;
• (B) deforming or inverting the aerofoil blades, in a transition region of the support structure where a transition line that passes through the first axis of rotation is perpendicular to the fluid flow direction, between:
• (i) a first condition, during a primary phase of the rotary cycle, in which the aerofoil blades have a first reflexed camber aerofoil section for generating a lift force in a first direction thereby to impart a torque on the support structure in a first rotational direction;
• and
• (ii) a second condition, during a secondary phase of the rotary cycle, in which the aerofoil blades have a second reflexed camber aerofoil section for generating a lift force in a second direction thereby to impart a torque on the support structure in the first rotational direction;
• (C) converting the mechanical energy of the support structure into electrical energy;
• wherein the aerofoil blades are freely rotatable throughout the rotary cycle in response to forces induced on the aerofoil blades by fluid flow passing there over.