Patent ID: 6533536
Filing Date: 2003-03-18
Classification: F03B,Y02E,Y10T

Abstract:
A turbine installation comprising:a turbine disposed in a flow of water for producing electrical energy, the turbine including, a plurality of runner blades, each blade comprising a hydrofoil being bounded by an inner surface and a distal outer surface, a leading edge and a trailing edge separated by a water directing surface, the blades being adjustable in pitch from a maximum pitch position in which an inner portion of the water directing surface extends substantially in a direction of the water flow, to a minimum pitch position in which an outer portion of the water directing surface is substantially perpendicular to the water flow, and a hollow hub having spaced apart inner and outer surfaces and a hub longitudinal axis, each blade being pivotally connected to the hub about a rotational axis, at least a portion of the outer surface of the hub swept by the inner surfaces of the blades during rotation of the blades from the maximum pitch to the minimum pitch being spherically-shaped, and the inner surfaces of the blades substantially conforming to the spherical outer surface portion of the hub, thereby reducing inner gaps formed therebetween; and an electrical closed-loop control system including an electrical controller and a plurality of sensors, the sensors selectively generating electrical signals indicative of turbine speed, blade pitch and net head, the electrical controller receiving and processing the electrical signals from the sensors and capable of adjusting the blades in position in response thereto.