US 5,375,324 A · Vertical axis wind turbine with pultruded blades

Abstract

A pultruded composite blade for a Darrieus-type vertical axis wind turbine is disclosed, along with a method for fabricating such a blade. The blade is a composite structure with a uniform cross-section with reinforcing fibers at least some of which extend parallel to a lengthwise central axis and run continuously from end to end. The composite blade is pultruded straight and, when installed on the tower, the blade is elastically bent into a curved shape that approximates a troposkein. The composite structure includes a skin composed of multiple layers of resin-coated glass fabric that define an airfoil shape. The composite structure also includes one or more internal ribs or spars composed of multiple layers of resin-coated glass fabric.

Claims13

Dependent claims

A method for constructing a Darrieus-type vertical axis wind turbine comprising the steps of:

fabricating a plurality of blades by a pultrusion process;
erecting a rotatable, vertical tower having blade root attachment points near the top and bottom thereof;
installing one end of each blade to the blade root attachment point near the top of the tower, elastically bending the blade to a curved shape, and installing the other end of the blade to the blade root attachment point near the bottom of the tower.

A method for fabricating blades for a Darrieus-type vertical axis wind turbine comprising the steps of:

providing a pultrusion mold having a cavity of uniform cross-section and extending between two open ends thereof and having a lengthwise mold axis extending therethrough, wherein an interior surface of the pultrusion mold defines an airfoil shaped surface;
providing fibers coated with resin to the pultrusion mold;
pulling the fibers coated with resin through the pultrusion mold while heating the pultrusion mold to substantially cure the resin before it exits the mold to form a continuous blade pultrusion;
cutting the blade pultrusion into blades of equal length;
forming an attachment means at each end of each blade;
and
elastically bending the blade into a curved shape upon installation onto a Darrieus-type vertical axis wind turbine.

4 more elements

Dependencies are inferred from the claim text.

Vertical axis wind turbine with pultruded blades

Life of this patent

Vertical axis wind turbine with pultruded blades

Life of this patent

Abstract

Claims13