Foundation for a wind turbine

Abstract

This invention comprises a wind turbine foundation with a hollow central body in the shape of a truncated cone which has an upper flange or a pedestal to connect with the tower (not shown), and a lower slab in the shape of a plane ring. In the preferred embodiment, the foundation leans the interior surface of the cone and the lower slab on earth from the local terrain, which takes on the role of permanent formwork; in an alternative embodiment, the interior of the foundation is left hollow and accommodates components of the wind turbine within it; and in a final alternative embodiment, the foundation is placed over the surface of the terrain which supports only the base of the lower slab, the central body not being buried.

1 . Wind turbine foundation with means of attachment to the tower at its upper part characterized because it consists of a solid of revolution in the shape of a hollow cone ( 1 ) whose interior surface is seated upon permanent formwork of non-excavated earth in the shape of a cone, and which has a second solid of revolution in the shape of a ring ( 2 ) at its lower base. 
     
     
         2 . Wind turbine foundation in accordance with  claim 1  characterized because the generatrix of the cone ( 1 ) is a surface in the shape of a rhomboid, with two short sides parallel to the horizontal and the other two longer sides formed preferably by straight lines which are angled relative to horizontal between 20 and 60° degrees, and are separated by a distance (e) of 0.25-1.2 m between them. 
     
     
         3 . Wind turbine foundation in accordance with  claim 1  characterized because the lower ring ( 2 ) has a radius (R) between 8 and 14 m, a width (L) between 2.5 and 5 m and a height (c) between 0.25 and 0.6 m. 
     
     
         4 . Wind turbine foundation in accordance with  claim 1  characterized because the upper mouth of the cone has a diameter (Dp) between 4 and 12 m. 
     
     
         5 . Wind turbine foundation in accordance with  claim 1  characterized because the total height (H) is between 2.5 and 4.5 m. 
     
     
         6 . Wind turbine foundation in accordance with  claim 1  characterized because either the two long sides of the generatrix are curves, or alternatively they are formed by the combination of one long straight side and one long curved side. 
     
     
         7 . Wind turbine foundation in accordance with  claim 1  characterized because alternatively the thickness (e) of the wall of the cone ( 1 ) varies with depth in the direction of the base ( 2 ). 
     
     
         8 . Wind turbine foundation in accordance with  claim 1  characterized because either the upper and/or lower surface of the ring has an inclination relative to the horizontal between 0 and 45°, and/or because alternatively the central body ( 1 ) connects with the interior radius of the ring ( 2 ) so that there is no projection into the interior of the cone ( 1 ). 
     
     
         9 . Wind turbine foundation in accordance with  claim 1  characterized because alternatively the earth in the hollow interior of the cone ( 2 ) is evacuated and used to house components of the wind turbine in the resulting free space. 
     
     
         10 . Wind turbine foundation in accordance with  claim 1  characterized because alternatively the lower plane ring ( 3 ) lays down directly on the surface of the ground.