Strain isolated attachment for one-piece wind turbine rotor hub

Abstract

A wind turbine rotor hub attachment that extends inside a one-piece two-bladed wind turbine rotor hub, and secures to its shear web(s). This isolates the attachment from the high strains on the hub exterior, and allows balanced loads to flow across the hub, so that only unbalanced air loads and torque, plus net rotor loads such as thrust and weight, are passed across from the rotor to the wind turbine main shaft. This solves the excess motion problem of central teeter hinges, is mechanically simpler, and reduces overall weight and cost compared to the conventional practice of using individual blades bolted to a separate central hub. A method for connecting a one-piece two bladed wind turbine rotor to a main shaft using a strain isolating attachment to the rotor hub shear web(s) is included.

1 . The wind turbine rotor hub attachment comprising a wind turbine rotor hub attachment that rotates with a wind turbine main shaft, extends inside a one-piece wind turbine rotor hub structure, and is rigidly secured to at least one main shear web of the one-piece wind turbine rotor hub structure wherein a wind turbine rotor comprises said one-piece turbine rotor hub structure, combined with partial span pitch, wherein an outer span of turbine rotor blades pivot relative to said one-piece wind turbine rotor hub structure. 
     
     
         2 . The wind turbine rotor hub attachment comprising a wind turbine rotor hub attachment that rotates with a wind turbine main shaft, extends inside a one-piece wind turbine rotor hub structure, and is rigidly secured directly to at least one main shear web of the one-piece wind turbine rotor hub wherein an external cylinder or cone rotates with the wind turbine main shaft, and the external cylinder or cone is connected to load transfer struts that penetrate a rotor hub shell to reach inward past a nacelle side spar cap to the main shear web of a single spar one-piece wind turbine rotor hub. 
     
     
         3 . The wind turbine rotor hub attachment of  claim 2  wherein the load transfer struts are secured to a web mating structure that secures to one main shear web near a main shear web mid height, wherein said web mating structure is comprised of mating plates on both sides of said main shear web, and backbones perpendicular to a plane of said main shear web and mating plates. 
     
     
         4 . The elongated web mating structure of  claim 3  wherein one or more lateral fingers are attached on the outboard region of the web mating structure and the lateral fingers are oriented across the main shear web, toward the spar caps, and attach securely to said web. 
     
     
         5 . A method for securing a one-piece wind turbine rotor hub to a wind turbine main shaft comprising extending a wind turbine rotor hub attachment inside a one-piece wind turbine rotor hub and securing the wind turbine rotor hub attachment to at least one main shear web of the one-piece wind turbine rotor hub wherein the wind turbine rotor comprises said one-piece rotor hub with partial span pitch, wherein the outer span of the rotor blades pivot relative to said one-piece hub.