Cylinder for varying the pitch angle of the blades of a horizontal axis windmill, and method of manufacture of the same

摘要

A cylindrical body arranged between a shaft body and a blade of a horizontal axis wind turbine is constituted of a cylindrical barrel portion, a first flange portion fixed to a first end of the barrel portion so that the blade is connected thereto, and a second flange portion fixed to a second end of the barrel portion and connected to the shaft body. The barrel portion is constituted of a cylindrically formed rubber stock and a plurality of filamentary bodies embedded in the rubber stock and arranged in a state inclined by a prescribed angle with respect to a direction parallel to an axial direction. When tensile force F develops in the barrel portion due to centrifugal force resulting from rotation of the blade, both opening ends of the barrel portion twistedly rotate due to actions of the filamentary bodies. Thus, it follows that the pitch angle of the blade connected to the first flange portion automatically varies with a wind speed.