Vertical axis windmill

摘要

The windmill has two or three vanes (2) with profiles which are perpendicular to their axis , which are each mounted on bearings. The vanes can move through and angle of sixty to one hundred degrees. The larger section if the vanes, with respect to mass and surface area, are movable on the axle through retraction to a further open position. The vanes can have helical spring, hydraulic or pneumatic dampers, which are fastened on open side to the vane and on the other to the rotor, so that the pivot angle range of the vane can be defined for reduced noise.