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US 5,531,567 AGranted
Vertical axis wind turbine with blade tensioner
AssigneeFloWind Corporation
InventorJohn R. Hulls
Life of this patent
Estimating the term…
Abstract
A Darrieus-type vertical axis wind turbine with tensioned blades is disclosed, along with various mechanisms for tensioning the blades. When the wind turbine is stationary in high wind conditions, the blades are tensioned to resist buckling. When the wind turbine is coming up to operational speed, or slowing down to a stop, the blades may also be tensioned to change the dynamic resonance characteristics of the rotor to avoid operation at resonant frequencies.
Claims15
A Darrieus-type vertical axis wind turbine comprising:
- a vertical tower supported for rotation;
- one or more blades each coupled to the tower for rotation therewith, wherein each blade has an upper root coupled to the tower by a blade root attachment means proximate the top of the tower and a lower root coupled to the tower by a blade root attachment means proximate the bottom of the tower;
- blade supporting means for supporting an intermediate portion of each blade away from the tower;
- and
- blade tensioning means for changing the tensile forces on a blade.
2 more elements
A Darrieus-type vertical axis wind turbine comprising:
- a vertical tower supported for rotation;
- three blades each coupled to the tower at the top and bottom thereof, wherein each blade includes three sections joined by two intermediate pin joints;
- three pairs of horizontal struts coupled between the tower and the pin joints of the blades, wherein each pair of struts is coupled between one blade and the tower, wherein one strut of each pair of struts is an extensible strut that includes means for extending the distance between the tower and the pin joint attachment to apply a tensile load to the blade.
A Darrieus-type vertical axis wind turbine comprising:
- a vertical tower supported for rotation;
- one or more blades each coupled to the tower for rotation therewith, wherein each blade has an upper root coupled to the tower by a blade root attachment means proximate the top of the tower and a lower root coupled to the tower by a blade root attachment means proximate the bottom of the tower;
- blade supporting means for supporting an intermediate portion of each blade away from the tower;
- and
- blade tensioning means for applying a tensile force to the blade.
2 more elements
Dependencies are inferred from the claim text.