ROTOR OF VERTICAL AXIAL-FLOW WINDMILL Russian patent published in 1998 - IPC

FIELD: wind-power engineering. SUBSTANCE: windmill has its blades hinged on cross-arms, that is, their axis of revolution is parallel to rotor axis located on airfoil chord at distance equal to 1/5-1/20 of chord length from front point of airfoil. Blade pin mounts specially shaped cam and cross-arm carries adjustable flexible members which function to create varying torque on pin through cam up to definite wind load when blade turns. If the latter turns through angle exceeding rated value, it acquires wind-vane position and maintains it until wind load creates adequate operating conditions again. EFFECT: provision for starting windmill at weak winds and for its protection against strong winds exceeding permissible load. 2 dwg