Patent ID: 7989973
Filing Date: 2011-08-02
Classification: E02B,F03B,F03D,F05B,Y02E,Y02P

Abstract:
1. Power generation apparatus comprising a wing-shaped blade having opposite sides, opposite ends and leading and trailing edges extending between said ends; a blade shaft extending along an axis in the blade that is in close parallel relation to the leading edge of the blade and fixed to move with the blade; supports for supporting the blade shaft so that when the blade is positioned in a moving fluid stream with said leading edge facing upstream the blade can oscillate about said axis between first and second extreme positions on opposite sides of a neutral position; lift differential producing means in the blade for producing a lift differential at the opposite sides of the blade in the presence of the moving fluid stream; means for switching the lift differential producing means so that one blade side or the other produces the greater lift in the presence of the moving fluid stream; coordinating means for coordinating the switching means with the swinging of the blade so that the switching occurs only at each extreme position of the blade to produce a blade lift which urges the blade toward the other extreme position so that the blade oscillates between said extreme positions in the presence of the moving fluid stream; first and second fluid boundaries located adjacent to the respective first and second extreme positions of the blade close to trailing edge of the blade when the blade is in said first and second extreme positions for simultaneously causing a substantial blocking of the flow of the moving fluid stream on the blade side facing each extreme position and a rapid increase in said flow on the opposite blade side when the blade reaches each extreme position to impel the blade toward the other extreme position, and a power takeoff device which reciprocates in response to the oscillation of the blade so that the apparatus can drive an external machine.