Alfred J Eggers

US Patent:

51619520, Nov 10, 1992

Filed:

Sep 24, 1990

Appl. No.:

7/586808

Inventors:

Alfred J. Eggers - Atherton CA

Assignee:

Rann, Inc. - Palo Alto CA

International Classification:

B63H 126

US Classification:

416223R

Abstract:

Dual-plant blade construction for wind turbine rotors having a horizontal shaft having a rotor hub adapted to be mounted on the horizontal shaft and having a horizontal axis. First and second sets of straight blades are secured to said rotor hub in circumferentially equally spaced apart positions on the rotor hub. Each of said sets of blades include first and second blades having tip and root portions with the root portions of the blades being secured to the rotor hub at spaced apart positions along the axis of the rotor hub and the tip portions of the blades being secured to each other whereby there is generated substantially equal and opposite cyclic spanwise forces and minimal cyclic flatwise moments in the first and second blades in response to non-steady aerodynamic normal forces acting on these blades in non-uniform turbulent winds.