Horizontal axis wind generator having adaptive cyclic pitch control

Patent · Tue Nov 03 04:00:00 EST 1981

OSTI ID:5777680

Hohenemser, K H

Cyclic pitch variation of the rotor blades of a horizontal axis wind energy conversion machine permit its operation at substantially design rotor speed and rotor torque over a range of wind speeds, by heading the rotor progressively out of the wind through a range from approximately 20* for light winds to a near 90* setting for gales, at which the power output is interrupt to permit the rotor to idle. Changes in wind direction will cause the rotor to follow the wind even though so headed out of it. By allowing the blades substantial freedom to adapt their pitch to side winds, the present construction allows rapid rates of yaw into a shifting wind, such as may destroy conventional rotors by the attendant gyroscopic forces. Further, by actively controlling their pitch, aerodynamic forces exerted by the cyclic pitch change blades substantially balance out the gyroscopic forces attendant to yaw. The preferred rotor uses only two blades mounted on a common shaft which oscillates cyclically in the hub. Since cyclic variation of blade pitch establishes a cyclic pitch center of rotation offset from the rotor axis; by moving this offset the rotor is caused to yaw at a controlled rate in a desired sense.

• Assignee: IFI; EDB-82-039019
• Patent Number(s): US 4298313
• OSTI ID: 5777680
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
170602* -- Wind Energy Engineering-- Turbine Design & Operation
CONTROL
INCLINATION
MACHINERY
MOTION
ROTATION
ROTORS
TURBINE BLADES
TURBINES
TURBOMACHINERY
WIND TURBINES