摘要 |
A horizontal axis wind turbine with a ball-and-socket hub is disclosed. The hub provides for a second vertical axis, the hub axis, intersecting the center of the hub that enables a change in orientation of the rotor axis without changing the orientation of the main shaft axis. The cause for the rotation around the hub axis is an imbalance in torque applied by the blades across a wind shear axis due to a gradient in wind velocity. Rotation around the hub axis will continue until back-and-forth rotation of the blades is such that the torque is balanced across a wind shear axis and the rotor axis is set at an optimal angle. As changes in wind direction occur, the torque will become imbalanced, and the hub will rotate until a new optimal angle is achieved. The present turbine design allows for the hub to freely rotate ±20° around the hub axis and continuously maintain orientation of the rotor axis at an optimal angle. When a control limit is reached, a computer signals the yaw axis motor to rotate the main shaft axis until it is aligned with the rotor axis. Laser measuring devices and linear actuators located in the front of the nacelle provide for monitoring and control of the hub movement. |