Abstract: An arrangement and a method of rotating a hub of a wind turbine are provided. A wind turbine includes a hub mounted to a nacelle, whereby the hub is rotatable around an axis of rotation in respect to the nacelle. A rotor blade is arranged at the hub that leads to a torque around the axis of rotation of the hub. A counter weight is attached to the hub, whereby the counter weight has a mass that leads to a counter-torque around the axis of rotation. The counter-torque interacts with the torque during the installation of a second rotor blade to the hub. The counter weight is mounted to the hub by a mechanical arrangement that is rotatable in respect to the hub around the axis of rotation of the hub. The mechanical arrangement and the counter weight are rotatable in respect to the hub into a certain predetermined position.

Abstract: A direct driven wind turbine includes an electrical generator with a rotor and a stator, a hub constructed to receive a rotor blade, and an actuator device. The hub is connected to the rotor of the electrical generator. The hub and the rotor of the electrical generator are rotatable mounted in respect to the stator of the generator. The actuator device is constructed and arranged to rotate the rotor of the electrical generator and the hub of the wind turbine in respect to the stator of the electrical generator, wherein the actuator device is at least one motor.

Abstract: A system for lifting a blade of a wind turbine is proposed. The system includes a yoke device lifted by a crane, an upper bracket device and a lower bracket device that are mounted to the yoke device for holding the blade. The upper bracket device engages a first section of the blade and the lower bracket device engages a second section of the blade. The lower bracket device is movably mounted to the yoke device in such a way that the blade is insertable into the system in an open position of the lower bracket device. The lower bracket device is movably mounted to the yoke device in such a way that the blade is spatially fixed by both the upper bracket device and the lower bracket device in a closed position of the lower bracket device.

Abstract: An arrangement and a method of rotating a hub of a wind turbine are provided. A wind turbine includes a hub mounted to a nacelle, whereby the hub is rotatable around an axis of rotation in respect to the nacelle. A rotor blade is arranged at the hub that leads to a torque around the axis of rotation of the hub. A counter weight is attached to the hub, whereby the counter weight has a mass that leads to a counter-torque around the axis of rotation. The counter-torque interacts with the torque during the installation of a second rotor blade to the hub. The counter weight is mounted to the hub by a mechanical arrangement that is rotatable in respect to the hub around the axis of rotation of the hub. The mechanical arrangement and the counter weight are rotatable in respect to the hub into a certain predetermined position.

Abstract: A direct driven wind turbine includes an electrical generator with a rotor and a stator, a hub for receiving a rotor blade, and actuator device. The hub is connected to the rotor of the electrical generator, and the hub and the rotor of the electrical generator are rotatable mounted in respect to the stator of the generator. The actuator device is constructed and arranged to rotate the hub of the wind turbine in respect to the stator of the electrical generator. The actuator device is the electrical generator, wherein the electrical generator of the wind turbine is used as a motor to rotate the hub of the wind turbine.

Abstract: A system for lifting a blade of a wind turbine is proposed. The system includes a yoke device lifted by a crane, an upper bracket device and a lower bracket device that are mounted to the yoke device for holding the blade. The upper bracket device engages a first section of the blade and the lower bracket device engages a second section of the blade. The lower bracket device is movably mounted to the yoke device in such a way that the blade is insertable into the system in an open position of the lower bracket device. The lower bracket device is movably mounted to the yoke device in such a way that the blade is spatially fixed by both the upper bracket device and the lower bracket device in a closed position of the lower bracket device.

Abstract: A clamp for clamping a blade for a wind turbine is provided. The clamp includes a first contact surface adapted to contact a portion of a surface of the blade and a second contact surface adapted to contact another portion of the surface of the blade. The second contact surface is displaceable relative to the first contact surface. The clamp also includes a bar connected in an adjustable orientation relative to the first contact surface. Further, a method of installing wind turbine blades at a hub rotatable around a rotation axis along a horizontal direction is provided.

Abstract: A tower segment erection tool having a frame with a first side, a second side showing in the opposite direction than the first side and a holding mechanism for holding the frame with its first side at the bottom of a tower segment to be erected. A first support element adjoins the frame's second side such that it is located substantially under a section of the tower segment's peripheral wall when the tool is attached to the tower segment to be erected. The first support element has a curved surface allowing a rolling motion of the tower segment erection tool A second support element adjoins the frame's second side and has a foot that is spaced from the curved surface of the first support element such that it is located substantially in the tower segment's centre axis and that it is further away from the tower segment's bottom in a direction parallel to the tower segment's centre axis than the curved surface when the tower segment erection tool is attached to the tower segment to be erected.

Abstract: A tower segment erection tool having a frame with a first side, a second side showing in the opposite direction than the first side and a holding mechanism for holding the frame with its first side at the bottom of a tower segment to be erected. A first support element adjoins the frame's second side such that it is located substantially under a section of the tower segment's peripheral wall when the tool is attached to the tower segment to be erected. The first support element has a curved surface allowing a rolling motion of the tower segment erection tool A second support element adjoins the frame's second side and has a foot that is spaced from the curved surface of the first support element such that it is located substantially in the tower segment's centre axis and that it is further away from the tower segment's bottom in a direction parallel to the tower segment's centre axis than the curved surface when the tower segment erection tool is attached to the tower segment to be erected.