A robot (4) to bolt down a series of nut bolts (5) in a joint circular flange connection (18) of a wind turbine (1), which robot (4) comprises at least two wheels (12) and a drive (8) to transport the robot (4) along the series of nut bolts (5) and a tool (7) to bolt down a nut bolt (5) with a predefined torque and a position sensor (11) to position the tool (7) above the nut bolt (5) to be bolted down and a robot control system (17) to control the tightening process and document parameters relevant for the stability of each bolted down nut bolt (5).

The present invention relates to a wind turbine and to a method for installing a generator for a wind turbine, said wind turbine comprising a nacelle being installed on top of a tower and comprising a mainframe for installation of e.g. a generator and a main shaft. The nacelle further comprises a nacelle cover extending over said main frame from the hub and to a rear end, covering components installed on the main frame. The nacelle cover according to the invention comprises at least a first part and a second part, said first part having a interface for engagement with a corresponding interface on said second part, where said second part of the nacelle cover is housing a generator, and where said generator and said second part of a nacelle cover is construed as one unit. By having the generator and the second part of the nacelle cover as a single unit, installation can be done in one go and then only one hoist with a crane is needed.

The invention relates to a method to rotate the rotor 9 of a wind turbine 1 and to means to be used in this method.

A direct driven wind turbine 1 comprises an electrical generator 3 with a rotor 9 and a stator 10, a hub 4 constructed to receive a rotor blade 6 and actuator means. The hub 4 is connected to the rotor 9 of the electrical generator. The hub 4 and the rotor 9 of the electrical generator 3 are rotatable mounted in respect to the stator 10 of the generator 3. The actuator means are constructed and arranged to rotate the rotor 9 of the electrical generator 3 and the hub 4 of the wind turbine 1 in respect to the stator 10 of the electrical generator 3, wherein the actuator means is at least one motor 13.

Rotor blade (1) for a wind turbine, having an elongate blade base body with a number of connecting elements (4) each comprising at least one axially extending connecting portion (5) adapted to be connected with at least one corresponding connecting portion of a rotor hub of a wind turbine, wherein the respective connecting elements (4) are connected to at least two circumferentially extending connecting members (3) with the connecting members (3) being adjacently disposed in circumferential direction so as to build a ring-like shape.

The present invention provides a nacelle main frame structure and drive train assembly (1) for being mounted on a tower (2) of a wind turbine. The nacelle main frame structure and drive train assembly (1) comprises a nacelle main frame structure (4) comprising a central part (6) connecting a first part (7) which, during wind turbine operation and/or servicing activities, takes up loads of a rotor (9) supported by that first part (7), to a second part (8) which connects the nacelle main frame structure (4) to the tower (2) of the wind turbine in a rotatable manner around a vertical axis of the tower (2). The nacelle main frame structure and drive train assembly (1) furthermore comprises a drive train (5) of which at least part is located between the first part (7) and the second part (8) of the nacelle main frame structure (4). The central part (6) of the nacelle main frame structure (4) is located substantially above at least part of the drive train (5) and is such that at least part of the drive train (5) can only be removed from the nacelle main frame structure (4) by lowering at least part of the drive train (5) from the nacelle main frame structure (4).

The invention discloses a steel tower (8) for a wind turbine having a plurality of segments (12, 14, 16, 18, 20, 22) arranged above each other. The segments may comprise steel having different quality. The quality of the steel may be determined by the yield limit of the steel.

The invention relates to a method for positioning an airship at a wind turbine generator. The method comprises the step of docking the airship at the wind turbine generator with a forwards docking section, a rearwards docking section, a sideways docking section, or an upwards docking section of the airship being connected to the wind turbine generator. Docking of the airship may be performed at one of the following components of the wind turbine generator: the nacelle, the hub, the tower, one or more of the blades, the foundation, or a substation of the wind turbine generator. The invention also relates to use of an airship for being connecting to a wind turbine generator and for loading or unloading wind turbine generator components or personnel to or from the wind turbine generator.

The present invention relates to an assembly stand and an assembly method for assembling a gear unit and a main shaft unit of a wind turbine. The assembly stand comprises a main shaft frame unit and a gear frame unit arranged on a base frame, wherein both frame units comprises adjustment means for adjusting the position of the main shaft unit and the gear unit in at least a horizontal or vertical direction. The main shaft unit and the gear unit are aligned by using a light source emitting a light beam onto removable guiding elements. The main shaft unit is positioned on a slidable seat and pulled into contact with the gear unit by pulling elements located on a moveable unit. The pulling element is connected to the gear unit via a wire extending through the main shaft unit.