The invention relates to a method of prolonging pitch bearing lifetime for a wind turbine as well as the pitch bearing itself. The method comprises the steps of: stopping the rotor (4) from rotating; removing a plurality of first fastening means used for mounting the blade (5) to the outer bearing ring (24); mounting a strengthening arc structure (10) on said outer bearing ring (24), opposite the blade (5); installing a plurality of second fastening means, thereby connecting said blade (5) and said strengthening arc structure (10) to said outer bearing ring (24).

The invention relates to a method for handling a load, in particular a blade, of an offshore wind turbine system comprising a wind turbine, wherein a crane is temporarily mounted on the platform, the crane having a tower of which a plurality of elements can be telescoped relative to each other. The invention also relates to a crane and to devices suitable for carrying out this method.

The present disclosure relates to devices for wind turbine blades and methods for reducing vibrations in wind turbines with a rotor in standstill. A device comprises a portion configured to protrude beyond a leading edge of the wind turbine blade. A device comprising a portion configured to protrude beyond the leading edge of the wind turbine may be releasably attached around a wind turbine blade substantially along a chordwise direction. The device may be detached from the blade before the wind turbine starts to operate.

A wind turbine blade is provided, including a hollow blade body with a blade root and a base plate arranged at a root-side end section of the blade, which base plate includes a manhole through which the interior of the blade is accessible, wherein the base plate is provided with mounting means arranged at the or adjacent to the manhole and adapted to directly or indirectly mount at least one ladder to the base plate.

Disclosed is a method for lifting and lowering blades without using a crane, which uses an aligning and inserting device to solve the problem caused by the tilt and coning of the first/last 200-400 mm of the blade. The device comprises at least one hoist (4) and a pair of cables (5) coordinated by a pulley (10) and screwed to a bearing (12) by means of connecting elements at the ends thereof. The cables (5) are screwed diametrically opposite and as close as possible to the centre of gravity (CG) of the blade. After the initial descent, the blade is secured and a stiffening plate (20) is added to the blade root (13), and the lowering device, formed by a drumless hoist (18) and a set of pulleys (19), is used to lower the blade by means of a passing cable (22) joined to the plate (20). A crane disposed on the ground moves an auxiliary sling placed on the tip (23) of the blade and helps to navigate the transition piece (24) and bottom part (25) of a tower.

A robotic maintenance device (40) and method for repairing damage (26) around the leading edge (22) of a wind turbine blade (20) are provided. The maintenance device (40) includes a main chassis (42) that is configured to be mounted on the wind turbine blade (20), an applicator head (46) for applying a coating material (32) onto an exterior surface (30) of the blade (20) to cover and fill in damaged areas (26), and an environmental control module (60). The environmental control module (60) is located proximate the applicator head (46) and includes a tent (62) that selectively deploys over a portion of the leading edge (22) of the blade (20) behind operations of the applicator head (46) to define a curing zone. The coating material (32) within the curing zone can cure on the wind turbine blade (20) to complete the repair while remaining shielded from local environmental conditions such as wind and rain around the wind turbine blade (20). For example, the tent (62) can be configured to extend over a fixed length and move over that length behind the moving robotic maintenance device (40), or the tent (62) can be configured to secure on the blade (20) and be extended as the maintenance device (40) moves and conducts repair operations, with the tent (62) being retractable at the end of the maintenance process.

A system and method for repairing fatigue cracks in a multi-layer composite body. The method includes repairing fatigue cracks at a first interface between a first layer of the multi-layer composite body and a second layer of the multi-layer composite body. The method also includes repairing fatigue cracks at a second interface between the second layer of the multi-layer composite body and a third layer of the multi-layer composite body. The method further includes anchoring the second interface with the third layer of the multi-layer composite body to prevent failure from fatigue cracks.

Provided is a method for repairing a root of a rotor blade of a wind turbine, the root including several bores for receiving a bolt and extending form the root front surface into the blade, wherein at least a part of the front surface blade material surrounding the bore is removed using a removing tool and that at least one shim plate is attached to the processed front surface surrounding the bore.

A drive track (38) for a vehicle includes a frame (80), a drive pulley (86) rotatably coupled to the frame (80) and coupled to a drive (92), an idler pulley (88) rotatably coupled to the frame (80), and a track wheel (96) disposed about the frame (80). The track wheel (96) includes a continuous belt (98) and a plurality of link assemblies (100) coupled to the belt (98). Each link assembly (100) includes a plurality of alignment elements (102) configured to engage with a surface. The alignment elements (102) are configured such that rotation of the belt (98) defines a first movement direction of the vehicle, and are further configured to permit movement of the vehicle in a second movement direction perpendicular to the first movement direction under the weight of the vehicle. The vehicle may be a robotic device (34) for repairing a leading edge (26) of a wind turbine blade (20) and the drive track (38) allows the device (34) to remain aligned with the leading edge (26), such as a curved leading edge (26).

In an example there is provided a temporary work platform assembly for installation inside a wind turbine rotor blade. The work platform assembly comprises a platform for supporting a person during service or maintenance of the wind turbine blade, and a support structure for sup-porting the platform. The support structure is adapted for connection to an internal surface of the wind turbine blade. The platform comprises a plurality of panels.