A pitch controlled wind turbine (1) comprising a tower (2), a nacelle (3) mounted on the tower (2), a hub (4) mounted rotatably on the nacelle (3), and at least three wind turbine blades (5) is disclosed. Each wind turbine blade (5) extends between a root end (6) connected to the hub (4), and a tip end (7). The wind turbine (1) further comprises at least three blade connecting members (8), each blade connecting member (8) extending between a connection point (9) on one wind turbine blade (5) and a connection point (9) on a neighbouring wind turbine blade (5). The wind turbine blades (5) each comprises an inboard blade part (5a) comprising the root end (6) and an outboard blade part (5b) comprising the tip end (7), the inboard blade part (5a) and the outboard blade part (5b) being connected to each other at a split position (10). The split position (10) is arranged between the root end (6) and the connection point (9).

A method for removing a metal insert from a wind turbine rotor blade part includes providing a wind turbine rotor blade part. The wind turbine rotor blade part includes a fibrous composite material and a metal insert held in the fibrous composite material. The metal insert is configured to fasten the wind turbine rotor blade part to a wind turbine rotor hub or to another wind turbine rotor blade part. A connecting layer is disposed between the metal insert and the fibrous composite material and connects the metal insert to the fibrous composite material in a stable manner. The method further includes weakening the connecting layer such that the connecting layer is connecting the metal insert to the fibrous composite material in a less stable manner, and removing the metal insert from the fibrous composite material.

A method of manufacturing a root ring for a wind turbine blade comprising winding metal sheet material onto a mandrel to form a metal section proximate a hub end of the root ring. Sheet fibre material is also wound onto the mandrel to form a fibre section of the root ring proximate a tipwards end of the root ring. The metal sheet material is interleaved with the sheet fibre material to form a transition section of the root ring between the metal section and the fibre section.

The invention relates to an elastic rotary bearing for two-blade rotors that are used in wind turbines for high load cycles. The invention relates in particular to a new type of rotor hub for, in particular, elastically mounted two-blade rotors of wind turbines into which an elastic rotary bearing is integrated, which in turn is composed of two rotational joint units composed of layer elements and cone elements.

A system for a wind turbine nacelle having a shaft housing, a blade shaft that extends through the shaft housing and is rotatable relative to the shaft housing, a blade holder connected to the blade shaft, and an outer bearing between the blade shaft and the shaft housing includes a conical spring. The conical spring engages a portion of the outer bearing to exert a preload force on the outer bearing. The system further includes a backstop surrounding the blade shaft and having an interference fit with the blade shaft and a pin extending through the blade shaft and the blade holder. The pin is positioned to prevent the blade shaft from moving relative to the backstop.

A method of manufacturing a root ring for a wind turbine blade comprising winding metal sheet material onto a mandrel to form a metal section proximate a hub end of the root ring. Sheet fibre material is also wound onto the mandrel to form a fibre section of the root ring proximate a tipwards end of the root ring. The metal sheet material is interleaved with the sheet fibre material to form a transition section of the root ring between the metal section and the fibre section.

The present invention relates to a root end assembly (100) for incorporating a plurality of fastening members (74) into the root end of a wind turbine blade shell part during a moulding operation. The root end assembly (100) comprises a mounting plate (70) with a plurality of apertures (72) and a plurality of sheath members (83), each sheath member being disposed in a respective aperture of the plurality of apertures (72). Connection members (78) are received in the sheath members (83), and a plurality of said fastening members (74) are releasably attached to a respective connection member of the plurality of connection members (78) such that the fastening members (74) extend substantially normal to a first surface (77) of the mounting plate (70). The apertures (72) are dimensioned for allowing translational movement of the sheath members (83) in the respective apertures (72).

The invention relates to a method for securing a bushing in a blade root of a wind turbine blade according to the preamble of claim 1. The method is known in the state of the art. The known method uses an additional cavity in axial direction of the blade root. The cavities in axial and radial direction are used for accommodation of a T-bolt type bushing. The known method is not suitable for pen-type bushing. The invention has for its purpose to provide a method, which is suitable for securing a pen-type bushing in the blade root, which method can also be used to replace an existing pen-type bushing in a blade root.

A root portion for a wind turbine blade is provided, including: an inner wall, an outer wall, a filler, an inner volume, mounting inserts, and a transversal holding arrangement, wherein the transversal holding arrangement includes at least one inlay beam extending from the inner wall and/or the outer wall into a mounting insert hole of at least one mounting insert for holding the mounting insert in the root portion during operation of the wind turbine blade, and wherein the mounting insert hole is a through hole and the at least one inlay beam extends from the inner wall through the mounting insert hole to the outer wall. A wind turbine blade with the root portion, a method of producing the root portion and a method for modifying a root portion is further provided.

According to a first aspect of the present invention there is provided a method of repowering a horizontal-axis wind turbine The wind turbine comprises a rotor rotatably mounted to a nacelle, the rotor comprising a plurality of used first wind turbine blades connected to a hub, and each blade comprising a blade shell. Each blade extends in a radial direction from a blade root to a blade tip and in a chordwise direction between a leading edge and a trailing edge. The rotor defines a rotor axis and a first rotor diameter. The method comprises increasing the rotor diameter such that the rotor defines a second rotor diameter that is greater than the first rotor diameter. The method further comprises attaching a connecting fixture to each blade, each connecting fixture defining a connection point for connecting a blade connecting member to the blade. The method further comprises connecting a blade connecting member between corresponding connection points of a pair of wind turbine blades such that each blade is connected to at least one other blade by a blade connecting member.