Abstract: A pitch actuator for a wind turbine pitch system, the pitch actuator having an actuator rod, a drive end of which is defined by a clevis fork arrangement having first fork member and a second fork member that extend in a direction along a rod axis and terminate at a tip end. The first and second fork members define respective clevis openings for receiving a clevis pin therethrough, said clevis openings each having an opening perimeter profile comprising: a first perimeter section defined by a leading circular arc that is centred on the rod axis and oriented in the direction of the tip end of the fork members, the circular arc defining a nominal radius and a central angle of less than 120 degrees, and second and third flared perimeter sections that flank respective sides of the first perimeter section, each of which define an enlarged clearance zone with respect to at least part of an imaginary circle defined by the nominal radius of the first perimeter section.

Abstract: A rotor hub for a wind turbine which can be configured between an in use or ‘operational’ configuration and a transportation configuration. In the transportation configuration the rotor hub has a reduced external size compared to when it is in the operational configuration. The rotor hub comprises a generally hollow hub body having a first end and a second end spaced along a hub rotational axis, wherein the first end defines a rotor connection flange configured to connect the rotor hub to a main shaft, and wherein a second end defines a nose region of the hub. The hub also defines at least one blade aperture defined between the first end and the second end, a blade bearing associated with the or each blade aperture, and a pitch actuator associated with the blade bearing.

Abstract: A pitch system for rotating a blade of a wind turbine relative to a hub. The pitch system comprises a blade bearing including an inner bearing ring and an outer bearing ring, wherein the outer bearing ring is rotatable relative to the inner bearing ring, and an actuator system configured to control relative rotational movement between the inner bearing ring and outer bearing ring, comprising. The actuator system comprises a first load transfer beam arrangement spanning at least first and second fixing positions associated with the inner bearing ring, a second load transfer beam arrangement spanning at least first and second fixing positions associated with the outer bearing ring, and a first linear actuator coupled between the first load transfer beam arrangement and the second load transfer beam arrangement. A benefit of the pitch system of the invention is that it achieves a reduction in mass yet retains a stiff connection between the hub and an associated blade.

Abstract: A pitch actuator for a wind turbine pitch system, the pitch actuator having an actuator rod, a drive end of which is defined by a clevis fork arrangement having first fork member and a second fork member that extend in a direction along a rod axis and terminate at a tip end. The first and second fork members define respective clevis openings for receiving a clevis pin therethrough, said clevis openings each having an opening perimeter profile comprising: a first perimeter section defined by a leading circular arc that is centred on the rod axis and oriented in the direction of the tip end of the fork members, the circular arc defining a nominal radius and a central angle of less than 120 degrees, and second and third flared perimeter sections that flank respective sides of the first perimeter section, each of which define an enlarged clearance zone with respect to at least part of an imaginary circle defined by the nominal radius of the first perimeter section.

Abstract: A rotor hub for a wind turbine which can be configured between an in use or ‘operational’ configuration and a transportation configuration. In the transportation configuration the rotor hub has a reduced external size compared to when it is in the operational configuration. The rotor hub comprises a generally hollow hub body having a first end and a second end spaced along a hub rotational axis, wherein the first end defines a rotor connection flange configured to connect the rotor hub to a main shaft, and wherein a second end defines a nose region of the hub. The hub also defines at least one blade aperture defined between the first end and the second end, a blade bearing associated with the or each blade aperture, and a pitch actuator associated with the blade bearing.

Abstract: Wind turbine pitch actuator mounting structure A mounting structure is described for attaching a pitch actuator to a hub of a wind turbine. The mounting structure has one or more legs each having a proximal end and a distal end, and a flexible intermediate portion between the proximal and distal ends. The mounting structure further comprises an actuator attachment portion for attaching to a wind turbine blade pitch actuator. The actuator attachment portion is arranged at the distal end(s) of the one or more legs. The proximal end(s) of the one or more legs are configured for attachment to a wind turbine hub. The flexible intermediate portion(s) of the one or more legs are configured to flex in use to absorb loads acting on the pitch actuator. The mounting structure therefore allows the pitch actuator to pivot in a first plane by virtue of the flexible legs.

Abstract: A drive assembly for adjusting the pitch of a wind turbine blade comprises a stator having a cylindrical body and a drive member positioned at least partially within the cylindrical body and movable along an axis thereof. A mounting pin extends through an aperture in a wall of the cylindrical body for pivotally mounting the stator to a wind turbine structure.

Abstract: Wind turbine pitch actuator mounting structure A mounting structure is described for attaching a pitch actuator to a hub of a wind turbine. The mounting structure has one or more legs each having a proximal end and a distal end, and a flexible intermediate portion between the proximal and distal ends. The mounting structure further comprises an actuator attachment portion for attaching to a wind turbine blade pitch actuator. The actuator attachment portion is arranged at the distal end(s) of the one or more legs. The proximal end(s) of the one or more legs are configured for attachment to a wind turbine hub. The flexible intermediate portion(s) of the one or more legs are configured to flex in use to absorb loads acting on the pitch actuator. The mounting structure therefore allows the pitch actuator to pivot in a first plane by virtue of the flexible legs.

Abstract: Pitch cylinders for adjusting a pitch angle of a blade, methods of assembling pitch cylinders, and the use of pitch cylinders in wind turbines are disclosed. The pitch cylinder includes a cylinder barrel having a first thread with a first pitch, a piston arranged in and extending out of the cylinder barrel for coupling to a blade or hub, and a trunnion to couple the cylinder barrel to the other of the blade or hub. The cylinder barrel extends through the trunnion. The trunnion has a first thread with a second pitch different from the first pitch, and a sleeve arranged between the trunnion and the cylinder barrel that extends through the sleeve. The sleeve has an inner sleeve thread with the first pitch engaged with the first cylinder barrel thread and an outer sleeve thread with the second pitch engaged with the first trunnion thread.

Abstract: A drive assembly for adjusting the pitch of a wind turbine blade comprises a stator having a cylindrical body and a drive member positioned at least partially within the cylindrical body and movable along an axis thereof. A mounting pin extends through an aperture in a wall of the cylindrical body for pivotally mounting the stator to a wind turbine structure.

Abstract: The present disclosure relates to wind turbines, pitch adjustment cylinders for adjusting a pitch angle of a blade of a wind turbine, to methods of assembling pitch adjustment cylinders, and to use of pitch adjustment cylinders in wind turbine, wherein the pitch adjustment cylinder comprises a cylinder barrel having an first cylinder barrel thread with a first thread pitch, a piston arranged movably in the cylinder barrel and extending out of the cylinder barrel for coupling to one of the blade and a hub of the wind turbine, a trunnion adapted to couple the cylinder barrel to the other one of the blade and the hub of the wind turbine, wherein the cylinder barrel extends through the trunnion, the trunnion has an first trunnion thread with a second thread pitch being different from the first thread pitch; and a sleeve arranged at least partially between the trunnion and the cylinder barrel, wherein the cylinder barrel extends through the sleeve, the sleeve has an inner sleeve thread with the first thread pitch

Abstract: A wind turbine comprises a hub, a blade rotatably mounted to the hub, and a pitch system. The pitch system includes a support, a first drive configured to rotate the blade relative to the support, a second drive configured to rotate the support relative to the hub. The support is configured to be selectively fixed relative to the blade and the hub such that the first or second drive may be used to pitch the blade. A method of pitch corresponding to this operation is provided.

Abstract: A wind turbine comprises a hub, a blade rotatably mounted to the hub, and a pitch system. The pitch system includes a support, a first drive configured to rotate the blade relative to the support, a second drive configured to rotate the support relative to the hub. The support is configured to be selectively fixed relative to the blade and the hub such that the first or second drive may be used to pitch the blade. A method of pitch corresponding to this operation is provided.