Abstract: A method for manufacturing a pitch bearing or a yaw bearing for a wind turbine includes forming an outer race of the bearing of a base material. The method also includes forming an inner race of the bearing of the base material. Further, one of the inner race or the outer race defines a circumferential surface comprising a plurality of gear teeth. The method further includes arranging the inner race within the outer race. In addition, the method includes providing a plurality of roller elements between the outer and inner races. Moreover, the method includes applying a coating material to at least a portion of the plurality of gear teeth via an additive manufacturing process. The coating material is different than the base material. As such, the coating material provides at least one of increased hardness, strength, or durability to the base material.

Abstract: Apparatus, systems, and methods are contemplated for electric powered vertical takeoff and landing (eVTOL) aircraft. Such are craft are engineered to carry safely carry at least 500 pounds (approx. 227 kg) using a few (e.g., 2-4) rotors, generally variable speed rigid (non-articulated) rotors. It is contemplated that one or more rotors generate a significant amount of lift (e.g., 70%) during rotorborne flight (e.g., vertical takeoff, hover, etc), and tilt to provide forward propulsion during wingborne flight. The rotors preferably employ individual blade control, and are battery powered. The vehicle preferably flies in an autopilot or pilotless mode and has a relatively small (e.g., less than 45? diameter) footprint.

Abstract: A cage for a stacked I/O connector that provides heat dissipation sufficient to support operation of QSFP-DD transceivers with a conventionally-sized cooling fan. The cage includes a second channel, between a first and a third channel that are sized and positioned adjacent ports of a connector so as to receive two transceivers. A face of the second channel may have a pattern of openings that enables a high airflow yet blocks electromagnetic radiation that would otherwise contribute to EMI. An element, adjacent the channel that similarly has a pattern of holes enabling high airflow, may further block EMI.

Abstract: Rotor restraining and rotating apparatus and methods for a wind turbine (1) are described. An apparatus (200) has a rotatable control element (204) associated with a rotor (8, 203) of the wind turbine, the control element being at least part-circular in form, the control element comprising a plurality of engagement formations (205) disposed on a periphery thereof. The apparatus also has a control member (206), comprising a plurality of engagement formations (207). The control member is movable (208) in a first degree of freedom between: (a) a non-restraining position; and (b) a restraining position in which the control member engagement formations are able to engage the control element engagement formations to restrain rotation of the control element. The control member is also movable (209) in a second degree of freedom.

Abstract: This disclosure relates to a drivable working machine, including a vehicle, a concrete placing boom that can be rotated on a vehicle-fixed carrying structure by means of a slewing gear, and a plurality of supporting legs arranged on the carrying structure for supporting the carrying structure in a working position. A compensation device is provided to compensate a rotational deflection of the carrying structure from the working position. The compensation device has a sensing unit for sensing the rotational deflection and acts on at least one supporting leg by means of an associated actuator to reduce the rotational deflection.

Abstract: A turbofan engine (300; 600; 700) comprising a fan shaft (120) configured to rotate about an axis (500) of the engine. A fan drive gear system (60) is configured to drive the fan shaft. The fan drive gear system has a centerplane (540). A first spool comprises a high pressure turbine (326) and a high pressure compressor (324). A second spool comprises an intermediate pressure turbine (328), a lower pressure compressor, and a shaft (334) coupling the intermediate pressure turbine to the lower pressure compressor. A third spool comprises a lower pressure turbine (330) coupled to the fan drive gear system to drive the fan. The engine has a plurality of main bearings. The turbofan engine has a single stage fan. Of the main bearings, at least one is a shaft-engaging bearing engaging a driving shaft (336) coupled to the fan drive gear system. A closest (340; 640) of the shaft-engaging bearings engaging the driving shaft behind the fan drive gear system has a centerplane (550) and a characteristic radius (RB).

Abstract: An engine includes systems for changing the pitch of propeller blades, a system for an upstream propeller including a linear actuator and a transmission mechanism connecting the actuator to the blades to transform the sliding of the actuator into a rotation of the blades, the upstream propeller including a rotatable housing rigidly connected to a rotatable shaft supported in a static housing of the turbine engine by an upstream bearing and by a downstream bearing. The rotatable housing of the upstream propeller includes a support rigidly connected to the rotatable housing and surrounding the static housing. The actuator is annular and fixed outside to the support, the transfer mechanism includes connecting rods and rotatable radial arms traversing the gaseous flow path, and the downstream bearing is radially located between the static housing and the support.

Abstract: A hydraulic system for controlling orientation of fan blades in a turbine engine including at least one set of adjustable pitch fan blades actuated by actuators that are connected to a hydraulic pump, and a small pitch protection valve controlled by an associated solenoid valve to make it possible on the ground, when the orientation of the blades is substantially perpendicular to the axis of the turbine engine, to pass from a first operating zone in which a speed of pitch variation of the blades is low to a second operating zone in which a speed of pitch variation is considerably higher, wherein operating pressure of the hydraulic pump is controlled by the solenoid valve controlling the small pitch protection valve to define two outlet levels corresponding to the two operating zones.

Abstract: A pitchlock system includes a ballscrew screw mounted along an axis of rotation of an actuator, the ballscrew screw has an internal ballscrew bore; a pitchlock nut mounted about the ballscrew screw, the pitchlock nut including an internal pitchlock nut thread; a ballscrew ballnut mounted about the ballscrew screw and axially adjacent the pitchlock nut; a pitchlock actuation rod mounted axially within the internal ballscrew bore, the pitchlock actuation rod having an internal pitchlock actuation bore and a ball bearing aperture for receiving multiple ball bearings; a pitchlock retainer pin mounted axially within the internal pitchlock actuation bore; and a belleville spring which biases the ballscrew screw towards an axially fixed surface of the actuator in a pitchlock position, the ballscrew screw being movable between an operational position and the pitchlock position.

Abstract: The invention relates to a sealing device for the partition penetration of a connecting rod of a turboprop fan blade orientation control system. The device includes a bellows (60) of trunconical shape designed to allow passage of the connecting rod (50a) and having, at its wider end, means (62, 64) of attachment to the partition (58) to be sealed and, at its narrower end, an O-ring through which the connecting rod is free to slide.

Abstract: A partial pitch wind turbine blade in which the pitch system of the blade functions as a lightning receptor. As the pitch system is of a relatively large dimension, it is able to dissipate the effects of a lightning strike without damage, and removes the needs for additional blade features normally used to conduct lightning around or away from the pitch system.

Abstract: A device for controlling orientation of fan blades of a turboprop including at least one set of fan blades having adjustable orientation attached in rotation to a rotating ring mechanically connected to a turbine rotor. Each blade of the set is coupled to a blade root support pivotably mounted on the rotating ring by a conical gear train including a first gear wheel attached to the blade root support and a second gear wheel attached to the rotating ring and bearing a counterweight that is eccentric with respect to its axis of rotation. A cylinder attached in rotation to the turbine rotor and a rod of which is connected to each counterweight through a connecting arm makes it possible to impart synchronous angular displacement to all the counterweights about the axis of rotation of their respective gear wheel.

Abstract: A partial pitch wind turbine is described wherein the wind turbine blade has an inner blade section designed for stall-controlled operation and an outer blade section designed for pitch-controlled operation. The different blade profiles for the different sections allow for the efficient operation of the blade while providing for the control of the wind turbine to effectively reduce blade root moments. The outer blade sections can be pitched out of the wind to reduce root moments due to the outer blade sections, while the increasing power capture of the inner blade section maintains nominal power output.

Abstract: A wind turbine blade is configured such that the lift force from the blade airfoil is always normal, or nearly normal, to the shaft torque. This condition maximizes energy conversion. This objective may be achieved by a) having the airfoil chord always aligned to the actual wind direction (subject only to small angle of attack variations), and b) slowing the turbine rotation rate so that no blade twist is needed. As a result, blade tip speed due to shaft rotation is less than the wind speed, and preferably much less. This low tip speed eliminates any hazard to birds. The lift force from the blade airfoil directly drives the torque on the shaft, so the control problem simplifies to adjusting the blade angle of attack to keep the lift constant across varying wind speeds.

Abstract: An electrical energy generating device for a propfan-type aircraft propulsion unit rotor. The propulsion unit includes a turbomachine that drives in rotation at least one rotor including a plurality of blades arranged around an annular crown moving with the blades, which forms with its outer wall part of an outer envelope of the propulsion unit, the outer envelope being subjected to atmospheric conditions outside the propulsion unit. The turbomachine generates a flow of hot gases that exit via an annular hot vein, which is concentric with the moving annular crown, and defined for part of its surface by an inner wall of the moving annular crown, and includes, within the moving annular part, a mechanism to transform thermal energy into electrical energy, preferably by thermal diodes. Such a device, as an example, can find application to a device for controlling a pitch of rotors of a propfan-type propulsion unit.

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 ram air turbine (RAT) in which a cam follower is operably coupled to turbine blades such that a cam follower position determines turbine blade pitch.

Abstract: The invention is based on the problem of creating an additional device to act as a “secondary emergency device” in the case that one or more standard emergency devices fail to adjust the blade angle of one or multiple rotor blades into a position of power limitation. The method of braking a wind turbine in an emergency by adjusting the rotor blades for wind turbines with power control via the principle of pitch control or active stall control and of holding the position of a rotor blade for each rotor blade with at least one actuator and at least one holding brake is a redundant measure for an emergency. This enables one or more holding brakes to open depending on the rotor-blade direction that is required and to close or to be kept closed when an adjustment of a rotor-blade direction is not desired.

Abstract: A hydraulic system for controlling orientation of fan blades in a turbine engine including at least one set of adjustable pitch fan blades actuated by actuators that are connected to a hydraulic pump, and a small pitch protection valve controlled by an associated solenoid valve to make it possible on the ground, when the orientation of the blades is substantially perpendicular to the axis of the turbine engine, to pass from a first operating zone in which a speed of pitch variation of the blades is low to a second operating zone in which a speed of pitch variation is considerably higher, wherein operating pressure of the hydraulic pump is controlled by the solenoid valve controlling the small pitch protection valve to define two outlet levels corresponding to the two operating zones.

Abstract: An operating method for a two-bladed wind turbine which comprises a rotor including two blades and a hub to which the two blades are coupled, the operating method includes a pitch-angle adjusting step of adjusting pitch angles of the two blades such that chords of the two blades are substantially parallel to a perpendicular direction to a rotational plane of the rotor during violent wind and a rotor holding step of holding the rotor at an azimuth angle such that the two blades are substantially parallel to a horizontal direction during the violent wind.

Abstract: A method of deploying offshore wind turbine assemblies includes mounting a wind turbine assembly horizontally on a vessel and transporting the wind turbine assembly to an offshore site. The wind turbine assembly is raised to a vertical condition at the site and attached to anchor weights. Blades are attached to the turbine head after the wind turbine assembly is in the vertical condition. In one embodiment, the wind turbine assembly can include a tower including tapered lower and upper sections joined together at their respective wide ends, a turbine head connected to the upper section, and a platform connected to the lower section. The platform includes a buoy tank partially filled with ballast to provide mass and buoyancy. A wave piercing cowling is rotatively attached to the lower section. The turbine head can include an adjustable journal bearing, scabbard blade mounts, and a gearless induction generator with flux adjusting capabilities.

Abstract: A rotorcraft including a fuselage, one or more motor-driven rotors for vertical flight, and a control system. The motors drive the one or more rotors in either of two directions of rotation to provide for flight in either an upright or an inverted orientation. An orientation sensor is used to control the primary direction of thrust, and operational instructions and gathered information are automatically adapted based on the orientation of the fuselage with respect to gravity. The rotors are configured with blades that invert to conform to the direction of rotation.

Abstract: The present application includes a blade-pitch control system with an indexing swashplate. A swashplate assembly has a non-rotating portion and a rotating portion and an indexing portion of the mast. The swashplate assembly is translatably affixed to the indexing portion. A pitch link connects the rotating portion of the swashplate assembly to each blade. Translation of the swashplate assembly along the indexing portion causes a change in pitch of the blades and a corresponding indexing of the rotating portion of the swashplate assembly relative to the mast, the indexing causing a change in an angular orientation of each pitch link, thus providing for selected pitch-flap coupling between flapping motion of the yoke and pitch motion of the blades.

Abstract: Wind turbine rotor comprising a hub, a plurality of blades, at least one pitch system for rotating a blade substantially along its longitudinal axis and at least one pitch retention system, wherein a pitch retention system comprises a cam profile and a cam follower, and one of the hub and a blade comprises said cam profile and the other of the hub and blade comprises said cam follower, and wherein the cam follower comprises a pushing member and a contact member, wherein the pushing member is arranged to push the contact member towards the cam profile, and the cam profile comprises a local depression, and wherein the cam follower and cam profile are arranged such that when the blade is in a pitch position at or below nominal wind speed, the contact member can be retained in said local depression.

Abstract: A device for locking a rotor blade of a wind turbine which has an adjustment system for the blade pitch angle of the rotor blade, wherein the adjustment system has a drive which features a motor and a gearbox with an input shaft that bears an external toothing, characterized by a locking pin rotatably mounted around its longitudinal axis, which engages with the external toothing in a locking position, and releases the external toothing in an unlocked position, wherein the locking pin has an end portion whose free end stands eccentric to the longitudinal axis of the locking pin.

Abstract: The main subject matter of the invention is a device (1) for setting a turbomachine propeller blade (2), characterised in that it comprises a first disc (3) and a second disc (4) respectively provided with first (5) and second (6) coupling means, the first (3) and second (4) discs being coaxial, means of tilting (9, 10, 11, 12) at least one of the first (3) and second (4) discs with respect to the other, the device (1) being configured so that, during a tilting of at least one of the first (3) and second (4) discs with respect to the other, the coupling distance (D) of said at least one blade (2) on the first (3) and second (4) discs remains constant, bringing about the rotation of said at least one blade (2).

Abstract: A wind turbine blade pitch angle adjusting apparatus for adjusting the pitch angle of a blade of a wind turbine is provided. The apparatus includes an electric pitch motor able to output a maximum motor torque Tm and a pitch brake assembly able to generate a maximum brake assembly torque Tb. The pitch brake assembly includes a plurality of individual pitch brakes each able to generate a maximum individual brake torque Tsb, the maximum brake assembly torque Tb is the sum of all maximum individual brake torques Tsb, and the maximum motor torque Tm is higher than the maximum individual brake torque Tsb of any one of the pitch brakes.

Abstract: A pitch lock system for a wind turbine with a rotor, at least one pitchable blade and a interface having a pitch bearing system with a first bearing ring, a second bearing ring and a pitch drive installed at a support plate at a structural part connected to the first bearing ring and interacting with teeth on a toothed element, where the toothed element is in fixed connection with the second bearing part. The pitch lock system has at least a base plate and an arrangement for fastening the base plate indirectly to the first bearing ring and a locking pawl that can be fasten to the base plate with an element on the locking pawl interacting with the toothed element.

Abstract: A variable pitch propulsor system with a propeller pitchlock system having a pitchlock solenoid valve located in communication with a pitchlock pressure circuit to selectively actuate pitchlocking in response to a controller. The pitchlock solenoid valve includes an electro-mechanical device which is normally closed but may be commanded to electrically open and dump the pitchlock pressure which causes actuation of the pitchlock system. The pitchlock solenoid provides a mechanism which will selectively pitchlock the propulsor system; permits a built in test routine to determine the condition of the pitchlock system through a commanded propeller pitchlock sequence; requires no mechanical link between the rotating and non-rotating propeller components to initiate pitchlock; is independent of engine and gearbox configurations; and can initiate pitchlock remotely with a signal from a remote location.

Abstract: A hydraulic lock system includes a spring pack defined between a female spring support and a male spring support, the spring pack includes a multiple of serrated washers, each of which defines an inner diameter which is greater than a diameter of the actuator rod and an outer diameter greater than an inner diameter of the cylinder.

Abstract: A blade pitch control mechanism for a propeller assembly (10) includes an actuation shaft (24) having a spherical member (28) located at a propeller axis (22). A yoke (40) is located around the spherical member (28) and is rotatable thereon about a yoke tilt axis (62) substantially perpendicular to the propeller axis (22). The yoke (40) includes a plurality of propeller blade attachments (44), each receptive of a propeller blade (14). The plurality of blade attachments (44) are configured such that rotation of the yoke (40) about the yoke tilt axis (62) results in rotation of each propeller blade (14) about a blade pitch change axis (48).

Abstract: Wind turbine rotor comprising a hub, a plurality of blades, and at least one pitch system for rotating a blade substantially along its longitudinal axis and comprising one or more pitch brakes, wherein a pitch brake comprises at least a brake disc element and a first brake pad, and wherein one of the hub and a blade comprises said brake disc element and the other of the hub and blade comprises said first brake pad, the brake disc element and brake pad being arranged such that when the blade is substantially in or near the below rated so pitch position the brake disc element and pad are in frictional contact with each other.

Abstract: The object of the invention is to construct a horizontal-axis wind turbine comprising a dual-system pitch drive unit for one blade that is independent up to the transmission mechanism or a dual-system yaw drive unit for one wind turbine nacelle that is independent up to the transmission mechanism, and to provide the dual system with new applicability. The horizontal-axis wind turbine of the present invention has a hub 1 and a blade 2 that are connected by way of an interposed section 5b, 6b, 7 which can freely rotate around the pitch axis of the blade with respect to both the hub and the blade; and further comprises: a hub-side interposed section drive unit 10 that relatively rotates the interposed section with respect to the hub, and a blade-side interposed section drive unit 11 that relatively rotates the blade with respect to the interposed section.

Abstract: In the case of a variable-pitch propeller or repeller according to the invention, the pitch-adjusting device is arranged in the hub and formed in such a way that it allows only a numerically limited number of different blade pitches, preferably just two blade pitches, for which purpose the pitch-adjusting device comprises an electrical drive device, for moving the blades from a first blade pitch to a second of the numerically limited number of blade pitches, and an electrically actuable locking device, for locking the blades in the numerically limited number of different blade pitches.

Abstract: A system and method for pitching a rotor blade in a wind turbine are disclosed. The method includes collecting in an individual pitch controller for the rotor blade a pitch offset angle relative to a collective pitch angle. The method further includes determining a synchronized pitch offset angle. The method further includes, after an emergency condition occurs, pitching the rotor blade towards the synchronized pitch offset angle.

Abstract: A folding blade assembly for a mobile wind turbine system is disclosed that includes a hub configured to be coupled to a generator and a blade coupled to the hub with a movable joint. The movable joint includes a first member coupled to the hub and including an aperture, a second member coupled to the blade and including an aperture, and a pin extending through the apertures of the first and second members such that the second member is movable relative to the first member about the pin. The movable joint further includes a lock coupled to the first member and the second member and having an engaged position and a disengaged position, where the second member is movable relative to the first member when the lock is in the disengaged position.

Abstract: A wind power generator having a nacelle, which is mounted to an upper end of a support tower, supports in rotary manner a rotor, and is oriented around a rotation axis by an orienting device provided with at least one gearmotor. The gearmotor presents an output gear coupled with a crown gear fixed to the support tower and is hinged to the nacelle so as to rotate around a fulcrum axis, which is substantially parallel to the rotation axis under the thrust of an actuation device.

Abstract: A variable pitch propulsor system with a propeller pitchlock system which utilizes a follower style pitchlock ballscrew screw which tracks the actuator axial stroke. The pitchlock system transfers the propeller yoke loads, from the ballscrew ballnut to the pitchlock nut allowing the propeller to pitchlock; utilizes the same screw thread lead angle for normal ballscrew back driving operation as well as pitch locking capabilities; provides a single ballscrew which is capable of both being back driven by the ballnut and structurally adequate for reacting the blade loads resulting from any flight condition; and minimizes the requirement of additional rotation and torque transferring interfaces between the ballscrew and pitchlock nut.

Abstract: The present invention relates to a control system for a wind turbine, comprising an electrical device that is arranged for being used during normal operation of a wind turbine and a power source that is arranged to be used as an emergency power supply to a blade pitch motor, wherein the blade pitch motor is arranged to test at least one property of said power source. The invention also relates to a method for testing a power source.

Abstract: A method of controlling at least one wind turbine blade during the stopping process of the rotor in a wind turbine system is disclosed. The method optimizes the control velocity of the process in response to one or more feedback values of the system and/or one or more feedback values from the surroundings of the system by altering the angular pitch velocity from 10°/sec during the initial stage of the stopping process to 5°/sec at the final stage of the stopping process. A control system and a wind turbine as well as use hereof are also disclosed.

Abstract: Wind turbine having a rotor, a nacelle frame (13) housing with electrical generation means coupled to the rotor hub (11), braking means and control means of the drive train rotational position, the nacelle frame (13) and the rotor hub (11) having an arrangement for preventing the rotor hub (11) rotation when certain maintenance or assembly activities should be carried out, the arrangement including at least one sliding pin (21) in the nacelle (13), first actuating means (31) for pushing/pulling it axially into/from at least one corresponding hole (23) in the rotor hub (11) and means for allowing vertical and lateral adjustment displacements of the sliding pin (21) so that it can remain concentrically aligned with the hole (23) when it is inserted into it.

Abstract: An electrical energy generating device for a propfan-type aircraft propulsion unit rotor. The propulsion unit includes a turbomachine that drives in rotation at least one rotor including a plurality of blades arranged around an annular crown moving with the blades, which forms with its outer wall part of an outer envelope of the propulsion unit, the outer envelope being subjected to atmospheric conditions outside the propulsion unit. The turbomachine generates a flow of hot gases that exit via an annular hot vein, which is concentric with the moving annular crown, and defined for part of its surface by an inner wall of the moving annular crown, and includes, within the moving annular part, a mechanism to transform thermal energy into electrical energy, preferably by thermal diodes. Such a device, as an example, can find application to a device for controlling a pitch of rotors of a propfan-type propulsion unit.

Abstract: A system for a wind turbine rotor blade, the system includes a pitch system that has a pitch bearing and a wind turbine hub, the bearing being attached to the hub and being attachable to a wind turbine rotor blade, and also including a pitch gear coupled to the pitch system. The pitch gear includes a first discrete segment and one or more other discrete segments, each segment having a plurality of teeth for engaging with and actuator such as a pinion. At least the first segment is held in place by releasable fasteners and extends along the pitch gear by a predetermined amount. The predetermined amount that the first segment extends along the pitch gear is determined based on anticipated wear of the pitch gear.

Abstract: A driving device for a rotor blade of a wind turbine has an asynchronous machine (6) for adjusting the rotor blade, an electrically operable brake (5) disposed at the driving unit for fixing or braking the driving unit and an electrical supplying device (2), via which the asynchronous machine is connectable with a three-phase power supply network. The supplying device comprises a rectifier (21), an inverted rectifier (23) and a direct-voltage intermediate circuit. A direct-voltage regulator (24) is provided which is connected with the intermediate circuit, via which the brake is electrically supplied. By supplying the brake by the intermediate circuit, an additional voltage source for the brake can be spared and the brake can be implemented extremely simply.

Abstract: A link pin exchanging device for a wind turbine generator that can efficiently carry out exchange of the link pin in the rotor hub, and a link pin exchanging method. The link pin exchanging device comprises an actuator for moving the link pin so that the link pin disengages from the link mechanism, and a reaction force receiving member for receiving a reaction force that acts on the actuator, independent from the wall surface of the rotor hub that intersects with the operating direction of the actuator.

Abstract: A method for limiting blade pitch is provided. The method includes providing a brake assembly that is actuatable to limit blade pitch, providing a limit stop assembly including a stop wheel and a traveler movable relative to the stop wheel, and coupling the limit stop assembly to the brake assembly such that the limit stop assembly actuates the brake assembly when the traveler engages the stop wheel.

Abstract: A hydraulic lock system includes a spring pack defined between a female spring support and a male spring support, the spring pack includes a multiple of serrated washers, each of which defines an inner diameter which is greater than a diameter of the actuator rod and an outer diameter greater than an inner diameter of the cylinder.

Abstract: Some general aspects of the invention provide a device (151, 152, 114) for adjustment of a pivotally mounted rotor blade (101) of a wind energy converter. The device comprises a first drive (151) and a second drive (152) that cooperate to turn the rotor blade (101) between an operating position and a feathered position. The device further comprises a first activatable lockout (191) connected to the rotor blade (101), which in an activated state prevents turning of the rotor blade (101) into the operating position, but allows turning of the rotor blade (101) into the feathered position. Under further aspects, the invention provides a wind energy converter comprising the device (151, 152, 114) and a method for adjusting a rotor blade (101), which is pivotally mounted on a rotor hub (103) of a wind energy converter.

Abstract: A method for monitoring wear of a blade pitch brake within a rotor blade pitch control system of a wind turbine is described. The rotor blade pitch control system includes a blade pitch actuator. The method includes engaging the blade pitch brake and measuring a blade pitch displacement while the blade pitch brake is engaged. The method further includes determining a brake wear level based on the measured blade pitch displacement while the blade pitch brake is engaged, and generating a brake wear level output signal corresponding to the brake wear level.

Abstract: A pitch change apparatus is provided for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly. The apparatus has a unison ring which is coaxial with the propeller assembly. The unison ring is movable to drive respective mechanisms for varying the pitch of the blades. The apparatus further has a plurality of pitch lock assemblies circumferentially distributed around the unison ring. Each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades. The pitch lock assembly moves from the free to the locked state when the assembly receives a signal to lock the blades.