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: A system of counter-rotating propellers for an aircraft turbine engine including a first and a second propeller, each including a stalling control system for the blades, a rotating actuating mechanism for sliding an element to move the angle of attack of the blades, and a disengaging mechanism for rigidly fixing in rotation the rotating actuating mechanism. The system is designed so that when the disengaging mechanism is engaged, a relative rotation speed is created between the elements and the associated rotating actuating mechanism thereof, bringing the blades into a neutral position thereof for feathering.

Abstract: A pitch drive apparatus of a wind generator is made with a simple structure, and the wind generator is capable of preventing reliability of the pitch drive apparatus from being deteriorated. The wind generator includes a wind turbine rotor blade having a blade root mounted so as to be turnable around an axis center O with respect to a rotor head, and a pitch drive apparatus for turning and driving the wind turbine rotor blade around the axis center O to change a pitch angle thereof. The pitch drive apparatus has an electric cylinder functioning as a linear actuator.

Abstract: A wind turbine for generating electrical power, the turbine having a rotor assembly comprising a hub, a rim and a plurality of blade members extending between the hub and rim, and at least two anemometers mounted at stationary locations relative to the rotor assembly or on the rotor assembly itself, wherein the pitch of individual blade members is adjustable in response to differences in wind speed detected by the anemometers as the rotor assembly rotates.

Abstract: A system for actively controlling the span-wise rotational twist of a hollow beam along its longitudinal axis, including a hollow beam structure having a leading edge and a trailing edge region, the beam being split along its length, an actuator arranged between split surfaces of the beam, the actuator adapted to move the split surfaces in a longitudinal direction relative to each other, inducing a twist in the beam. The hollow beam is affixed to an external structure at one or both ends, with only the zero warping displacement points of the beam being attached to the external structure, material or device. In one embodiment, the actuator is a plurality of solid blocks with high thermal expansion coefficients arranged between frames of the split surfaces of the beam, with alternating blocks being heated by resistance heaters to cause expansion in the spanwise longitudinal direction.

Abstract: An actuator device for actuating a swivel-mounted member carried by a rotor of a propulsion engine including: at least one electricity source; an electric actuator for swiveling the swivel-mounted member; a power supply circuit connecting the electricity source to the actuator; and an inertial device connected to the power supply circuit, the inertial device configured to convert electrical energy coming from the power supply circuit into mechanical energy, to store the mechanical energy, and to convert the mechanical energy into electrical energy for the power supply circuit.

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: The invention relates to a rotary connection of a rotor blade (2) to the rotor hub (3) of a wind energy plant, having a rotary mounting which is configured as a large anti-friction bearing (4) with a bearing inner ring (5) and a bearing outer ring (6), one bearing ring (5) of which rotary mounting is connected to the blade root (8) of the rotor blade (2), and the other bearing ring (6) of which rotary mounting is connected to the rotor hub (3), and having a blade-angle adjustment means which is configured as a gearwheel mechanism with a crown gear (15) which is embodied in sections and with a pinion which is connected to the drive shaft of an actuating motor, the crown gear (15) of which blade-angle adjustment means is arranged on one bearing ring (5), and the actuating motor of which blade-angle adjustment means is fastened to the component (3); which is connected to the other bearing ring (6).

Abstract: A method is presented that reduces vibrations of a wind turbine in a situation where yawing of a wind rotor of said wind turbine is at least temporarily not possible. The method includes adjusting a first pitch angle of a first rotor blade and a second pitch angle of a second rotor blade such that the first and second pitch angles differ by at least 30 degrees.

Abstract: Method for the emergency braking of a wind power plant, in which at least one rotor blade of the wind power plant is adjusted into its feathering position, wherein a first phase, in which the at least one rotor blade is adjusted with a first speed, and a second phase, in which the at least one rotor blade is adjusted as of a predetermined first blade pitch angle with a second speed, which is increased until a maximum speed is reached and/or until a second determined blade pitch angle is reached.

Abstract: A pitch system for a wind turbine installation having an electrically driven pitch drive associated with each rotor blade and an electric motor arranged in a rotating part of the wind turbine installation for blade adjustments. A power and control unit is associated with the motor and has line connections for the transmission of power and control data from the power and control unit to the motor and vice versa. The line connections are passed via a first rotating bushing arranged at a connecting point between the rotating part and an axially adjacent stationary region. The pitch system also includes second rotating bushing which operates mechanically and electrically separately from the first rotating bushing and is connectable to the power and control unit and to the motor for maintaining reliable transmission of the power and control data if the first rotating bushing fails.

Abstract: A twist mechanism for twisting a rotary-wing blade (2). A twist member (8) is movable by an actuator (11) of the centrifugal force type, which twist member has at least one flyweight (14) for driving a rotary member (13) about a pivot axis (A). The flyweight (14) is radially movable on the rotary member (13) by movement means. The centrifugal force FC to which the flyweight (14) is subjected as a result of the blade (2) being caused to rotate induces drive torque CM for causing the rotary member (13) to pivot, thereby causing the twist member (8) to be moved. The twist member (8) is in engagement with the blade (2) at its free end and is connected to the rotary member (13) via remote mechanical transmission means (12).

Abstract: Disclosed is a simultaneous twin pitch adjustment system that includes a flexible shafting cord operatively connected to first and second couplers. The couplers are supported by posts and are operatively connected to pitch communicators. A handle is supported by each post and is configured such that manipulation of the handle translates to adjustment of the pitch of an associated rotor blade assembly. When the simultaneous twin pitch adjustment system is engaged, manipulation of one handle further translates, via the flexible shafting cord, to adjustment of the pitch of another rotor blade assembly in an amount essentially equal to the amount the associated rotor blade assembly is adjusted.

Abstract: The invention is related to a rotor shaft for a wind energy plant, wherein the rotor shaft is at least partially hollow, comprising a line pipe, extending in the interior of the rotating rotor shaft and being stationary and accommodating electric lines, a transmission device, arranged at least partially in the rotor shaft, for the electric connection between a stationary nacelle and a rotating rotor of the wind energy plant, wherein the transmission device features a first body, stationary and connected to the line pipe, and a second body rotating with the rotor shaft, and wherein there is an electric sliding contact between the first and the second body, a casing surrounding the transmission device and formed separately from the second body, which is connected to the rotor shaft and/or adapted to be connected to a rotor hub of the wind energy plant, and which rotates with the rotor shaft, and a torque transmitting connection between the casing and the second body of the transmission device.

Abstract: A blade pitch driving apparatus of a wind-driven generator and a driving method therefor are adapted to receive an external electrical power and impel a blade toward a corresponding pitch angle according to a pitch command. The apparatus includes an UPS, a permanent magnet synchronous motor drive (PMSM drive), an AC pitch motor (ACPM) and a hub controller. The hub controller normally switches the external power to the PMSM drive, receives the pitch command and control the ACPM to impel the blade toward the corresponding pitch angle. When the PMSM drive fails or the external electrical power is interrupted, the hub controller switches the electrical power of the UPS to the ACPM and controls the blade being impelled toward a feathered position.

Abstract: An apparatus and method for reducing asymmetric rotor load in a wind turbine includes calculating a time delay for pitching each blade toward feather upon initiation of a shutdown condition. The blades with the larger blade angle begin moving toward feather with an initial pitch rate, while the blade with the smallest blade angle begins moving toward feather with a final pitch rate. Once all the blades have reached approximately an identical blade angle, the blades move simultaneously together to feather at the final pitch rate. By introducing the time delay for pitching the blades having higher blade angles at the final pitch rate, a simple, time-based correction of initial conditions during shutdown reduces the extreme loads on turbine components.

Abstract: An electric linear actuator is disposed to pitch a blade of a hingeless, swashplateless rotor in rotary motion. This actuator can be equipped with an electric motor advantageously made fault tolerant by winding the motor for at least 4, 5, 6, 8, or even 12 phases. Rotational motion of the electric motor is preferably converted to a translatory linear actuator output motion using a planetary roller screw coupling the rotation of the motor with pitch of the blade. The output link of the actuator can be advantageously coupled to the planetary roller screw using an internal spherical joint providing an isolated load path through the actuator. It is contemplated that a preferred rotorcraft having an electric blade pitch actuator might also be equipped with a controller that could provide the vehicle with individual blade control, in which the pitch of any rotor blade can be controlled independently of the others.

Abstract: A propeller for a marine propulsion system is disclosed which comprises a propeller hub having a casing formed from three segments (16a, 16b, 16c), each of which has a part of an opening (28) for mounting a propeller blade (34). A locking and unlocking mechanism (51, 54, 95, 100) is provided for disengaging the propeller blades to enable pitch adjustment of the blades. A push rod (50) is connected to the mechanism (100) to cause disengagement and adjustment of the pitch of the blades. The mechanism (100) includes a claw (101) having pivotally connected fingers (95). The hub also has a slide ring (51) having a load surface (61) is provided for receiving load when the propeller blades are unlocked to enable pitch adjustment to take place.

Abstract: An assembly for changing the pitch of fan blades rotatably attached to a hub includes a main drive shaft configured to rotate the hub. The main drive shaft is rotated by a first motor. A secondary drive shaft is coupled to the main drive shaft via a gearing system located within the hub. The secondary drive shaft is also driven by a second motor. When driven by the second motor, the secondary drive shaft manipulates the gearing system to alter the pitch of the fan blades.

Abstract: A tandem set of angular contact ball bearings each having an inner ring, an outer ring and balls therebetween, wherein each bearing contains balls that are spaced from each other by slug ball separators. A rotary wing aircraft rotor head assembly includes a rotor head member, a plurality of spindles attached to the head member at equal interval around the center of the head member, and a stack of ball bearings mounted on each spindle. Each bearing has an inner ring, an outer ring, and a plurality of balls between the inner ring and the outer ring, and slug ball separators between adjacent balls, and there is a mounting collar on the ball bearings.

Abstract: There is provided a wind turbine generator that includes an improved grease supply and discharge system of lubricant oil used in a blade rotating ring bearing of a wind turbine blade, and can reliably recover discharged grease. The wind turbine generator includes a pitch control mechanism that can adjust a pitch angle of the wind turbine blade via the blade rotating ring bearing provided between the wind turbine blade and a rotor head, a grease supply and discharge device is provided in the rotor head, and the grease supply and discharge device includes a grease supply device that pumps lubricant oil in a supplied grease tank with a grease supply pump and supplies the lubricant oil to the blade rotating ring bearing, and a grease discharge device that forcibly sucks and recovers the discharged grease from the blade rotating ring bearing.

Abstract: A system and method are provided to increase efficiency of turbines in wind farms. A sensor is configured to generate a wind map of an inflow of wind. A controller is configured to generate a control signal based the wind map. A pitch adjustment device configured to adjust pitch of a blade of the turbine based on the control signal.

Abstract: A turboprop including a rotary casing fitted with adjustable-pitch blades enabling thrust to be managed. Each blade is coupled, for the purpose of adjusting its pitch, to a control member of an annular actuator carried by the rotary casing.

Abstract: A fluid turbine comprising a rotor, having an axis of rotation, comprising at least two rotor blades disposed at a radius from the axis of rotation, each rotor blade having a pitch axis and a variable pitch angle. The fluid turbine comprises a phase-adjustable mechanism operable to control the pitch angle of at least one rotor blade about its pitch axis and to vary the pitch angle of the rotor blade between various pitch angles as the blade moves radially about the axis of rotation of the rotor.

Abstract: A rotor blade for a wind turbine comprises a rotor blade body with a root for connecting the rotor blade to a hub of a wind turbine, a tip, a leading edge and a trailing edge. The blade has a movable part, and motion transmitting means for connecting to an actuator being placed preferably outside the blade body, and transmitting motion from the actuator to the movable part. The motion transmitting means is electrically non-conductive, whereby the risk of lightning stroke accidents is reduced.

Abstract: A method for adjusting a pivotally mounted rotor blade of a wind energy converter includes controlling a first drive and a second drive to collectively turn the rotor blade into an operating position; detecting whether a failure of the first drive has occurred; activating, when the failure of the first drive has occurred, a first activatable lockout connected to the rotor blade, which prevents turning of the rotor blade into the operating position while allowing turning of the rotor blade into a feathered position; and controlling, when the failure of the first drive has occurred, the second drive to turn the rotor blade into the feathered position.

Abstract: Disclosed a horizontal axis wind turbine including: a rotor; a nacelle; a tower; an independent pitch control device; and a yaw control device, wherein the horizontal axis wind turbine is an up-wind type one including a waiting mode, wherein (1) the independent pitch control device performs a first step of changing all the blades to be in feathering states when the wind speed exceeds the predetermined value, a second step of changing the blades to be in reverse feathering states one by one sequentially, and a third step of holding all the blades in the reverse feathering states, and (2) the yaw control device controls a yaw brake to take a braking value allowing the yaw rotation when the wind speed exceeds the predetermined value, wherein the rotor is allowed to swing a leeward of the tower by executing the control operations (1) and (2) as the waiting mode.

Abstract: A propeller system includes a propeller hub which supports a multiple of propeller blades. A tailshaft extends from a propeller hub portion of the propeller hub along an axis of rotation with a propeller pitch change yoke mounted within the propeller hub for movement along an axis of rotation to change a pitch of the multiple of propeller blades, the propeller pitch change yoke in sliding engagement with the tailshaft.

Abstract: A wind turbine (20) includes a turbine wheel (22). Radially extending sailwing assemblies (30) are supported between the axle structure (28) and the perimeter rail (26) of the turbine wheel. The sailwing assemblies include sail end supports (52, 53), sail support cables (54, 55) extending between the sail end supports, and sailwings (58) that are supported by the sail support cables and extend between the axle structure (28) and the perimeter rail (26) of the turbine wheel. The sail end supports (52, 53) may be pivoted to form a pitch in the sailwings (58) and pivoted with respect to each other to form a twist in the sailwings, and sail spreader bars (70) may be mounted in the sailwings and connected to the sail support cables (54, 55) to adjust the effective width and loft of the sailwings.

Abstract: A system for driving a wind turbine blade (46) into a feathered position during an emergency stopping process of a wind turbine rotor. The system comprises a hydraulic actuator (3) functionally connected to the blade (46) for changing the pitch of the blade (46) during movement of the hydraulic actuator (3) and an emergency accumulator (8) connected to the hydraulic actuator (3) for driving the hydraulic actuator (3) with fluid from the emergency accumulator (8). The emergency accumulator (8) comprises a resilient member for accumulating the fluid in the emergency accumulator (8) under resilient pressure or a weight member (74) comprising a weight member upon the fluid in the emergency accumulator. The resilient member (14) or weight member (74) is configured for driving the fluid out of the emergency accumulator due to the expansion or retraction of the resilient member.

Abstract: An impeller arrangement comprises an impeller 10 having at least one first vane surface 26 orientated such that the application of fluid under pressure thereto applies a torque to the impeller 10 in a first rotary direction, at least one second vane surface 28 orientated such that the application of fluid under pressure thereto applies a torque to the impeller 10 in a second, opposite rotary direction, and a valve 34 operable to control the supply of fluid to the first and second vane surfaces 26, 28.

Abstract: A method of assembling a wind turbine. The method includes coupling a pitch bearing to a hub that includes a wall. The pitch bearing includes a plurality of sets of pitch bearing teeth. At least one blade is coupled to the pitch bearing such that the blade is rotatable about a pitch axis. A plurality of pitch gearbox brackets are coupled to the hub wall. A pitch drive system is selectively coupled to one of the plurality of pitch gearbox brackets, wherein a predetermined set of pitch bearing teeth are in contact with the pitch drive system.

Abstract: A method and system for repairing a wind turbine component in a wind turbine is provided. A damaged region of a drive assembly affects the wind turbine component. The method includes the steps of, providing a replacement wind turbine component, providing a mount for the replacement wind turbine component, and installing the replacement wind turbine component and mount in an undamaged region of the drive assembly. The replacement wind turbine component and mount are located to avoid interaction with the damaged region.

Abstract: A system for providing variable pitch to a rotor blade of an aircraft engine includes a rotatable hub; at least one blade mounted on the rotatable hub; a gear mechanism operably connected to the rotatable hub; a timing ring rotatably and operably connected to the gear mechanism; and a pitch arm operably connecting the timing ring and the at least one blade mounted on the rotatable hub. In the operation of the system, the gear mechanism facilitates the rotation of the timing ring to vary the pitch of the at least one blade mounted on the rotatable hub.

Abstract: The present invention provides an improvement for a wind turbine (20) having at least one blade (21) mounted on a hub (22) for controlled rotation about a blade axis (yb-yb) to vary the pitch of the blade relative to an airstream. The hub is mounted on a nacelle (23) for rotation about a hub axis (xh-xh). The wind turbine includes a main pitch control system for selectively controlling the pitch of the blade, and/or a safety pitch control system for overriding the main blade pitch control system and for causing the blade to move toward a feathered position in the event of an overspeed or fault condition.

Abstract: A high volume low speed (HVLS) fan provides improved air circulation and thermal control in a building by incorporating composite fan blades pivotable to both positive and negative pitch angles. The blades are molded of polymer material over a metal tube core for strength and ease of attachment to the fan hub, and have a symmetrical airfoil shape to produce an efficient bi-directional conical airflow. The fan includes a control unit providing manual and automated intelligent control over blade angle and rotational speed, as well as startup with approximately zero blade angle for more economical power consumption and less motor wear. The fan structure and mounting system allows the fan to be installed at an optimal height inside a variety of buildings to provide increased efficiency of air destratification and air mixing. An array of multiple HVLS fans with alternating directions of airflow can further increase efficiency of air movement.

Abstract: A rotorcraft blade is provided with a rigid attachment filler (1) and with a spar (40) that extends from a root (51) of the blade to a free end (52) of the blade, the attachment filler (1) having top, bottom, front, rear, left side, and right side faces (2, 3, 4, 5, 7, and 6). The spar (40) then includes a succession of fiber layers (31, 32, 33) that hold the attachment filler (1) captive at the root (51) of the blade, the spar (40) being secured to the top, bottom, front, rear, and left side faces (2, 3, 4, 5, and 7) of the attachment filler (1).

Abstract: A device for controlling a turbine blade pitch, comprising a turbine blade spindle (14) for connection to the turbine blade rotatably connected to a support element (28). An actuator (32) is connected to the spindle (14) and via an actuation element (38) to the support element (28). The actuator (32) is operable to rotate the spindle (14) about a spindle longitudinal axis, thus effecting a turbine pitch adjustment. Preferably, the support element (28) comprises a toothed arc (28), connected via gear wheels to a pitch adjusting drive unit (18). The invention provides an auxiliary, and/or emergency pitch adjustment device, suitable for e.g. rapid turbine feathering.

Abstract: This invention relates to a method and a Propeller Pitch Control Arrangement, comprising a propeller hub (1) having a number of interface fittings (10) for adjustable pitch positioning of a propeller blade, a positioning device (3), within said hub (1), having a number of propeller control interfaces (34) and an actuator arrangement (2, 4, 55) arranged to move and position said positioning device (3) to enable varying pitch for said propeller blades, characterized in—that said actuator arrangement includes a rotatable shaft (2) with threads (20) interacting with mating threads (30) at said positioning device (3), and,—that said rotatable shaft (2) is driven by a motor device (4, 5) positioned adjacent said hub (1).

Abstract: Described herein is an improved wind turbine with a dynamic blade configuration.

Abstract: The invention provides a pitch drive apparatus of a wind generator and the wind generator capable of, with a simple structure, preventing reliability of the pitch drive apparatus from being deteriorated. The wind generator includes a wind turbine rotor blade having a blade root mounted so as to be turnable around an axis center O with respect to a rotor head, and a pitch drive apparatus for turning and driving the wind turbine rotor blade around the axis center O to change a pitch angle thereof. The pitch drive apparatus has an electric cylinder functioning as a linear actuator.

Abstract: A windmill pitch driving apparatus is provided, which is capable of achieving improved output torque and reduced size as well as reduced weight. Lubricating oil is enclosed in a casing 11 such that crankshaft bearings 27 and external tooth bearings 28 are immersed in the lubricating oil during a single rotation of a main shaft portion 104. With an electric motor 108 located on the upper side and an axis P of an output shaft 15 corresponding to the vertical direction, an oil level 40 of the lubricating oil enclosed in the casing 11 is below the level of a seal member 19a and such that at least part of a driving force transmission path from an input shaft 13 to crankshafts 21 is exposed to the air enclosed in the casing 11.

Abstract: A blade pitch actuation mechanism for a plurality of propeller blades supported in a blade hub comprises a plurality of bearing assemblies, a bearing support plate and a yoke. The plurality of bearing assemblies receives a plurality of actuation trunnion pins from the plurality of propeller blades. The bearing support plate is connected to the plurality of bearing assemblies and unifies the plurality of bearing assemblies in a ring-like configuration. The yoke is connected to the bearing support plate and translates within the hub to adjust the pitch of the plurality of propeller blades.

Abstract: Provided are a pitch actuator for a wind turbine generator and a wind turbine generator that can be prevented from losing their reliability. Provided are a cylinder (12) and a rod (13) that rotate a wind turbine rotor blade about an axis thereof relative to a rotor head to change a pitch angle; a cylinder bearing (14, 15) supporting the cylinder (12) so as to be rotatable relative to the rotor head about a first rotation axis (L1) extending substantially parallel to the axis of the wind turbine rotor blade and about a second rotation axis (L2) extending in a direction crossing both the first rotation axis (L1) and the axis of the cylinder (12) and the rod (13); and a rod bearing (16) rotatably supporting an end of the rod (13) on an end surface of the wind turbine rotor blade.

Abstract: A variable rotor blade mechanism for use in a gas turbine engine comprises a blade rotor, a blade, a harmonic drive system, a stepper motor and a bracket. The blade rotor rotates absolutely about an axial engine centerline during operation of the gas turbine engine. The blade extends radially from the blade rotor and is configured to be adjustable by rotation about a radial axis. The harmonic drive system is mounted to the blade rotor and connected to the blade to rotate the blade about the radial axis. The stepper motor drives the harmonic drive with relative rotational input with respect to the absolute rotation of the blade rotor. The bracket is disposed about the engine centerline and supports the stepper motor stationary with respect to the rotation of blade rotor such that the relative rotational input to the stepper motor is generated.

Abstract: The present invention relates to a rotor blade adjusting drive for adjusting the pitch angle of a rotor blade of a wind power plant, comprising a drive train which at the output end can be connected with the rotor blade and/or a bearing member supporting the rotor blade, and a spring accumulator connectable with the drive train, which includes a spring accumulator shaft, a spring accumulator housing and a spring means which can be tensioned by rotating spring accumulator shaft and spring accumulator housing relative to each other, wherein the spring accumulator shaft and/or the spring accumulator housing can be uncoupled from the drive train and is rotatable with respect to the same for biasing the spring accumulator, wherein a braking device is provided for retarding and/or holding the spring accumulator shaft and/or the spring accumulator housing against the spring bias in the uncoupled condition of the spring accumulator.

Abstract: A wind energy plant with a rotor hub housing, which is connectable to at least one pitch bearing via joining means, and with at least one rotor blade, the blade root of which is connected to the pitch bearing, wherein a stiffening element is provided, which is fastened between the pitch bearing and the rotor hub housing.

Abstract: A method for operating a device to vary a blade setting angle on a rotor blade of a wind power plant, comprising two variable drives each per rotor blade, a bearing element acting between the rotor blade and rotor hub which has a freely rotatable bearing ring, wherein the method has the following process steps: setting the bearing ring into a permanent rotation by a first drive, and adjusting the setting angle of the rotor blade by a second drive.

Abstract: The invention relates to a wind turbine rotor comprising at least one blade and at least on pitch mechanism comprising a ring shaped motor for controlling the blade. The wind turbine rotor is characterized in that, the ring shaped motor controls the blade through gearing means of a planetary type. The invention further relates to a rotation controlling mechanism comprising, at least one ring shaped motor for controlling the rotation of at least one first part in relation to at least one second part. The rotation controlling mechanism is characterized in that, the ring shaped motor controls the relative rotation through gearing means of a planetary type. Even further the invention relates to a method for controlling at least one blade of a wind turbine rotor.

Abstract: A system for adjusting the pitch of a counter-rotating propeller has a propeller shaft, a forward propeller driven by the propeller shaft, and an aft propeller connected with the forward propeller. The forward propeller has a hub, blades mounted within the hub, and an actuator connected with an end of the blades. The aft propeller has a hub, blades mounted within the hub, and a cam assembly connected with an end of the blades. The actuator of the forward propeller has a forward end and an aft end, wherein the aft end is connected with the cam assembly of the aft propeller. Thus, when the actuator moves in an axial direction, the cam assembly moves relative to the actuator and the pitch of the forward propeller blades and the pitch of the aft propeller blades are simultaneously adjusted.