Abstract: The present disclosure is directed to a bearing for a wind turbine. The bearing includes an outer race, an inner race, and a radially-split center race configured between the inner race and the outer race. Further, the center race includes a first race portion and a separate second race portion. In addition, the first and second race portions are arranged together in an axial direction. The bearing also includes a first set of rolling elements positioned between the inner race and the center race and a second set of rolling elements positioned between the center race and the outer race.

Abstract: A method for manufacturing a planet gear or a sun gear of a gearbox of a wind turbine includes forming a base of the planet gear via at least one of casting or forging. The base of the planet gear includes an inner circumferential surface and an outer circumferential surface. Therefore, at least one of the inner circumferential surface or the outer circumferential surface of the planet gear includes a plurality of net or near-net gear teeth. The method also includes applying a coating material to at least a portion of the base of the gear and at least a portion of the plurality of gear teeth of the gear via an additive manufacturing process so as to increase a hardness of the portions of the base and the plurality of gear teeth that includes the coating material.

Abstract: Wind turbine comprising at least a pitch bearing comprising at least two rings, each of the at least two rings attached to a wind turbine component, being a first wind turbine component a blade and a second wind turbine component a hub, and further comprising at least one bearing reinforcement attached to at least one of the two rings. The invention also relates to the pitch bearing of the wind turbine.

Abstract: A rotary wing aircraft includes an airframe including an extending tail. The airframe includes a longitudinal axis that extends through the extending tail. The rotary wing aircraft also includes a main rotor assembly including at least one rotor hub supporting a plurality of rotor blades configured and disposed to rotate about a main rotor axis, at least one elevator arranged at the extending tail, and a control system operably connected to the main rotor assembly and the at least one elevator. The control system is configured and disposed to adjust each of a pitch rate and an attitude of the airframe by selectively adjusting a position of the at least one elevator.

Abstract: A non-ducted tail rotor comprising a hub and at least five blades, each of the blades extending to a free end that, in rotation, describes a circle presenting a given “maximum” radius. The hub is rigidly secured to a drive shaft, the hub comprising a hollow circular body centered on an axis of rotation, the body presenting an “internal” radius between the axis of rotation and an outer periphery of the body, the internal radius lying in the range 0.2 times to 0.4 times the maximum radius, each blade presenting a root extended by an airfoil element projecting from the body, extending from the root to the free end, the root being swivel-hinged to the outer periphery about a pitch axis.

Abstract: A rotor assembly for a wind turbine is provided. The rotor assembly includes a central hub with a central rotation axis, and a plurality of vanes. Each of the vanes is attached to the central hub, and each of the vanes includes in part a cable system which cooperates with each respective vane and the central hub. The cable system includes a pair of cables. Both of the cables are aligned with the longitudinal axis of the respective vane, viewed along the central rotation axis. And both of the cables are on either side of a plane covered by the longitudinal axis of the respective vane. The plurality of vanes are only structurally interconnected via the central hub, and the cable system of each of the vanes has only one single pair of cables.

Abstract: A turbine for extracting power from a flowing fluid comprises a blade for interaction with the fluid, the blade being rotatable both about a primary axis and a blade axis. The blade axis is proximate to the blade, substantially parallel to the primary axis and spaced therefrom. Rotation actuating means is provided to rotate the blade about the blade axis in dependence upon the rotation of the blade about the primary axis such that the rotation angle of the blade about the blade axis is a function of the rotation angle of the blade about the primary axis. The rotation of the blade about the blade axis is in the same direction of rotation as the blade axis about the primary axis.

Abstract: A hub assembly for a tilt rotor includes a yoke having a plurality of yoke arms located substantially orthogonal to a central axis of the hub assembly. An inboard pitch change bearing assembly substantially surrounds a yoke arm of the plurality of yoke arms. An outboard pitch change bearing assembly is located at the yoke arm. The inboard pitch change bearing assembly and the outboard pitch change bearing assembly are operably connectable with a rotor blade to allow pitch change of the rotor blade relative to the yoke about a pitch change axis.

Abstract: The present invention relates to a method for curtailing electrical power supplied from a wind turbine or a group of wind turbines to an associated power supply grid, the method comprising the steps of determining an available electrical power level from the wind turbine facility and setting a wind speed independent curtailment level. The curtailment level may be a percentage of an actual available electrical power level or a fixed power level. The method further comprises the step of operating the wind turbine facility in such a way that the generated electrical power supplied from the wind turbine facility equals the difference between an actual available electrical power level and the curtailment level. The present invention further relates to a wind turbine facility and a curtailing controller for carrying out the invention.

Abstract: A system for controlling at least two sets of variable geometry equipment of a turbine engine. The turbine engine includes at least one first body and a second body, the first set of equipment being a stage of variable stator vanes of a compressor of the first body moving between a closed position during idling and an open position at high speed, and the second set of equipment being at least one bleed valve of a compressor of the second body moving between an open position during idling and a closed position at high speed. The actuator drives the second set of equipment by an actuating part that is actuated over part of the course of the actuator and idle on an abutment over the rest of the course, and by a sliding joining element providing a backlash in the actuation of the second set of equipment.

Abstract: A system for controlling at least two sets of variable geometry equipment of a gas turbine engine including at least one first body and a second body, the first set of equipment being a stage of variable stator vanes of a compressor of the first body moving between a closed position during idling and an open position at high speed, and the second set of equipment being at least one bleed valve of a compressor of the second body moving between an open position during idling and a closed position at high speed. An actuator actuates the two sets of equipment.

Abstract: A control system for controlling at least two variable-geometry devices of a turbomachine, and a turbomachine including such a control system, the system including an actuator that actuates both devices; one of the devices including at least one stage of variable-pitch stator vanes, and the other device being an air-bleed valve for a turbomachine body. The system is configured to control progression opening of the vane stage and progressive closing of the air-bleed valve as an actuation parameter of the actuator increases. As a result, the control system serves advantageously to control two devices using a single control system.

Abstract: A system for controlling at least two variable-geometry equipments of a gas turbine engine is disclosed. The engine includes at least a first core rotating at a first speed and a second core rotating at a second speed. The first equipment includes at least one variable-pitch stator blade of a compressor of the first core and the second equipment includes at least one air bleed valve of a compressor of the second engine core moving between an open position at idle speed and a closed position at high speed. The system includes an actuator which actuates both equipments.

Abstract: A system for controlling at least two variable-geometry equipments of a gas turbine engine is disclosed. The engine includes at least a first core rotating at a first speed and a second core rotating at a second speed. The first equipment includes at least one variable-pitch stator blade of a compressor of the first core and the second equipment includes at least one air bleed valve of a compressor of the second engine core moving between an open position at idle speed and a closed position at high speed. The system includes an actuator which actuates both equipments.

Abstract: A system for controlling at least two variable-geometry equipments of a turbomachine, in which the first equipment is a variable pitch stator blade stage of a compressor of a first core moving between a closed position at idle speed and an open position at high speed, and the second equipment is at least one bleed valve of a compressor of a second core moving between an open position at idle speed and a closed position at high speed, is disclosed. The actuator operates over a portion of its travel a first branch of an angle transmission member which actuates the first equipment and leaves this branch at rest on an abutment over the rest of its travel. The actuator operates the second equipment via a sliding junction member arranging a free travel in the actuation of said second equipment.

Abstract: A helicopter is fitted with a main rotor (1) having at least two blades (10, 20), each blade (10, 20) being provided with attachment elements (11, 21) for attaching it to a hub (2) of the rotor (1). The rotor is also fitted with one lift element (12, 22) per blade (10, 20), each lift element (12, 22) being mechanically linked to a single blade (10, 20) to vary the pitch of the single blade (10, 20) with which the lift element (12, 22) is linked.

Abstract: The present invention relates to a helicopter provided with a main rotor (1) having at least two blades (10, 20), each blade (10, 20) being provided with attachment means (11, 21) attaching it to a hub (2) of the rotor (1). The helicopter is provided with one lift element (12, 22) per blade (10, 20), said lift element being provided with a tiltable tab (19, 29), each lift element (12, 22) being mechanically connected to a single blade (10, 20) to vary the pitch of said single blade (10, 20).

Abstract: Controller for a blade adjustment angle for at least one rotor blade of a wind power plant, in which a first controller branch is switched for the determination of the blade adjustment angle depending on the operating states of the wind power plant, wherein at least one differentiating member is provided in the switched first controller branch.

Abstract: A trim tab assembly includes first and second shape memory alloy (SMA) actuators and a trim tab substrate which provide elastic/plastic locking in response to an induced strain actuation.

Abstract: A rotor aircraft has a tilting hub for cyclic control operated by either a tilting spindle or swash plate mounted to the upper end of the drive shaft. A spinner housing with two separate half portions encloses the hub. The blades of the rotor have root portions that are integrally joined to the separate half portions. During a collective pitch change, the half portions rotate relative to each other, but at advance ratios greater than about 0.7, when the collective can be held constant, the spinner half portions can be in perfect alignment. Concentric control sleeves surround the drive shaft for changing collective pitch as well as cyclic pitch.

Abstract: A multi-bladed tail rotor assembly is disclosed that provides higher aerodynamic performance, damage tolerant design with 10,000-hour life expectancy, and which requires low maintenance through the use of composites and elastomerics. The tail rotor hub assembly includes two stacked yoke assemblies having multi-bladed teetering rotors, each mounted on a single drive mast. Each yoke assembly includes a yoke hub having a transverse bore therethrough, a bearing assembly disposed within the bore, and retention means for aligning and securing the bearing assembly within the bore. Each bearing assembly includes a trunnion portion having trunnion arms that extend outwardly from a trunnion body portion, and an elastomeric bearing disposed about each trunnion arm. The tail rotor assembly utilizes a composite twist strap flexure to accommodate collective pitch control integral with each rotor blade.

Abstract: A fan having stable pre-loading device includes a stator, at least one bearing, a rotor having a blade structure, a shaft and a rigid spacer. Among these, the bearing is formed in the space of the stator. One terminal of the shaft is coupled to the stator. The elastic device is formed on the bearing. The rigid spacer is formed on and thus compresses the elastic device. Another terminal of the shaft passing the rigid spacer as well as the elastic device is coupled to the inner ring of the bearing.

Abstract: A multi-bladed tail rotor assembly is disclosed that provides higher aerodynamic performance, damage tolerant design with 10,000-hour life expectancy, and which requires low maintenance through the use of composites and elastomerics. The tail rotor hub assembly includes two stacked yoke assemblies having multi-bladed teetering rotors, each mounted on a single drive mast. Each yoke assembly includes a yoke hub having a transverse bore therethrough, a bearing assembly disposed within the bore, and retention means for aligning and securing the bearing assembly within the bore. Each bearing assembly includes a trunnion portion having trunnion arms that extend outwardly from a trunnion body portion, and an elastomeric bearing disposed about each trunnion arm. The tail rotor assembly utilizes a composite twist strap flexure to accommodate collective pitch control integral with each rotor blade.

Abstract: A rotorcraft, in particular helicopter, rotor includes a tubular pylon driven in rotation about its axis, which is the rotation axis of the rotor, from its foot. A hub is attached to the pylon by a flared base and includes two annular plates substantially radial to the rotor axis and spaced from each other along the rotor axis so that relative to the pylon one is an axially inside plate and the other is an axially outside plate. Each of at least two blades has its root connected to the hub by retaining and articulation arrangements retained between the plates of the hub and enabling relative angular movement of the blade at least in pitch about a longitudinal blade pitch change axis controlled by displacement by a pitch rod of a pitch lever attached to the blade root.

Abstract: An actively controlled helicopter rotor blade includes a trailing edge flap actuated by a fast-acting actuator. A lightweight, rugged, fast-acting actuator suitable for use as the flap actuator comprises a pair of column actuators composed of a smart material such as piezoelectric, magnetostrictive, shape memory alloy or other material that exhibits a shape change when subjected to an external stimulus. Each of the column actuators is composed of multiple piezoelectric ceramic actuator elements bonded together to form the individual columns. Each of the column actuators engages the base of an actuator tube that, in turn, is urged against the column actuators by a tension member. Differential voltage applied to the columns causes a differential elongation of the column actuators, which causes the actuator tube to pivot about an axis proximal the tips of the column actuators. The movement of the actuator tube is coupled by a linkage to the rotor blade flap.

Abstract: Each blade of the rotor has a rigid root oversleeve connected to a torsionable and flexible root strip by two laminated, spherical support half bearings, fixed by their outer frame with double rigid horns the lateral ends of which facing each other on each side of the strip and half bearings are clamped towards each other and against struts so as to allow a significant, calibrated pre-compression of the half bearings. The double horns and/or struts are fixed axially to the oversleeves by fixing elements distinct from the compression means of the double horns on the struts and perpendicular to these compression horns on the struts and perpendicular to these compression elements. One of the struts, possibly in a single piece with one double horn, is also in a single piece with a pitch lever.

Abstract: A semi-articulated stiff-in-plane (SASTIP) rotor hub is provided. The hub includes a cylindrical composite shell (12). A plurality of flexure mount assemblies (16) are positioned around the periphery of the hub shell. Each flexure mount assembly includes both an upper and a lower flexure (64), (66). The outboard ends of the upper and lower flexures attach to an outboard bearing support (34). The inboard end of each flexure is maintained within first and second clamp plates (76), (78) that are mounted within hub flexure openings (38), (40). The flexure clamp plates (76), (78) additionally attach circumferentially to annular CF rings (24), (26), (28), (30) positioned within the hub shell. A blade shaft (14) extends through the outboard bearing (72) and connects to a spindle. The spindle is supported by a spherical bearing that is mounted within the hub shell (12) at a circular spindle hole.

Abstract: An apparatus for compensating for spatial phase angle phase errors in the flapping angle oscillations of a rotor blade is disclosed. The apparatus receives a measured aircraft roll and a measured aircraft pitch. Gyroscopic moments resulting from these measured rolls and pitches are determined, and compensating gyroscopic moments are then generated and summed with commanded pitch and roll accelerations. Flapping angle phase lags of the rotor blade swashplate are added to the summed signals to cancel any flapping angle phase leads, caused by changes in aircraft or rotor blade speed caused by installation configurations of the rotor blade swashplate.

Abstract: A main rotor is provided for use in a rotary winged model aircraft. The main rotor includes a rotor hub assembly rotatable about a vertical axis and at least two main rotor blades. Each of the main rotor blades extends in a radial direction from the rotor hub assembly. The main rotor blades each include a tip end positioned to lie in spaced-apart relation to the rotor hub assembly and a root end coupled to the rotor hub assembly for pivotable folding movement from an initial horizontal position perpendicular to the vertical axis about a horizontal axis through a desired folding angle of about 90.degree.. Forces transmitted to the rotor hub by the rotor blade during a crash-landing of a rotary winged model aircraft including the main rotor are minimized due to movement of the rotor blades through the desired folding angle.

Abstract: A blade pitch control system for a rotary wing aircraft which incorporates a mast and rotor which is pivotally adapted for movement of the mast between a generally horizontal stored position and a vertical position for operation in a helicopter mode. The pitch control system incorporates a motion amplification mechanism such as a star gear arrangement connected to the pitch horn to amplify control motions which are transmitted to the pitch horns through a push-pull control tube generally parallel to the folding axis of the rotor blade. In another embodiment, the push-pull tube inputs parallel to the mast axis. A locking mechanism retains the blades so pitch changes cannot be made during a predetermined portion of the blade coning cycle.

Abstract: The invention relates to a flapping restrainer device for the blades of a rotorcraft main rotor, and a rotor head comprising the same. The lower restrainers comprise a reciprocal star-shaped plate (32), having as many radial branches (33) as blades, and each one of the branches being engaged into a radial opening (6) of the hub (3). Outside the latter, the star-shaped plate (32) cooperates with supporting runners (47) integral with the blades. The upper restrainers comprise, for each blade, a stop which is retractable by the effect of the centrifugal force and which is composed of a lever (52), pivoting on a pivot (53) carried by the hub (3), and a first arm (55) of which constitutes a stop finger directed towards an upper supporting component (60) integral with the blade, while a second arm (56) carries a governor weight (57) and a nose (58) for support against a shoulder (59) integral with the hub (3).

Abstract: A control for a helicopter tail rotor where inboard twist sections on opposite sides of a central hub section are adjacent to pitch horns mounted outboard the margins of the twist sections and extend to a negative delta.sub.3 connection point located at the virtual bending axis of each twist section. The rotor teeters on the tail mast with the span axis of the rotor at an angle of the order of 30.degree. to 45.degree. from the teetering axis.

Abstract: A system of rotatably and pivotally mounted radially extended bent supports for radially extending windmill rotor vanes in combination with axially movable radially extended control struts connected to the vanes with semi-automatic and automatic torque and other sensing and servo units provide automatic adjustment of the windmill vanes relative to their axes of rotation to produce mechanical output at constant torque or at constant speed or electrical quantities dependent thereon.

Abstract: A system of rotatably and pivotally mounted radially extended bent supports for radially extending windmill rotor vanes in combination with axially movable radially extended control struts connected to the vanes with semi-automatic and automatic torque and other sensing and servo units provide automatic adjustment of the windmill vanes relative to their axes of rotation to produce mechanical output at constant torque or at constant speed or electrical quantities dependent thereon.

Abstract: Improved stability is provided in a hingeless helicopter rotor by inclining the principal elastic flexural axes and coupling pitching of the rotor blade with the lead-lag bending of the blade. The primary elastic flex axes can be inclined by constructing the blade of materials that display non-uniform stiffness and the specification describes various cross section distributions and the inclined flex axes resulting therefrom. Also described are arrangements for varying the pitch of the rotor blade in a predetermined relationship with lead-lag bending of the blade, i.e., bending of the blade in a plane parallel to its plane of rotation.