Abstract: A turbine stage includes a first airfoil and a second airfoil extending respectively from a first platform and a second platform that form an endwall for a flow passage. The endwall has a nominal surface that is axisymmetric about an axis of the turbine stage. The endwall further includes at least one contoured region that is non-axisymmetric with respect to the axis. The at least one contoured region extends from the first platform to the second platform across a platform splitline. The global maximum variation in elevation ?EW of the endwall is at least 3% of an axial chord length L of the airfoils on the endwall. The maximum variation in elevation ?MF at the mate facea of the platforms lies in the range 15-60% ?EW.

Abstract: A wind turbine drive control device according to one aspect of the present invention is a wind turbine drive control device for controlling a plurality of drive devices for moving two structures included in a wind power generation device relative to each other, the wind turbine drive control device including: an obtaining unit for obtaining a plurality of information items related to loads occurring between each of the plurality of drive devices and one of the two structures that receives forces generated by the plurality of drive devices; and a control unit for controlling the plurality of drive devices in such a manner that, in a state where each of the plurality of drive devices is controlled to generate a predetermined braking force, the braking force of at least one first drive device among the plurality of drive devices is increased, based on the plurality of information items.

Abstract: A fan can include a motor for driving a set of blades to move a volume of air about a space. A cage can be provided to encase the set of blades to protect the fan, as well as permit a volume of air to move through the cage. A mount bracket couples to the cage, and can include a first portion including a first pair of hooks connecting the first portion to the cage, with the first portion including a pair of apertures and an attachment feature, and a second portion including a second pair of hooks connecting the first portion to the cage, with the second portion including a pair of extensions configured to secure to the first portion at the pair of apertures. The attachment feature is configured to couple an accessory to the cage via the mount bracket.

Abstract: A service tube assembly for an aircraft engine, comprising: a service tube having a threaded end portion, an opposed end portion and an annular tube surface proximate to the threaded end portion; a housing having an outer surface defining a tube socket extending in the outer surface, and a ramp extending toward the tube socket so as to define an engagement direction, the tube socket engaged with the threaded end portion of the service tube; a locking member having a bottom surface disposed against the ramp and an engagement surface facing toward the service tube, the locking member slidable along the ramp in the engagement direction between a first member position in which the engagement surface is spaced from the annular tube surface and a second member position in which the engagement surface contacts the annular tube surface; and a fastener releasably holding the locking member against the ramp.

Abstract: A vane arm connection system for a gas turbine engine includes a vane stem having a head with flat contact surfaces; a vane arm having a claw, the claw having opposed arms having inwardly facing surfaces engaging the flat contact surfaces of the head; and a torque transfer member having a body defining an opening for engaging the flat contact surfaces of the head of the vane stem, and at least one arm extending from the body to contact the claw, whereby load from torque is transferred away from the inwardly facing surfaces.

Abstract: In one embodiment of the present disclosure, there is provided a drive tube and swashplate trunnion assembly. The drive tube and swashplate trunnion assembly includes a drive tube having a plurality of grooves formed on an outer surface of the drive tube; a swashplate trunnion having a plurality of grooves formed on an inner surface of the swashplate trunnion, wherein individual grooves of the plurality of grooves on the swashplate trunnion mate with individual grooves of the plurality of grooves on the drive tube to form a plurality of channels; and a plurality of cylindrical bearings, wherein each of said cylindrical bearings is disposed within an individual channel of the plurality of channels.

Abstract: A variable-pitch bladed disc including a plurality of blades, each at a variable pitch in relation to a rotation axis of the blade and each having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each having a root and a tip, each root being mounted at the tip of a corresponding rotor connecting shaft by way of a pivot so as to allow each blade to rotate about the blade rotation axis, the first blade having a first blade inclination, such that the first blade is inclined in a fixed manner with respect to the blade rotation axis of the first blade, and the second blade having a second blade inclination different from the first blade inclination.

Abstract: A turbomachine defines an axial direction, a radial direction perpendicular to the axial direction, and a circumferential direction extending concentrically around the axial direction. The turbomachine includes a nozzle having an inner platform, an outer platform, and an airfoil. The airfoil includes a leading edge, a trailing edge downstream of the leading edge, a pressure side surface, and a suction side surface opposite the pressure side surface. The trailing edge defines a circular arc between the inner platform and the outer platform.

Abstract: An example embodiment of a turbine engine assembly includes a low spool including a low spool accessory drive gear driven by a low rotor shaft, a high spool including a high spool accessory drive gear driven by a high rotor shaft concentric around a portion of the low rotor shaft, and a differential gear assembly adapted to offtake power from rotation of one or both of the low spool and the high spool to drive one or more accessory loads. The differential gear assembly includes a differential bullgear and one or more idler gears each including a plurality of teeth meshed with the low spool accessory drive gear and the high spool accessory drive gear, and a bearing surface. The differential bull gear includes a plurality of teeth and a corresponding at least one bearing surface engaging with the bearing surface of each of the one or more idler gears. The plurality of teeth are adapted to mesh with an accessory drive system to transfer the power offtake and drive the one or more accessory loads.

Abstract: A feedback device for use in a gas turbine engine, and methods and systems for controlling a pitch for an aircraft-bladed rotor, are provided. The feedback device is composed of a circular disk and a plurality of position markers. The circular disk is coupled to rotate with a rotor of the gas turbine engine, to move along a longitudinal axis of the rotor, and has first and second opposing faces defining a root surface that extends between and circumscribes the first and second faces. The plurality of position markers extend radially from the root surface, are circumferentially spaced around the circular disk, and extending along the longitudinal axis from a first end portion to a second end portion. At least part of the first end portion and/or of the second end portion comprises a material having higher magnetic permeability than that of a remainder of the position markers.

Abstract: A propeller control unit (PCU) has: a pitch angle actuator; a valve operable to selectively fluidly connect the pitch angle actuator with a source of oil for controlling pitch angles of blades of a propeller and with a drain line for draining oil out of the pitch angle actuator for feathering the blades; and a bypass line having an inlet hydraulically between the valve and an inlet of the drain line, the bypass line having an outlet hydraulically between the inlet of the drain line and an outlet of the drain line.

Abstract: A method of controlling a wind turbine for the avoidance of edgewise vibrations. The method comprises the steps of determining a whirling mode frequency of a rotor blade of the wind turbine; determining a rotational frequency of the rotor blade corresponding to the speed of the rotor blade; determining a threshold value for the whirling mode frequency based on the rotational frequency; and, reducing the speed of the rotor blade if the whirling mode frequency substantially equals or is less than the threshold value.

Abstract: A compact and unobtrusive rotor control mechanism is presented that provides collective and cyclic pitch change to both rotors of a coaxial rotor system as well as a differential collective pitch change to one or both rotors simultaneously.

Abstract: A rotor assembly includes a plurality of wheels and a tie bolt that extends through the plurality of wheels and applies a compressive force to the plurality of wheels. The tie bolt includes a first segment with a first stiffness and a second segment with a second stiffness to allow for thermal growth of the plurality of wheels.

Abstract: A system includes a gas turbine component having a recessed portion with a recessed surface in a hard-to-weld (HTW) material. The system includes a plate disposed over the recessed portion. The plate has an easy-to-weld (ETW) material. The plate has an outer surface and an inner surface, and the inner surface faces the recessed portion. The system includes a braze material disposed within the recessed portion between the recessed surface and the inner surface of the plate. The braze material is configured to bond the recessed surface of the recessed portion with the inner surface of the plate when the braze material is heated to a brazing temperature. The system includes a filler material disposed on the outer surface of the plate disposed over the recessed portion. Application of the filler material to the outer surface of the plate is configured to heat the braze material to the brazing temperature.

Abstract: The disclosure provides a liquid storage device configured for storing a working liquid and including a casing and a liquid driving device. The casing includes a reservoir and an accommodation part detachably disposed on the reservoir. The reservoir has a reservoir chamber. The liquid driving device is disposed in the accommodation part and forms a liquid chamber. The liquid driving device includes an impeller located in the liquid chamber and configured to force the working liquid to flow towards the liquid chamber from the reservoir chamber.

Abstract: A roller element device, in particular for a gas turbine engine, comprises an outer ring with an inner raceway, an inner ring with an outer raceway, and roller elements which are arranged between the raceways so as to roll thereon, wherein the outer ring and the inner ring are each connected via a connecting portion to a respective fixing portion for fixing to one of two components which are rotatable relative to each other about a rotation axis, and the connecting portions are formed such that the two raceways can be jointly tilted at least in portions relative to the rotation axis.

Abstract: Systems, methods, lift fans, and aircraft involving active flow control of a ducted fan or fan-in-wing configuration are described.

Abstract: A lubrication system for a drive train of a wind turbine includes an oil reservoir having an outlet, a supply valve, a gearbox having an oil inlet and oil outlet, a drain valve and a siphon is provided. The oil reservoir is coupled to the supply valve and the supply valve is coupled to the inlet of the gearbox. The oil outlet of the gearbox is coupled to the drain valve and to a first end of the siphon. The supply valve is configured to open in an off-grid state of the wind turbine and the drain valve is configured to close in the off-grid state of the wind turbine. The siphon is configured to adjust an internal oil level in the gearbox in the off-grid state of the wind turbine.

Abstract: Rotor hubs having pitch control systems and related methods are disclosed herein. An example apparatus includes a housing including a first housing arm to support a first blade grip and a first blade spindle and a second housing arm to support a second blade grip and a second blade spindle. The example apparatus includes a first pitch link and a second pitch link. The example apparatus includes a first pitch arm coupled to the first pitch link and one of the first blade grip or the first blade spindle and a second pitch arm coupled to the second pitch link and one of the second blade grip or the second blade spindle. The second pitch arm is to extend past the first housing arm to couple with the one of the second blade grip or the second blade spindle.