Abstract: A fluid pressure regulating system includes an auxiliary fluid circuit having a high pressure region and a low pressure region, a pump connected to the auxiliary fluid circuit and configured to discharge fluid into the high pressure region of the auxiliary fluid circuit, and a check valve connecting the high pressure region of the auxiliary fluid circuit to a main fluid interface line. The fluid pressure regulating system also includes a pressure regulating valve connecting the high pressure region of the auxiliary fluid circuit and the low pressure region of the auxiliary fluid circuit. The pressure regulating valve includes an aperture defining a fluid path from the high pressure region of the auxiliary fluid circuit to the low pressure region of the auxiliary fluid circuit. The aperture has a variable area as a function of fluid pressure within the main fluid interface line.

Abstract: An airfoil assembly includes an airfoil body extending between a leading edge, a trailing edge, a suction side, and a pressure side. A first sheath having an outer side and an inner side forms a cavity for receiving at least a portion of the airfoil body and is bonded on the inner side to the leading edge of the airfoil body. The first sheath is formed of a titanium-based metallic material. A second sheath is bonded to the outer side of the first sheath.

Abstract: A propeller rotor has a hub mounting a plurality of blades. A counterweight is movably mounted on the blade. A pitch change mechanism for changing an angle of incidence of an airfoil is associated with each of the blades. The counterweight twists the blades toward an increased pitch direction should the pitch change mechanism fail. A stop member stops rotation of the counterweight as the blade moves to a feather position.

Abstract: A propeller rotor has a hub mounting a plurality of blades and a drive shaft for driving the hub and the blades about a central axis. A motor to change its position is operably connected to drive at least one counterweight. A sensor senses vibration on the propeller rotor and communicates with a controller. The controller controls the motor to change a position of the counterweight in response to a sensed imbalance. A method of operating a propeller rotor is also disclosed.

Abstract: A propeller system for an aircraft includes a propeller assembly rotatable about a central axis and a reduction gearbox operably connected to the propeller assembly via a propeller shaft. An electrical power transfer system is positioned such that the gearbox is located axially between the electrical power transfer system and the propeller assembly. The electrical power transfer system includes a slip ring assembly secured to an oil transfer tube extending to the propeller assembly and a brush block interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly. The brush block is positioned such that brush block tips of the brush block extend toward the slip ring assembly in a substantially radial direction relative to the central axis of the propeller assembly.

Abstract: A propeller system for an aircraft includes a propeller assembly rotatable about a central axis and a reduction gearbox operably connected to the propeller assembly via a propeller shaft. An electrical power transfer system is positioned such that the gearbox is located axially between the electrical power transfer system and the propeller assembly. The electrical power transfer system includes a slip ring assembly operably connected to an oil transfer tube extending to the propeller assembly and a brush block interactive with the slip ring assembly to transfer electrical power to a plurality of lead wires extending from the slip ring assembly to the propeller assembly. The brush block is positioned such that brush block tips of the brush block extend toward the slip ring assembly in a substantially axial direction relative to the central axis.

Abstract: A rotating assembly includes a shaft having a driven end and a driving end. At least one rotating member coupled to the driven end. A support member is operatively connected to the at least one rotating member. A dynamic balancing system is operatively coupled to the support member. The dynamic balancing system includes a first balancing weight rotatably mounted to the support member. The first balancing weight is operatively connected to a first motor. A second balancing weight is rotatably mounted to the support member. The second balancing weight is operatively connected to a second motor. A controller is operatively connected to the first and second motors. The controller is configured and disposed to signal each of the first and second motors to rotate and to establish a desired position of the first balancing weight and the second balancing weight relative to at least one rotating member.

Abstract: A tapered roller bearing element includes a first end and a second end, the second end having a second end radius. There is an apex ring between the two ends having an apex ring radius. There is also a base cone extending between the first end and the apex ring, the base cone tapering outwardly at a base cone angle. In addition, a relief cone extends between the apex ring and the second end, the relief cone tapers inwardly at a relief cone angle, and relief cone angle is larger than the base cone angle.

Abstract: A propeller blade pitch actuation system includes a propeller control module (PCM), a PCM drain line, a first drain line, a drain line restriction, a second drain line, and a valve. The PCM drain line connects to the PCM to drain hydraulic fluid. The first drain line is downstream of the PCM drain line and the drain line restriction is downstream of the first drain line. The second drain line is downstream of the PCM drain line. The valve includes a first valve position and a second valve position. The first valve position connects the PCM drain line to the first drain line and the second valve position connects the PCM drain line to the second drain line. Hydraulic pressure of the first drain line between the valve and the drain line restriction is greater than hydraulic pressure of the second drain line.

Abstract: A propeller blade includes a foam core having a slot formed through it from a camber side to a face side, an internal stiffener disposed through the slot and including flanges in contact with both the camber and face sides and a structural layer that surrounds at least a portion of the foam core and in contact with the flanges on both the camber and face sides.

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 propeller blade includes a foam core and a structural layer that surrounds at least a portion of the foam core and includes a face side and a camber side is disclosed. The propeller blade also includes an insert disposed in the foam core in operable contact with the face side and the camber side of the structural layer.

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: A mounting assembly for a propeller assembly component includes a monolithic piece having a housing and a mounting pad. An auxiliary component is directly mounted to the mounting pad of the monolithic piece.

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 split slip ring assembly formed from first and second halves of a slip ring having a contact surface for rotational engagement with a stationary brush element for transferring electrical signals there between. The contact surface has a smooth surface at the junction of the first and second halves. A fastener locates the first and second halves to form a ring shape. An electrical contact on the ring carries electrical signals between the slip ring and the brush element. An alignment element aligns the first and second halves to form the smooth surface at their junction.

Abstract: A fan blade for a turbine engine includes an exterior surface defining an airfoil that is provided by leading and trailing edges, opposing generally chord-wise surfaces interconnecting the leading and trailing edges, and a tip. The airfoil extends from a root. A fan rotor includes a slot that receives the root. A spar is constructed from a first material and includes opposing sides. The spar provides at least a portion of the exterior surface. A sheath is constructed from a second material different than the first material. The sheath is arranged on both of the opposing sides to provide at least a portion of the exterior surface at the opposing surfaces.

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes measuring a speed of a first rotor and deriving a speed of a second rotor and controlling a pitch of the first rotor and the second rotor.

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes mechanically linking a pitch change system of a first rotor with a pitch change system of a second rotor and commanding a Blade Angle (Beta1 commanded) of the first rotor such that a Blade Angle (Beta2 Actual) of the second rotor is a function of the commanded Blade Angle (Beta1 commanded) to provide a linear relationship between an actual Blade angle (Beta1 Actual) and Beta1 commanded of the first rotor and a non-linear relationship between Beta2 Actual and Beta1 commanded.

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.