Abstract: Systems and methods include providing an aircraft with a fuselage and a wing assembly rotatable relative to the fuselage about a stow axis between a flight position and a stowed position. The aircraft includes an engine reduction gearbox having a retractable driveshaft that selectively engages the mid-wing gearbox via axially translatable motion along a rotation axis when the wing assembly is in the flight position. The mid-wing gearbox includes a plunger seal that is displaced in response to contact with the retractable driveshaft. Displacement of the plunger seal allows lubricant to flow through an inner bore in the retractable driveshaft, across splines of the retractable driveshaft and the mid-wing gearbox, and through lubrication ports in the mid-wing gearbox to lubricate the engine reduction gearbox, splines of the retractable driveshaft and the mid-wing gearbox, and the mid-wing gearbox via a single lubrication system.

Abstract: A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located below the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is mounted on the top surface of the wing. The engine and proprotor assembly are connected via a series of one or more gearboxes that route the engine output from the engine to the proprotor.

Abstract: A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located on the top surface of the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is also mounted on the top surface of the wing. The engine and proprotor assembly are connected via a series of one or more gearboxes that route the engine output from the engine to the proprotor.

Abstract: Systems and methods include providing an aircraft with a fuselage and a wing assembly rotatable relative to the fuselage about a stow axis between a flight position and a stowed position. The aircraft includes a gearbox having a retractable driveshaft that selectively engages the mid-wing gearbox via axially translatable motion along a rotation axis when the wing assembly is in the flight position. The retractable driveshaft also selectively disengages the mid-wing gearbox in the flight position to allow selectively rotation of the wing assembly about the stow axis from the flight position to the stowed position resulting in the mid-wing gearbox being misaligned with the retractable driveshaft when the wing assembly is in the stowed position.

Abstract: A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located below the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is mounted on the top surface of the wing. The engine and proprotor assembly are connected via a series of one or more gearboxes that route the engine output from the engine to the proprotor.

Abstract: A tiltrotor aircraft includes a propulsion system with a fixed engine and a rotatable proprotor. The engine is located on the top surface of the wing of the tiltrotor aircraft, and the rotatable proprotor assembly is also mounted on the top surface of the wing. The engine and proprotor assembly are connected via a series of one or more gearboxes that route the engine output from the engine to the proprotor.

Abstract: The present disclosure provides a lubricating system for a dual splined hollow shaft. A fluid dam is formed circumferentially within the hollow shaft to control the lubrication of the dual splines. The fluid dam includes a pair of sidewalls extending radially inward from the inner wall of the hollow shaft to a height defined by a top wait. A channel formed through the pair of sidewalls permits the movement of lubricant between splines of the hollow shaft. An egress port extends from the top wall of the dam through the outer wall of the hollow shaft to permit lubricant to exit the hollow shaft.

Abstract: Systems and methods include providing an aircraft with a fuselage and a wing assembly rotatable relative to the fuselage about a stow axis between a flight position and a stowed position. The aircraft includes an engine reduction gearbox having a retractable driveshaft that selectively engages the mid-wing gearbox via axially translatable motion along a rotation axis when the wing assembly is in the flight position. The mid-wing gearbox includes a plunger seal that is displaced in response to contact with the retractable driveshaft. Displacement of the plunger seal allows lubricant to flow through an inner bore in the retractable driveshaft, across splines of the retractable driveshaft and the mid-wing gearbox, and through lubrication ports in the mid-wing gearbox to lubricate the engine reduction gearbox, splines of the retractable driveshaft and the mid-wing gearbox, and the mid-wing gearbox via a single lubrication system.

Abstract: Systems and methods include providing an aircraft with a fuselage and a wing assembly rotatable relative to the fuselage about a stow axis between a flight position and a stowed position. The aircraft includes a gearbox having a retractable driveshaft that selectively engages the mid-wing gearbox via axially translatable motion along a rotation axis when the wing assembly is in the flight position. The retractable driveshaft also selectively disengages the mid-wing gearbox in the flight position to allow selectively rotation of the wing assembly about the stow axis from the flight position to the stowed position resulting in the mid-wing gearbox being misaligned with the retractable driveshaft when the wing assembly is in the stowed position.

Abstract: A drivetrain subassembly includes a clutch portion and a gear shaft portion connected by an integrated inner race/gear shaft member. The clutch portion includes a sprag clutch configured to transfer torque from an engine to a rotor system while allowing the rotor system to continue to rotate in the event of an engine failure. The inner race of the clutch portion is integrally formed with the gear shaft of the gear shaft portion of the subassembly. The gear shaft is configured to rotate about the longitudinal axis of the sprag clutch for transmitting torque from the sprag clutch to a downstream drivetrain component.

Abstract: The present disclosure provides a lubricating system for a dual splined hollow shaft. A fluid dam is formed circumferentially within the hollow shaft to control the lubrication of the dual splines. The fluid dam includes a pair of sidewalls extending radially inward from the inner wall of the hollow shaft to a height defined by a top wait. A channel formed through the pair of sidewalls permits the movement of lubricant between splines of the hollow shaft. An egress port extends from the top wall of the dam through the outer wall of the hollow shaft to permit lubricant to exit the hollow shaft.

Abstract: The present disclosure provides a lubricating system for a dual splined hollow shaft. A fluid dam is formed circumferentially within the hollow shaft to control the lubrication of the dual splines. The fluid dam includes a pair of sidewalls extending radially inward from the inner wall of the hollow shaft to a height defined by a top wall. A channel formed through the pair of sidewalls permits the movement of lubricant between splines of the hollow shaft. An egress port extends from the top wall of the dam through the outer wall of the hollow shaft to permit lubricant to exit the hollow shaft.

Abstract: The present disclosure provides a lubricating system for a dual splined hollow shaft. A fluid dam is formed circumferentially within the hollow shaft to control the lubrication of the dual splines. The fluid dam includes a pair of sidewalls extending radially inward from the inner wall of the hollow shaft to a height defined by a top wall. A channel formed through the pair of sidewalls permits the movement of lubricant between splines of the hollow shaft. An egress port extends from the top wall of the dam through the outer wall of the hollow shaft to permit lubricant to exit the hollow shaft.