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 rotor assembly includes a pitch spider, rotor blade assemblies, and pitch horn joints. The pitch spider has a body and pitch spider legs extending from the body. Each blade rotor assembly includes a rotor blade, a pitch adapter joined to the rotor blade and connecting the rotor blade to the rotor hub, and a pitch horn. Each pitch horn joint joins one of the rotor blade assemblies to a corresponding pitch spider leg. Each pitch horn joint includes a pitch horn joint bolt extending from the pitch horn of the rotor blade assembly to the pitch spider leg along a pitch horn joint axis, the pitch horn joint bolt fixed to the pitch horn; a spherical bearing having an inner ring and an outer ring; and a slider sleeve coupled to the spherical bearing, the slider sleeve enabling the pitch horn to translate along the pitch horn joint axis.

Abstract: One embodiment includes a swashplate assembly for a rotary aircraft, including: a rotating ring configured to rotate with a drive shaft of the rotary aircraft; a non-rotating ring coupled to the rotating ring and rotationally decoupled from the rotating ring, wherein the non-rotating ring does not rotate with the rotating ring and drive shaft; an outer casing disposed around the gearbox; and an anti-drive mechanism to maintain the outer casing rotationally stationary relative to the gearbox, the anti-drive mechanism including a key and slot system between the gearbox and the outer casing.

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 rotor assembly includes a pitch spider, rotor blade assemblies, and pitch horn joints. The pitch spider has a body and pitch spider legs extending from the body. Each blade rotor assembly includes a rotor blade, a pitch adapter joined to the rotor blade and connecting the rotor blade to the rotor hub, and a pitch horn. Each pitch horn joint joins one of the rotor blade assemblies to a corresponding pitch spider leg. Each pitch horn joint includes a pitch horn joint bolt extending from the pitch horn of the rotor blade assembly to the pitch spider leg along a pitch horn joint axis, the pitch horn joint bolt fixed to the pitch horn; a spherical bearing having an inner ring and an outer ring; and a slider sleeve coupled to the spherical bearing, the slider sleeve enabling the pitch horn to translate along the pitch horn joint axis.

Abstract: One embodiment includes a swashplate assembly for a rotary aircraft, including: a rotating ring configured to rotate with a drive shaft of the rotary aircraft; a non-rotating ring coupled to the rotating ring and rotationally decoupled from the rotating ring, wherein the non-rotating ring does not rotate with the rotating ring and drive shaft; an outer casing disposed around the gearbox; and an anti-drive mechanism to maintain the outer casing rotationally stationary relative to the gearbox, the anti-drive mechanism including a key and slot system between the gearbox and the outer casing.

Abstract: A rotor hub and method to dampen a force exerted on a rotor hub by a rotor blade during flight. The rotor hub including a central member rotatably coupled to a rotor mast, a blade grip rigidly attached to a blade and movably coupled to the central member, and an adjustable damper operably associated with the blade grip. The method includes damping the force exerted on the rotor hub with the adjustable damper and selectively adjusting the adjustable damper between a first spring rate and a second spring rate.

Abstract: A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub (31) and a plurality of step-over arms (61) connected to the hub and capable of pivoting relative to the hub about a pivot axis. Each of a plurality of pitch links (55) connects one of the step-over arms (61) to a flight control system for pivoting the connected step-over arm (61) about the pivot axis and relative to the hub in response to inputs from the control system. Each of a plurality of step-over links (69) connects one of the step-over arms (61) to one of the blades for rotating the associated blade about the pitch axis in response to pivoting of the associated step-over arm.

Abstract: A rotor hub and method to dampen a force exerted on a rotor hub by a rotor blade during flight. The rotor hub including a central member rotatably coupled to a rotor mast, a blade grip rigidly attached to a blade and movably coupled to the central member, and an adjustable damper operably associated with the blade grip. The method includes damping the force exerted on the rotor hub with the adjustable damper and selectively adjusting the adjustable damper between a first spring rate and a second spring rate.

Abstract: A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.

Abstract: A rotor hub assembly for a rotary-wing aircraft has a central member and a plurality of blade grips adapted for attaching rotor blades to the central member. The blade grips are pivotally attached to the central member and are capable of pivoting about a pivot axis generally normal to a plane of rotation of the blades. The pivoting allows for in-plane motion of the blades relative to the central member. A damper is operably connected to each blade grip for damping the in-plane motion of the associated blade, each damper being selectively switchable between at least two spring rates.

Abstract: A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub (31) and a plurality of step-over arms (61) connected to the hub and capable of pivoting relative to the hub about a pivot axis. Each of a plurality of pitch links (55) connects one of the step-over arms (61) to a flight control system for pivoting the connected step-over arm (61) about the pivot axis and relative to the hub in response to inputs from the control system. Each of a plurality of step-over links (69) connects one of the step-over arms (61) to one of the blades for rotating the associated blade about the pitch axis in response to pivoting of the associated step-over arm.

Abstract: A rotor hub assembly for a rotary-wing aircraft has a central member and a plurality of blade grips adapted for attaching rotor blades to the central member. The blade grips are pivotally attached to the central member and are capable of pivoting about a pivot axis generally normal to a plane of rotation of the blades. The pivoting allows for in-plane motion of the blades relative to the central member. A damper is operably connected to each blade grip for damping the in-plane motion of the associated blade, each damper being selectively switchable between at least two spring rates.

Abstract: A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.