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 yoke and bearing fitting assembly for a multi-blade aircraft rotor is disclosed. The assembly has a yoke having arms extending generally radially from a central portion of the yoke, the arms each having opposing surfaces. An aperture is formed in each arm and extends between the surfaces. A bearing fitting has a body configured for insertion into the aperture of the yoke and has two rims protruding from a periphery of the body, the body also having a bearing mount adapted for mounting a pitch change bearing assembly to the yoke. Each rim abuts one of the surfaces of the associated yoke arm when the bearing fitting is installed within the aperture, so as to create clamping forces between the rims and the arm and the arm. The bearing fitting transmits forces from the pitch bearing assembly into the yoke.

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 yoke and bearing fitting assembly for a multi-blade aircraft rotor is disclosed. The assembly has a yoke having arms extending generally radially from a central portion of the yoke, the arms each having opposing surfaces. An aperture is formed in each arm and extends between the surfaces. A bearing fitting has a body configured for insertion into the aperture of the yoke and has two rims protruding from a periphery of the body, the body also having a bearing mount adapted for mounting a pitch change bearing assembly to the yoke. Each rim abuts one of the surfaces of the associated yoke arm when the bearing fitting is installed within the aperture, so as to create clamping forces between the rims and the arm and the arm. The bearing fitting transmits forces from the pitch bearing assembly into the yoke.

Abstract: A yoke for a rotary wing aircraft rotor system has a plurality of arms, each arm having a root. Each root has a notched portion configured to allow passage of a portion of a blade-pitch control system through the notched portion.

Abstract: A joint is configured for use with a rotary-wing aircraft having at least one engine. A driver is coupled to an output shaft of the engine, the driver being rotatable about an axis. A yoke is at least partially rotatable relative to the driver about a first center of rotation, the center of rotation being located on the axis. A plurality of upright links couple the yoke to the driver, each link being translatable relative to the yoke, the driver, or both. Each link is also rotatable relative to the yoke, the driver, or both, about a second center of rotation.

Abstract: An assembly for providing flexure to a blade of a rotary blade system includes an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces has a layer of cushioning material positioned thereon and secured thereto. An alternate embodiment includes an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle. Another alternate embodiment includes a similar assembly having a twist-shank type of yoke for providing rotation of attached blades about their respective pitch axes.

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 constant-velocity joint is configured for use with a rotary-wing aircraft having at least one engine. A driver is coupled to an output shaft of the engine, the driver being rotatable about an axis. A yoke is at least partially rotatable relative to the driver about a first center of rotation, the center of rotation being located on the axis. A plurality of upright links couple the yoke to the driver, each link being translatable relative to the yoke, the driver, or both. Each link is also rotatable relative to the yoke, the driver, or both, about a second center of rotation.

Abstract: A yoke for a rotary wing aircraft rotor system has a plurality of arms, each arm having a root. Each root has a notched portion configured to allow passage of a portion of a blade-pitch control system through the notched portion.

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: An assembly for providing flexure to a blade of a rotary blade system includes an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces has a layer of cushioning material positioned thereon and secured thereto. An alternate embodiment includes an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle. Another alternate embodiment includes a similar assembly having a twist-shank type of yoke for providing rotation of attached blades about their respective pitch axes.

Abstract: An improved door for a horizontal axis fabric treatment machine. The door is designed to removably cover an access opening in a perforated inner drum and includes a series of interwoven elongated fabric strips which are attached at each end to the drum by a series of buckles. The buckles include a frame portion attached to the drum and a tongue portion attached to an end of the elongated fabric strip. The fabric strips define living hinges adjacent each end thereof, allowing the door to open in a number of directions. The access opening is revealed by opening the buckles on three sides of the door, and pivoting the door about the living hinge provided on the fourth side. The buckles allow the door to be completely removed and replaced without tools. The door exploits membrane stiffness to retain, support, and transfer the weight or load from the door to the surrounding drum.

Abstract: The present invention is directed towards a removable heat exchanger for a fabric treating machine. The machine generally includes a perforated spin tub and an imperforate outer shell. In one embodiment the heat exchangers, which are removably mounted to an inner surface of the outer shell, are guided during installation and removal by guide clips. Spacers maintain the heat exchangers a predetermined distance from the inner surface of the outer shell. Retainer clips are provided to releasably retain the heat exchanger in position relative to the spin tub during operation of the machine. In a second embodiment the heat exchangers, which are mounted within side pockets provided by the outer shell. In both the first and second embodiments, the heat exchangers are held in place by jacking bolts. The removable heat exchanger of the present invention improves upon welded-in-place internal heat exchangers and external heat exchangers.

Abstract: A fuel delivery system for a turbine engine having a primary fuel flow circuit and a secondary fuel flow circuit. The primary fuel flow circuit has a unstaged-first manifold and a staged-second manifold. A control valve and flow meter regulate the amount of fuel flow to the unstaged and staged manifolds with a first mode of operation providing fuel to the unstaged manifold only, and a second mode of operation providing fuel to both the staged and unstaged manifolds. When high power is required of the engine, a secondary fuel circuit is provided with a secondary manifold which is connected to a distribution valve which opens when fuel flow is at a predetermined level. The invention allows fuel to be efficiently atomized at various levels of powered operation by having a control center which controls the opening and closing of the distribution valve and control valve based upon fuel flow rates fuel/air ratios and air start core speed.

Abstract: A combustor dome assembly having a venturi and an auxiliary wall concentric with the venturi to provide an annular passage for channeling or directing a high velocity air jet from a swirler to a combustion chamber associated with a downstream end of the venturi, thereby facilitating the atomization of a film of water flowing along an inner surface of the venturi and out of the downstream end. In an alternative embodiment, a deflector is used (instead of the auxiliary wall) to direct the air flow towards the downstream end. The downstream end of the venturi may have a curved edge to permit the film of water flowing along an inner surface of the venturi to turn substantially perpendicular to the air flowing past the downstream end of the venturi which further enhances atomization of water. The venturi may also comprise a flange which is positioned in operative relationship with the downstream end for increasing the turbulence at the downstream end.

Abstract: In accordance with one aspect of the invention, a venturi having a heat shield along its inner diameter and a thermal barrier coating along its outer diameter is provided, whereby the temperature gradient of the venturi is lowered and metal distress and erosion caused by water injected therethrough is reduced. In an alternate embodiment, a floating insert is placed within an area along the venturi's inner diameter, where it is held in position by a heat shield.