Abstract: A hybrid yoke including a center and yoke arms connected to flexure arms. An inboard centrifugal force bearing assembly connects to the yoke arm and a grip and an outboard shear bearing assembly connects to the flexure arm and the grip. In use, the center and yoke arms carry the centrifugal force at a position inboard of the flexure arm.

Abstract: A high stiffness hub assembly for a rotor system operable to rotate with a mast of a rotorcraft. The hub assembly includes a yoke and a constant velocity joint assembly. The yoke has a plurality of blade arms each configured to hold a rotor blade. The constant velocity joint assembly provides a torque path from the mast to the yoke that includes a trunnion assembly, a plurality of drive links and a plurality of pillow blocks. The trunnion assembly is coupled to the mast and has a plurality of outwardly extending trunnions. Each drive link has a leading bearing coupled to one of the trunnions and a trailing bearing coupled to one of the pillow blocks. Each pillow block is independently mounted between an upper surface of the yoke and a hub plate.

Abstract: A rotor blade assembly for a tiltrotor aircraft comprising a rotor blade pivotally connected to a yoke with dual concentric blade bolts having a common central axis providing a pivotal axis inboard of an outboard CF bearing and the yoke tip. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A folding yoke comprising a center yoke pivotally connected to separate foldable flexible yoke arms permits rotor blade fold about a single through bolt connection inboard of a set of bearings. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A folding rotor blade assembly for a tiltrotor aircraft comprising a rotor blade pivotally connected to a grip with dual concentric blade bolts having a common central axis providing a pivotal axis inboard of an outboard bearing. A folding spindle connects the outboard bearing to an outboard tip of a yoke. The outboard bearing and the spindle fold with the rotor blade relative to the yoke. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A yoke split into separate, individual yoke arms permit rotor blade fold about inboard yoke arm bolts in a rotor blade assembly for rotorcraft and tiltrotor aircraft. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A folding yoke comprising a bilateral center yoke pivotally connected to separate foldable yoke arms permits rotor blade fold about a single through bolt connection inboard of a set of bearings. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A folding rotor blade assembly for a tiltrotor aircraft comprising a rotor blade pivotally connected to a yoke with dual concentric blade bolts having a common central axis providing a pivotal axis inboard of an outboard shear bearing. In use, the compact folded arrangement of the rotor blades reduces folded aircraft dimensions in response to ever increasing restricted storage space parameters.

Abstract: A high stiffness hub assembly for a proprotor system operable to rotate with a mast of a tiltrotor aircraft having helicopter and airplane flight modes. The hub assembly includes a yoke and a constant velocity joint assembly. The yoke has four blade arms each adapted to hold a proprotor blade. The constant velocity joint assembly provides a torque path from the mast to the yoke that includes a trunnion assembly, four drive links and four pillow blocks. The trunnion assembly is coupled to the mast and has four outwardly extending trunnions. Each drive link has a leading bearing coupled to one of the trunnions and a trailing bearing coupled to one of the pillow blocks. Each pillow block is independently mounted between an upper surface of the yoke and a hub plate with two connection members that extend through the yoke and the pillow block.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket with an outboard surface. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a shear bearing and a centrifugal force bearing having an integral shoe with an outboard surface. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. The integral shoes are coupled to the yoke such that there is a spaced apart relationship between the outboard surfaces of the integral shoes and the outboard surfaces of the pockets to prevent centrifugal force load transfer therebetween.

Abstract: A proprotor system for a tiltrotor aircraft having helicopter and airplane flight modes includes a yoke having a plurality of blade arms each having an inboard pocket. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets with each bearing assembly including a bearing cage, a shear bearing and a centrifugal force bearing. Each of a plurality of inboard beams is disposed at least partially between one of the centrifugal force bearings and one of the shear bearings. Each of a plurality of proprotor blades is coupled to one of the inboard beams. Hub bolts couple each of the bearing cages to the yoke such that the hub bolts provide centrifugal force load paths between the bearing assemblies and the yoke inboard of the inboard pockets.

Abstract: A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode includes a yoke having a plurality of blade arms each having an inboard pocket with a load transfer surface. Each of a plurality of bearing assemblies is disposed at least partially within one of the inboard pockets. Each of a plurality of inboard beams is disposed at least partially between a centrifugal force bearing and a shear bearing of each bearing assembly and has a proprotor blade coupled thereto. Each of a plurality of independent shoes is coupled between one of the centrifugal force bearings and the yoke. Each shoe has a load transfer surface that has a contact relationship with the load transfer surface of the respective inboard pocket forming a centrifugal force load path therebetween.

Abstract: A proprotor system for a tiltrotor aircraft having a helicopter flight mode and an airplane flight mode. The proprotor system includes a yoke having a plurality of blade arms with inboard pockets. A centrifugal force and shear bearing assembly is disposed in each of the inboard pockets of the yoke. Each of a plurality of proprotor blades is coupled to the yoke by one of the bearing assemblies such that each proprotor blade has a pitch change degree of freedom about a pitch change axis and a tilting degree of freedom about a focal point. Each bearing assembly includes a centrifugal force bearing coupled to the yoke, a shear bearing coupled to the yoke and an inboard beam coupled between the centrifugal force bearing and the shear bearing. Each inboard beam is coupled to a respective proprotor blade.

Abstract: A high stiffness hub assembly for a proprotor system operable to rotate with a mast of a tiltrotor aircraft having helicopter and airplane flight modes. The hub assembly includes a yoke and a constant velocity joint assembly. The yoke has four blade arms each adapted to hold a proprotor blade. The constant velocity joint assembly provides a torque path from the mast to the yoke that includes a trunnion assembly, four drive links and four pillow blocks. The trunnion assembly is coupled to the mast and has four outwardly extending trunnions. Each drive link has a leading bearing coupled to one of the trunnions and a trailing bearing coupled to one of the pillow blocks. Each pillow block is independently mounted between an upper surface of the yoke and a hub plate with two connection members that extend through the yoke and the pillow block.

Abstract: The present invention includes methods of preparing a composite structure comprising: placing a first ply of a fibrous material with a curable material on a layup tool; adding one or more additional plies on the first ply, wherein each of the one or more additional plies has a perimeter that is different in size around the perimeter than a previous ply to form a taper; and curing the composite structure, wherein the curable material is selected to minimize, limit, control, or eliminate the outflow of the curable material along the perimeter of the composite structure during the curing step.

Abstract: An engine mount assembly for coupling an engine to an airframe includes a torsion bar, a lateral movement control assembly and a vertical movement control assembly. The torsion bar has a torsional stiffness and is coupled between the engine and the airframe such that torsional movement of the engine causes torsion in the torsion bar. The lateral movement control assembly has a lateral stiffness and is coupled between the torsion bar and the airframe such that lateral movement of the engine causes rotation of the torsion bar which reacts on lateral movement control assembly. The vertical movement control assembly has a vertical stiffness and is coupled between the engine and the airframe such that vertical movement of the engine reacts on the vertical movement control assembly. The engine mount assembly, thereby enables torsional, lateral and vertical movement of the engine to be independently controlled.

Abstract: An engine mount assembly for coupling an engine to an airframe. The engine mount assembly includes a torsion bar coupled between the engine and the airframe. The torsion bar has upper and lower tapered bosses. Upper and lower arm assemblies couple the engine to the torsion bar. Each arm assembly has an end bell crank with a tapered socket that is adapted to receive a respective tapered boss therein to secure the end bell cranks to the torsion bar such that the end bell cranks rotate with the torsion bar responsive to movements of the engine.