| Patent application number | Description | Published |
| 20080247876 | Soft In-Plane Tiltrotor Hub - 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. | 10-09-2008 |
| 20080267778 | Torque Coupling for Rotary-Wing Aircraft - A torque coupling ( | 10-30-2008 |
| 20080292468 | Stiff-in-Plane Gimbaled Tiltrotor Hub - A rotor-hub for a rotary-wing aircraft is disclosed. The rotor-hub comprises a yoke comprising a plurality of yoke arms and a plurality of yoke straps, wherein the yoke arms are joined together by the yoke straps, and wherein a plurality of inner walls of the yoke define a central void space. A pitch horn is movably connected to the yoke and a portion of the pitch horn is located within the central void space. A connecting shell is fixedly attached to the yoke. | 11-27-2008 |
| 20090179107 | Yoke with Notched Arm Roots - 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. | 07-16-2009 |
| 20090325718 | Constant Velocity Joint for Tiltrotor Hubs - 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. | 12-31-2009 |
| 20100009764 | Rotary-Wing Aircraft Torque Coupling with Pad Bearings - A torque coupling for a rotor head of a rotary-wing aircraft is configured for rotation with a mast and for causing rotation of an attached yoke. The coupling has trunnions that rotate with the mast and extend generally radially. Pad-bearing assemblies each have a central member coupled to one of the trunnions with a laminated spherical bearing and have laminated pad bearings affixed to opposing sides of the central member. The laminated bearings have alternating rigid and elastomeric layers. A bearing mount is affixed to each pad bearing and is connected to a yoke for rotating the yoke with the mast. The pad-bearing assemblies allow for relative motion between each central member and the associated trunnion and between each central member and the bearing mounts through elastic shear deformation, and this allows for gimballing of the attached yoke relative to the mast. | 01-14-2010 |
| 20100021301 | Step-Over Blade-Pitch Control System - A pitch control system for blades on a rotor of an aircraft has a gimballing rotor hub ( | 01-28-2010 |
| 20100090055 | Vibration-Attenuating Hard-Mounted Pylon - A preferred embodiment of a pylon has six pylon mounting links for mounting the pylon to an airframe. Each link is considered “near-rigid” and has a spherical-bearing rod-end on both ends such that the link can only transmit axial loads. At least one of the links has a mass carried within the link and selectively moveable by an actuating means along the axis of the link in an oscillatory manner for attenuating vibrations traveling axially through the link. The actuating means may be an electromechanical, hydraulic, pneumatic, or piezoelectric system. By mounting each link in a selected orientation relative to the other links, the actuating means may be operated in a manner that attenuates axial vibration that would otherwise be transmitted through the link and into the airframe. | 04-15-2010 |
| 20100209242 | Rotor Hub Vibration Attenuator - A vibration attenuator for an aircraft has at least one weight mounted in a rotating system of a rotor hub of the aircraft, each weight being rotatable about an axis of rotation of the hub relative to the hub and to each other weight. Drive means are provided for rotating each weight about the axis of rotation at a selected speed for creating oscillatory shear forces that oppose and attenuate rotor-induced vibrations having a selected frequency. | 08-19-2010 |
| 20100230529 | CF BEARING WITH STEADY PITCHING MOMENT - A centrifugal force bearing having a means for providing a steady pitching moment is disclosed. The centrifugal force bearing may optionally comprise a coning means. A rotor system having the centrifugal force bearing is disclosed. A rotary-wing aircraft having the centrifugal force bearing is disclosed. | 09-16-2010 |
| 20100266411 | Constant-Velocity Joint with Torque-Combining Differential - A constant-velocity drive system for an aircraft rotor has a gimbal mechanism and a differential torque-combining mechanism. The gimbal mechanism has gimbals driven in rotation by a rotor mast about a mast axis, the gimbals providing for gimballing relative to the mast about gimbal axes generally perpendicular to the mast axis. The differential torque-combining mechanism is connected to the gimbal mechanism and configured to be driven in rotation about the mast axis by the gimbal mechanism. The differential mechanism is capable of gimballing relative to the mast about the gimbal axes, the differential torque-combining mechanism having an output component attached to a yoke of the rotor for driving the yoke in rotation with the differential torque-combining mechanism. | 10-21-2010 |
| 20100301160 | Method and Apparatus for Improved Vibration Isolation - A vibration isolator is disclosed having a housing which defines a fluid chamber. A piston, which is movable to and from a down position, is disposed within the housing. A vibration isolation fluid is disposed within the fluid chamber. A passage having a predetermined diameter extends through the piston to permit the vibration isolation fluid to flow from one fluid chamber to the other. An elastic element is provided for reducing transmission of vibrations from the piston to the housing when the piston is at the down position. | 12-02-2010 |
| 20100314492 | Multiple Drive-Path Transmission with Torque-Splitting Differential Mechanism - A transmission for a rotary-wing aircraft has a differential torque-splitting mechanism associated with an input shaft. The differential has a drive disk coaxial with the shaft and integral in rotation with the shaft, a first driven member coaxial with the shaft and generally adjacent the drive disk, and a second driven member coaxial with the shaft and generally adjacent the drive disk. At least one pin engages each of the drive disk, the first driven member, and the second driven member. The first driven member is configured to drive a first transfer gear, and the second driven member is configured to drive a second transfer gear for supplying torque to a bull gear associated with a rotor mast. | 12-16-2010 |
| 20110027083 | Lead-Lag Damper for Rotor Hubs - A lead-lag damper for a rotor assembly has a body mounted to either an inboard portion of a blade assembly or a fixed portion of the rotor assembly. A piston carried within the body is configured to allow for relative motion between the body and the piston. The piston defines opposing chambers within the body, the chambers being in fluid communication through a fluid passage. A link connects the piston to the other of the inboard portion of the blade assembly and the fixed portion of the rotor assembly, and the link engages a central portion of the piston. The piston acts on fluid in the chambers during relative motion between the piston and the body and causes fluid flow between the chambers through the fluid passage. Flow through the passage acts to damp lead-lag motion of the blade assembly relative to the fixed portion of the rotor assembly. | 02-03-2011 |