Textron Innovations Inc.

Bell Helicopter Textron Inc.

Thomas C Campbell

Frank B Stamps

James Braswell, Jr

Richard Erler Rauber

Patrick R Tisdale

David Popelka

David A Popelka

James L Braswell

Bryan Kenneth Baskin

Michael Reaugh Smith

Daniel Bryan Robertson

Christopher Michael Bothwell

Ernst C Schellhase

Charles L Hollimon

Lawrence M Corso

Thomas J Newman

Keith Alan Stanney

Tom Donovan

Christopher Mike Bothwell

Mark E Wasikowski

Michael R Smith

Paul Branson Sherrill

David Allen Haynie

Ron Measom

Joseph J Zierer

Michael J Southerland

Tricia Hiros

Charles L Baskin

Tim Ledbetter

Ryan Smith

Joe J Zierer

John J Corrigan, Iii

James Lee Braswell

John J Iii Corrigan

Mark Wasikowski

Keith Stanney

Paul Sherrill

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.

Dual spring rate damper

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.

Yoke and bearing fitting assembly for rotors

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

Step-over blade-pitch control system

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.

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.

Yoke with notched arm roots

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.

Joint for tiltrotor hubs

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.

Assembly for providing flexure to blade system

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.

Soft in-plane tiltrotor hub

Growing community of inventors

Keller, TX, United States of America

Thomas C Campbell