Sikorsky Aircraft Corporation

United Technologies Corporation

Lockheed Martin Corporation

Bruce D Hansen

Edward H Bittner

Christopher John Mussel

Edward J Karedes

William P Fallon, Jr

Yuriy Gmirya

Bryan Kenneth Baskin

Clark VanTine Cooper

James P Cycon

Harsh Vinayak

Fred W Kohlhepp

Vincent F Millea

Tapas K Mukherji

Shane Lewis

Lawrence Mark Zunski

William Patrick Murphy

Jonathan Buckley

Wei Hu

Michael E Dandorph

A gear system for a rotary wing aircraft includes a first gear including an inner gear portion having a first pitch and an outer gear portion having a second pitch that is distinct from the first pitch. A second gear includes a third pitch driven at a driving rotational speed. An actuator member is coupled to the second gear while driven at the driving rotational speed. The actuator member shifts the second gear along the first gear to engage with one of the inner gear portion and the outer gear portion to drive the first gear at a first rotational speed and engage with other one of the inner gear portion and the outer gear portion to drive the first gear at a second rotational speed. A controller is operable to control the actuator member to shift the second gear between the inner gear portion and the outer gear portion.

Multi-speed gear box for a rotary wing aircraft

A hybrid gear includes a first portion having a plurality of first engagement features formed from a first material and having a first stiffness and a second portion having a plurality of second engagement features in intermeshing arrangement with the plurality of first engagement features. The plurality of second engagement features is formed from a second material distinct from the first material and having a second stiffness. The first stiffness of the plurality of first engagement features is within 20% of the second stiffness of the plurality of second engagement features.

Hybrid gear construction

A method of manufacturing a part is provided. The method includes heating a gear in the presence of carbon to carburize a material of the gear to create a carburized gear, the gear having a plurality of gear teeth and which comprises a selected material. Next, the carburized gear is high pressure gas quenched to drive the carbon into the material of the gear to create a quenched gear. Next, the quenched gear is at least one of cavitation peened and laser peened to create a peened gear. Finally, superfinishing is performed on surfaces of the peened gear.

Methods and processes of forming gears

A herringbone gear includes a cylindrical body having a circumferential face having a width. A first helical gear tooth on the circumferential face has a first configuration, a second helical gear tooth on the circumferential face has a second configuration, and a transition on the circumferential face extends between the first helical gear tooth and the second helical gear tooth. An involute form taken within a transverse plane of the circumferential face remains constant over the width.

Advanced herringbone gear design

A method of making bearings includes treating a metallic surface of a bearing raceway with a pulsed electrochemical processing nozzle to transform the amorphous oxide into a crystalline structure on the metallic surface electro-chemically and convert the metallic surface into a ceramic like hardness surface. Treating the metallic surface can include forming a gradient in material composition transitioning from a purely metallic material at a cross-sectional position within the bearing raceway to a purely crystalline structure material at the ceramic like hardness surface of the bearing raceway.

Electro-chemical hardening of bearing raceways

A gearbox is provided having a housing, a gear having a plurality of teeth operationally configured within the housing, and a laser peening device located within the housing and configured to perform active laser peening on a predetermined surface of the gear while the gear is rotated within the housing. A method of maintaining compressive residual stresses in a gear is provided, the method including operating a gearbox to rotate a gear within the gearbox and laser peening a predetermined surface of the gear with a laser peening device located within the gearbox.

Active peening of gear teeth in an assembled gearbox

A method of manufacturing a gear, the method includes applying a first charge to a workpiece and applying a second, opposite charge to an electrochemical machining (ECM) attachment, the ECM attachment having a pattern. The method further includes simultaneously forming a plurality of surfaces of a gear tooth in the workpiece using the pattern of the ECM attachment while applying the first charge to the workpiece and applying the second charge to the ECM attachment and turning the workpiece and the ECM attachment in opposite rotational directions. The plurality of surfaces includes at least one end face and a top land of the gear tooth.

Precision electrochemical machine for gear manufacture

A method of carburizing a steel component having a composition of Fe-16.3Co-7.5Ni-3.5Cr-1.75Mo-0.2W-0.11C-0.03Ti-0.02V includes generating a low pressure vacuum in a carburization furnace having the steel component therein, heating the steel component to an optimal carburization temperature while in the low pressure vacuum, performing a boost cycle to introduce carbon rich gas into the carburization furnace while the steel component is at the optimal carburization temperature and in the low pressure vacuum, and performing a diffuse cycle by ceasing introduction of the carbon rich gas into the carburization furnace to allow for diffusion of the carbon into the steel component to occur and while the steel component is at the optimal carburization temperature and in the low pressure vacuum. The boost cycle and the diffuse cycle are repeated to achieve a carbon content at a surface of the steel component of between 0.40 wt. % and 0.55 wt. %.

Carburization of steel components

A method of manufacturing a gear is provided. The method includes forming a plurality of gear teeth in a surface of a gear, the gear teeth having tooth faces defining tooth edges including tooth edge flanks and tooth edge top land and generating a convex contour at an edge break of at least one of the tooth edge flanks and tooth edge top land.

Convex gear tooth edge break

A surface processing method includes the step of increasing a surface hardness of a metal having a nominal composition that includes about 0.21-0.25 wt % carbon, about 2.9-3.3 wt % chromium, about 11-12 wt % nickel, about 13-14 wt % cobalt, about 1.1-1.3 wt % molybdenum, and a balance of iron from a first hardness to a second hardness. For example, the method is used to produce a surface-hardened component that includes a core section having a first hardness between about 51 HRand 55 HRand a case section having a second hardness that is greater than the first hardness.

Gear material for an enhanced rotorcraft drive system

A method for improving acoustic and vibrational properties of gears includes determining the transmission errors of intermeshing gears due to stiffness variations in the gear teeth, performing Gear Tooth Topological (GTT) modifications to compensate for the errors, and isotropically processing the gears to produce an ultra-smooth surface finish. Additional errors from isotropic processing, machining, loading, thermal effects and/or load sharing may be summed with the errors from the stiffness variations and used for the GTT modifications. The teachings of the present invention may reduce noise by as much as 13 to 15 dB.

Gear tooth topological modification for reducing noise and vibration in transmission systems

A drive train assembly for a rotor assembly having ducted, coaxial counter-rotating rotors includes a sprag clutch, an engine coupling subassembly, a transmission coupling subassembly, and a drive shaft mechanically interconnected at the ends thereof to the engine and transmission coupling subassemblies, respectively. The drive train assembly is design optimized to maximize the functional capability of the sprag clutch, the engine coupling subassembly including an external crown spline coupling, internal spline coupling combination that is mounted in combination with the sprag clutch so that loads transmitted through the external crown spline coupling react through the center of the sprag clutch. Further, the drive train assembly is design optimized to maximize allowable axial, angular, and/or parallel misalignments between the engine and the rotor assembly as a result of the mechanical interconnection of the drive shaft to the external crown spline coupling, internal spline coupling combination of the engine coupling subassembly and to the external crown spline coupling, gear spline coupling combination of the transmission coupling subassembly. The drive shaft is configured as a torque tube having inside and outside diameters sized to provide torsionally soft drive shaft such that the drive shaft functions as a torsional spring to isolate spline coupling teeth, the sprag clutch, transmission gearing, and the rotor assembly from vibratory torque generated by the engine.

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Shelton, CT, United States of America

Bruce D Hansen