Abstract: A rotary shaft assembly includes a rotary shaft having a first end portion, a second end portion opposite the first end portion, a longitudinal axis extending centrally through the first and second end portions, and a shaft body that defines a bore between the first and second end portions. An anti-flailing mechanism is positioned within the bore of the shaft body. The anti-flailing mechanism is coupled to rotary shaft and extends at least partially between the first and second end portions to contain the rotary shaft about the longitudinal axis when the rotary shaft fails.

Abstract: A bearing anti-creep interface having a drive shaft, a bearing race, and a hub. The drive shaft extends along a rotational axis. The bearing race has an inner surface press-fit onto the drive shaft and an axial end surface defining a bearing race interface surface. The hub has an inner surface rotationally coupled to the drive shaft and an axial end surface defining a hub interface surface. The hub interface surface is in contact with the bearing race interface surface to form an interlockingjoint. The interlocking joint is configured to transfer rotational creep force of the bearing race about the rotational axis and relative to the drive shaft into an axial pressure force applied to the hub in a direction parallel with the rotational axis.

Abstract: A gearbox includes a housing defining an interior. The housing includes outer walls and inner walls defining other structure within the housing, and at least one wall of the housing includes a semi-hollow volume. A main lubricant reservoir is disposed within the interior of the housing, and at least one pump is arranged in the interior of the housing for pumping lubricant from the main lubricant reservoir and distributing the lubricant throughout the housing. The semi-hollow volume of the at least one wall stores lubricant during normal operation of the pump, and when a loss of lubricant occurs within the housing, lubricant seeps from the semi-hollow volume to distribute lubricant throughout the housing.

Abstract: A rotary shaft assembly includes a rotary shaft having a first end portion, a second end portion opposite the first end portion, a longitudinal axis extending centrally through the first and second end portions, and a shaft body that defines a bore between the first and second end portions. An anti-flailing mechanism is positioned within the bore of the shaft body. The anti-flailing mechanism is coupled to rotary shaft and extends at least partially between the first and second end portions to contain the rotary shaft about the longitudinal axis when the rotary shaft fails.

Abstract: A vibration control assembly includes a housing having an interior region and an inner mass including a cage disposed within the interior region of the housing and being rotatable within the housing about a first axis and a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis. At least one driving source includes a stator and is operable to interact with a magnetic field of the inner mass to drive rotation of the inner mass about at least one of the first axis and the second axis, wherein the at least one driving source is mounted within the interior region of the housing.

Abstract: A vibration control assembly includes a housing having an interior region and an inner mass including a cage disposed within the interior region of the housing and being rotatable within the housing about a first axis and a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis. At least one driving source includes a stator and is operable to interact with a magnetic field of the inner mass to drive rotation of the inner mass about at least one of the first axis and the second axis, wherein the at least one driving source is mounted within the interior region of the housing.

Abstract: A coaxial split torque gearbox comprises a first pinion meshed with a first gear; a second pinion attached to the first gear and meshed with a first bull gear, the first bull gear operable for transferring torque to cause a first rotor to rotate; and a third pinion attached to a second gear and meshed with a second bull gear, the second bull gear operable for transferring torque to cause a second rotor to rotate, the second gear being meshed with the first gear, and a number of teeth of the first gear being different than a number of teeth of the second gear.

Abstract: A vibration control assembly for an aircraft including a housing operatively coupled to the aircraft. Also included is a cage disposed within an interior region of the housing, the cage rotatable within the housing about a first axis. Further included is a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis, wherein a controllable moment is imposed on the aircraft upon rotation of the gyroscope wheel to counter vibratory moments produced by the vehicle.

Abstract: A gear train includes a first gear having teeth meshed with teeth of a second gear. Each tooth of the first gear includes a coast side and a drive side opposed to the coast side. The drive side has a pressure angle that is greater than that of the coast side. The gear train can be part of a powertrain system for a rotorcraft, and can replace a traditional gear train in a retrofit or new build. The first gear is a planet gear and the second gear is a ring gear wherein the planet gear and ring gear are in a planetary gear train configuration.

Abstract: A vibration control assembly includes a housing having an interior region and an inner mass including a cage disposed within the interior region of the housing and being rotatable within the housing about a first axis and a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis. At least one driving source includes a stator and is operable to interact with a magnetic field of the inner mass to drive rotation of the inner mass about at least one of the first axis and the second axis, wherein the at least one driving source is mounted within the interior region of the housing.

Abstract: A vibration control assembly for an aircraft including a housing operatively coupled to the aircraft. Also included is a cage disposed within an interior region of the housing, the cage rotatable within the housing about a first axis. Further included is a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis, wherein a controllable moment is imposed on the aircraft upon rotation of the gyroscope wheel to counter vibratory moments produced by the vehicle.

Abstract: An aspect includes, a coaxial split torque gearbox comprises a first pinion meshed with a first gear; a second pinion attached to the first gear and meshed with a first bull gear, the first bull gear operable for transferring torque to cause a first rotor to rotate; and a third pinion attached to a second gear and meshed with a second bull gear, the second bull gear operable for transferring torque to cause a second rotor to rotate, the second gear being meshed with the first gear, and a number of teeth of the first gear being different than a number of teeth of the second gear.

Abstract: A vibration control assembly for an aircraft including a housing operatively coupled to the aircraft. Also included is a cage disposed within an interior region of the housing, the cage rotatable within the housing about a first axis. Further included is a gyroscope wheel disposed within the cage and rotatable about a second axis other than the first axis, wherein a controllable moment is imposed on the aircraft upon rotation of the gyroscope wheel to counter vibratory moments produced by the vehicle.

Abstract: A gearbox for a rotary wing aircraft including a sump, a primary lubricant reservoir fluidically connected to the sump, one or more primary lubricant jets fluidically connected to the primary lubricant reservoir, an auxiliary lubricant reservoir fluidically connected to the sump, one or more auxiliary lubricant jets fluidically connected to the auxiliary lubricant reservoir, and at least one valve selectively fluidically connecting the sump and the primary lubricant reservoir based on a first lubricant pressure and the sump and the auxiliary lubricant reservoir based on a second lubricant pressure at the at least one valve.

Abstract: A vibration damping device is configured to reduce vibration that causes lateral flexing of an elongated member that extends along a centerline. The device includes a split sleeve co-extending with and disposed about the elongated member, and a spring that extends about the sleeve and exerts a force that biases the sleeve radially inward.

Abstract: 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.

Abstract: A hanger bearing assembly for a shaft assembly includes a plurality of bearing elements arranged around a circumference of a shaft assembly, each bearing element having a bearing element diameter. A bearing inner race is positioned between the plurality of bearing elements and the shaft assembly and extends circumferentially about the shaft assembly. The bearing inner race includes an outer wall interactive with the plurality of bearing elements. The outer wall has a linear profile extending in an axial direction. A bearing outer race is positioned radially outboard of the plurality of bearing elements and extends circumferentially about the shaft assembly. The bearing outer race includes an inner surface interactive with the plurality of bearing elements and having a curvilinear inner surface profile extending in the axial direction.

Abstract: A gearbox oil cooling assembly for a gearbox driving a drive shaft having a drive shaft coupling. The assembly includes a heat exchanger to receive and cool an oil from the gearbox and having an inlet. Also included is an impeller axially disposed between the heat exchanger and the drive shaft coupling, wherein the impeller is operatively coupled to, and rotated by, the drive shaft operatively coupled to the drive shaft coupling. Further included is an exhaust duct operatively coupled to the heat exchanger and disposed radially outwardly around the impeller and defining an airflow pathway through which air passes through the inlet, the impeller and through the exhaust duct according to the rotation of the impeller to cool the oil in the heat exchanger.

Abstract: A rotor apparatus is provided and includes a first rotor shaft disposed to rotatably support a first rotor, a second rotor shaft disposed to rotatably support a second rotor and first and second bearing elements disposed to support the first rotor shaft within the second rotor shaft and to pre-load the first rotor shaft in one of tension and compression and the second rotor shaft in the other one of tension and compression.

Abstract: 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.