Abstract: A gearbox assembly includes a first gear coupled to a first shaft, a second gear coupled to a second shaft, and a plurality of planet gears that mesh with the first gear and the second gear. The first shaft includes a first shaft stiff portion and a first shaft flexible portion that includes a greater flexibility than a flexibility of the first shaft stiff portion such that the first gear moves in a radial direction. The second shaft includes a second shaft stiff portion and a second shaft flexible portion that includes a greater flexibility than a flexibility of the second shaft stiff portion such that the second gear moves in the radial direction. The first gear and the second gear move to distribute loads substantially equally on the plurality of planet gears.

Abstract: A lubrication system for a gas turbine engine includes a tank, a circulation pump, and a heat exchanger. The circulation pump generates a flow of lubricant from the tank to, e.g., a power gear box of the gas turbine engine and the heat exchanger removes an amount of heat from such flow of lubricant provided to the power gear box. The lubrication system also includes one or more valves in the flow of lubricant for controlling a flowrate and/or temperature of the lubricant provided to, e.g., the power gear box to increase an efficiency and/or durability of the power gear box.

Abstract: A lubrication system for a gas turbine engine includes a tank, a circulation pump, and a heat exchanger. The circulation pump generates a flow of lubricant from the tank to, e.g., a power gear box of the gas turbine engine and the heat exchanger removes an amount of heat from such flow of lubricant provided to the power gear box. The lubrication system also includes one or more valves in the flow of lubricant for controlling a flowrate and/or temperature of the lubricant provided to, e.g., the power gear box to increase an efficiency and/or durability of the power gear box.

Abstract: A lubrication system for a gas turbine engine includes a tank, a circulation pump, and a heat exchanger. The circulation pump generates a flow of lubricant from the tank to, e.g., a power gear box of the gas turbine engine and the heat exchanger removes an amount of heat from such flow of lubricant provided to the power gear box. The lubrication system also includes one or more valves in the flow of lubricant for controlling a flowrate and/or temperature of the lubricant provided to, e.g., the power gear box to increase an efficiency and/or durability of the power gear box.

Abstract: A gas turbine gearbox input shaft including a gear coupling engaged with an engine power gearbox and extending along a central engine axis thereof. The shaft may include a separable tuning segment coaxially joined to the gear coupling, and a spool coupling joined to the separable tuning segment opposite of the gear coupling, the spool coupling being engaged with an engine turbine spool. Methods of using the input shaft are also provided.

Abstract: A lubrication system for a gas turbine engine includes a tank, a circulation pump, and a heat exchanger. The circulation pump generates a flow of lubricant from the tank to, e.g., a power gear box of the gas turbine engine and the heat exchanger removes an amount of heat from such flow of lubricant provided to the power gear box. The lubrication system also includes one or more valves in the flow of lubricant for controlling a flowrate and/or temperature of the lubricant provided to, e.g., the power gear box to increase an efficiency and/or durability of the power gear box.

Abstract: A gas turbine engine including a core engine and a variable pitch fan arranged in flow communication with the core engine is provided. The variable pitch fan includes a plurality of blades coupled to a disk, the blades and disk configured to rotate together about an axial direction of the engine. A rotatable front hub may be provided over a front end of the variable pitch fan, including the disk. The gas turbine engine additionally includes a plurality of trunnion mechanisms coupling each of the plurality of fan blades to the disk. Each trunnion mechanism includes a bearing having one or more components formed of a non-ferrous material, decreasing a weight of the respective trunnion mechanism and allowing for, e.g., a smaller front hub.

Abstract: A gearbox support apparatus includes a gearbox carrier having a central axis, the carrier configured to mount one or more rotating gears therein, the carrier including spaced-apart forward and aft walls, and a pin disposed between the forward and aft walls. The gearbox support apparatus includes an inner race connected to the pin as a single integral component incorporating two pairs of raised guides defining a forward raceway and an aft raceway.

Abstract: An epicyclic gearbox comprises a gearbox housing including an inner cavity receiving an input shaft from a low pressure turbine and an output shaft connected to a fan. A sun gear is disposed within the housing and at least one planetary gear engages and orbits the sun gear. The at least one planetary gear is formed of a first material and an insert is disposed between a gear rim of the at least one planetary gear and a journal. The insert is formed of a second material distinct from the first material and of a weight which is lighter than the first material. The gearbox may include but is not limited to both star gearbox and planetary gearbox configurations.

Abstract: A method of verifying the operation of an accelerometer is provided. The method includes channeling a high frequency signal through a positive lead of the accelerometer, and detecting a signal at a negative lead of the accelerometer. If the detected signal is substantially similar to the high frequency signal channeled through the positive lead, the integrity of the accelerometer is verified.

Abstract: A method of verifying the operation of an accelerometer is provided. The method includes channeling a high frequency signal through a positive lead of the accelerometer, and detecting a signal at a negative lead of the accelerometer. If the detected signal is substantially similar to the high frequency signal channeled through the positive lead, the integrity of the accelerometer is verified.

Abstract: A method and apparatus for assembling a rotatable machine is provided. The machine includes a plurality of blades that extend radially outwardly from a rotor. The method includes determining a moment weight of each blade in a row of blades, determining a geometric parameter of each blade in the same row of blades, and determining a mapping order of each blade using the moment weight and the geometric parameter. The apparatus includes a computer system that includes a software product code segment for minimizing imbalance in a bladed rotor wherein the segment is configured to receive a moment weight value for each blade to be installed in said rotor, receive a geometric parameter value for each blade to be installed in said rotor, calculate a blade location on the rotor based on the received values, and generate a blade map based on the calculated location.

Abstract: A method and apparatus for assembling a rotatable machine is provided. The machine includes a plurality of blades that extend radially outwardly from a rotor. The method includes determining a moment weight of each blade in a row of blades, determining a geometric parameter of each blade in the same row of blades, and determining a mapping order of each blade using the moment weight and the geometric parameter. The apparatus includes a computer system that includes a software product code segment for minimizing imbalance in a bladed rotor wherein the segment is configured to receive a moment weight value for each blade to be installed in said rotor, receive a geometric parameter value for each blade to be installed in said rotor, calculate a blade location on the rotor based on the received values, and generate a blade map based on the calculated location.