Abstract: The present disclosure is directed to a turbine engine defining a longitudinal direction, a radial direction, and a circumferential direction. The turbine engine includes a power turbine including a first turbine rotor assembly interdigitated with a second turbine rotor assembly along the longitudinal direction; a gear assembly coupled to the first turbine rotor assembly and the second turbine rotor assembly, wherein the gear assembly includes a first input interface coupled to the first turbine rotor assembly, a second input interface coupled to the second turbine rotor assembly, and one or more third gears coupled to the first input interface and the second input interface therebetween; and a first output shaft and a second output shaft, wherein each of the first output shaft and the second output shaft are configured to couple to an electrical load device.

Abstract: A gas turbine engine including a first frame including a first mount member defining a stiffness K1; a second frame including a second mount member defining a stiffness K2 and a third mount member defining a stiffness K3; and a gear assembly. The gear assembly includes a first rotatable component, a second rotatable component, and a torque transfer component. The first mount member is coupled to the first rotatable component. The second mount member is coupled to the second rotatable component. The third mount member is coupled to the torque transfer component. The stiffness K1 is less than or equal to 10% of the stiffness K3.

Abstract: A planetary gear system can include a sun gear, an outer ring gear, and at least one planet gear driving the sun gear and planet gear. The planet gear can include an inner ring having an inner race, an outer ring having an outer race circumscribing and confronting the inner race. A plurality of rolling elements can be located between and in contact with the inner and outer races, which can include least one damper.

Abstract: A gas turbine engine including a first frame including a first mount member defining a stiffness K1; a second frame including a second mount member defining a stiffness K2 and a third mount member defining a stiffness K3; and a gear assembly. The gear assembly includes a first rotatable component, a second rotatable component, and a torque transfer component. The first mount member is coupled to the first rotatable component. The second mount member is coupled to the second rotatable component. The third mount member is coupled to the torque transfer component. The stiffness K1 is less than or equal to 10% of the stiffness K3.

Abstract: A planet gearbox is provided for connection to a carrier of an epicyclic gearing arrangement with a single input and single output and including a sun gear, a ring gear and at least one double helix planet gear rotatable on a cylindrical roller bearing with a cage having a cross-web thickness of 15% to 25% of the diameter of the cylindrical rollers and an L/D ratio exceeding 1.0. A gas turbine engine includes a fan and LP shaft, which couples a compressor to a turbine. An epicyclic gearing arrangement has a single input from the LP shaft coupled to a sun gear, a single output coupled to the fan's shaft, and a planet bearing cage having a cross-web thickness measuring 15% to 25% of the roller's diameter.

Abstract: A planetary gear system is disclosed. The planetary gear system includes a carrier, a planet gear defining a central planet axis, a pin coupling the planet gear to the carrier and a bearing disposed between the planet gear and the pin. The bearing includes a plurality of rolling elements. Each of the rolling elements is in contact with an inner race and an outer race. The planet gear has a formed therein cooling passage for allowing a coolant to pass therethrough to cool the planet gear.

Abstract: An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. A spring film damper is disposed between the outer surface of the bearing's outer ring and the opposing inner surface of the planet gear and includes an annular gap. The support pin and/or outer ring include oil feed holes that open into the respective annular gap(s).

Abstract: A planetary gear system is disclosed. The planetary gear system includes a carrier, a planet gear defining a central planet axis, a pin coupling the planet gear to the carrier and a bearing disposed between the planet gear and the pin. The bearing includes a plurality of rolling elements. Each of the rolling elements is in contact with an inner race and an outer race. The planet gear has a formed therein cooling passage for allowing a coolant to pass therethrough to cool the planet gear.

Abstract: A gearbox includes a gearbox housing, at least one gear, and a plurality of scavenge ports. The gearbox housing has a top portion, two horizontal portions, and a bottom portion opposite the top portion. The bottom portion is oriented in the direction a fluid would drain under the influence of gravity during normal operations. The two horizontal portions are oriented at a right angle relative to the bottom portion. The at least one gear is disposed within the gearbox housing and has a first axial position. The plurality of scavenge ports are defined by the gearbox housing. The plurality of scavenge ports are aligned axially with the at least one gear at the first axial position. At least one scavenge port of the plurality of scavenge ports is located within the gearbox housing at the two horizontal portions.

Abstract: A planet gear rotatable on a planet bearing with cylindrical rollers is mounted to a carrier of an epicyclic gearing arrangement. Either the cylindrical outer surface of the support pin or the opposing cylindrical inner surface of the inner ring of the planet bearing includes a network of interconnected grooves. The support pin includes oil feed holes intersecting the grooves. Passages through the planet bearing's inner ring also connect to the grooves. A gas turbine engine includes a fan and LP shaft, which couples a compressor to a turbine. An epicyclic gearing arrangement has a single input from the LP shaft coupled to a sun gear, a single output coupled to the fan's shaft, and a planet bearing with a network of interconnected grooves.

Abstract: A planetary gear system can include a sun gear, an outer ring gear, and at least one planet gear driving the sun gear and planet gear. The planet gear can include an inner ring having an inner race, an outer ring having an outer race circumscribing and confronting the inner race. A plurality of rolling elements can be located between and in contact with the inner and outer races, which can include least one damper.

Abstract: The present disclosure is directed to a turbine engine defining a longitudinal direction, a radial direction, and a circumferential direction. The turbine engine includes a power turbine including a first turbine rotor assembly interdigitated with a second turbine rotor assembly along the longitudinal direction; a gear assembly coupled to the first turbine rotor assembly and the second turbine rotor assembly, wherein the gear assembly includes a first input interface coupled to the first turbine rotor assembly, a second input interface coupled to the second turbine rotor assembly, and one or more third gears coupled to the first input interface and the second input interface therebetween; and a first output shaft and a second output shaft, wherein each of the first output shaft and the second output shaft are configured to couple to an electrical load device.

Abstract: A roller bearing cage that includes a cylindrical body including a plurality of pocket holes defined within and positioned circumferentially about the cylindrical body. Each pocket hole includes a pair of side portions and a pair of end portions meeting with the pair of side portions at a corner portion. The corner portion is contoured with a compound radius.

Abstract: An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. A spring film damper is disposed between the cylindrical outer surface of the support pin and the opposing inner surface of the inner ring of the planet bearing and includes an annular gap.

Abstract: A gearbox includes a gearbox housing, at least one gear, and a plurality of scavenge ports. The gearbox housing has a top portion, two horizontal portions, and a bottom portion opposite the top portion. The bottom portion is oriented in the direction a fluid would drain under the influence of gravity during normal operations. The two horizontal portions are oriented at a right angle relative to the bottom portion. The at least one gear is disposed within the gearbox housing and has a first axial position. The plurality of scavenge ports are defined by the gearbox housing. The plurality of scavenge ports are aligned axially with the at least one gear at the first axial position. At least one scavenge port of the plurality of scavenge ports is located within the gearbox housing at the two horizontal portions.

Abstract: A roller bearing cage that includes a cylindrical body including a plurality of pocket holes defined within and positioned circumferentially about the cylindrical body. Each pocket hole includes a pair of side portions and a pair of end portions meeting with the pair of side portions at a corner portion. The corner portion is contoured with a compound radius.

Abstract: The present disclosure is directed to a system for monitoring an acoustic signal in a gas turbine engine. The system includes a gas turbine engine component that emits the acoustic signal. A microphone senses the acoustic signal and creates a microphone signal indicative of one or more characteristics of the acoustic signal. A controller receives the microphone signal and is configured to analyze the microphone signal to identify a gearbox event peak. If the gearbox event peak is present, the controller quantifies an amplitude of the gearbox event peak. The controller compares the amplitude of the gearbox event peak to a threshold to determine whether the gas turbine engine component needs maintenance.

Abstract: An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. A spring film damper is disposed between the outer surface of the bearing's outer ring and the opposing inner surface of the planet gear and includes an annular gap. The support pin and/or outer ring include oil feed holes that open into the respective annular gap(s).

Abstract: An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. A spring film damper is disposed between the cylindrical outer surface of the support pin and the opposing inner surface of the inner ring of the planet bearing and includes an annular gap.

Abstract: An epicyclic gearing arrangement includes a planet gear rotatable on a planet bearing that is mounted via a support pin to a carrier of the epicyclic gearing arrangement. An attenuation spring is disposed between the outer surface of the bearing's outer ring and the opposing inner surface of the planet gear and includes an annular gap. A spring film damper is disposed between the cylindrical outer surface of the support pin and the opposing inner surface of the inner ring of the planet bearing and includes an annular gap. The support pin (96) and/or outer ring include oil feed holes that open into the respective annular gap(s). A gas turbine engine includes an epicyclic gearing arrangement having such a planet bearing.