Abstract: A gearbox assembly for a gas turbine engine used in an aircraft having passive lubrication capabilities during wind milling includes a gearbox housing, a gear train assembly housed within the gearbox housing, a lubricant in the gearbox housing for lubricating the gear train assembly, and a first scavenge port formed in the gearbox housing. The first scavenge port is changeable between an open position and a closed position. Further, the first scavenge port remains in the open position during normal operation of the gas turbine engine to allow the lubricant to drain from the gearbox housing. Upon occurrence of a loss of lubricant pressure in the gearbox assembly, the first scavenge port is changed to the closed position to trap at least a portion of the lubricant in the gearbox housing. Thus, the trapped lubricant provides passive lubrication to the gear train assembly during the loss of lubricant pressure.

Abstract: A bearing cage for a roller bearing assembly. The roller bearing assembly includes an inner ring, an outer ring, and a plurality of roller elements. The bearing cage includes an annular body extending along an axial direction. The annular body is configured to be positioned between the inner annular ring and the outer annular ring and configured to receive a plurality of roller elements. The annular body includes a first end including a first inner radial surface opposite the inner annular ring. The annular body further includes a second end opposite the first end. The second end includes a second inner radial surface opposite the inner annular ring. The first end extends axially beyond the inner annular ring and the second end extends axially beyond the inner annular ring.

Abstract: A gear includes a first gear rim, a second gear rim, and an axial groove. The first gear rim has a first gear rim rotational stiffness and includes a plurality of first gear teeth. The second gear rim has a second gear rim rotational stiffness. The second gear rim includes a plurality of second gear teeth complementing the plurality of first gear teeth defining a plurality of complementary first gear teeth and a plurality of complementary second gear teeth. The axial groove extends between the first gear rim and the second gear rim. The axial groove has an axial groove rotational stiffness that less than at least one of the first gear rim rotational stiffness and the second gear rim rotational stiffness.

Abstract: A gearbox assembly for a gas turbine engine used in an aircraft having passive lubrication capabilities during wind milling includes a gearbox housing, a gear train assembly housed within the gearbox housing, a lubricant in the gearbox housing for lubricating the gear train assembly, and a first scavenge port formed in the gearbox housing. The first scavenge port is changeable between an open position and a closed position. Further, the first scavenge port remains in the open position during normal operation of the gas turbine engine to allow the lubricant to drain from the gearbox housing. Upon occurrence of a loss of lubricant pressure in the gearbox assembly, the first scavenge port is changed to the closed position to trap at least a portion of the lubricant in the gearbox housing. Thus, the trapped lubricant provides passive lubrication to the gear train assembly during the loss of lubricant pressure.

Abstract: A bearing cage for a roller bearing assembly is provided. The roller bearing assembly includes an outer annular ring, an inner annular ring including an outer radial surface, and a plurality of roller elements. The bearing cage includes an annular body configured to be positioned between the inner annular ring and the outer annular ring and configured to receive the plurality of roller elements. The annular body includes a first end including a first inner radial surface opposite the inner annular ring and a second end including a second inner radial surface opposite the inner annular ring, wherein the annular body extends from the first end to the second end in an axial direction. The annular body includes a first lubricant interface configured to receive oil and defined by the first inner radial surface and a second lubricant interface configured to receive oil and defined by the second inner radial surface.

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 bearing cage for a roller bearing assembly is provided. The roller bearing assembly includes an outer annular ring, an inner annular ring including an outer radial surface, and a plurality of roller elements. The bearing cage includes an annular body configured to be positioned between the inner annular ring and the outer annular ring and configured to receive the plurality of roller elements. The annular body includes a first end including a first inner radial surface opposite the inner annular ring and a second end including a second inner radial surface opposite the inner annular ring, wherein the annular body extends from the first end to the second end in an axial direction. The annular body includes a first lubricant interface configured to receive oil and defined by the first inner radial surface and a second lubricant interface configured to receive oil and defined by the second inner radial surface.

Abstract: A bearing cage for a roller bearing assembly. The roller bearing assembly includes an inner ring, an outer ring, and a plurality of roller elements. The bearing cage includes an annular body extending along an axial direction. The annular body is configured to be positioned between the inner annular ring and the outer annular ring and configured to receive a plurality of roller elements. The annular body includes a first end including a first inner radial surface opposite the inner annular ring. The annular body further includes a second end opposite the first end. The second end includes a second inner radial surface opposite the inner annular ring. The first end extends axially beyond the inner annular ring and the second end extends axially beyond the inner annular ring.

Abstract: Embodiments of a compliant shaft for engines are provided herein. In some embodiments, a compliant shaft for a turbine engine may include: a body having a first end configured to be coupled to a shaft of a turbine and a second end coupled to a gear of a gear box, wherein at least a portion of the body is flexible.

Abstract: A bearing cage for a roller bearing assembly includes an annular body defining a circumferential centerline extending therethrough. The annular body includes an outer circumferential surface, an opposing inner circumferential surface, and a plurality of circumferentially spaced roller cavities defined therein. Each roller cavity of the plurality of roller cavities is configured to receive an associated roller element. Each roller cavity includes a first radial cross-wall defined within the annular body extending from the outer circumferential surface to the inner circumferential surface. Each roller cavity further includes an opposing second radial cross-wall defined within the annular body extending from the outer circumferential surface to the inner circumferential surface. At least a portion of the first radial cross-wall and at least a portion of the second radial cross-wall are complimentary to the associated roller element.

Abstract: A gear includes a first gear rim, a second gear rim, and an axial groove. The first gear rim has a first gear rim rotational stiffness and includes a plurality of first gear teeth. The second gear rim has a second gear rim rotational stiffness. The second gear rim includes a plurality of second gear teeth complementing the plurality of first gear teeth defining a plurality of complementary first gear teeth and a plurality of complementary second gear teeth. The axial groove extends between the first gear rim and the second gear rim. The axial groove has an axial groove rotational stiffness that less than at least one of the first gear rim rotational stiffness and the second gear rim rotational stiffness.

Abstract: A bearing cage for a roller bearing assembly includes an annular body defining a circumferential centerline extending therethrough. The annular body includes an outer circumferential surface, an opposing inner circumferential surface, and a plurality of circumferentially spaced roller cavities defined therein. Each roller cavity of the plurality of roller cavities is configured to receive an associated roller element. Each roller cavity includes a first radial cross-wall defined within the annular body extending from the outer circumferential surface to the inner circumferential surface. Each roller cavity further includes an opposing second radial cross-wall defined within the annular body extending from the outer circumferential surface to the inner circumferential surface. At least a portion of the first radial cross-wall and at least a portion of the second radial cross-wall are complimentary to the associated roller element.

Abstract: A planet gear includes an annular planet gear ring including an annular planet gear rim. The annular planet gear rim has an inner radius and an outer radius. The inner radius and the outer radius define a rim thickness therebetween. The annular planet gear rim further has a bending stress neutral axis. The bending stress neutral axis radius and the rim thickness define a ratio including values in a range from and including about 3 to and including about 10.

Abstract: Embodiments of a compliant shaft for engines are provided herein. In some embodiments, a compliant shaft for a turbine engine may include: a body having a first end configured to be coupled to a shaft of a turbine and a second end coupled to a gear of a gear box, wherein at least a portion of the body is flexible.

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 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 wherein the ratio of each cylindrical roller's length to each cylindrical roller's diameter exceeds 1.0. A gas turbine engine includes a shaft coupling a compressor of a compressor section to a turbine of a turbine section. An epicyclic gearing arrangement has a single input from the shaft coupled to a sun gear, a single output from the carrier that is coupled to the shaft of a fan and includes a planet gearbox with cylindrical rollers having a length-to-diameter ratio exceeding 1.0.

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: Embodiments of a bearing are provided herein. In one embodiment a bearing may include a bearing assembly having an inner race and an outer race; a plurality of rolling elements disposed between the inner race and the outer race, wherein at least one of the inner race, the outer race, and the plurality of rolling elements is at least partially fabricated from an AlMgB14 containing ceramic matrix composite.

Abstract: Embodiments of a bearing are provided herein. In one embodiment a bearing may include a bearing assembly having an inner race and an outer race; a plurality of rolling elements disposed between the inner race and the outer race, wherein at least one of the inner race, the outer race, and the plurality of rolling elements is at least partially fabricated from an AlMgB14 containing ceramic matrix composite.

Abstract: A device operating in an environment includes a fiber optic sensing system having one or more fiber optic sensors disposed in the device and configured to detect one or more parameters related to the device. The parameters may include temperature, strain, pressure, vibration, or combinations thereof.