A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor supported on a propulsor shaft, a turbine section including a turbine shaft, and an epicyclic gear train interconnecting the propulsor shaft and the turbine shaft. The epicyclic gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth intermeshing with the intermediate gears. The first and second portions have axially opposed faces abutting one another at a radial interface and respective flanges extending along the radial interface radially outward from the teeth. The first and second portions define a trough axially between and separating the teeth of the first portion from the teeth of the second portion. The first and second portions include facing recesses that form an internal annular cavity along the radial interface.

Apparatus and associated methods relate to a unitary ring gear-flange body (URGFB). In an illustrative example, the flange body may be spin-formed and may, for example, include a riser body extending substantially parallel to a longitudinal axis and a flange extending substantially radially outward from the riser body. To the riser body may, for example, be welded a ring gear to form a unitary assembly, the ring gear having an axis of revolution aligned with the longitudinal axis. A continuous coating may, for example, be applied to at least a selected portion of a surface of the unitary assembly. Various embodiments may advantageously provide a cost-efficient, weight-efficient, and/or time-efficient unitary body which may, for example, be coupled to machinery to provide a shaftless torque-transmitter.

Systems and methods in accordance with embodiments of the invention implement bulk metallic glass-based macroscale gears. In one embodiment, a method of fabricating a bulk metallic glass-based macroscale gear, where at least either the thickness of the gear is greater than 3 mm or the diameter of the gear is greater than 9 mm, includes: obtaining design parameters of the gear to be formed; selecting a bulk metallic glass from which the gear will be formed based on the obtained design parameters, where the selected bulk metallic glass is characterized by a resistance to standard modes of wear and a resistance to brittle fracture such that a gear can be formed from the selected bulk metallic glass that accords with the obtained design parameters; and fabricating the gear from the selected bulk metallic glass that accords with the obtained design parameters.

A mutual-lapping device and mutual-lapping method for improving processing precision based on the principle of error averaging is proposed. The device including driving friction wheel, driving belt pulley, transmission belt A, connecting rod A, rotation shaft segment A, multi-ball sleeve, mutual-lapping gear A, tension spring, driven friction wheel, pendulum bar of the driven friction wheel, driven belt pulley, transmission belt B, connecting rod B, pressure spring of tensioning pulley, tensioner mechanism, rotation shaft segment B and mutual-lapping gear B. By mutual lapping the high-precision gears, not only the pitch deviation, tooth profile deviation, helix deviation and runout can be reduced synchronously, but also the machining cost is low. Meanwhile, the effect of improving pitch accuracy, profile accuracy, helix accuracy and runout accuracy and reducing surface roughness is remarkable.

Systems and methods in accordance with embodiments of the invention implement bulk metallic glass-based macroscale gears. In one embodiment, a method of fabricating a bulk metallic glass-based macroscale gear, where at least either the thickness of the gear is greater than 3 mm or the diameter of the gear is greater than 9 mm, includes: obtaining design parameters of the gear to be formed; selecting a bulk metallic glass from which the gear will be formed based on the obtained design parameters, where the selected bulk metallic glass is characterized by a resistance to standard modes of wear and a resistance to brittle fracture such that a gear can be formed from the selected bulk metallic glass that accords with the obtained design parameters; and fabricating the gear from the selected bulk metallic glass that accords with the obtained design parameters.

In a method for manufacturing a hollow wheel which includes an internal toothing and an external toothing, wherein the internal toothing is a gear toothing, a workpiece is machined by way of a stamping tool. The workpiece has a tubular section with a longitudinal axis and a first stabilisation section for the shape stabilisation of the tubular section during the machining. The tubular section is inserted into a die having an internal die toothing. The workpiece is machined on the inner side by the stamping tool so as to simultaneously produce internal and external toothing by way of the workpiece executing a rotation movement with a temporally varying rotation speed and the stamping tool executing radially oscillating movements that are synchronised with the rotation movement.

A mutual-lapping device and mutual-lapping method for improving processing precision based on the principle of error averaging is proposed. The device including driving friction wheel, driving belt pulley, transmission belt A, connecting rod A, rotation shaft segment A, multi-ball sleeve, mutual-lapping gear A, tension spring, driven friction wheel, pendulum bar of the driven friction wheel, driven belt pulley, transmission belt B, connecting rod B, pressure spring of tensioning pulley, tensioner mechanism, rotation shaft segment B and mutual-lapping gear B. By mutual lapping the high-precision gears, not only the pitch deviation, tooth profile deviation, helix deviation and runout can be reduced synchronously, but also the machining cost is low. Meanwhile, the effect of improving pitch accuracy, profile accuracy, helix accuracy and runout accuracy and reducing surface roughness is remarkable.

A gas turbine engine according to an example of the present disclosure includes, among other things, a fan section including a turbo fan supported on a turbo fan shaft, a turbine section including a turbine shaft, and an epicyclic gear train interconnecting the turbo fan shaft and the turbine shaft. The epicyclic gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth, the first and second portions arranged about and intermeshing with the intermediate gears, the first and second portions abutting one another at a radial interface, the first and second portions including respective flanges extending along the radial interface radially outward from the teeth, and the teeth of the first and second portions being oppositely angled teeth.

An epicyclic gear train for a gas turbine engine according to an example of the present disclosure includes, among other things, a gutter having an annular channel, a sun gear rotatable about an axis, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear arranged about and intermeshing with the intermediary gears, the ring gear having an aperture axially aligned with the annular channel. The ring gear includes axially spaced apart walls that extend radially outward to define a passageway, and the passageway is arranged radially between the aperture and the annular channel such that the walls inhibit an axial flow of an oil passing from the aperture toward the annular channel.

Systems and methods in accordance with embodiments of the invention implement tailored metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a method of fabricating a flexspline of a strain wave gear includes: forming a MG-based composition into a flexspline using one of a thermoplastic forming technique and a casting technique; where the forming of the MG-based composition results in a formed MG-based material; where the formed flexspline is characterized by: a minimum thickness of greater than approximately 1 mm and a major diameter of less than approximately 4 inches.