In one aspect, there is provided a planetary gearbox, comprising a sun gear, a plurality of planet gear assemblies, each planet gear assembly having a main gear meshed with the sun gear, a fore lateral gear and an aft lateral gear disposed on opposite sides of the main gear and rotating therewith, a diameter of the main gear being different than a diameter of the fore and aft lateral gears, a planet carrier rotatably supporting at least some of the planet gear assemblies, and at least one fore ring gear meshed with the fore lateral gears, at least one aft ring gear meshed with the aft lateral gears, wherein one of the sun gear, the planet carrier, and the ring gears is configured to be operatively connected to an input, one is configured to be operatively connected to an output, and rotation of a remaining one is limited.

A turbomachine engine includes a fan assembly and a core engine comprising a turbine and an input shaft rotatable with the turbine is provided. A single-stage epicyclic gear assembly receives the input shaft at a first speed and drives an output shaft coupled to the fan assembly at a second speed. A sun gear rotates about a longitudinal centerline of the gear assembly and has a sun gear-mesh region along the longitudinal centerline of the gear assembly where the sun gear is configured to contact a plurality of planet gears. A ring gear-mesh region is provided along the longitudinal centerline of the gear assembly where a ring gear is configured to contact the plurality of planet gears. The sun gear-mesh region is axially offset from the ring gear-mesh region along the longitudinal centerline.

A complex planetary assembly includes an input, an output, a ring gear, a first stage planetary assembly and a second stage planetary assembly. The first stage planetary assembly includes a first sun gear, a first carrier including a first plurality of pins extending therefrom, and a first plurality of planet gears. Each of the first plurality of planet gears is rotatably coupled to one of the first plurality of pins. The second stage planetary assembly includes a second sun gear, a second carrier including a second plurality of pins extending therefrom, and a second plurality of planet gears. Each of the second plurality of planet gears is rotatably coupled to one of the second plurality of pins. At each of the first or second plurality of pins on the first or second carrier, at least two planet gears of the first or second plurality of planet gears are coupled and coaxially arranged adjacent to one another.

A reduction gearbox is provided that includes a planetary gear arrangement disposed in a casing. The planetary gear arrangement includes a sun gear, planet gear assemblies, and a fore and aft ring gears. The sun gear is configured in communication with a cantilevered end of an input. Each planet gear assembly has a main gear meshed with the sun gear, a fore lateral gear and an aft lateral gear disposed on opposite sides of the main gear and rotating therewith. The main gear has a main gear pitch diameter and the fore and aft lateral gears having a lateral gear pitch diameter. The fore ring gear is meshed with the fore lateral gears. The aft ring gear is meshed with the aft lateral gears. The aft ring gear is independent of the fore ring gear. The planet gear assemblies are in communication with an output.

A reduction gearbox is provided that includes a planetary gear arrangement disposed in a casing. The planetary gear arrangement includes a sun gear, planet gear assemblies, and fore and aft ring gears. The sun gear is configured for communication with an input. Each planet gear assembly has a main gear meshed with the sun gear, fore and aft lateral gears disposed on opposite sides of the main gear and rotating therewith. The main gear has a main gear pitch diameter and the fore and aft lateral gears having a lateral gear pitch diameter. The fore ring gear is meshed with the fore lateral gears. The aft ring gear is meshed with the aft lateral gears. The aft ring gear is independent of the fore ring gear. The planet gear assemblies are in communication with an output. The fore and aft ring gears are mechanically engaged with the casing.

A balanced speed reducer of a dual-ring gear variable-line-speed planetary row includes a dual-ring gear variable-line-speed planetary row, an input end (6), an output end (7), a locking end (8), and auxiliary devices such as bearings. The dual-ring gear planetary row includes a left ring gear (1), a right ring gear (2), and a planet carrier (3). A left planetary gear (4) and a right planetary gear (5) that are connected on each planetary gear shaft have the same rotation speed. The left planetary gear (4) meshes with the left ring gear (1), and the right planetary gear (5) meshes with the right ring gear (2). The number of gear sets is not less than two. A teeth number combination and a number of gear sets are set according to a range specifying parameter and following a principle of matching the teeth number combination with the number of gear sets. A rule for manufacturing and assembling planetary gears is executed. A regulation on gear reference circle radii is executed. By connecting the planetary carrier (3) to the input end (6), connecting one ring gear to the output end (7), and connecting the other ring gear to the locking end (8), a speed reducer that has a corresponding left transmission ratio and right transmission ratio, can be actually assembled and provides balanced operation is formed.

A mechanical reduction gear of a turbine engine, in particular for an aircraft, includes a sun gear having external toothing, a ring gear which extends around the sun gear and has internal toothing, planet gears which are in mesh with the sun gear and the ring gear and which have toothings of different diameters, a planet carrier which supports bearings for guiding the planet gears in rotation, and a lubrication circuit of the reduction gear. The planet carrier has a hydrodynamic abutment on which the sun gear is configured to bear axially.

In one embodiment of the present disclosure, there is provided a planetary gear system. The planetary gear system includes a split double helical ring gear having a first ring gear with first helical ring teeth and a second ring gear with second helical ring teeth, a split double helical sun gear having a first sun gear with first helical sun teeth and a second sun gear with second helical sun teeth, a sun gear coupler coupling the first sun gear and the second sun gear; and a single-piece double helical planet pinion having a first helical planet teeth portion and a second helical planet teeth portion, where the first helical planet teeth mesh with the first helical sun teeth and the first helical ring teeth, and the second helical planet teeth mesh with the second helical sun teeth and the second helical ring teeth.

A mechanical reduction gear of a turbine engine, in particular for an aircraft, includes a sun gear having external toothing, a ring gear which extends around the sun gear and has internal toothing, planet gears which are in mesh with the sun gear and the ring gear and which have toothings of different diameters, a planet carrier which supports bearings for guiding the planet gears in rotation, and a lubrication circuit of the reduction gear. The planet carrier has a hydrodynamic abutment on which the sun gear is configured to bear axially.

A planetary gear train for an aircraft engine, has: a sun gear; planet gear assemblies having main gears meshed with the sun gear, fore lateral gears and aft lateral gears disposed on opposite sides of the main gears and rotating therewith; journal bearings rotatably supporting the planet gear assemblies for rotation about rotation axes, gaps defined between the journal bearings and the planetary gear assemblies; a planet carrier supporting the journal bearings; a fore ring gear meshed with the fore lateral gears; an aft ring gear meshed with the aft lateral gears; and a lubrication system extending within the planet carrier and hydraulically connected to the gaps between the journal bearings and the planet gear assemblies.