A planetary gearset having a first planet gear, a second planet gear, and pinion gears. The pinion gears mesh with the first planet gear and with the second planet gear, and each pinion gear is pivotally mounted around a shaft. A pinion gear carrier supports each shaft. Each shaft has a radially inner cylindrical portion mounted on the pinion gear carrier, a radially outer cylindrical portion about which the pinion gear is pivotally mounted and a flange extending radially from the radially outer cylindrical portion. The radially outer periphery of the flange is mounted on the pinion gear carrier. The radially outer cylindrical portion and the radially inner cylindrical portion are connected to each other by a radially extending connecting zone.

A planetary gearset having a first planet gear, a second planet gear, and pinion gears. The pinion gears mesh with the first planet gear and with the second planet gear, and each pinion gear is pivotally mounted around a shaft. A pinion gear carrier supports each shaft. Each shaft has a radially inner cylindrical portion mounted on the pinion gear carrier, a radially outer cylindrical portion about which the pinion gear is pivotally mounted and a flange extending radially from the radially outer cylindrical portion. The radially outer periphery of the flange is mounted on the pinion gear carrier. The radially outer cylindrical portion and the radially inner cylindrical portion are connected to each other by a radially extending connecting zone.

An epicyclic gear assembly includes a carrier that includes a first plate axially spaced from a second plate by a connector. A first epicyclic gear set is supported adjacent the first plate and includes a first set of circumferentially offset intermediate gears meshing with a first sun gear and a first ring gear. A second epicyclic gear set is axially spaced from the first epicyclic gear set and supported adjacent the second plate and includes a second set of circumferentially offset intermediate gears meshing with a second sun gear and a second ring gear. The first epicyclic gear is set and the second epicyclic gear set maintain relative intermeshing alignment during flexure-induced deformation of the carrier. The first ring gear includes a first set of teeth that extends from a first flexible flange and the second ring gear includes a second set of teeth that extends from a second flexible flange.

An epicyclic gear assembly includes a carrier that includes a first plate axially spaced from a second plate by a connector. A first epicyclic gear set is supported adjacent the first plate and includes a first set of circumferentially offset intermediate gears meshing with a first sun gear and a first ring gear. A second epicyclic gear set is axially spaced from the first epicyclic gear set and supported adjacent the second plate and includes a second set of circumferentially offset intermediate gears meshing with a second sun gear and a second ring gear. The first epicyclic gear is set and the second epicyclic gear set maintain relative intermeshing alignment during flexure-induced deformation of the carrier. The first ring gear includes a first set of teeth that extends from a first flexible flange and the second ring gear includes a second set of teeth that extends from a second flexible flange.

A carrier assembly for a planetary gear assembly includes a planet frame defining a central aperture therethrough, the central aperture defining a rotation axis, the planet frame configured to rotatably support a plurality of planet gears, and a carrier connected to the planet frame via a stud. At least one of a portion of the carrier proximate the stud and a portion of the stud between the carrier and the planet frame has a dimension reduction, such as a thickness reduction, therein.

An apparatus and method for reducing planet gear misalignment of planet gears mounted on a planet-carrier in an epicyclic gearing. The apparatus and method of the present disclosure specifically provide for a stiffness-reducing feature, a pillar, and a side-plate, each with a respective stiffness. In several embodiments, the feature stiffness is less than the pillar stiffness which is at least 10% less than the side-plate stiffness. The stiffness-reducing feature and the pillar may make up a pylon which has an axis. The pylon axis may form an angle with the side plate which is less than 90 and greater than 20.

An apparatus and method for reducing planet gear misalignment of planet gears mounted on a planet-carrier in an epicyclic gearing. The apparatus and method of the present disclosure specifically provide for a stiffness-reducing feature, a pillar, and a side-plate, each with a respective stiffness. In several embodiments, the feature stiffness is less than the pillar stiffness which is at least 10% less than the side-plate stiffness. The stiffness-reducing feature and the pillar may make up a pylon which has an axis. The pylon axis may form an angle with the side plate which is less than 90 and greater than 20.

A gas turbine engine including a first frame including a first mount member defining a stiffness K.sub.1; a second frame including a second mount member defining a stiffness K.sub.2 and a third mount member defining a stiffness K.sub.3; 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 K.sub.1 is less than or equal to 10% of the stiffness K.sub.3.

A gas turbine engine including a first frame including a first mount member defining a stiffness K.sub.1; a second frame including a second mount member defining a stiffness K.sub.2 and a third mount member defining a stiffness K.sub.3; 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 K.sub.1 is less than or equal to 10% of the stiffness K.sub.3.

A torque transfer device has plural planets arranged for planetary rotation about one or more sun gears and within one or more ring gears. Each planet includes at least one planetary gear set comprising plural planetary gears connected to rotate together, but having a different diameter to form a differential gear system. To improve load sharing, the plural planetary gears of each planetary gear set may have a different helical angle, the plural planetary gear sets being axially movable with respect to one another. Alternatively or in addition, the planetary gears may be made flexible with respect to radial forces.