A ride-on vehicle, such as for a child, includes a vehicle body and one or more wheels that support the vehicle body relative to a surface. At least one of the wheels includes a hub motor arrangement that provides a drive torque for propelling the vehicle. The hub motor arrangement includes a housing defining an interior space. An axle or other mounting element(s) define an axis of rotation of the housing. Preferably, the axle or other mounting element(s) do not pass completely through the housing. A motor drives the housing through a transmission. Preferably, the motor is a standard, compact motor that is positioned on the axis of rotation and can be laterally offset from a central plane of the housing. In some embodiments, a traction element is carried directly by the housing.

A ride-on vehicle, such as for a child, includes a vehicle body and one or more wheels that support the vehicle body relative to a surface. At least one of the wheels includes a hub motor arrangement that provides a drive torque for propelling the vehicle. The hub motor arrangement includes a housing defining an interior space. An axle or other mounting element(s) define an axis of rotation of the housing. Preferably, the axle or other mounting element(s) do not pass completely through the housing. A motor drives the housing through a transmission. Preferably, the motor is a standard, compact motor that is positioned on the axis of rotation and can be laterally offset from a central plane of the housing. In some embodiments, a traction element is carried directly by the housing.

A drivetrain for an aircraft includes an engine, a driveshaft receiving rotational energy from the engine and a gearbox including a planetary gear system receiving rotational energy from the driveshaft. The planetary gear system includes a sun gear, planet gears, a ring gear and an integral carrier forming flexured carrier posts. Each flexured carrier post supports a respective one of the planet gears and has a fixed proximal end and a cantilevered distal end. The planetary gear system includes flexured roller races, each having a fixed end and a cantilevered end. The fixed end of each flexured roller race is coupled to the cantilevered distal end of a respective flexured carrier post. The planet gears engage with the flexured roller races to rotate about the flexured carrier posts. The cantilevered ends of the flexured roller races experience cantilevered motion to absorb loads from the planet gears.

A drivetrain for an aircraft includes an engine, a driveshaft receiving rotational energy from the engine and a gearbox including a planetary gear system receiving rotational energy from the driveshaft. The planetary gear system includes a sun gear, planet gears, a ring gear and an integral carrier forming flexured carrier posts. Each flexured carrier post supports a respective one of the planet gears and has a fixed proximal end and a cantilevered distal end. The planetary gear system includes flexured roller races, each having a fixed end and a cantilevered end. The fixed end of each flexured roller race is coupled to the cantilevered distal end of a respective flexured carrier post. The planet gears engage with the flexured roller races to rotate about the flexured carrier posts. The cantilevered ends of the flexured roller races experience cantilevered motion to absorb loads from the planet gears.

A drivetrain for an aircraft includes an engine, a driveshaft receiving rotational energy from the engine and a gearbox including a planetary gear system receiving rotational energy from the driveshaft. The planetary gear system includes a sun gear, planet gears, a ring gear and an integral carrier forming flexured carrier posts. Each flexured carrier post supports a respective one of the planet gears and has a fixed proximal end and a cantilevered distal end. The planetary gear system includes flexured roller races, each having a fixed end and a cantilevered end. The fixed end of each flexured roller race is coupled to the cantilevered distal end of a respective flexured carrier post. The planet gears engage with the flexured roller races to rotate about the flexured carrier posts. The cantilevered ends of the flexured roller races experience cantilevered motion to absorb loads from the planet gears.

A drivetrain for an aircraft includes an engine, a driveshaft receiving rotational energy from the engine and a gearbox including a planetary gear system receiving rotational energy from the driveshaft. The planetary gear system includes a sun gear, planet gears, a ring gear and an integral carrier forming flexured carrier posts. Each flexured carrier post supports a respective one of the planet gears and has a fixed proximal end and a cantilevered distal end. The planetary gear system includes flexured roller races, each having a fixed end and a cantilevered end. The fixed end of each flexured roller race is coupled to the cantilevered distal end of a respective flexured carrier post. The planet gears engage with the flexured roller races to rotate about the flexured carrier posts. The cantilevered ends of the flexured roller races experience cantilevered motion to absorb loads from the planet gears.

A planet gear housing assembly is disclosed in an epicyclical gear system of a gas turbine engine. The planet gear housing assembly comprises an aft planet carrier assembly, a forward planet carrier assembly, and a plurality of planet gears. The planet gear housing assembly includes one or more of the following features: a stiffening member positioned between the forward and aft planet carrier assemblies, a static curvic joint coupling the forward and aft planet carrier assemblies, a plurality of roller element bearings to carry the plurality of planet gears, and one or more bearing springs disposed between a bearing and a carrier housing to accommodate relative movement.

A geared architecture for a gas turbine engine includes a central gear supported for rotation about the axis, a plurality of intermediate gears engaged with the central gear and a ring gear circumscribing the intermediate gears. A first flexible coupling is provided between an input shaft driven by a turbine section and the sun gear. The geared architecture provides a power density comprising a power measured in horsepower (HP) related to a weight of the geared architecture within a defined range that benefits overall engine weight and efficiency.

A geared architecture for a gas turbine engine includes a central gear supported for rotation about the axis, a plurality of intermediate gears engaged with the central gear and a ring gear circumscribing the intermediate gears. A first flexible coupling is provided between an input shaft driven by a turbine section and the sun gear. The geared architecture provides a power density comprising a power measured in horsepower (HP) related to a weight of the geared architecture within a defined range that benefits overall engine weight and efficiency.

A lubricating and cooling core for a mechanical reduction gear of a turbine engine, for example of an aircraft, is configured to be mounted in an axis of a planet gear of the reduction gear. The core includes first and second coaxial and substantially frusto-conical shields, each having a first end with a greater diameter and a second opposite end with a smaller diameter, the shields being secured to one another by their second ends and being configured to extend inside the axis and to cover at least a radially internal surface of the axis to define with the latter at least one annular cavity for the circulation of oil for lubricating and cooling the axis, the second ends of the first and second shields having fluid connection means configured to connect the at least one cavity to a source of lubricating and cooling oil.