A prime mover includes a stator fixed to a housing and a rotor relatively rotatable relative to the stator. The prime mover outputs torque from the rotor by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. One bearing portion rotatably supports the rotor. The speed reducer includes an input portion that is coaxial and integrally rotatable with the rotor and receives the torque from the rotor.

A state changing unit is capable of contacting a clutch, and being configured to receive a force along the axial direction from a translation portion and change a state of the clutch to an engaged state or a disengaged state according to a position of the translation portion in an axial direction relative to a housing. A fixed end is non-rotatable relative to the housing. A return spring is disposed on a side of the fixed end opposite to the clutch, and capable of urging the translation portion in a direction away from the clutch with respect to the fixed end.

A state changing unit is provided radially outward of a translation portion and movable in an axial direction relative to the translation portion. The state changing unit is in contact with or separated from the clutch. The state changing unit receives a force in the axial direction from the translation portion such that the state changing unit is pressed against the clutch. The state changing unit is capable of changing a state of the clutch to an engaged state or a disengaged state according to a position of the translation portion in the axial direction relative to the housing. A movement restriction portion is provided on the translation portion and located between the state changing unit and the clutch. The movement restriction portion contacts the state changing unit and restricts movement of the state changing unit relative to the translation portion toward the clutch.

A housing includes an accommodation space for a prime mover and a speed reducer. A rotational translation unit includes a rotation portion that rotates relative to the housing upon receiving torque outputted from the speed reducer, and a translation portion that moves relative to the housing in an axial direction according to rotation of the rotation portion. The accommodation space is between the rotation portion and the housing. A clutch in a clutch space allows or interrupts transmission of torque between a first transmission portion and a second transmission portion. The rotation portion is between the clutch space and the accommodation space. A sealing member has an annular shape in contact with the rotation portion, and maintains an air-tight or liquid-tight state between the accommodation space and the clutch space.

A planetary gearbox is provided that includes 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 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 planetary gear mechanism includes a sun gear attached to the motor rotation shaft to rotate about the central axis extending vertically, a fixed internal gear radially outside the sun gear, planetary gears radially outside the sun gear and radially inside the fixed internal gear to mesh with the sun gear and the fixed internal gear, a movable internal gear above the fixed internal gear and radially outside the planetary gears to mesh with the planetary gears and to rotate about the central axis, and a carrier that holds upper and lower surfaces of the planetary gears.

A prime mover includes a stator fixed to the housing and a rotor rotatable relative to the stator. The prime mover outputs torque by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. A rotational translation unit includes a rotation portion that rotates relative to the housing upon receiving the torque from the speed reducer, and a translation portion that moves relative to the housing in an axial direction. A clutch allows torque transmission in an engaged state, and interrupts the torque transmission in a disengaged state. A state changing unit changes the state of the clutch by receiving a force along the axial direction from the translation portion. Cogging torque generated between the rotor and the stator is set to such a magnitude that the rotor is stoppable at any rotation position relative to the stator.

A gas turbine engine includes an engine core, a fan and a gearbox interconnecting the engine core and the fan. The engine core is configured to drive rotation of at least one shaft. The power gearbox is configured to transfer torque from the at least one shaft to an output shaft at a reduced rate. The output shaft is coupled to the fan to drive the fan at the reduced rate and provide trust for the gas turbine engine.

An electric wheel-end assembly comprising a mounting portion, a spindle having an inboard end connected to the mounting portion and an outboard end distal from the mounting portion. A hub is rotatably mounted to the spindle via one or more bearings disposed between the inboard and outboard ends of the spindle. A reduction gearbox is disposed at the distal end of the spindle. An input shaft comprising an inboard end having a drive receiving portion arranged to releasably connect to a drive shaft of an electric motor, extends through the spindle to deliver a rotational input to the drive input of the reduction gearbox, the drive output of the reduction gearbox being connected to the hub to drive the hub in rotation about the spindle.

A prime mover includes a stator fixed to a housing and a rotor relatively rotatable relative to the stator. The prime mover outputs torque from the rotor by being supplied with electric power. A speed reducer reduces the torque of the prime mover and outputs the reduced torque. One bearing portion rotatably supports the rotor. The speed reducer includes an input portion that is coaxial and integrally rotatable with the rotor and receives the torque from the rotor.