A gear transmission for aeronautical applications including an input shaft rotating about an axis, an output shaft rotating about the axis, and a transfer group for transferring the torque from the input shaft to the output shaft. The transfer group includes a first torque splitting stage, receiving the torque from the input shaft, and a second torque splitting stage, receiving the torque from the first stage. The first stage presents at least one first rotating member and the second stage presents at least one second rotating member. The input shaft and the first rotating member cooperate with one another at respective interaction surfaces. The rotating members cooperate with one another at respective friction surfaces. One of the interaction surfaces has first engagement elements, and another of the interaction surfaces has second engagement elements that are clutch coupled to one another.

A coupling structure includes a shaft, a tube, and a connection assembly. An end of the shaft is formed with a plurality of axial insertion troughs extended in an axial direction and arranged in an alternate manner. The tube includes a penetration-axle hole formed in a center thereof and corresponding to the penetration-axle section of the shaft. A plurality of radial insertion troughs, in the form of a recessed surface, are formed in an inner circumferential surface of the penetration-axle hole of the tube. The connection assembly includes a coupling block that has an outer circumference formed with a plurality of radial insertion blocks corresponding to the radial insertion troughs of the tube and a plurality of axial insertion blocks corresponding to the axial insertion troughs of the shaft, so that a fastening member may be used to selectively fasten the coupling block between the shaft and the tube.

A structure includes a transmission axle rotatably mounted at a center of a housing. The transmission axle includes a sun gear mounted thereon. An internally-toothed ring track is fixed to an inner circumference of the housing. A planetary gear set is arranged between the sun gear and the internally-toothed ring track. The planetary gear set includes a plurality of stepped planetary gears arranged around the sun gear for self-spinning and orbiting around the sun gear. Each stepped planetary gear includes a first toothed portion meshing with both the sun gear and the internally-toothed ring track and a second toothed portion rotatable in unison with the first toothed portion. An output member is fit over the planetary gear set and includes an inner circumference formed with an internal toothed circumference meshing with the second toothed portion of each stepped planetary gear.

A mechanism includes a housing, a transmission axle arranged at a center of the housing, an internally toothed ring track fixed to an inner circumference of the housing, and a coaxial gear set arranged between the transmission axle and the internally toothed ring track. The coaxial gear set includes a sun gear, a planetary gear set, and an output member. The planetary gear set includes a first carrier frame and a second carrier frame rotatably arranged at two ends of the sun gear. Multiple planetary gears are rotatably arranged between the first and second carrier frames and around the sun gear. Each of the planetary gears is in meshing engagement with the output member. The coaxial gear set is made in a modularized form for subsequent assembly in an optional manner, so as to provide an efficacy of easing assembling and servicing operations.

Provided is a dual clutch transmission. First and second input shafts are mounted concentrically. First and second output shafts are mounted in parallel to the first input shaft and respectively include output gears engaged with a ring gear of a differential. The rotations of first and second gears are restrained by the first input shaft. The rotations of third and fourth gears are restrained by the second input shaft. The rotations of fifth and sixth gears engaged with the second and third gears, respectively, are restrained by the first output shaft. The rotation of a seventh gear engaged with the first gear is restrained by the second output shaft. An eighth gear is engaged with the second gear to be rotatable about the second output shaft. The rotation of a ninth gear engaged with the fourth gear and restrained by the eighth gear is restrained by the second output shaft.

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 reduction drive assembly includes a planetary gear assembly. The planetary gear assembly includes a first gear carrier that includes a first plate and projections extending therefrom. The first plate defines first support openings. The planetary gear assembly includes a second gear carrier that defines second support openings and joint openings. The joint openings receive the projections to couple the first and second gear carriers. The planetary gear assembly includes a sun gear coupled to an output shaft and disposed between the first and second gear carriers. The planetary gear assembly includes planet gears disposed around the sun gear between the first and second gear carriers. Each of the planet gears has a carrier pin. Each carrier pin is received by one of the first support openings and one of the second support openings to retain the planet gears between the first and second gear carriers.

A reduction drive assembly includes a spindle that defines an aperture and a motor output shaft extending through the aperture. The reduction drive assembly includes an output hub and a planetary gear assembly. The planetary gear assembly includes a ring gear fixed to the output hub, a first stage sun gear coupled to and driven by the motor output shaft, a second stage sun gear, a planetary gear carrier engaged to the second stage sun gear, first stage planetary gears each of which is supported by a respective support pin of the planetary gear carrier and meshed with the first stage sun gear and the ring gear, carrier pins extending from a first end of the spindle, and second stage reduction gears each of which is rotationally mounted on a respective one of the carrier pins and is meshed with the second stage sun gear and the ring gear.

Torque of a prime mover is input into a sun gear. A planetary gear revolves in a circumferential direction of the sun gear while rotating and meshing with the sun gear. A carrier has an annular shape, rotatably supports the planetary gear, and is rotatable relative to the sun gear. A first ring gear is fixed to a housing, and meshes with the planetary gear. A second ring gear meshes with the planetary gear, is different from the first ring gear in number of teeth of a tooth portion, and outputs torque to a rotation portion. At least a part of the sun gear in an axial direction is located radially inward of the carrier. At least a part of the first ring gear and at least a part of the second ring gear in the axial direction are located radially outward of the carrier.

A prime mover includes a stator fixed to a housing, and a rotor 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. The speed reducer includes a sun gear to which the torque from the rotor is input, and a planetary gear that revolves in a circumferential direction of the sun gear while rotating in a state of meshing with the sun gear. The rotor and the sun gear are formed separately, and are disposed coaxially so as to be integrally rotatable.