A power transmission device includes a pinion gear having a large pinion gear and a small pinion gear, a carrier that supports the pinion gear, a ring gear that engages with the small pinion gear, an oil supply unit positioned above a horizontal line that passes through a revolution center of the pinion gear, and a downstream side wall part facing a gear surface of the large pinion gear. The downstream side wall part is arranged to be adjacent to the oil supply unit further downstream in a revolution direction of the pinion gear than the oil supply unit when viewed from an axial direction.

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 power transmission device includes a bearing, a differential mechanism, a case that houses the differential mechanism, a pinion gear supported by the case, a wall part that overlaps the case in an axial direction, a plate that is provided between the wall part and the case in the axial direction, and that supports the case with the bearing being interposed, and a parking pawl that is rotatably fixed to the plate in a position that overlaps the plate in the axial direction.

A power transmission device includes a box, a case disposed in the box, a differential mechanism housed in the case, and a planetary gear mechanism disposed in the box and supported by the case. The planetary gear mechanism includes a sun gear and a pinion gear that engages with the sun gear. The box has a shelf part above a horizontal line that passes through a revolution center of the pinion gear. The shelf part is arranged at a position that does not overlap the sun gear when viewed from radially above.

An actuator is provided which includes a stationary frame; an output plate disposed within said stationary frame; a top plate; a stator disposed between said stationary frame and said top plate, said stator describing an annulus; a rotor disposed within the annulus of said stator; a principal bearing disposed between said stationary frame and said output plate; a pinion gear; and a star gear which meshes with said pinion gear.

A gear assembly including a first gear including a rim and a plurality of teeth. The plurality of teeth is configured to contact one or more of another plurality of teeth. A non-axisymmetric structure is defined at the rim. The non-axisymmetric structure is a non-contacting structure of the gear assembly.

A gas turbine engine includes a fan section that includes a fan rotatable about an engine axis. A compressor section includes a low pressure compressor rotatable about the engine axis. A turbine section includes a fan drive turbine for driving the fan and the low pressure compressor. A speed reduction device connects the fan drive turbine to the fan and the low pressure compressor. The speed reduction device includes a sun gear driven by an inner shaft. A plurality of intermediate gears surround the sun gear. A carrier supports the plurality of intermediate gears for driving the low pressure compressor. A ring gear is located radially outward from the intermediate gears and includes a forward portion for driving a fan drive shaft and an aft portion.

A planetary transmission (2) includes a stepped planetary gear (24), or planetary gears, which are connected to each other, that is/are disposed radially between a first shaft (6) and axially-adjacent first and second ring gears (12, 16). The stepped planetary gear, or connected planetary gears, include(s) a first gearing region (26) that meshes with a sun gear (8) on the first shaft (6) and the first ring gear (12), as well as a helically-toothed second gearing region (28) that meshes with the second ring gear (16). A cylindrical support region (32) is coaxially provided on/around the first shaft. The stepped planetary gear or the connected planetary gears is/are supported on the cylindrical support region of the first shaft by the outer circumferential surface of the second gearing region. The second gearing region lies on the addendum circle of the second gearing region.

A gear mechanism (1′) for increasing torque, comprising: an input shaft (2′); at least one intermediate shaft (5); where the at least one intermediate shaft (5′) is parallel and offset from the input shaft (2′); at least one force transmitting member (6′) connecting the input shaft (2′) and the at least one intermediate shaft (5′); where the at least one force transmitting member (6′) is configured for rotating the at least one intermediate shaft (5′) in the same direction as the input shaft (2′); the at least one intermediate shaft (5′) is mating with at least one fixed mating member (9′) and is rotatably connected to a rotatable support member (11); the support member (11′) is rotatable about the input shaft (2) and connected to an output shaft (14′).

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.