A modular gear transmission and associated systems. The modular gear transmission has an assembled configuration, and the modular gear transmission comprises a first transmission body and a first transmission gear set. The first transmission gear set comprises a first protruding gear, a first intermediate gear set comprising at least one intermediate transmission gear, and a first transmission socket. The first transmission body is configured so that, when the modular gear transmission is in the assembled configuration, the first transmission body engages the first transmission gear set to hold the first transmission gear set in a rotatable configuration. The first protruding gear is configured so that, when the modular gear transmission is in the assembled configuration, the first protruding gear protrudes from the first transmission body and is rotatably engaged with the first intermediate gear set, the first protruding gear configured to rotate around a first referential axis of rotation.

A cordless blind device that can be operated in various types such as manual, semiautomatic, and automatic types is proposed. The cordless blind device includes: a winding roll, a screen, a driving motor, a weight connected to a lower end of the screen; a torsion spring applying torque in a direction in which the screen is wound; and a rotation conversion module transmitting power in two directions between the driving motor and the winding roll, in which when the driving motor does not generate driving force, the torque applied by the torsion spring, the torque applied by the weight, and resistance by the rotation conversion module and the driving motor make equilibrium, so the screen remains stopped, and when an external force is applied upward or downward to the weight, the equilibrium of the forces breaks, so the screen is wound on or unwound from the winding roll.

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.

A planetary gearbox includes a ring gear accommodated in a housing part, the ring gear particularly has on its radially outer surface, in particular its radially outer side, an annular groove, the annular groove, in particular a circumferential annular groove in the circumferential direction, and a spring element is accommodated in the annular groove, which projects at least partially into an annular groove introduced into the housing part.

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.

A mechanical gearbox for turbomachine, in particular for aircraft. The gearbox includes a sun gear including an external toothing, a ring gear including an internal toothing, and planet gears which are meshed with the sun gear and the stationary ring gear. The planet gears are carried by a movable planet carrier and each having external toothings of different diameters. The movable planet carrier includes a movable ring gear which carries an internal toothing and which is independent of the stationary ring gear, each of the planet gears being meshed with the sun gear and the stationary and movable ring gears.

A planetary transmission includes first and second ring gears and a double planet with first and second gears rotatably disposed about a common shaft and arranged such that the gear teeth of the first gear of the double planet engage into the gear teeth of the first ring gear, and the gear teeth of the second gear of the double planet engage into the gear teeth of the second ring gear. The first gear of the double planet is preloaded in a clockwise direction such that the gear teeth of the first gear of the double planet are in contact with the gear teeth of the first ring gear, and the second gear of the double planet is preloaded in a counterclockwise direction such that the gear teeth of the second gear of the double planet are in contact with the gear teeth of the second ring gear.

A transmission device for splitting torque between two coaxial gears, in particular for a planetary gearing for aeronautic applications, has a motion input member and two transmission members, which are coaxial and have respective shafts provided with gears at an axial end and respective external flanges, at the opposite axial end; the two flanges are axially facing and placed abutting against each other, and are fixed to the motion input member so as to split the torque transmitted from the motion input member between the two flanges; one of the two shafts is axially hollow and houses, with radial clearance, an intermediate portion of the other shaft; the latter is formed by at least two pieces which are coaxial and fixed to each other.

An epicyclic gearbox includes a sun gear assembly, a planet gear assembly, and a ring gear assembly engaged with a forward planet gear and an aft planet gear of the planet gear assembly. A first axial shroud is also provided positioned forward of the forward planet gear or aft of the aft planet gear along an axial direction. The first axial shroud covers substantially all of a forward side of the forward planet gear or an aft side of the aft planet gear. The planet gear assembly is coupled to a planet gear carrier, the planet gear carrier including a radial shroud including one or more radial shroud surfaces extending along at least a portion of an outer circumference of the forward planet gear and along at least a portion of an outer circumference of the aft planet gear.

A planet carrier for a speed-reducing unit with a planetary gear set is provided. The planet carrier generally includes a torque transmission part having a longitudinal axis and an annular cage extending about the axis and connected to one longitudinal end of the part. The cage may include two sides extending radially relative to the axis and connected by bridges, and seats extending axially between the flanks and configured to support planetary gears rotatably mounted about the seats. The curved members may include at least two corresponding bars each inclined relative to a longitudinal plane passing both through the axis and substantially through the corresponding bar.