Currently, there is no efficient mechanism for speed increasing with very high transmission ratio. Therefore, a planetary mechanism is proposed, with two suns (0b, 3b), having teeth numbers: Z.sub.1,Z.sub.4, one stationary (0b) and one (3b) constituting the input of mechanism, a carrier (1a, 1b, 1c, 1d) constituting the output, and a planetic shaft (2b) with two planets (2a, 2c), cooperating with corresponding suns (0b, 3b) and having teeth numbers: Z.sub.2,Z.sub.3, where the term: Z.sub.1/Z.sub.2.Z.sub.3/Z.sub.4 is closest to 1, so the transmission ratio between moving sun (3b) and carrier (1a, 1b, 1c, 1d) is maximum possible. In a specific case, named “Three Successive Integers Mechanism”, this transmission ratio is equal to k.sup.2, where k is integer, easily taking high value. The applications are unlimited, while some are: —wind turbine, —electric assisted bicycle, —energy storage unit of enormous kinetic energy with k.sup.4 times increased moment of inertia, —mechanically driven supercharger for ICE or fuel cell, —robotic articulated arm (as speed reducer).

Pericyclic transmission having at least one input shaft (58) rotatable about an axis of rotation and at least one inclined bearing seat (55, 56) secured to the input shaft with the inclined bearing seat being oriented at an inclination angle with respect to the axis of rotation of the input shaft. An input gear (52, 54) is attached to each inclined bearing seat with the input gear being oriented at the inclination angle and having an axis of rotation inclined to the axis of rotation of the input shaft by the inclination angle whereby upon rotation of the input shaft, the input gear performs at least a nutating motion. The transmission also includes an intermediate gear (51, 53) in mesh with the input gear with the intermediate gear having an axis of rotation coincident with the axis of rotation of the input shaft. The intermediate gear communicates with a transmission output.

An electrically-actuated variable camshaft timing (VCT) device, comprising: an input configured to receive rotational force from an electric motor; an output configured to couple with a camshaft of an internal combustion engine; a planet gear having radially outwardly extending gear teeth configured to engage ring gears and a radially-inwardly-facing surface; a planet pin, supporting the planet gear, having an outer surface and an axis of rotation about which the planet gear rotates; and a spring applying force in a substantially axial direction along the axis of rotation that moves the planet gear in a radial direction.

A method for manufacturing a mechanical reducer for an aircraft turbomachine including a central pinion, an outer crown, N planet pinions, where N≥3, each planet pinion including a first stage meshing with the central pinion, and a second stage meshing with the outer crown, the method including the assembly marking, wherein N teeth of the central pinion are marked, and N pairs of teeth of the first stage of each planet pinion are marked, the N planet pinions each being marked identically, and the assembly of the mechanical reducer, so that the teeth of the pairs of marked teeth of the first stage of each planet pinion are disposed on either side of a marked tooth of the central pinion.

Embodiments of the invention are shown in the figures, where a gas turbine engine for an aircraft includes: an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan including a plurality of fan blades; and a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan about a rotational axis at a lower rotational speed than the core shaft, wherein the gearbox is an epicyclic gearbox with a plurality of planet gears arranged in first and second sets of planet gears, the planet gears of the first set being positioned displaced relative to the planet gears of the second set in a direction parallel to the rotational axis.

A transmission having a housing (18), at least a first input (20) rotatable about a first input axis (I.sub.A1), and at least a first output (26) rotatable about a first output axis (O.sub.A1). The transmission further includes a first outer side gear (14) connected to and drivable by the first input, a first planet gear set comprising a first inner planet gear (11) and a first outer planet gear (15) with the inner and outer planet gears being rigidly connected to, and in axial alignment with, one another. The first planet gear set is rotatable (22, 24) via the first outer side gear and is also rotatable (23) about the first output axis. The transmission further includes a second outer side gear (16) in mesh with the first outer planet gear, and a second inner side gear (12) connected to the first output and being rotatable about the first output axis via the first inner planet gear.

A mechanical reduction gear of a turbomachine, in particular of an aircraft. The reduction gear includes a sun gear, a ring gear surrounded by a ring gear carrier, and planet gears meshed with the sun gear and the ring gear. The ring gear carrier includes an axial abutment on which the ring gear is configured to bear, and helical external splines which are engaged in complementary internal splines of the ring gear carrier and which are configured to cooperate by sliding with the internal splines so as to force the ring gear to be held against the abutment in operation.

A spindle drive assembly for opening and/or closing a vehicle flap is described, having a spindle and a spindle drive motor coupled thereto by means of a two-stage epicyclic gearing. A ratio of a number of teeth of each planet gear of a first epicyclic gearing stage to a number of teeth of each planet gear of a second epicyclic gearing stage is selected such that, in operation, a first sound frequency that is emitted by the first epicyclic gearing stage differs by an integer multiple of a semitone from a second sound frequency that is emitted by the second epicyclic gearing stage. In addition, a vehicle flap with such a spindle drive assembly is presented.

In one aspect, there is provided a planetary gearbox, comprising 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 diameter of the main gear being different than a diameter of the fore and aft lateral gears, 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 reducer contains: a sun gear rod, a gear assembly, a first external gear, and a second external gear. The sun gear rod includes an extension and a toothed section. The gear assembly includes a post, a first planetary gear, and a second planetary gear. Some of multiple teeth of the first planetary gear and some of multiple teeth of the second planetary gear expose outside the post. A number of the multiple teeth of the first planetary gear is different from a number of the multiple teeth of the second planetary gear. The first external gear includes a first surrounding portion and a first toothed portion which meshes with the first planetary gear. The second external gear includes a second surrounding portion and a second toothed portion which meshes with the second planetary gear.