A mechanical reduction gear for a turbomachine, in particular for an aircraft, this reduction gear including a sun gear having an axis of rotation, a ring gear which extends around the sun gear and which is configured to be fixed in rotation around the axis, planet gears which are in mesh with the sun gear and the ring gear and which are held by a planet carrier which is configured to be fixed or in rotation around the axis, each planet gear including a first toothing of average diameter D1 for the meshing with the sun gear, and a second toothing of average diameter D2, different from D1, for the meshing with the ring gear, wherein the first and second toothings of each planet gear include herringbone teeth and are symmetrical with respect to a plane perpendicular to the axis and passing substantially in the middle of the planet gear.

A vehicle parking mechanism according to the disclosure is a mechanism provided in a vehicle power transmission device that transmits power output from an electric motor to left and right axles and through two planetary gear mechanisms and a differential device, wherein, in a carrier of one of the two planetary gear mechanisms and, a piston engaged and disengaged with and from a carrier of the other is slidably provided, wherein the piston is engaged with the carrier of the other planetary gear mechanism when a vehicle is stopped, and wherein the piston is disengaged from the carrier of the other planetary gear mechanism other than when the vehicle is stopped.

A planetary gear train for an aircraft engine, has: a sun gear; planet gear assemblies having main gears meshed with the sun gear, fore lateral gears and aft lateral gears disposed on opposite sides of the main gears and rotating therewith; journal bearings rotatably supporting the planet gear assemblies for rotation about rotation axes, gaps defined between the journal bearings and the planetary gear assemblies; a planet carrier supporting the journal bearings; a fore ring gear meshed with the fore lateral gears; an aft ring gear meshed with the aft lateral gears; and a lubrication system extending within the planet carrier and hydraulically connected to the gaps between the journal bearings and the planet gear assemblies.

A planet-carrier for an epicyclic gearing is provided with a ring having a plurality of plate sectors and a plurality of connection sectors, alternating with one another about a first axis; a connection structure connects in an angularly fixed manner the connection sectors to a rotating member or to a static member; the planet-carrier is also provided with a plurality of pins, which are fixed with respect to the plate sectors and protrude in opposite directions from the plate sectors along respective second axes, parallel and eccentric with respect to the first axis; each pin has two coaxial outer surfaces, adapted to support respective planet gears of the gearing and symmetrical to each other with respect to a symmetry plane orthogonal to the first axis; the plate sectors are asymmetrical with respect to this symmetry plane.

In one aspect, there is provided a gear train having a sun gear, planet gear assemblies. Each planet gear assembly has 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 is different than a diameter of the fore and aft lateral gears. Each planet gear assembly is rotatably mounted on a bearing for rotation about an axis. The bearing includes a journal defining two undercuts. A planet carrier rotatably supports the planet gear assemblies. Ring gears are meshed with the fore and aft lateral gears. One of the sun gear, the planet carrier, and the ring gears connected to an input, one is connected to an output, and rotation of a remaining one is limited.

A spreader device includes a container portion configured to contain spread substance, a spreader portion having a rotor configured to spread the spread substance contained in the container portion, and an attachment portion configured to be attached to a vehicle body. The spreader portion includes at least three spreader portions. Preferably, each of the at least three spreader portions has a different spreading direction. Preferably, the spreader portion includes a first spreader portion having a first rotor configured to spread the spread substance contained in the container portion, a second spreader portion having a second rotor configured to spread the spread substance contained in the container portion, and a third spreader portion having a third rotor configured to spread the spread substance contained in the container portion.

There is provided a variable speed increaser including a planetary gear transmission device which changes the speed of a rotational driving force of the electric driving device and transmits the changed rotation driving force to a driving target, and a rotation rate controller. The electric driving device includes a constant-speed motor having a constant-speed rotor, and a variable-speed motor having a variable-speed rotor and driven in a regenerative mode and in a power mode. A rotation rate of the output shaft varies within an operation range between a maximum rotation rate and a minimum rotation rate. The constant-speed motor has a rated torque which allows the output shaft to have the maximum rotation rate by itself. The rotation rate controller changes the rotation rate of the output shaft rotating within the operation range by driving the variable-speed motor only in the regenerative mode.

A transmission device to divide torque between gears. The device comprising a coaxial motion input member and transmission members and comprising shafts having gears at an axial end. Flanges which project radially outwards from the shafts, at the opposite axial end with respect to the gears, are axially facing and arranged abutting against each other, and are fixed to the motion input member to divide the torque transmitted by the motion input member between the flanges. The second shaft being axially hollow. The first shaft comprising a first intermediate portion having an outside diameter smaller than the inside diameter of the second shaft and housed at least with radial clearance in the second shaft. The flanges comprise respective portions configured to deform under the action of forces acting between the motion input member and the gears to enable a fluctuation of the shafts with respect to an axis.

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.

A gearbox assembly for a gas turbine engine comprises a planetary gearbox having at least one ring gear and at least one planet gear, which exerts a force on the ring gear in the direction of a force vector as it rolls on said ring gear; and a holding device for fastening the at least one ring gear on another structure, having a first section, which extends in the axial direction on one side of the force vector and/or of a straight-line extension thereof, and having a second section, which extends in the axial direction on the other side of the force vector and/or of the straight-line extension thereof. A gas turbine engine and a method for producing a gearbox assembly are furthermore made available.