A mechanical gearbox for an aircraft turbomachine includes a sun gear having an axis (X) of rotation, a ring gear around the sun gear, and planet gears meshed with the sun gear and the ring gear. Each planet gear has a first toothing meshed with the sun gear and a second toothing meshed with the ring gear. The first toothing includes a series of upstream teeth and a series of downstream teeth located on either side of a plane (H) perpendicular to the axis (X) of rotation of the sun gear. The second toothing includes a series of upstream teeth and a series of downstream teeth located on either side of said plane (H) and separated from one another by said first toothing, these teeth being parallel to one another and to the axis (Y) of rotation of the planet gear.

A mechanical gearbox for an aircraft turbomachine includes a sun gear having an axis (X) of rotation, a ring gear around the sun gear, and planet gears meshed with the sun gear and the ring gear. Each planet gear has a first toothing meshed with the sun gear and a second toothing meshed with the ring gear. The first toothing includes a series of upstream teeth and a series of downstream teeth located on either side of a plane (H) perpendicular to the axis (X) of rotation of the sun gear. The second toothing includes a series of upstream teeth and a series of downstream teeth located on either side of said plane (H) and separated from one another by said first toothing, these teeth being parallel to one another and to the axis (Y) of rotation of the planet gear.

In a cycloid transmission a second input side eccentric cam and a first output side eccentric cam are integrally fixed to a rotary shaft to be eccentric in the same phase, a first input side eccentric cam is fixed to the rotary shaft so that the first input side eccentric cam is eccentric in a phase different from that of the second input side eccentric cam and that of the first output side eccentric cam, a second output side eccentric cam is rotatably attached to the rotary shaft, a second input side cycloid gear and a first output side cycloid gear are integrally formed to be rotated in synchronism with each other in the same phase, and a first input side cycloid gear is connected to the second output side cycloid gear by a connection member to be rotated in synchronism with each other in the same phase.

A speed reducing device includes a motor and a speed reducing mechanism. The speed reducing mechanism includes at least one roller assembly, a cycloid disc, at least one fixing disc and a positioning assembly. The roller assembly is disposed within a rotor portion of the motor. While the roller assembly is rotated with the rotor portion, the roller assembly is eccentrically revolved. The roller assembly includes a wheel disc and at least one roller. The cycloid disc includes a main body and at least one cycloid tooth structure. The cycloid tooth structure is protruded from an outer periphery of the main body and in contact with the corresponding roller. While the roller assembly is eccentrically revolved, the at least one cycloid tooth structure is pushed against the corresponding roller, so that the cycloid disc is correspondingly rotated.

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 roller screw mechanism is provided comprising a screw with an outer thread, and a nut disposed around and coaxially with the screw and comprising an inner thread; and with rollers that each have an outer thread and inserted between the screw and the nut, each roller having two ends each provided with an outer gear teeth, each outer gear teeth having, in cross-section, an outer diameter less than or equal to a root diameter of the outer thread of the rollers; and two synchronizing gear teeth disposed coaxially to the screw and in which the outer gear teeth of the rollers engage, wherein the outer gear teeth of the rollers have teeth with a flank having, in cross-section, a convex hypotrochoidal profile and the synchronizing gear teeth have teeth with a flank having, in cross-section, a hypotrochoidal or epitrochoidal profile.

A speed reduction device including a first internally meshing planetary gear mechanism and a second internally meshing planetary gear mechanism, including: a housing; an input shaft rotatably supported by the housing at its first shaft portion through a first bearing; a planetary gear member rotatably supported by an eccentric shaft portion of the input shaft through a second bearing; and an output shaft rotatably supported by a second shaft portion of the input shaft through a third bearing, wherein a distance in an axial direction between a first support position and a second support position is equal to a distance in the axial direction between the second support position and a third support position, and a distance in the axial direction between the second support position and an input-side meshing position is equal to a distance in the axial direction between the second support position and an output-side meshing position.

A speed reduction device including a first internally meshing planetary gear mechanism and a second internally meshing planetary gear mechanism, including: a housing; an input shaft rotatably supported by the housing at its first shaft portion through a first bearing; a planetary gear member rotatably supported by an eccentric shaft portion of the input shaft through a second bearing; and an output shaft rotatably supported by a second shaft portion of the input shaft through a third bearing, wherein a distance in an axial direction between a first support position and a second support position is equal to a distance in the axial direction between the second support position and a third support position, and a distance in the axial direction between the second support position and an input-side meshing position is equal to a distance in the axial direction between the second support position and an output-side meshing position.

In a cycloid transmission a second input side eccentric cam and a first output side eccentric cam are integrally fixed to a rotary shaft to be eccentric in the same phase, a first input side eccentric cam is fixed to the rotary shaft so that the first input side eccentric cam is eccentric in a phase different from that of the second input side eccentric cam and that of the first output side eccentric cam, a second output side eccentric cam is rotatably attached to the rotary shaft, a second input side cycloid gear and a first output side cycloid gear are integrally formed to be rotated in synchronism with each other in the same phase, and a first input side cycloid gear is connected to the second output side cycloid gear by a connection member to be rotated in synchronism with each other in the same phase.

A reduction assembly, attachable to a torque limiting device, comprising a drive shaft having an input segment, an eccentric segment, and an output segment, wherein the input segment and the output segment each have a centerline running along a same first axis, and wherein the eccentric segment has a center line running along a second axis, the second axis being parallel to the first axis and positioned a first distance away from the first axis. The assembly further comprising a disk assembly having a disk with a body, a plurality of lobes positioned concentrically on the body, and an opening extending through the body, the opening configured to slidably engage the eccentric segment of the drive shaft. The assembly further comprising a disk receptacle configured to engage with the disk, the receptacle having a floor and a wall with a plurality of protrusions extending from the wall, wherein the number of the plurality of protrusions is equal to one more than the number of the plurality of lobes on the disk.