A compact transmission, in particular for use within a single-wheel drive unit, includes a gear carrier fixed to the frame, which has a continuous central recess, and a main transmission having an internally toothed ring gear rotatably mounted on the outside of the gear carrier, externally toothed gears arranged in front of the one of the end faces of the gear carrier and meshing with the ring gear, and an input sun shaft. The compact transmission further includes a transmission pre-stage arranged within the central recess, and a pre-stage input shaft having an externally toothed pre-stage sun wheel, a pre-stage ring gear, and at least one pre-stage intermediate gear meshing with both the pre-stage sun wheel and with the pre-stage ring gear. An additional carrier is fastened to the transmission carrier, via which the pre-stage intermediate gears are held captively in the central recess.

A method of manufacturing a planet carrier of a gearbox comprises manufacturing a plurality of preforms. Each preform comprises a base portion, a first end portion connected to a first end of the base portion, a second end portion connected to a second end of the base portion, a first side portion connected to a first side of the base portion, a second side portion connected to a second side of the base portion and a top portion. The first and second end portions and the first and second side portions are folded relative to the base portion and the top portion is folded and the adjacent edges of the portions of each preform are secured together to form a support structure. A first ring and a second ring are manufactured. The first and second end portions of each support structure are secured to the first and second rings respectively.

An epicyclic gear train of an aircraft powerplant is provided. The epicyclic gear train includes a sun gear having a rotation axis, a ring gear, a plurality of intermediate gears circumscribed by the ring gear and being meshed with the sun gear and with the ring gear, a carrier supporting the intermediate gears, and a torque frame attaching the carrier to a stationary structure of the aircraft powerplant to prevent rotation of the carrier and of the intermediate gears about the rotation axis of the sun gear. The torque frame is attached to the carrier at a connection. The torque frame and the carrier cooperatively define a lubricant passage extending through the connection and supplying lubricant to at least one of the intermediate gears.

A one-piece planetary carrier includes first and second side walls connected to one another by a plurality of webs. At least one of the webs has a curved outer surface which is directed substantially outward in a radial direction and belongs to a lateral surface of the web. The web includes a transition to the first side wall and a transition to the second side wall. The curved outer surface is convexly curved about a first axis of curvature at the transition to the first skis wall and the transition to the second side wall. The curved outer surface has at least one anticlastic region which lies in an axial central section and an axial edge section of the web, with a combination of the axial central section with the axial edge section substantially defining an axial dimension of the planetary carrier.

A power transmission device includes a motor, a planetary gear mechanism having a portion that overlaps the motor in an axial direction, an axial direction wall part having a portion positioned between the planetary gear mechanism and the motor, a plate provided between the axial direction wall part and a pinion gear having the gear mechanism, and a box in which the motor, the planetary gear mechanism, the axial direction wall part, and the plate are housed. The box defines a breather hole that communicates with a breather chamber. The box has a radial direction wall part having a portion positioned between the plate and the breather chamber in a radial direction. The plate has a portion positioned between the pinion gear and the breather hole.

A friction bearing of a planetary gearbox has a first rotationally fixed component and a second component rotatably connected thereto. Oil in the region of an oil feed pocket of the first component is directed into the bearing clearance between the components. The oil is directed into the oil feed pocket via at least one first line that opens into the oil feed pocket. Oil is also directed via at least one second line into the oil feed pocket, the port region of said second line into the oil feed pocket in the circumferential direction of the bearing clearance and in the main rotation direction of the second component in relation to the first component and/or in the axial direction of the friction bearing being spaced apart from the port region of the first line into the oil feed pocket.

A planetary gearbox has a sun gear, planet gears, a ring gear and plain bearing pins. A plain bearing pin is arranged in a respective planet gear, wherein the plain bearing pin and the planet gear form a lubricated plain bearing which includes a plain bearing gap, and on its contact face, the plain bearing pin forms a feed pocket which is configured to receive oil and output it to the plain bearing. On its contact face, the plain bearing pin forms an additional feed pocket which is configured to receive oil and output it to the plain bearing, is spaced from the feed pocket in the circumferential direction, and is connected to the feed pocket such that oil from the additional feed pocket can flow on the contact face of the plain bearing pin to the feed pocket.

The invention concerns a planetary gear box, which has a sun gear, a plurality of planet gears, a ring gear and a plurality of plain bearing pins. Here, a plain bearing pin is arranged in each planet gear, wherein the plain bearing pin and the planet gear form a lubricated plain bearing, and the plain bearing pin forms a crowning at its contact face, wherein the outer diameter of the contact face decreases from a maximum outer diameter towards at least one axial end of the contact face. The crowning of the contact face is configured such that the contact face is concavely shaped adjacent to at least one axial end of the contact face or to a cylindrical region adjoining the axial end.

A planetary gearbox of a gas turbine engine has a planet gear which, via a bearing, is arranged rotatably on a planet pin of a rotatable planet carrier. Oil is introduced through an opening, arranged radially within the bearing, into an oil feed which is open at a feed side and which is connected to the bearing and rotationally joined to the carrier. As the carrier rotates, the oil downstream of the opening is conducted toward the bearing unit by centrifugal force. The open oil feed is, between the opening and the bearing, configured an oil filter through which the oil is conducted. The filter extends counter to the flow direction of the oil from the opening in the direction of the bearing unit, in a flow direction of the oil in the open oil feed.

A planetary gearbox having a sun gear, a plurality of planet gears, a ring gear, and a plurality of journal bearing pins. At its axially forward face side and/or at its axially rearward face side, each planet gear forms a recess that extends inside the planet gear starting from the face side. The planet gear forms a protrusion at its axially forward face side and/or at its axially rearward face side. The protrusion has an axial extent and a radial extent, wherein the radial extent is limited at the respective face side to the area between the planet gear inner bore and the radial inner limit of the respective recess in the planet gear, and wherein the protrusion is configured to provide for a flow path for oil emerging from the journal bearing that guides the oil away from the journal bearing.