Abstract: A plain bearing for a mechanical reducer for a turbomachine is integrally formed and includes a cylindrical body. The cylindrical body has an external cylindrical guide surface, a first axial mounting extension, a first circumferential edge extending around the first extension, a second axial mounting extension, and a second circumferential edge extending around the second extension. The plain bearing further includes an attachment cover connected to the first axial extension and extending axially opposite said first edge.

Abstract: A drive assembly for a mechanical reducer for a turbomachine, in particular for an aircraft, includes planet gears, a planet carrier having at least one transverse wall, plain bearings for guiding the planet gears in rotation, and an oil supply circuit for the plain bearings. The planet carrier has collars for attaching the planet gears to the at least one transverse wall, and each of the planet gears includes at least one external cylindrical surface for forming an oil film with an internal cylindrical surface portion of each of the collars for forming said oil film.

Abstract: Lubrication device for a turbomachine reduction gear, the device comprising an annular lubricating oil collecting cup delimited by a first wall and a second wall, said cup being divided by internal walls extending between the first wall and the second wall so as to define a plurality of angular sectors forming oil collection basins, the basins being circumferentially adjacent around the axis and comprising lubricating oil outlets, characterized in that one or more of said internal walls have openings allowing oil to pass between the circumferentially adjacent basins, characterized in that said openings (58) are formed in one or more of said internal walls so as to define one or more rows of openings in said one or more internal walls.

Abstract: The present invention relates to an oil transfer device (1) for lubricating a planet carrier, movable in rotation, of an epicyclic gear train for a turbomachine, the device (1) extending around an axis (A) and having: an annular casing (11) which extends around the axis (A), the casing (11) comprising a plurality of oil feed grooves (14), axially juxtaposed, each having an oil ejection opening configured to lead radially to a lubrication circuit of the planet carrier to be lubricated, the device (1) being characterized in that one of the oil feed grooves (14) is a high-pressure oil feed groove (14), called a high-pressure groove (14a), and another of the other oil feed grooves (14) is a low-pressure oil feed groove (14), called a low-pressure groove (14b), axially juxtaposed to the high-pressure groove (14a), the grooves (14) being arranged axially along the axis (X) so that the oil is able to be transferred axially from the high-pressure groove (14a) to the low-pressure groove (14b).

Abstract: A mechanical reduction gear for a turbomachine, in particular for an aircraft, the reduction gear including a sun gear, a ring gear, planet gears which are meshed with the sun gear and the ring gear, hydrodynamic bearings for guiding the planet gears in rotation, these bearings being carried by a planet carrier and including cylindrical bodies which are engaged in the planet gears and which are configured so as to be supplied with oil and so as to form guiding oil films between the bodies and the planet gears, wherein each of the planet gears is guided by two hydrodynamic bearings independent of each other and disposed on either side of the plane.

Abstract: A pivot (14) with a longitudinal axis (Y) for a bearing of a mechanical reduction gear, comprising a first annular part (14a) including an axial passage (17) and a second annular part (14b) mounted around the first annular part (14a), the first annular part (14a) delimiting with the second annular part (14b) a lubrication circuit at least one oil inlet (20) of which opens out inwards of the first annular part (14a) into the axial passage (17) and at least one oil outlet (28) of which opens radially outwards of the second annular part (14b).

Abstract: A pivot (14) with a longitudinal axis (Y) for a bearing of a mechanical reduction gear, comprising a first annular part (14a) including an axial passage (17) and a second annular part (14b) mounted around the first annular part (14a), the first annular part (14a) delimiting with the second annular part (14b) a lubrication circuit at least one oil inlet (20) of which opens out inwards of the first annular part (14a) into the axial passage (17) and at least one oil outlet (28) of which opens radially outwards of the second annular part (14b).

Abstract: A mechanical gearbox for aircraft includes a sun gear with an external toothing, a ring gear with an internal toothing, and planet gears which are meshed with the sun gear and the ring gear and which each have a first toothing of average diameter D32 meshed with the toothing of the sun gear, and a second toothing of average diameter D28, different from D32, meshed with the internal toothing of the ring gear. The planet gears are guided by hydrodynamic bearings which each include a first smooth guiding surface extending at least partly under the first toothing, and a second smooth guiding surface extending at least partly under the second toothing.

Abstract: Lubrication device for a turbomachine reduction gear, the device comprising an annular lubricating oil collecting cup delimited by a first wall and a second wall, said cup being divided by internal walls extending between the first wall and the second wall so as to define a plurality of angular sectors forming oil collection basins, the basins being circumferentially adjacent around the axis and comprising lubricating oil outlets, characterized in that one or more of said internal walls have openings allowing oil to pass between the circumferentially adjacent basins, characterized in that said openings (58) are formed in one or more of said internal walls so as to define one or more rows of openings in said one or more internal walls.

Abstract: A mechanical reduction gear for a turbomachine, in particular for an aircraft, the reduction gear including a sun gear, a ring gear, planet gears which are meshed with the sun gear and the ring gear, hydrodynamic bearings for guiding the planet gears in rotation, these bearings being carried by a planet carrier and including cylindrical bodies which are engaged in the planet gears and which are configured so as to be supplied with oil and so as to form guiding oil films between the bodies and the planet gears, wherein each of the planet gears is guided by two hydrodynamic bearings independent of each other and disposed on either side of the plane.

Abstract: A mechanical gearbox for aircraft includes a sun gear with an external toothing, a ring gear with an internal toothing, and planet gears which are meshed with the sun gear and the ring gear and which each have a first toothing of average diameter D32 meshed with the toothing of the sun gear, and a second toothing of average diameter D28, different from D32, meshed with the internal toothing of the ring gear. The planet gears are guided by hydrodynamic bearings which each include a first smooth guiding surface extending at least partly under the first toothing, and a second smooth guiding surface extending at least partly under the second toothing.

Abstract: The invention relates to a pivot pin (5) for an epicyclic gear train sliding bearing, having axially opposed, laterally open circumferential grooves (25a) providing flexibility to the pivot pin, each groove having a radial width and at least one depth (P). At least one of the circumferential grooves (25a,25b) has a said width and/or depth (P) which varies circumferentially.

Abstract: The present invention relates to an oil transfer device (1) for lubricating a planet carrier, movable in rotation, of an epicyclic gear train for a turbomachine, the device (1) extending around an axis (A) and having: an annular casing (11) which extends around the axis (A), the casing (11) comprising a plurality of oil feed grooves (14), axially juxtaposed, each having an oil ejection opening configured to lead radially to a lubrication circuit of the planet carrier to be lubricated, the device (1) being characterized in that one of the oil feed grooves (14) is a high-pressure oil feed groove (14), called a high-pressure groove (14a), and another of the other oil feed grooves (14) is a low-pressure oil feed groove (14), called a low-pressure groove (14b), axially juxtaposed to the high-pressure groove (14a), the grooves (14) being arranged axially along the axis (X) so that the oil is able to be transferred axially from the high-pressure groove (14a) to the low-pressure groove (14b).

Abstract: 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 that extends around the sun gear, planet gears which are meshed with the sun gear and the ring gear, and a lubricating oil distributor which is configured to supply oil to the internal cavities of tubular supports of the planet gears, wherein each of the tubular supports includes a first angular sector including oil conveying pipes and a first outer peripheral surface for forming an oil film, and a second angular sector including a second outer peripheral surface in which a breaking tub of the oil film and recovering of the oil is formed.

Abstract: An oil pipe cover for a mechanical reduction gear of a turbomachine, for example of an aircraft, is configured to be fixed to a planet carrier of the reduction gear and to be mounted on an axial end of a hydrodynamic bearing tubular support of a planet gear of the reduction gear. The oil pipe cover has an annular body extending around an axis (Y) and having a mounting central orifice on the axial end. The body has two diametrically opposed circumferential deflectors: a first deflector having a circumferential oil guiding surface located radially outwards with respect to the axis (Y), and a second deflectors having a circumferential oil guiding surface located radially inwards with respect to the axis (Y).

Abstract: The invention relates to a pivot pin (5) for an epicyclic gear train sliding bearing, the pivot pin having axially opposed, laterally open circumferential grooves (25a), providing flexibility to the pivot pin and which radially separate two axially opposite lateral end portions of a central shank from two lateral cantilevered portions (27a,27b) of the pivot pin. At least one of the cantilevered lateral portions is hollowed out by at least one recess (65a).

Abstract: An oil pipe cover for a mechanical reduction gear of a turbomachine, for example of an aircraft, is configured to be fixed to a planet carrier of the reduction gear and to be mounted on an axial end of a hydrodynamic bearing tubular support of a planet gear of the reduction gear. The oil pipe cover has an annular body extending around an axis (Y) and having a mounting central orifice on the axial end. The body has two diametrically opposed circumferential deflectors: a first deflector having a circumferential oil guiding surface located radially outwards with respect to the axis (Y), and a second deflectors having a circumferential oil guiding surface located radially inwards with respect to the axis (Y).

Abstract: 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 that extends around the sun gear, planet gears which are meshed with the sun gear and the ring gear, and a lubricating oil distributor which is configured to supply oil to the internal cavities of tubular supports of the planet gears, wherein each of the tubular supports includes a first angular sector including oil conveying pipes and a first outer peripheral surface for forming an oil film, and a second angular sector including a second outer peripheral surface in which a breaking tub of the oil film and recovering of the oil is formed.

Abstract: The invention relates to a pivot pin (5) for an epicyclic gear train sliding bearing, having axially opposed, laterally open circumferential grooves (25a) providing flexibility to the pivot pin, each groove having a radial width and at least one depth (P). At least one of the circumferential grooves (25a,25b) has a said width and/or depth (P) which varies circumferentially.

Abstract: The invention relates to a pivot pin (5) for an epicyclic gear train sliding bearing, the pivot pin having axially opposed, laterally open circumferential grooves (25a), providing flexibility to the pivot pin and which radially separate two axially opposite lateral end portions of a central shank from two lateral cantilevered portions (27a,27b) of the pivot pin. At least one of the cantilevered lateral portions is hollowed out by at least one recess (65a).