SATELLITE MOUNT FOR A MECHANICAL REDUCTION GEARBOX ON AN AIRCRAFT TURBOMACHINE

Abstract

Planet carrier (113) for a mechanical gearbox (110) of a turbomachine (1), comprising a cage (120), planets (112) and bearing shafts (113a) for these planets (112), the planets (112) being distributed around the main axis (X) and traversed axially by the bearing shafts (113a) to guide them in rotation about secondary axes (Y) parallel to said main axis (X), characterized in that it further comprises lubrication sleeves (130) which are mounted respectively in the internal cavities (113b) of the bearing shafts (113a). Abbreviated figure: Figure 3

Description

Title of the invention: SATELLITE MOUNT FOR A MECHANICAL REDUCTION GEARBOX OF AN AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The present invention relates to the field of mechanical reducers for turbomachinery, in particular aircraft, and in particular reducers equipped with double-stage gearing satellites. Technical background

[0002] The state of the art includes in particular documents WO-A1-2010 / 092263, FR-A1-2 987 416, FR-A1-3 011 901, FR-A1-3 041 054 and FR-Al-3 058 493.

[0003] The role of a mechanical reducer is to modify the speed and torque ratio between the input shaft and the output shaft of a mechanical system.

[0004] New generations of turbofan engines, particularly those with a high bypass ratio, include a mechanical gearbox to drive the shaft of a fan. Typically, the purpose of the gearbox is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan-driving shaft.

[0005] Such a reduction gear comprises a central pinion, called the sun gear, a ring gear, and pinions called planet gears, which mesh between the sun gear and the ring gear. The planet gears are held by a frame called a planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis X of the turbomachine. The planet gears each have a different axis of revolution and are equally spaced on the same operating diameter around the axis of the planetary gears. These axes are parallel to the longitudinal axis X.

[0006] Several gearbox architectures exist. In the state of the art of turbofan engines, gearboxes are of the planetary or epicyclic type. In other similar applications, there are so-called differential or "compound" architectures.

[0007] - On a planetary gearbox, the planet carrier is fixed and the ring gear constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0008] - On an epicyclic reducer, the ring gear is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar panel.

[0009] - On a differential reducer, no element is fixed for rotation. The ring rotates in the opposite direction to the solar panel and the satellite carrier.

[0010] Reducers can be composed of one or more meshing stages. This meshing is achieved in various ways such as by contact, by friction or by magnetic fields.

[0011] In this application, the term "stage" or "toothing" refers to a series of teeth interlocking with a series of complementary teeth. A toothing can be internal or external.

[0012] A satellite may comprise one or two gear stages. A single-stage satellite comprises teeth that may be straight, helical, or chevron-shaped, and whose teeth are located on the same diameter. These teeth cooperate with both the sun gear and the crown gear.

[0013] A two-stage satellite comprises two sets of teeth or two series of teeth which are located on different diameters. A first set of teeth cooperates with the sun gear and a second set of teeth cooperates with the crown gear.

[0014] One of the problems with a reducer concerns its lubrication.

[0015] Lubricating the various components of a gearbox is essential for the proper functioning of the system to prevent adverse events (gear seizure, pressure loss, bearing failure, etc.). A gearbox whose components are subjected to high mechanical stress, or which has a number of components requiring lubrication, has an inherently higher oil requirement. Distributing oil to all components presents a technical challenge in providing the flow rates necessary to ensure the proper functioning of each component at all operating points, while minimizing the number of parts and mechanical interfaces, and integrating the system easily within the gearbox to limit its overall size.

[0016] Current lubrication solutions offer a single oil inlet for the gearbox housing. Distribution is carried out either from the front or upstream side, or from the rear or downstream side of the gearbox, via a wheel or ring fixed to the planet carrier. Delivering oil to the various stations is relatively easy in the case of a single-stage gearbox because the propellers of each planet are close together.

[0017] Integration becomes more complex in two-stage architectures (due to the distance between the propellers, the satellites, and the ring gear). It then becomes necessary to design a lubrication system that allows oil to flow from the front to the rear of the gearbox, through the gearbox (or from the rear to the front in the case of a single oil inlet downstream of the gearbox).

[0018] The invention proposes an improvement to this technology, which is simple, efficient and economical. Summary of the invention

[0019] The invention relates to a planet carrier for a mechanical turbomachine gearbox, in particular for aircraft, this planet carrier having a main axis and comprising a cage, planets and bearing axes for these planets,

[0020] the cage comprising two annular discs extending around the main axis,

[0021] the bearing shafts being distributed around the main axis and being mounted between the discs of the cage, each of the bearing shafts having a generally elongated shape and comprising a first longitudinal end connected to a first of the discs, and a second opposite longitudinal end connected to a second of the discs, each of the bearing shafts being tubular and comprising an internal cavity which opens axially at the level of said first and second longitudinal ends,

[0022] the satellites being distributed around the main axis and traversed axially by the bearing axes to guide them in rotation around secondary axes parallel to said main axis,

[0023] characterized in that it further comprises lubrication sleeves which are mounted respectively in the internal cavities of the bearing shafts, each of the sleeves having a generally elongated shape and comprising at least a first lubricating oil inlet port which is located at a first longitudinal end of the sleeve and at the level of the first longitudinal end of the corresponding bearing shaft, and a first lubricating oil outlet port which is located at a second opposite longitudinal end of the sleeve and at the level of the second longitudinal end of the corresponding bearing shaft, each of the sleeves defining at least a first oil passage circuit between the inlet and outlet ports, and a second oil passage circuit around the sleeve and between the sleeve and the corresponding bearing shaft.

[0024] The invention thus proposes to circulate oil from one side of the planet carrier, and therefore of the gearbox, to the other through the planet carrier bearing shafts. These bearing shafts are hollowed out to accommodate the lubrication sleeves. This maximizes the use of the available space inside the bearing shafts to design mechanical parts that supply oil both to the bearings for lubrication and to the other side of the gearbox for, for example, the lubrication of gears or meshings.

[0025] This invention is notably compatible with: - of a multi-stage reducer; - of a planetary reducer; - with straight or herringbone teeth.

[0026] The satellite carrier according to the invention may comprise one or more of the following features, taken individually or in combination with each other: The first and second circuits are independent of each other and do not communicate with each other; Each of the sleeves includes a second oil inlet port which is independent of the first oil inlet port and which allows the supply of said second circuit; the first and second circuits are in fluidic communication; said first oil inlet port allows both the first and second circuits to be supplied; said first circuit includes a straight pipeline which extends between the first oil inlet and outlet ports; said second circuit includes a tubular conduit which extends between the sleeve and the bearing axis, and at least one radial conduit in fluidic communication with the tubular conduit; said at least one radial pipeline has an internal radial end connected to said second oil inlet port, and an external radial end connected to the tubular pipeline; said at least one radial pipeline has an internal radial end connected to said first oil inlet port, and an external radial end connected to the tubular pipeline; said at least one radial pipe has a radially internal end connected to said straight pipe, and a radially external end connected to the tubular pipe; said radially internal end is connected to said first oil inlet port or to said straight pipeline by a flow restrictor; at least one annular sealing gasket is mounted between the first longitudinal end of each sleeve and the first longitudinal end of the corresponding bearing shaft, and at least one other annular sealing gasket is mounted between the second longitudinal end of each sleeve and the second longitudinal end of the corresponding bearing shaft, said second circuit extending between these gaskets; Each of the sleeves is formed from a single piece; Each of the sleeves is formed by the assembly of at least two parts, a first elongated tubular part intended to form said second circuit, and at least a second elongated tubular part mounted inside the first part and intended to form said first circuit as well as at least one of said first oil inlet and outlet ports; The first part is formed from a single piece with a ring that is located coaxially inside the first part and connected to the first part by an annular veil of material, said at least a second piece being engaged in this ring; - said annular veil of material includes openings; - an oil supply system is located on one side of the planet carrier and is connected to the first oil inlet ports of the sleeves, and a nozzle lubrication system is located on the opposite side of the planet carrier and is connected to the first oil outlet ports;

[0027] — each of the bearing shafts includes radial through-holes which open into the internal cavity of the bearing shaft and are in fluidic communication with said second circuit;

[0028] — the cage is formed from a single piece.

[0029] The present invention further relates to a mechanical reducer for an aircraft turbomachine, this reducer comprising a satellite carrier as described above, a solar element which is housed in the cage and which is meshed with the satellites, and a ring which extends around the cage and which is meshed with the satellites.

[0030] The present invention further relates to an aircraft turbomachine comprising a satellite carrier or a reduction gear as described above. Brief description of the figures

[0031] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0032] [Fig-1] [Fig.1] is a schematic axial cross-sectional view of a turbomachine aircraft,

[0033] [Fig.2] [Fig.2] is a partial and very schematic axial section of a mechanical reducer,

[0034] [Fig.3] [Fig.3] is a partial schematic axial cross-sectional view of a carrier satellites according to a first embodiment of the invention, and more specifically shows a bearing shaft and a lubrication sleeve of this satellite carrier,

[0035] [Fig.4] [Fig.4] is a front view of the lubrication sleeve of [Fig.3],

[0036] [Fig. 5] [Fig. 5] is a perspective view of the lubrication sleeve of the [Fig.3],

[0037] [Fig.6] [Fig.6] is a partial schematic axial cross-sectional view of a carrier satellites according to a second embodiment of the invention, and more precisely shows a bearing shaft and a lubrication sleeve of this satellite carrier,

[0038] [Fig.7] [Fig.7] is a front view of the lubrication sleeve of [Fig.6],

[0039] [Fig.8] [Fig.8] is a perspective view of the lubrication sleeve of the [Fig.6]

[0040] [Fig.9] [Fig.9] is a partial schematic axial cross-sectional view of a carrier satellites according to a third embodiment of the invention, and more precisely shows a bearing shaft and a lubrication sleeve of this satellite carrier,

[0041] [Fig. 10] [Fig. 10] is a front view of the lubrication sleeve of [Fig. 9],

[0042] [Fig. 11] [Fig. 11] is a perspective view of the lubrication sleeve of the [Fig.9], and

[0043] [Fig. 12] [Fig. 12] is a partial schematic axial cross-sectional view of a reducer according to the invention. Detailed description of the invention

[0044] Figure 1 describes a turbomachine 1 which conventionally comprises a rotation shaft X, a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1e, a high-pressure turbine Id, a low-pressure turbine 1e, and an exhaust nozzle Ih. The high-pressure compressor 1b and the high-pressure turbine Id are connected by a high-pressure shaft 2 and together form a high-pressure (HP) housing. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and together form a low-pressure (LP) housing.

[0045] The blower S is driven by a blower shaft 4 which is driven to the BP shaft 3 by means of a reducer 10. This reducer 10 is generally of the planetary or epicycloidal type.

[0046] The following description relates to a planetary type reducer in which the ring is mobile in rotation.

[0047] The reducer 10 is positioned in the upstream part of the turbomachine. A fixed structure schematically comprising, here, an upstream part 5a and a downstream part 5b which make up the motor or stator housing 5 is arranged to form an enclosure E surrounding the reducer 10. This enclosure E is here closed upstream by seals at the level of a bearing allowing the passage of the blower shaft 4, and downstream by seals at the level of the passage of the BP shaft 3.

[0048] Figure 2 shows a reducer 10 which can take the form of different architectures depending on whether certain parts are fixed or rotating. At the input, the reducer 10 is connected to the shaft BP 3, for example via internal splines 7a. Thus, the shaft BP 3 drives a planetary gear called the sun gear 11. Conventionally, the sun gear 11, whose axis of rotation coincides with that of the turbomachine X, drives a series of gears called planet gears 12, which are equally spaced on the same diameter around the axis of rotation X. This diameter is equal to twice the operating center distance between the sun gear 11 and the planet gears 12. The number of planet gears 12 is generally defined between three and seven for this type of application.

[0049] The set of satellites 12 is held by a chassis called a satellite carrier 13. Each satellite 12 rotates around its own Y axis, and meshes with the ring 14. In this planetary configuration, the set of satellites 12 is held by a satellite carrier 13 which is fixed to the motor housing or stator 5. Each satellite drives the ring which is brought to the blower shaft 4 via a ring carrier 15.

[0050] Each satellite 12 is mounted to rotate freely by means of a bearing 8, for example, a roller bearing or hydrodynamic bearing. Each bearing 8 is mounted on one of the axes 13a of the satellite carrier 13, and all the axes 13a are positioned relative to each other by means of a cage of the satellite carrier 13. There is a number of axes 13a and bearings 8 equal to the number of satellites 12. For reasons of operation, assembly, manufacturing, inspection, repair, or replacement, the axes 13a and cage may be separated into several parts.

[0051] In the present application, an axis 13a is referred to as a bearing or support axis.

[0052] For the same reasons mentioned above, the teeth of a reducer can be separated into several helices, each with a median plane. In the example shown, ring 14 is separated into two half-rings: An upstream half-crown 14a consists of a rim 14aa and a mounting half-flange 14ab. The upstream helix of the reduction gear's teeth is located on the rim 14aa. This upstream helix meshes with that of the satellite 12, which in turn meshes with that of the solar 11. A downstream half-crown 14b consists of a rim 14ba and a mounting flange half 14bb. The downstream helix of the reduction gear teeth is located on the rim 14ba. This downstream helix meshes with that of the satellite 12, which in turn meshes with that of the solar 11.

[0053] The mounting half-flange 14ab of the upstream crown 14a and the mounting half-flange 14bb of the downstream crown 14b form the mounting flange 14c of the crown. The crown 14 is fixed to a crown carrier by assembling the mounting flange 14c of the crown and the mounting flange 15a of the crown carrier 15 using a bolted assembly, for example.

[0054] The arrows in [Fig. 2] describe the oil flow in the gearbox 10. The oil enters the gearbox 10 from the stator section 5 into a distributor 16 by various means, which will not be specified in this view because they are specific to one or more types of architecture. The distributor 16 is divided into two parts, generally each repeated with the same number of planetary gears 12. The injectors 17a lubricate the gear teeth, and the arms 17b lubricate the bearings. The oil is supplied to the injector 17a and exits through the end 17c to lubricate the gear teeth. The oil is also supplied to the arm 17b and circulates via the supply port 17d of the shaft of the bearing 13a. The oil then circulates in an internal cavity 13b of the shaft 13a and then exits through ports 13c in order to lubricate the bearings 8 of the satellites 12.

[0055] Figures 3 to 5 illustrate a first embodiment of the invention and in particular of a chassis constituting a satellite carrier 113.

[0056] Within the framework of the present invention, the satellite carrier 113 is defined as essentially comprising: a cage 120, satellites 112 and bearing or support axes 113a for the satellites 112.

[0057] The cage 120 comprises two disks 120a, 120b which are parallel and spaced apart from each other and extend perpendicularly to the X axis. The disks 120a, 120b have a general circular shape and are centered on the X axis.

[0058] The disks 120a, 120b can be connected to each other by bridges which are not shown in the drawings. These bridges define, for example, between themselves and with the disks, housings configured to receive the satellites 112.

[0059] The cage 120 is preferably of the monobloc type, the discs 120a, 120b and the bridges forming a single piece.

[0060] In the example shown, the disks 120a, 120b include aligned mounting holes 124 for the shafts 113a.

[0061] The axes 113a are distributed around the X axis and are mounted between the disks 120a, 120b.

[0062] Each of the axes 113a has a general elongated shape and comprises a first longitudinal end 122 connected to a first disk 120a, and a second opposite longitudinal end 126 connected to the second disk 120b.

[0063] In the example shown, the first end is engaged in one of the orifices 124 of the first disk 120a, and the second end 126 is engaged in one of the orifices 124 of the second disk 120b.

[0064] Each of the axes 113a is tubular and includes an internal cavity 113b which opens axially at the ends 122, 126.

[0065] The satellites 112 are distributed around the X-axis and are traversed axially by the axes 113a to guide their rotation around the Y-axes. The satellites 112 can be mounted directly on the axes 113a if the latter define smooth bearings for guiding the satellites. Alternatively, roller bearings could be mounted between the axes 113a and the satellites 112 for their guidance.

[0066] The planet carrier 113 further includes lubrication sleeves 130 which are mounted respectively in the internal cavities 113b of the shafts 113a.

[0067] Each of the sleeves 130 has a generally elongated shape and includes at least one first lubricating oil inlet port 132 and one first lubricating oil outlet port 134.

[0068] The first inlet port 132 is located at a first longitudinal end 136 of the sleeve 130 and at the level of the first end 122 of the axis 113a.

[0069] At least one annular sealing gasket 140 is preferably mounted between the first longitudinal end 136 of each sleeve 130 and the first longitudinal end 122 of the shaft 113a. The gasket 140 surrounds the first longitudinal end 136.

[0070] At least one other annular sealing gasket 142 is mounted between the second longitudinal end 138 of each sleeve 130 and the second longitudinal end 126 of the shaft 113a. The gasket 142 surrounds the second longitudinal end 138.

[0071] The first exit port 134 is located at a second longitudinal end 138 opposite the sleeve 130 and at the level of the second end 126 of the axis 113a.

[0072] Each of the sleeves 130 defines at least a first circuit 144 for the passage of oil between the inlet and outlet ports 132, 134, and a second circuit 146 for the passage of oil around the sleeve 130 and between the sleeve 130 and the corresponding shaft 113a.

[0073] The second circuit 146 preferably extends between the joints 140, 142 and is connected to the aforementioned ports 113c.

[0074] The first circuit 144 includes a straight conduit 148 which extends between the input and output ports 132, 134.

[0075] The second circuit 146 may include a tubular conduit 150 extending between the sleeve 130 and the axis 113a, and at least one radial conduit 152 in fluidic communication with the tubular conduit 150. The second circuit 146 may include several radial conduits 152 distributed around the Y axis.

[0076] In the embodiment of figures 3 to 5, the first and second circuits 144, 146 are independent of each other and do not communicate with each other.

[0077] Each of the sleeves 130 can include a second oil inlet port 148 which is independent of the first port 132 and which allows the second circuit 146 to be supplied.

[0078] The radial pipe or each radial pipe 152 has an internal radial end connected to the second port 148, and an external radial end connected to the tubular pipe 150.

[0079] In the example shown in Figures 3 to 5, each of the sleeves 130 is formed in one piece. These figures show that the sleeve 130 is hollow and that the tubular channel 150 is formed as a projection on an internal cylindrical surface of the sleeve body 130. It is further shown that the ports 132, 148 are located next to each other and are formed at the level of a material web 154 which extends transversely in the body of the sleeve 130 and in which the radial channel or channels 152 are formed. This material web 154 may include openings 156 in order to lighten the sleeve 130.

[0080] In figures 3 to 5, the arrows show the path of the oil from ports 132, 148 to circuits 144, 146. The oil arriving through port 132 flows through pipe 148 to reach port 134 and thus passes axially through the satellite carrier 113. The oil arriving through port 148 supplies pipes 152, 150 and the bearings 108 of the satellites 112 through ports 113c.

[0081] In the embodiment variants of figures 6 to 8 on the one hand, and 9 to 11 on the other hand, the first and second circuits 144, 146 are in fluidic communication.

[0082] For this purpose, the first oil inlet port 132 is configured to supply both the first and second circuits 144, 146.

[0083] In the embodiment variant of figures 6 to 8, the radial pipe or each radial pipe 152 has an internal radial end connected to the first port 132 or to the straight pipe 144, and an external radial end connected to the tubular pipe 150.

[0084] Each of the sleeves 130 can be formed by assembling at least two parts.

[0085] In the variant shown in Figures 6 to 8, each sleeve 130 is formed by assembling three parts. In the variant shown in Figures 9 to 11, each sleeve 130 is formed by assembling two parts.

[0086] A first tubular piece 160 of elongated shape is intended to form the second circuit 150. At least one other tubular piece 162, 164 of elongated shape is mounted inside the first piece 160 and is intended to form the first circuit 144 as well as at least one of said first ports 132, 134.

[0087] In the example shown, the first part 160 is formed of a single piece with a ring 166 which is located coaxially inside the first part 160 and connected to the first part 160 by an annular veil of material 154.

[0088] In the variant shown in Figures 6 to 8, the straight conduit 144 is formed by two parts 162, 164 which are arranged coaxially end to end and which are engaged in the ring 166. Part 162 comprises a longitudinal end engaged by male-female insertion in the ring 166 and an opposite longitudinal end forming the inlet port 132. Part 164 comprises a longitudinal end engaged by male-female insertion in the ring 166 and an opposite longitudinal end forming the outlet port 134.

[0089] Each radial pipe 152 may be in fluidic communication with an axial clearance provided between the ends opposite parts 162, 164, or with one or more radial passages in one of these parts. In the case of Figures 6 to 8, it is part 162 that includes this type of passage. In particular, the passage in part 162 forms a flow restrictor 168, that is to say, a small-section passage designed to reduce the flow rate of the fluid passing through it.

[0090] In the variant of figures 9 to 11, the straight channel 144 is formed by a single piece 162 which passes axially through the ring 166. The piece 162 includes a longitudinal end forming the inlet port 132, and an opposite longitudinal end forming the outlet port 134.

[0091] The or each radial channel 152 can be in fluidic communication with one or more radial passages of the part, which can also be in the form of flow restrictor(s) 168.

[0092] The veil 154 which connects the ring 166 to the part 160 is preferably openwork to include openings 156.

[0093] In Figures 6 to 11, the arrows show the path of the oil from port 132 to circuits 144, 146. The oil arriving through port 132 flows through pipe 148 to reach port 134 and thus passes axially through the planet carrier 113. A portion of this oil passes through restrictor(s) 168 to supply pipes 152, 150 and the bearings 108 of the planets 112 via ports 113c. It is therefore understood that restrictor(s) 168 is / are sized to generate a sufficient oil flow for the lubrication of the bearings 108.

[0094] Fig. 12 shows a satellite carrier s 113 and a reducer 110 according to the invention.

[0095] An oil supply system 170 is located on one side of the satellite carrier 113 and is connected to the ports 132 of the sleeves 130.

[0096] A lubrication system 172 equipped with nozzles 174 is located on an opposite side of the planet carrier 113 and is connected to the ports 134 of the sleeves 130.

[0097] The satellite carrier 113 is advantageously fixed, the reducer 110 then being of the planetary type as mentioned above.

[0098] The satellites 112 can be double-stage as shown and therefore comprise two separate gears meshed respectively with the solar (not visible) and the crown 114.

[0099] Bearings 108 are interposed here between the satellites 112 and the axes 113a.

[0100] The invention avoids axial stresses that could be caused by sealing flanges on the upstream and downstream side plates of the planet carrier. The invention allows the planet carrier to maintain freedom of movement under load, which must not be disrupted by the lubrication system. The invention also allows for simplifications at the level of the annular cage's discs 120, eliminating the need for sealing flanges.

[0101] The invention offers several other advantages, including: - reducing the number of mechanical parts in the lubrication system, - reducing the number of mechanical interfaces in this system lubrication, the reduction of bulk, the reduction of mass, etc.

Claims

1. Demands Planet carrier (113) for a mechanical gearbox (110) of a turbomachine (1), particularly an aircraft, this planet carrier (113) having a main axis (X) and comprising a cage (120), planets (112) and bearing shafts (113a) of these planets (112), the cage comprising two annular disks (120a, 120b) extending around the main axis (X), the bearing shafts (113a) being distributed around the main axis (X) and being mounted between the disks (120a, 120b) of the cage (120), each of the bearing shafts (113a) having a generally elongated shape and comprising a first longitudinal end (122) connected to a first of the disks (120a), and a second opposite longitudinal end (124) connected to a second of the disks (120b), each of the bearing shafts (113a) being tubular and comprising an internal cavity (113b) which opens axially at the level of said first and second longitudinal extremities (122, 124),the satellites (112) being distributed around the main axis (X) and traversed axially by the bearing axes (113a) to guide them in rotation around secondary axes (Y) parallel to said main axis (X), characterized in that it further comprises lubrication sleeves (130) which are mounted respectively in the internal cavities (113b) of the bearing axes (113a), each of the sleeves (130) having a generally elongated shape and comprising at least a first lubricating oil inlet port (132) which is located at a first longitudinal end (136) of the sleeve (130) and at the level of the first longitudinal end (122) of the corresponding bearing axis (113a), and a first lubricating oil outlet port (134) which is located at a second opposite longitudinal end (138) of the sleeve (130) and at the level of the second longitudinal end (124) of the corresponding bearing axis (113a),each of the sleeves (130) defining at least a first oil passage circuit (144) between the inlet and outlet ports (132, 134), and a second oil passage circuit (146) around the sleeve (130) and between the sleeve (130) and the corresponding bearing shaft (113a).

2. Satellite carrier (113) according to claim 1, wherein the first and second circuits (144, 146) are independent of each other and do not communicate with each other.

3. Satellite carrier (113) according to claim 2, in which each of the sleeves (130) includes a second oil inlet port (148) which is independent of the first oil inlet port (132) and which allows supplying said second circuit (146).

4. Satellite carrier (113) according to claim 1, wherein the first and second circuits (144, 146) are in fluidic communication.

5. Satellite carrier (113) according to claim 4, wherein said first oil inlet port (132) supplies both the first and second circuits (144, 146).

6. Satellite carrier (113) according to any one of the preceding claims, wherein said first circuit (144) comprises a straight conduit (148) extending between the first oil inlet and outlet ports (132, 134).

7. Satellite carrier (113) according to any one of the preceding claims, wherein said second circuit (146) comprises a tubular conduit (150) extending between the sleeve (130) and the bearing axis (113a), and at least one radial conduit (152) in fluidic communication with the tubular conduit (150).

8. Satellite carrier (113) according to claim 7, depending on claim 3, wherein said at least one radial conduit (152) has a radially internal end connected to said second oil inlet port (148), and a radially external end connected to the tubular conduit (150).

9. Satellite carrier (113) according to claim 7, depending on claim 5, wherein said at least one radial conduit (152) has a radially internal end connected to said first oil inlet port (132), and a radially external end connected to the tubular conduit (150).

10. Satellite carrier (113) according to claim 7, depending on claim 6, wherein said at least one radial channel (152) has a radially internal end connected to said straight channel (148), and a radially external end connected to the tubular channel (150).

11. Satellite carrier (113) according to claim 9 or 10, wherein said radially inner end is connected to said first port (132) oil inlet or to said straight pipeline (148) by a flow restrictor (168).

12. Planet carrier (113) according to any one of the preceding claims, wherein at least one annular sealing seal (140) is mounted between the first longitudinal end (136) of each sleeve (130) and the first longitudinal end (122) of the corresponding bearing shaft (113a), and at least one other annular sealing seal (142) is mounted between the second longitudinal end (138) of each sleeve (130) and the second longitudinal end (124) of the corresponding bearing shaft (113a), said second circuit (146) extending between these seals (140, 142).

13. Satellite carrier (113) according to any one of claims 1 to 12, wherein each of the sleeves (130) is formed of a single piece.

14. Satellite carrier (113) according to any one of claims 1 to 12, wherein each of the sleeves (130) is formed by the assembly of at least two parts (162, 164), a first tubular part (162) of elongated shape intended to form said second circuit (146), and at least a second tubular part (164) of elongated shape mounted inside the first part (162) and intended to form said first circuit (144) as well as at least one of said first ports (132, 134) for oil inlet and outlet.

15. Satellite carrier (113) according to claim 14, wherein the first part (162) is formed in one piece with a ring (166) which is located coaxially inside the first part (162) and connected to the first part (162) by an annular veil of material (154), said at least a second part (164) being engaged in this ring (166).

16. Satellite carrier (113) according to claim 15, wherein said annular sail of material (154) comprises openings (166).

17. Planet carrier (113) according to any one of the preceding claims, wherein an oil supply system (170) is located on one side of the planet carrier (113) and is connected to the first oil inlet ports (132) of the sleeves (130), and a nozzle lubrication system (172) (174) is located on an opposite side of the planet carrier (113) and is connected to the first oil outlet ports (134).

18. Mechanical gearbox (110) for an aircraft turbomachine, said gearbox comprising a planet carrier (113) according to one of the 16 previous claims, a solar element (111) which is housed in the cage (120) and which is meshed with the satellites (112), and a ring (114) which extends around the cage (120) and which is meshed with the satellites (112).

19. Aircraft turbomachine (1), comprising a reduction gear (110) according to the preceding claim.