PLANET CARRIER FOR A REDUCTION GEARBOX OF AN AIRCRAFT TURBOCHARGER

Abstract

The planet carrier (213) for a reduction gear (10) of a turbomachine (1), particularly an aircraft turbomachine, comprises: - a carrier frame (220) having at its periphery axial housings (280) distributed about said axis (X), - a carrier frame holder (222) comprising axial fingers (282) distributed about the axis (X) and engaged in said axial housings (280), and - connecting elements connecting said fingers (282) to walls of said housings (280), each of these connecting elements comprising a pivot (289) extending in a radial direction (A) relative to said axis (X), this pivot (289) being borne by one of the members and having an external surface (292) which in axial section has a convex shape and which collaborates with a cylindrical internal surface (285a) of an orifice (285) of the other of these members.

Description

[0001] DESCRIPTION

[0002] TITLE: SATELLITE CARRIER FOR AN AIRCRAFT TURBOMACHINE SPEED REDUCER

[0003] Technical field of the invention

[0004] The present invention relates to a planet carrier for an aircraft turbomachine speed reducer, as well as a speed reducer for an aircraft turbomachine.

[0005] Technical approval plan

[0006] The state of the art includes in particular documents FR-A1 -2 987 416, FRAI -2 853 382, ​​FR-A1 -3 041 054, FR-A1 -3 052 213, FR-A1 -3 073 915, FRAI -3 084 428.

[0007] The role of a mechanical reducer is to modify the speed ratio and torque between the input shaft and the output shaft of a mechanism.

[0008] New generations of dual-flow turbomachines, particularly those with a high bypass ratio, include a mechanical reducer to drive the shaft of a fan. Typically, the reducer is used to transform the so-called fast rotation speed of the shaft of a power turbine into a slower rotation speed for the shaft driving the fan.

[0009] Such a reducer comprises a central pinion, called a sun gear, a crown gear and pinions called planet gears, which are meshed between the sun gear and the crown gear. The planet gears are held by a frame called a planet carrier. The sun gear, the crown gear and the planet carrier are planet gears because their axes of revolution coincide with the longitudinal axis of the turbomachine. The planet gears each have a different axis of revolution and are equally distributed over the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis of the turbomachine. There are several reducer architectures. In the state of the art of double-flow turbomachines, the reducers are of the planetary or epicyclic type. In other similar applications, there are so-called differential or "compound" architectures.

[0010] - on a planetary reducer, the planet carrier is fixed and the crown constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0011] - on an epicyclic reducer, the crown is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar.

[0012] - on a differential reducer, no element is fixed in rotation. The crown rotates in the opposite direction to the sun and the planet carrier.

[0013] Gearboxes can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, friction or even by magnetic field. There are several types of contact meshing such as with straight or herringbone teeth.

[0014] The planet carrier may be in one piece or in the form of a cage and a cage carrier. The cage comprises an internal cavity in which the sun gear, the planet gears and the guide bearings for these planet gears are housed. The sun gear comprises internal splines for coupling to a first shaft of the turbomachine and the cage carrier comprises a cylindrical portion comprising external splines for coupling to another shaft.

[0015] The connection of the cage to the cage holder is generally rigid. Alternatively, a technology can be envisaged in which the cage is connected to the cage holder by “flexible” connections, as described in document FRAI -2 853 382. In such a case, the cage holder comprises an annular row of axial fingers which are engaged in axial housings of the cage and which are connected to walls of these housings by connecting elements which allow at least one degree of freedom of the finger in the housing. There are two types of flexible connection for this application, the ball joint connection and the sliding pivot connection.

[0016] In the case of a flexible ball joint, each finger carries a ball joint crossed by a cylindrical pin extending into the housing of the cage. The flexible connection is therefore a ball joint between the cage and the cage holder and more particularly the fingers in their housings.

[0017] In the case of a flexible sliding pivot connection, each finger is crossed by a pivot extending into the cage housing. The flexible connection is a sliding connection between the cage and the cage holder and more particularly of the fingers in their housings, in radial directions relative to the axis of the reducer.

[0018] In operation, when the planet carrier is torqued, the fingers will flex and transmit the torque to the cage. The flexible connections prevent the fingers from being flexed to the cage. The cage carrier keeps the cage in its plane of symmetry in order to balance the recovery of forces on either side of the planets.

[0019] The present invention relates more particularly to flexible sliding pivot connections between a cage and a cage holder. In the current technique, the pivot comprises a perfectly cylindrical external surface which cooperates with a perfectly cylindrical internal surface of an orifice of the finger and which is capable of sliding in a radial direction in this orifice. This sliding is made possible by the presence of a small but controlled clearance between the cylindrical surfaces of the pivot and the orifice.

[0020] During operation, significant forces are transmitted via these links along the axis of each pivot, which generates misalignments between the cage and the cage holder. These misalignments cause a significant increase in the contact pressure between the pivots and the internal surfaces of the orifices, which is mainly concentrated at one end of each pivot.

[0021] The present invention provides an improvement which provides a simple, effective and economical solution to this problem. Summary of the invention

[0022] The invention relates to a planet carrier for a turbomachine speed reducer, in particular an aircraft speed reducer, this reducer having a main axis and comprising:

[0023] - a cage comprising an internal cavity configured to receive a sun gear centered on said axis and satellites arranged around the axis and meshed with the sun gear as well as with a crown intended to surround the cage, the cage comprising at its periphery axial housings distributed around said axis,

[0024] - a cage holder comprising axial fingers distributed around the axis and engaged in said axial housings, and

[0025] - elements for connecting said fingers to walls of said housings, each of these connecting elements comprising a pivot extending in a radial direction relative to said axis, this pivot being carried by one of the members chosen from the finger and at least one of the walls and being capable of sliding along this radial direction in an orifice of the other of these members, characterized in that:

[0026] - the pivot comprises an external surface which has a convex shape in axial section, preferably rounded, and which cooperates with a cylindrical internal surface of said orifice, or

[0027] - the orifice comprises an internal surface which has a convex shape in axial section, preferably rounded, and which cooperates with a cylindrical external surface of said pivot.

[0028] The present invention therefore relates to two configurations. In the first configuration, the external surface of each of the pivots is therefore "domed" and the top or crest of this surface is the preferred place of support on the internal surface of the corresponding orifice. This makes it possible to move the area of ​​application of the contact pressure from one of the axial ends of the pivot to the level of this top or crest and for example to the middle of the external surface. The contact spot is not located at one end of the pivot, and there is no risk of it being truncated, which could generate poor distribution of the contact pressure and stress concentrations. The solution implemented therefore makes it possible to limit the level of contact pressure in the sliding pivot connections of a planet carrier likely to be subject to misalignments between its cage and its cage holder.

[0029] Alternatively, and according to the second configuration, it is the internal surface of the orifice which is "domed". The function and advantages of this configuration are the same as those mentioned just above.

[0030] The present invention is compatible

[0031] - a single-stage or multi-stage reducer;

[0032] - a planetary, epicyclic or differential reducer; and

[0033] - straight, helical or herringbone teeth.

[0034] - all types of bearings for satellites, whether rolling, hydrodynamic, etc.

[0035] The planet carrier according to the invention may comprise one or more of the following features, taken in isolation from one another, or in combination with one another:

[0036] - the external surface of the pivot or the internal surface of the orifice has a radius of curvature which is greater than 100 times an axial dimension of this surface;

[0037] - the external surface of the pivot or the internal surface of the orifice has a radius of curvature which is greater than 50 times an average diameter of this surface;

[0038] - said external surface of the pivot has an axial dimension which is equal to an axial dimension of said internal surface of the orifice and / or to an axial distance of engagement of the pivot in the orifice;

[0039] - the pivot is carried by the cage, and the orifice is formed in the finger of the cage holder; - the finger is inserted between two walls of the housing, the pivot passing through the orifice of the finger and being mounted in holes in these walls;

[0040] - the holes in the walls have different diameters;

[0041] - the pivot comprises at least two coaxial sections of different diameters, said external surface being located on one of these sections;

[0042] - the pivot comprises three adjacent sections having at least some different diameters;

[0043] - said external surface is located on one of the sections of intermediate diameter, which is located between a section of smaller diameter and a section of larger diameter.

[0044] The present invention also relates to a mechanical reducer for an aircraft turbomachine, comprising a planet carrier according to one of the preceding claims, a sun gear mounted in said cavity and centered on said axis, a ring extending around the sun gear, and satellites mounted in said cavity and meshed with the sun gear and the ring gear.

[0045] The invention further relates to a turbomachine, in particular for an aircraft, comprising a reduction gear as described above.

[0046] Brief description of the figures

[0047] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:

[0048] [Fig. 1] Figure 1 is a schematic axial sectional view of a turbomachine using the invention;

[0049] [Fig. 2] Figure 2 is a schematic axial sectional view of an epicyclic gear reducer;

[0050] [Fig. 3] Figure 3 is a perspective view of a cage of a reducer planet carrier;

[0051] [Fig. 4] Figure 4 is an axial sectional view of the cage of Figure 3 and a cage carrier, the cage and the cage carrier forming a reducer planet carrier and being connected by flexible ball joints; [Fig. 5] Figure 5 is a detail view of Figure 4;

[0052] [Fig. 6] Figure 6 is an exploded perspective view of a cage and cage carrier assembly forming a reducer planet carrier, the cage and the cage carrier being connected by flexible sliding pivot links;

[0053] [Fig. 7] Figure 7 is a partial axial sectional view of a portion of the planet carrier of Figure 6;

[0054] [Fig. 8] Figure 8 is a detail view of Figure 7;

[0055] [Fig. 9] Figure 9 is an enlarged schematic view of a detail of Figure 7 and illustrates the present invention.

[0056] Detailed description of the invention

[0057] Figure 1 describes a turbomachine 1 which comprises, in a conventional manner, a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1c, a high-pressure turbine 1d, a low-pressure turbine 1e and an exhaust nozzle 1h. The high-pressure compressor 1b and the high-pressure turbine 1d are connected by a high-pressure shaft 2 and form with it a high-pressure (HP) body. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and form with it a low-pressure (LP) body.

[0058] The blower S is driven by a blower shaft 4 which is connected to the LP shaft 3 by means of a reducer 10. This reducer is generally of the planetary or epicyclic type.

[0059] Although the following description concerns a planetary or epicyclic type reducer, it also applies to a mechanical differential in which its three essential components, namely the planet carrier, the crown and the sun gear, are mobile in rotation, the rotation speed of one of these components depending in particular on the difference in speeds of the other two components.

[0060] The reducer 10 is positioned in the upstream part of the turbomachine. A fixed structure comprising schematically, here, an upstream part 5a and a downstream part 5b which composes the motor casing or stator 5 is arranged so as 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 fan shaft 4 to pass through, and downstream by seals at the level of the passage of the LP shaft 3.

[0061] Figure 1 shows a part of 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 LP shaft 3, for example via splines 7. Thus, the LP shaft 3 drives a planetary pinion called the sun gear 11. Conventionally, the sun gear 11, whose axis of rotation coincides with the axis X of the turbomachine 1, drives a series of pinions called satellites 12, which are equally distributed over 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 satellites 12. The number of satellites 12 is generally defined between three and seven for this type of application.

[0062] All of the satellites 12 are held by a frame called the satellite carrier 12. Each satellite 12 rotates around its own Y axis, and meshes with the crown 14.

[0063] At the output of the reducer 10, we have: o In an epicyclic configuration, the set of planet gears 12 rotates the planet carrier 13 around the axis X of the turbomachine. The ring gear 14 is fixed to the engine casing or stator 5 via a ring gear carrier 15 and the planet carrier 12 is fixed to the fan shaft 4. o In a planetary configuration, the set of planet gears 12 is held by a planet carrier 12 which is fixed to the engine casing or stator 5. Each planet gear drives the ring gear which is attached to the fan shaft 4 via a ring gear carrier 15.

[0064] Each planet gear 12 is mounted to rotate freely using a bearing 8, for example of the rolling bearing or hydrostatic bearing type. Each bearing 8 is mounted on one of the axes 13a of the planet carrier 12 and all the axes are positioned relative to each other using one or more structural frames of the planet carrier 12. There are a number of axes and bearings equal to the number of planet gears. For reasons of operation, assembly, manufacturing, inspection, repair or replacement, the axes 13a and the frame may be separated into several parts.

[0065] For the same reasons mentioned above, the teeth of a reducer can be separated into several helices. In our example we detail the operation of a reducer 10 with several helices with a crown separated into two half-crowns: o A front half-crown 14a consisting of a rim 14aa and a half-fixing flange 14ab. On the rim 14aa is the front helix of the reducer teeth. This front helix meshes with that of the satellite 12 which meshes with that of the solar 11. o A rear half-crown 14b consisting of a rim 14ba and a half-fixing flange 14bb. On the rim 14ba is the rear helix of the reducer teeth. This rear helix meshes with that of the satellite 12 which meshes with that of the solar 11.

[0066] The half-flange 14ab of the front crown 14a and the half-flange 14bb of the rear crown 14b form the crown fixing flange 14c. The crown 14 is fixed to the crown carrier 15 by assembling the crown fixing flange 14c and the crown carrier fixing flange 15a using a bolted assembly for example. In the following, a half-flange may be called a flange.

[0067] The arrows in Figure 1 describe the oil routing in the reducer 10. The oil arrives in the reducer 10 from the stator part 5 in the distributor 16 by different means which will not be specified in this view because they are specific to one or more types of architecture. The distributor 16 is separated into two parts, generally each repeated by the same number of satellites. The injectors 17a have the function of lubricating the teeth, and the arms 17b have the function of lubricating the bearings 8. The oil is brought to the injector 17a to exit through the end 17c in order to lubricate the teeth. The oil is also supplied to each arm 17b and circulates via the supply opening 17d of the bearing 8. The oil then circulates through the axis 13a in one or more buffer zones 13b and then exits through orifices 13c in order to lubricate the bearings 8 of the satellites.

[0068] In figures 3 to 5, the elements already described in the above are designated by the same references increased by one hundred.

[0069] Figures 3 to 5 represent a particular technology of planet carrier 113, this planet carrier comprising a cage 120 and a cage carrier 122 connected by “flexible” ball joints.

[0070] The cage 120 comprises two radial annular walls 136, 138 which are parallel to each other and perpendicular to the X axis, as well as a cylindrical wall 140 which extends between the external peripheries of these walls 136, 138.

[0071] The cylindrical wall 140 is here of the double-skin type and comprises an outer skin 140a interrupted by the slots 143 and an inner skin 140b interrupted by the same slots 143. The outer skin 140a separated by five slots 143 forms five outer bridges and the inner skin 140b separated by five slots 143 forms five inner bridges. Each pair of lower and upper bridges forms a yoke to accommodate the finger 182 of the cage holder 122. In other words, the bridges of each pair define between them a housing 180 for receiving a finger 182 of the cage holder 122. The bridges provide the structural connection between the walls 136 and 138. Oblong slots 180 are made in at least one of the walls 136 and 138 so as to allow the finger 182 to pass between the inner and outer bridges.

[0072] The cage 120 thus comprises an annular row of housings 180. These housings 180 receive the axial fingers 182 secured to a substantially radial annular wall 182a of the cage holder 122. The wall 182a is located at an axial end of the cage holder 122. The fingers 182 extend axially from the wall 182a and are engaged by axial translation in the housings 180. Each finger 182 comprises, substantially in its middle, a ring 184 for mounting the ball joint 186 intended to be crossed by a cylindrical pin 188 carried by the cage 120.

[0073] The ring 184 has a substantially radial orientation relative to the axis X. It has a generally cylindrical shape. The cage 120 and the ball joint 186 have a thickness, measured in a radial direction relative to the axis X, which is less than the inter-bridge distance or the radial thickness of the oblong slot 180, so as to be able to be engaged in this housing concomitantly with the finger 182 supporting these parts.

[0074] Each housing 180 is crossed by a pin 188 which has a substantially radial orientation relative to the axis X. Each pin 188 comprises a cylindrical body 188a connected at an axial end, here radially internal, to an external annular collar 188b. The pin 188 is here engaged by radial translation from the inside through radial orifices of the bridges, its collar 188b being intended to come into radial support on a flat face 191 of the external bridge of the cage 120. After insertion of the pin 188 into the orifices of the bridges, until the collar 188b is pressed against the external bridge, the collar 188b is fixed to this bridge for example by screwing.

[0075] In figures 6 to 9, the elements already described in the above are designated by the same references increased by another hundred.

[0076] Figures 6 to 9 represent a particular technology of planet carrier 213, this planet carrier comprising a cage 220 and a cage carrier 222 connected by “flexible” sliding pivot links.

[0077] The cage 220 comprises two radial annular walls 236, 238 which are parallel to each other and perpendicular to the X axis, as well as a cylindrical wall 240 which extends between the external peripheries of these walls 236, 238. The walls 236, 238, 240 define between them a cavity for receiving the solar and the satellites of the reducer. The cylindrical wall 240 is here of the double-skin type and comprises an external skin 240a interrupted by the slots 243 and an internal skin 240b interrupted by the same slots 243. The external skin 240a separated by five slots 243 forms five external bridges and the internal skin 240b separated by five slots 243 forms five internal bridges.

[0078] The lights 243 are intended to be crossed by the satellites housed in the cavity of the planet carrier, in order to allow their meshing with the crown of the reducer.

[0079] Each pair of lower and upper bridges forms a yoke to accommodate the finger 282 of the cage holder 222. In other words, the bridges of each pair define between them a housing 280 for receiving a finger 282 of the cage holder 222. The bridges provide the structural connection between the walls 236 and 238. Oblong-shaped openings 280a are made in at least one of the walls 236 and 238 so as to allow the finger 282 to pass between the inner and outer bridges.

[0080] The cage 220 thus comprises an annular row of housings 280. These housings 280 receive the axial fingers 282 secured to a substantially radial annular wall 282a of the cage holder 222. The wall 282a is located at an axial end of the cage holder 222. The fingers 282 extend axially from the wall 282a and are engaged by axial translation in the housings 280.

[0081] Each finger 282 comprises an orifice 285 intended to be crossed by a pivot 289 carried by the cage 220.

[0082] Each orifice 285 has a substantially radial orientation relative to the axis X and comprises an internal surface 285a which is cylindrical. The main axis of the orifice 285 is denoted A and is therefore oriented radially relative to the axis X. The finger 282 has a thickness, measured along this axis A, which is less than the inter-bridge distance or the radial thickness of the oblong slot 280a, so as to be able to be engaged in this housing 280. The orifice 285 and its surface 285a have a length L1 measured along this axis A (see FIG. 7). Each housing 280 is crossed by a pivot 289 which has a radial orientation relative to the axis X and which extends along an axis A. Each pivot 289 comprises a body 289a connected at an axial end, here radially external, to an external annular collar 289b.The pivot 289 is here engaged by radial translation from the outside through radial holes 290, 292 of the bridges, its collar 289b being intended to come into radial support on a flat face 291 of the external bridge of the cage 220. After insertion of the pivot 289 into the holes 290, 292 of the bridges, until the collar 289b is placed in support on the external bridge, the collar 289b is fixed to this bridge for example by screwing.

[0083] Hole 290 of the outer bridge has a diameter D1 and hole 292 of the inner bridge has a diameter D2 which is less than D1 (see figure 8).

[0084] The pivot 289, and in particular its body 289a, comprises two adjacent sections 289a1, 289a2 of different diameters. The section 289a2 of smaller diameter is engaged in the hole 292 and therefore has a diameter equal to or close to D2. The section 289a1 of larger diameter is located between the collar 289b and the section 289a2, and comprises two parts. A first part of the section 289a1 located on the side of the collar 289b is engaged in the hole 290 and therefore has a diameter equal to or close to D1. A second part of the section 289a1 located on the side of the section 289a1, and more particularly between the first part of the section 289a1 and this section 289a2, is engaged in the orifice 285 of the finger 282.

[0085] Alternatively, it could be considered that the pivot 289, and in particular its body 289a, comprises three adjacent sections, the section 289a1 in fact forming two sections where the external surfaces 293 and 294 are located. The section comprising the surface 293 may have a larger diameter than the section comprising the surface 294. The surface 293 is then located on the section of intermediate diameter, which is located between the section 289a2 of smaller diameter and the section with the surface 293 of larger diameter. The external surfaces 293, 295 of the section 289a2 and of the first part of the section 289a1 are cylindrical. On the contrary, the external surface 294 of the second part of the section 289a1 has in axial section a convex shape, preferably rounded (see the enlarged view on the right of figure 9). Other convex shapes are possible, for example elliptical, logarithmic, etc.

[0086] The external surface 294 has an axial length or dimension L2 measured along the axis A. In the example shown, the axial distance of engagement of the pivot 289 in the orifice 285 is substantially equal to L2 which is substantially equal to L1.

[0087] The external surface 294 advantageously has a relatively large radius of curvature R so as to have contact surfaces between the pivot 289 and the finger 282 which are as large as possible, while distributing the bearing pressures on these contact surfaces in a controlled manner. This radius of curvature R is measured in a plane passing through the axis A.

[0088] Preferably, the outer surface 294 has a radius of curvature R which is greater than 100 times an axial dimension L2 of this surface.

[0089] Alternatively or as an additional characteristic, the external surface 294 has a radius of curvature R which is greater than 50 times an average diameter D1 of this surface.

[0090] In a variant of the invention not shown, the pivots 289 could be carried by the cage holder 222 instead of being carried by the cage 220. The fingers 282 crossed by these pivots 289 would then be carried by the cage 220 and no longer by the cage holder 222 as in the aforementioned case. It is then the cage holder 222 which would comprise the housings 280 for receiving these fingers 282.

[0091] In yet another variant not shown, the “domed” surface would be the internal surface 285a of the orifice 285 (instead of the external surface of the pivot) and the external surface 294 of the pivot 289 would then be cylindrical.

Claims

DEMANDS 1. Satellite carrier (213) for a turbomachine (1) speed reducer (10), in particular for aircraft, this reducer having a main axis (X) and comprising: - a cage (220) having an internal cavity configured to receive a solar element (11) centered on said axis (X) and satellites (12) arranged around the axis (X) and meshed with the solar element (11) as well as with a ring (14) intended to surround the cage (220), the cage (220) having at its periphery axial housings (280) distributed around said axis (X), - a cage holder (222) comprising axial fingers (282) distributed around the axis (X) and engaged in said axial housings (280), and - connecting elements of said fingers (282) to walls of said housings (280), each of these connecting elements comprising a pivot (289) extending in a radial direction (A) with respect to said axis (X), this pivot (289) being carried by one of the components selected from the finger (282) and at least one of the walls and being able to slide along this radial direction (A) in an orifice (285) of the other of these components, characterized in that: - the pivot (289) comprises an external surface (294) which has a convex, preferably rounded, shape in axial section, and which cooperates with a cylindrical internal surface (285a) of said orifice (285), or - the orifice (285) includes an internal surface (285a) which has in axial section a convex shape, preferably rounded, and which cooperates with an external cylindrical surface (294) of said pivot (289).

2. Satellite carrier (213) according to claim 1, wherein the external surface (294) of the pivot (289) or the internal surface (285a) of the orifice (285) has a radius of curvature that is greater than 100 times an axial dimension (L2) of this surface (294, 285a).

3. Satellite carrier (213) according to claim 1 or 2, wherein the external surface (294) of the pivot (289) or the internal surface (285a) of the orifice (285) has a radius of curvature that is greater than 50 times an average diameter (D1) of this surface (294, 285a).

4. Satellite carrier (213) according to any one of the preceding claims, wherein said external surface (294) of the pivot (289) has an axial dimension (L2) which is equal to an axial dimension (L1) of said internal surface (285a) of the orifice (285) and / or to an axial engagement distance of the pivot (289) in the orifice (285).

5. Satellite carrier (213) according to any one of the preceding claims, wherein the pivot (289) is carried by the cage (220), and the orifice (285) is formed in the finger (282) of the cage carrier (222).

6. Satellite carrier (213) according to the preceding claim, in which the finger (282) is interposed between two walls of the housing (280), the pivot (289) passing through the orifice (285) of the finger (282) and being mounted in holes (290, 292) of these walls.

7. Satellite carrier (213) according to the preceding claim, in which the holes (290, 292) in the walls have different diameters.

8. Satellite carrier (213) according to any one of the preceding claims, wherein the pivot (289) comprises at least two coaxial sections (289a1, 289a2) of different diameters, said external surface (294) being located on one of these sections (289a1).

9. Satellite carrier (213) according to any one of the preceding claims, wherein the pivot (289) comprises three adjacent sections having at least some different diameters.

10. Satellite carrier (213) according to any one of the preceding claims, wherein said external surface (294) is located on one of the intermediate diameter sections, which is located between a section of smaller diameter and a section of larger diameter.

11. Mechanical reducer (210) for an aircraft turbomachine (1), comprising a satellite carrier (213) according to any one of the preceding claims, a solar array (11) mounted in said cavity and centered on said axis (X), a ring (14) extending around the solar array (11), and satellites (12) mounted in said cavity and meshed with the solar (11) and the crown (14).

12. Turbomachine (1), in particular for aircraft, comprising a reduction gear (210) according to the preceding claim.