WO2026003460A1 - Planet carrier for a mechanical reduction gear of an aircraft turbine engine - Google Patents

Abstract

The invention relates to a planet carrier (110) for a mechanical reduction gear (6) of a turbine engine (1), comprising a cage (114) formed as a single piece and comprising two disks (114a, 114b) connected together by bridges (116), a first of the disks (114a) comprising first holes (124a) and annular grooves (128) around the first holes (124a), each annular groove (128) extending around a ring of material (130) which has an axial dimension (L1) less than a maximum axial depth (Q1) of the groove (128), and a thickness (E1) or radial dimension that is constant along this inner cylindrical surface (125).

Description

DESCRIPTION

TITLE: SATELLITE MOUNT FOR A MECHANICAL REDUCTION GEARBOX ON AN AIRCRAFT TURBOMACHINE

Technical field of the invention

The present invention relates to the field of mechanical reducers for turbomachinery, in particular aircraft, and in particular reducers equipped with double-stage geared satellites.

Technical background

The state of the art includes in particular documents US-A1 -2013/184120, EP-A1 -2 532 928, JP-A-S54 81458, W0-A1 -2010/092263, FR-A1-2 987 416, FR-A1 -3 011 901, FR-A1 -3 041 054 and FR-A1 -3 058 493.

The role of a mechanical reducer is to modify the speed and torque ratio between the input and output shafts of a mechanical system.

Newer generations of turbofan engines, particularly those with a high bypass ratio, incorporate a mechanical gearbox to drive the fan shaft. Typically, the gearbox's purpose is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan shaft.

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 the planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the longitudinal X-axis of the turbomachine. The planet gears each have a different axis of revolution and are evenly spaced on the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal X-axis. Several gearbox architectures exist. In state-of-the-art turbomachinery, gearboxes are of the planetary or epicyclic type. In other similar applications, differential or compound architectures exist.

- On a planetary reducer, the planet carrier is fixed and the ring forms the output shaft of the device which rotates in the opposite direction to the sun.

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

- On a differential gearbox, no element is fixed in rotation. The ring rotates in the opposite direction to the solar and satellite carrier.

Gearboxes can consist of one or more meshing stages. This meshing is achieved in various ways, such as by contact, friction, or magnetic fields.

In this application, the terms "stage" or "dentation" refer to a series of interlocking teeth with a series of complementary teeth. A dentation can be internal or external.

A satellite can have one or two gear stages. A single-stage satellite has teeth that can be straight, helical, or chevron-shaped, with teeth on the same diameter. These teeth cooperate with both the sun gear and the crown gear.

A two-stage satellite comprises two sets of teeth or two series of teeth located on different diameters. One set of teeth cooperates with the sun gear and a second set of teeth cooperates with the crown gear.

There are two satellite carrier technologies: monobloc satellite carriers and satellite carriers that consist of a cage and a cage carrier connected together by flexible links.

The present invention relates to monobloc type satellite carriers. A satellite carrier of this type comprises a cage formed in one piece with a portion of shaft. The cage consists of two annular discs connected by bridges, these bridges defining satellite reception slots between themselves and the discs. The discs have mounting holes for the axial ends of the satellite guidance bearings. These holes are commonly called "reception holes".

One of the problems with this type of gearbox concerns the transmission of forces during operation and the risk of planet gear misalignment. In a one-piece planet carrier, the forces applied to the planets are transmitted via the bearings to the planet carrier's discs. The planet carrier's configuration does not allow for the centered distribution of these forces due to the presence of the ring gear. Therefore, force balancing must be achieved through the planet carrier's geometry. However, the planet carrier is a complex component with limited space available to accommodate this specific geometry.

The Applicant has already proposed in document FR-A1-3 136 533 to make modifications in the form of annular grooves around the openings of one of the cage's discs. Each groove makes it possible to reduce the disc's thickness locally, around each of its openings, in order to increase its flexibility (or reduce its stiffness).

The invention offers an improvement to this technology, which is simple, efficient and economical.

Summary of the invention

The invention relates to a satellite carrier for a mechanical turbomachine gearbox, particularly for aircraft, this satellite carrier having a main axis and comprising a cage formed in one piece and having two disks extending around the axis and connected to each other by bridges which are distributed around the axis, a first of the disks having first orifices which are distributed around the axis and which are axially aligned with second orifices of a second of the disks, each of the first and second orifices having an internal cylindrical surface, and said first disk comprising an annular groove around each of its first orifices, each annular groove extending continuously around the corresponding first orifice and opening in an axial direction, characterized in that each annular groove extends around a ring of material which comprises at its inner periphery the internal cylindrical surface of the corresponding first orifice, this internal cylindrical surface having an axial dimension less than a maximum axial depth of the groove, and each ring of material having a constant thickness or radial dimension along this internal cylindrical surface and being connected to the rest of the first disk by a veil of material which has a minimum thickness less than this thickness.

The aim of this invention is to offer a solution for a one-piece cage satellite carrier that does not generate any moment in the satellites when operating with an epicyclic or planetary gear train.

This invention is notably compatible with:

- a single stage or double stage reducer;

- of a planetary, epicycloidal or differential reducer;

- a one-piece satellite carrier;

- of any type of toothing (straight, helical or herringbone);

- hydrodynamic bearings and/or rolling elements.

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 disc comprises a first radial annular face onto which each groove opens, each ring having a first longitudinal end which is aligned in a radial direction with this first annular face;

- the first disk comprises a second radial annular face, opposite said first radial annular face, each ring having a second longitudinal end, opposite said first end longitudinal, which is set back axially with respect to this second annular face;

- the axial dimension of each ring of material represents between 50 and 90%, and preferably between 40 and 80%, of an axial dimension of the disk measured between its first and second radial annular faces;

- each layer of material is located radially between a bottom of the corresponding groove and a cylindrical bore of the first disc which is centered on the first corresponding orifice and which opens onto said second radial annular face;

- each cylindrical bore has a constant diameter which is greater than a diameter of the internal cylindrical surface and which is less than a minimum diameter of the throat;

- each bore has an axial dimension which represents between 10 and 50%, and preferably between 20 and 40%, of an axial dimension of the disc measured between its first and second radial annular faces;

- the satellite carrier further includes a portion of a shaft which is centered on the central axis and whose longitudinal end is connected to said first annular face;

- each throat opens into the cage;

- each groove opens on the opposite side to the portion of the tree;

-- each of the first orifices is surrounded by a single groove;

-- the number of grooves in the first disc is equal to the number of first orifices in this first disc;

-- the axial dimension of each ring of material is less than an axial dimension of the disk at the level of which the groove is formed;

- the throat is delimited by two cylindrical walls, respectively internal and external, which face each other and are connected together by a concave curved annular wall;

- the thickness of the ring of material is less than a width or radial dimension of the corresponding groove. The present invention further relates to a mechanical reducer for an aircraft turbomachine, this reducer comprising a satellite carrier according to one of the preceding claims, satellites which are guided by bearings whose axial ends are engaged in said first and second orifices, and in particular on the internal cylindrical surfaces of these first and second orifices, and a solar element which is housed in the cage and which is meshed with the satellites.

The present invention also relates to an aircraft turbomachine comprising a satellite carrier or a reduction gear as described above.

Brief description of the figures

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:

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

[Fig.2] Figure 2 is a partial axial view of a mechanical reducer,

[Fig. 3] Figure 3 is an axial cross-sectional view of a mechanical reducer equipped with double-stage meshing satellites, and illustrates the prior art of the invention,

[Fig. 4] Figure 4 is a perspective view of the planet carrier of the reducer in Figure 3.

[Fig. 5] Figure 5 is a partial axial view of a planet carrier and a mechanical reducer of the prior art,

[Fig. 6] Figure 6 is a perspective view of a satellite carrier according to one embodiment of the invention,

[Fig. 7] Figure 7 is a perspective and axial cross-sectional view of the satellite carrier in Figure 7, on a larger scale, and

[Fig.8] Figure 8 is another perspective and axial section view of the satellite carrier in Figure 7, on a larger scale. Detailed description of the invention

Figure 1 depicts a turbomachine 1 which, in a conventional manner, comprises a rotational shaft X, 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 together form a high-pressure (HP) unit. 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) unit.

The blower S is driven by a blower shaft 4 which is driven to the BP shaft 3 by means of a reducer 6. This reducer 6 is generally of the planetary or epicycloidal type.

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

The gearbox 6 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 gearbox 6. This enclosure E is 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.

Figure 2 shows a gearbox 6 which can take on different forms depending on whether certain parts are fixed or rotating. At the input, the gearbox 6 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 7. Typically, the sun gear 7, whose axis of rotation coincides with that of the turbomachine X, drives a series of gears called sun gears 8, which are equally spaced around the same diameter around the axis of rotation X. This diameter is equal to twice the center distance of operation between the solar 7 and the satellites 8. The number of satellites 8 is generally defined between three and seven for this type of application.

The set of satellites 8 is held by a frame called the satellite carrier 10. Each satellite 8 rotates around its own Y axis, and meshes with the ring 9.

■ In this planetary configuration, the set of satellites 8 is held by a satellite carrier 10 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 12.

Each satellite 8 is mounted to rotate freely using a bearing 11, for example, a roller bearing or hydrodynamic bearing. Each bearing 11 is mounted on one of the axes 10b of the satellite carrier 10, and all the axes are positioned relative to each other using one or more structural frames 10a of the satellite carrier 10. There is a number of axes 10b and bearings 11 equal to the number of satellites. For operational, assembly, manufacturing, inspection, repair, or replacement purposes, the axes 10b and the frame 10a may be separated into several parts.

For the same reasons mentioned above, the teeth of a gearbox can be separated into several helices, each with a median plane P. In the example shown, the ring gear is separated into two half-ring gears:

■ An upstream half-crown 9a consisting of a rim 9aa and a mounting half-flange 9ab. On the rim 9aa is the upstream helix of the reduction gear teeth. This upstream helix meshes with that of the satellite 8, which meshes with that of the solar 7.

■ A downstream half-crown 9b consisting of a rim 9ba and a mounting half-flange 9bb. On the rim 9ba is the downstream helix of the reduction gear teeth. This downstream helix meshes with that of the satellite 8, which meshes with that of the solar 7.

The half-flange for fixing 9ab of the upstream crown 9a and the half-flange for fixing 9bb of the downstream crown 9b form the fixing flange 9c of the crown. The crown 9 is fixed to a crown carrier by assembling the crown mounting flange 9c and the crown carrier mounting flange 12a using a bolted assembly for example.

The arrows in Figure 2 illustrate the oil flow within the gearbox 6. The oil enters the gearbox 6 from the stator section 5 via a distributor 13 by various means, which will not be detailed in this view as they are specific to one or more types of architecture. The distributor is generally divided into two sections, each typically repeated with the same number of planetary gears. Injectors 13a lubricate the gear teeth, and arms 13b lubricate the bearings. Oil is supplied to injector 13a and exits through end 13c to lubricate the gear teeth. Oil is also supplied to arm 13b and flows through the bearing's supply port 13d. The oil then flows through the shaft in one or more buffer zones 10c and exits through ports 10d to lubricate the planetary gear bearings.

Figures 3 and 4 represent a 6-speed gearbox of an aircraft turbomachine according to the prior art.

The reducer 6 includes a planet carrier 10 which is configured to be mobile in rotation around the X axis and which is of the monobloc type, i.e. formed from a single piece.

This satellite carrier 10 includes a cage 14 and a shaft portion 15.

The portion of the shaft 15 has a general tubular shape and is elongated along the X axis and includes a free longitudinal end, here on the left in the drawings, and an opposite longitudinal end for connection to the cage 14.

The shaft portion 15 includes an external gear 15a for meshing, for example with a blower.

The cage 14 comprises two annular disks 14a, 14b which are parallel and spaced apart and extend perpendicularly to the X axis. The disks 14a, 14b have a general circular shape and are centered on the X axis. The disc 14a, called the first disc, on the left in the drawing, is connected to the portion of the tree 15. The other disc 14b is called the second disc.

The disks 14a, 14b are connected to each other by bridges 16 which define between themselves and with the disks housings 18 configured to receive the satellites 8. The housings 18 open radially outwards at the outer periphery of the cage 14, and also open radially inwards by passing through an internal tubular wall 20 of the cage 14. The bridges 16 can be solid or partially hollow.

The wall 20 extends around the X axis, from the first disk 14a towards the second disk 14b. Here it extends substantially in the axial continuation of the portion of the tree 15. This wall 20 internally delimits a space 22 for housing the solar 7.

This space 22 comprises two adjacent parts. The first part 22a is surrounded by the wall 20 which includes an internal cylindrical surface 22a for mounting a bearing 23 for guiding one end of the solar element 7. The second part 22b, located at the level of the openings of the housings 18, receives the opposite end of the solar element 7, which includes an external toothed gear 7b for meshing with the satellites 8. The solar element 7 also includes an internal toothed gear 7a for coupling to a shaft, for example, of a turbine.

Each housing unit 18 comprises a first part 18a, located on the side of the first disc 14a, and a second part 18b, located on the side of the second disc 14b. Housing units 18 open onto the outer periphery of shaft 14, at the level of its two parts 18a and 18b, and onto the inner periphery of shaft 14, at the level of the second part 18b only.

The discs 14a, 14b include aligned mounting holes 24 for the satellites 8 and in particular for the plain bearings 26 of these satellites 8. Each bearing 26 has a general cylindrical shape which extends parallel to the X axis and whose longitudinal ends include extensions 26a housed in the holes 24 forming seats. As is known, each bearing 26 may include an internal oil circulation bore 26b which generally communicates with oil supply channels to the external cylindrical surface 26c of the bearing for the purpose of forming an oil film on this surface 26c.

The satellites 8 are here of the double-stage meshing type and each comprise a tubular body 8a equipped with a first external toothing 28 and connected by a web 30 to a second external toothing 32.

The teeth 28, 32 are arranged next to each other and more particularly are located respectively in two planes perpendicular to the X axis.

The first tooth 28, located on the left in the drawings, is situated on the side of the first disc 14a and therefore at the level of the first part 18a of the housing. As can be seen in Figure 3, this tooth 28 meshes with the ring gear 9.

The second toothed section 32, located on the right in the drawings, is situated on the side of the second disk 14b and therefore at the level of the second part 18b of the housing. As can be seen in Figure 3, this toothed section 32 meshes with the toothed section 7b of the solar element 7.

As can be seen in Figure 3, the bridges 16 extend radially, between the housings 18, from the wall 20 and the inner periphery of the discs 14a, 14b to the outer periphery of the discs.

In this type of planet carrier, it is important to ensure the transfer of forces during operation between the turbine and the planet carrier. The forces are initially transmitted through the shaft section 15 and then to the upstream disc 14a. They then pass through the upstream disc 14a to transmit through the bearings 26 and the planets 8. This transmission of forces via one of the discs risks causing the planets 8 to tilt and therefore misalignment between their teeth 28, 32 and those of the sun gear 7 and the ring gear 9. The Applicant has already proposed a solution to this problem, which is illustrated in Figure 5 and described in the aforementioned document.

The satellite carrier 110 includes a cage 114 which has two annular disks 114a, 114b which are parallel and spaced apart and extend perpendicularly to the X axis. The disks 114a, 114b have a general circular shape and are centered on the X axis.

The disk 114a, called the first disk, on the right in the drawing, is connected to a portion of tree 115. The other disk 114b is called the second disk.

The disks 114a, 114b are connected to each other by bridges 116 which define between each other and with the disks housings 118 configured to receive the satellites 8.

The disks 114a, 114b include aligned ports 124a, 124b for mounting the satellites 8 and in particular for guiding bearings of these satellites 8. The ports 124a of the first disk 114a are called first ports, and the ports 124b of the second disk 114b are called second ports.

As can be seen in Figure 5, the first disc 114a has groove-type thinnings 128 around each of the first orifices 124a.

The present invention offers an improvement to this technology.

Figures 6 to 8 illustrate one embodiment of a satellite carrier according to the invention.

The following description concerns the characteristics of the planet carrier according to the invention. This planet carrier is intended to be mounted in a mechanical gearbox of the aforementioned type, which will not be described in detail hereafter. The preceding description, made in conjunction with Figures 1 to 4, can thus be used to describe a gearbox comprising a planet carrier according to the invention. The satellite carrier 110 of figures 6 to 8 comprises a cage 114 and a shaft portion 115. The cage 114 is formed in one piece and can also be formed in one piece with the shaft portion 115.

The portion of the shaft 115 has a general tubular shape and is elongated along the X axis and includes a free longitudinal end, here on the right in the drawings, and an opposite longitudinal end for connection to the cage 114.

The shaft portion 115 may include an external meshing toothing, for example with a blower shaft.

The cage 114 comprises two annular disks 114a, 114b which are parallel and spaced apart and extend perpendicularly to the X axis. The disks 114a, 114b have a general circular shape and are centered on the X axis.

The disk 114a, called the first disk, on the right in figure 6, is connected to the portion of shaft 115. The other disk 114b is called the second disk.

The disks 114a and 114b are connected to each other by bridges 116 which define, between themselves and with the disks, slots 118 configured to receive the satellites. The slots 118 open radially outwards at the outer periphery of the cage 114, and also radially inwards.

The 116 bridges are preferably solid and are as straight and rigid as possible within the framework of the present invention.

The discs 114a, 114b include aligned mounting ports 124a, 124b for the satellites and, in particular, for the satellite guide bearings. Each bearing may have a generally cylindrical shape extending parallel to the X-axis, and its longitudinal ends include extensions housed in the ports 124a, 124b, forming seats or recesses. The ports 124a of the first disc 14a are called the first ports, and the ports 124b of the second disc 14b are called the second ports. As is known, each satellite bearing may include an internal oil circulation bore as described above. Each of the orifices 124a, 124b has an internal cylindrical surface 125, 126. The internal cylindrical surfaces 126 of the orifices 124b may have an axial dimension identical to that of the second disk 124b.

The first disc 114a has an annular groove 128 around each of its first orifices 124a.

Each annular groove 128 extends continuously around the corresponding first orifice 124a and opens axially (Figure 7), preferably inside the cage 114, i.e., towards the second disc 114b. According to the invention, each annular groove 128 extends around a ring of material 130, which is more clearly visible in Figures 7 and 8, and which includes at its inner periphery the internal cylindrical surface 125 of the corresponding first orifice 124a.

This internal cylindrical surface 125 has an axial dimension L1 less than a maximum axial depth Q1 of the groove 128 (figure 7).

The groove 128 is preferably delimited by two cylindrical walls, respectively internal 128a and external 128b, which face each other and are connected together by a concave curved annular wall 128c.

Each ring of material 130 has a constant thickness E1 or radial dimension along this internal cylindrical surface 125 and is connected to the rest of the first disk 114a by a veil of material 132 which has a minimum thickness E2 less than this thickness E1 (figure 7).

The thickness E1 of the ring of material 130 is preferably less than a width E3 or radial dimension of the corresponding groove 128 (figure 7).

The first disk 114a preferably includes a first radial annular face 134 on which the grooves 128 open. Each ring 130 may include a first longitudinal end 130a which is aligned in a radial direction with this first annular face 134.

The first disk 114b preferably comprises a second radial annular face 136, opposite the first radial annular face 134. Each ring 130 may have a second longitudinal end 130b, opposite the first longitudinal end 130a, which is axially recessed relative to this second annular face 136.

Preferably, the axial dimension L1 of each ring of material 130 is less than an axial dimension L2 of the disk 114a at the level of which the groove 128 is formed (figure 7).

The axial dimension L1 of each ring of material 130 can represent between 50 and 90%, and preferably between 40 and 80%, of the axial dimension L2 of the disk measured between its first and second radial annular faces 134, 136 (figure 7).

Each layer of material 132 is preferably located radially between a bottom of the corresponding groove 128 and a cylindrical bore 138 of the first disc 114a which communicates with the orifice 124a and which opens onto the second radial annular face 136.

Each cylindrical bore 138 preferably has a constant diameter D2 which is greater than a diameter D1 of the internal cylindrical surface 125 and which is less than a minimum diameter D3 of the groove (figure 7).

Each bore 138 can have an axial dimension L3 which represents between 10 and 50%, and preferably between 20 and 40%, of the axial dimension L2 of the disk 114a measured between its first and second radial annular faces 134, 136 (figure 7).

The invention offers several advantages, including:

- an easy solution to implement in a confined space;

- measurable and configurable gain in flexibility;

- Improved centralization of forces on a monobloc satellite carrier.

Claims

DEMANDS 1. Planet carrier (110) for a mechanical gearbox (6) of a turbomachine (1), particularly an aircraft, said planet carrier (110) having a main axis (X) and comprising a cage (114) formed in one piece and comprising two disks (114a, 114b) extending around the axis (X) and connected to each other by bridges (116) which are distributed around the axis (X), a first of the disks (114a) having first orifices (124a) which are distributed around the axis (X) and which are axially aligned with second orifices (124b) of a second of the disks (114b), each of the first and second orifices (124a, 124b) having an internal cylindrical surface (125, 126), and said first disk (114a) having an annular groove (128) around of each of its first orifices (124a), each annular groove (128) extending continuously around the corresponding first orifice (124a) and opening in an axial direction, characterized in that each annular groove (128) extends around a ring of material (130) which includes at its inner periphery the internal cylindrical surface (125) of the corresponding first orifice (124a), this internal cylindrical surface (125) having an axial dimension (L1) less than a maximum axial depth (Q1) of the groove (128), and each ring of material (130) having a constant thickness (E1) or radial dimension along this internal cylindrical surface (125) and being connected to the rest of the first disk (114a) by a veil of material (132) which has a minimum thickness (E2) less than this thickness (E1). 2. Satellite carrier (110) according to claim 1, in which the first disc (114a) comprises a first radial annular face (134) into which each groove (128) opens, each ring (130) having a first longitudinal end (130a) which is aligned in a radial direction with this first annular face (134). 3. Satellite carrier (110) according to claim 2, wherein the first disk (114a) comprises a second radial annular face (136), opposite to said first radial annular face (134), each ring (130) having a second longitudinal end (130b), opposite said first longitudinal end (130a), which is axially recessed with respect to this second annular face (136). 4. Satellite carrier (110) according to claim 3, wherein the axial dimension (L1) of each ring of material (130) represents between 50 and 90%, and preferably between 40 and 80%, of an axial dimension (L2) of the disk (114a) measured between its first and second radial annular faces (134, 136). 5. Satellite carrier (110) according to claim 3 or 4, in which each web of material (132) is located radially between a bottom of the corresponding groove (128) and a cylindrical bore (138) of the first disc (114a) which is centered on the first corresponding orifice (124a) and which opens onto said second radial annular face (136). 6. Planet carrier (110) according to claim 5, wherein each cylindrical bore (138) has a constant diameter (D2) which is greater than a diameter (D1) of the internal cylindrical surface (125) and which is less than a minimum diameter (D3) of the groove (128). 7. Satellite carrier (110) according to claim 5 or 6, wherein each bore (138) has an axial dimension (L3) which represents between 10 and 50%, and preferably between 20 and 40%, of an axial dimension (L2) of the disk (114a) measured between its first and second radial annular faces (134, 136). 8. Satellite carrier (110) according to any one of claims 2 to 7, wherein it further comprises a portion of shaft (115) which is centered on the central axis (X) and of which a longitudinal end is connected to said first annular face (134). 9. Satellite carrier (110) according to any one of the preceding claims, wherein each groove (128) opens into the inside of the cage (114). 10. Satellite carrier (110) according to claim 9 depending on claim 8, in which each groove (128) opens on the side opposite the portion of shaft (115). 11. Satellite carrier (110) according to any one of the preceding claims, in which the groove (128) is delimited by two cylindrical walls, respectively internal (128a) and external (128b), which face each other and which are connected together by a concave curved annular wall (128c). 12. Satellite carrier (110) according to any one of the preceding claims, wherein the thickness (E1) of the ring of material (130) is less than a width (E3) or radial dimension of the corresponding groove (128). 13. Mechanical reducer (6) for an aircraft turbomachine, this reducer comprising a satellite carrier (110) according to one of the preceding claims, satellites (8) which are guided by bearings whose axial ends are engaged in said first and second orifices (124a, 124b), and in particular on the internal cylindrical surfaces (125, 126) of these first and second orifices (124a, 124b), and a solar element (7) which is housed in the cage (114) and which is meshed with the satellites (8). 14. Aircraft turbomachine (1), comprising a reduction gear (6) according to the preceding claim.