Assembly of counter-rotating turbomachinery for aircraft

Abstract

Each turbomachine (1, 100) comprises an output shaft (3, 103), an input shaft (5, 105), and a reduction gear, one (104) of which is an epicyclic gear and the other (4) a planetary gear. Each reduction gear has a sun gear (15, 115), a ring gear (13, 113), a planet carrier (16, 116), bearings (22, 122) mounted on said planet carrier, and two-stage planets (14, 114) rotatably mounted on said bearings, with their first stage (18, 118) meshing with the sun gear and their second stage (19, 119) meshing with the ring gear. The planet carriers (16, 116) are identical. (See Figure 2 for abbreviations.)

Description

Title of the invention: Set of counter-rotating turbomachines for aircraft. Technical field

[0001] The present invention relates, in general, to assemblies of counter-rotating turbomachines for aircraft propulsion.

[0002] More specifically, the invention relates to such assemblies in which one of the turbomachines is equipped with an epicyclic gear reducer and the other with a planetary gear reducer, as well as to aircraft equipped with such assemblies. Previous techniques

[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] With regard to aircraft turbomachinery, and in particular double-flow turbomachinery, especially those with a very high bypass ratio, the mechanical reducer has the role of driving the shaft of a fan by transforming the so-called high rotational speed of the shaft of a power turbine into a slower rotational speed for the shaft driving the fan.

[0005] Such a reducer comprises a central pinion, called the solar pinion, which is driven by a drive shaft which receives the drive torque, a ring gear, which transmits the torque, at the output to the blower shaft, and pinions called satellite gears which are meshed between the solar pinion and the ring gear.

[0006] The satellites are held by a chassis called a satellite carrier. The solar array, the corona, and the satellite carrier are planetary because their axis of revolution coincides with the longitudinal axis X of the turbomachine.

[0007] The satellites have different axes of revolution distributed over the same operating diameter around the axis of the planetary gears

[0008] These axes are parallel to the longitudinal axis X.

[0009] There are several reducer architectures.

[0010] In the state of the art of double-flow turbomachinery, the reducers are of the planetary or epicyclic type.

[0011] In other similar applications, there are so-called differential architectures.

[0012] On a planetary reducer, also called a planetary gear train, the planet carrier s is fixed and the ring constitutes the output shaft of the device which rotates in the opposite direction to the sun.

[0013] On an epicycloidal reducer, also called an epicycloidal gear train, the ring is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the sun.

[0014] On a differential reducer, no element is fixed for rotation. The ring rotates in the opposite direction to the sun and the satellite carrier.

[0015] Reducers can be composed of one or more gearing stages.

[0016] This meshing is achieved, for example, by contact, by friction, or by magnetic fields. There are several types of contact meshing, for example, spur, helical, or herringbone gears.

[0017] In order to improve the performance of aircraft, and in particular those with unfaired engines, it is relevant to rotate the propulsion part in different directions from one engine to another.

[0018] A known solution is to equip one of these motors with a planetary gear reducer and the other with an epicyclic gear reducer.

[0019] A U.S. patent application US 2023 / 0130860 describes an aircraft equipped with two turbomachines whose directions of rotation are opposite to each other. One of the turbomachines is equipped with a planetary gear reducer and the other with an epicyclic gear reducer. Each reducer comprises two-stage satellites, the first stage of which is engaged with the sun and the second stage with the corona.

[0020] Such a solution helps to minimize the number of different parts from one engine to another and thus optimize industrial processes and reduce costs. Description of the invention

[0021] The invention aims to further improve the solution previously described.

[0022] The invention proposes for this purpose a set of two counter-rotating turbomachines for aircraft each comprising an output shaft, an input shaft and a reduction gear connecting the input shaft to the output shaft, the reduction gear of one of said turbomachines being epicyclic, the reduction gear of the other of said turbomachines being planetary, said reduction gears each having a sun gear, a ring gear, a planet carrier, bearings mounted on the planet carrier and two-stage planets mounted rotatably on said bearings with their first stage in contact with the sun gear and their second stage in contact with the ring gear, characterized in that the planet carrier of the epicyclic reduction gear and the planet carrier of the planetary reduction gear are identical.

[0023] Since the planet carriers of the epicyclic gear reducer and the planetary gear reducer are identical, that is to say, in particular, they have the same shape and the same dimensions, the supply of the two satellite carriers is simplified and the set of two turbomachines is economical to produce.

[0024] In addition, the epicyclic gear reducer and the planetary gear reducer will have similar dimensions and masses, which simplifies their integration into the corresponding turbomachines, especially if these turbomachines are otherwise similar.

[0025] Moreover, since the reducers have two-stage satellites, the reduction ratio of each reducer can be finely adjusted and within a wide range of values, by varying the diameters of the first and / or second stage of the satellites from one reducer to another.

[0026] It should be noted that it is particularly possible to ensure that the reduction ratios of the reducers and / or the rotation speeds of the output shafts are substantially the same.

[0027] According to another feature, each planet carrier comprises a generally cylindrical support portion and an annular flange extending axially from said support portion, said bearings being mounted on said support portion, the planet carrier of the epicyclic gear reducer being disposed in the corresponding turbomachine with its annular flange facing towards the output shaft and connected to the output shaft, the planet carrier of the planetary gear reducer being disposed in the corresponding turbomachine with its annular flange facing away from the output shaft and connected to the stator.

[0028] According to yet another characteristic, said reducers are configured to offer substantially the same reduction ratio.

[0029] For example, the solar and first stage of the satellites of the epicycloidal gear reducer have respectively the same diameter as the solar and first stage of the satellites of the planetary gear reducer.

[0030] In addition, the bearings of the planetary gear reducer are rolling bearings, while the bearings of the epicyclic gear reducer are smooth.

[0031] Advantageously, at least one of the bearings of the epicyclic gear reducer and at least one of the bearings of the planetary gear reducer are identical.

[0032] Furthermore, each planet carrier comprises a generally cylindrical support portion having two opposing lateral walls and an annular peripheral wall extending from one of the lateral walls to the other, axial openings being provided in the lateral walls for the insertion and mounting of said bearings, radial openings being provided in the peripheral wall for the insertion and mounting of said planets, at least one bearing of the epicyclic gear reducer having an internal axis and an external axis arranged around the internal axis and fixed against rotation relative to the internal axis, said internal axis being configured to be inserted through one of said axial openings and said external axis being configured to be inserted through one of said radial openings for said mounting of said bearing.

[0033] Furthermore, each satellite includes a generally annular body delimiting an internal passage in which a corresponding bearing is received, the epicyclic gear reducer having at least one annular recess formed in the body of a satellite and / or in said corresponding bearing, said recess being at least partially concentric with a corresponding portion of the second stage of said satellite.

[0034] Again, the satellite carriers are each in one piece.

[0035] The invention also relates to an aircraft comprising a set of two counter-rotating turbomachines as described above, the aircraft having a fuselage and two wings extending respectively on either side of the fuselage, each turbomachine being mounted on a corresponding wing.

[0036] According to another feature, the aircraft has a fuselage and two masts extending respectively on either side of the fuselage, each turbomachine being mounted on a corresponding mast, said masts being located at the rear of the aircraft. Brief description of the drawings

[0037] Other purposes, advantages and features will become apparent from the following description, given for illustrative purposes only and made with reference to the accompanying drawings on which:

[0038] Fig. 1 is a schematic axial cross-sectional view of a turbomachine from an assembly of turbomachines according to the invention, comprising a planetary gear reducer;

[0039] Fig. 2 is a cross-sectional view of the front parts of the two turbomachines of an assembly according to the invention;

[0040] Fig. 3 is a perspective view of the planet carrier of a gearbox of the turbomachine illustrated in Fig. 1;

[0041] Figures [Fig. 4] and [Fig. 5] illustrate alternative embodiments of the reducer in [Fig. 3]; and

[0042] Fig. 6 schematically illustrates an aircraft equipped with two sets of turbomachinery according to the invention. DETAILED DESCRIPTION

[0043] Figure [1] shows a turbomachine, here a turbojet for aircraft, designated by the general numerical reference 1, with longitudinal axis XX.

[0044] This turbomachine 1 is a double-flow turbojet which comprises, from front to back, considering the direction of the airflow admitted into the turbomachine, a fan 2, an output shaft 3, a reducer 4 and an input shaft 5.

[0045] The blower 2 is linked to the output shaft 3. The output shaft 3 and the input shaft 5 are connected by the reducer 4.

[0046] The turbomachine 1 further comprises a low-pressure coupling having a low-pressure compressor 6, a low-pressure turbine 7 and a low-pressure shaft 8 connecting the low-pressure compressor 6 and the low-pressure turbine 7.

[0047] The low-pressure shaft 8 extends forward here beyond the low-pressure compressor 6 so as to form the input shaft 5.

[0048] The turbomachine 1 further comprises, between the low-pressure compressor 6 and the low-pressure turbine 7, a high-pressure coupling having a high-pressure compressor 9, a high-pressure turbine 10 and a high-pressure shaft 11 connecting the high-pressure compressor 9 and the high-pressure turbine 10.

[0049] The turbomachine 1 also includes a combustion equipment comprising an annular combustion chamber 12 located between the high-pressure compressor 9 and the high-pressure turbine 10.

[0050] The high-pressure compressor 9 compresses and sends fresh air from outside, from the front of the aircraft, to the combustion chamber 12 located approximately in the center of the turbomachine 1.

[0051] The hot gases from the combustion pass through the high-pressure turbines 10 and low-pressure turbines 7 before escaping through an exhaust nozzle.

[0052] The low-pressure turbine 7 drives the low-pressure shaft 8 and the input shaft 5 in rotation, the latter driving the output shaft 3 by means of the reducer 4, and thus the blower 2.

[0053] The blower 2 at the inlet / front of the turbomachine 1 sends air to the low pressure compressors 6 and high pressure compressors 9.

[0054] The reducer 4 includes a central pinion 15, called the solar pinion, a ring gear 13 and pinions 14 called satellites which are meshed between the solar pinion 15 and the ring gear 13.

[0055] The reducer 4 further includes a planet carrier 16 and bearings 22 integral with the planet carrier 16 and on which the satellites 14 are mounted rotatably.

[0056] The solar element 15, the crown 13 and the satellite carrier 16 are planetary elements because their axis of revolution coincides with the longitudinal axis X of the turbomachine 1.

[0057] The satellites 14 have different axes of revolution distributed over the same operating diameter around the axis of the planetary gears. These axes are parallel to the longitudinal axis X.

[0058] The satellites 14 are double-stage, that is to say, they each have a first stage 18 in contact with the solar 15 and a second stage 19 in contact with the corona 13.

[0059] The first stage 18 has a first predetermined diameter DI while the second stage 19 has a second predetermined diameter D2 smaller than the first diameter DI.

[0060] It should be noted that the reduction ratio offered by the reducer 4 depends in particular on the respective values ​​of these diameters.

[0061] The solar 15 is linked to the input shaft 5. The ring 13 is linked to the output shaft 3. The planet carrier 16 is linked to the stator 17 of the turbomachine 1.

[0062] The turbomachine 1 includes for this purpose a rotor flange 20 connecting the ring 13 to the output shaft 3, and a stator flange 21 connecting the planet carrier 16 to the stator 17.

[0063] The driving torque transmitted to the solar 15 by the input shaft 5 is transmitted to the ring 13 by the satellites 14, then to the output shaft 3 by the ring 13.

[0064] The configuration of the reducer 4 described above is called planetary, or with planetary gear train, because the planet carrier 16 is fixed while in operation the ring 13 rotates in the opposite direction to that of the solar 15.

[0065] With reference to figures 2 and 3, we will describe in more detail the elements of the reducer 4 and its integration into the front part of the turbomachine 1.

[0066] The satellite carrier 16 comprises a generally cylindrical support portion 23 and an annular flange 24 extending axially from the support portion 23.

[0067] The support portion 23 comprises a first lateral wall 25 and a second lateral wall 26, facing each other, as well as an annular peripheral wall 27 extending from one to the other of the lateral walls 25.

[0068] The first lateral wall 25 extends radially beyond the annular peripheral wall 27 so as to form a rim 31.

[0069] The first side wall 25, second side wall 26 and annular peripheral wall 27 delimit between themselves an internal space intended to receive the solar 15, the satellites 14 and the bearings 22.

[0070] A first central through-opening 37 and a second central through-opening 38 are provided in the first lateral wall 25 and the second lateral wall 26 respectively. The central openings 37 and 38 are circular and coaxial.

[0071] First axial openings 28 and second axial openings 29 are provided in the first lateral wall 25 and the second lateral wall 26 respectively. The first axial openings 28 and the second axial openings 29 are regularly distributed around the first central opening 37 and around the second central opening 38 respectively. The first axial openings 28 and the second axial openings 29 are through openings.

[0072] The axial openings 28 and 29 are circular. Each first axial opening 28 is opposite a corresponding second axial opening 29 with which it is coaxial. Each first axial opening 28 has a diameter greater than that of the corresponding second axial opening 29.

[0073] Radial through openings 30 are provided in the annular peripheral wall 27. The radial openings 30 are generally rectangular.

[0074] The annular flange 24 extends from the second side wall 26, on the side opposite the first side wall 25. The annular flange 24 comprises a first portion 45 extending in line with the annular peripheral wall 27 and a second portion 46 extending transversely to the first portion 45 and opposite the wall 26, the flange 24 thus having an L-shaped cross-section. Openings are provided in the flange 24, here in the second portion 46, for the passage of fasteners such as screws.

[0075] It will be noted that in [Fig.3], a variant of the satellite carrier 16 has been shown in which the annular flange 24 is devoid of a second portion 46.

[0076] The annular flange 24 is continuous all along its circumference, that is to say, it does not have any interruption.

[0077] The planet carrier 16 is arranged in the turbomachine 1 with its annular flange 24 turned away from the output shaft 3. In other words, the wall 25 is turned towards the output shaft 3 and the wall 26 is turned towards the input shaft 5.

[0078] The bearings 22 each have a shaft 32 and a contact interface 33 arranged around the shaft 32.

[0079] The shaft 32 is generally cylindrical and comprises a first mounting portion 34, a second mounting portion 35 and a support portion 36 extending from the first mounting portion 34 to the second mounting portion 35.

[0080] The first mounting portion 34 has a diameter greater than that of the second mounting portion 35 and that of the support portion 36.

[0081] The interface 33 here includes bearings mounted on the support portion 36.

[0082] Each bearing 22 is mounted on the planet carrier 16 with its first portion of assembly 34 engaged in an axial opening 28 and its second portion of assembly 35 engaged in the corresponding axial opening 29.

[0083] Thus, each bearing 22 is arranged in the turbomachine 1 with its mounting portion 34 facing the output shaft 3 and its mounting portion 35 facing the input shaft 5.

[0084] The crown 13 is annular and has two toothed parts 39 connected by a rim 40 of generally U-shaped cross-section.

[0085] The crown 13 is arranged around the satellite carrier 16 and extends opposite the annular peripheral wall 27.

[0086] Each satellite 14 comprises a generally annular body having an inner face delimiting an internal passage 41 and an outer face radially opposite to the inner face.

[0087] The external face is stepped and has a central toothed portion of diameter DI forming the first stage 18 and two lateral toothed portions of diameter D2 arranged on either side of the central toothed portion and together forming the second stage 19.

[0088] Each satellite 14 is mounted on the satellite carrier s 16 with a corresponding bearing 22 engaged in its internal passage 41, each bearing of the interface 33 being aligned with a corresponding lateral toothed portion of the first stage 19. Furthermore, the central toothed portion of the first stage 18 and the lateral toothed portions of the second stage 19 project through a corresponding radial opening 30. In addition, the central toothed portion of the first stage 18 is received in the space delimited by the rim 40 and the toothed portions 39 of the ring 13, while each lateral toothed portion of the second stage 19 meshes with a corresponding toothed portion 39 of the ring 13.

[0089] The solar 15 is arranged between the central openings 37 and 38, the input shaft 5 extending through the second central opening 38.

[0090] To assemble the elements of the reducer, the input shaft 5 and the solar element 15 are each inserted into the internal space of the support portion 23 through one of the central openings 37 or 38. In addition, the satellite elements 14 are each inserted through a corresponding radial opening 30. After the insertion of the satellite elements 14, the bearings 22 are each inserted through a corresponding axial opening 28 and the internal passage 41 of a corresponding satellite element 14.

[0091] The stator flange 21 extends between a first end fixed to the annular flange 24 and a second end, opposite the first end, fixed to the stator 17. The first end is here more precisely fixed to the second portion 46 of the flange 24. The second end is more precisely fixed to a region 42 of the stator 17 located substantially opposite the reducer 4.

[0092] The rotor flange 20 has a first end 43 fixed to the rim 40 of the crown 13 and a second end 44, opposite the first end 43, fixed to the output shaft 3. This second end 44 is more precisely fixed to a part 47 of the output shaft 3 located opposite the wall 25 and in the extension of the annular peripheral wall 27.

[0093] The ends of the flanges 20 and 21 are here fixed by screws to the stator 17, output shaft 3, ring 13 and planet carrier 16.

[0094] In [Fig.2], next to the turbomachine 1, another turbomachine 100 is shown, with which the turbomachine 1 forms a unit.

[0095] In what follows, each element of the turbomachine 100 bears the same numerical reference as the corresponding element of the turbomachine 1, but with 100 added.

[0096] The turbomachine 100 is similar to the turbomachine 1, except essentially that its reducer 104 is in a so-called epicyclic configuration, or epicyclic gear train, that is to say that its ring gear 113 is linked to the stator 117 while its planet carrier 116 is linked to the output shaft 103.

[0097] In such a configuration of the reducer 104, the ring 113 is fixed while in operation its satellite carrier s 116 rotates in the same direction as its solar 115.

[0098] The satellite carrier 116 is identical to the satellite carrier 16, that is to say, it has in particular the same shape and dimensions. The satellite carriers 16 and 116 are produced on the same industrial production line. The satellite carriers 16 and 116 are made of the same material. The satellite carriers 16 and 116 have the same mass. The satellite carriers 16 and 116 are each made in one piece.

[0099] The planet carrier 116 is, on the other hand, in a reversed position relative to the planet carrier 16. More precisely, the planet carrier 116 is arranged in the turbomachine 100 with its annular flange 124 turned towards the output shaft 103. In other words, the side wall 126 is turned towards the output shaft 103 and the side wall 125 is turned towards the input shaft 105.

[0100] The stator flange 121 has its first end fixed to the rim 140 of the crown 113 and its second end fixed to the region 142 of the stator 117.

[0101] The annular flange 124 is directly fixed to the part 147 of the output shaft 103. It should be noted that the turbomachine 100 is thus devoid of a rotor flange such as the rotor flange 20.

[0102] The satellites 114 are identical to the satellites 14 except that the diameter of the second stage 119 is larger than that of the second stage 19. In addition, the diameter of the internal passage 141 is larger than that of the internal passage 4L

[0103] The diameter of the second stage 119 is determined so that the reduction ratio of the reducer 104 is substantially the same as that of the reducer 4.

[0104] It will be noted that here the diameter of the first stage 118 is identical to that of the first stage 18. In an unillustrated variant, the satellites such as 114 and 14 differ further in that the diameter of the first stage such as 118 is not the same as that of the first stage such as 18, the diameter of the solar such as 115 being adapted accordingly.

[0105] It should also be noted that since the diameter of the first stage 118 is identical to that of the first stage 18 and the diameter of the solar 115 is identical to that of the solar 15, then the center distance between the satellites 14, 114 and the solar 15, 115 is conserved from one reducer to the other 4, 104.

[0106] The crown 113 is identical to the crown 13 except that the radial distance between the rim 140 and the toothed parts 139 is shorter in order to be adapted to the diameter of the second stage 119.

[0107] The bearings 122 are similar to the bearings 22, except that the shaft 132 is here in two parts and thus comprises an internal shaft 48 and an external shaft 49 arranged around the internal shaft 48 and immobilized in rotation with respect to the internal shaft 48.

[0108] Rotational immobilization is for example ensured by the cooperation of a rib and a groove of complementary shapes, one being integral with the internal axis 48 and the other being integral with the external axis 49.

[0109] The internal axis 48 forms the mounting portions 134 and 135 while the portion of the internal axis 48 between the mounting portions 134 and 135 and the external axis 49 form the support portion 136.

[0110] The bearings of the contact interface 133 are mounted on the external shaft 49 and have a larger diameter than the bearings of the interface 33. It should be noted that the dimensions of the bearings of the interface 133 do not allow them to pass through the axial opening 128 and that the bearings must therefore be introduced through the radial opening 130.

[0111] Thus, to assemble the bearings 122 to the other elements of the reducer 104, the external shaft 49 is inserted into the internal passage 141 of the satellite 114 and is inserted with the satellite 114 through a corresponding radial opening 130. The internal shaft 48 is then inserted through the corresponding axial opening 128.

[0112] Like the planet carriers 16 and 116, the bearings 122 are in a reversed position relative to the bearings 22. Thus, each bearing 122 is arranged in the turbomachine 100 with its mounting portion 135 facing the output shaft 103 and its mounting portion 134 facing the input shaft 105.

[0113] It will be noted that the solar 115 and the input tree 105 are identical to the solar 15 and the input tree 5 respectively.

[0114] It will also be noted that the stator 117 and the output shaft 103 are identical to the stator 17 and the output shaft 3 respectively.

[0115] It will be noted that in turbomachine 1 the output shaft 3 rotates in the opposite direction to that of solar 15, while in turbomachine 100 the output shaft 103 rotates in the same direction as solar 115. The blowers being fixed to the output shafts 3 and 103, the turbomachines 1 and 100 form a set of counter-rotating turbomachines, that is to say configured so that in operation the blower of one of the turbomachines 1 rotates in one direction while the blower of the other turbomachine 100 rotates in the opposite direction.

[0116] Figure 4 shows the planetary gear reducer 4 and the epicyclic gear reducer 104 in a variant in which the external axis 49 and the interface 133 of the reducer 104 are configured differently.

[0117] More specifically, the external axis 49 has on the opposite side to the internal axis 48 a smooth surface forming the interface 133.

[0118] Thus the bearings 22 of the planetary gear reducer 4 are rolling bearings while the bearings 122 of the epicyclic gear reducer 104 are smooth.

[0119] In addition, the reducer 104 has annular recesses 50 formed in the external axis 49 and each at least partially concentric with a corresponding portion of the second stage 119. The recesses 50 are configured to provide flexibility in the deformation of the second stage 119 along the radial direction.

[0120] Figure 5 shows the planetary gear reducer 4 and the epicyclic gear reducer 104 in a variant in which the bearings 22 and 122 are identical.

[0121] In this configuration, the radial distance between the lateral toothed portions of the external surface forming the second stage 119 and the internal passage 141 is greater for satellite 114 than for satellite 14.

[0122] In addition, the annular recesses 50 are here provided in the body of the satellite 114.

[0123] Moreover, the bearings 22 and 122 are plain here. In an unillustrated variant, the bearings such as 22 and 122 are identical but have rolling bearings rather than plain bearings.

[0124] Figure 6 shows an aircraft 51 equipped with two assemblies, each consisting of a turbomachine such as 1 and a turbomachine such as 100.

[0125] The aircraft 51 comprises a fuselage 52 and two wings 53 and 54 extending respectively on either side of the fuselage 52.

[0126] For each assembly, the turbomachines 1 and 100 are each mounted on a corresponding wing 53 and 54.

[0127] Each assembly is configured so that the blowers of turbomachines 1 and 100 rotate substantially at the same speed, but in opposite directions.

Claims

Demands

1. A set of two counter-rotating aircraft turbomachines (51), each comprising an output shaft (3, 103), an input shaft (5, 105) and a reduction gear (4, 104) connecting the input shaft (5, 105) to the output shaft (3, 103), the reduction gear (104) of one of said turbomachines (100) being epicyclic, the reduction gear (4) of the other of said turbomachines (1) being planetary, said reduction gears (4, 104) each having a sun gear (15, 115), a ring gear (13, 113), a planet carrier (16, 116), bearings (22, 122) mounted on the planet carrier (16, 116) and planets (14, 114) double-stage rotaryly mounted on said bearings (22, 122) with their first stage (18, 118) in contact with the solar (15, 115) and their second stage (19, 119) in contact with the ring (13, 113), characterized in that the planet carrier (116) of the epicyclic gear reducer (104) and the planet carrier (16) of the planetary gear reducer (4) are identical.

2. Assembly according to claim 1, wherein each planet carrier (16, 116) comprises a generally cylindrical support portion (23, 123) and an annular flange (24, 124) extending axially from said support portion (23, 123), said bearings (22, 122) being mounted on said support portion (23, 123), the planet carrier (116) of the epicyclic gear reducer (104) being disposed in the corresponding turbomachine (100) with its annular flange (124) facing the output shaft (103) and connected to the output shaft (103), the planet carrier (16) of the planetary gear reducer (4) being disposed in the corresponding turbomachine (1) with its annular flange (24) facing away from the output shaft (3) and connected to a stator (17) of the corresponding turbomachine (1).

3. Assembly according to claim 1 or 2, wherein said reducers (16, 116) are configured to provide substantially the same reduction ratio.

4. Assembly according to any one of claims 1 to 3, wherein the solar (115) and the first stage (118) of the satellites (114) of the epicyclic gear reducer (104) have respectively the same diameter as the solar (15) and the first stage (18) of the satellites (14) of the planetary gear reducer (4).

5. Assembly according to any one of claims 1 to 4, wherein the bearings (22) of the planetary gear reducer (4) are rolling bearings, while the bearings (122) of the epicyclic gear reducer (104) are smooth.

6. Assembly according to any one of claims 1 to 4, wherein at least one of the bearings (122) of the epicyclic gear reducer (104) and at least one of the bearings (22) of the planetary gear reducer (4) are identical.

7. An assembly according to any one of claims 1 to 6, wherein each planet carrier (16, 116) comprises a generally cylindrical support portion (23, 123) having two opposing side walls (25, 26, 125, 126) and an annular peripheral wall (27, 127) extending from one of the side walls to the other, axial openings (28, 29, 128, 129) being provided in the side walls for the insertion and mounting of said bearings (22, 122), radial openings (30, 130) being provided in the peripheral wall (27, 127) for the insertion and mounting of said planets (22, 122), at least one bearing (122) of the epicyclic gear reducer (104) comprising a internal axis (48) and an external axis (49) arranged around the internal axis (48) and fixed in rotation with respect to the internal axis (48),said internal shaft (48) being configured to be inserted through one of said axial openings (128) and said external shaft (49) being configured to be inserted through one of said radial openings (130) for said mounting of said bearing (122).

8. Assembly according to any one of claims 1 to 7, wherein each satellite (14, 114) comprises a generally annular body delimiting an internal passage (41, 141) in which a corresponding bearing (22, 122) is received, the epicyclic gear reducer having at least one annular recess (50) formed in the body of a satellite (114) and / or in said corresponding bearing (122), said recess (50) being at least partially concentric with a corresponding portion of the second stage (119) of said satellite (114).

9. Assembly according to any one of claims 1 to 8, wherein the satellite carriers (16, 116) are each in one piece.

10. Aircraft equipped with at least one set of two counter-rotating turbomachines (1, 100) according to any one of claims 1 to 9, the aircraft having a fuselage (52) and two wings (53, 54) extending respectively on either side of the fuselage (52), each turbomachine (1, 100) being mounted on a corresponding wing (53, 54), or the aircraft has a fuselage and two masts extending respectively on either side of the fuselage, each turbomachine being mounted on a corresponding mast, said masts being located at the tail of the aircraft.

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