TURBOMACHINE FOR AN AIRCRAFT

Abstract

Turbomachine (10) for an aircraft, said turbomachine (10) comprising a gas generator having at least one compressor (1a, 1b), a combustion chamber (1c) and at least one turbine (1d, 1e), said at least one turbine (1d, 1e) having a shaft (3) connected by a mechanical reduction gear (6) to a propulsion propeller (S), the shaft (3) being coupled to the solar element (11) by a reverse-rotating gearbox (20) with the same rotational speed such that a rotation of the shaft (3) about its axis (X) at a given speed causes a rotation in the opposite direction of the solar element (11) about the same axis (X) at the same speed. Figure for the abbreviation: Figure 3

Description

Title of the invention: TURBOMACHINE FOR AN AIRCRAFT

[0001] The present invention relates to the field of aircraft turbomachinery, in particular equipped with mechanical reducers. Technical background

[0002] 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.

[0003] New generations of turbofan engines, particularly those with a high bypass ratio, include a mechanical gearbox to drive the shaft of a propulsion propeller such as a fan. Typically, the gearbox's purpose is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the propeller-driving shaft.

[0004] Such a reduction gear comprises a central pinion, called the sun gear, a ring gear, and pinions called planet gears, which mesh between the sun gear and the ring gear. The planet gears are held by a frame called a planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis of the turbomachine. The planet gears each have a different axis of revolution and are equally spaced on the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis of the turbomachine.

[0005] Several gearbox architectures exist. In the state of the art of turbofan engines, gearboxes are of the planetary or epicyclic type. In other similar applications, there are so-called differential or "compound" architectures.

[0006] - on a planetary reducer, the planet carrier is fixed and the ring constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0007] - on an epicyclic reducer, the ring gear is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar panel.

[0008] - on a differential reducer, no element is fixed for rotation. The ring rotates in the opposite direction to the solar panel and the satellite carrier.

[0009] Gear reducers can be composed of one or more meshing stages. This meshing is achieved in various ways, such as by contact, friction, or magnetic field. There are several types of contact meshing, such as with spur or herringbone teeth.

[0010] In order to improve the performance of an aircraft equipped with turbomachinery, it may be preferable to rotate the propulsion propellers in different directions from one turbomachine to another. In such solutions, and in order to optimize costs and the In industrial processes, it is necessary to minimize the number of different parts from one turbomachine to another.

[0011] The reducer is a device ideally positioned in the motor to reverse the direction of rotation of the propeller without impacting the compressor and the turbine.

[0012] The invention addresses this need, with the objective of minimizing the impact on the performance of the reducer in question compared to an optimized configuration without reversal of direction. Summary of the invention

[0013] The invention proposes a turbomachine for an aircraft, this turbomachine comprising a gas generator having at least one compressor, a combustion chamber and at least one turbine, said at least one turbine having a shaft connected by a mechanical reducer to a propulsion propeller, the reducer having a solar element coupled to the shaft, a ring extending around the solar element, and satellites which are meshed respectively with the solar element and the ring and which are carried by a satellite carrier,

[0014] characterized in that the shaft is coupled to the solar element by a gearbox with reversing direction of rotation and the same rotational speed so that a rotation of the shaft around its axis at a given speed causes a rotation in the opposite direction of the solar element around the same axis at the same speed.

[0015] The solution proposes adding, upstream of a reducer, a direction reversing gear case, that is to say, a gear case whose sole purpose is to reverse the direction of rotation. This case is integrated between the input shaft and the sun gear of the reducer.

[0016] The solution proposed below is notably compatible: • of a simple or multi-stage reducer; • of an epicyclic, planetary or differential reducer, • of straight, herringbone, helical, etc. teeth.

[0017] The turbomachine according to the invention may comprise one or more of the following features, taken individually or in combination with each other: • The gearbox includes:

[0018] - a first shaft section centered on said axis and comprising a first set of teeth annular section extending around the axis, this first section being rotationally fixed to said tree,

[0019] - a second shaft section centered on said axis and comprising a second set of teeth annular extending around the axis, this second segment being fixed in rotation to the said solar system, and

[0020] - sprockets comprising at least one first sprocket meshed with the first teeth of the first section, and at least one second pinion meshed with the second teeth of the second section as well as with said at least one first pinion; • said first section of tree is formed in one piece with said tree, or is coupled to said tree by grooves; • said second section of tree is formed in one piece with said solar, or is coupled to said solar by grooves; • said sprockets comprise only a first sprocket meshed with the first teeth of the first section, and a second sprocket meshed with the second teeth of the second section as well as with said first sprocket; • said first pinion has a first set of teeth meshed with the first set of teeth of the first section, and a second set of teeth meshed with a third set of teeth of the second pinion which has a fourth set of teeth meshed with the second set of teeth of the second section; • the first and fourth teeth of the sprockets have the same first diameter, and the second and third teeth of the sprockets have the same second diameter which is different from the first diameter, and for example larger than the first diameter;

[0021] — the first and second pinions are identical;

[0022] — the first and second pinions differ only in the type of their teeth, which is chosen from straight, helical or chevron teeth; • the second and third teeth are meshed exactly at the level of said axis, or at a distance from this axis; • said sprockets comprise several first sprockets meshed with the first teeth of the first section, and several second sprockets meshed with the second teeth of the second section, each of the second sprockets being further meshed with one or two of said first sprockets;

[0023] — said pinions have two teeth of different or the same diameter diameter, or a single tooth; • the housing includes or carries bearings, in particular plain or with rollers, for guiding said first and second sections, and / or bearings, in particular plain or with rollers, for guiding the gears; • the housing includes a casing which is attached to a stator of the turbomachine; • The casing includes an arrangement of branches comprising:

[0024] - at least two first branches oriented parallel to said axis and forming or supporting pinion guide bearings,

[0025] - at least two second branches oriented radially with respect to said axis and diametrically opposed with respect to the axis, and each comprising an end radially external, connected to one of the longitudinal ends of each of the first two branches, and

[0026] - at least two third branches oriented radially with respect to said axis and diametrically opposed with respect to the axis, and each comprising a radially external end connected to the other of the longitudinal ends of each of the first two branches;

[0027] — each of the second branches comprises a radially internal end forming or supporting the guide bearing of the first section;

[0028] — each of the third branches comprises a radially internal end forming or supporting the guide bearing of the second section; • the housing further comprises two lateral annular fixing arms extending around the axis and each carrying an annular fixing flange to a corresponding flange of the stator, a first of these annular arms being located at the junction between the radially external ends of the second arms and the aforementioned longitudinal ends of the first arms, and a second of these annular arms being located at the junction between the radially external ends of the third arms and the other aforementioned longitudinal ends of the first arms.

[0029] The present invention also relates to an aircraft comprising at least two turbomachines, each turbomachine comprising a gas generator comprising at least one compressor, a combustion chamber and at least one turbine, said at least one turbine comprising a shaft connected by a mechanical reduction gear to a propulsion propeller, the reduction gear comprising a solar element coupled to the shaft, a ring extending around the solar element, and satellites which are meshed respectively with the solar element and the ring and which are carried by a satellite carrier,

[0030] characterized in that one of the turbomachines is as defined above, and the other of the turbomachines has its shaft which is coupled to the solar by a gearbox with reversing direction of rotation and at the same speed of rotation, which is inactive, so that a rotation of the shaft around its axis at a given speed causes a rotation in the same direction of the solar around the same axis at the same speed.

[0031] Advantageously, the inactive housing comprises:

[0032] - a first shaft section centered on said axis and comprising a first set of teeth annular section extending around the axis, this first section being rotationally fixed to said tree,

[0033] - a second shaft section centered on said axis and comprising a second set of teeth annular section extending around the axis, this second segment being fixed in rotation to the said solar system,

[0034] - sprockets comprising at least one first sprocket meshed with the first teeth of the first section, and at least one second pinion meshed with the second teeth of the second section as well as with said at least one first pinion.

[0035] the first and second sections being rotationally fixed to a housing of the casing which carries said gears and which is free to rotate vis-à-vis a stator of the turbomachine. Brief description of the figures

[0036] 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:

[0037] [Fig-1] [Fig.1] is a schematic view of an aircraft equipped with turbomachinery,

[0038] [Fig.2] [Fig.2] is a schematic axial cross-sectional view of a turbomachine;

[0039] [Fig.3] [Fig.3] is a schematic axial cross-sectional view of a turbomachine according to the invention;

[0040] [Fig.4] [Fig.4] is a schematic cross-sectional view of a reducer and a gear housing for a turbomachine according to the invention;

[0041] [Fig.5] [Fig.5] is a schematic perspective and partial section view of the reducer and housing of the figure;

[0042] [Fig.6] [Fig.6] is a schematic axial cross-sectional view of a turbomachine according to the invention;

[0043] [Fig.7] [Fig.7] is a schematic cross-sectional view of a reducer and a gear housing for a turbomachine according to the invention;

[0044] [Fig.8] [Fig.8] is a schematic perspective and partial section view of the reducer and housing of the figure;

[0045] [Fig.9] [Fig.9] is a schematic perspective view of a gear housing according to one embodiment of the invention,

[0046] [Fig. 10] [Fig. 10] is a schematic perspective view of a gear housing according to one embodiment of the invention,

[0047] [Fig. 11] [Fig. 11] is a schematic perspective view of a gear housing according to one embodiment of the invention,

[0048] [Fig. 12] [Fig. 12] is a schematic perspective view of a gear housing according to an embodiment of the invention. Detailed description of the invention

[0049] Fig. 1 shows an aircraft comprising a central fuselage and two lateral wings, each carrying one or two turbomachines 10. As mentioned above, it may be more efficient to rotate the propulsion propellers of the turbomachines 10 in opposite directions. The turbomachines 10 located on For example, one of the wings can rotate in a first direction of rotation, and the turbomachines 10 located on the other wing can rotate in a second direction opposite to the first. Alternatively, the two turbomachines 10 located on each wing could rotate in opposite directions.

[0050] Figure 2 shows a turbomachine 10 comprising, in a conventional manner, a fan propeller S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1e, a high-pressure turbine Id, a low-pressure turbine 1e, and an exhaust nozzle Ih. The high-pressure compressor 1b and the high-pressure turbine Id are connected by a high-pressure shaft 2 and together form a high-pressure (HP) housing. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and together form a low-pressure (LP) housing.

[0051] The blower propeller S is driven by a blower shaft 4 which is connected to the BP shaft 3 by means of a mechanical reducer 6. This reducer 6 is generally of the planetary or epicyclic type.

[0052] Although the following description relates to a planetary or epicycloidal 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 rotational speed of one of these components depending in particular on the difference in speeds of the other two components.

[0053] The reducer 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 so as to form an enclosure E surrounding the reducer 6. This enclosure E is here closed upstream by seals at the level of a bearing allowing the passage of the blower shaft 4, and downstream by seals at the level of the passage of the BP shaft 3.

[0054] Figure 3 shows a turbomachine 10 according to the invention. The preceding description made with reference to Figure 2 applies to the turbomachine 10 of Figure 3.

[0055] In [Fig. 3], the reducer 6 is more clearly visible and schematically represented. The reducer is associated with a gear case 20 which is located here just at the input of the reducer 6.

[0056] The reducer 6 can take the form of different architectures depending on whether certain parts are fixed or rotating. At the input, the reducer 6 is connected to the shaft BP 3 by the housing 20 and includes a solar element 11 coupled to the shaft BP 3 by the housing 20.

[0057] Conventionally, the solar element 11, whose axis of rotation coincides with the X-axis of the turbomachine 10, drives a series of gears called satellites 12, which are equidistant circumferentially on the same diameter around the axis of rotation X. This diameter is equal to twice the operating center distance between the solar element 11 and 12 satellites. The number of 12 satellites is usually defined between three and seven for this type of application.

[0058] The set of satellites 12 is held by a frame called a satellite carrier 13. Each satellite 12 rotates around its own Y axis, and meshes with a ring 14.

[0059] At the output of reducer 6, we have: • In an epicyclic configuration, the set of satellites 12 drives the planet carrier 13 in rotation around the X axis of the turbomachine. The ring 14 is fixed to the motor or stator housing 5 via a ring carrier 15 and the planet carrier 13 is fixed to the blower shaft 4; • In a planetary configuration, the set of satellites 12 is held by a satellite carrier 13 which is fixed to the motor or stator housing 5. Each satellite drives the ring which is brought to the blower shaft 4 via a ring carrier 15.

[0060] Each satellite 12 is mounted freely in rotation by means of a bearing around a Y axis. The Y axes of rotation of the satellites 12 are distributed around the X axis and parallel to this X axis.

[0061] The particularity of the turbomachine 10 of [Fig.3] is related to the fact that the shaft BP 3 is coupled to the solar 11 by the gearbox 20 with reversing direction of rotation and at the same speed of rotation so that a rotation of the shaft BP 3 around the axis X at a given speed causes a rotation in the opposite direction of the solar 11 around the axis X at the same speed.

[0062] Figures 4 and 5 show a more concrete example of the realization of the reducer 6 and the housing 20.

[0063] In the example shown, the gear housing 20 comprises:

[0064] - a first shaft segment 22 centered on the X axis and comprising a first annular teeth 22a extending around the X axis, this first section 22 being rotationally fixed to the shaft BP 3,

[0065] - a second shaft section 24 centered on the X axis and comprising a second set of teeth annular 24a extending around the X axis, this second segment 24 being rotationally fixed to the solar 11, and

[0066] - pinions 26, 28 comprising at least one first pinion 26 meshed with the first toothing 22a of the first section 22, and at least one second pinion 28 meshed with the second toothing 24a of the second section 24 as well as with said at least one first pinion 26.

[0067] The first shaft section 22 can be formed in one piece with the shaft BP 3, or be coupled to this shaft by splines 30 as in the example shown.

[0068] The second shaft section 24 can be formed in one piece with the solar 11, or be coupled to the solar 11 by grooves 32 as in the example shown.

[0069] In the example shown, the gears 26, 28 consist only of gears 26, 28, of which there are two. The first gear 26 is meshed with the first tooth 22a of the first section 22, and the second gear 28 is meshed with the second tooth 24a of the second section 24 as well as with the first gear 26.

[0070] It can be seen in the figures that the first pinion 26 can include a first tooth 26a meshed with the first tooth 22a of the first section 22, and a second tooth 26b meshed with a third tooth 28a of the second pinion 28 which includes a fourth tooth 28b meshed with the second tooth 24a of the second section 24.

[0071] The first and fourth teeth 26a, 28b of the gears 26, 28 preferably have the same first diameter DI. The second and third teeth 26b, 28a of the gears 26, 28 preferably have the same second diameter D2 which is different from the first diameter D1, and for example larger than the first diameter DI.

[0072] The first and second pinions 26, 28 can be identical, as in the example shown.

[0073] Alternatively, the first and second pinions 26, 28 may differ only in the type of their teeth, which is chosen from straight, helical or herringbone teeth.

[0074] The second and third teeth 26b, 28a can be meshed exactly at the level of the X axis, as is the case in this embodiment.

[0075] Since the housing has three external gears, the direction of rotation is reversed between its input and output. However, it is understood that the output rotational speed is equal to the input speed. This allows the same parameters to be maintained at the input of the main gearbox and therefore avoids redesigning it. It should be noted that if the gearbox is equipped with helical or herringbone gears, since the direction of rotation is reversed at the input of the main gearbox, it may be desirable to "reverse" the gears in order to maintain the direction of the axial forces on the teeth.

[0076] The housing 20 may include or carry bearings 34, 36, in particular plain, for guiding the first and second sections 22, 24, and / or bearings 38, 40 for guiding the pinions 26, 28.

[0077] The housing 20 preferably includes a casing 42 which is fixed to the stator 5 of the turbomachine 10, as schematically illustrated in [Fig.3].

[0078] In the example shown, the housing 42 comprises a branch arrangement including at least:

[0079] - at least two first straight branches 44 parallel to the X axis and forming or supporting the 38, 40 pinion guide bearings,

[0080] - at least two second branches 46 straight oriented radially with respect to to the X-axis and diametrically opposite with respect to the X-axis, and each comprising a radially external end 46b connected to one of the longitudinal ends of each of the first two branches 38, 40, and

[0081] - at least two third branches 48 straight and oriented radially with respect to to the X axis and diametrically opposite with respect to the X axis, and each comprising a radially external end 48b connected to the other of the longitudinal ends of each of the first two branches 38, 40.

[0082] In the case where the first section 22 is guided by the bearing 34, each of the second branches 46 can include a radially internal end 46a forming or carrying the bearing 34 for guiding the first section 22.

[0083] In the case where the second section 24 is guided by the bearing 36, each of the third branches 47 can include a radially internal end 47a forming or carrying the bearing 36 for guiding the second section 24.

[0084] The housing 42 may further comprise two lateral annular mounting arms 50, 52 extending around the X axis and each carrying an annular flange 50a, 52a for mounting to a corresponding flange of the stator 5. A first of these annular arms 50 is located at the junction between the radially external ends 46b of the second arms 46 and the aforementioned longitudinal ends of the first arms 38, 40. A second of these annular arms 52 is located at the junction between the radially external ends 48b of the third arms 48 and the other aforementioned longitudinal ends of the first arms 38, 40.

[0085] In the context of the aircraft 1 according to the invention mentioned above in relation to [Fig.1], this aircraft comprises at least two turbomachines 10.

[0086] Each turbomachine 10 is of the type illustrated in [Fig.2].

[0087] Among these turbomachines 10, one is as defined above with reference to figures 3 to 5. The other turbomachine 10' is preferably of the type illustrated in figures 6 to 8.

[0088] This turbomachine 10' has its shaft BP 3 which is coupled to the solar 11 of the reducer 6 by a gearbox 20' with reversing direction of rotation and at the same speed of rotation, which is inactive or passivated, so that a rotation of the shaft BP 3 around its axis X at a given speed causes a rotation in the same direction of the solar 11 around the same axis X at the same speed.

[0089] The goal here is that the turbomachines 10, 10' have their propellers S which operate in opposite directions of rotation while having similar masses.

[0090] The inactive housing 20' of the turbomachine 10' may include:

[0091] - a first shaft segment 22 centered on the X axis and comprising a first annular teeth 22a extending around the X axis, this first section 22 being rotationally fixed to the shaft BP 3,

[0092] - a second shaft section 24 centered on the X axis and comprising a second set of teeth annular 24a extending around the X axis, this second segment 24 being rotationally fixed to the solar 11, and

[0093] - pinions 26, 28 comprising at least one first pinion 26 meshed with the first toothing 22a of the first section 22, and at least one second pinion 28 meshed with the second toothing 24a of the second section 24 as well as with said at least one first pinion 26.

[0094] The first and second sections 22, 24 are rotationally fixed to the casing 42 of the housing 20', this casing 42 carrying the pinions 26, 28 and being free in rotation vis-à-vis the stator 5 of the turbomachine 10'.

[0095] For this purpose, in the example shown, the first and second sections 22, 24 include grooves 54, 56 engaged in complementary grooves of the housing 42, for example in place of the bearings 34, 36 mentioned above.

[0096] Thus, the housing 42 will be driven in rotation by the shaft 3, and consequently the gears 26, 28 will follow the rotation of the assembly. There is no meshing.

[0097] It is worth noting that the housing 42 can retain the aforementioned flanges 50a, 52a. Depending on the type of turbomachine 10 or 10', it will then be decided whether these flanges 50a, 52a are attached to the stator 5 or not. This allows for a single reference for the housing 42. Thus, in the illustrations, it can be seen that, for the turbomachine 10', the housing 42 has free flanges 50a, 52a and splines 54, 56. For a reverse-rotating turbomachine 10, the flanges 50a, 52a are attached to the stator 5 and the splines are left free.

[0098] Figures 9 to 12 illustrate variant embodiments of the gear housing 20, 20' which can be used in the context of the turbomachine 10 or the turbomachine 10'.

[0099] In the case of [Fig. 9], there are two pinions 26, 28, as in the embodiment of Figures 4 and 5, the description of which applies here. The difference lies in the fact that the second and third gear teeth 26b, 28a are meshed together at a distance from the X axis.

[0100] In figures 10 to 12, several first pinions 26 are meshed with the first toothing 22a of the first section 22, and several second pinions 28 are meshed with the second toothing 24a of the second section 24. This solution allows the rotational torque to be distributed over several pinions.

[0101] In [Fig.10], each of the second pinions 28 is meshed with one of the first pinions 26. The first and second pinions 26, 28 comprise two teeth of different diameters.

[0102] In [Fig. 1 1], each of the second gears 28 is meshed with two adjacent first gears 26, and each first gear 26 is meshed with two adjacent second gears 28. The first and second gears 26, 28 comprise two sets of teeth with different diameters.

[0103] In [Fig.12], the pinions 26, 28 have two teeth of the same diameter, or a single tooth.

Claims

Demands

1. Turbomachine (10) for an aircraft, said turbomachine (10) comprising a gas generator having at least one compressor (la, 1b), a combustion chamber (le) and at least one turbine (Id, le), said at least one turbine (Id, le) having a shaft (3) connected by a mechanical reduction gear (6) to a propulsion propeller (S), the reduction gear (6) having a sun gear (11) coupled to the shaft (3), a ring gear (14) extending around the sun gear (11), and satellites (12) which are meshed respectively with the sun gear (11) and the ring gear (14) and which are carried by a satellite carrier (13), characterized in that the shaft (3) is coupled to the sun gear (11) by a reversing gearbox (20) with the same rotational speed such that a rotation of the shaft (3) about its axis (X) at a given speed causes a rotation in the opposite direction of the sun (11) around the same axis (X) at the same speed.

2. Turbomachine (10) according to claim 1, wherein the gear housing (20) comprises: - a first shaft section (22) centered on said axis (X) and having a first annular toothing (22a) extending around the axis (X), this first section (22) being rotationally fixed to said shaft (3), - a second shaft section (24) centered on said axis (X) and having a second annular toothing (24a) extending around the axis (X), this second section (24) being rotationally fixed to said sun gear (11), and - pinions (26, 28) comprising at least one first pinion (26) meshed with the first toothing (22a) of the first section (22), and at least one second pinion (24) meshed with the second toothing (24a) of the second section (24) as well as with said at least one first pinion (26).

3. Turbomachine (10) according to claim 2, wherein said first shaft section (22) is formed in one piece with said shaft (3), or is coupled to said shaft (3) by splines (30).

4. Turbomachine (10) according to claim 2 or 3, wherein said second shaft section (24) is formed in one piece with said solar (11), or is coupled to said solar (11) by splines (32).

5. Turbomachine (10) according to any one of claims 2 to 4, wherein said pinions (26, 28) comprise only a first pinion (26) meshed with the first toothing (22a) of the first section (22), and a second pinion (24) meshed with the second toothing (24a) of the second section (24) as well as with said first pinion (26).

6. Turbomachine (10) according to claim 5, wherein said first pinion (26) has a first tooth (26a) meshed with the first tooth (22a) of the first section (22), and a second tooth (26b) meshed with a third tooth (28a) of the second pinion (28) which has a fourth tooth (28b) meshed with the second tooth (24a) of the second section (24).

7. Turbomachine (10) according to claim 6, wherein the first and fourth teeth (26a, 28b) of the gears (26, 28) have the same first diameter (Dl), and the second and third teeth (26b, 28a) of the gears (26, 28) have the same second diameter (D2) which is different from the first diameter (Dl), and for example larger than the first diameter (Dl).

8. Turbomachine (10) according to claim 6 or 7, wherein the second and third gears (26b, 28a) are meshed exactly at said axis (X), or at a distance from said axis (X).

9. Turbomachine (10) according to any one of claims 2 to 4, wherein said gears (26, 28) comprise several first gears (26) meshed with the first toothing (22a) of the first section (22), and several second gears (28) meshed with the second toothing (24a) of the second section (24), each of the second gears (24) being further meshed with one or two of said first gears (26).

10. Turbomachine (10) according to any one of claims 2 to 9, wherein the housing (20) comprises or carries bearings (34, 36), in particular plain, for guiding said first and second sections (22, 24), and / or bearings (28, 40), in particular plain, for guiding the gears (26, 28).

11. Turbomachine (10) according to any one of the preceding claims, wherein the casing (20) comprises a housing (42) which is fixed to a stator (5) of the turbomachine (10).

12. Turbomachine (10) according to claims 10 and 11, wherein the casing (42) comprises an arrangement of branches including: - at least two first branches (44) oriented parallel to said axis (X) and forming or carrying bearings (38, 40) for guiding the gears (26, 28), - at least two second branches (46) oriented radially with respect to said axis (X) and diametrically opposite with respect to the axis (X), and each comprising a radially external end (46b) connected to one of the longitudinal ends of each of the first two branches (44), and - at least two third branches (48) oriented radially with respect to said axis (X) and diametrically opposite with respect to the axis (X), and each comprising a radially external end (48b) connected to the other of the longitudinal ends of each of the first two branches (44).

13. Turbomachine (10) according to claim 12, wherein the housing (42) further comprises two lateral annular attachment arms (50, 52) extending around the axis (X) and each carrying an annular flange (50a, 52a) for attachment to a corresponding flange of the stator (5), a first of these annular arms (50) being located at the junction between the radially external ends (56b) of the second arms (46) and the aforementioned longitudinal ends of the first arms (44), and a second of these annular arms (52) being located at the junction between the radially external ends (48b) of the third arms (48) and the aforementioned other longitudinal ends of the first arms (44).

14. Aircraft comprising at least two turbomachines (10, 10'), each turbomachine (10, 10') comprising a gas generator comprising at least one compressor (la, 1b), a combustion chamber (le) and at least one turbine (Id, le), said at least one turbine (Id, le) comprising a shaft (3) connected by a mechanical reduction gear (6) to a propulsion propeller (S), the reduction gear (6) comprising a solar element (11) coupled to the shaft (3), a ring gear (14) extending around the solar element (11), and satellites (12) which are meshed respectively with the solar element (11) and the ring gear (14) and which are carried by a satellite carrier (13), characterized in that one of the turbomachines (10) is as defined in one of the preceding claims, and the other of the turbomachines (10') has its shaft (3) which is coupled to the solar (11) by a gearbox (20') with reversing direction of rotation and the same speed of rotation, which is inactive, so that a rotation of the shaft (3) around its axis (X) at a given speed causes a rotation in the same direction of the solar (11) around the same axis (X) at the same speed.

15. Aircraft according to the preceding claim, wherein the inactive housing (20') comprises: - a first shaft section (22) centered on said axis (X) and having a first annular toothing (22a) extending around the axis (X), this first section (22) being rotationally fixed to said shaft (X), - a second shaft section (24) centered on said axis (X) and having a second annular toothing (24a) extending around the axis (X), this second section (24) being rotationally fixed to said sun (11), - pinions (26, 28) comprising at least one first pinion (26) meshed with the first toothing (22a) of the first section (22), and at least one second pinion (28) meshed with the second toothing (24a) of the second section (24) as well as with said at least one first pinion (22).the first and second sections (22, 24) being rotationally fixed to a casing (42) of the housing (20') which carries said pinions (26, 28) and which is free in rotation vis-à-vis a stator (5) of the turbomachine (10').

Images