TURBOMACHINE COMPRISING A SPEED REDUCER AND AT LEAST ONE ELECTRIC MOTOR.

Abstract

The invention relates to an assembly for an aircraft turbomachine, comprising a speed reducer (4) having an input pinion (40) connected to a power shaft (2) of the turbomachine and an output pinion (41) connected to a propeller shaft (3) of the turbomachine. According to the invention, the assembly comprises two electric machines (60), each configured to supply electrical power to the propeller shaft or to draw mechanical power from the propeller shaft, each electric machine comprising a rotor (61) and a stator (62), the stator being intended to be connected to a housing of the turbomachine, and in that the speed reducer comprises two substantially parallel intermediate transmission lines (55) configured to transmit torque from the input pinion (40) to the output pinion (41), each rotor (61) being driven in rotation respectively by a pinion of an intermediate line (55). Figure 3

Description

Title of the invention: TURBOMACHINE COMPRISING A SPEED REDUCER AND AT LEAST ONE ELECTRIC MACHINE. Scope of the invention

[0001] The present invention relates to the general field of aeronautics. It relates in particular to an assembly for a turbomachine equipped with a mechanical speed reducer and at least one electrical machine cooperating with the mechanical reducer. Technical background

[0002] 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.

[0003] Aircraft equipped with turboprop engines are generally fitted with a mechanical gearbox (known by the English acronym "PGB" for Propeller Gear Box) which allows the rotational speeds between the turbine and the propeller to be adjusted while also generating an offset between the axis of rotation of the propeller and the axis of rotation of the turbine. This offset allows for proper vertical integration of the air intake beneath this gearbox.

[0004] In order to improve the performance and efficiency of these turboprop engines during certain flight phases (take-off, taxiing, etc.), several solutions are possible. One of these solutions consists of hybridizing the turboprop engine by adding an electric machine (in motor mode) to the gearbox to provide additional power during the relevant flight phases. It is also possible to use this electric machine (in generator mode) to recover energy during certain flight phases.

[0005] Several gearbox architectures exist. In the state of the art of turboprop engines, gearboxes are of the planetary type with offset or epicyclic type with offset. There are also so-called compound architectures. - On a planetary offset reducer, the planet carrier is fixed and the ring gear forms the output shaft of the device which rotates in the opposite direction to the sun. - On an epicyclic offset 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. - In a compound gearbox, no element is fixed in rotation and the power is divided over two parallel intermediate lines. The output wheel rotates in the same direction as the input pinion.

[0006] An epicyclic offset gearbox comprises an input pinion that meshes with a gear in stage no. 1, which in turn drives a central pinion called the sun gear, which meshes with pinions called planet gears, which are themselves meshed with a ring gear. The planet gears are held by a frame called the planet carrier. The sun gear, the ring gear, and the planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis X of the propeller. The planet gears each have a different axis of revolution, equally spaced on the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis X.

[0007] A compound gearbox comprises an input pinion, from which two intermediate pinions (called idlers) draw power. The idler pinions then drive the output line via a second set of teeth. By varying the number of teeth on the different pinions, it is possible to obtain a speed reduction ratio between the input and output lines.

[0008] Reducers can be composed of one or more meshing stages. This meshing is achieved in various ways such as by contact, by friction or by magnetic fields.

[0009] There are several types of contact meshing such as with straight, helical or chevron teeth.

[0010] French patent document FR-B1-3073569 describes a speed reducer IA for driving the shaft 2A of a propeller 3A of a rotating turboprop engine as illustrated in [Fig. 1]. The speed reducer IA is equipped with an electric machine 4A for supplying electrical power to the aircraft. The electric machine 4A is arranged within the volume dedicated to the speed reducer IA so as not to affect the overall dimensions in this area of ​​the turboprop engine. The electric machine 4A comprises a hollow rotor 5A which is removably connected to and coaxial with the propeller shaft 2A. In particular, the propeller shaft 2A passes through the rotor 5A. The electric machine IA comprises a stator 6A which is connected to a stator housing 7A of the turboprop engine. The stator housing 7A surrounds the shaft 2A and includes a bore in which the stator 6A is mounted. The latter extends outside the rotor 6A. The configuration of the electric machine is compact.However, this type of integration is viable as long as the electrical power required by the aircraft equipment remains moderate. Indeed, the more powerful the electric motor, the larger its size, which can significantly limit its integration within the gearbox. Yet, many pieces of equipment are increasingly powered by electricity to reduce their environmental impact.

[0011] The turbomachine can be equipped with several electric machines to increase electrical power, which can impact the size of the stator housing and the nacelle surrounding the turboprop gas generator.

[0012] Furthermore, when the speed reducer is of the compound type, it is necessary to balance the loads between the two intermediate lines as described in patent documents EP-B1-3356699, FR-A1-3035163, and EP-A1-3274609, because the distribution between the lines is not equal. However, these documents do not take into account the integration of electrical machines with respect to the speed reducer, and in particular the balancing of their loads. The configurations in these documents generally provide for a hydraulic balance or flexural elements on the shafts to balance the loads.

[0013] There is a need to resolve all or part of the aforementioned drawbacks. Summary of the invention

[0014] The objective of the present invention is to provide a simple and economical solution for integrating two electrical machines in cooperation with a speed reducer without impacting the size and configuration of nearby components.

[0015] We achieve this objective in accordance with the invention by means of an assembly for an aircraft turbomachine, the assembly comprising:

[0016] - a power shaft, - a propeller shaft centered on a longitudinal axis X and intended to drive at least one propeller of the turbomachine, and - at least one speed reducer intended to be driven by the power shaft and to rotate the propeller shaft at a speed different from that of the power shaft, the speed reducer comprising an input pinion connected to the power shaft and an output pinion connected to the propeller shaft, the assembly comprising two electric machines, each configured to supply electrical power to the propeller shaft or to extract mechanical power from the propeller shaft, each electric machine comprising a rotor and a stator, the stator being intended to be connected to a housing of the turbomachine, and

[0017] the speed reducer comprising two intermediate transmission lines which are substantially parallel and which are configured to transmit torque from the input pinion to the output pinion, each rotor being driven in rotation respectively by a pinion of an intermediate line.

[0018] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, arranging two electric machines, each with its own rotor driven by an intermediate line, allows the total electrical power of the two machines to be distributed over two separate lines. This also makes it possible to regulate load imbalances between the two transmission lines while limiting axial space requirements. More precisely, the two electric machines create a balancing system. With two electric machines, it is possible The aim is to inject slightly more power into the less loaded line and slightly less power into the more loaded line so that the loads between the two lines balance. A reverse imbalance in the power supplied can also be created. Furthermore, the configuration of the electrical machines and the compound gearbox avoids impacting the radial and axial dimensions.

[0019] The assembly also includes one or more of the following features, taken alone or in combination:

[0020] - the input pinion comprises an input shaft offset relative to an output shaft of the output pinion.

[0021] - each intermediate transmission line includes a first intermediate gear intermediate mounted to rotate around an axis of rotation and comprising a first set of teeth intended to mesh with an external set of teeth of the input pinion.

[0022] - each intermediate transmission line includes a second intermediate gear intermediate mounted to rotate around an axis of rotation and comprising a second set of teeth intended to mesh with an external set of teeth of the output pinion.

[0023] - the input pinion meshes with the first two intermediate pinions of the lines of intermediate transmission and the output pinion meshes with two second intermediate pinions of the intermediate transmission lines and in that each first intermediate pinion and each second intermediate pinion comprises a first helix and a second helix each meshing with a corresponding helix of the input pinion and the output pinion.

[0024] - the speed reducer comprises at least two drive wheels which are each on the one hand, driven in rotation respectively by the first intermediate pinion of an intermediate transmission line and which on the other hand, drives in rotation a complementary pinion mounted on each rotor, the complementary pinion of the rotor comprising an axis of rotation parallel to the input axis and parallel to the axis of the drive wheel.

[0025] - each drive wheel includes a first external toothing meshing with an external toothing of a first intermediate pinion and a second external toothing meshing with an external toothing of the complementary pinion.

[0026] - the stator extends radially outside the rotor.

[0027] - the electrical machines are arranged downstream of the speed reducer.

[0028] - - the axis of rotation of the first intermediate pinion is parallel to the longitudinal axis.

[0029] - - the axis of the second intermediate pinion is parallel to the longitudinal axis.

[0030] - - the rotation axis of the output pinion is coaxial with the longitudinal axis.

[0031] - - the electrical machine is annular.

[0032] - - the electrical machine has a general cylindrical shape.

[0033] The invention also relates to a turbomachine comprising an assembly exhibiting any of the preceding characteristics and an air inlet arranged below the speed reducer, in a vertical direction perpendicular to the longitudinal axis.

[0034] The invention further relates to an aircraft equipped with such a turbomachine. Brief description of the figures

[0035] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent upon reading the following detailed explanatory description, of embodiments of the invention given by way of purely illustrative and non-limiting examples, with reference to the accompanying schematic drawings in which:

[0036] Fig. 1 represents an example of a turboprop engine comprising a reduction mechanism and an electrical machine according to the prior art;

[0037] Figure 2 illustrates an example of the arrangement of a reduction mechanism in a turbomachine according to the invention;

[0038] Fig. 3 is a bottom view of an example arrangement of a reduction mechanism and at least one electrical machine according to the invention;

[0039] Fig. 4 is a perspective view of an example of a reduction mechanism cooperating with two electrical machines according to the invention;

[0040] Fig. 5 is a perspective view of an example of the arrangement of an air inlet of a turbomachine according to the invention;

[0041] Fig. 6 is a front view of the reduction mechanism according to Fig. 5; and

[0042] The [Fig.7] is a rear view of the reduction mechanism according to the [Fig.5]; Detailed description of the invention

[0043] Fig. 1 shows an axial cross-sectional view of a turbomachine equipped with a reduction mechanism and which has already been described previously.

[0044] Figure 2 represents a turbomachine 1 with longitudinal axis X. The turbomachine 1 shown is a turboprop equipped with a single unfaired propeller intended for mounting on an aircraft. The turboprop may include a pair of counter-rotating, unfaired propellers. Turboprops are known by the English term "open rotor." Of course, the turbomachine may be a single-flow or turbofan engine.

[0045] The turbomachine comprises a power shaft 2 (shown in dashed lines in [Fig. 2]), a propeller shaft 3, and a reduction mechanism. The reduction mechanism is advantageously a speed reducer 4, which is intended to be driven by the power shaft 2 and to rotate the propeller shaft 3 at a speed different from that of the power shaft.

[0046] Advantageously, the speed of the power shaft 2 is greater than that of Propeller shaft 3. For example, the speed of the power shaft 2 is approximately 25,000 revolutions per minute, while the speed of the propeller shaft 3 is approximately 2,000 revolutions per minute. This allows for efficient drive of the propeller shaft 3 for effective aircraft propulsion.

[0047] The propeller shaft 3 has an axis of rotation A which is centered on the longitudinal axis X. Advantageously, the propeller shaft 3 extends between a first end 3a and a second end 3b.

[0048] The turbomachine advantageously comprises an unfaired propeller 5 which is connected to the propeller shaft 3. The propeller shaft 3 is intended to drive the propeller 5 in rotation so as to provide propulsion for the aircraft. The propeller 5 comprises a cylindrical housing 6 which is fixed to the first end 3a of the propeller shaft 3.

[0049] Each propeller 5 comprises blades 7 arranged regularly around the longitudinal axis X. The blades 7 include feet, each housed in a recess provided in a ring (not shown) and extending from this ring. The ring is centered on the longitudinal axis X and is rotationally fixed to the cylindrical housing 6.

[0050] As we can see in [Fig.2], the speed reducer 4 is positioned in the upstream part of the turbomachine.

[0051] In the present invention, the terms "upstream" and "downstream" are defined with respect to the flow of gases in the turbomachine and here along the longitudinal axis X and to the [Fig.2] from left to right.

[0052] The speed reducer 4 is arranged within the internal volume of a nacelle 8 where space is limited. The nacelle 8 includes the cylindrical propeller housing 6. The nacelle 8 generally surrounds the turbomachine's gas generator.

[0053] In particular, the turbomachine schematically comprises a stator housing 11. The stator housing 11 is arranged to form an enclosure 12 surrounding the speed reducer 4. The stator housing 11 is advantageously independent of the turbomachine housings, such as the turbomachine inlet housing. The stator housing 11 is attached to the turbomachine nacelle 8. A lubricant mist is present in the enclosure 12. The propeller shaft 3 passes through the enclosure 12, at least partially, along the longitudinal axis X.

[0054] The stator housing 11 advantageously, but not exclusively, comprises at least an upstream portion 13 and a downstream portion 14. The upstream portion 13 and the downstream portion 14 are separated from each other here. The upstream portion 13 of the stator housing 11 includes a first opening 15 allowing the passage of the propeller shaft 3. The first opening 15 is delimited by a cylindrical wall 16 centered on the longitudinal axis X.

[0055] The downstream part 14 includes a second opening 17 allowing passage to less in part of the pitch change system 10. The second opening 17 is delimited by a cylindrical skirt 18 which is centered on the longitudinal axis X.

[0056] The upstream part 13 and the downstream part 14 are fixed together, for example, by means of a radial flange and a bolted connection. The downstream part 14 can be made in one piece or in two portions 14a, 14b as is the case in [Fig.2].

[0057] With reference to [Fig. 3], the propeller shaft 3 is driven in rotation relative to the housing 11 by means of bearings. In the present example, two upstream bearings 19 are mounted upstream of the housing 12. Advantageously, the two upstream bearings 19 are mounted upstream of the speed reducer 4. Each upstream bearing 19 comprises an inner ring integral with the propeller shaft 3 and an outer ring integral with the cylindrical wall 16 of the housing. In the illustrated example, the first upstream bearing 19a comprises roller bearings and the second upstream bearing 19b comprises ball bearings.

[0058] The propeller shaft 3 is also advantageously driven downstream by a downstream bearing 23. The downstream bearing 23 is mounted downstream of the housing 12. More precisely, the downstream bearing 23 is mounted downstream of an output pinion 41, which will be described in more detail later. The downstream bearing 23 comprises an inner ring integral with a cylindrical shaft 45 of the output pinion 4L. The downstream bearing 23 comprises an outer ring integral with an annular wall 26 of the stator housing 11.

[0059] The enclosure 12 is advantageously but not exclusively closed upstream by seals at the upstream bearings 19 allowing passage of the propeller shaft 3, and downstream by seals at the cylindrical skirt 18.

[0060] In [Fig. 3], the speed reducer 4 comprises a gear train with intermediate transmission lines, which is also called a compound reducer or "compound" in Anglo-Saxon terminology. The speed reducer 4 is also known by the English acronym PGB for "Propeller Gear Box" or RGB for "Reduction Gear Box". The compound-type speed reducer requires a load balancing system to equalize the loads between intermediate lines.

[0061] The speed reducer 4 comprises an input pinion 40 and an output pinion 41, which are rotatable. The input pinion 40 is connected to the power shaft. Advantageously, the input pinion 40 is supported by a shaft 42 and is coaxial. In the present embodiment, the input pinion 40 has an input shaft 43 that is parallel to the longitudinal axis X of the turbomachine. The power shaft 2 is coupled to the shaft 42 of the input pinion 40, for example, by means of splines, so that the power shaft 2 is fixed to the input pinion 40. The power shaft 2 thus drives the input pinion 40 in rotation.

[0062] The power shaft 2 is advantageously a turbine shaft comprising classically a turbomachine.

[0063] The output pinion 41 is connected to the propeller shaft 3. The connection is made, for example, by means of splines so that the propeller shaft 3 is fixed to the output pinion 4L. The output pinion 41 has an output axis 44 which is parallel to the input axis 43 of the input pinion 40. In particular, the output axis 44 coincides with that of the propeller shaft 3 (and with the longitudinal axis). In other words, the output pinion is free to rotate about the axis 44, which is collinear with the longitudinal axis X. In other words, the input axis 43 of the input pinion 40 is offset, here radially, from the output axis 44 of the output pinion 4L.

[0064] In [Fig.4], the output pinion 41 in this embodiment comprises a cylindrical shaft 45 extending along the output axis 44. The output pinion 41 comprises a rim 46 which extends radially around the cylindrical shaft 45 and which carries at least one external toothing 47.

[0065] In Figures 3 and 4, the speed reducer 4 includes torque transmission means 48 which are configured to transmit torque from the input pinion 40 to the output pinion 4L. In particular, the power transmitted by the input pinion 40 is distributed by the torque transmission means 48 before being transferred to the output pinion 4L.

[0066] In the present example, the torque transmission means 48 comprise two intermediate transmission lines 55. The two intermediate lines 55 are substantially parallel (more or less inclined at 5°) and are substantially identical. In another example configuration, the intermediate lines 55 may be inclined at an angle greater than 5°.

[0067] In [Fig. 4], and advantageously, each intermediate transmission line 55 comprises a first intermediate gear 49 rotatably mounted about an axis of rotation B. The axes of rotation of the intermediate gears 49 are also parallel to the longitudinal axis. Each of the two intermediate gears 49 comprises an external tooth profile 50 which meshes with an external tooth profile 51 of the input gear 40.

[0068] With reference to Figures 4 and 5, each intermediate transmission line 55 advantageously comprises a second intermediate gear 52 rotatably mounted about an axis of rotation C. This axis is coaxial with a corresponding intermediate line 55. The axes of the second intermediate gears 52 are also parallel to the longitudinal axis. Each second intermediate gear 52 comprises an external toothed portion 53 which meshes with the external toothed portion 47 of the output gear 4L

[0069] Advantageously, the first intermediate gears 49 and the second intermediate gears 52 are rotationally fixed. In particular, the first gear 49 and second gear 52 of each intermediate row 55 are supported by a shaft 54. Advantageously, but not limitingly, the shaft 54 ​​extends between a first end and a second end. Each first intermediate gear 49 is disposed at the first end of the shaft 54 ​​and each second intermediate gear 52 is disposed at the second end of the shaft 54.

[0070] Advantageously, the second intermediate gears 52 are arranged upstream of the first intermediate gears 49.

[0071] The teeth of the pinions 40, 41, 49, 52 may be straight (parallel to the longitudinal axis), helical, or herringbone. Similarly, the pinion teeth may be separated into several helices for reasons of operation, assembly, manufacturing, inspection, repair, or replacement.

[0072] With reference to Figures 4 and 5, at least one of the input pinions, output pinion, first intermediate pinions and second intermediate pinions is separated into two half-portions: • a first portion consisting of a rim which carries the first helix of the teeth. This first helix meshes with that of another pinion of the speed reducer; • a second portion consisting of a rim which carries the second helix of the teeth. This second helix meshes with that of another pinion.

[0073] In the present embodiment, the input pinion 40 comprises two half-portions, each carrying a first helix 51a and a second helix 51b, respectively. The first helix 51a meshes with a first helix 50a of each of the first intermediate pinions 49, and the second helix 51b meshes with a second helix 50b of each of the first intermediate pinions 49. The output pinion 41 comprises two half-portions, each carrying a first helix 47a and a second helix 47b, respectively. The first helix 47a meshes with a first helix 53a of each of the second pinions 52, and the second helix 47b meshes with a second helix 53b of each of the second intermediate pinions 52.

[0074] Advantageously, the direction of the first helix is ​​different from that of the second helix. The directions are opposite.

[0075] Of course, each of the pinions can be formed from a single piece.

[0076] As illustrated in Figures 2 to 7, the speed reducer 4 cooperates with at least one electric machine 60. More precisely, the electric machine 60 is located downstream of the speed reducer 4 and within the available space for the speed reducer 4. This configuration helps to minimize its footprint in the turbomachine. The electric machine 60 is configured to supply electrical power to the propeller shaft and the aircraft (generator mode). The electric machine can also advantageously draw mechanical power from the propeller shaft (motor mode). The aircraft includes an electrical circuit for this purpose. (not shown) which is connected on one side to the electrical machine 60 and on the other side to various aircraft equipment.

[0077] In the present example, there are two electrical machines 60. The arrangement of two electrical machines makes it possible to increase the electrical power to supply the different equipment.

[0078] With reference to [Fig. 4], each electric machine 60 comprises a rotor 61 and a stator 62. The rotor 61 is configured to be driven in rotation about an axis of rotation D. The axis of rotation is parallel to the longitudinal axis. In particular, the axis of rotation is also parallel to the axis of rotation of the intermediate lines 55. The stator 62 is connected to the housing 11 of the turbomachine.

[0079] According to an advantageous feature, the first intermediate pinion 49 of the speed reducer is intended to drive the rotor 61 of each electric machine 60 in rotation.

[0080] For this purpose, the speed reducer 4 comprises at least one drive wheel 63 driven on the one hand by a first intermediate pinion 49 and driving on the other hand a complementary pinion 64. In the present example, there are advantageously two drive wheels 63. In other words, there are also two complementary pinions 64, each being driven via a drive wheel 63.

[0081] Each complementary pinion 64 is advantageously mounted on a rotor 61. The complementary pinion 64 comprises an axis parallel and coaxial with the axis of rotation of the rotor D.

[0082] Advantageously, each rotor 61 schematically represented in the figures has a cylindrical body 61a with a right circular cross-section. The cylindrical body 61a can be solid or hollow.

[0083] Advantageously, but not exclusively, the complementary pinion 64 is formed as a single piece with the rotor 61. In this case, the complementary pinion 64 is mounted radially outside a shaft 65 extending from the body of the rotor 61. Alternatively, the complementary pinion 64 is attached to the shaft 65 of the rotor 61.

[0084] Each drive wheel 63 comprises a first external toothing 66 meshing with the external toothing 50 of a complementary pinion 64. Advantageously, but not limitingly, the external diameter DI (shown in Figures 3 and 5) of the first external toothing 66 is less than the external diameter D2 (also shown in [Fig.3]) of the first complementary pinion 49.

[0085] Advantageously, each drive wheel 63 comprises a second external toothing 67 meshing with an external toothing 68 of a complementary pinion 64. According to this embodiment, the external diameter D3 (represented on [Fig.5]) of the external toothing 68 is less than the diameter DI of the first external toothing 66.

[0086] As shown in [Fig.3], each drive wheel 63 extends between a first end 63a and a second end 63b. The first external toothing 66 is located at the first end 63a and the second external toothing 67 is located at the second end 63b.

[0087] The axis of rotation of each drive wheel 63 is thus offset from the axes of the input and output pinions 40, 4L

[0088] Advantageously, the external teeth of each drive wheel 63 remain in the same radial plane. Generally, the gears do not move along the longitudinal axis.

[0089] The stator 62 of the electric machine 60 extends radially outward from the rotor 61. Advantageously, the stator 62 comprises a cylindrical body 62ab coaxial with the axis of the rotor 61. In the present example, the stator 62 is fixed to the housing 11. The stator 62 is hollow and receives the rotor 61 extending inside it. In particular, the cylindrical body 62a also includes an internal bore.

[0090] Of course, the stator 62 and rotor 61 can have different shapes as long as they are complementary and easily integrated into the available volume of the turbomachine.

[0091] As can be seen in Figures 5, 6, and 7, the turbomachine also includes an air inlet 30 arranged below the speed reducer 4 in a vertical direction perpendicular to the longitudinal axis. Advantageously, the air inlet 30 is extended downstream by an air duct 31 extending below the speed reducer 4. The air inlet 30 is defined in a radial plane arranged upstream of the output pinion 4L. Advantageously, the air duct 31 has an S-shaped form. The air duct 31 has an air outlet 32 ​​defined in a radial plane located downstream of the electric machines 60. The electric machines 60 and the speed reducer 4 are located, in particular, in a recessed area of ​​the air duct 31, which delimits the available volume.This will allow different types of power to be provided without impacting the size in the volume where the speed reducer is located and also the size within the speed reducer 4.

[0092] Each electric machine 60 can operate interchangeably in motor mode and in generator motor mode as explained previously.

[0093] In the case where each electric machine 60 operates in generator mode (the propeller shaft 3 or the turbomachine sends power to the electric machines 60), the input pinion 40 meshes with the first intermediate pinions 49 as can be seen in Figures 3, 4, 6 and 7. The rotation of the first intermediate pinions 49 causes the rotation of the second intermediate pinions 52. The rotation of the first intermediate pinions 49 also causes the rotation of the complete pinions 64 of each rotor 61 via the drive wheels 63. Similarly, the second intermediate gears 52 mesh with the output gear 41 which is coupled with the propeller shaft 3.

[0094] In the case where each electric machine 60 operates in motor mode (the electric machines send power to the propeller shaft 3), the complementary pinions 64 of each rotor 61 are driven in rotation and drive the drive wheels 63 via the external teeth 68 which mesh with the second teeth 67. The first external teeth 66 of the drive wheels 63 (which also carry the first teeth 66) drive the output pinion 41 via the first and second intermediate pinions 49, 52.

Claims

Claims

1. Assembly for an aircraft turbomachine, the assembly comprising: - a power shaft (2), - a propeller shaft (3) centered on a longitudinal axis X and intended to drive at least one propeller (5) of the turbomachine, and - at least one speed reducer (4) intended to be driven by the power shaft (2) and to rotate the propeller shaft (3) at a speed different from that of the power shaft (2), the speed reducer (4) comprising an input pinion (40) connected to the power shaft (2) and an output pinion (41) connected to the propeller shaft (3), characterized in that the assembly comprises two electrical machines (60) which are each configured to supply electrical power to the propeller shaft (3) or to take mechanical power from the propeller shaft (3), each electrical machine (60) comprising a rotor (61) and a stator (62), the stator (62) being intended to be connected to a casing (11) of the turbomachine,and in that the speed reducer (4) comprises two intermediate transmission lines (55) which are substantially parallel and which are configured to transmit the torque from the input pinion (40) to the output pinion (41), each rotor (61) being driven in rotation respectively by a pinion of an intermediate line (55).,

2. Assembly according to the preceding claim, characterized in that the input pinion (40) comprises an input axis (43) offset relative to an output axis of the output pinion (41).

3. Assembly according to one of the preceding claims, characterized in that each intermediate transmission line (55) comprises a first intermediate pinion (49) rotatably mounted around an axis of rotation and comprising a first toothing intended to mesh with an external toothing (51) of the input pinion (40).

4. Assembly according to one of the preceding claims, characterized in that each intermediate transmission line (55) comprises a second intermediate pinion (52) rotatably mounted around an axis of rotation and comprising a second toothing (53) intended to mesh with an external toothing (47) of the output pinion (41).

5. Assembly (1) according to claims 3 and 4, characterized in that the input pinion (40) meshes with two first intermediate pinions (49) of the intermediate transmission lines (55) and the output pinion (41) meshes with two second intermediate gears (52) of the intermediate transmission lines (55) and in that each first intermediate gear (49) and each second intermediate gear (52) comprises a first helix (50a, 53a) and a second helix (50b, 3b) each meshing with a corresponding helix (47a, 47b, 51a, 51b) of the input gear (40) and the output gear (41).

6. An assembly according to claim 3 or claims 3 and 4 or claim 5, characterized in that the speed reducer (4) comprises at least two drive wheels (63) which are each, on the one hand, driven in rotation respectively by the first intermediate pinion (49) of an intermediate transmission line (55) and which, on the other hand, drives in rotation a complementary pinion (64) mounted on each rotor (61), the complementary pinion (64) of the rotor (61) comprising an axis of rotation parallel to the input axis (43) and parallel to the axis of the drive wheel (63).

7. Assembly according to the preceding claim, characterized in that each drive wheel (63) comprises a first external toothing (66) meshing with an external toothing of a first intermediate pinion (49) and a second external toothing (67) meshing with an external toothing (68) of the complementary pinion (64).

8. Assembly according to any one of the preceding claims, characterized in that the stator (62) extends radially outside the rotor (61).

9. Assembly (1) according to any one of the preceding claims, characterized in that the electrical machines (60) are arranged downstream of the speed reducer.

10. Turbomachine (1) comprising an assembly according to any one of the preceding claims and an air inlet (30) arranged below the speed reducer (4), in a vertical direction perpendicular to the longitudinal axis (X).

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