GEARED MOTOR FOR AN AIRCRAFT

Abstract

Geared motor (10), in particular for an aircraft, this geared motor (10) comprising: - an electric motor (12), - a mechanical reducer (14), the reducer (14) comprising a sun gear (26) rotatable about an axis (A), a crown (28), and satellites (30) interposed between the sun gear (26) and the crown (28) and meshed with the sun gear (26) and the crown (28), the satellites (30) being carried by a planet carrier (32), - an annular casing (42) surrounding the motor (12) and the reducer (14), and - a circuit (60) for lubricating the gears of the reducer (14), characterized in that it further comprises a heat exchanger (100), this exchanger (100) comprising an oil network (102) which is supplied by said circuit (60) and which is formed in or on said casing (42) to extend around the motor (12) and the reducer (14). Figure for abstract: Figure 1

Description

Title of the invention: REDUCED MOTOR FOR AN AIRCRAFT Technical field of the invention

[0001] The present invention relates in particular to a geared motor, in particular for an aircraft, as well as an aircraft comprising such a geared motor. Technical approval plan

[0002] The state of the art includes in particular documents FR-A1-2 987 416, FR-Al-2 853 382, ​​FR-A1-3 041 054, FR-A1-3 073 915, FR-A1-3 084 428.

[0003] The combination of an electric motor and a mechanical reducer forms a geared motor.

[0004] The role of a mechanical reducer is to modify the speed ratio and the torque between the input axis and the output axis of a mechanism.

[0005] New generations of dual-flow turbomachines, particularly those with a high bypass ratio, include a mechanical reducer to drive the shaft of a fan (also called a "fan"). Usually, the reducer aims to transform the so-called fast rotation speed of the shaft of a power turbine into a slower rotation speed for the shaft driving the fan.

[0006] Such a reducer comprises a central pinion, called a sun gear, a crown gear and pinions called satellites, which are engaged between the sun gear and the crown gear. The satellites are held by a frame called a planet carrier. The sun gear, the crown gear and the planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis of the turbomachine. The satellites each have a different axis of revolution equally distributed over the same operating diameter around the axis of the planetary gears. These axes are parallel to the longitudinal axis of the turbomachine.

[0007] There are several reducer architectures. In the state of the art of double-flow turbomachines, the reducers are of the planetary or epicyclic type. In other similar applications, there are so-called differential or "compound" architectures.

[0008] - on a planetary reducer, the planet carrier is fixed and the crown constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0009] - on an epicyclic reducer, the crown is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar.

[0010] - on a differential reducer, no element is fixed in rotation. The crown rotates in the opposite direction of the solar and the satellite carrier.

[0011] Reducers can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, by friction or even by magnetic field. There are several types of contact meshing such as with straight or herringbone teeth.

[0012] A reducer needs to be lubricated to function properly. It is difficult to provide a lubrication unit outside the reducer because the electric motor is not designed for this purpose. One solution to this problem could be to splash the rotating parts of the reducer in oil. The "splashing" thus obtained would however not be sufficiently effective to ensure good lubrication of the gears.

[0013] When lubricating the gears of the reducer, the oil absorbs thermal energy and therefore also serves for heat dissipation in addition to lubrication. This thermal energy leads to an increase in the temperature of the oil. The higher the oil temperature, the lower the viscosity of the oil and the less effective the lubrication provided by the oil. It is therefore important to limit the increase in the temperature of the lubricating oil and ideally to cool it.

[0014] The present invention provides a solution to this need, which is simple, effective and economical. Summary of the invention

[0015] The invention relates to a geared motor, in particular for an aircraft, this geared motor comprising:

[0016] - an electric motor,

[0017] - a mechanical reducer, the reducer comprising a rotating mobile sun gear around an axis, a crown, and satellites interposed between the sun and the crown and meshed with the sun and the crown, the satellites being carried by a satellite carrier,

[0018] - an annular casing surrounding the motor and the reducer, and

[0019] - a lubrication circuit for the gears of the reducer,

[0020] characterized in that it further comprises a heat exchanger, this heat exchanger comprising an oil network which is supplied by said lubrication circuit and which is formed in or on said casing in order to extend around the electric motor and the reducer.

[0021] The particularity of the invention is linked to the fact that a heat exchanger is integrated into the geared motor in order to cool the lubricating oil of the reducer. The exchanger comprises a first circuit which is an oil circuit supplied by the lubrication circuit of the geared motor. The heat exchanger is preferably a surface type heat exchanger or ACOC (acronym for Air-Cooled Oil-Cooled), this heat exchanger comprising a surface intended to be cooled by a flow of air. This surface may be an external surface of the geared motor, such as of a geared motor housing.

[0022] The present invention is compatible: - a single-stage or multi-stage reducer; - straight, helical or herringbone teeth; - any type of single-piece or cage and cage-carrier type planet carrier; - any type of satellite guide bearings, such as rolling elements or hydrodynamic.

[0023] The geared motor according to the invention may comprise one or more of the following characteristics, taken in isolation from one another, or in combination with one another; these characteristics having in particular the advantages of optimizing the compactness of the geared motor: • the oil network has an annular shape around the axis; • the oil network comprises at least one helical channel which extends around the axis; • the oil network comprises at least one channel which winds or undulates around the axis; • the planet carrier is fixed to said casing, and the crown is movable in rotation around the axis; • the oil network is connected to said lubrication circuit by at least one conduit formed in the planet carrier; • the geared motor further comprises cooling fins which are formed on the casing or carried by the casing and which extend all around the axis and the oil network; • the oil network has a dimension along the axis which is greater than or equal to 80% of a dimension along the axis of said casing, or of a cylindrical wall of said casing in which the oil network is formed; • the oil network has a radial thickness with respect to the axis which is greater than or equal to 30% of a radial thickness with respect to the axis of said casing, or of a cylindrical wall of said casing in which the oil network is formed; • the oil network includes an oil inlet connected to the lubrication circuit, and an oil outlet; • the lubrication circuit is autonomous and installed inside the geared motor, the lubrication circuit comprising a lubricating oil reservoir, a pump located in the reservoir and capable of being immersed in the lubricating oil contained in the reservoir, the pump comprising a rotor which is coupled to the solar and capable of being driven in rotation by the solar for drawing oil from the reservoir and supplying it with oil of the oil network; • the oil outlet of the oil network is in fluid communication with the reservoir so that the oil leaving the oil network is able to flow into the reservoir; • the pump is connected to the oil network by an annular oil distributor which extends around the axis; • the oil distributor comprises an internal annular channel for circulating oil and supplying oil to several nozzles which are distributed circumferentially around the axis and which are configured to lubricate at least certain gears of the satellites; • the oil distributor is formed in one piece with the nozzles; • the oil distributor is surrounded by the oil network and is connected to this network of oil through a conduit formed in the planet carrier; • the oil distributor comprises fixing lugs to the planet carrier;

[0024] — the reservoir is located in the solar, and in particular is formed by the solar, in especially when the geared motor is in a default operating position;

[0025] — in the default position, the main axis of the geared motor is vertically oriented;

[0026] — in another position, in which the main axis of the geared motor is oriented horizontally, the oil contained in the gear motor can be stored inside the planet carrier and / or the casing;

[0027] — the solar has a general L or C shape in axial section and comprises a wall internal cylindrical wall which comprises or carries external teeth, a radial annular wall which extends from the internal cylindrical wall towards the outside, and an external cylindrical wall which extends around the internal cylindrical wall and which is connected to the external periphery of the radial wall, at least some of these walls of the solar defining between them said reservoir;

[0028] — the solar further comprises an internal cylindrical rib which is located between the internal and external cylindrical walls, and at a distance from the latter, and which is connected to the radial wall, this rib defining the tank with the radial wall and the internal cylindrical wall;

[0029] — the pump is connected to the nozzles by an annular distributor which extends around the axis;

[0030] — the pump and the nozzles are carried by the distributor;

[0031] — the nozzles extend inside the crown, parallel to the axis, and are in intercalated between the satellites;

[0032] — the number of nozzles is equal to the number of satellites, each of the satellites being associated with a nozzle which is located between this satellite and an adjacent satellite;

[0033] — the number of nozzles is equal to twice the number of satellites, each of which tellites being associated with two nozzles which are located on either side of the satellite;

[0034] — the geared motor further comprises a system for controlling the oil in the mo- toreducer;

[0035] — the control system comprises a sensor or window through which a operator can visualize the presence of oil, or even the oil pressure, in the geared motor;

[0036] — the window or sensor is located on a housing of the geared motor and is aligned with the projection axis of an oil projection nozzle;

[0037] — the oil projection nozzle is carried by the planet carrier and connected to said dis tributor, preferably by an oil pipe formed in the planet carrier;

[0038] — the pump is of the gerotor type, or vane or gear type;

[0039] — the pump rotor and the satellites are driven by the same toothing of the solar;

[0040] — the distributor also supplies plain bearings for guiding the satellites;

[0041] — the reducer is coupled to the geared motor.

[0042] The invention further relates to an aircraft comprising a geared motor as described above, in particular for driving a propulsion propeller. Brief description of the figures

[0043] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:

[0044] [Fig-1] [Fig.l] is an exploded perspective schematic view of a geared motor according to the invention;

[0045] [Fig.2] [Fig.2] is a schematic axial sectional view of the geared motor of the [Fig.l];

[0046] [Fig.3] [Fig.3] is a schematic axial sectional view of the geared motor of the [Fig.l], in a first position and illustrates the storage of the oil in the reservoir in this first position;

[0047] [Fig.4] [Fig.4] is a schematic axial sectional view of the geared motor of the [Fig.l], in a second position and illustrates the storage of the oil from the reservoir in this second position;

[0048] [Fig.5] [Fig.5] is a schematic cross-sectional view of the geared motor of [Fig.l], and shows a lubrication circuit of this geared motor;

[0049] [Fig.6] [Fig.6] is a schematic axial sectional view of the geared motor of the [Fig.l], and shows a heat exchanger of the geared motor;

[0050] [Fig.7] [Fig.7] is a schematic perspective view of an embodiment of an oil network of the heat exchanger of the geared motor; and

[0051] [Fig.8] [Fig.8] is a schematic perspective view of an alternative embodiment of an oil network of the heat exchanger of the geared motor. Detailed description of the invention

[0052] Figures 1 to 6 illustrate an embodiment of a geared motor 10 according to the invention, this geared motor being particularly suitable for use in an aircraft.

[0053] The aircraft is for example of the VTOL type, that is to say vertical takeoff and landing. The geared motor 10 can for example be used to drive the propulsion propeller or one of the propulsion propellers of the aircraft.

[0054] Advantageously, the geared motor 10 is designed to drive the propeller around a vertical axis. However, it is understood from the following description that the axis of rotation of the propeller can have any orientation.

[0055] The geared motor 10 comprises an electric motor 12 and a mechanical reducer 14.

[0056] The electric motor 12 has an annular shape and is aligned on an axis A, which is a common axis with the reducer 14.

[0057] As mentioned above, this axis A can be oriented vertically, in particular during takeoff or landing of the aircraft.

[0058] The electric motor 12 comprises a rotor 16 and a stator 18. In the example shown, the rotor 16 is located inside the stator 18.

[0059] In the example shown, the rotor 16 comprises an annular row of permanent magnets 20. These magnets 20 may be separated from each other by spacers. The number of magnets 20 may be greater than 20 or 30 for example.

[0060] The stator 18 may comprise an annular row of windings (not shown) which are formed by winding around cores 24. The number of cores 24 is for example equal to the number of permanent magnets 20.

[0061] The reducer 14 may be of the planetary type, that is to say that it comprises a movable crown and a fixed planet carrier.

[0062] The reducer 14 thus comprises a sun gear 26 movable in rotation around the axis A, a crown 28 movable in rotation around this axis A, and satellites 30 interposed between the sun gear 26 and the crown 28 and meshed with the sun gear 26 and the crown 28.

[0063] The satellites 30 are carried by a planet carrier 32 which is fixed. Conventionally, each of the satellites 32 is mounted on an axis which forms a smooth bearing or around which a rolling bearing is mounted.

[0064] In the example shown, the solar 26 has a general L-shape in axial section. or C and includes:

[0065] - an internal cylindrical wall 26a which comprises or carries an external toothing 33,

[0066] - a radial annular wall 26b which extends from the internal cylindrical wall 26a outwards,

[0067] - and possibly an external cylindrical wall 26c which extends around the wall internal cylindrical 26a and which is connected to the external periphery of the radial wall 26b.

[0068] In the example shown, the rotor 16 is directly fixed to the external periphery of the radial wall 26b or to the external cylindrical wall 26c, or the stator 18 is directly carried by the external periphery of the radial wall 26b or by the external cylindrical wall 26c.

[0069] Advantageously, the geared motor 10 comprises a first bearing 34 for guiding the sun gear 26, which is mounted between the sun gear 26 and the planet carrier 32, and a second bearing 36 for guiding the sun gear 26, which is mounted between the sun gear 26 and the ring gear 28.

[0070] The first bearing 34 preferably has a diameter greater than that D2 of the toothing 33 of the sun 26

[0071] The second bearing 36 preferably has a diameter smaller than that of the teeth 33 of the sun 26.

[0072] In the example shown, the first bearing 34 is carried by the radial wall 26b, and the second bearing 36 is located inside the internal cylindrical wall 26c.

[0073] In the example also shown, the crown 28 has a general L or C shape in axial section and comprises:

[0074] - an external cylindrical wall 28a which comprises or carries an internal toothing 38,

[0075] - a radial annular wall 28b which extends from the external cylindrical wall 28a inward,

[0076] - and possibly an internal cylindrical wall 28c which extends inside the external cylindrical wall 28a and which is connected to the internal periphery of the radial wall 28b.

[0077] The rotor 16 may extend at least partly around the internal teeth 38 of the crown 28.

[0078] The geared motor 10 further comprises an output shaft 50 in the example shown, which is coupled by splines 40 to the internal periphery of the radial wall 28b or to the internal cylindrical wall 28c.

[0079] As in the example shown, the planet carrier 32 is fixed to a casing 42 of the geared motor 10.

[0080] The stator 18 of the motor 12 can be fixed directly to the casing 42 or carried directly by the casing 42.

[0081] The casing 42 may have a general L or C shape in axial section and comprise:

[0082] - an external cylindrical wall 42a,

[0083] - a radial annular wall 42b which extends from the outer cylindrical wall towards the interior,

[0084] - and possibly an internal cylindrical wall 42c which extends inside the external cylindrical wall 42a and which is connected to the internal periphery of the radial wall 42b.

[0085] The geared motor 10 may comprise a bearing 44 for guiding the output shaft 50, this bearing 44 being mounted between the output shaft 50 and the internal periphery of the radial wall 42b or the internal cylindrical wall 42c of the casing 42.

[0086] The planet carrier 32 can be fixed to the radial wall 42b of the casing 42, as in the example shown.

[0087] In the example shown, the geared motor 10 further comprises a lubrication circuit 60 for the gears of the reducer 14, i.e. the gears between the teeth of the sun gear 26 and the planet gears 30, and between the teeth of the planet gears 30 and the crown wheel 28.

[0088] Advantageously, the lubrication circuit 60 is autonomous and is installed inside the geared motor 10. This lubrication circuit 60 comprises a reservoir 62 of lubricating oil, at least one pump 64 located in the reservoir 62 and capable of being immersed in the lubricating oil 66 contained in the reservoir 62, and nozzles 68 connected to the pump 64.

[0089] The pump 64 comprises a rotor 64a which is coupled to the solar 26 and which is capable of being driven in rotation by the solar 26 for drawing oil 66 from the reservoir 62 and supplying oil to the nozzles 68.

[0090] Advantageously, it is the same toothing 33 of the sun gear 26 which drives both the satellites 32 and the rotor 64a of the pump 64.

[0091] The pump 64 is for example of the gerotor or vane or gear type.

[0092] [Fig.3] shows the geared motor 10 in its default position in the aircraft. It is oriented so that its axis A is vertical so that the propeller which drives it rotates around the vertically oriented axis A. In this position, the reservoir 62 is located in the solar 26, and in particular is formed by the solar 26.

[0093] In the example shown, at least some of the walls 26a, 26b, 26c of the solar 26 define between them the reservoir 62.

[0094] The solar 26 may comprise an internal cylindrical rib 26d which is located between the internal and external cylindrical walls 26a, 26c, and at a distance from the latter, and which is connected to the radial wall 26b.

[0095] The rib 26d may define the reservoir 62 with the radial wall 26b and the internal cylindrical wall 26a.

[0096] [Fig.4] shows the geared motor 10 in another position in which it is oriented so that its axis A is horizontal. It may be the same geared motor 10 mounted in the same aircraft but which has adopted a different orientation in which its propeller rotates around the horizontally oriented axis A. In this position, the oil 66 has flowed into the geared motor 10 and adopts a new position. In the example shown, the oil is contained inside the planet carrier 32 and the casing 42.

[0097] The lubrication circuit 60 preferably comprises a distributor 70 which connects the pump 64 to the nozzles 68, and which is visible in FIGS. 1 and 5 in particular.

[0098] The distributor 70 preferably has an annular shape and extends around the axis A.

[0099] The distributor 70 comprises an internal annular oil circulation channel and oil supply to the nozzles 68.

[0100] The distributor 70 is fixed to the planet carrier 32 and for this purpose comprises fixing lugs 82 which are applied and fixed to the planet carrier 32, by means of screws 84 or bolts for example.

[0101] The distributor 70 is preferably formed in a single piece with the legs 82 and at least a portion of the nozzles 68.

[0102] The nozzles 68 can extend inside the crown 28, parallel to the axis A, and be interposed between the satellites 30.

[0103] In a first embodiment, the number of nozzles 68 is equal to the number of satellites 30, each of the satellites 30 being associated with a nozzle 68 which is located between this satellite and a circumferentially adjacent satellite.

[0104] In an alternative embodiment, which is that illustrated in the drawings, the number of nozzles 68 is equal to twice the number of satellites 30, each of the satellites 30 being associated with two nozzles 68 which are located on either side of the satellite. This configuration is advantageous because the nozzles 68 are capable of lubricating the gears, upstream and downstream of the satellites 30, regardless of the direction of rotation of the solar 26.

[0105] [Fig.6] shows a system 80 for controlling the oil in the geared motor 10, this control system 80 comprising a window 82 through which an operator or a sensor 83 can view the presence of oil, or even the oil pressure, in the geared motor 10. Alternatively, this window 82 could be replaced by a sensor.

[0106] In the example shown, the window 82 is formed in or carried by the casing 42 of the geared motor 10.

[0107] The window 82 is aligned with an oil pipe 84 formed in the planet carrier 30, this oil pipe 84 being connected to the distributor 70 and being supplied with oil by the latter. It is therefore understood that the distributor 70 supplies both the nozzles 68 and the pipe 84 formed in the planet carrier 30.

[0108] The pipe 84 may have an elongated shape along an axis B parallel to the axis A, and comprise one end connected by a nozzle 88 to the distributor 70 and an opposite end connected to an oil projection nozzle 86. This nozzle 86 is configured to spray oil onto the window 82 (or the sensor 83) to allow the operator to check the presence or even the pressure of the oil in the geared motor 10. It is thus understood that the window 82, the nozzle 86 and the pipe 84 extend on the same axis B in the example shown.

[0109] Advantageously, in addition to supplying oil to the nozzles 68 and the pipe 84, the distributor 70 can be configured to supply oil to the internal cavities of the plain bearings of the satellites 30. The distributor 70 is then connected to a series of end pieces 90 which are each aligned and connected to the plain bearings (Figures 1 and 5).

[0110] Integrating the lubrication circuit directly into the geared motor 10 makes it possible to avoid adding components external to the geared motor. Using the solar 26 as an oil reservoir rather than an attached reservoir makes it possible to reduce the number of parts, and to limit the size and mass of the lubrication circuit. Furthermore, using a lubrication circuit rather than simply splashing the rotating parts of the geared motor makes it possible to improve the performance and efficiency of the geared motor.

[0111] According to the invention, the geared motor 10 further comprises a heat exchanger 100 (see [Fig.6]).

[0112] This exchanger 100 comprises an oil network 102 which is supplied by the lubrication circuit 60, which is of the type described previously or of another type, and which is formed in or on the casing 42 in order to extend around the motor 12 and the reducer 14.

[0113] This oil network 102 preferably has an annular shape around the axis A.

[0114] Figures 7 and 8 illustrate embodiments of this oil network 102.

[0115] In [Fig.7], the oil network 102 comprises at least one helical channel 104 which extends around the axis A.

[0116] In [Fig.8], the oil network 102 comprises at least one channel 106 which winds or undulates around the axis A.

[0117] It can be seen in these figures that the distributor 70 is surrounded by the oil network 102, and can be connected to the latter by one or more conduits 108.

[0118] The oil network 102 comprises at least one oil inlet 102a connected to the circuit 60, and at least one oil outlet 102b.

[0119] The inlet 102a of the oil network 102 is preferably connected to the lubrication circuit 60 by at least one conduit 108 formed in the planet carrier 32. In the example shown in [Fig.6], this conduit 108 is at least partly formed by the pipe 84 of the planet carrier 32.

[0120] It is therefore understood that, in the example shown, the exchanger 100 is connected to the lubrication circuit 60 and in particular the pump 64 by the distributor 70. The distributor 70 is connected to the exchanger 100 by a particular outlet 70a, which is connected to the pipe 84 and to the conduit 108 by the aforementioned end piece 88.

[0121] The oil outlet 102b of the oil network 102 is preferably in fluid communication with the reservoir 66 so that the oil leaving the oil network 102 is able to flow into the reservoir 66.

[0122] The oil network 102 may have a dimension L1 along the axis A which is greater than or equal to 80% of a dimension L2 along the axis A of the casing 42, or of the cylindrical wall 42a of the casing 42 in which the oil network 102 is formed.

[0123] The oil network 102 may have a radial thickness E1 with respect to the axis A which is greater than or equal to 30% of a radial thickness E2 with respect to the axis A of the casing 42, or of the cylindrical wall 42a of the casing 42 in which the oil network 102 is formed.

[0124] The heat exchanger 100 is preferably of the surface type or ACOC (acronym for Air-Cooled Oil-Cooled), this heat exchanger comprising a surface 100a intended to be cooled by an air flow.

[0125] This surface 100a is here an external surface of the geared motor 10, and in particular the external surface of the casing 42 and its wall 42a.

[0126] The geared motor 10 preferably comprises cooling fins 110 on this surface 100a. These fins 110 are formed projecting from the casing 42 or carried by the casing 42 and extend all around the axis A and the oil network 102.

[0127] The fins 110 may have a dimension L3 along the axis A which is greater than or equal to L1 and for example equal to L2. The fins 110 may have a radial thickness E3 with respect to the axis A which is greater than or equal to E2.

[0128] The present invention provides several advantages, including:

[0129] - the integration of the exchanger directly into the geared motor makes it possible to avoid the addition of an external exchanger and therefore allows a gain in space and mass;

[0130] - this integration also makes it possible to contain the oil in the geared motor and thus reduces sealing problems since in the event of a leak the oil would flow into the reducer and not outside;

[0131] - being able to cool the oil allows the oil's characteristics to be preserved and therefore improve the performance of the geared motor compared to a splash lubrication system; etc.

Claims

Claims

1. Geared motor (10), in particular for an aircraft, this geared motor (10) comprising: - an electric motor (12), - a mechanical reducer (14), the reducer (14) comprising a sun gear (26) rotatable about an axis (A), a crown (28), and satellites (30) interposed between the sun gear (26) and the crown (28) and meshed with the sun gear (26) and the crown (28), the satellites (30) being carried by a planet carrier (32), - an annular casing (42) surrounding the motor (12) and the reducer (14), and - a lubrication circuit (60) for the gears of the reducer (14), characterized in that it further comprises a heat exchanger (100), this heat exchanger (100) comprising an oil network (102) which is supplied by said circuit of lubrication (60) and which is formed in or on said casing (42) so as to extend around the electric motor (12) and the reducer (14).

2. Geared motor (10) according to claim 1, wherein the oil network (102) has an annular shape around the axis (A).

3. Geared motor (10) according to claim 1 or 2, wherein the oil network (102) comprises at least one helical channel (104) which extends around the axis (A).

4. A geared motor (10) according to claim 1 or 2, wherein the oil network (102) comprises at least one channel (106) which winds or undulates around the axis (A).

5. Geared motor (10) according to one of the preceding claims, in which the planet carrier (32) is fixed to said casing (42), and the crown (28) is rotatable around the axis (A).

6. Geared motor (10) according to claim 5, in which the oil network (102) is connected to said lubrication circuit (60) by at least one conduit (108) formed in the planet carrier (32).

7. Geared motor (10) according to one of the preceding claims, further comprising cooling fins (110) which are formed on the casing (42) or carried by the casing (42) and which extend all around the axis (A) and the oil network (102).

8. Geared motor (10) according to one of the preceding claims, in which the oil network (102) has a dimension (L1) along the axis (A) which is greater than or equal to 80% of a dimension (L2) along the axis (A) of said casing (42), or of a cylindrical wall of said casing (42) in which the oil network (102) is formed.

9. Geared motor (10) according to one of the preceding claims, in which the oil network (102) has a radial thickness (El) with respect to the axis (A) which is greater than or equal to 30% of a radial thickness (E2) with respect to the axis (A) of said casing (42), or of a cylindrical wall of said casing (42) in which the oil network (102) is formed.

10. Geared motor (10) according to one of the preceding claims, in which the oil network (102) comprises an oil inlet (102a) connected to the lubrication circuit (60) and an oil outlet (102b).

11. Geared motor (10) according to one of the preceding claims, in which the lubrication circuit (60) is autonomous and installed inside the geared motor (10), the lubrication circuit (60) comprising a reservoir (62) of lubricating oil (66), a pump (64) located in the reservoir (62) and capable of being immersed in the lubricating oil (66) contained in the reservoir (62), the pump (64) comprising a rotor (64a) which is coupled to the solar (26) and capable of being driven in rotation by the solar (26) for drawing oil from the reservoir (62) and supplying oil to the oil network (102).

12. A geared motor (10) according to claim 11, dependent on claim 10, wherein the oil outlet (102b) of the oil network (102) is in fluid communication with the reservoir (66) so that oil leaving the oil network (102) is able to flow into the reservoir (66).

13. Geared motor (10) according to claim 11 or 12, wherein the pump (64) is connected to the oil network (102) by an annular oil distributor (70) which extends around the axis (A).

14. Geared motor (10) according to claim 13, in which the oil distributor (70) comprises an internal annular channel for circulating oil and supplying oil to several nozzles (68) which are distributed circumferentially around the axis (A) and which are configured to lubricate at least certain meshes of the planet gears (30).

15. A geared motor (10) according to claim 14, wherein the oil distributor (70) is formed integrally with the nozzles (68).

16. Geared motor (10) according to one of claims 13 to 15, in which the oil distributor (70) is surrounded by the oil network (102) and is connected to this oil network (102) by a conduit (108) formed in the planet carrier (32).

17. Geared motor (10) according to one of claims 13 to 16, in which the oil distributor (70) comprises lugs (82) for attachment to the planet carrier (32).

18. Aircraft, comprising a geared motor (10) according to one of the preceding claims for driving a propulsion propeller.

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