GEAR MOTOR FOR AN AIRCRAFT

Abstract

Geared motor (10) for an aircraft, said geared motor (10) comprising an electric motor (12) and a mechanical reducer (14), the reducer (14) comprising a rotating solar element (26) about an axis (A), a ring gear (28), and satellite gears (30) interposed between the solar element (26) and the ring gear (28) and meshed with the solar element (26) and the ring gear (28), the satellite gears (30) being carried by a satellite carrier (32), the geared motor further comprising a lubrication circuit (60) for the gears of the reducer (14), characterized in that the lubrication circuit (60) is self-contained and installed inside the geared motor (10). Figure for the abbreviation: Figure 1

Description

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

[0001] The present invention relates in particular to a geared motor for an aircraft, as well as to an aircraft comprising such a geared motor. Technical Downstream 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 torque between the input shaft and the output shaft of a mechanism.

[0005] New generations of turbofan engines, particularly those with a high bypass ratio, include a mechanical gearbox to drive the shaft of a fan. Typically, the purpose of the gearbox is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan-driving shaft.

[0006] 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, 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.

[0007] 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.

[0008] - 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.

[0009] - 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.

[0010] - 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.

[0011] 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 straight or herringbone teeth.

[0012] A gearbox requires lubrication to function correctly. It is difficult to incorporate a lubrication system external to the gearbox because the electric motor is not designed for this purpose. One solution to this problem could be to splash the rotating parts of the gearbox in oil. However, the resulting "bubbling" would not be sufficiently effective to ensure adequate lubrication of the gears.

[0013] The present invention proposes a solution to this problem, which is simple, effective and economical. Summary of the invention

[0014] The invention relates to a geared motor for an aircraft, this geared motor comprising an electric motor and a mechanical reducer, the reducer comprising a solar element movable around an axis, a ring gear, and satellites interposed between the solar element and the ring gear and meshed with the solar element and the ring gear, the satellites being carried by a satellite carrier, the geared motor further comprising a lubrication circuit for the gears of the reducer, characterized in that the lubrication circuit is autonomous and installed inside the geared motor, the lubrication circuit comprising a reservoir of lubricating oil, at least one pump located in the reservoir and suitable for immersion in the lubricating oil contained in the reservoir, and nozzles connected to the pump, the pump comprising a rotor which is driven in rotation by the solar element for drawing oil from the reservoir and supplying oil to said nozzles.

[0015] The distinctive feature of the invention lies in the fact that the lubrication of the gearbox, and in particular its gears, is carried out autonomously by a circuit integrated into the gearbox. The circuit comprises a reservoir, at least one pump, and nozzles. The entire circuit is located inside the gearbox. The gearbox is therefore designed to contain its own lubrication reservoir. The pump is immersed in the oil in the reservoir and supplies the nozzles. As soon as the gearbox is running, the solar panel rotates and the pump is activated to supply oil to the nozzles.

[0016] The present invention is compatible with: - of a single-stage or multi-stage reducer; - of straight, helical or chevron teeth; - of any type of one-piece satellite carrier or of the cage and cage carrier type; - of all types of satellite guidance bearings, such as rolling element bearings or hydrodynamic.

[0017] The geared motor according to the invention may comprise one or more of the following characteristics The following characteristics, taken individually or in combination with each other; these characteristics have the particular advantage of making the geared motor more compact: • the reservoir is delimited or located in the solar, and preferably is formed by the solar, in particular when the geared motor is in a default operating position;

[0018] — in the default position, the main axis of the geared motor is oriented vertically;

[0019] — in another position, in which the main axis of the geared motor is oriented horizontally, the oil contained in the geared motor can be stored inside the planet carrier and / or the casing; • the solar exhibits in axial section a general L or C shape and comprises an internal cylindrical wall which includes or carries an external toothing, a radial annular wall which extends outwards from the internal cylindrical wall, 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; • the solar panel further includes an internal cylindrical rib which is located between the internal and external cylindrical walls, and at a distance from them, and which is connected to the radial wall, this rib defining the reservoir with the radial wall and the internal cylindrical wall; • the pump is connected to the nozzles by an annular oil distributor which extends around the axis; • the pump and the nozzles are carried by the oil distributor which includes mounting brackets for the planet carrier; • the jets extend inside the crown, parallel to the axis, and are intercalated circumferentially between the satellites; • the number of nozzles is equal to the number of satellites, each satellite being associated with a nozzle which is located between that satellite and a circumferentially adjacent satellite; • the number of nozzles is equal to twice the number of satellites, each satellite being associated with two nozzles which are located circumferentially on either side of the satellite; • the geared motor also includes an oil control system in the geared motor;

[0020] - the control system includes a sensor or a window through which a The operator can see the presence of oil, or even the oil pressure, in the geared motor;

[0021] - the window or sensor is located on a housing of the geared motor and is aligned on the projection axis of an oil spray nozzle;

[0022] - the oil spray nozzle is carried by the planet carrier and connected fluid- dically to the oil distributor, preferably via an oil channel formed in the satellite carrier; • the pump is of the gerotor, vane, or gear type; • the satellite carrier is fixed and the crown is mobile in rotation around the axis.

[0023] — the pump rotor and the satellites are driven by the same gear teeth of the solar;

[0024] — the distributor also supplies plain bearings for guiding the satellites;

[0025] — the reducer is coupled to the geared motor.

[0026] 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

[0027] 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:

[0028] [Fig-1] [Fig.1] is a schematic exploded perspective view of a geared motor according to the invention;

[0029] [Fig.2] [Fig.2] is a schematic axial cross-sectional view of the geared motor of the [Fig.l];

[0030] [Fig.3] [Fig.3] is a schematic axial cross-sectional view of the geared motor of the [Fig.l], in a first position and illustrates the storage of the oil from the reservoir in this first position;

[0031] [Fig.4] [Fig.4] is a schematic axial cross-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;

[0032] [Fig.5] [Fig.5] is a schematic cross-sectional view of the geared motor of Fig. 1 shows a lubrication circuit for this geared motor; and

[0033] [Fig.6] [Fig.6] is a partial schematic axial cross-sectional view of the geared motor of [Fig.1], and shows a control window for the geared motor. Detailed description of the invention

[0034] 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.

[0035] The aircraft is, for example, of the VTOL type, i.e., vertical takeoff and landing. The geared motor 10 can, for example, be used to drive the propeller of propulsion or one of the aircraft's propulsion propellers.

[0036] 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.

[0037] The geared motor 10 comprises an electric motor 12 and a mechanical reducer 14.

[0038] The electric motor 12 has an annular shape and is aligned on an axis A, which is a common axis with the reducer 14.

[0039] As mentioned above, this axis A can be oriented vertically, in particular during takeoff or landing of the aircraft.

[0040] 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.

[0041] In the example shown, the rotor 16 comprises an annular row of permanent magnets 20. These magnets 20 can be separated from each other by spacers. The number of magnets 20 can be greater than 20 or 30, for example.

[0042] The stator 18 may include 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.

[0043] The reducer 14 can be of the planetary type, that is to say, it includes a movable ring and a fixed planet carrier.

[0044] The reducer 14 thus comprises a solar 26 movable in rotation around the axis A, a ring 28 movable in rotation around this axis A, and satellites 30 intercalated between the solar 26 and the ring 28 and meshed with the solar 26 and the ring 28.

[0045] The satellites 30 are carried by a fixed satellite carrier 32. Conventionally, each of the satellites 32 is mounted on an axis that forms a plain bearing or around which a roller bearing is mounted.

[0046] In the example shown, the solar element 26 has a general L or C shape in axial section and comprises:

[0047] - an internal cylindrical wall 26a which includes or carries external teeth 33,

[0048] - a radial annular wall 26b extending from the internal cylindrical wall 26a outwards,

[0049] - 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.

[0050] In the example shown, the rotor 16 is directly fixed to the outer periphery of the radial wall 26b or to the outer cylindrical wall 26c, or the stator 18 is directly carried by the outer periphery of the radial wall 26b or by the outer cylindrical wall 26c.

[0051] Advantageously, the geared motor 10 comprises a first guide bearing 34 of the solar 26, which is mounted between solar 26 and satellite carrier s 32, and a second bearing 36 for guiding solar 26, which is mounted between solar 26 and the ring 28.

[0052] The first bearing 34 preferably has a diameter greater than that D2 of the teeth 33 of the solar 26

[0053] The second bearing 36 preferably has a diameter smaller than that of the teeth 33 of the solar 26.

[0054] In the example shown, the first bearing 34 is supported by the radial wall 26b, and the second bearing 36 is located inside the internal cylindrical wall 26c.

[0055] In the example also shown, the crown 28 has, in axial section, a general L or C shape and comprises:

[0056] - an external cylindrical wall 28a which includes or carries internal teeth 38,

[0057] - a radial annular wall 28b extending from the external cylindrical wall 28a inward,

[0058] - 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.

[0059] The rotor 16 can extend at least partially around the internal teeth 38 of the crown 28.

[0060] The geared motor 10 further includes an output shaft 50 in the example shown, which is coupled by splines 40 to the inner periphery of the radial wall 28b or to the inner cylindrical wall 28c.

[0061] As in the example shown, the satellite carrier 32 is fixed to a housing 42 of the geared motor 10.

[0062] The stator 18 of the motor 12 can be fixed directly to the housing 42 or carried directly by the housing 42.

[0063] The housing 42 may have a general L or C shape in axial section and comprise:

[0064] - an external cylindrical wall 42a,

[0065] - a radial annular wall 42b extending from the outer cylindrical wall towards the interior,

[0066] - 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.

[0067] The geared motor 10 may include a bearing 44 for guiding the output shaft 50, this bearing 44 being mounted between the output shaft 50 and the inner periphery of the radial wall 42b or the inner cylindrical wall 42c of the housing 42.

[0068] The satellite carrier 32 can be fixed to the radial wall 42b of the housing 42, as in the example shown.

[0069] According to the invention, the geared motor 10 further comprises a lubrication circuit 60 of the gears of the reducer 14, that is to say of the gears between the teeth of the solar 26 and the satellites 30, and between the teeth of the satellites 30 and the crown 28.

[0070] The lubrication circuit 60 is self-contained and is installed inside the geared motor 10. This lubrication circuit 60 includes a lubricating oil reservoir 62, at least one pump 64 located in the reservoir 62 and suitable for immersion in the lubricating oil 66 contained in the reservoir 62, and nozzles 68 connected to the pump 64.

[0071] The pump 64 includes a rotor 64a which is coupled to the solar 26 and which is capable of being driven in rotation by the solar 26 for the extraction of oil 66 from the reservoir 62 and the supply of oil to the nozzles 68.

[0072] Advantageously, it is the same toothing 33 of the solar 26 which drives both the satellites 32 and the rotor 64a of the pump 64.

[0073] The pump 64 is for example of the gerotor type or vane type or gear type.

[0074] Figure 3 shows the geared motor 10 in its default position in the aircraft. is oriented so that its axis A is vertical, allowing the propeller that drives it to rotate around the vertically oriented axis A. In this position, the reservoir 62 is located within the solar 26, and in particular is formed by the solar 26.

[0075] In the example shown, at least some of the walls 26a, 26b, 26c of the solar 26 define the reservoir 62 between them.

[0076] The solar 26 may include an internal cylindrical rib 26d which is located between the internal and external cylindrical walls 26a, 26c, and at a distance from them, and which is connected to the radial wall 26b.

[0077] The rib 26d can define the reservoir 62 with the radial wall 26b and the internal cylindrical wall 26a.

[0078] Figure 4 shows the geared motor 10 in another position in which it is oriented so that its axis A is horizontal. This could be the same geared motor 10 mounted in the same aircraft but with 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 is now in a new position. In the example shown, the oil is contained inside the planet carrier 32 and the housing 42. In this position, the pump 64 is temporarily no longer immersed in the oil.

[0079] The lubrication circuit 60 preferably includes a distributor 70 which connects the pump 64 to the nozzles 68, and which is visible in particular in Figures 1 and 5.

[0080] The distributor 70 preferably has an annular shape to extend around the axis A.

[0081] The distributor 70 is fixed to the satellite carrier 32 and includes for this purpose mounting tabs 82 which are applied and fixed to the satellite carrier 32, by means of screws 84 or bolts for example.

[0082] The distributor 70 is preferably formed in one piece with the legs 82 and at least part of the nozzles 68.

[0083] The jets 68 can extend inside the ring 28, parallel to the axis A, and be circumferentially intercalated between the satellites 30.

[0084] 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.

[0085] In one embodiment, which is illustrated in the drawings, the number of nozzles 68 is equal to twice the number of satellites 30, each satellite 30 being associated with two nozzles 68 located on either side of the satellite. This configuration is advantageous because the nozzles 68 are capable of lubricating the gears, both upstream and downstream of the satellites 30, regardless of the direction of rotation of the solar element 26.

[0086] Fig. 6 shows an oil control system 80 in the geared motor 10, this control system 80 having a window 82 through which an operator or a sensor 83 can visualize the presence of oil, or even the oil pressure, in the geared motor 10. Alternatively, this window 82 could be replaced by a sensor.

[0087] In the example shown, the window 82 is formed in or carried by the housing 42 of the geared motor 10.

[0088] The window 82 is aligned with an oil line 84 formed in the planet carrier 30, this oil line 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 line 84 formed in the planet carrier 30.

[0089] The pipe 84 may have an elongated shape along an axis B parallel to axis A, and include one end connected by a fitting 88 to the distributor 70 and an opposite end connected to an oil spray 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 and even the pressure of oil in the geared motor 10. It is thus understood that the window 82, the nozzle 86, and the pipe 84 extend along the same axis B in the example shown.

[0090] Advantageously, in addition to supplying oil to the nozzles 68 and the channel 84, the distributor 70 can be configured to supply oil to internal cavities of the plain bearings of the satellites 30. The distributor 70 is then connected to a series of nozzles 90 which are each aligned and connected to the plain bearings (Figures 1 and 5).

[0091] Integrating the lubrication circuit directly into the geared motor 10 eliminates the need for external components. Using the solar element 26 as an oil reservoir, rather than a separate reservoir, reduces the number of parts and limits the size and weight of the lubrication circuit. Furthermore, using a lubrication circuit rather than simply splashing the rotating parts of the geared motor improves the performance and efficiency of the geared motor.

Claims

Demands

1. A geared motor (10) for an aircraft, said geared motor (10) comprising an electric motor (12) and a mechanical gearbox (14), the gearbox (14) comprising a rotating solar element (26) about an axis (A), a ring gear (28), and planetary gears (30) interposed between the solar element (26) and the ring gear (28) and meshed with the solar element (26) and the ring gear (28), the planetary gears (30) being carried by a planetary gear carrier (32), the geared motor further comprising a lubrication circuit (60) for the gears of the gearbox (14), characterized in that the lubrication circuit (60) is self-contained 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 be immersed in the lubricating oil (66) contained in the reservoir (62), and the nozzles (68) connected to the pump (64),the pump (64) comprising a rotor (64a) which is driven in rotation by the solar element (26) for drawing oil from the reservoir (62) and supplying oil to said nozzles (68).

2. Geared motor (10) according to claim 1, wherein the reservoir (62) is delimited by the solar (26), and preferably is formed by the solar (26).

3. Geared motor (10) according to claim 1 or 2, wherein the solar (26) has in axial section a general L or C shape and comprises an internal cylindrical wall (26a) which includes or carries an external toothing (33), a radial annular wall (26b) which extends outwards from the internal cylindrical wall (26a), and an external cylindrical wall (26c) which extends around the internal cylindrical wall (26a) and which is connected to the external periphery of the radial wall (26b), at least some of these walls (26a, 26b, 26c) of the solar (26) defining between them said reservoir (62).

4. Geared motor (10) according to claim 3, wherein the solar (26) further comprises an internal cylindrical rib (26d) which is situated between the internal and external cylindrical walls (26a, 26c), and at a distance from them, and which is connected to the radial wall (26b), this rib (26d) defining the reservoir (62) with the radial wall (26b) and the internal cylindrical wall (26a).

5. Geared motor (10) according to any one of the preceding claims, wherein the pump (64) is connected to the nozzles (68) by a distributor of annular oil (70) which extends around the axis (A).

6. Geared motor (10) according to any one of the preceding claims, wherein the pump (64) and the nozzles (68) are carried by the oil distributor (70) which includes tabs (82) for fixing to the planet carrier (32).

7. Geared motor (10) according to any one of the preceding claims, wherein the jets (68) extend inside the ring (28), parallel to the axis (A), and are circumferentially intercalated between the satellites (30).

8. Geared motor (10) according to any one of the preceding claims, wherein 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 that satellite (30) and a circumferentially adjacent satellite (30).

9. Geared motor (10) according to any one of claims 1 to 7, wherein 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 circumferentially on either side of the satellite (30).

10. Geared motor (10) according to any one of the preceding claims, further comprising an oil control system (80) in the geared motor (10), this control system (80) comprising a sensor (83) or a window (82) through which an operator can view the presence of oil, or even the oil pressure, in the geared motor (10).

11. Geared motor (10) according to claim 10, wherein the window (82) or the sensor (83) is located on a housing (42) of the geared motor (10) and is aligned with the projection axis (B) of an oil spray nozzle (86).

12. Geared motor (10) according to claim 11, wherein the oil spray nozzle (86) is carried by the planet carrier (32) and fluidly connected to the oil distributor (70), preferably by an oil channel (84) formed in the planet carrier (32).

13. Geared motor (10) according to any one of the preceding claims, wherein the pump (64) is of the gerotor or vane or gear type.

14. Geared motor (10) according to any one of the preceding claims, wherein the planet carrier (32) is fixed and the ring (28) is movable in rotation about the axis (A).

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

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