Speed reduction device comprising a casing provided with oil guide reliefs, and aeronautical propulsion assembly comprising such a device

Abstract

Speed reduction device (10) for an aeronautical propulsion unit, comprising a crown (10A), a sun gear (10B) and at least one satellite gear (10C), an oil supply circuit (30) for at least one element among the sun gear (10B), the crown (10A), the at least one satellite gear (10C) and the satellite carrier (10D), and an annular casing (12) housing the crown (10A), the sun gear (10B), the at least one satellite gear (10C) and the satellite carrier (10D), the annular casing (12) having a radially internal face (12A) and an oil collector (13), the oil collector (13) being configured to discharge the oil by gravity, the radially internal face (12A) comprising a plurality of reliefs (14) distributed in the circumferential direction (C) Figure for the abstract: Fig. 3.

Description

Title of the invention: Speed ​​reduction device comprising a casing provided with oil guide reliefs, and aeronautical propulsion assembly comprising such a device Technical field

[0001] The present disclosure relates to a speed reduction device for an aeronautical propulsion unit and an aeronautical propulsion unit equipped with such a speed reduction device.

[0002] In the present disclosure, the term "aeronautical propulsion system" designates all turbomachines or gas turbine devices producing motive power, dedicated to the propulsion of an aircraft and equipped with a nacelle or not. Among these devices, a distinction is made in particular between turbojets providing the thrust necessary for propulsion by reaction to the ejection of gas at high speed, and turbo-engines in which the motive power is provided by the rotation of an engine shaft. For example, turboshafts are used as helicopter engines. Turbo-propellers (turboshaft driving a propeller) are turboshafts used as aircraft engines. Prior art

[0003] Various speed reduction devices for aeronautical propulsion units are known, for example from FR3095243 or FR3041054. However, the lubricating and / or cooling oil circuit of the rotating elements within the speed reduction devices is constantly aimed at being improved, in particular from the point of view of oil recovery, oil recirculation, from the thermal point of view and / or from the point of view of mass. Statement of the invention

[0004] One embodiment relates to a speed reduction device for an aeronautical propulsion unit, the speed reduction device comprising a crown, a sun gear and at least one satellite gear rotatably mounted on a satellite carrier, the diameter of the crown being greater than the diameter of the sun gear, an oil supply circuit for at least one element among the sun gear, the crown, the at least one satellite gear and the satellite carrier, and an annular casing housing the crown, the sun gear, the at least one satellite gear and the satellite carrier, the annular casing having a radially internal face facing the crown and an oil collector comprising an oil discharge orifice, in which, considered in the direction of gravity, gravity being oriented from top to bottom, the oil collector is arranged in a lower part of the casing and configured to evacuate the oil by gravity, the radially internal face of the annular casing comprising a plurality of reliefs distributed in the circumferential direction, the plurality of reliefs being configured to circulate the oil coming from the at least one element and received by the radially internal face, along the radially internal face to the oil collector.

[0005] Generally, the axial direction corresponds to the direction of the axis of rotation of the satellite carrier or the ring gear which corresponds, when the speed reduction device is mounted on a propulsion unit, to the axis of rotation of the gas generator. A radial direction is a direction perpendicular to the axial direction. The azimuthal or circumferential direction corresponds to the direction describing a ring around the axial direction. The three directions axial, radial and azimuthal (or circumferential) correspond respectively to the directions defined by the coast, the radius and the angle in a cylindrical coordinate system. Furthermore, upstream and downstream are defined relative to the normal flow direction of the fluid (from upstream to downstream) through the aeronautical propulsion unit.Finally, unless otherwise specified, the adjectives interior / internal and exterior / external are used in reference to the radial direction so that the internal (i.e. radially internal) part of an element is closer to the axis defining the axial direction than the external (i.e. radially external) part of the same element.

[0006] A speed reduction device for an aeronautical propulsion unit is, for example, a device configured to couple in rotation a drive shaft of a gas generator, for example a low-pressure body shaft when the propulsion unit comprises a low-pressure body and a high-pressure body, with a fan shaft, shrouded or unshrouded, and configured to drive the fan shaft at a rotational speed lower than the rotational speed of the drive shaft. Hereinafter, and unless otherwise indicated, the term "reduction device" means "speed reduction device".

[0007] For example, the speed reduction device may be an epicyclic gear train reduction device, for example of the "epicyclic" or "planetary" type according to the terminology sometimes used by those skilled in the art. Such a device may comprise a single stage, two stages or more than two stages.

[0008] According to a first variant, the reduction device may be of the planetary or "star" type and comprise a sun gear, which forms the input of the reduction device. The axis of rotation of the sun gear forms the axis of rotation of the reduction device, and may be the same as the axis of the propulsion assembly. The sun gear is configured to be rotated by a drive shaft. The ring gear forms the output of the reduction device. The ring gear is coaxial with the sun gear and configured to rotate a fan shaft around the axis. Several planet gears, or planet pinions, may be distributed circumferentially around the axis between the sun gear and the crown wheel. Each planet gear is meshed with the sun gear and with the crown wheel. The planet gears are mounted on a planet carrier which is configured to be fixed relative to a stator part of a propulsion unit, for example relative to a casing upstream of a compressor.

[0009] According to a second variant, the reduction device may be of the epicyclic or “planetary” type in English. In this case, compared to the planetary type according to the first variant, the crown is configured to be fixedly mounted on a stator part of the propulsion unit and the propeller shaft is driven in rotation by the planet carrier (which is therefore mobile in rotation relative to the stator part of the propulsion unit, for example relative to a casing upstream of the compressor). The stator parts of the first and second variants may correspond to different parts of the same element, or else correspond to separate elements.

[0010] Whatever the configuration of the reduction device, the diameter of the crown is greater than the diameter of the satellite carrier which is itself greater than the diameter of the sun pinion. The satellites are radially arranged between the sun pinion and the crown, and the output rotation speed is lower than the input rotation speed.

[0011] The reduction ratio of the reduction device may be greater than or equal to 2.5 and less than or equal to 14.0.

[0012] The casing may comprise a single manifold or several manifolds. The manifold, or each manifold, may comprise a single orifice, or several orifices. Considered according to the direction of gravity, in particular when the speed reduction device is mounted on an aeronautical propulsion unit, in normal position of use (i.e. when the aircraft on which the propulsion unit is mounted is in normal conditions of use, i.e. on the ground, in cruising flight, in the takeoff phase or in the landing phase), the manifold is arranged in the lower part of the casing.For example, the casing has a median plane perpendicular to the direction of gravity and comprising the axis of rotation of the planet carrier or the crown wheel, and considered according to the orientation of gravity, the part of the casing arranged above this median plane forms an upper part of the casing and the part of the casing arranged below this median plane forms the lower part of the casing. According to a variant, the upper / lower parts can extend over 25% of the extent of the casing according to the direction of gravity, from the highest / lowest point, respectively, of the casing considered according to the direction of gravity. The collector is configured so that the oil drains by gravity, that is to say that it flows naturally through the orifice by gravitational effect.

[0013] The reliefs can be projecting or hollow reliefs and, considered individually, are distinct from deflectors (i.e. each relief does not form a deflector on its own). deflector, is not sufficient to guide an oil flow on its own). The reliefs are configured to act in synergy and to, all together, guide the circulation of oil received on the radially internal face by projection due to the rotation of the various lubricated rotating elements of the reduction device, all along the radially internal face, and this from the point of impact of the various oil projections to the collector. For example, each of the reliefs can facilitate the adhesion of the oil projections on the radially internal face during the impact of the projections on the radially internal face, and thus avoid possible rebounds of the projections elsewhere within the reduction device. Such rebounds of the oil projections can lead to recirculation of all or part of the oil projections towards the rotating parts of the reducer, which can induce undue energy losses and undesirable heating of the oil.By synergistic effect, all of the reliefs can then promote the flow of the oil thus recovered on the radially internal face towards the collector, for example towards the discharge orifice, and “calm” an oil flow which would possibly tend to become turbulent.

[0014] The annular casing may have a radially external face, opposite the radially internal face. This radially external face may be subjected, in operation when the reduction device is mounted on an aeronautical propulsion unit, to a temperature different from the temperature prevailing within the casing and / or the temperature of the oil. The reliefs may promote heat exchanges between the recovered oil projections and the radially external face of the casing, for example to cool the oil, for example if the annular casing internally delimits a primary gas stream at the inlet of a gas generator, upstream of a compressor.

[0015] In some embodiments, each of the plurality of reliefs may be comprised of a projection extending radially inward from the radially inner face.

[0016] For example, the reliefs may be normal to (or extend perpendicularly from) the radially inner face. Such raised reliefs may be particularly effective, for example, for both oil redirection and cooling.

[0017] According to a variant, the plurality of reliefs may also comprise a portion extending radially outwards from the radially external face. In other words, the reliefs may comprise a radially internal portion and a radially external portion, for example in the radial extension of one another. In other words, the reliefs may extend radially on either side of the wall of the casing. This may make it possible to increase the heat exchange surface between the wall and the air outside the enclosure. With an outside air temperature lower than that of the oil in the enclosure, it is understood that the cooling of the oil is improved. due to better heat evacuation thanks to the cooling of the reliefs by the outside air and the continuity of material of the reliefs between the radially internal portion and the radially external portion.

[0018] In some embodiments, each projection may have a radial thickness less than or equal to 40.00 mm (forty millimeters), for example less than or equal to 25.00 mm (twenty-five millimeters), and greater than 0.10 mm (ten hundredths of a millimeter).

[0019] Such radial thicknesses can make it possible to obtain a good balance between the effectiveness of the reliefs and the added mass that they can represent.

[0020] In some embodiments, the plurality of reliefs may all be disposed at positions distinct from the position of the oil collector.

[0021] For example, the reliefs may all be arranged axially and circumferentially at positions distinct from the axial and azimuthal position of the oil collector, and in particular from the oil discharge orifice. In other words, considered in the radial direction, the reliefs do not extend in front of the oil collector, and in particular in front of the oil discharge orifice of the oil collector. Such a configuration may make it possible to optimize the efficiency of the oil collector by freeing up as much as possible access to the collector from the enclosure delimited by the casing while the reliefs ensure the adhesion and guidance of the oil projections received by the radially internal face of the casing.

[0022] In some embodiments, the plurality of reliefs may form at least one regular pattern, for example a herringbone pattern, a broken line pattern, a spike pattern, a star pattern, a curved line pattern, a straight line pattern, a rice grain pattern, or any combination of these shapes.

[0023] Such patterns can improve the synergy of the reliefs, and the efficiency of the adhesion and guidance of the recovered oil. This can also improve the efficiency of the cooling, in the case of an annular casing whose external radial face is colder than the internal radial face.

[0024] In certain embodiments, the reliefs of the plurality of reliefs may each have a radial end, the reliefs each having an evolving shape tapering from the radially internal face to the radial end.

[0025] For example, the evolving shape may become thinner when considered in a transverse section of the relief. Such a configuration may make it possible to optimize the mass that the plurality of reliefs may represent, to improve the adhesion and the guidance of the oil projections received by the radially internal face of the casing and / or to allow better heat exchange with the oil.

[0026] In some embodiments, the speed reduction device may include an axis and an axial plane extending parallel to the axis and containing the axis, the axial plane passing through the oil collector, the reliefs of the plurality of reliefs being arranged symmetrically with respect to the axial plane.

[0027] In other words, the axial plane extends radially parallel to the axis (or to the axial direction), and contains the axis. The axial plane may, for example, pass through the geometric center of the orifice of the oil collector. For example, such a configuration may optimize the guidance of the oil by gravity towards the collector, for example the reliefs being oriented towards the collector (or towards the low point of the reducer), that is to say in the direction of the shortest circumferential path to reach the collector. Such a configuration may make it possible to ensure a certain versatility of the reliefs, which may have the same efficiency regardless of the direction of rotation of the rotating elements of the reducer.

[0028] In some embodiments, the speed reduction device may include an axis and a radial plane extending perpendicular to the axis, the plurality of reliefs being arranged symmetrically with respect to the radial plane.

[0029] In other words, the radial plane extends parallel to the radial direction and perpendicular to the axis (or to the axial direction). The radial plane may, for example, pass through the geometric center of the orifice of the oil collector. For example, such a configuration may make it possible to optimize the guiding of the oil by gravity towards the collector, for example the reliefs being oriented circumferentially and / or axially towards the collector. For example, the casing may have a concave shape with a concavity oriented radially inwards, so that such a configuration of the reliefs may make it possible to optimize the guiding of the oil towards the bottom of the concave shape, i.e. towards the point radially furthest from the axis of the radially internal face, which may further improve the guiding by gravity towards the collector, for example towards the orifice (which may, for example, also be arranged in the bottom of the concave shape).

[0030] In certain embodiments, the speed reduction device may comprise an intermediate gutter arranged radially between the casing and the crown, the gutter being perforated.

[0031] In other words, the gutter comprises through holes. The shape of the holes in the gutter can be configured to promote the guidance of oil projections towards predetermined impact zones of the radially internal face of the casing, for example zones where the reliefs extend. In general, the gutter can be perforated so as to optimize the circulation of the oil within the reduction device.

[0032] In some embodiments, the crown is rotatable and has a plurality of radially extending through conduits configured to conduct oil from the inside of the crown to the outside of the crown, the conduits having each at least one portion inclined relative to the radial direction.

[0033] For example, the conduits may each be parallel to a plane perpendicular to the axial direction, and be inclined in whole or in part with respect to the radial direction within said perpendicular plane. According to another example, the conduits may each be parallel to a so-called radial plane, extending radially and comprising the axis of revolution of the crown or of the satellite carrier, and be inclined in whole or in part with respect to the radial direction within the radial plane (i.e. form an angle strictly less than 90° with the axial direction). According to yet another example, the conduits may each be inclined in the radial direction according to a combination of the two preceding examples.For example, the casing may comprise two parts forming two half-casings and assembled together via two respective radial flanges and each having a joint plane extending perpendicular to the axial direction, the ducts being formed by the two flanges, for example in the two joint planes.

[0034] One embodiment relates to an aeronautical propulsion assembly comprising a speed reduction device according to any one of the embodiments described in the present disclosure. Brief description of the drawings

[0035] The object of the present disclosure and its advantages will be better understood upon reading the detailed description given below of different embodiments given as non-limiting examples. This description refers to the appended pages of figures, in which:

[0036] [Fig-1] [Fig.l] represents an aircraft equipped with a propulsion unit for aircraft,

[0037] [Fig.2] [Fig.2] schematically represents a sectional view of the aircraft propulsion unit of [Fig.l],

[0038] [Fig.3] [Fig.3] schematically represents a radial sectional view of the speed reducer of the aircraft propulsion unit of [Fig.2],

[0039] [Fig.4] [Fig.4] schematically represents an axial sectional view of the speed reducer of the aircraft propulsion unit of [Fig.2]

[0040] [Fig.5] [Fig.5] shows several variants of relief shapes and patterns,

[0041] [Fig.6] [Fig.6] shows a variant of the casing comprising a single pattern of reliefs,

[0042] [Fig.7] [Fig.7] represents a variant of casing comprising two distinct patterns, and

[0043] [Fig.8] [Fig.8] represents a form of gutter days. Description of the embodiments

[0044] [Fig. 1] represents an aircraft 100, in this example an airplane, equipped with two turbomachines 50, in this example two aeronautical propulsion units 50, in this example two turbojets 50, namely one turbomachine 50 per wing 101, a single turbomachine 50 and a single wing 101 being represented in [Fig. 1]. According to a variant, the aircraft 100 can be equipped with more than one turbomachine 50 per wing 101, each wing 101 being provided with the same number of turbomachines 50.

[0045] [Fig. 2] represents a schematic sectional view of the turbomachine 50, according to plane II of [Fig. 1]. The turbomachine 50 comprises a fan 52, which may be ducted or unducted, and a gas generator 54 (in the example of [Fig. 1] the fan 52 being ducted). In this example, the gas generator 54 comprises, from upstream to downstream, the gases flowing within the turbomachine 50 from upstream to downstream, a compressor 54A (or compressor section 54A), a combustion chamber 54B, and a turbine 54C (or turbine section 54C). In this example, the fan 52 may be driven in rotation by a shaft of the gas generator 54, for example a shaft of a low-pressure body, via a speed reducer 10.

[0046] The gas generator 54 may be of the double-body type and comprise a low-pressure body 60A and a high-pressure body 60B. The low-pressure body 60A may comprise a low-pressure compressor 62A rotatably coupled with a low-pressure turbine 66A via a low-pressure shaft 63A. The high-pressure body 60B may comprise a high-pressure compressor 62B disposed downstream of the low-pressure compressor 62A and upstream of the combustion chamber 54B, and a high-pressure turbine 66B, disposed downstream of the combustion chamber 54B and upstream of the low-pressure turbine 66A, and rotatably coupled with the high-pressure compressor 62B via a high-pressure shaft 63B. The compressor 54A of the gas generator 54 may comprise the low- and high-pressure compressors 62A and 62B. The turbine 54C of the gas generator 30 may comprise the low and high pressure turbines 66A and 66B. [Fig.2] is schematic, each compressor and each turbine being able to have one or more stages, each stage comprising a moving wheel and a stator or rectifier.

[0047] [Fig. 3] represents a sectional view of the speed reducer 10 along plane III of [Fig. 2]. [Fig. 4] represents the reducer 10 along a section IV of [Fig. 3]. Subsequently, and unless otherwise indicated, the reducer 10 is described with reference to FIGS. 3 and 4. The reducer 10 comprises a crown 10A, a sun gear 10B, at least one satellite gear 10C rotatably mounted on a satellite carrier 10D. The reducer 10 may be of the planetary or epicyclic type. In this example, the reducer 10 comprises three satellite gears 10C, but the reducer 10 may comprise fewer than three satellite gears or more than three satellite gears. The diameter DI of the crown 10A is greater than the diameter D2 of the sun gear 10B. For the readability of [Fig. 3], the teeth of the crown 10A, the sun pinion 10B, and the at least one satellite pinion 10C are not shown. The at least one satellite pinion 10C meshes with the sun pinion 10B and the crown 10A. The sun pinion 10B rotates around the axis X of the reducer 10, which in this example coincides with the axis of the propulsion assembly 50 when the reducer 10 is mounted within the propulsion assembly 50.

[0048] The reducer 10 comprises an oil supply circuit 30, configured to supply oil to at least one element among the sun gear 10B, the crown 10A, the at least one satellite gear 10C and the satellite carrier 10D, for example for the lubrication and / or cooling of all or part of the bearings and / or the teeth of this at least one element.

[0049] The reducer 10 comprises an annular casing 12 housing the crown 10A, the sun gear 10B, the at least one satellite gear 10C and the satellite carrier 10D. The annular casing 12 has a radially internal face 12A facing the crown 10A. The casing 12 may have a radially external face 12B, which may for example delimit a radially internal portion of a primary gas stream, i.e. the gas stream circulating in the gas generator 54, and be in direct contact with the gases circulating from the fan 52 to the low-pressure compressor 54A.

[0050] The casing 12 has an oil collector 13, in this example a single collector 13, comprising an oil discharge orifice 13A, in this example a single orifice 13A. Considered in the direction of gravity G, gravity G being oriented from the top H to the bottom B, the oil collector 13 is arranged in a lower part 12BA of the casing 12. For example, the casing 12 has a median plane PM perpendicular to the direction of gravity G and comprising the axis of rotation X of the planet carrier or the crown wheel, and considered in the orientation of gravity G, the part of the casing arranged above this median plane PM forms an upper part 12HA of the casing 12 and the part of the casing arranged below this median plane PM forms the lower part 12BA of the casing 12. The oil collector 13 is configured to discharge the oil by gravity. For example, as seen in [Fig.4], the casing 12 may have a concave shape with a concavity oriented radially inwards (i.e. towards the axis X). For example, the orifice 13A is provided at the lowest point of the casing 12 considered in the direction of Earth gravity G, Earth gravity G being oriented from top to bottom, in the bottom of the concave or semi-toric shape of the casing 12. The oil supply circuit 13 may be configured to recover the oil from the collector 13, for example via a recovery pipe 30A and to reinject oil into the reducer 10 towards the at least one element among the sun gear 10B, the crown 10A, the at least one satellite gear 10C and the satellite carrier 10D, for example via an injection pipe 30B. For example, the circuit 30 may comprise an oil circulation pump 30C. Circuit 30 can also distribute oil to . other components of the propulsion assembly 50, but not necessarily. The circuit 30 may include a heat exchanger (not shown) for cooling and / or heating the oil, but not necessarily.

[0051] The radially internal face 12A of the annular casing 12 is provided with a plurality of reliefs 14 distributed along the circumferential direction C. The plurality of reliefs 14 is configured to circulate the oil coming from the at least one element among the sun gear 10B, the crown 10A, the at least one satellite gear 10C and the satellite carrier 10D, and received by the radially internal face 12A, along the radially internal face 12A along the circumferential direction C, to the oil collector 13.

[0052] For example, as shown in [Fig. 3], each relief 14 of the plurality of reliefs may consist of a projection extending radially (i.e. in the radial direction R) inwards from the radially inner face 12A.

[0053] For example, each projection has a radial thickness E less than or equal to 40.00 mm, for example less than or equal to 25.00 mm, and greater than 0.10 mm. For the purposes of the present disclosure, the radial thickness E is understood as the maximum thickness of the relief 14, in a cross-section normal to the radially internal face 12A.

[0054] For example, the reliefs 14 of the plurality of reliefs may all be arranged at positions distinct from the position of the oil collector 13, in particular from the orifice 13A.

[0055] For example, each relief 14 of the plurality of reliefs may have the shape of a continuous or broken rectilinear line, a curved line, a spike, a star, a grain of rice, etc. In the example shown in Figures 3 and 4, the reliefs have the shape of a grain of rice. For example, the plurality of reliefs may form at least one regular pattern. In the example shown in Figures 3 and 4, the plurality of reliefs form a pattern of grains of rice M9.

[0056] [Fig. 5] shows several variants of relief shapes and patterns. In the left column (or first column), the reliefs are seen in development along the circumferential direction C, from the inside of the casing 12, the axial X and circumferential C directions being indicated. In the right column (or second column) is shown the shape of the cross-section of the relief of the left column on the corresponding line, the radial direction R being indicated. In the examples shown, the reliefs 14 each have an evolving shape that tapers from the radially internal face 12A to the radial end 14' (see right column). The shape of the cross-section of the reliefs may have rectilinear or curved sides, and / or have a regular or irregular geometric shape.

[0057] In the examples of the first and second lines of [Fig. 5], the reliefs 14a and 14b have a curved line shape (see left column), in this example in the form of an arc, and form curved line patterns. In the first line, the pattern M1 comprises two rows symmetrical to each other according to the axial direction X, the rows extending in the circumferential direction C. In the second row, the pattern M2 comprises two rows symmetrical to each other in the axial direction X, the rows extending in the circumferential direction C.

[0058] In the examples of the third, sixth and seventh lines of [Fig. 5], the reliefs 14c, 14f and 14g have a rectilinear line shape (see left column), in this example in the form of a segment. In these examples, the reliefs form patterns of discontinuous rectilinear lines. In the third line, the pattern M3 comprises five rows of reliefs 14c symmetrical to each other in the axial direction X relative to the central row, the rows extending in the circumferential direction C. In this example, the pattern alternates in the axial direction X rows of reliefs 14c extending parallel to the circumferential direction C and rows of reliefs 14c extending at a non-zero angle with the circumferential direction C, the latter all having the same orientation.In the sixth line, the pattern M6 comprises two rows of reliefs 14f symmetrical to each other along the axial direction X, the rows extending along the circumferential direction C. In this example pattern, the reliefs 14f extend at a non-zero angle with the circumferential direction C, all the reliefs 14f having the same orientation. In the seventh line, the pattern M7 comprises five rows of reliefs 14g symmetrical to each other along the axial direction X, the rows extending along the circumferential direction C. In this example pattern, the reliefs 14g extend parallel to the circumferential direction C.

[0059] In the example of the fourth row of [Fig. 5], the reliefs 14d have a star shape (see left column), and together form a star pattern M4. Such a star pattern can have a "tranquilizing" effect on the oil flow, and separate / break up oil "packets" greater than a predetermined volume or size. In this example the stars are two-by-two orthogonal four-pointed stars, one pair of opposing points extending parallel to the circumferential direction C and another pair of opposing points extending parallel to the axial direction X. In this example, the stars are arranged in a staggered pattern within the star pattern.

[0060] In the example of the fifth row of [Fig. 5], the reliefs 14e have a chevron or broken line shape (see left column), and together form a pattern M5 of chevrons or broken lines (a broken line shape not necessarily having a chevron shape). In this example, the pattern comprises a single row of chevrons, extending in the circumferential direction C, all the chevrons having the same orientation.

[0061] In the example of the eighth line of [Fig.5], the 14h reliefs present a straight line shape (see left column), in this example a continuous line, and together form an M8 pattern of straight lines, in this example a grid. In this example, the grid is a regular grid, comprising a series of 14h reliefs extending parallel to the circumferential direction C and a series of 14h reliefs extending parallel to the axial direction X. Such a grid can "calm" the oil flow and prevent splashing.

[0062] In the examples of the reliefs 14a, 14b, 14c, 14f, 14g and 14h of the first, second, third, sixth, seventh and eighth lines of [Fig. 5], the shape of the cross-section (see right-hand column), normal to the radially internal face 12A, of the reliefs has a trapezoidal shape, for example an isosceles trapezoidal shape, the large side of the two parallel sides of the trapezoid being arranged on the side of the radially internal face 12A. The dimensions of these sections can vary from one shape to another.

[0063] In the example of the star-shaped relief 14d of the fourth line of [Fig. 5], the cross-section (see right-hand column) has a pyramidal shape with a first portion forming a wide base and a second portion surmounting the first portion in the radial direction R, forming a tapered apex (and narrow compared to the wide base). In this example, the base has the shape of a triangle with a truncated apex and the tapered apex has the shape of a triangle whose height is greater than the side forming the junction with the base.

[0064] In the example of chevron-shaped relief 14e of the fifth line of [Fig.5], the cross-section (see right-hand column) has a polygonal shape, the base being wider than the top. Such a shape can be adjusted at the time of design according to the angle of incidence intended for the oil projections. It is understood that the direction of rotation of the rotating elements of the reducer can influence this angle of incidence. Thus a relief shape can be adapted to suit a given direction of rotation and not suit the reverse direction of rotation.

[0065] [Fig. 6] represents a developed view of an example of the radially internal face 12A. In this variant, the reliefs 14 all have a chevron shape and form a single pattern M. For example, all the chevrons have the same orientation. Any other shape of pattern is conceivable instead of the chevron pattern, in particular the patterns shown in [Fig. 5] or the rice grain patterns of [Fig. 4].

[0066] [Fig. 7] represents a developed view of another example of the radially internal face 12A. In this variant, the reliefs 14 all have a chevron shape and form two distinct patterns, namely a pattern MA and a pattern MB. In this example, within each pattern, the shape of each relief is oriented towards the collector 12, for example towards the orifice 13A, along the most circumferential path short. For example, in the MA pattern all the chevrons have the same first orientation while in the MB pattern all the chevrons have the same second orientation, opposite to the first orientation. In this example, the plane PI is an axial plane extending parallel to the X axis and containing the X axis, the axial plane PI passing through the oil collector 13, in this example through the geometric center of the orifice 13A. The reliefs 14 of the plurality of reliefs are in this example arranged symmetrically with respect to the axial plane PI. Any other form of pattern is conceivable instead of the chevron pattern, in particular the patterns shown in [Fig.5] or the rice grain patterns of [Fig.4].

[0067] In the examples of Figures 4, 6 and 7, a radial plane P2 extends perpendicular to the axis X. In this example, the radial plane P2 can pass through the geometric center of the orifice 13A. The reliefs 14 of the plurality of reliefs can be arranged symmetrically with respect to the radial plane P2. Any other form of pattern is conceivable instead of the patterns shown in Figures 4, 6 and 7, in particular the patterns shown in [Fig. 5] (where the plane P2 is shown for information purposes and in a non-limiting manner).

[0068] With reference to [Fig. 3], the reducer 10 may comprise an intermediate gutter 16 arranged radially between the casing 12 and the crown 10A, the gutter 16 being perforated. For example, the gutter 16 may comprise a plurality of holes 16A regularly distributed along the circumferential direction C. An example of the shape of the holes is visible in [Fig. 8] which represents a partial developed view of the gutter 16. The holes 16A may have a parallelogram shape with rounded or broken corners.

[0069] Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes may be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various illustrated / mentioned embodiments may be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

Claims

Claims

1. Speed ​​reduction device (10) for an aeronautical propulsion unit (50), the speed reduction device (10) comprising a crown (10A), a sun gear (10B) and at least one satellite gear (10C) rotatably mounted on a satellite carrier (10D), the diameter (D1) of the crown (10A) being greater than the diameter (D2) of the sun gear (10B), an oil supply circuit (30) for at least one element among the sun gear (10B), the crown (10A), the at least one satellite gear (10C) and the satellite carrier (10D), and an annular casing (12) housing the crown (10A), the sun gear (10B), the at least one satellite gear (10C) and the satellite carrier (10D), the annular casing (12) having a radially internal face (12A) facing the crown (10A) and an oil collector (13) comprising an oil discharge orifice (13A), in which, considered in the direction of gravity (G),gravity being oriented from the top (H) to the bottom (B), the oil collector (13) is arranged in a lower part (12BA) of the casing (12) and configured to evacuate the oil by gravity, the radially internal face (12A) of the annular casing (12) comprising a plurality of reliefs (14) distributed in the circumferential direction (C), the plurality of reliefs (14) being configured to circulate the oil coming from the at least one element and received by the radially internal face (12A), along the radially internal face (12A) to the oil collector (13).,

2. A speed reduction device (10) according to claim 1, wherein each relief (14) of the plurality of reliefs consists of a projection extending radially inwardly from the radially inner face (12A).

3. Speed ​​reduction device (10) according to claim 2, wherein each projection has a radial thickness (E) less than or equal to 40.00 mm, for example less than or equal to 25.00 mm, and greater than 0.10 mm.

4. A speed reduction device (10) according to any one of claims 1 to 3, wherein the reliefs (14) of the plurality of reliefs are all arranged at positions distinct from the position of the oil collector (13).

5. Speed ​​reduction device (10) according to any one of claims 1 to 4, wherein the plurality of reliefs (14) forms at least one regular pattern (M; MA, MB), for example a pattern in herringbone (M5), a broken line pattern (M5), a spike pattern, a star pattern (M4), a curved line pattern (M1, M2), a straight line pattern (M3, M6, M7, 8), a rice grain pattern (M9), or any combination of these shapes.

6. Speed ​​reduction device (10) according to any one of claims 1 to 5, in which the reliefs (14) of the plurality of reliefs each have a radial end (14'), the reliefs (14) each having an evolving shape tapering from the radially internal face (12A) to the radial end (14').

7. A speed reduction device (10) according to any one of claims 1 to 6, comprising an axis (X) and an axial plane (PI) extending parallel to the axis (X) and containing the axis (X), the axial plane (PI) passing through the oil collector (13), the reliefs (14) of the plurality of reliefs being arranged symmetrically with respect to the axial plane (PD-

8. A speed reduction device (10) according to any one of claims 1 to 7, comprising an axis (X) and a radial plane (P2) extending perpendicular to the axis (X), the reliefs (14) of the plurality of reliefs being arranged symmetrically with respect to the radial plane (P2).

9. Speed ​​reduction device (10) according to any one of claims 1 to 8, comprising an intermediate gutter (16) arranged radially between the casing (12) and the crown (10A), the gutter (16) being perforated.

10. An aeronautical propulsion assembly (50) comprising a speed reduction device (10) according to any one of claims 1 to 9.

Images