Speed ​​reduction device comprising a housing with oil guide reliefs, and aeronautical propulsion assembly comprising such a device

Abstract

Speed ​​reduction device (10) for an aeronautical propulsion assembly, comprising a ring gear (10A), a sun gear (10B) and at least one satellite gear (10C), an oil supply circuit (30) of at least one element among the sun gear (10B), the ring gear (10A), the at least one satellite gear (10C) and the satellite carrier (10D), and an annular housing (12) housing the ring gear (10A), the sun gear (10B), the at least one satellite gear (10C) and the satellite carrier (10D), the annular housing (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 along the circumferential direction (C) Figure for the abstract: Fig. 3.

Description

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

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

[0002] In this description, the term "aeronautical propulsion system" refers to all turbomachinery or gas turbine devices producing motive power, dedicated to the propulsion of an aircraft and equipped with or without a nacelle. Among these devices, a distinction is made in particular between turbojets, which provide the thrust necessary for propulsion by reaction to the high-speed ejection of gas, and turboshaft engines, in which motive power is provided by the rotation of a drive shaft. For example, turboshaft engines are used as helicopter engines. Turboprop engines (turboshafts driving a propeller) are turboshaft engines used as aircraft engines. Previous technique

[0003] Various speed reduction devices for aeronautical propulsion assemblies are known, for example from FR3095243 or FR3041054. However, the oil circuit for lubricating and / or cooling the rotating elements within the speed reduction devices is constantly being improved, particularly with regard to oil recovery, oil recirculation, thermal performance and / or mass. Description of the invention

[0004] One embodiment relates to a speed reduction device for an aeronautical propulsion assembly, the speed reduction device comprising a ring gear, a sun gear, and at least one satellite gear rotatably mounted on a satellite carrier, the diameter of the ring gear being greater than the diameter of the sun gear, an oil supply circuit for at least one element among the sun gear, the ring gear, the at least one satellite gear, and the satellite carrier, and an annular housing accommodating the ring gear, the sun gear, the at least one satellite gear, and the satellite carrier, the annular housing having a radially internal face opposite the ring gear and an oil collector comprising an oil drain port, wherein, considered along the direction of gravity, with gravity oriented from top to bottom, the oil collector is disposed in a lower part of the housing and configured to evacuate the oil by gravity, the radially internal face of the annular casing comprises a plurality of reliefs distributed along the circumferential direction, the plurality of reliefs being configured to circulate the oil from 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, when the speed reduction device is mounted on a propulsion unit, corresponds 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 elevation, radius, and angle in a cylindrical coordinate system. Furthermore, upstream and downstream are defined with respect 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 with 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 system is, for example, a device configured to rotationally couple a drive shaft of a gas generator, for example a low-pressure casing shaft when the propulsion system comprises a low-pressure casing and a high-pressure casing, with a fan shaft, ducted or unducted, and configured to drive the fan shaft at a rotational speed lower than the rotational speed of the drive shaft. Hereinafter, and unless otherwise specified, "speed 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 one stage, two stages, or more than two stages.

[0008] According to a first embodiment, the reduction device may be of the planetary or "star" type and include a sun pinion, which forms the input of the reduction device. The axis of rotation of the sun pinion forms the axis of rotation of the reduction device and may coincide with the axis of the propulsion assembly. The sun pinion is configured to be driven in rotation by a drive shaft. The ring gear forms the output of the reduction device. The ring gear is coaxial with the sun pinion and configured to drive a blower shaft in rotation around the axis. Several satellites, or satellite gears, can be distributed circumferentially around the axis between the sun pinion and the ring gear. Each satellite is meshed with both the sun pinion and the ring gear. The satellites are mounted on a satellite carrier configured to be fixed relative to a stator portion of a propulsion assembly, for example, relative to a compressor upstream housing.

[0009] According to a second variant, the reduction device may be of the epicyclic or "planetary" type. In this case, compared to the planetary type according to the first variant, the ring gear is configured to be fixedly mounted on a stator portion of the propulsion assembly, and the propeller shaft is driven in rotation by the planet carrier (which is therefore rotatable relative to the stator portion of the propulsion assembly, for example, relative to a housing upstream of the compressor). The stator portions of the first and second variants may correspond to different parts of the same element, or to distinct elements.

[0010] Regardless of the configuration of the reduction device, the diameter of the ring gear is greater than the diameter of the satellite carrier, which is itself greater than the diameter of the solar pinion. The satellites are radially arranged between the solar pinion and the ring gear, and the output rotational speed is less than the input rotational speed.

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

[0012] The housing may comprise a single manifold or several manifolds. The manifold, or each manifold, may comprise a single orifice, or several orifices. Considered in the direction of gravity, in particular when the speed reduction device is mounted on an aeronautical propulsion assembly, in normal operating position (i.e. when the aircraft on which the propulsion assembly is mounted is in normal operating conditions, i.e. on the ground, in cruise flight, in takeoff phase or in landing phase), the manifold is located in the lower part of the housing.For example, the housing has a median plane perpendicular to the direction of gravity and encompassing the axis of rotation of the satellite carrier or ring gear. Considered in the direction of gravity, the portion of the housing located above this median plane forms the upper part of the housing, and the portion of the housing located below this median plane forms the lower part of the housing. In one variation, the upper / lower portions can extend over 25% of the housing's extent in the direction of gravity, from the highest / lowest point, respectively, of the housing considered in that direction. The manifold is configured so that the oil drains by gravity; that is, it flows naturally through the orifice due to gravitational pull.

[0013] Reliefs can be projecting or recessed and, considered individually, are distinct from deflectors (i.e., each relief does not by itself form a deflector The deflector alone is insufficient to guide the flow of oil. The reliefs are configured to act synergistically and, together, guide the circulation of oil sprayed onto the radially inner face by the rotation of the various lubricated rotating elements of the reduction device, along the entire length of the radially inner face, from the point of impact of the individual oil sprays to the manifold. For example, each relief can facilitate the adhesion of the oil sprays to the radially inner face upon impact, thus preventing potential rebounds of the sprays elsewhere within the reduction device. Such rebounds of oil sprays can lead to the recirculation of all or part of the oil sprays towards the rotating parts of the gearbox, which can induce undue energy losses and undesirable heating of the oil.Through a synergistic effect, the overall relief can then promote the flow of the oil thus recovered on the radially inner face towards the collector, for example towards the drain orifice, and "calm" an oil flow that might otherwise 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, during operation when the reduction device is mounted on an aeronautical propulsion assembly, to a temperature different from the temperature inside the casing and / or the oil temperature. The contours may promote heat exchange between the recovered oil spray 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 certain embodiments, each relief of the plurality of reliefs may consist of a projection extending radially inwards from the radially internal face.

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

[0017] According to one embodiment, the plurality of reliefs may also include 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, radially extending from one another. That is to say, the reliefs may extend radially on either side of the housing wall. This can increase the heat exchange surface area 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 oil cooling is improved. due to better heat dissipation 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 reliefs of the plurality of reliefs can all be arranged in positions distinct from the position of the oil collector.

[0021] For example, the ridges can 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 drain port. In other words, considered in the radial direction, the ridges do not extend in front of the oil collector, and in particular in front of the oil drain port of the oil collector. Such a configuration can optimize the efficiency of the oil collector by maximizing access to the collector from the enclosure delimited by the housing, while the ridges ensure the adhesion and guidance of oil spray received by the radially inner face of the housing.

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

[0023] Such patterns can improve the synergy of the reliefs and the effectiveness of the adhesion and guidance of the recovered oil. This can also improve cooling efficiency in the case of an annular housing where the outer radial face is cooler than the inner radial face.

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

[0025] For example, the evolving shape can be thinned when considered in a cross-section of the relief. Such a configuration can optimize the mass that the plurality of reliefs can represent, improve the adhesion and guidance of the oil spray received by the radially inner face of the housing, and / or allow for 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 the axial direction) and contains the axis. The axial plane may, for example, pass through the geometric center of the oil collector orifice. For example, such a configuration can optimize the gravity-driven guidance of the oil to the collector, for instance, with the reliefs oriented towards the collector (or towards the lowest point of the gearbox), that is, along the direction of the shortest circumferential path to reach the collector. Such a configuration can ensure a certain versatility of the reliefs, which can exhibit the same efficiency regardless of the direction of rotation of the gearbox's rotating elements.

[0028] In some embodiments, the speed reduction device may include an axis and a radial plane extending perpendicularly to the axis, the reliefs of 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 axial direction). The radial plane may, for example, pass through the geometric center of the oil collector orifice. For example, such a configuration may optimize the guidance of the oil by gravity towards the collector, for example, with the reliefs oriented circumferentially and / or axially towards the collector. For example, the housing may have a concave shape with the concavity oriented radially inwards, so that such a configuration of the reliefs may optimize the guidance of the oil towards the bottom of the concave shape, i.e., towards the point radially furthest from the axis of the radially inner face, which may further improve the guidance by gravity towards the collector, for example, towards the orifice (which may, for example, also be located in the bottom of the concave shape).

[0030] In some embodiments, the speed reduction device may include an intermediate gutter arranged radially between the housing and the crown, the gutter being perforated.

[0031] In other words, the gutter includes through-holes. The shape of the gutter's openings can be configured to guide oil spray towards predetermined impact zones on the radially inner face of the housing, for example, areas where the contours extend. Generally, the gutter can be perforated to optimize oil circulation within the reduction device.

[0032] In certain embodiments, the ring is rotating and has a plurality of radially extending through conduits configured to conduct oil from the inside of the ring to the outside of the ring, the conduits having each at least one portion inclined with respect to the radial direction.

[0033] For example, the conduits may each be parallel to a plane perpendicular to the axial direction and inclined wholly or partly 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 ring gear or satellite carrier, and inclined wholly or partly with respect to the radial direction within the radial plane (i.e., forming an angle strictly less than 90° with the axial direction). According to yet another example, the conduits may each be inclined along the radial direction according to a combination of the two preceding examples.For example, the housing may comprise two parts forming two half-housings and assembled together via two respective radial flanges, each having a parting plane extending perpendicularly to the axial direction, the conduits being formed by the two flanges, for example in the two parting planes.

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

[0035] The purpose of this presentation and its advantages will be better understood upon reading the detailed description below of various embodiments given by way of non-limiting examples. This description refers to the attached figure pages, on which:

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

[0037] [Fig.2] Fig.2 schematically represents a cross-sectional view of the aircraft propulsion assembly of Fig.1.

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

[0039] [Fig.4] The [Fig.4] schematically represents an axial cross-sectional view of the speed reducer of the aircraft propulsion assembly of the [Fig.2]

[0040] [Fig.5] Fig.5 represents several variants of relief shapes and motifs,

[0041] [Fig.6] Fig.6 represents a variant of the crankcase comprising a single motif of reliefs,

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

[0043] [Fig.8] The [Fig.8] represents a form of gutter openings. Description of the implementation methods

[0044] Figure 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 turbojet engines 50, namely one turbomachine 50 per wing 101, with only one turbomachine 50 and one wing 101 being shown in Figure 1. According to one variant, the aircraft 100 can be equipped with more than one turbomachine 50 per wing 101, each wing 101 being fitted with the same number of turbomachines 50.

[0045] Figure 2 shows a schematic cross-sectional view of the turbomachine 50, according to Figure 1. The turbomachine 50 comprises a fan 52, which may be shrouded or unshrouded, and a gas generator 54 (in the example of Figure 1, the fan 52 is shrouded). In this example, the gas generator 54 comprises, 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 can 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 twin-spool type and comprise a low-pressure spool 60A and a high-pressure spool 60B. The low-pressure spool 60A may comprise a low-pressure compressor 62A rotationally coupled to a low-pressure turbine 66A via a low-pressure shaft 63A. The high-pressure spool 60B may comprise a high-pressure compressor 62B located downstream of the low-pressure compressor 62A and upstream of the combustion chamber 54B, and a high-pressure turbine 66B located downstream of the combustion chamber 54B and upstream of the low-pressure turbine 66A, and rotationally coupled to the high-pressure compressor 62B via a high-pressure shaft 63B. The compressor 54A of the gas generator 54 may comprise the low-pressure and high-pressure compressors 62A and 62B. The turbine 54C of the gas generator 30 can include the low and high pressure turbines 66A and 66B. The [Fig.2] is schematic, each compressor and each turbine being able to have one or more stages, each stage comprising a rotating wheel and a stator or rectifier.

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

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

[0049] The reducer 10 comprises an annular housing 12 accommodating the ring gear 10A, the sun gear 10B, at least one planet gear 10C and the planet carrier 10D. The annular housing 12 has a radially internal face 12A opposite the ring gear 10A. The housing 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 flowing in the gas generator 54, and be in direct contact with the gases flowing from the blower 52 to the low-pressure compressor 54A.

[0050] The housing 12 has an oil collector 13, in this example a single collector 13, comprising an oil drain port 13A, in this example a single port 13A. Considered along the direction of gravity G, with gravity G oriented from the top H to the bottom B, the oil collector 13 is located in a lower portion 12BA of the housing 12. For example, the housing 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 ring gear, and considered along the orientation of gravity G, the portion of the housing located above this median plane PM forms an upper portion 12HA of the housing 12 and the portion of the housing located below this median plane PM forms the lower portion 12BA of the housing 12. The oil collector 13 is configured to drain the oil by gravity. For example, as can be seen in the [Fig.[4], the housing 12 may have a concave shape with the concavity oriented radially inwards (i.e., towards the X-axis). For example, the orifice 13A is provided at the lowest point of the housing 12 considered in the direction of Earth's gravity G, Earth's gravity G being oriented from top to bottom, in the bottom of the concave or semi-toric shape of the housing 12. The oil supply circuit 13 may be configured to recover oil from the manifold 13, for example via a recovery line 30A, and to reinject oil into the reduction gear 10 towards at least one element among the sun gear 10B, the ring gear 10A, at least one planet gear 10C, and the planet carrier 10D, for example via an injection line 30B. For example, the circuit 30 may include an oil circulation pump 30C. Circuit 30 can also distribute oil to . Other components of the propulsion assembly 50 may be included, but not necessarily. The circuit 30 may include a heat exchanger (not shown) to cool and / or heat the oil, but not necessarily.

[0051] The radially internal face 12A of the annular housing 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 from at least one element among the solar pinion 10B, the ring 10A, at least one satellite pinion 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 can consist of a projection extending radially (i.e. along the radial direction R) inwards from the radially internal 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 this description, the radial thickness E is understood to be 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 can all be arranged in 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 form of a continuous or broken straight 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 rice grains M9.

[0056] Figure 5 shows several variations of relief shapes and patterns. In the left-hand column (or first column), the reliefs are shown in development along the circumferential direction C, from inside the housing 12, with the axial direction X and circumferential direction C indicated. In the right-hand column (or second column), the shape of the cross-section of the relief in the left-hand column is shown on the corresponding line, with the radial direction R indicated. In the examples shown, the reliefs 14 each exhibit a tapering shape from the radially internal face 12A to the radial end 14' (see right-hand column). The shape of the cross-section of the reliefs may have straight or curved sides, and / or a regular or irregular geometric shape.

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

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

[0059] In the example in 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 "calming" effect on the oil flow and separate / break up oil "clumps" exceeding a predetermined volume or size. In this example, the stars are four-pointed stars, orthogonal in pairs, with one pair of opposite points extending parallel to the circumferential direction C and another pair of opposite 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 along the circumferential direction C, all the chevrons having the same orientation.

[0061] In the example of the eighth line of [Fig. 5], the reliefs 14h present a The straight line shape (see left column), in this example a continuous line, 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 flow of oil and prevent splashing.

[0062] In the examples of reliefs 14a, 14b, 14c, 14f, 14g and 14h of the first, second, third, sixth, seventh and eighth rows of [Fig.5], the shape of the cross-section (see right column), normal to the radially internal face 12A, of the reliefs has a trapezoidal shape, for example an isosceles trapezoidal shape, the longer side of the two parallel sides of the trapezoid being disposed 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 in the fourth row 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 (which is narrow relative to the wide base). In this example, the base has a truncated triangular shape, and the tapered apex has a triangular shape whose height is greater than the side forming the junction with the base.

[0064] In the example of the chevron-shaped relief 14e in the fifth row of [Fig. 5], the cross-section (see right-hand column) has a polygonal shape, with the base being wider than the apex. Such a shape can be adjusted during the design phase according to the intended angle of incidence for oil spray. It is understood that the direction of rotation of the rotating elements of the gearbox can influence this angle of incidence. Thus, a relief shape can be adapted to suit a given direction of rotation but not to the opposite direction.

[0065] Figure 6 shows 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 motif M. For example, all the chevrons have the same orientation. Any other motif shape is conceivable instead of the chevron motif, in particular the motifs shown in Figure 5 or the rice grain motifs of Figure 4.

[0066] Figure 7 shows 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 pattern MA all the chevrons have the same first orientation, while in pattern MB all the chevrons have the same second orientation, opposite to the first. In this example, plane PI is an axial plane extending parallel to and containing the X-axis, axial plane PI passing through the oil collector 13, in this example through the geometric center of orifice 13A. The reliefs 14 of the plurality of reliefs are in this example arranged symmetrically with respect to axial plane PI. Any other pattern shape is conceivable in place of the chevron pattern, in particular the patterns shown in [Fig. 5] or the rice grain patterns of [Fig. 4].

[0067] In the examples in Figures 4, 6, and 7, a radial plane P2 extends perpendicularly to the X-axis. In this example, the radial plane P2 may pass through the geometric center of the opening 13A. The reliefs 14 of the plurality of reliefs may be arranged symmetrically with respect to the radial plane P2. Any other form of motif is conceivable in place of the motifs shown in Figures 4, 6, and 7, in particular the motifs shown in [Fig. 5] (where plane P2 is shown by way of illustration and not limitation).

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

[0069] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can 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 embodiments illustrated / mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered in an illustrative rather than a 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.

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