Lubricating oil recovery gutter for mechanical gearbox including an improved deflector

Abstract

Lubricating oil recovery gutter for mechanical gearbox comprising an improved deflector. Lubricating oil recovery gutter (100), particularly for mechanical gearbox of aircraft turbomachinery, comprising an annular main body (101) about a central axis (X), and a deflector (300) fixed to the main body and configured to allow the oil to be evacuated radially from an internal cavity of the main body (101) to the outside of the gutter, the deflector (300) comprising a main sleeve (330) disposed in continuity with the main body (101), and a discharge channel (310) configured to deflect oil from the main sleeve (330) and having a curved shape such that a first end (311) of the discharge channel, communicating with the internal cavity, is tangent to the main body (101),and a second end (312) of the discharge channel is directed outwards relative to the annular main body (101). Figure for the abbreviation: Fig. 4.

Description

Title of the invention: Lubricating oil recovery gutter for a mechanical gearbox comprising an improved deflector technical field

[0001] The present exposition relates to the field of mechanical gearboxes for aircraft turbomachinery, such as planetary gearboxes, among others. The present exposition relates in particular to a lubrication oil recovery trough for such a mechanical gearbox, comprising a deflector, and a power transmission device comprising such a mechanical gearbox and such a trough. Previous technique

[0002] Mechanical reducers are commonly used in mechanics, particularly in the field of aeronautics. Their role is to modify the speed and torque ratio between an input shaft and an output shaft of a mechanical system.

[0003] New generations of multiflow turbomachinery, particularly those with a high bypass ratio, include a mechanical gearbox to drive the shaft of a fan or propeller. Typically, the gearbox transforms the high rotational speed of the power turbine shaft into a slower rotational speed for the fan-driving shaft.

[0004] Such a reduction gear conventionally comprises a central pinion, called the "sun pinion," an outer ring gear, and pinions, called "satellite pinions," which mesh between the sun pinion and the outer ring gear. The satellite pinions are held by a frame called a planet carrier. The sun pinion, the outer ring gear, and the planet carrier are planetary components because their axes of revolution coincide with the longitudinal axis of the turbomachine. In contrast, the planet gears each have an axis of revolution different from the axis of revolution of the turbomachine, and are distributed at regular intervals around the same operating diameter of the planetary gears. These axes of the planet gears are parallel to the longitudinal axis of the turbomachine.

[0005] Several mechanical gearbox architectures exist. Known mechanical gearboxes used in turbofan engines are of the planetary or epicyclic type. Differential architectures also exist. These different types of mechanical gearboxes are distinguished as follows: - On a planetary gearbox, the planet carrier is fixed and the outer ring gear forms the output shaft of the device, which rotates in the opposite direction to the pinion solar. - On an epicyclic reducer, the outer ring is fixed and the planet carrier constitutes the output shaft of the device, which rotates in the same direction as the solar pinion. - On a differential gearbox, no element is fixed for rotation. The outer ring rotates in the opposite direction to the solar pinion and the satellite carrier.

[0006] In a planetary gearbox, in particular, the lubricating and cooling oil used to lubricate the various gears of the gearbox is generally discharged by centrifugal force through radial channels formed in a flange of the outer ring gear. To prevent the oil from being projected outwards and to limit losses, it is known to use oil recovery gutters arranged around the flange of the outer rings, allowing the oil projected by centrifugal force to be collected.

[0007] However, existing oil channels do not allow for satisfactory oil recovery. In particular, some channels do not retain the oil, which can then fall back onto the rotating parts of the gearbox by gravity. Other channels may partially retain the oil, but cannot prevent a significant amount of oil from rebounding off the channel walls due to centrifugal acceleration and the tangential ejection velocity of the oil, and falling back onto the rotating parts. When oil contained by a channel falls back onto a rotating part (the ring gear, the ring gear carrier, the ring gear flange, for example), it can cause significant momentum losses.Similarly, the deflectors positioned at the bottom of the gutter, which are intended to guide oil from the main part of the gutter to a suction point, do not allow for sufficiently efficient oil collection.

[0008] There is therefore a need for a gutter that can remedy at least partially the aforementioned disadvantages. Description of the invention

[0009] The present description relates to a lubrication oil recovery trough, particularly for a mechanical gearbox of an aircraft turbomachine, comprising an annular main body about a central axis, and a deflector fixed to the main body and configured to allow the oil to be evacuated radially from an internal cavity of the main body to the outside of the trough, the deflector comprising a main sleeve disposed in continuity with the main body, and a discharge channel configured to divert oil from the main sleeve and having a curved shape such that a first end of the discharge channel, com communicating with the internal cavity, is tangent to the main body, and a second end of the evacuation channel is directed outwards relative to the annular main body.

[0010] It is understood that the second end of the discharge channel is directed radially outwards, or in a substantially radial direction outwards relative to the main annular body.

[0011] In the present description, the terms "radial", "axial", "tangent" and their derivatives are considered with respect to the central axis of the main annular body of the gutter, or the main axis of rotation of the mechanical speed reducer described later. Thus, a radial direction is a direction perpendicular to the central axis, and the expression "outward" or "radially outward" means that the oil is discharged radially away from the central axis.

[0012] Similarly, the terms "top," "bottom," "lower," "upper," and their derivatives are considered with respect to a vertical direction, corresponding to the normal direction of gravity. It is therefore understood that the deflector is preferably fixed to a lower portion of the main body, so as to collect the oil flowing downwards into the internal cavity of the main body.

[0013] It is understood that the internal cavity of the main body is the cavity used to collect the oil projected by the mechanical reducer, and through which said recovered oil circulates. This recovered oil therefore flows downwards into the internal cavity, towards the deflector.

[0014] It is further understood that the main sleeve is arranged in continuity with the main body, having a radius of curvature equal to the radius of curvature of said main body. The main sleeve may be integral with the main body, and in other words, a portion of said main body, or it may be a separate part of the main body, attached to it.

[0015] Conversely, the discharge channel deviates with respect to the central sleeve, and therefore with respect to the main body. More precisely, the first end of the discharge channel is arranged in continuity with the main body, being tangent to it, and then deviates progressively, by its curved shape, from the first end to the second end.

[0016] It is thus understood that, in a front view of the gutter parallel to the central axis, the drainage channel has a first curvature, for example in the form of a circular arc, contained in a plane perpendicular to the central axis. In other words, the curvature of the drainage channel comprises a tangential component and a radial component allowing the oil to be progressively diverted from the main body towards the outside of the gutter.

[0017] This deflector architecture, and in particular the shape of the discharge channel, This system allows the lubricating oil to be gradually diverted and guided from the main body of the gutter to an external suction point, enabling the oil to be collected and reused. This gradual guidance limits the slowing of the oil flow and the risk of oil accumulation (known as the "clogging" effect) that could lead to gutter overflow. This improves the oil recovery rate and reduces losses.

[0018] In some embodiments, the curved shape of the discharge channel includes an axial component such that the discharge channel is configured to deflect oil from the main sleeve in the direction of the central axis.

[0019] It is thus understood that, in a top view of the deflector perpendicular to the central axis, the discharge channel has a second curvature contained in a plane parallel to the central axis. In other words, the curvature of the discharge channel comprises a tangential component, an axial component, and a radial component, allowing the oil to be progressively diverted from the internal cavity of the main body, laterally relative to the main body and relative to the main sleeve, and then radially towards the outside of the gutter.

[0020] This configuration further improves the oil recovery rate and reduces losses by positioning the outlet of the recovered oil in the gutter as close as possible to, and directly opposite, the suction point. The axial component thus provides flexibility in integrating the gearbox within the housing surrounding it by placing the oil outlet vertically above the suction point. Furthermore, this frees up space under the deflector, allowing for the installation of a mounting flange to secure the gutter to a housing via the deflector.

[0021] In certain embodiments, an oil deflection angle of the discharge channel relative to the main sleeve is an angle between a first line tangent to the annular main body and perpendicular to the central axis, and a second line connecting a first point on a mean curvature line of the discharge channel to a second point disposed along said mean curvature line, the first point belonging to the first line and being disposed at the first end of the discharge channel and the second point being located at a distance D from the first point where 0 < D < 30 mm, the deflection angle being less than 40°.

[0022] It is understood that the deflection angle defines the lateral, or tangential (i.e., the deflection relative to the tangent to the main body), deflection of the discharge channel relative to the main sleeve, or relative to the main body. This deflection angle value of less than 40° allows for the gradual guidance of the oil as it passes from the internal cavity of the main body of the gutter towards the inlet. of the discharge channel, limiting the turbulence generated during this diversion and thus improving the efficiency of oil recovery.

[0023] In certain embodiments, a distance B between the first end and the second end of the discharge channel in a direction parallel to the central axis, and a distance C between said first and second ends in a direction perpendicular to the central axis and to a radial direction of the main annular body, are such that B < C. This relationship B < C allows for progressive guidance of the oil, thus further improving the efficiency of the oil recovery.

[0024] In some embodiments, the discharge channel has, between the first end and the second end, a closed section S.

[0025] It is understood that, regardless of the cross-sectional area S of the drainage channel considered between the inlet and outlet of said channel, said cross-section S is closed. In other words, the drainage channel has no opening between its first and second ends, so that the oil cannot escape during its passage through the drainage channel. This improves the efficiency of guiding the oil out of the gutter. Preferably, the cross-sectional area of ​​the drainage channel is sized according to the oil flow rate to be recovered, to ensure a flow velocity of between 1.5 and 5 m / s in the channel when it is saturated.

[0026] In certain embodiments, in a view parallel to the central axis, an angle [3 between a line passing through the central axis and the first end of the evacuation channel, and a line passing through the central axis and the second end of the evacuation channel, is such that 5° < [3 < 120°.

[0027] It is understood that the view parallel to the central axis corresponds to a front view of the gutter. Furthermore, for the first and second ends, a central point is considered in the inlet and outlet sections of the discharge channel, respectively. The angle [3] is therefore the angular range over which the discharge channel extends in this front view. These values ​​allow for the gradual guidance of the oil between its intake by the deflector and its radial ejection outwards from the gutter.

[0028] In some embodiments, the main sleeve contains an internal enclosure communicating with the internal cavity of the main body of the gutter, a radial separating wall dividing the internal enclosure into a first oil collection chamber in fluidic communication with the discharge channel, and a second oil collection chamber comprising a bottom wall having a discharge opening.

[0029] Preferably, the first collection chamber forms the first end of the discharge channel, that is, the portion of the discharge channel arranged in continuity with the internal cavity of the main body and tangent to the main body. In other In terms, the first end of the discharge channel coincides with the main sleeve, before the discharge channel deviates from said main sleeve towards the second end of the discharge channel.

[0030] It is thus understood that the radial separation wall, which is a wall extending in a radial plane perpendicular to the central axis, allows for a hermetic and axial separation of the first and second chambers, such that a portion of the oil flowing into the internal cavity of the main body towards the deflector is diverted on one side of the radial wall towards the first chamber, i.e., towards the drain channel, and another portion of the oil is diverted towards the second chamber and discharged from the latter through the drain opening. Thus, even if a larger quantity of oil is discharged through the drain channel, it is possible to recover some oil through the drain opening as well, thereby improving the recovery rate.

[0031] In some embodiments, the internal cavity of the main body of the gutter comprises an inlet chamber and an outlet cavity communicating with the inlet chamber over at least part of the circumference of the main body, the inlet chamber being configured to recover the lubricating oil from the reducer and divert it to the outlet cavity, the outlet cavity communicating with the first collection chamber and the inlet chamber communicating with the second collection chamber.

[0032] Since the inlet chamber diverts the oil projected by the reducer towards the discharge cavity, it is understood that most of the oil from said reducer flows towards the deflector via the discharge cavity, such that most of the oil collected in the main body of the gutter is discharged via the deflector's discharge channel. In other words, most of the oil collected by the gutter can benefit from the advantages of the deflector's design, being gradually guided towards the suction point via the discharge channel.

[0033] In addition, the portion of the oil remaining in the intake chamber, i.e. not having been diverted from the intake chamber to the evacuation cavity or having looped back into the evacuation cavity and having returned to the intake chamber, can also be evacuated to the outside via the second collection chamber and the evacuation opening.

[0034] In some embodiments, the main body includes a segregation wall separating the inlet chamber and the outlet cavity over a portion of the circumference of the main body upstream of the deflector.

[0035] It is understood that the discharge cavity communicates with the intake chamber over most of the circumference of the main body, except for a portion upstream of the deflector and adjacent to it, where the segregation wall prevents communication between the discharge cavity and the intake chamber.

[0036] Thus, the portions of oil flowing respectively into the inlet chamber and the outlet cavity are separated and isolated from each other by means of the segregation wall, even before their admission into the first and second collection chambers of the deflector. This makes it possible to further increase the quantity of oil discharged via the outlet channel, and thus further improve the recovery rate.

[0037] In certain embodiments, the main body comprises, in a cutting plane parallel to the central axis, a first radial wall extending radially with respect to the central axis, at least one inclined wall extending from an external radial end of the first radial wall, a guide portion having a general U-shape extending from an end of the inclined wall, and a second radial wall extending radially outwards with respect to the central axis from an end of the guide portion, a space delimited by the first radial wall, the second radial wall and the inclined wall forming the lubrication oil intake chamber, and a space delimited by the guide portion and the second radial wall forming the lubrication oil discharge cavity.

[0038] The first radial wall and the second radial wall extend radially, that is, perpendicularly to the central axis. In other words, the first radial wall and the second radial wall are annular walls extending in a radial plane perpendicular to the central axis. The first and second radial walls are therefore parallel to each other.

[0039] It is further understood that the inclined wall is inclined with respect to the first radial wall from which it extends, and therefore inclined with respect to the radial direction. The inclined wall thus has a frustoconical shape and flares outwards from the first radial wall.

[0040] Furthermore, it is understood that the guide portion extends from the inclined wall at one end to the second radial wall at another end. The U-shaped gutter may, in particular, have two lateral walls and a curved bottom. It is thus understood, according to these characteristics, that the main body of the gutter has the general shape of a "G" along the cross-sectional plane parallel to the central axis.

[0041] Thus, the presence of the first and second radial walls, parallel to each other, forms an inlet section that allows for the efficient recovery, in the intake chamber, of the lubricating oil projected when the recovery trough is arranged around a mechanical reducer. Furthermore, the inclined wall allows the ejected oil to be diverted towards the U-shaped guide portion, this the latter then guiding the oil, given its shape, towards the bottom of the drainage cavity formed between the guiding portion and the second radial wall.

[0042] The configuration of the main body of the lubricating oil recovery trough described herein, generally in the shape of a "G" or snail, thus improves the efficiency of recovering the oil ejected by the operating mechanical gearbox. This is achieved by preventing the oil from falling back onto the rotating parts of the gearbox by gravity, limiting the amount of oil rebounding off the trough walls, and efficiently guiding the oil towards the deflector. This makes it possible to limit gearbox efficiency losses due to momentum transfers of the oil, and therefore to further improve the recovery rate.

[0043] In some embodiments, the main sleeve has a first end fixed to a first circumferential end of the main body, and a second end fixed to a second circumferential end of the main body, the main sleeve comprising a circumferential separating wall separating the first end of the main sleeve from its second end.

[0044] It is understood that the annular main body forms an open ring, its two circumferential ends being connected by the main sleeve of the deflector to which they are attached. The circumferential separation wall prevents oil reaching the deflector via the first end of the main sleeve from flowing back into the main body in the opposite direction, via the second end of the main sleeve. The circumferential separation wall thus facilitates the evacuation of oil through the drain channel or the drain opening, thereby further improving the recovery rate.

[0045] In some embodiments, the second collection chamber at least is isolated from the second end of the main sleeve by the circumferential separation wall, a bottom wall of the main sleeve between the second end of the main sleeve and the circumferential separation wall comprising at least one radial discharge orifice.

[0046] In other words, the first and second collection chambers are arranged on the side of the first end of the main sleeve relative to the circumferential separating wall, the latter preventing the second collection chamber from communicating with the second end of the main sleeve. The first collection chamber also does not communicate with the second end of the main sleeve but only with the discharge channel. Thus, the portion of oil flowing into the internal cavity of the main body of the gutter towards the deflector, and being collected via the second end of the main sleeve (which does not communicate with the first and second collection chambers), can be discharged to the outside through at least one radial discharge port.

[0047] The present description also relates to a power transmission assembly for an aircraft turbomachine, comprising: - a mechanical reducer comprising a central pinion and an outer ring gear coaxial with each other around a main axis of rotation, and satellite pinions meshing with the central pinion and the outer ring gear, the outer ring gear comprising two half-rings each having an external annular flange fixed to each other, - at least one radial oil ejection channel formed between the annular flanges and configured to eject lubricating oil by centrifugal force, - a gutter according to any of the preceding embodiments arranged radially around the annular flanges, such that the internal cavity of the gutter is radially opposite the first radial oil ejection channel.

[0048] The annular gutter, in particular the main body, being arranged around the outer ring, and in particular the annular flanges, the central axis of the gutter and the main axis of rotation of the reducer are coaxial. It is further understood that the external annular flanges extend radially outwards, that is to say in a direction perpendicular to the main axis of rotation, a radial plane comprising the interface of junction between the annular flanges and being perpendicular to the main axis of rotation.

[0049] The radial oil ejection channel can be an orifice formed at the interface between the external annular flanges of the outer ring, in a radial direction perpendicular to the main axis of rotation. Furthermore, the mechanical speed reducer is preferably a planetary or differential reducer, with the outer ring rotating around the central axis. Consequently, during the rotation of the outer ring, the lubricating oil circulating in the mechanical reducer can be evacuated radially outwards by centrifugal force, via the radial oil ejection channel, towards the gutter, in particular towards the internal cavity, specifically towards the intake chamber arranged radially opposite the radial oil ejection channel.

[0050] In some embodiments, the deflector is arranged in a lower part of the gutter, so that the second end of the drainage channel is arranged vertically from the main axis of rotation in a direction of gravity, the first end of the drainage channel being offset from the second end by an angle [3 in a direction opposite to a direction of rotation of the outer ring, where 5° < [3 < 120°.

[0051] Given the kinetic energy transferred to the oil by the rotation of the outer ring, the oil ejected by the latter will flow preferentially into the internal cavity of the main body of the gutter in the same direction as the direction of rotation of the crown. In other words, most of the oil ejected by the outer crown flows into the internal cavity in the direction of rotation of the outer crown. Therefore, offsetting the first end of the discharge channel relative to the second end in the opposite direction to the rotation of the outer crown improves the efficiency of the device and increases the oil recovery rate.

[0052] In addition, a smaller quantity of oil can flow into the internal cavity of the main body of the gutter by gravity in the opposite direction to the direction of rotation of the external crown, and be evacuated via the radial evacuation orifice(s) formed in the bottom wall of the main sleeve.

[0053] The present description also relates to an aircraft turbomachine comprising a power transmission device according to any one of the preceding embodiments. Brief description of the drawings

[0054] The invention and its advantages will be better understood upon reading the following detailed description of various embodiments of the invention, given by way of non-limiting examples. This description refers to the accompanying figure pages, on which:

[0055] [Fig. 1] Fig. 1 is an axial cross-sectional view of a turbomachine comprising a planetary gearbox,

[0056] [Fig.2] Fig.2 schematically represents a detailed view of the turbomachine of the [Fig.1], in particular of a power transmission device comprising the planetary reducer of the [Fig.1],

[0057] [Fig. 3] [Fig. 3] represents a perspective view of a gutter according to a mode of the realization of the invention,

[0058] [Fig.4] Fig.4 schematically represents a front view of an assembly comprising an oil recovery gutter according to the invention, supported by a housing and arranged around the outer ring of the planetary reducer,

[0059] [Fig. 5] Fig. 5 schematically represents a side view in a plane of section BB of the whole of [Fig.4],

[0060] [Fig.6] [Fig.6] Schematically represents a cross-section of the body main component of the oil recovery gutter of the invention,

[0061] [Fig.7] Fig.7 represents a perspective view from above of a deflector of the oil recovery gutter of the invention,

[0062] [Fig.8] Fig.8 represents a perspective view of the underside of the deflector of the oil recovery gutter of the invention,

[0063] [Fig.9] Fig.9 represents a partial perspective view of the underside of the de- gutter deflector of figures 7 and 8, at an opposite end,

[0064] [Fig. 10] Fig. 10 represents a partial perspective view of the gutter of the invention, at the level of a junction between the deflector and the main body of the gutter,

[0065] [Fig. 11] The [Fig. 11] schematically represents a plan view from the top of the deflector. Description of the implementation methods

[0066] In the following description, the terms "radial", "axial", "tangential", "internal", "external", and their derivatives are considered with respect to the central axis X of the gutter 100 described below, or to the principal axis of rotation Y of the mechanical reducer 10. Thus, a radial direction R is perpendicular to the central axis X, and an axial direction is parallel to the central axis X. Similarly, a radial wall is perpendicular to the central axis X, and an axial wall is parallel to the central axis X. Furthermore, a tangential direction T is perpendicular to the central axis X and to the radial direction R.

[0067] Furthermore, the terms "top", "bottom", "lower", "upper", "above" or "below" and their derivatives are considered with respect to a vertical direction, corresponding to the normal direction of gravity. In particular, the lower parts of the gutter correspond to the regions located at the bottom in the figures.

[0068] Figure 1 shows, in cross-section along a vertical plane passing through its principal axis Y, an aircraft turbomachine, in particular a geared turbofan engine 1. It comprises, from upstream to downstream along the airflow, a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6, and a low-pressure turbine 7.

[0069] In such a geared turbojet 1, the high-pressure turbine 6 drives the high-pressure compressor 4 by means of a high-pressure shaft 8. The low-pressure turbine 7, also called the high-speed turbine, drives the low-pressure compressor 3, also called the high-speed compressor, by means of a low-pressure shaft 9. The high-speed turbine 7 also drives the rotor shaft 2a of the fan 2 via a mechanical speed reducer 10 (hereafter referred to simply as the "mechanical reducer 10"). In this way, the fan 2 can be driven at a reduced speed, which is aerodynamically advantageous, while the low-pressure compressor 3 can be driven at a higher speed, which is thermodynamically advantageous. The mechanical reducer 10 may be a planetary mechanical reducer.Alternatively, the mechanical reducer can be an epicyclic gear reducer, or a differential reducer. It should also be noted that the invention applies to mechanical reducers comprising monobloc planet carriers or of the "cage and cage carrier" type.

[0070] Fig. 2 represents, in section and along the same vertical plane passing through its principal axis Y, a detailed and schematic view of the turbojet 1 of Fig. 1, in particular of the power transmission device 1' comprising the mechanical reducer 10, and Fig. 6 represents, in addition to the gutter 100 described in detail later, a detailed view of a radially external end of the device 1' of Fig. 2.

[0071] The mechanical reducer 10 is, for example, a two-stage planetary gear reducer formed by a gear train known by the English acronym RGB for "Reduction Gearbox". Certain parts, such as the planet carriers or the housing surrounding the reducer, are masked to facilitate description. The mechanical reducer 10 comprises a sun pinion 30, having a plurality of teeth on its radially external face, and an outer ring gear 50 having a plurality of teeth on its radially internal face. The sun pinion 30 and the outer ring gear 50 are coaxial and axisymmetric about the main axis of rotation Y. The mechanical reducer 10 further comprises planet gears 40, conventionally at least three, each being arranged between the sun pinion 30 and the outer ring gear 50, meshing with them, and each rotating about an axis of rotation substantially parallel to the main axis of rotation Y.

[0072] Conventionally, the outer ring 50 comprises two half-rings 50A, 50B, each comprising an external annular flange 52A, 52B. The two half-rings 50A, 50B are assembled via the external annular flanges 52A, 52B and axial fastening means such as screws and nuts (not shown).

[0073] In addition, the solar pinion 30 is coupled to the low-pressure shaft 9, and the outer ring 50 is coupled to the blower 2 via the rotor shaft 2a.

[0074] Furthermore, in this example, the external annular flange 52B of the other of the two half-crowns 50B is fixed to a radial flange of another rotating part (not shown), for example a part for fairing the mechanical reducer 10.

[0075] In such a reducer 10, the lubricating oil which is used to lubricate and cool the various bearings and teeth of the reducer 10 is generally projected by centrifugal force through the outer ring 50. In order to facilitate the ejection of this oil, radial oil ejection channels are formed through the outer ring 50, in particular via radial oil ejection planes formed between the various radial flanges.

[0076] More specifically, in this example, a radial plane PI is formed by the junction interface between the external annular flanges 52A, 52B of the half-crowns 50A, 50B. It should be noted that the invention also applies to configurations comprising several radial oil ejection planes. Radial oil ejection channels 80 (only one is visible in [Fig.6]) are formed in this radial plane PI, and are distributed circumferentially around the principal axis of rotation Y. The radial oil ejection plane PI is perpendicular to the principal axis of rotation Y.

[0077] After the lubricating oil is ejected radially outwards via the radial oil ejection channels 80, and in the absence of a gutter, the oil then flows by gravity down through an enclosure formed by the housing 200 surrounding the gearbox, where it can be pumped back into the gearbox for reuse. However, this recovery method has drawbacks related to the lack of control over oil spray. Furthermore, the oil can also fall back, at least partially, onto rotating parts, thus generating additional parasitic losses.

[0078] To limit these drawbacks, an annular oil recovery gutter 100 (more simply referred to as gutter 100 in the rest of the description) is arranged around the outer ring 50, and allows the oil projected by the radial oil ejection channels 80 to be collected. The gutter 100 according to the invention is described with reference to Figures 3 to 12.

[0079] Fig. 3 represents a perspective view of the gutter 100, and Fig. 4 schematically represents a front view, parallel to the central axis X of the gutter 100, of an assembly comprising the outer ring 50, the gutter 100 and a fixed housing 200 of the turbojet 1, carrying the gutter 100. The front view corresponds to a view in the plane TR perpendicular to the central axis X, defined by the tangential direction T and radial direction R.

[0080] Furthermore, [Fig. 5] schematically represents a lateral cross-sectional view of this assembly, perpendicular to the central axis X, in a cross-sectional plane BB of the assembly of [Fig. 4]. The lateral view corresponds to a view in the plane XR defined by the axial direction X and the radial direction R. It should be noted that when the gutter 100 is arranged in the turbojet 1, particularly in the power transmission device 1' around the outer ring 50, the central axis X of the gutter 100 is coaxial and coincides with the main axis of rotation Y of the gearbox 10, in other words, of the turbojet 1.

[0081] The gutter 100 includes, on its radially external periphery, an annular flange 170 fixed to an annular flange 210 of the housing 200 (deliberately represented in a simplified manner), disposed along a radially internal face of said housing 200. Thus, the gutter 100 fixed to the fixed housing 200 is itself fixed and immobile relative to the housing 200 of the turbojet 1.

[0082] Furthermore, the gutter 100 comprises, on the one hand, a main body 101 annular around the central axis X, and on the other hand, in its lower part, a drainage conduit, hereinafter referred to as a deflector 300, fixed to the main body 101. The oil diverted into the evacuation cavity 160 described below can thus flow along it by gravity to the deflector 300 through which it can be evacuated to a suction point outside the mechanical reducer 10 without falling back on the various mechanical parts of it, and possibly be reused to lubricate these mechanical parts again.

[0083] Furthermore, the gutter 100 is arranged radially around the outer ring 50, such that the external annular flanges 52A, 52B are arranged radially opposite an inlet section of the gutter 100 allowing the oil ejected through the radial oil ejection channels 80 to be collected.

[0084] In this regard, the gutter 100, and in particular the main body 101 and the deflector 300, according to an embodiment of the invention have a particularly advantageous shape.

[0085] Initially, the main body 101 is illustrated in more detail in [Fig. 6], which shows a cross-section, perpendicular to an azimuthal direction, of the main body 101 positioned opposite a radially external end of the outer ring 50, in particular its external annular flanges 52A, 52B. It should be noted that, to simplify the following description, which focuses on the structure and geometry of the main body 101 of the gutter 100, certain elements such as the housing 200 or the lower part of the outer ring 50 are intentionally obscured in [Fig. 6]. In fact, apart from the gutter 100, only the radial ends of the radial flanges 52A, 52B of the outer ring 50 are shown.

[0086] By "radially opposite", it is understood that the external annular flanges 52A, 52B, in particular the radial channels 80 and the radial oil ejection plane PI, are arranged in the same axial position along the central axis X, as the inlet section of the gutter 100, and in particular its intake chamber 150 described below, so as to recover the oil ejected by said radial oil ejection channels 80.

[0087] Furthermore, the main body 101, according to this section, has the general shape of a "G," or even a snail. It includes, in particular, a first radial wall 110, annular in shape around the central axis X. An inclined wall 120, frustoconical in shape, extends from a radially external end of the first radial wall 110, an internal radial end of the first radial wall 110 being a free end. It should be noted that in this non-limiting example, the inclined wall 120 is formed in two parts and comprises two inclined walls 121, 122.

[0088] Furthermore, a guide portion 130 extends from a radially external end of the inclined wall 120. The guide portion 130 has, according to this section of the gutter 100, the general shape of a "U". In particular, the guide portion 130 comprises a first axial wall 131 extending from the radial end of the 120. external dilement of the inclined wall 120 in a direction away from the first radial wall 110, a curved wall 133 extending from an axial end of the first axial wall 131, this portion of the gutter then making a half turn so as to return towards the first radial wall 110, and a second axial wall 132 extending from the other end of the curved wall 133 in the direction of the first radial wall 110.

[0089] The gutter 100 finally includes a second radial wall 140 extending radially outwards from an axial end of the second axial wall 132, which is annular in shape around the central axis X. The first radial wall 110 and the second axial wall 140 are parallel to each other and perpendicular to the central axis X. They are each arranged axially on either side of the assembly formed by the radial flanges 52A, 52B.

[0090] Thus, the first and second radial walls 110, 140 form an inlet section of the gutter 100, through which passes the oil ejected by the radial oil ejection channels 80, and allowing this oil to be recovered efficiently.

[0091] In particular, the first radial wall 110, the inclined wall 120, and a first face of the second radial wall 140, define an intake chamber 150, into which the oil ejected by the radial oil ejection channels 80 is admitted. In addition, the guide portion 130 and a second face, opposite to the first face, of the second radial wall 140, define a lubricating oil discharge cavity 160, into which the oil from the intake chamber 150 is transferred and can flow out. In particular, the oil ejected and projected by the radial oil ejection channels 80 impacts the inclined wall 120. Due to the inclination of the latter, the oil impacting the inclined wall 120 is deflected towards the evacuation cavity 160. The oil is then guided by the U-shaped guide portion 130, in particular by the curved wall 133, towards the bottom of said evacuation cavity 160.

[0092] In particular, the second radial wall 140 forms a lateral wall of a guide basin that directs the oil towards the deflector, the second axial wall 132 forming the bottom of this basin. In this respect, a radial opening between the radially external end 140a of the second radial wall 140 and the first axial wall 131 allows the oil to pass from the inlet chamber 150 to the outlet cavity 160, after being deflected by the inclined wall 120. It should be noted, however, that on a portion of the circumference of the main body 101, this radial opening is closed by a segregation wall 142 ([Fig. 10]), preventing the inlet chamber 150 and the outlet cavity 160 from communicating with each other.The segregation wall 142 is a wall extending in a radial plane perpendicular to the central axis X, and preferably extends over less than 10% of the circumference of the main body 101, upstream of the deflector 300 described below, in a direction of oil flow from the body. main 101 towards the first end 331 of the main sleeve 330 of the deflector 300.

[0093] Given the architecture described above, most of the oil recovered by the gutter 100 flows into the discharge cavity 160, thus forming a main flow A flowing downwards towards the deflector 300. A smaller quantity of oil remains in the intake chamber 150 and forms a secondary flow B.

[0094] In a second step, the deflector 300 will be described in detail in the rest of the description, in particular with reference to figures 4 and 7 to 11.

[0095] The deflector 300 comprises a main sleeve 330 fixed to the main body 101, and extending circumferentially between a first end 331 and a second end 332. The main sleeve 330 is arranged in continuity with the main body 101, and has the same radius of curvature as the latter. More specifically, the first end 331 of the main sleeve 330 is fixed to a first circumferential end 101a of the main body 101, for example by interlocking or welding, and the second end 332 of the main sleeve is fixed to a second circumferential end 101b of the main body 101, for example by interlocking or welding.

[0096] The main sleeve 330 includes an inner enclosure I. A circumferential separating wall 350, disposed in the inner enclosure I, separates the first end 331 and the second end 332 of the main sleeve 330, preventing the oil from flowing from the first end 331 of the main sleeve 330 to the second end 332, and vice versa.

[0097] Furthermore, on the side of the first end 331 of the main sleeve 330 relative to the circumferential separating wall 350, the main sleeve 330 comprises a radial separating wall 340 disposed within the inner chamber I, separating the inner chamber I into a first oil collection chamber Cl (hereinafter referred to as first chamber Cl) and a second oil collection chamber C2 (hereinafter referred to as second chamber C2) comprising a bottom wall 320 having a discharge opening 322. The first chamber Cl is in fluidic communication with the discharge cavity 160 and collects the main flow A (the path of which is shown by arrows in [Fig. 7]). The second chamber C2 is in fluidic communication with the inlet chamber 150 and collects the secondary flow B (the path of which is shown by arrows in Figures 7 and 8).

[0098] The radial separating wall 340, which is a wall extending in a radial plane perpendicular to the central axis X, allows for the hermetic and axial separation of the first chamber C1 and the second chamber C2, such that the portion of the oil flowing into the discharge cavity 160 from the main body 101 towards the The deflector 300 is diverted to one side of the radial separating wall 340 towards the first chamber C1, and the portion of the oil flowing into the inlet chamber 510 of the main body 101 is diverted to the other side of the radial separating wall 340 towards the second chamber C2. Thus, the secondary flow B of oil entering the second chamber C2 is evacuated from the latter through the evacuation opening 322 formed in the bottom wall 320, the oil being otherwise blocked tangentially by the circumferential separating wall 350, and therefore being forced to evacuate through the evacuation opening 322.

[0099] Furthermore, the radial separation wall 340 is arranged in continuity with the segregation wall 142 of the main body 101, preferably in contact with it ([Fig. 10]). Thus, the portions of oil flowing respectively into the inlet chamber 150 and into the outlet cavity 160 are separated and isolated from each other by means of the segregation wall 142, even before their admission into the first and second collection chambers Cl, C2.

[0100] Furthermore, the deflector 300 includes a discharge channel 310 attached to and deviating from the main sleeve 330. The discharge channel 310 extends between a first end 311 through which the main flow A of lubricating oil is admitted, and a second end 312 through which the oil is discharged. The first end 311 may be continuous with the first chamber Cl, or coincide with it, as illustrated in particular in Figures 7 and 8. In other words, in the latter case, the first end 311 of the discharge channel 310 coincides with the first end 331 of the main sleeve 330, being situated in the same plane as it.

[0101] Thus, at the first end 311, the discharge channel 310 is tangent to the main body 101 and in particular to the discharge cavity 160, along the tangential direction T. More precisely, a mean curvature line of the discharge channel 310 is such that, at the first end 311, the curvature line is tangent to the mean curvature line of the discharge cavity 160 of the main body 101 and in continuity with this curvature line.

[0102] Furthermore, at the second end 312 of the discharge channel 310, said mean curvature line of the discharge channel 310 is directed downwards and radially with respect to the central axis X, in the radial direction R.

[0103] Thus, in a front view of the gutter 100 parallel to the central axis X, the drainage channel 310 has a first curvature contained in the plane TR perpendicular to the central axis X, defined by the tangential direction T and the radial direction R ([Fig. 4]). In other words, the curvature of the drainage channel 310 comprises a tangential component and a radial component that allow the oil to be progressively deflected and guided from the main body 101 towards the outside of the gutter 100, in particular towards a suction point.

[0104] The curvature of the discharge channel 310 relative to the main sleeve 330 also includes an axial component. More specifically, in a top view of the deflector 300 perpendicular to the central axis X ([Fig. 11]), the discharge channel 310 has a second curvature contained in the plane TX formed by the axial direction X and the tangential direction T, perpendicular to the radial direction R. In other words, the curvature of the discharge channel 310 includes a tangential component, an axial component, and a radial component, allowing the oil to be progressively diverted from the discharge cavity 160 of the main body 101.

[0105] Furthermore, in this top view of the deflector 300 in the TX plane, an oil deflection angle E° tangential to the discharge channel 310, that is to say the deflection of the discharge channel 310 with respect to the tangential direction T (in other words with respect to the main sleeve 330) and in the axial direction X, is defined as follows.

[0106] The deflection angle E° of the discharge channel is an angle between a first straight line DI perpendicular to the central axis X and to the radial direction R, preferably tangent to the annular gutter 100 at a first point 01 on the mean line of curvature of the discharge channel 310, and a second straight line D2 connecting the first point 01 to a second point 02 located along said mean line of curvature. The first point 01 is located at the first end 311 of the discharge channel 310 and corresponds substantially to an inflection point of a mean line of oil flow, and the second point 02 is located at a distance D from the first point 01 where 0 < D < 30 mm.

[0107] Thus, the angle of deviation E° in this view is less than 40°. In other words, regardless of the position of the second point 02 along the mean curvature line, as long as the distance D between the first and second points is such that 0 < D < 30 mm, the angle of deviation E° remains less than 40°. The fact that D is less than or equal to 30 mm means that only the upstream portion of the discharge channel 310, relative to the direction of oil flow from the main body 101 to the second end 312 of the discharge channel 310, is considered. Note that the tangential deviation is also visible in Figures 8 and 10.

[0108] According to this same view in the TX plane, the length B is the distance between the first end 311 and the second end 312 of the discharge channel 310 in the axial direction parallel to the central axis X. In other words, B is the distance between the first point 01 and a third point 03 located on the mean curvature line of the discharge channel 310, in the outlet plane of the discharge channel 310 at its second end 312. Similarly, the length C is the distance between points 01 and 03 in the tangential direction T perpendicular to the central axis X and to the direction radial R, with B < C.

[0109] It is understood that, according to the description, the discharge channel has a curved, left-handed shape, resembling a trumpet extending in three dimensions. Consequently, the distance between the first end 311 and the second end 312 of the discharge channel 310 comprises three components, including distances B and C. In other words, in a top view of the deflector 300, in the XT plane, B corresponds to the axial component of the distance between the first and second ends 311, 312, and C corresponds to the tangential component.

[0110] Furthermore, the discharge channel 310 has a closed cross-section S between the first end 311 and the second end 312 ([Fig. 8]). In other words, regardless of the cross-section S of the discharge channel 310 considered between the inlet and outlet of said channel, the discharge channel 310 has no openings, so that the oil cannot escape during its passage through the discharge channel 310.

[0111] In addition, the cross-section of the discharge channel is dimensioned according to the oil flow rate to be recovered, to ensure a flow velocity of between 1.5 and 5 m / s in the pipe when it is saturated.

[0112] Furthermore, in a front view of the gutter 100, parallel to the central axis X, that is to say in the plane TR ([Fig.4]), an angle [3 between the line D3 passing through the central axis X and the first end 311 of the drainage channel 310 (for example the first point 01), and a line D4 passing through the central axis X and the second end 312 (for example the third point 03) of the drainage channel 310, is such that 5° < [3 < 120°.

[0113] It is understood that the line D4 extends in the radial direction R, corresponding to a vertical direction with respect to the direction of gravity. The angle [3] is therefore the angular range over which the discharge channel 310 extends between its ends 311, 312, in this front view.

[0114] Furthermore, the deflector 300 is disposed in a lower part of the gutter 300 when the latter is disposed around the outer ring 50 of the reducer 10, so that the second end 312 of the discharge channel 310 is disposed vertically from the main axis of rotation Y, in other words from the central axis X. Thus, the first end 311 of the discharge channel 310 is offset with respect to the second end 312 by the angle [3, in a direction opposite to a direction of rotation co of the outer ring 50.

[0115] In other words, in the front view of the gutter 100, the angular range [3] over which the drainage channel 310 extends is not centered on the vertical axis, i.e., on the line D4, corresponding to the direction of gravity, but is offset along the circumference of the gutter 100 in the opposite direction to the direction of rotation co of the outer ring 50 of the reducer 10. In other words, the first end 311 of the discharge channel 310, through which the oil is collected, is closer to the top of the gutter 100 than the second end 312 of the discharge channel 310 through which the oil is discharged, said second end 312 being aligned vertically with the principal axis of rotation Y (or the central axis X).

[0116] [Fig.9] represents a partial perspective view of the deflector 300, on the side of the second end 332 opposite the first end 331 with respect to the circumferential separating wall 350. It will be noted in this regard that the structure of the main sleeve 330 at this end has a "G" shape similar to that of the main body 101 of the gutter 100 described with reference to [Fig.6], and can thus fit into the main body 101 by matching shape.

[0117] A bottom wall 324 of the main sleeve 330 between the second end 332 of the main sleeve 330 and the circumferential separating wall 350 includes at least one radial discharge port 326, in this example two radial discharge ports 326, disposed respectively in the portions of the internal enclosure I located in the extension of the accumulation chamber 150 and the discharge cavity 160 of the main body 101.

[0118] It will be noted that, according to this non-limiting example, this region of the inner enclosure I, on the side of the second end 332 of the main sleeve 330 with respect to the circumferential separating wall 350, does not include a radial separating wall, unlike the region of the inner enclosure I on the side of the first end 331 of the main sleeve 330 with respect to the circumferential separating wall 350, which includes the radial separating wall 340.

[0119] Given this architecture of the gutter 100, the lubricating oil used for the lubrication of the reducer 10 is ejected by the rotation of the outer ring 50, the direction of rotation co of the latter preferentially carrying the oil in the direction going towards the first end 331 of the main sleeve 330 of the deflector 300. In particular, given the "G" shape of the main body of the gutter 100, most of the oil ejected and recovered by the gutter 100 flows into the evacuation cavity 160 and is evacuated by the deflector 300 through the evacuation channel 310 via the main flow A, being guided progressively towards the second end 312 so as to be evacuated radially towards a suction point.

[0120] In this flow direction, corresponding to the direction of rotation co of the outer ring, a smaller quantity of oil is discharged through the second chamber C2 and the radial opening 322 via the secondary flow B. In addition, a certain quantity of oil, less than the quantity of oil flowing into the channel 100 in the direction of rotation co, flows into the channel 100, particularly into the main body 101, in the opposite direction to the direction of rotation co. In this portion of the body main 101 of the gutter, corresponding to the portion to the left of the right D4 on the [Fig.4], the oil flows by gravity towards the second end 332 of the main sleeve 330 of the deflector, and is evacuated to the outside of the gutter through the radial evacuation orifice(s) 326.

[0121] It will also be noted that the deflector 300 may include a radial flange 370, arranged under the main sleeve 330, and allowing the deflector 300 to be fixed to the annular flange 210 of the housing 200, in the same way as the flange 170 of the main body 101.

[0122] 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

Demands

1. A lubrication oil recovery gutter (100), particularly for a mechanical gearbox (10) of an aircraft turbomachine, comprising an annular main body (101) about a central axis (X), and a deflector (300) fixed to the main body and configured to allow the oil to drain radially from an internal cavity (150, 160) of the main body (101) to the outside of the gutter, the deflector (300) comprising a main sleeve (330) disposed in continuity with the main body (101), and a discharge channel (310) configured to deflect oil from the main sleeve (330) and having a curved shape such that a first end (311) of the discharge channel, communicating with the internal cavity (150, 160), is tangent to the main body (101), the discharge channel (310) then deflecting gradually, through its curved shape,up to a second end (312) directed outwards relative to the main annular body (101).

2. Gutter (100) according to claim 1, wherein the curved shape of the discharge channel (310) includes an axial component such that the discharge channel (310) is configured to deflect oil from the main sleeve (330) in the direction of the central axis (X).

3. Gutter (100) according to claim 2, wherein an oil deflection angle (E) of the discharge channel (310) with respect to the main sleeve (330) is an angle between a first straight line (Dl) tangent to the annular main body (101) and perpendicular to the central axis (X), and a second straight line (D2) connecting a first point (01) of a mean curvature line of the discharge channel (310) to a second point (02) disposed along said mean line, the first point (01) belonging to the first straight line (Dl) and being disposed at the first end (311) of the discharge channel (310) and the second point (02) being located at a distance D from the first point (01) where 0 < D < 30 mm, the deflection angle (E) being less than 40°.

4. Gutter (100) according to claim 2 or 3, wherein a distance B between the first end (311) and the second end (312) of the drainage channel (310) is in a direction parallel to the central axis (X), and a distance C between said first and second ends (311, 312) is in a direction perpendicular to the central axis (X) and to a radial direction (R) of the annular main body (101), are such that B

5. \ V-. Gutter (100) according to any one of claims 1 to 4, wherein the drainage channel (310) has, between the first end and the second end, a closed section S.

6. Gutter (100) according to any one of claims 1 to 5, wherein, in a view parallel to the central axis (X), an angle [3 between a straight line (D3) passing through the central axis (X) and the first end (311) of the drainage channel (310), and a straight line (D4) passing through the central axis (X) and the second end (312) of the drainage channel, is such that 5° < [3 < 120°.

7. Gutter (100) according to any one of claims 1 to 6, in which the main sleeve (330) encloses an inner chamber (I) communicating with the internal cavity (150, 160) of the main body (101) of the gutter, a radial separating wall (340) separating the inner chamber (I) into a first oil collection chamber (C1) in fluidic communication with the discharge channel (310), and a second oil collection chamber (C2) comprising a bottom wall (320) having a discharge opening (322).

8. Gutter (100) according to claim 7, wherein the internal cavity of the main body (101) of the gutter comprises an inlet chamber (150) and an outlet cavity (160) communicating with the inlet chamber (150) over at least a portion of the circumference of the main body (101), the inlet chamber (150) being configured to be disposed in the same axial position along the central axis (X) as a radial plane (PI) of oil ejection from the reducer (10) so as to recover the lubricating oil from the reducer (10) and divert it to the outlet cavity (160), the outlet cavity (160) communicating with the first collection chamber (C1) and the inlet chamber (150) communicating with the second collection chamber (C2).

9. Gutter (100) according to claim 8, wherein the main body (101) includes a segregation wall (142) separating the inlet chamber (150) and the outlet cavity (160) over a portion of the circumference of the main body (101) upstream of the deflector (300).

10. Gutter (100) according to claim 8 or 9, wherein the main body (101) comprises, in a cutting plane parallel to the central axis (X), a first radial wall (110) extending radially by relative to the central axis, at least one inclined wall (120) extending from an external radial end of the first radial wall (110), a guide portion (130) having a general U-shape extending from one end of the inclined wall (120), and a second radial wall (140) extending radially outwards relative to the central axis (X) from one end of the guide portion (130), a space delimited by the first radial wall (110), the second radial wall (140) and the inclined wall (120) forming the lubricating oil inlet chamber (150), and a space delimited by the guide portion (130) and the second radial wall (140) forming the lubricating oil outlet cavity (160).

11. Gutter (100) according to any one of claims 1 to 10, wherein the main sleeve (330) has a first end (331) fixed to a first circumferential end (101a) of the main body (101), and a second end (332) fixed to a second circumferential end (101b) of the main body (101), the main sleeve (330) comprising a circumferential separating wall (350) separating the first end (331) of the main sleeve from its second end (332).

12. Gutter (100) according to claim 7 and claim 11, wherein the second collection chamber (C2) at least is isolated from the second end (332) of the main sleeve (330) by the circumferential separating wall (350), a bottom wall (324) of the main sleeve between the second end (332) of the main sleeve and the circumferential separating wall (350) comprising at least one radial discharge orifice (326).

13. Power transmission assembly (1') for an aircraft turbomachine, comprising: - a mechanical reducer (10) including a central pinion (30) and an outer ring gear (50) coaxial with each other about a principal axis of rotation (Y), and planetary gears (40) meshing with the central pinion (30) and the outer ring gear (50), the outer ring gear (50) comprising two half-rings (50A, 50B) each having an external annular flange (52A, 52B) fixed to each other, - at least one radial oil ejection channel (80) formed between the annular flanges (52A, 52B) and configured to eject lubricating oil by centrifugal force, - a gutter (100) according to any one of claims 1 to 12 arranged radially around the annular flanges (52A, 52B), such that the internal cavity (150, 160) of the gutter is radially opposite the first radial oil ejection channel (80).

14. Assembly according to claim 13, wherein the deflector (300) is disposed in a lower part of the gutter (100), such that the second end (312) of the discharge channel (310) is disposed vertically from the main axis of rotation (Y) in a direction of gravity, the first end (311) of the discharge channel (310) being offset from the second end by an angle [3 in a direction opposite to a direction of rotation (œ) of the outer ring (50), where 5° < [3 < 120°.

Images