Mechanical reduction gear for an aircraft turbine engine

Abstract

The invention relates to a mechanical reduction gear (10) for an aircraft turbine engine (1), the reduction gear comprising: - a sun gear (11), - a ring gear (14), - planet gears (12) rotatably guided by bearings (8) and meshed with the sun gear (11) and the ring gear (14), and - a planet carrier (213) comprising a cage (220) in which the sun gear (11) and the planet gears (12) and the bearings (8) thereof are mounted, the cage (220) comprising an annular row of slots (300) in which shims (400) are mounted and fixed which are able to stiffen the cage (220) during operation under load.

Description

[0001] DESCRIPTION

[0002] TITLE: MECHANICAL REDUCTION GEAR FOR AN AIRCRAFT TURBOMACHINE

[0003] Technical field of the invention

[0004] The present invention relates to a mechanical reducer for an aircraft turbomachine, as well as a turbomachine comprising such a reducer.

[0005] Technical Downstream Plan

[0006] The state of the art includes in particular documents CN-A-116 292 857, FRAI -2 987 416, FR-A1-2 853 382, ​​FR-A1-3 041 054, FR-A1-3073 915, FRAI -3 084 428.

[0007] The role of a mechanical reducer is to modify the speed ratio and torque between the input shaft and the output shaft of a mechanism.

[0008] Newer generations of turbofan engines, particularly those with a high bypass ratio, incorporate a mechanical gearbox to drive the fan shaft. Typically, the gearbox's purpose is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan shaft.

[0009] Such a gearbox comprises a central pinion, called the sun gear, a ring gear, and pinions called planet gears, which mesh between the sun gear and the ring gear. The planet gears are held by a frame called the planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis of the turbomachine. The planet gears each have a different axis of revolution and are evenly spaced around the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis of the turbomachine. Several gearbox architectures exist. In state-of-the-art turbomachinery, gearboxes are of the planetary or epicyclic type. In other similar applications, differential or compound architectures exist.

[0010] - on a planetary reducer, the planet carrier is fixed and the ring forms the output shaft of the device which rotates in the opposite direction to the sun.

[0011] - on an epicyclic reducer, the ring is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar.

[0012] - On a differential gearbox, no element is fixed in rotation. The ring rotates in the opposite direction to the solar and satellite carrier.

[0013] Gearboxes can consist of one or more meshing stages. This meshing is achieved in various ways, such as by contact, friction, or magnetic field. There are several types of contact meshing, such as with spur or herringbone teeth.

[0014] The satellite carrier can be a single unit or consist of a cage and a cage-bearing assembly. The cage comprises an internal cavity housing the solar array, the satellites, and their guidance bearings. The solar array has internal splines for coupling to a first shaft of the turbomachine, and the cage-bearing assembly has a cylindrical portion with external splines for coupling to another shaft.

[0015] The cage connection to the cage holder is generally rigid. Alternatively, a technology can be considered in which the cage is connected to the cage holder by "flexible" connections, as described in FRAI-2 853 382. In such a case, the cage holder comprises an annular row of axial fingers that carry first connecting elements. These first connecting elements cooperate with second connecting elements mounted in housings in the cage to form the flexible connections between the cage holder and the cage, which allow at least one degree of freedom.

[0016] During operation, the planet carrier is subjected to stresses that tend to deform it. This is the case for a one-piece planet carrier or a cage-and-cage type. These deformations cause the planets to tilt, leading to a degradation of the meshing and the risk of an asymmetrical oil film forming when using plain or hydrodynamic planetary guidance bearings, or the risk of roller tilting when using roller bearings for planetary guidance. These stresses and deformations must be rebalanced to limit or even eliminate these effects.

[0017] Satellite misalignment is an important point to monitor to avoid excessive stress on the gear teeth. To address this, the design of the satellite carrier can be optimized for flexibility to reduce or even eliminate this misalignment. Specifically, incorporating flexible zones into the carrier cage has already been proposed.

[0018] However, the introduction of such flexibility zones can compromise the mechanical strength of the reducer.

[0019] Indeed, a structural component like the satellite carrier is sized according to several operating conditions, divided into two categories: nominal conditions (corresponding to the torques encountered during the different phases of flight) and exceptional conditions (encountered during specific events). The latter are more severe than nominal conditions but occur much less frequently during the engine's lifetime. They must nevertheless be taken into account during the sizing process and require reinforcement of the structure. It is therefore understandable that there is an impact on the mass and flexibility of the gearbox when designing areas of flexibility for these conditions.

[0020] The present invention offers a solution to this problem, which is simple, effective and economical.

[0021] Summary of the invention: The invention relates to a mechanical gearbox for an aircraft turbomachine, this gearbox comprising:

[0022] - a solar panel centered on a central axis,

[0023] - a corona centered on the central axis and extending around the sun,

[0024] - satellites guided in rotation by bearings centered on bearing axes that are parallel to the central axis, the satellites being meshed with the sun and the corona, and

[0025] - a satellite carrier comprising a cage formed from a single piece in which the solar array and the satellites and their bearings are mounted, the cage comprising:

[0026] - a first disc centered on the central axis and extending perpendicularly to this central axis, this first disc having first bearing holes centered respectively on the bearing axes and which are suitable for receiving first longitudinal ends of the bearings,

[0027] - a second disc centered on the central axis and extending parallel and axially at a distance from the first disc, this second disc having second bearing ports which are respectively centered on the bearing axes and which are suitable for receiving second longitudinal ends of the bearings, and

[0028] - bridges extending between the first and second discs and connecting them together, the bridges being separated circumferentially from each other by openings intended to be passed through by the satellites for the purpose of their meshing with the ring, characterized in that the cage has around the central axis an annular row of lights which are formed in the first disc and which extend radially from the outer periphery of the cage where they open radially outwards next to said openings to the inner periphery of the cage, and in that wedges are mounted in these lights and are fixed to the cage, each of these wedges having at least one bearing face which is opposite a face of the corresponding light and which is able to be separated from this face of the light by a predetermined clearance in normal operation, and to come into contact with this face of the light during a deformation of the cage.

[0029] To avoid the aforementioned problem, the invention proposes implementing a bypass mechanism for exceptional loading conditions. Under normal operating conditions, due to clearances between the shims and the cage, the shims are not operational and do not participate in the transmission of forces. When these clearances are eliminated, the shims create additional load paths. These clearances are eliminated when the cage deforms beyond a certain threshold corresponding to the exceptional loading conditions described above. Indeed, during exceptional loading, the cage deformations bring the shims into contact with the cage, generating additional load paths that relieve stress on the cage's flexible areas.

[0030] The present invention is compatible with:

[0031] - of a multi-stage reducer;

[0032] - of a planetary, epicycloidal or differential reducer;

[0033] - with straight or herringbone teeth.

[0034] The reducer according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0035] - the opening of each of the lights at the outer periphery of the cage has a general U-shape;

[0036] - the U shape comprises a central and straight part formed in the first disc and extending in a plane perpendicular to the central axis, and two lateral parts formed respectively in two bridges;

[0037] - the lateral parts are perpendicular to the median part and extend respectively in two planes passing through the central axis;

[0038] - the middle part has an axial width or dimension that is less than a circumferential width or dimension of each of the lateral parts; - the wedges have a shape complementary to the opening of the lights at the outer periphery of the cage;

[0039] - the opening of each of the lights at the outer periphery of the cage receives a single wedge, or two wedges;

[0040] - the wedges have a general U or L shape;

[0041] - the wedges each include a fixing part which is connected to a support tab in the case of an L-shaped wedge, and which extends between two support tabs in the case of a U-shaped wedge, the or each support tab having said at least one bearing face;

[0042] - where each support leg is thicker than the fixing part;

[0043] - the fixing part includes one or more holes for the passage of fixing elements;

[0044] - the fixing part is connected to the support leg(s) by a sheet of elastically deformable material;

[0045] - the layer of material has a minimum thickness less than that of the fixing part;

[0046] - each support leg has a general parallelepiped shape and includes on a first side said at least one support face, and on a second side opposite the first side another face which is in permanent contact with a face of the corresponding light in particular in normal operation;

[0047] - the fixing part is located in the middle part of the corresponding light, and the support leg or each support tab is located in one of the lateral parts of this light;

[0048] -- each of the bridges has a general T-shape due to the lateral parts of the lights, and includes a portion of greater circumferential width located on the side of the second disc, and a portion of lesser circumferential width located on the side of the first disc; -- the portion of lesser width of each of the bridges has a circumferential width or dimension which represents at least 1 / 3 of a circumferential width or dimension of the portion of greater width;

[0049] -- each of the bridges includes, on the side of the first disc, a V-shaped notch;

[0050] -- said V-shaped notch is formed in the part with the smallest circumferential width of each of the bridges;

[0051] - the cage is formed from a single piece with a cage holder which has a portion-of-a-tree shape and may include external grooves for coupling to another tree;

[0052] -- the satellite carrier is of the monobloc type;

[0053] - the support faces are located in planes passing through the central axis; the support faces or the planes can be inclined to each other at an angle between 20 and 80°.

[0054] The present invention also relates to an aircraft turbomachine comprising a reducer as described above.

[0055] Brief description of the figures

[0056] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0057] [Fig.1] Figure 1 is a schematic axial cross-sectional view of a turbomachine using the invention;

[0058] [Fig.2] Figure 2 is a schematic axial cross-sectional view of a mechanical reducer;

[0059] [Fig.3] Figure 3 is a perspective view of a cage and cage-carrier assembly forming a mechanical reducer planet carrier;

[0060] [Fig.4] Figure 4 is an axial and partial cross-sectional view of part of the satellite carrier of Figure 3;

[0061] [Fig.5] Figure 5 is a detail view of Figure 4; [Fig.6] Figure 6 is a schematic front view of the satellite carrier of Figure 3;

[0062] [Fig.7] Figure 7 is a schematic perspective view of a satellite carrier for a reducer according to the invention;

[0063] [Fig.8] Figure 8 is a larger scale view of part of the satellite carrier of Figure 7 and shows a light and an opening of the satellite carrier cage;

[0064] [Fig.9] Figure 9 is a schematic perspective view of a wedge for the satellite carrier cage, according to a first embodiment of the invention; [Fig.10] Figure 10 is a partial schematic view of the wedge of Figure 9 mounted in one of the openings of the satellite carrier cage;

[0065] [Fig. 11] Figure 11 is a schematic perspective view of a wedge for the satellite carrier cage, according to a second embodiment of the invention;

[0066] [Fig. 12] Figure 12 is a partial schematic perspective view of the satellite carrier cage with the wedge from Figure 11 mounted in one of its openings; and

[0067] [Fig. 13] Figure 13 is a very schematic view of a method of attaching a wedge to the cage of the satellite carrier.

[0068] Detailed description of the invention

[0069] Figure 1 depicts a turbomachine 1 which conventionally comprises a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1c, a high-pressure turbine 1d, a low-pressure turbine 1e, and an exhaust nozzle 1h. The high-pressure compressor 1b and the high-pressure turbine 1d are connected by a high-pressure shaft 2 and together form a high-pressure (HP) housing. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and together form a low-pressure (LP) housing. The fan S is driven by a fan shaft 4 which is connected to the LP shaft 3 by means of a mechanical gearbox 10. This gearbox 10 is generally of the planetary or epicyclic type.

[0070] Although the following description relates to a planetary or epicycloidal type reducer, it also applies to a mechanical differential in which its three essential components, namely the planet carrier, the ring and the sun gear, are mobile in rotation, the rotational speed of one of these components depending in particular on the difference in speeds of the other two components.

[0071] The gearbox 10 is positioned in the upstream part of the turbomachine. A fixed structure schematically comprising, here, an upstream part 5a and a downstream part 5b which make up the motor or stator housing 5 is arranged to form an enclosure E surrounding the gearbox 10. This enclosure E is closed upstream by seals at the level of a bearing allowing the passage of the blower shaft 4, and downstream by seals at the level of the passage of the BP shaft 3.

[0072] Figure 1 shows part of a gearbox 10, which can take different forms depending on whether certain parts are fixed or rotating. At the input, the gearbox 10 is connected to the shaft BP 3, for example, via splines 7. Thus, the shaft BP 3 drives a planetary gear called the sun gear 11. Typically, the sun gear 11, whose axis of rotation coincides with the X-axis of the turbomachine 1, drives a series of gears called sun gears 12, which are equally spaced circumferentially on the same diameter around the X-axis of rotation. This diameter is equal to twice the operating center distance between the sun gear 11 and the sun gears 12. The number of sun gears 12 is generally defined as between three and seven for this type of application.

[0073] The set of satellites 12 is held by a frame called the satellite carrier 12. Each satellite 12 rotates around its own Y axis, and meshes with the ring 14.

[0074] At the output of the gearbox 10, we have: In an epicyclic configuration, the set of planet gears 12 drives the planet carrier 13 in rotation around the X-axis of the turbomachine. The ring gear 14 is fixed to the motor or stator housing 5 via a ring carrier 15, and the planet carrier 12 is fixed to the fan shaft 4. In a planetary configuration, the set of planet gears 12 is held by a planet carrier 12, which is fixed to the motor or stator housing 5. Each planet gear drives the ring gear, which is connected to the fan shaft 4 via a ring carrier 15.

[0075] Each satellite 12 is mounted to rotate freely around a Y-axis using a bearing 8. The Y-axis rotations of the satellites 12 are distributed around and parallel to the X-axis. The bearings 8 are, for example, of the roller bearing or hydrodynamic bearing type. Each bearing 8 is mounted on a physical axis 13a of the satellite carrier 12, and all these physical axes 13a are positioned relative to each other using one or more structural frames of the satellite carrier 12. There is a number of physical axes 13a and bearings 8 equal to the number of satellites 12. For operational, assembly, manufacturing, inspection, repair, or replacement purposes, the axes 13a and the frame may be separated into several parts.

[0076] For the same reasons mentioned previously, the teeth of a reduction gear can be separated into several helices. In our example, we detail the operation of a multi-helix reduction gear 10 with a ring gear divided into two half-rings: A front half-ring 14a consisting of a rim 14aa and a mounting flange half 14ab. The front helix of the reduction gear teeth is located on the rim 14aa. This front helix meshes with that of the satellite gear 12, which meshes with that of the solar gear 11. A rear half-ring 14b consisting of a rim 14ba and a mounting flange half 14bb. The rear helix of the reduction gear teeth is located on the rim 14ba. This rear helix meshes with that of the satellite gear 12, which meshes with that of the solar gear 11. The front crown 14a fixing half-flange and the rear crown 14b fixing half-flange form the crown fixing flange 14c.The crown 14 is fixed to the crown carrier 15 by joining the crown's mounting flange 14c and the crown carrier's mounting flange 15a using, for example, a bolted assembly. In what follows, a half-flange may be referred to as a flange.

[0077] The arrows in Figure 1 describe the oil flow within the gearbox 10. The oil enters the gearbox 10 from the stator section 5 into the distributor 16 by various means, which will not be detailed in this view as they are specific to one or more types of architecture. The distributor 16 is divided into two parts, each generally repeated with the same number of planetary gears. The injectors 17a lubricate the gear teeth, and the arms 17b lubricate the bearings 8. The oil is supplied to the injector 17a and exits through the end 17c to lubricate the gear teeth. The oil is also supplied to each arm 17b and flows through the supply mouth 17d of the bearing 8. The oil then flows through the shaft 13a into one or more buffer zones 13b and then out through ports 13c to lubricate the bearings 8 of the satellites.

[0078] The satellite carrier 13 in Figure 2 is formed from a single piece in the example shown.

[0079] In figures 3 to 5, the elements already described above are designated by the same references plus one hundred.

[0080] Figures 3 to 5 represent a particular satellite carrier technology 113, this satellite carrier comprising a cage 120 and a cage carrier 122 connected by ball joints.

[0081] The cage 120 comprises two radial annular discs or walls 136, 138 which are parallel to each other and perpendicular to the X axis, as well as a cylindrical wall 140 which extends between the external peripheries of these discs walls 136, 138.

[0082] The cylindrical wall 140 is of the double-skinned type and comprises an outer skin 140a interrupted by openings 143 and an inner skin 140b interrupted by the same openings 143. The outer skin 140a, separated by five openings 143, forms five outer brackets, and the inner skin 140b, separated by five openings 143, forms five inner brackets. Each pair of lower and upper brackets forms a clevis to receive the finger 182 of the cage holder 122. In other words, the brackets of each pair define a recess 180 for receiving a finger 182 of the cage holder 122. The brackets provide the structural connection between the walls 136 and 138. Oblong openings 180a are made in at least one of the walls 136 and 138 to allow the finger 182 to pass between the inner and outer brackets. These 180a lights open into the 180 housing units.

[0083] The cage 120 thus comprises an annular row of housings 180. These housings 180 receive the axial fingers 182 which are integral with an annular wall 182a substantially radial to the cage holder 122. The wall 182a is located at an axial end of the cage holder 122. The fingers 182 extend axially from the wall 182a and are engaged by axial translation in the housings 180.

[0084] Each finger 182 includes, substantially in its middle, a mounting ring 184 for the ball joint 186 intended to be traversed by a cylindrical pin 188 carried by the cage 120.

[0085] The ring 184 has a substantially radial orientation with respect to the X-axis. It has a generally cylindrical shape. The cage 120 and the ball joint 186 have a thickness, measured in a radial direction with respect to the X-axis, which is less than the inter-bridge distance or the radial thickness of the oblong slot 180a, so that they can be engaged in this housing concurrently with the support finger 182 for these parts.

[0086] Each housing 180 is traversed by a pin 188 which has a substantially radial orientation with respect to the X-axis. Each pin 188 comprises a cylindrical body 188a connected at an axial end, here radially internal, to an external annular collar 188b. The pin 188 is engaged by radial translation from the inside through radial holes in the bridges, its collar 188b being designed to bear radially against a flat face 191 of the outer bridge of the cage 120. After insertion of the pin 188 into the holes in the bridges, until the collar 188b bears against the outer bridge, the collar 188b is fixed to this bridge, for example by screwing.

[0087] Figure 6 shows a detail of the disks or walls 136, 138 of the planet carrier 113. In these figures, it can be seen that each of the walls 136, 138 includes first orifices 192, 194 centered respectively on the Y axes of rotation of the planets of the gearbox. In the example shown, there are five orifices 192, 194 on each of the walls 136, 138.

[0088] The invention proposes an improvement for a mechanical gearbox for an aircraft turbomachine.

[0089] As in the examples described above, the mechanical reducer 10 according to the invention comprises:

[0090] - a solar 11 centered on a central axis X,

[0091] - a corona 14 centered on the central axis X and extending around the solar 11,

[0092] - satellites 12 guided in rotation by bearings 8 centered on bearing axes Y which are parallel to the central axis X, the satellites 12 being meshed with the solar 11 and the crown 14, and

[0093] - a satellite carrier.

[0094] The satellite carrier is preferably of the monobloc type as illustrated in Figure 2. The preceding descriptions in relation to Figures 2 to 6 may be used to illustrate and describe the invention insofar as they are not contrary to or contradict what follows.

[0095] Figures 7 to 10 illustrate an embodiment of a satellite carrier 213 according to the invention. The satellite carrier 213 comprises a cage 220 formed in one piece and in which the solar array and the satellites and their bearings are intended to be mounted.

[0096] The cage 220 is formed in one piece with a cage holder 222 which has a tree gate shape and may include external grooves for coupling to another tree.

[0097] Cage 220 includes:

[0098] - a first disk 236 centered on the X axis, called the first axis or central axis, and extending perpendicularly to this X axis, this first disk 236 having first bearing orifices 292 centered respectively on the Y axes, called bearing axes or second axes, which are parallel to the X axis and arranged around this X axis,

[0099] - a second disk 238 centered on the X axis and parallel and at a distance from the disk 236, this second disk 238 having second bearing ports 294 which are respectively centered on the Y axes, and

[0100] - bridges 296 which extend between the discs 236, 238 and connect them together, these bridges 296 being formed in one piece with the discs 236, 238, and the bridges being separated circumferentially from each other by openings 243 intended to be crossed by the satellites in view of their meshing with the crown.

[0101] The first disc 236 is for example a front or upstream disc, and the second disc 238 is for example a rear or downstream disc, by reference to the position of the reducer in the turbomachine and to the flow of gases in the turbomachine.

[0102] The first disk 236 is preferably the disk connected to the cage carrier 222. The openings 292 and 294 are used to mount the satellites, and in particular the satellite guidance bearings, in the satellite carrier 213. The bearings have longitudinal ends designed to fit into these openings 292 and 294. The bearings are plain (hydrodynamic) or rolling bearings, for example. The distinctive feature of the cage 220 in Figures 7 and 8 is that it has, around its central axis, an annular row of openings 300 that are formed at least partially in one of the disks, such as the first disk 236, for example, and that extend radially.

[0103] The lights 300 extend radially from the outer periphery of cage 220 where they open radially outwards next to the openings 243, to the inner periphery of cage 220.

[0104] In the example shown in the drawings, we can see that the outlet of each of the lights 300 at the outer periphery of the cage 220 has a general U shape (figures 7 and 8).

[0105] This U-shaped form includes a central and straight part 300a formed in the first disk 236 and extending in a plane Q1 perpendicular to the central axis X, and two lateral parts 300b, 300c formed respectively in two bridges 296.

[0106] The lateral parts 300b, 300c of each of the lights 300 open onto the inner periphery of the bridges 296.

[0107] Each of the bridges 296 may include on its inner periphery a single orifice 297 into which the inner peripheries of the lateral parts 300a, 300c of two adjacent lumens 300 open. This opening may have a general O-shape, as seen in Figure 7.

[0108] The lateral parts 300b, 300c are perpendicular to the median part 300a and extend respectively in two planes Q2, Q3 passing through the central axis X.

[0109] The central part 300a preferably has a width L1 or axial dimension, in particular maximum, which is less than a width L2 or circumferential dimension, in particular maximum, of each of the lateral parts 300b, 300c. The width L1 is measured in the axial direction while the width L2 is measured in the circumferential direction with respect to the central axis X.

[0110] The middle portion 300a can have a circumferential length greater than the circumferential dimension of an opening 243. Figure 7 shows that each of the bridges 296 can have a general T-shape due to the lateral portions 300b, 300c of the openings 300. Each of the bridges 296 comprises a portion 296a with a greater circumferential width located on the side of the second disk 238, and a portion 296b with a smaller circumferential width located on the side of the first disk 236.

[0111] The narrower portion 296b of each of the 296 bridges has a width L3, or circumferential dimension, that is at least 1 / 3 of a width L4, or circumferential dimension, of the wider portion. Widths L3 and L4 are measured circumferentially with respect to the central axis X.

[0112] Each of the bridges 296 may include, on the side of the first disc 236, a V-shaped notch 298 (Figure 8). This notch 298 is formed in the portion 296b with the smallest circumferential width of each of the bridges 296. Each notch 298 preferably has a symmetrical shape with respect to a plane passing through the central axis X and the midpoint of the bridge 296. Each notch 298 flares axially on the side opposite the second disc 238.

[0113] As illustrated in figures 7 and following, the invention proposes to mount 400 wedges in the 300 slots.

[0114] Each of these wedges 400 has at least one bearing face 402 which is opposite a face 404 of the corresponding light 300 and which is able to be separated from this face of the light 300 by a predetermined clearance J in normal operation, and to come into contact with this face 404 of the light 300 during a deformation of the cage 220 corresponding in particular to an exceptional case mentioned above.

[0115] The 400 wedges preferably have a shape complementary to the opening of the 300 lights at the outer periphery of the cage 220.

[0116] The outlet of each of the 300 lights can receive a single shim 400 as is the case in the embodiment of figures 7 to 10, or two shims 400 as is the case in the variant embodiment of figures 11 and 12.

[0117] In the embodiment of figures 7 to 10, the wedges 400 have a general U-shape and each includes a fixing part 406 which extends between two support lugs 408. Each support lug 408 having a bearing face 402.

[0118] In the embodiment shown in Figures 11 and 12, the wedges 400 have a general L-shape and each comprises a fixing portion 406 which is connected to a single support lug 408. The support lug 408 of each wedge 400 has a bearing face 402. The wedges 400 of Figures 11 and 12 are intended to be used in pairs, the wedges 400 of the pair being identical, only one of these wedges being shown in Figures 11 and 12. It is understood that the fixing portion 406 can be located in the central portion 300a of the corresponding slot 300, and the support lug(s) 408 can be located in one of the lateral portions 300b, 300c of this slot 300, as illustrated in the drawings.

[0119] Each support leg 408 is preferably thickened relative to the fixing part 406.

[0120] In the embodiment shown in Figures 7 to 10, the fastening portion 406 includes one or more holes 410 for fasteners 412 such as screws, bolts, or rivets. These holes 410 are aligned with corresponding holes 414 (Figure 13) in the cage 220 for mounting these fasteners 412.

[0121] In the embodiment shown in Figures 11 and 12, the fastening portion 406 includes one or more holes 410 for fasteners 412 such as screws, bolts, or rivets. The fastening portions 406 of the wedges 400 in the pair are intended to be pressed against each other, particularly in the axial direction, so that their holes 410 are aligned with each other and with corresponding holes 414 in the cage 220 for mounting these fasteners 412 (Figures 12 and 13). When the two wedges 400 of the pair are mounted in a light 300, the lateral parts 300b, 300c of the light 300 respectively accommodate the support lugs 408 of the two wedges, and their fixing parts 406 are stacked one on top of the other and housed in the middle part 300a of the light 300.

[0122] The figures of the two embodiments show that the fixing part 406 can be connected to the support leg 408 by a web of elastically deformable material 416, particularly in bending.

[0123] The material veil 416 preferably has a minimum thickness Emin less than the thickness E of the fixing part 406 (figure 10).

[0124] Advantageously, each support leg 408 has a general parallelepiped shape to form a relatively massive force transmission block.

[0125] Each support leg 408 may include on a first side the aforementioned support face 402, and on a second side opposite the first side another face 418 which may be in permanent contact with a face 420 of the corresponding light 300 in normal operation.

[0126] The 400 wedges can be made from a different material than the 220 cage.

[0127] In normal operation, the shims 400 are not in contact with the cage 220 of the satellite carrier at the level of their bearing faces 402. These shims 400 are dimensioned so as to be in contact via these faces 402 only on very loaded phases, beyond the limit phase, so that the torque passes through them and the flexibility of the cage 220 conferred by the openings 300 is relieved of the peak load forces.

[0128] Preferably, the faces 402 are located in planes passing through the central axis X, which allows the shims 400 to come into contact with the cage 220 via these faces 402 during a bending deformation of the cage 220 about the central axis X. The bearing faces 402 or the aforementioned planes may be inclined to each other at an angle between 20 and 80°, this angle being measured in a plane perpendicular to the axis X.

[0129] In the examples shown, which are not exhaustive, the second bearing holes 294 of the second disk 238 may have diameters D1 larger than those D2 of the first bearing holes 292 (Figure 7). This is because the second bearing holes 294 can accommodate mounting covers for the second longitudinal ends of the bearings. These second longitudinal ends are engaged in holes in the covers, which are themselves engaged in the second bearing holes 294 of the second disk 238. The holes in the covers may have a diameter equal to the diameter D2 of the first bearing holes 292.

Claims

DEMANDS 1. Mechanical gearbox (10) for an aircraft turbomachine (1), this gearbox comprising: - a solar (11) centered on a central axis (X), - a corona (14) centered on the central axis (X) and extending around the solar (11), - satellites (12) guided in rotation by bearings (8) centered on bearing axes (Y) which are parallel to the central axis (X), the satellites (12) being meshed with the solar element (11) and the corona (14), and - a satellite carrier (213) comprising a cage (220) formed in one piece and in which are mounted the solar array (11) and the satellites (12) and their bearings (8), the cage (220) comprising: - a first disk (236) centered on the central axis (X) and extending perpendicularly to this central axis (X), this first disk (236) having first bearing orifices (292) centered respectively on the bearing axes (Y) and which receive first longitudinal ends (8a) of the bearings (8), - a second disk (238) centered on the central axis (X) and extending parallel and axially at a distance from the first disk (236), this second disk (238) having second bearing ports (294) which are respectively centered on the bearing axes (Y) and which receive second longitudinal ends (8b) of the bearings (8), and - bridges (296) extending between the first and second discs (236) and connecting them, the bridges (296) being circumferentially separated from each other by openings (243) through which the satellites (12) pass for their engagement with the ring (14), characterized in that the cage (220) comprises around the central axis (X) an annular row of lights (300) formed in the first disc (236) and extending radially from the outer periphery of the cage (220) where they open radially outwards next to said openings (243) to the inner periphery of the cage (220), and in that wedges (400) are mounted in these lights (300) and are fixed to the cage (220), each of these wedges (400) having at least one bearing face (402) which is opposite a face (404) of the corresponding light (300) and which is able to be separated from this face of the light by a predetermined clearance (J) in normal operation, and to come into contact with this face of the light (300) during a deformation of the cage (220).

2. Reducer (10) according to claim 1, wherein the outlet of each of the lights (300) at the outer periphery of the cage (220) has a general U-shape.

3. Reducer (10) according to claim 2, wherein the U-shaped form comprises a central and straight part (300a) formed in the first disk (236) and extending in a plane (Q1) perpendicular to the central axis (X), and two lateral parts (300b, 300c) formed respectively in two bridges (296).

4. Reducer (10) according to claim 3, wherein the lateral parts (300b, 300c) are perpendicular to the median part (300a) and extend respectively in two planes (Q2, Q3) passing through the central axis (X).

5. Reducer (10) according to claim 3 or 4, wherein the middle part (300a) has a width (L1) or axial dimension which is less than a width (L2) or circumferential dimension of each of the lateral parts (300b, 300c).

6. Reducer (10) according to any one of the preceding claims, wherein the wedges (400) have a shape complementary to the opening of the lights (300) at the outer periphery of the cage (220).

7. Reducer (10) according to any one of the preceding claims, wherein the outlet of each of the lights (300) at the outer periphery of the cage (220) receives a single wedge (400), or two wedges (400).

8. Reducer (10) according to any one of the preceding claims, wherein the shims (400) have a general U or L shape.

9. Reducer (10) according to claim 8, wherein the wedges (400) each comprise a fixing part (406) which is connected to a support lug (408) in the case of an L-shaped wedge, and which extends between two support lugs (408) in the case of a U-shaped wedge, the or each support lug (408) comprising said at least one bearing face (402).

10. Reducer (10) according to claim 9, wherein the support leg or each support leg (408) is thickened relative to the fixing part (406).

11. Reducer (10) according to claim 9 or 10, wherein the fixing part (406) includes one or more holes (410) for the passage of fixing elements (412).

12. Reducer (10) according to any one of claims 9 to 11, wherein the fixing part (406) is connected to the support leg or each support leg (408) by a web of elastically deformable material (416).

13. Reducer (10) according to claim 12, wherein the material veil (416) has a minimum thickness (Emin) less than that (E) of the fixing part (406).

14. Reducer (10) according to any one of claims 9 to 13, wherein the support leg or each support leg (408) has a general parallelepiped shape and comprises on a first side said at least one support face (402), and on a second side opposite the first side another face (418) which is in permanent contact with a face (420) of the corresponding light (300) in particular in normal operation.

15. Reducer (10) according to any one of claims 9 to 13, depending on any one of claims 3 to 5, wherein the fixing part (406) is located in the middle part (300a) of the corresponding light (300), and the support lug or each support lug (408) is located in one of the lateral parts (300b, 300c) of this light (300).

16. Reducer (10) according to any one of the preceding claims, wherein the cage (220) is formed in one piece with a cage holder (222) which has a tree-section shape and may include external grooves for coupling to another tree.

17. Reducer (10) according to any one of the preceding claims, in which the bearing faces (402) are located in planes passing through the central axis (X).

18. Turbomachine (1), in particular for aircraft, comprising a reduction gear (10) according to any one of the preceding claims.

Images