Assembly for a mechanical reducer of an aircraft
Patent Information
- Application Number
- EP2024722677
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-04-06
- Filing Date
- 2024-04-04
- Publication Date
- 2026-02-11
AI Technical Summary
Mechanical splash gearboxes in aircraft systems face challenges in ensuring uniform lubrication of all meshing components, leading to inefficiencies and potential wear due to uneven oil distribution.
The integration of oil scoops with the planet carrier, which are regularly distributed around the axis and interspersed between satellites, redirecting oil to ensure lubrication of gears by scooping and directing it towards the meshing components, compatible with various gearbox types and configurations.
This solution effectively ensures that all meshing components are adequately lubricated, enhancing the operational efficiency and longevity of the gearbox by ensuring consistent oil distribution and reducing wear.
Smart Images
Figure FR2024050439_10102024_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] TITLE: ASSEMBLY FOR AN AIRCRAFT MECHANICAL REDUCER
[0003] Technical field of the invention
[0004] The present invention relates to an assembly for an aircraft mechanical reducer, and in particular for an aircraft turbomachine or for a system for driving a wheel of an aircraft landing gear. This assembly comprises satellites and a satellite carrier.
[0005] Technical background
[0006] The state of the art includes in particular documents FR-A1 -3 025 780, FR-B1 -3 066 792, FR-B1 -3 071 023, FR-3 072 749, FR-B1 -3 098 562, FR-B1 - 3 101 129, and US-A-5,669,844.
[0007] The role of a mechanical reducer is to modify the speed and torque ratio between the input shaft and the output shaft of a mechanical system.
[0008] New generations of dual-flow turbomachines, particularly those with a high bypass ratio, include a mechanical reducer to drive the shaft of a fan. Typically, the reducer's purpose is to transform the so-called fast rotation speed of a power turbine shaft into a slower rotation speed for the shaft driving the fan.
[0009] A system for driving a wheel of a landing gear may further comprise a mechanical reducer, as proposed by the Applicant in document EP-A1-3 882 136.
[0010] Such a reducer comprises a central pinion, called a sun gear, a crown gear and pinions called planet gears, which are meshed between the sun gear and the crown gear. The planet gears are held by a frame called a planet carrier. The sun gear, the crown gear and the planet carrier are planet gears because their axes of revolution coincide with the axis of the turbomachine or the wheel of a landing gear. The planet gears each have a different axis of revolution equally distributed over the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis X.
[0011] There are several gearbox architectures. In the state of the art, gearboxes are planetary or epicyclic. In other similar applications, there are so-called differential or "compound" architectures.
[0012] - On a planetary reducer, the planet carrier is fixed and the crown constitutes the output shaft of the device which rotates in the opposite direction to the solar.
[0013] - On an epicyclic reducer, the crown is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar.
[0014] - On a differential reducer, no element is fixed in rotation. The crown rotates in the opposite direction to the sun and the planet carrier.
[0015] Gearboxes can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, friction or even magnetic fields. There are several types of contact meshing such as straight, helical or herringbone teeth.
[0016] Gearboxes can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, friction or even magnetic fields.
[0017] A satellite may comprise one or two meshing stages. In the present application, the term "stage" or "toothing" means a series of meshing teeth with a series of complementary teeth. A toothing may be internal or external. A single-stage satellite comprises a toothing which may be straight, helical or herringbone and whose teeth are located on the same diameter. This toothing cooperates with both the sun gear and the crown. A double-stage satellite comprises two toothings or two series of teeth which are located on different diameters. A first toothing cooperates with the sun gear and a second toothing cooperates with the crown gear.
[0018] There is also a configuration, called Wolfrom, in which the satellites are double-stage and have a first toothing that cooperates with the sun and a crown, and a second toothing that cooperates with a second crown. The reducer thus comprises two crowns, one of which is fixed and the other mobile.
[0019] A mechanical reducer must be lubricated to ensure its operation and also to evacuate the calories generated during operation. For this, lubricating oil is used.
[0020] There are two technologies for lubricating a mechanical reducer.
[0021] The first technology involves lubricating the gearbox using oil jets. The jets are supplied with oil and spray oil onto the gears, i.e., the teeth of the sun gear, the planet gears, and the crown(s). This oil is then drained and recovered for recycling.
[0022] Another technology is to use an oil splash reducer. The oil is permanently present in the reducer, which includes a sealed enclosure for retaining this oil. The oil level in the reducer enclosure is such that at least part of the planet gears, the planet carrier, and the crown gear(s) splash in the oil, i.e. are permanently bathed in the oil.
[0023] In a splash reducer, due to gravity, the oil flows and is stored in the lower part of the housing and the reducer. Therefore, the teeth located in the lower part are immersed in oil while the teeth in the upper part are not immersed in oil. During operation, the rotating elements contained in the housing rotate at high speeds and carry the oil. The oil tends to be centrifuged and form an oil ring inside the housing. One of the problems with a mechanical splash reducer is ensuring that all its gears are well lubricated.
[0024] The invention provides a simple, effective and economical solution to this problem.
[0025] Summary of the invention
[0026] The invention relates to an assembly comprising satellites and a satellite carrier for a mechanical splash reducer, in particular for an aircraft, this assembly having an annular shape around a longitudinal axis, the satellites being regularly spaced around said axis and each comprising two cylindrical longitudinal ends, the satellite carrier having an annular shape around said axis and comprising housings for receiving the satellites, these housings being regularly distributed around said axis and each being delimited axially by two walls extending respectively in two planes perpendicular to said axis, and two lateral partitions extending between the walls, these walls comprising orifices for mounting said longitudinal ends of the satellites, characterized in that it further comprises oil scoops which are integral with the satellite carrier and which are regularly distributed around said axis and interposed between the satellites,each of these scoops comprising at least one curved bucket whose concavity extends partly around one of the satellites and is separated from this satellite by one of said partitions.,
[0027] As mentioned above, during operation, an oil ring forms around the reducer in its enclosure. The invention makes it possible to force the oil to move and, for example, to redirect it towards gears to be lubricated in the reducer. For this purpose, the assembly formed by the planet gears and the planet carrier includes oil scoops.
[0028] The solution proposed below is compatible with a single-stage or multi-stage reducer. It is compatible with an epicyclic, differential or Wolfrom type reducer. It is also compatible with straight, helical or herringbone teeth. It is compatible with any type of planet carrier, and in particular with a single-piece planet carrier. It is also compatible with any type of bearing, whether it is composed of rolling elements, a hydrodynamic bearing, etc. It is compatible with the use of the assembly and the reducer in a double-flow turbomachine, for example to drive a fan or a propeller. It is also compatible with the use of the assembly and the reducer in a system for driving a wheel of a landing gear.
[0029] The assembly according to the invention may comprise one or more of the following characteristics, taken in isolation from one another, or in combination with one another:
[0030] - each of the scoops comprises two curved cups whose concavities are oriented in opposite directions to extend respectively around the satellites between which the scoop is mounted,
[0031] - the two buckets of each of the scoops are connected to each other by a fixing plate to the planet carrier,
[0032] - each of the scoops is made of a single piece,
[0033] - the bucket and the satellite around which the concavity of the bucket extends are located at a circumferential distance from each other which is greater than or equal to half a maximum radius of the satellite,
[0034] - the or each bucket has an axial dimension which is less than an axial dimension of said partitions,
[0035] - Dext_CI < Dext_Go < Dext_Sa, and Dint_Sa < Dint_Go < Dint_CI, in which:
[0036] Dext_CI is the diameter of a circumference centered on said axis and passing through radially external ends of said partitions,
[0037] Dext_Go is the diameter of a circumference centered on said axis and passing through radially external ends of said buckets,
[0038] Dext_Sa is the maximum diameter of a circumference centered on said axis and passing through the satellites, Dint_Sa is the minimum diameter of a circumference centered on said axis and passing through the satellites,
[0039] Dint_Go is the diameter of a circumference centered on said axis and passing through radially inner ends of said buckets, and
[0040] Dint_CI is the diameter of a circumference centered on said axis and passing through radially internal ends of said partitions.
[0041] - each of the scoops is fixed by screws or bolts to the satellite carrier, these screws or bolts also being used to fix two rings of the satellite carrier respectively forming said walls of said housings; as a variant, each of the scoops is welded to the satellite carrier,
[0042] -- said walls comprise first walls connected to each other to form a first ring of the planet carrier, this first ring extending substantially in a plane perpendicular to said longitudinal axis,
[0043] -- said walls comprise second walls which are at a circumferential distance from each other and which are connected to each other by bridges of material to form a second ring of the planet carrier, the second walls extending substantially in a plane perpendicular to said longitudinal axis, and said bridges of material extending outside this plane,
[0044] - the scoops are formed in one piece with the planet carrier or part of the planet carrier;
[0045] - said partitions are formed in a single piece with one of the walls of the planet carrier.
[0046] The present invention also relates to a mechanical splash reducer, in particular for an aircraft, this reducer comprising:
[0047] - a mobile solar system rotating around a longitudinal axis,
[0048] - at least one crown mounted around the solar and said longitudinal axis, and
[0049] - an assembly as described above which is rotatable around said longitudinal axis, the satellites of this assembly being mounted between the sun and the crown(s) and meshed with the sun and the crown, these satellites having axes of rotation parallel to said axis, and
[0050] - a sealed enclosure in which the solar, the first crown, and said assembly are located, this enclosure being configured to contain oil intended to be scooped by the oil scoops of said assembly.
[0051] According to one embodiment of the invention, the satellites are double-stage and comprise a first stage meshed with a first crown movable around said longitudinal axis and the sun, and a second stage meshed with a second crown which is fixed with respect to said longitudinal axis.
[0052] Advantageously, the or each bucket of each of the scoops is axially offset from the crown to scoop oil next to the crown, or is axially offset from the fixed crown and radially aligned with the movable crown to scoop oil at the level of this movable crown, or is axially offset from the movable crown and radially aligned with the fixed crown to scoop oil at the level of this fixed crown.
[0053] The invention further relates to a turbomachine or a system for driving a landing gear wheel, in particular an aircraft wheel, comprising at least one assembly or mechanical reducer as described above.
[0054] Brief description of the figures
[0055] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:
[0056] [Fig. 1] Figure 1 is a schematic axial sectional view of an aircraft turbomachine,
[0057] [Fig. 2] Figure 2 is a partial schematic view in axial section of a planetary mechanical reducer with oil jets,
[0058] [Fig. 3] Figure 3 is a partial schematic axial sectional view of a planetary mechanical splash reducer, [Fig. 4] Figure 4 is a partial schematic axial sectional view of a Wolfrom mechanical splash reducer,
[0059] [Fig. 5] Figure 5 is a schematic front view of an assembly according to an embodiment of the invention, for a mechanical splash reducer,
[0060] [Fig. 6] Figure 6 is an enlarged schematic view of part of the assembly of Figure 5, and illustrates the operation of the reducer and the rotation of the assembly,
[0061] [Fig. 7] Fig. 7 is another diagrammatic view on a larger scale of part of the assembly of Fig. 5, and illustrates the operation of the reducer and the rotation of the assembly,
[0062] [Fig. 8] Figure 8 is a partial schematic perspective view of a reducer comprising an alternative embodiment of an assembly according to the invention,
[0063] [Fig. 9] Figure 9 is a partial schematic perspective view of a reducer comprising another alternative embodiment of an assembly according to the invention,
[0064] [Fig. 10] Figure 10 is a schematic perspective view of a wheel of an aircraft landing gear and a drive system for this wheel.
[0065] Detailed description of the invention
[0066] Figure 1 describes a turbomachine 1 which comprises, in a conventional manner, 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 form with it a high-pressure (HP) body. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and form with it a low-pressure (LP) body. The fan S is driven by a fan shaft 4 which is rotated with the LP shaft 3 by means of a reduction gear 6. This reduction gear 6 may be of the planetary, epicyclic or Wolfrom type for example.
[0067] Although the following description concerns a planetary or epicyclic type reducer, it also applies to a mechanical differential in which the three components, namely the planet carrier, the crown wheel and the sun gear, are mobile in rotation, the rotation speed of one of these components depending in particular on the difference in speeds of the other two components. It also applies to the particular case of a double-stage reducer of the Wolfrom type.
[0068] The reducer 6 is positioned in the upstream part of the turbomachine. A fixed structure comprising schematically, here, an upstream part 5a and a downstream part 5b which composes the motor casing or stator 5 is arranged so as to form an enclosure E surrounding the reducer 6. This enclosure E is here closed upstream by seals at the level of a bearing allowing the fan shaft 4 to pass through, and downstream by seals at the level of the passage of the LP shaft 3.
[0069] Figure 2 shows a reducer 6 which can take the form of different architectures depending on whether certain parts are fixed or rotating. At the input, the reducer 6 is connected to the LP shaft 3, for example via internal splines 7a. Thus the LP shaft 3 drives a planetary pinion called the sun gear 7. Conventionally, the sun gear 7, whose axis of rotation is the same as that of the turbomachine X, drives a series of pinions called satellites 8, which are distributed over the same diameter around the axis of rotation X. This diameter is equal to twice the operating center distance between the sun gear 7 and the satellites 8. The number of satellites 8 is generally defined between three and seven for this type of application.
[0070] The set of satellites 8 is held by a satellite carrier 10. Each satellite 8 rotates around its own Y axis, and meshes with the crown 9.
[0071] At the output we have: ■ in an epicyclic configuration, the set of satellites 8 drives the planet carrier 10 in rotation around the X axis of the turbomachine. The crown is fixed to the engine casing or stator 5 via a crown carrier 12 and the planet carrier 10 is fixed to the fan shaft 4.
[0072] ■ in a planetary configuration, all of the planet gears 8 are held by a planet gear carrier 10 which is fixed to the engine casing or stator 5. Each planet gear drives the crown wheel which is attached to the fan shaft 4 via a crown wheel carrier 12.
[0073] Each satellite 8 is mounted to rotate freely using a bearing 11, for example of the rolling bearing or hydrodynamic plain bearing type. In the case of a plain bearing, the bearing 11 comprises a bearing body 10b and the bearing bodies 10b of the different plain bearings are positioned relative to each other and are carried by walls 10a1, 10a2 of the planet carrier 10. The walls 10a1, 10a2 have an annular shape and are perpendicular to the axis X. They are axially spaced from each other and receive between them the bearings 11, the satellites 8 and the solar 7.
[0074] There are a number of bearings 11 equal to the number of satellites 8. For reasons of operation, assembly, manufacturing, control, repair or replacement, the bearings 11 (and in particular the bearing bodies 10b) and the walls 10a1, 10a2 can be separated into several parts.
[0075] For the same reasons mentioned above, the 8d toothing of a reducer can be separated into several helices, each having a median plane P. In our example, we detail the operation of a multi-helix reducer with a crown separated into two half-crowns:
[0076] ■ an upstream half-crown 9a consisting of a rim 9aa and a fixing half-flange 9ab. On the rim 9aa is the upstream helix of the gear teeth. This upstream helix meshes with that of the satellite 8 which meshes with that of the solar 7.
[0077] ■ a downstream half-crown 9b consisting of a rim 9ba and a half-fixing flange 9bb. On the rim 9ba is the downstream helix of the gear teeth. This downstream helix meshes with that of the satellite 8 which meshes with that of the solar 7.
[0078] If the propeller widths vary between the sun gear 7, the satellites 8 and the crown 9 because of the tooth overlaps, they are all centered on a median plane P for the upstream propellers and on another median plane P for the downstream propellers.
[0079] The half-clamp 9ab of the upstream crown 9a and the half-clamp 9bb of the downstream crown 9b form the crown mounting flange 9c. The crown 9 is fixed to a crown carrier by assembling the crown mounting flange 9c and the crown carrier mounting flange 12a using a bolted assembly for example.
[0080] Alternatively, the flange 9c of the crown 9 could be replaced by splines.
[0081] The arrows in Figure 2 describe the routing of the oil in the reducer 6. The oil arrives in the reducer 6 from the stator part 5 in the distributor 13 by different means which will not be specified in this view because they are specific to one or more types of architecture. The distributor is separated into two parts, generally each repeated by the same number of satellites. The injectors 13a have the function of lubricating the teeth and the arms 13b have the function of lubricating the bearings 11. The oil is brought to injectors 13a to exit through ends 13c in order to lubricate with oil the teeth of the satellites 8, the sun 7 and also the crown 9. The oil is also brought to the arm 13b and circulates via the supply mouth 13d of the bearing body 10b in an internal cavity 10c of the latter.The oil then circulates in this cavity 10c to supply oil passage orifices 10d to an external cylindrical guide surface of the corresponding satellite.
[0082] The reducer 6 in Figure 2 is thus a reducer of the type with oil jets or injectors.
[0083] On the contrary, the present invention relates to a splash type reducer, two examples of which are illustrated in Figures 3 and 4. In Figure 3, the reducer 106 is a splash planetary reducer, that is to say its ring gear 109 is movable and its planet carrier 110 is fixed, or an epicyclic splash reducer, that is to say its ring gear is fixed and its planet carrier is movable. As seen in this figure, the reducer 106 is enclosed in a sealed enclosure Q.
[0084] The enclosure Q may be formed by one or more annular casings 120, 122 assembled together. Sealing is ensured by seals 124 or the like which are, for example, located:
[0085] - between the casing 120, 122 of the enclosure Q and the solar 107 or the shaft secured to the solar or coupled with the solar,
[0086] - between the crown 109 or the crown carrier 112 and the casing 120, 122 of the enclosure Q.
[0087] When stopped, the oil H1 contained in the enclosure Q is located in the lower part of the reducer 106 and in particular of the enclosure Q. A part of the crown 109, the satellites 108 and the planet carrier 110 bathe or splash in this oil. In operation, a ring of oil H2 forms inside the enclosure Q, all around the axis X.
[0088] In Figure 4, the reducer 206 is a Wolfrom splash reducer, that is, it comprises two crowns 209a, 209b, namely a movable crown 209a and a fixed crown 209b. As seen in this figure, the reducer 206 is also enclosed in a sealed enclosure Q.
[0089] The satellites 208 are double-stage and comprise a first stage 208a meshed with the first ring 209a and the sun gear 207, and a second stage 208b meshed with a second ring 209b which is fixed with respect to said longitudinal axis X.
[0090] The enclosure Q may be formed by one or more annular casings 220, 222 assembled together. The fixed crown 209b is here fixed to the casing(s) 220, 222 of the enclosure Q, and in particular interposed between two casings 220, 222 of the enclosure Q. The seal is ensured by annular seals 225 or the like which are for example located:
[0091] - between the casing 220, 222 of the enclosure Q and the solar 207 or the shaft secured to the solar or coupled with the solar,
[0092] - between the casing 220, 222 of the enclosure Q and the movable crown 209a, and
[0093] - between the mobile crown 209a and the solar 207 or the shaft secured to the solar or coupled with the solar.
[0094] There may also be seals between the planet carrier 210 and the solar 207 or the shaft secured to the solar or coupled with the solar, as well as between this solar 207 or this shaft and the movable crown 209a or the element secured in rotation to the movable crown.
[0095] The rotating mobile elements are guided by rolling bearings 224 which are for example located:
[0096] - between the casing 220, 222 of the enclosure Q and the movable crown 209a,
[0097] - between the casing 220, 222 of the enclosure and the planet carrier 210,
[0098] - between the satellite carrier 20 and the satellites 208, and
[0099] - between the mobile crown 209a and the solar 207 or the shaft secured to the solar or coupled with the solar.
[0100] When stopped, the oil H1 is located in the lower part of the reducer 206 and in particular of the enclosure Q. A part of the crowns 209a, 209b, the satellites 208 and the planet carrier 210 are immersed or splashed in this oil. In operation, a ring of oil H2 forms inside the enclosure Q, all around the axis X.
[0101] The present invention relates to an assembly 230 for a mechanical reducer 106, 206 of an aircraft, this assembly 230 comprising satellites 232 and a planet carrier 234. This assembly 230 is rotatable around the X axis, so the reducer 106, 206 can be of the epicyclic, differential or Wolfrom type. Furthermore, this reducer 106, 206 can be used in a turbomachine 1 such as that illustrated in FIG. 1, for driving a fan S, or in another context such as in a system for driving a wheel for an aircraft landing gear (see FIG. 10).
[0102] The assembly 230 according to the invention can cooperate with a single crown 109 as in the case of the reducer 106 of figure 3, or with two separate crowns, respectively mobile 209a and fixed 209b, as in the reducer 206 of figure 4.
[0103] Figures 5 to 7 illustrate a first embodiment of an assembly 230 according to the invention, and Figures 8 and 9 illustrate alternative embodiments of this assembly 230.
[0104] The satellites 232 are regularly spaced around the axis X and each comprise two cylindrical longitudinal ends 232a, as is also visible in Figures 3 and 4. Each of the satellites 232 may comprise a single toothing 232b intended to be meshed with the sun 107 and the crown 109. Alternatively, each of the satellites 232 may comprise two toothings 232b, one of which is meshed with the sun 207 and the movable crown 209a and the other of which is meshed with the fixed crown 209b.
[0105] In a manner known per se, the or each toothing 232b of each satellite 232 may be formed in a single piece with a physical axis centered on the Y axis and comprising the two longitudinal ends 232a. This is for example the case of one of the teeth of the satellites 208 of FIG. 4 (the one on the left), which is formed in a single piece with the two longitudinal ends. Alternatively, the or each toothing 232b of each satellite 232 could be mounted by shrink-fitting onto a physical axis comprising these longitudinal ends 232a. This is for example the case of the other of the teeth of the satellites 208 of FIG. 4 (the one on the right) and of the toothing of the satellites 108 of FIG. 3, which are each mounted by a plain bearing on a physical body comprising two longitudinal ends 232a for mounting on the planet carrier.
[0106] We note: Dext_Sa, the maximum diameter of a circumference C1 centered on the X axis and passing through the satellites 232, and
[0107] Dint_Sa, the minimum diameter of a C2 circumference centered on the X axis and passing through the 232 satellites.
[0108] The satellite carrier 234 has an annular shape around the axis X and comprises housings 238 for receiving the satellites 232. These housings 238 are regularly distributed around the axis X and are each delimited axially by two walls 240, 242 extending respectively in two planes perpendicular to the axis X, and two lateral partitions 244 extending between the walls 240, 242.
[0109] The walls 240, 242 comprise the holes 236 for mounting the longitudinal ends 232a of the satellites 232.
[0110] The walls 240, 242 defining the housings 238 comprise first walls 240 connected to each other to form a first ring A1 around the axis. This first ring A1 extends mainly in a plane perpendicular to the axis X.
[0111] The second walls 242 are at a circumferential distance from each other, and are connected to each other by material bridges 243 to form a second ring A2 around the axis X. These material bridges 243 are intended to be applied and fixed to the first ring A1 to secure the two rings A1, A2 of the planet carrier 234 together. The second walls 242 thus define free circumferential spaces E between them.
[0112] Each of the second walls 242 is connected to the partitions 244 by its circumferential ends. The aforementioned spaces E are thus delimited in the circumferential direction by these partitions 244.
[0113] The partitions 244 may diverge from one another radially outwards, as in the example shown. For example, they form between them an angle α greater than or equal to 60°, measured in a plane perpendicular to the X axis (figure 5). Alternatively, this angle α may be less than 60° or even negative depending on the need. We note:
[0114] Dext_CI, the diameter of a circumference C3 centered on the X axis and passing through the radially external ends of the partitions 244, and
[0115] Dint_CI, the diameter of a circumference C4 centered on the X axis and passing through the radially inner ends of the partitions 244.
[0116] In particular, we can see in Figure 1 that:
[0117] Dext_CI < Dext_Sa, and
[0118] Dint_CI > Dint_Sa.
[0119] The assembly 230 according to the invention further comprises oil scoops 250 which are integral with the planet carrier 234 and which are regularly distributed around the X axis and interposed between the satellites 232.
[0120] Each of the scoops 250 comprises at least one curved bucket 252, 254 whose concavity 256 extends partly around one of the satellites 232 and is separated from this satellite by one of the partitions 244.
[0121] In an oil jet reducer such as that shown in Figure 2, oil collectors may be interposed between the planet gears. These collectors have concavities surrounding the planet gears, as close as possible to their teeth, and the function of these collectors is to collect the oil sprayed by the teeth and guide its flow.
[0122] In the present invention, the scoops 250 do not have the same function because they are separated by the partitions 244 from the teeth 232b of the satellites 232, and are also at a distance from these teeth.
[0123] We therefore understand that the 250 scoops are housed in the aforementioned spaces E.
[0124] Each of the scoops 250 may comprise a single bucket 252 whose concavity 256 is oriented according to the direction of rotation of the planet carrier 234, as will be described in more detail below.
[0125] In the example shown, each of the scoops 250 comprises two curved cups 252, 254 whose concavities 256 are oriented in opposite directions to extend respectively around the satellites 232 between which the scoop 250 is mounted. The two cups 252, 254 of each scoop 250 can be connected to each other by a plate 258 for fixing to the planet carrier 234. This plate 258 extends for example in a plane perpendicular to the axis X and is applied axially against the planet carrier 234, and in particular against the first ring A1 formed by the first walls 240.
[0126] The plate 258 comprises axial orifices which are aligned with orifices of the planet carrier 234 for the passage of fixing means (not shown) of the screw-nut type or the like.
[0127] Alternatively, the plate 258 can be fixed to the planet carrier by welding. In this case, the plate 258 does not include holes for its fixing.
[0128] These fixing means can also be used for fixing the two rings A1, A2 of the planet carrier 234. The holes in the plate 258 are then aligned with holes in the two rings A1, A2 of the planet carrier 234.
[0129] Each of the scoops 250 may be formed from a single piece, as in the example shown. The bucket(s) 252, 254 and the plate 258 are thus formed from a single piece.
[0130] The bucket 252, 254 and the satellite 232 around which the concavity 256 of the bucket extends, are located at a circumferential distance H from each other which is for example greater than or equal to half the maximum radius R of the satellite 232 (figure 6).
[0131] The or each bucket 252, 254 has an axial dimension L1 which is less than an axial dimension L2 of the partitions 244.
[0132] We note:
[0133] Dext_Go, the diameter of a circumference C5 centered on the X axis and passing through the radially outer ends of the buckets 252, 254,
[0134] Dint_Go, the diameter of a D6 circumference centered on the X axis and passing through the radially inner ends of the buckets.
[0135] Preferably:
[0136] - Dext_CI < Dext_Go < Dext_Sa, and
[0137] - Dint_Sa < Dint_Go < Dint_CI. In a variant not shown, the scoops are formed in one piece with the planet carrier or a part of the planet carrier, and for example with one of these rings A1, A2.
[0138] The operation of the assembly 230 is schematically represented in Figures 6 and 7.
[0139] At start-up and during operation, the assembly 230 rotates around the X axis and its lower part is immersed in the oil H1 present in the reducer 106, 206 or arranged all around the reducer to form a ring H2 in the enclosure. The scoops 250 force the oil to move (arrows T) and direct this oil in a predetermined direction, for example towards gears to be lubricated. The gearing to be lubricated is for example that between the satellites and the fixed crown in the context of a Wolfrom type reducer.
[0140] Alternatively, the 250 scoops could simply collect oil from the bottom and bring it to the top. Once at the top, the oil could trickle down onto the elements requiring lubrication.
[0141] When there is a single scoop 250 between two adjacent satellites 232, their concavities 256 are oriented according to the direction of rotation of the assembly 230 so that the oil can be recovered and displaced by these concavities.
[0142] In the embodiment variant of Figure 8, the reducer 106 is of the epicyclic type and comprises a single crown 109. Each scoop 250 is positioned so that its bucket(s) 252, 254 is axially offset from the crown 109 to scoop oil next to the crown 109. In the present case, Dext-Go may be greater than or equal to the internal diameter of the crown 109.
[0143] In the embodiment variant of Figure 9, the reducer 206 is of the Wolfrom type and comprises two crowns, respectively mobile 209a and fixed 209b. Each scoop 250 is positioned so that its bucket(s) 252, 254 is axially offset from the crown 209b and radially aligned with the crown 209a. The scoops 250 are configured to scoop oil at the crown 209a. In the present case, Dext-Go may be greater than or equal to the internal diameter of the crown 209b and is less than the internal diameter of the crown 209a.
[0144] In these figures 8 and 9, the references 260 designate the aforementioned means of fixing the plates 258 of the scoops 250 to the planet carrier 234.
[0145] Figure 10 shows a system 310 for driving at least one wheel 312 of an aircraft landing gear 314.
[0146] The wheel 312 comprises a rim 316 which has an axis of rotation X. Conventionally, this rim 316 has a generally tubular or disc shape and carries a tire 318 at its periphery.
[0147] The system 310 comprises an electric motor 320 and a mechanical transmission system 322 between a shaft of the motor 320 and the rim 316 of the wheel 312.
[0148] In the example shown, the motor 320 and the system 322 each have a generally annular shape and are centered on the X axis. They are arranged next to each other and the system 322 is installed between the motor 320 and the rim 316. A part of the system 322, or even also a part of the motor 320, could be housed in the rim 16 to reduce the size of the system 310. The motor 320 and the system 322 can be protected by an external cylindrical cover 326 projecting on one side of the rim 316 or the tire 318.
[0149] The mechanical transmission system 322 comprises a mechanical reducer 328 similar to the reducer 106, 206 described above and including an assembly 230 within the meaning of the invention.
Claims
CLAIMS 1. Assembly (230) comprising satellites (232) and a planet carrier (234) for a mechanical splash reducer (106, 206), in particular for an aircraft, this assembly (230) having an annular shape around a longitudinal axis (X), the satellites (232) being regularly spaced around said axis (X) and each comprising two cylindrical longitudinal ends (232a), the planet carrier (234) having an annular shape around said axis (X) and comprising housings (238) for receiving the satellites (232), these housings (238) being regularly distributed around said axis (X) and each being delimited axially by two walls (240, 242) extending respectively in two planes perpendicular to said axis (X), and two lateral partitions (244) extending between the walls (240, 242), these walls (240, 242) comprising holes (236) for mounting said longitudinal ends (232a) of the satellites (232),characterized in that it further comprises oil scoops (250) which are integral with the planet carrier (234) and which are regularly distributed around said axis (X) and interposed between the planets (232), each of these scoops (250) comprising at least one curved cup (252, 254) whose concavity (256) extends partly around one of the planets (232) and is separated from this planet (232) by one of said partitions (244)., 2. Assembly (230) according to claim 1, in which each of the scoops (250) comprises two curved cups (252, 254) whose concavities (256) are oriented in opposite directions to extend respectively around the satellites (232) between which the scoop (250) is mounted.
3. Assembly (230) according to claim 2, in which the two buckets (252, 254) of each of the scoops (250) are connected to each other by a plate (258) for fixing to the planet carrier (234).
4. Assembly (230) according to one of the preceding claims, in which each of the scoops (250) is formed from a single piece.
5. Assembly (230) according to one of the preceding claims, in which the bucket (252, 254) and the satellite (234) around which the concavity (256) of the bucket extends, are located at a circumferential distance (H) from each other which is greater than or equal to half of a maximum radius (R) of the satellite (234).
6. Assembly (230) according to one of the preceding claims, in which the or each bucket (252, 254) has an axial dimension (L1) which is less than an axial dimension (L2) of said partitions (244).
7. Assembly (230) according to one of the preceding claims, in which: - Dext_CI < Dext_Go < Dext_Sa, and - Dint_Sa < Dint_Go < Dint_CI, in which: Dext_CI is the diameter of a circumference (C3) centered on said axis (X) and passing through radially external ends of said partitions (244), Dext_Go is the diameter of a circumference (C5) centered on said axis (X) and passing through radially external ends of said buckets (252, 254), Dext_Sa is the maximum diameter of a circumference (C1) centered on said axis (X) and passing through the satellites (232), Dint_Sa is the minimum diameter of a circumference (C2) centered on said axis (X) and passing through the satellites (232), Dint_Go is the diameter of a circumference (C6) centered on said axis (X) and passing through radially internal ends of said buckets (252, 254), and Dint_CI is the diameter of a circumference (C4) centered on said axis and passing through radially internal ends of said partitions (244).
8. Assembly (230) according to one of the preceding claims, in which each of the scoops (250) is fixed by screws or bolts (260) on the planet carrier (234), these screws or bolts (260) also being used to fix two rings (A1, A2) of the planet carrier (234) respectively forming said walls (240, 242) of said housings (238).
9. Assembly (230) according to one of the preceding claims, in which said partitions (244) are formed in a single piece with one of the walls (240, 242) of the planet carrier (234).
10. Assembly (230) according to one of the preceding claims, in which the scoops (250) are formed in one piece with the planet carrier (234) or a part of the planet carrier.
11. Mechanical splash reducer (106, 206), in particular for an aircraft, this reducer (106, 206) comprising: - a solar (107, 207) mobile in rotation around a longitudinal axis (X), - at least one crown (109, 209a) mounted around the solar (107, 207) and said longitudinal axis (X), and - an assembly (230) according to one of the preceding claims which is rotatable around said longitudinal axis (X), the satellites (108, 208) of this assembly being mounted between the sun (107, 207) and the crown (109, 209a) and meshed with the sun and the crown, these satellites (108, 208) having axes of rotation (Y) parallel to said axis (X), and - a sealed enclosure (Q) in which the solar (107, 207), the first crown (109, 209a), and said assembly (203) are located, this enclosure (Q) being configured to contain oil intended to be scooped by the oil scoops (250) of said assembly.
12. Reducer (106, 206) according to claim 11, in which the satellites (232) are double-stage and comprise a first stage meshed with a first crown (209a) movable around said longitudinal axis (X) and the sun (107, 207), and a second stage meshed with a second crown (209b) which is fixed with respect to said longitudinal axis (X).
13. Reducer (6) according to claim 11 or 12, in which the or each bucket (252, 254) of each of the scoops (250) is axially offset from the crown (109) to scoop oil next to the crown (109), or is axially offset from the fixed crown (209b) and radially aligned with the movable crown (209a) to scoop oil at the level of this movable crown (209a).
14. Turbomachine (1), in particular for an aircraft, comprising at least one assembly (230) according to one of claims 1 to 10 or a mechanical reducer (106, 206) according to one of claims 11 to 13.
15. Drive system (210) for a wheel (212) of landing gear (214), in particular for an aircraft, comprising at least one assembly (230) according to one of claims 1 to 10 or a mechanical reducer (106, 206) according to one of claims 11 to 13.