FIXED HOUSING FOR AN AIRCRAFT MECHANICAL REDUCER

Abstract

Fixed housing (122, 222) for a mechanical splash-type gearbox (106, 206), particularly for aircraft, this housing (122, 222) having an annular shape around a longitudinal axis (X) and comprising: - a cylindrical wall (230) extending around the axis (X) and connected to an annular mounting flange (232), this cylindrical wall (230) having a first internal cylindrical surface (230a), and - an annular wall (234) extending around the axis (X) and having its external periphery connected to the cylindrical wall (230), this annular wall (234) having a second annular surface (234a) connected to the first surface (230a), said first and second surfaces (230a, 234a) defining an annular space (E) configured to receive an oil ring (H2), characterized in that it further comprises less an oil deflector (240) projecting from at least one of the said first and second surfaces (230a, 234a). Figure for the abbreviation: Figure 5

Description

Title of the invention: FIXED HOUSING FOR AN AIRCRAFT MECHANICAL REDUCER Technical field of the invention

[0001] The present invention relates to a fixed housing for an aircraft mechanical reducer, and in particular for an aircraft turbomachine or for a drive system for a wheel of an aircraft landing gear. Technical background

[0002] The state of the art includes in particular documents FR-A1-3 025 780, FR-Bl-3 066 792, FR-B1-3 071 023, FR-3 072 749, FR-B1-3 098 562 and FR-Bl-3 101 129.

[0003] 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.

[0004] New generations of turbofan engines, particularly those with a high bypass ratio, include a mechanical gearbox to drive the shaft of a fan. Typically, the purpose of the gearbox is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan-driving shaft.

[0005] A wheel drive system of a landing gear may further include a mechanical reducer, as proposed by the Applicant in document EP-A1-3 882 136.

[0006] Such a reduction gear 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 a planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the axis of the turbomachine or landing gear wheel. The planet gears each have a different axis of revolution, equally spaced on the same operating diameter around the axis of the planet gears. These axes are parallel to the longitudinal axis X.

[0007] Several gearbox architectures exist. In the state of the art, gearboxes are of the planetary or epicyclic type. In other similar applications, there are so-called differential or "compound" architectures.

[0008] - On a planetary gearbox, the planet carrier is fixed and the ring gear constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0009] - On an epicyclic reducer, the ring gear is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar panel.

[0010] - On a differential reducer, no element is fixed for rotation. The ring rotates in the opposite direction to the solar panel and the satellite carrier.

[0011] Gear reducers can be composed of one or more meshing stages. This meshing is achieved in various ways, such as by contact, friction, or magnetic fields. There are several types of contact meshing, such as with spur, helical, or herringbone teeth.

[0012] Reducers can be composed of one or more meshing stages. This meshing is achieved in various ways such as by contact, by friction or by magnetic fields.

[0013] A satellite may comprise one or two gear stages. In this application, "stage" or "gear" means a series of meshing teeth with a series of complementary teeth. A gear may be internal or external. A single-stage satellite comprises a gear that may be straight, helical, or chevron-shaped, and whose teeth are located on the same diameter. This gear cooperates with both the sun gear and the crown gear.

[0014] A two-stage satellite comprises two sets of teeth or two series of teeth which are located on different diameters. A first set of teeth cooperates with the sun gear and a second set of teeth cooperates with the crown gear.

[0015] There is also a configuration, called Wolfrom, in which the satellites are double-staged and comprise a first set of teeth that cooperate with the sun gear and a ring gear, and a second set of teeth that cooperate with a second ring gear. The reduction gear thus comprises two ring gears, one of which is fixed and the other movable.

[0016] A mechanical reducer must be lubricated to ensure its operation and also to dissipate the heat generated during operation. For this purpose, lubricating oil is used.

[0017] There are two technologies for lubricating a mechanical reducer.

[0018] The first technology consists of lubricating the gearbox with oil jets. The jets are supplied with oil and spray oil onto the gears, i.e. the teeth of the solar cell, the satellites and the ring gear(s). This oil is then drained away and recovered for recycling.

[0019] Another technology involves using an oil-splash gearbox. Oil is constantly present in the gearbox, which includes a sealed housing for retaining this oil. The oil level in the gearbox housing is such that at least part of the planet gears, the planet carrier, and the ring gear(s) are constantly immersed in the oil.

[0020] In a splash-jet gearbox, due to gravity, the oil flows and collects in the lower part of the housing and the gearbox. Therefore, the gears located in the lower part are immersed in oil, while the gears in the upper part are not. During operation, the rotating elements contained within the housing rotate at high speeds and carry the oil along. The oil tends to be centrifuged and form an oil ring inside the enclosure.

[0021] One of the problems of a mechanical splash gearbox is to ensure that all its gears are well lubricated.

[0022] The invention provides a simple, effective and economical solution to this problem. Summary of the invention

[0023] The invention relates to a fixed housing for a mechanical splash-type gearbox, particularly for aircraft, this housing having an annular shape around a longitudinal axis and comprising:

[0024] - a cylindrical wall extending around the axis and connected to an annular flange of fixing, this cylindrical wall comprising a first internal cylindrical surface, and

[0025] - an annular wall extending around the axis and having its outer periphery connected to the cylindrical wall, this annular wall comprising a second annular surface connected to the first surface,

[0026] said first and second surfaces defining an annular space configured to receive an oil ring,

[0027] characterized in that it further comprises at least one oil deflector projecting on at least one of said first and second surfaces.

[0028] As mentioned above, during operation, an oil ring forms around the gearbox, particularly inside the housing and the casing that forms this housing. The oil ring is located at the annular space of the casing, on the aforementioned surfaces. The invention makes it possible to detach the oil from the casing and divert this oil towards gears or components to be lubricated within the gearbox. To this end, the casing includes at least one oil deflector intended to be located at the level of this oil ring.

[0029] The solution proposed below is compatible with single-stage or multi-stage gearboxes. It is compatible with planetary, epicyclic, differential, or Wolfrom-type gearboxes. It is also compatible with spur, helical, or herringbone gears. It is compatible with all types of planet carriers, and in particular with a one-piece planet carrier. Furthermore, it is compatible with all types of bearings, whether composed of rolling elements, hydrodynamic bearings, etc. It is compatible with the use of the ring gear and gearbox in a turbofan engine, for example, for driving a fan or a propeller. It is also compatible with the use of the ring gear and gearbox in a landing gear wheel drive system.

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036] The housing according to the invention may comprise one or more of the following features, taken individually or in combination with each other: • the casing includes a single deflector which is located on said first surface, or even also on said second surface; • the deflector is located at 12 o'clock by analogy with the face of a clock when the housing is in the operating position in which said longitudinal axis is horizontal; • the deflector or deflectors have a generally elongated shape, particularly along said longitudinal axis; • the deflector(s) extend from the second surface to the flange; • The deflector(s) have a general cross-sectional shape. angular; • the deflector or deflectors comprise a first side oriented in a circumferential direction, which has a concave curved shape, and optionally a second side oriented in an opposite circumferential direction, which has a concave curved shape; • the sides of the deflector(s) have different curved shapes and in particular curved shapes having different radii of curvature; • the deflector(s) has an arrowhead shape, one base of which is connected to the second surface and the tip is located on the flange side, or conversely, the base of which is located on the flange side and the tip is located on the side of the second surface; • the deflector(s) includes: - two lateral surfaces extending from the second surface towards the flange, and - two end surfaces extending from the tip towards the second surface, these end surfaces being concave and being connected respectively to the lateral surfaces to form curved edges extending from the second surface to the tip; — the two lateral surfaces form an angle greater than 90 and less than 180° between them, measured in a plane perpendicular to the longitudinal axis; — Alternatively, the two lateral surfaces form an angle of less than 90° between them, measured in a plane perpendicular to the longitudinal axis; these surfaces may be parallel. The present invention also relates to a mechanical reducer, particularly for an aircraft, this reducer comprising: - a mobile solar panel rotating around a longitudinal axis,

[0037] - at least a first ring mounted around the solar element and said longitudinal axis,

[0038] - satellites mounted between the solar system and the corona and meshed with the solar system and the crown, these satellites having axes of rotation parallel to said axis and being carried by a satellite carrier, and

[0039] - a sealed enclosure in which the solar array, corona, satellites and the satellite carrier, this enclosure being formed at least in part by a casing as described above.

[0040] Advantageously, the satellites are two-stage and comprise a first stage meshed with the first ring which is movable around said longitudinal axis and the solar, and a second stage meshed with a second ring which is fixed with respect to said longitudinal axis.

[0041] The reducer according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0042] — the housing is mounted in a sealed manner on the solar panel or on a shaft attached to the solar panel or coupled with this solar panel,

[0043] — the housing is fixed to said fixed ring, and in particular the housing flange is fixed to a fixed crown flange,

[0044] — alternatively, in a planetary or differential configuration for example, the The casing is fixed directly to a stator.

[0045] — the housing is mounted in a sealed manner on a fixed portion that rotates said movable crown,

[0046] — alternatively, in an epicycloidal or differential configuration for example, the The casing is mounted in a sealed manner on a fixed portion of the satellite carrier that rotates securely.

[0047] The invention further relates to a turbomachine or a landing gear wheel drive system, in particular of an aircraft, comprising at least one casing or mechanical reducer as described above. Brief description of the figures

[0048] 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:

[0049] [Fig-1] [Fig.1] is a schematic axial cross-sectional view of a turbomachine aircraft,

[0050] [Fig.2] [Fig.2] is a partial schematic axial cross-sectional view of a reducer planetary mechanics with oil jets,

[0051] [Fig. 3] [Fig. 3] is a partial schematic axial cross-sectional view of a reducer planetary sloshing mechanism,

[0052] [Fig.4] [Fig.4] is a partial schematic axial cross-sectional view of a Wolfrom mechanical bubble reducer,

[0053] [Fig.5] [Fig.5] is another partial schematic perspective and axial section view of a reducer comprising a fixed housing according to an embodiment of the invention,

[0054] [Fig.6] [Fig.6] is a schematic perspective view of the housing of [Fig.5],

[0055] [Fig.7] [Fig.7] is a view similar to that of [Fig.6] and illustrates the crankcase during the operation of the reducer,

[0056] [Fig.8] [Fig.8] is a partial schematic view of an alternative embodiment of a housing according to the invention, and

[0057] [Fig. 9] [Fig. 9] is a schematic perspective view of an aircraft landing gear wheel and a drive system for that wheel. Detailed description of the invention

[0058] Figure 1 describes a turbomachine 1 which conventionally comprises a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1e, a high-pressure turbine Id, a low-pressure turbine 1e, and an exhaust nozzle Ih. The high-pressure compressor 1b and the high-pressure turbine Id 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.

[0059] The blower S is driven by a blower shaft 4 which is driven in rotation with the shaft BP 3 by means of a reducer 6. This reducer 6 can be of the planetary, epicyclic or Wolfrom type for example.

[0060] Although the following description relates to a planetary or epicyclic type gearbox, it also applies to a mechanical differential in which the three components—the planet carrier, the ring gear, and the sun gear—are free to rotate, the rotational speed of one of these components depending, in particular, on the difference in speeds of the other two components. It also applies to the specific case of a two-stage Wolfrom-type gearbox.

[0061] The reducer 6 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 reducer 6. This enclosure E is here 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.

[0062] Figure 2 shows a reducer 6 which can take the form of different architectural The structure varies depending on whether certain parts are fixed or rotating. At the input, the gearbox 6 is connected to the shaft BP 3, for example, via internal splines 7a. Thus, the shaft BP 3 drives a planetary gear called the sun gear 7. Typically, the sun gear 7, whose axis of rotation coincides with that of the turbomachine X, drives a series of gears called sun gears 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 sun gears 8. The number of sun gears 8 is generally defined between three and seven for this type of application.

[0063] 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 ring 9.

[0064] 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 ring gear is fixed to the motor or stator housing 5 via a ring carrier 12 and the planet carrier 10 is fixed to the fan shaft 4. • In a planetary configuration, the set of satellites 8 is held by a satellite carrier 10 which is fixed to the motor or stator housing 5. Each satellite drives the ring which is brought to the blower shaft 4 via a ring carrier 12.

[0065] Each satellite 8 is mounted to rotate freely by means of a bearing 11, for example of the rolling 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 supported by walls 10a1, 10a2 of the satellite carrier 10.

[0066] The walls lOal, 10a2 have an annular shape and are perpendicular to the X axis. They are at an axial distance from each other and receive between them the bearings 11, the satellites 8 and the solar 7.

[0067] There is a number of bearings 11 equal to the number of satellites 8. For reasons of operation, assembly, manufacture, control, repair or replacement, the bearings 11 (and in particular the bearing bodies 10b) and the walls 10a1, 10a2 can be separated into several pieces.

[0068] For the same reasons mentioned above, the teeth 8d of a gearbox can be separated into several helices, each having a median plane P. In our example, we detail the operation of a multi-helix gearbox with a ring gear separated into two half-ring gears: • an upstream half-crown 9a consisting of a rim 9aa and a mounting flange half 9ab. The upstream helix of the reduction gear teeth is located on the rim 9aa. This upstream helix meshes with that of the satellite 8 which meshes with that of solar 7. • a downstream half-crown 9b consisting of a rim 9ba and a mounting flange half 9bb. On the rim 9ba is the downstream helix of the reduction gear teeth. This downstream helix meshes with that of the satellite 8, which meshes with that of the solar 7.

[0069] If the helix widths vary between the solar 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 helices and on another median plane P for the downstream helices.

[0070] The mounting half-flange 9ab of the upstream crown 9a and the mounting half-flange 9bb of the downstream crown 9b form the mounting flange 9c of the crown. The crown 9 is fixed to a crown carrier by assembling the mounting flange 9c of the crown and the mounting flange 12a of the crown carrier using, for example, a bolted assembly.

[0071] Alternatively, the flange 9c of the crown 9 could be replaced by grooves.

[0072] The arrows in [Fig.2] describe the flow of oil into reducer 6. The oil enters the gearbox 6 from the stator section 5 via the distributor 13 by various means, which will not be detailed in this view as they are specific to one or more types of architecture. The distributor is generally divided into two parts, each typically repeated with the same number of planetary gears. The injectors 13a lubricate the gear teeth, and the arms 13b lubricate the bearings 11. The oil is brought to injectors 13a and comes out through ends 13c to lubricate with oil the teeth of the satellites 8, the solar 7 and also the ring 9. The oil is also brought to the arm 13b and circulates via the supply mouth 13d of the bearing body 10b into an internal cavity 10c of the latter. The oil then circulates in this cavity 10c to supply oil passage orifices lOd to ​​an external cylindrical surface for guiding the corresponding satellite.

[0073] The reducer 6 of [Fig.2] is thus a reducer of the type with oil jets or injectors.

[0074] On the contrary, the present invention relates to a reducer of the splash-type, two examples of which are illustrated in figures 3 and 4.

[0075] In [Fig. 3], the reducer 106 is a splash-type planetary reducer, meaning that its ring gear 109 is movable and its planet carrier 110 is fixed. As can be seen in this figure, the reducer 106 is enclosed in a sealed housing Q.

[0076] The enclosure Q can be formed by one or more annular housings 120, 122 assembled together. Sealing is ensured by gaskets 124 or similar seals which are located, for example:

[0077] - between the casing 120, 122 of the enclosure Q and the solar element 107 or the shaft attached to the solar or coupled with solar power

[0078] - between the crown 109 or the crown carrier 112 and the housing 120, 122 of the enclosure Q.

[0079] When stationary, the oil H1 contained in the housing Q is located in the lower part of the gearbox 106 and, in particular, of the housing Q. Part of the ring gear 109, the planet gears 108, and the planet carrier 110 are immersed or bubble in this oil. During operation, a ring of oil H2 forms inside the housing Q, all around the X-axis.

[0080] In [Fig. 4], the reducer 206 is a Wolfrom splash-type reducer, that is to say, it comprises two rings 209a, 209b, namely a movable ring 209a and a fixed ring 209b. As can be seen in this figure, the reducer 206 is also enclosed in a hermetically sealed housing Q.

[0081] The satellites 208 are two-stage and comprise a first stage 208a meshed with the first ring 209a and the solar 207, and a second stage 208b meshed with a second ring 209b which is fixed with respect to said longitudinal axis X.

[0082] The enclosure Q can be formed by one or more annular housings 220, 222 assembled together. The fixed ring 209b is here fixed to the housing(s) 220, 222 of the enclosure Q, and in particular interposed between two housings 220, 222 of the enclosure Q.

[0083] Sealing is ensured by annular seals 225 or similar seals which are located, for example:

[0084] - between the casing 220, 222 of the enclosure Q and the solar element 207 or the shaft attached to the solar or coupled with solar power

[0085] - between the housing 220, 222 of the enclosure Q and the movable ring 209a, and

[0086] - between the movable ring 209a and the solar element 207 or the shaft attached to the solar element or coupled with solar power.

[0087] There may also be seals between the satellite carrier 210 and the solar 207 or the shaft attached to or coupled with the solar, as well as between this solar 207 or this shaft and the movable ring 209a or the element attached in rotation to the movable ring.

[0088] The rotating moving parts are guided by roller bearings 224 which are, for example, located:

[0089] - between the housing 220, 222 of the enclosure Q and the movable ring 209a,

[0090] - between the housing 220, 222 of the enclosure and the satellite carrier 210,

[0091] - between the satellite carrier 20 and the satellites 208, and

[0092] - between the movable ring 209a and the solar element 207 or the shaft attached to the solar element or coupled with solar power.

[0093] When stopped, the H1 oil is located in the lower part of the reducer 206 and in particular of The enclosure Q. Part of the rings 209a, 209b, the satellites 208 and the satellite carrier 210 are immersed or bubbled in this oil. During operation, a ring of H2 oil forms inside the enclosure Q, all around the X-axis.

[0094] The present invention relates to a fixed housing 122, 222 for a mechanical gearbox 106, 206 for an aircraft. Since the housing 122, 222 is fixed, the gearbox 106, 206 can be of the planetary, epicyclic, differential, or Wolfrom type. Furthermore, this gearbox 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 wheel drive system for an aircraft landing gear (see [Fig. 9]).

[0095] Figures 5 to 7 illustrate a first embodiment of a housing 122, 222 according to the invention, and [Fig.8] illustrates a variant embodiment of this housing.

[0096] The housing 122, 222 is preferably metallic. Its main material is therefore a metallic alloy.

[0097] In [Fig. 5], it can be seen that the housing 122, 222 delimits at least in part the enclosure Q which surrounds and encloses the rest of the reducer, this enclosure Q being sealed and containing oil for the bubbling of the reducer. In this enclosure Q are located the solar element 107, 207, the satellite elements 108, 208, the ring(s) 109, 209a, 209b depending on the configuration of the reducer 106, 206, and the satellite carrier 110, 210 (not visible in [Fig. 5]), as mentioned above.

[0098] The housing 122, 222 has an annular shape around the X axis and comprises:

[0099] - a cylindrical wall 230 extending around the X axis and connected to a flange annular fixing 232, this cylindrical wall 230 comprising a first internal cylindrical surface 230a, and

[0100] - an annular wall 234 extending around the axis X and having its external periphery connected to the cylindrical wall 230, this annular wall 234 comprising a second annular surface 234a connected to the first surface 230a.

[0101] The flange 232 of the housing 122, 222 is fixed to a flange of the fixed ring 209b and could be fixed to a flange of another housing of the enclosure, such as the housing 120 of [Fig.3].

[0102] The first and second surfaces 230a, 234a define an annular space E configured to receive the aforementioned oil ring H2.

[0103] In the example shown, the housing 122, 222 has a general L-shaped cross-section, its annular wall 234 being a radial wall. Alternatively, the wall 234 could be a frustoconical wall.

[0104] As also mentioned above, the housing 122, 222 could be mounted on other elements of the reducer in a sealed manner by means of gaskets (see figures 3 and 4).

[0105] According to the invention, the housing 122, 222 comprises at least one oil deflector 240 projecting on at least one of the first and second surfaces 230a, 234a.

[0106] In the embodiments illustrated in the drawings, the housing 122, 222 comprises a single deflector 240 which is located essentially on the first surface 230a. However, it can be seen that the deflector 240 is connected to the second surface 234a.

[0107] In the examples shown, the deflector 240 is located at 12 o'clock by analogy with the dial of a clock when the housing 122, 222 is in the operating position in which its longitudinal axis X is horizontal.

[0108] The deflector 240 has a generally elongated shape, particularly along the longitudinal axis X. In the examples shown, it extends axially from the second surface 234a to the flange 232.

[0109] The deflector or deflectors 240 may have a generally triangular cross-sectional shape, as illustrated in Figures 5 to 7

[0110] The deflector 240 may include a first side 240a oriented in a circumferential direction, which has a concave curved shape, and optionally a second side 240b oriented in an opposite circumferential direction, which has a concave curved shape ([Fig.6]).

[0111] The sides 240a, 240b of the deflector(s) 240 may have identical or different curved shapes, and in particular curved shapes with different radii of curvature. These radii of curvature may be chosen according to the direction of rotation of the oil in the ring H2.

[0112] Alternatively, the deflector 240 may have an arrowhead shape of which a base 240c is connected to the second surface 234a and the tip 240d is located on the side of the flange 232, as illustrated in the alternative embodiment of [Fig.8].

[0113] In the example shown, the deflector 240 may include:

[0114] - two lateral surfaces 240e, 240f extending from the second surface 234a in direction of flange 232, these surfaces 240e, 240f forming between them an angle α greater than 90° and less than 180°, measured in a plane perpendicular to the longitudinal axis X, and

[0115] - two end surfaces 240g, 240h extending from the tip 240d in direction of the second surface 234a, these end surfaces 240g, 240h being concave curved and being connected respectively to the lateral surfaces to form curved edges 242 extending from the second surface 234a to the tip 240d.

[0116] Alternatively, the surfaces 240e, 240f could form an angle α of less than 90°, or even as low as 0°. In the latter case, these surfaces would be parallel.

[0117] The operation of the housing 122, 222 according to the invention is similar regardless of its embodiment. This operation is schematically represented in [Fig.7].

[0118] During the operation of the reducer 106, 206, an oil ring H2 forms in the reducer 106, 206 and in particular in the enclosure Q, between the surfaces 230a, 234a.

[0119] In this ring H2, the oil is set in rotation by the ring 109 or the movable ring 209a (arrow Fl). This rotating oil reaches the deflector 240, which alters its trajectory and detaches it from the surface 230a, or even from the surface 234a. The oil is then diverted in a predetermined direction, for example, towards gears to be lubricated (arrows F2). The gear to be lubricated is, for example, that between the planets 108, 208 and the ring(s) 109, 209a, 209b.

[0120] Although the preceding examples illustrate a deflector 240 located at the top of the housing 122, 222, it is possible to position it anywhere around the housing 122, 222, as required. It is also possible to add multiple instances of these deflectors 240.

[0121] On the other hand, although the illustrations are based on a 122, 222 Wolfrom type reducer housing, this solution is compatible with all types of reducers described in the introduction (epicycloidal, planetary, Wolfrom, ...), single stage or multi-stage.

[0122] Fig. 9 shows a drive system 310 for at least one wheel 312 of an aircraft landing gear 314.

[0123] The wheel 312 has a rim 316 which has an axis of rotation X. In a conventional manner, this rim 316 has a general tubular or disc shape and carries a tire 318 on its periphery.

[0124] The system 310 includes 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.

[0125] 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 side by side, and the system 322 is installed between the motor 320 and the rim 316. Part of the system 322, or even 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 from one side of the rim 316 or the tire 318.

[0126] The mechanical transmission system 322 includes a mechanical reducer 328 similar to the reducer 106, 206 described above and including a housing 122, 222 within the meaning of the invention.

Claims

Demands

1. Fixed housing (122, 222) for a mechanical splash-type gearbox (106, 206), particularly for aircraft, said housing (122, 222) having an annular shape about a longitudinal axis (X) and comprising: - a cylindrical wall (230) extending around the axis (X) and connected to an annular mounting flange (232), this cylindrical wall (230) having a first internal cylindrical surface (230a), and - an annular wall (234) extending around the axis (X) and having its external periphery connected to the cylindrical wall (230), this annular wall (234) having a second annular surface (234a) connected to the first surface (230a), said first and second surfaces (230a, 234a) defining an annular space (E) configured to receive an oil ring (H2), characterized in this that it further comprises at least one oil deflector (240) projecting on at least one of said first and second surfaces (230a, 234a).

2. Carter (122, 222) according to claim 1, wherein it comprises a single deflector (240) which is located on said first surface (230a).

3. Housing (122, 222) according to claim 2, wherein the deflector (240) is located at 12 o'clock by analogy with the dial of a clock when the housing (122, 222) is in the operating position in which said longitudinal axis is horizontal.

4. Carter (122, 222) according to any one of the preceding claims, wherein the deflector or each deflector (240) has a generally elongated shape, in particular along said longitudinal axis (X).

5. Carter (122, 222) according to any one of the preceding claims, wherein the deflector or each deflector (240) extends from the second surface (234a) to the flange (232).

6. Carter (122, 222) according to any one of claims 1 to 4, wherein the or each deflector (240) has in cross section a general triangular shape.

7. Carter (122, 222) according to any one of claims 1 to 5, wherein the deflector or each deflector (240) comprises a first side (240a) oriented in a circumferential direction, which has a concave curved shape, and optionally a second side (240b) oriented in an opposite circumferential direction, which has a concave curved shape.

8. Carter (122, 222) according to claim 6, wherein the sides (240a, 240b) of the or of each deflector (240) have different curved shapes and in particular curved shapes having different radii of curvature.

9. Carter (122, 222) according to any one of claims 1 to 4, wherein the deflector or each deflector (240) has an arrowhead shape of which a base (240c) is connected to the second surface and the tip (240d) is located on the side of the flange (232), or conversely whose base is located on the side of the flange and the tip is located on the side of the second surface.

10. A housing (122, 222) according to claim 9, wherein the deflector or deflectors (240) comprise: - two lateral surfaces (240e, 240f) extending from the second surface (234a) towards the flange (232), these surfaces (240e, 240f) forming an angle (a) greater than 90° and less than 180° between them, measured in a plane perpendicular to the longitudinal axis (X), and - two end surfaces (240g, 240h) extending from the tip (240d) towards the second surface (234a), these end surfaces (240g, 240h) being concave and being connected respectively to the lateral surfaces to form curved edges (242) extending from the second surface (234a) to the tip (240d).

11. A mechanical reducer (106, 206), particularly for an aircraft, said reducer (106, 206) comprising: - a solar element (107, 207) movable in rotation about a longitudinal axis (X), - at least one first ring (109, 209a) mounted around the solar element (7) and said longitudinal axis (X), - satellites (108, 208) mounted between the solar element (107, 207) and the ring (109, 209a) and meshed with the solar element and the ring, these satellites (108, 208) having axes of rotation (Y) parallel to said axis (X) and being carried by a satellite carrier (110, 210), and - a sealed enclosure (Q) in which are located the solar element (107, 207), the ring (109, 209a), the satellites (108, 208) and the satellite carrier (110, 210), this enclosure (Q) being formed at least in part by a housing (122, 222) according to one of the preceding claims.

12. Reducer (106, 206) according to claim 11, wherein the satellites (108, 208) are double-stage and comprise a first stage meshed with the first ring which is movable about said longitudinal axis and the solar (107, 207), and a second stage meshed with a second ring (209b) which is fixed with respect to said longitudinal axis (X).

13. Turbomachine (1), in particular aircraft, comprising at least one casing (122, 222) according to any one of claims 1 to 10 or a mechanical reducer (106, 206) according to claim 11 or 12.

14. A system (310) for driving a wheel (312) of a landing gear (314), in particular of an aircraft, comprising at least one housing (122, 222) according to any one of claims 1 to 10 or a mechanical reducer (106, 206) according to claim 11 or 12.

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