Accessory gearbox for an aircraft turbine engine

Abstract

The invention relates to an accessory gearbox (14) for an aircraft turbine engine, the accessory gearbox (14) comprising: - a casing (16) comprising first and second walls (17, 18) facing one another; - a gear (19a) that is rotatable about an axis (A) and arranged axially between the first and second walls (17, 18), wherein the gear (19a) is rotatably guided relative to the casing (16) via first and second bearings arranged axially on either side of the gear (19a); characterised in that the accessory gearbox (14) internally comprises first and second pumps (22, 23) arranged axially on either side of the gear (19a), wherein the first and second pumps (22, 23) are housed, respectively, in first and second cavities in the casing (16), and wherein the first and second pumps (22, 23) comprise, respectively, a first rotor and a second rotor which are rotated by the gear (19a).

Description

[0001] DESCRIPTION

[0002] TITLE: ACCESSORY CASE FOR AIRCRAFT

[0003] Technical field of the invention

[0004] The present invention relates to an accessory housing for an aircraft turbomachine, as well as an aircraft turbomachine comprising such an accessory housing.

[0005] Technical background

[0006] An aircraft turbomachine includes various transmission (e.g., gears) and guidance (e.g., roller bearings or hydrodynamic bearings) components that are lubricated with lubricant (usually oil) via a lubrication system, ensuring proper operation and minimizing wear. The lubrication system comprises a lubrication circuit through which the lubricant circulates via a lubrication unit. The lubrication unit is mounted on and rotated by an accessory gearbox. The accessory gearbox is known by the acronym AGB, for "Accessory Gearbox." The lubrication unit includes a supply pump and a scavenging pump. Specifically, the supply pump delivers the lubricant from the reservoir to the various components requiring lubrication.The recovery pump, meanwhile, allows the oil to be conveyed from the enclosures in which the parts to be lubricated are placed to the lubricant reservoir.

[0007] Engine manufacturers are now finding that the lubrication system is a reliable device that requires little maintenance.

[0008] In addition, engine manufacturers seek to reduce the size and mass of the various equipment (especially the lubrication unit) attached to the accessory box, in order to generally optimize the overall performance of the turbomachine, and possibly incorporate new or larger equipment, to cope with new constraints (for example, higher electrical consumption of the aircraft).

[0009] The objective of the present invention is therefore to provide a simple, effective, and economical solution to the aforementioned problem. Prior art includes documents WO2024 / 153876A1, JP2001317375A, and US2024 / 093773A1.

[0010] Summary of the invention

[0011] The invention thus proposes an accessory housing for an aircraft turbomachine, the accessory housing comprising:

[0012] - a casing comprising first and second walls facing each other;

[0013] - a movable gear rotating about an axis A and arranged axially between the first and second walls, the gear being guided in rotation relative to the housing via first and second bearings arranged axially on either side of the gear; characterized in that the accessory housing includes internally first and second pumps arranged axially on either side of the gear, the first and second pumps being respectively housed in first and second cavities of the housing, the first and second pumps respectively comprising a first rotor and a second rotor which are driven in rotation by the gear.

[0014] Integrating the pumps into the accessory housing allows for significant gains in size and weight, benefiting the overall performance of the turbomachine.

[0015] In addition, such gains in size and mass make it possible to consider incorporating new or larger equipment to cope with new constraints (for example, higher electrical consumption of the aircraft).

[0016] Such integration also makes it possible to consider the integration of the various accessories (filters, strainers, valves, sensors, pipes, etc.) which are associated with the pumps, in order to further maximize the gains in size and mass.

[0017] Such integration also allows the pumps to be freely associated with one of the gears in the accessory box, and in particular with a gear with a high rotational speed, in order to increase the performance of the pumps.

[0018] Such integration of pumps is not problematic from a maintenance point of view since pumps are reliable devices that require little maintenance.

[0019] Finally, the pumps draw in and expel lubricant which is also used to lubricate the various components of the accessory box, facilitating the implementation of certain functions, including the integration of piping and sealing.

[0020] The accessory housing according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0021] - the first cavity is formed in a first support of the housing which protrudes axially from the first wall, the first support being in one piece with the first wall of the housing;

[0022] - the first cavity is axially delimited by a bottom wall of the first support and by a first cap attached to the casing;

[0023] - the first bearing is housed at least partly in a first housing which is formed externally in the first support, and the first pump includes an inlet and an outlet formed at least partly in the first support;

[0024] - the first pump comprises several first modules arranged axially next to each other, each first module comprising a rotating movable element which is arranged axially between two fixed flanges;

[0025] - the second cavity is formed in a second support of the casing which protrudes axially from the second wall, the second support being one piece with the second wall of the casing;

[0026] - the second cavity is axially delimited by a bottom wall of the second support and by a second cap attached to the casing;

[0027] - the second bearing is housed at least partly in a second housing which is formed externally in the second support, and the second pump includes an inlet and an outlet formed at least partly in the second support;

[0028] - the second pump comprises several second modules arranged axially next to each other, each second module comprising a rotating mobile element which is arranged axially between two fixed flanges;

[0029] - The bearings and pumps are arranged according to one of the following configurations:

[0030] -- a first configuration in which the first bearing is arranged axially between the first pump and the gear, and the second bearing is arranged axially between the second pump and the gear;

[0031] -- a second configuration in which the first pump is arranged axially between the first bearing and the gear, and the second pump is arranged axially between the second bearing and the gear;

[0032] -- a third configuration in which the first bearing is arranged axially between the first pump and the gear, and the second pump is arranged axially between the second bearing and the gear.

[0033] The present invention also relates to an aircraft turbomachine comprising an accessory housing as described above. Brief description of the figures

[0034] The invention will be better understood and other details, features and advantages of the invention will become more apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings, in which:

[0035] [Fig.1] Figure 1 is a schematic longitudinal half-section view of a turbomachine comprising an accessory housing according to the invention;

[0036] [Fig.2] Figure 2 is a schematic view of the accessory box equipped with its equipment;

[0037] [Fig.3] Figure 3 is a front view of the accessory housing;

[0038] [Fig.4] Figure 4 is a cross-sectional view of the accessory housing according to section plane IV-IV of figures 2 and 3 which illustrates the integration of the first and second pumps;

[0039] [Fig.5] Figure 5 is a detailed view illustrating the integration of the second pump;

[0040] [Fig.6] Figure 6 is a detailed exploded view illustrating the integration of the first pump;

[0041] [Fig.7] Figure 7 is a detailed exploded view illustrating the integration of the second pump;

[0042] [Fig.8] Figure 8 is a schematic view of a first variant of the embodiment;

[0043] [Fig.9] Figure 9 is a schematic view of a second variant embodiment.

[0044] Detailed description of the invention

[0045] Figure 1 schematically represents a turbomachine 1 with longitudinal axis X for an aircraft 2, such as an airplane.

[0046] The turbomachine 1 comprises a movable, unducted fan 3 and a fixed, unducted stator 4. Such a turbomachine 1 is more commonly known by the English acronym USF for "Unducted Single Fan". As illustrated in Figure 1, the fan 3 rotates about the X-axis. The fan 3 is driven in rotation by a power turbine 5 coupled to a gas generator 6, the power turbine 5 and the gas generator 6 both being located downstream of the fan 3. The fan 3 is driven in rotation by the power turbine 5 via a speed reducer 7. The speed reducer 7 reduces the rotational speed of the fan 3 relative to that of the power turbine 5, while simultaneously increasing its torque. The speed reducer 7 is, for example, an epicyclic gear reducer. The blower 3 has an annular row of blades 8 with fixed or variable pitch.

[0047] The speed reducer 7 is obviously optional. The present invention applies equally to direct drive motors (without a reducer) and indirect drive motors (with a reducer).

[0048] The straightener 4 is fixed in rotation about the X axis. The straightener 4 is configured to straighten at least part of the airflow F generated by the blower 3. The straightener 4 is arranged here directly downstream of the blower 3. The straightener 4 comprises an annular row of guide vanes 9 with fixed or variable pitch.

[0049] The gas generator 6 conventionally comprises, from upstream to downstream along the direction of airflow F, at least one compressor, one combustion chamber, and at least one expansion turbine (or high-pressure turbine). The rotors of a compressor and an expansion turbine of the same housing are rotationally linked to each other via a drive shaft. When the turbomachine 1 operates in "propulsion" mode, the fan 3 generates an airflow F which splits into a minor primary flow f1 and a major secondary flow f2. The minor primary flow f1 enters a closed primary channel 10 of the engine via an air inlet 11 located between the fan 3 and the rectifier 4, so as to supply the gas generator 6. The major secondary flow f2, on the other hand, flows around the fairings of the nacelle 12 in an open secondary channel 13, so as to propel the aircraft 2.The turbomachine 1 further includes an accessory housing 14 according to the invention which is disposed in an intervein compartment 15, the intervein compartment 15 being placed radially between the closed primary vein 10 and the open secondary vein 13.

[0050] The example illustrated in Figure 1 is in no way limiting; the accessory housing 14 according to the invention could be placed in another location and in other types of turbomachine 1, for example a turboprop, a turbojet, a turbomotor, or even a turbomachine generally comprising one or more shrouded or unshrouded fans.

[0051] Accessory case 14 includes:

[0052] - a casing 16 comprising first and second walls 17, 18 facing each other;

[0053] - a gear wheel 19a movable in rotation around an axis A and disposed axially between the first and second walls 17, 18, the gear wheel 19a being guided in rotation relative to the casing 16 via first and second bearings 20, 21 disposed axially on either side of the gear wheel 19a.

[0054] According to the invention, the accessory housing 14 internally comprises first and second pumps 22, 23 arranged axially on either side of the gear 19a. The first and second pumps 22, 23 are respectively housed in first and second cavities 24, 25 of the housing 16. The first and second pumps 22, 23 respectively comprise a first rotor 26 and a second rotor 27 which are driven in rotation by the gear 19a.

[0055] The integration of the pumps 22, 23 into the accessory housing 14 allows for significant gains in size and mass, to the benefit of the overall performance of the turbomachine 1.

[0056] Furthermore, such size and weight reductions allow for the incorporation of new or larger equipment to address new constraints (for example, increased electrical consumption of aircraft 2). This integration also makes it possible to incorporate the various accessories (filters, strainers, valves, sensors, piping, etc.) associated with pumps 22 and 23, thereby further maximizing size and weight savings.

[0057] This integration also allows the pumps 22 and 23 to be freely connected to one of the gears in the accessory housing 14. More specifically, and generally speaking, increasing the speed of a pump reduces its displacement (and therefore the size of the cavity in which it is housed) while maintaining the same flow rate. However, beyond a critical speed, the pump's performance drops significantly. Conversely, reducing the speed of a pump improves its performance (or efficiency) at the same flow rate. However, beyond a critical speed, the pump's performance drops significantly. Thus, the ability to freely connect the pumps to the gears allows for the optimization of these pumps on a case-by-case basis.

[0058] Such integration of pumps 22, 23 is not problematic from a maintenance point of view since pumps 22, 23 are reliable devices that require little maintenance.

[0059] Finally, pumps 22, 23 draw in and expel lubricant which is also used to lubricate the various components of the accessory housing 14, which facilitates the implementation of certain functions, including the integration of pipes and sealing.

[0060] By convention in this application, "axial" or "axially" means any direction parallel to the axis A of the gear 19a or to the axis X of the turbomachine 1, and "radial" or "radially" means any direction perpendicular to the axis A of the gear 19a or to the axis X of the turbomachine 1.

[0061] Advantageously, as illustrated in Figure 2, the gear 19a is part of a gear train 28 comprising a plurality (or cascade) of gears 19a-19g located inside the housing 16 and meshed with each other. Advantageously, the gear 19a comprises external teeth 63 whose axial dimension (or width) is between 2 mm and 40 mm.

[0062] Advantageously, the ratio between the width of the external teeth 63 and the width of the accessory housing 14 is between 0.01 and 0.5.

[0063] The first pump 22 can be housed partly or totally in the first cavity 24 of the housing 16. Similarly, the second pump 23 can be housed partly or totally in the second cavity 25 of the housing 16.

[0064] Advantageously, as illustrated in Figures 4 and 6, the first cavity 24 is formed in a first support 29 (or first boss) of the housing 16 which projects axially from the first wall 17, the first support 29 being in one piece (or monobloc) with the first wall 17 of the housing 16. The first support 29 can project axially inwards and / or outwards from the housing 16.

[0065] Advantageously, in the same way and as illustrated in figures 4, 5 and 7, the second cavity 25 is formed in a second support 30 (or second boss) of the housing 16 which projects axially from the second wall 18, the second support 30 being in one piece (or monobloc) with the second wall 18 of the housing 16.

[0066] The second support 30 can protrude axially towards the inside and / or outside of the housing 16.

[0067] Advantageously, as illustrated in figure 4, the first cavity 24 is axially delimited by a bottom wall 31 of the first support 29 and by a first cap 32 attached to the housing 16.

[0068] Alternatively, the first cavity 24 could be axially delimited by two caps.

[0069] Advantageously, in the same manner and as illustrated in Figure 4, the second cavity 25 is axially delimited by a bottom wall 33 of the second support 30 and by a second cap 34 attached to the housing 16. Alternatively, the second cavity 25 could be axially delimited by two caps. Advantageously, as illustrated in Figure 4, the first rolling bearing 20 is housed at least partially in a first housing 35 which is formed externally in the first support 29.

[0070] Advantageously, in the same way and as illustrated in figure 4, the second bearing 21 is housed at least partly in a second housing 36 which is formed externally in the second support 30.

[0071] Bearings 20, 21 and pumps 22, 23 can be arranged in one of the following configurations:

[0072] - a first configuration in which the first bearing 20 is arranged axially between the first pump 22 and the gear 19a, and the second bearing 21 is arranged axially between the second pump 23 and the gear 19a; (figure 4)

[0073] - a second configuration in which the first pump 22 is arranged axially between the first bearing 20 and the gear 19a, and the second pump 23 is arranged axially between the second bearing 21 and the gear 19a; (figure 8)

[0074] - a third configuration in which the first bearing 20 is arranged axially between the first pump 22 and the gear 19a, and the second pump 23 is arranged axially between the second bearing 21 and the gear 19a. (figure 9)

[0075] Advantageously, the axial distance between the first and second bearing housings 20, 21 is between 5 mm and 150 mm. The present invention aims to reduce the axial distance between the first and second bearing housings 20, 21.

[0076] Advantageously, the ratio between the axial distance between the first and second bearing housings 20, 21 (expressed in millimeters (mm)) and the width of the accessory housing 14 (expressed in millimeters (mm)) is between 0.05 and 0.95. The present invention aims to reduce the axial distance between the first and second bearing housings 20, 21, and thus to reduce this ratio. The first pump 22 can be a lubricant supply pump or a lubricant recovery pump. Similarly, the second pump 23 can be a lubricant supply pump or a lubricant recovery pump.

[0077] Advantageously, the first and second pumps 22 and 23 are Gerotor pumps. This type of pump has the advantage of being compact and reliable. Indeed, Gerotor pumps can comprise several pump modules arranged side by side (or in series) along a shaft. Alternatively, the first and second pumps 22 and 23 could be vane pumps.

[0078] Advantageously, a lubricant supply pump is part of a supply circuit. The supply circuit allows the lubricant to be conveyed from the lubricant reservoir to the various components to be lubricated located in different enclosures of the turbomachine 1.

[0079] Advantageously, a lubricant recovery pump is part of a recovery circuit. The recovery circuit allows the lubricant to be conveyed from one or more chambers of the turbomachine 1, in which the components to be lubricated are located, to the lubricant reservoir.

[0080] Advantageously, the first pump 22 comprises several first modules 37 arranged axially side by side, each first module 37 comprising a rotating movable element 37a which is arranged axially between two fixed flanges 37b. The movable elements 37a of the various first modules 37 form part of the first rotor 26 of the first pump 22.

[0081] Advantageously, in the same manner, the second pump 23 comprises several second modules 38 arranged axially side by side, each second module 38 comprising a rotating movable element 38a which is arranged axially between two fixed flanges 38b. The movable elements 38a of the various second modules 38 form part of the second rotor 27 of the second pump 23. A pump module 37, 38 which is directly adjacent to a cap 32, 34 may have one of its two flanges formed within the cap 32, 34, so as to minimize the axial footprint of the pump.

[0082] Similarly, a pump module 37, 38 which is directly adjacent to a bottom wall 31, 33 of a support 29, 30 may have one of the two flanges which is formed in the bottom wall 31, 33, so as to minimize the axial footprint of the pump.

[0083] Advantageously, the ratio between the number of pump modules 37, 38 and the thrust of the turbomachine 1 (expressed in kilonewtons (kN)) is between 0.01 and 0.5 kN -1 .

[0084] Advantageously, the ratio between the number of pump modules 37, 38 and the diameter of the blower 3 (expressed in meters (m)) is between 1 and 8 m' 1 .

[0085] The first rotor 26 (first pump 22), the second rotor 27 (second pump 23) and the gear 19a can be coaxial or radially offset from each other.

[0086] The first rotor 26 of the first pump 22 and the second rotor 27 of the second pump 23 can be driven in rotation by the toothed wheel 19a via one or two transmission shafts 39, 40.

[0087] When the first and second rotors 26, 27 are driven in rotation via two transmission shafts, the two shafts can be driven according to one of the following configurations:

[0088] - the two transmission shafts are linked in rotation with the toothed wheel 19a;

[0089] - a first transmission shaft 39 is rotationally linked with the toothed wheel 19a, the second transmission shaft 40 being rotationally linked with the first shaft 39.

[0090] Two elements are for example linked in rotation via means of connection (such as splines) or by shrink fitting.

[0091] Advantageously, the first pump 22 comprises an inlet 41a and an outlet 41b formed at least partly in the first support 29. Advantageously, in the same way, the second pump 23 comprises an inlet 42a and an outlet 42b formed at least partly in the second support 30.

[0092] Advantageously, the inlet 41a and outlet 41b of the first pump 22 are respectively connected to an inlet port and an outlet port formed in the housing 16. The inlet and outlet ports are intended to be connected to external pipes which can be partially formed in the housing 16.

[0093] Advantageously, in the same way, the inlet 42a and the outlet 42b of the second pump 23 are respectively connected to an inlet port and an outlet port formed in the housing 16. The inlet and outlet ports are intended to be connected to external pipes which can be partially formed in the housing 16.

[0094] Advantageously, the inlet 41 of the first pump 22 is connected to the corresponding inlet port via one or more internal pipes. The internal pipe(s) may be formed partly or entirely within the housing 16.

[0095] Advantageously, the outlet 41b of the first pump 22 is connected to the corresponding outlet port via one or more internal channels. The internal channel(s) may be formed partly or entirely within the housing 16.

[0096] Advantageously, the inlet 42a of the second pump 23 is connected to the corresponding inlet port via one or more internal channels. The internal channel(s) may be formed partly or entirely within the housing 16.

[0097] Advantageously, the outlet 42b of the second pump 23 is connected to the corresponding outlet port via one or more internal channels. The internal channel(s) may be formed partly or entirely within the housing 16. Advantageously, a filter 43 is disposed downstream of the outlet 41b of the feed pump 22 and upstream of the corresponding outlet port, according to the direction of lubricant flow.

[0098] The filter 43 can be formed partly or entirely within the housing 16.

[0099] The filter 43 can be associated with a pressure relief valve 44 (also known by the English acronym PRV for "Pressure Relief Valve"), a bypass valve 45 (more commonly called "Bypass") which opens if the filter 43 becomes clogged, and a differential pressure sensor 46 (also known by the English acronym OFDP for "Oil Filter Differential Pressure") which is used to control the pressure relief valve 44 and the bypass valve 45. More specifically, the differential pressure sensor 46 is a sensor that measures the pressure at the inlet and outlet of the filter 43. It detects, by means of the pressure difference, whether the filter 43 is clogged. Thus, if the inlet pressure of the filter 43 is very high compared to its outlet pressure, the filter 43 will be considered clogged and the oil will be diverted through the bypass.

[0100] The overpressure valve 44, the bypass valve 45 and the differential pressure sensor 46 can be formed in part or in whole in the housing 16.

[0101] A strainer can be positioned upstream of the inlet 42a of the recovery pump 23, following the direction of lubricant flow. The strainer can be formed partially or entirely within the housing 16.

[0102] One or more sensors can be associated with the first and second pumps 22, 23. The sensor(s) can be formed partly or entirely in the housing 16.

[0103] One or more accessories can be associated with the first and second pumps 22, 23. The accessory(ies) can be formed in part or in whole in the housing 16.

[0104] The present invention is particularly compatible with the following characteristics:

[0105] - lubricant flow rates ranging from 200 l / h (litre / hour) to 20000 l / h;

[0106] - Feed pump modules from 1 to 40 modules; - Recovery pump modules from 1 to 40 modules;

[0107] - filters from 1 to 10;

[0108] - rotation speeds from 5000 rpm (revolutions per minute) to 40000 rpm;

[0109] - lubricant pressures from 1 bar to 10 bars.

[0110] According to the embodiment illustrated in the figures, the first and second walls 17, 18 are axially connected to each other by a peripheral wall 47. The housing 16 comprises a frame 48, and first and second covers 49, 50 attached to the frame 48. The frame 48 is a solid part obtained, for example, by molding or additive manufacturing. The first wall 17 is partly formed by the frame 48 and partly by the first cover 49. The second wall 18 is also partly formed by the frame 48 and partly by the second cover 50. The frame 48 also includes several brackets 51, to allow its attachment to a structural housing of the turbomachine 1.

[0111] According to the embodiment illustrated in the figures, the gear 19a is part of a gear train 28 comprising a plurality (or cascade) of gears 19a-19g placed inside the housing 16 and meshed with each other.

[0112] The gear train 28 is rotationally linked to a rotor of the gas generator 6 via an input gearbox 52 (also known as an IGB for "Inlet Gearbox"), a radial drive shaft 53 (also known as a RDS for "Radial Drive Shaft"), a transfer gearbox 54 (also known as a TGB for "Transfer Gearbox"), and a horizontal drive shaft 55 (also known as a HDS for "Horizontal Drive Shaft"). The gears 19b-19g are rotationally linked to the rotors of various equipment (or accessories) mounted on the first and second walls 17, 18 of the housing 16, either to drive them or to be driven by them.

[0113] More specifically, as illustrated in particular in Figure 2, the gear 19b is rotationally linked with the rotor of an air turbine starter 56 (also known by the English acronym ATS for "Air Turbine Starter"). The gear 19c is rotationally linked with the rotor of an integrated-drive generator 57 (also known by the English acronym IDG for "Integrated Driven Generator").

[0114] The toothed wheel 19d is rotationally linked with the rotor of a permanent magnet alternator 58 (also known by the English acronym PMA for "Permanent Magnet Alternator").

[0115] The 19th gear is linked in rotation with a 59th hand crank drive end (also known by the English acronym HOP for "Hand Crank Pad").

[0116] The gear wheels 19f are rotationally linked with the rotor of the main fuel pump 60 (also known by the English acronym MFP for "Main Fuel Pump").

[0117] The toothed wheel 19g is linked in rotation with the rotor of a hydraulic pump 61 (also known by the English acronym EDP for "Engine Driven Pump >>).

[0118] The various equipment 56-61 (or accessories) attached to the first and second walls 17, 18 of the housing 16 are not part of the accessory housing 14.

[0119] According to the embodiment illustrated in the figures and in particular figure 4, the gear 19a comprises an internal hub 62 and an external toothing 63 which are radially connected to each other via a web 64. Compared to the prior art, the axial dimension of the internal hub 62 has been significantly reduced to allow the integration of the pumps 22, 23 within the housing 14.

[0120] According to the embodiment illustrated in the figures, the first and second pumps 22, 23 are part of a lubrication system.

[0121] More specifically, the first pump 22 is a lubricant supply pump (hereinafter referred to as supply pump 22) which is part of a supply circuit. The supply circuit carries the lubricant from the lubricant reservoir to the various components to be lubricated located in different enclosures of the turbomachine 1. The second pump 23 is a lubricant recovery pump (hereinafter referred to as recovery pump 23) which is part of a recovery circuit. The recovery circuit carries the lubricant from the enclosures of the transfer case 54, in which the components to be lubricated are located, back to the lubricant reservoir.

[0122] The supply and recovery pumps 22, 23 are here Gerotor pumps.

[0123] According to the embodiment illustrated in the figures, and in particular in Figure 4, the feed pump 22 is housed in the first cavity 24 of the housing 16. More precisely, the first cavity 24 is formed in a first support 29 of the housing 16 which projects axially inwards from the first wall 17. The first support 29 is integral with a portion of the first wall 17 which is formed here in the frame 48. The feed pump 22 is located here axially between the first wall 17 and the gear 19a. The first cavity 24 is axially delimited by a bottom wall 31 of the first support 29 at a distal end of the first support 29 and by a first cap 32 attached to the first wall 17 at a proximal end of the first support 29. The bottom wall 31 of the first support 29 is thus directly adjacent (or in the immediate vicinity) to the veil 64 of the gear 19a.

[0124] The first bearing 20 is arranged axially between the feed pump 22 and the gear 19a.

[0125] More precisely, the first bearing 20 is partially housed in a first housing 35, which is formed externally in the first support 29 and at the distal end of the first support 29. The first bearing 20 is thus directly adjacent to the web 64 of the gear 19a. The first bearing 20 comprises an outer ring partially housed in the first housing 35, an inner ring mounted on a first bearing surface 65 of the hub 62 of the gear 19a, and rolling elements (here, rollers) arranged between the outer and inner rings. The outer ring is axially restrained by an external flange that bears against the first support 29. The inner ring is axially restrained by a shoulder that defines the first bearing surface 65 of the gear 19a.

[0126] According to the embodiment illustrated in the figures, and in particular in Figure 4, the recovery pump 23 is housed in the second cavity 25 of the housing 16. More precisely, the second cavity 25 is formed in a second support 30 of the housing 16 which projects axially inwards from the second wall 18. The second support 30 is integral with a portion of the second wall 18 which is formed here in the second cover 50. The recovery pump 23 is located here axially between the second wall 18 and the gear 19a. The second cavity 25 is axially delimited by a bottom wall 33 of the second support 30 at a distal end of the second support 30 and by a second cap 34 attached to the second wall 18 at a proximal end of the second support 30. The bottom wall 33 of the second support 30 is thus directly adjacent (or in the immediate vicinity) to the veil 64 of the gear 19a.

[0127] The second bearing 21 is arranged axially between the recovery pump 23 and the gear 19a.

[0128] More precisely, the second bearing 21 is partially housed in a second housing 36, which is formed externally in the second support 30 and at the distal end of the second support 30. The second bearing 21 is thus directly adjacent to the web 64 of the gear 19a. The second bearing 21 comprises an outer ring partially housed in the second housing 36, an inner ring mounted on a second bearing surface 66 of the hub 62 of the gear 19a, and rolling elements (here, rollers) arranged between the outer and inner rings. The outer ring is axially restrained by an external flange that bears against the second support 30. The inner ring is axially restrained by a shoulder that defines the second bearing surface 66 of the gear 19a.

[0129] According to the embodiment illustrated in the figures, the accessory housing 14 is delimited externally in particular by the housing 16 (the frame 48 and the first and second covers 49, 50) as well as by the first and second caps 32, 34 (at the level of the supply and recovery pumps 22, 23).

[0130] According to the embodiment illustrated in the figures, and in particular Figures 4 and 6, the feed pump 22 comprises two first modules 37 arranged axially side by side. Each first module 37 is cylindrical and includes a rotatable element 37a arranged axially between two fixed flanges 37b. The rotatable elements 37a of the first two modules 37 form part of the rotor 26 of the feed pump 22. The first module 37 that is directly adjacent to the first cap 32 has one of its two flanges 37b formed within the first cap 32. The first module 37 that is directly adjacent to the bottom wall 31 of the first support 29 has one of its two flanges 37b formed within the bottom wall 31. The feed pump 22 comprises an inlet 41a and an outlet 41b, both formed entirely within the first support 29.

[0131] As illustrated in Figure 2, the supply circuit includes a filter 43 located downstream of the outlet 41b of the supply pump 22, following the direction of lubricant flow. The filter 43 is associated with a pressure relief valve 44, a bypass valve 45, and a differential pressure sensor 46.

[0132] According to the embodiment illustrated in the figures, and in particular Figures 4, 5, and 7, the recovery pump 23 comprises two secondary modules 38 arranged axially side by side. Each secondary module 38 is cylindrical and includes a rotatable element 38a arranged axially between two fixed flanges 38b. The rotatable elements 38a of the two secondary modules 38 form part of the rotor 27 of the recovery pump 23. The secondary module 38 that is directly adjacent to the secondary cap 34 has one of its two flanges 38b formed within the secondary cap 34. The secondary module 38 that is directly adjacent to the bottom wall 33 of the secondary support 30 has one of its two flanges 38b formed within the bottom wall 33. The recovery pump 23 includes an inlet 42a and an outlet 42b, both formed entirely within the secondary support 30.

[0133] According to the embodiment illustrated in the figures, and in particular Figure 4, the rotors 26, 27 of the supply and recovery pumps 22, 23 are driven in rotation by the gear 19a via two drive shafts 39, 40. A first drive shaft 39 connects the rotor 26 of the supply pump 22 to the gear 19a. The first drive shaft 39 is connected to the gear 19a via additional splines. A second drive shaft 40 connects the rotor 27 of the recovery pump 23 to the first shaft 39. The second shaft 40 is connected to the first shaft 39 via additional splines or by shrink fitting.

[0134] In general, and in comparison to previous art, the frame 48 of the casing 16 presents in particular the following structural modifications:

[0135] - creation of a first pump cavity (or well) 24 on the line of the gear wheel 19a to accommodate the first pump modules 37;

[0136] - creation of internal channels for the lubricant;

[0137] - creation of a first pump cap 32 which is fixed onto the frame 48;

[0138] - creation of ports (or interfaces) on frame 48 to accommodate external lubricant lines.

[0139] Furthermore, in general and in comparison to the prior art, the second cover 50 of the casing 16 presents in particular the following structural modifications:

[0140] - creation of a second pump cavity (or well) 25 on the line of the gear wheel 19a to accommodate the second pump modules 38;

[0141] - creation of internal channels for the lubricant;

[0142] - creation of a second pump cap 34 which is fixed onto the second cover 50;

[0143] - Creation of ports (or interfaces) on the second cover 50 to accommodate external lubricant lines. According to the embodiment illustrated in the figures, and in particular Figure 2, the accessory housing 14 also includes internally:

[0144] - two lubricant recovery pumps 67 whose rotors are driven by the toothed wheel 19f, these two recovery pumps 67 allowing the lubricant to be conveyed from the rear enclosures of the turbomachine 1 to the lubricant reservoir;

[0145] - two lubricant recovery pumps 68 whose rotors are driven by the toothed wheel 19c, these two recovery pumps 68 allowing the lubricant to be conveyed from the forward enclosures of the turbomachine 1 to the lubricant reservoir;

[0146] - a lubricant recovery pump 69 whose rotor is driven by the toothed wheel 19c, this recovery pump 69 allowing the lubricant to be conveyed from the enclosure of the accessory housing 14 to the lubricant reservoir.

[0147] According to the first embodiment illustrated in Figure 8, the feed pump 22 is arranged axially between the first bearing 20 and the gear 19a. The recovery pump 23 is arranged axially between the second bearing 21 and the gear 19a.

[0148] According to the second embodiment illustrated in Figure 9, the first bearing 20 is arranged axially between the feed pump 22 and the gear 19a. The recovery pump 23 is arranged axially between the second bearing 21 and the gear 19a.

Claims

DEMANDS 1. Accessory housing (14) for an aircraft turbomachine (1) (2), the accessory housing (14) comprising: - a casing (16) comprising first and second walls (17, 18) facing each other; - a gear wheel (19a) movable in rotation around an axis (A) and arranged axially between the first and second walls (17, 18), the gear wheel (19a) being guided in rotation relative to the casing (16) via first and second bearing supports (20, 21) arranged axially on either side of the gear wheel (19a); characterized in that the accessory housing (14) internally comprises first and second pumps (22, 23) arranged axially on either side of the toothed wheel (19a), the first and second pumps (22, 23) being respectively housed in first and second cavities (24, 25) of the housing (16), the first and second pumps (22, 23) comprising respectively a first rotor (26) and a second rotor (27) which are driven in rotation by the toothed wheel (19a).

2. Accessory housing (14) according to claim 1, characterized in that the first cavity (24) is formed in a first support (29) of the housing (16) which projects axially from the first wall (17), the first support (29) being in one piece with the first wall (17) of the housing (16).

3. Accessory housing (14) according to claim 2, characterized in that the first cavity (24) is axially delimited by a bottom wall (31) of the first support (29) and by a first cap (32) attached to the housing (16).

4. Accessory housing (14) according to any one of claims 2 to 3, characterized in that the first bearing (20) is housed at least partly in a first housing (35) which is formed externally in the first support (29), and in that the first pump (22) comprises an inlet (41 a) and an outlet (41 b) formed at least partly in the first support (29).

5. Accessory housing (14) according to any one of the preceding claims, characterized in that the first pump (22) comprises several first modules (37) arranged axially next to each other, each first module (37) comprising a rotating movable element (37a) which is arranged axially between two fixed flanges (37b).

6. Accessory housing (14) according to any one of the preceding claims, characterized in that the second cavity (25) is formed in a second support (30) of the housing (16) which projects axially from the second wall (18), the second support (30) being integral with the second wall (18) of the housing (16).

7. Accessory housing (14) according to the preceding claim, characterized in that the second cavity (25) is axially delimited by a bottom wall (33) of the second support (30) and by a second cap (34) attached to the housing (16).

8. Accessory housing (14) according to any one of claims 6 to 7, characterized in that the second bearing housing (21) is housed at least in part in a second housing (36) which is formed externally in the second support (30), and in that the second pump (23) comprises an inlet (42a) and an outlet (42b) formed at least in part in the second support (30).

9. Accessory housing (14) according to any one of the preceding claims, characterized in that the bearings (20, 21) and the pumps (22, 23) are arranged in one of the following configurations: - a first configuration in which the first bearing (20) is arranged axially between the first pump (22) and the gear (19a), and the second bearing (21) is arranged axially between the second pump (23) and the gear (19a); - a second configuration in which the first pump (22) is arranged axially between the first bearing (20) and the gear (19a), and the second pump (23) is arranged axially between the second bearing (21) and the gear (19a); - a third configuration in which the first bearing (20) is arranged axially between the first pump (22) and the gear (19a), and the second pump (23) is arranged axially between the second bearing (21) and the gear (19a).

10. Aircraft turbomachine (1) (2) comprising an accessory housing (14) according to any one of the preceding claims.

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