Assembly comprising accessory gearbox and lubrication unit

Abstract

The invention relates to an assembly (E) for an aircraft turbomachine (1), the assembly (E) comprising:-an accessory gearbox (21) comprising: a first and a second wall (25, 26) defining between them an inner cavity (27) and a gear train (28) arranged in the inner cavity (27) and intended to be driven by a shaft (9, 8) of the turbomachine (1), and-a lubrication unit arranged in the first wall (25) and the second wall (26) and intended to be driven by the shaft (9, 8) of the turbomachine (1), the lubrication unit comprises an oil supply pump (22) and an oil recovery pump (23), each comprising at least one rotor (22c, 23c) driven by the gear train (28), the assembly (E) being characterized in that the rotors (22c, 23c) of the supply and recovery pumps (22, 23) are arranged on both sides of the gear train (28) and the rotor (22c) of the supply pump (22) is arranged in the inner cavity (27).

Description

Technical Field

[0001] The invention relates to an assembly for an aircraft turbomachine, comprising an accessory gearbox and a lubrication unit. Background Art

[0002] Documents EP-A1-3 054 128 and US-A1-2012117982 describe the prior art.

[0003] An aircraft turbomachine generally extends along and around a longitudinal axis and comprises a gas generator which generally comprises, from upstream to downstream in the direction of gas flow in the turbomachine, a fan, a low-pressure compressor, a high-pressure compressor, a gas combustor, a high-pressure turbine and a low-pressure turbine.

[0004] The low-pressure compressor's rotor is typically connected to the low-pressure turbine's rotor via a low-pressure shaft. The high-pressure compressor's rotor is connected to the high-pressure turbine's rotor via a high-pressure shaft. The shafts are guided in rotation by guide bearings, which require lubrication to ensure proper function.

[0005] Therefore, it is known to spray lubricating oil onto the guide bearing. In order to protect the relevant components of the turbine from the influence of this lubricating oil, the guide bearing is usually arranged in a lubricating housing.

[0006] In order to ensure lubrication of the bearings in the lubricating housing, the turbine generally comprises an oil circuit. The oil circuit is generally a closed circuit comprising a bearing lubrication circuit and an oil recovery circuit for lubricating the housing.

[0007] The oil circuit typically includes a lubrication unit connected to an oil tank. The lubrication unit includes a supply pump and a recovery pump. The supply pump draws oil from the oil tank and distributes it to the lubrication housing via a supply circuit, while the recovery pump draws oil from the lubrication housing and returns it to the oil tank via a recovery circuit. The lubrication unit typically includes a housing with an oil inlet and outlet for each pump, and a drive shaft for driving the rotors of these pumps. The drive shaft is typically guided for rotation within the lubrication unit's housing.

[0008] In order to drive the rotor of the lubrication unit's pump, the lubrication unit is typically mounted and secured to an accessory gearbox (AGB). The accessory gearbox is used to transmit mechanical power from the turbine to accessories of the turbine, such as the lubrication unit's pump. The accessory gearbox typically includes a housing having a first wall and a second wall defining an interior cavity therebetween, within which a gear train is arranged, the gear train having a series of intermeshing pinions. The housing of the lubrication unit is secured to one of the walls of the accessory gearbox, and one end of the drive shaft of the rotor is rotationally coupled to one of the pinions of the gear train.

[0009] This configuration of a gearbox and lubrication unit is not entirely satisfactory. Indeed, the assembly has a considerable mass. Its size also makes it difficult to integrate into a turbine, as its size does not fit into the turbine's highly restricted area.

[0010] Document FR-A1-2 928 696 proposes an assembly comprising an accessory gearbox having a housing with a first wall and a second wall, between which a gear train with a series of intermeshing pinions is arranged. The assembly also includes a first drive shaft for an oil feed pump and its rotor, and a second drive shaft for a hydraulic pump and its rotor. The oil feed pump is fixed to the first wall, and the first drive shaft is rotationally coupled to the pinions of the gear train. The hydraulic pump is fixed to the second wall, and the second drive shaft is rotationally coupled to the pinions of the gear train that are coupled to the first drive shaft.

[0011] While this solution reduces the overall volume, it's not entirely satisfactory. Each pump takes up a significant amount of space, increasing the overall volume on either side of the accessory gearbox. Consequently, the overall weight isn't reduced. Furthermore, the presence of two pumps mounted and fixed to each wall increases the number of connections to the accessory gearbox, complicating the assembly's installation.

[0012] Document WO-A1-2021116570 proposes an assembly comprising a plate and an accessory gearbox, the accessory gearbox comprising a housing having a first wall and a second wall. The plate is connected to one of the walls of the housing. The plate has means for securing various devices (also known as accessories) that can be driven by the gear train of the accessory gearbox. The devices include, in particular, a fuel pump, and the plate also includes fluid inlet and outlet pipes.

[0013] While this reduces the overall volume, there's still room for improvement. Indeed, the plate remains relatively bulky considering the functions it encompasses. Furthermore, its presence doesn't significantly reduce the number of connections to the accessory gearbox. Consequently, assembly remains relatively complex.

[0014] Under such circumstances, it is necessary to provide an assembly comprising an accessory gearbox and a lubrication unit comprising an oil supply pump and an oil recovery pump, which assembly is space-saving, lightweight and easy to assemble. Summary of the Invention

[0015] To this end, the present invention proposes an assembly for an aircraft turbine, comprising:

[0016] -Accessory gearbox, accessory gearbox includes:

[0017] a first wall and a second wall, the first wall and the second wall defining an inner cavity therebetween, and

[0018] a gear train arranged in the inner cavity, the gear train being intended to be driven by the shaft of the turbine, and

[0019] A lubrication unit comprising an oil supply pump and an oil recovery pump, each comprising at least one rotor driven by a gear train.

[0020] The assembly is notable in that the rotors of the feed pump and the recovery pump are arranged on both sides of the gear train, and the rotor of the feed pump is arranged in the inner cavity.

[0021] According to the present invention, the feed pump's rotor is located within the gearbox's inner cavity. In other words, the feed pump's rotor resides within the gearbox. This eliminates the need for a bulky housing for the lubrication unit containing the feed pump's rotor. The overall size of the lubrication unit, and therefore the overall size of the assembly, is significantly reduced.

[0022] Furthermore, according to the present invention, the rotors of the supply pump and the recovery pump are arranged on both sides of the gear train. This feature allows the load on the accessory gearbox to be balanced.

[0023] Thanks to the invention, the volume and weight of the assembly are significantly reduced without increasing the number of connections between the lubrication unit and the gearbox.

[0024] This simplifies installation of the components.

[0025] The present invention may include one or more of the following features, alone or in combination with each other:

[0026] - the supply pump comprises an oil inlet and an oil outlet provided on the first wall,

[0027] - the first wall comprises a cylindrical body extending in a protruding manner and having a cylindrical housing opening into the inner cavity and fluidically connected to the oil inlet and the oil outlet, in which the rotor of the feed pump is arranged,

[0028] - the first wall also comprises a receiving bowl for the oil filter, which extends into the inner cavity and is connected to the cylindrical body by an oil outlet pipe,

[0029] The recovery pump comprises a housing, the housing comprising at least one oil inlet and an inner receiving portion, a rotor of the recovery pump being arranged in the inner receiving portion, the housing being mounted and fixed to the second wall,

[0030] the housing comprises at least one oil outlet pipe, the at least one oil outlet pipe being fluidically connected to an oil outlet orifice of a recovery pump, the orifice being formed in the first wall,

[0031] - the gearbox further comprises an oil circulation channel in the inner cavity, the oil circulation channel connecting the tube to the orifice,

[0032] the feed pump comprises two rotors driven by a gear train, and / or the recovery pump comprises at least two rotors driven by a gear train,

[0033] - the rotor or rotors of the supply pump are driven by a first drive shaft coupled to the gear train, and the rotor or rotors of the recovery pump are driven by a second drive shaft coupled to the gear train, the first shaft and the second shaft extending on either side of the gear train, respectively,

[0034] - the gear train comprises a series of gears meshing together, and the first drive shaft and the second drive shaft are rotationally coupled to a single gear of the gear train,

[0035] - The first wall and / or the second wall comprises at least one valve.

[0036] The invention also relates to a turbomachine for an aircraft, the turbomachine comprising:

[0037] - a fan configured to drive an air flow, the air flow being separated into a primary air flow and a secondary air flow,

[0038] - a main duct for the flow of the main air flow,

[0039] - a secondary duct for the flow of a secondary air flow,

[0040] - A pipe compartment that separates the primary and secondary pipes.

[0041] The turbine is notable in that it further comprises an assembly according to any one of the preceding features, the assembly being located in the duct compartment. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Further features and advantages will emerge from the following description of non-limiting embodiments of the invention with reference to the accompanying drawings, in which:

[0043] Figure 1 is a longitudinal sectional view of an example of an aircraft turbine according to the invention;

[0044] Figure 2 It is a schematic diagram of the oil circuit including the lubrication circuit and the oil recovery circuit.

[0045] Figure 3 is a perspective view of an assembly according to the invention comprising an accessory gearbox and a lubrication unit,

[0046] Figure 4 yes Figure 3 a side view in which the first wall is visible,

[0047] Figure 5 yes Figure 4 an enlarged view of the first wall, wherein the first cover of the first wall has been removed,

[0048] Figure 6 yes Figure 3 A side view, in which the second wall is visible,

[0049] Figure 7 yes Figure 3 Another side view, in which the second wall is visible,

[0050] Figure 8 yes Figure 6 An enlarged view of the second wall with the cover removed.

[0051] Figure 9 This is a perspective view of the recovery pump.

[0052] Figure 10 This is an exploded perspective view of the recovery pump.

[0053] Figure 11 is a schematic diagram of an assembly according to the present invention. DETAILED DESCRIPTION

[0054] exist Figure 1 An example of an aircraft turbomachine 1 according to the invention is shown very schematically in . The turbomachine 1 is, for example, a turboprop engine.

[0055] The turbine 1 extends along a longitudinal axis A. An air flow F flows through the turbine 1 .

[0056] For the purposes of the present invention, the terms “upstream” and “downstream” are understood with respect to the flow direction of the air flow F along the longitudinal axis A in the turbomachine 1 .

[0057] Furthermore, the terms “longitudinal” and “longitudinally” refer to the longitudinal axis A of the turbine 1 . The terms “radial” and “radially” refer to radial axes perpendicular to the longitudinal axis A. The terms “outer” and “inner” are to be understood with respect to distances from the longitudinal axis A on radial axes perpendicular to the longitudinal axis A.

[0058] The turbomachine 1 includes, from upstream to downstream, a fan 2 , a low-pressure compressor 3 , a high-pressure compressor 4 , a combustion chamber 5 , a high-pressure turbine 6 , and a low-pressure turbine 7 .

[0059] Each compressor 3, 4 comprises a compressor rotor 3a, 4a, and each turbine 6, 7 comprises a turbine rotor 6a, 7a. The compressors 3a, 4a and the turbine rotors 6a, 7a are composed of a plurality of stages, each comprising an impeller.

[0060] The compressor rotor 3a of the low-pressure compressor 3 is connected to the turbine rotor 7a of the low-pressure turbine 7 via a low-pressure shaft 8. They form a low-pressure body.

[0061] The compressor rotor 4a of the high-pressure compressor 4 is connected to the turbine rotor 6a of the high-pressure turbine 6 via a high-pressure shaft 9. They form a high-pressure body.

[0062] The low-pressure shaft 8 and the high-pressure shaft 9 are centered on the longitudinal axis A and are rotatable about the longitudinal axis A. The high-pressure shaft 9 is coaxially arranged around the low-pressure shaft 8 .

[0063] Air flow F passes through fan 2 and is divided into a primary air flow F1 and a secondary air flow F2. The primary air flow F1 passes through primary duct v1, while the secondary air flow F2 passes through secondary duct v2, which surrounds the primary duct. The primary air flow F1 then passes through low-pressure compressor 3 and high-pressure compressor 4. The compressed primary air flow F1 then passes through combustion chamber 5, where it mixes with fuel. The gases produced by combustion pass through high-pressure turbine 6 and low-pressure turbine 7. The energy in the gases is converted into mechanical energy by turbine rotor 7a of low-pressure turbine 7, which drives the rotation of low-pressure shaft 8 and, consequently, low-pressure compressor 3.

[0064] Fan 2 includes a disk rotatable about a longitudinal axis A and blades 2 a uniformly distributed on the disk. Fan 2 is, for example, non-ducted. Unlike ducted fan 2, fan 2 does not include a fan housing surrounding blades 2 a. In another example (not shown), fan 2 is ducted.

[0065] The disc is driven in rotation by a fan shaft 10. Advantageously, the fan shaft 10 is connected to the low-pressure shaft 8, for example, via a reduction gear 11. The reduction gear 11 is mechanical. For example, the reduction gear 11 can have an epicyclic or planetary gear system. The reduction gear 11 typically includes a sun gear and a ring gear (not shown) centered on the longitudinal axis A. The reduction gear 11 also includes planetary gears meshing with the sun gear and the ring gear. The reduction gear 11 also includes a planet carrier.

[0066] The sun gear is rotationally fixed to the low-pressure shaft 8 and forms the input of the reduction gear 11 , while one or the other of the ring gear and the planet carrier, depending on the configuration of the reduction gear 11 , is rotationally fixed to the fan shaft 10 and forms the output of the reduction gear 11 .

[0067] The reduction gear 11 enables the fan shaft 10 to be driven at a lower speed than the rotational speed of the low-pressure shaft 8. This can increase the bypass ratio of the turbine 1.

[0068] The turbine 1 further includes an inter-compressor housing 12 axially arranged between the low-pressure compressor 3 and the high-pressure compressor 4 . For example, the inter-compressor housing 12 includes an inner shell and an outer shell centered on the longitudinal axis A. The inner shell and the outer shell are connected, for example, by an arm.

[0069] The turbine 1 may further include an inlet casing 13. The inlet casing 13 is axially arranged between the fan 2 and the low-pressure compressor 3. For example, the inlet casing 13 includes an inner shell and an outer shell centered on the longitudinal axis A. The inner shell and the outer shell are connected, for example, by an arm.

[0070] The turbine 1 may further include an inter-turbine casing 14 . The inter-turbine casing 14 is arranged axially between the high-pressure turbine 6 and the low-pressure turbine 7 .

[0071] The turbine 1 may further comprise a duct compartment v3 located between the primary duct v1 and the secondary duct v2.

[0072] Fan shaft 10 is guided in rotation by a first bearing 15a and, advantageously, a second bearing 15b. The first and second bearings 15a, 15b are radially arranged between fan shaft 10 and inlet housing 13. Each of first and second bearings 15a, 15b, for example, comprises a bearing arranged between an outer ring and an inner ring. The outer ring is supported by a first bearing support 16a, which extends radially inward from inlet housing 13. The inner ring is carried by fan shaft 10. The rolling bearing is, for example, a single row of balls. Advantageously, the rolling bearing comprises two rows of balls.

[0073] The low-pressure shaft 8 is guided in rotation by at least a third bearing 15c and a fourth bearing 15d. The third bearing 15c is radially arranged between the inlet housing 13 and the low-pressure shaft 8. The third bearing 15c includes a bearing, such as a row of balls, radially arranged between an inner ring and an outer ring. The outer ring is supported by a second bearing support 16b connected to the inlet housing 13. The inner ring is supported by the low-pressure shaft 8. The fourth bearing 15d is radially arranged between the inter-compressor housing 12 and the low-pressure shaft 8. The fourth bearing 15d includes a bearing, such as a row of balls, radially arranged between an inner ring and an outer ring. The outer ring is supported by a third bearing support 16c connected to the inter-compressor housing 12. The inner ring is supported by the low-pressure shaft 8.

[0074] The high-pressure shaft 9 is guided in rotation by a fifth bearing 15e. For example, the fifth bearing 15e is radially arranged between the high-pressure shaft 9 and the inter-turbine housing 14. The fifth bearing 15e includes, for example, a bearing comprising a row of balls and a row of rollers radially arranged between an outer ring and an inner ring. The inner ring is supported by the high-pressure shaft 9, while the outer ring is supported by a fourth bearing support 16d connected to the inter-turbine housing 14.

[0075] For example, the low-pressure shaft 8 can be guided in rotation by a downstream sixth bearing 15 f , which is radially arranged between the downstream end of the low-pressure shaft 8 and the inter-turbine casing 14 .

[0076] The bearings 15a, 15b, 15c, 15d, 15e, 15f and the reduction gear 11 must be lubricated with oil to ensure that they operate normally. In order to prevent oil from contaminating the relevant components of the turbine 1, the bearings 15a, 15b, 15c, 15d, 15e and the reduction gear 11 are arranged in a lubricating housing.

[0077] To this end, the turbine 1 further comprises at least one lubrication housing, in particular a first upstream housing 17, a second upstream lubrication housing 18 and a downstream lubrication housing 19, the first bearing 15a, the second bearing 15b and the third bearing 15c and the reduction gear 11 being arranged in the first upstream housing 17, the fourth bearing 15d being arranged in the second upstream lubrication housing 18, and the fifth bearing 15e and the sixth bearing 15f being arranged in the downstream lubrication housing 19.

[0078] The upstream lubrication housings 17, 18 and the downstream lubrication housing 19 are annular. Each of the upstream lubrication housings 17, 18 and the downstream lubrication housing 19 is externally bounded by a stationary component such as a casing and internally bounded by a rotating component such as a shaft.

[0079] For example, a first upstream lubrication housing 17 is located in the inner shell of the inlet housing 13 and is internally bounded by the fan shaft 10. A second upstream lubrication housing 18 is located in the inner shell of the compressor inter-housing 12 and is internally bounded by the low-pressure shaft 8, and a downstream lubrication housing 18 is located in the inner shell of the turbine inter-housing 14 and is internally bounded by the high-pressure shaft 9.

[0080] The number of lubrication housings may vary depending on the configuration of the turbine 1. In the following, the upstream lubrication housings 17, 18 and the downstream lubrication housing 19 will be interchangeably referred to as "lubrication housings".

[0081] Reference Figure 2 The lubricating housings 17, 18, and 19 are supplied with oil by at least one oil circuit C. The oil circuit C of the turbine 1 is a closed circuit. The oil circuit C includes an oil supply circuit C1 and an oil recovery circuit C2 connected to the oil tank 20 and the lubricating housings 17, 18, and 19.

[0082] In order to enable oil to circulate in the supply circuit C1 and the recovery circuit C2, the turbine 1 further includes an assembly E, which includes an accessory gearbox 21 and a lubrication unit, which includes a supply pump 22 and a recovery pump 23, which are mounted on the accessory gearbox 21 and connected to the supply circuit C1 and the recovery circuit C2, respectively.

[0083] The accessory gear box 21 (referred to as the gear box for short) is housed in the pipe compartment v3, for example. Figure 3The gearbox 21 includes a housing 24 . The housing 24 extends substantially along an elongated direction Y between a first end 24 a and an opposite second end 24 b. The housing 24 includes a first wall 25 and a second wall 26 and an inner cavity 27 defined by the first wall 25 and the second wall 26 .

[0084] The first wall 25 and the second wall 26 extend substantially along the elongation direction Y. Preferably, the first wall 25 and the second wall 26 are curved. For example, the first wall 25 and the second wall 26 are integral or assembled together by fastening means such as screws and nuts. The first wall 25 and the second wall 26 each have an inner surface facing the inner cavity 27 and an opposing outer surface.

[0085] Reference Figure 4 , the first wall 25 includes a first structural component 25a and a first cover 25b.

[0086] Reference Figure 4 and Figure 5 The first structural component 25a is, for example, located on the second end 24b side of the housing 24. The first structural component 25a has a first window 25c that passes through the outer and inner surfaces of the first wall 25 and opens into the inner cavity 27. The first structural component 25a also includes a cylindrical body 251a extending from the outer surface of the first wall 25 and a connecting block 252a. The connecting block 252a is supported by the cylindrical body 251a and has opposing side surfaces extending from the cylindrical body 251a and connected by a central surface. The surfaces are flat. The connecting block 252a also includes a transverse surface 252a' opposing the outer surface of the first wall 25. The transverse surface 252a' connects the side surfaces to the central surface. The cylindrical body 251a is hollow and includes a cylindrical receiving portion 251b. The cylindrical receiving portion 251b opens into the inner cavity 27.

[0087] The first structural component 25a also comprises an oil filter associated with the feed pump 22 and arranged in a cylindrical receiving bowl 250a. The receiving bowl 250a extends inside the inner cavity 27 and opens into the first structural component 25a.

[0088] The first structural component 25a also includes an oil outlet pipe 253a, which connects the outlet of the cylindrical body 251a to the receiving bowl 250a, which is designed to accommodate an oil filter. Thus, the pipe 253a connects the outlet of the feed pump 22 to the inlet of the oil filter. The pipe 253a can be curved, for example.

[0089] The first cover 25b is located on the first end 24a side of the housing 24. The first cover 25b covers the first window 25c. Thus, the first window 25c is closed by the first cover 25b. The first cover 25b is removable. The first cover 25b is mounted and secured to the first structural member 25c using a removable fixing device, such as a screw and nut assembly 25d. The first cover 25b has a bracket 250b for securing accessories or equipment.

[0090] Reference Figure 6 、 Figure 7 and Figure 8 , the second wall 26 includes a second structural member 26a and a second cover 26b.

[0091] The second structural member 26a is located on the first end portion 24a side of the box body 24. The second structural member 26a has a second window 26c that passes through the outer surface and the inner surface of the second wall 26 and opens to the inner cavity 27.

[0092] The second structural member 26a further includes a bracket 260a for securing accessories or equipment.

[0093] The second cover 26b is located on the second end 24b side of the housing 24. The second cover 26b covers the second window 26c. Thus, the second window 26c is closed by the second cover 26b. The second cover 26b is removable. The second cover 26b is mounted and fixed to the second structural member 26a using a removable fixing device, such as a set of screws and nuts 26d.

[0094] The first cover 25b and the second cover facilitate installation and maintenance of the assembly E.

[0095] For example, the first structural member 25a and the second structural member 26a form an integral component.

[0096] The housing 24 is manufactured, for example, by additive manufacturing or lost wax casting.

[0097] The first wall 25 and / or the second wall 26 may also comprise at least one valve seat. The first wall 25 and / or the second wall 26 may comprise in particular a bypass valve 41a and / or a flap valve 41b of the pressure relief valve (PRV) type, a sensor or any other device required for operating the feed pump 22.

[0098] The inner cavity 27 extends in the direction of elongation Y. The inner cavity 27 is delimited by a first wall 25 and a second wall 26 .

[0099] Reference Figure 11Gearbox 21 further includes a gear train 28 disposed within interior cavity 27. Gear train 28 comprises a series of gears 29, each coaxially mounted around a corresponding shaft 30. Gears 29 mesh together. Gears 29 of gear train 28 are driven, for example, by drawing mechanical power from low-pressure shaft 8 or high-pressure shaft 9. The drawn mechanical power is transmitted to gear train 28 via a drive shaft 40 coupled to one of shafts 30.

[0100] The gear train 28 is also coupled to the rotor of accessories or equipment. Accessories (also referred to as equipment) include, for example, a main fuel pump 34 (MFP) and / or a permanent magnet alternator 35 (PMA) and / or an engine driven pump 36 (EDP) and / or an auxiliary hand crank pad (HCP) and / or an integrated drive generator 38 (IDG) and / or an air turbine starter (ATS).

[0101] The gearbox 21 also includes at least one clevis for suspending from a fixed structure of the turbine 1. For example, a first clevis 40a is connected to one of the first end 24a and / or the second end 24b of the housing 24. Preferably, the gearbox 21 includes a first clevis 40a connected to the first end 24a of the housing 24 and a second clevis 40b connected to the second end 24b of the housing 24. Each clevis 40a, 40b preferably includes two ears, each with a hole for passing a pin. The clevises 40a, 40b enable the gearbox 21 to be secured to the turbine 1, for example, to the housing in the duct compartment v3.

[0102] The charge pump 22 can pump oil from the oil tank 20 and circulate the oil in the charge circuit C1 .

[0103] Reference Figure 3 、 Figure 4 and Figure 5 The supply pump 22 includes an oil inlet 22a connected to the oil tank 20 and an oil outlet 22b connected to the lubricating housings 17, 18, 19. According to a particularly advantageous mode of the present invention, the oil inlet 22a and the oil outlet 22b are provided on the first wall 25, in particular, on the first structural member 25a of the first wall 25. Figure 5 As can be seen more clearly in FIG, the oil inlet 22a is formed, for example, in a connection block 252a, and the oil outlet 22b is formed in a support 254a, which is shaped to connect to an outlet pipe forming part of the supply circuit C1. Since the oil filter is located downstream of the supply pump 22 according to the oil flow in the supply circuit C1, the pipe 253a connects the oil outlet of the cylindrical body 251a with the inlet of the oil filter associated with the supply pump 22.

[0104] Therefore, the oil inlet 22a and oil outlet 22b of the supply pump 22 are formed directly on the first wall 25 of the gearbox 21. This feature allows the use of a dedicated housing for the supply pump 22, thereby reducing the overall size. As a result, the overall size and weight of the assembly E are significantly reduced. The number of connections between the gearbox 21 and the lubrication unit is also reduced, thereby improving the reliability of the assembly E.

[0105] The feed pump 22 further comprises at least one rotor 22c. Advantageously, the feed pump 22 comprises two rotors 22c. The presence of the two rotors 22c enables the diameter of the feed pump 22 to be reduced and the reliability of the feed pump 22 to be improved, while providing a more stable output compared to a feed pump having a single rotor (with a similar flow rate).

[0106] According to the present invention, one or more rotors 22c of the feed pump 22 are arranged in the inner cavity 27 of the gearbox 21. In particular, the rotor 22c is located in the cylindrical receiving portion 251b.

[0107] This characteristic allows the use of a dedicated housing for the feed pump 22, thereby reducing the overall dimensions. The overall dimensions and mass of the assembly E are therefore significantly reduced. This feature of the invention makes it possible to reduce the volume of the assembly E.

[0108] The supply pump 22 also includes a first drive shaft 22d for the rotor 22c. The rotor 22c is coaxially mounted around the first drive shaft 22d. Therefore, it should be understood that the first drive shaft 22d is also located within the inner cavity 27. The first drive shaft 22d is coupled to a gear train 28. The first drive shaft 22d is coupled to a gear 29 of the gear train 28 to drive the gear 29 to rotate.

[0109] The recovery pump 23 enables the oil to be pumped out of the lubricating housings 17 , 18 , 19 and enables the pumped oil to circulate into the recovery circuit C2 .

[0110] Reference Figure 9 and Figure 10 The recovery pump 23 advantageously comprises a housing 230 mounted and fixed to the second wall 26 of the gearbox 21. Preferably, the housing 230 is fixed to the second cover 26b of the second wall 26.

[0111] The housing 230 has a generally tubular shape extending between a first end 230a and a second end 230b. The first end 230a is open, while the second end 230b is closed. The housing 230 includes a cylindrical body 231 and a connecting block 232, which extends between the first end 230a and the second end 230b. The connecting block 232 is supported by the cylindrical body 231 and has opposing side surfaces 232a, 232b extending from the cylindrical body 231 and connected by a center surface 232c. Surfaces 232a, 232b, and 232c are flat. The housing 230 also includes a flange 233 for securing to the second wall 26 and a tubular inner receptacle 234 extending into the cylindrical body 231. The flange 233 is located on the first end 230a of the cylindrical body 231.

[0112] The recovery pump 23 also includes at least one oil inlet 23a connected to the lubrication housings 17, 18, and 19. Advantageously, the recovery pump 23 includes a plurality of oil inlets 23a, for example, two to ten oil inlets 23a, each of which is connected to the lubrication housings 17, 18, and 19. The oil inlet 23a is provided in the housing 230, advantageously in the connection block 232, and in particular on the central surface 232c of the connection block 232.

[0113] The recovery pump 23 also includes at least one receptacle 23b for receiving a filter 23b'. Advantageously, the recovery pump 23 includes as many receptacles 23b as oil inlets 23a. The receptacles 23b are formed in the connecting block 232, specifically on the second side surface 232b of the connecting block 232 and / or on the surface of the connecting block 232 opposite the end flange 233. Each receptacle 23b has a circular cross-section and communicates with a corresponding oil inlet 23a. The filters 23b' are respectively disposed in the corresponding receptacles 23b.

[0114] The recovery pump 23 further includes an oil outlet pipe 235 fluidly connected to an oil outlet orifice 236 connected to the oil tank 20 .

[0115] The tube 235 is fixed to the housing 230. The tube 235 is connected to the cylindrical body 231. The tube 235 is angled. The tube 235 includes a first portion 235a and a second portion 235b, the first portion 235a being connected to the cylindrical body 231 and opposite the second end 232b, and the second portion 235b forming a right angle with the first portion 231. The second portion 235b is fluidly connected to the orifice 236. According to a first embodiment, the tube 235 extends into the inner cavity 27 and passes through the second wall 26. According to this first example, the tube 235 opens into the orifice 236. According to another example, the gearbox 21 further includes an oil circulation channel in the inner cavity 27, which connects the tube 235 to the orifice 236.

[0116] The aperture 236 is formed in the first wall 25. For example, the aperture 236 is formed in the first cover 25b of the first wall 25.

[0117] The recovery pump 23 further includes at least one rotor 23c. Advantageously, the recovery pump 23 includes a plurality of rotors 23c. Preferably, the recovery pump 23 includes as many rotors 23c as the oil inlet ports 23a. The rotors 23c are arranged in the inner receiving portion 234 of the housing 230.

[0118] According to the present invention, the rotors 22c, 23c of the feed pump 22 and the recovery pump 23 are arranged on both sides of the gear train 28. This feature of the present invention balances the load on the gear train.

[0119] The recovery pump 23 also includes a second drive shaft 23d for the rotor 23c. The rotor 23c is mounted around the second drive shaft 23d, which extends into the inner chamber 234 of the housing 230. The second drive shaft 23d includes an end portion 23d' that extends outside the inner chamber 234. The second drive shaft 23d is coupled to the gear train 28. For example, the end portion 23d' includes a spline for coupling with the shaft 30 of the gear 29 of the gear train 28. Preferably, the second drive shaft 23d is coupled to the same gear 29 that is coupled to the first drive shaft 22d of the supply pump 22.

[0120] Preferably, the first drive shaft 22 d and the second drive shaft 23 d extend on both sides of the gear train 28 , respectively.

Claims

1. An assembly (E) for an aircraft turbomachine (1), said assembly (E) comprising: - an accessory gearbox (21), said accessory gearbox comprising: a first wall and a second wall (25, 26), wherein the first wall and the second wall define an inner cavity (27) therebetween, and a gear train (28) arranged in the inner cavity (27), the gear train being intended to be driven by the shaft (9, 8) of the turbine (1), and a lubrication unit comprising an oil supply pump (22) and an oil recovery pump (23), said supply pump and said recovery pump (22, 23) each comprising at least one rotor (22c, 23c) driven by said gear train (28), The assembly (E) is characterized in that the rotors (22c, 23c) of the supply pump and the recovery pump (22, 23) are arranged on both sides of the gear train (28), and the rotor (22c) of the supply pump (22) is arranged in the inner cavity (27).

2. Assembly according to the preceding claim, characterized in that The supply pump (22) includes an oil inlet (22a) and an oil outlet (22b) provided on the first wall (25).

3. Assembly according to the preceding claim, characterized in that The first wall (25) includes a cylindrical body (251a) extending in a protruding manner and having a cylindrical receiving portion (251b) that opens into the inner cavity (27) and is fluidically connected to the oil inlet and the oil outlet (22a, 22b), and the rotor (22c) of the supply pump (22) is arranged in the cylindrical receiving portion (251b).

4. Assembly according to any one of the preceding claims, characterized in that The first wall (25) also includes a receiving bowl (250a) for the oil filter, the receiving bowl (250a) extending into the inner cavity (27) and connected to the cylindrical body (251a) via an oil outlet pipe (253a).

5. Assembly according to any one of the preceding claims, characterized in that The recovery pump (23) comprises a housing (230), the housing comprising at least one oil inlet (23a) and an inner storage portion (234), a rotor (23c) of the recovery pump (23) being arranged in the inner storage portion, and the housing (230) being mounted and fixed to the second wall (26).

6. Assembly according to the preceding claim, characterized in that The housing (230) includes at least one oil outlet pipe (235) fluidly connected to an oil outlet orifice (236) of the recovery pump (23), the orifice (236) being formed on the first wall (25).

7. Assembly according to the preceding claim, characterized in that The gearbox (21) further includes an oil circulation passage in the inner cavity (27), the oil circulation passage connecting the tube (235) to the orifice (236).

8. Assembly according to any one of the preceding claims, characterized in that The supply pump (22) includes two rotors (22c) driven by the gear train (28), and / or the recovery pump (23) includes at least two rotors (23c) driven by the gear train (28).

9. Assembly according to any one of the preceding claims, characterized in that One or more rotors (22c) of the supply pump (22) are driven by a first drive shaft (22d) coupled to the gear train (28), and one or more rotors (23c) of the recovery pump (23) are driven by a second drive shaft (23d) coupled to the gear train (28), with the first and second shafts (22d, 23d) extending on both sides of the gear train (28), respectively.

10. Assembly according to the preceding claim, characterized in that The gear train (28) includes a series of gears (29) meshed together, and the first and second drive shafts (22d, 23d) are rotationally coupled to a single gear (29) of the gear train (28).

11. Assembly according to any one of the preceding claims, characterized in that The first wall (25) and / or the second wall (26) comprises at least one valve.

12. A turbomachine (1) for an aircraft, comprising: a fan (2) configured to drive an air flow (F) which is separated into a primary air flow (F1) and a secondary air flow (F2), - a main duct (v1) for the flow of said main air flow (F1), - a secondary duct (v2) for the flow of said secondary air flow (F2), - a duct compartment (v3) separating the primary duct (v1) and the secondary duct (v2), characterized in that the turbine further comprises an assembly (E) according to any one of the preceding claims, said assembly being located in the duct compartment (v3).

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