Turbine engine module comprising an oil supply circuit

Abstract

The invention relates to a module comprising: - an oil tank (22), - an oil supply circuit (23) comprising: - a first pump (25) comprising an oil inlet (26) connected to the tank (22) and an oil outlet (27), and - a first heat exchanger (28) comprising a first circuit for oil and a second circuit for a cooling fluid, - a cooling circuit (24) comprising: - a second pump (30) comprising an oil inlet (32) connected to the tank (22) and an oil outlet (33), - a second heat exchanger (31) comprising a first circuit for oil and a second circuit for a cooling fluid, and - a control member (34) for controlling the second pump (30), the control member being configured to regulate the flow rate of the second pump (30).

Description

Technical Field

[0001] This invention relates to the field of modules for aircraft turbine engines, the module including a lubrication enclosure and a supply circuit for supplying oil to the lubrication enclosure. Background Technology

[0002] In particular, turbine engines used in aircraft typically extend along and around a longitudinal axis. A turbine engine includes a gas generator, which typically includes a low-pressure compressor, a high-pressure compressor, a gas combustion chamber, a high-pressure turbine, and a low-pressure turbine, running from upstream to downstream along the direction of gas flow in the turbine engine.

[0003] The rotor of a low-pressure compressor is typically connected to the rotor of a low-pressure turbine via a low-pressure shaft. The rotor of a high-pressure compressor is connected to the rotor of a high-pressure turbine via a high-pressure shaft.

[0004] The turbine engine also includes a fan located upstream of the gas generator, which is driven by a fan shaft to rotate about a longitudinal axis. The fan shaft can be connected to a low-pressure shaft via a reduction gear.

[0005] The high-pressure and low-pressure shafts are guided to rotate via guide bearings, which must be lubricated to ensure proper operation. The reducer also has gears, which require lubrication to ensure proper functioning.

[0006] Therefore, lubricating oil is sprayed onto the guide bearing and into the gearbox. To protect the turbine engine's components from the lubricating oil, the guide bearing and gearbox are typically housed in a lubrication enclosure. The guide bearing located upstream of the turbine engine is housed in one or more upstream lubrication enclosures, and the guide bearing located downstream of the turbine engine is housed in one or more downstream lubrication enclosures.

[0007] To supply oil to the lubrication enclosure of a turbine engine, the turbine engine typically includes an oil system. The oil system generally includes an oil tank and an oil supply circuit connected to the lubrication enclosure. The supply circuit includes a pump having an oil inlet connected to the oil tank and an oil outlet connected to the lubrication enclosure. The pump is typically driven by one of the turbine engine shafts (e.g., the high-pressure shaft or the low-pressure shaft) via an accessory gearbox (AGB). Therefore, the flow rate of the supply circuit pump is proportional to the rotational speed of the turbine engine's drive shaft.

[0008] When temperatures exceed a certain level, the oil circulating in a turbine engine risks coking, which can damage the turbine engine's oil system or components. Furthermore, exceeding a certain oil temperature can damage the lubrication of enclosures and gearbox gears. In such cases, oil cooling within the turbine engine becomes a significant challenge.

[0009] To reduce oil temperature, it is known to install a heat exchanger in the supply circuit, between the lubrication enclosure and the pump.

[0010] However, in certain turbine engine configurations, this oil system configuration remains somewhat inadequate. The more lubrication enclosures there are, the greater the cooling requirements. Therefore, the trend is to increase the number of heat exchangers in the supply circuit, between the pump and the lubrication enclosures. The more heat exchangers there are, the greater the pressure losses in the supply circuit. These pressure losses have a direct impact on pump operation, subjecting the pump to increased back pressure as a function of these pressure losses, thus forcing the pump to become too large. The heat exchangers can also become too large, increasing the weight and size of the turbine engine.

[0011] Therefore, there is a need to provide a turbine engine module that includes a lubrication enclosure and a lubrication system, wherein the cooling of the lubricating oil and the hydraulic performance of the system are improved. Summary of the Invention

[0012] Therefore, the present invention proposes a module for a turbine engine of an aircraft, the module comprising: - At least one lubricated enclosure. -Mechanical power shaft, and - An oil system, which includes: - Oil tank, - An oil supply circuit for supplying oil to the lubricated enclosure, the supply circuit comprising: - A first pump, driven by a power shaft, includes an oil inlet and an oil outlet connected to the tank, and - A first heat exchanger, comprising a first oil circuit connecting the oil outlet of the first pump to a lubrication enclosure and a second circuit for cooling fluid.

[0013] A significant feature of the module according to the invention is that the oil system further includes: - A cooling circuit for oil, comprising: - A second pump, which includes an oil inlet and an oil outlet connected to the tank. - A second heat exchanger, comprising a first oil circuit connecting the oil outlet of the second pump to the tank and a second circuit for cooling the fluid, and - A control component for controlling the second pump, which is configured to regulate the flow rate of the second pump.

[0014] According to the present invention, the oil system includes a supply circuit dedicated to supplying oil to the lubrication enclosure and an oil cooling circuit dedicated to cooling the oil.

[0015] The cooling circuit is a closed loop. The second heat exchanger connects the second pump to the tank. Therefore, the cooling circuit forms a separate loop from the supply circuit.

[0016] Because of this configuration, it is no longer necessary to increase the number of heat exchangers or make the heat exchangers too large in order to operate at higher oil pressures in the supply circuit. In particular, this limits the pressure loss in the supply circuit and thus limits the back pressure of the first pump. This advantage helps to limit the size of the first pump from becoming too large.

[0017] Furthermore, according to the present invention, the flow rate of the second pump in the cooling circuit is controlled by a control component, while the first pump is driven by a power shaft, such that the flow rate of the first pump is proportional to the rotational speed of the power shaft.

[0018] Thanks to the first pump and the first heat exchanger, the cooling of the oil supplied to the lubrication enclosure remains constant.

[0019] Because of its adjustable flow rate, the second pump can adapt its flow rate to the cooling requirements of the turbine engine. For example, when oil cooling is not required, the second pump may not be driven.

[0020] This invention may include one or more of the following features, used individually or in combination: --The supply circuit and the cooling circuit are independent of each other. - The second pump is an electric pump. - The second heat exchanger is an air / oil type exchanger, and the first heat exchanger is a fuel / oil type exchanger. - The supply circuit includes an additional heat exchanger installed between the first heat exchanger and the lubrication enclosure. - The additional heat exchanger is of the air / oil type. - The air / oil exchange surface area of ​​the cooling circuit is at least 50% larger than that of the oil system. - The cooling circuit includes an additional heat exchanger installed between the second heat exchanger and the tank. - The additional heat exchanger is of the air / oil type. -A hydraulic control system and a third pump, the third pump comprising: - The oil inlet connected to the tank, and - The oil outlet connected to the hydraulic control system. - The third pump is driven by a power shaft. Attached Figure Description

[0021] Other features and advantages will become apparent from the following description of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which: [ Figure 1 ] Figure 1This is a perspective view of the aircraft turbine used in this invention. [ Figure 2 ] Figure 2 Is it installed to Figure 1 A schematic diagram of the longitudinal section of the gas generator in a turbine engine. [ Figure 3 ] Figure 3 This is a schematic diagram of a lubrication system according to an embodiment of the present invention. [ Figure 4 ] Figure 4 This is a schematic diagram of a lubrication system according to another embodiment of the present invention. [ Figure 5 ] Figure 5 This is a schematic diagram of a lubrication system according to an embodiment of the present invention. Detailed Implementation

[0022] Figure 1 An example of a turbine engine 1 according to the invention is shown, which is particularly a turbine engine for aircraft. For example, the turbine engine 1 is a two-flow turbojet engine. Preferably, the turbine engine 1 has a non-ducted fan, also known as an "open rotor". The turbine engine 1 can have any other architecture and, for example, take the form of a turboprop engine.

[0023] Turbine engine 1 is modular. Turbine engine 1 comprises multiple modules assembled together. In the remainder of the specification, the terms "turbine engine module" and "turbine engine" are used interchangeably.

[0024] Turbine engine 1 extends along the longitudinal axis X. Gas flow F flows through turbine engine 1.

[0025] For the purposes of this invention, the terms "upstream" and "downstream" are understood relative to the flow direction of the airflow F in the turbine engine 1. Figure 1 and Figure 2 In the middle, the gas flow F flows from left to right.

[0026] Furthermore, the terms "longitudinal," "longitudinally," "radial," and "radially" refer to the longitudinal axis X of the turbine engine 1. The terms "external" and "internal" are defined relative to the distance between the longitudinal axis X and the radial axis perpendicular to the longitudinal axis X.

[0027] The turbine engine 1 includes a fan 2 and a gas generator G from upstream to downstream.

[0028] The fan 2 includes a disk and at least a first annular row of blades 2a. The disk is rotatable about a longitudinal axis X. The first annular row of blades 2a is supported by the disk and is evenly spaced about the longitudinal axis X. The first row of blades 2a is rotatable about the longitudinal axis X.

[0029] The fan 2 may include a second annular row of blades 2b located downstream of the first row of blades. Preferably, the second row of blades 2b is fixed in terms of rotation about the longitudinal axis X.

[0030] The blades 2a of the first annular row and / or the blades 2b of the second annular row can be blades with variable pitch angles. Therefore, the blades 2a and 2b can rotate about the elongation axis extending radially from the blades 2a and 2b.

[0031] exist Figure 1 In the example shown, fan 2 is a non-ducted type. In this example, the first row of blades 2a and the second row of blades 2b are not surrounded by a fan nacelle or casing.

[0032] Figure 2 A gas generator G is shown. The gas generator G includes 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 from upstream to downstream.

[0033] Each compressor 3, 4 includes compressor rotors 3a, 4a, and each turbine 6, 7 includes turbine rotors 6a, 7a. The compressor rotors 3a, 4a and the turbine rotors 6a, 7a consist of multiple stages, each stage including an impeller.

[0034] 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 power shaft called the low-pressure shaft 8. The compressor rotor of the low-pressure compressor and the turbine rotor of the low-pressure turbine form the low-pressure body.

[0035] 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 power shaft called the high-pressure shaft 9. The compressor rotor of the high-pressure compressor and the turbine rotor of the high-pressure turbine form a high-pressure body.

[0036] The low-pressure shaft 8 and the high-pressure shaft 9 are centered on the longitudinal axis X and can rotate around the longitudinal axis X. The high-pressure shaft 9 is arranged coaxially around the low-pressure shaft 8.

[0037] The gas flow F passes through fan 2 and is split into a primary airflow F1 and a secondary airflow F2. The primary airflow passes through a main duct v1, and the secondary airflow passes through a secondary duct v2 surrounding the primary duct. The primary airflow F1 passes through low-pressure compressor 3 and high-pressure compressor 4. The compressed primary airflow F1 passes through combustion chamber 5, where it mixes with fuel. The combustion gases pass through high-pressure turbine 6 and low-pressure turbine 7. The energy in the gases is converted into mechanical energy by the turbine rotor 7a of low-pressure turbine 7, thereby driving the low-pressure shaft 8 to rotate and thus driving the low-pressure compressor 3 to rotate.

[0038] Advantageously, the first annular vane 2a is driven to rotate by a fan shaft 10, which is connected to the low-pressure shaft 8, for example, via a reducer 11. The reducer 11 is mechanical. For example, the reducer may have planetary or rotary gears. Not shown, the reducer 11 typically includes a ring gear and a sun gear centered on the longitudinal axis X. The reducer also includes planetary gears meshing with the sun gear and the ring gear. The reducer also includes a planet carrier.

[0039] The sun gear is fixed to the low-pressure shaft 8 in terms of rotation and forms the inlet of the reducer 11, while, depending on the configuration of the reducer 11, one or the ring gear and the planet carrier are fixed to the fan shaft 10 in terms of rotation and form the outlet of the reducer 11.

[0040] The reducer 11 drives the fan shaft 10 at a lower speed than the low-pressure shaft 8. This allows for an increase in the bypass ratio of the turbine engine 1.

[0041] The turbine engine 1 also includes a compressor housing 12, which is axially arranged between the low-pressure compressor 3 and the high-pressure compressor 4. The compressor housing 12 includes, for example, an inner shroud and an outer shroud centered on the longitudinal axis X. The inner shroud and the outer shroud are connected, for example, by an arm.

[0042] The turbine engine 1 may also include an intake casing 13. The intake casing 13 is axially arranged between the fan 2 and the low-pressure compressor 3. The intake casing 13 includes, for example, an inner shroud and an outer shroud centered on the longitudinal axis X. The inner shroud and the outer shroud are connected, for example, by an arm.

[0043] The turbine engine 1 may also include a turbine housing 14. The turbine housing 14 is axially arranged between the high-pressure turbine 6 and the low-pressure turbine 7.

[0044] The turbine engine 1 may also include a pipe compartment v3, which is located between the main pipe v1 and the secondary pipe v2.

[0045] The turbine engine 1 includes at least one bearing 15. In particular, the fan shaft 10 is guided to rotate by a first bearing 15a and advantageously by a second bearing 15b. The first bearing 15a and the second bearing 15b are arranged radially between the fan shaft 10 and the intake housing 13.

[0046] The low-pressure shaft 8 is guided to rotate by at least a third bearing 15c and a fourth bearing 15d. The third bearing 15c is arranged radially between the intake housing 13 and the low-pressure shaft 8. The fourth bearing 15d is arranged radially between the compressor housing 12 and the low-pressure shaft 8.

[0047] The high-pressure shaft 9 is guided to rotate by the fifth bearing 15e. For example, the fifth bearing 15e is arranged radially between the high-pressure shaft 9 and the turbine housing 14.

[0048] For example, the low-pressure shaft 8 can be guided to rotate downstream by a sixth bearing 15f, which is radially arranged between the downstream end of the low-pressure shaft 8 and the turbine housing 14.

[0049] For example, each bearing includes a rolling bearing. For example, a rolling bearing is at least one row of balls or rollers.

[0050] The bearing 15 and the reducer 11 are lubricated with oil to ensure their smooth operation. To prevent oil contamination of related components of the turbine engine 1, the bearing 15 and the reducer 11 are arranged in a lubrication enclosure.

[0051] For this purpose, the turbine engine 1 also includes at least one lubrication enclosure 16, specifically a first upstream enclosure 17, a second upstream lubrication enclosure 18, and a downstream lubrication enclosure 19. A first bearing 15a, a second bearing 15b, a third bearing 15c, and a reducer 11 are arranged in the first upstream enclosure 17, a fourth bearing 15d is arranged in the second upstream lubrication enclosure 18, and a fifth bearing 15e and a sixth bearing 15f are arranged in the downstream lubrication enclosure 19.

[0052] Depending on the configuration of the turbine engine 1, the number of bearings 15 and lubrication enclosures 16 can vary.

[0053] Each lubrication enclosure 16 is annular. Each lubrication enclosure 16 is defined externally by a fixed wall such as a housing and internally by a movable wall such as a shaft.

[0054] For example, the first upstream lubrication enclosure 17 is located in the inner cover of the intake housing 13 and is internally defined by the fan shaft 10. The second upstream lubrication enclosure 18 is located in the inner cover of the compressor housing 12 and is internally defined by the low-pressure shaft 8, and the downstream lubrication enclosure 19 is located in the inner cover of the turbine housing 14 and is internally defined by the high-pressure shaft 9.

[0055] A fixed wall and a movable wall define a lubrication space between the fixed wall and the movable wall, in which one or more bearings 15 and / or reducers 11 are located.

[0056] Additionally, the turbine engine 1 may include a hydraulic control system 20. The hydraulic control system 20 is connected to at least one of the multiple rows of blades 2a, 2b of the fan 2. The hydraulic control system 20 typically includes a hydraulic actuator (not shown), such as a hydraulic cylinder for changing the blade pitch angle of at least one of the multiple rows of blades 2a, 2b.

[0057] refer to Figure 3 , Figure 4 and Figure 5In order to supply oil to one or more lubrication enclosures 16 and advantageously to the hydraulic control system 20, the turbine engine 1 includes an oil system 21.

[0058] The oil system 21 includes an oil tank 22, an oil supply circuit 23 for at least one lubricating enclosure 16, and an oil cooling circuit 24.

[0059] Supply circuit 23 and cooling circuit 24 are independent. Supply circuit 23 and cooling circuit 24 are not connected by hydraulic lines and operate independently of each other.

[0060] The supply circuit 23 may be connected to one or more lubrication enclosures 16. Preferably, the supply circuit 23 is connected to a first upstream lubrication enclosure 17, a second upstream lubrication enclosure 18, and a downstream lubrication enclosure 19. The supply circuit 23 includes at least one first pump 25, which is installed between the tank 22 and the lubrication enclosure 16.

[0061] The first pump 25 typically includes an oil inlet 26 and an oil outlet 27.

[0062] Oil inlet 26 is connected to tank 22.

[0063] The first pump 25 is mechanical. The first pump 25 is driven by one of the power shafts 8 and 9 of the turbine engine 1. Typically, the first pump 25 is driven by the high-pressure shaft 9. For example, the first pump 25 is mechanically connected to the high-pressure shaft 9 via an accessory gearbox (AGB). Therefore, the flow rate of the first pump 25 depends on the rotational speed of the high-pressure shaft 9.

[0064] The supply circuit 23 also includes a first heat exchanger 28. The first heat exchanger 28 is installed between the first pump 25 and the lubrication enclosure 16. Preferably, the first heat exchanger 28 is of the fuel / oil type.

[0065] The first heat exchanger 28 typically includes a first oil circuit connecting the outlet 27 of the first pump 25 to the lubrication enclosure 16 and a second circuit for cooling fluid. Preferably, the cooling fluid is fuel. In particular, the fuel may be paraffin wax used in the combustion chamber 5. The fuel is a cold source fluid, thus allowing the oil to be cooled without the need for another cooling fluid.

[0066] In addition, the oil is continuously cooled by the first pump 25 driven by the power shafts 8 and 9.

[0067] Conversely, the fuel is also heated, which prevents certain turbine engine components, such as servo valves, from icing.

[0068] according to Figure 4In the illustrated embodiment, the supply circuit 23 may further include an additional heat exchanger 29, which is installed between the first heat exchanger 28 and the lubrication enclosure 16 (particularly the first upstream lubrication enclosure 17). The second upstream lubrication enclosure 18 and the downstream lubrication enclosure 19 are connected to the first pump 28 via the first heat exchanger 28.

[0069] Advantageously, the auxiliary heat exchanger 29 is of the air / oil type. Therefore, the cooling fluid is air. This auxiliary heat exchanger 29 improves oil cooling before the oil enters the lubrication enclosure 17 (particularly the first upstream lubrication enclosure 17). If the first upstream lubrication enclosure 17 houses the reducer (e.g., regarding...) Figure 2 The aforementioned reducer 11 typically has a greater cooling requirement.

[0070] To minimize oil loss, one or more lubrication enclosures 16 can be connected to tank 22 via a first oil return loop 23'.

[0071] According to the present invention, the cooling circuit 24 includes a second pump 30 and a second heat exchanger 31.

[0072] The second pump 30 has an oil inlet 32 ​​and an oil outlet 33 connected to the reservoir 22.

[0073] The second pump 30 has a flow rate controlled by a control member 34. The control member 34 is configured to adjust or regulate the flow rate of the second pump 30 according to the needs of the turbine engine 1.

[0074] Particularly preferably, the second pump 30 is electric, i.e., driven to rotate by an electric motor. Then, the control member 34 is electronic and configured to control the rotational speed of the electric motor driving the second pump 30.

[0075] The second pump 30 can be mechanical. According to this example, the second pump 30 is driven by power shafts 8, 9 (such as low-pressure shaft 8 or high-pressure shaft 9) via an accessory gearbox. For example, the control component 34 includes a gearbox and a clutch, thereby enabling control of the rotational speed of the second pump 30 and thus the flow rate of the second pump 30, particularly if the second pump 30 is a positive displacement pump with a fixed displacement.

[0076] Alternatively, in the case of a second mechanical pump 30 still driven by power shafts 8 and 9, the second pump 30 may have a variable displacement, and the control member 34 will be configured to act on the displacement of the second pump 30 and thus on the flow rate of the second pump 30, so that the second pump 30 has a stable drive speed.

[0077] In another example, the second pump 30 may be pneumatically driven.

[0078] The second heat exchanger 31 is installed between the second pump 30 and the tank 22. The second heat exchanger 31 includes a first oil circuit connecting the outlet 33 of the second pump 30 to the tank 22 and a second circuit for cooling fluid.

[0079] Preferably, the second heat exchanger 31 is of the air / oil type. Therefore, the cooling fluid is air.

[0080] Because of the independence of the supply circuit 23 and the cooling circuit 24, it is no longer necessary to increase the number of heat exchangers or make the size of the first heat exchanger 28 in the supply circuit 23 too large. In particular, this limits the pressure loss in the supply circuit 23 and thus limits the back pressure of the first pump 25. This advantage helps to limit the size of the first pump 25 from becoming too large.

[0081] Because of the second pump 30 with regulated flow, the second heat exchanger 31 is only used when additional cooling is required. Otherwise, the second pump 30 is not driven. This also optimizes fuel heating by preventing oil overcooling.

[0082] exist Figure 3 and Figure 4 In the illustrated embodiment, the cooling circuit 24 may include an auxiliary heat exchanger 35 installed between the second heat exchanger 31 and the tank 22. Preferably, the auxiliary heat exchanger 35 is of the air / oil type.

[0083] In a preferred embodiment, the air / oil exchange surface area of ​​the cooling circuit 24 is at least 50% larger than the air / oil exchange surface area of ​​the oil system 21. As a result, the air / oil exchange surface area in the cooling circuit 24 is greater than the air / oil exchange surface area in the supply circuit 23.

[0084] exist Figure 5 In the illustrated embodiment, the oil system 21 may include a third pump 36 installed between the oil tank 22 and the hydraulic control system 20. Therefore, the third pump 36 includes an oil inlet 37 connected to the tank 22 and an oil outlet 38 connected to the hydraulic control system 20.

[0085] The third pump 36 can be mechanical. For example, the third pump 36 is driven by power shafts 8 and 9 (such as low-pressure shaft 8 or high-pressure shaft 9).

[0086] To minimize oil loss, the hydraulic control system 20 can be connected to the tank 22 via the second return loop 39.

Claims

1. A module for a turbine engine (1) of an aircraft, the module comprising: - At least one lubricated enclosure (16). -Mechanical power shafts (8, 9), and - Oil system (21), the oil system comprising: - Oil tank (22) - An oil supply circuit (23) for supplying oil to the lubricating enclosure (16), the supply circuit (23) comprising: - A first pump (25), driven by the power shaft (8, 9), and including an oil inlet (26) and an oil outlet (27) connected to the tank (22), and - A first heat exchanger (28), the first heat exchanger comprising a first oil circuit connecting the oil outlet (27) of the first pump (25) to the lubrication enclosure (26) and a second circuit for cooling fluid. The oil system (21) is characterized in that it further includes: - A cooling circuit (24) for oil, the cooling circuit (24) comprising: - Second pump (30), the second pump includes an oil inlet (32) and an oil outlet (33) connected to the tank (22). - A second heat exchanger (31), the second heat exchanger comprising a first oil circuit connecting the oil outlet (33) of the second pump (30) to the tank (22) and a second circuit for cooling fluid, and - A control member (34) for controlling the second pump (30), the control member being configured to regulate the flow rate of the second pump (30).

2. The module according to the preceding claim, characterized in that, The second pump (30) is an electric pump.

3. The module according to any one of the preceding claims, characterized in that, The second heat exchanger (31) is an air / oil type exchanger, and the first heat exchanger (28) is a fuel / oil type exchanger.

4. The module according to any one of the preceding claims, characterized in that, The supply circuit (23) includes an additional heat exchanger (29) installed between the first heat exchanger (28) and the lubrication enclosure (16).

5. The module according to the preceding claim, characterized in that, The additional heat exchanger (29) is of the air / oil type.

6. The module according to claims 3 and 5, characterized in that, The air / oil exchange surface area of ​​the cooling circuit (24) is at least 50% larger than the air / oil exchange surface area of ​​the oil system (21).

7. The module according to any one of the preceding claims, characterized in that, The cooling circuit (24) includes an additional heat exchanger (35) installed between the second heat exchanger (31) and the tank (22).

8. The module according to the preceding claim, characterized in that, The additional heat exchanger (35) is of the air / oil type.

9. The module according to any one of the preceding claims, characterized in that, The module includes a hydraulic control system (20), and the oil system (21) further includes a third pump (36), the third pump comprising: - The oil inlet (37) connected to the tank (22), and - Oil outlet (38) connected to the hydraulic control system (20).

10. The module according to the preceding claim, characterized in that, The third pump (36) is driven by the power shaft (8, 9).

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