Oil tank with centrifugal impeller compatible with negative G for turbine engine

Abstract

The invention relates to a tank (40) for an aircraft turbomachine, said tank comprising:-an enclosure (54) capable of containing oil and having a main axis intended to be oriented vertically in a mounted position; an oil inlet (66) located in an upper portion of the enclosure; -an oil outlet (74) located in the lower portion of the enclosure; wherein the tank further comprises a wheel (80) arranged in the lower portion of the enclosure and drivable in rotation by a drive means (82) to cause the oil to centrifugally abut against a retaining wall (56.1) of the enclosure and against the oil outlet so as to maintain the supply of oil to said oil outlet during a flight phase in which the aircraft is in a zero-gravity or heavy-weight state.

Description

Technical Field

[0001] This invention relates to the field of turbine tanks. More specifically, this invention relates to the field of oil tanks for lubricating turbine components, particularly ductless variable pitch propellers and / or variable pitch rectifiers. Background Technology

[0002] Aircraft turbines that include at least one ductless propeller are called "open rotors" or "unducted fans." Within this category, there are turbines with two ductless counter-rotating propellers (called unducted fan (UDF)) or turbines with a single ductless propeller and a rectifier (which includes multiple stator blades) (called unducted single fan (USF)).

[0003] These turbines are turboprop engines, which differ from turbojet engines in that they use an external propeller (ductless) instead of an internal fan.

[0004] One or more propellers that form the propulsion component typically include a system (also known as a variable pitch system) for actuating the pitch of the blades of one or more propellers. This system allows the propeller blades to be oriented according to the needs of the aircraft's flight phases (takeoff, cruise, landing, etc.) to ensure thrust management in all flight conditions of the turbine.

[0005] In the case of a turbine having a single ductless propeller and rectifier, the rectifier may also include a variable pitch system to improve turbine performance. An example of such a turbine is disclosed in published patent document FR 3 107 319 A1.

[0006] Variable pitch systems may require a continuous oil supply to enable actuation of blade pitch and management of engine thrust under all flight conditions (both normal and extreme). In the prior art, these systems are supplied by a main lubrication circuit to ensure oil supply to various engine components (bearings, gearboxes, etc.) for lubrication and / or cooling. This circuit is supplied by the turbine's main tank, which, among other things, includes an oil inlet at the top and an oil outlet at the bottom, allowing for oil supply during flight attitudes under gravity or with a positive load factor (positive G).

[0007] While these fuel tanks are perfectly adequate when the aircraft is flying in a positive G-force, they no longer fully guarantee the supply of fuel to the pitch actuation system when the aircraft is in a phase of flight with a zero or negative load factor (zero G or negative G) (i.e. when the aircraft is being maneuvered or encountering upwind gusts).

[0008] In reality, zero-gravity or negative-gravity flight phases are temporary flight phases (typically lasting less than 30 seconds for civilian aircraft), during which the aircraft experiences negative acceleration (e.g., when the aircraft experiences a sudden drop in altitude).

[0009] As a result, the oil contained in the main tank overflows and is no longer located near the lower outlet. This interrupts the oil supply, causing airflow to one or more variable pitch loops, which has adverse consequences for the turbine's operation and could lead to loss of aircraft control.

[0010] Tanks can be used, such as those used in combat aircraft where negative G-phase flight is frequent and necessary. However, these tanks are pressurized, which means significant overweight and high additional costs, making them incompatible with turbines that include at least one ductless propeller.

[0011] Furthermore, a known solution to avoid damaging the propeller pitch actuation circuit is to ensure oil supply through a system other than the turbine's main oil tank in the case of negative G. However, this solution involves significant volume and mass within the turbine and complex management of delivering oil to the variable pitch system.

[0012] Published patent document FR 3 010 133 A1 discloses a tank including an inclined baffle with a through-hole at its end for continuous supply to a turbine. However, the solution proposed in this document still has room for improvement, such as in the case of negative G flight, to have a larger available volume of oil to supply the turbine components, and not to impede the volume when returning to positive G. Summary of the Invention

[0013] Technical issues

[0014] The present invention aims to overcome at least one of the disadvantages of the prior art described above. More specifically, the present invention aims to provide a fuel tank designed to enable an aircraft to perform temporary flight phases completely safely under load without increasing the weight and cost of the tank.

[0015] Technical solution

[0016] This invention relates to an oil tank for an aircraft turbine, the oil tank comprising:

[0017] -A casing that can hold oil and has a main axis;

[0018] - Oil inlet, located in the upper part of the casing;

[0019] - Oil outlet, located in the lower part of the casing;

[0020] The oil tanks also include:

[0021] - A wheel, which is arranged in the lower part of the shell and can be driven to rotate by a drive device, so that the oil centrifugally abuts against the retaining wall of the shell and centrifugally abuts against the oil outlet, thereby maintaining the oil supply to the oil outlet during the flight phase when the aircraft is in zero gravity or heavy gravity.

[0022] Advantageously, the oil inlet is the inlet for oil mixed with air.

[0023] According to an advantageous embodiment of the invention, the wheel has a rotation axis that is parallel to the main axis or inclined at an angle of -20° relative to the main axis.

[0024] Advantageously, the axis of rotation of the wheel passes through the casing, and the axis of rotation can be driven by a drive unit.

[0025] Advantageously, the drive unit includes an electric motor.

[0026] Advantageously, the training facilities are located inside the enclosure.

[0027] According to an advantageous embodiment of the invention, the wheel is adjacent to the bottom wall of the casing.

[0028] According to an advantageous embodiment of the invention, the retaining wall is a tapered shape having a smaller diameter section and a larger diameter section.

[0029] Preferably, the wheel being adjacent to the bottom wall of the casing means that the smaller diameter section is opposite the bottom wall and is at a distance from the bottom wall corresponding to at most 20% of the total height of the lower part of the casing.

[0030] According to an advantageous embodiment of the invention, the oil outlet passes through the retaining wall in the larger diameter section.

[0031] According to an advantageous embodiment of the invention, the conical shape of the retaining wall has an angle between 10° and 50°.

[0032] According to an advantageous embodiment of the invention, the retaining wall is a side wall of the enclosure, with a smaller diameter section adjacent to the bottom wall of the enclosure.

[0033] According to an advantageous embodiment of the invention, the wheel has a conical outer shell, the conical shape of which is parallel to or inclined at an angle of less than 20° relative to the conical shape of the retaining wall.

[0034] According to an advantageous embodiment of the invention, the enclosure further includes a transverse wall that defines an upper compartment and a lower compartment within the enclosure. The upper compartment includes an oil inlet, and the lower compartment includes a wheel, a retaining wall, and an oil outlet. The transverse wall includes at least one passage that fluidly connects the lower compartment to the upper compartment.

[0035] According to an advantageous embodiment of the invention, at least one passage includes a conduit extending from the transverse wall into the wheel.

[0036] According to an advantageous embodiment of the invention, the pipe extends along the main direction of the pipe at at least 80% of the height of the wheel.

[0037] According to an advantageous embodiment of the invention, at least one passage includes a valve that allows oil to flow from the upper compartment to the lower compartment and blocks oil from flowing from the lower compartment to the upper compartment.

[0038] Advantageously, the oil tank includes an oil outlet located on the upper compartment and adjacent to the transverse wall.

[0039] According to an advantageous embodiment of the invention, the oil outlet on the lower compartment is an auxiliary oil outlet, and the oil tank includes an auxiliary oil inlet located on the lower compartment.

[0040] The present invention also relates to a hydraulic system for an aircraft turbine, the hydraulic system comprising:

[0041] - Oil tank;

[0042] - The turbine's lubrication circuit is hydraulically connected to the oil tank;

[0043] - A hydraulic control circuit for at least one hydraulic actuator, the hydraulic control circuit being hydraulically connected to an oil tank;

[0044] The oil tank is according to the present invention, wherein the lubrication circuit is hydraulically connected to the oil inlet and oil outlet arranged on the casing, and the hydraulic control circuit is hydraulically connected to the auxiliary inlet and auxiliary outlet.

[0045] Advantageously, the oil inlet is the inlet for oil mixed with air.

[0046] The present invention also relates to an aircraft turbine, the aircraft turbine comprising:

[0047] - Ductless propeller, which propels the incoming airflow, the propeller includes variable pitch blades actuated by at least one hydraulic actuator.

[0048] - A hydraulic system that provides lubrication to the turbine and controls at least one hydraulic actuator;

[0049] The hydraulic system is the hydraulic system according to the present invention.

[0050] The present invention also relates to a turbine comprising:

[0051] - A ductless propeller that propels an incoming airflow, the propeller including a variable pitch system for actuating the pitch of the propeller blades.

[0052] - An oil tank, used for lubricating turbine components; wherein the tank includes:

[0053] -A casing that can hold oil and has a main axis;

[0054] - Oil inlet, located in the upper part of the casing;

[0055] - Oil outlet, located in the lower part of the casing;

[0056] - A wheel, which is arranged in the lower part of the shell and can be driven to rotate by a drive device, so that the oil centrifugally abuts against the retaining wall of the shell and centrifugally against the oil outlet, thereby maintaining the oil supply to the oil outlet during the zero-gravity or heavy-gravity flight phase of the aircraft.

[0057] According to an advantageous embodiment of the invention, the variable pitch system is a first variable pitch system, the turbine further includes a rectifier comprising a plurality of stator blades extending from a fixed housing, the rectifier includes a second variable pitch system, and an auxiliary outlet is hydraulically connected to a second closed loop, the second closed loop including components of the first system and / or the second variable pitch system of the turbine.

[0058] Advantages of the invention

[0059] A particular advantage of the present invention is that it enables the supply of oil to various components of the turbine (especially including one or more variable pitch systems) while ensuring an uninterrupted supply of pure oil, free of any air, to one or more variable pitch systems during flight phases in zero gravity and negative gravity conditions.

[0060] Advantageously, the centrifugal force generated by the wheel can press the hydraulic pressure against the retaining wall to overcome gravity during all phases of flight. Therefore, the hydraulic control of the turbine's propeller pitch actuation system can remain operational during all phases of flight.

[0061] In addition, the tank is compact, which helps to reduce the overall size and weight of the turbine. Attached Figure Description

[0062] [ Figure 1 [Illustrated axial cross-sectional view of an aircraft turbine according to the present invention;]

[0063] [ Figure 2 It shows Figure 1 A schematic diagram of the hydraulic system of the turbine;

[0064] [ Figure 3 A cross-sectional view of an oil tank according to the present invention is shown;

[0065] [ Figure 4 It shows Figure 3 The deformation of the oil tank;

[0066] [ Figure 5 This illustrates the flight phase during which the aircraft is under negative gravity. Figure 3 A cross-sectional view of the oil tank. Detailed Implementation

[0067] The accompanying drawings illustrate the components schematically and are not drawn to scale. In particular, some dimensions have been enlarged to facilitate reading the drawings.

[0068] Figure 1 An axial cross-sectional view of an aircraft turbine according to the present invention is schematically shown. This aircraft turbine is a type of turbine known as an open rotor or unducted fan, particularly an unducted single fan (USF) turbine.

[0069] In the following description, the terms "internal" and "external" refer to the positioning relative to the turbine's axis of rotation, and here along the longitudinal axis X (even in...). Figure 1 (From left to right in the figures). The terms "radial," "inner," and "outer" are defined relative to the radial direction perpendicular to the longitudinal axis X. Upstream and downstream refer to the flow direction within the turbine. Furthermore, elements that are the same or substantially the same and / or have the same function shown in the figures are indicated by the same reference numerals.

[0070] Turbine 2 typically includes, from upstream to downstream, a first compression stage (referred to as low-pressure compressor 4), a second compression stage (referred to as high-pressure compressor 6), a combustion chamber 8, a subsequent high-pressure turbine 9, and a low-pressure turbine 10.

[0071] The turbine 2 includes a propeller 14, which is arranged upstream of a dividing nozzle 16. The dividing nozzle is carried by a housing 24 and is capable of dividing the incoming airflow F into a secondary flow F2 and a main flow F1. The main flow flows in a main flow channel 18 and passes through each of the aforementioned stages of the turbine 2.

[0072] The main airflow 18 is radially defined by an inner radial wall 20 and an outer radial wall 22. The inner radial wall 20 is supported by an inner shell 12. The outer radial wall 22 is supported by an outer shell 24. The main airflow F1 enters the main airflow 18 through an annular air inlet 17 and exits through a main nozzle 19 located downstream of the main airflow 18. The main airflow F1 can be accelerated by the main nozzle 19 to generate the reverse thrust required for aircraft flight.

[0073] The turbine includes a rotating housing 26 centered on and rotating about a longitudinal axis X. The rotating housing 26 carries the crowns of movable blades 28 forming a propeller 14. The rotating housing 26 is movably mounted relative to the inner housing 12 that carries the rotating housing.

[0074] The airflow F entering the turbine passes through the blades 28 of the propeller 14 to form a secondary airflow F2. This secondary airflow flows around the outer casing 24. Each blade 28 of the propeller 14 includes a root 30 and an aerodynamic section extending radially outward from the root 30, the root including a pivot. In practice, the root 30 is mounted to pivot about axis A (perpendicular to X), thereby enabling the blades 28 of the propeller 14 to pivot. This pivoting is controlled by a first variable pitch system of the turbine 2.

[0075] The low-pressure compressor 4 and the low-pressure turbine 10 are mechanically connected by a low-pressure shaft 11. The low-pressure shaft drives the propeller 14 through a reducer 32. The propeller 14 compresses the air outside the outer casing 24 and provides most of the thrust of the turbine 2. The reducer 32 can be a planetary gear type.

[0076] Turbine 2 includes a rectifier 34 through which a secondary flow F2 passes, the secondary flow being a portion of the airflow F propelled radially outward relative to the longitudinal axis X. The rectifier 34 includes a plurality of stator blades 36 (or stator blades or fixed blades) (referred to as outlet guide vanes (OGVs)). The stator blades 36 are regularly distributed around the longitudinal axis X and extend radially within the secondary airflow F2. The stator blades 36 are carried by a fixed structure attached to the housing 24. Specifically, each stator blade 36 extends radially from a foot 38, which is pivotally mounted around an axis B (perpendicular to X), thereby enabling the stator blades 36 of the rectifier 34 to pivot. This pivoting is controlled by a second variable pitch system of turbine 2.

[0077] The turbine 2 also includes an oil tank 40 for lubricating and / or cooling the components of the turbine 2. For this purpose, the oil tank 40 is the main oil tank of the turbine 2 and also enables the supply of oil to the first and second variable pitch systems of the turbine 2. Preferably, the tank 40 is arranged in a straight line with the outer casing 24. The structure and operation of the oil tanks 40 and 400 will be described in detail below in this specification.

[0078] Figure 2 yes Figure 1 A schematic diagram of the hydraulic system 39 of the turbine. The hydraulic system 39 includes different closed loops connected to the oil tank of the present invention.

[0079] Reference Figure 2 The oil tank 40 is hydraulically connected to the lubrication and cooling circuit 42 of the turbine engine, which includes a supply pump 43, an exchanger 44, and an engine housing 45. The engine housing ensures lubrication of the bearings, gearbox, and bearings, and ensures the air / oil seal of the engine.

[0080] The lubrication circuit 42 also includes at least one recovery pump 46, which is configured to recover oil from the engine casing 45 and direct the oil to the oil reservoir 40. Circuit 42 may correspond to the lubrication assembly of a turbine.

[0081] The oil tank 40 is also hydraulically connected to a circuit 48 for actuating the pitch of the propeller blades, also known as the hydraulic control circuit 48, and is used to... Figure 1 The turbine’s first variable pitch system (i.e., propeller 14) supplies oil.

[0082] The hydraulic control circuit 48 can also independently of or in combination with the first variable pitch system to... Figure 1 The turbine's second variable pitch system (i.e., rectifier 34) supplies oil.

[0083] Hydraulic control circuit 48 can provide lubrication and / or cooling for the variable pitch system. In this regard, circuit 48 includes booster pump 49, which recovers oil from the lower part of tank 40 to direct the oil to exchanger 50.

[0084] Preferably, in addition to lubrication and cooling functions, the hydraulic control circuit 48 is also configured to hydraulically control the variable pitch system. In this regard, the circuit 48 includes a pitch actuation pump 51 capable of hydraulically controlling a pitch actuation system or hydraulic actuator 52, which may correspond to a first variable pitch system and / or a second variable pitch system of the turbine.

[0085] In this configuration, the stepper actuation pump 51 enables the actuation of the hydraulic actuator 52, thereby causing Figure 1 The foot pivots at 30 and 38.

[0086] Preferably, the hydraulic control circuit 48 includes a bypass valve 53, which allows selection between a cooling function or actuation of the pitch of the variable pitch system.

[0087] Advantageously, the hydraulic system 39 includes a connection (shown in dashed lines) between the hydraulic control circuit 48 and the lubrication circuit 42 to collect any leakage from the propeller pitch actuation cylinder and re-inject the oil from the inlet 66 into the tank 40.

[0088] Figure 3 A cross-sectional view of an oil tank 40 is shown. The tank includes an oil inlet 66 for mixing oil with air, leading to a main casing 54 capable of containing oil (not shown here for better simplification), and more specifically, to an oil degassing device 68 to allow the removal of air 70 mixed with oil at the oil inlet 66. The oil inlet 66 preferably originates from... Figure 2 At least one recovery pump 46.

[0089] The main casing 54 has a main axis R, which preferably corresponds to a main direction R, which is intended to be in Figure 1 The turbine 2 is vertically oriented in the installation position.

[0090] Preferably, the main axis R corresponds to the main extension direction of the main enclosure 54. Therefore, the main axis R defines the direction of the maximum dimension of the enclosure 54.

[0091] Preferably, the main axis R of the enclosure 54 follows the direction of gravity (perpendicular to the horizontal plane). However, the main axis R may be tilted relative to the direction of gravity at an angle of up to 45° or more, so as to form an angle of less than 90°.

[0092] Based on the direction of gravity (a force perpendicular to the horizontal plane and directed downwards), the upper compartment 58 is located above the lower compartment 56.

[0093] Alternatively, the cap 54 of the can 40 may have a generally elliptical and / or curved shape. Preferably, the cap 54 comprises a generally cylindrical shape.

[0094] Tank 40 includes a transverse wall 60 that defines an upper compartment 58 and a lower compartment 56 in the casing. The upper compartment corresponds to the upper portion of the casing 54 that includes an oil inlet 66, and the lower compartment corresponds to the lower portion of the casing 54 and includes an oil outlet 74.

[0095] Tank 40 also includes an oil outlet 72, which is preferably arranged in a straight line with the side wall of the upper compartment 58 and is preferably adjacent to the transverse wall 60. In this configuration, the oil inlet 66 and the oil outlet 72 form a... Figure 2 The circuit corresponding to lubrication circuit 42.

[0096] The lower compartment 56 is formed by a retaining wall 56.1, which corresponds to the sidewall of the casing 54, specifically to the sidewall of the lower portion of the casing 54. Preferably, the retaining wall 56.1 comprises a conical shape having a smaller diameter section 56.2 and a larger diameter section 56.3. Preferably, the bottom wall 54.1 is formed together with the retaining wall 56.1.

[0097] Advantageously, the arrangement of the lower compartment 56 within the main casing 54 enables rapid exchange of oil flow between the lower compartment and the main casing.

[0098] In this configuration, the cone angle α of the tapered shape of the retaining wall 56.1 is between 10° and 50°, preferably between 20° and 45°, and more preferably 30°. The cone angle α is between the retaining wall 56.1 and the main (vertical) direction; however, the inclination of the retaining wall 56.1 may be less than 20° relative to the main direction.

[0099] The lower compartment 56 includes an auxiliary oil inlet 67, which is preferably arranged in a straight line with the bottom wall 54.1. The auxiliary oil inlet 67 is preferably oriented tangentially to the retaining wall 56.1 so that the incoming oil flow is oriented in a manner similar to that generated by the wheel 80.

[0100] The lower compartment 56 also includes an auxiliary oil outlet 74, which passes through the reference retaining wall 56.1 in the larger diameter section 56.3. For this purpose, the auxiliary inlet 67 and the auxiliary outlet 74 enable the formation of a closed loop to supply oil to… Figure 2 The hydraulic control circuit 48 supplies oil.

[0101] Preferably, the inlet 67 is located in one end of the bottom wall 54.1 adjacent to the retaining wall 56.1 and close to the auxiliary outlet 74. Advantageously, this allows for minimizing the oil path between the inlet 67 and the outlet 74 in the lower compartment 56.

[0102] The tank 40 also includes a wheel 80, which is arranged in the lower compartment 56 and also has a conical shape. In fact, the wheel 80 includes a housing 80.1, which has a conical shape parallel to the conical shape of the retaining wall 56.1.

[0103] In this regard, the outer casing 80.1 includes a smaller diameter segment 80.2 and a larger diameter segment 80.3, which are located at approximately the same level as segments 56.2 and 56.3 of the retaining wall 56.1, respectively. Preferably, the smaller diameter segment 80.2 of the wheel 80 is adjacent to the lower wall 54.1 of the cover 54.

[0104] Preferably, the smaller diameter section 80.2 of the wheel 80 is opposite to the bottom wall 54.1 and is at a distance from the bottom wall corresponding to at most 20% of the total height H of the lower compartment 56. The wheel 80 is driven to rotate by a drive device 82 connected to the wheel in the lower compartment 56 via a shaft (not shown) of the wheel 80 having a rotation axis 82.1, which is preferably parallel to the main vertical direction of the tank 40, or inclined at at most 20° from said main direction.

[0105] exist Figure 3 As can be seen, the drive unit 82 is schematically shown located on the outside of the tank and below the bottom wall 54.1. In this configuration, the drive unit 82 can correspond to... Figure 1 The turbine includes a reducer and / or a right-angle drive. For this purpose, the shaft drives the wheel 80 to rotate after resuming rotational motion via the reducer and / or right-angle drive. To this end, the bottom wall 54.1 may include a bearing and at least one seal, the at least one seal being used to ensure the sealing of the lower compartment 56.

[0106] However, the drive unit 82 can correspond to an electric motor, which is arranged in the lower compartment 56 between the smaller diameter section 80.2 and the bottom 54.1. This motor can also be arranged in the upper compartment 58 and preferably in line with the transverse wall 60. Advantageously, this arrangement ensures space savings within the tank 40.

[0107] Figure 4 It shows Figure 3 An alternative to the tank 40' is provided, wherein the lower compartment 56 of the tank 40' is arranged outside the upper compartment 58. Advantageously, this allows for the integration of the tank 40' into the particularly harsh environment of the turbine. In this regard, one or more hydraulic lines 62' can connect the two compartments 58 and 54. In this configuration, the one or more hydraulic lines 62' can be flexible and / or can be integrated with the passageway 62 of the lower compartment.

[0108] exist Figure 4 As can be seen, the main casing 54 of tank 40' includes a transverse wall 60' corresponding to the bottom wall 60' of upper compartment 58. Advantageously, the wall 60' may have a tapered shape to facilitate oil flow toward channel 62 during the return to positive gravity after a negative gravity event.

[0109] Figure 5 A cross-sectional view of fuel tank 40 is shown during the flight phase of the aircraft in negative G-force. Here, G+ refers to positive gravity, and G- refers to negative gravity.

[0110] It should be noted that tank 40 is capable of ensuring a constant supply of pure oil during the G-phase, and each G-phase lasts from a fraction of a second to 45 seconds. Advantageously, the size of tank 40 can be designed to ensure a constant supply of oil even for periods exceeding 45 seconds.

[0111] The transverse wall 60 preferably includes an oil passage corresponding to the conduit 62, which fluidly connects the upper compartment 58 to the lower compartment 56.

[0112] In an alternative not shown, the transverse wall 60 may have a tapered shape to facilitate oil flow toward the channel 62 during the return to G+.

[0113] Preferably, the conduit 62 extends over at least 80% of the height h of the wheel 80; more preferably, the conduit 62 extends over at least 80% of the total height H of the lower compartment 56 and over the entire height h of the wheel 80. In this configuration, the bottom wall 54.1 of the casing 54 is adjacent to the distal end 62.1 of the conduit 62.

[0114] Preferably, the conduit 62 extends into the wheel 80 such that the housing 80.1 completely surrounds the conduit 62. The conduit is slightly offset from the axis of rotation 82.1 of the wheel 80 so that the shaft of the drive unit 82 can pass through it.

[0115] Advantageously, in the G- state, the conduit 62 defines an oil buffer volume between the distal end 62.1 and the transverse wall 60, which is designed to be drawn toward the auxiliary oil outlet 74 to supply oil to the hydraulic control circuit and to remain uninterrupted throughout the entire duration of the aircraft's events G0 and G-.

[0116] Preferably, the height h of the wheel 80 corresponds to approximately 80% (±10%) of the total height H of the lower compartment 56. However, in an alternative not shown, the wheel 80 may be located entirely in the lower half of the lower compartment 56. In practice, the height h of the wheel 80 can be optimized based on the dimensions of the tank 40 and the rotational speed of the wheel 80. For example, a small wheel 80 near the bottom 54.1 may be sufficient to generate the amount of movement required to allow oil to reach the auxiliary oil outlet 74. In this regard, the height h of the wheel 80 may correspond to more than 20% and / or less than 90% of the total height H of the lower compartment 56.

[0117] The distal end 62.1 may include a check valve (not shown), which is preferably sensitive to changes in gravity. For this purpose, the valve is capable of allowing oil to flow from the upper compartment 58 to the lower compartment 56 in the G+ state and preventing oil from flowing from the lower compartment 56 to the upper compartment 58 in the G- state. This advantageously maximizes the retention of oil in the lower compartment 56 in the G- state.

[0118] Meanwhile, the transverse wall 60 may also include a valve (not shown) or wing that is sensitive to changes in gravity, which allows oil to be advantageously held in the lower compartment 56 in the G- state and to be accelerated back into the compartment in the G+ state.

[0119] In addition, the transverse wall 60 may also include an exhaust port 60.1 that allows air to be rapidly exhausted from the lower compartment 56 so that oil can be rapidly returned to the compartment when the aircraft returns to the G+ state after the G- state.

[0120] During the G- phase, the buffered volume of oil held in the lower compartment 56 is centrifugally pressed against the retaining wall 56.1 by the wheel 80. In fact, the wheel 80 is driven to rotate throughout the entire duration of G0 and G-. For this purpose, the oil centrifugally presses against the retaining wall 56.1 and centrifugally against the auxiliary oil outlet 74.

[0121] Preferably, the drive unit 82 drives the wheel 80 to rotate during all flight phases (G+, G0, and G-) of the aircraft. Advantageously, this allows oil to continuously press against the retaining wall 56.1 to reach the outlet 74 (the movement of the oil is shown in dashed lines), and further ensures... Figure 2 The operation and continuous supply of the hydraulic control circuit 48.

[0122] However, if the drive unit 82 corresponds to an electric motor, the wheel 80 can be controlled to be driven to rotate only during events G0 and G-.

[0123] Preferably, the conical outer shell 80.1 may correspond to a porous surface having multiple pouch-like portions capable of containing oil, thereby maximizing the centrifugal force generated on the oil by the rotation of the wheel 80. Similarly, the outer shell 80.1 may include a hollow portion or groove extending over the entire height h of the wheel 80. Preferably, the outer shell 80.1 includes a spoon-shaped structure and / or multiple blades (in... Figure 5 (Indicated by shading in the image), the spoon-shaped structure and / or multiple blades extend over the entire height h and advantageously have a helical track around axis 82.1. In this structure, the oil has an annular swirling path on the retaining wall 56.1.

[0124] Advantageously, wheel 80 enables the centrifugal force to be effectively transferred to the oil buffer volume in the lower compartment of tank 40 to guide the oil flow toward auxiliary outlet 74.

[0125] Advantageously, the turbine of the present invention can ensure the continuous and safe operation of the turbine's variable pitch system due to the following main oil tank, which enables the oil supply to be ensured during flight phases in zero gravity or heavy gravity conditions, thereby supplying the variable pitch system with pure oil free of any air in an uninterrupted manner.

Claims

1. An oil tank (40) for an aircraft turbine (2), the oil tank comprising: - a capsule (54) capable of containing oil and having a main axis; - an oil inlet (66) located in the upper part of the enclosure (54); - an oil outlet (74) located in the lower part of the enclosure (54); Characterized in that the oil tank (40) further comprises: - a wheel (80) which is arranged in the lower part of the enclosure (54) and can be driven in rotation by a drive device (82) so as to centrifugally press the oil against a retaining wall (56.1) of the enclosure (54) and against the oil outlet (74) so ​​as to maintain the supply of oil to the oil outlet (74) during flight phases in which the aircraft is in zero gravity or negative gravity.

2. The oil tank (40) according to claim 1, wherein: The wheel (80) has an axis of rotation (82.1) which is parallel to the main axis (R) or inclined at an angle of minus 20° relative to the main axis (R).

3. The oil tank (40) according to claim 1 or 2, wherein: The wheel (80) is adjacent to the bottom wall (54.1) of the enclosure (54).

4. The oil tank (40) according to any one of claims 1 to 3, wherein: The retaining wall (56.1) is of a conical shape having a smaller diameter section (56.2) and a larger diameter section (56.3).

5. The oil tank (40) according to claim 4, wherein: The oil outlet (74) penetrates the retaining wall (56.1) at the larger diameter section (56.3).

6. The oil tank (40) according to claim 4 or 5, wherein: The conical shape of the retaining wall (56.1) has an angle (α) between 10° and 50°.

7. The oil tank (40) according to any one of claims 4 to 6, wherein: The retaining wall (56.1) is a side wall of the enclosure (54), and the smaller diameter section (56.2) is adjacent to the bottom wall (54.1) of the enclosure (54).

8. The oil tank (40) according to any one of claims 4 to 7, wherein: The wheel (80) has an outer housing (80.1) of conical shape, the conical shape of the outer housing being parallel to the conical shape of the retaining wall (56.1) or inclined at an angle of less than 20° relative to the conical shape of the retaining wall (56.1).

9. The oil tank (40) according to any one of claims 1 to 8, wherein: The enclosure (54) further comprises a transverse wall (60) defining an upper compartment (58) and a lower compartment (56) in the enclosure, the upper compartment comprising the oil inlet (66), the lower compartment comprising the wheel (80), the retaining wall (56.1) and the oil outlet (74), the transverse wall (60) comprising at least one passage (62) fluidically connecting the lower compartment (56) with the upper compartment (58).

10. The oil tank (40) according to claim 9, wherein: The at least one passageway comprises a duct (62) extending from the transverse wall (60) into the wheel (80).

11. The oil tank (40) according to claim 10, wherein: The duct (62) extends over at least 80% of the height (h) of the wheel (80) along a main direction of the duct (62).

12. The oil tank (40) according to any one of claims 9 to 11, wherein: The at least one passageway (62) includes a valve adapted to enable oil to flow from the upper compartment (58) to the lower compartment (56) and to block oil from flowing from the lower compartment (56) to the upper compartment (58).

13. The oil tank (40) according to any one of claims 9 to 12, wherein: The oil outlet (74) on the lower compartment (56) is an auxiliary oil outlet (74), and the oil tank (40) includes an auxiliary oil inlet (67) located on the lower compartment (56).

14. A hydraulic system (39) for an aircraft turbine (2), the hydraulic system comprising: - oil tank (40); - a lubrication circuit (42) of the turbine (2), the lubrication circuit being hydraulically connected to the oil tank (40); - a hydraulic control circuit (48) of at least one hydraulic actuator (52), said hydraulic control circuit being hydraulically connected to said oil tank (40); It is characterized in that the oil tank (40) is an oil tank according to any one of claims 1 to 12, the lubrication circuit is hydraulically connected to the oil inlet (66) and the oil outlet (72) arranged on the shell (54), and the hydraulic control circuit (48) is hydraulically connected to the auxiliary inlet (67) and the auxiliary outlet (74).

15. An aircraft turbomachine (2), comprising: - an unducted propeller (14) which propels the incoming air flow (F), the propeller (14) comprising variable pitch blades (28) actuated by at least one hydraulic actuator (52); a hydraulic system (39) capable of providing lubrication for the turbine (2) and of controlling the at least one hydraulic actuator (52); Characterized in that the hydraulic system (39) is a hydraulic system according to claim 14.

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