MODULE FOR AN AIRCRAFT TURBOMACHINE
The aircraft turbomachine module addresses the issue of bulkiness, weight, and cost by using a hydraulic pump with axial pistons and a tilting main tray, eliminating the need for a rotating electric transformer and resulting in a more compact, lightweight, and energy-efficient design.
Patent Information
- Application Number
- FR2022003561
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2022-04-15
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2042-04-15
AI Technical Summary
Existing aircraft turbomachine modules with variable timing blades are bulky, heavy, and costly due to the need for a rotating electric transformer to power the hydraulic pump and actuator.
A compact, lightweight turbomachine module design that eliminates the need for a rotating electric transformer by using a hydraulic pump with axial pistons connected to a tilting main tray, which varies the flow rate and eliminates the need for a rotating electric motor.
The module is more compact, lighter, and energy-efficient, reducing the size, mass, and cost of the turbomachine while maintaining efficient blade positioning and operation.
Smart Images
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Abstract
Description
Title of the invention: MODULE FOR AN AIRCRAFT TURBOMACHINE Technical field of the invention
[0001] The invention relates to the field of modules for aircraft turbomachines. The invention relates more particularly to modules comprising a rotating hub and variable-pitch blades carried by the hub, such as fan or propeller modules. Technical background
[0002] An aircraft turbomachine generally comprises a module extending around a longitudinal axis and having a hub that is movable in rotation around the longitudinal axis and on which blades are mounted. The module is typically connected to a gas generator. The gas generator comprises, for example, from upstream to downstream, a low-pressure compressor, a high-pressure compressor, a combustion chamber, a high-pressure turbine, a low-pressure turbine and a gas exhaust nozzle. The rotor of the high-pressure compressor is connected to the rotor of the high-pressure turbine by a high-pressure shaft and the rotor of the low-pressure compressor is connected to the rotor of the low-pressure turbine by a low-pressure shaft. The low-pressure shaft is furthermore connected to a drive shaft of the hub of the module to drive it in rotation.
[0003] The module is for example a fan or a propeller. In the case of a fan, the blades are surrounded by an external casing fixed to a nacelle of the aircraft. In the case of a propeller, the fan blades are mounted outside the nacelle and are therefore not surrounded by an external casing.
[0004] In order to optimize the operation of the module and ensure its operability according to the flight phases of the aircraft, in particular by maintaining a sufficient pumping margin, it is known to modify the orientation of the blades during the flight of the aircraft. For this purpose, the blades are movable around a pitch axis which extends perpendicular to the longitudinal axis. The blades are said to be variable pitch or variable pitch. For example, the variable pitch blades can occupy a so-called reverse thrust position in which they make it possible to generate counter-thrust to participate in slowing down the aircraft and a feathering position in which, in the event of failure or breakdown, they make it possible to limit their resistance.
[0005] In order to rotate the blades around their pitch axes, the turbomachine module typically comprises a device for changing the pitch of the blades. Document FR-A1-3 087 232 describes a turbomachine comprising a fan module having a hub movable about a longitudinal axis and on which variable-pitch blades are mounted. The module comprises a device for changing the pitch of the blades comprising a hydraulic actuator connected to the blades and a pump for supplying fluid to the hydraulic actuator. According to this document, the pump is rotationally fixed to the hub.
[0006] To operate the pump and regulate its flow rate, the module further comprises an electric motor integral in rotation with the pump.
[0007] Such a configuration is not entirely satisfactory. Indeed, since the electric motor is rotating and the energy source supplying the motor is in a fixed frame of reference, it is necessary to provide an energy transfer from a fixed frame of reference to a rotating frame of reference. To this end, the module of the prior art further comprises a rotating electrical transformer making it possible to supply the motor with electrical energy from an electrical energy source located in a fixed frame of reference of the turbomachine.
[0008] However, the turbomachine module has a size that makes it difficult to add an electrical transformer. Adding a transformer involves increasing the size of the module. Also, the mass and cost of the transformer are significant.
[0009] There is therefore a need to provide a turbomachine module for an aircraft, comprising a hub carrying variable-pitch blades, which is compact, lightweight, and inexpensive. Summary of the invention
[0010] To this end, the invention proposes a module for an aircraft turbomachine, the module comprising a longitudinal axis and comprising:
[0011] - a hub centered on the longitudinal axis and intended to be movable in rotation around the longitudinal axis,
[0012] - blades carried by the hub, each of the blades being movable around an axis of wedge extending radially relative to the longitudinal axis,
[0013] - a device for changing the setting of the blades around their setting axes, the device comprising:
[0014] a hydraulic actuator intended to be movable in rotation about the longitudinal axis and configured to drive the blades about their setting axes, and
[0015] a fluid supply pump for the hydraulic actuator comprising axial pistons intended to be movable in rotation about the longitudinal axis and configured to transfer the fluid to the hydraulic actuator, a connecting plate connected to the axial pistons and cooperating with an annular main plate centered on the longitudinal axis, the main plate being intended to be fixed in rotation about the longitudinal axis and is tiltable relative to the longitudinal axis, the connecting plate being arranged between the main plate and the axial pistons, the axial pistons being movable in translation in a direction parallel to the longitudinal axis, the inclination of the main plate causing a movement of the axial pistons in this direction.
[0016] According to the invention, the module comprises a pump having axial pistons connected to a connecting plate and driven in translation by a main plate.
[0017] The stroke of the pistons varies according to the inclination of the main plate, which makes it possible to vary the flow rate of the pump. Depending on the flow rate of the pump, the hydraulic actuator can vary the setting of the blades according to the desired angle.
[0018] Since the pump has a variable flow rate, it is no longer necessary to provide a rotating electric motor to regulate the flow rate of the pump. This eliminates the need for a rotating electrical transformer to supply the motor with electrical energy.
[0019] The module according to the invention is therefore more compact, lightweight and consumes little energy.
[0020] Also, according to the invention, the main plate is fixed in rotation. This makes it possible to simplify the configuration of the pump and the module.
[0021] Furthermore, according to the invention, the axial pistons are rotating. This makes it possible to avoid a rotating hydraulic transfer ensuring the transfer of fluid between the pump and the hydraulic actuator, thus limiting fluid leaks.
[0022] The invention may comprise one or more of the following features, taken in isolation from one another or in combination with one another:
[0023] - the pump comprises a casing mounted around the main plate and the plate connecting and intended to be fixed in rotation around the longitudinal axis,
[0024] - the main plate is tiltable at an angle of inclination a between -45° and 45°, an angle a of 0° corresponding to a position of the main plate in which it is perpendicular to the longitudinal axis,
[0025] - the device further comprises an actuator connected to the main plate and configured to tilt the main plate relative to the longitudinal axis,
[0026] - the connecting plate is intended to be movable in rotation around the long axis horizontal and is supported flat on the main plate,
[0027] - the axial pistons are connected to the connecting plate by a ball joint,
[0028] - the pump comprises a transmission shaft centered on the longitudinal axis, integral rotating connecting plate, and around which the main plate is mounted,
[0029] - a drive shaft integral in rotation with the hub and configured to drive in rotation the transmission axis around the longitudinal axis,
[0030] - the device further comprises an auxiliary actuator connected to the connecting plate and intended to rotate the connecting plate around the longitudinal axis,
[0031] - the auxiliary actuator is connected to the connecting plate by a splined connection or a cardan joint or an Oldham joint or a recessed joint,
[0032] — the hydraulic actuator is a cylinder integral in rotation with the shaft drive, the hydraulic actuator comprising a housing and a rod arranged inside the housing, and a first and a second chamber connected to the pump defined in the housing, the rod or the housing being movable in translation and connected to the blades,
[0033] — the housing or the rod is integral in rotation with the drive shaft.
[0034] The invention also relates to a turbomachine for an aircraft comprising a module according to any one of the preceding characteristics. Brief description of the figures
[0035] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the appended drawings in which:
[0036] [Fig.l] is a schematic representation in axial section of a half aircraft turbomachine;
[0037] [Fig.2] is a schematic representation in axial section of a module according to the invention;
[0038] [Fig.3a] is a functional schematic representation of a module according to an exemplary embodiment of the invention;
[0039] [Fig.3b] is a functional schematic representation of a module according to another exemplary embodiment of the invention;
[0040] [Fig.4a] is a schematic representation of the pump plate equipping the module, the plate being in a first position;
[0041] [Fig.4b] is a schematic representation of the pump plate equipping the module, the plate being in a second position;
[0042] [Fig.5] is a schematic representation of a module according to a particular embodiment of the invention;
[0043] [Fig.6] is a schematic representation of a module according to a particular embodiment of the invention. Detailed description of the invention
[0044] An aircraft comprises a fuselage and at least two wings extending on either side of the fuselage along the axis of the fuselage. At least one turbomachine 1 is mounted under each wing. The turbomachine 1 may be a turbojet, for example a turbomachine equipped with a ducted fan equipped with variable pitch blades, known by the acronym VPF for “Variable Pitch Fan” in English. Alternatively, the turbomachine 1 may be a turboprop, for example a turbomachine equipped with an unducted propeller (“open rotor”, “USF” for “Unducted Single Fan” or “UDF” for “Unducted Dual Fan”). Of course, the invention applies to other types of turbomachinery.
[0045] In the present invention, the terms "axial" and "axially" are defined with respect to a longitudinal axis X of the turbomachine 1 or of a module 3 of the turbomachine 1. The terms "upstream", "downstream", are defined with respect to the circulation of gases in the turbomachine 1 and here along the longitudinal axis X (and even from left to right in [Fig.l]). Similarly, the terms "radial", "radially", are defined with respect to a radial axis Z perpendicular to the longitudinal axis X. The terms "internal", "interior", "external" and "exterior" are defined with respect to the distance from the longitudinal axis X along the radial axis Z.
[0046] [Fig.l] illustrates an example of the turbomachine 1. The turbomachine 1 comprises a gas generator 2 and a module 3 according to the invention.
[0047] The gas generator 2 comprises, from upstream to downstream, a low-pressure compressor 4, a high-pressure compressor 5, a combustion chamber 6, a high-pressure turbine 7 and a low-pressure turbine 8. The rotors of the low-pressure compressor 4 and the low-pressure turbine 8 are mechanically connected by a low-pressure shaft 9 so as to form a low-pressure body. The rotors of the high-pressure compressor 5 and the high-pressure turbine 7 are mechanically connected by a high-pressure shaft 10 so as to form a high-pressure body. The high-pressure shaft 10 extends radially at least partly outside the low-pressure shaft 9. The low-pressure shaft 9 and the high-pressure shaft 10 are coaxial. The high-pressure body is guided in rotation about the longitudinal axis X by a first upstream rolling bearing 11 and a second downstream rolling bearing 12.The first bearing 11 is mounted radially between an inter-compressor casing 13 and an upstream end of the high-pressure shaft 10. The inter-compressor casing 13 is arranged axially between the low- and high-pressure compressors 4, 5. The second bearing 12 is mounted between an inter-turbine casing 14 and a downstream end of the high-pressure shaft 10. The inter-turbine casing 14 is arranged axially between the low- and high-pressure turbines 8, 7. The low-pressure body is guided in rotation about the longitudinal axis X via a third bearing 15 with rolling bearings and a fourth bearing 16 with rolling bearings. The fourth bearing 16 is for example a double bearing. The fourth bearing 16 is mounted between an exhaust casing 17 and a downstream end of the low pressure shaft 9. The exhaust casing 17 is located downstream of the low pressure turbine 8. The third bearing 15 is mounted between an inlet casing 18 and an upstream end of the low pressure shaft 9.The inlet casing 18 is arranged upstream of the low pressure compressor 4. More particularly, the inlet casing 18 is arranged axially between the module 3 and the low pressure compressor 4.
[0048] In the example of [Fig.l], the module 3 is mounted upstream of the gas generator 2. Advantageously, according to this example, a rectifier 20 is arranged downstream of the module 3. The rectifier 20 comprises, for example, vanes 200 mounted on the inlet casing 18. Such vanes 200 are called OGVs for “Outlet Guide Vanes” in English. The rectifier 20 makes it possible to straighten the flow downstream of the module 3 to optimize the operation of the turbomachine 1.
[0049] According to another embodiment not shown, the module 3 is mounted downstream of the gas generator 2.
[0050] Furthermore, the module 3 according to the invention comprises blades 30.
[0051] In the example of [Fig.l], the blades 30 are surrounded by an external casing 19. A nacelle (not shown) is attached to the outer casing 19. In this example, module 3 is a fan module.
[0052] According to another example not shown, the module 3 is a propeller module. The blades 30 are not surrounded by an external casing and the blades 30 are, according to this example, arranged around the nacelle.
[0053] With reference to [Fig. 2], the module 3 according to the invention further comprises a hub 43. The hub 43 is annular and centered on the longitudinal axis X. It comprises an internal space 310. The hub 43 is secured to a cone centered on the longitudinal axis X. The cone is arranged upstream of the hub 43. The cone forms an air inlet nozzle in the turbomachine 1. The hub 43 is for example connected to the cone by a fixing arm 43a extending radially relative to the longitudinal axis X. The fixing arm 43a is connected to the cone and to the hub 43 by a set of screws and nuts 43b for example. The hub 43 comprises internal housings distributed regularly around the longitudinal axis X.
[0054] The blades 30 are carried by the hub 43 and regularly distributed on the hub 43. They extend radially from the hub 43. The blades 30 are driven in rotation around the longitudinal axis X. Each blade 30 comprises a root 41 and a blade 40 extending radially outwards from the root 4L.
[0055] The foot 41 comprises for example a tenon mounted in a sleeve. The foot 41 is pivotally mounted along a wedging axis C in the internal housing of the hub 43. Advantageously, one foot 41 is mounted per internal housing. The sleeve is centered on the wedging axis C and is housed in the internal housing of the hub 43.
[0056] The wedging axis C is parallel to the radial axis Z and therefore extends radially relative to the longitudinal axis X. The foot 41, via the sleeve in particular, is pivotally mounted in the hub 43 by means of two guide bearings 44 mounted in each internal housing and in a superimposed manner along the radial axis Z. These bearings 44 are preferably, but not limited to, ball bearings.
[0057] The hub 43 is rotatable about the longitudinal axis X. To drive the hub 43 in rotation about the longitudinal axis X and therefore the blades 30, the module 3 comprises a drive shaft 32. The drive shaft 32 is arranged at less partly in the internal space 310. It is centered on the longitudinal axis X. The drive shaft 32 is guided in rotation in the internal space 310 by a first guide bearing 32a and a second guide bearing 32b. The first guide bearing 32a is for example a ball bearing. The second guide bearing 32b is for example a roller bearing. The first guide bearing 32a is arranged downstream of the second guide bearing 32b. The first guide bearing 32a comprises balls 320a arranged between an outer ring 321a and an inner ring 322a. The second guide bearing 32b comprises rollers 320b arranged for example between the outer ring 321a and the inner ring 322a. The inner ring 322a is integral with the drive shaft 32 and the outer ring 321a is carried by a bearing support 34. The first and second guide bearings 32a, 32b may share the same outer and inner rings or be formed from separate rings.The bearing support 34 is fixed. It extends radially between an end flange 34a connected to the input casing 18 and a sole 34b which cooperates with the outer ring 321a.
[0058] The drive shaft 32 comprises an upstream end on which a journal 53 is fixed. The journal 53 extends radially outwards. The journal 53 is connected for example by a first flange 52 to the hub 43 to drive it in rotation about the longitudinal axis X.
[0059] The drive shaft 32 is driven in rotation by the low pressure shaft 9 for example. In order to reduce the rotation speed of the drive shaft 32 relative to the low pressure shaft 9, the module 3 advantageously comprises a mechanical speed reducer 33 connecting the low pressure shaft 9 to the drive shaft 32.
[0060] With reference to [Fig. 1], the speed reducer 33 is arranged in a lubrication enclosure 35. The lubrication enclosure 35 is for example arranged axially between the third bearing 15 and the second guide bearing 32b, inside the input casing 18.
[0061] The speed reducer 33 is for example a speed reducer 33 with a planetary or epicyclic gear train. The speed reducer 33 comprises an inner sun gear, also called a sun gear, intended to cooperate with the low pressure shaft 9, an outer ring gear integral in rotation with the drive shaft 32 or connected to a fixed structure of the turbomachine 1 such as the input casing 18 and a planet carrier fixed in rotation, for example integral with the input casing 18 or integral in rotation with the drive shaft 32. The speed reducer 33 further comprises satellites which mesh with the sun gear and the outer ring gear.
[0062] Each blade 30 is rotatable around the setting axis C. For this purpose, according to the invention, the module 3 comprises a device 45 for changing the setting of the blades 30 around their setting axes C. The device 45 is advantageously at least partly arranged in the internal space 310 of the hub 43. This makes it possible to facilitate the maintenance of the device 45 because it is easily accessible. The device 45 is arranged upstream of the speed reducer 33. The device 45 comprises a hydraulic actuator 46 movable in rotation about the longitudinal axis X and configured to drive the blades 30 about their setting axes C. The hydraulic actuator 46 is for example a hydraulic cylinder. It is for example arranged in the internal space 310. The hydraulic actuator 46 is integral in rotation with the drive shaft 32. The drive shaft 32 has for example a ferrule 50 which extends radially inwards from the drive shaft 32 and which is connected to the hydraulic actuator 46.
[0063] The hydraulic actuator 46 comprises a housing 48 and a rod 49. The housing 48 is cylindrical, centered on the longitudinal axis X. Such a configuration makes it possible to limit the size of the hydraulic actuator 46 in the hub 43 both axially and radially. The housing 48 extends radially around the rod 49.
[0064] The rod 49 extends axially between a first end 49a and a second end 49b.
[0065] The hydraulic actuator 46 further comprises a first chamber 46a and a second chamber 46b. The first and second chambers 46a, 46b are defined inside the housing 48 and are axially delimited by an annular wall 46c arranged in the housing 48. The annular wall 46c is for example integral with the second end 49b of the rod 49.
[0066] According to a first example illustrated in [Fig.3a], the rod 49 is movable in translation in the housing 48. The rod 49 moves in translation along the longitudinal axis X in the housing 48. According to this example, the housing 48 is integral with the drive shaft 32. The ferrule 50 is connected to the housing 48.
[0067] According to another example illustrated in [Fig.3b], the housing 48 is movable in translation along the longitudinal axis X. According to this example, the rod 49 is integral in rotation with the drive shaft 32. The ferrule 50 is connected to the rod 49.
[0068] The rod 49 or the housing 48 moves in translation under the effect of the pressure of a fluid circulating in each chamber 46a, 46b.
[0069] The device 45 advantageously comprises a connecting mechanism 47 connecting the blades 30 to the hydraulic actuator 46 and in particular to the rod 49 or to the housing 48 of the hydraulic actuator 46. The connecting mechanism 47 makes it possible to transform the translational movement of the hydraulic actuator 46 into a rotational movement of the blades 30. The connecting mechanism 47 comprises an annular part 47a, a connecting rod 47b and an eccentric 47c. The annular part 47a is removably fixed to the rod 49 as illustrated in [Fig. 3a] and for example to the second end 49b or to the housing 48 as illustrated in [Fig. 3b]. The annular part 47a is furthermore removably connected to the connecting rod 47b. The connecting rod 47b cooperates with the eccentric 47c which is integral with the blade 30 and in particular connected to the foot 41. The annular part 47a thus allows disassembly of the hydraulic actuator 46 during maintenance operations for example without intervening on the blades 30 which remain fixed to the connecting rods 47b by means of the eccentric 47c.
[0070] In order to drive the rod 49 or the housing 48 in translation to drive the blades 30 around their setting axes C via the connecting mechanism 47, the device 45 according to the invention further comprises a pump 54 for supplying fluid to the hydraulic actuator 46. The pump 54 is for example arranged upstream of the reducer 33. The pump 54 is arranged inside the drive shaft 32.
[0071] Pump 54 is a reversible hydraulic pump with variable displacement and axial pistons.
[0072] The pump 54 is connected to the first and second chambers 46a, 46b of the hydraulic actuator 46.
[0073] With reference to Figures 3a and 3b, the pump 54 comprises a transmission shaft 54a around which a main plate 54e is mounted. The transmission shaft 54a is centered on the longitudinal axis X and is driven in rotation by the drive shaft 32 via, for example, an accessory gear box (AGB).
[0074] Advantageously, the pump 54 further comprises a casing 54b mounted around the main plate 54e. The casing 54b is for example annular and centered on the longitudinal axis X. The casing 54b is fixed in rotation relative to the longitudinal axis X. It is connected to a fixed part of the module 3 or of the turbomachine 1 such as the inlet casing 18.
[0075] According to the invention, the pump 54 comprises axial pistons 54c configured to transfer the fluid to the hydraulic actuator 46. The axial pistons 54c are cylindrical or substantially cylindrical and have an axis of revolution parallel to the longitudinal axis X. The pump 54 comprises at least two axial pistons 54c which are advantageously regularly distributed around the longitudinal axis X. The axial pistons 54c are integral in rotation with the transmission axis 54a.
[0076] According to the invention, the axial pistons 54c are movable in translation in a direction D parallel to the longitudinal axis X. Advantageously, the axial pistons 54c are movable in translation in two opposite directions in the direction D, and for example from upstream to downstream and from downstream to upstream. More particularly, each axial piston 54c is movable in translation in a fluid receiving chamber 54d arranged for example in a barrel 54f opposite the main plate 54e. There are as many receiving chambers 54d as there are axial pistons 54c. According to another example not shown, each receiving chamber 54d is arranged in a separate barrel, that is to say there are as many barrels as there are receiving chambers 54d. Each receiving chamber 54d is rotationally integral with the transmission shaft 54a. They are for example rotationally integral with the hydraulic actuator 46, in particular with the housing 48.
[0077] The main plate 54e is annular and centered on the longitudinal axis X. It extends in particular in a radial plane relative to the longitudinal axis X and therefore relative to the transmission axis 54a. The main plate 54e is fixed in rotation around the longitudinal axis X. It is therefore not driven in rotation by the transmission axis 54a.
[0078] According to the invention, the main plate 54e is tiltable relative to the longitudinal axis X. The main plate 54e is therefore mounted to be able to rotate about an axis of rotation Y which is perpendicular to the longitudinal axis X and the radial axis Z. The main plate 54e is for example connected to the transmission axis 54a by a pivot connection Y' having an axis parallel to the axis of rotation Y.
[0079] Advantageously, the main plate 54e is tiltable according to an angle of inclination a of between -45° and 45°, it being understood that the angle a of 0° corresponds to a position of the main plate 54e in which it is perpendicular to the longitudinal axis X.
[0080] Advantageously, the device 45 further comprises an actuator 55 connected to the main plate 54e. The actuator 55 is configured to tilt the main plate 54e relative to the longitudinal axis X. The actuator 55 is for example of the electric type such as an electric cylinder or hydraulic type such as a hydraulic cylinder. The actuator 55 is integral with the main plate 54e and is therefore fixed in rotation about the longitudinal axis X. It is for example connected to the main plate 54e by a ball joint. Such a configuration makes it easier to tilt the main plate 54e by the actuator 55 without complicating the configuration of the module 3. The actuator 55 can also be connected to a casing of the module 3 or of the turbomachine 1 by a ball joint as well.
[0081] According to the invention, the pump 54 comprises a connecting plate 54g connected to the axial pistons 54c and arranged between the main plate 54e and the axial pistons 54c. The connecting plate 54g is mounted around the transmission axis 54a. The connecting plate 54g and the main plate 54e are coaxial. Advantageously, the main plate 54e has an external diameter greater than the external diameter of the connecting plate 54g. The main plate 54e cooperates with the connecting plate 54g. Advantageously, the connecting plate 54g is integral in rotation with the main plate 54e around the axis of rotation Y. The connecting plate 54g is thus tiltable in a manner correlated with the main plate 54e. The connecting plate 54g is preferably tiltable at an angle identical to the angle of inclination a of the main plate 54e. The connecting plate 54g is for example in flat support on the main plate 54e.Preferably, the connecting plate 54g is movable in rotation around the longitudinal axis X. It is integral in rotation with the transmission axis 54a.
[0082] The axial pistons 54c are connected to the connecting plate 54g by a ball joint 54h.
[0083] The axial pistons 54c being connected to the connecting plate 54g, the inclination of the main plate 54e causes the inclination of the connecting plate 54g and a movement of the axial pistons 54c in the direction D. The stroke of the axial pistons 54c in the receiving chambers 54d is then variable according to the inclination of the main plate 54e. This makes it possible to regulate the flow rate of the pump 54. Advantageously, as illustrated in [Fig.4a], when the angle of inclination a of the main plate 54e is between 0° and 45°, the pump 54 is in delivery mode while when the angle of inclination a of the main plate 54e is between -45° and 0° as illustrated in [Fig.4b], the pump 54 is in intake mode.
[0084] According to a preferred embodiment of the invention illustrated in [Fig. 5], the device 45 further comprises an auxiliary actuator 56 connected to the connecting plate 54g advantageously by means of a splined connection such as short splines with curved teeth or a cardan connection or an Oldham joint connection or a recessed connection. The auxiliary actuator 56 is intended to drive the connecting plate 54g in rotation. The auxiliary actuator 56 is for example an electric motor comprising a rotor connected to the connecting plate 54g and a stator arranged around the rotor in a coaxial manner. The rotor is for example centered on the longitudinal axis X and the stator is connected to a fixed structure of the turbomachine 1 or of the module 3.
[0085] Such an auxiliary actuator 56 allows the rotational drive of the connecting plate 54g around the longitudinal axis X when the drive shaft 32 is not active. Typically, during maintenance phases of the turbomachine 1, the drive shaft 32 is fixed in rotation and therefore does not drive the connecting plate 54g in rotation around the longitudinal axis X via the drive axis 54a of the pump 54. During these phases, the rotational drive of the connecting plate 54g is ensured by the auxiliary actuator 56. The auxiliary actuator 56 is for example coupled to the pump 54 by means of gears coupled by dogs allowing the auxiliary actuator 56 to drive the connecting plate 54g only when the drive shaft 32 is not driven in rotation.
[0086] The splined, cardan, Oldham joint or even recessed connection are preferred connections since they are compatible with the angle of inclination of the 54g connection plate.
[0087] With reference to [Fig. 6], advantageously, in order to control and regulate the speed of the actuator 55 and possibly of the auxiliary actuator 56, the module 3 further comprises a control box 57 and an electronic control circuit 58. The control box 57 is supplied with electrical energy by an electrical energy source 59 located in the turbomachine 1 for example. The electronic circuit of control 58 is for example located in the turbomachine 1. The electronic control circuit 58 is for example a digital computer such as a FADEC for “Full Authority Digital Electronic Computer” in English.
[0088] The module 3 advantageously comprises a sensor 60. The sensor 60 makes it possible to measure information II which is transmitted to the electronic control circuit 58. The information II is for example the position of the housing 48 or of the rod 49 of the hydraulic actuator 46. The sensor 60 is for example a linear sensor of the LVDT type for “Linear Variable Differential Transformer” in English. The sensor 60 is configured to measure the position of the rod 49 or of the housing 48 of the hydraulic actuator 46. It is for example arranged in the hydraulic actuator 46. According to another example not shown, the sensor 60 is a position sensor. It makes it possible to measure the position of the blades 30.
[0089] The sensor 60 provides the information II to the electronic control circuit 58. The electronic control circuit 58 will then provide an order to the control box 57 which will determine the position of the actuator 55 and if necessary control the rotation of the auxiliary actuator 56 in order to regulate the flow rate of the pump 54 via the inclination of the auxiliary plate 54g and modify the position of the rod 49 or of the box 48 of the hydraulic actuator 46 according to the desired setting of the vanes 30.
[0090] The electronic control circuit 58 also or alternatively receives a signal SI on the flight conditions of the aircraft and / or the state of the turbomachine 1. The signal SI is also or alternatively taken into account to provide the order 01 to the control box 57.
[0091] The pump 54 is fluidically connected to a hydraulic circuit C. The hydraulic supply circuit C comprises for example a first circuit C1 connecting at least one of the receiving chambers 54d of the pump 54 to the first chamber 46a of the hydraulic actuator 46 and a second circuit C2 connecting the second chamber 46b of the hydraulic actuator 46 to at least one of the receiving chambers 54d of the pump 54.
[0092] The hydraulic supply circuit C is a closed circuit. It is independent of a hydraulic lubrication circuit of the turbomachine 1 intended for example to lubricate the reducer 33. The fluid of the hydraulic supply circuit C supplying the hydraulic actuator 46 is for example a hydraulic liquid. The liquid is for example pressurized oil or a phosphate ester such as Skydrol. The fluid is thus a fluid circulating in a closed circuit in the hydraulic supply circuit C and is independent of the lubrication circuit of the turbomachine 1. The fluid can therefore be different from the oil used in the lubrication circuit of the turbomachine 1. The fluid can thus have a lower freezing point or even viscosity characteristics more suited to the conditions of the turbomachine 1, in particular when the operating temperatures of the turbomachine 1 are low. For example, the fluid of the hydraulic supply circuit C has a freezing point of between -70°C and -50°C, in particular between -65°C and -60°C. Also, the pressure of the fluid in the hydraulic supply circuit C is advantageously greater than 100 bars, preferably greater than 200 bars and even more preferably between 250 bars and 350 bars. The hydraulic supply circuit C being closed, it is not ventilated and it is consequently possible to implement high pressures in the hydraulic circuit. This makes it possible to reduce the size of the hydraulic actuator 46.
[0093] With reference to [Fig. 6], advantageously, the hydraulic circuit C comprises for example a hydraulic accumulator 61 which makes it possible to compensate for variations in the volume of the fluid due to its compressibility and its expansion. The hydraulic accumulator 61 is in fluid communication with the pump 54. The hydraulic accumulator 61 can be integrated into the pump 54. The hydraulic accumulator 61 is integral in rotation with the hydraulic actuator 46 and is thus movable in rotation about the longitudinal axis X.
[0094] The axial pistons 54c and the hydraulic accumulator 61 being movable in rotation relative to the longitudinal axis X, it is possible according to the invention to do without a rotating hydraulic transfer device.
[0095] Thanks to the invention, the inclination of the main plate 54e drives the axial pistons 54c in translation. This makes it possible to vary the stroke of the axial pistons 54c and therefore the flow rate of the pump 54. The volume in the first and second chambers 46a, 46b of the hydraulic actuator 46 varies, which drives the rod 49 or the housing 48 of the hydraulic actuator 46 in translation, resulting in the rotation of the blades 30 around their setting axes C.
[0096] Thanks to the invention, additional components such as a rotating electrical transformer associated with an electric motor making it possible to vary the flow rate of the pump 54 or a rotating oil transfer allowing the transfer of oil between the pump 54 and the hydraulic actuator 46 are therefore dispensed with, also reducing oil leaks and the need to add recovery pumps. In addition, the electrical consumption is low since there is no operational electric motor during the flight phases of the aircraft, the drive of the pump 54 being ensured by the drive shaft 32.
[0097] Also, the pump 54 being advantageously reversible, there is no need for a flow reversal valve and a controlled circuit during the flight phases of the aircraft.
Claims
Claims
1. Module (3) for an aircraft turbomachine (1), the module (3) having a longitudinal axis (X) and comprising: - a hub (43) centered on the longitudinal axis (X) and intended to be movable in rotation about the longitudinal axis (X), - blades (30) carried by the hub (43), each of the blades (30) being movable about a setting axis (C) extending radially relative to the longitudinal axis (X), - a device (45) for changing the setting of the blades (30) about their setting axes (C), the device (45) comprising: a hydraulic actuator (46) intended to be movable in rotation about the longitudinal axis (X) and configured to drive the blades (30) about their setting axes (C), and a pump (54) for supplying fluid to the hydraulic actuator (46) comprising: axial pistons (54c) intended to be movable in rotation around the longitudinal axis (X) and configured to transfer the fluid to the hydraulic actuator (46),a connecting plate (54g) connected to the axial pistons (54c) and cooperating with an annular main plate (54e) centered on the longitudinal axis (X), the main plate (54e) being intended to be fixed in rotation around the longitudinal axis (X) and inclinable relative to the longitudinal axis (X), the connecting plate (54g) being arranged between the main plate (54e) and the axial pistons (54c), the axial pistons (54c) being movable in translation in a direction (D) parallel to the longitudinal axis (X), the inclination of the main plate (54e) causing a movement of the axial pistons (54c) in the direction (D), the device (45) further comprising an auxiliary actuator (56) connected to the connecting plate (54g) and intended to drive the connecting plate (54g) in rotation around the longitudinal axis (X).,
2. Module according to the preceding claim, in which the pump (54) comprises a casing (54b) mounted around the main plate (54e) and the connecting plate (54g) and intended to be fixed in rotation around the longitudinal axis (X).
3. Module according to any one of the preceding claims, in which the main plate (54e) is tiltable at an angle inclination a between -45° and 45°, an angle a of 0° corresponding to a position of the main plate (54e) in which it is perpendicular to the longitudinal axis (X).
4. Module according to any one of the preceding claims, wherein the device (45) further comprises an actuator (55) connected to the main plate (54e) and configured to tilt the main plate (54e) relative to the longitudinal axis (X).
5. Module according to any one of the preceding claims, in which the connecting plate (54g) is intended to be movable in rotation around the longitudinal axis (X) and is in flat support on the main plate (54e).
6. Module according to any one of the preceding claims, in which the axial pistons (54c) are connected to the connecting plate (54g) by a ball joint (54h).
7. Module according to any one of the preceding claims, in which the pump (54) comprises a transmission axis (54a) centered on the longitudinal axis (X), integral in rotation with the connecting plate (54g), and around which the main plate (54e) is mounted.
8. Module according to the preceding claim, further comprising a drive shaft (32) integral in rotation with the hub (43) and configured to drive the transmission axis (54a) in rotation around the longitudinal axis (X).
9. A module according to any preceding claim, wherein the auxiliary actuator (56) is connected to the connecting plate (54g) by a splined connection or a cardan connection or an Oldham joint connection or a recessed connection.
10. Turbomachine (1) for an aircraft comprising a module (3) according to any one of the preceding claims.