MODULE FOR AN AIRCRAFT TURBOMACHINE

Abstract

The invention relates to a module (3) comprising a device (45) for changing the pitch of the blades (30) around their pitch axes (C), this device (45) comprising: a hydraulic actuator (46) rotatable around the longitudinal axis (X) and configured to drive the blades (30) around their pitch axes (C), a fluid supply pump (54) for the hydraulic actuator (46), this supply pump (54) comprising a drive shaft rotatable around the longitudinal axis (X) and a casing fixed in rotation around the longitudinal axis (X), and an electric machine (55) configured to actuate the supply pump (54), the electric machine (55) comprising a rotary member for driving the drive shaft and a fixed member which is fixed in rotation relative to the longitudinal axis (X). Figure: 2

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 an aircraft turbomachine. 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 can rotate 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 drive the blades in rotation around their pitch axis, the turbomachine module typically comprises a device for changing the pitch of the blades. arranged inside the hub of the module. 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, a pump for supplying fluid to the hydraulic actuator and an electric motor for actuating the supply pump.

[0006] According to this document, the feed pump is rotatable about the longitudinal axis and the electric motor is movable about the longitudinal axis, that is to say that the fixed member of the motor, also called stator, is fixed to the hub of the module and is therefore in a rotating frame of reference of the module. The blade pitch changing device further comprises a rotating electrical transformer making it possible to supply electrical energy to the motor from an electrical energy source located in a fixed frame of reference of the turbomachine.

[0007] Document FR-A1-2 831 225 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, a pump for supplying fluid to the hydraulic actuator and an electric motor for actuating the supply pump. According to this document, the supply pump and the electric motor are movable in rotation about the longitudinal axis. In this context, the device for changing the pitch of the blades 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 reference frame of the turbomachine.

[0008] These configurations are not entirely satisfactory in that the electric motor is constantly driven in rotation, leading to significant electrical power consumption and motor sizing. Furthermore, 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. In addition, the rotational drive of the feed pump around the axis of the turbomachine is problematic. Indeed, it has been found that at high rotational drive speeds of the module, the pump could suffer irreversible damage.

[0009] There is therefore a need to provide a turbomachine module for an aircraft, comprising a hub carrying variable-pitch blades, which is reliable, compact, lightweight, low-energy consuming and inexpensive. Summary of the invention

[0010] To this end, the invention proposes a module for an aircraft turbomachine, this module comprising a longitudinal axis and comprising:

[0011] - a hub movable in rotation around the longitudinal axis,

[0012] - blades carried by the hub, each of these blades being mobile in rotation around a setting axis extending radially relative to the longitudinal axis, and

[0013] - a device for changing the setting of the blades around their setting axes, this device comprising:

[0014] a hydraulic actuator movable in rotation around the longitudinal axis and configured to drive the blades around their setting axes,

[0015] a fluid supply pump for the hydraulic actuator, this supply pump comprising a drive shaft movable in rotation around the longitudinal axis and a casing fixed in rotation around the longitudinal axis, and

[0016] an electric machine configured to actuate the feed pump, the electric machine comprising a rotary member for driving the drive shaft and a fixed member which is fixed in rotation relative to the longitudinal axis.

[0017] The hydraulic actuator ensures the driving of the blades around their axes of timing to optimize the performance of the module according to the flight phases of the aircraft. The hydraulic actuator is supplied with fluid by the feed pump. The feed pump is actuated by the electric machine which provides electrical energy to the pump for its operation. According to the invention, the casing of the feed pump as well as the fixed member of the electric machine are fixed in rotation relative to the longitudinal axis. In other words, the feed pump and the electric machine supplying electrical energy to the feed pump are fixed in rotation relative to the longitudinal axis of the module.

[0018] Consequently, the electrical machine and the feed pump are in a fixed frame of reference of the module. Unlike the module of the prior art in which the electric motor is in a rotating frame of reference, that is to say that both the fixed member and the mobile member are driven in rotation around the longitudinal axis, such a configuration according to the invention makes it possible to dispense with a rotating electrical transformer to transfer the electrical energy from an energy source located in a fixed frame of reference of the module to the electrical machine. The module is therefore simplified and more compact. Also, since the fixed member of the machine is no longer driven in rotation around the longitudinal axis of the turbomachine, the electrical power consumption of the module is lower. This makes it possible to size the electrical machine accordingly.Finally, such a module is more reliable since the rotational drive of the hub no longer impacts the components of the device such as the feed pump which now has a casing which is also fixed in rotation relative to the axis. longitudinal.

[0019] The invention may comprise one or more of the following features, taken in isolation from one another or in combination with one another:

[0020] - the device comprises a fluid transfer unit arranged axially between the feed pump and the hydraulic actuator and comprising a first hub fixed in rotation about the longitudinal axis having an internal passage in fluid communication with the feed pump and a second hub movable in rotation about the longitudinal axis arranged around the first hub and having second channels in fluid communication with the hydraulic actuator and the internal passage;

[0021] - the feed pump is a reversible fixed displacement pump;

[0022] - the electric machine is an electric motor;

[0023] - a drive shaft configured to rotate the hub and a mechanical speed reducer configured to connect the drive shaft to a low pressure shaft of the turbomachine, the speed reducer being arranged downstream of the electrical machine and comprising a first element intended to cooperate with the low pressure shaft, a second element integral in rotation with the drive shaft and a third element fixed in rotation and connected to the fixed member of the electrical machine;

[0024] - the first element is a solar, the second element is a crown and the third element is a planet carrier;

[0025] - the device comprises a hydraulic accumulator fixed in rotation relative to the longitudinal axis and in fluid communication with the feed pump, the hydraulic accumulator being arranged downstream of the hydraulic actuator;

[0026] - the device comprises a hydraulic accumulator arranged upstream of the hydraulic actuator and integral with the hydraulic actuator, the hydraulic accumulator being in fluid communication with the feed pump;

[0027] - the pump has an operating regime which is a function of a power of the electric machine, the module further comprising an electronic control circuit connected to the electric machine configured to modulate the power of the electric machine;

[0028] - the electronic control circuit is configured to receive a transmitted order by a control unit, the order being a function of information relating to the aircraft and / or the turbomachine and / or the position of the blades relative to their pitch axes and received by the control unit. Brief description of the figures

[0029] Other characteristics and advantages will emerge from the following description of a non-limiting embodiment of the invention with reference to the attached drawings on which:

[0030] [Fig.l] [Fig.l] is a schematic representation in axial section of a half aircraft turbomachine;

[0031] [Fig.2] [Fig.2] is an axial sectional view of the module according to a first mode of realization of the invention;

[0032] [Fig.3] [Fig.3] is a functional schematic representation of the module according to the first embodiment of the invention;

[0033] [Fig.4] [Fig.4] is an axial sectional view of the module according to a second mode of realization of the invention;

[0034] [Fig.5] [Fig.5] is a partial sectional view of an example of a transfer unit that can equip the module of the invention. Detailed description of the invention

[0035] 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 is mounted under each wing. The turbomachine 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 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 turbomachine.

[0036] In the present invention, and generally, the terms "upstream", "downstream", "axial" and "axially" are defined with respect to the circulation of gases in the turbomachine and here along the longitudinal axis X (and even from left to right in [Fig. 1]). Similarly, the terms "radial", "radially", "internal", "internal", "external" and "external" are defined with respect to a radial axis Z perpendicular to the longitudinal axis X and with respect to the distance from the longitudinal axis X.

[0037] [Fig.l] illustrates an example of a turbomachine 1. The turbomachine 1 comprises a gas generator 2 and a module 3 according to the invention. 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 bearing 11 with rolling bearings and a second downstream bearing 12 with rolling bearings. The first bearing 11 is mounted 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 rolling bearing 15 and a fourth rolling bearing 16. The fourth bearing 16 is for example a double bearing. The double 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.

[0038] In the example of [Fig. 1], the module 3 is mounted upstream of the gas generator 2. Advantageously, according to this example, a rectifier 20 is arranged axially between the module 3 and the low-pressure compressor 4. 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.

[0039] According to another embodiment not shown, the module 3 is mounted downstream of the gas generator 2.

[0040] Furthermore, the module 3 according to the invention comprises blades 30.

[0041] In the example of [Fig.l], the blades 30 are surrounded by an external casing 19. The external casing 19 is attached to a nacelle (not shown) of the aircraft. In this example, module 2 is a fan module.

[0042] According to another example not shown, the module 2 is a propeller module. The blades 30 are not surrounded by an external casing. The blades 30 are, according to this example, arranged around the nacelle.

[0043] As visible in Figures 2 and 4, the blades 30 are carried by a hub 43. The hub 43 is annular. It is arranged around the longitudinal axis X. The blades 30 are regularly distributed around the hub 43. The blades 30 extend radially from the hub 43. It comprises an internal space 310. The hub 43 further comprises internal housings regularly distributed around the longitudinal axis X.

[0044] The hub 43 is integral with a cone 31 centered on the longitudinal axis X. The cone 31 is arranged upstream of the hub 43. The cone 31 forms an air inlet nozzle in the turbomachine 1. The hub 43 is for example connected to the cone 31 by a fixing arm 43a extending radially relative to the longitudinal axis X. The fixing arm 43a is connected to the cone 31 and to the hub 43 by a set of screws and nuts 43b for example.

[0045] 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.

[0046] The foot 41 comprises a tenon 41b connected to a sleeve 41a. The foot 41 is pivotally mounted along a wedging axis C in the internal housing of the hub 43. The sleeve 41a is centered on the wedging axis C. The sleeve 41a is housed in the internal housing of the hub 43. Advantageously, one foot 41 is mounted per internal housing.

[0047] The wedging axis C is parallel to the radial axis Z. The foot 41 is pivotally mounted 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.

[0048] 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 least 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 between an outer ring 321b and an inner ring 322b.The inner rings 322a, 322b are integral with the drive shaft 32a and the outer rings 321a, 321b are carried by a bearing support 34. The bearing support 34 is fixed. It extends radially between an end flange 34a connected to the input casing 18 and first and second soles 34b, 34c which cooperate respectively with the outer rings 321a, 321b.

[0049] 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 an intermediate arm 530 itself connected to the hub 43 to drive it in rotation about the longitudinal axis X.

[0050] The drive shaft 32 is rotated by the low pressure shaft 9 for example. In order to reduce the rotation speed of the drive shaft 32 relative to to the low pressure shaft 9, the module 3 advantageously comprises a mechanical speed reducer 33. The speed reducer 33 is arranged in a lubrication enclosure 35 extending axially between the third bearing 15 and the second guide bearing 32b. In order to limit lubricant leaks outside the lubrication enclosure 35, a sealing device 350 is arranged upstream of the second bearing 32b. The sealing device 350 comprises, for example, a dynamic seal.

[0051] The speed reducer 33 comprises a first element 36 which cooperates with the low pressure shaft 9, a second element 37 integral in rotation with the drive shaft 32 and a third element 38 fixed in rotation. The third element 38 is for example connected to a stator of the turbomachine 1 such as the input casing 18 or of the module 3. The speed reducer 33 further comprises satellites 39.

[0052] The first element 36 is an inner planetary gear coupled in rotation with the low pressure shaft 9, the second element 37 is an outer ring gear coupled in rotation with the drive shaft 32 and the third element 38 is a planet carrier fixed in rotation relative to the longitudinal axis X. The planet carrier is for example integral with the input casing 18. The planet carrier has at least one passage 380. The passage 380 is a through passage. In this configuration of the reducer 33, the planet gears 39 are carried by the third element 38 and each rotates about an axis substantially parallel to the longitudinal axis X. Each planet gear 39 meshes with the first element 36 and the second element 37. The planet gears 39 are arranged radially between the first element 36 and the second element 37.In this configuration, the first element 36 which is the planetary gear forms the input of the speed reducer 33 while the second element 37 which is the outer ring gear forms the output of the speed reducer 33. The speed reducer 33 is a speed reducer 33 with a planetary gear train.

[0053] Each blade 30 is rotatable about 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 about their setting axes C. The device 45 is an electro-hydraulic device. The device 45 is arranged at least partly in the internal space 310 of the hub 43. The device 45 is arranged upstream of the speed reducer 33. The device 45 comprises a hydraulic actuator 46 which is rotatable about the longitudinal axis X and configured to drive the blades 30 about their setting axes C. The actuator 46 is for example a hydraulic cylinder.

[0054] The actuator 46 comprises a housing 48 and a body 49 which moves in translation in the housing 48. The housing 48 is integral in rotation with the drive shaft 32. The housing 48 is cylindrical, centered on the longitudinal axis X. Such a configuration makes it possible to limit the size of the actuator 46 in the hub 43 both axially and radially. The housing 48 comprises a ferrule 50 which extends radially outward from an external surface of the housing 48. The ferrule 50 comprises a second flange 51 which is fixed to the first flange 52 of the journal 53.

[0055] The movable body 49 moves in translation along the longitudinal axis X in the housing 48. The housing 48 extends radially around the movable body 49. The movable body 49 is in the form of an axial rod which extends between a first end 49a and a second end 49b. The actuator 46 further comprises a first chamber 46a and a second chamber 46b. The first and second chambers 46a, 46b are axially delimited by an annular wall 46c arranged in the housing 48. The annular wall 46c is integral with the second end 49b of the movable body 49. The movable body 49 moves in translation under the effect of the pressure of a fluid circulating in each chamber 46a, 46b.

[0056] The actuator 46 further comprises a pipe 46d. The pipe 46d has an axis parallel to the longitudinal axis X. The pipe 46d is for example arranged in an external wall of the housing 48. The pipe 46d opens into the second chamber 46b.

[0057] The device 45 advantageously comprises a connecting mechanism 47 secured to the blades 30 and the 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 movable body 49 and for example to the second end 49a. The annular part 47a comprises a connecting flange which is 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 root 41 of the blade 30. 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.

[0058] In order to drive the movable body 49 in translation to drive the blades 30 around their setting axis C via the connecting mechanism 47, the device 45 according to the invention further comprises a pump 54 for supplying fluid to the actuator 46. The pump 54 is for example arranged axially between the reducer 33 and the hydraulic actuator 46. The pump 54 is arranged inside the drive shaft 32. The pump 54 comprises a drive axis and a casing, also called a pump body, arranged around the drive axis. The drive shaft is for example centered on the longitudinal axis X and is rotatable about the longitudinal axis X. According to the invention, the casing of the pump 54 is fixed relative to the longitudinal axis X. Advantageously, the casing of the pump 54 is integral with the third element 38 of the reducer 33. The casing of the pump 54 is integral with the planet carrier s. Such a configuration of the pump 54 allows to increase the longevity of the pump 54 which is not driven in rotation around the longitudinal axis X.

[0059] The pump 54 is a volumetric type hydraulic pump. The pump 54 is for example an axial or radial piston pump. By axial piston pump is meant a pump whose drive axis is parallel to the piston axis and by radial piston pump is meant a pump whose piston axis is inclined relative to the drive axis. The pump 54 is for example a reversible fixed displacement pump. Thus, the pump 54 can rotate in a first direction of rotation and in a second direction of rotation opposite to the first direction. In the first direction of rotation, the pump 54 delivers a fluid into the first chamber 46a while in the second direction of rotation, the pump 54 delivers a fluid into the second chamber 46b. A pump having this type of drive has a longer service life than a variable displacement pump.

[0060] The pump 54 is fluidically connected to a hydraulic supply circuit C. The hydraulic supply circuit C is a closed circuit. It is independent of a lubrication circuit of the turbomachine 1, for example intended to lubricate the reducer 33, for example. The hydraulic supply circuit C comprises a hydraulic accumulator 59. The hydraulic accumulator 59 constitutes a reservoir of pressurized fluid configured to provide a flow rate to the pump 54. The fluid is, for example, pressurized oil. The hydraulic accumulator 59 constitutes an advantageous reservoir in the context of the invention in that it makes it possible to compensate for variations in the volume of the fluid due to its compressibility and its expansion.

[0061] The hydraulic accumulator 59 is in fluid communication with the pump 54.

[0062] The hydraulic supply circuit C comprises a main circuit C1 connecting the pump 54 to the hydraulic actuator 46 and a recovery circuit C2 connecting the hydraulic actuator 46 to the pump 54. The hydraulic supply circuit C comprises for example a safety valve 590 and a non-return valve 591.

[0063] According to a first embodiment shown in [Fig. 1], the hydraulic accumulator 59 is arranged downstream of the hydraulic actuator 46. The hydraulic accumulator 59 is fixed in rotation relative to the longitudinal axis X. It is for example integrated into the feed pump 54.

[0064] According to a second embodiment shown in [Fig. 4], the hydraulic accumulator 59 is arranged upstream of the hydraulic actuator 46. The hydraulic accumulator 59 is movable in rotation relative to the longitudinal axis X. It is for example integral with the hydraulic actuator 46.

[0065] Furthermore, the device 45 advantageously comprises a transfer unit 56 for the fluid, for example shown in [Fig. 5]. The transfer unit 56 ensures the transfer of the fluid from the pump 54 which is fixed in rotation to the actuator 46 which is movable in rotation around the longitudinal axis X. The transfer unit 56 has very little impact on the weight and size of the module 3 compared to an electrical transformer.

[0066] The transfer unit 56 is arranged axially between the hydraulic actuator 46 and the pump 54, inside the drive shaft 32. The transfer unit 56 is mounted on the hydraulic circuit C. The transfer unit 56 comprises a first hub 57 fixed in rotation about the longitudinal axis X. The first hub 57 is for example centered on the longitudinal axis X. The first hub 57 is secured for example to the third element 36 of the speed reducer 33. The first hub 57 has an internal passage 57a for circulation of the fluid 57a in fluid communication with the pump 54. The first hub 57 further comprises holes 57c allowing the passage of the fluid from the internal passage 57a to grooves 57b formed on an external surface of the first hub 57. The grooves 57b are annular. The transfer unit 56 further comprises a second hub 58 movable in rotation around the longitudinal axis X.According to the example shown, the second hub 58 is arranged around the first hub 57 in a coaxial manner. The second hub 58 is for example integral in rotation with the actuator 46. Furthermore, the second hub 58 has channels 58a in fluid communication with the actuator 46 and the grooves 57b. The channels 58a are for example in fluid communication with the pipe 46d of the actuator 46. The channels 58a extend radially relative to the longitudinal axis X. They are formed in a wall of the second hub 58.

[0067] According to another example not shown of the transfer unit 56, the second hub 58 is arranged inside the first hub 57.

[0068] According to the invention, the device 45 further comprises an electric machine 55. The electric machine 55 makes it possible to supply the pump 54 with electrical energy in order to ensure its operation. The speed of the pump 54 is determined by the quantity of electrical energy delivered by the electric machine 55. The electric machine 55 thus allows the use of a reversible fixed displacement pump since it is the electric machine 55 which modulates the quantity of fluid that the pump 54 can deliver to the hydraulic actuator 46. The electric machine 55 is for example an electric motor. The electric motor is preferably vector controlled. The electric motor is for example reversible and variable speed.

[0069] The electric machine 55 is, according to one example, arranged axially between the pump 54 and the speed reducer 33, inside the drive shaft 32.

[0070] According to an example not shown, the electrical machine 55, the feed pump 54 and the accumulator 59 are substantially coaxial.

[0071] The electrical machine 55 comprises a rotating member and a fixed member (not shown). The rotating and fixed members are annular and for example centered on the longitudinal axis X. The rotating member is for example arranged outside or inside the fixed member. The rotating member rotates the drive shaft of the pump 54. The fixed member is connected to the third element 38 of the reducer 33, i.e. to the planet carrier. The fixed member is connected to an electrical power cable 66. The power cable 66 passes through the passage of the third element 38 of the reducer 33. Alternatively, the power cable 66 passes through the satellites 39. The power cable 66 is connected to an electrical power supply device 61 which is fixed in rotation relative to the longitudinal axis X. The electrical power supply device 61 is, for example, located in the turbomachine 1 or in a compartment of the aircraft. Thus, thanks to the invention, no rotating electrical transfer is necessary to supply electrical energy to the electrical machine 55. This makes it possible to reduce the weight and size of the module 3.

[0072] Advantageously, the module 3 further comprises an electronic control circuit 60, which is fixed in rotation about the longitudinal axis. The electronic control circuit 60 is connected to the electric machine 55 and in particular to the fixed member via the power cable 66 for transporting the electrical energy. The electronic control circuit 60 makes it possible to modulate the power of the electric machine 55 according to, for example, information II, 12 relating to the flight conditions of the aircraft and / or the state of the turbomachine and / or the position of the blades 30 relative to their pitch axes C. Thus, the electric machine 55 is only driven as needed and its speed and direction of rotation are imposed by the electronic control circuit 60. It is therefore no longer necessary according to the invention to oversize the electric machine 55.The electronic control circuit 60 is connected to the electrical power supply device 61 by an electrical cable 62.

[0073] Advantageously, the electronic control circuit 60 operates under the control of a control unit 63. The control unit 63 is for example located in the turbomachine 1 or in a compartment of the aircraft. The control unit 63 is for example a digital computer such as a FADEC for “Full Authority Digital Electronic Computer” in English. The control unit 63 is configured to transmit an order 01 to the electronic control circuit 60 as a function of the information II, 12. The information II is for example relative to the state of the turbomachine 1 and / or of the aircraft. The information 12 is for example relative to the position of the blades relative to the pitch axis (C).

[0074] Advantageously, the module 3 comprises a sensor 65. The sensor 65 makes it possible to measure data and translate the data to transmit the information II relating to the position of the blades relative to the setting axis (C) which is transmitted to the electronic control circuit 60 via the control unit 63.

[0075] According to a first embodiment shown in Figures 2 and 4, the sensor 65 is a position sensor. The position sensor is configured to measure the position of the foot 41 of the blade 30. The position sensor cooperates for example with the foot 41. The sensor 65 is for example of the electromagnetic type.

[0076] According to another embodiment not shown, the sensor 65 is for example a linear sensor of the LVDT type for “Linear Variable Differential Transformer” in English. The sensor 65 is configured to measure the position of the mobile body 49 of the hydraulic actuator 46. It is for example arranged in the hydraulic actuator 46.

[0077] The sensor 65 provides the information II to the control unit 63 which will send the order 01 to the electronic control circuit 60 which is a function of this information II.

[0078] The electronic control circuit 60 will then supply electrical energy to the electric machine 55 accordingly, which will act on the feed pump 54. According to the order transmitted to the electronic control circuit 60, the latter modulates the speed of the electric machine 55 in order to adapt the speed of the feed pump 54 according to the desired setting of the blades 30.

[0079] According to the invention, it is therefore not necessary to have an electrical transformer to supply current to the electrical machine 55 since the latter is fixed in rotation around the longitudinal axis X. Also, according to the invention, it is possible to modulate the electrical power of the electrical machine 55 and therefore of the feed pump 54 in order to control the hydraulic actuator 46 accordingly. It is therefore not necessary to add a hydraulic distributor between the feed pump 54 and the hydraulic actuator 46 to modulate the movement of the mobile body 49 of the hydraulic actuator 46 according to the desired setting of the blades 30. Such a configuration therefore simplifies the module 3 and reduces its size.

Claims

Claims

1. Module (3) for an aircraft turbomachine (1), this module (3) having a longitudinal axis (X) and comprising: - a hub (43) rotatable about the longitudinal axis (X), - blades (30) carried by the hub (43), each of these blades (30) being rotatable about a setting axis (C) extending radially relative to the longitudinal axis (X), and - a device (45) for changing the setting of the blades (30) about their setting axes (C), this device (45) comprising: a hydraulic actuator (46) rotatable about the longitudinal axis (X) and configured to drive the blades (30) about their setting axes (C), a pump (54) for supplying fluid to the hydraulic actuator (46), this supply pump (54) comprising a drive axis rotatable about the longitudinal axis (X) and a fixed envelope rotating around the longitudinal axis (X),and an electric machine (55) configured to actuate the feed pump (54), the electric machine (55) comprising a rotary member for driving the drive shaft and a fixed member which is fixed in rotation relative to the longitudinal axis (X).,

2. Module (3) according to the preceding claim, characterized in that the device (45) comprises a fluid transfer unit (56) arranged axially between the feed pump (54) and the hydraulic actuator (46) and comprising a first hub (57) fixed in rotation about the longitudinal axis (X) having an internal passage (57a) in fluid communication with the feed pump (54) and a second hub (58) movable in rotation about the longitudinal axis (X) arranged around the first hub (57) and having second channels (58a) in fluid communication with the hydraulic actuator (46) and the internal passage (57a).

3. Module (3) according to any one of the preceding claims, characterized in that the feed pump (54) is a reversible fixed displacement pump.

4. Module (3) according to any one of the preceding claims, characterized in that the electric machine (55) is an electric motor.

5. Module (3) according to any one of the preceding claims, characterized in that it comprises a drive shaft (32) configured to rotate the hub (43) and a mechanical speed reducer (33) configured to connect the drive shaft (32) to a low pressure shaft (9) of the turbomachine (1), the speed reducer (33) being arranged downstream of the electric machine (55) and comprising a first element (36) intended to cooperate with the low pressure shaft (9), a second element (37) integral in rotation with the drive shaft (32) and a third element (38) fixed in rotation and connected to the fixed member of the electric machine (55).

6. Module (3) according to the preceding claim, characterized in that the first element (36) is a solar, the second element (37) is a crown and the third element (38) is a satellite carrier.

7. Module (3) according to any one of the preceding claims, characterized in that the device (45) comprises a hydraulic accumulator (59) fixed in rotation relative to the longitudinal axis (X) and in fluid communication with the feed pump (54), the hydraulic accumulator (59) being arranged downstream of the hydraulic actuator (46).

8. Module (3) according to any one of claims 1 to 6, characterized in that the device comprises a hydraulic accumulator (59) arranged upstream of the hydraulic actuator (46) and integral with the hydraulic actuator (46), the hydraulic accumulator (59) being in fluid communication with the supply pump (54).

9. Module (3) according to any one of the preceding claims, characterized in that the pump (54) has an operating regime which is a function of a power of the electric machine (55), the module further comprising an electronic control circuit (60) connected to the electric machine (55) configured to modulate the power of the electric machine (55).

10. Module (3) according to the preceding claim, characterized in that the electronic control circuit (60) is configured to receive an order (01) transmitted by a control unit (63), the order (01) being a function of information (II, 12) relating to the aircraft and / or to the turbomachine (1) and / or to the position of the blades (30) relative to their setting axes and received by the control unit (63).

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