Fan module for an aircraft turbomachine

Abstract

The invention relates to a fan module for an aircraft turbomachine, the fan module having a longitudinal axis (X) and comprising: - variable-pitch blades (30) regularly distributed around the longitudinal axis (X), each having a pitch axis (C), and - a system for changing the pitch of the blades (30), characterized in that the changing system comprises: actuation devices (52) for the blades (30), each actuation device (52) being connected to a blade (30), each actuation device (52) comprising: - a drive mechanism (54) for rotating the blade (30) connected to the blade (30), and - an actuator (53) configured to actuate the drive mechanism (54). (Short figure: 2)

Description

Title of the invention: Fan module for an aircraft turbomachine Technical field of the invention

[0001] The invention relates to the field of fan modules for aircraft turbomachinery.

[0002] The invention relates in particular to blower modules comprising variable pitch blades.

[0003] The invention relates more particularly to blower modules comprising variable-pitch blades and a system for changing the blade pitch. Technical background

[0004] In a well-known manner, an aircraft turbomachine extends along a longitudinal axis and comprises, from upstream to downstream, a blower, a low-pressure compressor, a high-pressure compressor, an annular combustion chamber, a high-pressure turbine and a low-pressure turbine.

[0005] The blower typically comprises a hub centered on the longitudinal axis and free to rotate about this axis. The blower further comprises blades regularly distributed around the hub.

[0006] To optimize fan operation, the blades are typically variable pitch. Variable pitch blades are those whose pitch or orientation, and more specifically the pitch angle, can be modified according to flight parameters. The pitch angle of a blade corresponds to the angle, in a longitudinal plane perpendicular to the blade's axis of rotation, between the blade chord and the fan's plane of rotation. Variable pitch blades can thus occupy a thrust reversal position (known as "reverse") in which they generate counter-thrust to contribute to slowing the aircraft, and a feathering position in which, in the event of a failure or malfunction, they reduce their resistance to airflow. Between these two extreme positions, the blade can assume any position.

[0007] To vary the blade pitch angle, the blower typically includes a blade pitch change system. Such a system typically includes a hydraulic actuator rotatably fixed to the hub. The hydraulic actuator is configured to drive the blades in rotation about their pitch axes. The hydraulic actuator typically includes a housing centered on the longitudinal axis and a body that moves in translation along the longitudinal axis inside of the envelope. The moving body is connected to the blades, possibly via a linkage mechanism that transforms the translational movement of the body into a rotational movement of the blades. The moving body is thus translationally movable in one position where it imposes a feathering position and another where it imposes a thrust reversal position on the blades. Between these two extreme positions, the moving body can assume any position.

[0008] The hydraulic actuator is typically supplied with a fluid, typically oil, via a supply circuit, the pressure of the fluid in the casing causing the movement of the body.

[0009] The hydraulic actuator is thus the only actuator capable of rotating all the blades to adjust their pitch angle according to flight conditions. Consequently, if this hydraulic actuator fails, for example, if the power supply circuit is broken or one of the hydraulic actuator's components breaks, it is no longer possible to control the blade pitch angle. In such a case, it is necessary to secure the blades in the feathered position.

[0010] To this end, document FR-A1-3 098 788 describes a blower module comprising a hub centered on the module axis and variable-pitch blades regularly distributed around the hub. The blower module further comprises a blade pitch-changing system including a hydraulic actuator rotatably fixed to the hub.

[0011] According to this document, the module further includes a blade pitch control system in case of hydraulic actuator failure. The control system comprises a set of weights capable of being moved by centrifugal force into a position in which the hydraulic actuator forces the blades into a flagging position.

[0012] Although this safety system compensates for a failure of the hydraulic actuator, it is not entirely satisfactory. The presence of a safety system in addition to the hydraulic actuator complicates the blower module and increases its size. Furthermore, the safety system itself is not entirely satisfactory. Indeed, the weights act under the effect of centrifugal force, which makes the safety system unreliable and difficult to control. Moreover, the hydraulic actuator must be oversized to counteract the additional forces exerted by the weights. Also, to reach the flag position, the body of the hydraulic actuator must travel a significant distance, which necessitates multiplying the number of weights and thus considerably increasing the volume of the module to accommodate such a safety system. The large number of weights also considerably increases the module's mass.

[0013] In this context, there is a need to provide a blower module comprising variable pitch blades, whose safety is improved while being compact and lightweight. Summary of the invention

[0014] To this end, the invention proposes a fan module for an aircraft turbomachine, the fan module having a longitudinal axis and comprising:

[0015] - blades with variable pitch regularly distributed around the longitudinal axis and each presenting a calibration axis, and

[0016] - a system for changing the blade pitch.

[0017] The blower module is remarkable in that the changeover system comprises:

[0018] blade actuation devices, each actuation device being connected to a blade, each actuation device comprising:

[0019] - a blade rotation drive mechanism connected to the blade, and

[0020] - an actuator configured to actuate the drive mechanism.

[0021] According to the invention, the blade pitch change system comprises a plurality of blade actuation devices.

[0022] Each blade actuation device includes a mechanism for rotating the blades around their shimming axes and an actuator for this drive mechanism.

[0023] Thus, each blade is set in rotation around its staking axis by its own actuation device.

[0024] Thanks to this redundancy of actuation devices and their independence, in the event of failure of at least one of the devices, it is possible to put the other blades in the flag position thanks to the functional actuation devices.

[0025] Also, it is possible to position the blades according to a pitch angle which can vary from one blade to another.

[0026] Finally, it is also possible to manage individually a positioning fault of one or a plurality of blades.

[0027] It is therefore possible to guarantee the safety of the blower module by feathering the blades despite the failure of one of the devices, without implementing an additional safety system.

[0028] By eliminating such an additional safety system, the blower module is simplified, less bulky and more reliable.

[0029] The module according to the invention may comprise one or more of the following features, taken individually or in combination with each other:

[0030] — a hub centered on the longitudinal axis and carrying the blades, each actuator being connected to the hub,

[0031] - each actuation device further comprises a control device for the actuator configured to control the actuator speed, the pitch of each blade being determined by the speed of each respective actuator,

[0032] - each control device is configured to transmit a command to command to each respective actuator to impose a specific position on each of the blades,

[0033] - each actuator comprises an electric motor,

[0034] - each actuator further comprises a mechanical reducer,

[0035] - each actuator further includes a sensor configured to determine the engine rotation speed,

[0036] - each actuation device includes a power supply device the actuator,

[0037] - the actuation devices are regularly distributed around the axis longitudinal,

[0038] - each actuator and each drive mechanism are rotationally fixed blades,

[0039] - each drive mechanism includes a nut connected to one of the blades or to The actuator and a screw around which the nut is mounted, the screw being connected to one of the blades or to the actuator, the screw or nut being driven in rotation by the actuator. Brief description of the figures

[0040] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which:

[0041] [Fig-1] [Fig.1] is a schematic representation of half a turbomachine aircraft to which the invention applies;

[0042] [Fig.2] [Fig.2] is a schematic representation of a blower module according to the invention equipping the turbomachine of [Fig.l];

[0043] [Fig.3] [Fig.3] is a kinematic diagram of an actuation device for a blade of the module of the [Fig.2],

[0044] [Fig.4] [Fig.4] is a schematic longitudinal cross-sectional view of a transmission device connected to an actuator of the actuation device of the [Fig.3]. Detailed description of the invention

[0045] An aircraft may comprise a fuselage and at least two wings extending from either side of the fuselage along the fuselage axis. At least one turbomachine 1 is mounted, for example, under each wing.

[0046] According to another example, an aircraft may include a fuselage and at least one turbomachine attached to the fuselage.

[0047] To facilitate its manufacture, assembly, mounting, and disassembly, the turbomachine 1 is modular, meaning that it comprises several modules that are manufactured independently of each other and then assembled together. The modularity of the turbomachine 1 also facilitates its maintenance.

[0048] Such a turbomachine 1 is illustrated for example by [Fig. 1]. The turbomachine 1 has a longitudinal axis X.

[0049] In the present application, the terms "axial", "axially", "radial" and "radially" are defined with respect to the longitudinal axis X. The terms "upstream", "downstream" are defined with respect to the direction of gas flow in the turbomachine 1 along the longitudinal axis X. The terms "internal", "inside", "external", "outside", "externally" are defined with respect to the distance from the longitudinal axis X along a radial axis perpendicular to the longitudinal axis X.

[0050] The turbomachine 1 includes a gas generator 2 and a blower module 3 arranged for example upstream of the gas generator 2.

[0051] The gas generator 2 typically 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 and form a low-pressure housing. The rotors of the high-pressure compressor 5 and the high-pressure turbine 7 are mechanically connected by a high-pressure shaft 10 and form a high-pressure housing. The high-pressure shaft 10 is arranged coaxially around the low-pressure shaft 9.

[0052] The high-pressure body is guided in rotation about the longitudinal axis by a first bearing 11 upstream and a second bearing 12 downstream. The first bearing 11 is mounted radially between an inter-compressor housing 13 and an upstream end of the high-pressure shaft 10. The inter-compressor housing 13 is arranged axially between the low-pressure compressor 4 and the high-pressure compressor 5. The second bearing 12 is mounted radially between an inter-turbine housing 14 and a downstream end of the high-pressure shaft 10. The inter-turbine housing 14 is arranged axially between the low-pressure turbine 7 and the high-pressure turbine 8.

[0053] The low-pressure body is guided in rotation about the longitudinal axis X by a third bearing 15 and a fourth, preferably double, bearing 16. These are mounted radially between an exhaust housing 17 and a downstream end of the low-pressure shaft 9. The exhaust housing 17 is located downstream of the low-pressure turbine 8. The third bearing 15 is mounted radially between an inlet housing 18 and an upstream end of the low-pressure shaft 9. The housing The inlet 18 is arranged axially between the blower module 3 and the low-pressure compressor 4.

[0054] According to the example in [Fig. 1], the fan module 3 comprises, for example, a fan casing 19 which carries a nacelle 20. The fan module 3 is of the enclosed type. The turbomachine 1 is, according to this example, a turbojet engine.

[0055] According to another example not shown, the fan module 3 is unducted (open rotor, USF for Unducted Single Fan or UDF for Unducted Fan). The turbomachine 1 is, in this example, a turboprop. Of course, the invention applies to other types of turbomachinery.

[0056] The blower module 3 compresses an airflow F which splits into a primary airflow Fl and a secondary airflow F2 at a separation nozzle 21. The latter is carried by the inlet housing 18 centered on the longitudinal axis X. The inlet housing 18 is extended downstream by an inter-vein housing 22. The primary airflow Fl flows in a primary vein 23 which passes through the gas generator 2 and exits through a primary nozzle 24.

[0057] The secondary airflow F2 circulates in a secondary vein 25 and escapes from it through a secondary nozzle 26 of the nacelle 20. The primary vein 23 and the secondary vein 25 are separated by the inter-vein housing 22.

[0058] The blower module 3 comprises a series of blades 30 extending radially around a hub 31. The hub 31 is movable in rotation about the longitudinal axis X. It is driven in rotation by a blower shaft 32 centered on the longitudinal axis X.

[0059] The blower shaft 32 is driven in rotation by a power transmission shaft with longitudinal axis X via a power transmission mechanism 33. In the present example, the power transmission shaft is the low pressure shaft 9. The blower shaft 32 and the low pressure shaft 9 are, for example, coaxial.

[0060] The power transmission mechanism 33 is, for example, a mechanical speed reducer 34 that reduces the rotational speed of the blower shaft 32 relative to the speed of the low-pressure shaft 9. Furthermore, the speed reducer 34 allows for the arrangement of a blower module 3 with a large diameter in order to increase the dilution ratio. The reducer 34 is of the planetary gear train type. It is housed in a lubrication chamber 35 in which it is lubricated. The lubrication chamber 35 is, for example, located inside the inlet housing 18. Typically, the speed reducer 34 comprises a sun gear 36 (or inner planet gear), planet gears 37, a planet carrier 38, and an outer ring gear 39 (or outer planet gear). In this example, the solar 36 is centered on the longitudinal axis X and is rotationally coupled with The power shaft follows the longitudinal axis X. The satellites 37 are carried by the satellite carrier 38 and each rotates around an axis substantially parallel to the longitudinal axis X. Each of the satellites 37 meshes with the solar element 36 and the outer ring 39. The satellites 37 are arranged radially between the solar element 36 and the outer ring 39. The outer ring 39 is rotationally coupled with the blower shaft 32. The ring 39 is centered on the longitudinal axis X. Thus, the solar element 36 forms the input of the speed reducer 34 while the outer ring 39 forms its output. The planet carrier 38, on the other hand, is fixed relative to the ring 39. The planet carrier 38 is in particular fixed to a fixed structure of the turbomachine 1 via a support ferrule 40. The latter is fixed to the inlet casing 18 of the turbomachine 1.The support ferrule 40 is also fixed to a first bearing support 41, fixed, integral with the input housing 18. The first bearing support 41 is installed downstream of the speed reducer 34. Alternatively, the planet carrier 38 is fixed to a radially internal ferrule of the input housing 18 or directly to a second bearing support 44 arranged upstream of the speed reducer 34.

[0061] The third bearing 15 is mounted downstream of the speed reducer 34. A fifth bearing 42 is arranged upstream of the reducer 34 and a sixth bearing 43 is arranged upstream of the fifth bearing 42. The outer rings of these bearings are carried by the second bearing support 44. The inner rings are integral with the blower shaft 32.

[0062] According to the invention, the fan module 3 comprises a series of variable-pitch blades 30. Each blade 30 comprises a foot 45 and a body 46 extending radially outwards from the foot 45. In the example shown in Figure 1, the blades 30 are surrounded by the fan housing 19. They can, however, be free, as in a turboprop engine.

[0063] The body 46 of each blade 30 has an aerodynamic shape. It comprises a leading edge and a trailing edge connected by an intrados face and an extrados face.

[0064] The foot 45 and the body 46 may be made from a single piece of material or separately. In the latter case, the body 46 fits into the foot 45 via a dovetail joint, for example.

[0065] The hub 31 is centered on the longitudinal axis X and includes housings 47 distributed regularly around the longitudinal axis X. Each housing 47 receives the foot 45 of a blade 30. There are thus as many housings 47 as feet 45.

[0066] The foot 45 of each blade 30 is pivotally mounted about a shim C in the hub 31. The shim C extends radially with respect to the longitudinal axis X. The foot 45 is pivotally mounted, for example, by means of at least two guide bearings 47a mounted in each housing 47 and superimposed along the axis of C alignment. These 47a bearings are preferably, but not exclusively, roller bearings.

[0067] In order to modify the pitch of the blades 30 according to the flight phases of the aircraft, the fan module 3 further includes a system 50 for changing the pitch of the blades 30. The changing system 50 is arranged in particular upstream of the speed reducer 34.

[0068] According to the invention, the gear-changing system 50 comprises a plurality of actuating devices 52, each actuating device 52 being connected to a blade 30. Each blade 30 is thus connected to its own actuating device 52. There are therefore as many actuating devices 52 as there are blades 30. The actuating devices 52 are regularly distributed around the longitudinal axis X.

[0069] With reference to [Fig.2], each actuation device 52 comprises an actuator 53 and a blade drive mechanism 54 configured to rotate the blade 30 around its pitch axis C.

[0070] Each actuator 53 is mobile in rotation around the longitudinal axis X. It is rotationally fixed to the hub 31. It is connected to the hub 31 by a link 55.

[0071] Each actuator 53 is preferably of the electric type. It comprises a motor 56 and advantageously a reducer 57, the assembly also being called a geared motor.

[0072] The motor 56 is an electric motor. It can be of the permanent magnet or asynchronous type. The motor 56 comprises a rotor 56a and a stator 56b arranged, for example, coaxially around the rotor 56a.

[0073] The reducer 57 is a mechanical reducer. It allows the output speed of the motor 56 to be reduced relative to the input speed of the motor 56. The reducer 57 comprises, for example, an input shaft connected to the rotor 56a of the motor 56 and an output shaft connected to the drive mechanism 54.

[0074] The reducer 57 may include an assembly configured to limit the rotation of the rotor 56a to less than one revolution. It may also include a removable hook to block the travel of the rotor 56a.

[0075] Advantageously, the motor 56 or geared motor is a brake motor. Thus, each actuator 53 can also include a mechanical brake (not shown). This mechanical brake is configured to prevent the rotor 56a from rotating according to a command given by an electromagnet, for example, in response to a loss of power to the motor 56. The brake is a fail-safe brake. This allows the actuation device 52 to be deactivated in the event of a loss of power to the actuator 53.

[0076] Each actuator 53 may also include a sensor configured to determine the rotational speed of the motor 56. The sensor may be a tachometer or a position sensor located on the rotor 56a of the motor 56. The sensor can reduce the movement to less than one rotation.

[0077] Preferably, each actuation device 52 includes a power supply device 530 for the actuator 53. Preferably, each power supply device 530 supplies electrical power to the actuator 53. Each power supply device 530 includes a transformer and / or a generator.

[0078] The generator makes it possible to transform mechanical energy, taken for example from the high-pressure shaft 10, into electrical energy. The advantage of the generator is that it does not require the routing of electrical cables.

[0079] The transformer is, for example, rotating. It allows the transfer of electrical energy from an electrical energy source located in a fixed frame to the actuator 53 which is located in a rotating frame.

[0080] Each power supply device 530 comprises a rotor 530a and a stator 530b. The rotor and stator 530a, 530b are coaxial. Advantageously, the stator 530b is located around the rotor 530a. The stator 530b is, for example, connected to a housing of the turbomachine 1, and the rotor 530a is, for example, rotationally fixed to the actuator 52.

[0081] Each power supply device 530 may further include a rectifier. The rectifier allows the alternating current supply from the generator or transformer to be converted into a direct current supply.

[0082] Each power supply device 530 may further include an inverter. Each inverter allows control of the current injected into each motor 56.

[0083] Each drive mechanism 54 transforms the rotational movement of the actuator 53 into a linear movement to rotate the blade 30 around its alignment axis C. Each drive mechanism 54 is thus connected to both the blade 30 and the actuator 53. Each drive mechanism 54 is therefore free to rotate around the longitudinal axis X.

[0084] Preferably, each drive mechanism 54 is electromechanical. It comprises a screw-nut mechanism. The screw-nut mechanism includes a nut 58 and a screw 59 around which the nut 58 is mounted coaxially. As can be seen more clearly in [Fig. 4], the screw 59 has a central axis Y that extends parallel to the longitudinal axis X of the blower module 3. Advantageously, the screw 59 extends between a first end 59a and a second axially opposite end 59b.

[0085] The screw 59 is driven in rotation around its central axis Y by the actuator 53. In particular, the first end 59a is connected to the rotor, for example to the output shaft of the reducer 57 for its drive in rotation.

[0086] The nut 58 is moved translationally along the screw 59 by the rotation of the screw 59. The nut 58 is connected to the blade 30. The translational movement of the nut 58 causes the blade 30 to rotate around its alignment axis C. The nut 58 is connected to the blade 30, for example, by a linkage 60. The linkage 60 comprises a first linkage portion 60a to the blade 30 and a second linkage portion 60b to the nut 58. The first linkage portion 60a may be located around the foot 45 or around an attachment member 60c connected to the blade 30.

[0087] According to another example, the screw 59 is connected to the blade 30, and the nut 58 is connected to the actuator 53 and is driven in rotation by the actuator 53 around the central axis Y. The rotation of the nut 58 causes the screw 59 to move in translation. The translational movement of the screw 59 causes the blade 30 to rotate around its alignment axis C. The screw 59 can be connected to the blade 30 by the linkage 60.

[0088] The drive mechanism 54 occupies at least two extreme axial positions in which it respectively imposes a feathering position and a thrust reversal position on the blade 30. The drive mechanism 54 can occupy any position between the two extreme positions depending on the different flight phases of the aircraft to impose a pitch angle on the blade 30 located between the feathering and thrust reversal positions. One of the axial positions is a feathering position, which therefore corresponds to a position in which it imposes a feathering position on the blade 30, and another position, called the pitch position, is an axial position in which it imposes a pitch angle on the blades 30 different from the feathering and thrust reversal positions. Each drive mechanism 54 can occupy another position, called the thrust reversal position, in which it imposes a thrust reversal position on the blade 30, known in English as "reverse".The stall position of the drive mechanism 54 is therefore an intermediate axial position located between the flag and thrust reversal positions. The evolution of the axial positions of each drive mechanism 54 is achieved by the drive of the actuator 53.

[0089] Each drive mechanism 54 is, for example, of the roller screw type. According to another example, the screw-nut mechanism is of the ball screw type. It may therefore further comprise at least one annular row of balls 58a located between the nut 58 and the screw 59.

[0090] According to the invention, each actuator 53 is controlled by a control device 600. Each actuation device 52 may include a control device 600 or a single control device 600 may control all the actuators 53 of each actuation device 52.

[0091] The control device or devices 600 are electrically operated. The control device or devices 600 impose a speed on the actuator 53 and therefore the position axial of the drive mechanism 54. This has the effect of controlling 600 the pitch angle of the blades 30 in a predetermined position.

[0092] The control device or each control device 600 is configured to transmit a power control command 01 to the actuator 53 to rotate the blade 30.

[0093] The blades 30 can thus be controlled independently of each other.

[0094] The blower module 3 may also include a position sensor each blade 30 configured to transmit an SI signal relating to the position of each blade 30 to a computer 61. The computer 61 may be a FADEC.

[0095] Lee each control device 600 can also transmit a signal S2 relating to the theoretical position of the blade 30 according to the control order 01.

[0096] In a mode, called nominal mode, each control unit transmits the command 01 to the actuator 53 to set the blade 30 in a predetermined position. The position may differ from one blade 30 to another. This is particularly advantageous for a cyclic pitch.

[0097] If the signal SI transmitted by the sensor and the signal S2 transmitted by the control device(s) 600 indicate a positioning deviation of a blade 30, each control device 600 transmits a command order 01 to feather the blades 30.

[0098] In the absence of a command order 01, the blades 30 are automatically feathered.

[0099] In the absence of power to all the actuators 53, the blades 30 are locked in their last position or a flag position is imposed depending on the amount of energy remaining to control the actuators 53.

[0100] In the absence of power to an actuator 53 or failure of an actuator 53, the other control devices 600 transmit a control order 01 to feather their blades 30.

[0101] Thanks to the blade pitch adjustment system 50 of the invention, the blades 30 can be controlled independently of each other. This makes it possible to guarantee that the blades 30 will feather in the event of a failure of an actuator 53 without requiring an additional blade feathering safety system. By eliminating the need for such a dedicated safety system, the size of the blower module 3 is reduced. The blower module is also more reliable and less expensive. Maintenance of the blower module 3 is also simplified.

[0102] Alternatively, each actuator 53 could be of the hydraulic type. Each actuator 53 could include, for example, a hydraulic cylinder. According to this alternative, each power supply device 530 could include a hydraulic power supply circuit connected to the cylinder, for example.

Claims

Demands

1. Fan module (3) for an aircraft turbomachine (1), the fan module (3) having a longitudinal axis (X) and comprising: - variable pitch blades (30) regularly distributed around the longitudinal axis (X) and each having a pitch axis (C), and - a system for changing the pitch of the blades (30), characterized in that the changing system (50) comprises: actuation devices (52) for the blades (30), each actuation device (52) being connected to a blade (30), each actuation device (52) comprising: - a drive mechanism (54) for rotating the blade (30) connected to the blade (30), and - an actuator (53) configured to actuate the drive mechanism (54).

2. Blower module according to the preceding claim, characterized in that each actuation device (52) further comprises a control device (600) for the actuator (53) configured to control the speed of the actuator (53), the pitch of each blade (30) being imposed by the speed of each respective actuator (53).

3. Blower module according to the preceding claim, characterized in that each control device (600) is configured to transmit a control command (01) to each respective actuator (53) to impose a pitch on each of the blades (30).

4. Blower module according to any one of the preceding claims, characterized in that each actuator (53) comprises an electric motor (56).

5. Blower module according to the preceding claim, characterized in that each actuator (53) further comprises a mechanical reducer (57).

6. Blower module according to claim 4 or 5, characterized in that each actuator (53) further comprises a sensor configured to determine the rotational speed of the motor (56).

7. Blower module according to any one of the preceding claims, characterized in that each actuation device (52) comprises a power supply device (530) for the actuator (53).

8. Blower module according to any one of the preceding claims, characterized in that the actuation devices (52) are regularly distributed around the longitudinal axis (X).

9. Blower module according to any one of the preceding claims, characterized in that each actuator (52) and each drive mechanism (54) are rotationally fixed to the blades (30).

10. Blower module according to any one of the preceding claims, characterized in that each drive mechanism (54) comprises a nut (58) connected to one of the blades (30) or to the actuator (52) and a screw (59) around which the nut (58) is mounted, the screw (59) being connected to one of the blades (30) or to the actuator (52), the screw (59) or the nut (58) being driven in rotation by the actuator (52).

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