Propeller pitch adjustment and blade de-icing system comprising a differential speed main generator

Abstract

Pitch adjustment and de-icing system for the blades of a propeller comprising a differential speed main generator. Pitch adjustment and de-icing system (10) for the blades (14) of a propeller (12) comprising a first rotary drive element (20); a second rotary drive element (22); an epicyclic gear train (24) configured such that said second rotary drive element (22) is driven in rotation at a second rotational speed, lower than said first rotational speed; an electric motor (80) used to adjust the pitch of the propeller blades; a de-icing device (90) for said blades; a main generator (60) with differential speed comprising a wound inductor (62) carried by the first rotating drive element and an armature (64) carried by the second rotating drive element and configured to deliver an alternating voltage (VgAC);an AC-DC rectifier (66) configured to deliver a main DC voltage (VgDC) from said AC voltage (VgAC); an excitation device (52) configured to supply a DC excitation voltage (VeDC) to the wound inductor of the main generator; a power supply device (40) configured to supply a DC supply voltage (Va'DC) to the excitation device (52); and a regulation unit (70, 71) configured to regulate said main DC voltage (VgDC) to a constant value, by adjusting the DC supply voltage (Va'DC) supplied by the power supply device to the inductor of the exciter machine. Figure for the abstract: Fig. 1.

Description

Title of the invention: Propeller pitch adjustment and de-icing system comprising a differential speed main generator technical field

[0001] The present invention relates to the technical field of systems for simultaneously adjusting the pitch of an aircraft propeller blades and de-icing said blades. The aircraft may comprise a turboprop engine or, alternatively, a turbofan, in which case the propeller is also called a fan. The invention also relates to an aircraft comprising such a system. Previous technique

[0002] Most propeller blades on turboprop engines or turbofans are equipped with a de-icing device using heated mats that prevent ice formation. The heating mats are traditionally powered by a brush-type commutator, which has several drawbacks. In particular, these brush-type commutators wear out quickly and require regular maintenance. Furthermore, these devices are very heavy and bulky.

[0003] Known solutions propose transferring electrical energy from the fixed frame to a rotating frame using a rotating transformer, with or without brushes. However, such a rotating transformer is not satisfactory due to the significant integration constraints it imposes. In particular, such a rotating transformer has a large diameter if it is located downstream of the step actuation system and is integral with the external fixed structure of the turbomachine. Furthermore, it creates difficulties in accessing the fixed support if it is located upstream of the conventional hydraulic step actuation system. The use of a rotating transformer also generates difficulties for routing the harnesses to supply the primary circuit of the rotating transformer in the fixed frame.

[0004] Moreover, a conventional hydraulic pitch control system has a hydraulic transfer from the fixed part to the rotating part which does not offer easy access to the fixed part on the cone side of the turbomachine.

[0005] Furthermore, a three-phase or single-phase rotating transformer transfers the electrical power corresponding to the requirement, which determines its significant mass. A DC / AC power converter of equivalent power must therefore be provided.

[0006] It may therefore be desirable to design a system that overcomes all or part of the aforementioned constraints.

[0007] Document FR3131277 describes a solution for powering the electric motor allowing the pitch of a propeller blades and the de-icing device of said propeller blades to be adjusted by means of a main generator comprising a stator supported by a fixed support and a rotor supported by a rotating support. This main generator is further associated with an exciter machine connected upstream of said generator.

[0008] The solution described in this document eliminates the need for a rotating transformer, a heavy and bulky device, as well as the DC / AC power converters required for a rotating transformer. Furthermore, the fact that such a main electric generator generates electrical power in the rotating frame of its rotor reduces the length of the electrical connections, grouped into power harnesses, between this generator and, respectively, the electric motor for blade pitch adjustment and the de-icing device.

[0009] One drawback of the solution described in this document is that the system supplying power to the electric motor for adjusting the propeller blade pitch and the de-icing device is driven by the aircraft's low rotation, i.e., at the propeller's rotational speed. Consequently, the main generator and the excitation device that make up this power supply system are large and have a significant footprint and weight.

[0010] Another drawback of the solution described in this document is that regulating the voltage supplied by the main generator to meet the power requirements of the de-icing device involves a wide voltage range. Consequently, the electric motor for adjusting the propeller blade pitch must be sized to withstand a wide voltage range, which will result in a significant mass. Description of the invention

[0011] One object of the present invention is to propose a pitch adjustment and de-icing system for the blades of an aircraft propeller that remedies the aforementioned drawbacks.

[0012] To this end, the invention relates to a pitch adjustment and de-icing system for the blades of an aircraft propeller, the system comprising: - a first rotary drive element configured to be driven in rotation by a turbomachine of the aircraft at a first rotation speed; - a second rotating drive element carrying the propeller; - an epicyclic gear train comprising: an internal planetary gear attached to the first rotating drive element and configured to be driven in rotation around a main axis; at least one satellite geared with said inner planetary; an outer planetary gear configured to be driven around said main axis and meshed with said at least one satellite, said second rotating drive element being fixed to the outer planetary gear so that said second rotating drive element is driven in rotation at a second rotational speed, lower than said first rotational speed, when the first rotating drive element is set in rotation at said first rotational speed; - an electric motor comprising a stator carried by the second rotating drive element and a rotor used to adjust the pitch of the aircraft propeller blades; - a de-icing device for said propeller blades carried by the second rotating drive element; - a main differential speed generator comprising a wound inductor carried by the first rotary drive element, so that it is configured to be driven in rotation at said first speed of rotation, and an armature carried by the second rotary drive element, so that it is configured to be driven in rotation at said second speed of rotation, the armature being configured to deliver an alternating voltage; - an AC-DC rectifier connected to the armature of the main generator and configured to deliver a main DC voltage to the electric motor and the defrosting device, from said AC voltage supplied by the armature of the main generator; - an excitation device configured to provide a continuous excitation voltage to the wound inductor of the main generator, the excitation device comprising an exciter machine including an inductor carried by the second rotating drive element and a wound armature carried by the first rotating drive element; - a power supply device for powering the excitation device, configured to provide a continuous supply voltage to the inductor of the exciter machine of the excitation device, the power supply device comprising a permanent magnet generator including a permanent magnet inductor carried by the first rotating drive element and an armature carried by the second drive element; and - a control unit configured to regulate said main DC voltage delivered by said AC-DC rectifier to a constant value, by adjusting the DC supply voltage supplied by the power supply device to the inductor of the exciter machine.

[0013] By way of non-limiting agreement, the aircraft advantageously comprises a turbomachine for the rotational drive of the first rotary drive element. Said tur- The turbomachine advantageously includes said propeller. For example, said turbomachine may be a turbofan or a turbojet, in which case said propeller is called a fan and said blades are called vanes, or a turboprop. In other words, the term "propeller" covers both the propeller of a turboprop engine and the fan of a turbojet. The term "blades" covers both the blades of a turboprop engine's propeller and the fan blades of a turbojet. The aircraft's propeller is driven by the second rotating drive element, so it rotates at said second rotational speed, which is lower than the rotational speed of the first rotating drive element and the inner planetary gear.

[0014] The electric motor allows the orientation of the propeller blades considered to be adjusted around their longitudinal axes, also called blade pitching.

[0015] Without limitation, the electric motor may be a synchronous or asynchronous motor. Preferably, the stator and rotor of the electric motor rotate about the main axis. Preferably, the electric motor is configured to drive an actuation system configured to adjust the orientation of the aircraft propeller blades. Without limitation, the actuation system may be electrohydraulic (EHA), comprising, for example, a pump, or electromechanical (EMA), comprising, for example, a screw and a nut. These actuation systems allow the orientation of the aircraft propeller blades to be adjusted.

[0016] The stator of the electric motor is driven in rotation by the second rotating drive element and is therefore configured to rotate at said second rotational speed. The rotor of the electric motor rotates relative to said stator and therefore relative to said second rotating drive element. In other words, the stator and the rotor of the electric motor are both driven in rotation and are also each arranged in a separate rotating frame of reference.

[0017] The de-icing device advantageously comprises a plurality of heating mats associated with the propeller blades of the aircraft.

[0018] The epicyclic gear train advantageously comprises a planet carrier that is fixed relative to a portion of the aircraft frame, said at least one planet being pivotally mounted relative to said planet carrier. The outer planet gear is also called the ring gear.

[0019] It is understood that the first rotary drive element is configured to drive the inner planetary gear in rotation, which then drives the outer planetary gear in rotation via the satellite. The satellite is meshed with both the inner planetary gear and the outer planetary gear.

[0020] Said epicyclic gear train is configured to transmit the rotational motion from the first rotary drive element to the second rotary drive element, while allowing a reduction in rotational speed between these two elements of rotary drives, according to a reduction ratio specific to the epicyclic gear train. The epicyclic gear train constitutes a reducer with a reduction ratio less than 1. The outer planetary gear rotates at a reduced speed relative to the rotational speed of the inner planetary gear, according to the reduction ratio of said epicyclic gear train. Preferably, the epicyclic gear train is configured such that the second rotational speed at which the second rotary drive element rotates is approximately 10 times lower than the first rotational speed at which the first rotary drive element and the inner planetary gear rotate.

[0021] The first rotational speed at which the first rotary drive element, and therefore the internal planetary gear, rotates advantageously corresponds to the rotational speed of a low-pressure turbine in the aircraft's turbomachine. The first rotary drive element may include a first drive shaft. The second rotary drive element may include a second drive shaft.

[0022] Since the wound field winding of the main generator, the wound armature of the exciter machine, and the permanent magnet field winding of the permanent magnet generator are carried by the first rotary drive element, they are rotationally linked to said first rotary drive element. They describe the same rotational motion as said first rotary drive element. They are therefore configured to be driven in rotation at said first rotational speed when the first rotary drive element is driven in rotation at said first rotational speed.

[0023] The stator of the electric motor, the de-icing device for said propeller blades, the armature of the main generator, the field winding of the exciter machine, and the armature of the permanent magnet generator, being carried by the second rotary drive element, are rotationally linked to said second rotary drive element. They describe the same rotational motion as the second rotary drive element. They are therefore configured to be driven in rotation at said second rotational speed when the first rotary drive element is driven in rotation at said first rotational speed.

[0024] The assembly formed by the main generator, the excitation device and the power supply device forms a three-stage variable frequency generator (VFG).

[0025] The armature of the permanent magnet generator of the power supply device is configured to deliver an alternating voltage. The power supply device advantageously includes a rectifier configured to deliver a direct current voltage from the alternating voltage delivered by said permanent magnet generator. Preferably, the permanent magnet generator of the power supply device is a ge- synchronous neratrix.

[0026] The excitation device is configured to supply, to the wound inductor of the main generator, said continuous excitation voltage from the continuous supply voltage supplied by the power supply device.

[0027] The excitation machine of the excitation device is configured to deliver an alternating voltage. The excitation device advantageously includes a rectifier configured to deliver said DC excitation voltage to the wound inductor of the main generator from the alternating voltage delivered by said excitation machine.

[0028] The excitation voltage supplied by the excitation device to the wound inductor of the main generator enables the latter to generate a magnetic field. Taking into account the relative motion of the wound inductor with respect to the armature, caused by their difference in rotational speeds, and the magnetic field generated by the wound inductor of the main generator, the armature of the main generator delivers an alternating voltage, used to electrically power the electric motor as well as the de-icing device.

[0029] The main generator is configured to provide said alternating voltage from said direct excitation voltage supplied by the excitation device.

[0030] Preferably, the wound inductor and the armature of the main generator rotate around the main axis.

[0031] The AC-DC rectifier is configured to deliver a DC voltage from an AC voltage. The AC-DC rectifier is configured to provide shared power to the de-icing device and the electric motor for adjusting the propeller blade pitch. Preferably, the AC-DC rectifier is of the uncontrolled or passive type. Preferably, the AC-DC rectifier is mounted on the second rotary drive element.

[0032] The AC-DC rectifier device is not necessarily directly connected to the defrosting device and the electric motor.

[0033] Preferably, said AC-DC rectifier comprises a rectifier element, for example an AC / DC converter. Preferably, said rectifier element comprises two output terminals and said AC-DC rectifier further comprises a filter capacitor connected between said output terminals of the rectifier element.

[0034] The main generator of the system according to the invention is said to have differential speed, insofar as its wound field winding and its armature are both driven in rotation at different speeds. In other words, the difference between the second rotational speed of the second rotating drive element, and therefore of the armature of the main generator, and the first rotational speed of the first rotating drive element, and therefore of the wound field winding of the main generator, constitutes the differential velocity.

[0035] Also, the armature and the wound field winding of the main differential-speed generator according to the invention are both driven in rotation, unlike the prior art system cited in which only the wound armature of the main generator is driven in rotation at low speed while the field winding is fixed because it is supported by the planet carrier of the epicyclic gear train. In other words, the wound field winding as well as the armature of the main differential-speed generator of the system according to the invention are positioned in two rotating frames considered with respect to a portion of the aircraft frame.

[0036] One advantage is to allow the dimensions and therefore the size of the main generator to be reduced, while still having sufficient power to supply the electric motor and the propeller blade de-icing device.

[0037] The rotational speed of the wound inductor of the main generator of the system according to the invention corresponds to the drive speed of the aircraft's turbomachine.

[0038] The invention also eliminates the need for a rotating transformer, thereby reducing the system's weight and size. Furthermore, the invention avoids the difficulties of routing harnesses for supplying power to the primary circuit of a rotating transformer. Moreover, it is not necessary to implement multiple DC / AC converters, which are required when a rotating transformer is used.

[0039] Furthermore, according to the invention, the control unit regulates the main DC voltage, delivered by the AC-DC rectifier and used to power the electric motor and the defrosting device, so as to maintain it at a constant value. The invention makes it possible to maintain said main DC voltage at a constant value even if the power drawn by the defrosting system or the electric motor suddenly increases or decreases. In particular, the main DC voltage is maintained constant despite possible variations in the electric motor's speed setpoint and therefore despite fluctuations in the energy drawn by the latter, leading to different current demands on the armature of the main generator and at the output of the AC-DC rectifier.This eliminates the need to adjust the control of the defrosting system and the heating mats according to the speed setting of the electric motor and the electrical energy it draws.

[0040] Another advantage is that it is not necessary to size the electric motor for adjusting the blade pitch to withstand a wide voltage range. Therefore, the weight and size of the electric motor can be reduced.

[0041] It is understood that the regulation of the main DC voltage is achieved indirectly, by adjusting the supply voltage provided by the power supply device.

[0042] The regulating unit is advantageously configured to regulate the main DC voltage by controlling the power supply device, in order to adjust the DC supply voltage it provides.

[0043] Preferably, the armature of the permanent magnet generator is configured to deliver a first alternating voltage, and the power supply device further comprises: an AC-DC converter carried by the second rotary drive element and configured to deliver a first DC voltage from said first AC voltage; and a DC / DC converter carried by the second rotary drive element and configured to deliver said DC supply voltage from the first DC voltage delivered by the AC-DC converter.

[0044] The AC-DC converter is connected between the armature of the permanent magnet generator and the DC / DC converter. The DC / DC converter is controllable.

[0045] The DC / DC converter can be controlled to adjust said DC supply voltage which it delivers according to voltage requirements, in particular at the output of the AC-DC rectifier.

[0046] Preferably, said control unit is configured to control said DC / DC converter so as to adjust said DC supply voltage it delivers, in order to regulate said main DC voltage supplied by said AC-DC rectifier to a constant value. It is understood that the control unit is connected to the DC / DC converter and provides control signals to the latter.

[0047] In this embodiment, the DC / DC converter is controllable.

[0048] Advantageously, the control unit is configured to adjust the supply voltage delivered by the power supply device based on a measurement of the main DC voltage delivered by the AC-DC rectifier. The control unit allows for the control of this main DC voltage. One advantage is that the regulation is more precise, since it takes into account the voltage variations at the output of the AC-DC rectifier.

[0049] Preferably, the control unit includes a measuring element configured to measure said main DC voltage.

[0050] Preferably, said control unit is configured to control said DC / DC converter based on said measurement of said main DC voltage delivered by said AC-DC rectifier. It is understood that the control unit is configured to adjust the DC supply voltage delivered by the DC / DC converter based on the measured main DC voltage. This adjustment is achieved by comparing the measured main DC voltage to a reference value, and by adjusting the main DC voltage towards this reference value.

[0051] Preferably, the system further comprises an inverter device configured to supply an alternating voltage to the stator of the electric motor from the direct current voltage delivered by the AC-DC rectifier. The inverter device allows control of the frequency and amplitude of the alternating voltage supplied to the electric motor.

[0052] Preferably, the inverter device includes a DC / AC converter, even more preferably consists of a DC / AC converter.

[0053] Advantageously, the system further comprises a motor control module configured to regulate the voltage at the stator of the electric motor, based on a setpoint for the pitch of the aircraft propeller blades and a measurement of the orientation of the aircraft propeller blades, said motor control module being carried by the second rotary drive element. The control module advantageously allows adjustment of the frequency and amplitude of the alternating voltage supplied to the electric motor. The electric motor control module allows adjustment of the rotational speed and direction of rotation of the electric motor rotor.

[0054] It is understood that the control module is arranged in a rotating frame and that it rotates at said second rotational speed. One advantage is to eliminate the need for a means of transmitting control signals between the control module and the electric motor.

[0055] Preferably, the motor control module is configured to control said inverter device, in particular to adjust said alternating voltage supplied by the latter to the stator of the electric motor.

[0056] Preferably, the system comprises at least one propeller blade orientation measurement device carried by the second rotary drive element and configured to deliver said propeller blade orientation measurement to the engine control module. The engine control module is advantageously configured to control the inverter device based on said propeller blade orientation measurement.

[0057] Said measuring device advantageously comprises a plurality of sensors, each associated with one of the propeller blades. It is understood that said measuring device is driven in rotation with the second rotating drive element and is disposed in a rotating frame of reference.

[0058] Insofar as said measuring device and the motor control module are Since both are mounted on the second rotating drive element and are therefore positioned in a rotating frame, it is not necessary to transfer the measurement from the rotating frame to the fixed frame. Similarly, it is not necessary to equip the system with means to transmit measurement data from a sensor located in the rotating frame to an engine control module that would be fixed relative to a portion of the aircraft frame.

[0059] Preferably, the system comprises a control device configured to generate said propeller pitch setpoint for the aircraft propeller and which is fixed relative to a portion of the aircraft frame, the system further comprising at least one signal transfer element configured to transfer said propeller pitch setpoint from said control device to the engine control module. The signal transfer system allows the setpoint signal(s) to be transferred from a fixed reference frame to a rotating reference frame.

[0060] Indeed, the signal transfer unit allows the setpoint signal to be transferred from the control device, which is located in a fixed frame, to the motor control module which is carried by the second rotating drive element, and which is therefore located in a rotating frame.

[0061] Preferably, the system further comprises a control module for the defrosting device powered by said main DC voltage delivered by the AC-DC rectifier and carried by the second rotary drive element.

[0062] The control module is connected to the AC-DC rectifier. The defrosting device control module allows the defrosting device to be controlled in order to control the defrosting of the propeller blades. The control module regulates the power supplied to the defrosting device, and in particular to the heating mats. It is advantageously configured to selectively power the heating mats of the defrosting device, preferably according to a chosen sequence. In other words, it allows the blades to be selected for defrosting.

[0063] Preferably, said control module is powered by the first DC voltage delivered by the AC-DC converter of the power supply device. Preferably, said control module is connected to the output of said AC-DC converter of the power supply device.

[0064] Preferably, the control device is further configured to generate a defrost command. The system advantageously includes at least one signal transfer element configured to transfer said defrost command from said control device to the defrost device control module. The signal transfer element enables the transmission of said defrost command from the fixed reference frame to the rotating reference frame in which the defrost device control module is located.

[0065] Advantageously, the wound armature of the exciter machine of the excitation device is configured to deliver an alternating excitation voltage, the excitation device further comprising a diode bridge carried by the first rotating drive element, the diode bridge being configured to deliver said direct excitation voltage to the wound inductor of the main generator, from said alternating excitation voltage.

[0066] The diode bridge is configured to supply the wound inductor of the main generator with a DC voltage derived from the AC voltage supplied by the exciter of the excitation device. In other words, the diode bridge is configured to rectify the AC voltage supplied by the exciter. It forms an uncontrolled or passive rectifier element.

[0067] The diode bridge is arranged in the rotating frame. It rotates at the same speed as the wound armature of the exciter machine and the wound field winding of the main generator.

[0068] The invention also relates to an aircraft comprising at least one propeller comprising a plurality of blades, and a pitch adjustment and de-icing system for the propeller blades as described above.

[0069] The aircraft advantageously comprises a turbomachine, for example a turbojet, a turbofan or a turboprop, including said propeller. Brief description of the drawings

[0070] The invention will be better understood upon reading the following description of an embodiment of the invention given by way of non-limiting example, with reference to the accompanying drawings, in which:

[0071] [Fig. 1] [Fig. 1] illustrates a system for adjusting the pitch and de-icing the blades of an aircraft propeller according to the invention; and

[0072] [Fig.2] [Fig.2] is a cross-sectional view, centered on the propeller area, of a part of a turbomachine comprising the system according to the invention. Description of the implementation methods

[0073] The invention relates to a pitch adjustment and de-icing system for the blades of an aircraft propeller, as well as to an aircraft comprising such a system.

[0074] Fig. 1 shows a pitch adjustment and de-icing system 10 for the blades of an aircraft propeller, according to the invention.

[0075] In this non-limiting example, the aircraft comprises a turbomachine 100, which may be a turbojet, a turbofan, or a turboprop. A portion of this turbomachine 100 is illustrated in [Fig. 1]. The turbomachine comprises a propeller 12 having a plurality of blades 14. Only one of said blades 14 is illustrated in [Fig. 1].

[0076] Said turbomachine 100 further comprises said system 10 for pitch adjustment and de-icing of the aircraft propeller blades, according to the invention. The system 10 comprises an electric motor 80 for adjusting the pitch of the propeller blades 14 of the propeller 12 and a de-icing device 90 for the blades, which will be described subsequently.

[0077] The system 10 further comprises a first rotary drive element 20 and a second rotary drive element 22, both configured to rotate about a principal axis X. Each of said first and second rotary drive elements 20, 22 comprises a drive shaft. The first rotary drive element 20 is configured to be driven in rotation by a low-pressure turbine of the turbomachine 100, at a first rotational speed, which is a high speed.

[0078] The system 10 comprises an epicyclic gear train 24 forming a reduction device. More specifically, this epicyclic gear train 24 comprises an inner planet gear 26, a planet carrier 28, at least one planet gear 30, only one of which is illustrated in [Fig. 1], and an outer planet gear 32. The inner planet gear 26 is rotationally linked and fixed to the first rotating drive element 20. It is configured to be driven in rotation at said first rotational speed of the low-pressure turbine, around the main axis X. The planet carrier 28 is fixed relative to a portion of the aircraft frame. The planet gear 30 is meshed with the inner planet gear 26 and with the outer planet gear 32 and rotates relative to the planet carrier. The outer planetary gear 32 is rotationally linked and fixed to the second rotating drive element 22. The outer planetary gear 32 rotates around the main axis X.The rotation of the first rotary drive element 20, and therefore of the inner planetary gear 26, at a first rotational speed causes the rotation of the outer planetary gear 32, and therefore of the second rotary drive element 22, at a second rotational speed lower than the first rotational speed, according to a reduction ratio of the reducing device. The epicyclic gear train 24 has a reduction ratio of less than 1, preferably a reduction ratio of approximately 1 / 10. According to the invention, the first rotary drive element 20 and the second rotary drive element 22 are both driven in rotation, at different rotational speeds.

[0079] The aircraft propeller 12 is carried by the second rotating drive element 22, so that it rotates at the second rotational speed, around the main axis X, as illustrated in [Fig.2] showing a cross-sectional view of a part of the turbomachine 100 comprising the system 10 according to the invention, in the area of ​​the propeller 12.

[0080] As illustrated in [Fig. 2], the system further comprises a power supply device 40 including a permanent magnet generator 42. The permanent magnet generator 42 includes a permanent magnet inductor 44 equipped with permanent magnets and an armature 46. The permanent magnet inductor 44 of the generator The permanent magnets are carried by the first rotating drive element 20 and rotate at said first rotational speed. The armature 46 of the permanent magnet generator 42 is carried by the second rotating drive element 22 and rotates at said second rotational speed. The field winding 44 and the armature 46 both rotate relative to a portion of the aircraft frame, around the principal axis X, and are therefore each arranged in a separate rotating frame. The armature comprises a winding.

[0081] Given the magnetic field generated by the permanent magnets of the permanent magnet inductor 44 and the relative movement of the armature with respect to the inductor, said armature 46 of the permanent magnet generator generates a first alternating voltage VaAC. This first alternating voltage VaAc is three-phase.

[0082] The power supply device 40 further includes an AC-DC converter 48 connected to the armature 46 of the permanent magnet generator 42. It forms a rectifier element configured to deliver a first DC voltage VaDC from said first AC voltage VaAC generated by the permanent magnet generator 42.

[0083] The power supply device 40 further includes a controllable DC / DC converter 50 configured to convert the first DC voltage VaDc delivered by the AC-DC converter 48 into a DC supply voltage Va'Dc having a different amplitude from the DC voltage it receives.

[0084] The AC-DC converter 48 and the DC / DC converter 50 are carried by the second rotary drive element 22 and therefore rotate at the second rotational speed. They are arranged in a rotating frame.

[0085] The system 10 further comprises an excitation device 52 connected in cascade with the power supply device 40. The excitation device 52 comprises an excitation machine 54 connected to the DC / DC converter 50 of the power supply device. The excitation machine comprises an inductor 56 and a wound armature 58. As illustrated in [Fig. 2], the inductor 56 is carried by, and integral with, the second rotary drive element 22. The inductor rotates at the second speed, which corresponds to the rotational speed of the propeller 12. The wound armature 58 of the excitation machine 54 is carried by the first rotary drive element 20. It therefore rotates at the first speed, which advantageously corresponds to the rotational speed of the aircraft's low-pressure turbine.

[0086] The inductor 56 and the wound armature 58 of the exciter machine both rotate relative to a portion of the aircraft frame, around the main axis X, and are therefore each disposed in a separate rotating frame.

[0087] The DC supply voltage Va'Dc delivered by the DC / DC converter 50 of the power supply device is supplied to the inductor 56 of the exciter machine 54, for the latter's power supply. The inductor 56 of the exciter machine This allows for the generation of a magnetic field. Given this magnetic field and the relative motion between the inductor 56 and the armature 58 of the exciter machine, due to the difference in their rotational speeds, the wound armature 58 generates an alternating excitation voltage VeAC. This alternating excitation voltage VeAc is three-phase.

[0088] The excitation device 52 further comprises a diode bridge 59 connected to the wound armature 58 of the exciter machine 54. It forms a rectifier configured to deliver a DC excitation voltage VeDC from the AC excitation voltage VeAC generated by the exciter machine. The diode bridge 59 of the excitation device 52 is supported by the first rotary drive element 20 and rotates at the first rotational speed.

[0089] According to the invention, the system further comprises a main differential-speed generator 60, which includes a wound inductor 62 and an armature 64. The wound inductor 62 is connected to the excitation device 52, and more specifically to the output of the diode bridge 59. The wound inductor 62 comprises at least one winding and receives the DC excitation voltage VeDc, so that it is configured to generate a magnetic field. The wound inductor 62 is carried by, and fixed to, the first rotary drive element 20. It also rotates about the main axis X at the first rotational speed of the first rotary drive element 20, which here corresponds to the rotational speed of the aircraft's low-pressure turbine. The armature 64 is carried by the second rotary drive element 22.It is also configured to rotate at the second rotational speed of the second rotary drive element 22, in the magnetic field generated by the wound inductor, when the first rotary drive element 20 is driven in rotation. The difference between the second rotational speed of the second rotary drive element 22, and therefore of the armature 64 of the main generator 60, and the first rotational speed of the first rotary drive element 20, and therefore of the wound inductor 62 of the main generator, constitutes the differential speed.

[0090] Given the relative rotational motion of the wound inductor 62 with respect to the armature 64, caused by their difference in rotational speeds, and the magnetic field generated by the wound inductor, the armature of the main generator 60 delivers an alternating voltage VgAC which is used to power the electric motor 80 and the defrosting device 90, which will be described later. This alternating voltage VgAC is three-phase.

[0091] The assembly consisting of the power supply device 40, the excitation device 52 and the main generator 60 forms a three-stage variable frequency generator (VFG).

[0092] The system 10 further includes an AC-DC rectifier 66 electrically connected The AC / DC rectifier 66 is connected to the armature 64 of the main generator 60. It consists of an AC / DC converter 68 forming a rectifier unit and a filter capacitor 69 connected between the output terminals of the AC / DC converter. The AC / DC rectifier 66 is configured to deliver a DC voltage VgDC from the AC voltage VgAc supplied by the main generator 60. The AC / DC rectifier 66 is mounted on the second rotary drive element 22 and is positioned in the rotating frame.

[0093] The de-icing device 90 comprises a plurality of heating mats, each associated with one of the blades 14 of the aircraft's propeller 12. The system 10 also includes a control module 94 for the de-icing device. The de-icing device 90 is electrically powered by the main generator 60, via the control module 94 and the AC-DC rectifier 66.

[0094] More specifically, the control module 94 comprises a plurality of switches and is configured to selectively drive the heating mats of the defrosting device 90 according to a chosen sequence, based on the main DC voltage VgDc supplied by the AC-DC rectifier 66. The control module 94 allows selection of the blades to be defrosted. The control module 94 is configured to control the defrosting device according to a defrosting setpoint C2.

[0095] According to the invention, the system 10 also includes a control unit 70, 71 configured to regulate said DC voltage VgDC supplied by said AC-DC rectifier 66 to a constant value. Said control unit 70, 71 operates a servo control of said DC voltage VgDC in order to maintain it constant. To this end, the control unit 70, 71 is configured to adjust the DC supply voltage Va'DC provided by the DC / DC converter 50 of the power supply device by driving said DC / DC converter 50 of the power supply device 40, according to a measurement of said main DC voltage VgDC delivered by said AC-DC rectifier 66, in order to maintain the main DC voltage VgDC constant. The control of the DC / DC converter 50 is carried out according to a measurement of the main DC voltage VgDC delivered by said AC-DC rectifier 66.The control unit includes a measuring element 70 of the main DC voltage VgDC delivered by said AC-DC rectifier 66 and a control element 71 configured to control the DC / DC converter 50, from said measurement of the main DC voltage VgDC-.

[0096] The control unit 70,71 is also carried by the second rotary drive element 22 and is disposed in the rotating frame.

[0097] The system 10 further includes an inverter 72 connected to the AC-DC rectifier 66. The inverter 72 is configured to supply an alternating voltage V The voltage VgDC supplied by the AC-DC rectifier 66 is applied to the stator 82 of the electric motor. The inverter 72 is also supported by the second rotary drive element 22 and positioned in the rotating frame. The assembly formed by the AC-DC rectifier 66 and the inverter 72 allows adjustment of the frequency and amplitude of the AC voltage Vm supplied to the electric motor 80.

[0098] The system includes a measuring device 86 for the orientation of the propeller blades 14 of the aircraft propeller 12. This measuring device 86 comprises a plurality of sensors associated with the propeller blades 14. The measuring device 86 is carried by the second rotary drive element 22. It is configured to provide a measurement m of the orientation of the propeller blades, considered along the longitudinal axis of said blades.

[0099] The system further includes a control module 74 for the electric motor 80. This control module 74 is configured to control the inverter 72 in order to regulate the alternating voltage Vm supplying the stator 82 of the electric motor, based on a setpoint Ci for the pitch of the aircraft propeller blades 14 and the measurement m of the orientation of the aircraft propeller blades provided by the measuring device 86. Said control module 74 for the electric motor 80 is carried by the second rotary drive element 22 and rotates at said second rotational speed. It is located in the rotating frame.

[0100] The system includes a control device 88 configured to generate the propeller pitch setpoint Ci for the propeller blades 14 of the propeller 12. This control device 88 is fixed relative to a portion of the aircraft frame and is therefore located in the fixed reference frame. The system 10 further includes a signal transfer element 96 configured to transfer the propeller pitch setpoint Ci from the control device 88 to the engine control module 74 of the engine 80. In other words, the transfer element allows the setpoint signal Ci to be transferred from the fixed reference frame to the rotating reference frame.

[0101] The control device 88 is further configured to generate said defrosting setpoint C2 for the control module 94 of the defrosting device 90, which is used to control the heating mats. The system 10 further includes a signal transfer element 98 configured to transfer said defrosting setpoint C2 from said control device 88 to the control module 94 of the defrosting device 90. In other words, the signal transfer element 98 allows the defrosting setpoint signal C2 to be transferred from the fixed reference frame to the rotating reference frame.

[0102] The stator 82 of the electric motor 80 is supported by the second rotating drive element 22 so that it is positioned in the rotating frame. Said stator 82 rotates about the main axis X, at said second rotational speed, cor responding to the rotational speed of the propeller. The electric motor further comprises a rotor 84 coupled to the stator 82 and driven in rotation around the main axis X when the motor is energized.

[0103] The system further includes an actuation system 16 configured to adjust the orientation of the propeller blades 12. The actuation system 16 may be electrohydraulic or electromechanical. Said actuation system 16 is driven by the rotor 84 of the electric motor 80. It is configured to convert the rotational motion of the rotor 84 into a translational motion of a cylinder (electrohydraulic system) or a nut (electromechanical system). This translational motion is then converted into a rotational motion of the propeller blades 14 via a connecting rod and crank mechanism 18.

Claims

1. Demands System (10) for adjusting the pitch and de-icing the blades (14) of a propeller (12) of an aircraft, the system comprising: - a first rotary drive element (20) configured to be driven in rotation by a turbomachine of the aircraft has a first rotational speed; - a second rotating drive element (22) carrying the propeller (12); - an epicyclic gear train (24) comprising: an internal planetary gear (26) attached to the first rotating drive element (20) and configured to be driven in rotation around a main axis; at least one satellite (30) meshed with said inner planetary; an outer planetary gear (32) configured to be driven around said main axis and meshed with said at least one satellite, said second rotating drive element (22) being fixed to the outer planetary gear so that said second rotating drive element (22) is driven in rotation at a second rotational speed, lower than said first rotational speed, when the first rotating drive element is set in rotation at said first rotational speed; - an electric motor (80) comprising a stator (82) carried by the second rotating drive element and a rotor (84) used to adjust the pitch of the aircraft propeller blades; - a de-icing device (90) for said propeller blades carried by the second rotating drive element; - a main generator (60) with differential speed comprising a wound inductor (62) carried by the first rotary drive element, so that it is configured to be driven in rotation at said first speed of rotation, and an armature (64) carried by the second rotary drive element, so that it is configured to be driven in rotation at said second speed of rotation, the armature being configured to deliver an alternating voltage (VgAc); - an AC-DC rectifier (66) connected to the armature of the main generator and configured to deliver a main DC voltage (VgDC) to the electric motor (80) and the defrosting device (90), from said AC voltage (VgAc) supplied by the armature of the main generator;

2.

3.

4. - an excitation device (52) configured to provide a continuous excitation voltage (VeDC) to the wound inductor of the main generator, the excitation device comprising an exciter machine (54) comprising an inductor (56) carried by the second rotary drive element and a wound armature (58) carried by the first rotary drive element; - a power supply device (40) for supplying the excitation device, configured to provide a DC supply voltage (Va'DC) to the inductor (56) of the exciter machine (54) of the excitation device (52), the power supply device comprising a permanent magnet generator (42) comprising a permanent magnet inductor (44) carried by the first rotating drive element and an armature (46) carried by the second drive element; and - a regulation unit (70,71) configured to regulate said main DC voltage (VgDc) delivered by said AC-DC rectifier (66) to a constant value, by adjusting the DC supply voltage (Va'DC) supplied by the power supply device to the inductor of the exciter machine. System according to claim 1, wherein the armature (46) of the permanent magnet generator (42) is configured to deliver a first alternating voltage (VaAC), and wherein the power supply device (40) further comprises: an AC-DC converter (48) carried by the second rotary drive element (22) and configured to deliver a first direct current voltage (VaDC) from said first alternating voltage (VaAC); and a DC / DC converter (50) carried by the second rotary drive element (22) and configured to deliver said DC supply voltage (Va'DC) from the first DC voltage (VaDC) delivered by the AC-DC converter. System according to claim 2, wherein said control unit (70,71) is configured to control said DC / DC converter (50) so as to adjust said DC supply voltage (Va'DC) which it delivers, in order to regulate said main DC voltage (VgDc) delivered by said AC-DC rectifier (66) to a constant value. A system according to any one of claims 1 to 3, wherein the regulating unit (70, 71) is configured to adjust the DC supply voltage (Va'DC) delivered by the power supply device. based on a measurement of said main DC voltage (VgDC) delivered by said AC-DC rectifier (66).

5. System according to claims 3 and 4, wherein said control unit (70,71) is configured to control said DC / DC converter (50) as a function of said measurement of said main DC voltage (VgDC) delivered by said AC-DC rectifier (66).

6. System according to any one of claims 1 to 5, further comprising an inverter device (72) configured to supply an alternating voltage (Vm) to the stator (82) of the electric motor (80) from the main direct voltage (VgDC) delivered by the AC-DC rectifier (66).

7. System according to any one of claims 1 to 6, further comprising a motor control module (74) of the motor (80) configured to regulate the voltage (Vm) to the stator (82) of the electric motor, from a setpoint (Ci) of the pitch of the blades (14) of the propeller (12) of the aircraft and a measurement (m) of the orientation of the blades of the propeller of the aircraft, said motor control module being carried by the second rotary drive element (22).

8. System according to claims 6 and 7, wherein the control module (74) of the motor (80) is configured to control the inverter device (72) in order to regulate said alternating voltage (Vm) supplied by said inverter device to the stator (82) of the electric motor.

9. System according to claim 7 or 8, further comprising at least one device for measuring the orientation of the blades (14) of the propeller (12) of the aircraft carried by the second rotary drive element (22) and configured to deliver said measurement (m) of the orientation of the propeller blades to the control module (74) of the engine (80).

10. A system according to any one of claims 7 to 9, further comprising a control device (88) configured to generate said propeller (14) pitch setpoint (Ci) of the aircraft propeller (12) and fixed relative to a portion of the aircraft frame, the system further comprising at least one signal transfer element (96) configured to transfer said propeller (12) pitch setpoint from said control device to the engine (80) control module (74).

11. A system according to any one of claims 1 to 10, further comprising a control module (94) for the defrosting device (90) powered by said main DC voltage (VgDc) delivered by the re- alternating-continuous trainer (66) and carried by the second rotating drive element (22).

12. System according to any one of claims 1 to 11, wherein the wound armature (58) of the exciter machine (54) of the excitation device (52) is configured to deliver an alternating excitation voltage (VeAC), the excitation device further comprising a diode bridge (59) carried by the first rotary drive element (20), the diode bridge being configured to deliver said direct current excitation voltage (VeDC) to the wound inductor of the main generator, from said alternating excitation voltage.

13. Aircraft comprising at least one propeller (12) comprising a plurality of blades (14) and a system (10) for pitch adjustment and de-icing of the propeller blades according to any one of claims 1 to 12.

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